Index: linux-5.0.19-rt11/Documentation/preempt-locking.txt =================================================================== @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:55 @ preemption must be disabled around such Note, some FPU functions are already explicitly preempt safe. For example, kernel_fpu_begin and kernel_fpu_end will disable and enable preemption. -However, fpu__restore() must be called with preemption disabled. RULE #3: Lock acquire and release must be performed by same task Index: linux-5.0.19-rt11/Documentation/printk-ringbuffer.txt =================================================================== --- /dev/null +++ linux-5.0.19-rt11/Documentation/printk-ringbuffer.txt @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +struct printk_ringbuffer +------------------------ +John Ogness <john.ogness@linutronix.de> + +Overview +~~~~~~~~ +As the name suggests, this ring buffer was implemented specifically to serve +the needs of the printk() infrastructure. The ring buffer itself is not +specific to printk and could be used for other purposes. _However_, the +requirements and semantics of printk are rather unique. If you intend to use +this ring buffer for anything other than printk, you need to be very clear on +its features, behavior, and pitfalls. + +Features +^^^^^^^^ +The printk ring buffer has the following features: + +- single global buffer +- resides in initialized data section (available at early boot) +- lockless readers +- supports multiple writers +- supports multiple non-consuming readers +- safe from any context (including NMI) +- groups bytes into variable length blocks (referenced by entries) +- entries tagged with sequence numbers + +Behavior +^^^^^^^^ +Since the printk ring buffer readers are lockless, there exists no +synchronization between readers and writers. Basically writers are the tasks +in control and may overwrite any and all committed data at any time and from +any context. For this reason readers can miss entries if they are overwritten +before the reader was able to access the data. The reader API implementation +is such that reader access to entries is atomic, so there is no risk of +readers having to deal with partial or corrupt data. Also, entries are +tagged with sequence numbers so readers can recognize if entries were missed. + +Writing to the ring buffer consists of 2 steps. First a writer must reserve +an entry of desired size. After this step the writer has exclusive access +to the memory region. Once the data has been written to memory, it needs to +be committed to the ring buffer. After this step the entry has been inserted +into the ring buffer and assigned an appropriate sequence number. + +Once committed, a writer must no longer access the data directly. This is +because the data may have been overwritten and no longer exists. If a +writer must access the data, it should either keep a private copy before +committing the entry or use the reader API to gain access to the data. + +Because of how the data backend is implemented, entries that have been +reserved but not yet committed act as barriers, preventing future writers +from filling the ring buffer beyond the location of the reserved but not +yet committed entry region. For this reason it is *important* that writers +perform both reserve and commit as quickly as possible. Also, be aware that +preemption and local interrupts are disabled and writing to the ring buffer +is processor-reentrant locked during the reserve/commit window. Writers in +NMI contexts can still preempt any other writers, but as long as these +writers do not write a large amount of data with respect to the ring buffer +size, this should not become an issue. + +API +~~~ + +Declaration +^^^^^^^^^^^ +The printk ring buffer can be instantiated as a static structure: + + /* declare a static struct printk_ringbuffer */ + #define DECLARE_STATIC_PRINTKRB(name, szbits, cpulockptr) + +The value of szbits specifies the size of the ring buffer in bits. The +cpulockptr field is a pointer to a prb_cpulock struct that is used to +perform processor-reentrant spin locking for the writers. It is specified +externally because it may be used for multiple ring buffers (or other +code) to synchronize writers without risk of deadlock. + +Here is an example of a declaration of a printk ring buffer specifying a +32KB (2^15) ring buffer: + +.... +DECLARE_STATIC_PRINTKRB_CPULOCK(rb_cpulock); +DECLARE_STATIC_PRINTKRB(rb, 15, &rb_cpulock); +.... + +If writers will be using multiple ring buffers and the ordering of that usage +is not clear, the same prb_cpulock should be used for both ring buffers. + +Writer API +^^^^^^^^^^ +The writer API consists of 2 functions. The first is to reserve an entry in +the ring buffer, the second is to commit that data to the ring buffer. The +reserved entry information is stored within a provided `struct prb_handle`. + + /* reserve an entry */ + char *prb_reserve(struct prb_handle *h, struct printk_ringbuffer *rb, + unsigned int size); + + /* commit a reserved entry to the ring buffer */ + void prb_commit(struct prb_handle *h); + +Here is an example of a function to write data to a ring buffer: + +.... +int write_data(struct printk_ringbuffer *rb, char *data, int size) +{ + struct prb_handle h; + char *buf; + + buf = prb_reserve(&h, rb, size); + if (!buf) + return -1; + memcpy(buf, data, size); + prb_commit(&h); + + return 0; +} +.... + +Pitfalls +++++++++ +Be aware that prb_reserve() can fail. A retry might be successful, but it +depends entirely on whether or not the next part of the ring buffer to +overwrite belongs to reserved but not yet committed entries of other writers. +Writers can use the prb_inc_lost() function to allow readers to notice that a +message was lost. + +Reader API +^^^^^^^^^^ +The reader API utilizes a `struct prb_iterator` to track the reader's +position in the ring buffer. + + /* declare a pre-initialized static iterator for a ring buffer */ + #define DECLARE_STATIC_PRINTKRB_ITER(name, rbaddr) + + /* initialize iterator for a ring buffer (if static macro NOT used) */ + void prb_iter_init(struct prb_iterator *iter, + struct printk_ringbuffer *rb, u64 *seq); + + /* make a deep copy of an iterator */ + void prb_iter_copy(struct prb_iterator *dest, + struct prb_iterator *src); + + /* non-blocking, advance to next entry (and read the data) */ + int prb_iter_next(struct prb_iterator *iter, char *buf, + int size, u64 *seq); + + /* blocking, advance to next entry (and read the data) */ + int prb_iter_wait_next(struct prb_iterator *iter, char *buf, + int size, u64 *seq); + + /* position iterator at the entry seq */ + int prb_iter_seek(struct prb_iterator *iter, u64 seq); + + /* read data at current position */ + int prb_iter_data(struct prb_iterator *iter, char *buf, + int size, u64 *seq); + +Typically prb_iter_data() is not needed because the data can be retrieved +directly with prb_iter_next(). + +Here is an example of a non-blocking function that will read all the data in +a ring buffer: + +.... +void read_all_data(struct printk_ringbuffer *rb, char *buf, int size) +{ + struct prb_iterator iter; + u64 prev_seq = 0; + u64 seq; + int ret; + + prb_iter_init(&iter, rb, NULL); + + for (;;) { + ret = prb_iter_next(&iter, buf, size, &seq); + if (ret > 0) { + if (seq != ++prev_seq) { + /* "seq - prev_seq" entries missed */ + prev_seq = seq; + } + /* process buf here */ + } else if (ret == 0) { + /* hit the end, done */ + break; + } else if (ret < 0) { + /* + * iterator is invalid, a writer overtook us, reset the + * iterator and keep going, entries were missed + */ + prb_iter_init(&iter, rb, NULL); + } + } +} +.... + +Pitfalls +++++++++ +The reader's iterator can become invalid at any time because the reader was +overtaken by a writer. Typically the reader should reset the iterator back +to the current oldest entry (which will be newer than the entry the reader +was at) and continue, noting the number of entries that were missed. + +Utility API +^^^^^^^^^^^ +Several functions are available as convenience for external code. + + /* query the size of the data buffer */ + int prb_buffer_size(struct printk_ringbuffer *rb); + + /* skip a seq number to signify a lost record */ + void prb_inc_lost(struct printk_ringbuffer *rb); + + /* processor-reentrant spin lock */ + void prb_lock(struct prb_cpulock *cpu_lock, unsigned int *cpu_store); + + /* processor-reentrant spin unlock */ + void prb_lock(struct prb_cpulock *cpu_lock, unsigned int *cpu_store); + +Pitfalls +++++++++ +Although the value returned by prb_buffer_size() does represent an absolute +upper bound, the amount of data that can be stored within the ring buffer +is actually less because of the additional storage space of a header for each +entry. + +The prb_lock() and prb_unlock() functions can be used to synchronize between +ring buffer writers and other external activities. The function of a +processor-reentrant spin lock is to disable preemption and local interrupts +and synchronize against other processors. It does *not* protect against +multiple contexts of a single processor, i.e NMI. + +Implementation +~~~~~~~~~~~~~~ +This section describes several of the implementation concepts and details to +help developers better understand the code. + +Entries +^^^^^^^ +All ring buffer data is stored within a single static byte array. The reason +for this is to ensure that any pointers to the data (past and present) will +always point to valid memory. This is important because the lockless readers +may be preempted for long periods of time and when they resume may be working +with expired pointers. + +Entries are identified by start index and size. (The start index plus size +is the start index of the next entry.) The start index is not simply an +offset into the byte array, but rather a logical position (lpos) that maps +directly to byte array offsets. + +For example, for a byte array of 1000, an entry may have have a start index +of 100. Another entry may have a start index of 1100. And yet another 2100. +All of these entry are pointing to the same memory region, but only the most +recent entry is valid. The other entries are pointing to valid memory, but +represent entries that have been overwritten. + +Note that due to overflowing, the most recent entry is not necessarily the one +with the highest lpos value. Indeed, the printk ring buffer initializes its +data such that an overflow happens relatively quickly in order to validate the +handling of this situation. The implementation assumes that an lpos (unsigned +long) will never completely wrap while a reader is preempted. If this were to +become an issue, the seq number (which never wraps) could be used to increase +the robustness of handling this situation. + +Buffer Wrapping +^^^^^^^^^^^^^^^ +If an entry starts near the end of the byte array but would extend beyond it, +a special terminating entry (size = -1) is inserted into the byte array and +the real entry is placed at the beginning of the byte array. This can waste +space at the end of the byte array, but simplifies the implementation by +allowing writers to always work with contiguous buffers. + +Note that the size field is the first 4 bytes of the entry header. Also note +that calc_next() always ensures that there are at least 4 bytes left at the +end of the byte array to allow room for a terminating entry. + +Ring Buffer Pointers +^^^^^^^^^^^^^^^^^^^^ +Three pointers (lpos values) are used to manage the ring buffer: + + - _tail_: points to the oldest entry + - _head_: points to where the next new committed entry will be + - _reserve_: points to where the next new reserved entry will be + +These pointers always maintain a logical ordering: + + tail <= head <= reserve + +The reserve pointer moves forward when a writer reserves a new entry. The +head pointer moves forward when a writer commits a new entry. + +The reserve pointer cannot overwrite the tail pointer in a wrap situation. In +such a situation, the tail pointer must be "pushed forward", thus +invalidating that oldest entry. Readers identify if they are accessing a +valid entry by ensuring their entry pointer is `>= tail && < head`. + +If the tail pointer is equal to the head pointer, it cannot be pushed and any +reserve operation will fail. The only resolution is for writers to commit +their reserved entries. + +Processor-Reentrant Locking +^^^^^^^^^^^^^^^^^^^^^^^^^^^ +The purpose of the processor-reentrant locking is to limit the interruption +scenarios of writers to 2 contexts. This allows for a simplified +implementation where: + +- The reserve/commit window only exists on 1 processor at a time. A reserve + can never fail due to uncommitted entries of other processors. + +- When committing entries, it is trivial to handle the situation when + subsequent entries have already been committed, i.e. managing the head + pointer. + +Performance +~~~~~~~~~~~ +Some basic tests were performed on a quad Intel(R) Xeon(R) CPU E5-2697 v4 at +2.30GHz (36 cores / 72 threads). All tests involved writing a total of +32,000,000 records at an average of 33 bytes each. Each writer was pinned to +its own CPU and would write as fast as it could until a total of 32,000,000 +records were written. All tests involved 2 readers that were both pinned +together to another CPU. Each reader would read as fast as it could and track +how many of the 32,000,000 records it could read. All tests used a ring buffer +of 16KB in size, which holds around 350 records (header + data for each +entry). + +The only difference between the tests is the number of writers (and thus also +the number of records per writer). As more writers are added, the time to +write a record increases. This is because data pointers, modified via cmpxchg, +and global data access in general become more contended. + +1 writer +^^^^^^^^ + runtime: 0m 18s + reader1: 16219900/32000000 (50%) records + reader2: 16141582/32000000 (50%) records + +2 writers +^^^^^^^^^ + runtime: 0m 32s + reader1: 16327957/32000000 (51%) records + reader2: 16313988/32000000 (50%) records + +4 writers +^^^^^^^^^ + runtime: 0m 42s + reader1: 16421642/32000000 (51%) records + reader2: 16417224/32000000 (51%) records + +8 writers +^^^^^^^^^ + runtime: 0m 43s + reader1: 16418300/32000000 (51%) records + reader2: 16432222/32000000 (51%) records + +16 writers +^^^^^^^^^^ + runtime: 0m 54s + reader1: 16539189/32000000 (51%) records + reader2: 16542711/32000000 (51%) records + +32 writers +^^^^^^^^^^ + runtime: 1m 13s + reader1: 16731808/32000000 (52%) records + reader2: 16735119/32000000 (52%) records + +Comments +^^^^^^^^ +It is particularly interesting to compare/contrast the 1-writer and 32-writer +tests. Despite the writing of the 32,000,000 records taking over 4 times +longer, the readers (which perform no cmpxchg) were still unable to keep up. +This shows that the memory contention between the increasing number of CPUs +also has a dramatic effect on readers. + +It should also be noted that in all cases each reader was able to read >=50% +of the records. This means that a single reader would have been able to keep +up with the writer(s) in all cases, becoming slightly easier as more writers +are added. This was the purpose of pinning 2 readers to 1 CPU: to observe how +maximum reader performance changes. Index: linux-5.0.19-rt11/arch/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/Kconfig +++ linux-5.0.19-rt11/arch/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:31 @ config OPROFILE tristate "OProfile system profiling" depends on PROFILING depends on HAVE_OPROFILE + depends on !PREEMPT_RT_FULL select RING_BUFFER select RING_BUFFER_ALLOW_SWAP help Index: linux-5.0.19-rt11/arch/alpha/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/alpha/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/alpha/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #ifndef _ALPHA_SPINLOCK_TYPES_H #define _ALPHA_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - typedef struct { volatile unsigned int lock; } arch_spinlock_t; Index: linux-5.0.19-rt11/arch/arm/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/Kconfig +++ linux-5.0.19-rt11/arch/arm/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:55 @ config ARM select HARDIRQS_SW_RESEND select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6 - select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU + select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU && !PREEMPT_RT_BASE select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:93 @ config ARM select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_PREEMPT_LAZY select HAVE_RCU_TABLE_FREE if SMP && ARM_LPAE select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RSEQ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2136 @ config NEON config KERNEL_MODE_NEON bool "Support for NEON in kernel mode" - depends on NEON && AEABI + depends on NEON && AEABI && !PREEMPT_RT_BASE help Say Y to include support for NEON in kernel mode. Index: linux-5.0.19-rt11/arch/arm/include/asm/irq.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/include/asm/irq.h +++ linux-5.0.19-rt11/arch/arm/include/asm/irq.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:26 @ #endif #ifndef __ASSEMBLY__ +#include <linux/cpumask.h> + struct irqaction; struct pt_regs; Index: linux-5.0.19-rt11/arch/arm/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/arm/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #ifndef __ASM_SPINLOCK_TYPES_H #define __ASM_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - #define TICKET_SHIFT 16 typedef struct { Index: linux-5.0.19-rt11/arch/arm/include/asm/switch_to.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/include/asm/switch_to.h +++ linux-5.0.19-rt11/arch/arm/include/asm/switch_to.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:7 @ #include <linux/thread_info.h> +#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM +void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p); +#else +static inline void +switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { } +#endif + /* * For v7 SMP cores running a preemptible kernel we may be pre-empted * during a TLB maintenance operation, so execute an inner-shareable dsb @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:36 @ extern struct task_struct *__switch_to(s #define switch_to(prev,next,last) \ do { \ __complete_pending_tlbi(); \ + switch_kmaps(prev, next); \ last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \ } while (0) Index: linux-5.0.19-rt11/arch/arm/include/asm/thread_info.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/include/asm/thread_info.h +++ linux-5.0.19-rt11/arch/arm/include/asm/thread_info.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:52 @ struct cpu_context_save { struct thread_info { unsigned long flags; /* low level flags */ int preempt_count; /* 0 => preemptable, <0 => bug */ + int preempt_lazy_count; /* 0 => preemptable, <0 => bug */ mm_segment_t addr_limit; /* address limit */ struct task_struct *task; /* main task structure */ __u32 cpu; /* cpu */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:146 @ extern int vfp_restore_user_hwstate(stru #define TIF_SYSCALL_TRACE 4 /* syscall trace active */ #define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */ #define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */ -#define TIF_SECCOMP 7 /* seccomp syscall filtering active */ +#define TIF_SECCOMP 8 /* seccomp syscall filtering active */ +#define TIF_NEED_RESCHED_LAZY 7 #define TIF_NOHZ 12 /* in adaptive nohz mode */ #define TIF_USING_IWMMXT 17 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:157 @ extern int vfp_restore_user_hwstate(stru #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) +#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY) #define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:173 @ extern int vfp_restore_user_hwstate(stru * Change these and you break ASM code in entry-common.S */ #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ - _TIF_NOTIFY_RESUME | _TIF_UPROBE) + _TIF_NOTIFY_RESUME | _TIF_UPROBE | \ + _TIF_NEED_RESCHED_LAZY) #endif /* __KERNEL__ */ #endif /* __ASM_ARM_THREAD_INFO_H */ Index: linux-5.0.19-rt11/arch/arm/kernel/asm-offsets.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/kernel/asm-offsets.c +++ linux-5.0.19-rt11/arch/arm/kernel/asm-offsets.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:59 @ int main(void) BLANK(); DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count)); + DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count)); DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit)); DEFINE(TI_TASK, offsetof(struct thread_info, task)); DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); Index: linux-5.0.19-rt11/arch/arm/kernel/entry-armv.S =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/kernel/entry-armv.S +++ linux-5.0.19-rt11/arch/arm/kernel/entry-armv.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:219 @ __irq_svc: #ifdef CONFIG_PREEMPT ldr r8, [tsk, #TI_PREEMPT] @ get preempt count - ldr r0, [tsk, #TI_FLAGS] @ get flags teq r8, #0 @ if preempt count != 0 + bne 1f @ return from exeption + ldr r0, [tsk, #TI_FLAGS] @ get flags + tst r0, #_TIF_NEED_RESCHED @ if NEED_RESCHED is set + blne svc_preempt @ preempt! + + ldr r8, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count + teq r8, #0 @ if preempt lazy count != 0 movne r0, #0 @ force flags to 0 - tst r0, #_TIF_NEED_RESCHED + tst r0, #_TIF_NEED_RESCHED_LAZY blne svc_preempt +1: #endif svc_exit r5, irq = 1 @ return from exception @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:245 @ svc_preempt: 1: bl preempt_schedule_irq @ irq en/disable is done inside ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS tst r0, #_TIF_NEED_RESCHED + bne 1b + tst r0, #_TIF_NEED_RESCHED_LAZY reteq r8 @ go again - b 1b + ldr r0, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count + teq r0, #0 @ if preempt lazy count != 0 + beq 1b + ret r8 @ go again + #endif __und_fault: Index: linux-5.0.19-rt11/arch/arm/kernel/entry-common.S =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/kernel/entry-common.S +++ linux-5.0.19-rt11/arch/arm/kernel/entry-common.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:59 @ __ret_fast_syscall: cmp r2, #TASK_SIZE blne addr_limit_check_failed ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing - tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK + tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP) + bne fast_work_pending + tst r1, #_TIF_SECCOMP bne fast_work_pending @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:98 @ __ret_fast_syscall: cmp r2, #TASK_SIZE blne addr_limit_check_failed ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing - tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK + tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP) + bne do_slower_path + tst r1, #_TIF_SECCOMP beq no_work_pending +do_slower_path: UNWIND(.fnend ) ENDPROC(ret_fast_syscall) Index: linux-5.0.19-rt11/arch/arm/kernel/process.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/kernel/process.c +++ linux-5.0.19-rt11/arch/arm/kernel/process.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:331 @ unsigned long arch_randomize_brk(struct } #ifdef CONFIG_MMU +/* + * CONFIG_SPLIT_PTLOCK_CPUS results in a page->ptl lock. If the lock is not + * initialized by pgtable_page_ctor() then a coredump of the vector page will + * fail. + */ +static int __init vectors_user_mapping_init_page(void) +{ + struct page *page; + unsigned long addr = 0xffff0000; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + + pgd = pgd_offset_k(addr); + pud = pud_offset(pgd, addr); + pmd = pmd_offset(pud, addr); + page = pmd_page(*(pmd)); + + pgtable_page_ctor(page); + + return 0; +} +late_initcall(vectors_user_mapping_init_page); + #ifdef CONFIG_KUSER_HELPERS /* * The vectors page is always readable from user space for the Index: linux-5.0.19-rt11/arch/arm/kernel/signal.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/kernel/signal.c +++ linux-5.0.19-rt11/arch/arm/kernel/signal.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:655 @ do_work_pending(struct pt_regs *regs, un */ trace_hardirqs_off(); do { - if (likely(thread_flags & _TIF_NEED_RESCHED)) { + if (likely(thread_flags & (_TIF_NEED_RESCHED | + _TIF_NEED_RESCHED_LAZY))) { schedule(); } else { if (unlikely(!user_mode(regs))) Index: linux-5.0.19-rt11/arch/arm/kernel/smp.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/kernel/smp.c +++ linux-5.0.19-rt11/arch/arm/kernel/smp.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:687 @ void handle_IPI(int ipinr, struct pt_reg break; case IPI_CPU_BACKTRACE: - printk_nmi_enter(); irq_enter(); nmi_cpu_backtrace(regs); irq_exit(); - printk_nmi_exit(); break; default: Index: linux-5.0.19-rt11/arch/arm/mach-at91/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/mach-at91/Kconfig +++ linux-5.0.19-rt11/arch/arm/mach-at91/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:110 @ config SOC_AT91SAM9 AT91SAM9X35 AT91SAM9XE +comment "Clocksource driver selection" + +config ATMEL_CLOCKSOURCE_PIT + bool "Periodic Interval Timer (PIT) support" + depends on SOC_AT91SAM9 || SOC_SAMA5 + default SOC_AT91SAM9 || SOC_SAMA5 + select ATMEL_PIT + help + Select this to get a clocksource based on the Atmel Periodic Interval + Timer. It has a relatively low resolution and the TC Block clocksource + should be preferred. + +config ATMEL_CLOCKSOURCE_TCB + bool "Timer Counter Blocks (TCB) support" + default SOC_AT91RM9200 || SOC_AT91SAM9 || SOC_SAMA5 + select ATMEL_TCB_CLKSRC + help + Select this to get a high precision clocksource based on a + TC block with a 5+ MHz base clock rate. + On platforms with 16-bit counters, two timer channels are combined + to make a single 32-bit timer. + It can also be used as a clock event device supporting oneshot mode. + config HAVE_AT91_UTMI bool Index: linux-5.0.19-rt11/arch/arm/mach-imx/cpuidle-imx6q.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/mach-imx/cpuidle-imx6q.c +++ linux-5.0.19-rt11/arch/arm/mach-imx/cpuidle-imx6q.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:20 @ #include "hardware.h" static int num_idle_cpus = 0; -static DEFINE_SPINLOCK(cpuidle_lock); +static DEFINE_RAW_SPINLOCK(cpuidle_lock); static int imx6q_enter_wait(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { - spin_lock(&cpuidle_lock); + raw_spin_lock(&cpuidle_lock); if (++num_idle_cpus == num_online_cpus()) imx6_set_lpm(WAIT_UNCLOCKED); - spin_unlock(&cpuidle_lock); + raw_spin_unlock(&cpuidle_lock); cpu_do_idle(); - spin_lock(&cpuidle_lock); + raw_spin_lock(&cpuidle_lock); if (num_idle_cpus-- == num_online_cpus()) imx6_set_lpm(WAIT_CLOCKED); - spin_unlock(&cpuidle_lock); + raw_spin_unlock(&cpuidle_lock); return index; } Index: linux-5.0.19-rt11/arch/arm/mm/fault.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/mm/fault.c +++ linux-5.0.19-rt11/arch/arm/mm/fault.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:440 @ do_translation_fault(unsigned long addr, if (addr < TASK_SIZE) return do_page_fault(addr, fsr, regs); + if (interrupts_enabled(regs)) + local_irq_enable(); + if (user_mode(regs)) goto bad_area; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:510 @ do_translation_fault(unsigned long addr, static int do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) { + if (interrupts_enabled(regs)) + local_irq_enable(); + do_bad_area(addr, fsr, regs); return 0; } Index: linux-5.0.19-rt11/arch/arm/mm/highmem.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm/mm/highmem.c +++ linux-5.0.19-rt11/arch/arm/mm/highmem.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:37 @ static inline pte_t get_fixmap_pte(unsig return *ptep; } +static unsigned int fixmap_idx(int type) +{ + return FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id(); +} + void *kmap(struct page *page) { might_sleep(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:62 @ EXPORT_SYMBOL(kunmap); void *kmap_atomic(struct page *page) { + pte_t pte = mk_pte(page, kmap_prot); unsigned int idx; unsigned long vaddr; void *kmap; int type; - preempt_disable(); + preempt_disable_nort(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:88 @ void *kmap_atomic(struct page *page) type = kmap_atomic_idx_push(); - idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id(); + idx = fixmap_idx(type); vaddr = __fix_to_virt(idx); #ifdef CONFIG_DEBUG_HIGHMEM /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:102 @ void *kmap_atomic(struct page *page) * in place, so the contained TLB flush ensures the TLB is updated * with the new mapping. */ - set_fixmap_pte(idx, mk_pte(page, kmap_prot)); +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = pte; +#endif + set_fixmap_pte(idx, pte); return (void *)vaddr; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:118 @ void __kunmap_atomic(void *kvaddr) if (kvaddr >= (void *)FIXADDR_START) { type = kmap_atomic_idx(); - idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id(); + idx = fixmap_idx(type); if (cache_is_vivt()) __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = __pte(0); +#endif #ifdef CONFIG_DEBUG_HIGHMEM BUG_ON(vaddr != __fix_to_virt(idx)); - set_fixmap_pte(idx, __pte(0)); #else (void) idx; /* to kill a warning */ #endif + set_fixmap_pte(idx, __pte(0)); kmap_atomic_idx_pop(); } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { /* this address was obtained through kmap_high_get() */ kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); } pagefault_enable(); - preempt_enable(); + preempt_enable_nort(); } EXPORT_SYMBOL(__kunmap_atomic); void *kmap_atomic_pfn(unsigned long pfn) { + pte_t pte = pfn_pte(pfn, kmap_prot); unsigned long vaddr; int idx, type; struct page *page = pfn_to_page(pfn); - preempt_disable(); + preempt_disable_nort(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); type = kmap_atomic_idx_push(); - idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id(); + idx = fixmap_idx(type); vaddr = __fix_to_virt(idx); #ifdef CONFIG_DEBUG_HIGHMEM BUG_ON(!pte_none(get_fixmap_pte(vaddr))); #endif - set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot)); +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = pte; +#endif + set_fixmap_pte(idx, pte); return (void *)vaddr; } +#if defined CONFIG_PREEMPT_RT_FULL +void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) +{ + int i; + + /* + * Clear @prev's kmap_atomic mappings + */ + for (i = 0; i < prev_p->kmap_idx; i++) { + int idx = fixmap_idx(i); + + set_fixmap_pte(idx, __pte(0)); + } + /* + * Restore @next_p's kmap_atomic mappings + */ + for (i = 0; i < next_p->kmap_idx; i++) { + int idx = fixmap_idx(i); + + if (!pte_none(next_p->kmap_pte[i])) + set_fixmap_pte(idx, next_p->kmap_pte[i]); + } +} +#endif Index: linux-5.0.19-rt11/arch/arm64/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/Kconfig +++ linux-5.0.19-rt11/arch/arm64/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:149 @ config ARM64 select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_PREEMPT_LAZY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RCU_TABLE_FREE select HAVE_RCU_TABLE_INVALIDATE Index: linux-5.0.19-rt11/arch/arm64/crypto/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/crypto/Kconfig +++ linux-5.0.19-rt11/arch/arm64/crypto/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:22 @ config CRYPTO_SHA512_ARM64 config CRYPTO_SHA1_ARM64_CE tristate "SHA-1 digest algorithm (ARMv8 Crypto Extensions)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_HASH select CRYPTO_SHA1 config CRYPTO_SHA2_ARM64_CE tristate "SHA-224/SHA-256 digest algorithm (ARMv8 Crypto Extensions)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_HASH select CRYPTO_SHA256_ARM64 config CRYPTO_SHA512_ARM64_CE tristate "SHA-384/SHA-512 digest algorithm (ARMv8 Crypto Extensions)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_HASH select CRYPTO_SHA512_ARM64 config CRYPTO_SHA3_ARM64 tristate "SHA3 digest algorithm (ARMv8.2 Crypto Extensions)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_HASH select CRYPTO_SHA3 config CRYPTO_SM3_ARM64_CE tristate "SM3 digest algorithm (ARMv8.2 Crypto Extensions)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_HASH select CRYPTO_SM3 config CRYPTO_SM4_ARM64_CE tristate "SM4 symmetric cipher (ARMv8.2 Crypto Extensions)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_ALGAPI select CRYPTO_SM4 config CRYPTO_GHASH_ARM64_CE tristate "GHASH/AES-GCM using ARMv8 Crypto Extensions" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_HASH select CRYPTO_GF128MUL select CRYPTO_AES @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:66 @ config CRYPTO_GHASH_ARM64_CE config CRYPTO_CRCT10DIF_ARM64_CE tristate "CRCT10DIF digest algorithm using PMULL instructions" - depends on KERNEL_MODE_NEON && CRC_T10DIF + depends on KERNEL_MODE_NEON && CRC_T10DIF && !PREEMPT_RT_BASE select CRYPTO_HASH config CRYPTO_AES_ARM64 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:75 @ config CRYPTO_AES_ARM64 config CRYPTO_AES_ARM64_CE tristate "AES core cipher using ARMv8 Crypto Extensions" - depends on ARM64 && KERNEL_MODE_NEON + depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_ALGAPI select CRYPTO_AES_ARM64 config CRYPTO_AES_ARM64_CE_CCM tristate "AES in CCM mode using ARMv8 Crypto Extensions" - depends on ARM64 && KERNEL_MODE_NEON + depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_ALGAPI select CRYPTO_AES_ARM64_CE select CRYPTO_AES_ARM64 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:89 @ config CRYPTO_AES_ARM64_CE_CCM config CRYPTO_AES_ARM64_CE_BLK tristate "AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_BLKCIPHER select CRYPTO_AES_ARM64_CE select CRYPTO_AES_ARM64 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:97 @ config CRYPTO_AES_ARM64_CE_BLK config CRYPTO_AES_ARM64_NEON_BLK tristate "AES in ECB/CBC/CTR/XTS modes using NEON instructions" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_BLKCIPHER select CRYPTO_AES_ARM64 select CRYPTO_AES @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:105 @ config CRYPTO_AES_ARM64_NEON_BLK config CRYPTO_CHACHA20_NEON tristate "ChaCha20, XChaCha20, and XChaCha12 stream ciphers using NEON instructions" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_BLKCIPHER select CRYPTO_CHACHA20 config CRYPTO_NHPOLY1305_NEON tristate "NHPoly1305 hash function using NEON instructions (for Adiantum)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_NHPOLY1305 config CRYPTO_AES_ARM64_BS tristate "AES in ECB/CBC/CTR/XTS modes using bit-sliced NEON algorithm" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE select CRYPTO_BLKCIPHER select CRYPTO_AES_ARM64_NEON_BLK select CRYPTO_AES_ARM64 Index: linux-5.0.19-rt11/arch/arm64/include/asm/alternative.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/include/asm/alternative.h +++ linux-5.0.19-rt11/arch/arm64/include/asm/alternative.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:38 @ void apply_alternatives_module(void *sta static inline void apply_alternatives_module(void *start, size_t length) { } #endif +#ifdef CONFIG_KVM_ARM_HOST +void kvm_compute_layout(void); +#else +static inline void kvm_compute_layout(void) { } +#endif + #define ALTINSTR_ENTRY(feature,cb) \ " .word 661b - .\n" /* label */ \ " .if " __stringify(cb) " == 0\n" \ Index: linux-5.0.19-rt11/arch/arm64/include/asm/preempt.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/include/asm/preempt.h +++ linux-5.0.19-rt11/arch/arm64/include/asm/preempt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:73 @ static inline bool __preempt_count_dec_a * interrupt occurring between the non-atomic READ_ONCE/WRITE_ONCE * pair. */ - return !pc || !READ_ONCE(ti->preempt_count); + if (!pc || !READ_ONCE(ti->preempt_count)) + return true; +#ifdef CONFIG_PREEMPT_LAZY + if (current_thread_info()->preempt_lazy_count) + return false; + return test_thread_flag(TIF_NEED_RESCHED_LAZY); +#else + return false; +#endif } static inline bool should_resched(int preempt_offset) { +#ifdef CONFIG_PREEMPT_LAZY + u64 pc = READ_ONCE(current_thread_info()->preempt_count); + if (pc == preempt_offset) + return true; + + if ((pc & ~PREEMPT_NEED_RESCHED) != preempt_offset) + return false; + + if (current_thread_info()->preempt_lazy_count) + return false; + return test_thread_flag(TIF_NEED_RESCHED_LAZY); +#else u64 pc = READ_ONCE(current_thread_info()->preempt_count); return pc == preempt_offset; +#endif } #ifdef CONFIG_PREEMPT Index: linux-5.0.19-rt11/arch/arm64/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/arm64/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:19 @ #ifndef __ASM_SPINLOCK_TYPES_H #define __ASM_SPINLOCK_TYPES_H -#if !defined(__LINUX_SPINLOCK_TYPES_H) && !defined(__ASM_SPINLOCK_H) -# error "please don't include this file directly" -#endif - #include <asm-generic/qspinlock_types.h> #include <asm-generic/qrwlock_types.h> Index: linux-5.0.19-rt11/arch/arm64/include/asm/thread_info.h =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/include/asm/thread_info.h +++ linux-5.0.19-rt11/arch/arm64/include/asm/thread_info.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:45 @ struct thread_info { #ifdef CONFIG_ARM64_SW_TTBR0_PAN u64 ttbr0; /* saved TTBR0_EL1 */ #endif + int preempt_lazy_count; /* 0 => preemptable, <0 => bug */ union { u64 preempt_count; /* 0 => preemptible, <0 => bug */ struct { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:91 @ void arch_release_task_struct(struct tas #define TIF_FOREIGN_FPSTATE 3 /* CPU's FP state is not current's */ #define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */ #define TIF_FSCHECK 5 /* Check FS is USER_DS on return */ +#define TIF_NEED_RESCHED_LAZY 6 #define TIF_NOHZ 7 #define TIF_SYSCALL_TRACE 8 #define TIF_SYSCALL_AUDIT 9 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:110 @ void arch_release_task_struct(struct tas #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_FOREIGN_FPSTATE (1 << TIF_FOREIGN_FPSTATE) +#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY) #define _TIF_NOHZ (1 << TIF_NOHZ) #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:123 @ void arch_release_task_struct(struct tas #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \ - _TIF_UPROBE | _TIF_FSCHECK) + _TIF_UPROBE | _TIF_FSCHECK | _TIF_NEED_RESCHED_LAZY) +#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY) #define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ _TIF_NOHZ) Index: linux-5.0.19-rt11/arch/arm64/kernel/alternative.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/kernel/alternative.c +++ linux-5.0.19-rt11/arch/arm64/kernel/alternative.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:227 @ static int __apply_alternatives_multi_st void __init apply_alternatives_all(void) { /* better not try code patching on a live SMP system */ + kvm_compute_layout(); stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask); } Index: linux-5.0.19-rt11/arch/arm64/kernel/asm-offsets.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/kernel/asm-offsets.c +++ linux-5.0.19-rt11/arch/arm64/kernel/asm-offsets.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:44 @ int main(void) BLANK(); DEFINE(TSK_TI_FLAGS, offsetof(struct task_struct, thread_info.flags)); DEFINE(TSK_TI_PREEMPT, offsetof(struct task_struct, thread_info.preempt_count)); + DEFINE(TSK_TI_PREEMPT_LAZY, offsetof(struct task_struct, thread_info.preempt_lazy_count)); DEFINE(TSK_TI_ADDR_LIMIT, offsetof(struct task_struct, thread_info.addr_limit)); #ifdef CONFIG_ARM64_SW_TTBR0_PAN DEFINE(TSK_TI_TTBR0, offsetof(struct task_struct, thread_info.ttbr0)); Index: linux-5.0.19-rt11/arch/arm64/kernel/entry.S =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/kernel/entry.S +++ linux-5.0.19-rt11/arch/arm64/kernel/entry.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:613 @ el1_irq: #ifdef CONFIG_PREEMPT ldr x24, [tsk, #TSK_TI_PREEMPT] // get preempt count - cbnz x24, 1f // preempt count != 0 - bl el1_preempt + cbnz x24, 2f // preempt count != 0 + + ldr w24, [tsk, #TSK_TI_PREEMPT_LAZY] // get preempt lazy count + cbnz w24, 2f // preempt lazy count != 0 + + ldr x0, [tsk, #TSK_TI_FLAGS] // get flags + tbz x0, #TIF_NEED_RESCHED_LAZY, 2f // needs rescheduling? 1: + bl el1_preempt +2: #endif #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_on @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:636 @ el1_preempt: 1: bl preempt_schedule_irq // irq en/disable is done inside ldr x0, [tsk, #TSK_TI_FLAGS] // get new tasks TI_FLAGS tbnz x0, #TIF_NEED_RESCHED, 1b // needs rescheduling? + tbnz x0, #TIF_NEED_RESCHED_LAZY, 1b // needs rescheduling? ret x24 #endif Index: linux-5.0.19-rt11/arch/arm64/kernel/fpsimd.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/kernel/fpsimd.c +++ linux-5.0.19-rt11/arch/arm64/kernel/fpsimd.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:162 @ static void sve_free(struct task_struct __sve_free(task); } +static void *sve_free_atomic(struct task_struct *task) +{ + void *sve_state = task->thread.sve_state; + + WARN_ON(test_tsk_thread_flag(task, TIF_SVE)); + + task->thread.sve_state = NULL; + return sve_state; +} + /* * TIF_SVE controls whether a task can use SVE without trapping while * in userspace, and also the way a task's FPSIMD/SVE state is stored @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:560 @ int sve_set_vector_length(struct task_st * non-SVE thread. */ if (task == current) { + preempt_disable(); local_bh_disable(); fpsimd_save(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:571 @ int sve_set_vector_length(struct task_st if (test_and_clear_tsk_thread_flag(task, TIF_SVE)) sve_to_fpsimd(task); - if (task == current) + if (task == current) { local_bh_enable(); + preempt_enable(); + } /* * Force reallocation of task SVE state to the correct size @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:829 @ asmlinkage void do_sve_acc(unsigned int sve_alloc(current); + preempt_disable(); local_bh_disable(); fpsimd_save(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:843 @ asmlinkage void do_sve_acc(unsigned int WARN_ON(1); /* SVE access shouldn't have trapped */ local_bh_enable(); + preempt_enable(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:906 @ void fpsimd_thread_switch(struct task_st void fpsimd_flush_thread(void) { int vl, supported_vl; + void *mem = NULL; if (!system_supports_fpsimd()) return; + preempt_disable(); local_bh_disable(); memset(¤t->thread.uw.fpsimd_state, 0, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:920 @ void fpsimd_flush_thread(void) if (system_supports_sve()) { clear_thread_flag(TIF_SVE); - sve_free(current); + mem = sve_free_atomic(current); /* * Reset the task vector length as required. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:956 @ void fpsimd_flush_thread(void) set_thread_flag(TIF_FOREIGN_FPSTATE); local_bh_enable(); + preempt_enable(); + kfree(mem); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:969 @ void fpsimd_preserve_current_state(void) if (!system_supports_fpsimd()) return; + preempt_disable(); local_bh_disable(); fpsimd_save(); local_bh_enable(); + preempt_enable(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1031 @ void fpsimd_restore_current_state(void) if (!system_supports_fpsimd()) return; + preempt_disable(); local_bh_disable(); if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1040 @ void fpsimd_restore_current_state(void) } local_bh_enable(); + preempt_enable(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1053 @ void fpsimd_update_current_state(struct if (!system_supports_fpsimd()) return; + preempt_disable(); local_bh_disable(); current->thread.uw.fpsimd_state = *state; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1066 @ void fpsimd_update_current_state(struct clear_thread_flag(TIF_FOREIGN_FPSTATE); local_bh_enable(); + preempt_enable(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1112 @ void kernel_neon_begin(void) BUG_ON(!may_use_simd()); + preempt_disable(); local_bh_disable(); __this_cpu_write(kernel_neon_busy, true); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1126 @ void kernel_neon_begin(void) preempt_disable(); local_bh_enable(); + preempt_enable(); } EXPORT_SYMBOL(kernel_neon_begin); Index: linux-5.0.19-rt11/arch/arm64/kernel/signal.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/kernel/signal.c +++ linux-5.0.19-rt11/arch/arm64/kernel/signal.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:929 @ asmlinkage void do_notify_resume(struct /* Check valid user FS if needed */ addr_limit_user_check(); - if (thread_flags & _TIF_NEED_RESCHED) { + if (thread_flags & _TIF_NEED_RESCHED_MASK) { /* Unmask Debug and SError for the next task */ local_daif_restore(DAIF_PROCCTX_NOIRQ); Index: linux-5.0.19-rt11/arch/arm64/kvm/va_layout.c =================================================================== --- linux-5.0.19-rt11.orig/arch/arm64/kvm/va_layout.c +++ linux-5.0.19-rt11/arch/arm64/kvm/va_layout.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:36 @ static u8 tag_lsb; static u64 tag_val; static u64 va_mask; -static void compute_layout(void) +__init void kvm_compute_layout(void) { phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start); u64 hyp_va_msb; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:124 @ void __init kvm_update_va_mask(struct al BUG_ON(nr_inst != 5); - if (!has_vhe() && !va_mask) - compute_layout(); for (i = 0; i < nr_inst; i++) { u32 rd, rn, insn, oinsn; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:168 @ void kvm_patch_vector_branch(struct alt_ return; } - if (!va_mask) - compute_layout(); - /* * Compute HYP VA by using the same computation as kern_hyp_va() */ Index: linux-5.0.19-rt11/arch/hexagon/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/hexagon/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/hexagon/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:24 @ #ifndef _ASM_SPINLOCK_TYPES_H #define _ASM_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - typedef struct { volatile unsigned int lock; } arch_spinlock_t; Index: linux-5.0.19-rt11/arch/ia64/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/ia64/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/ia64/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #ifndef _ASM_IA64_SPINLOCK_TYPES_H #define _ASM_IA64_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - typedef struct { volatile unsigned int lock; } arch_spinlock_t; Index: linux-5.0.19-rt11/arch/ia64/kernel/mca.c =================================================================== --- linux-5.0.19-rt11.orig/arch/ia64/kernel/mca.c +++ linux-5.0.19-rt11/arch/ia64/kernel/mca.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1827 @ format_mca_init_stack(void *mca_data, un ti->cpu = cpu; p->stack = ti; p->state = TASK_UNINTERRUPTIBLE; - cpumask_set_cpu(cpu, &p->cpus_allowed); + cpumask_set_cpu(cpu, &p->cpus_mask); INIT_LIST_HEAD(&p->tasks); p->parent = p->real_parent = p->group_leader = p; INIT_LIST_HEAD(&p->children); Index: linux-5.0.19-rt11/arch/mips/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/mips/Kconfig +++ linux-5.0.19-rt11/arch/mips/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2603 @ config MIPS_CRC_SUPPORT # config HIGHMEM bool "High Memory Support" - depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !CPU_MIPS32_3_5_EVA + depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !CPU_MIPS32_3_5_EVA && !PREEMPT_RT_FULL config CPU_SUPPORTS_HIGHMEM bool Index: linux-5.0.19-rt11/arch/mips/include/asm/switch_to.h =================================================================== --- linux-5.0.19-rt11.orig/arch/mips/include/asm/switch_to.h +++ linux-5.0.19-rt11/arch/mips/include/asm/switch_to.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:45 @ extern struct task_struct *ll_task; * inline to try to keep the overhead down. If we have been forced to run on * a "CPU" with an FPU because of a previous high level of FP computation, * but did not actually use the FPU during the most recent time-slice (CU1 - * isn't set), we undo the restriction on cpus_allowed. + * isn't set), we undo the restriction on cpus_mask. * * We're not calling set_cpus_allowed() here, because we have no need to * force prompt migration - we're already switching the current CPU to a @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:60 @ do { \ test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) && \ (!(KSTK_STATUS(prev) & ST0_CU1))) { \ clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND); \ - prev->cpus_allowed = prev->thread.user_cpus_allowed; \ + prev->cpus_mask = prev->thread.user_cpus_allowed; \ } \ next->thread.emulated_fp = 0; \ } while(0) Index: linux-5.0.19-rt11/arch/mips/kernel/mips-mt-fpaff.c =================================================================== --- linux-5.0.19-rt11.orig/arch/mips/kernel/mips-mt-fpaff.c +++ linux-5.0.19-rt11/arch/mips/kernel/mips-mt-fpaff.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:180 @ asmlinkage long mipsmt_sys_sched_getaffi if (retval) goto out_unlock; - cpumask_or(&allowed, &p->thread.user_cpus_allowed, &p->cpus_allowed); + cpumask_or(&allowed, &p->thread.user_cpus_allowed, p->cpus_ptr); cpumask_and(&mask, &allowed, cpu_active_mask); out_unlock: Index: linux-5.0.19-rt11/arch/mips/kernel/traps.c =================================================================== --- linux-5.0.19-rt11.orig/arch/mips/kernel/traps.c +++ linux-5.0.19-rt11/arch/mips/kernel/traps.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:894 @ static void mt_ase_fp_affinity(void) * restricted the allowed set to exclude any CPUs with FPUs, * we'll skip the procedure. */ - if (cpumask_intersects(¤t->cpus_allowed, &mt_fpu_cpumask)) { + if (cpumask_intersects(¤t->cpus_mask, &mt_fpu_cpumask)) { cpumask_t tmask; current->thread.user_cpus_allowed - = current->cpus_allowed; - cpumask_and(&tmask, ¤t->cpus_allowed, + = current->cpus_mask; + cpumask_and(&tmask, ¤t->cpus_mask, &mt_fpu_cpumask); set_cpus_allowed_ptr(current, &tmask); set_thread_flag(TIF_FPUBOUND); Index: linux-5.0.19-rt11/arch/powerpc/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/Kconfig +++ linux-5.0.19-rt11/arch/powerpc/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:108 @ config LOCKDEP_SUPPORT config RWSEM_GENERIC_SPINLOCK bool + default y if PREEMPT_RT_FULL config RWSEM_XCHGADD_ALGORITHM bool - default y + default y if !PREEMPT_RT_FULL config GENERIC_LOCKBREAK bool @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:222 @ config PPC select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_PREEMPT_LAZY select HAVE_RCU_TABLE_FREE if SMP select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE if PPC64 && CPU_LITTLE_ENDIAN @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:399 @ menu "Kernel options" config HIGHMEM bool "High memory support" - depends on PPC32 + depends on PPC32 && !PREEMPT_RT_FULL source "kernel/Kconfig.hz" Index: linux-5.0.19-rt11/arch/powerpc/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/powerpc/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #ifndef _ASM_POWERPC_SPINLOCK_TYPES_H #define _ASM_POWERPC_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - typedef struct { volatile unsigned int slock; } arch_spinlock_t; Index: linux-5.0.19-rt11/arch/powerpc/include/asm/stackprotector.h =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/include/asm/stackprotector.h +++ linux-5.0.19-rt11/arch/powerpc/include/asm/stackprotector.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:27 @ static __always_inline void boot_init_st unsigned long canary; /* Try to get a semi random initial value. */ +#ifdef CONFIG_PREEMPT_RT_FULL + canary = (unsigned long)&canary; +#else canary = get_random_canary(); +#endif canary ^= mftb(); canary ^= LINUX_VERSION_CODE; canary &= CANARY_MASK; Index: linux-5.0.19-rt11/arch/powerpc/include/asm/thread_info.h =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/include/asm/thread_info.h +++ linux-5.0.19-rt11/arch/powerpc/include/asm/thread_info.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:41 @ struct thread_info { int cpu; /* cpu we're on */ int preempt_count; /* 0 => preemptable, <0 => BUG */ + int preempt_lazy_count; /* 0 => preemptable, + <0 => BUG */ unsigned long local_flags; /* private flags for thread */ #ifdef CONFIG_LIVEPATCH unsigned long *livepatch_sp; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:104 @ void arch_setup_new_exec(void); #define TIF_SINGLESTEP 8 /* singlestepping active */ #define TIF_NOHZ 9 /* in adaptive nohz mode */ #define TIF_SECCOMP 10 /* secure computing */ -#define TIF_RESTOREALL 11 /* Restore all regs (implies NOERROR) */ -#define TIF_NOERROR 12 /* Force successful syscall return */ + +#define TIF_NEED_RESCHED_LAZY 11 /* lazy rescheduling necessary */ +#define TIF_SYSCALL_TRACEPOINT 12 /* syscall tracepoint instrumentation */ + #define TIF_NOTIFY_RESUME 13 /* callback before returning to user */ #define TIF_UPROBE 14 /* breakpointed or single-stepping */ -#define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */ #define TIF_EMULATE_STACK_STORE 16 /* Is an instruction emulation for stack store? */ #define TIF_MEMDIE 17 /* is terminating due to OOM killer */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:118 @ void arch_setup_new_exec(void); #endif #define TIF_POLLING_NRFLAG 19 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_32BIT 20 /* 32 bit binary */ +#define TIF_RESTOREALL 21 /* Restore all regs (implies NOERROR) */ +#define TIF_NOERROR 22 /* Force successful syscall return */ + /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:140 @ void arch_setup_new_exec(void); #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT) #define _TIF_EMULATE_STACK_STORE (1<<TIF_EMULATE_STACK_STORE) #define _TIF_NOHZ (1<<TIF_NOHZ) +#define _TIF_NEED_RESCHED_LAZY (1<<TIF_NEED_RESCHED_LAZY) #define _TIF_FSCHECK (1<<TIF_FSCHECK) #define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU) #define _TIF_SYSCALL_DOTRACE (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:150 @ void arch_setup_new_exec(void); #define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ _TIF_NOTIFY_RESUME | _TIF_UPROBE | \ _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \ - _TIF_FSCHECK) + _TIF_FSCHECK | _TIF_NEED_RESCHED_LAZY) #define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR) +#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY) /* Bits in local_flags */ /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */ Index: linux-5.0.19-rt11/arch/powerpc/kernel/asm-offsets.c =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/asm-offsets.c +++ linux-5.0.19-rt11/arch/powerpc/kernel/asm-offsets.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:164 @ int main(void) OFFSET(TI_FLAGS, thread_info, flags); OFFSET(TI_LOCAL_FLAGS, thread_info, local_flags); OFFSET(TI_PREEMPT, thread_info, preempt_count); + OFFSET(TI_PREEMPT_LAZY, thread_info, preempt_lazy_count); OFFSET(TI_TASK, thread_info, task); OFFSET(TI_CPU, thread_info, cpu); Index: linux-5.0.19-rt11/arch/powerpc/kernel/entry_32.S =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/entry_32.S +++ linux-5.0.19-rt11/arch/powerpc/kernel/entry_32.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:396 @ ret_from_syscall: MTMSRD(r10) lwz r9,TI_FLAGS(r12) li r8,-MAX_ERRNO - andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) + lis r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@h + ori r0,r0, (_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@l + and. r0,r9,r0 bne- syscall_exit_work cmplw 0,r3,r8 blt+ syscall_exit_cont @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:516 @ syscall_dotrace: b syscall_dotrace_cont syscall_exit_work: - andi. r0,r9,_TIF_RESTOREALL + andis. r0,r9,_TIF_RESTOREALL@h beq+ 0f REST_NVGPRS(r1) b 2f 0: cmplw 0,r3,r8 blt+ 1f - andi. r0,r9,_TIF_NOERROR + andis. r0,r9,_TIF_NOERROR@h bne- 1f lwz r11,_CCR(r1) /* Load CR */ neg r3,r3 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:531 @ syscall_exit_work: 1: stw r6,RESULT(r1) /* Save result */ stw r3,GPR3(r1) /* Update return value */ -2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) +2: andis. r0,r9,(_TIF_PERSYSCALL_MASK)@h beq 4f /* Clear per-syscall TIF flags if any are set. */ - li r11,_TIF_PERSYSCALL_MASK + lis r11,_TIF_PERSYSCALL_MASK@h addi r12,r12,TI_FLAGS 3: lwarx r8,0,r12 andc r8,r8,r11 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:893 @ resume_kernel: cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ bne restore andi. r8,r8,_TIF_NEED_RESCHED + bne+ 1f + lwz r0,TI_PREEMPT_LAZY(r9) + cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ + bne restore + lwz r0,TI_FLAGS(r9) + andi. r0,r0,_TIF_NEED_RESCHED_LAZY beq+ restore +1: lwz r3,_MSR(r1) andi. r0,r3,MSR_EE /* interrupts off? */ beq restore /* don't schedule if so */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:911 @ resume_kernel: */ bl trace_hardirqs_off #endif -1: bl preempt_schedule_irq +2: bl preempt_schedule_irq CURRENT_THREAD_INFO(r9, r1) lwz r3,TI_FLAGS(r9) - andi. r0,r3,_TIF_NEED_RESCHED - bne- 1b + andi. r0,r3,_TIF_NEED_RESCHED_MASK + bne- 2b #ifdef CONFIG_TRACE_IRQFLAGS /* And now, to properly rebalance the above, we tell lockdep they * are being turned back on, which will happen when we return @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1244 @ global_dbcr0: #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */ do_work: /* r10 contains MSR_KERNEL here */ - andi. r0,r9,_TIF_NEED_RESCHED + andi. r0,r9,_TIF_NEED_RESCHED_MASK beq do_user_signal do_resched: /* r10 contains MSR_KERNEL here */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1265 @ recheck: MTMSRD(r10) /* disable interrupts */ CURRENT_THREAD_INFO(r9, r1) lwz r9,TI_FLAGS(r9) - andi. r0,r9,_TIF_NEED_RESCHED + andi. r0,r9,_TIF_NEED_RESCHED_MASK bne- do_resched andi. r0,r9,_TIF_USER_WORK_MASK beq restore_user Index: linux-5.0.19-rt11/arch/powerpc/kernel/entry_64.S =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/entry_64.S +++ linux-5.0.19-rt11/arch/powerpc/kernel/entry_64.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:256 @ system_call_exit: ld r9,TI_FLAGS(r12) li r11,-MAX_ERRNO - andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) + lis r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@h + ori r0,r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@l + and. r0,r9,r0 bne- .Lsyscall_exit_work andi. r0,r8,MSR_FP @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:375 @ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr. If TIF_NOERROR is set, just save r3 as it is. */ - andi. r0,r9,_TIF_RESTOREALL + andis. r0,r9,_TIF_RESTOREALL@h beq+ 0f REST_NVGPRS(r1) b 2f 0: cmpld r3,r11 /* r11 is -MAX_ERRNO */ blt+ 1f - andi. r0,r9,_TIF_NOERROR + andis. r0,r9,_TIF_NOERROR@h bne- 1f ld r5,_CCR(r1) neg r3,r3 oris r5,r5,0x1000 /* Set SO bit in CR */ std r5,_CCR(r1) 1: std r3,GPR3(r1) -2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) +2: andis. r0,r9,(_TIF_PERSYSCALL_MASK)@h beq 4f /* Clear per-syscall TIF flags if any are set. */ - li r11,_TIF_PERSYSCALL_MASK + lis r11,(_TIF_PERSYSCALL_MASK)@h addi r12,r12,TI_FLAGS 3: ldarx r10,0,r12 andc r10,r10,r11 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:785 @ _GLOBAL(ret_from_except_lite) bl restore_math b restore #endif -1: andi. r0,r4,_TIF_NEED_RESCHED +1: andi. r0,r4,_TIF_NEED_RESCHED_MASK beq 2f bl restore_interrupts SCHEDULE_USER @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:847 @ resume_kernel: #ifdef CONFIG_PREEMPT /* Check if we need to preempt */ + lwz r8,TI_PREEMPT(r9) + cmpwi 0,r8,0 /* if non-zero, just restore regs and return */ + bne restore andi. r0,r4,_TIF_NEED_RESCHED + bne+ check_count + + andi. r0,r4,_TIF_NEED_RESCHED_LAZY beq+ restore + lwz r8,TI_PREEMPT_LAZY(r9) + /* Check that preempt_count() == 0 and interrupts are enabled */ - lwz r8,TI_PREEMPT(r9) +check_count: cmpwi cr0,r8,0 bne restore ld r0,SOFTE(r1) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:875 @ resume_kernel: /* Re-test flags and eventually loop */ CURRENT_THREAD_INFO(r9, r1) ld r4,TI_FLAGS(r9) - andi. r0,r4,_TIF_NEED_RESCHED + andi. r0,r4,_TIF_NEED_RESCHED_MASK bne 1b /* Index: linux-5.0.19-rt11/arch/powerpc/kernel/irq.c =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/irq.c +++ linux-5.0.19-rt11/arch/powerpc/kernel/irq.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:769 @ void irq_ctx_init(void) } } +#ifndef CONFIG_PREEMPT_RT_FULL void do_softirq_own_stack(void) { struct thread_info *curtp, *irqtp; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:787 @ void do_softirq_own_stack(void) if (irqtp->flags) set_bits(irqtp->flags, &curtp->flags); } +#endif irq_hw_number_t virq_to_hw(unsigned int virq) { Index: linux-5.0.19-rt11/arch/powerpc/kernel/misc_32.S =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/misc_32.S +++ linux-5.0.19-rt11/arch/powerpc/kernel/misc_32.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:45 @ * We store the saved ksp_limit in the unused part * of the STACK_FRAME_OVERHEAD */ +#ifndef CONFIG_PREEMPT_RT_FULL _GLOBAL(call_do_softirq) mflr r0 stw r0,4(r1) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:62 @ _GLOBAL(call_do_softirq) stw r10,THREAD+KSP_LIMIT(r2) mtlr r0 blr +#endif /* * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp); Index: linux-5.0.19-rt11/arch/powerpc/kernel/misc_64.S =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/misc_64.S +++ linux-5.0.19-rt11/arch/powerpc/kernel/misc_64.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:35 @ .text +#ifndef CONFIG_PREEMPT_RT_FULL _GLOBAL(call_do_softirq) mflr r0 std r0,16(r1) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:46 @ _GLOBAL(call_do_softirq) ld r0,16(r1) mtlr r0 blr +#endif _GLOBAL(call_do_irq) mflr r0 Index: linux-5.0.19-rt11/arch/powerpc/kernel/traps.c =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/traps.c +++ linux-5.0.19-rt11/arch/powerpc/kernel/traps.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:177 @ extern void panic_flush_kmsg_start(void) extern void panic_flush_kmsg_end(void) { - printk_safe_flush_on_panic(); kmsg_dump(KMSG_DUMP_PANIC); bust_spinlocks(0); debug_locks_off(); Index: linux-5.0.19-rt11/arch/powerpc/kernel/watchdog.c =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kernel/watchdog.c +++ linux-5.0.19-rt11/arch/powerpc/kernel/watchdog.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:184 @ static void watchdog_smp_panic(int cpu, wd_smp_unlock(&flags); - printk_safe_flush(); - /* - * printk_safe_flush() seems to require another print - * before anything actually goes out to console. - */ if (sysctl_hardlockup_all_cpu_backtrace) trigger_allbutself_cpu_backtrace(); Index: linux-5.0.19-rt11/arch/powerpc/kvm/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/kvm/Kconfig +++ linux-5.0.19-rt11/arch/powerpc/kvm/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:181 @ config KVM_E500MC config KVM_MPIC bool "KVM in-kernel MPIC emulation" depends on KVM && E500 + depends on !PREEMPT_RT_FULL select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQFD select HAVE_KVM_IRQ_ROUTING Index: linux-5.0.19-rt11/arch/powerpc/platforms/cell/spufs/sched.c =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/platforms/cell/spufs/sched.c +++ linux-5.0.19-rt11/arch/powerpc/platforms/cell/spufs/sched.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:144 @ void __spu_update_sched_info(struct spu_ * runqueue. The context will be rescheduled on the proper node * if it is timesliced or preempted. */ - cpumask_copy(&ctx->cpus_allowed, ¤t->cpus_allowed); + cpumask_copy(&ctx->cpus_allowed, current->cpus_ptr); /* Save the current cpu id for spu interrupt routing. */ ctx->last_ran = raw_smp_processor_id(); Index: linux-5.0.19-rt11/arch/powerpc/platforms/ps3/device-init.c =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/platforms/ps3/device-init.c +++ linux-5.0.19-rt11/arch/powerpc/platforms/ps3/device-init.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:755 @ static int ps3_notification_read_write(s } pr_debug("%s:%u: notification %s issued\n", __func__, __LINE__, op); - res = wait_event_interruptible(dev->done.wait, - dev->done.done || kthread_should_stop()); + res = swait_event_interruptible_exclusive(dev->done.wait, + dev->done.done || kthread_should_stop()); if (kthread_should_stop()) res = -EINTR; if (res) { Index: linux-5.0.19-rt11/arch/powerpc/platforms/pseries/iommu.c =================================================================== --- linux-5.0.19-rt11.orig/arch/powerpc/platforms/pseries/iommu.c +++ linux-5.0.19-rt11/arch/powerpc/platforms/pseries/iommu.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:41 @ #include <linux/of.h> #include <linux/iommu.h> #include <linux/rculist.h> +#include <linux/locallock.h> #include <asm/io.h> #include <asm/prom.h> #include <asm/rtas.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:195 @ static int tce_build_pSeriesLP(struct io } static DEFINE_PER_CPU(__be64 *, tce_page); +static DEFINE_LOCAL_IRQ_LOCK(tcp_page_lock); static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum, long npages, unsigned long uaddr, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:216 @ static int tce_buildmulti_pSeriesLP(stru direction, attrs); } - local_irq_save(flags); /* to protect tcep and the page behind it */ + /* to protect tcep and the page behind it */ + local_lock_irqsave(tcp_page_lock, flags); tcep = __this_cpu_read(tce_page); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:228 @ static int tce_buildmulti_pSeriesLP(stru tcep = (__be64 *)__get_free_page(GFP_ATOMIC); /* If allocation fails, fall back to the loop implementation */ if (!tcep) { - local_irq_restore(flags); + local_unlock_irqrestore(tcp_page_lock, flags); return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr, direction, attrs); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:262 @ static int tce_buildmulti_pSeriesLP(stru tcenum += limit; } while (npages > 0 && !rc); - local_irq_restore(flags); + local_unlock_irqrestore(tcp_page_lock, flags); if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) { ret = (int)rc; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:420 @ static int tce_setrange_multi_pSeriesLP( u64 rc = 0; long l, limit; - local_irq_disable(); /* to protect tcep and the page behind it */ + /* to protect tcep and the page behind it */ + local_lock_irq(tcp_page_lock); tcep = __this_cpu_read(tce_page); if (!tcep) { tcep = (__be64 *)__get_free_page(GFP_ATOMIC); if (!tcep) { - local_irq_enable(); + local_unlock_irq(tcp_page_lock); return -ENOMEM; } __this_cpu_write(tce_page, tcep); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:473 @ static int tce_setrange_multi_pSeriesLP( /* error cleanup: caller will clear whole range */ - local_irq_enable(); + local_unlock_irq(tcp_page_lock); return rc; } Index: linux-5.0.19-rt11/arch/s390/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/s390/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/s390/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #ifndef __ASM_SPINLOCK_TYPES_H #define __ASM_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - typedef struct { int lock; } __attribute__ ((aligned (4))) arch_spinlock_t; Index: linux-5.0.19-rt11/arch/sh/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/sh/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/sh/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #ifndef __ASM_SH_SPINLOCK_TYPES_H #define __ASM_SH_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - typedef struct { volatile unsigned int lock; } arch_spinlock_t; Index: linux-5.0.19-rt11/arch/sh/kernel/irq.c =================================================================== --- linux-5.0.19-rt11.orig/arch/sh/kernel/irq.c +++ linux-5.0.19-rt11/arch/sh/kernel/irq.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:151 @ void irq_ctx_exit(int cpu) hardirq_ctx[cpu] = NULL; } +#ifndef CONFIG_PREEMPT_RT_FULL void do_softirq_own_stack(void) { struct thread_info *curctx; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:179 @ void do_softirq_own_stack(void) "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" ); } +#endif #else static inline void handle_one_irq(unsigned int irq) { Index: linux-5.0.19-rt11/arch/sparc/kernel/irq_64.c =================================================================== --- linux-5.0.19-rt11.orig/arch/sparc/kernel/irq_64.c +++ linux-5.0.19-rt11/arch/sparc/kernel/irq_64.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:857 @ void __irq_entry handler_irq(int pil, st set_irq_regs(old_regs); } +#ifndef CONFIG_PREEMPT_RT_FULL void do_softirq_own_stack(void) { void *orig_sp, *sp = softirq_stack[smp_processor_id()]; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:872 @ void do_softirq_own_stack(void) __asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp)); } +#endif #ifdef CONFIG_HOTPLUG_CPU void fixup_irqs(void) Index: linux-5.0.19-rt11/arch/x86/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/Kconfig +++ linux-5.0.19-rt11/arch/x86/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:186 @ config X86 select HAVE_PCI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_PREEMPT_LAZY select HAVE_RCU_TABLE_FREE if PARAVIRT select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE select HAVE_REGS_AND_STACK_ACCESS_API @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:273 @ config ARCH_MAY_HAVE_PC_FDC def_bool y depends on ISA_DMA_API +config RWSEM_GENERIC_SPINLOCK + def_bool PREEMPT_RT_FULL + config RWSEM_XCHGADD_ALGORITHM - def_bool y + def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL config GENERIC_CALIBRATE_DELAY def_bool y @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:956 @ config CALGARY_IOMMU_ENABLED_BY_DEFAULT config MAXSMP bool "Enable Maximum number of SMP Processors and NUMA Nodes" depends on X86_64 && SMP && DEBUG_KERNEL - select CPUMASK_OFFSTACK + select CPUMASK_OFFSTACK if !PREEMPT_RT_FULL ---help--- Enable maximum number of CPUS and NUMA Nodes for this architecture. If unsure, say N. Index: linux-5.0.19-rt11/arch/x86/crypto/aesni-intel_glue.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/crypto/aesni-intel_glue.c +++ linux-5.0.19-rt11/arch/x86/crypto/aesni-intel_glue.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:418 @ static int ecb_encrypt(struct skcipher_r err = skcipher_walk_virt(&walk, req, true); - kernel_fpu_begin(); while ((nbytes = walk.nbytes)) { + kernel_fpu_begin(); aesni_ecb_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr, nbytes & AES_BLOCK_MASK); + kernel_fpu_end(); nbytes &= AES_BLOCK_SIZE - 1; err = skcipher_walk_done(&walk, nbytes); } - kernel_fpu_end(); return err; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:440 @ static int ecb_decrypt(struct skcipher_r err = skcipher_walk_virt(&walk, req, true); - kernel_fpu_begin(); while ((nbytes = walk.nbytes)) { + kernel_fpu_begin(); aesni_ecb_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr, nbytes & AES_BLOCK_MASK); + kernel_fpu_end(); nbytes &= AES_BLOCK_SIZE - 1; err = skcipher_walk_done(&walk, nbytes); } - kernel_fpu_end(); return err; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:462 @ static int cbc_encrypt(struct skcipher_r err = skcipher_walk_virt(&walk, req, true); - kernel_fpu_begin(); while ((nbytes = walk.nbytes)) { + kernel_fpu_begin(); aesni_cbc_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr, nbytes & AES_BLOCK_MASK, walk.iv); + kernel_fpu_end(); nbytes &= AES_BLOCK_SIZE - 1; err = skcipher_walk_done(&walk, nbytes); } - kernel_fpu_end(); return err; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:484 @ static int cbc_decrypt(struct skcipher_r err = skcipher_walk_virt(&walk, req, true); - kernel_fpu_begin(); while ((nbytes = walk.nbytes)) { + kernel_fpu_begin(); aesni_cbc_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr, nbytes & AES_BLOCK_MASK, walk.iv); + kernel_fpu_end(); nbytes &= AES_BLOCK_SIZE - 1; err = skcipher_walk_done(&walk, nbytes); } - kernel_fpu_end(); return err; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:541 @ static int ctr_crypt(struct skcipher_req err = skcipher_walk_virt(&walk, req, true); - kernel_fpu_begin(); while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) { + kernel_fpu_begin(); aesni_ctr_enc_tfm(ctx, walk.dst.virt.addr, walk.src.virt.addr, nbytes & AES_BLOCK_MASK, walk.iv); + kernel_fpu_end(); nbytes &= AES_BLOCK_SIZE - 1; err = skcipher_walk_done(&walk, nbytes); } if (walk.nbytes) { + kernel_fpu_begin(); ctr_crypt_final(ctx, &walk); + kernel_fpu_end(); err = skcipher_walk_done(&walk, 0); } - kernel_fpu_end(); return err; } Index: linux-5.0.19-rt11/arch/x86/crypto/cast5_avx_glue.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/crypto/cast5_avx_glue.c +++ linux-5.0.19-rt11/arch/x86/crypto/cast5_avx_glue.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:64 @ static inline void cast5_fpu_end(bool fp static int ecb_crypt(struct skcipher_request *req, bool enc) { - bool fpu_enabled = false; + bool fpu_enabled; struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm); struct skcipher_walk walk; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:79 @ static int ecb_crypt(struct skcipher_req u8 *wsrc = walk.src.virt.addr; u8 *wdst = walk.dst.virt.addr; - fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes); + fpu_enabled = cast5_fpu_begin(false, &walk, nbytes); /* Process multi-block batch */ if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:108 @ static int ecb_crypt(struct skcipher_req } while (nbytes >= bsize); done: + cast5_fpu_end(fpu_enabled); err = skcipher_walk_done(&walk, nbytes); } - - cast5_fpu_end(fpu_enabled); return err; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:214 @ static int cbc_decrypt(struct skcipher_r { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm); - bool fpu_enabled = false; + bool fpu_enabled; struct skcipher_walk walk; unsigned int nbytes; int err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:222 @ static int cbc_decrypt(struct skcipher_r err = skcipher_walk_virt(&walk, req, false); while ((nbytes = walk.nbytes)) { - fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes); + fpu_enabled = cast5_fpu_begin(false, &walk, nbytes); nbytes = __cbc_decrypt(ctx, &walk); + cast5_fpu_end(fpu_enabled); err = skcipher_walk_done(&walk, nbytes); } - - cast5_fpu_end(fpu_enabled); return err; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:293 @ static int ctr_crypt(struct skcipher_req { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm); - bool fpu_enabled = false; + bool fpu_enabled; struct skcipher_walk walk; unsigned int nbytes; int err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:301 @ static int ctr_crypt(struct skcipher_req err = skcipher_walk_virt(&walk, req, false); while ((nbytes = walk.nbytes) >= CAST5_BLOCK_SIZE) { - fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes); + fpu_enabled = cast5_fpu_begin(false, &walk, nbytes); nbytes = __ctr_crypt(&walk, ctx); + cast5_fpu_end(fpu_enabled); err = skcipher_walk_done(&walk, nbytes); } - cast5_fpu_end(fpu_enabled); - if (walk.nbytes) { ctr_crypt_final(&walk, ctx); err = skcipher_walk_done(&walk, 0); Index: linux-5.0.19-rt11/arch/x86/crypto/chacha_glue.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/crypto/chacha_glue.c +++ linux-5.0.19-rt11/arch/x86/crypto/chacha_glue.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:134 @ static int chacha_simd_stream_xor(struct struct chacha_ctx *ctx, u8 *iv) { u32 *state, state_buf[16 + 2] __aligned(8); - int next_yield = 4096; /* bytes until next FPU yield */ int err = 0; BUILD_BUG_ON(CHACHA_STATE_ALIGN != 16); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:146 @ static int chacha_simd_stream_xor(struct if (nbytes < walk->total) { nbytes = round_down(nbytes, walk->stride); - next_yield -= nbytes; } chacha_dosimd(state, walk->dst.virt.addr, walk->src.virt.addr, nbytes, ctx->nrounds); - if (next_yield <= 0) { - /* temporarily allow preemption */ - kernel_fpu_end(); - kernel_fpu_begin(); - next_yield = 4096; - } - + kernel_fpu_end(); err = skcipher_walk_done(walk, walk->nbytes - nbytes); + kernel_fpu_begin(); } return err; Index: linux-5.0.19-rt11/arch/x86/crypto/glue_helper.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/crypto/glue_helper.c +++ linux-5.0.19-rt11/arch/x86/crypto/glue_helper.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:41 @ int glue_ecb_req_128bit(const struct com void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req)); const unsigned int bsize = 128 / 8; struct skcipher_walk walk; - bool fpu_enabled = false; + bool fpu_enabled; unsigned int nbytes; int err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:54 @ int glue_ecb_req_128bit(const struct com unsigned int i; fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit, - &walk, fpu_enabled, nbytes); + &walk, false, nbytes); for (i = 0; i < gctx->num_funcs; i++) { func_bytes = bsize * gctx->funcs[i].num_blocks; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:72 @ int glue_ecb_req_128bit(const struct com if (nbytes < bsize) break; } + glue_fpu_end(fpu_enabled); err = skcipher_walk_done(&walk, nbytes); } - - glue_fpu_end(fpu_enabled); return err; } EXPORT_SYMBOL_GPL(glue_ecb_req_128bit); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:117 @ int glue_cbc_decrypt_req_128bit(const st void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req)); const unsigned int bsize = 128 / 8; struct skcipher_walk walk; - bool fpu_enabled = false; + bool fpu_enabled; unsigned int nbytes; int err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:131 @ int glue_cbc_decrypt_req_128bit(const st u128 last_iv; fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit, - &walk, fpu_enabled, nbytes); + &walk, false, nbytes); /* Start of the last block. */ src += nbytes / bsize - 1; dst += nbytes / bsize - 1; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:163 @ int glue_cbc_decrypt_req_128bit(const st done: u128_xor(dst, dst, (u128 *)walk.iv); *(u128 *)walk.iv = last_iv; + glue_fpu_end(fpu_enabled); err = skcipher_walk_done(&walk, nbytes); } - glue_fpu_end(fpu_enabled); return err; } EXPORT_SYMBOL_GPL(glue_cbc_decrypt_req_128bit); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:177 @ int glue_ctr_req_128bit(const struct com void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req)); const unsigned int bsize = 128 / 8; struct skcipher_walk walk; - bool fpu_enabled = false; + bool fpu_enabled; unsigned int nbytes; int err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:191 @ int glue_ctr_req_128bit(const struct com le128 ctrblk; fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit, - &walk, fpu_enabled, nbytes); + &walk, false, nbytes); be128_to_le128(&ctrblk, (be128 *)walk.iv); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:215 @ int glue_ctr_req_128bit(const struct com } le128_to_be128((be128 *)walk.iv, &ctrblk); + glue_fpu_end(fpu_enabled); err = skcipher_walk_done(&walk, nbytes); } - glue_fpu_end(fpu_enabled); - if (nbytes) { le128 ctrblk; u128 tmp; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:279 @ int glue_xts_req_128bit(const struct com { const unsigned int bsize = 128 / 8; struct skcipher_walk walk; - bool fpu_enabled = false; + bool fpu_enabled; unsigned int nbytes; int err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:290 @ int glue_xts_req_128bit(const struct com /* set minimum length to bsize, for tweak_fn */ fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit, - &walk, fpu_enabled, + &walk, false, nbytes < bsize ? bsize : nbytes); /* calculate first value of T */ tweak_fn(tweak_ctx, walk.iv, walk.iv); while (nbytes) { + fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit, + &walk, fpu_enabled, + nbytes < bsize ? bsize : nbytes); nbytes = __glue_xts_req_128bit(gctx, crypt_ctx, &walk); + glue_fpu_end(fpu_enabled); + fpu_enabled = false; err = skcipher_walk_done(&walk, nbytes); nbytes = walk.nbytes; } - glue_fpu_end(fpu_enabled); - return err; } EXPORT_SYMBOL_GPL(glue_xts_req_128bit); Index: linux-5.0.19-rt11/arch/x86/entry/common.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/entry/common.c +++ linux-5.0.19-rt11/arch/x86/entry/common.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:34 @ #include <asm/vdso.h> #include <linux/uaccess.h> #include <asm/cpufeature.h> +#include <asm/fpu/api.h> #include <asm/nospec-branch.h> #define CREATE_TRACE_POINTS @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:138 @ static long syscall_trace_enter(struct p #define EXIT_TO_USERMODE_LOOP_FLAGS \ (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_UPROBE | \ - _TIF_NEED_RESCHED | _TIF_USER_RETURN_NOTIFY | _TIF_PATCH_PENDING) + _TIF_NEED_RESCHED_MASK | _TIF_USER_RETURN_NOTIFY | _TIF_PATCH_PENDING) static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:153 @ static void exit_to_usermode_loop(struct /* We have work to do. */ local_irq_enable(); - if (cached_flags & _TIF_NEED_RESCHED) + if (cached_flags & _TIF_NEED_RESCHED_MASK) schedule(); +#ifdef ARCH_RT_DELAYS_SIGNAL_SEND + if (unlikely(current->forced_info.si_signo)) { + struct task_struct *t = current; + force_sig_info(t->forced_info.si_signo, &t->forced_info, t); + t->forced_info.si_signo = 0; + } +#endif if (cached_flags & _TIF_UPROBE) uprobe_notify_resume(regs); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:208 @ __visible inline void prepare_exit_to_us if (unlikely(cached_flags & EXIT_TO_USERMODE_LOOP_FLAGS)) exit_to_usermode_loop(regs, cached_flags); + /* Reload ti->flags; we may have rescheduled above. */ + cached_flags = READ_ONCE(ti->flags); + + fpregs_assert_state_consistent(); + if (unlikely(cached_flags & _TIF_NEED_FPU_LOAD)) + switch_fpu_return(); + #ifdef CONFIG_COMPAT /* * Compat syscalls set TS_COMPAT. Make sure we clear it before Index: linux-5.0.19-rt11/arch/x86/entry/entry_32.S =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/entry/entry_32.S +++ linux-5.0.19-rt11/arch/x86/entry/entry_32.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:772 @ END(ret_from_exception) ENTRY(resume_kernel) DISABLE_INTERRUPTS(CLBR_ANY) .Lneed_resched: + # preempt count == 0 + NEED_RS set? cmpl $0, PER_CPU_VAR(__preempt_count) +#ifndef CONFIG_PREEMPT_LAZY jnz restore_all_kernel +#else + jz test_int_off + + # atleast preempt count == 0 ? + cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count) + jne restore_all_kernel + + movl PER_CPU_VAR(current_task), %ebp + cmpl $0,TASK_TI_preempt_lazy_count(%ebp) # non-zero preempt_lazy_count ? + jnz restore_all_kernel + + testl $_TIF_NEED_RESCHED_LAZY, TASK_TI_flags(%ebp) + jz restore_all_kernel +test_int_off: +#endif testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ? jz restore_all_kernel call preempt_schedule_irq Index: linux-5.0.19-rt11/arch/x86/entry/entry_64.S =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/entry/entry_64.S +++ linux-5.0.19-rt11/arch/x86/entry/entry_64.S @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:651 @ retint_kernel: btl $9, EFLAGS(%rsp) /* were interrupts off? */ jnc 1f 0: cmpl $0, PER_CPU_VAR(__preempt_count) +#ifndef CONFIG_PREEMPT_LAZY jnz 1f +#else + jz do_preempt_schedule_irq + + # atleast preempt count == 0 ? + cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count) + jnz 1f + + movq PER_CPU_VAR(current_task), %rcx + cmpl $0, TASK_TI_preempt_lazy_count(%rcx) + jnz 1f + + btl $TIF_NEED_RESCHED_LAZY,TASK_TI_flags(%rcx) + jnc 1f +do_preempt_schedule_irq: +#endif call preempt_schedule_irq jmp 0b 1: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1054 @ bad_gs: jmp 2b .previous +#ifndef CONFIG_PREEMPT_RT_FULL /* Call softirq on interrupt stack. Interrupts are off. */ ENTRY(do_softirq_own_stack) pushq %rbp @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1065 @ ENTRY(do_softirq_own_stack) leaveq ret ENDPROC(do_softirq_own_stack) +#endif #ifdef CONFIG_XEN_PV idtentry hypervisor_callback xen_do_hypervisor_callback has_error_code=0 Index: linux-5.0.19-rt11/arch/x86/ia32/ia32_signal.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/ia32/ia32_signal.c +++ linux-5.0.19-rt11/arch/x86/ia32/ia32_signal.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:224 @ static void __user *get_sigframe(struct size_t frame_size, void __user **fpstate) { - struct fpu *fpu = ¤t->thread.fpu; - unsigned long sp; + unsigned long sp, fx_aligned, math_size; /* Default to using normal stack */ sp = regs->sp; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:238 @ static void __user *get_sigframe(struct ksig->ka.sa.sa_restorer) sp = (unsigned long) ksig->ka.sa.sa_restorer; - if (fpu->initialized) { - unsigned long fx_aligned, math_size; - - sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size); - *fpstate = (struct _fpstate_32 __user *) sp; - if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned, - math_size) < 0) - return (void __user *) -1L; - } + sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size); + *fpstate = (struct _fpstate_32 __user *) sp; + if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned, + math_size) < 0) + return (void __user *) -1L; sp -= frame_size; /* Align the stack pointer according to the i386 ABI, Index: linux-5.0.19-rt11/arch/x86/include/asm/fpu/api.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/fpu/api.h +++ linux-5.0.19-rt11/arch/x86/include/asm/fpu/api.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:13 @ #ifndef _ASM_X86_FPU_API_H #define _ASM_X86_FPU_API_H +#include <linux/bottom_half.h> /* * Use kernel_fpu_begin/end() if you intend to use FPU in kernel context. It @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:25 @ extern void kernel_fpu_begin(void); extern void kernel_fpu_end(void); extern bool irq_fpu_usable(void); +extern void fpregs_mark_activate(void); +extern void kernel_fpu_resched(void); + +/* + * Use fpregs_lock() while editing CPU's FPU registers or fpu->state. + * A context switch will (and softirq might) save CPU's FPU register to + * fpu->state and set TIF_NEED_FPU_LOAD leaving CPU's FPU registers in a random + * state. + */ +static inline void fpregs_lock(void) +{ + preempt_disable(); + local_bh_disable(); +} + +static inline void fpregs_unlock(void) +{ + local_bh_enable(); + preempt_enable(); +} + +#ifdef CONFIG_X86_DEBUG_FPU +extern void fpregs_assert_state_consistent(void); +#else +static inline void fpregs_assert_state_consistent(void) { } +#endif + +/* + * Load the task FPU state before returning to userspace. + */ +extern void switch_fpu_return(void); /* * Query the presence of one or more xfeatures. Works on any legacy CPU as well. Index: linux-5.0.19-rt11/arch/x86/include/asm/fpu/internal.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/fpu/internal.h +++ linux-5.0.19-rt11/arch/x86/include/asm/fpu/internal.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:17 @ #include <linux/compat.h> #include <linux/sched.h> #include <linux/slab.h> +#include <linux/mm.h> #include <asm/user.h> #include <asm/fpu/api.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:28 @ /* * High level FPU state handling functions: */ -extern void fpu__initialize(struct fpu *fpu); extern void fpu__prepare_read(struct fpu *fpu); extern void fpu__prepare_write(struct fpu *fpu); extern void fpu__save(struct fpu *fpu); -extern void fpu__restore(struct fpu *fpu); extern int fpu__restore_sig(void __user *buf, int ia32_frame); extern void fpu__drop(struct fpu *fpu); -extern int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu); +extern int fpu__copy(struct task_struct *dst, struct task_struct *src); extern void fpu__clear(struct fpu *fpu); extern int fpu__exception_code(struct fpu *fpu, int trap_nr); extern int dump_fpu(struct pt_regs *ptregs, struct user_i387_struct *fpstate); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:124 @ extern void fpstate_sanitize_xstate(stru err; \ }) +#define kernel_insn_err(insn, output, input...) \ +({ \ + int err; \ + asm volatile("1:" #insn "\n\t" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: movl $-1,%[err]\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE(1b, 3b) \ + : [err] "=r" (err), output \ + : "0"(0), input); \ + err; \ +}) + #define kernel_insn(insn, output, input...) \ asm volatile("1:" #insn "\n\t" \ "2:\n" \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:175 @ static inline void copy_kernel_to_fxregs } } +static inline int copy_kernel_to_fxregs_err(struct fxregs_state *fx) +{ + if (IS_ENABLED(CONFIG_X86_32)) + return kernel_insn_err(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx)); + else + return kernel_insn_err(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx)); +} + static inline int copy_user_to_fxregs(struct fxregs_state __user *fx) { if (IS_ENABLED(CONFIG_X86_32)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:200 @ static inline void copy_kernel_to_fregs( kernel_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx)); } +static inline int copy_kernel_to_fregs_err(struct fregs_state *fx) +{ + return kernel_insn_err(frstor %[fx], "=m" (*fx), [fx] "m" (*fx)); +} + static inline int copy_user_to_fregs(struct fregs_state __user *fx) { return user_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:431 @ static inline int copy_user_to_xregs(str } /* + * Restore xstate from kernel space xsave area, return an error code instead an + * exception. + */ +static inline int copy_kernel_to_xregs_err(struct xregs_state *xstate, u64 mask) +{ + u32 lmask = mask; + u32 hmask = mask >> 32; + int err; + + XSTATE_OP(XRSTOR, xstate, lmask, hmask, err); + + return err; +} + +/* * These must be called with preempt disabled. Returns * 'true' if the FPU state is still intact and we can * keep registers active. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:562 @ static inline void fpregs_activate(struc trace_x86_fpu_regs_activated(fpu); } +static inline void __fpregs_load_activate(void) +{ + struct fpu *fpu = ¤t->thread.fpu; + int cpu = smp_processor_id(); + + if (WARN_ON_ONCE(current->mm == NULL)) + return; + + if (!fpregs_state_valid(fpu, cpu)) { + copy_kernel_to_fpregs(&fpu->state); + fpregs_activate(fpu); + fpu->last_cpu = cpu; + } + clear_thread_flag(TIF_NEED_FPU_LOAD); +} + /* * FPU state switching for scheduling. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:586 @ static inline void fpregs_activate(struc * - switch_fpu_prepare() saves the old state. * This is done within the context of the old process. * - * - switch_fpu_finish() restores the new state as - * necessary. + * - switch_fpu_finish() sets TIF_NEED_FPU_LOAD; the floating point state + * will get loaded on return to userspace, or when the kernel needs it. + * + * The FPU context is only stored/restore for user task and ->mm is used to + * distinguish between kernel and user threads. + * + * If TIF_NEED_FPU_LOAD is cleared then the CPU's FPU registers are saved in + * the current thread's FPU registers state. + * If TIF_NEED_FPU_LOAD is set then CPU's FPU registers may not hold current()'s + * FPU registers. It is required to load the registers before returning to + * userland or using the content otherwise. */ static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu) { - if (static_cpu_has(X86_FEATURE_FPU) && old_fpu->initialized) { + if (static_cpu_has(X86_FEATURE_FPU) && current->mm) { if (!copy_fpregs_to_fpstate(old_fpu)) old_fpu->last_cpu = -1; else @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:609 @ switch_fpu_prepare(struct fpu *old_fpu, /* But leave fpu_fpregs_owner_ctx! */ trace_x86_fpu_regs_deactivated(old_fpu); - } else - old_fpu->last_cpu = -1; + } } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:617 @ switch_fpu_prepare(struct fpu *old_fpu, */ /* - * Set up the userspace FPU context for the new task, if the task - * has used the FPU. + * Load PKRU from the FPU context if available. Delay loading the loading of the + * complete FPU state until the return to userland. */ -static inline void switch_fpu_finish(struct fpu *new_fpu, int cpu) +static inline void switch_fpu_finish(struct fpu *new_fpu) { - bool preload = static_cpu_has(X86_FEATURE_FPU) && - new_fpu->initialized; + struct pkru_state *pk; + u32 pkru_val = init_pkru_value; - if (preload) { - if (!fpregs_state_valid(new_fpu, cpu)) - copy_kernel_to_fpregs(&new_fpu->state); - fpregs_activate(new_fpu); - } -} + if (!static_cpu_has(X86_FEATURE_FPU)) + return; -/* - * Needs to be preemption-safe. - * - * NOTE! user_fpu_begin() must be used only immediately before restoring - * the save state. It does not do any saving/restoring on its own. In - * lazy FPU mode, it is just an optimization to avoid a #NM exception, - * the task can lose the FPU right after preempt_enable(). - */ -static inline void user_fpu_begin(void) -{ - struct fpu *fpu = ¤t->thread.fpu; + set_thread_flag(TIF_NEED_FPU_LOAD); + + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) + return; - preempt_disable(); - fpregs_activate(fpu); - preempt_enable(); + /* + * PKRU state is switched eagerly because it needs to be valid before we + * return to userland e.g. for a copy_to_user() operation. + */ + if (current->mm) { + pk = get_xsave_addr(&new_fpu->state.xsave, XFEATURE_PKRU); + if (pk) + pkru_val = pk->pkru; + } + __write_pkru(pkru_val); } /* Index: linux-5.0.19-rt11/arch/x86/include/asm/fpu/signal.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/fpu/signal.h +++ linux-5.0.19-rt11/arch/x86/include/asm/fpu/signal.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:25 @ int ia32_setup_frame(int sig, struct ksi extern void convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk); -extern void convert_to_fxsr(struct task_struct *tsk, +extern void convert_to_fxsr(struct fxregs_state *fxsave, const struct user_i387_ia32_struct *env); unsigned long Index: linux-5.0.19-rt11/arch/x86/include/asm/fpu/types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/fpu/types.h +++ linux-5.0.19-rt11/arch/x86/include/asm/fpu/types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:297 @ struct fpu { unsigned int last_cpu; /* - * @initialized: - * - * This flag indicates whether this context is initialized: if the task - * is not running then we can restore from this context, if the task - * is running then we should save into this context. - */ - unsigned char initialized; - - /* * @state: * * In-memory copy of all FPU registers that we save/restore Index: linux-5.0.19-rt11/arch/x86/include/asm/fpu/xstate.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/fpu/xstate.h +++ linux-5.0.19-rt11/arch/x86/include/asm/fpu/xstate.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8 @ #include <linux/types.h> #include <asm/processor.h> #include <linux/uaccess.h> +#include <asm/user.h> /* Bit 63 of XCR0 is reserved for future expansion */ #define XFEATURE_MASK_EXTEND (~(XFEATURE_MASK_FPSSE | (1ULL << 63))) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:50 @ extern void __init update_regset_xstate_ u64 xstate_mask); void fpu__xstate_clear_all_cpu_caps(void); -void *get_xsave_addr(struct xregs_state *xsave, int xstate); -const void *get_xsave_field_ptr(int xstate_field); +void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); +const void *get_xsave_field_ptr(int xfeature_nr); int using_compacted_format(void); int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset, unsigned int size); int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset, unsigned int size); Index: linux-5.0.19-rt11/arch/x86/include/asm/pgtable.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/pgtable.h +++ linux-5.0.19-rt11/arch/x86/include/asm/pgtable.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:26 @ #ifndef __ASSEMBLY__ #include <asm/x86_init.h> +#include <asm/fpu/xstate.h> +#include <asm/fpu/api.h> extern pgd_t early_top_pgt[PTRS_PER_PGD]; int __init __early_make_pgtable(unsigned long address, pmdval_t pmd); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:132 @ static inline int pte_dirty(pte_t pte) static inline u32 read_pkru(void) { if (boot_cpu_has(X86_FEATURE_OSPKE)) - return __read_pkru(); + return __read_pkru_ins(); return 0; } static inline void write_pkru(u32 pkru) { - if (boot_cpu_has(X86_FEATURE_OSPKE)) - __write_pkru(pkru); + struct pkru_state *pk; + + if (!boot_cpu_has(X86_FEATURE_OSPKE)) + return; + + pk = get_xsave_addr(¤t->thread.fpu.state.xsave, XFEATURE_PKRU); + /* + * The PKRU value in xstate needs to be in sync with the value that is + * written to the CPU. The FPU restore on return to userland would + * otherwise load the previous value again. + */ + fpregs_lock(); + if (pk) + pk->pkru = pkru; + __write_pkru(pkru); + fpregs_unlock(); } static inline int pte_young(pte_t pte) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1374 @ static inline pmd_t pmd_swp_clear_soft_d #define PKRU_WD_BIT 0x2 #define PKRU_BITS_PER_PKEY 2 +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +extern u32 init_pkru_value; +#else +#define init_pkru_value 0 +#endif + static inline bool __pkru_allows_read(u32 pkru, u16 pkey) { int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY; Index: linux-5.0.19-rt11/arch/x86/include/asm/preempt.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/preempt.h +++ linux-5.0.19-rt11/arch/x86/include/asm/preempt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:92 @ static __always_inline void __preempt_co * a decrement which hits zero means we have no preempt_count and should * reschedule. */ -static __always_inline bool __preempt_count_dec_and_test(void) +static __always_inline bool ____preempt_count_dec_and_test(void) { return GEN_UNARY_RMWcc("decl", __preempt_count, e, __percpu_arg([var])); } +static __always_inline bool __preempt_count_dec_and_test(void) +{ + if (____preempt_count_dec_and_test()) + return true; +#ifdef CONFIG_PREEMPT_LAZY + if (current_thread_info()->preempt_lazy_count) + return false; + return test_thread_flag(TIF_NEED_RESCHED_LAZY); +#else + return false; +#endif +} + /* * Returns true when we need to resched and can (barring IRQ state). */ static __always_inline bool should_resched(int preempt_offset) { +#ifdef CONFIG_PREEMPT_LAZY + u32 tmp; + + tmp = raw_cpu_read_4(__preempt_count); + if (tmp == preempt_offset) + return true; + + /* preempt count == 0 ? */ + tmp &= ~PREEMPT_NEED_RESCHED; + if (tmp != preempt_offset) + return false; + if (current_thread_info()->preempt_lazy_count) + return false; + return test_thread_flag(TIF_NEED_RESCHED_LAZY); +#else return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset); +#endif } #ifdef CONFIG_PREEMPT Index: linux-5.0.19-rt11/arch/x86/include/asm/signal.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/signal.h +++ linux-5.0.19-rt11/arch/x86/include/asm/signal.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:31 @ typedef struct { #define SA_IA32_ABI 0x02000000u #define SA_X32_ABI 0x01000000u +/* + * Because some traps use the IST stack, we must keep preemption + * disabled while calling do_trap(), but do_trap() may call + * force_sig_info() which will grab the signal spin_locks for the + * task, which in PREEMPT_RT_FULL are mutexes. By defining + * ARCH_RT_DELAYS_SIGNAL_SEND the force_sig_info() will set + * TIF_NOTIFY_RESUME and set up the signal to be sent on exit of the + * trap. + */ +#if defined(CONFIG_PREEMPT_RT_FULL) +#define ARCH_RT_DELAYS_SIGNAL_SEND +#endif + #ifndef CONFIG_COMPAT typedef sigset_t compat_sigset_t; #endif Index: linux-5.0.19-rt11/arch/x86/include/asm/smap.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/smap.h +++ linux-5.0.19-rt11/arch/x86/include/asm/smap.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:61 @ static __always_inline void stac(void) alternative("", __stringify(__ASM_STAC), X86_FEATURE_SMAP); } +static __always_inline unsigned long smap_save(void) +{ + unsigned long flags; + + asm volatile (ALTERNATIVE("", "pushf; pop %0; " __stringify(__ASM_CLAC), + X86_FEATURE_SMAP) + : "=rm" (flags) : : "memory", "cc"); + + return flags; +} + +static __always_inline void smap_restore(unsigned long flags) +{ + asm volatile (ALTERNATIVE("", "push %0; popf", X86_FEATURE_SMAP) + : : "g" (flags) : "memory", "cc"); +} + /* These macros can be used in asm() statements */ #define ASM_CLAC \ ALTERNATIVE("", __stringify(__ASM_CLAC), X86_FEATURE_SMAP) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:89 @ static __always_inline void stac(void) static inline void clac(void) { } static inline void stac(void) { } +static inline unsigned long smap_save(void) { return 0; } +static inline void smap_restore(unsigned long flags) { } + #define ASM_CLAC #define ASM_STAC Index: linux-5.0.19-rt11/arch/x86/include/asm/special_insns.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/special_insns.h +++ linux-5.0.19-rt11/arch/x86/include/asm/special_insns.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:95 @ static inline void native_write_cr8(unsi #endif #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS -static inline u32 __read_pkru(void) +static inline u32 __read_pkru_ins(void) { u32 ecx = 0; u32 edx, pkru; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:110 @ static inline u32 __read_pkru(void) return pkru; } -static inline void __write_pkru(u32 pkru) +static inline void __write_pkru_ins(u32 pkru) { u32 ecx = 0, edx = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:121 @ static inline void __write_pkru(u32 pkru asm volatile(".byte 0x0f,0x01,0xef\n\t" : : "a" (pkru), "c"(ecx), "d"(edx)); } + +static inline void __write_pkru(u32 pkru) +{ + /* + * WRPKRU is relatively expensive compared to RDPKRU. + * Avoid WRPKRU when it would not change the value. + */ + if (pkru == __read_pkru_ins()) + return; + __write_pkru_ins(pkru); +} + #else -static inline u32 __read_pkru(void) +static inline u32 __read_pkru_ins(void) { return 0; } Index: linux-5.0.19-rt11/arch/x86/include/asm/stackprotector.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/stackprotector.h +++ linux-5.0.19-rt11/arch/x86/include/asm/stackprotector.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:63 @ */ static __always_inline void boot_init_stack_canary(void) { - u64 canary; + u64 uninitialized_var(canary); u64 tsc; #ifdef CONFIG_X86_64 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:74 @ static __always_inline void boot_init_st * of randomness. The TSC only matters for very early init, * there it already has some randomness on most systems. Later * on during the bootup the random pool has true entropy too. + * For preempt-rt we need to weaken the randomness a bit, as + * we can't call into the random generator from atomic context + * due to locking constraints. We just leave canary + * uninitialized and use the TSC based randomness on top of it. */ +#ifndef CONFIG_PREEMPT_RT_FULL get_random_bytes(&canary, sizeof(canary)); +#endif tsc = rdtsc(); canary += tsc + (tsc << 32UL); canary &= CANARY_MASK; Index: linux-5.0.19-rt11/arch/x86/include/asm/thread_info.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/thread_info.h +++ linux-5.0.19-rt11/arch/x86/include/asm/thread_info.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:59 @ struct task_struct; struct thread_info { unsigned long flags; /* low level flags */ u32 status; /* thread synchronous flags */ + int preempt_lazy_count; /* 0 => lazy preemptable + <0 => BUG */ }; #define INIT_THREAD_INFO(tsk) \ { \ .flags = 0, \ + .preempt_lazy_count = 0, \ } #else /* !__ASSEMBLY__ */ #include <asm/asm-offsets.h> +#define GET_THREAD_INFO(reg) \ + _ASM_MOV PER_CPU_VAR(cpu_current_top_of_stack),reg ; \ + _ASM_SUB $(THREAD_SIZE),reg ; + #endif /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:98 @ struct thread_info { #define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */ #define TIF_UPROBE 12 /* breakpointed or singlestepping */ #define TIF_PATCH_PENDING 13 /* pending live patching update */ +#define TIF_NEED_FPU_LOAD 14 /* load FPU on return to userspace */ #define TIF_NOCPUID 15 /* CPUID is not accessible in userland */ #define TIF_NOTSC 16 /* TSC is not accessible in userland */ #define TIF_IA32 17 /* IA32 compatibility process */ +#define TIF_NEED_RESCHED_LAZY 18 /* lazy rescheduling necessary */ #define TIF_NOHZ 19 /* in adaptive nohz mode */ #define TIF_MEMDIE 20 /* is terminating due to OOM killer */ #define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:129 @ struct thread_info { #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY) #define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING) +#define _TIF_NEED_FPU_LOAD (1 << TIF_NEED_FPU_LOAD) #define _TIF_NOCPUID (1 << TIF_NOCPUID) #define _TIF_NOTSC (1 << TIF_NOTSC) #define _TIF_IA32 (1 << TIF_IA32) +#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY) #define _TIF_NOHZ (1 << TIF_NOHZ) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:171 @ struct thread_info { #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW) +#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY) + #define STACK_WARN (THREAD_SIZE/8) /* Index: linux-5.0.19-rt11/arch/x86/include/asm/trace/fpu.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/trace/fpu.h +++ linux-5.0.19-rt11/arch/x86/include/asm/trace/fpu.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:16 @ DECLARE_EVENT_CLASS(x86_fpu, TP_STRUCT__entry( __field(struct fpu *, fpu) - __field(bool, initialized) + __field(bool, load_fpu) __field(u64, xfeatures) __field(u64, xcomp_bv) ), TP_fast_assign( __entry->fpu = fpu; - __entry->initialized = fpu->initialized; + __entry->load_fpu = test_thread_flag(TIF_NEED_FPU_LOAD); if (boot_cpu_has(X86_FEATURE_OSXSAVE)) { __entry->xfeatures = fpu->state.xsave.header.xfeatures; __entry->xcomp_bv = fpu->state.xsave.header.xcomp_bv; } ), - TP_printk("x86/fpu: %p initialized: %d xfeatures: %llx xcomp_bv: %llx", + TP_printk("x86/fpu: %p load: %d xfeatures: %llx xcomp_bv: %llx", __entry->fpu, - __entry->initialized, + __entry->load_fpu, __entry->xfeatures, __entry->xcomp_bv ) Index: linux-5.0.19-rt11/arch/x86/include/asm/uaccess.h =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/include/asm/uaccess.h +++ linux-5.0.19-rt11/arch/x86/include/asm/uaccess.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:723 @ static __must_check inline bool user_acc #define user_access_begin(a,b) user_access_begin(a,b) #define user_access_end() __uaccess_end() +#define user_access_save() smap_save() +#define user_access_restore(x) smap_restore(x) + #define unsafe_put_user(x, ptr, label) \ __put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), label) Index: linux-5.0.19-rt11/arch/x86/kernel/apic/io_apic.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/apic/io_apic.c +++ linux-5.0.19-rt11/arch/x86/kernel/apic/io_apic.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1725 @ static bool io_apic_level_ack_pending(st return false; } -static inline bool ioapic_irqd_mask(struct irq_data *data) +static inline bool ioapic_prepare_move(struct irq_data *data) { /* If we are moving the irq we need to mask it */ if (unlikely(irqd_is_setaffinity_pending(data))) { - mask_ioapic_irq(data); + if (!irqd_irq_masked(data)) + mask_ioapic_irq(data); return true; } return false; } -static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked) +static inline void ioapic_finish_move(struct irq_data *data, bool moveit) { - if (unlikely(masked)) { + if (unlikely(moveit)) { /* Only migrate the irq if the ack has been received. * * On rare occasions the broadcast level triggered ack gets @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1767 @ static inline void ioapic_irqd_unmask(st */ if (!io_apic_level_ack_pending(data->chip_data)) irq_move_masked_irq(data); - unmask_ioapic_irq(data); + /* If the irq is masked in the core, leave it */ + if (!irqd_irq_masked(data)) + unmask_ioapic_irq(data); } } #else -static inline bool ioapic_irqd_mask(struct irq_data *data) +static inline bool ioapic_prepare_move(struct irq_data *data) { return false; } -static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked) +static inline void ioapic_finish_move(struct irq_data *data, bool moveit) { } #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1786 @ static void ioapic_ack_level(struct irq_ { struct irq_cfg *cfg = irqd_cfg(irq_data); unsigned long v; - bool masked; + bool moveit; int i; irq_complete_move(cfg); - masked = ioapic_irqd_mask(irq_data); + moveit = ioapic_prepare_move(irq_data); /* * It appears there is an erratum which affects at least version 0x11 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1845 @ static void ioapic_ack_level(struct irq_ eoi_ioapic_pin(cfg->vector, irq_data->chip_data); } - ioapic_irqd_unmask(irq_data, masked); + ioapic_finish_move(irq_data, moveit); } static void ioapic_ir_ack_level(struct irq_data *irq_data) Index: linux-5.0.19-rt11/arch/x86/kernel/asm-offsets.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/asm-offsets.c +++ linux-5.0.19-rt11/arch/x86/kernel/asm-offsets.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:42 @ static void __used common(void) BLANK(); OFFSET(TASK_TI_flags, task_struct, thread_info.flags); + OFFSET(TASK_TI_preempt_lazy_count, task_struct, thread_info.preempt_lazy_count); OFFSET(TASK_addr_limit, task_struct, thread.addr_limit); BLANK(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:96 @ static void __used common(void) BLANK(); DEFINE(PTREGS_SIZE, sizeof(struct pt_regs)); + DEFINE(_PREEMPT_ENABLED, PREEMPT_ENABLED); /* TLB state for the entry code */ OFFSET(TLB_STATE_user_pcid_flush_mask, tlb_state, user_pcid_flush_mask); Index: linux-5.0.19-rt11/arch/x86/kernel/cpu/common.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/cpu/common.c +++ linux-5.0.19-rt11/arch/x86/kernel/cpu/common.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:375 @ static bool pku_disabled; static __always_inline void setup_pku(struct cpuinfo_x86 *c) { + struct pkru_state *pk; + /* check the boot processor, plus compile options for PKU: */ if (!cpu_feature_enabled(X86_FEATURE_PKU)) return; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:387 @ static __always_inline void setup_pku(st return; cr4_set_bits(X86_CR4_PKE); + pk = get_xsave_addr(&init_fpstate.xsave, XFEATURE_PKRU); + if (pk) + pk->pkru = init_pkru_value; /* * Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE * cpuid bit to be set. We need to ensure that we Index: linux-5.0.19-rt11/arch/x86/kernel/cpu/resctrl/pseudo_lock.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ linux-5.0.19-rt11/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1513 @ static int pseudo_lock_dev_mmap(struct f * may be scheduled elsewhere and invalidate entries in the * pseudo-locked region. */ - if (!cpumask_subset(¤t->cpus_allowed, &plr->d->cpu_mask)) { + if (!cpumask_subset(current->cpus_ptr, &plr->d->cpu_mask)) { mutex_unlock(&rdtgroup_mutex); return -EINVAL; } Index: linux-5.0.19-rt11/arch/x86/kernel/fpu/core.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/fpu/core.c +++ linux-5.0.19-rt11/arch/x86/kernel/fpu/core.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:104 @ static void __kernel_fpu_begin(void) kernel_fpu_disable(); - if (fpu->initialized) { - /* - * Ignore return value -- we don't care if reg state - * is clobbered. - */ - copy_fpregs_to_fpstate(fpu); - } else { - __cpu_invalidate_fpregs_state(); + if (current->mm) { + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) { + set_thread_flag(TIF_NEED_FPU_LOAD); + /* + * Ignore return value -- we don't care if reg state + * is clobbered. + */ + copy_fpregs_to_fpstate(fpu); + } } + __cpu_invalidate_fpregs_state(); } static void __kernel_fpu_end(void) { - struct fpu *fpu = ¤t->thread.fpu; - - if (fpu->initialized) - copy_kernel_to_fpregs(&fpu->state); - kernel_fpu_enable(); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:136 @ void kernel_fpu_end(void) } EXPORT_SYMBOL_GPL(kernel_fpu_end); +void kernel_fpu_resched(void) +{ + WARN_ON_FPU(!this_cpu_read(in_kernel_fpu)); + + if (should_resched(PREEMPT_OFFSET)) { + kernel_fpu_end(); + cond_resched(); + kernel_fpu_begin(); + } +} +EXPORT_SYMBOL_GPL(kernel_fpu_resched); + /* * Save the FPU state (mark it for reload if necessary): * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:157 @ void fpu__save(struct fpu *fpu) { WARN_ON_FPU(fpu != ¤t->thread.fpu); - preempt_disable(); + fpregs_lock(); trace_x86_fpu_before_save(fpu); - if (fpu->initialized) { + + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) { if (!copy_fpregs_to_fpstate(fpu)) { copy_kernel_to_fpregs(&fpu->state); } } + trace_x86_fpu_after_save(fpu); - preempt_enable(); + fpregs_unlock(); } EXPORT_SYMBOL_GPL(fpu__save); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:200 @ void fpstate_init(union fpregs_state *st } EXPORT_SYMBOL_GPL(fpstate_init); -int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) +int fpu__copy(struct task_struct *dst, struct task_struct *src) { + struct fpu *dst_fpu = &dst->thread.fpu; + struct fpu *src_fpu = &src->thread.fpu; + dst_fpu->last_cpu = -1; - if (!src_fpu->initialized || !static_cpu_has(X86_FEATURE_FPU)) + if (!static_cpu_has(X86_FEATURE_FPU)) return 0; WARN_ON_FPU(src_fpu != ¤t->thread.fpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:219 @ int fpu__copy(struct fpu *dst_fpu, struc memset(&dst_fpu->state.xsave, 0, fpu_kernel_xstate_size); /* - * Save current FPU registers directly into the child - * FPU context, without any memory-to-memory copying. + * If the FPU registers are not current just memcpy() the state. + * Otherwise save current FPU registers directly into the child's FPU + * context, without any memory-to-memory copying. * * ( The function 'fails' in the FNSAVE case, which destroys - * register contents so we have to copy them back. ) + * register contents so we have to load them back. ) */ - if (!copy_fpregs_to_fpstate(dst_fpu)) { - memcpy(&src_fpu->state, &dst_fpu->state, fpu_kernel_xstate_size); - copy_kernel_to_fpregs(&src_fpu->state); - } + fpregs_lock(); + if (test_thread_flag(TIF_NEED_FPU_LOAD)) + memcpy(&dst_fpu->state, &src_fpu->state, fpu_kernel_xstate_size); + + else if (!copy_fpregs_to_fpstate(dst_fpu)) + copy_kernel_to_fpregs(&dst_fpu->state); + + fpregs_unlock(); + + set_tsk_thread_flag(dst, TIF_NEED_FPU_LOAD); trace_x86_fpu_copy_src(src_fpu); trace_x86_fpu_copy_dst(dst_fpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:247 @ int fpu__copy(struct fpu *dst_fpu, struc * Activate the current task's in-memory FPU context, * if it has not been used before: */ -void fpu__initialize(struct fpu *fpu) +static void fpu__initialize(struct fpu *fpu) { WARN_ON_FPU(fpu != ¤t->thread.fpu); - if (!fpu->initialized) { - fpstate_init(&fpu->state); - trace_x86_fpu_init_state(fpu); - - trace_x86_fpu_activate_state(fpu); - /* Safe to do for the current task: */ - fpu->initialized = 1; - } + set_thread_flag(TIF_NEED_FPU_LOAD); + fpstate_init(&fpu->state); + trace_x86_fpu_init_state(fpu); } -EXPORT_SYMBOL_GPL(fpu__initialize); /* * This function must be called before we read a task's fpstate. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:266 @ EXPORT_SYMBOL_GPL(fpu__initialize); * * - or it's called for stopped tasks (ptrace), in which case the * registers were already saved by the context-switch code when - * the task scheduled out - we only have to initialize the registers - * if they've never been initialized. + * the task scheduled out. * * If the task has used the FPU before then save it. */ void fpu__prepare_read(struct fpu *fpu) { - if (fpu == ¤t->thread.fpu) { + if (fpu == ¤t->thread.fpu) fpu__save(fpu); - } else { - if (!fpu->initialized) { - fpstate_init(&fpu->state); - trace_x86_fpu_init_state(fpu); - - trace_x86_fpu_activate_state(fpu); - /* Safe to do for current and for stopped child tasks: */ - fpu->initialized = 1; - } - } } /* * This function must be called before we write a task's fpstate. * - * If the task has used the FPU before then invalidate any cached FPU registers. - * If the task has not used the FPU before then initialize its fpstate. + * Invalidate any cached FPU registers. * * After this function call, after registers in the fpstate are * modified and the child task has woken up, the child task will @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:296 @ void fpu__prepare_write(struct fpu *fpu) */ WARN_ON_FPU(fpu == ¤t->thread.fpu); - if (fpu->initialized) { - /* Invalidate any cached state: */ - __fpu_invalidate_fpregs_state(fpu); - } else { - fpstate_init(&fpu->state); - trace_x86_fpu_init_state(fpu); - - trace_x86_fpu_activate_state(fpu); - /* Safe to do for stopped child tasks: */ - fpu->initialized = 1; - } + /* Invalidate any cached state: */ + __fpu_invalidate_fpregs_state(fpu); } /* - * 'fpu__restore()' is called to copy FPU registers from - * the FPU fpstate to the live hw registers and to activate - * access to the hardware registers, so that FPU instructions - * can be used afterwards. - * - * Must be called with kernel preemption disabled (for example - * with local interrupts disabled, as it is in the case of - * do_device_not_available()). - */ -void fpu__restore(struct fpu *fpu) -{ - fpu__initialize(fpu); - - /* Avoid __kernel_fpu_begin() right after fpregs_activate() */ - kernel_fpu_disable(); - trace_x86_fpu_before_restore(fpu); - fpregs_activate(fpu); - copy_kernel_to_fpregs(&fpu->state); - trace_x86_fpu_after_restore(fpu); - kernel_fpu_enable(); -} -EXPORT_SYMBOL_GPL(fpu__restore); - -/* * Drops current FPU state: deactivates the fpregs and * the fpstate. NOTE: it still leaves previous contents * in the fpregs in the eager-FPU case. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:314 @ void fpu__drop(struct fpu *fpu) preempt_disable(); if (fpu == ¤t->thread.fpu) { - if (fpu->initialized) { - /* Ignore delayed exceptions from user space */ - asm volatile("1: fwait\n" - "2:\n" - _ASM_EXTABLE(1b, 2b)); - fpregs_deactivate(fpu); - } + /* Ignore delayed exceptions from user space */ + asm volatile("1: fwait\n" + "2:\n" + _ASM_EXTABLE(1b, 2b)); + fpregs_deactivate(fpu); } - fpu->initialized = 0; - trace_x86_fpu_dropped(fpu); preempt_enable(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:332 @ void fpu__drop(struct fpu *fpu) */ static inline void copy_init_fpstate_to_fpregs(void) { + fpregs_lock(); + if (use_xsave()) copy_kernel_to_xregs(&init_fpstate.xsave, -1); else if (static_cpu_has(X86_FEATURE_FXSR)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:343 @ static inline void copy_init_fpstate_to_ if (boot_cpu_has(X86_FEATURE_OSPKE)) copy_init_pkru_to_fpregs(); + + fpregs_mark_activate(); + fpregs_unlock(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:363 @ void fpu__clear(struct fpu *fpu) /* * Make sure fpstate is cleared and initialized. */ - if (static_cpu_has(X86_FEATURE_FPU)) { - preempt_disable(); - fpu__initialize(fpu); - user_fpu_begin(); + fpu__initialize(fpu); + if (static_cpu_has(X86_FEATURE_FPU)) copy_init_fpstate_to_fpregs(); - preempt_enable(); - } } /* + * Load FPU context before returning to userspace. + */ +void switch_fpu_return(void) +{ + if (!static_cpu_has(X86_FEATURE_FPU)) + return; + + __fpregs_load_activate(); +} +EXPORT_SYMBOL_GPL(switch_fpu_return); + +#ifdef CONFIG_X86_DEBUG_FPU +/* + * If current FPU state according to its tracking (loaded FPU ctx on this CPU) + * is not valid then we must have TIF_NEED_FPU_LOAD set so the context is loaded on + * return to userland. + */ +void fpregs_assert_state_consistent(void) +{ + struct fpu *fpu = ¤t->thread.fpu; + + if (test_thread_flag(TIF_NEED_FPU_LOAD)) + return; + WARN_ON_FPU(!fpregs_state_valid(fpu, smp_processor_id())); +} +EXPORT_SYMBOL_GPL(fpregs_assert_state_consistent); +#endif + +void fpregs_mark_activate(void) +{ + struct fpu *fpu = ¤t->thread.fpu; + + fpregs_activate(fpu); + fpu->last_cpu = smp_processor_id(); + clear_thread_flag(TIF_NEED_FPU_LOAD); +} +EXPORT_SYMBOL_GPL(fpregs_mark_activate); + +/* * x87 math exception handling: */ Index: linux-5.0.19-rt11/arch/x86/kernel/fpu/init.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/fpu/init.c +++ linux-5.0.19-rt11/arch/x86/kernel/fpu/init.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:242 @ static void __init fpu__init_system_ctx_ WARN_ON_FPU(!on_boot_cpu); on_boot_cpu = 0; - - WARN_ON_FPU(current->thread.fpu.initialized); } /* Index: linux-5.0.19-rt11/arch/x86/kernel/fpu/regset.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/fpu/regset.c +++ linux-5.0.19-rt11/arch/x86/kernel/fpu/regset.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:18 @ */ int regset_fpregs_active(struct task_struct *target, const struct user_regset *regset) { - struct fpu *target_fpu = &target->thread.fpu; - - return target_fpu->initialized ? regset->n : 0; + return regset->n; } int regset_xregset_fpregs_active(struct task_struct *target, const struct user_regset *regset) { - struct fpu *target_fpu = &target->thread.fpu; - - if (boot_cpu_has(X86_FEATURE_FXSR) && target_fpu->initialized) + if (boot_cpu_has(X86_FEATURE_FXSR)) return regset->n; else return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:268 @ convert_from_fxsr(struct user_i387_ia32_ memcpy(&to[i], &from[i], sizeof(to[0])); } -void convert_to_fxsr(struct task_struct *tsk, +void convert_to_fxsr(struct fxregs_state *fxsave, const struct user_i387_ia32_struct *env) { - struct fxregs_state *fxsave = &tsk->thread.fpu.state.fxsave; struct _fpreg *from = (struct _fpreg *) &env->st_space[0]; struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0]; int i; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:348 @ int fpregs_set(struct task_struct *targe ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &env, 0, -1); if (!ret) - convert_to_fxsr(target, &env); + convert_to_fxsr(&target->thread.fpu.state.fxsave, &env); /* * update the header bit in the xsave header, indicating the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:369 @ int fpregs_set(struct task_struct *targe int dump_fpu(struct pt_regs *regs, struct user_i387_struct *ufpu) { struct task_struct *tsk = current; - struct fpu *fpu = &tsk->thread.fpu; - int fpvalid; - - fpvalid = fpu->initialized; - if (fpvalid) - fpvalid = !fpregs_get(tsk, NULL, - 0, sizeof(struct user_i387_ia32_struct), - ufpu, NULL); - return fpvalid; + return !fpregs_get(tsk, NULL, 0, sizeof(struct user_i387_ia32_struct), + ufpu, NULL); } EXPORT_SYMBOL(dump_fpu); Index: linux-5.0.19-rt11/arch/x86/kernel/fpu/signal.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/fpu/signal.c +++ linux-5.0.19-rt11/arch/x86/kernel/fpu/signal.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8 @ #include <linux/compat.h> #include <linux/cpu.h> +#include <linux/pagemap.h> #include <asm/fpu/internal.h> #include <asm/fpu/signal.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:65 @ static inline int save_fsave_header(stru struct user_i387_ia32_struct env; struct _fpstate_32 __user *fp = buf; + fpregs_lock(); + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) + copy_fxregs_to_kernel(&tsk->thread.fpu); + fpregs_unlock(); + convert_from_fxsr(&env, tsk); if (__copy_to_user(buf, &env, sizeof(env)) || @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:153 @ static inline int copy_fpregs_to_sigfram * buf == buf_fx for 64-bit frames and 32-bit fsave frame. * buf != buf_fx for 32-bit frames with fxstate. * - * If the fpu, extended register state is live, save the state directly - * to the user frame pointed by the aligned pointer 'buf_fx'. Otherwise, - * copy the thread's fpu state to the user frame starting at 'buf_fx'. + * Try to save it directly to the user frame with disabled page fault handler. + * If this fails then do the slow path where the FPU state is first saved to + * task's fpu->state and then copy it to the user frame pointed by the aligned + * pointer 'buf_fx'. * * If this is a 32-bit frame with fxstate, put a fsave header before * the aligned state at 'buf_fx'. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:166 @ static inline int copy_fpregs_to_sigfram */ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size) { - struct fpu *fpu = ¤t->thread.fpu; - struct xregs_state *xsave = &fpu->state.xsave; struct task_struct *tsk = current; int ia32_fxstate = (buf != buf_fx); + int ret; ia32_fxstate &= (IS_ENABLED(CONFIG_X86_32) || IS_ENABLED(CONFIG_IA32_EMULATION)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:181 @ int copy_fpstate_to_sigframe(void __user sizeof(struct user_i387_ia32_struct), NULL, (struct _fpstate_32 __user *) buf) ? -1 : 1; - if (fpu->initialized || using_compacted_format()) { - /* Save the live register state to the user directly. */ - if (copy_fpregs_to_sigframe(buf_fx)) - return -1; - /* Update the thread's fxstate to save the fsave header. */ - if (ia32_fxstate) - copy_fxregs_to_kernel(fpu); - } else { - /* - * It is a *bug* if kernel uses compacted-format for xsave - * area and we copy it out directly to a signal frame. It - * should have been handled above by saving the registers - * directly. - */ - if (boot_cpu_has(X86_FEATURE_XSAVES)) { - WARN_ONCE(1, "x86/fpu: saving compacted-format xsave area to a signal frame!\n"); - return -1; - } +retry: + fpregs_lock(); + /* + * Load the FPU register if they are not valid for the current task. + * With a valid FPU state we can attempt to save the state directly to + * userland's stack frame which will likely succeed. If it does not, + * resolve the fault in the user memory and try again. + */ + if (test_thread_flag(TIF_NEED_FPU_LOAD)) + __fpregs_load_activate(); - fpstate_sanitize_xstate(fpu); - if (__copy_to_user(buf_fx, xsave, fpu_user_xstate_size)) - return -1; + pagefault_disable(); + ret = copy_fpregs_to_sigframe(buf_fx); + pagefault_enable(); + fpregs_unlock(); + + if (ret) { + if (!fault_in_pages_writeable(buf_fx, fpu_user_xstate_size)) + goto retry; + return -EFAULT; } /* Save the fsave header for the 32-bit frames. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:214 @ int copy_fpstate_to_sigframe(void __user } static inline void -sanitize_restored_xstate(struct task_struct *tsk, +sanitize_restored_xstate(union fpregs_state *state, struct user_i387_ia32_struct *ia32_env, u64 xfeatures, int fx_only) { - struct xregs_state *xsave = &tsk->thread.fpu.state.xsave; + struct xregs_state *xsave = &state->xsave; struct xstate_header *header = &xsave->header; if (use_xsave()) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:245 @ sanitize_restored_xstate(struct task_str */ xsave->i387.mxcsr &= mxcsr_feature_mask; - convert_to_fxsr(tsk, ia32_env); + if (ia32_env) + convert_to_fxsr(&state->fxsave, ia32_env); } } /* * Restore the extended state if present. Otherwise, restore the FP/SSE state. */ -static inline int copy_user_to_fpregs_zeroing(void __user *buf, u64 xbv, int fx_only) +static int copy_user_to_fpregs_zeroing(void __user *buf, u64 xbv, int fx_only) { if (use_xsave()) { - if ((unsigned long)buf % 64 || fx_only) { + if (fx_only) { u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE; copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); return copy_user_to_fxregs(buf); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:274 @ static inline int copy_user_to_fpregs_ze static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) { + struct user_i387_ia32_struct *envp = NULL; int ia32_fxstate = (buf != buf_fx); struct task_struct *tsk = current; struct fpu *fpu = &tsk->thread.fpu; int state_size = fpu_kernel_xstate_size; + struct user_i387_ia32_struct env; u64 xfeatures = 0; int fx_only = 0; + int ret = 0; ia32_fxstate &= (IS_ENABLED(CONFIG_X86_32) || IS_ENABLED(CONFIG_IA32_EMULATION)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:295 @ static int __fpu__restore_sig(void __use if (!access_ok(buf, size)) return -EACCES; - fpu__initialize(fpu); - if (!static_cpu_has(X86_FEATURE_FPU)) return fpregs_soft_set(current, NULL, 0, sizeof(struct user_i387_ia32_struct), @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:317 @ static int __fpu__restore_sig(void __use } } + /* + * The current state of the FPU registers does not matter. By setting + * TIF_NEED_FPU_LOAD unconditionally it is ensured that the our xstate + * is not modified on context switch and that the xstate is considered + * to loaded again on return to userland (overriding last_cpu avoids the + * optimisation). + */ + set_thread_flag(TIF_NEED_FPU_LOAD); + __fpu_invalidate_fpregs_state(fpu); + + if ((unsigned long)buf_fx % 64) + fx_only = 1; + /* + * For 32-bit frames with fxstate, copy the fxstate so it can be + * reconstructed later. + */ if (ia32_fxstate) { - /* - * For 32-bit frames with fxstate, copy the user state to the - * thread's fpu state, reconstruct fxstate from the fsave - * header. Validate and sanitize the copied state. - */ - struct user_i387_ia32_struct env; - int err = 0; + ret = __copy_from_user(&env, buf, sizeof(env)); + if (ret) + goto err_out; + envp = &env; + } else { + fpregs_lock(); + pagefault_disable(); + ret = copy_user_to_fpregs_zeroing(buf_fx, xfeatures, fx_only); + pagefault_enable(); + if (!ret) { + fpregs_mark_activate(); + fpregs_unlock(); + return 0; + } + fpregs_unlock(); + } - /* - * Drop the current fpu which clears fpu->initialized. This ensures - * that any context-switch during the copy of the new state, - * avoids the intermediate state from getting restored/saved. - * Thus avoiding the new restored state from getting corrupted. - * We will be ready to restore/save the state only after - * fpu->initialized is again set. - */ - fpu__drop(fpu); + if (use_xsave() && !fx_only) { + u64 init_bv = xfeatures_mask & ~xfeatures; if (using_compacted_format()) { - err = copy_user_to_xstate(&fpu->state.xsave, buf_fx); + ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx); } else { - err = __copy_from_user(&fpu->state.xsave, buf_fx, state_size); + ret = __copy_from_user(&fpu->state.xsave, buf_fx, state_size); - if (!err && state_size > offsetof(struct xregs_state, header)) - err = validate_xstate_header(&fpu->state.xsave.header); + if (!ret && state_size > offsetof(struct xregs_state, header)) + ret = validate_xstate_header(&fpu->state.xsave.header); } + if (ret) + goto err_out; - if (err || __copy_from_user(&env, buf, sizeof(env))) { - fpstate_init(&fpu->state); - trace_x86_fpu_init_state(fpu); - err = -1; - } else { - sanitize_restored_xstate(tsk, &env, xfeatures, fx_only); + sanitize_restored_xstate(&fpu->state, envp, xfeatures, fx_only); + + fpregs_lock(); + if (unlikely(init_bv)) + copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); + ret = copy_kernel_to_xregs_err(&fpu->state.xsave, xfeatures); + + } else if (use_fxsr()) { + ret = __copy_from_user(&fpu->state.fxsave, buf_fx, state_size); + if (ret) { + ret = -EFAULT; + goto err_out; } - local_bh_disable(); - fpu->initialized = 1; - fpu__restore(fpu); - local_bh_enable(); + sanitize_restored_xstate(&fpu->state, envp, xfeatures, fx_only); - return err; - } else { - /* - * For 64-bit frames and 32-bit fsave frames, restore the user - * state to the registers directly (with exceptions handled). - */ - user_fpu_begin(); - if (copy_user_to_fpregs_zeroing(buf_fx, xfeatures, fx_only)) { - fpu__clear(fpu); - return -1; + fpregs_lock(); + if (use_xsave()) { + u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE; + copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); } + + ret = copy_kernel_to_fxregs_err(&fpu->state.fxsave); + } else { + ret = __copy_from_user(&fpu->state.fsave, buf_fx, state_size); + if (ret) + goto err_out; + fpregs_lock(); + ret = copy_kernel_to_fregs_err(&fpu->state.fsave); } + if (!ret) + fpregs_mark_activate(); + fpregs_unlock(); - return 0; +err_out: + if (ret) + fpu__clear(fpu); + return ret; } static inline int xstate_sigframe_size(void) Index: linux-5.0.19-rt11/arch/x86/kernel/fpu/xstate.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/fpu/xstate.c +++ linux-5.0.19-rt11/arch/x86/kernel/fpu/xstate.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:808 @ void fpu__resume_cpu(void) } /* - * Given an xstate feature mask, calculate where in the xsave + * Given an xstate feature nr, calculate where in the xsave * buffer the state is. Callers should ensure that the buffer * is valid. */ -static void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask) +static void *__raw_xsave_addr(struct xregs_state *xsave, int xfeature_nr) { - int feature_nr = fls64(xstate_feature_mask) - 1; - - if (!xfeature_enabled(feature_nr)) { + if (!xfeature_enabled(xfeature_nr)) { WARN_ON_FPU(1); return NULL; } - return (void *)xsave + xstate_comp_offsets[feature_nr]; + return (void *)xsave + xstate_comp_offsets[xfeature_nr]; } /* * Given the xsave area and a state inside, this function returns the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:833 @ static void *__raw_xsave_addr(struct xre * * Inputs: * xstate: the thread's storage area for all FPU data - * xstate_feature: state which is defined in xsave.h (e.g. - * XFEATURE_MASK_FP, XFEATURE_MASK_SSE, etc...) + * xfeature_nr: state which is defined in xsave.h (e.g. XFEATURE_FP, + * XFEATURE_SSE, etc...) * Output: * address of the state in the xsave area, or NULL if the * field is not present in the xsave buffer. */ -void *get_xsave_addr(struct xregs_state *xsave, int xstate_feature) +void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr) { /* * Do we even *have* xsave state? @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:852 @ void *get_xsave_addr(struct xregs_state * have not enabled. Remember that pcntxt_mask is * what we write to the XCR0 register. */ - WARN_ONCE(!(xfeatures_mask & xstate_feature), + WARN_ONCE(!(xfeatures_mask & BIT_ULL(xfeature_nr)), "get of unsupported state"); /* * This assumes the last 'xsave*' instruction to - * have requested that 'xstate_feature' be saved. + * have requested that 'xfeature_nr' be saved. * If it did not, we might be seeing and old value * of the field in the buffer. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:865 @ void *get_xsave_addr(struct xregs_state * or because the "init optimization" caused it * to not be saved. */ - if (!(xsave->header.xfeatures & xstate_feature)) + if (!(xsave->header.xfeatures & BIT_ULL(xfeature_nr))) return NULL; - return __raw_xsave_addr(xsave, xstate_feature); + return __raw_xsave_addr(xsave, xfeature_nr); } EXPORT_SYMBOL_GPL(get_xsave_addr); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:883 @ EXPORT_SYMBOL_GPL(get_xsave_addr); * Note that this only works on the current task. * * Inputs: - * @xsave_state: state which is defined in xsave.h (e.g. XFEATURE_MASK_FP, - * XFEATURE_MASK_SSE, etc...) + * @xfeature_nr: state which is defined in xsave.h (e.g. XFEATURE_FP, + * XFEATURE_SSE, etc...) * Output: * address of the state in the xsave area or NULL if the state * is not present or is in its 'init state'. */ -const void *get_xsave_field_ptr(int xsave_state) +const void *get_xsave_field_ptr(int xfeature_nr) { struct fpu *fpu = ¤t->thread.fpu; - if (!fpu->initialized) - return NULL; /* * fpu__save() takes the CPU's xstate registers * and saves them off to the 'fpu memory buffer. */ fpu__save(fpu); - return get_xsave_addr(&fpu->state.xsave, xsave_state); + return get_xsave_addr(&fpu->state.xsave, xfeature_nr); } #ifdef CONFIG_ARCH_HAS_PKEYS @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1015 @ int copy_xstate_to_kernel(void *kbuf, st * Copy only in-use xstates: */ if ((header.xfeatures >> i) & 1) { - void *src = __raw_xsave_addr(xsave, 1 << i); + void *src = __raw_xsave_addr(xsave, i); offset = xstate_offsets[i]; size = xstate_sizes[i]; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1101 @ int copy_xstate_to_user(void __user *ubu * Copy only in-use xstates: */ if ((header.xfeatures >> i) & 1) { - void *src = __raw_xsave_addr(xsave, 1 << i); + void *src = __raw_xsave_addr(xsave, i); offset = xstate_offsets[i]; size = xstate_sizes[i]; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1158 @ int copy_kernel_to_xstate(struct xregs_s u64 mask = ((u64)1 << i); if (hdr.xfeatures & mask) { - void *dst = __raw_xsave_addr(xsave, 1 << i); + void *dst = __raw_xsave_addr(xsave, i); offset = xstate_offsets[i]; size = xstate_sizes[i]; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1212 @ int copy_user_to_xstate(struct xregs_sta u64 mask = ((u64)1 << i); if (hdr.xfeatures & mask) { - void *dst = __raw_xsave_addr(xsave, 1 << i); + void *dst = __raw_xsave_addr(xsave, i); offset = xstate_offsets[i]; size = xstate_sizes[i]; Index: linux-5.0.19-rt11/arch/x86/kernel/ima_arch.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/ima_arch.c +++ linux-5.0.19-rt11/arch/x86/kernel/ima_arch.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:20 @ static enum efi_secureboot_mode get_sb_m size = sizeof(secboot); + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_info("ima: secureboot mode unknown, no efi\n"); + return efi_secureboot_mode_unknown; + } + /* Get variable contents into buffer */ status = efi.get_variable(efi_SecureBoot_name, &efi_variable_guid, NULL, &size, &secboot); Index: linux-5.0.19-rt11/arch/x86/kernel/irq_32.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/irq_32.c +++ linux-5.0.19-rt11/arch/x86/kernel/irq_32.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:133 @ void irq_ctx_init(int cpu) cpu, per_cpu(hardirq_stack, cpu), per_cpu(softirq_stack, cpu)); } +#ifndef CONFIG_PREEMPT_RT_FULL void do_softirq_own_stack(void) { struct irq_stack *irqstk; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:150 @ void do_softirq_own_stack(void) call_on_stack(__do_softirq, isp); } +#endif bool handle_irq(struct irq_desc *desc, struct pt_regs *regs) { Index: linux-5.0.19-rt11/arch/x86/kernel/process.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/process.c +++ linux-5.0.19-rt11/arch/x86/kernel/process.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:104 @ int arch_dup_task_struct(struct task_str dst->thread.vm86 = NULL; #endif - return fpu__copy(&dst->thread.fpu, &src->thread.fpu); + return fpu__copy(dst, src); } /* Index: linux-5.0.19-rt11/arch/x86/kernel/process_32.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/process_32.c +++ linux-5.0.19-rt11/arch/x86/kernel/process_32.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:41 @ #include <linux/io.h> #include <linux/kdebug.h> #include <linux/syscalls.h> +#include <linux/highmem.h> #include <asm/pgtable.h> #include <asm/ldt.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:206 @ start_thread(struct pt_regs *regs, unsig } EXPORT_SYMBOL_GPL(start_thread); +#ifdef CONFIG_PREEMPT_RT_FULL +static void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) +{ + int i; + + /* + * Clear @prev's kmap_atomic mappings + */ + for (i = 0; i < prev_p->kmap_idx; i++) { + int idx = i + KM_TYPE_NR * smp_processor_id(); + pte_t *ptep = kmap_pte - idx; + + kpte_clear_flush(ptep, __fix_to_virt(FIX_KMAP_BEGIN + idx)); + } + /* + * Restore @next_p's kmap_atomic mappings + */ + for (i = 0; i < next_p->kmap_idx; i++) { + int idx = i + KM_TYPE_NR * smp_processor_id(); + + if (!pte_none(next_p->kmap_pte[i])) + set_pte(kmap_pte - idx, next_p->kmap_pte[i]); + } +} +#else +static inline void +switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { } +#endif + /* * switch_to(x,y) should switch tasks from x to y. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:274 @ __switch_to(struct task_struct *prev_p, /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */ - switch_fpu_prepare(prev_fpu, cpu); + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) + switch_fpu_prepare(prev_fpu, cpu); /* * Save away %gs. No need to save %fs, as it was saved on the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:305 @ __switch_to(struct task_struct *prev_p, switch_to_extra(prev_p, next_p); + switch_kmaps(prev_p, next_p); + /* * Leave lazy mode, flushing any hypercalls made here. * This must be done before restoring TLS segments so - * the GDT and LDT are properly updated, and must be - * done before fpu__restore(), so the TS bit is up - * to date. + * the GDT and LDT are properly updated. */ arch_end_context_switch(next_p); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:331 @ __switch_to(struct task_struct *prev_p, if (prev->gs | next->gs) lazy_load_gs(next->gs); - switch_fpu_finish(next_fpu, cpu); - this_cpu_write(current_task, next_p); + switch_fpu_finish(next_fpu); + /* Load the Intel cache allocation PQR MSR. */ resctrl_sched_in(); Index: linux-5.0.19-rt11/arch/x86/kernel/process_64.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/process_64.c +++ linux-5.0.19-rt11/arch/x86/kernel/process_64.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:531 @ __switch_to(struct task_struct *prev_p, WARN_ON_ONCE(IS_ENABLED(CONFIG_DEBUG_ENTRY) && this_cpu_read(irq_count) != -1); - switch_fpu_prepare(prev_fpu, cpu); + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) + switch_fpu_prepare(prev_fpu, cpu); /* We must save %fs and %gs before load_TLS() because * %fs and %gs may be cleared by load_TLS(). @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:550 @ __switch_to(struct task_struct *prev_p, /* * Leave lazy mode, flushing any hypercalls made here. This * must be done after loading TLS entries in the GDT but before - * loading segments that might reference them, and and it must - * be done before fpu__restore(), so the TS bit is up to - * date. + * loading segments that might reference them. */ arch_end_context_switch(next_p); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:578 @ __switch_to(struct task_struct *prev_p, x86_fsgsbase_load(prev, next); - switch_fpu_finish(next_fpu, cpu); - /* * Switch the PDA and FPU contexts. */ this_cpu_write(current_task, next_p); this_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p)); + switch_fpu_finish(next_fpu); + /* Reload sp0. */ update_task_stack(next_p); Index: linux-5.0.19-rt11/arch/x86/kernel/signal.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/signal.c +++ linux-5.0.19-rt11/arch/x86/kernel/signal.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:248 @ get_sigframe(struct k_sigaction *ka, str unsigned long sp = regs->sp; unsigned long buf_fx = 0; int onsigstack = on_sig_stack(sp); - struct fpu *fpu = ¤t->thread.fpu; + int ret; /* redzone */ if (IS_ENABLED(CONFIG_X86_64)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:267 @ get_sigframe(struct k_sigaction *ka, str sp = (unsigned long) ka->sa.sa_restorer; } - if (fpu->initialized) { - sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32), - &buf_fx, &math_size); - *fpstate = (void __user *)sp; - } + sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32), + &buf_fx, &math_size); + *fpstate = (void __user *)sp; sp = align_sigframe(sp - frame_size); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:281 @ get_sigframe(struct k_sigaction *ka, str return (void __user *)-1L; /* save i387 and extended state */ - if (fpu->initialized && - copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0) + ret = copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size); + if (ret < 0) return (void __user *)-1L; return (void __user *)sp; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:769 @ handle_signal(struct ksignal *ksig, stru /* * Ensure the signal handler starts with the new fpu state. */ - if (fpu->initialized) - fpu__clear(fpu); + fpu__clear(fpu); } signal_setup_done(failed, ksig, stepping); } Index: linux-5.0.19-rt11/arch/x86/kernel/traps.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kernel/traps.c +++ linux-5.0.19-rt11/arch/x86/kernel/traps.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:458 @ dotraplinkage void do_bounds(struct pt_r * which is all zeros which indicates MPX was not * responsible for the exception. */ - bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR); + bndcsr = get_xsave_field_ptr(XFEATURE_BNDCSR); if (!bndcsr) goto exit_trap; Index: linux-5.0.19-rt11/arch/x86/kvm/lapic.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kvm/lapic.c +++ linux-5.0.19-rt11/arch/x86/kvm/lapic.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2302 @ int kvm_create_lapic(struct kvm_vcpu *vc apic->vcpu = vcpu; hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC, - HRTIMER_MODE_ABS_PINNED); + HRTIMER_MODE_ABS_PINNED_HARD); apic->lapic_timer.timer.function = apic_timer_fn; if (timer_advance_ns == -1) { apic->lapic_timer.timer_advance_ns = 1000; Index: linux-5.0.19-rt11/arch/x86/kvm/vmx/vmx.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kvm/vmx/vmx.c +++ linux-5.0.19-rt11/arch/x86/kvm/vmx/vmx.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6638 @ static void vmx_vcpu_run(struct kvm_vcpu */ if (static_cpu_has(X86_FEATURE_PKU) && kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) { - vcpu->arch.pkru = __read_pkru(); + vcpu->arch.pkru = __read_pkru_ins(); if (vcpu->arch.pkru != vmx->host_pkru) __write_pkru(vmx->host_pkru); } Index: linux-5.0.19-rt11/arch/x86/kvm/x86.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/kvm/x86.c +++ linux-5.0.19-rt11/arch/x86/kvm/x86.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3694 @ static void fill_xsave(u8 *dest, struct */ valid = xstate_bv & ~XFEATURE_MASK_FPSSE; while (valid) { - u64 feature = valid & -valid; - int index = fls64(feature) - 1; - void *src = get_xsave_addr(xsave, feature); + u64 xfeature_mask = valid & -valid; + int xfeature_nr = fls64(xfeature_mask) - 1; + void *src = get_xsave_addr(xsave, xfeature_nr); if (src) { u32 size, offset, ecx, edx; - cpuid_count(XSTATE_CPUID, index, + cpuid_count(XSTATE_CPUID, xfeature_nr, &size, &offset, &ecx, &edx); - if (feature == XFEATURE_MASK_PKRU) + if (xfeature_nr == XFEATURE_PKRU) memcpy(dest + offset, &vcpu->arch.pkru, sizeof(vcpu->arch.pkru)); else @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3710 @ static void fill_xsave(u8 *dest, struct } - valid -= feature; + valid -= xfeature_mask; } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3737 @ static void load_xsave(struct kvm_vcpu * */ valid = xstate_bv & ~XFEATURE_MASK_FPSSE; while (valid) { - u64 feature = valid & -valid; - int index = fls64(feature) - 1; - void *dest = get_xsave_addr(xsave, feature); + u64 xfeature_mask = valid & -valid; + int xfeature_nr = fls64(xfeature_mask) - 1; + void *dest = get_xsave_addr(xsave, xfeature_nr); if (dest) { u32 size, offset, ecx, edx; - cpuid_count(XSTATE_CPUID, index, + cpuid_count(XSTATE_CPUID, xfeature_nr, &size, &offset, &ecx, &edx); - if (feature == XFEATURE_MASK_PKRU) + if (xfeature_nr == XFEATURE_PKRU) memcpy(&vcpu->arch.pkru, src + offset, sizeof(vcpu->arch.pkru)); else memcpy(dest, src + offset, size); } - valid -= feature; + valid -= xfeature_mask; } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6972 @ int kvm_arch_init(void *opaque) goto out; } +#ifdef CONFIG_PREEMPT_RT_FULL + if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) { + pr_err("RT requires X86_FEATURE_CONSTANT_TSC\n"); + r = -EOPNOTSUPP; + goto out; + } +#endif + r = -ENOMEM; x86_fpu_cache = kmem_cache_create("x86_fpu", sizeof(struct fpu), __alignof__(struct fpu), SLAB_ACCOUNT, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:7913 @ static int vcpu_enter_guest(struct kvm_v wait_lapic_expire(vcpu); guest_enter_irqoff(); + fpregs_assert_state_consistent(); + if (test_thread_flag(TIF_NEED_FPU_LOAD)) + switch_fpu_return(); + if (unlikely(vcpu->arch.switch_db_regs)) { set_debugreg(0, 7); set_debugreg(vcpu->arch.eff_db[0], 0); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8175 @ static int complete_emulated_mmio(struct /* Swap (qemu) user FPU context for the guest FPU context. */ static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) { - preempt_disable(); + fpregs_lock(); + copy_fpregs_to_fpstate(¤t->thread.fpu); /* PKRU is separately restored in kvm_x86_ops->run. */ __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu->state, ~XFEATURE_MASK_PKRU); - preempt_enable(); + + fpregs_mark_activate(); + fpregs_unlock(); + trace_kvm_fpu(1); } /* When vcpu_run ends, restore user space FPU context. */ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) { - preempt_disable(); + fpregs_lock(); + copy_fpregs_to_fpstate(vcpu->arch.guest_fpu); copy_kernel_to_fpregs(¤t->thread.fpu.state); - preempt_enable(); + + fpregs_mark_activate(); + fpregs_unlock(); + ++vcpu->stat.fpu_reload; trace_kvm_fpu(0); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8896 @ void kvm_vcpu_reset(struct kvm_vcpu *vcp if (init_event) kvm_put_guest_fpu(vcpu); mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu->state.xsave, - XFEATURE_MASK_BNDREGS); + XFEATURE_BNDREGS); if (mpx_state_buffer) memset(mpx_state_buffer, 0, sizeof(struct mpx_bndreg_state)); mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu->state.xsave, - XFEATURE_MASK_BNDCSR); + XFEATURE_BNDCSR); if (mpx_state_buffer) memset(mpx_state_buffer, 0, sizeof(struct mpx_bndcsr)); if (init_event) Index: linux-5.0.19-rt11/arch/x86/math-emu/fpu_entry.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/math-emu/fpu_entry.c +++ linux-5.0.19-rt11/arch/x86/math-emu/fpu_entry.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:116 @ void math_emulate(struct math_emu_info * unsigned long code_base = 0; unsigned long code_limit = 0; /* Initialized to stop compiler warnings */ struct desc_struct code_descriptor; - struct fpu *fpu = ¤t->thread.fpu; - - fpu__initialize(fpu); #ifdef RE_ENTRANT_CHECKING if (emulating) { Index: linux-5.0.19-rt11/arch/x86/mm/highmem_32.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/mm/highmem_32.c +++ linux-5.0.19-rt11/arch/x86/mm/highmem_32.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:35 @ EXPORT_SYMBOL(kunmap); */ void *kmap_atomic_prot(struct page *page, pgprot_t prot) { + pte_t pte = mk_pte(page, prot); unsigned long vaddr; int idx, type; - preempt_disable(); + preempt_disable_nort(); pagefault_disable(); if (!PageHighMem(page)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:49 @ void *kmap_atomic_prot(struct page *page idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); BUG_ON(!pte_none(*(kmap_pte-idx))); - set_pte(kmap_pte-idx, mk_pte(page, prot)); +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = pte; +#endif + set_pte(kmap_pte-idx, pte); arch_flush_lazy_mmu_mode(); return (void *)vaddr; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:95 @ void __kunmap_atomic(void *kvaddr) * is a bad idea also, in case the page changes cacheability * attributes or becomes a protected page in a hypervisor. */ +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = __pte(0); +#endif kpte_clear_flush(kmap_pte-idx, vaddr); kmap_atomic_idx_pop(); arch_flush_lazy_mmu_mode(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:110 @ void __kunmap_atomic(void *kvaddr) #endif pagefault_enable(); - preempt_enable(); + preempt_enable_nort(); } EXPORT_SYMBOL(__kunmap_atomic); Index: linux-5.0.19-rt11/arch/x86/mm/iomap_32.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/mm/iomap_32.c +++ linux-5.0.19-rt11/arch/x86/mm/iomap_32.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:62 @ EXPORT_SYMBOL_GPL(iomap_free); void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) { + pte_t pte = pfn_pte(pfn, prot); unsigned long vaddr; int idx, type; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:72 @ void *kmap_atomic_prot_pfn(unsigned long type = kmap_atomic_idx_push(); idx = type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); - set_pte(kmap_pte - idx, pfn_pte(pfn, prot)); + WARN_ON(!pte_none(*(kmap_pte - idx))); + +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = pte; +#endif + set_pte(kmap_pte - idx, pte); arch_flush_lazy_mmu_mode(); return (void *)vaddr; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:128 @ iounmap_atomic(void __iomem *kvaddr) * is a bad idea also, in case the page changes cacheability * attributes or becomes a protected page in a hypervisor. */ +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = __pte(0); +#endif kpte_clear_flush(kmap_pte-idx, vaddr); kmap_atomic_idx_pop(); } Index: linux-5.0.19-rt11/arch/x86/mm/mpx.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/mm/mpx.c +++ linux-5.0.19-rt11/arch/x86/mm/mpx.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:145 @ int mpx_fault_info(struct mpx_fault_info goto err_out; } /* get bndregs field from current task's xsave area */ - bndregs = get_xsave_field_ptr(XFEATURE_MASK_BNDREGS); + bndregs = get_xsave_field_ptr(XFEATURE_BNDREGS); if (!bndregs) { err = -EINVAL; goto err_out; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:193 @ static __user void *mpx_get_bounds_dir(v * The bounds directory pointer is stored in a register * only accessible if we first do an xsave. */ - bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR); + bndcsr = get_xsave_field_ptr(XFEATURE_BNDCSR); if (!bndcsr) return MPX_INVALID_BOUNDS_DIR; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:379 @ static int do_mpx_bt_fault(void) const struct mpx_bndcsr *bndcsr; struct mm_struct *mm = current->mm; - bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR); + bndcsr = get_xsave_field_ptr(XFEATURE_BNDCSR); if (!bndcsr) return -EINVAL; /* Index: linux-5.0.19-rt11/arch/x86/mm/pkeys.c =================================================================== --- linux-5.0.19-rt11.orig/arch/x86/mm/pkeys.c +++ linux-5.0.19-rt11/arch/x86/mm/pkeys.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:21 @ #include <asm/cpufeature.h> /* boot_cpu_has, ... */ #include <asm/mmu_context.h> /* vma_pkey() */ +#include <asm/fpu/internal.h> /* init_fpstate */ int __execute_only_pkey(struct mm_struct *mm) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:43 @ int __execute_only_pkey(struct mm_struct * dance to set PKRU if we do not need to. Check it * first and assume that if the execute-only pkey is * write-disabled that we do not have to set it - * ourselves. We need preempt off so that nobody - * can make fpregs inactive. + * ourselves. */ - preempt_disable(); if (!need_to_set_mm_pkey && - current->thread.fpu.initialized && !__pkru_allows_read(read_pkru(), execute_only_pkey)) { - preempt_enable(); return execute_only_pkey; } - preempt_enable(); /* * Set up PKRU so that it denies access for everything @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:130 @ int __arch_override_mprotect_pkey(struct * in the process's lifetime will not accidentally get access * to data which is pkey-protected later on. */ -static u32 init_pkru_value = PKRU_AD_KEY( 1) | PKRU_AD_KEY( 2) | PKRU_AD_KEY( 3) | PKRU_AD_KEY( 4) | PKRU_AD_KEY( 5) | PKRU_AD_KEY( 6) | PKRU_AD_KEY( 7) | PKRU_AD_KEY( 8) | PKRU_AD_KEY( 9) | @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:146 @ void copy_init_pkru_to_fpregs(void) { u32 init_pkru_value_snapshot = READ_ONCE(init_pkru_value); /* - * Any write to PKRU takes it out of the XSAVE 'init - * state' which increases context switch cost. Avoid - * writing 0 when PKRU was already 0. - */ - if (!init_pkru_value_snapshot && !read_pkru()) - return; - /* * Override the PKRU state that came from 'init_fpstate' * with the baseline from the process. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:165 @ static ssize_t init_pkru_read_file(struc static ssize_t init_pkru_write_file(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos) { + struct pkru_state *pk; char buf[32]; ssize_t len; u32 new_init_pkru; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:188 @ static ssize_t init_pkru_write_file(stru return -EINVAL; WRITE_ONCE(init_pkru_value, new_init_pkru); + pk = get_xsave_addr(&init_fpstate.xsave, XFEATURE_PKRU); + if (!pk) + return -EINVAL; + pk->pkru = new_init_pkru; return count; } Index: linux-5.0.19-rt11/arch/xtensa/include/asm/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/arch/xtensa/include/asm/spinlock_types.h +++ linux-5.0.19-rt11/arch/xtensa/include/asm/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #ifndef __ASM_SPINLOCK_TYPES_H #define __ASM_SPINLOCK_TYPES_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - typedef struct { volatile unsigned int slock; } arch_spinlock_t; Index: linux-5.0.19-rt11/block/blk-core.c =================================================================== --- linux-5.0.19-rt11.orig/block/blk-core.c +++ linux-5.0.19-rt11/block/blk-core.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:450 @ void blk_queue_exit(struct request_queue percpu_ref_put(&q->q_usage_counter); } +static void blk_queue_usage_counter_release_wrk(struct work_struct *work) +{ + struct request_queue *q = + container_of(work, struct request_queue, mq_pcpu_wake); + + wake_up_all(&q->mq_freeze_wq); +} + static void blk_queue_usage_counter_release(struct percpu_ref *ref) { struct request_queue *q = container_of(ref, struct request_queue, q_usage_counter); - wake_up_all(&q->mq_freeze_wq); + if (wq_has_sleeper(&q->mq_freeze_wq)) + schedule_work(&q->mq_pcpu_wake); } static void blk_rq_timed_out_timer(struct timer_list *t) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:536 @ struct request_queue *blk_alloc_queue_no spin_lock_init(&q->queue_lock); init_waitqueue_head(&q->mq_freeze_wq); + INIT_WORK(&q->mq_pcpu_wake, blk_queue_usage_counter_release_wrk); /* * Init percpu_ref in atomic mode so that it's faster to shutdown. Index: linux-5.0.19-rt11/block/blk-ioc.c =================================================================== --- linux-5.0.19-rt11.orig/block/blk-ioc.c +++ linux-5.0.19-rt11/block/blk-ioc.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:12 @ #include <linux/blkdev.h> #include <linux/slab.h> #include <linux/sched/task.h> +#include <linux/delay.h> #include "blk.h" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:119 @ static void ioc_release_fn(struct work_s spin_unlock(&q->queue_lock); } else { spin_unlock_irqrestore(&ioc->lock, flags); - cpu_relax(); + cpu_chill(); spin_lock_irqsave_nested(&ioc->lock, flags, 1); } } Index: linux-5.0.19-rt11/block/blk-mq.c =================================================================== --- linux-5.0.19-rt11.orig/block/blk-mq.c +++ linux-5.0.19-rt11/block/blk-mq.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:608 @ static void __blk_mq_complete_request(st return; } - cpu = get_cpu(); + cpu = get_cpu_light(); + /* + * Avoid SMP function calls for completions because they acquire + * sleeping spinlocks on RT. + */ +#ifdef CONFIG_PREEMPT_RT_FULL + shared = true; +#else if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) shared = cpus_share_cache(cpu, ctx->cpu); +#endif if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { rq->csd.func = __blk_mq_complete_request_remote; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:628 @ static void __blk_mq_complete_request(st } else { q->mq_ops->complete(rq); } - put_cpu(); + put_cpu_light(); } static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1470 @ static void __blk_mq_delay_run_hw_queue( return; if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { - int cpu = get_cpu(); + int cpu = get_cpu_light(); if (cpumask_test_cpu(cpu, hctx->cpumask)) { __blk_mq_run_hw_queue(hctx); - put_cpu(); + put_cpu_light(); return; } - put_cpu(); + put_cpu_light(); } kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3405 @ static bool blk_mq_poll_hybrid_sleep(str kt = nsecs; mode = HRTIMER_MODE_REL; - hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode); + hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode, current); hrtimer_set_expires(&hs.timer, kt); - hrtimer_init_sleeper(&hs, current); do { if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE) break; Index: linux-5.0.19-rt11/block/blk-mq.h =================================================================== --- linux-5.0.19-rt11.orig/block/blk-mq.h +++ linux-5.0.19-rt11/block/blk-mq.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:154 @ static inline struct blk_mq_ctx *__blk_m */ static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) { - return __blk_mq_get_ctx(q, get_cpu()); + return __blk_mq_get_ctx(q, get_cpu_light()); } static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx) { - put_cpu(); + put_cpu_light(); } struct blk_mq_alloc_data { Index: linux-5.0.19-rt11/block/blk-softirq.c =================================================================== --- linux-5.0.19-rt11.orig/block/blk-softirq.c +++ linux-5.0.19-rt11/block/blk-softirq.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:56 @ static void trigger_softirq(void *data) raise_softirq_irqoff(BLOCK_SOFTIRQ); local_irq_restore(flags); + preempt_check_resched_rt(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:95 @ static int blk_softirq_cpu_dead(unsigned this_cpu_ptr(&blk_cpu_done)); raise_softirq_irqoff(BLOCK_SOFTIRQ); local_irq_enable(); + preempt_check_resched_rt(); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:147 @ do_local: goto do_local; local_irq_restore(flags); + preempt_check_resched_rt(); } static __init int blk_softirq_init(void) Index: linux-5.0.19-rt11/crypto/cryptd.c =================================================================== --- linux-5.0.19-rt11.orig/crypto/cryptd.c +++ linux-5.0.19-rt11/crypto/cryptd.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:42 @ MODULE_PARM_DESC(cryptd_max_cpu_qlen, "S struct cryptd_cpu_queue { struct crypto_queue queue; struct work_struct work; + spinlock_t qlock; }; struct cryptd_queue { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:121 @ static int cryptd_init_queue(struct cryp cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu); crypto_init_queue(&cpu_queue->queue, max_cpu_qlen); INIT_WORK(&cpu_queue->work, cryptd_queue_worker); + spin_lock_init(&cpu_queue->qlock); } pr_info("cryptd: max_cpu_qlen set to %d\n", max_cpu_qlen); return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:146 @ static int cryptd_enqueue_request(struct struct cryptd_cpu_queue *cpu_queue; atomic_t *refcnt; - cpu = get_cpu(); - cpu_queue = this_cpu_ptr(queue->cpu_queue); + cpu_queue = raw_cpu_ptr(queue->cpu_queue); + spin_lock_bh(&cpu_queue->qlock); + cpu = smp_processor_id(); + err = crypto_enqueue_request(&cpu_queue->queue, request); refcnt = crypto_tfm_ctx(request->tfm); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:165 @ static int cryptd_enqueue_request(struct atomic_inc(refcnt); out_put_cpu: - put_cpu(); + spin_unlock_bh(&cpu_queue->qlock); return err; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:181 @ static void cryptd_queue_worker(struct w cpu_queue = container_of(work, struct cryptd_cpu_queue, work); /* * Only handle one request at a time to avoid hogging crypto workqueue. - * preempt_disable/enable is used to prevent being preempted by - * cryptd_enqueue_request(). local_bh_disable/enable is used to prevent - * cryptd_enqueue_request() being accessed from software interrupts. */ - local_bh_disable(); - preempt_disable(); + spin_lock_bh(&cpu_queue->qlock); backlog = crypto_get_backlog(&cpu_queue->queue); req = crypto_dequeue_request(&cpu_queue->queue); - preempt_enable(); - local_bh_enable(); + spin_unlock_bh(&cpu_queue->qlock); if (!req) return; Index: linux-5.0.19-rt11/crypto/crypto_user_stat.c =================================================================== --- linux-5.0.19-rt11.orig/crypto/crypto_user_stat.c +++ linux-5.0.19-rt11/crypto/crypto_user_stat.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:23 @ #define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x)) -static DEFINE_MUTEX(crypto_cfg_mutex); - extern struct sock *crypto_nlsk; struct crypto_dump_info { Index: linux-5.0.19-rt11/crypto/scompress.c =================================================================== --- linux-5.0.19-rt11.orig/crypto/scompress.c +++ linux-5.0.19-rt11/crypto/scompress.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:27 @ #include <linux/cryptouser.h> #include <net/netlink.h> #include <linux/scatterlist.h> +#include <linux/locallock.h> #include <crypto/scatterwalk.h> #include <crypto/internal/acompress.h> #include <crypto/internal/scompress.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:38 @ static void * __percpu *scomp_src_scratc static void * __percpu *scomp_dst_scratches; static int scomp_scratch_users; static DEFINE_MUTEX(scomp_lock); +static DEFINE_LOCAL_IRQ_LOCK(scomp_scratches_lock); #ifdef CONFIG_NET static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:148 @ static int scomp_acomp_comp_decomp(struc void **tfm_ctx = acomp_tfm_ctx(tfm); struct crypto_scomp *scomp = *tfm_ctx; void **ctx = acomp_request_ctx(req); - const int cpu = get_cpu(); + const int cpu = local_lock_cpu(scomp_scratches_lock); u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu); u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu); int ret; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:183 @ static int scomp_acomp_comp_decomp(struc 1); } out: - put_cpu(); + local_unlock_cpu(scomp_scratches_lock); return ret; } Index: linux-5.0.19-rt11/drivers/block/zram/zcomp.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/block/zram/zcomp.c +++ linux-5.0.19-rt11/drivers/block/zram/zcomp.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:119 @ ssize_t zcomp_available_show(const char struct zcomp_strm *zcomp_stream_get(struct zcomp *comp) { - return *get_cpu_ptr(comp->stream); + struct zcomp_strm *zstrm; + + zstrm = *get_local_ptr(comp->stream); + spin_lock(&zstrm->zcomp_lock); + return zstrm; } void zcomp_stream_put(struct zcomp *comp) { - put_cpu_ptr(comp->stream); + struct zcomp_strm *zstrm; + + zstrm = *this_cpu_ptr(comp->stream); + spin_unlock(&zstrm->zcomp_lock); + put_local_ptr(zstrm); } int zcomp_compress(struct zcomp_strm *zstrm, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:182 @ int zcomp_cpu_up_prepare(unsigned int cp pr_err("Can't allocate a compression stream\n"); return -ENOMEM; } + spin_lock_init(&zstrm->zcomp_lock); *per_cpu_ptr(comp->stream, cpu) = zstrm; return 0; } Index: linux-5.0.19-rt11/drivers/block/zram/zcomp.h =================================================================== --- linux-5.0.19-rt11.orig/drivers/block/zram/zcomp.h +++ linux-5.0.19-rt11/drivers/block/zram/zcomp.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:17 @ struct zcomp_strm { /* compression/decompression buffer */ void *buffer; struct crypto_comp *tfm; + spinlock_t zcomp_lock; }; /* dynamic per-device compression frontend */ Index: linux-5.0.19-rt11/drivers/block/zram/zram_drv.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/block/zram/zram_drv.c +++ linux-5.0.19-rt11/drivers/block/zram/zram_drv.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:58 @ static void zram_free_page(struct zram * static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, struct bio *bio); +#ifdef CONFIG_PREEMPT_RT_BASE +static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) +{ + size_t index; + + for (index = 0; index < num_pages; index++) + spin_lock_init(&zram->table[index].lock); +} + +static int zram_slot_trylock(struct zram *zram, u32 index) +{ + int ret; + + ret = spin_trylock(&zram->table[index].lock); + if (ret) + __set_bit(ZRAM_LOCK, &zram->table[index].flags); + return ret; +} + +static void zram_slot_lock(struct zram *zram, u32 index) +{ + spin_lock(&zram->table[index].lock); + __set_bit(ZRAM_LOCK, &zram->table[index].flags); +} + +static void zram_slot_unlock(struct zram *zram, u32 index) +{ + __clear_bit(ZRAM_LOCK, &zram->table[index].flags); + spin_unlock(&zram->table[index].lock); +} + +#else + +static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) { } static int zram_slot_trylock(struct zram *zram, u32 index) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:107 @ static void zram_slot_unlock(struct zram { bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags); } +#endif static inline bool init_done(struct zram *zram) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1192 @ static bool zram_meta_alloc(struct zram if (!huge_class_size) huge_class_size = zs_huge_class_size(zram->mem_pool); + zram_meta_init_table_locks(zram, num_pages); return true; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1255 @ static int __zram_bvec_read(struct zram unsigned long handle; unsigned int size; void *src, *dst; + struct zcomp_strm *zstrm; zram_slot_lock(zram, index); if (zram_test_flag(zram, index, ZRAM_WB)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1286 @ static int __zram_bvec_read(struct zram size = zram_get_obj_size(zram, index); + zstrm = zcomp_stream_get(zram->comp); src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO); if (size == PAGE_SIZE) { dst = kmap_atomic(page); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1294 @ static int __zram_bvec_read(struct zram kunmap_atomic(dst); ret = 0; } else { - struct zcomp_strm *zstrm = zcomp_stream_get(zram->comp); dst = kmap_atomic(page); ret = zcomp_decompress(zstrm, src, size, dst); kunmap_atomic(dst); - zcomp_stream_put(zram->comp); } zs_unmap_object(zram->mem_pool, handle); + zcomp_stream_put(zram->comp); zram_slot_unlock(zram, index); /* Should NEVER happen. Return bio error if it does. */ Index: linux-5.0.19-rt11/drivers/block/zram/zram_drv.h =================================================================== --- linux-5.0.19-rt11.orig/drivers/block/zram/zram_drv.h +++ linux-5.0.19-rt11/drivers/block/zram/zram_drv.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:66 @ struct zram_table_entry { unsigned long element; }; unsigned long flags; + spinlock_t lock; #ifdef CONFIG_ZRAM_MEMORY_TRACKING ktime_t ac_time; #endif Index: linux-5.0.19-rt11/drivers/char/random.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/char/random.c +++ linux-5.0.19-rt11/drivers/char/random.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1234 @ static __u32 get_reg(struct fast_pool *f return *ptr; } -void add_interrupt_randomness(int irq, int irq_flags) +void add_interrupt_randomness(int irq, int irq_flags, __u64 ip) { struct entropy_store *r; struct fast_pool *fast_pool = this_cpu_ptr(&irq_randomness); - struct pt_regs *regs = get_irq_regs(); unsigned long now = jiffies; cycles_t cycles = random_get_entropy(); __u32 c_high, j_high; - __u64 ip; unsigned long seed; int credit = 0; if (cycles == 0) - cycles = get_reg(fast_pool, regs); + cycles = get_reg(fast_pool, NULL); c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0; j_high = (sizeof(now) > 4) ? now >> 32 : 0; fast_pool->pool[0] ^= cycles ^ j_high ^ irq; fast_pool->pool[1] ^= now ^ c_high; - ip = regs ? instruction_pointer(regs) : _RET_IP_; + if (!ip) + ip = _RET_IP_; fast_pool->pool[2] ^= ip; fast_pool->pool[3] ^= (sizeof(ip) > 4) ? ip >> 32 : - get_reg(fast_pool, regs); + get_reg(fast_pool, NULL); fast_mix(fast_pool); add_interrupt_bench(cycles); Index: linux-5.0.19-rt11/drivers/char/tpm/tpm-dev-common.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/char/tpm/tpm-dev-common.c +++ linux-5.0.19-rt11/drivers/char/tpm/tpm-dev-common.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:28 @ #include "tpm-dev.h" static struct workqueue_struct *tpm_dev_wq; -static DEFINE_MUTEX(tpm_dev_wq_lock); static void tpm_async_work(struct work_struct *work) { Index: linux-5.0.19-rt11/drivers/char/tpm/tpm_tis.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/char/tpm/tpm_tis.c +++ linux-5.0.19-rt11/drivers/char/tpm/tpm_tis.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:56 @ static inline struct tpm_tis_tcg_phy *to return container_of(data, struct tpm_tis_tcg_phy, priv); } +#ifdef CONFIG_PREEMPT_RT_FULL +/* + * Flushes previous write operations to chip so that a subsequent + * ioread*()s won't stall a cpu. + */ +static inline void tpm_tis_flush(void __iomem *iobase) +{ + ioread8(iobase + TPM_ACCESS(0)); +} +#else +#define tpm_tis_flush(iobase) do { } while (0) +#endif + +static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr) +{ + iowrite8(b, iobase + addr); + tpm_tis_flush(iobase); +} + +static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr) +{ + iowrite32(b, iobase + addr); + tpm_tis_flush(iobase); +} + static bool interrupts = true; module_param(interrupts, bool, 0444); MODULE_PARM_DESC(interrupts, "Enable interrupts"); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:178 @ static int tpm_tcg_write_bytes(struct tp struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); while (len--) - iowrite8(*value++, phy->iobase + addr); + tpm_tis_iowrite8(*value++, phy->iobase, addr); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:205 @ static int tpm_tcg_write32(struct tpm_ti { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - iowrite32(value, phy->iobase + addr); + tpm_tis_iowrite32(value, phy->iobase, addr); return 0; } Index: linux-5.0.19-rt11/drivers/clocksource/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/drivers/clocksource/Kconfig +++ linux-5.0.19-rt11/drivers/clocksource/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:402 @ config ARMV7M_SYSTICK This options enables support for the ARMv7M system timer unit config ATMEL_PIT + bool "Atmel PIT support" if COMPILE_TEST + depends on HAS_IOMEM select TIMER_OF if OF - def_bool SOC_AT91SAM9 || SOC_SAMA5 + help + Support for the Periodic Interval Timer found on Atmel SoCs. config ATMEL_ST bool "Atmel ST timer support" if COMPILE_TEST @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:416 @ config ATMEL_ST help Support for the Atmel ST timer. +config ATMEL_TCB_CLKSRC + bool "Atmel TC Block timer driver" if COMPILE_TEST + depends on HAS_IOMEM && ATMEL_TCLIB + select TIMER_OF if OF + help + Support for Timer Counter Blocks on Atmel SoCs. + +config ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK + bool "TC Block use 32 KiHz clock" + depends on ATMEL_TCB_CLKSRC + default y + help + Select this to use 32 KiHz base clock rate as TC block clock. + config CLKSRC_EXYNOS_MCT bool "Exynos multi core timer driver" if COMPILE_TEST depends on ARM || ARM64 Index: linux-5.0.19-rt11/drivers/clocksource/Makefile =================================================================== --- linux-5.0.19-rt11.orig/drivers/clocksource/Makefile +++ linux-5.0.19-rt11/drivers/clocksource/Makefile @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6 @ obj-$(CONFIG_TIMER_OF) += timer-of.o obj-$(CONFIG_TIMER_PROBE) += timer-probe.o obj-$(CONFIG_ATMEL_PIT) += timer-atmel-pit.o obj-$(CONFIG_ATMEL_ST) += timer-atmel-st.o -obj-$(CONFIG_ATMEL_TCB_CLKSRC) += tcb_clksrc.o +obj-$(CONFIG_ATMEL_TCB_CLKSRC) += timer-atmel-tcb.o obj-$(CONFIG_X86_PM_TIMER) += acpi_pm.o obj-$(CONFIG_SCx200HR_TIMER) += scx200_hrt.o obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o Index: linux-5.0.19-rt11/drivers/clocksource/tcb_clksrc.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/clocksource/tcb_clksrc.c +++ /dev/null @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1 @ -// SPDX-License-Identifier: GPL-2.0 -#include <linux/init.h> -#include <linux/clocksource.h> -#include <linux/clockchips.h> -#include <linux/interrupt.h> -#include <linux/irq.h> - -#include <linux/clk.h> -#include <linux/err.h> -#include <linux/ioport.h> -#include <linux/io.h> -#include <linux/platform_device.h> -#include <linux/syscore_ops.h> -#include <linux/atmel_tc.h> - - -/* - * We're configured to use a specific TC block, one that's not hooked - * up to external hardware, to provide a time solution: - * - * - Two channels combine to create a free-running 32 bit counter - * with a base rate of 5+ MHz, packaged as a clocksource (with - * resolution better than 200 nsec). - * - Some chips support 32 bit counter. A single channel is used for - * this 32 bit free-running counter. the second channel is not used. - * - * - The third channel may be used to provide a 16-bit clockevent - * source, used in either periodic or oneshot mode. This runs - * at 32 KiHZ, and can handle delays of up to two seconds. - * - * A boot clocksource and clockevent source are also currently needed, - * unless the relevant platforms (ARM/AT91, AVR32/AT32) are changed so - * this code can be used when init_timers() is called, well before most - * devices are set up. (Some low end AT91 parts, which can run uClinux, - * have only the timers in one TC block... they currently don't support - * the tclib code, because of that initialization issue.) - * - * REVISIT behavior during system suspend states... we should disable - * all clocks and save the power. Easily done for clockevent devices, - * but clocksources won't necessarily get the needed notifications. - * For deeper system sleep states, this will be mandatory... - */ - -static void __iomem *tcaddr; -static struct -{ - u32 cmr; - u32 imr; - u32 rc; - bool clken; -} tcb_cache[3]; -static u32 bmr_cache; - -static u64 tc_get_cycles(struct clocksource *cs) -{ - unsigned long flags; - u32 lower, upper; - - raw_local_irq_save(flags); - do { - upper = readl_relaxed(tcaddr + ATMEL_TC_REG(1, CV)); - lower = readl_relaxed(tcaddr + ATMEL_TC_REG(0, CV)); - } while (upper != readl_relaxed(tcaddr + ATMEL_TC_REG(1, CV))); - - raw_local_irq_restore(flags); - return (upper << 16) | lower; -} - -static u64 tc_get_cycles32(struct clocksource *cs) -{ - return readl_relaxed(tcaddr + ATMEL_TC_REG(0, CV)); -} - -void tc_clksrc_suspend(struct clocksource *cs) -{ - int i; - - for (i = 0; i < ARRAY_SIZE(tcb_cache); i++) { - tcb_cache[i].cmr = readl(tcaddr + ATMEL_TC_REG(i, CMR)); - tcb_cache[i].imr = readl(tcaddr + ATMEL_TC_REG(i, IMR)); - tcb_cache[i].rc = readl(tcaddr + ATMEL_TC_REG(i, RC)); - tcb_cache[i].clken = !!(readl(tcaddr + ATMEL_TC_REG(i, SR)) & - ATMEL_TC_CLKSTA); - } - - bmr_cache = readl(tcaddr + ATMEL_TC_BMR); -} - -void tc_clksrc_resume(struct clocksource *cs) -{ - int i; - - for (i = 0; i < ARRAY_SIZE(tcb_cache); i++) { - /* Restore registers for the channel, RA and RB are not used */ - writel(tcb_cache[i].cmr, tcaddr + ATMEL_TC_REG(i, CMR)); - writel(tcb_cache[i].rc, tcaddr + ATMEL_TC_REG(i, RC)); - writel(0, tcaddr + ATMEL_TC_REG(i, RA)); - writel(0, tcaddr + ATMEL_TC_REG(i, RB)); - /* Disable all the interrupts */ - writel(0xff, tcaddr + ATMEL_TC_REG(i, IDR)); - /* Reenable interrupts that were enabled before suspending */ - writel(tcb_cache[i].imr, tcaddr + ATMEL_TC_REG(i, IER)); - /* Start the clock if it was used */ - if (tcb_cache[i].clken) - writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(i, CCR)); - } - - /* Dual channel, chain channels */ - writel(bmr_cache, tcaddr + ATMEL_TC_BMR); - /* Finally, trigger all the channels*/ - writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR); -} - -static struct clocksource clksrc = { - .name = "tcb_clksrc", - .rating = 200, - .read = tc_get_cycles, - .mask = CLOCKSOURCE_MASK(32), - .flags = CLOCK_SOURCE_IS_CONTINUOUS, - .suspend = tc_clksrc_suspend, - .resume = tc_clksrc_resume, -}; - -#ifdef CONFIG_GENERIC_CLOCKEVENTS - -struct tc_clkevt_device { - struct clock_event_device clkevt; - struct clk *clk; - void __iomem *regs; -}; - -static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt) -{ - return container_of(clkevt, struct tc_clkevt_device, clkevt); -} - -/* For now, we always use the 32K clock ... this optimizes for NO_HZ, - * because using one of the divided clocks would usually mean the - * tick rate can never be less than several dozen Hz (vs 0.5 Hz). - * - * A divided clock could be good for high resolution timers, since - * 30.5 usec resolution can seem "low". - */ -static u32 timer_clock; - -static int tc_shutdown(struct clock_event_device *d) -{ - struct tc_clkevt_device *tcd = to_tc_clkevt(d); - void __iomem *regs = tcd->regs; - - writel(0xff, regs + ATMEL_TC_REG(2, IDR)); - writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); - if (!clockevent_state_detached(d)) - clk_disable(tcd->clk); - - return 0; -} - -static int tc_set_oneshot(struct clock_event_device *d) -{ - struct tc_clkevt_device *tcd = to_tc_clkevt(d); - void __iomem *regs = tcd->regs; - - if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) - tc_shutdown(d); - - clk_enable(tcd->clk); - - /* slow clock, count up to RC, then irq and stop */ - writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE | - ATMEL_TC_WAVESEL_UP_AUTO, regs + ATMEL_TC_REG(2, CMR)); - writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); - - /* set_next_event() configures and starts the timer */ - return 0; -} - -static int tc_set_periodic(struct clock_event_device *d) -{ - struct tc_clkevt_device *tcd = to_tc_clkevt(d); - void __iomem *regs = tcd->regs; - - if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) - tc_shutdown(d); - - /* By not making the gentime core emulate periodic mode on top - * of oneshot, we get lower overhead and improved accuracy. - */ - clk_enable(tcd->clk); - - /* slow clock, count up to RC, then irq and restart */ - writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO, - regs + ATMEL_TC_REG(2, CMR)); - writel((32768 + HZ / 2) / HZ, tcaddr + ATMEL_TC_REG(2, RC)); - - /* Enable clock and interrupts on RC compare */ - writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); - - /* go go gadget! */ - writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, regs + - ATMEL_TC_REG(2, CCR)); - return 0; -} - -static int tc_next_event(unsigned long delta, struct clock_event_device *d) -{ - writel_relaxed(delta, tcaddr + ATMEL_TC_REG(2, RC)); - - /* go go gadget! */ - writel_relaxed(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, - tcaddr + ATMEL_TC_REG(2, CCR)); - return 0; -} - -static struct tc_clkevt_device clkevt = { - .clkevt = { - .name = "tc_clkevt", - .features = CLOCK_EVT_FEAT_PERIODIC | - CLOCK_EVT_FEAT_ONESHOT, - /* Should be lower than at91rm9200's system timer */ - .rating = 125, - .set_next_event = tc_next_event, - .set_state_shutdown = tc_shutdown, - .set_state_periodic = tc_set_periodic, - .set_state_oneshot = tc_set_oneshot, - }, -}; - -static irqreturn_t ch2_irq(int irq, void *handle) -{ - struct tc_clkevt_device *dev = handle; - unsigned int sr; - - sr = readl_relaxed(dev->regs + ATMEL_TC_REG(2, SR)); - if (sr & ATMEL_TC_CPCS) { - dev->clkevt.event_handler(&dev->clkevt); - return IRQ_HANDLED; - } - - return IRQ_NONE; -} - -static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) -{ - int ret; - struct clk *t2_clk = tc->clk[2]; - int irq = tc->irq[2]; - - ret = clk_prepare_enable(tc->slow_clk); - if (ret) - return ret; - - /* try to enable t2 clk to avoid future errors in mode change */ - ret = clk_prepare_enable(t2_clk); - if (ret) { - clk_disable_unprepare(tc->slow_clk); - return ret; - } - - clk_disable(t2_clk); - - clkevt.regs = tc->regs; - clkevt.clk = t2_clk; - - timer_clock = clk32k_divisor_idx; - - clkevt.clkevt.cpumask = cpumask_of(0); - - ret = request_irq(irq, ch2_irq, IRQF_TIMER, "tc_clkevt", &clkevt); - if (ret) { - clk_unprepare(t2_clk); - clk_disable_unprepare(tc->slow_clk); - return ret; - } - - clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff); - - return ret; -} - -#else /* !CONFIG_GENERIC_CLOCKEVENTS */ - -static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) -{ - /* NOTHING */ - return 0; -} - -#endif - -static void __init tcb_setup_dual_chan(struct atmel_tc *tc, int mck_divisor_idx) -{ - /* channel 0: waveform mode, input mclk/8, clock TIOA0 on overflow */ - writel(mck_divisor_idx /* likely divide-by-8 */ - | ATMEL_TC_WAVE - | ATMEL_TC_WAVESEL_UP /* free-run */ - | ATMEL_TC_ACPA_SET /* TIOA0 rises at 0 */ - | ATMEL_TC_ACPC_CLEAR, /* (duty cycle 50%) */ - tcaddr + ATMEL_TC_REG(0, CMR)); - writel(0x0000, tcaddr + ATMEL_TC_REG(0, RA)); - writel(0x8000, tcaddr + ATMEL_TC_REG(0, RC)); - writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR)); /* no irqs */ - writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR)); - - /* channel 1: waveform mode, input TIOA0 */ - writel(ATMEL_TC_XC1 /* input: TIOA0 */ - | ATMEL_TC_WAVE - | ATMEL_TC_WAVESEL_UP, /* free-run */ - tcaddr + ATMEL_TC_REG(1, CMR)); - writel(0xff, tcaddr + ATMEL_TC_REG(1, IDR)); /* no irqs */ - writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(1, CCR)); - - /* chain channel 0 to channel 1*/ - writel(ATMEL_TC_TC1XC1S_TIOA0, tcaddr + ATMEL_TC_BMR); - /* then reset all the timers */ - writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR); -} - -static void __init tcb_setup_single_chan(struct atmel_tc *tc, int mck_divisor_idx) -{ - /* channel 0: waveform mode, input mclk/8 */ - writel(mck_divisor_idx /* likely divide-by-8 */ - | ATMEL_TC_WAVE - | ATMEL_TC_WAVESEL_UP, /* free-run */ - tcaddr + ATMEL_TC_REG(0, CMR)); - writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR)); /* no irqs */ - writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR)); - - /* then reset all the timers */ - writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR); -} - -static int __init tcb_clksrc_init(void) -{ - static char bootinfo[] __initdata - = KERN_DEBUG "%s: tc%d at %d.%03d MHz\n"; - - struct platform_device *pdev; - struct atmel_tc *tc; - struct clk *t0_clk; - u32 rate, divided_rate = 0; - int best_divisor_idx = -1; - int clk32k_divisor_idx = -1; - int i; - int ret; - - tc = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK); - if (!tc) { - pr_debug("can't alloc TC for clocksource\n"); - return -ENODEV; - } - tcaddr = tc->regs; - pdev = tc->pdev; - - t0_clk = tc->clk[0]; - ret = clk_prepare_enable(t0_clk); - if (ret) { - pr_debug("can't enable T0 clk\n"); - goto err_free_tc; - } - - /* How fast will we be counting? Pick something over 5 MHz. */ - rate = (u32) clk_get_rate(t0_clk); - for (i = 0; i < 5; i++) { - unsigned divisor = atmel_tc_divisors[i]; - unsigned tmp; - - /* remember 32 KiHz clock for later */ - if (!divisor) { - clk32k_divisor_idx = i; - continue; - } - - tmp = rate / divisor; - pr_debug("TC: %u / %-3u [%d] --> %u\n", rate, divisor, i, tmp); - if (best_divisor_idx > 0) { - if (tmp < 5 * 1000 * 1000) - continue; - } - divided_rate = tmp; - best_divisor_idx = i; - } - - - printk(bootinfo, clksrc.name, CONFIG_ATMEL_TCB_CLKSRC_BLOCK, - divided_rate / 1000000, - ((divided_rate % 1000000) + 500) / 1000); - - if (tc->tcb_config && tc->tcb_config->counter_width == 32) { - /* use apropriate function to read 32 bit counter */ - clksrc.read = tc_get_cycles32; - /* setup ony channel 0 */ - tcb_setup_single_chan(tc, best_divisor_idx); - } else { - /* tclib will give us three clocks no matter what the - * underlying platform supports. - */ - ret = clk_prepare_enable(tc->clk[1]); - if (ret) { - pr_debug("can't enable T1 clk\n"); - goto err_disable_t0; - } - /* setup both channel 0 & 1 */ - tcb_setup_dual_chan(tc, best_divisor_idx); - } - - /* and away we go! */ - ret = clocksource_register_hz(&clksrc, divided_rate); - if (ret) - goto err_disable_t1; - - /* channel 2: periodic and oneshot timer support */ - ret = setup_clkevents(tc, clk32k_divisor_idx); - if (ret) - goto err_unregister_clksrc; - - return 0; - -err_unregister_clksrc: - clocksource_unregister(&clksrc); - -err_disable_t1: - if (!tc->tcb_config || tc->tcb_config->counter_width != 32) - clk_disable_unprepare(tc->clk[1]); - -err_disable_t0: - clk_disable_unprepare(t0_clk); - -err_free_tc: - atmel_tc_free(tc); - return ret; -} -arch_initcall(tcb_clksrc_init); Index: linux-5.0.19-rt11/drivers/clocksource/timer-atmel-tcb.c =================================================================== --- /dev/null +++ linux-5.0.19-rt11/drivers/clocksource/timer-atmel-tcb.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/init.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/ioport.h> +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/sched_clock.h> +#include <linux/syscore_ops.h> +#include <soc/at91/atmel_tcb.h> + + +/* + * We're configured to use a specific TC block, one that's not hooked + * up to external hardware, to provide a time solution: + * + * - Two channels combine to create a free-running 32 bit counter + * with a base rate of 5+ MHz, packaged as a clocksource (with + * resolution better than 200 nsec). + * - Some chips support 32 bit counter. A single channel is used for + * this 32 bit free-running counter. the second channel is not used. + * + * - The third channel may be used to provide a 16-bit clockevent + * source, used in either periodic or oneshot mode. + * + * REVISIT behavior during system suspend states... we should disable + * all clocks and save the power. Easily done for clockevent devices, + * but clocksources won't necessarily get the needed notifications. + * For deeper system sleep states, this will be mandatory... + */ + +static void __iomem *tcaddr; +static struct +{ + u32 cmr; + u32 imr; + u32 rc; + bool clken; +} tcb_cache[3]; +static u32 bmr_cache; + +static u64 tc_get_cycles(struct clocksource *cs) +{ + unsigned long flags; + u32 lower, upper; + + raw_local_irq_save(flags); + do { + upper = readl_relaxed(tcaddr + ATMEL_TC_REG(1, CV)); + lower = readl_relaxed(tcaddr + ATMEL_TC_REG(0, CV)); + } while (upper != readl_relaxed(tcaddr + ATMEL_TC_REG(1, CV))); + + raw_local_irq_restore(flags); + return (upper << 16) | lower; +} + +static u64 tc_get_cycles32(struct clocksource *cs) +{ + return readl_relaxed(tcaddr + ATMEL_TC_REG(0, CV)); +} + +static void tc_clksrc_suspend(struct clocksource *cs) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(tcb_cache); i++) { + tcb_cache[i].cmr = readl(tcaddr + ATMEL_TC_REG(i, CMR)); + tcb_cache[i].imr = readl(tcaddr + ATMEL_TC_REG(i, IMR)); + tcb_cache[i].rc = readl(tcaddr + ATMEL_TC_REG(i, RC)); + tcb_cache[i].clken = !!(readl(tcaddr + ATMEL_TC_REG(i, SR)) & + ATMEL_TC_CLKSTA); + } + + bmr_cache = readl(tcaddr + ATMEL_TC_BMR); +} + +static void tc_clksrc_resume(struct clocksource *cs) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(tcb_cache); i++) { + /* Restore registers for the channel, RA and RB are not used */ + writel(tcb_cache[i].cmr, tcaddr + ATMEL_TC_REG(i, CMR)); + writel(tcb_cache[i].rc, tcaddr + ATMEL_TC_REG(i, RC)); + writel(0, tcaddr + ATMEL_TC_REG(i, RA)); + writel(0, tcaddr + ATMEL_TC_REG(i, RB)); + /* Disable all the interrupts */ + writel(0xff, tcaddr + ATMEL_TC_REG(i, IDR)); + /* Reenable interrupts that were enabled before suspending */ + writel(tcb_cache[i].imr, tcaddr + ATMEL_TC_REG(i, IER)); + /* Start the clock if it was used */ + if (tcb_cache[i].clken) + writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(i, CCR)); + } + + /* Dual channel, chain channels */ + writel(bmr_cache, tcaddr + ATMEL_TC_BMR); + /* Finally, trigger all the channels*/ + writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR); +} + +static struct clocksource clksrc = { + .rating = 200, + .read = tc_get_cycles, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .suspend = tc_clksrc_suspend, + .resume = tc_clksrc_resume, +}; + +static u64 notrace tc_sched_clock_read(void) +{ + return tc_get_cycles(&clksrc); +} + +static u64 notrace tc_sched_clock_read32(void) +{ + return tc_get_cycles32(&clksrc); +} + +#ifdef CONFIG_GENERIC_CLOCKEVENTS + +struct tc_clkevt_device { + struct clock_event_device clkevt; + struct clk *clk; + bool clk_enabled; + u32 freq; + void __iomem *regs; +}; + +static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt) +{ + return container_of(clkevt, struct tc_clkevt_device, clkevt); +} + +static u32 timer_clock; + +static void tc_clk_disable(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + + clk_disable(tcd->clk); + tcd->clk_enabled = false; +} + +static void tc_clk_enable(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + + if (tcd->clk_enabled) + return; + clk_enable(tcd->clk); + tcd->clk_enabled = true; +} + +static int tc_shutdown(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + void __iomem *regs = tcd->regs; + + writel(0xff, regs + ATMEL_TC_REG(2, IDR)); + writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); + return 0; +} + +static int tc_shutdown_clk_off(struct clock_event_device *d) +{ + tc_shutdown(d); + if (!clockevent_state_detached(d)) + tc_clk_disable(d); + + return 0; +} + +static int tc_set_oneshot(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + void __iomem *regs = tcd->regs; + + if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) + tc_shutdown(d); + + tc_clk_enable(d); + + /* count up to RC, then irq and stop */ + writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE | + ATMEL_TC_WAVESEL_UP_AUTO, regs + ATMEL_TC_REG(2, CMR)); + writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); + + /* set_next_event() configures and starts the timer */ + return 0; +} + +static int tc_set_periodic(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + void __iomem *regs = tcd->regs; + + if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) + tc_shutdown(d); + + /* By not making the gentime core emulate periodic mode on top + * of oneshot, we get lower overhead and improved accuracy. + */ + tc_clk_enable(d); + + /* count up to RC, then irq and restart */ + writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO, + regs + ATMEL_TC_REG(2, CMR)); + writel((tcd->freq + HZ / 2) / HZ, tcaddr + ATMEL_TC_REG(2, RC)); + + /* Enable clock and interrupts on RC compare */ + writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); + + /* go go gadget! */ + writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, regs + + ATMEL_TC_REG(2, CCR)); + return 0; +} + +static int tc_next_event(unsigned long delta, struct clock_event_device *d) +{ + writel_relaxed(delta, tcaddr + ATMEL_TC_REG(2, RC)); + + /* go go gadget! */ + writel_relaxed(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, + tcaddr + ATMEL_TC_REG(2, CCR)); + return 0; +} + +static struct tc_clkevt_device clkevt = { + .clkevt = { + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, + /* Should be lower than at91rm9200's system timer */ +#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK + .rating = 125, +#else + .rating = 200, +#endif + .set_next_event = tc_next_event, + .set_state_shutdown = tc_shutdown_clk_off, + .set_state_periodic = tc_set_periodic, + .set_state_oneshot = tc_set_oneshot, + }, +}; + +static irqreturn_t ch2_irq(int irq, void *handle) +{ + struct tc_clkevt_device *dev = handle; + unsigned int sr; + + sr = readl_relaxed(dev->regs + ATMEL_TC_REG(2, SR)); + if (sr & ATMEL_TC_CPCS) { + dev->clkevt.event_handler(&dev->clkevt); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx) +{ + unsigned divisor = atmel_tc_divisors[divisor_idx]; + int ret; + struct clk *t2_clk = tc->clk[2]; + int irq = tc->irq[2]; + + ret = clk_prepare_enable(tc->slow_clk); + if (ret) + return ret; + + /* try to enable t2 clk to avoid future errors in mode change */ + ret = clk_prepare_enable(t2_clk); + if (ret) { + clk_disable_unprepare(tc->slow_clk); + return ret; + } + + clk_disable(t2_clk); + + clkevt.regs = tc->regs; + clkevt.clk = t2_clk; + + timer_clock = divisor_idx; + if (!divisor) + clkevt.freq = 32768; + else + clkevt.freq = clk_get_rate(t2_clk) / divisor; + + clkevt.clkevt.cpumask = cpumask_of(0); + + ret = request_irq(irq, ch2_irq, IRQF_TIMER, "tc_clkevt", &clkevt); + if (ret) { + clk_unprepare(t2_clk); + clk_disable_unprepare(tc->slow_clk); + return ret; + } + + clockevents_config_and_register(&clkevt.clkevt, clkevt.freq, 1, 0xffff); + + return ret; +} + +#else /* !CONFIG_GENERIC_CLOCKEVENTS */ + +static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) +{ + /* NOTHING */ + return 0; +} + +#endif + +static void __init tcb_setup_dual_chan(struct atmel_tc *tc, int mck_divisor_idx) +{ + /* channel 0: waveform mode, input mclk/8, clock TIOA0 on overflow */ + writel(mck_divisor_idx /* likely divide-by-8 */ + | ATMEL_TC_WAVE + | ATMEL_TC_WAVESEL_UP /* free-run */ + | ATMEL_TC_ACPA_SET /* TIOA0 rises at 0 */ + | ATMEL_TC_ACPC_CLEAR, /* (duty cycle 50%) */ + tcaddr + ATMEL_TC_REG(0, CMR)); + writel(0x0000, tcaddr + ATMEL_TC_REG(0, RA)); + writel(0x8000, tcaddr + ATMEL_TC_REG(0, RC)); + writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR)); /* no irqs */ + writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR)); + + /* channel 1: waveform mode, input TIOA0 */ + writel(ATMEL_TC_XC1 /* input: TIOA0 */ + | ATMEL_TC_WAVE + | ATMEL_TC_WAVESEL_UP, /* free-run */ + tcaddr + ATMEL_TC_REG(1, CMR)); + writel(0xff, tcaddr + ATMEL_TC_REG(1, IDR)); /* no irqs */ + writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(1, CCR)); + + /* chain channel 0 to channel 1*/ + writel(ATMEL_TC_TC1XC1S_TIOA0, tcaddr + ATMEL_TC_BMR); + /* then reset all the timers */ + writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR); +} + +static void __init tcb_setup_single_chan(struct atmel_tc *tc, int mck_divisor_idx) +{ + /* channel 0: waveform mode, input mclk/8 */ + writel(mck_divisor_idx /* likely divide-by-8 */ + | ATMEL_TC_WAVE + | ATMEL_TC_WAVESEL_UP, /* free-run */ + tcaddr + ATMEL_TC_REG(0, CMR)); + writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR)); /* no irqs */ + writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR)); + + /* then reset all the timers */ + writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR); +} + +static const u8 atmel_tcb_divisors[5] = { 2, 8, 32, 128, 0, }; + +static const struct of_device_id atmel_tcb_of_match[] = { + { .compatible = "atmel,at91rm9200-tcb", .data = (void *)16, }, + { .compatible = "atmel,at91sam9x5-tcb", .data = (void *)32, }, + { /* sentinel */ } +}; + +static int __init tcb_clksrc_init(struct device_node *node) +{ + struct atmel_tc tc; + struct clk *t0_clk; + const struct of_device_id *match; + u64 (*tc_sched_clock)(void); + u32 rate, divided_rate = 0; + int best_divisor_idx = -1; + int clk32k_divisor_idx = -1; + int bits; + int i; + int ret; + + /* Protect against multiple calls */ + if (tcaddr) + return 0; + + tc.regs = of_iomap(node->parent, 0); + if (!tc.regs) + return -ENXIO; + + t0_clk = of_clk_get_by_name(node->parent, "t0_clk"); + if (IS_ERR(t0_clk)) + return PTR_ERR(t0_clk); + + tc.slow_clk = of_clk_get_by_name(node->parent, "slow_clk"); + if (IS_ERR(tc.slow_clk)) + return PTR_ERR(tc.slow_clk); + + tc.clk[0] = t0_clk; + tc.clk[1] = of_clk_get_by_name(node->parent, "t1_clk"); + if (IS_ERR(tc.clk[1])) + tc.clk[1] = t0_clk; + tc.clk[2] = of_clk_get_by_name(node->parent, "t2_clk"); + if (IS_ERR(tc.clk[2])) + tc.clk[2] = t0_clk; + + tc.irq[2] = of_irq_get(node->parent, 2); + if (tc.irq[2] <= 0) { + tc.irq[2] = of_irq_get(node->parent, 0); + if (tc.irq[2] <= 0) + return -EINVAL; + } + + match = of_match_node(atmel_tcb_of_match, node->parent); + bits = (uintptr_t)match->data; + + for (i = 0; i < ARRAY_SIZE(tc.irq); i++) + writel(ATMEL_TC_ALL_IRQ, tc.regs + ATMEL_TC_REG(i, IDR)); + + ret = clk_prepare_enable(t0_clk); + if (ret) { + pr_debug("can't enable T0 clk\n"); + return ret; + } + + /* How fast will we be counting? Pick something over 5 MHz. */ + rate = (u32) clk_get_rate(t0_clk); + for (i = 0; i < ARRAY_SIZE(atmel_tcb_divisors); i++) { + unsigned divisor = atmel_tcb_divisors[i]; + unsigned tmp; + + /* remember 32 KiHz clock for later */ + if (!divisor) { + clk32k_divisor_idx = i; + continue; + } + + tmp = rate / divisor; + pr_debug("TC: %u / %-3u [%d] --> %u\n", rate, divisor, i, tmp); + if (best_divisor_idx > 0) { + if (tmp < 5 * 1000 * 1000) + continue; + } + divided_rate = tmp; + best_divisor_idx = i; + } + + clksrc.name = kbasename(node->parent->full_name); + clkevt.clkevt.name = kbasename(node->parent->full_name); + pr_debug("%s at %d.%03d MHz\n", clksrc.name, divided_rate / 1000000, + ((divided_rate % 1000000) + 500) / 1000); + + tcaddr = tc.regs; + + if (bits == 32) { + /* use apropriate function to read 32 bit counter */ + clksrc.read = tc_get_cycles32; + /* setup ony channel 0 */ + tcb_setup_single_chan(&tc, best_divisor_idx); + tc_sched_clock = tc_sched_clock_read32; + } else { + /* we have three clocks no matter what the + * underlying platform supports. + */ + ret = clk_prepare_enable(tc.clk[1]); + if (ret) { + pr_debug("can't enable T1 clk\n"); + goto err_disable_t0; + } + /* setup both channel 0 & 1 */ + tcb_setup_dual_chan(&tc, best_divisor_idx); + tc_sched_clock = tc_sched_clock_read; + } + + /* and away we go! */ + ret = clocksource_register_hz(&clksrc, divided_rate); + if (ret) + goto err_disable_t1; + + /* channel 2: periodic and oneshot timer support */ +#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK + ret = setup_clkevents(&tc, clk32k_divisor_idx); +#else + ret = setup_clkevents(tc, best_divisor_idx); +#endif + if (ret) + goto err_unregister_clksrc; + + sched_clock_register(tc_sched_clock, 32, divided_rate); + + return 0; + +err_unregister_clksrc: + clocksource_unregister(&clksrc); + +err_disable_t1: + if (bits != 32) + clk_disable_unprepare(tc.clk[1]); + +err_disable_t0: + clk_disable_unprepare(t0_clk); + + tcaddr = NULL; + + return ret; +} +TIMER_OF_DECLARE(atmel_tcb_clksrc, "atmel,tcb-timer", tcb_clksrc_init); Index: linux-5.0.19-rt11/drivers/connector/cn_proc.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/connector/cn_proc.c +++ linux-5.0.19-rt11/drivers/connector/cn_proc.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:35 @ #include <linux/pid_namespace.h> #include <linux/cn_proc.h> +#include <linux/locallock.h> /* * Size of a cn_msg followed by a proc_event structure. Since the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:58 @ static struct cb_id cn_proc_event_id = { /* proc_event_counts is used as the sequence number of the netlink message */ static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; +static DEFINE_LOCAL_IRQ_LOCK(send_msg_lock); static inline void send_msg(struct cn_msg *msg) { - preempt_disable(); + local_lock(send_msg_lock); msg->seq = __this_cpu_inc_return(proc_event_counts) - 1; ((struct proc_event *)msg->data)->cpu = smp_processor_id(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:75 @ static inline void send_msg(struct cn_ms */ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT); - preempt_enable(); + local_unlock(send_msg_lock); } void proc_fork_connector(struct task_struct *task) Index: linux-5.0.19-rt11/drivers/cpufreq/Kconfig.x86 =================================================================== --- linux-5.0.19-rt11.orig/drivers/cpufreq/Kconfig.x86 +++ linux-5.0.19-rt11/drivers/cpufreq/Kconfig.x86 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:128 @ config X86_POWERNOW_K7_ACPI config X86_POWERNOW_K8 tristate "AMD Opteron/Athlon64 PowerNow!" - depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ + depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ && !PREEMPT_RT_BASE help This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors. Support for K10 and newer processors is now in acpi-cpufreq. Index: linux-5.0.19-rt11/drivers/crypto/chelsio/chtls/chtls_main.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/crypto/chelsio/chtls/chtls_main.c +++ linux-5.0.19-rt11/drivers/crypto/chelsio/chtls/chtls_main.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:33 @ */ static LIST_HEAD(cdev_list); static DEFINE_MUTEX(cdev_mutex); -static DEFINE_MUTEX(cdev_list_lock); static DEFINE_MUTEX(notify_mutex); static RAW_NOTIFIER_HEAD(listen_notify_list); Index: linux-5.0.19-rt11/drivers/firmware/efi/efi.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/firmware/efi/efi.c +++ linux-5.0.19-rt11/drivers/firmware/efi/efi.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:91 @ struct mm_struct efi_mm = { struct workqueue_struct *efi_rts_wq; -static bool disable_runtime; +static bool disable_runtime = IS_ENABLED(CONFIG_PREEMPT_RT_BASE); static int __init setup_noefi(char *arg) { disable_runtime = true; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:117 @ static int __init parse_efi_cmdline(char if (parse_option_str(str, "noruntime")) disable_runtime = true; + if (parse_option_str(str, "runtime")) + disable_runtime = false; + return 0; } early_param("efi", parse_efi_cmdline); Index: linux-5.0.19-rt11/drivers/gpu/drm/i915/i915_irq.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/gpu/drm/i915/i915_irq.c +++ linux-5.0.19-rt11/drivers/gpu/drm/i915/i915_irq.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1028 @ static bool i915_get_crtc_scanoutpos(str spin_lock_irqsave(&dev_priv->uncore.lock, irqflags); /* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */ + preempt_disable_rt(); /* Get optional system timestamp before query. */ if (stime) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1080 @ static bool i915_get_crtc_scanoutpos(str *etime = ktime_get(); /* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */ + preempt_enable_rt(); spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags); Index: linux-5.0.19-rt11/drivers/gpu/drm/i915/i915_request.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/gpu/drm/i915/i915_request.c +++ linux-5.0.19-rt11/drivers/gpu/drm/i915/i915_request.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:281 @ static void __retire_engine_request(stru GEM_BUG_ON(!i915_request_completed(rq)); - local_irq_disable(); - - spin_lock(&engine->timeline.lock); + spin_lock_irq(&engine->timeline.lock); GEM_BUG_ON(!list_is_first(&rq->link, &engine->timeline.requests)); list_del_init(&rq->link); spin_unlock(&engine->timeline.lock); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:295 @ static void __retire_engine_request(stru GEM_BUG_ON(!atomic_read(&rq->i915->gt_pm.rps.num_waiters)); atomic_dec(&rq->i915->gt_pm.rps.num_waiters); } - spin_unlock(&rq->lock); - - local_irq_enable(); + spin_unlock_irq(&rq->lock); /* * The backing object for the context is done after switching to the Index: linux-5.0.19-rt11/drivers/gpu/drm/i915/i915_trace.h =================================================================== --- linux-5.0.19-rt11.orig/drivers/gpu/drm/i915/i915_trace.h +++ linux-5.0.19-rt11/drivers/gpu/drm/i915/i915_trace.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5 @ #if !defined(_I915_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ) #define _I915_TRACE_H_ +#ifdef CONFIG_PREEMPT_RT_BASE +#define NOTRACE +#endif + #include <linux/stringify.h> #include <linux/types.h> #include <linux/tracepoint.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:686 @ DEFINE_EVENT(i915_request, i915_request_ TP_ARGS(rq) ); -#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS) +#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS) && !defined(NOTRACE) DEFINE_EVENT(i915_request, i915_request_submit, TP_PROTO(struct i915_request *rq), TP_ARGS(rq) Index: linux-5.0.19-rt11/drivers/gpu/drm/i915/intel_sprite.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/gpu/drm/i915/intel_sprite.c +++ linux-5.0.19-rt11/drivers/gpu/drm/i915/intel_sprite.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:39 @ #include <drm/drm_rect.h> #include <drm/drm_atomic.h> #include <drm/drm_plane_helper.h> +#include <linux/locallock.h> #include "intel_drv.h" #include "intel_frontbuffer.h" #include <drm/i915_drm.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:65 @ int intel_usecs_to_scanlines(const struc #define VBLANK_EVASION_TIME_US 100 #endif +static DEFINE_LOCAL_IRQ_LOCK(pipe_update_lock); + /** * intel_pipe_update_start() - start update of a set of display registers * @new_crtc_state: the new crtc state @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:116 @ void intel_pipe_update_start(const struc DRM_ERROR("PSR idle timed out 0x%x, atomic update may fail\n", psr_status); - local_irq_disable(); + local_lock_irq(pipe_update_lock); crtc->debug.min_vbl = min; crtc->debug.max_vbl = max; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:140 @ void intel_pipe_update_start(const struc break; } - local_irq_enable(); + local_unlock_irq(pipe_update_lock); timeout = schedule_timeout(timeout); - local_irq_disable(); + local_lock_irq(pipe_update_lock); } finish_wait(wq, &wait); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:177 @ void intel_pipe_update_start(const struc return; irq_disable: - local_irq_disable(); + local_lock_irq(pipe_update_lock); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:213 @ void intel_pipe_update_end(struct intel_ new_crtc_state->base.event = NULL; } - local_irq_enable(); + local_unlock_irq(pipe_update_lock); if (intel_vgpu_active(dev_priv)) return; Index: linux-5.0.19-rt11/drivers/gpu/drm/radeon/radeon_display.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/gpu/drm/radeon/radeon_display.c +++ linux-5.0.19-rt11/drivers/gpu/drm/radeon/radeon_display.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1816 @ int radeon_get_crtc_scanoutpos(struct dr struct radeon_device *rdev = dev->dev_private; /* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */ + preempt_disable_rt(); /* Get optional system timestamp before query. */ if (stime) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1909 @ int radeon_get_crtc_scanoutpos(struct dr *etime = ktime_get(); /* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */ + preempt_enable_rt(); /* Decode into vertical and horizontal scanout position. */ *vpos = position & 0x1fff; Index: linux-5.0.19-rt11/drivers/hv/hv.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/hv/hv.c +++ linux-5.0.19-rt11/drivers/hv/hv.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:113 @ int hv_post_message(union hv_connection_ static void hv_stimer0_isr(void) { struct hv_per_cpu_context *hv_cpu; + struct pt_regs *regs = get_irq_regs(); + u64 ip = regs ? instruction_pointer(regs) : 0; hv_cpu = this_cpu_ptr(hv_context.cpu_context); hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt); - add_interrupt_randomness(stimer0_vector, 0); + add_interrupt_randomness(stimer0_vector, 0, ip); } static int hv_ce_set_next_event(unsigned long delta, Index: linux-5.0.19-rt11/drivers/hv/hyperv_vmbus.h =================================================================== --- linux-5.0.19-rt11.orig/drivers/hv/hyperv_vmbus.h +++ linux-5.0.19-rt11/drivers/hv/hyperv_vmbus.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:34 @ #include <linux/atomic.h> #include <linux/hyperv.h> #include <linux/interrupt.h> +#include <linux/irq.h> #include "hv_trace.h" Index: linux-5.0.19-rt11/drivers/hv/vmbus_drv.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/hv/vmbus_drv.c +++ linux-5.0.19-rt11/drivers/hv/vmbus_drv.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1121 @ static void vmbus_isr(void) void *page_addr = hv_cpu->synic_event_page; struct hv_message *msg; union hv_synic_event_flags *event; + struct pt_regs *regs = get_irq_regs(); + u64 ip = regs ? instruction_pointer(regs) : 0; bool handled = false; if (unlikely(page_addr == NULL)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1166 @ static void vmbus_isr(void) tasklet_schedule(&hv_cpu->msg_dpc); } - add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0); + add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0, ip); } /* Index: linux-5.0.19-rt11/drivers/infiniband/hw/hfi1/affinity.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/infiniband/hw/hfi1/affinity.c +++ linux-5.0.19-rt11/drivers/infiniband/hw/hfi1/affinity.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1040 @ int hfi1_get_proc_affinity(int node) struct hfi1_affinity_node *entry; cpumask_var_t diff, hw_thread_mask, available_mask, intrs_mask; const struct cpumask *node_mask, - *proc_mask = ¤t->cpus_allowed; + *proc_mask = current->cpus_ptr; struct hfi1_affinity_node_list *affinity = &node_affinity; struct cpu_mask_set *set = &affinity->proc; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1048 @ int hfi1_get_proc_affinity(int node) * check whether process/context affinity has already * been set */ - if (cpumask_weight(proc_mask) == 1) { + if (current->nr_cpus_allowed == 1) { hfi1_cdbg(PROC, "PID %u %s affinity set to CPU %*pbl", current->pid, current->comm, cpumask_pr_args(proc_mask)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1059 @ int hfi1_get_proc_affinity(int node) cpu = cpumask_first(proc_mask); cpumask_set_cpu(cpu, &set->used); goto done; - } else if (cpumask_weight(proc_mask) < cpumask_weight(&set->mask)) { + } else if (current->nr_cpus_allowed < cpumask_weight(&set->mask)) { hfi1_cdbg(PROC, "PID %u %s affinity set to CPU set(s) %*pbl", current->pid, current->comm, cpumask_pr_args(proc_mask)); Index: linux-5.0.19-rt11/drivers/infiniband/hw/hfi1/sdma.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/infiniband/hw/hfi1/sdma.c +++ linux-5.0.19-rt11/drivers/infiniband/hw/hfi1/sdma.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:858 @ struct sdma_engine *sdma_select_user_eng { struct sdma_rht_node *rht_node; struct sdma_engine *sde = NULL; - const struct cpumask *current_mask = ¤t->cpus_allowed; unsigned long cpu_id; /* * To ensure that always the same sdma engine(s) will be * selected make sure the process is pinned to this CPU only. */ - if (cpumask_weight(current_mask) != 1) + if (current->nr_cpus_allowed != 1) goto out; cpu_id = smp_processor_id(); Index: linux-5.0.19-rt11/drivers/infiniband/hw/qib/qib_file_ops.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/infiniband/hw/qib/qib_file_ops.c +++ linux-5.0.19-rt11/drivers/infiniband/hw/qib/qib_file_ops.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1145 @ static __poll_t qib_poll(struct file *fp static void assign_ctxt_affinity(struct file *fp, struct qib_devdata *dd) { struct qib_filedata *fd = fp->private_data; - const unsigned int weight = cpumask_weight(¤t->cpus_allowed); + const unsigned int weight = current->nr_cpus_allowed; const struct cpumask *local_mask = cpumask_of_pcibus(dd->pcidev->bus); int local_cpu; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1626 @ static int qib_assign_ctxt(struct file * ret = find_free_ctxt(i_minor - 1, fp, uinfo); else { int unit; - const unsigned int cpu = cpumask_first(¤t->cpus_allowed); - const unsigned int weight = - cpumask_weight(¤t->cpus_allowed); + const unsigned int cpu = cpumask_first(current->cpus_ptr); + const unsigned int weight = current->nr_cpus_allowed; if (weight == 1 && !test_bit(cpu, qib_cpulist)) if (!find_hca(cpu, &unit) && unit >= 0) Index: linux-5.0.19-rt11/drivers/iommu/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/drivers/iommu/Kconfig +++ linux-5.0.19-rt11/drivers/iommu/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:96 @ config IOMMU_DMA bool select IOMMU_API select IOMMU_IOVA + select IRQ_MSI_IOMMU select NEED_SG_DMA_LENGTH config FSL_PAMU Index: linux-5.0.19-rt11/drivers/iommu/dma-iommu.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/iommu/dma-iommu.c +++ linux-5.0.19-rt11/drivers/iommu/dma-iommu.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:892 @ out_free_page: return NULL; } -void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) +int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr) { - struct device *dev = msi_desc_to_dev(irq_get_msi_desc(irq)); + struct device *dev = msi_desc_to_dev(desc); struct iommu_domain *domain = iommu_get_domain_for_dev(dev); struct iommu_dma_cookie *cookie; struct iommu_dma_msi_page *msi_page; - phys_addr_t msi_addr = (u64)msg->address_hi << 32 | msg->address_lo; unsigned long flags; - if (!domain || !domain->iova_cookie) - return; + if (!domain || !domain->iova_cookie) { + desc->iommu_cookie = NULL; + return 0; + } cookie = domain->iova_cookie; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:916 @ void iommu_dma_map_msi_msg(int irq, stru msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain); spin_unlock_irqrestore(&cookie->msi_lock, flags); - if (WARN_ON(!msi_page)) { - /* - * We're called from a void callback, so the best we can do is - * 'fail' by filling the message with obviously bogus values. - * Since we got this far due to an IOMMU being present, it's - * not like the existing address would have worked anyway... - */ - msg->address_hi = ~0U; - msg->address_lo = ~0U; - msg->data = ~0U; - } else { - msg->address_hi = upper_32_bits(msi_page->iova); - msg->address_lo &= cookie_msi_granule(cookie) - 1; - msg->address_lo += lower_32_bits(msi_page->iova); - } + msi_desc_set_iommu_cookie(desc, msi_page); + + if (!msi_page) + return -ENOMEM; + return 0; +} + +void iommu_dma_compose_msi_msg(struct msi_desc *desc, + struct msi_msg *msg) +{ + struct device *dev = msi_desc_to_dev(desc); + const struct iommu_domain *domain = iommu_get_domain_for_dev(dev); + const struct iommu_dma_msi_page *msi_page; + + msi_page = msi_desc_get_iommu_cookie(desc); + + if (!domain || !domain->iova_cookie || WARN_ON(!msi_page)) + return; + + msg->address_hi = upper_32_bits(msi_page->iova); + msg->address_lo &= cookie_msi_granule(domain->iova_cookie) - 1; + msg->address_lo += lower_32_bits(msi_page->iova); } Index: linux-5.0.19-rt11/drivers/irqchip/irq-gic-v2m.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/irqchip/irq-gic-v2m.c +++ linux-5.0.19-rt11/drivers/irqchip/irq-gic-v2m.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:113 @ static void gicv2m_compose_msi_msg(struc if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET) msg->data -= v2m->spi_offset; - iommu_dma_map_msi_msg(data->irq, msg); + iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg); } static struct irq_chip gicv2m_irq_chip = { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:170 @ static void gicv2m_unalloc_msi(struct v2 static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args) { + msi_alloc_info_t *info = args; struct v2m_data *v2m = NULL, *tmp; int hwirq, offset, i, err = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:190 @ static int gicv2m_irq_domain_alloc(struc hwirq = v2m->spi_start + offset; + err = iommu_dma_prepare_msi(info->desc, + v2m->res.start + V2M_MSI_SETSPI_NS); + if (err) + return err; + for (i = 0; i < nr_irqs; i++) { err = gicv2m_irq_gic_domain_alloc(domain, virq + i, hwirq + i); if (err) Index: linux-5.0.19-rt11/drivers/irqchip/irq-gic-v3-its.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/irqchip/irq-gic-v3-its.c +++ linux-5.0.19-rt11/drivers/irqchip/irq-gic-v3-its.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1182 @ static void its_irq_compose_msi_msg(stru msg->address_hi = upper_32_bits(addr); msg->data = its_get_event_id(d); - iommu_dma_map_msi_msg(d->irq, msg); + iommu_dma_compose_msi_msg(irq_data_get_msi_desc(d), msg); } static int its_irq_set_irqchip_state(struct irq_data *d, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2565 @ static int its_irq_domain_alloc(struct i { msi_alloc_info_t *info = args; struct its_device *its_dev = info->scratchpad[0].ptr; + struct its_node *its = its_dev->its; irq_hw_number_t hwirq; int err; int i; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2574 @ static int its_irq_domain_alloc(struct i if (err) return err; + err = iommu_dma_prepare_msi(info->desc, its->get_msi_base(its_dev)); + if (err) + return err; + for (i = 0; i < nr_irqs; i++) { err = its_irq_gic_domain_alloc(domain, virq + i, hwirq + i); if (err) Index: linux-5.0.19-rt11/drivers/irqchip/irq-gic-v3-mbi.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/irqchip/irq-gic-v3-mbi.c +++ linux-5.0.19-rt11/drivers/irqchip/irq-gic-v3-mbi.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:87 @ static void mbi_free_msi(struct mbi_rang static int mbi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args) { + msi_alloc_info_t *info = args; struct mbi_range *mbi = NULL; int hwirq, offset, i, err = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:108 @ static int mbi_irq_domain_alloc(struct i hwirq = mbi->spi_start + offset; + err = iommu_dma_prepare_msi(info->desc, + mbi_phys_base + GICD_SETSPI_NSR); + if (err) + return err; + for (i = 0; i < nr_irqs; i++) { err = mbi_irq_gic_domain_alloc(domain, virq + i, hwirq + i); if (err) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:151 @ static void mbi_compose_msi_msg(struct i msg[0].address_lo = lower_32_bits(mbi_phys_base + GICD_SETSPI_NSR); msg[0].data = data->parent_data->hwirq; - iommu_dma_map_msi_msg(data->irq, msg); + iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg); } #ifdef CONFIG_PCI_MSI @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:211 @ static void mbi_compose_mbi_msg(struct i msg[1].address_lo = lower_32_bits(mbi_phys_base + GICD_CLRSPI_NSR); msg[1].data = data->parent_data->hwirq; - iommu_dma_map_msi_msg(data->irq, &msg[1]); + iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), &msg[1]); } /* Platform-MSI specific irqchip */ Index: linux-5.0.19-rt11/drivers/irqchip/irq-ls-scfg-msi.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/irqchip/irq-ls-scfg-msi.c +++ linux-5.0.19-rt11/drivers/irqchip/irq-ls-scfg-msi.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:103 @ static void ls_scfg_msi_compose_msg(stru msg->data |= cpumask_first(mask); } - iommu_dma_map_msi_msg(data->irq, msg); + iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg); } static int ls_scfg_msi_set_affinity(struct irq_data *irq_data, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:144 @ static int ls_scfg_msi_domain_irq_alloc( unsigned int nr_irqs, void *args) { + msi_alloc_info_t *info = args; struct ls_scfg_msi *msi_data = domain->host_data; int pos, err = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:161 @ static int ls_scfg_msi_domain_irq_alloc( if (err) return err; + err = iommu_dma_prepare_msi(info->desc, msi_data->msiir_addr); + if (err) + return err; + irq_domain_set_info(domain, virq, pos, &ls_scfg_msi_parent_chip, msi_data, handle_simple_irq, NULL, NULL); Index: linux-5.0.19-rt11/drivers/leds/trigger/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/drivers/leds/trigger/Kconfig +++ linux-5.0.19-rt11/drivers/leds/trigger/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:66 @ config LEDS_TRIGGER_BACKLIGHT config LEDS_TRIGGER_CPU bool "LED CPU Trigger" + depends on !PREEMPT_RT_BASE help This allows LEDs to be controlled by active CPUs. This shows the active CPUs across an array of LEDs so you can see which Index: linux-5.0.19-rt11/drivers/md/bcache/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/drivers/md/bcache/Kconfig +++ linux-5.0.19-rt11/drivers/md/bcache/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ config BCACHE tristate "Block device as cache" + depends on !PREEMPT_RT_FULL select CRC64 help Allows a block device to be used as cache for other devices; uses Index: linux-5.0.19-rt11/drivers/md/raid5.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/md/raid5.c +++ linux-5.0.19-rt11/drivers/md/raid5.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2072 @ static void raid_run_ops(struct stripe_h struct raid5_percpu *percpu; unsigned long cpu; - cpu = get_cpu(); + cpu = get_cpu_light(); percpu = per_cpu_ptr(conf->percpu, cpu); + spin_lock(&percpu->lock); if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { ops_run_biofill(sh); overlap_clear++; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2133 @ static void raid_run_ops(struct stripe_h if (test_and_clear_bit(R5_Overlap, &dev->flags)) wake_up(&sh->raid_conf->wait_for_overlap); } - put_cpu(); + spin_unlock(&percpu->lock); + put_cpu_light(); } static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6828 @ static int raid456_cpu_up_prepare(unsign __func__, cpu); return -ENOMEM; } + spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock); return 0; } Index: linux-5.0.19-rt11/drivers/md/raid5.h =================================================================== --- linux-5.0.19-rt11.orig/drivers/md/raid5.h +++ linux-5.0.19-rt11/drivers/md/raid5.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:640 @ struct r5conf { int recovery_disabled; /* per cpu variables */ struct raid5_percpu { + spinlock_t lock; /* Protection for -RT */ struct page *spare_page; /* Used when checking P/Q in raid6 */ struct flex_array *scribble; /* space for constructing buffer * lists and performing address Index: linux-5.0.19-rt11/drivers/misc/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/drivers/misc/Kconfig +++ linux-5.0.19-rt11/drivers/misc/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:62 @ config ATMEL_TCLIB blocks found on many Atmel processors. This facilitates using these blocks by different drivers despite processor differences. -config ATMEL_TCB_CLKSRC - bool "TC Block Clocksource" - depends on ATMEL_TCLIB - default y - help - Select this to get a high precision clocksource based on a - TC block with a 5+ MHz base clock rate. Two timer channels - are combined to make a single 32-bit timer. - - When GENERIC_CLOCKEVENTS is defined, the third timer channel - may be used as a clock event device supporting oneshot mode - (delays of up to two seconds) based on the 32 KiHz clock. - -config ATMEL_TCB_CLKSRC_BLOCK - int - depends on ATMEL_TCB_CLKSRC - default 0 - range 0 1 - help - Some chips provide more than one TC block, so you have the - choice of which one to use for the clock framework. The other - TC can be used for other purposes, such as PWM generation and - interval timing. - config DUMMY_IRQ tristate "Dummy IRQ handler" default n Index: linux-5.0.19-rt11/drivers/misc/atmel_tclib.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/misc/atmel_tclib.c +++ linux-5.0.19-rt11/drivers/misc/atmel_tclib.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1 @ -#include <linux/atmel_tc.h> #include <linux/clk.h> #include <linux/err.h> #include <linux/init.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:12 @ #include <linux/slab.h> #include <linux/export.h> #include <linux/of.h> +#include <soc/at91/atmel_tcb.h> /* * This is a thin library to solve the problem of how to portably allocate @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:114 @ static int __init tc_probe(struct platfo struct resource *r; unsigned int i; + if (of_get_child_count(pdev->dev.of_node)) + return -EBUSY; + irq = platform_get_irq(pdev, 0); if (irq < 0) return -EINVAL; Index: linux-5.0.19-rt11/drivers/net/wireless/intersil/orinoco/orinoco_usb.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/net/wireless/intersil/orinoco/orinoco_usb.c +++ linux-5.0.19-rt11/drivers/net/wireless/intersil/orinoco/orinoco_usb.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:696 @ static void ezusb_req_ctx_wait(struct ez while (!ctx->done.done && msecs--) udelay(1000); } else { - wait_event_interruptible(ctx->done.wait, - ctx->done.done); + swait_event_interruptible_exclusive(ctx->done.wait, + ctx->done.done); } break; default: Index: linux-5.0.19-rt11/drivers/of/base.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/of/base.c +++ linux-5.0.19-rt11/drivers/of/base.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:141 @ static u32 phandle_cache_mask; /* * Caller must hold devtree_lock. */ -static void __of_free_phandle_cache(void) +static struct device_node** __of_free_phandle_cache(void) { u32 cache_entries = phandle_cache_mask + 1; u32 k; + struct device_node **shadow; if (!phandle_cache) - return; + return NULL; for (k = 0; k < cache_entries; k++) of_node_put(phandle_cache[k]); - kfree(phandle_cache); + shadow = phandle_cache; phandle_cache = NULL; + return shadow; } int of_free_phandle_cache(void) { unsigned long flags; + struct device_node **shadow; raw_spin_lock_irqsave(&devtree_lock, flags); - __of_free_phandle_cache(); + shadow = __of_free_phandle_cache(); raw_spin_unlock_irqrestore(&devtree_lock, flags); - + kfree(shadow); return 0; } #if !defined(CONFIG_MODULES) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:203 @ void of_populate_phandle_cache(void) u32 cache_entries; struct device_node *np; u32 phandles = 0; + struct device_node **shadow; raw_spin_lock_irqsave(&devtree_lock, flags); - __of_free_phandle_cache(); + shadow = __of_free_phandle_cache(); for_each_of_allnodes(np) if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:215 @ void of_populate_phandle_cache(void) if (!phandles) goto out; + raw_spin_unlock_irqrestore(&devtree_lock, flags); cache_entries = roundup_pow_of_two(phandles); phandle_cache_mask = cache_entries - 1; phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache), GFP_ATOMIC); + raw_spin_lock_irqsave(&devtree_lock, flags); if (!phandle_cache) goto out; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:234 @ void of_populate_phandle_cache(void) out: raw_spin_unlock_irqrestore(&devtree_lock, flags); + kfree(shadow); } void __init of_core_init(void) Index: linux-5.0.19-rt11/drivers/pci/switch/switchtec.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/pci/switch/switchtec.c +++ linux-5.0.19-rt11/drivers/pci/switch/switchtec.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:51 @ struct switchtec_user { enum mrpc_state state; - struct completion comp; + wait_queue_head_t cmd_comp; struct kref kref; struct list_head list; + bool cmd_done; u32 cmd; u32 status; u32 return_code; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:77 @ static struct switchtec_user *stuser_cre stuser->stdev = stdev; kref_init(&stuser->kref); INIT_LIST_HEAD(&stuser->list); - init_completion(&stuser->comp); + init_waitqueue_head(&stuser->cmd_comp); stuser->event_cnt = atomic_read(&stdev->event_cnt); dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:175 @ static int mrpc_queue_cmd(struct switcht kref_get(&stuser->kref); stuser->read_len = sizeof(stuser->data); stuser_set_state(stuser, MRPC_QUEUED); - init_completion(&stuser->comp); + stuser->cmd_done = false; list_add_tail(&stuser->list, &stdev->mrpc_queue); mrpc_cmd_submit(stdev); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:222 @ static void mrpc_complete_cmd(struct swi memcpy_fromio(stuser->data, &stdev->mmio_mrpc->output_data, stuser->read_len); out: - complete_all(&stuser->comp); + stuser->cmd_done = true; + wake_up_interruptible(&stuser->cmd_comp); list_del_init(&stuser->list); stuser_put(stuser); stdev->mrpc_busy = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:395 @ static int switchtec_dev_open(struct ino return PTR_ERR(stuser); filp->private_data = stuser; - nonseekable_open(inode, filp); + stream_open(inode, filp); dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:495 @ static ssize_t switchtec_dev_read(struct mutex_unlock(&stdev->mrpc_mutex); if (filp->f_flags & O_NONBLOCK) { - if (!try_wait_for_completion(&stuser->comp)) + if (!READ_ONCE(stuser->cmd_done)) return -EAGAIN; } else { - rc = wait_for_completion_interruptible(&stuser->comp); + rc = wait_event_interruptible(stuser->cmd_comp, + stuser->cmd_done); if (rc < 0) return rc; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:547 @ static __poll_t switchtec_dev_poll(struc struct switchtec_dev *stdev = stuser->stdev; __poll_t ret = 0; - poll_wait(filp, &stuser->comp.wait, wait); + poll_wait(filp, &stuser->cmd_comp, wait); poll_wait(filp, &stdev->event_wq, wait); if (lock_mutex_and_test_alive(stdev)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:555 @ static __poll_t switchtec_dev_poll(struc mutex_unlock(&stdev->mrpc_mutex); - if (try_wait_for_completion(&stuser->comp)) + if (READ_ONCE(stuser->cmd_done)) ret |= EPOLLIN | EPOLLRDNORM; if (stuser->event_cnt != atomic_read(&stdev->event_cnt)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1093 @ static void stdev_kill(struct switchtec_ /* Wake up and kill any users waiting on an MRPC request */ list_for_each_entry_safe(stuser, tmpuser, &stdev->mrpc_queue, list) { - complete_all(&stuser->comp); + stuser->cmd_done = true; + wake_up_interruptible(&stuser->cmd_comp); list_del_init(&stuser->list); stuser_put(stuser); } Index: linux-5.0.19-rt11/drivers/pwm/pwm-atmel-tcb.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/pwm/pwm-atmel-tcb.c +++ linux-5.0.19-rt11/drivers/pwm/pwm-atmel-tcb.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:20 @ #include <linux/ioport.h> #include <linux/io.h> #include <linux/platform_device.h> -#include <linux/atmel_tc.h> #include <linux/pwm.h> #include <linux/of_device.h> #include <linux/slab.h> +#include <soc/at91/atmel_tcb.h> #define NPWM 6 Index: linux-5.0.19-rt11/drivers/scsi/fcoe/fcoe.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/scsi/fcoe/fcoe.c +++ linux-5.0.19-rt11/drivers/scsi/fcoe/fcoe.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1461 @ err2: static int fcoe_alloc_paged_crc_eof(struct sk_buff *skb, int tlen) { struct fcoe_percpu_s *fps; - int rc; + int rc, cpu = get_cpu_light(); - fps = &get_cpu_var(fcoe_percpu); + fps = &per_cpu(fcoe_percpu, cpu); rc = fcoe_get_paged_crc_eof(skb, tlen, fps); - put_cpu_var(fcoe_percpu); + put_cpu_light(); return rc; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1652 @ static inline int fcoe_filter_frames(str return 0; } - stats = per_cpu_ptr(lport->stats, get_cpu()); + stats = per_cpu_ptr(lport->stats, get_cpu_light()); stats->InvalidCRCCount++; if (stats->InvalidCRCCount < 5) printk(KERN_WARNING "fcoe: dropping frame with CRC error\n"); - put_cpu(); + put_cpu_light(); return -EINVAL; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1697 @ static void fcoe_recv_frame(struct sk_bu */ hp = (struct fcoe_hdr *) skb_network_header(skb); - stats = per_cpu_ptr(lport->stats, get_cpu()); + stats = per_cpu_ptr(lport->stats, get_cpu_light()); if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) { if (stats->ErrorFrames < 5) printk(KERN_WARNING "fcoe: FCoE version " @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1729 @ static void fcoe_recv_frame(struct sk_bu goto drop; if (!fcoe_filter_frames(lport, fp)) { - put_cpu(); + put_cpu_light(); fc_exch_recv(lport, fp); return; } drop: stats->ErrorFrames++; - put_cpu(); + put_cpu_light(); kfree_skb(skb); } Index: linux-5.0.19-rt11/drivers/scsi/fcoe/fcoe_ctlr.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/scsi/fcoe/fcoe_ctlr.c +++ linux-5.0.19-rt11/drivers/scsi/fcoe/fcoe_ctlr.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:841 @ static unsigned long fcoe_ctlr_age_fcfs( INIT_LIST_HEAD(&del_list); - stats = per_cpu_ptr(fip->lp->stats, get_cpu()); + stats = per_cpu_ptr(fip->lp->stats, get_cpu_light()); list_for_each_entry_safe(fcf, next, &fip->fcfs, list) { deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:877 @ static unsigned long fcoe_ctlr_age_fcfs( sel_time = fcf->time; } } - put_cpu(); + put_cpu_light(); list_for_each_entry_safe(fcf, next, &del_list, list) { /* Removes fcf from current list */ Index: linux-5.0.19-rt11/drivers/scsi/libfc/fc_exch.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/scsi/libfc/fc_exch.c +++ linux-5.0.19-rt11/drivers/scsi/libfc/fc_exch.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:836 @ static struct fc_exch *fc_exch_em_alloc( } memset(ep, 0, sizeof(*ep)); - cpu = get_cpu(); + cpu = get_cpu_light(); pool = per_cpu_ptr(mp->pool, cpu); spin_lock_bh(&pool->lock); - put_cpu(); + put_cpu_light(); /* peek cache of free slot */ if (pool->left != FC_XID_UNKNOWN) { Index: linux-5.0.19-rt11/drivers/staging/android/vsoc.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/staging/android/vsoc.c +++ linux-5.0.19-rt11/drivers/staging/android/vsoc.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:440 @ static int handle_vsoc_cond_wait(struct return -EINVAL; wake_time = ktime_set(arg->wake_time_sec, arg->wake_time_nsec); - hrtimer_init_on_stack(&to->timer, CLOCK_MONOTONIC, - HRTIMER_MODE_ABS); + hrtimer_init_sleeper_on_stack(to, CLOCK_MONOTONIC, + HRTIMER_MODE_ABS, current); hrtimer_set_expires_range_ns(&to->timer, wake_time, current->timer_slack_ns); - - hrtimer_init_sleeper(to, current); } while (1) { Index: linux-5.0.19-rt11/drivers/tty/serial/8250/8250.h =================================================================== --- linux-5.0.19-rt11.orig/drivers/tty/serial/8250/8250.h +++ linux-5.0.19-rt11/drivers/tty/serial/8250/8250.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:258 @ static inline int serial_index(struct ua { return port->minor - 64; } + +void set_ier(struct uart_8250_port *up, unsigned char ier); +void clear_ier(struct uart_8250_port *up); +void restore_ier(struct uart_8250_port *up); Index: linux-5.0.19-rt11/drivers/tty/serial/8250/8250_core.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/tty/serial/8250/8250_core.c +++ linux-5.0.19-rt11/drivers/tty/serial/8250/8250_core.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:57 @ static struct uart_driver serial8250_reg static unsigned int skip_txen_test; /* force skip of txen test at init time */ -#define PASS_LIMIT 512 +/* + * On -rt we can have a more delays, and legitimately + * so - so don't drop work spuriously and spam the + * syslog: + */ +#ifdef CONFIG_PREEMPT_RT_FULL +# define PASS_LIMIT 1000000 +#else +# define PASS_LIMIT 512 +#endif #include <asm/serial.h> /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:277 @ static void serial8250_timeout(struct ti static void serial8250_backup_timeout(struct timer_list *t) { struct uart_8250_port *up = from_timer(up, t, timer); - unsigned int iir, ier = 0, lsr; + unsigned int iir, lsr; unsigned long flags; spin_lock_irqsave(&up->port.lock, flags); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:286 @ static void serial8250_backup_timeout(st * Must disable interrupts or else we risk racing with the interrupt * based handler. */ - if (up->port.irq) { - ier = serial_in(up, UART_IER); - serial_out(up, UART_IER, 0); - } + if (up->port.irq) + clear_ier(up); iir = serial_in(up, UART_IIR); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:310 @ static void serial8250_backup_timeout(st serial8250_tx_chars(up); if (up->port.irq) - serial_out(up, UART_IER, ier); + restore_ier(up); spin_unlock_irqrestore(&up->port.lock, flags); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:588 @ serial8250_register_ports(struct uart_dr #ifdef CONFIG_SERIAL_8250_CONSOLE +static void univ8250_console_write_atomic(struct console *co, const char *s, + unsigned int count) +{ + struct uart_8250_port *up = &serial8250_ports[co->index]; + + serial8250_console_write_atomic(up, s, count); +} + static void univ8250_console_write(struct console *co, const char *s, unsigned int count) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:681 @ static int univ8250_console_match(struct static struct console univ8250_console = { .name = "ttyS", + .write_atomic = univ8250_console_write_atomic, .write = univ8250_console_write, .device = uart_console_device, .setup = univ8250_console_setup, Index: linux-5.0.19-rt11/drivers/tty/serial/8250/8250_dma.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/tty/serial/8250/8250_dma.c +++ linux-5.0.19-rt11/drivers/tty/serial/8250/8250_dma.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:39 @ static void __dma_tx_complete(void *para ret = serial8250_tx_dma(p); if (ret) { p->ier |= UART_IER_THRI; - serial_port_out(&p->port, UART_IER, p->ier); + set_ier(p, p->ier); } spin_unlock_irqrestore(&p->port.lock, flags); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:104 @ int serial8250_tx_dma(struct uart_8250_p if (dma->tx_err) { dma->tx_err = 0; if (p->ier & UART_IER_THRI) { - p->ier &= ~UART_IER_THRI; - serial_out(p, UART_IER, p->ier); + set_ier(p, p->ier); } } return 0; Index: linux-5.0.19-rt11/drivers/tty/serial/8250/8250_port.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/tty/serial/8250/8250_port.c +++ linux-5.0.19-rt11/drivers/tty/serial/8250/8250_port.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:734 @ static void serial8250_set_sleep(struct serial_out(p, UART_EFR, UART_EFR_ECB); serial_out(p, UART_LCR, 0); } - serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0); + set_ier(p, sleep ? UART_IERX_SLEEP : 0); if (p->capabilities & UART_CAP_EFR) { serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(p, UART_EFR, efr); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1436 @ static void serial8250_stop_rx(struct ua up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); up->port.read_status_mask &= ~UART_LSR_DR; - serial_port_out(port, UART_IER, up->ier); + set_ier(up, up->ier); serial8250_rpm_put(up); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1454 @ static void __do_stop_tx_rs485(struct ua serial8250_clear_and_reinit_fifos(p); p->ier |= UART_IER_RLSI | UART_IER_RDI; - serial_port_out(&p->port, UART_IER, p->ier); + set_ier(p, p->ier); } } static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1507 @ static inline void __do_stop_tx(struct u { if (p->ier & UART_IER_THRI) { p->ier &= ~UART_IER_THRI; - serial_out(p, UART_IER, p->ier); + set_ier(p, p->ier); serial8250_rpm_put_tx(p); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1560 @ static inline void __start_tx(struct uar if (!(up->ier & UART_IER_THRI)) { up->ier |= UART_IER_THRI; - serial_port_out(port, UART_IER, up->ier); + set_ier(up, up->ier); if (up->bugs & UART_BUG_TXEN) { unsigned char lsr; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1666 @ static void serial8250_disable_ms(struct return; up->ier &= ~UART_IER_MSI; - serial_port_out(port, UART_IER, up->ier); + set_ier(up, up->ier); } static void serial8250_enable_ms(struct uart_port *port) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1680 @ static void serial8250_enable_ms(struct up->ier |= UART_IER_MSI; serial8250_rpm_get(up); - serial_port_out(port, UART_IER, up->ier); + set_ier(up, up->ier); serial8250_rpm_put(up); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2053 @ static void wait_for_xmitr(struct uart_8 } } +static atomic_t ier_counter = ATOMIC_INIT(0); +static atomic_t ier_value = ATOMIC_INIT(0); + +void set_ier(struct uart_8250_port *up, unsigned char ier) +{ + struct uart_port *port = &up->port; + unsigned int flags; + + console_atomic_lock(&flags); + if (atomic_read(&ier_counter) > 0) + atomic_set(&ier_value, ier); + else + serial_port_out(port, UART_IER, ier); + console_atomic_unlock(flags); +} + +void clear_ier(struct uart_8250_port *up) +{ + struct uart_port *port = &up->port; + unsigned int ier_cleared = 0; + unsigned int flags; + unsigned int ier; + + console_atomic_lock(&flags); + atomic_inc(&ier_counter); + ier = serial_port_in(port, UART_IER); + if (up->capabilities & UART_CAP_UUE) + ier_cleared = UART_IER_UUE; + if (ier != ier_cleared) { + serial_port_out(port, UART_IER, ier_cleared); + atomic_set(&ier_value, ier); + } + console_atomic_unlock(flags); +} +EXPORT_SYMBOL_GPL(clear_ier); + +void restore_ier(struct uart_8250_port *up) +{ + struct uart_port *port = &up->port; + unsigned int flags; + + console_atomic_lock(&flags); + if (atomic_fetch_dec(&ier_counter) == 1) + serial_port_out(port, UART_IER, atomic_read(&ier_value)); + console_atomic_unlock(flags); +} +EXPORT_SYMBOL_GPL(restore_ier); + #ifdef CONFIG_CONSOLE_POLL /* * Console polling routines for writing and reading from the uart while @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2132 @ out: static void serial8250_put_poll_char(struct uart_port *port, unsigned char c) { - unsigned int ier; struct uart_8250_port *up = up_to_u8250p(port); serial8250_rpm_get(up); - /* - * First save the IER then disable the interrupts - */ - ier = serial_port_in(port, UART_IER); - if (up->capabilities & UART_CAP_UUE) - serial_port_out(port, UART_IER, UART_IER_UUE); - else - serial_port_out(port, UART_IER, 0); + clear_ier(up); wait_for_xmitr(up, BOTH_EMPTY); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2148 @ static void serial8250_put_poll_char(str * and restore the IER */ wait_for_xmitr(up, BOTH_EMPTY); - serial_port_out(port, UART_IER, ier); + restore_ier(up); serial8250_rpm_put(up); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2460 @ void serial8250_do_shutdown(struct uart_ */ spin_lock_irqsave(&port->lock, flags); up->ier = 0; - serial_port_out(port, UART_IER, 0); + set_ier(up, 0); spin_unlock_irqrestore(&port->lock, flags); synchronize_irq(port->irq); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2771 @ serial8250_do_set_termios(struct uart_po if (up->capabilities & UART_CAP_RTOIE) up->ier |= UART_IER_RTOIE; - serial_port_out(port, UART_IER, up->ier); + set_ier(up, up->ier); if (up->capabilities & UART_CAP_EFR) { unsigned char efr = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3235 @ EXPORT_SYMBOL_GPL(serial8250_set_default #ifdef CONFIG_SERIAL_8250_CONSOLE -static void serial8250_console_putchar(struct uart_port *port, int ch) +static void serial8250_console_putchar_locked(struct uart_port *port, int ch) { struct uart_8250_port *up = up_to_u8250p(port); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3243 @ static void serial8250_console_putchar(s serial_port_out(port, UART_TX, ch); } +static void serial8250_console_putchar(struct uart_port *port, int ch) +{ + struct uart_8250_port *up = up_to_u8250p(port); + unsigned int flags; + + wait_for_xmitr(up, UART_LSR_THRE); + + console_atomic_lock(&flags); + serial8250_console_putchar_locked(port, ch); + console_atomic_unlock(flags); +} + /* * Restore serial console when h/w power-off detected */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3276 @ static void serial8250_console_restore(s serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); } +void serial8250_console_write_atomic(struct uart_8250_port *up, + const char *s, unsigned int count) +{ + struct uart_port *port = &up->port; + unsigned int flags; + + console_atomic_lock(&flags); + + touch_nmi_watchdog(); + + clear_ier(up); + + if (atomic_fetch_inc(&up->console_printing)) { + uart_console_write(port, "\n", 1, + serial8250_console_putchar_locked); + } + uart_console_write(port, s, count, serial8250_console_putchar_locked); + atomic_dec(&up->console_printing); + + wait_for_xmitr(up, BOTH_EMPTY); + restore_ier(up); + + console_atomic_unlock(flags); +} + /* * Print a string to the serial port trying not to disturb * any possible real use of the port... @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3312 @ void serial8250_console_write(struct uar { struct uart_port *port = &up->port; unsigned long flags; - unsigned int ier; - int locked = 1; touch_nmi_watchdog(); serial8250_rpm_get(up); + spin_lock_irqsave(&port->lock, flags); - if (oops_in_progress) - locked = spin_trylock_irqsave(&port->lock, flags); - else - spin_lock_irqsave(&port->lock, flags); - - /* - * First save the IER then disable the interrupts - */ - ier = serial_port_in(port, UART_IER); - - if (up->capabilities & UART_CAP_UUE) - serial_port_out(port, UART_IER, UART_IER_UUE); - else - serial_port_out(port, UART_IER, 0); + clear_ier(up); /* check scratch reg to see if port powered off during system sleep */ if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3326 @ void serial8250_console_write(struct uar up->canary = 0; } + atomic_inc(&up->console_printing); uart_console_write(port, s, count, serial8250_console_putchar); + atomic_dec(&up->console_printing); /* * Finally, wait for transmitter to become empty * and restore the IER */ wait_for_xmitr(up, BOTH_EMPTY); - serial_port_out(port, UART_IER, ier); + restore_ier(up); /* * The receive handling will happen properly because the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3347 @ void serial8250_console_write(struct uar if (up->msr_saved_flags) serial8250_modem_status(up); - if (locked) - spin_unlock_irqrestore(&port->lock, flags); + spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3368 @ static unsigned int probe_baud(struct ua int serial8250_console_setup(struct uart_port *port, char *options, bool probe) { + struct uart_8250_port *up = up_to_u8250p(port); int baud = 9600; int bits = 8; int parity = 'n'; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3377 @ int serial8250_console_setup(struct uart if (!port->iobase && !port->membase) return -ENODEV; + atomic_set(&up->console_printing, 0); + if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else if (probe) Index: linux-5.0.19-rt11/drivers/tty/serial/amba-pl011.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/tty/serial/amba-pl011.c +++ linux-5.0.19-rt11/drivers/tty/serial/amba-pl011.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2214 @ pl011_console_write(struct console *co, { struct uart_amba_port *uap = amba_ports[co->index]; unsigned int old_cr = 0, new_cr; - unsigned long flags; + unsigned long flags = 0; int locked = 1; clk_enable(uap->clk); - local_irq_save(flags); + /* + * local_irq_save(flags); + * + * This local_irq_save() is nonsense. If we come in via sysrq + * handling then interrupts are already disabled. Aside of + * that the port.sysrq check is racy on SMP regardless. + */ if (uap->port.sysrq) locked = 0; else if (oops_in_progress) - locked = spin_trylock(&uap->port.lock); + locked = spin_trylock_irqsave(&uap->port.lock, flags); else - spin_lock(&uap->port.lock); + spin_lock_irqsave(&uap->port.lock, flags); /* * First save the CR then disable the interrupts @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2257 @ pl011_console_write(struct console *co, pl011_write(old_cr, uap, REG_CR); if (locked) - spin_unlock(&uap->port.lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&uap->port.lock, flags); clk_disable(uap->clk); } Index: linux-5.0.19-rt11/drivers/tty/serial/omap-serial.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/tty/serial/omap-serial.c +++ linux-5.0.19-rt11/drivers/tty/serial/omap-serial.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1310 @ serial_omap_console_write(struct console pm_runtime_get_sync(up->dev); - local_irq_save(flags); - if (up->port.sysrq) - locked = 0; - else if (oops_in_progress) - locked = spin_trylock(&up->port.lock); + if (up->port.sysrq || oops_in_progress) + locked = spin_trylock_irqsave(&up->port.lock, flags); else - spin_lock(&up->port.lock); + spin_lock_irqsave(&up->port.lock, flags); /* * First save the IER then disable the interrupts @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1342 @ serial_omap_console_write(struct console pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); if (locked) - spin_unlock(&up->port.lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&up->port.lock, flags); } static int __init Index: linux-5.0.19-rt11/drivers/tty/sysrq.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/tty/sysrq.c +++ linux-5.0.19-rt11/drivers/tty/sysrq.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:211 @ static struct sysrq_key_op sysrq_showloc #endif #ifdef CONFIG_SMP -static DEFINE_SPINLOCK(show_lock); +static DEFINE_RAW_SPINLOCK(show_lock); static void showacpu(void *dummy) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:221 @ static void showacpu(void *dummy) if (idle_cpu(smp_processor_id())) return; - spin_lock_irqsave(&show_lock, flags); + raw_spin_lock_irqsave(&show_lock, flags); pr_info("CPU%d:\n", smp_processor_id()); show_stack(NULL, NULL); - spin_unlock_irqrestore(&show_lock, flags); + raw_spin_unlock_irqrestore(&show_lock, flags); } static void sysrq_showregs_othercpus(struct work_struct *dummy) Index: linux-5.0.19-rt11/drivers/usb/gadget/function/f_fs.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/usb/gadget/function/f_fs.c +++ linux-5.0.19-rt11/drivers/usb/gadget/function/f_fs.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1708 @ static void ffs_data_put(struct ffs_data pr_info("%s(): freeing\n", __func__); ffs_data_clear(ffs); BUG_ON(waitqueue_active(&ffs->ev.waitq) || - waitqueue_active(&ffs->ep0req_completion.wait) || + swait_active(&ffs->ep0req_completion.wait) || waitqueue_active(&ffs->wait)); destroy_workqueue(ffs->io_completion_wq); kfree(ffs->dev_name); Index: linux-5.0.19-rt11/drivers/usb/gadget/legacy/inode.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/usb/gadget/legacy/inode.c +++ linux-5.0.19-rt11/drivers/usb/gadget/legacy/inode.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:346 @ ep_io (struct ep_data *epdata, void *buf spin_unlock_irq (&epdata->dev->lock); if (likely (value == 0)) { - value = wait_event_interruptible (done.wait, done.done); + value = swait_event_interruptible_exclusive(done.wait, done.done); if (value != 0) { spin_lock_irq (&epdata->dev->lock); if (likely (epdata->ep != NULL)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:355 @ ep_io (struct ep_data *epdata, void *buf usb_ep_dequeue (epdata->ep, epdata->req); spin_unlock_irq (&epdata->dev->lock); - wait_event (done.wait, done.done); + swait_event_exclusive(done.wait, done.done); if (epdata->status == -ECONNRESET) epdata->status = -EINTR; } else { Index: linux-5.0.19-rt11/drivers/watchdog/watchdog_dev.c =================================================================== --- linux-5.0.19-rt11.orig/drivers/watchdog/watchdog_dev.c +++ linux-5.0.19-rt11/drivers/watchdog/watchdog_dev.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:150 @ static inline void watchdog_update_worke ktime_t t = watchdog_next_keepalive(wdd); if (t > 0) - hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL); + hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL_HARD); } else { hrtimer_cancel(&wd_data->timer); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:169 @ static int __watchdog_ping(struct watchd if (ktime_after(earliest_keepalive, now)) { hrtimer_start(&wd_data->timer, ktime_sub(earliest_keepalive, now), - HRTIMER_MODE_REL); + HRTIMER_MODE_REL_HARD); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:948 @ static int watchdog_cdev_register(struct return -ENODEV; kthread_init_work(&wd_data->work, watchdog_ping_work); - hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); wd_data->timer.function = watchdog_timer_expired; if (wdd->id == 0) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:995 @ static int watchdog_cdev_register(struct __module_get(wdd->ops->owner); kref_get(&wd_data->kref); if (handle_boot_enabled) - hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL); + hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL_HARD); else pr_info("watchdog%d running and kernel based pre-userspace handler disabled\n", wdd->id); Index: linux-5.0.19-rt11/fs/aio.c =================================================================== --- linux-5.0.19-rt11.orig/fs/aio.c +++ linux-5.0.19-rt11/fs/aio.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:130 @ struct kioctx { long nr_pages; struct rcu_work free_rwork; /* see free_ioctx() */ + struct work_struct free_work; /* see free_ioctx() */ /* * signals when all in-flight requests are done @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:616 @ static void free_ioctx_reqs(struct percp * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted - * now it's safe to cancel any that need to be. */ -static void free_ioctx_users(struct percpu_ref *ref) +static void free_ioctx_users_work(struct work_struct *work) { - struct kioctx *ctx = container_of(ref, struct kioctx, users); + struct kioctx *ctx = container_of(work, struct kioctx, free_work); struct aio_kiocb *req; spin_lock_irq(&ctx->ctx_lock); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:636 @ static void free_ioctx_users(struct perc percpu_ref_put(&ctx->reqs); } +static void free_ioctx_users(struct percpu_ref *ref) +{ + struct kioctx *ctx = container_of(ref, struct kioctx, users); + + INIT_WORK(&ctx->free_work, free_ioctx_users_work); + schedule_work(&ctx->free_work); +} + static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm) { unsigned i, new_nr; Index: linux-5.0.19-rt11/fs/autofs/expire.c =================================================================== --- linux-5.0.19-rt11.orig/fs/autofs/expire.c +++ linux-5.0.19-rt11/fs/autofs/expire.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:11 @ * option, any later version, incorporated herein by reference. */ +#include <linux/delay.h> #include "autofs_i.h" /* Check if a dentry can be expired */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:157 @ again: parent = p->d_parent; if (!spin_trylock(&parent->d_lock)) { spin_unlock(&p->d_lock); - cpu_relax(); + cpu_chill(); goto relock; } spin_unlock(&p->d_lock); Index: linux-5.0.19-rt11/fs/buffer.c =================================================================== --- linux-5.0.19-rt11.orig/fs/buffer.c +++ linux-5.0.19-rt11/fs/buffer.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:277 @ static void end_buffer_async_read(struct * decide that the page is now completely done. */ first = page_buffers(page); - local_irq_save(flags); - bit_spin_lock(BH_Uptodate_Lock, &first->b_state); + flags = bh_uptodate_lock_irqsave(first); clear_buffer_async_read(bh); unlock_buffer(bh); tmp = bh; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:290 @ static void end_buffer_async_read(struct } tmp = tmp->b_this_page; } while (tmp != bh); - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + bh_uptodate_unlock_irqrestore(first, flags); /* * If none of the buffers had errors and they are all @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:302 @ static void end_buffer_async_read(struct return; still_busy: - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); - return; + bh_uptodate_unlock_irqrestore(first, flags); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:329 @ void end_buffer_async_write(struct buffe } first = page_buffers(page); - local_irq_save(flags); - bit_spin_lock(BH_Uptodate_Lock, &first->b_state); + flags = bh_uptodate_lock_irqsave(first); clear_buffer_async_write(bh); unlock_buffer(bh); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:341 @ void end_buffer_async_write(struct buffe } tmp = tmp->b_this_page; } - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + bh_uptodate_unlock_irqrestore(first, flags); end_page_writeback(page); return; still_busy: - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); - return; + bh_uptodate_unlock_irqrestore(first, flags); } EXPORT_SYMBOL(end_buffer_async_write); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3363 @ struct buffer_head *alloc_buffer_head(gf struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags); if (ret) { INIT_LIST_HEAD(&ret->b_assoc_buffers); + buffer_head_init_locks(ret); preempt_disable(); __this_cpu_inc(bh_accounting.nr); recalc_bh_state(); Index: linux-5.0.19-rt11/fs/cifs/readdir.c =================================================================== --- linux-5.0.19-rt11.orig/fs/cifs/readdir.c +++ linux-5.0.19-rt11/fs/cifs/readdir.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:83 @ cifs_prime_dcache(struct dentry *parent, struct inode *inode; struct super_block *sb = parent->d_sb; struct cifs_sb_info *cifs_sb = CIFS_SB(sb); - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); cifs_dbg(FYI, "%s: for %s\n", __func__, name->name); Index: linux-5.0.19-rt11/fs/dcache.c =================================================================== --- linux-5.0.19-rt11.orig/fs/dcache.c +++ linux-5.0.19-rt11/fs/dcache.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2419 @ EXPORT_SYMBOL(d_rehash); static inline unsigned start_dir_add(struct inode *dir) { + preempt_disable_rt(); for (;;) { - unsigned n = dir->i_dir_seq; - if (!(n & 1) && cmpxchg(&dir->i_dir_seq, n, n + 1) == n) + unsigned n = dir->__i_dir_seq; + if (!(n & 1) && cmpxchg(&dir->__i_dir_seq, n, n + 1) == n) return n; cpu_relax(); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2430 @ static inline unsigned start_dir_add(str static inline void end_dir_add(struct inode *dir, unsigned n) { - smp_store_release(&dir->i_dir_seq, n + 2); + smp_store_release(&dir->__i_dir_seq, n + 2); + preempt_enable_rt(); } static void d_wait_lookup(struct dentry *dentry) { - if (d_in_lookup(dentry)) { - DECLARE_WAITQUEUE(wait, current); - add_wait_queue(dentry->d_wait, &wait); - do { - set_current_state(TASK_UNINTERRUPTIBLE); - spin_unlock(&dentry->d_lock); - schedule(); - spin_lock(&dentry->d_lock); - } while (d_in_lookup(dentry)); - } + struct swait_queue __wait; + + if (!d_in_lookup(dentry)) + return; + + INIT_LIST_HEAD(&__wait.task_list); + do { + prepare_to_swait_exclusive(dentry->d_wait, &__wait, TASK_UNINTERRUPTIBLE); + spin_unlock(&dentry->d_lock); + schedule(); + spin_lock(&dentry->d_lock); + } while (d_in_lookup(dentry)); + finish_swait(dentry->d_wait, &__wait); } struct dentry *d_alloc_parallel(struct dentry *parent, const struct qstr *name, - wait_queue_head_t *wq) + struct swait_queue_head *wq) { unsigned int hash = name->hash; struct hlist_bl_head *b = in_lookup_hash(parent, hash); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2467 @ struct dentry *d_alloc_parallel(struct d retry: rcu_read_lock(); - seq = smp_load_acquire(&parent->d_inode->i_dir_seq); + seq = smp_load_acquire(&parent->d_inode->__i_dir_seq); r_seq = read_seqbegin(&rename_lock); dentry = __d_lookup_rcu(parent, name, &d_seq); if (unlikely(dentry)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2495 @ retry: } hlist_bl_lock(b); - if (unlikely(READ_ONCE(parent->d_inode->i_dir_seq) != seq)) { + if (unlikely(READ_ONCE(parent->d_inode->__i_dir_seq) != seq)) { hlist_bl_unlock(b); rcu_read_unlock(); goto retry; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2568 @ void __d_lookup_done(struct dentry *dent hlist_bl_lock(b); dentry->d_flags &= ~DCACHE_PAR_LOOKUP; __hlist_bl_del(&dentry->d_u.d_in_lookup_hash); - wake_up_all(dentry->d_wait); + swake_up_all(dentry->d_wait); dentry->d_wait = NULL; hlist_bl_unlock(b); INIT_HLIST_NODE(&dentry->d_u.d_alias); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3080 @ __setup("dhash_entries=", set_dhash_entr static void __init dcache_init_early(void) { + unsigned int loop; + /* If hashes are distributed across NUMA nodes, defer * hash allocation until vmalloc space is available. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3098 @ static void __init dcache_init_early(voi NULL, 0, 0); + + for (loop = 0; loop < (1U << d_hash_shift); loop++) + INIT_HLIST_BL_HEAD(dentry_hashtable + loop); + d_hash_shift = 32 - d_hash_shift; } static void __init dcache_init(void) { + unsigned int loop; /* * A constructor could be added for stable state like the lists, * but it is probably not worth it because of the cache nature @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3131 @ static void __init dcache_init(void) NULL, 0, 0); + + for (loop = 0; loop < (1U << d_hash_shift); loop++) + INIT_HLIST_BL_HEAD(dentry_hashtable + loop); + d_hash_shift = 32 - d_hash_shift; } Index: linux-5.0.19-rt11/fs/eventpoll.c =================================================================== --- linux-5.0.19-rt11.orig/fs/eventpoll.c +++ linux-5.0.19-rt11/fs/eventpoll.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:574 @ static int ep_poll_wakeup_proc(void *pri static void ep_poll_safewake(wait_queue_head_t *wq) { - int this_cpu = get_cpu(); + int this_cpu = get_cpu_light(); ep_call_nested(&poll_safewake_ncalls, ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu); - put_cpu(); + put_cpu_light(); } #else Index: linux-5.0.19-rt11/fs/exec.c =================================================================== --- linux-5.0.19-rt11.orig/fs/exec.c +++ linux-5.0.19-rt11/fs/exec.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1034 @ static int exec_mmap(struct mm_struct *m } } task_lock(tsk); + preempt_disable_rt(); active_mm = tsk->active_mm; tsk->mm = mm; tsk->active_mm = mm; activate_mm(active_mm, mm); tsk->mm->vmacache_seqnum = 0; vmacache_flush(tsk); + preempt_enable_rt(); task_unlock(tsk); if (old_mm) { up_read(&old_mm->mmap_sem); Index: linux-5.0.19-rt11/fs/ext4/page-io.c =================================================================== --- linux-5.0.19-rt11.orig/fs/ext4/page-io.c +++ linux-5.0.19-rt11/fs/ext4/page-io.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:98 @ static void ext4_finish_bio(struct bio * * We check all buffers in the page under BH_Uptodate_Lock * to avoid races with other end io clearing async_write flags */ - local_irq_save(flags); - bit_spin_lock(BH_Uptodate_Lock, &head->b_state); + flags = bh_uptodate_lock_irqsave(head); do { if (bh_offset(bh) < bio_start || bh_offset(bh) + bh->b_size > bio_end) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:110 @ static void ext4_finish_bio(struct bio * if (bio->bi_status) buffer_io_error(bh); } while ((bh = bh->b_this_page) != head); - bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); - local_irq_restore(flags); + bh_uptodate_unlock_irqrestore(head, flags); if (!under_io) { #ifdef CONFIG_EXT4_FS_ENCRYPTION if (data_page) Index: linux-5.0.19-rt11/fs/fscache/cookie.c =================================================================== --- linux-5.0.19-rt11.orig/fs/fscache/cookie.c +++ linux-5.0.19-rt11/fs/fscache/cookie.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:965 @ inconsistent: return -ESTALE; } EXPORT_SYMBOL(__fscache_check_consistency); + +void __init fscache_cookie_init(void) +{ + int i; + + for (i = 0; i < (1 << fscache_cookie_hash_shift) - 1; i++) + INIT_HLIST_BL_HEAD(&fscache_cookie_hash[i]); +} Index: linux-5.0.19-rt11/fs/fscache/main.c =================================================================== --- linux-5.0.19-rt11.orig/fs/fscache/main.c +++ linux-5.0.19-rt11/fs/fscache/main.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:152 @ static int __init fscache_init(void) ret = -ENOMEM; goto error_cookie_jar; } + fscache_cookie_init(); fscache_root = kobject_create_and_add("fscache", kernel_kobj); if (!fscache_root) Index: linux-5.0.19-rt11/fs/fuse/readdir.c =================================================================== --- linux-5.0.19-rt11.orig/fs/fuse/readdir.c +++ linux-5.0.19-rt11/fs/fuse/readdir.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:161 @ static int fuse_direntplus_link(struct f struct inode *dir = d_inode(parent); struct fuse_conn *fc; struct inode *inode; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); if (!o->nodeid) { /* Index: linux-5.0.19-rt11/fs/inode.c =================================================================== --- linux-5.0.19-rt11.orig/fs/inode.c +++ linux-5.0.19-rt11/fs/inode.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:158 @ int inode_init_always(struct super_block inode->i_bdev = NULL; inode->i_cdev = NULL; inode->i_link = NULL; - inode->i_dir_seq = 0; + inode->__i_dir_seq = 0; inode->i_rdev = 0; inode->dirtied_when = 0; Index: linux-5.0.19-rt11/fs/libfs.c =================================================================== --- linux-5.0.19-rt11.orig/fs/libfs.c +++ linux-5.0.19-rt11/fs/libfs.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:93 @ static struct dentry *next_positive(stru struct list_head *from, int count) { - unsigned *seq = &parent->d_inode->i_dir_seq, n; + unsigned *seq = &parent->d_inode->__i_dir_seq, n; struct dentry *res; struct list_head *p; bool skipped; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:126 @ retry: static void move_cursor(struct dentry *cursor, struct list_head *after) { struct dentry *parent = cursor->d_parent; - unsigned n, *seq = &parent->d_inode->i_dir_seq; + unsigned n, *seq = &parent->d_inode->__i_dir_seq; spin_lock(&parent->d_lock); + preempt_disable_rt(); for (;;) { n = *seq; if (!(n & 1) && cmpxchg(seq, n, n + 1) == n) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:141 @ static void move_cursor(struct dentry *c else list_add_tail(&cursor->d_child, &parent->d_subdirs); smp_store_release(seq, n + 2); + preempt_enable_rt(); spin_unlock(&parent->d_lock); } Index: linux-5.0.19-rt11/fs/locks.c =================================================================== --- linux-5.0.19-rt11.orig/fs/locks.c +++ linux-5.0.19-rt11/fs/locks.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1061 @ static int flock_lock_inode(struct inode return -ENOMEM; } - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); if (request->fl_flags & FL_ACCESS) goto find_conflict; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1103 @ find_conflict: out: spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); if (new_fl) locks_free_lock(new_fl); locks_dispose_list(&dispose); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1141 @ static int posix_lock_inode(struct inode new_fl2 = locks_alloc_lock(); } - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); /* * New lock request. Walk all POSIX locks and look for conflicts. If @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1320 @ static int posix_lock_inode(struct inode } out: spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); /* * Free any unused locks. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1592 @ int __break_lease(struct inode *inode, u return error; } - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); time_out_leases(inode, &dispose); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1644 @ restart: locks_insert_block(fl, new_fl, leases_conflict); trace_break_lease_block(inode, new_fl); spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); locks_dispose_list(&dispose); error = wait_event_interruptible_timeout(new_fl->fl_wait, !new_fl->fl_blocker, break_time); - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); trace_break_lease_unblock(inode, new_fl); locks_delete_block(new_fl); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1667 @ restart: } out: spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); locks_dispose_list(&dispose); locks_free_lock(new_fl); return error; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1737 @ int fcntl_getlease(struct file *filp) ctx = smp_load_acquire(&inode->i_flctx); if (ctx && !list_empty_careful(&ctx->flc_lease)) { - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); time_out_leases(inode, &dispose); list_for_each_entry(fl, &ctx->flc_lease, fl_list) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1747 @ int fcntl_getlease(struct file *filp) break; } spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); locks_dispose_list(&dispose); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1821 @ generic_add_lease(struct file *filp, lon return -EINVAL; } - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); time_out_leases(inode, &dispose); error = check_conflicting_open(dentry, arg, lease->fl_flags); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1892 @ out_setup: lease->fl_lmops->lm_setup(lease, priv); out: spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); locks_dispose_list(&dispose); if (is_deleg) inode_unlock(inode); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1915 @ static int generic_delete_lease(struct f return error; } - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); list_for_each_entry(fl, &ctx->flc_lease, fl_list) { if (fl->fl_file == filp && @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1928 @ static int generic_delete_lease(struct f if (victim) error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose); spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); locks_dispose_list(&dispose); return error; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2651 @ locks_remove_lease(struct file *filp, st if (list_empty(&ctx->flc_lease)) return; - percpu_down_read_preempt_disable(&file_rwsem); + percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) if (filp == fl->fl_file) lease_modify(fl, F_UNLCK, &dispose); spin_unlock(&ctx->flc_lock); - percpu_up_read_preempt_enable(&file_rwsem); + percpu_up_read(&file_rwsem); locks_dispose_list(&dispose); } Index: linux-5.0.19-rt11/fs/namei.c =================================================================== --- linux-5.0.19-rt11.orig/fs/namei.c +++ linux-5.0.19-rt11/fs/namei.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1648 @ static struct dentry *__lookup_slow(cons { struct dentry *dentry, *old; struct inode *inode = dir->d_inode; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); /* Don't go there if it's already dead */ if (unlikely(IS_DEADDIR(inode))) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3138 @ static int lookup_open(struct nameidata struct dentry *dentry; int error, create_error = 0; umode_t mode = op->mode; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); if (unlikely(IS_DEADDIR(dir_inode))) return -ENOENT; Index: linux-5.0.19-rt11/fs/namespace.c =================================================================== --- linux-5.0.19-rt11.orig/fs/namespace.c +++ linux-5.0.19-rt11/fs/namespace.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:17 @ #include <linux/mnt_namespace.h> #include <linux/user_namespace.h> #include <linux/namei.h> +#include <linux/delay.h> #include <linux/security.h> #include <linux/cred.h> #include <linux/idr.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:328 @ int __mnt_want_write(struct vfsmount *m) * incremented count after it has set MNT_WRITE_HOLD. */ smp_mb(); - while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) - cpu_relax(); + while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) { + preempt_enable(); + cpu_chill(); + preempt_disable(); + } /* * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will * be set to match its requirements. So we must not load that until Index: linux-5.0.19-rt11/fs/nfs/delegation.c =================================================================== --- linux-5.0.19-rt11.orig/fs/nfs/delegation.c +++ linux-5.0.19-rt11/fs/nfs/delegation.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:154 @ again: sp = state->owner; /* Block nfs4_proc_unlck */ mutex_lock(&sp->so_delegreturn_mutex); - seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); + seq = read_seqbegin(&sp->so_reclaim_seqlock); err = nfs4_open_delegation_recall(ctx, state, stateid, type); if (!err) err = nfs_delegation_claim_locks(state, stateid); - if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) + if (!err && read_seqretry(&sp->so_reclaim_seqlock, seq)) err = -EAGAIN; mutex_unlock(&sp->so_delegreturn_mutex); put_nfs_open_context(ctx); Index: linux-5.0.19-rt11/fs/nfs/dir.c =================================================================== --- linux-5.0.19-rt11.orig/fs/nfs/dir.c +++ linux-5.0.19-rt11/fs/nfs/dir.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:443 @ static void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) { struct qstr filename = QSTR_INIT(entry->name, entry->len); - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); struct dentry *dentry; struct dentry *alias; struct inode *dir = d_inode(parent); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1493 @ int nfs_atomic_open(struct inode *dir, s struct file *file, unsigned open_flags, umode_t mode) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); struct nfs_open_context *ctx; struct dentry *res; struct iattr attr = { .ia_valid = ATTR_OPEN }; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1813 @ int nfs_rmdir(struct inode *dir, struct trace_nfs_rmdir_enter(dir, dentry); if (d_really_is_positive(dentry)) { +#ifdef CONFIG_PREEMPT_RT_BASE + down(&NFS_I(d_inode(dentry))->rmdir_sem); +#else down_write(&NFS_I(d_inode(dentry))->rmdir_sem); +#endif error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); /* Ensure the VFS deletes this inode */ switch (error) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1827 @ int nfs_rmdir(struct inode *dir, struct case -ENOENT: nfs_dentry_handle_enoent(dentry); } +#ifdef CONFIG_PREEMPT_RT_BASE + up(&NFS_I(d_inode(dentry))->rmdir_sem); +#else up_write(&NFS_I(d_inode(dentry))->rmdir_sem); +#endif } else error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); trace_nfs_rmdir_exit(dir, dentry, error); Index: linux-5.0.19-rt11/fs/nfs/inode.c =================================================================== --- linux-5.0.19-rt11.orig/fs/nfs/inode.c +++ linux-5.0.19-rt11/fs/nfs/inode.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2091 @ static void init_once(void *foo) atomic_long_set(&nfsi->nrequests, 0); atomic_long_set(&nfsi->commit_info.ncommit, 0); atomic_set(&nfsi->commit_info.rpcs_out, 0); +#ifdef CONFIG_PREEMPT_RT_BASE + sema_init(&nfsi->rmdir_sem, 1); +#else init_rwsem(&nfsi->rmdir_sem); +#endif mutex_init(&nfsi->commit_mutex); nfs4_init_once(nfsi); } Index: linux-5.0.19-rt11/fs/nfs/nfs4_fs.h =================================================================== --- linux-5.0.19-rt11.orig/fs/nfs/nfs4_fs.h +++ linux-5.0.19-rt11/fs/nfs/nfs4_fs.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:118 @ struct nfs4_state_owner { unsigned long so_flags; struct list_head so_states; struct nfs_seqid_counter so_seqid; - seqcount_t so_reclaim_seqcount; + seqlock_t so_reclaim_seqlock; struct mutex so_delegreturn_mutex; }; Index: linux-5.0.19-rt11/fs/nfs/nfs4proc.c =================================================================== --- linux-5.0.19-rt11.orig/fs/nfs/nfs4proc.c +++ linux-5.0.19-rt11/fs/nfs/nfs4proc.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2895 @ static int _nfs4_open_and_get_state(stru unsigned int seq; int ret; - seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); + seq = raw_seqcount_begin(&sp->so_reclaim_seqlock.seqcount); ret = _nfs4_proc_open(opendata, ctx); if (ret != 0) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2936 @ static int _nfs4_open_and_get_state(stru if (d_inode(dentry) == state->inode) { nfs_inode_attach_open_context(ctx); - if (read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) + if (read_seqretry(&sp->so_reclaim_seqlock, seq)) nfs4_schedule_stateid_recovery(server, state); } Index: linux-5.0.19-rt11/fs/nfs/nfs4state.c =================================================================== --- linux-5.0.19-rt11.orig/fs/nfs/nfs4state.c +++ linux-5.0.19-rt11/fs/nfs/nfs4state.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:513 @ nfs4_alloc_state_owner(struct nfs_server nfs4_init_seqid_counter(&sp->so_seqid); atomic_set(&sp->so_count, 1); INIT_LIST_HEAD(&sp->so_lru); - seqcount_init(&sp->so_reclaim_seqcount); + seqlock_init(&sp->so_reclaim_seqlock); mutex_init(&sp->so_delegreturn_mutex); return sp; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1618 @ static int nfs4_reclaim_open_state(struc * recovering after a network partition or a reboot from a * server that doesn't support a grace period. */ +#ifdef CONFIG_PREEMPT_RT_FULL + write_seqlock(&sp->so_reclaim_seqlock); +#else + write_seqcount_begin(&sp->so_reclaim_seqlock.seqcount); +#endif spin_lock(&sp->so_lock); - raw_write_seqcount_begin(&sp->so_reclaim_seqcount); restart: list_for_each_entry(state, &sp->so_states, open_states) { if (!test_and_clear_bit(ops->state_flag_bit, &state->flags)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1676 @ restart: spin_lock(&sp->so_lock); goto restart; } - raw_write_seqcount_end(&sp->so_reclaim_seqcount); spin_unlock(&sp->so_lock); +#ifdef CONFIG_PREEMPT_RT_FULL + write_sequnlock(&sp->so_reclaim_seqlock); +#else + write_seqcount_end(&sp->so_reclaim_seqlock.seqcount); +#endif return 0; out_err: nfs4_put_open_state(state); - spin_lock(&sp->so_lock); - raw_write_seqcount_end(&sp->so_reclaim_seqcount); - spin_unlock(&sp->so_lock); +#ifdef CONFIG_PREEMPT_RT_FULL + write_sequnlock(&sp->so_reclaim_seqlock); +#else + write_seqcount_end(&sp->so_reclaim_seqlock.seqcount); +#endif return status; } Index: linux-5.0.19-rt11/fs/nfs/unlink.c =================================================================== --- linux-5.0.19-rt11.orig/fs/nfs/unlink.c +++ linux-5.0.19-rt11/fs/nfs/unlink.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:16 @ #include <linux/sunrpc/clnt.h> #include <linux/nfs_fs.h> #include <linux/sched.h> -#include <linux/wait.h> +#include <linux/swait.h> #include <linux/namei.h> #include <linux/fsnotify.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:55 @ static void nfs_async_unlink_done(struct rpc_restart_call_prepare(task); } +#ifdef CONFIG_PREEMPT_RT_BASE +static void nfs_down_anon(struct semaphore *sema) +{ + down(sema); +} + +static void nfs_up_anon(struct semaphore *sema) +{ + up(sema); +} + +#else +static void nfs_down_anon(struct rw_semaphore *rwsem) +{ + down_read_non_owner(rwsem); +} + +static void nfs_up_anon(struct rw_semaphore *rwsem) +{ + up_read_non_owner(rwsem); +} +#endif + /** * nfs_async_unlink_release - Release the sillydelete data. * @task: rpc_task of the sillydelete @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:91 @ static void nfs_async_unlink_release(voi struct dentry *dentry = data->dentry; struct super_block *sb = dentry->d_sb; - up_read_non_owner(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem); + nfs_up_anon(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem); d_lookup_done(dentry); nfs_free_unlinkdata(data); dput(dentry); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:144 @ static int nfs_call_unlink(struct dentry struct inode *dir = d_inode(dentry->d_parent); struct dentry *alias; - down_read_non_owner(&NFS_I(dir)->rmdir_sem); + nfs_down_anon(&NFS_I(dir)->rmdir_sem); alias = d_alloc_parallel(dentry->d_parent, &data->args.name, &data->wq); if (IS_ERR(alias)) { - up_read_non_owner(&NFS_I(dir)->rmdir_sem); + nfs_up_anon(&NFS_I(dir)->rmdir_sem); return 0; } if (!d_in_lookup(alias)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:169 @ static int nfs_call_unlink(struct dentry ret = 0; spin_unlock(&alias->d_lock); dput(alias); - up_read_non_owner(&NFS_I(dir)->rmdir_sem); + nfs_up_anon(&NFS_I(dir)->rmdir_sem); /* * If we'd displaced old cached devname, free it. At that * point dentry is definitely not a root, so we won't need @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:205 @ nfs_async_unlink(struct dentry *dentry, data->cred = get_current_cred(); data->res.dir_attr = &data->dir_attr; - init_waitqueue_head(&data->wq); + init_swait_queue_head(&data->wq); status = -EBUSY; spin_lock(&dentry->d_lock); Index: linux-5.0.19-rt11/fs/ntfs/aops.c =================================================================== --- linux-5.0.19-rt11.orig/fs/ntfs/aops.c +++ linux-5.0.19-rt11/fs/ntfs/aops.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:109 @ static void ntfs_end_buffer_async_read(s "0x%llx.", (unsigned long long)bh->b_blocknr); } first = page_buffers(page); - local_irq_save(flags); - bit_spin_lock(BH_Uptodate_Lock, &first->b_state); + flags = bh_uptodate_lock_irqsave(first); clear_buffer_async_read(bh); unlock_buffer(bh); tmp = bh; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:124 @ static void ntfs_end_buffer_async_read(s } tmp = tmp->b_this_page; } while (tmp != bh); - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + bh_uptodate_unlock_irqrestore(first, flags); /* * If none of the buffers had errors then we can set the page uptodate, * but we first have to perform the post read mst fixups, if the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:157 @ static void ntfs_end_buffer_async_read(s unlock_page(page); return; still_busy: - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); - return; + bh_uptodate_unlock_irqrestore(first, flags); } /** Index: linux-5.0.19-rt11/fs/proc/array.c =================================================================== --- linux-5.0.19-rt11.orig/fs/proc/array.c +++ linux-5.0.19-rt11/fs/proc/array.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:384 @ static inline void task_context_switch_c static void task_cpus_allowed(struct seq_file *m, struct task_struct *task) { seq_printf(m, "Cpus_allowed:\t%*pb\n", - cpumask_pr_args(&task->cpus_allowed)); + cpumask_pr_args(task->cpus_ptr)); seq_printf(m, "Cpus_allowed_list:\t%*pbl\n", - cpumask_pr_args(&task->cpus_allowed)); + cpumask_pr_args(task->cpus_ptr)); } static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm) Index: linux-5.0.19-rt11/fs/proc/base.c =================================================================== --- linux-5.0.19-rt11.orig/fs/proc/base.c +++ linux-5.0.19-rt11/fs/proc/base.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1877 @ bool proc_fill_cache(struct file *file, child = d_hash_and_lookup(dir, &qname); if (!child) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); child = d_alloc_parallel(dir, &qname, &wq); if (IS_ERR(child)) goto end_instantiate; Index: linux-5.0.19-rt11/fs/proc/kmsg.c =================================================================== --- linux-5.0.19-rt11.orig/fs/proc/kmsg.c +++ linux-5.0.19-rt11/fs/proc/kmsg.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:21 @ #include <linux/uaccess.h> #include <asm/io.h> -extern wait_queue_head_t log_wait; - static int kmsg_open(struct inode * inode, struct file * file) { return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:43 @ static ssize_t kmsg_read(struct file *fi static __poll_t kmsg_poll(struct file *file, poll_table *wait) { - poll_wait(file, &log_wait, wait); + poll_wait(file, printk_wait_queue(), wait); if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC)) return EPOLLIN | EPOLLRDNORM; return 0; Index: linux-5.0.19-rt11/fs/proc/proc_sysctl.c =================================================================== --- linux-5.0.19-rt11.orig/fs/proc/proc_sysctl.c +++ linux-5.0.19-rt11/fs/proc/proc_sysctl.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:680 @ static bool proc_sys_fill_cache(struct f child = d_lookup(dir, &qname); if (!child) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); child = d_alloc_parallel(dir, &qname, &wq); if (IS_ERR(child)) return false; Index: linux-5.0.19-rt11/fs/squashfs/decompressor_multi_percpu.c =================================================================== --- linux-5.0.19-rt11.orig/fs/squashfs/decompressor_multi_percpu.c +++ linux-5.0.19-rt11/fs/squashfs/decompressor_multi_percpu.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:13 @ #include <linux/slab.h> #include <linux/percpu.h> #include <linux/buffer_head.h> +#include <linux/locallock.h> #include "squashfs_fs.h" #include "squashfs_fs_sb.h" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:29 @ struct squashfs_stream { void *stream; }; +static DEFINE_LOCAL_IRQ_LOCK(stream_lock); + void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, void *comp_opts) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:85 @ int squashfs_decompress(struct squashfs_ { struct squashfs_stream __percpu *percpu = (struct squashfs_stream __percpu *) msblk->stream; - struct squashfs_stream *stream = get_cpu_ptr(percpu); - int res = msblk->decompressor->decompress(msblk, stream->stream, bh, b, - offset, length, output); - put_cpu_ptr(stream); + struct squashfs_stream *stream; + int res; + + stream = get_locked_ptr(stream_lock, percpu); + + res = msblk->decompressor->decompress(msblk, stream->stream, bh, b, + offset, length, output); + + put_locked_ptr(stream_lock, stream); if (res < 0) ERROR("%s decompression failed, data probably corrupt\n", Index: linux-5.0.19-rt11/fs/timerfd.c =================================================================== --- linux-5.0.19-rt11.orig/fs/timerfd.c +++ linux-5.0.19-rt11/fs/timerfd.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:474 @ static int do_timerfd_settime(int ufd, i break; } spin_unlock_irq(&ctx->wqh.lock); - cpu_relax(); + + if (isalarm(ctx)) + hrtimer_grab_expiry_lock(&ctx->t.alarm.timer); + else + hrtimer_grab_expiry_lock(&ctx->t.tmr); } /* Index: linux-5.0.19-rt11/include/asm-generic/percpu.h =================================================================== --- linux-5.0.19-rt11.orig/include/asm-generic/percpu.h +++ linux-5.0.19-rt11/include/asm-generic/percpu.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8 @ #include <linux/compiler.h> #include <linux/threads.h> #include <linux/percpu-defs.h> +#include <linux/irqflags.h> #ifdef CONFIG_SMP Index: linux-5.0.19-rt11/include/linux/blkdev.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/blkdev.h +++ linux-5.0.19-rt11/include/linux/blkdev.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:16 @ #include <linux/llist.h> #include <linux/timer.h> #include <linux/workqueue.h> +#include <linux/kthread.h> #include <linux/pagemap.h> #include <linux/backing-dev-defs.h> #include <linux/wait.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:553 @ struct request_queue { #endif struct rcu_head rcu_head; wait_queue_head_t mq_freeze_wq; + struct work_struct mq_pcpu_wake; struct percpu_ref q_usage_counter; struct list_head all_q_node; Index: linux-5.0.19-rt11/include/linux/bottom_half.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/bottom_half.h +++ linux-5.0.19-rt11/include/linux/bottom_half.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:7 @ #include <linux/preempt.h> +#ifdef CONFIG_PREEMPT_RT_FULL +extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt); +#else + #ifdef CONFIG_TRACE_IRQFLAGS extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt); #else @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:20 @ static __always_inline void __local_bh_d barrier(); } #endif +#endif static inline void local_bh_disable(void) { Index: linux-5.0.19-rt11/include/linux/buffer_head.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/buffer_head.h +++ linux-5.0.19-rt11/include/linux/buffer_head.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:79 @ struct buffer_head { struct address_space *b_assoc_map; /* mapping this buffer is associated with */ atomic_t b_count; /* users using this buffer_head */ +#ifdef CONFIG_PREEMPT_RT_BASE + spinlock_t b_uptodate_lock; +#if IS_ENABLED(CONFIG_JBD2) + spinlock_t b_state_lock; + spinlock_t b_journal_head_lock; +#endif +#endif }; +static inline unsigned long bh_uptodate_lock_irqsave(struct buffer_head *bh) +{ + unsigned long flags; + +#ifndef CONFIG_PREEMPT_RT_BASE + local_irq_save(flags); + bit_spin_lock(BH_Uptodate_Lock, &bh->b_state); +#else + spin_lock_irqsave(&bh->b_uptodate_lock, flags); +#endif + return flags; +} + +static inline void +bh_uptodate_unlock_irqrestore(struct buffer_head *bh, unsigned long flags) +{ +#ifndef CONFIG_PREEMPT_RT_BASE + bit_spin_unlock(BH_Uptodate_Lock, &bh->b_state); + local_irq_restore(flags); +#else + spin_unlock_irqrestore(&bh->b_uptodate_lock, flags); +#endif +} + +static inline void buffer_head_init_locks(struct buffer_head *bh) +{ +#ifdef CONFIG_PREEMPT_RT_BASE + spin_lock_init(&bh->b_uptodate_lock); +#if IS_ENABLED(CONFIG_JBD2) + spin_lock_init(&bh->b_state_lock); + spin_lock_init(&bh->b_journal_head_lock); +#endif +#endif +} + /* * macro tricks to expand the set_buffer_foo(), clear_buffer_foo() * and buffer_foo() functions. Index: linux-5.0.19-rt11/include/linux/completion.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/completion.h +++ linux-5.0.19-rt11/include/linux/completion.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:12 @ * See kernel/sched/completion.c for details. */ -#include <linux/wait.h> +#include <linux/swait.h> /* * struct completion - structure used to maintain state for a "completion" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:28 @ */ struct completion { unsigned int done; - wait_queue_head_t wait; + struct swait_queue_head wait; }; #define init_completion_map(x, m) __init_completion(x) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:37 @ static inline void complete_acquire(stru static inline void complete_release(struct completion *x) {} #define COMPLETION_INITIALIZER(work) \ - { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) } + { 0, __SWAIT_QUEUE_HEAD_INITIALIZER((work).wait) } #define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \ (*({ init_completion_map(&(work), &(map)); &(work); })) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:88 @ static inline void complete_release(stru static inline void __init_completion(struct completion *x) { x->done = 0; - init_waitqueue_head(&x->wait); + init_swait_queue_head(&x->wait); } /** Index: linux-5.0.19-rt11/include/linux/console.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/console.h +++ linux-5.0.19-rt11/include/linux/console.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:148 @ static inline int con_debug_leave(void) struct console { char name[16]; void (*write)(struct console *, const char *, unsigned); + void (*write_atomic)(struct console *, const char *, unsigned); int (*read)(struct console *, char *, unsigned); struct tty_driver *(*device)(struct console *, int *); void (*unblank)(void); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:157 @ struct console { short flags; short index; int cflag; + unsigned long printk_seq; + int wrote_history; void *data; struct console *next; }; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:235 @ extern void console_init(void); void dummycon_register_output_notifier(struct notifier_block *nb); void dummycon_unregister_output_notifier(struct notifier_block *nb); +extern void console_atomic_lock(unsigned int *flags); +extern void console_atomic_unlock(unsigned int flags); + #endif /* _LINUX_CONSOLE_H */ Index: linux-5.0.19-rt11/include/linux/cpu.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/cpu.h +++ linux-5.0.19-rt11/include/linux/cpu.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:116 @ extern void cpu_hotplug_disable(void); extern void cpu_hotplug_enable(void); void clear_tasks_mm_cpumask(int cpu); int cpu_down(unsigned int cpu); +extern void pin_current_cpu(void); +extern void unpin_current_cpu(void); #else /* CONFIG_HOTPLUG_CPU */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:129 @ static inline int cpus_read_trylock(voi static inline void lockdep_assert_cpus_held(void) { } static inline void cpu_hotplug_disable(void) { } static inline void cpu_hotplug_enable(void) { } +static inline void pin_current_cpu(void) { } +static inline void unpin_current_cpu(void) { } + #endif /* !CONFIG_HOTPLUG_CPU */ /* Wrappers which go away once all code is converted */ Index: linux-5.0.19-rt11/include/linux/dcache.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/dcache.h +++ linux-5.0.19-rt11/include/linux/dcache.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:109 @ struct dentry { union { struct list_head d_lru; /* LRU list */ - wait_queue_head_t *d_wait; /* in-lookup ones only */ + struct swait_queue_head *d_wait; /* in-lookup ones only */ }; struct list_head d_child; /* child of parent list */ struct list_head d_subdirs; /* our children */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:240 @ extern struct dentry * d_alloc(struct de extern struct dentry * d_alloc_anon(struct super_block *); extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *, - wait_queue_head_t *); + struct swait_queue_head *); extern struct dentry * d_splice_alias(struct inode *, struct dentry *); extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *); extern struct dentry * d_exact_alias(struct dentry *, struct inode *); Index: linux-5.0.19-rt11/include/linux/delay.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/delay.h +++ linux-5.0.19-rt11/include/linux/delay.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:67 @ static inline void ssleep(unsigned int s msleep(seconds * 1000); } +#ifdef CONFIG_PREEMPT_RT_FULL +extern void cpu_chill(void); +#else +# define cpu_chill() cpu_relax() +#endif + #endif /* defined(_LINUX_DELAY_H) */ Index: linux-5.0.19-rt11/include/linux/dma-iommu.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/dma-iommu.h +++ linux-5.0.19-rt11/include/linux/dma-iommu.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:74 @ void iommu_dma_unmap_resource(struct dev size_t size, enum dma_data_direction dir, unsigned long attrs); /* The DMA API isn't _quite_ the whole story, though... */ -void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg); +/* + * iommu_dma_prepare_msi() - Map the MSI page in the IOMMU device + * + * The MSI page will be stored in @desc. + * + * Return: 0 on success otherwise an error describing the failure. + */ +int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr); + +/* Update the MSI message if required. */ +void iommu_dma_compose_msi_msg(struct msi_desc *desc, + struct msi_msg *msg); + void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list); #else struct iommu_domain; +struct msi_desc; struct msi_msg; struct device; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:115 @ static inline void iommu_put_dma_cookie( { } -static inline void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) +static inline int iommu_dma_prepare_msi(struct msi_desc *desc, + phys_addr_t msi_addr) +{ + return 0; +} + +static inline void iommu_dma_compose_msi_msg(struct msi_desc *desc, + struct msi_msg *msg) { } Index: linux-5.0.19-rt11/include/linux/fs.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/fs.h +++ linux-5.0.19-rt11/include/linux/fs.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:700 @ struct inode { struct block_device *i_bdev; struct cdev *i_cdev; char *i_link; - unsigned i_dir_seq; + unsigned __i_dir_seq; }; __u32 i_generation; Index: linux-5.0.19-rt11/include/linux/fscache.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/fscache.h +++ linux-5.0.19-rt11/include/linux/fscache.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:233 @ extern void __fscache_readpages_cancel(s extern void __fscache_disable_cookie(struct fscache_cookie *, const void *, bool); extern void __fscache_enable_cookie(struct fscache_cookie *, const void *, loff_t, bool (*)(void *), void *); +extern void fscache_cookie_init(void); /** * fscache_register_netfs - Register a filesystem as desiring caching services Index: linux-5.0.19-rt11/include/linux/hardirq.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/hardirq.h +++ linux-5.0.19-rt11/include/linux/hardirq.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:71 @ extern void irq_exit(void); #define nmi_enter() \ do { \ arch_nmi_enter(); \ - printk_nmi_enter(); \ lockdep_off(); \ ftrace_nmi_enter(); \ BUG_ON(in_nmi()); \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:87 @ extern void irq_exit(void); preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ ftrace_nmi_exit(); \ lockdep_on(); \ - printk_nmi_exit(); \ arch_nmi_exit(); \ } while (0) Index: linux-5.0.19-rt11/include/linux/highmem.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/highmem.h +++ linux-5.0.19-rt11/include/linux/highmem.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:11 @ #include <linux/mm.h> #include <linux/uaccess.h> #include <linux/hardirq.h> +#include <linux/sched.h> #include <asm/cacheflush.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:94 @ static inline void kunmap(struct page *p static inline void *kmap_atomic(struct page *page) { - preempt_disable(); + preempt_disable_nort(); pagefault_disable(); return page_address(page); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:103 @ static inline void *kmap_atomic(struct p static inline void __kunmap_atomic(void *addr) { pagefault_enable(); - preempt_enable(); + preempt_enable_nort(); } #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:115 @ static inline void __kunmap_atomic(void #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) +#ifndef CONFIG_PREEMPT_RT_FULL DECLARE_PER_CPU(int, __kmap_atomic_idx); +#endif static inline int kmap_atomic_idx_push(void) { +#ifndef CONFIG_PREEMPT_RT_FULL int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1; -#ifdef CONFIG_DEBUG_HIGHMEM +# ifdef CONFIG_DEBUG_HIGHMEM WARN_ON_ONCE(in_irq() && !irqs_disabled()); BUG_ON(idx >= KM_TYPE_NR); -#endif +# endif return idx; +#else + current->kmap_idx++; + BUG_ON(current->kmap_idx > KM_TYPE_NR); + return current->kmap_idx - 1; +#endif } static inline int kmap_atomic_idx(void) { +#ifndef CONFIG_PREEMPT_RT_FULL return __this_cpu_read(__kmap_atomic_idx) - 1; +#else + return current->kmap_idx - 1; +#endif } static inline void kmap_atomic_idx_pop(void) { -#ifdef CONFIG_DEBUG_HIGHMEM +#ifndef CONFIG_PREEMPT_RT_FULL +# ifdef CONFIG_DEBUG_HIGHMEM int idx = __this_cpu_dec_return(__kmap_atomic_idx); BUG_ON(idx < 0); -#else +# else __this_cpu_dec(__kmap_atomic_idx); +# endif +#else + current->kmap_idx--; +# ifdef CONFIG_DEBUG_HIGHMEM + BUG_ON(current->kmap_idx < 0); +# endif #endif } Index: linux-5.0.19-rt11/include/linux/hrtimer.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/hrtimer.h +++ linux-5.0.19-rt11/include/linux/hrtimer.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:41 @ enum hrtimer_mode { HRTIMER_MODE_REL = 0x01, HRTIMER_MODE_PINNED = 0x02, HRTIMER_MODE_SOFT = 0x04, + HRTIMER_MODE_HARD = 0x08, HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED, HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:52 @ enum hrtimer_mode { HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT, HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT, + HRTIMER_MODE_ABS_HARD = HRTIMER_MODE_ABS | HRTIMER_MODE_HARD, + HRTIMER_MODE_REL_HARD = HRTIMER_MODE_REL | HRTIMER_MODE_HARD, + + HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD, + HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD, }; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:192 @ enum hrtimer_base_type { * @nr_retries: Total number of hrtimer interrupt retries * @nr_hangs: Total number of hrtimer interrupt hangs * @max_hang_time: Maximum time spent in hrtimer_interrupt + * @softirq_expiry_lock: Lock which is taken while softirq based hrtimer are + * expired * @expires_next: absolute time of the next event, is required for remote * hrtimer enqueue; it is the total first expiry time (hard * and soft hrtimer are taken into account) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:221 @ struct hrtimer_cpu_base { unsigned short nr_hangs; unsigned int max_hang_time; #endif + spinlock_t softirq_expiry_lock; ktime_t expires_next; struct hrtimer *next_timer; ktime_t softirq_expires_next; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:373 @ DECLARE_PER_CPU(struct tick_device, tick /* Initialize timers: */ extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); +extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id, + enum hrtimer_mode mode, + struct task_struct *task); #ifdef CONFIG_DEBUG_OBJECTS_TIMERS extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); +extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, + clockid_t clock_id, + enum hrtimer_mode mode, + struct task_struct *task); extern void destroy_hrtimer_on_stack(struct hrtimer *timer); #else @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:393 @ static inline void hrtimer_init_on_stack { hrtimer_init(timer, which_clock, mode); } + +static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, + clockid_t clock_id, + enum hrtimer_mode mode, + struct task_struct *task) +{ + hrtimer_init_sleeper(sl, clock_id, mode, task); +} + static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:425 @ static inline void hrtimer_start(struct extern int hrtimer_cancel(struct hrtimer *timer); extern int hrtimer_try_to_cancel(struct hrtimer *timer); +extern void hrtimer_grab_expiry_lock(const struct hrtimer *timer); static inline void hrtimer_start_expires(struct hrtimer *timer, enum hrtimer_mode mode) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:506 @ extern long hrtimer_nanosleep(const stru const enum hrtimer_mode mode, const clockid_t clockid); -extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, - struct task_struct *tsk); - extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta, const enum hrtimer_mode mode); extern int schedule_hrtimeout_range_clock(ktime_t *expires, Index: linux-5.0.19-rt11/include/linux/idr.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/idr.h +++ linux-5.0.19-rt11/include/linux/idr.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:172 @ static inline bool idr_is_empty(const st * Each idr_preload() should be matched with an invocation of this * function. See idr_preload() for details. */ -static inline void idr_preload_end(void) -{ - preempt_enable(); -} +void idr_preload_end(void); /** * idr_for_each_entry() - Iterate over an IDR's elements of a given type. Index: linux-5.0.19-rt11/include/linux/interrupt.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/interrupt.h +++ linux-5.0.19-rt11/include/linux/interrupt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:446 @ extern int irq_set_irqchip_state(unsigne bool state); #ifdef CONFIG_IRQ_FORCED_THREADING +# ifdef CONFIG_PREEMPT_RT_BASE +# define force_irqthreads (true) +# else extern bool force_irqthreads; +# endif #else #define force_irqthreads (0) #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:519 @ struct softirq_action asmlinkage void do_softirq(void); asmlinkage void __do_softirq(void); -#ifdef __ARCH_HAS_DO_SOFTIRQ +#if defined(__ARCH_HAS_DO_SOFTIRQ) && !defined(CONFIG_PREEMPT_RT_FULL) void do_softirq_own_stack(void); #else static inline void do_softirq_own_stack(void) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:534 @ extern void __raise_softirq_irqoff(unsig extern void raise_softirq_irqoff(unsigned int nr); extern void raise_softirq(unsigned int nr); +extern void softirq_check_pending_idle(void); DECLARE_PER_CPU(struct task_struct *, ksoftirqd); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:599 @ static inline void tasklet_unlock(struct static inline void tasklet_unlock_wait(struct tasklet_struct *t) { - while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); } + while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { + local_bh_disable(); + local_bh_enable(); + } } #else #define tasklet_trylock(t) 1 Index: linux-5.0.19-rt11/include/linux/irq_work.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/irq_work.h +++ linux-5.0.19-rt11/include/linux/irq_work.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:21 @ /* Doesn't want IPI, wait for tick: */ #define IRQ_WORK_LAZY BIT(2) +/* Run hard IRQ context, even on RT */ +#define IRQ_WORK_HARD_IRQ BIT(3) #define IRQ_WORK_CLAIMED (IRQ_WORK_PENDING | IRQ_WORK_BUSY) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:57 @ static inline bool irq_work_needs_cpu(vo static inline void irq_work_run(void) { } #endif +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) +void irq_work_tick_soft(void); +#else +static inline void irq_work_tick_soft(void) { } +#endif + #endif /* _LINUX_IRQ_WORK_H */ Index: linux-5.0.19-rt11/include/linux/irqdesc.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/irqdesc.h +++ linux-5.0.19-rt11/include/linux/irqdesc.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:74 @ struct irq_desc { unsigned int irqs_unhandled; atomic_t threads_handled; int threads_handled_last; + u64 random_ip; raw_spinlock_t lock; struct cpumask *percpu_enabled; const struct cpumask *percpu_affinity; Index: linux-5.0.19-rt11/include/linux/irqflags.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/irqflags.h +++ linux-5.0.19-rt11/include/linux/irqflags.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:46 @ do { \ do { \ current->hardirq_context--; \ } while (0) -# define lockdep_softirq_enter() \ -do { \ - current->softirq_context++; \ -} while (0) -# define lockdep_softirq_exit() \ -do { \ - current->softirq_context--; \ -} while (0) #else # define trace_hardirqs_on() do { } while (0) # define trace_hardirqs_off() do { } while (0) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:58 @ do { \ # define lockdep_softirq_enter() do { } while (0) # define lockdep_softirq_exit() do { } while (0) #endif + +#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT_FULL) +# define lockdep_softirq_enter() \ +do { \ + current->softirq_context++; \ +} while (0) +# define lockdep_softirq_exit() \ +do { \ + current->softirq_context--; \ +} while (0) + +#else +# define lockdep_softirq_enter() do { } while (0) +# define lockdep_softirq_exit() do { } while (0) +#endif #if defined(CONFIG_IRQSOFF_TRACER) || \ defined(CONFIG_PREEMPT_TRACER) Index: linux-5.0.19-rt11/include/linux/jbd2.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/jbd2.h +++ linux-5.0.19-rt11/include/linux/jbd2.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:350 @ static inline struct journal_head *bh2jh static inline void jbd_lock_bh_state(struct buffer_head *bh) { +#ifndef CONFIG_PREEMPT_RT_BASE bit_spin_lock(BH_State, &bh->b_state); +#else + spin_lock(&bh->b_state_lock); +#endif } static inline int jbd_trylock_bh_state(struct buffer_head *bh) { +#ifndef CONFIG_PREEMPT_RT_BASE return bit_spin_trylock(BH_State, &bh->b_state); +#else + return spin_trylock(&bh->b_state_lock); +#endif } static inline int jbd_is_locked_bh_state(struct buffer_head *bh) { +#ifndef CONFIG_PREEMPT_RT_BASE return bit_spin_is_locked(BH_State, &bh->b_state); +#else + return spin_is_locked(&bh->b_state_lock); +#endif } static inline void jbd_unlock_bh_state(struct buffer_head *bh) { +#ifndef CONFIG_PREEMPT_RT_BASE bit_spin_unlock(BH_State, &bh->b_state); +#else + spin_unlock(&bh->b_state_lock); +#endif } static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) { +#ifndef CONFIG_PREEMPT_RT_BASE bit_spin_lock(BH_JournalHead, &bh->b_state); +#else + spin_lock(&bh->b_journal_head_lock); +#endif } static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) { +#ifndef CONFIG_PREEMPT_RT_BASE bit_spin_unlock(BH_JournalHead, &bh->b_state); +#else + spin_unlock(&bh->b_journal_head_lock); +#endif } #define J_ASSERT(assert) BUG_ON(!(assert)) Index: linux-5.0.19-rt11/include/linux/kernel.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/kernel.h +++ linux-5.0.19-rt11/include/linux/kernel.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:262 @ extern int _cond_resched(void); */ # define might_sleep() \ do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) + +# define might_sleep_no_state_check() \ + do { ___might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) # define sched_annotate_sleep() (current->task_state_change = 0) #else static inline void ___might_sleep(const char *file, int line, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:272 @ extern int _cond_resched(void); static inline void __might_sleep(const char *file, int line, int preempt_offset) { } # define might_sleep() do { might_resched(); } while (0) +# define might_sleep_no_state_check() do { might_resched(); } while (0) # define sched_annotate_sleep() do { } while (0) #endif Index: linux-5.0.19-rt11/include/linux/kmsg_dump.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/kmsg_dump.h +++ linux-5.0.19-rt11/include/linux/kmsg_dump.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:49 @ struct kmsg_dumper { bool registered; /* private state of the kmsg iterator */ - u32 cur_idx; - u32 next_idx; - u64 cur_seq; - u64 next_seq; + u64 line_seq; + u64 buffer_end_seq; }; #ifdef CONFIG_PRINTK Index: linux-5.0.19-rt11/include/linux/kthread.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/kthread.h +++ linux-5.0.19-rt11/include/linux/kthread.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:88 @ enum { struct kthread_worker { unsigned int flags; - spinlock_t lock; + raw_spinlock_t lock; struct list_head work_list; struct list_head delayed_work_list; struct task_struct *task; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:109 @ struct kthread_delayed_work { }; #define KTHREAD_WORKER_INIT(worker) { \ - .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ + .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \ .work_list = LIST_HEAD_INIT((worker).work_list), \ .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:167 @ extern void __kthread_init_worker(struct #define kthread_init_delayed_work(dwork, fn) \ do { \ kthread_init_work(&(dwork)->work, (fn)); \ - __init_timer(&(dwork)->timer, \ - kthread_delayed_work_timer_fn, \ - TIMER_IRQSAFE); \ + timer_setup(&(dwork)->timer, \ + kthread_delayed_work_timer_fn, 0); \ } while (0) int kthread_worker_fn(void *worker_ptr); Index: linux-5.0.19-rt11/include/linux/list_bl.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/list_bl.h +++ linux-5.0.19-rt11/include/linux/list_bl.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6 @ #define _LINUX_LIST_BL_H #include <linux/list.h> +#include <linux/spinlock.h> #include <linux/bit_spinlock.h> /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:37 @ struct hlist_bl_head { struct hlist_bl_node *first; +#ifdef CONFIG_PREEMPT_RT_BASE + raw_spinlock_t lock; +#endif }; struct hlist_bl_node { struct hlist_bl_node *next, **pprev; }; -#define INIT_HLIST_BL_HEAD(ptr) \ - ((ptr)->first = NULL) + +#ifdef CONFIG_PREEMPT_RT_BASE +#define INIT_HLIST_BL_HEAD(h) \ +do { \ + (h)->first = NULL; \ + raw_spin_lock_init(&(h)->lock); \ +} while (0) +#else +#define INIT_HLIST_BL_HEAD(h) (h)->first = NULL +#endif static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:134 @ static inline void hlist_bl_del_init(str static inline void hlist_bl_lock(struct hlist_bl_head *b) { +#ifndef CONFIG_PREEMPT_RT_BASE bit_spin_lock(0, (unsigned long *)b); +#else + raw_spin_lock(&b->lock); +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) + __set_bit(0, (unsigned long *)b); +#endif +#endif } static inline void hlist_bl_unlock(struct hlist_bl_head *b) { +#ifndef CONFIG_PREEMPT_RT_BASE __bit_spin_unlock(0, (unsigned long *)b); +#else +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) + __clear_bit(0, (unsigned long *)b); +#endif + raw_spin_unlock(&b->lock); +#endif } static inline bool hlist_bl_is_locked(struct hlist_bl_head *b) Index: linux-5.0.19-rt11/include/linux/locallock.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/locallock.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef _LINUX_LOCALLOCK_H +#define _LINUX_LOCALLOCK_H + +#include <linux/percpu.h> +#include <linux/spinlock.h> + +#ifdef CONFIG_PREEMPT_RT_BASE + +#ifdef CONFIG_DEBUG_SPINLOCK +# define LL_WARN(cond) WARN_ON(cond) +#else +# define LL_WARN(cond) do { } while (0) +#endif + +/* + * per cpu lock based substitute for local_irq_*() + */ +struct local_irq_lock { + spinlock_t lock; + struct task_struct *owner; + int nestcnt; + unsigned long flags; +}; + +#define DEFINE_LOCAL_IRQ_LOCK(lvar) \ + DEFINE_PER_CPU(struct local_irq_lock, lvar) = { \ + .lock = __SPIN_LOCK_UNLOCKED((lvar).lock) } + +#define DECLARE_LOCAL_IRQ_LOCK(lvar) \ + DECLARE_PER_CPU(struct local_irq_lock, lvar) + +#define local_irq_lock_init(lvar) \ + do { \ + int __cpu; \ + for_each_possible_cpu(__cpu) \ + spin_lock_init(&per_cpu(lvar, __cpu).lock); \ + } while (0) + +static inline void __local_lock(struct local_irq_lock *lv) +{ + if (lv->owner != current) { + spin_lock(&lv->lock); + LL_WARN(lv->owner); + LL_WARN(lv->nestcnt); + lv->owner = current; + } + lv->nestcnt++; +} + +#define local_lock(lvar) \ + do { __local_lock(&get_local_var(lvar)); } while (0) + +#define local_lock_on(lvar, cpu) \ + do { __local_lock(&per_cpu(lvar, cpu)); } while (0) + +static inline int __local_trylock(struct local_irq_lock *lv) +{ + if (lv->owner != current && spin_trylock(&lv->lock)) { + LL_WARN(lv->owner); + LL_WARN(lv->nestcnt); + lv->owner = current; + lv->nestcnt = 1; + return 1; + } else if (lv->owner == current) { + lv->nestcnt++; + return 1; + } + return 0; +} + +#define local_trylock(lvar) \ + ({ \ + int __locked; \ + __locked = __local_trylock(&get_local_var(lvar)); \ + if (!__locked) \ + put_local_var(lvar); \ + __locked; \ + }) + +static inline void __local_unlock(struct local_irq_lock *lv) +{ + LL_WARN(lv->nestcnt == 0); + LL_WARN(lv->owner != current); + if (--lv->nestcnt) + return; + + lv->owner = NULL; + spin_unlock(&lv->lock); +} + +#define local_unlock(lvar) \ + do { \ + __local_unlock(this_cpu_ptr(&lvar)); \ + put_local_var(lvar); \ + } while (0) + +#define local_unlock_on(lvar, cpu) \ + do { __local_unlock(&per_cpu(lvar, cpu)); } while (0) + +static inline void __local_lock_irq(struct local_irq_lock *lv) +{ + spin_lock_irqsave(&lv->lock, lv->flags); + LL_WARN(lv->owner); + LL_WARN(lv->nestcnt); + lv->owner = current; + lv->nestcnt = 1; +} + +#define local_lock_irq(lvar) \ + do { __local_lock_irq(&get_local_var(lvar)); } while (0) + +#define local_lock_irq_on(lvar, cpu) \ + do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0) + +static inline void __local_unlock_irq(struct local_irq_lock *lv) +{ + LL_WARN(!lv->nestcnt); + LL_WARN(lv->owner != current); + lv->owner = NULL; + lv->nestcnt = 0; + spin_unlock_irq(&lv->lock); +} + +#define local_unlock_irq(lvar) \ + do { \ + __local_unlock_irq(this_cpu_ptr(&lvar)); \ + put_local_var(lvar); \ + } while (0) + +#define local_unlock_irq_on(lvar, cpu) \ + do { \ + __local_unlock_irq(&per_cpu(lvar, cpu)); \ + } while (0) + +static inline int __local_lock_irqsave(struct local_irq_lock *lv) +{ + if (lv->owner != current) { + __local_lock_irq(lv); + return 0; + } else { + lv->nestcnt++; + return 1; + } +} + +#define local_lock_irqsave(lvar, _flags) \ + do { \ + if (__local_lock_irqsave(&get_local_var(lvar))) \ + put_local_var(lvar); \ + _flags = __this_cpu_read(lvar.flags); \ + } while (0) + +#define local_lock_irqsave_on(lvar, _flags, cpu) \ + do { \ + __local_lock_irqsave(&per_cpu(lvar, cpu)); \ + _flags = per_cpu(lvar, cpu).flags; \ + } while (0) + +static inline int __local_unlock_irqrestore(struct local_irq_lock *lv, + unsigned long flags) +{ + LL_WARN(!lv->nestcnt); + LL_WARN(lv->owner != current); + if (--lv->nestcnt) + return 0; + + lv->owner = NULL; + spin_unlock_irqrestore(&lv->lock, lv->flags); + return 1; +} + +#define local_unlock_irqrestore(lvar, flags) \ + do { \ + if (__local_unlock_irqrestore(this_cpu_ptr(&lvar), flags)) \ + put_local_var(lvar); \ + } while (0) + +#define local_unlock_irqrestore_on(lvar, flags, cpu) \ + do { \ + __local_unlock_irqrestore(&per_cpu(lvar, cpu), flags); \ + } while (0) + +#define local_spin_trylock_irq(lvar, lock) \ + ({ \ + int __locked; \ + local_lock_irq(lvar); \ + __locked = spin_trylock(lock); \ + if (!__locked) \ + local_unlock_irq(lvar); \ + __locked; \ + }) + +#define local_spin_lock_irq(lvar, lock) \ + do { \ + local_lock_irq(lvar); \ + spin_lock(lock); \ + } while (0) + +#define local_spin_unlock_irq(lvar, lock) \ + do { \ + spin_unlock(lock); \ + local_unlock_irq(lvar); \ + } while (0) + +#define local_spin_lock_irqsave(lvar, lock, flags) \ + do { \ + local_lock_irqsave(lvar, flags); \ + spin_lock(lock); \ + } while (0) + +#define local_spin_unlock_irqrestore(lvar, lock, flags) \ + do { \ + spin_unlock(lock); \ + local_unlock_irqrestore(lvar, flags); \ + } while (0) + +#define get_locked_var(lvar, var) \ + (*({ \ + local_lock(lvar); \ + this_cpu_ptr(&var); \ + })) + +#define put_locked_var(lvar, var) local_unlock(lvar); + +#define get_locked_ptr(lvar, var) \ + ({ \ + local_lock(lvar); \ + this_cpu_ptr(var); \ + }) + +#define put_locked_ptr(lvar, var) local_unlock(lvar); + +#define local_lock_cpu(lvar) \ + ({ \ + local_lock(lvar); \ + smp_processor_id(); \ + }) + +#define local_unlock_cpu(lvar) local_unlock(lvar) + +#else /* PREEMPT_RT_BASE */ + +#define DEFINE_LOCAL_IRQ_LOCK(lvar) __typeof__(const int) lvar +#define DECLARE_LOCAL_IRQ_LOCK(lvar) extern __typeof__(const int) lvar + +static inline void local_irq_lock_init(int lvar) { } + +#define local_trylock(lvar) \ + ({ \ + preempt_disable(); \ + 1; \ + }) + +#define local_lock(lvar) preempt_disable() +#define local_unlock(lvar) preempt_enable() +#define local_lock_irq(lvar) local_irq_disable() +#define local_lock_irq_on(lvar, cpu) local_irq_disable() +#define local_unlock_irq(lvar) local_irq_enable() +#define local_unlock_irq_on(lvar, cpu) local_irq_enable() +#define local_lock_irqsave(lvar, flags) local_irq_save(flags) +#define local_unlock_irqrestore(lvar, flags) local_irq_restore(flags) + +#define local_spin_trylock_irq(lvar, lock) spin_trylock_irq(lock) +#define local_spin_lock_irq(lvar, lock) spin_lock_irq(lock) +#define local_spin_unlock_irq(lvar, lock) spin_unlock_irq(lock) +#define local_spin_lock_irqsave(lvar, lock, flags) \ + spin_lock_irqsave(lock, flags) +#define local_spin_unlock_irqrestore(lvar, lock, flags) \ + spin_unlock_irqrestore(lock, flags) + +#define get_locked_var(lvar, var) get_cpu_var(var) +#define put_locked_var(lvar, var) put_cpu_var(var) +#define get_locked_ptr(lvar, var) get_cpu_ptr(var) +#define put_locked_ptr(lvar, var) put_cpu_ptr(var) + +#define local_lock_cpu(lvar) get_cpu() +#define local_unlock_cpu(lvar) put_cpu() + +#endif + +#endif Index: linux-5.0.19-rt11/include/linux/mm_types.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/mm_types.h +++ linux-5.0.19-rt11/include/linux/mm_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:15 @ #include <linux/completion.h> #include <linux/cpumask.h> #include <linux/uprobes.h> +#include <linux/rcupdate.h> #include <linux/page-flags-layout.h> #include <linux/workqueue.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:491 @ struct mm_struct { bool tlb_flush_batched; #endif struct uprobes_state uprobes_state; +#ifdef CONFIG_PREEMPT_RT_BASE + struct rcu_head delayed_drop; +#endif #ifdef CONFIG_HUGETLB_PAGE atomic_long_t hugetlb_usage; #endif Index: linux-5.0.19-rt11/include/linux/msi.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/msi.h +++ linux-5.0.19-rt11/include/linux/msi.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:80 @ struct msi_desc { struct device *dev; struct msi_msg msg; struct irq_affinity_desc *affinity; +#ifdef CONFIG_IRQ_MSI_IOMMU + const void *iommu_cookie; +#endif union { /* PCI MSI/X specific data */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:125 @ struct msi_desc { #define for_each_msi_entry_safe(desc, tmp, dev) \ list_for_each_entry_safe((desc), (tmp), dev_to_msi_list((dev)), list) +#ifdef CONFIG_IRQ_MSI_IOMMU +static inline const void *msi_desc_get_iommu_cookie(struct msi_desc *desc) +{ + return desc->iommu_cookie; +} + +static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc, + const void *iommu_cookie) +{ + desc->iommu_cookie = iommu_cookie; +} +#else +static inline const void *msi_desc_get_iommu_cookie(struct msi_desc *desc) +{ + return NULL; +} + +static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc, + const void *iommu_cookie) +{ +} +#endif + #ifdef CONFIG_PCI_MSI #define first_pci_msi_entry(pdev) first_msi_entry(&(pdev)->dev) #define for_each_pci_msi_entry(desc, pdev) \ Index: linux-5.0.19-rt11/include/linux/mutex.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/mutex.h +++ linux-5.0.19-rt11/include/linux/mutex.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:25 @ struct ww_acquire_ctx; +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ + , .dep_map = { .name = #lockname } +#else +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) +#endif + +#ifdef CONFIG_PREEMPT_RT_FULL +# include <linux/mutex_rt.h> +#else + /* * Simple, straightforward mutexes with strict semantics: * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:132 @ do { \ __mutex_init((mutex), #mutex, &__key); \ } while (0) -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ - , .dep_map = { .name = #lockname } -#else -# define __DEP_MAP_MUTEX_INITIALIZER(lockname) -#endif - #define __MUTEX_INITIALIZER(lockname) \ { .owner = ATOMIC_LONG_INIT(0) \ , .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:236 @ mutex_trylock_recursive(struct mutex *lo return mutex_trylock(lock); } +#endif /* !PREEMPT_RT_FULL */ + #endif /* __LINUX_MUTEX_H */ Index: linux-5.0.19-rt11/include/linux/mutex_rt.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/mutex_rt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_MUTEX_RT_H +#define __LINUX_MUTEX_RT_H + +#ifndef __LINUX_MUTEX_H +#error "Please include mutex.h" +#endif + +#include <linux/rtmutex.h> + +/* FIXME: Just for __lockfunc */ +#include <linux/spinlock.h> + +struct mutex { + struct rt_mutex lock; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +#define __MUTEX_INITIALIZER(mutexname) \ + { \ + .lock = __RT_MUTEX_INITIALIZER(mutexname.lock) \ + __DEP_MAP_MUTEX_INITIALIZER(mutexname) \ + } + +#define DEFINE_MUTEX(mutexname) \ + struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) + +extern void __mutex_do_init(struct mutex *lock, const char *name, struct lock_class_key *key); +extern void __lockfunc _mutex_lock(struct mutex *lock); +extern void __lockfunc _mutex_lock_io(struct mutex *lock); +extern void __lockfunc _mutex_lock_io_nested(struct mutex *lock, int subclass); +extern int __lockfunc _mutex_lock_interruptible(struct mutex *lock); +extern int __lockfunc _mutex_lock_killable(struct mutex *lock); +extern void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass); +extern void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock); +extern int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass); +extern int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass); +extern int __lockfunc _mutex_trylock(struct mutex *lock); +extern void __lockfunc _mutex_unlock(struct mutex *lock); + +#define mutex_is_locked(l) rt_mutex_is_locked(&(l)->lock) +#define mutex_lock(l) _mutex_lock(l) +#define mutex_lock_interruptible(l) _mutex_lock_interruptible(l) +#define mutex_lock_killable(l) _mutex_lock_killable(l) +#define mutex_trylock(l) _mutex_trylock(l) +#define mutex_unlock(l) _mutex_unlock(l) +#define mutex_lock_io(l) _mutex_lock_io(l); + +#define __mutex_owner(l) ((l)->lock.owner) + +#ifdef CONFIG_DEBUG_MUTEXES +#define mutex_destroy(l) rt_mutex_destroy(&(l)->lock) +#else +static inline void mutex_destroy(struct mutex *lock) {} +#endif + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define mutex_lock_nested(l, s) _mutex_lock_nested(l, s) +# define mutex_lock_interruptible_nested(l, s) \ + _mutex_lock_interruptible_nested(l, s) +# define mutex_lock_killable_nested(l, s) \ + _mutex_lock_killable_nested(l, s) +# define mutex_lock_io_nested(l, s) _mutex_lock_io_nested(l, s) + +# define mutex_lock_nest_lock(lock, nest_lock) \ +do { \ + typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \ + _mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \ +} while (0) + +#else +# define mutex_lock_nested(l, s) _mutex_lock(l) +# define mutex_lock_interruptible_nested(l, s) \ + _mutex_lock_interruptible(l) +# define mutex_lock_killable_nested(l, s) \ + _mutex_lock_killable(l) +# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock) +# define mutex_lock_io_nested(l, s) _mutex_lock_io(l) +#endif + +# define mutex_init(mutex) \ +do { \ + static struct lock_class_key __key; \ + \ + rt_mutex_init(&(mutex)->lock); \ + __mutex_do_init((mutex), #mutex, &__key); \ +} while (0) + +# define __mutex_init(mutex, name, key) \ +do { \ + rt_mutex_init(&(mutex)->lock); \ + __mutex_do_init((mutex), name, key); \ +} while (0) + +/** + * These values are chosen such that FAIL and SUCCESS match the + * values of the regular mutex_trylock(). + */ +enum mutex_trylock_recursive_enum { + MUTEX_TRYLOCK_FAILED = 0, + MUTEX_TRYLOCK_SUCCESS = 1, + MUTEX_TRYLOCK_RECURSIVE, +}; +/** + * mutex_trylock_recursive - trylock variant that allows recursive locking + * @lock: mutex to be locked + * + * This function should not be used, _ever_. It is purely for hysterical GEM + * raisins, and once those are gone this will be removed. + * + * Returns: + * MUTEX_TRYLOCK_FAILED - trylock failed, + * MUTEX_TRYLOCK_SUCCESS - lock acquired, + * MUTEX_TRYLOCK_RECURSIVE - we already owned the lock. + */ +int __rt_mutex_owner_current(struct rt_mutex *lock); + +static inline /* __deprecated */ __must_check enum mutex_trylock_recursive_enum +mutex_trylock_recursive(struct mutex *lock) +{ + if (unlikely(__rt_mutex_owner_current(&lock->lock))) + return MUTEX_TRYLOCK_RECURSIVE; + + return mutex_trylock(lock); +} + +extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); + +#endif Index: linux-5.0.19-rt11/include/linux/netdevice.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/netdevice.h +++ linux-5.0.19-rt11/include/linux/netdevice.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:425 @ typedef enum rx_handler_result rx_handle typedef rx_handler_result_t rx_handler_func_t(struct sk_buff **pskb); void __napi_schedule(struct napi_struct *n); + +/* + * When PREEMPT_RT_FULL is defined, all device interrupt handlers + * run as threads, and they can also be preempted (without PREEMPT_RT + * interrupt threads can not be preempted). Which means that calling + * __napi_schedule_irqoff() from an interrupt handler can be preempted + * and can corrupt the napi->poll_list. + */ +#ifdef CONFIG_PREEMPT_RT_FULL +#define __napi_schedule_irqoff(n) __napi_schedule(n) +#else void __napi_schedule_irqoff(struct napi_struct *n); +#endif static inline bool napi_disable_pending(struct napi_struct *n) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:631 @ struct netdev_queue { * write-mostly part */ spinlock_t _xmit_lock ____cacheline_aligned_in_smp; +#ifdef CONFIG_PREEMPT_RT_FULL + struct task_struct *xmit_lock_owner; +#else int xmit_lock_owner; +#endif /* * Time (in jiffies) of last Tx */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2670 @ void netdev_freemem(struct net_device *d void synchronize_net(void); int init_dummy_netdev(struct net_device *dev); -DECLARE_PER_CPU(int, xmit_recursion); #define XMIT_RECURSION_LIMIT 10 +#ifdef CONFIG_PREEMPT_RT_FULL +static inline int dev_recursion_level(void) +{ + return current->xmit_recursion; +} + +static inline int xmit_rec_read(void) +{ + return current->xmit_recursion; +} + +static inline void xmit_rec_inc(void) +{ + current->xmit_recursion++; +} + +static inline void xmit_rec_dec(void) +{ + current->xmit_recursion--; +} + +#else + +DECLARE_PER_CPU(int, xmit_recursion); static inline int dev_recursion_level(void) { return this_cpu_read(xmit_recursion); } +static inline int xmit_rec_read(void) +{ + return __this_cpu_read(xmit_recursion); +} + +static inline void xmit_rec_inc(void) +{ + __this_cpu_inc(xmit_recursion); +} + +static inline void xmit_rec_dec(void) +{ + __this_cpu_dec(xmit_recursion); +} +#endif + struct net_device *dev_get_by_index(struct net *net, int ifindex); struct net_device *__dev_get_by_index(struct net *net, int ifindex); struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3071 @ struct softnet_data { unsigned int dropped; struct sk_buff_head input_pkt_queue; struct napi_struct backlog; + struct sk_buff_head tofree_queue; }; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3926 @ static inline u32 netif_msg_init(int deb return (1U << debug_value) - 1; } +#ifdef CONFIG_PREEMPT_RT_FULL +static inline void netdev_queue_set_owner(struct netdev_queue *txq, int cpu) +{ + txq->xmit_lock_owner = current; +} + +static inline void netdev_queue_clear_owner(struct netdev_queue *txq) +{ + txq->xmit_lock_owner = NULL; +} + +static inline bool netdev_queue_has_owner(struct netdev_queue *txq) +{ + if (txq->xmit_lock_owner != NULL) + return true; + return false; +} + +#else + +static inline void netdev_queue_set_owner(struct netdev_queue *txq, int cpu) +{ + txq->xmit_lock_owner = cpu; +} + +static inline void netdev_queue_clear_owner(struct netdev_queue *txq) +{ + txq->xmit_lock_owner = -1; +} + +static inline bool netdev_queue_has_owner(struct netdev_queue *txq) +{ + if (txq->xmit_lock_owner != -1) + return true; + return false; +} +#endif + static inline void __netif_tx_lock(struct netdev_queue *txq, int cpu) { spin_lock(&txq->_xmit_lock); - txq->xmit_lock_owner = cpu; + netdev_queue_set_owner(txq, cpu); } static inline bool __netif_tx_acquire(struct netdev_queue *txq) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3984 @ static inline void __netif_tx_release(st static inline void __netif_tx_lock_bh(struct netdev_queue *txq) { spin_lock_bh(&txq->_xmit_lock); - txq->xmit_lock_owner = smp_processor_id(); + netdev_queue_set_owner(txq, smp_processor_id()); } static inline bool __netif_tx_trylock(struct netdev_queue *txq) { bool ok = spin_trylock(&txq->_xmit_lock); if (likely(ok)) - txq->xmit_lock_owner = smp_processor_id(); + netdev_queue_set_owner(txq, smp_processor_id()); return ok; } static inline void __netif_tx_unlock(struct netdev_queue *txq) { - txq->xmit_lock_owner = -1; + netdev_queue_clear_owner(txq); spin_unlock(&txq->_xmit_lock); } static inline void __netif_tx_unlock_bh(struct netdev_queue *txq) { - txq->xmit_lock_owner = -1; + netdev_queue_clear_owner(txq); spin_unlock_bh(&txq->_xmit_lock); } static inline void txq_trans_update(struct netdev_queue *txq) { - if (txq->xmit_lock_owner != -1) + if (netdev_queue_has_owner(txq)) txq->trans_start = jiffies; } Index: linux-5.0.19-rt11/include/linux/netfilter/x_tables.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/netfilter/x_tables.h +++ linux-5.0.19-rt11/include/linux/netfilter/x_tables.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:9 @ #include <linux/netdevice.h> #include <linux/static_key.h> #include <linux/netfilter.h> +#include <linux/locallock.h> #include <uapi/linux/netfilter/x_tables.h> /* Test a struct->invflags and a boolean for inequality */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:349 @ void xt_free_table_info(struct xt_table_ */ DECLARE_PER_CPU(seqcount_t, xt_recseq); +DECLARE_LOCAL_IRQ_LOCK(xt_write_lock); + /* xt_tee_enabled - true if x_tables needs to handle reentrancy * * Enabled if current ip(6)tables ruleset has at least one -j TEE rule. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:371 @ static inline unsigned int xt_write_recs { unsigned int addend; + /* RT protection */ + local_lock(xt_write_lock); + /* * Low order bit of sequence is set if we already * called xt_write_recseq_begin(). @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:404 @ static inline void xt_write_recseq_end(u /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */ smp_wmb(); __this_cpu_add(xt_recseq.sequence, addend); + local_unlock(xt_write_lock); } /* Index: linux-5.0.19-rt11/include/linux/nfs_fs.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/nfs_fs.h +++ linux-5.0.19-rt11/include/linux/nfs_fs.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:169 @ struct nfs_inode { /* Readers: in-flight sillydelete RPC calls */ /* Writers: rmdir */ +#ifdef CONFIG_PREEMPT_RT_BASE + struct semaphore rmdir_sem; +#else struct rw_semaphore rmdir_sem; +#endif struct mutex commit_mutex; #if IS_ENABLED(CONFIG_NFS_V4) Index: linux-5.0.19-rt11/include/linux/nfs_xdr.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/nfs_xdr.h +++ linux-5.0.19-rt11/include/linux/nfs_xdr.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1562 @ struct nfs_unlinkdata { struct nfs_removeargs args; struct nfs_removeres res; struct dentry *dentry; - wait_queue_head_t wq; + struct swait_queue_head wq; const struct cred *cred; struct nfs_fattr dir_attr; long timeout; Index: linux-5.0.19-rt11/include/linux/percpu-rwsem.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/percpu-rwsem.h +++ linux-5.0.19-rt11/include/linux/percpu-rwsem.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:32 @ static struct percpu_rw_semaphore name = extern int __percpu_down_read(struct percpu_rw_semaphore *, int); extern void __percpu_up_read(struct percpu_rw_semaphore *); -static inline void percpu_down_read_preempt_disable(struct percpu_rw_semaphore *sem) +static inline void percpu_down_read(struct percpu_rw_semaphore *sem) { might_sleep(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:50 @ static inline void percpu_down_read_pree __this_cpu_inc(*sem->read_count); if (unlikely(!rcu_sync_is_idle(&sem->rss))) __percpu_down_read(sem, false); /* Unconditional memory barrier */ - barrier(); /* - * The barrier() prevents the compiler from + * The preempt_enable() prevents the compiler from * bleeding the critical section out. */ -} - -static inline void percpu_down_read(struct percpu_rw_semaphore *sem) -{ - percpu_down_read_preempt_disable(sem); preempt_enable(); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:80 @ static inline int percpu_down_read_trylo return ret; } -static inline void percpu_up_read_preempt_enable(struct percpu_rw_semaphore *sem) +static inline void percpu_up_read(struct percpu_rw_semaphore *sem) { - /* - * The barrier() prevents the compiler from - * bleeding the critical section out. - */ - barrier(); + preempt_disable(); /* * Same as in percpu_down_read(). */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:95 @ static inline void percpu_up_read_preemp rwsem_release(&sem->rw_sem.dep_map, 1, _RET_IP_); } -static inline void percpu_up_read(struct percpu_rw_semaphore *sem) -{ - preempt_disable(); - percpu_up_read_preempt_enable(sem); -} - extern void percpu_down_write(struct percpu_rw_semaphore *); extern void percpu_up_write(struct percpu_rw_semaphore *); Index: linux-5.0.19-rt11/include/linux/percpu.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/percpu.h +++ linux-5.0.19-rt11/include/linux/percpu.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:22 @ #define PERCPU_MODULE_RESERVE 0 #endif +#ifdef CONFIG_PREEMPT_RT_FULL + +#define get_local_var(var) (*({ \ + migrate_disable(); \ + this_cpu_ptr(&var); })) + +#define put_local_var(var) do { \ + (void)&(var); \ + migrate_enable(); \ +} while (0) + +# define get_local_ptr(var) ({ \ + migrate_disable(); \ + this_cpu_ptr(var); }) + +# define put_local_ptr(var) do { \ + (void)(var); \ + migrate_enable(); \ +} while (0) + +#else + +#define get_local_var(var) get_cpu_var(var) +#define put_local_var(var) put_cpu_var(var) +#define get_local_ptr(var) get_cpu_ptr(var) +#define put_local_ptr(var) put_cpu_ptr(var) + +#endif + /* minimum unit size, also is the maximum supported allocation size */ #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10) Index: linux-5.0.19-rt11/include/linux/pid.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/pid.h +++ linux-5.0.19-rt11/include/linux/pid.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6 @ #define _LINUX_PID_H #include <linux/rculist.h> +#include <linux/atomic.h> enum pid_type { Index: linux-5.0.19-rt11/include/linux/posix-timers.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/posix-timers.h +++ linux-5.0.19-rt11/include/linux/posix-timers.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:18 @ struct cpu_timer_list { u64 expires, incr; struct task_struct *task; int firing; + int firing_cpu; }; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:118 @ struct k_itimer { struct { struct alarm alarmtimer; } alarm; - struct rcu_head rcu; } it; + struct rcu_head rcu; }; void run_posix_cpu_timers(struct task_struct *task); Index: linux-5.0.19-rt11/include/linux/preempt.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/preempt.h +++ linux-5.0.19-rt11/include/linux/preempt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:81 @ #include <asm/preempt.h> #define hardirq_count() (preempt_count() & HARDIRQ_MASK) -#define softirq_count() (preempt_count() & SOFTIRQ_MASK) #define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \ | NMI_MASK)) - /* * Are we doing bottom half or hardware interrupt processing? * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:97 @ * should not be used in new code. */ #define in_irq() (hardirq_count()) -#define in_softirq() (softirq_count()) #define in_interrupt() (irq_count()) -#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET) #define in_nmi() (preempt_count() & NMI_MASK) #define in_task() (!(preempt_count() & \ (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET))) +#ifdef CONFIG_PREEMPT_RT_FULL + +#define softirq_count() ((long)get_current()->softirq_count) +#define in_softirq() (softirq_count()) +#define in_serving_softirq() (get_current()->softirq_count & SOFTIRQ_OFFSET) + +#else + +#define softirq_count() (preempt_count() & SOFTIRQ_MASK) +#define in_softirq() (softirq_count()) +#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET) + +#endif /* * The preempt_count offset after preempt_disable(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:127 @ /* * The preempt_count offset after spin_lock() */ +#if !defined(CONFIG_PREEMPT_RT_FULL) #define PREEMPT_LOCK_OFFSET PREEMPT_DISABLE_OFFSET +#else +#define PREEMPT_LOCK_OFFSET 0 +#endif /* * The preempt_count offset needed for things like: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:180 @ extern void preempt_count_sub(int val); #define preempt_count_inc() preempt_count_add(1) #define preempt_count_dec() preempt_count_sub(1) +#ifdef CONFIG_PREEMPT_LAZY +#define add_preempt_lazy_count(val) do { preempt_lazy_count() += (val); } while (0) +#define sub_preempt_lazy_count(val) do { preempt_lazy_count() -= (val); } while (0) +#define inc_preempt_lazy_count() add_preempt_lazy_count(1) +#define dec_preempt_lazy_count() sub_preempt_lazy_count(1) +#define preempt_lazy_count() (current_thread_info()->preempt_lazy_count) +#else +#define add_preempt_lazy_count(val) do { } while (0) +#define sub_preempt_lazy_count(val) do { } while (0) +#define inc_preempt_lazy_count() do { } while (0) +#define dec_preempt_lazy_count() do { } while (0) +#define preempt_lazy_count() (0) +#endif + #ifdef CONFIG_PREEMPT_COUNT #define preempt_disable() \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:202 @ do { \ barrier(); \ } while (0) +#define preempt_lazy_disable() \ +do { \ + inc_preempt_lazy_count(); \ + barrier(); \ +} while (0) + #define sched_preempt_enable_no_resched() \ do { \ barrier(); \ preempt_count_dec(); \ } while (0) -#define preempt_enable_no_resched() sched_preempt_enable_no_resched() +#ifdef CONFIG_PREEMPT_RT_BASE +# define preempt_enable_no_resched() sched_preempt_enable_no_resched() +# define preempt_check_resched_rt() preempt_check_resched() +#else +# define preempt_enable_no_resched() preempt_enable() +# define preempt_check_resched_rt() barrier(); +#endif #define preemptible() (preempt_count() == 0 && !irqs_disabled()) +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) + +extern void migrate_disable(void); +extern void migrate_enable(void); + +int __migrate_disabled(struct task_struct *p); + +#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) + +extern void migrate_disable(void); +extern void migrate_enable(void); +static inline int __migrate_disabled(struct task_struct *p) +{ + return 0; +} + +#else +#define migrate_disable() preempt_disable() +#define migrate_enable() preempt_enable() +static inline int __migrate_disabled(struct task_struct *p) +{ + return 0; +} +#endif + #ifdef CONFIG_PREEMPT #define preempt_enable() \ do { \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:270 @ do { \ __preempt_schedule(); \ } while (0) +#define preempt_lazy_enable() \ +do { \ + dec_preempt_lazy_count(); \ + barrier(); \ + preempt_check_resched(); \ +} while (0) + #else /* !CONFIG_PREEMPT */ #define preempt_enable() \ do { \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:284 @ do { \ preempt_count_dec(); \ } while (0) +#define preempt_lazy_enable() \ +do { \ + dec_preempt_lazy_count(); \ + barrier(); \ +} while (0) + #define preempt_enable_notrace() \ do { \ barrier(); \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:328 @ do { \ #define preempt_disable_notrace() barrier() #define preempt_enable_no_resched_notrace() barrier() #define preempt_enable_notrace() barrier() +#define preempt_check_resched_rt() barrier() #define preemptible() 0 +#define migrate_disable() barrier() +#define migrate_enable() barrier() + +static inline int __migrate_disabled(struct task_struct *p) +{ + return 0; +} #endif /* CONFIG_PREEMPT_COUNT */ #ifdef MODULE @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:356 @ do { \ } while (0) #define preempt_fold_need_resched() \ do { \ - if (tif_need_resched()) \ + if (tif_need_resched_now()) \ set_preempt_need_resched(); \ } while (0) +#ifdef CONFIG_PREEMPT_RT_FULL +# define preempt_disable_rt() preempt_disable() +# define preempt_enable_rt() preempt_enable() +# define preempt_disable_nort() barrier() +# define preempt_enable_nort() barrier() +#else +# define preempt_disable_rt() barrier() +# define preempt_enable_rt() barrier() +# define preempt_disable_nort() preempt_disable() +# define preempt_enable_nort() preempt_enable() +#endif + #ifdef CONFIG_PREEMPT_NOTIFIERS struct preempt_notifier; Index: linux-5.0.19-rt11/include/linux/printk.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/printk.h +++ linux-5.0.19-rt11/include/linux/printk.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:62 @ static inline const char *printk_skip_he */ #define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT #define CONSOLE_LOGLEVEL_QUIET CONFIG_CONSOLE_LOGLEVEL_QUIET +#define CONSOLE_LOGLEVEL_EMERGENCY CONFIG_CONSOLE_LOGLEVEL_EMERGENCY extern int console_printk[]; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:70 @ extern int console_printk[]; #define default_message_loglevel (console_printk[1]) #define minimum_console_loglevel (console_printk[2]) #define default_console_loglevel (console_printk[3]) +#define emergency_console_loglevel (console_printk[4]) static inline void console_silent(void) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:150 @ static inline __printf(1, 2) __cold void early_printk(const char *s, ...) { } #endif -#ifdef CONFIG_PRINTK_NMI -extern void printk_nmi_enter(void); -extern void printk_nmi_exit(void); -extern void printk_nmi_direct_enter(void); -extern void printk_nmi_direct_exit(void); -#else -static inline void printk_nmi_enter(void) { } -static inline void printk_nmi_exit(void) { } -static inline void printk_nmi_direct_enter(void) { } -static inline void printk_nmi_direct_exit(void) { } -#endif /* PRINTK_NMI */ - #ifdef CONFIG_PRINTK asmlinkage __printf(5, 0) int vprintk_emit(int facility, int level, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:194 @ __printf(1, 2) void dump_stack_set_arch_ void dump_stack_print_info(const char *log_lvl); void show_regs_print_info(const char *log_lvl); extern asmlinkage void dump_stack(void) __cold; -extern void printk_safe_init(void); -extern void printk_safe_flush(void); -extern void printk_safe_flush_on_panic(void); +struct wait_queue_head *printk_wait_queue(void); #else static inline __printf(1, 0) int vprintk(const char *s, va_list args) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:258 @ static inline void show_regs_print_info( static inline void dump_stack(void) { } - -static inline void printk_safe_init(void) -{ -} - -static inline void printk_safe_flush(void) -{ -} - -static inline void printk_safe_flush_on_panic(void) -{ -} #endif extern int kptr_restrict; Index: linux-5.0.19-rt11/include/linux/printk_ringbuffer.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/printk_ringbuffer.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_PRINTK_RINGBUFFER_H +#define _LINUX_PRINTK_RINGBUFFER_H + +#include <linux/irq_work.h> +#include <linux/atomic.h> +#include <linux/percpu.h> +#include <linux/wait.h> + +struct prb_cpulock { + atomic_t owner; + unsigned long __percpu *irqflags; +}; + +struct printk_ringbuffer { + void *buffer; + unsigned int size_bits; + + u64 seq; + atomic_long_t lost; + + atomic_long_t tail; + atomic_long_t head; + atomic_long_t reserve; + + struct prb_cpulock *cpulock; + atomic_t ctx; + + struct wait_queue_head *wq; + atomic_long_t wq_counter; + struct irq_work *wq_work; +}; + +struct prb_entry { + unsigned int size; + u64 seq; + char data[0]; +}; + +struct prb_handle { + struct printk_ringbuffer *rb; + unsigned int cpu; + struct prb_entry *entry; +}; + +#define DECLARE_STATIC_PRINTKRB_CPULOCK(name) \ +static DEFINE_PER_CPU(unsigned long, _##name##_percpu_irqflags); \ +static struct prb_cpulock name = { \ + .owner = ATOMIC_INIT(-1), \ + .irqflags = &_##name##_percpu_irqflags, \ +} + +#define PRB_INIT ((unsigned long)-1) + +#define DECLARE_STATIC_PRINTKRB_ITER(name, rbaddr) \ +static struct prb_iterator name = { \ + .rb = rbaddr, \ + .lpos = PRB_INIT, \ +} + +struct prb_iterator { + struct printk_ringbuffer *rb; + unsigned long lpos; +}; + +#define DECLARE_STATIC_PRINTKRB(name, szbits, cpulockptr) \ +static char _##name##_buffer[1 << (szbits)] \ + __aligned(__alignof__(long)); \ +static DECLARE_WAIT_QUEUE_HEAD(_##name##_wait); \ +static void _##name##_wake_work_func(struct irq_work *irq_work) \ +{ \ + wake_up_interruptible_all(&_##name##_wait); \ +} \ +static struct irq_work _##name##_wake_work = { \ + .func = _##name##_wake_work_func, \ + .flags = IRQ_WORK_LAZY, \ +}; \ +static struct printk_ringbuffer name = { \ + .buffer = &_##name##_buffer[0], \ + .size_bits = szbits, \ + .seq = 0, \ + .lost = ATOMIC_LONG_INIT(0), \ + .tail = ATOMIC_LONG_INIT(-111 * sizeof(long)), \ + .head = ATOMIC_LONG_INIT(-111 * sizeof(long)), \ + .reserve = ATOMIC_LONG_INIT(-111 * sizeof(long)), \ + .cpulock = cpulockptr, \ + .ctx = ATOMIC_INIT(0), \ + .wq = &_##name##_wait, \ + .wq_counter = ATOMIC_LONG_INIT(0), \ + .wq_work = &_##name##_wake_work, \ +} + +/* writer interface */ +char *prb_reserve(struct prb_handle *h, struct printk_ringbuffer *rb, + unsigned int size); +void prb_commit(struct prb_handle *h); + +/* reader interface */ +void prb_iter_init(struct prb_iterator *iter, struct printk_ringbuffer *rb, + u64 *seq); +void prb_iter_copy(struct prb_iterator *dest, struct prb_iterator *src); +int prb_iter_next(struct prb_iterator *iter, char *buf, int size, u64 *seq); +int prb_iter_wait_next(struct prb_iterator *iter, char *buf, int size, + u64 *seq); +int prb_iter_seek(struct prb_iterator *iter, u64 seq); +int prb_iter_data(struct prb_iterator *iter, char *buf, int size, u64 *seq); + +/* utility functions */ +int prb_buffer_size(struct printk_ringbuffer *rb); +void prb_inc_lost(struct printk_ringbuffer *rb); +void prb_lock(struct prb_cpulock *cpu_lock, unsigned int *cpu_store); +void prb_unlock(struct prb_cpulock *cpu_lock, unsigned int cpu_store); + +#endif /*_LINUX_PRINTK_RINGBUFFER_H */ Index: linux-5.0.19-rt11/include/linux/radix-tree.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/radix-tree.h +++ linux-5.0.19-rt11/include/linux/radix-tree.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:242 @ unsigned int radix_tree_gang_lookup(cons unsigned int max_items); int radix_tree_preload(gfp_t gfp_mask); int radix_tree_maybe_preload(gfp_t gfp_mask); +void radix_tree_preload_end(void); void radix_tree_init(void); void *radix_tree_tag_set(struct radix_tree_root *, unsigned long index, unsigned int tag); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:260 @ unsigned int radix_tree_gang_lookup_tag_ unsigned int max_items, unsigned int tag); int radix_tree_tagged(const struct radix_tree_root *, unsigned int tag); -static inline void radix_tree_preload_end(void) -{ - preempt_enable(); -} - void __rcu **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, unsigned long max); Index: linux-5.0.19-rt11/include/linux/random.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/random.h +++ linux-5.0.19-rt11/include/linux/random.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:35 @ static inline void add_latent_entropy(vo extern void add_input_randomness(unsigned int type, unsigned int code, unsigned int value) __latent_entropy; -extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy; +extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip) __latent_entropy; extern void get_random_bytes(void *buf, int nbytes); extern int wait_for_random_bytes(void); Index: linux-5.0.19-rt11/include/linux/ratelimit.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/ratelimit.h +++ linux-5.0.19-rt11/include/linux/ratelimit.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:62 @ static inline void ratelimit_state_exit( return; if (rs->missed) { - pr_warn("%s: %d output lines suppressed due to ratelimiting\n", + pr_info("%s: %d output lines suppressed due to ratelimiting\n", current->comm, rs->missed); rs->missed = 0; } Index: linux-5.0.19-rt11/include/linux/rbtree.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/rbtree.h +++ linux-5.0.19-rt11/include/linux/rbtree.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:34 @ #include <linux/kernel.h> #include <linux/stddef.h> -#include <linux/rcupdate.h> +#include <linux/rcu_assign_pointer.h> struct rb_node { unsigned long __rb_parent_color; Index: linux-5.0.19-rt11/include/linux/rcu_assign_pointer.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/rcu_assign_pointer.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_RCU_ASSIGN_POINTER_H__ +#define __LINUX_RCU_ASSIGN_POINTER_H__ +#include <linux/compiler.h> +#include <asm/barrier.h> + +/** + * RCU_INITIALIZER() - statically initialize an RCU-protected global variable + * @v: The value to statically initialize with. + */ +#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v) + +/** + * rcu_assign_pointer() - assign to RCU-protected pointer + * @p: pointer to assign to + * @v: value to assign (publish) + * + * Assigns the specified value to the specified RCU-protected + * pointer, ensuring that any concurrent RCU readers will see + * any prior initialization. + * + * Inserts memory barriers on architectures that require them + * (which is most of them), and also prevents the compiler from + * reordering the code that initializes the structure after the pointer + * assignment. More importantly, this call documents which pointers + * will be dereferenced by RCU read-side code. + * + * In some special cases, you may use RCU_INIT_POINTER() instead + * of rcu_assign_pointer(). RCU_INIT_POINTER() is a bit faster due + * to the fact that it does not constrain either the CPU or the compiler. + * That said, using RCU_INIT_POINTER() when you should have used + * rcu_assign_pointer() is a very bad thing that results in + * impossible-to-diagnose memory corruption. So please be careful. + * See the RCU_INIT_POINTER() comment header for details. + * + * Note that rcu_assign_pointer() evaluates each of its arguments only + * once, appearances notwithstanding. One of the "extra" evaluations + * is in typeof() and the other visible only to sparse (__CHECKER__), + * neither of which actually execute the argument. As with most cpp + * macros, this execute-arguments-only-once property is important, so + * please be careful when making changes to rcu_assign_pointer() and the + * other macros that it invokes. + */ +#define rcu_assign_pointer(p, v) \ +({ \ + uintptr_t _r_a_p__v = (uintptr_t)(v); \ + \ + if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \ + WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \ + else \ + smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \ + _r_a_p__v; \ +}) + +#endif Index: linux-5.0.19-rt11/include/linux/rcupdate.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/rcupdate.h +++ linux-5.0.19-rt11/include/linux/rcupdate.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:45 @ #include <linux/lockdep.h> #include <asm/processor.h> #include <linux/cpumask.h> +#include <linux/rcu_assign_pointer.h> #define ULONG_CMP_GE(a, b) (ULONG_MAX / 2 >= (a) - (b)) #define ULONG_CMP_LT(a, b) (ULONG_MAX / 2 < (a) - (b)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:68 @ void __rcu_read_unlock(void); * types of kernel builds, the rcu_read_lock() nesting depth is unknowable. */ #define rcu_preempt_depth() (current->rcu_read_lock_nesting) +#ifndef CONFIG_PREEMPT_RT_FULL +#define sched_rcu_preempt_depth() rcu_preempt_depth() +#else +static inline int sched_rcu_preempt_depth(void) { return 0; } +#endif #else /* #ifdef CONFIG_PREEMPT_RCU */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:93 @ static inline int rcu_preempt_depth(void return 0; } +#define sched_rcu_preempt_depth() rcu_preempt_depth() + #endif /* #else #ifdef CONFIG_PREEMPT_RCU */ /* Internal to kernel */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:298 @ static inline void rcu_preempt_sleep_che #define rcu_sleep_check() \ do { \ rcu_preempt_sleep_check(); \ - RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map), \ + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) \ + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map),\ "Illegal context switch in RCU-bh read-side critical section"); \ RCU_LOCKDEP_WARN(lock_is_held(&rcu_sched_lock_map), \ "Illegal context switch in RCU-sched read-side critical section"); \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:355 @ static inline void rcu_preempt_sleep_che }) /** - * RCU_INITIALIZER() - statically initialize an RCU-protected global variable - * @v: The value to statically initialize with. - */ -#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v) - -/** - * rcu_assign_pointer() - assign to RCU-protected pointer - * @p: pointer to assign to - * @v: value to assign (publish) - * - * Assigns the specified value to the specified RCU-protected - * pointer, ensuring that any concurrent RCU readers will see - * any prior initialization. - * - * Inserts memory barriers on architectures that require them - * (which is most of them), and also prevents the compiler from - * reordering the code that initializes the structure after the pointer - * assignment. More importantly, this call documents which pointers - * will be dereferenced by RCU read-side code. - * - * In some special cases, you may use RCU_INIT_POINTER() instead - * of rcu_assign_pointer(). RCU_INIT_POINTER() is a bit faster due - * to the fact that it does not constrain either the CPU or the compiler. - * That said, using RCU_INIT_POINTER() when you should have used - * rcu_assign_pointer() is a very bad thing that results in - * impossible-to-diagnose memory corruption. So please be careful. - * See the RCU_INIT_POINTER() comment header for details. - * - * Note that rcu_assign_pointer() evaluates each of its arguments only - * once, appearances notwithstanding. One of the "extra" evaluations - * is in typeof() and the other visible only to sparse (__CHECKER__), - * neither of which actually execute the argument. As with most cpp - * macros, this execute-arguments-only-once property is important, so - * please be careful when making changes to rcu_assign_pointer() and the - * other macros that it invokes. - */ -#define rcu_assign_pointer(p, v) \ -({ \ - uintptr_t _r_a_p__v = (uintptr_t)(v); \ - \ - if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \ - WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \ - else \ - smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \ - _r_a_p__v; \ -}) - -/** * rcu_swap_protected() - swap an RCU and a regular pointer * @rcu_ptr: RCU pointer * @ptr: regular pointer Index: linux-5.0.19-rt11/include/linux/rtmutex.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/rtmutex.h +++ linux-5.0.19-rt11/include/linux/rtmutex.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:17 @ #define __LINUX_RT_MUTEX_H #include <linux/linkage.h> +#include <linux/spinlock_types_raw.h> #include <linux/rbtree.h> -#include <linux/spinlock_types.h> extern int max_lock_depth; /* for sysctl */ +#ifdef CONFIG_DEBUG_MUTEXES +#include <linux/debug_locks.h> +#endif + /** * The rt_mutex structure * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:38 @ struct rt_mutex { raw_spinlock_t wait_lock; struct rb_root_cached waiters; struct task_struct *owner; -#ifdef CONFIG_DEBUG_RT_MUTEXES int save_state; +#ifdef CONFIG_DEBUG_RT_MUTEXES const char *name, *file; int line; void *magic; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:89 @ do { \ #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) #endif -#define __RT_MUTEX_INITIALIZER(mutexname) \ - { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ +#define __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \ + .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ , .waiters = RB_ROOT_CACHED \ , .owner = NULL \ __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ - __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)} + __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) + +#define __RT_MUTEX_INITIALIZER(mutexname) \ + { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) } #define DEFINE_RT_MUTEX(mutexname) \ struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname) +#define __RT_MUTEX_INITIALIZER_SAVE_STATE(mutexname) \ + { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \ + , .save_state = 1 } + /** * rt_mutex_is_locked - is the mutex locked * @lock: the mutex to be queried @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:129 @ extern void rt_mutex_lock(struct rt_mute #endif extern int rt_mutex_lock_interruptible(struct rt_mutex *lock); +extern int rt_mutex_lock_killable(struct rt_mutex *lock); extern int rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout); Index: linux-5.0.19-rt11/include/linux/rwlock_rt.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/rwlock_rt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_RWLOCK_RT_H +#define __LINUX_RWLOCK_RT_H + +#ifndef __LINUX_SPINLOCK_H +#error Do not include directly. Use spinlock.h +#endif + +extern void __lockfunc rt_write_lock(rwlock_t *rwlock); +extern void __lockfunc rt_read_lock(rwlock_t *rwlock); +extern int __lockfunc rt_write_trylock(rwlock_t *rwlock); +extern int __lockfunc rt_read_trylock(rwlock_t *rwlock); +extern void __lockfunc rt_write_unlock(rwlock_t *rwlock); +extern void __lockfunc rt_read_unlock(rwlock_t *rwlock); +extern int __lockfunc rt_read_can_lock(rwlock_t *rwlock); +extern int __lockfunc rt_write_can_lock(rwlock_t *rwlock); +extern void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key); + +#define read_can_lock(rwlock) rt_read_can_lock(rwlock) +#define write_can_lock(rwlock) rt_write_can_lock(rwlock) + +#define read_trylock(lock) __cond_lock(lock, rt_read_trylock(lock)) +#define write_trylock(lock) __cond_lock(lock, rt_write_trylock(lock)) + +static inline int __write_trylock_rt_irqsave(rwlock_t *lock, unsigned long *flags) +{ + /* XXX ARCH_IRQ_ENABLED */ + *flags = 0; + return rt_write_trylock(lock); +} + +#define write_trylock_irqsave(lock, flags) \ + __cond_lock(lock, __write_trylock_rt_irqsave(lock, &(flags))) + +#define read_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + rt_read_lock(lock); \ + flags = 0; \ + } while (0) + +#define write_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + rt_write_lock(lock); \ + flags = 0; \ + } while (0) + +#define read_lock(lock) rt_read_lock(lock) + +#define read_lock_bh(lock) \ + do { \ + local_bh_disable(); \ + rt_read_lock(lock); \ + } while (0) + +#define read_lock_irq(lock) read_lock(lock) + +#define write_lock(lock) rt_write_lock(lock) + +#define write_lock_bh(lock) \ + do { \ + local_bh_disable(); \ + rt_write_lock(lock); \ + } while (0) + +#define write_lock_irq(lock) write_lock(lock) + +#define read_unlock(lock) rt_read_unlock(lock) + +#define read_unlock_bh(lock) \ + do { \ + rt_read_unlock(lock); \ + local_bh_enable(); \ + } while (0) + +#define read_unlock_irq(lock) read_unlock(lock) + +#define write_unlock(lock) rt_write_unlock(lock) + +#define write_unlock_bh(lock) \ + do { \ + rt_write_unlock(lock); \ + local_bh_enable(); \ + } while (0) + +#define write_unlock_irq(lock) write_unlock(lock) + +#define read_unlock_irqrestore(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + (void) flags; \ + rt_read_unlock(lock); \ + } while (0) + +#define write_unlock_irqrestore(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + (void) flags; \ + rt_write_unlock(lock); \ + } while (0) + +#define rwlock_init(rwl) \ +do { \ + static struct lock_class_key __key; \ + \ + __rt_rwlock_init(rwl, #rwl, &__key); \ +} while (0) + +/* + * Internal functions made global for CPU pinning + */ +void __read_rt_lock(struct rt_rw_lock *lock); +int __read_rt_trylock(struct rt_rw_lock *lock); +void __write_rt_lock(struct rt_rw_lock *lock); +int __write_rt_trylock(struct rt_rw_lock *lock); +void __read_rt_unlock(struct rt_rw_lock *lock); +void __write_rt_unlock(struct rt_rw_lock *lock); + +#endif Index: linux-5.0.19-rt11/include/linux/rwlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/rwlock_types.h +++ linux-5.0.19-rt11/include/linux/rwlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ #ifndef __LINUX_RWLOCK_TYPES_H #define __LINUX_RWLOCK_TYPES_H +#if !defined(__LINUX_SPINLOCK_TYPES_H) +# error "Do not include directly, include spinlock_types.h" +#endif + /* * include/linux/rwlock_types.h - generic rwlock type definitions * and initializers Index: linux-5.0.19-rt11/include/linux/rwlock_types_rt.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/rwlock_types_rt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_RWLOCK_TYPES_RT_H +#define __LINUX_RWLOCK_TYPES_RT_H + +#ifndef __LINUX_SPINLOCK_TYPES_H +#error "Do not include directly. Include spinlock_types.h instead" +#endif + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define RW_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname } +#else +# define RW_DEP_MAP_INIT(lockname) +#endif + +typedef struct rt_rw_lock rwlock_t; + +#define __RW_LOCK_UNLOCKED(name) __RWLOCK_RT_INITIALIZER(name) + +#define DEFINE_RWLOCK(name) \ + rwlock_t name = __RW_LOCK_UNLOCKED(name) + +/* + * A reader biased implementation primarily for CPU pinning. + * + * Can be selected as general replacement for the single reader RT rwlock + * variant + */ +struct rt_rw_lock { + struct rt_mutex rtmutex; + atomic_t readers; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +#define READER_BIAS (1U << 31) +#define WRITER_BIAS (1U << 30) + +#define __RWLOCK_RT_INITIALIZER(name) \ +{ \ + .readers = ATOMIC_INIT(READER_BIAS), \ + .rtmutex = __RT_MUTEX_INITIALIZER_SAVE_STATE(name.rtmutex), \ + RW_DEP_MAP_INIT(name) \ +} + +void __rwlock_biased_rt_init(struct rt_rw_lock *lock, const char *name, + struct lock_class_key *key); + +#define rwlock_biased_rt_init(rwlock) \ + do { \ + static struct lock_class_key __key; \ + \ + __rwlock_biased_rt_init((rwlock), #rwlock, &__key); \ + } while (0) + +#endif Index: linux-5.0.19-rt11/include/linux/rwsem-rt.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/rwsem-rt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef _LINUX_RWSEM_RT_H +#define _LINUX_RWSEM_RT_H + +#ifndef _LINUX_RWSEM_H +#error "Include rwsem.h" +#endif + +#include <linux/rtmutex.h> +#include <linux/swait.h> + +#define READER_BIAS (1U << 31) +#define WRITER_BIAS (1U << 30) + +struct rw_semaphore { + atomic_t readers; + struct rt_mutex rtmutex; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +#define __RWSEM_INITIALIZER(name) \ +{ \ + .readers = ATOMIC_INIT(READER_BIAS), \ + .rtmutex = __RT_MUTEX_INITIALIZER(name.rtmutex), \ + RW_DEP_MAP_INIT(name) \ +} + +#define DECLARE_RWSEM(lockname) \ + struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname) + +extern void __rwsem_init(struct rw_semaphore *rwsem, const char *name, + struct lock_class_key *key); + +#define __init_rwsem(sem, name, key) \ +do { \ + rt_mutex_init(&(sem)->rtmutex); \ + __rwsem_init((sem), (name), (key)); \ +} while (0) + +#define init_rwsem(sem) \ +do { \ + static struct lock_class_key __key; \ + \ + __init_rwsem((sem), #sem, &__key); \ +} while (0) + +static inline int rwsem_is_locked(struct rw_semaphore *sem) +{ + return atomic_read(&sem->readers) != READER_BIAS; +} + +static inline int rwsem_is_contended(struct rw_semaphore *sem) +{ + return atomic_read(&sem->readers) > 0; +} + +extern void __down_read(struct rw_semaphore *sem); +extern int __down_read_killable(struct rw_semaphore *sem); +extern int __down_read_trylock(struct rw_semaphore *sem); +extern void __down_write(struct rw_semaphore *sem); +extern int __must_check __down_write_killable(struct rw_semaphore *sem); +extern int __down_write_trylock(struct rw_semaphore *sem); +extern void __up_read(struct rw_semaphore *sem); +extern void __up_write(struct rw_semaphore *sem); +extern void __downgrade_write(struct rw_semaphore *sem); + +#endif Index: linux-5.0.19-rt11/include/linux/rwsem.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/rwsem.h +++ linux-5.0.19-rt11/include/linux/rwsem.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:23 @ #include <linux/osq_lock.h> #endif +#ifdef CONFIG_PREEMPT_RT_FULL +#include <linux/rwsem-rt.h> +#else /* PREEMPT_RT_FULL */ + struct rw_semaphore; #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:121 @ static inline int rwsem_is_contended(str return !list_empty(&sem->wait_list); } +#endif /* !PREEMPT_RT_FULL */ + +/* + * The functions below are the same for all rwsem implementations including + * the RT specific variant. + */ + /* * lock for reading */ Index: linux-5.0.19-rt11/include/linux/sched.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/sched.h +++ linux-5.0.19-rt11/include/linux/sched.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:32 @ #include <linux/mm_types_task.h> #include <linux/task_io_accounting.h> #include <linux/rseq.h> +#include <asm/kmap_types.h> /* task_struct member predeclarations (sorted alphabetically): */ struct audit_context; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:106 @ struct task_group; __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ TASK_PARKED) -#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0) - #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0) -#define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0) - #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \ (task->flags & PF_FROZEN) == 0 && \ (task->state & TASK_NOLOAD) == 0) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:135 @ struct task_group; smp_store_mb(current->state, (state_value)); \ } while (0) +#define __set_current_state_no_track(state_value) \ + current->state = (state_value); + #define set_special_state(state_value) \ do { \ unsigned long flags; /* may shadow */ \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:147 @ struct task_group; current->state = (state_value); \ raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ } while (0) + #else /* * set_current_state() includes a barrier so that the write of current->state @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:192 @ struct task_group; #define set_current_state(state_value) \ smp_store_mb(current->state, (state_value)) +#define __set_current_state_no_track(state_value) \ + __set_current_state(state_value) + /* * set_special_state() should be used for those states when the blocking task * can not use the regular condition based wait-loop. In that case we must @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:606 @ struct task_struct { #endif /* -1 unrunnable, 0 runnable, >0 stopped: */ volatile long state; + /* saved state for "spinlock sleepers" */ + volatile long saved_state; /* * This begins the randomizable portion of task_struct. Only @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:668 @ struct task_struct { unsigned int policy; int nr_cpus_allowed; - cpumask_t cpus_allowed; + const cpumask_t *cpus_ptr; + cpumask_t cpus_mask; +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) + int migrate_disable; + int migrate_disable_update; + int pinned_on_cpu; +# ifdef CONFIG_SCHED_DEBUG + int migrate_disable_atomic; +# endif + +#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) +# ifdef CONFIG_SCHED_DEBUG + int migrate_disable; + int migrate_disable_atomic; +# endif +#endif +#ifdef CONFIG_PREEMPT_RT_FULL + int sleeping_lock; +#endif #ifdef CONFIG_PREEMPT_RCU int rcu_read_lock_nesting; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:851 @ struct task_struct { #ifdef CONFIG_POSIX_TIMERS struct task_cputime cputime_expires; struct list_head cpu_timers[3]; +#ifdef CONFIG_PREEMPT_RT_BASE + struct task_struct *posix_timer_list; +#endif #endif /* Process credentials: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:898 @ struct task_struct { /* Signal handlers: */ struct signal_struct *signal; struct sighand_struct *sighand; + struct sigqueue *sigqueue_cache; + sigset_t blocked; sigset_t real_blocked; /* Restored if set_restore_sigmask() was used: */ sigset_t saved_sigmask; struct sigpending pending; +#ifdef CONFIG_PREEMPT_RT_FULL + /* TODO: move me into ->restart_block ? */ + struct kernel_siginfo forced_info; +#endif unsigned long sas_ss_sp; size_t sas_ss_size; unsigned int sas_ss_flags; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:933 @ struct task_struct { raw_spinlock_t pi_lock; struct wake_q_node wake_q; + struct wake_q_node wake_q_sleeper; #ifdef CONFIG_RT_MUTEXES /* PI waiters blocked on a rt_mutex held by this task: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:964 @ struct task_struct { int softirqs_enabled; int softirq_context; #endif +#ifdef CONFIG_PREEMPT_RT_FULL + int softirq_count; +#endif #ifdef CONFIG_LOCKDEP # define MAX_LOCK_DEPTH 48UL @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1215 @ struct task_struct { unsigned int sequential_io; unsigned int sequential_io_avg; #endif +#ifdef CONFIG_PREEMPT_RT_BASE + struct rcu_head put_rcu; +#endif +#ifdef CONFIG_PREEMPT_RT_FULL +# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32 + int kmap_idx; + pte_t kmap_pte[KM_TYPE_NR]; +# endif +#endif #ifdef CONFIG_DEBUG_ATOMIC_SLEEP unsigned long task_state_change; #endif +#ifdef CONFIG_PREEMPT_RT_FULL + int xmit_recursion; +#endif int pagefault_disabled; #ifdef CONFIG_MMU struct task_struct *oom_reaper_list; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1453 @ extern struct pid *cad_pid; #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */ #define PF_MEMSTALL 0x01000000 /* Stalled due to lack of memory */ #define PF_UMH 0x02000000 /* I'm an Usermodehelper process */ -#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */ +#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */ #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1658 @ extern struct task_struct *find_get_task extern int wake_up_state(struct task_struct *tsk, unsigned int state); extern int wake_up_process(struct task_struct *tsk); +extern int wake_up_lock_sleeper(struct task_struct *tsk); extern void wake_up_new_task(struct task_struct *tsk); #ifdef CONFIG_SMP @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1741 @ static inline int test_tsk_need_resched( return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); } +#ifdef CONFIG_PREEMPT_LAZY +static inline void set_tsk_need_resched_lazy(struct task_struct *tsk) +{ + set_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY); +} + +static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk) +{ + clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY); +} + +static inline int test_tsk_need_resched_lazy(struct task_struct *tsk) +{ + return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY)); +} + +static inline int need_resched_lazy(void) +{ + return test_thread_flag(TIF_NEED_RESCHED_LAZY); +} + +static inline int need_resched_now(void) +{ + return test_thread_flag(TIF_NEED_RESCHED); +} + +#else +static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk) { } +static inline int need_resched_lazy(void) { return 0; } + +static inline int need_resched_now(void) +{ + return test_thread_flag(TIF_NEED_RESCHED); +} + +#endif + + +static inline bool __task_is_stopped_or_traced(struct task_struct *task) +{ + if (task->state & (__TASK_STOPPED | __TASK_TRACED)) + return true; +#ifdef CONFIG_PREEMPT_RT_FULL + if (task->saved_state & (__TASK_STOPPED | __TASK_TRACED)) + return true; +#endif + return false; +} + +static inline bool task_is_stopped_or_traced(struct task_struct *task) +{ + bool traced_stopped; + +#ifdef CONFIG_PREEMPT_RT_FULL + unsigned long flags; + + raw_spin_lock_irqsave(&task->pi_lock, flags); + traced_stopped = __task_is_stopped_or_traced(task); + raw_spin_unlock_irqrestore(&task->pi_lock, flags); +#else + traced_stopped = __task_is_stopped_or_traced(task); +#endif + return traced_stopped; +} + +static inline bool task_is_traced(struct task_struct *task) +{ + bool traced = false; + + if (task->state & __TASK_TRACED) + return true; +#ifdef CONFIG_PREEMPT_RT_FULL + /* in case the task is sleeping on tasklist_lock */ + raw_spin_lock_irq(&task->pi_lock); + if (task->state & __TASK_TRACED) + traced = true; + else if (task->saved_state & __TASK_TRACED) + traced = true; + raw_spin_unlock_irq(&task->pi_lock); +#endif + return traced; +} + /* * cond_resched() and cond_resched_lock(): latency reduction via * explicit rescheduling in places that are safe. The return @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1876 @ static __always_inline bool need_resched return unlikely(tif_need_resched()); } +#ifdef CONFIG_PREEMPT_RT_FULL +static inline void sleeping_lock_inc(void) +{ + current->sleeping_lock++; +} + +static inline void sleeping_lock_dec(void) +{ + current->sleeping_lock--; +} + +#else + +static inline void sleeping_lock_inc(void) { } +static inline void sleeping_lock_dec(void) { } +#endif + /* * Wrappers for p->thread_info->cpu access. No-op on UP. */ Index: linux-5.0.19-rt11/include/linux/sched/mm.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/sched/mm.h +++ linux-5.0.19-rt11/include/linux/sched/mm.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:52 @ static inline void mmdrop(struct mm_stru __mmdrop(mm); } +#ifdef CONFIG_PREEMPT_RT_BASE +extern void __mmdrop_delayed(struct rcu_head *rhp); +static inline void mmdrop_delayed(struct mm_struct *mm) +{ + if (atomic_dec_and_test(&mm->mm_count)) + call_rcu(&mm->delayed_drop, __mmdrop_delayed); +} +#else +# define mmdrop_delayed(mm) mmdrop(mm) +#endif + /* * This has to be called after a get_task_mm()/mmget_not_zero() * followed by taking the mmap_sem for writing before modifying the Index: linux-5.0.19-rt11/include/linux/sched/task.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/sched/task.h +++ linux-5.0.19-rt11/include/linux/sched/task.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:93 @ extern void sched_exec(void); #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0) +#ifdef CONFIG_PREEMPT_RT_BASE +extern void __put_task_struct_cb(struct rcu_head *rhp); + +static inline void put_task_struct(struct task_struct *t) +{ + if (atomic_dec_and_test(&t->usage)) + call_rcu(&t->put_rcu, __put_task_struct_cb); +} +#else extern void __put_task_struct(struct task_struct *t); static inline void put_task_struct(struct task_struct *t) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:109 @ static inline void put_task_struct(struc if (atomic_dec_and_test(&t->usage)) __put_task_struct(t); } - +#endif struct task_struct *task_rcu_dereference(struct task_struct **ptask); #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT Index: linux-5.0.19-rt11/include/linux/sched/wake_q.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/sched/wake_q.h +++ linux-5.0.19-rt11/include/linux/sched/wake_q.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:54 @ static inline void wake_q_init(struct wa head->lastp = &head->first; } -extern void wake_q_add(struct wake_q_head *head, - struct task_struct *task); -extern void wake_up_q(struct wake_q_head *head); +extern void __wake_q_add(struct wake_q_head *head, + struct task_struct *task, bool sleeper); +static inline void wake_q_add(struct wake_q_head *head, + struct task_struct *task) +{ + __wake_q_add(head, task, false); +} + +static inline void wake_q_add_sleeper(struct wake_q_head *head, + struct task_struct *task) +{ + __wake_q_add(head, task, true); +} + +extern void __wake_up_q(struct wake_q_head *head, bool sleeper); +static inline void wake_up_q(struct wake_q_head *head) +{ + __wake_up_q(head, false); +} + +static inline void wake_up_q_sleeper(struct wake_q_head *head) +{ + __wake_up_q(head, true); +} #endif /* _LINUX_SCHED_WAKE_Q_H */ Index: linux-5.0.19-rt11/include/linux/seqlock.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/seqlock.h +++ linux-5.0.19-rt11/include/linux/seqlock.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:224 @ static inline int read_seqcount_retry(co return __read_seqcount_retry(s, start); } - - -static inline void raw_write_seqcount_begin(seqcount_t *s) +static inline void __raw_write_seqcount_begin(seqcount_t *s) { s->sequence++; smp_wmb(); } -static inline void raw_write_seqcount_end(seqcount_t *s) +static inline void raw_write_seqcount_begin(seqcount_t *s) +{ + preempt_disable_rt(); + __raw_write_seqcount_begin(s); +} + +static inline void __raw_write_seqcount_end(seqcount_t *s) { smp_wmb(); s->sequence++; } +static inline void raw_write_seqcount_end(seqcount_t *s) +{ + __raw_write_seqcount_end(s); + preempt_enable_rt(); +} + /** * raw_write_seqcount_barrier - do a seq write barrier * @s: pointer to seqcount_t @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:441 @ typedef struct { /* * Read side functions for starting and finalizing a read side section. */ +#ifndef CONFIG_PREEMPT_RT_FULL static inline unsigned read_seqbegin(const seqlock_t *sl) { return read_seqcount_begin(&sl->seqcount); } +#else +/* + * Starvation safe read side for RT + */ +static inline unsigned read_seqbegin(seqlock_t *sl) +{ + unsigned ret; + +repeat: + ret = READ_ONCE(sl->seqcount.sequence); + if (unlikely(ret & 1)) { + /* + * Take the lock and let the writer proceed (i.e. evtl + * boost it), otherwise we could loop here forever. + */ + spin_unlock_wait(&sl->lock); + goto repeat; + } + smp_rmb(); + return ret; +} +#endif static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:482 @ static inline unsigned read_seqretry(con static inline void write_seqlock(seqlock_t *sl) { spin_lock(&sl->lock); - write_seqcount_begin(&sl->seqcount); + __raw_write_seqcount_begin(&sl->seqcount); +} + +static inline int try_write_seqlock(seqlock_t *sl) +{ + if (spin_trylock(&sl->lock)) { + __raw_write_seqcount_begin(&sl->seqcount); + return 1; + } + return 0; } static inline void write_sequnlock(seqlock_t *sl) { - write_seqcount_end(&sl->seqcount); + __raw_write_seqcount_end(&sl->seqcount); spin_unlock(&sl->lock); } static inline void write_seqlock_bh(seqlock_t *sl) { spin_lock_bh(&sl->lock); - write_seqcount_begin(&sl->seqcount); + __raw_write_seqcount_begin(&sl->seqcount); } static inline void write_sequnlock_bh(seqlock_t *sl) { - write_seqcount_end(&sl->seqcount); + __raw_write_seqcount_end(&sl->seqcount); spin_unlock_bh(&sl->lock); } static inline void write_seqlock_irq(seqlock_t *sl) { spin_lock_irq(&sl->lock); - write_seqcount_begin(&sl->seqcount); + __raw_write_seqcount_begin(&sl->seqcount); } static inline void write_sequnlock_irq(seqlock_t *sl) { - write_seqcount_end(&sl->seqcount); + __raw_write_seqcount_end(&sl->seqcount); spin_unlock_irq(&sl->lock); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:529 @ static inline unsigned long __write_seql unsigned long flags; spin_lock_irqsave(&sl->lock, flags); - write_seqcount_begin(&sl->seqcount); + __raw_write_seqcount_begin(&sl->seqcount); return flags; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:539 @ static inline unsigned long __write_seql static inline void write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags) { - write_seqcount_end(&sl->seqcount); + __raw_write_seqcount_end(&sl->seqcount); spin_unlock_irqrestore(&sl->lock, flags); } Index: linux-5.0.19-rt11/include/linux/serial_8250.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/serial_8250.h +++ linux-5.0.19-rt11/include/linux/serial_8250.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:14 @ #ifndef _LINUX_SERIAL_8250_H #define _LINUX_SERIAL_8250_H +#include <linux/atomic.h> #include <linux/serial_core.h> #include <linux/serial_reg.h> #include <linux/platform_device.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:130 @ struct uart_8250_port { #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA unsigned char msr_saved_flags; + atomic_t console_printing; + struct uart_8250_dma *dma; const struct uart_8250_ops *ops; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:183 @ void serial8250_init_port(struct uart_82 void serial8250_set_defaults(struct uart_8250_port *up); void serial8250_console_write(struct uart_8250_port *up, const char *s, unsigned int count); +void serial8250_console_write_atomic(struct uart_8250_port *up, const char *s, + unsigned int count); int serial8250_console_setup(struct uart_port *port, char *options, bool probe); extern void serial8250_set_isa_configurator(void (*v) Index: linux-5.0.19-rt11/include/linux/signal.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/signal.h +++ linux-5.0.19-rt11/include/linux/signal.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:258 @ static inline void init_sigpending(struc } extern void flush_sigqueue(struct sigpending *queue); +extern void flush_task_sigqueue(struct task_struct *tsk); /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ static inline int valid_signal(unsigned long sig) Index: linux-5.0.19-rt11/include/linux/skbuff.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/skbuff.h +++ linux-5.0.19-rt11/include/linux/skbuff.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:292 @ struct sk_buff_head { __u32 qlen; spinlock_t lock; + raw_spinlock_t raw_lock; }; struct sk_buff; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1752 @ static inline void skb_queue_head_init(s __skb_queue_head_init(list); } +static inline void skb_queue_head_init_raw(struct sk_buff_head *list) +{ + raw_spin_lock_init(&list->raw_lock); + __skb_queue_head_init(list); +} + static inline void skb_queue_head_init_class(struct sk_buff_head *list, struct lock_class_key *class) { Index: linux-5.0.19-rt11/include/linux/smp.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/smp.h +++ linux-5.0.19-rt11/include/linux/smp.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:209 @ static inline int get_boot_cpu_id(void) #define get_cpu() ({ preempt_disable(); smp_processor_id(); }) #define put_cpu() preempt_enable() +#define get_cpu_light() ({ migrate_disable(); smp_processor_id(); }) +#define put_cpu_light() migrate_enable() + /* * Callback to arch code if there's nosmp or maxcpus=0 on the * boot command line: Index: linux-5.0.19-rt11/include/linux/spinlock.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/spinlock.h +++ linux-5.0.19-rt11/include/linux/spinlock.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:301 @ static inline void do_raw_spin_unlock(ra }) /* Include rwlock functions */ -#include <linux/rwlock.h> +#ifdef CONFIG_PREEMPT_RT_FULL +# include <linux/rwlock_rt.h> +#else +# include <linux/rwlock.h> +#endif /* * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:316 @ static inline void do_raw_spin_unlock(ra # include <linux/spinlock_api_up.h> #endif +#ifdef CONFIG_PREEMPT_RT_FULL +# include <linux/spinlock_rt.h> +#else /* PREEMPT_RT_FULL */ + /* * Map the spin_lock functions to the raw variants for PREEMPT_RT=n */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:440 @ static __always_inline int spin_is_conte #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) +#endif /* !PREEMPT_RT_FULL */ + /* * Pull the atomic_t declaration: * (asm-mips/atomic.h needs above definitions) Index: linux-5.0.19-rt11/include/linux/spinlock_api_smp.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/spinlock_api_smp.h +++ linux-5.0.19-rt11/include/linux/spinlock_api_smp.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:190 @ static inline int __raw_spin_trylock_bh( return 0; } -#include <linux/rwlock_api_smp.h> +#ifndef CONFIG_PREEMPT_RT_FULL +# include <linux/rwlock_api_smp.h> +#endif #endif /* __LINUX_SPINLOCK_API_SMP_H */ Index: linux-5.0.19-rt11/include/linux/spinlock_rt.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/spinlock_rt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_SPINLOCK_RT_H +#define __LINUX_SPINLOCK_RT_H + +#ifndef __LINUX_SPINLOCK_H +#error Do not include directly. Use spinlock.h +#endif + +#include <linux/bug.h> + +extern void +__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key); + +#define spin_lock_init(slock) \ +do { \ + static struct lock_class_key __key; \ + \ + rt_mutex_init(&(slock)->lock); \ + __rt_spin_lock_init(slock, #slock, &__key); \ +} while (0) + +extern void __lockfunc rt_spin_lock(spinlock_t *lock); +extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock); +extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass); +extern void __lockfunc rt_spin_unlock(spinlock_t *lock); +extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock); +extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags); +extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock); +extern int __lockfunc rt_spin_trylock(spinlock_t *lock); +extern int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock); + +/* + * lockdep-less calls, for derived types like rwlock: + * (for trylock they can use rt_mutex_trylock() directly. + * Migrate disable handling must be done at the call site. + */ +extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock); +extern void __lockfunc __rt_spin_trylock(struct rt_mutex *lock); +extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock); + +#define spin_lock(lock) rt_spin_lock(lock) + +#define spin_lock_bh(lock) \ + do { \ + local_bh_disable(); \ + rt_spin_lock(lock); \ + } while (0) + +#define spin_lock_irq(lock) spin_lock(lock) + +#define spin_do_trylock(lock) __cond_lock(lock, rt_spin_trylock(lock)) + +#define spin_trylock(lock) \ +({ \ + int __locked; \ + __locked = spin_do_trylock(lock); \ + __locked; \ +}) + +#ifdef CONFIG_LOCKDEP +# define spin_lock_nested(lock, subclass) \ + do { \ + rt_spin_lock_nested(lock, subclass); \ + } while (0) + +#define spin_lock_bh_nested(lock, subclass) \ + do { \ + local_bh_disable(); \ + rt_spin_lock_nested(lock, subclass); \ + } while (0) + +# define spin_lock_irqsave_nested(lock, flags, subclass) \ + do { \ + typecheck(unsigned long, flags); \ + flags = 0; \ + rt_spin_lock_nested(lock, subclass); \ + } while (0) +#else +# define spin_lock_nested(lock, subclass) spin_lock(lock) +# define spin_lock_bh_nested(lock, subclass) spin_lock_bh(lock) + +# define spin_lock_irqsave_nested(lock, flags, subclass) \ + do { \ + typecheck(unsigned long, flags); \ + flags = 0; \ + spin_lock(lock); \ + } while (0) +#endif + +#define spin_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + flags = 0; \ + spin_lock(lock); \ + } while (0) + +static inline unsigned long spin_lock_trace_flags(spinlock_t *lock) +{ + unsigned long flags = 0; +#ifdef CONFIG_TRACE_IRQFLAGS + flags = rt_spin_lock_trace_flags(lock); +#else + spin_lock(lock); /* lock_local */ +#endif + return flags; +} + +/* FIXME: we need rt_spin_lock_nest_lock */ +#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0) + +#define spin_unlock(lock) rt_spin_unlock(lock) + +#define spin_unlock_bh(lock) \ + do { \ + rt_spin_unlock(lock); \ + local_bh_enable(); \ + } while (0) + +#define spin_unlock_irq(lock) spin_unlock(lock) + +#define spin_unlock_irqrestore(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + (void) flags; \ + spin_unlock(lock); \ + } while (0) + +#define spin_trylock_bh(lock) __cond_lock(lock, rt_spin_trylock_bh(lock)) +#define spin_trylock_irq(lock) spin_trylock(lock) + +#define spin_trylock_irqsave(lock, flags) \ + rt_spin_trylock_irqsave(lock, &(flags)) + +#define spin_unlock_wait(lock) rt_spin_unlock_wait(lock) + +#ifdef CONFIG_GENERIC_LOCKBREAK +# define spin_is_contended(lock) ((lock)->break_lock) +#else +# define spin_is_contended(lock) (((void)(lock), 0)) +#endif + +static inline int spin_can_lock(spinlock_t *lock) +{ + return !rt_mutex_is_locked(&lock->lock); +} + +static inline int spin_is_locked(spinlock_t *lock) +{ + return rt_mutex_is_locked(&lock->lock); +} + +static inline void assert_spin_locked(spinlock_t *lock) +{ + BUG_ON(!spin_is_locked(lock)); +} + +#endif Index: linux-5.0.19-rt11/include/linux/spinlock_types.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/spinlock_types.h +++ linux-5.0.19-rt11/include/linux/spinlock_types.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:12 @ * Released under the General Public License (GPL). */ -#if defined(CONFIG_SMP) -# include <asm/spinlock_types.h> -#else -# include <linux/spinlock_types_up.h> -#endif - -#include <linux/lockdep.h> - -typedef struct raw_spinlock { - arch_spinlock_t raw_lock; -#ifdef CONFIG_DEBUG_SPINLOCK - unsigned int magic, owner_cpu; - void *owner; -#endif -#ifdef CONFIG_DEBUG_LOCK_ALLOC - struct lockdep_map dep_map; -#endif -} raw_spinlock_t; - -#define SPINLOCK_MAGIC 0xdead4ead - -#define SPINLOCK_OWNER_INIT ((void *)-1L) - -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname } -#else -# define SPIN_DEP_MAP_INIT(lockname) -#endif +#include <linux/spinlock_types_raw.h> -#ifdef CONFIG_DEBUG_SPINLOCK -# define SPIN_DEBUG_INIT(lockname) \ - .magic = SPINLOCK_MAGIC, \ - .owner_cpu = -1, \ - .owner = SPINLOCK_OWNER_INIT, +#ifndef CONFIG_PREEMPT_RT_FULL +# include <linux/spinlock_types_nort.h> +# include <linux/rwlock_types.h> #else -# define SPIN_DEBUG_INIT(lockname) +# include <linux/rtmutex.h> +# include <linux/spinlock_types_rt.h> +# include <linux/rwlock_types_rt.h> #endif -#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \ - { \ - .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \ - SPIN_DEBUG_INIT(lockname) \ - SPIN_DEP_MAP_INIT(lockname) } - -#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \ - (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname) - -#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x) - -typedef struct spinlock { - union { - struct raw_spinlock rlock; - -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map)) - struct { - u8 __padding[LOCK_PADSIZE]; - struct lockdep_map dep_map; - }; -#endif - }; -} spinlock_t; - -#define __SPIN_LOCK_INITIALIZER(lockname) \ - { { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } } - -#define __SPIN_LOCK_UNLOCKED(lockname) \ - (spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname) - -#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x) - -#include <linux/rwlock_types.h> - #endif /* __LINUX_SPINLOCK_TYPES_H */ Index: linux-5.0.19-rt11/include/linux/spinlock_types_nort.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/spinlock_types_nort.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_SPINLOCK_TYPES_NORT_H +#define __LINUX_SPINLOCK_TYPES_NORT_H + +#ifndef __LINUX_SPINLOCK_TYPES_H +#error "Do not include directly. Include spinlock_types.h instead" +#endif + +/* + * The non RT version maps spinlocks to raw_spinlocks + */ +typedef struct spinlock { + union { + struct raw_spinlock rlock; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map)) + struct { + u8 __padding[LOCK_PADSIZE]; + struct lockdep_map dep_map; + }; +#endif + }; +} spinlock_t; + +#define __SPIN_LOCK_INITIALIZER(lockname) \ + { { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } } + +#define __SPIN_LOCK_UNLOCKED(lockname) \ + (spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname) + +#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x) + +#endif Index: linux-5.0.19-rt11/include/linux/spinlock_types_raw.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/spinlock_types_raw.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_SPINLOCK_TYPES_RAW_H +#define __LINUX_SPINLOCK_TYPES_RAW_H + +#include <linux/types.h> + +#if defined(CONFIG_SMP) +# include <asm/spinlock_types.h> +#else +# include <linux/spinlock_types_up.h> +#endif + +#include <linux/lockdep.h> + +typedef struct raw_spinlock { + arch_spinlock_t raw_lock; +#ifdef CONFIG_DEBUG_SPINLOCK + unsigned int magic, owner_cpu; + void *owner; +#endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} raw_spinlock_t; + +#define SPINLOCK_MAGIC 0xdead4ead + +#define SPINLOCK_OWNER_INIT ((void *)-1L) + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname } +#else +# define SPIN_DEP_MAP_INIT(lockname) +#endif + +#ifdef CONFIG_DEBUG_SPINLOCK +# define SPIN_DEBUG_INIT(lockname) \ + .magic = SPINLOCK_MAGIC, \ + .owner_cpu = -1, \ + .owner = SPINLOCK_OWNER_INIT, +#else +# define SPIN_DEBUG_INIT(lockname) +#endif + +#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \ + { \ + .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \ + SPIN_DEBUG_INIT(lockname) \ + SPIN_DEP_MAP_INIT(lockname) } + +#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \ + (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname) + +#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x) + +#endif Index: linux-5.0.19-rt11/include/linux/spinlock_types_rt.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/linux/spinlock_types_rt.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __LINUX_SPINLOCK_TYPES_RT_H +#define __LINUX_SPINLOCK_TYPES_RT_H + +#ifndef __LINUX_SPINLOCK_TYPES_H +#error "Do not include directly. Include spinlock_types.h instead" +#endif + +#include <linux/cache.h> + +/* + * PREEMPT_RT: spinlocks - an RT mutex plus lock-break field: + */ +typedef struct spinlock { + struct rt_mutex lock; + unsigned int break_lock; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} spinlock_t; + +#ifdef CONFIG_DEBUG_RT_MUTEXES +# define __RT_SPIN_INITIALIZER(name) \ + { \ + .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ + .save_state = 1, \ + .file = __FILE__, \ + .line = __LINE__ , \ + } +#else +# define __RT_SPIN_INITIALIZER(name) \ + { \ + .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ + .save_state = 1, \ + } +#endif + +/* +.wait_list = PLIST_HEAD_INIT_RAW((name).lock.wait_list, (name).lock.wait_lock) +*/ + +#define __SPIN_LOCK_UNLOCKED(name) \ + { .lock = __RT_SPIN_INITIALIZER(name.lock), \ + SPIN_DEP_MAP_INIT(name) } + +#define DEFINE_SPINLOCK(name) \ + spinlock_t name = __SPIN_LOCK_UNLOCKED(name) + +#endif Index: linux-5.0.19-rt11/include/linux/spinlock_types_up.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/spinlock_types_up.h +++ linux-5.0.19-rt11/include/linux/spinlock_types_up.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3 @ #ifndef __LINUX_SPINLOCK_TYPES_UP_H #define __LINUX_SPINLOCK_TYPES_UP_H -#ifndef __LINUX_SPINLOCK_TYPES_H -# error "please don't include this file directly" -#endif - /* * include/linux/spinlock_types_up.h - spinlock type definitions for UP * Index: linux-5.0.19-rt11/include/linux/srcutree.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/srcutree.h +++ linux-5.0.19-rt11/include/linux/srcutree.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:48 @ struct srcu_data { unsigned long srcu_gp_seq_needed; /* Furthest future GP needed. */ unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */ bool srcu_cblist_invoking; /* Invoking these CBs? */ - struct delayed_work work; /* Context for CB invoking. */ + struct timer_list delay_work; /* Delay for CB invoking */ + struct work_struct work; /* Context for CB invoking. */ struct rcu_head srcu_barrier_head; /* For srcu_barrier() use. */ struct srcu_node *mynode; /* Leaf srcu_node. */ unsigned long grpmask; /* Mask for leaf srcu_node */ Index: linux-5.0.19-rt11/include/linux/suspend.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/suspend.h +++ linux-5.0.19-rt11/include/linux/suspend.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:199 @ struct platform_s2idle_ops { void (*end)(void); }; +#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION) +extern bool pm_in_action; +#else +# define pm_in_action false +#endif + #ifdef CONFIG_SUSPEND extern suspend_state_t mem_sleep_current; extern suspend_state_t mem_sleep_default; Index: linux-5.0.19-rt11/include/linux/swait.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/swait.h +++ linux-5.0.19-rt11/include/linux/swait.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:163 @ static inline bool swq_has_sleeper(struc extern void swake_up_one(struct swait_queue_head *q); extern void swake_up_all(struct swait_queue_head *q); extern void swake_up_locked(struct swait_queue_head *q); +extern void swake_up_all_locked(struct swait_queue_head *q); +extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); extern void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state); extern long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:302 @ do { \ __ret; \ }) +#define __swait_event_lock_irq(wq, condition, lock, cmd) \ + ___swait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, \ + raw_spin_unlock_irq(&lock); \ + cmd; \ + schedule(); \ + raw_spin_lock_irq(&lock)) + +#define swait_event_lock_irq(wq_head, condition, lock) \ + do { \ + if (condition) \ + break; \ + __swait_event_lock_irq(wq_head, condition, lock, ); \ + } while (0) + #endif /* _LINUX_SWAIT_H */ Index: linux-5.0.19-rt11/include/linux/swap.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/swap.h +++ linux-5.0.19-rt11/include/linux/swap.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:15 @ #include <linux/fs.h> #include <linux/atomic.h> #include <linux/page-flags.h> +#include <linux/locallock.h> #include <asm/page.h> struct notifier_block; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:332 @ extern unsigned long nr_free_pagecache_p /* linux/mm/swap.c */ +DECLARE_LOCAL_IRQ_LOCK(swapvec_lock); extern void lru_cache_add(struct page *); extern void lru_cache_add_anon(struct page *page); extern void lru_cache_add_file(struct page *page); Index: linux-5.0.19-rt11/include/linux/thread_info.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/thread_info.h +++ linux-5.0.19-rt11/include/linux/thread_info.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:100 @ static inline int test_ti_thread_flag(st #define test_thread_flag(flag) \ test_ti_thread_flag(current_thread_info(), flag) -#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) +#ifdef CONFIG_PREEMPT_LAZY +#define tif_need_resched() (test_thread_flag(TIF_NEED_RESCHED) || \ + test_thread_flag(TIF_NEED_RESCHED_LAZY)) +#define tif_need_resched_now() (test_thread_flag(TIF_NEED_RESCHED)) +#define tif_need_resched_lazy() test_thread_flag(TIF_NEED_RESCHED_LAZY)) + +#else +#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) +#define tif_need_resched_now() test_thread_flag(TIF_NEED_RESCHED) +#define tif_need_resched_lazy() 0 +#endif #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES static inline int arch_within_stack_frames(const void * const stack, Index: linux-5.0.19-rt11/include/linux/timer.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/timer.h +++ linux-5.0.19-rt11/include/linux/timer.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:175 @ extern void add_timer(struct timer_list extern int try_to_del_timer_sync(struct timer_list *timer); -#ifdef CONFIG_SMP +#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL) extern int del_timer_sync(struct timer_list *timer); #else # define del_timer_sync(t) del_timer(t) Index: linux-5.0.19-rt11/include/linux/trace_events.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/trace_events.h +++ linux-5.0.19-rt11/include/linux/trace_events.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:65 @ struct trace_entry { unsigned char flags; unsigned char preempt_count; int pid; + unsigned short migrate_disable; + unsigned short padding; + unsigned char preempt_lazy_count; }; #define TRACE_EVENT_TYPE_MAX \ Index: linux-5.0.19-rt11/include/linux/uaccess.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/uaccess.h +++ linux-5.0.19-rt11/include/linux/uaccess.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:185 @ static __always_inline void pagefault_di */ static inline void pagefault_disable(void) { + migrate_disable(); pagefault_disabled_inc(); /* * make sure to have issued the store before a pagefault @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:202 @ static inline void pagefault_enable(void */ barrier(); pagefault_disabled_dec(); + migrate_enable(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:273 @ extern long strncpy_from_unsafe(char *ds #define user_access_end() do { } while (0) #define unsafe_get_user(x, ptr, err) do { if (unlikely(__get_user(x, ptr))) goto err; } while (0) #define unsafe_put_user(x, ptr, err) do { if (unlikely(__put_user(x, ptr))) goto err; } while (0) +static inline unsigned long user_access_save(void) { return 0UL; } +static inline void user_access_restore(unsigned long flags) { } #endif #ifdef CONFIG_HARDENED_USERCOPY Index: linux-5.0.19-rt11/include/linux/vmstat.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/vmstat.h +++ linux-5.0.19-rt11/include/linux/vmstat.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:57 @ DECLARE_PER_CPU(struct vm_event_state, v */ static inline void __count_vm_event(enum vm_event_item item) { + preempt_disable_rt(); raw_cpu_inc(vm_event_states.event[item]); + preempt_enable_rt(); } static inline void count_vm_event(enum vm_event_item item) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:69 @ static inline void count_vm_event(enum v static inline void __count_vm_events(enum vm_event_item item, long delta) { + preempt_disable_rt(); raw_cpu_add(vm_event_states.event[item], delta); + preempt_enable_rt(); } static inline void count_vm_events(enum vm_event_item item, long delta) Index: linux-5.0.19-rt11/include/linux/wait.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/wait.h +++ linux-5.0.19-rt11/include/linux/wait.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:13 @ #include <asm/current.h> #include <uapi/linux/wait.h> +#include <linux/atomic.h> typedef struct wait_queue_entry wait_queue_entry_t; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:492 @ do { \ int __ret = 0; \ struct hrtimer_sleeper __t; \ \ - hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); \ - hrtimer_init_sleeper(&__t, current); \ + hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, HRTIMER_MODE_REL, \ + current); \ if ((timeout) != KTIME_MAX) \ hrtimer_start_range_ns(&__t.timer, timeout, \ current->timer_slack_ns, \ Index: linux-5.0.19-rt11/include/linux/workqueue.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/workqueue.h +++ linux-5.0.19-rt11/include/linux/workqueue.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:458 @ __alloc_workqueue_key(const char *fmt, u extern void destroy_workqueue(struct workqueue_struct *wq); -struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask); -void free_workqueue_attrs(struct workqueue_attrs *attrs); -int apply_workqueue_attrs(struct workqueue_struct *wq, - const struct workqueue_attrs *attrs); int workqueue_set_unbound_cpumask(cpumask_var_t cpumask); extern bool queue_work_on(int cpu, struct workqueue_struct *wq, Index: linux-5.0.19-rt11/include/net/gen_stats.h =================================================================== --- linux-5.0.19-rt11.orig/include/net/gen_stats.h +++ linux-5.0.19-rt11/include/net/gen_stats.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:9 @ #include <linux/socket.h> #include <linux/rtnetlink.h> #include <linux/pkt_sched.h> +#include <net/net_seq_lock.h> struct gnet_stats_basic_cpu { struct gnet_stats_basic_packed bstats; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:40 @ int gnet_stats_start_copy_compat(struct spinlock_t *lock, struct gnet_dump *d, int padattr); -int gnet_stats_copy_basic(const seqcount_t *running, +int gnet_stats_copy_basic(net_seqlock_t *running, struct gnet_dump *d, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b); -void __gnet_stats_copy_basic(const seqcount_t *running, +void __gnet_stats_copy_basic(net_seqlock_t *running, struct gnet_stats_basic_packed *bstats, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b); -int gnet_stats_copy_basic_hw(const seqcount_t *running, +int gnet_stats_copy_basic_hw(net_seqlock_t *running, struct gnet_dump *d, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:68 @ int gen_new_estimator(struct gnet_stats_ struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct net_rate_estimator __rcu **rate_est, spinlock_t *lock, - seqcount_t *running, struct nlattr *opt); + net_seqlock_t *running, struct nlattr *opt); void gen_kill_estimator(struct net_rate_estimator __rcu **ptr); int gen_replace_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct net_rate_estimator __rcu **ptr, spinlock_t *lock, - seqcount_t *running, struct nlattr *opt); + net_seqlock_t *running, struct nlattr *opt); bool gen_estimator_active(struct net_rate_estimator __rcu **ptr); bool gen_estimator_read(struct net_rate_estimator __rcu **ptr, struct gnet_stats_rate_est64 *sample); Index: linux-5.0.19-rt11/include/net/neighbour.h =================================================================== --- linux-5.0.19-rt11.orig/include/net/neighbour.h +++ linux-5.0.19-rt11/include/net/neighbour.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:461 @ static inline int neigh_hh_bridge(struct } #endif -static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) +static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) { unsigned int hh_alen = 0; unsigned int seq; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:503 @ static inline int neigh_hh_output(const static inline int neigh_output(struct neighbour *n, struct sk_buff *skb) { - const struct hh_cache *hh = &n->hh; + struct hh_cache *hh = &n->hh; if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) return neigh_hh_output(hh, skb); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:544 @ struct neighbour_cb { #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) -static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, +static inline void neigh_ha_snapshot(char *dst, struct neighbour *n, const struct net_device *dev) { unsigned int seq; Index: linux-5.0.19-rt11/include/net/net_seq_lock.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/net/net_seq_lock.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +#ifndef __NET_NET_SEQ_LOCK_H__ +#define __NET_NET_SEQ_LOCK_H__ + +#ifdef CONFIG_PREEMPT_RT_BASE +# define net_seqlock_t seqlock_t +# define net_seq_begin(__r) read_seqbegin(__r) +# define net_seq_retry(__r, __s) read_seqretry(__r, __s) + +#else +# define net_seqlock_t seqcount_t +# define net_seq_begin(__r) read_seqcount_begin(__r) +# define net_seq_retry(__r, __s) read_seqcount_retry(__r, __s) +#endif + +#endif Index: linux-5.0.19-rt11/include/net/sch_generic.h =================================================================== --- linux-5.0.19-rt11.orig/include/net/sch_generic.h +++ linux-5.0.19-rt11/include/net/sch_generic.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:13 @ #include <linux/percpu.h> #include <linux/dynamic_queue_limits.h> #include <linux/list.h> +#include <net/net_seq_lock.h> #include <linux/refcount.h> #include <linux/workqueue.h> #include <net/gen_stats.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:108 @ struct Qdisc { struct sk_buff_head gso_skb ____cacheline_aligned_in_smp; struct qdisc_skb_head q; struct gnet_stats_basic_packed bstats; - seqcount_t running; + net_seqlock_t running; struct gnet_stats_queue qstats; unsigned long state; struct Qdisc *next_sched; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:143 @ static inline bool qdisc_is_running(stru { if (qdisc->flags & TCQ_F_NOLOCK) return spin_is_locked(&qdisc->seqlock); +#ifdef CONFIG_PREEMPT_RT_BASE + return spin_is_locked(&qdisc->running.lock) ? true : false; +#else return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; +#endif } static inline bool qdisc_run_begin(struct Qdisc *qdisc) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:158 @ static inline bool qdisc_run_begin(struc } else if (qdisc_is_running(qdisc)) { return false; } +#ifdef CONFIG_PREEMPT_RT_BASE + if (try_write_seqlock(&qdisc->running)) + return true; + return false; +#else /* Variant of write_seqcount_begin() telling lockdep a trylock * was attempted. */ raw_write_seqcount_begin(&qdisc->running); seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); return true; +#endif } static inline void qdisc_run_end(struct Qdisc *qdisc) { +#ifdef CONFIG_PREEMPT_RT_BASE + write_sequnlock(&qdisc->running); +#else write_seqcount_end(&qdisc->running); +#endif if (qdisc->flags & TCQ_F_NOLOCK) spin_unlock(&qdisc->seqlock); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:495 @ static inline spinlock_t *qdisc_root_sle return qdisc_lock(root); } -static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) +static inline net_seqlock_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) { struct Qdisc *root = qdisc_root_sleeping(qdisc); Index: linux-5.0.19-rt11/include/linux/atmel_tc.h =================================================================== --- linux-5.0.19-rt11.orig/include/linux/atmel_tc.h +++ /dev/null @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1 @ -/* - * Timer/Counter Unit (TC) registers. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - */ - -#ifndef ATMEL_TC_H -#define ATMEL_TC_H - -#include <linux/compiler.h> -#include <linux/list.h> - -/* - * Many 32-bit Atmel SOCs include one or more TC blocks, each of which holds - * three general-purpose 16-bit timers. These timers share one register bank. - * Depending on the SOC, each timer may have its own clock and IRQ, or those - * may be shared by the whole TC block. - * - * These TC blocks may have up to nine external pins: TCLK0..2 signals for - * clocks or clock gates, and per-timer TIOA and TIOB signals used for PWM - * or triggering. Those pins need to be set up for use with the TC block, - * else they will be used as GPIOs or for a different controller. - * - * Although we expect each TC block to have a platform_device node, those - * nodes are not what drivers bind to. Instead, they ask for a specific - * TC block, by number ... which is a common approach on systems with many - * timers. Then they use clk_get() and platform_get_irq() to get clock and - * IRQ resources. - */ - -struct clk; - -/** - * struct atmel_tcb_config - SoC data for a Timer/Counter Block - * @counter_width: size in bits of a timer counter register - */ -struct atmel_tcb_config { - size_t counter_width; -}; - -/** - * struct atmel_tc - information about a Timer/Counter Block - * @pdev: physical device - * @regs: mapping through which the I/O registers can be accessed - * @id: block id - * @tcb_config: configuration data from SoC - * @irq: irq for each of the three channels - * @clk: internal clock source for each of the three channels - * @node: list node, for tclib internal use - * @allocated: if already used, for tclib internal use - * - * On some platforms, each TC channel has its own clocks and IRQs, - * while on others, all TC channels share the same clock and IRQ. - * Drivers should clk_enable() all the clocks they need even though - * all the entries in @clk may point to the same physical clock. - * Likewise, drivers should request irqs independently for each - * channel, but they must use IRQF_SHARED in case some of the entries - * in @irq are actually the same IRQ. - */ -struct atmel_tc { - struct platform_device *pdev; - void __iomem *regs; - int id; - const struct atmel_tcb_config *tcb_config; - int irq[3]; - struct clk *clk[3]; - struct clk *slow_clk; - struct list_head node; - bool allocated; -}; - -extern struct atmel_tc *atmel_tc_alloc(unsigned block); -extern void atmel_tc_free(struct atmel_tc *tc); - -/* platform-specific ATMEL_TC_TIMER_CLOCKx divisors (0 means 32KiHz) */ -extern const u8 atmel_tc_divisors[5]; - - -/* - * Two registers have block-wide controls. These are: configuring the three - * "external" clocks (or event sources) used by the timer channels; and - * synchronizing the timers by resetting them all at once. - * - * "External" can mean "external to chip" using the TCLK0, TCLK1, or TCLK2 - * signals. Or, it can mean "external to timer", using the TIOA output from - * one of the other two timers that's being run in waveform mode. - */ - -#define ATMEL_TC_BCR 0xc0 /* TC Block Control Register */ -#define ATMEL_TC_SYNC (1 << 0) /* synchronize timers */ - -#define ATMEL_TC_BMR 0xc4 /* TC Block Mode Register */ -#define ATMEL_TC_TC0XC0S (3 << 0) /* external clock 0 source */ -#define ATMEL_TC_TC0XC0S_TCLK0 (0 << 0) -#define ATMEL_TC_TC0XC0S_NONE (1 << 0) -#define ATMEL_TC_TC0XC0S_TIOA1 (2 << 0) -#define ATMEL_TC_TC0XC0S_TIOA2 (3 << 0) -#define ATMEL_TC_TC1XC1S (3 << 2) /* external clock 1 source */ -#define ATMEL_TC_TC1XC1S_TCLK1 (0 << 2) -#define ATMEL_TC_TC1XC1S_NONE (1 << 2) -#define ATMEL_TC_TC1XC1S_TIOA0 (2 << 2) -#define ATMEL_TC_TC1XC1S_TIOA2 (3 << 2) -#define ATMEL_TC_TC2XC2S (3 << 4) /* external clock 2 source */ -#define ATMEL_TC_TC2XC2S_TCLK2 (0 << 4) -#define ATMEL_TC_TC2XC2S_NONE (1 << 4) -#define ATMEL_TC_TC2XC2S_TIOA0 (2 << 4) -#define ATMEL_TC_TC2XC2S_TIOA1 (3 << 4) - - -/* - * Each TC block has three "channels", each with one counter and controls. - * - * Note that the semantics of ATMEL_TC_TIMER_CLOCKx (input clock selection - * when it's not "external") is silicon-specific. AT91 platforms use one - * set of definitions; AVR32 platforms use a different set. Don't hard-wire - * such knowledge into your code, use the global "atmel_tc_divisors" ... - * where index N is the divisor for clock N+1, else zero to indicate it uses - * the 32 KiHz clock. - * - * The timers can be chained in various ways, and operated in "waveform" - * generation mode (including PWM) or "capture" mode (to time events). In - * both modes, behavior can be configured in many ways. - * - * Each timer has two I/O pins, TIOA and TIOB. Waveform mode uses TIOA as a - * PWM output, and TIOB as either another PWM or as a trigger. Capture mode - * uses them only as inputs. - */ -#define ATMEL_TC_CHAN(idx) ((idx)*0x40) -#define ATMEL_TC_REG(idx, reg) (ATMEL_TC_CHAN(idx) + ATMEL_TC_ ## reg) - -#define ATMEL_TC_CCR 0x00 /* Channel Control Register */ -#define ATMEL_TC_CLKEN (1 << 0) /* clock enable */ -#define ATMEL_TC_CLKDIS (1 << 1) /* clock disable */ -#define ATMEL_TC_SWTRG (1 << 2) /* software trigger */ - -#define ATMEL_TC_CMR 0x04 /* Channel Mode Register */ - -/* Both modes share some CMR bits */ -#define ATMEL_TC_TCCLKS (7 << 0) /* clock source */ -#define ATMEL_TC_TIMER_CLOCK1 (0 << 0) -#define ATMEL_TC_TIMER_CLOCK2 (1 << 0) -#define ATMEL_TC_TIMER_CLOCK3 (2 << 0) -#define ATMEL_TC_TIMER_CLOCK4 (3 << 0) -#define ATMEL_TC_TIMER_CLOCK5 (4 << 0) -#define ATMEL_TC_XC0 (5 << 0) -#define ATMEL_TC_XC1 (6 << 0) -#define ATMEL_TC_XC2 (7 << 0) -#define ATMEL_TC_CLKI (1 << 3) /* clock invert */ -#define ATMEL_TC_BURST (3 << 4) /* clock gating */ -#define ATMEL_TC_GATE_NONE (0 << 4) -#define ATMEL_TC_GATE_XC0 (1 << 4) -#define ATMEL_TC_GATE_XC1 (2 << 4) -#define ATMEL_TC_GATE_XC2 (3 << 4) -#define ATMEL_TC_WAVE (1 << 15) /* true = Waveform mode */ - -/* CAPTURE mode CMR bits */ -#define ATMEL_TC_LDBSTOP (1 << 6) /* counter stops on RB load */ -#define ATMEL_TC_LDBDIS (1 << 7) /* counter disable on RB load */ -#define ATMEL_TC_ETRGEDG (3 << 8) /* external trigger edge */ -#define ATMEL_TC_ETRGEDG_NONE (0 << 8) -#define ATMEL_TC_ETRGEDG_RISING (1 << 8) -#define ATMEL_TC_ETRGEDG_FALLING (2 << 8) -#define ATMEL_TC_ETRGEDG_BOTH (3 << 8) -#define ATMEL_TC_ABETRG (1 << 10) /* external trigger is TIOA? */ -#define ATMEL_TC_CPCTRG (1 << 14) /* RC compare trigger enable */ -#define ATMEL_TC_LDRA (3 << 16) /* RA loading edge (of TIOA) */ -#define ATMEL_TC_LDRA_NONE (0 << 16) -#define ATMEL_TC_LDRA_RISING (1 << 16) -#define ATMEL_TC_LDRA_FALLING (2 << 16) -#define ATMEL_TC_LDRA_BOTH (3 << 16) -#define ATMEL_TC_LDRB (3 << 18) /* RB loading edge (of TIOA) */ -#define ATMEL_TC_LDRB_NONE (0 << 18) -#define ATMEL_TC_LDRB_RISING (1 << 18) -#define ATMEL_TC_LDRB_FALLING (2 << 18) -#define ATMEL_TC_LDRB_BOTH (3 << 18) - -/* WAVEFORM mode CMR bits */ -#define ATMEL_TC_CPCSTOP (1 << 6) /* RC compare stops counter */ -#define ATMEL_TC_CPCDIS (1 << 7) /* RC compare disables counter */ -#define ATMEL_TC_EEVTEDG (3 << 8) /* external event edge */ -#define ATMEL_TC_EEVTEDG_NONE (0 << 8) -#define ATMEL_TC_EEVTEDG_RISING (1 << 8) -#define ATMEL_TC_EEVTEDG_FALLING (2 << 8) -#define ATMEL_TC_EEVTEDG_BOTH (3 << 8) -#define ATMEL_TC_EEVT (3 << 10) /* external event source */ -#define ATMEL_TC_EEVT_TIOB (0 << 10) -#define ATMEL_TC_EEVT_XC0 (1 << 10) -#define ATMEL_TC_EEVT_XC1 (2 << 10) -#define ATMEL_TC_EEVT_XC2 (3 << 10) -#define ATMEL_TC_ENETRG (1 << 12) /* external event is trigger */ -#define ATMEL_TC_WAVESEL (3 << 13) /* waveform type */ -#define ATMEL_TC_WAVESEL_UP (0 << 13) -#define ATMEL_TC_WAVESEL_UPDOWN (1 << 13) -#define ATMEL_TC_WAVESEL_UP_AUTO (2 << 13) -#define ATMEL_TC_WAVESEL_UPDOWN_AUTO (3 << 13) -#define ATMEL_TC_ACPA (3 << 16) /* RA compare changes TIOA */ -#define ATMEL_TC_ACPA_NONE (0 << 16) -#define ATMEL_TC_ACPA_SET (1 << 16) -#define ATMEL_TC_ACPA_CLEAR (2 << 16) -#define ATMEL_TC_ACPA_TOGGLE (3 << 16) -#define ATMEL_TC_ACPC (3 << 18) /* RC compare changes TIOA */ -#define ATMEL_TC_ACPC_NONE (0 << 18) -#define ATMEL_TC_ACPC_SET (1 << 18) -#define ATMEL_TC_ACPC_CLEAR (2 << 18) -#define ATMEL_TC_ACPC_TOGGLE (3 << 18) -#define ATMEL_TC_AEEVT (3 << 20) /* external event changes TIOA */ -#define ATMEL_TC_AEEVT_NONE (0 << 20) -#define ATMEL_TC_AEEVT_SET (1 << 20) -#define ATMEL_TC_AEEVT_CLEAR (2 << 20) -#define ATMEL_TC_AEEVT_TOGGLE (3 << 20) -#define ATMEL_TC_ASWTRG (3 << 22) /* software trigger changes TIOA */ -#define ATMEL_TC_ASWTRG_NONE (0 << 22) -#define ATMEL_TC_ASWTRG_SET (1 << 22) -#define ATMEL_TC_ASWTRG_CLEAR (2 << 22) -#define ATMEL_TC_ASWTRG_TOGGLE (3 << 22) -#define ATMEL_TC_BCPB (3 << 24) /* RB compare changes TIOB */ -#define ATMEL_TC_BCPB_NONE (0 << 24) -#define ATMEL_TC_BCPB_SET (1 << 24) -#define ATMEL_TC_BCPB_CLEAR (2 << 24) -#define ATMEL_TC_BCPB_TOGGLE (3 << 24) -#define ATMEL_TC_BCPC (3 << 26) /* RC compare changes TIOB */ -#define ATMEL_TC_BCPC_NONE (0 << 26) -#define ATMEL_TC_BCPC_SET (1 << 26) -#define ATMEL_TC_BCPC_CLEAR (2 << 26) -#define ATMEL_TC_BCPC_TOGGLE (3 << 26) -#define ATMEL_TC_BEEVT (3 << 28) /* external event changes TIOB */ -#define ATMEL_TC_BEEVT_NONE (0 << 28) -#define ATMEL_TC_BEEVT_SET (1 << 28) -#define ATMEL_TC_BEEVT_CLEAR (2 << 28) -#define ATMEL_TC_BEEVT_TOGGLE (3 << 28) -#define ATMEL_TC_BSWTRG (3 << 30) /* software trigger changes TIOB */ -#define ATMEL_TC_BSWTRG_NONE (0 << 30) -#define ATMEL_TC_BSWTRG_SET (1 << 30) -#define ATMEL_TC_BSWTRG_CLEAR (2 << 30) -#define ATMEL_TC_BSWTRG_TOGGLE (3 << 30) - -#define ATMEL_TC_CV 0x10 /* counter Value */ -#define ATMEL_TC_RA 0x14 /* register A */ -#define ATMEL_TC_RB 0x18 /* register B */ -#define ATMEL_TC_RC 0x1c /* register C */ - -#define ATMEL_TC_SR 0x20 /* status (read-only) */ -/* Status-only flags */ -#define ATMEL_TC_CLKSTA (1 << 16) /* clock enabled */ -#define ATMEL_TC_MTIOA (1 << 17) /* TIOA mirror */ -#define ATMEL_TC_MTIOB (1 << 18) /* TIOB mirror */ - -#define ATMEL_TC_IER 0x24 /* interrupt enable (write-only) */ -#define ATMEL_TC_IDR 0x28 /* interrupt disable (write-only) */ -#define ATMEL_TC_IMR 0x2c /* interrupt mask (read-only) */ - -/* Status and IRQ flags */ -#define ATMEL_TC_COVFS (1 << 0) /* counter overflow */ -#define ATMEL_TC_LOVRS (1 << 1) /* load overrun */ -#define ATMEL_TC_CPAS (1 << 2) /* RA compare */ -#define ATMEL_TC_CPBS (1 << 3) /* RB compare */ -#define ATMEL_TC_CPCS (1 << 4) /* RC compare */ -#define ATMEL_TC_LDRAS (1 << 5) /* RA loading */ -#define ATMEL_TC_LDRBS (1 << 6) /* RB loading */ -#define ATMEL_TC_ETRGS (1 << 7) /* external trigger */ -#define ATMEL_TC_ALL_IRQ (ATMEL_TC_COVFS | ATMEL_TC_LOVRS | \ - ATMEL_TC_CPAS | ATMEL_TC_CPBS | \ - ATMEL_TC_CPCS | ATMEL_TC_LDRAS | \ - ATMEL_TC_LDRBS | ATMEL_TC_ETRGS) \ - /* all IRQs */ - -#endif Index: linux-5.0.19-rt11/include/soc/at91/atmel_tcb.h =================================================================== --- /dev/null +++ linux-5.0.19-rt11/include/soc/at91/atmel_tcb.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +/* + * Timer/Counter Unit (TC) registers. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __SOC_ATMEL_TCB_H +#define __SOC_ATMEL_TCB_H + +#include <linux/compiler.h> +#include <linux/list.h> + +/* + * Many 32-bit Atmel SOCs include one or more TC blocks, each of which holds + * three general-purpose 16-bit timers. These timers share one register bank. + * Depending on the SOC, each timer may have its own clock and IRQ, or those + * may be shared by the whole TC block. + * + * These TC blocks may have up to nine external pins: TCLK0..2 signals for + * clocks or clock gates, and per-timer TIOA and TIOB signals used for PWM + * or triggering. Those pins need to be set up for use with the TC block, + * else they will be used as GPIOs or for a different controller. + * + * Although we expect each TC block to have a platform_device node, those + * nodes are not what drivers bind to. Instead, they ask for a specific + * TC block, by number ... which is a common approach on systems with many + * timers. Then they use clk_get() and platform_get_irq() to get clock and + * IRQ resources. + */ + +struct clk; + +/** + * struct atmel_tcb_config - SoC data for a Timer/Counter Block + * @counter_width: size in bits of a timer counter register + */ +struct atmel_tcb_config { + size_t counter_width; +}; + +/** + * struct atmel_tc - information about a Timer/Counter Block + * @pdev: physical device + * @regs: mapping through which the I/O registers can be accessed + * @id: block id + * @tcb_config: configuration data from SoC + * @irq: irq for each of the three channels + * @clk: internal clock source for each of the three channels + * @node: list node, for tclib internal use + * @allocated: if already used, for tclib internal use + * + * On some platforms, each TC channel has its own clocks and IRQs, + * while on others, all TC channels share the same clock and IRQ. + * Drivers should clk_enable() all the clocks they need even though + * all the entries in @clk may point to the same physical clock. + * Likewise, drivers should request irqs independently for each + * channel, but they must use IRQF_SHARED in case some of the entries + * in @irq are actually the same IRQ. + */ +struct atmel_tc { + struct platform_device *pdev; + void __iomem *regs; + int id; + const struct atmel_tcb_config *tcb_config; + int irq[3]; + struct clk *clk[3]; + struct clk *slow_clk; + struct list_head node; + bool allocated; +}; + +extern struct atmel_tc *atmel_tc_alloc(unsigned block); +extern void atmel_tc_free(struct atmel_tc *tc); + +/* platform-specific ATMEL_TC_TIMER_CLOCKx divisors (0 means 32KiHz) */ +extern const u8 atmel_tc_divisors[5]; + + +/* + * Two registers have block-wide controls. These are: configuring the three + * "external" clocks (or event sources) used by the timer channels; and + * synchronizing the timers by resetting them all at once. + * + * "External" can mean "external to chip" using the TCLK0, TCLK1, or TCLK2 + * signals. Or, it can mean "external to timer", using the TIOA output from + * one of the other two timers that's being run in waveform mode. + */ + +#define ATMEL_TC_BCR 0xc0 /* TC Block Control Register */ +#define ATMEL_TC_SYNC (1 << 0) /* synchronize timers */ + +#define ATMEL_TC_BMR 0xc4 /* TC Block Mode Register */ +#define ATMEL_TC_TC0XC0S (3 << 0) /* external clock 0 source */ +#define ATMEL_TC_TC0XC0S_TCLK0 (0 << 0) +#define ATMEL_TC_TC0XC0S_NONE (1 << 0) +#define ATMEL_TC_TC0XC0S_TIOA1 (2 << 0) +#define ATMEL_TC_TC0XC0S_TIOA2 (3 << 0) +#define ATMEL_TC_TC1XC1S (3 << 2) /* external clock 1 source */ +#define ATMEL_TC_TC1XC1S_TCLK1 (0 << 2) +#define ATMEL_TC_TC1XC1S_NONE (1 << 2) +#define ATMEL_TC_TC1XC1S_TIOA0 (2 << 2) +#define ATMEL_TC_TC1XC1S_TIOA2 (3 << 2) +#define ATMEL_TC_TC2XC2S (3 << 4) /* external clock 2 source */ +#define ATMEL_TC_TC2XC2S_TCLK2 (0 << 4) +#define ATMEL_TC_TC2XC2S_NONE (1 << 4) +#define ATMEL_TC_TC2XC2S_TIOA0 (2 << 4) +#define ATMEL_TC_TC2XC2S_TIOA1 (3 << 4) + + +/* + * Each TC block has three "channels", each with one counter and controls. + * + * Note that the semantics of ATMEL_TC_TIMER_CLOCKx (input clock selection + * when it's not "external") is silicon-specific. AT91 platforms use one + * set of definitions; AVR32 platforms use a different set. Don't hard-wire + * such knowledge into your code, use the global "atmel_tc_divisors" ... + * where index N is the divisor for clock N+1, else zero to indicate it uses + * the 32 KiHz clock. + * + * The timers can be chained in various ways, and operated in "waveform" + * generation mode (including PWM) or "capture" mode (to time events). In + * both modes, behavior can be configured in many ways. + * + * Each timer has two I/O pins, TIOA and TIOB. Waveform mode uses TIOA as a + * PWM output, and TIOB as either another PWM or as a trigger. Capture mode + * uses them only as inputs. + */ +#define ATMEL_TC_CHAN(idx) ((idx)*0x40) +#define ATMEL_TC_REG(idx, reg) (ATMEL_TC_CHAN(idx) + ATMEL_TC_ ## reg) + +#define ATMEL_TC_CCR 0x00 /* Channel Control Register */ +#define ATMEL_TC_CLKEN (1 << 0) /* clock enable */ +#define ATMEL_TC_CLKDIS (1 << 1) /* clock disable */ +#define ATMEL_TC_SWTRG (1 << 2) /* software trigger */ + +#define ATMEL_TC_CMR 0x04 /* Channel Mode Register */ + +/* Both modes share some CMR bits */ +#define ATMEL_TC_TCCLKS (7 << 0) /* clock source */ +#define ATMEL_TC_TIMER_CLOCK1 (0 << 0) +#define ATMEL_TC_TIMER_CLOCK2 (1 << 0) +#define ATMEL_TC_TIMER_CLOCK3 (2 << 0) +#define ATMEL_TC_TIMER_CLOCK4 (3 << 0) +#define ATMEL_TC_TIMER_CLOCK5 (4 << 0) +#define ATMEL_TC_XC0 (5 << 0) +#define ATMEL_TC_XC1 (6 << 0) +#define ATMEL_TC_XC2 (7 << 0) +#define ATMEL_TC_CLKI (1 << 3) /* clock invert */ +#define ATMEL_TC_BURST (3 << 4) /* clock gating */ +#define ATMEL_TC_GATE_NONE (0 << 4) +#define ATMEL_TC_GATE_XC0 (1 << 4) +#define ATMEL_TC_GATE_XC1 (2 << 4) +#define ATMEL_TC_GATE_XC2 (3 << 4) +#define ATMEL_TC_WAVE (1 << 15) /* true = Waveform mode */ + +/* CAPTURE mode CMR bits */ +#define ATMEL_TC_LDBSTOP (1 << 6) /* counter stops on RB load */ +#define ATMEL_TC_LDBDIS (1 << 7) /* counter disable on RB load */ +#define ATMEL_TC_ETRGEDG (3 << 8) /* external trigger edge */ +#define ATMEL_TC_ETRGEDG_NONE (0 << 8) +#define ATMEL_TC_ETRGEDG_RISING (1 << 8) +#define ATMEL_TC_ETRGEDG_FALLING (2 << 8) +#define ATMEL_TC_ETRGEDG_BOTH (3 << 8) +#define ATMEL_TC_ABETRG (1 << 10) /* external trigger is TIOA? */ +#define ATMEL_TC_CPCTRG (1 << 14) /* RC compare trigger enable */ +#define ATMEL_TC_LDRA (3 << 16) /* RA loading edge (of TIOA) */ +#define ATMEL_TC_LDRA_NONE (0 << 16) +#define ATMEL_TC_LDRA_RISING (1 << 16) +#define ATMEL_TC_LDRA_FALLING (2 << 16) +#define ATMEL_TC_LDRA_BOTH (3 << 16) +#define ATMEL_TC_LDRB (3 << 18) /* RB loading edge (of TIOA) */ +#define ATMEL_TC_LDRB_NONE (0 << 18) +#define ATMEL_TC_LDRB_RISING (1 << 18) +#define ATMEL_TC_LDRB_FALLING (2 << 18) +#define ATMEL_TC_LDRB_BOTH (3 << 18) + +/* WAVEFORM mode CMR bits */ +#define ATMEL_TC_CPCSTOP (1 << 6) /* RC compare stops counter */ +#define ATMEL_TC_CPCDIS (1 << 7) /* RC compare disables counter */ +#define ATMEL_TC_EEVTEDG (3 << 8) /* external event edge */ +#define ATMEL_TC_EEVTEDG_NONE (0 << 8) +#define ATMEL_TC_EEVTEDG_RISING (1 << 8) +#define ATMEL_TC_EEVTEDG_FALLING (2 << 8) +#define ATMEL_TC_EEVTEDG_BOTH (3 << 8) +#define ATMEL_TC_EEVT (3 << 10) /* external event source */ +#define ATMEL_TC_EEVT_TIOB (0 << 10) +#define ATMEL_TC_EEVT_XC0 (1 << 10) +#define ATMEL_TC_EEVT_XC1 (2 << 10) +#define ATMEL_TC_EEVT_XC2 (3 << 10) +#define ATMEL_TC_ENETRG (1 << 12) /* external event is trigger */ +#define ATMEL_TC_WAVESEL (3 << 13) /* waveform type */ +#define ATMEL_TC_WAVESEL_UP (0 << 13) +#define ATMEL_TC_WAVESEL_UPDOWN (1 << 13) +#define ATMEL_TC_WAVESEL_UP_AUTO (2 << 13) +#define ATMEL_TC_WAVESEL_UPDOWN_AUTO (3 << 13) +#define ATMEL_TC_ACPA (3 << 16) /* RA compare changes TIOA */ +#define ATMEL_TC_ACPA_NONE (0 << 16) +#define ATMEL_TC_ACPA_SET (1 << 16) +#define ATMEL_TC_ACPA_CLEAR (2 << 16) +#define ATMEL_TC_ACPA_TOGGLE (3 << 16) +#define ATMEL_TC_ACPC (3 << 18) /* RC compare changes TIOA */ +#define ATMEL_TC_ACPC_NONE (0 << 18) +#define ATMEL_TC_ACPC_SET (1 << 18) +#define ATMEL_TC_ACPC_CLEAR (2 << 18) +#define ATMEL_TC_ACPC_TOGGLE (3 << 18) +#define ATMEL_TC_AEEVT (3 << 20) /* external event changes TIOA */ +#define ATMEL_TC_AEEVT_NONE (0 << 20) +#define ATMEL_TC_AEEVT_SET (1 << 20) +#define ATMEL_TC_AEEVT_CLEAR (2 << 20) +#define ATMEL_TC_AEEVT_TOGGLE (3 << 20) +#define ATMEL_TC_ASWTRG (3 << 22) /* software trigger changes TIOA */ +#define ATMEL_TC_ASWTRG_NONE (0 << 22) +#define ATMEL_TC_ASWTRG_SET (1 << 22) +#define ATMEL_TC_ASWTRG_CLEAR (2 << 22) +#define ATMEL_TC_ASWTRG_TOGGLE (3 << 22) +#define ATMEL_TC_BCPB (3 << 24) /* RB compare changes TIOB */ +#define ATMEL_TC_BCPB_NONE (0 << 24) +#define ATMEL_TC_BCPB_SET (1 << 24) +#define ATMEL_TC_BCPB_CLEAR (2 << 24) +#define ATMEL_TC_BCPB_TOGGLE (3 << 24) +#define ATMEL_TC_BCPC (3 << 26) /* RC compare changes TIOB */ +#define ATMEL_TC_BCPC_NONE (0 << 26) +#define ATMEL_TC_BCPC_SET (1 << 26) +#define ATMEL_TC_BCPC_CLEAR (2 << 26) +#define ATMEL_TC_BCPC_TOGGLE (3 << 26) +#define ATMEL_TC_BEEVT (3 << 28) /* external event changes TIOB */ +#define ATMEL_TC_BEEVT_NONE (0 << 28) +#define ATMEL_TC_BEEVT_SET (1 << 28) +#define ATMEL_TC_BEEVT_CLEAR (2 << 28) +#define ATMEL_TC_BEEVT_TOGGLE (3 << 28) +#define ATMEL_TC_BSWTRG (3 << 30) /* software trigger changes TIOB */ +#define ATMEL_TC_BSWTRG_NONE (0 << 30) +#define ATMEL_TC_BSWTRG_SET (1 << 30) +#define ATMEL_TC_BSWTRG_CLEAR (2 << 30) +#define ATMEL_TC_BSWTRG_TOGGLE (3 << 30) + +#define ATMEL_TC_CV 0x10 /* counter Value */ +#define ATMEL_TC_RA 0x14 /* register A */ +#define ATMEL_TC_RB 0x18 /* register B */ +#define ATMEL_TC_RC 0x1c /* register C */ + +#define ATMEL_TC_SR 0x20 /* status (read-only) */ +/* Status-only flags */ +#define ATMEL_TC_CLKSTA (1 << 16) /* clock enabled */ +#define ATMEL_TC_MTIOA (1 << 17) /* TIOA mirror */ +#define ATMEL_TC_MTIOB (1 << 18) /* TIOB mirror */ + +#define ATMEL_TC_IER 0x24 /* interrupt enable (write-only) */ +#define ATMEL_TC_IDR 0x28 /* interrupt disable (write-only) */ +#define ATMEL_TC_IMR 0x2c /* interrupt mask (read-only) */ + +/* Status and IRQ flags */ +#define ATMEL_TC_COVFS (1 << 0) /* counter overflow */ +#define ATMEL_TC_LOVRS (1 << 1) /* load overrun */ +#define ATMEL_TC_CPAS (1 << 2) /* RA compare */ +#define ATMEL_TC_CPBS (1 << 3) /* RB compare */ +#define ATMEL_TC_CPCS (1 << 4) /* RC compare */ +#define ATMEL_TC_LDRAS (1 << 5) /* RA loading */ +#define ATMEL_TC_LDRBS (1 << 6) /* RB loading */ +#define ATMEL_TC_ETRGS (1 << 7) /* external trigger */ +#define ATMEL_TC_ALL_IRQ (ATMEL_TC_COVFS | ATMEL_TC_LOVRS | \ + ATMEL_TC_CPAS | ATMEL_TC_CPBS | \ + ATMEL_TC_CPCS | ATMEL_TC_LDRAS | \ + ATMEL_TC_LDRBS | ATMEL_TC_ETRGS) \ + /* all IRQs */ + +#endif Index: linux-5.0.19-rt11/init/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/init/Kconfig +++ linux-5.0.19-rt11/init/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:817 @ config CFS_BANDWIDTH config RT_GROUP_SCHED bool "Group scheduling for SCHED_RR/FIFO" depends on CGROUP_SCHED + depends on !PREEMPT_RT_FULL default n help This feature lets you explicitly allocate real CPU bandwidth @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1671 @ choice config SLAB bool "SLAB" + depends on !PREEMPT_RT_FULL select HAVE_HARDENED_USERCOPY_ALLOCATOR help The regular slab allocator that is established and known to work @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1692 @ config SLUB config SLOB depends on EXPERT bool "SLOB (Simple Allocator)" + depends on !PREEMPT_RT_FULL help SLOB replaces the stock allocator with a drastically simpler allocator. SLOB is generally more space efficient but @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1734 @ config SLAB_FREELIST_HARDENED config SLUB_CPU_PARTIAL default y - depends on SLUB && SMP + depends on SLUB && SMP && !PREEMPT_RT_FULL bool "SLUB per cpu partial cache" help Per cpu partial caches accellerate objects allocation and freeing Index: linux-5.0.19-rt11/init/Makefile =================================================================== --- linux-5.0.19-rt11.orig/init/Makefile +++ linux-5.0.19-rt11/init/Makefile @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:37 @ silent_chk_compile.h = : include/generated/compile.h: FORCE @$($(quiet)chk_compile.h) $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \ - "$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(KBUILD_CFLAGS)" + "$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CONFIG_PREEMPT_RT_FULL)" "$(CC) $(KBUILD_CFLAGS)" Index: linux-5.0.19-rt11/init/init_task.c =================================================================== --- linux-5.0.19-rt11.orig/init/init_task.c +++ linux-5.0.19-rt11/init/init_task.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:53 @ static struct sighand_struct init_sighan .signalfd_wqh = __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh), }; +#if defined(CONFIG_POSIX_TIMERS) && defined(CONFIG_PREEMPT_RT_BASE) +# define INIT_TIMER_LIST .posix_timer_list = NULL, +#else +# define INIT_TIMER_LIST +#endif + /* * Set up the first task table, touch at your own risk!. Base=0, * limit=0x1fffff (=2MB) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:80 @ struct task_struct init_task .static_prio = MAX_PRIO - 20, .normal_prio = MAX_PRIO - 20, .policy = SCHED_NORMAL, - .cpus_allowed = CPU_MASK_ALL, + .cpus_ptr = &init_task.cpus_mask, + .cpus_mask = CPU_MASK_ALL, .nr_cpus_allowed= NR_CPUS, .mm = NULL, .active_mm = &init_mm, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:128 @ struct task_struct init_task INIT_CPU_TIMERS(init_task) .pi_lock = __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock), .timer_slack_ns = 50000, /* 50 usec default slack */ + INIT_TIMER_LIST .thread_pid = &init_struct_pid, .thread_group = LIST_HEAD_INIT(init_task.thread_group), .thread_node = LIST_HEAD_INIT(init_signals.thread_head), Index: linux-5.0.19-rt11/init/main.c =================================================================== --- linux-5.0.19-rt11.orig/init/main.c +++ linux-5.0.19-rt11/init/main.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:651 @ asmlinkage __visible void __init start_k softirq_init(); timekeeping_init(); time_init(); - printk_safe_init(); perf_event_init(); profile_init(); call_function_init(); Index: linux-5.0.19-rt11/kernel/Kconfig.locks =================================================================== --- linux-5.0.19-rt11.orig/kernel/Kconfig.locks +++ linux-5.0.19-rt11/kernel/Kconfig.locks @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:228 @ config ARCH_SUPPORTS_ATOMIC_RMW config MUTEX_SPIN_ON_OWNER def_bool y - depends on SMP && ARCH_SUPPORTS_ATOMIC_RMW + depends on SMP && ARCH_SUPPORTS_ATOMIC_RMW && !PREEMPT_RT_FULL config RWSEM_SPIN_ON_OWNER def_bool y - depends on SMP && RWSEM_XCHGADD_ALGORITHM && ARCH_SUPPORTS_ATOMIC_RMW + depends on SMP && RWSEM_XCHGADD_ALGORITHM && ARCH_SUPPORTS_ATOMIC_RMW && !PREEMPT_RT_FULL config LOCK_SPIN_ON_OWNER def_bool y Index: linux-5.0.19-rt11/kernel/Kconfig.preempt =================================================================== --- linux-5.0.19-rt11.orig/kernel/Kconfig.preempt +++ linux-5.0.19-rt11/kernel/Kconfig.preempt @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +config PREEMPT + bool + select PREEMPT_COUNT + +config PREEMPT_RT_BASE + bool + select PREEMPT + +config HAVE_PREEMPT_LAZY + bool + +config PREEMPT_LAZY + def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT_FULL choice prompt "Preemption Model" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:50 @ config PREEMPT_VOLUNTARY Select this if you are building a kernel for a desktop system. -config PREEMPT +config PREEMPT__LL bool "Preemptible Kernel (Low-Latency Desktop)" depends on !ARCH_NO_PREEMPT - select PREEMPT_COUNT + select PREEMPT select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK help This option reduces the latency of the kernel by making @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:70 @ config PREEMPT embedded system with latency requirements in the milliseconds range. +config PREEMPT_RTB + bool "Preemptible Kernel (Basic RT)" + select PREEMPT_RT_BASE + help + This option is basically the same as (Low-Latency Desktop) but + enables changes which are preliminary for the full preemptible + RT kernel. + +config PREEMPT_RT_FULL + bool "Fully Preemptible Kernel (RT)" + depends on IRQ_FORCED_THREADING + select PREEMPT_RT_BASE + select PREEMPT_RCU + help + All and everything + endchoice config PREEMPT_COUNT Index: linux-5.0.19-rt11/kernel/cgroup/cpuset.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/cgroup/cpuset.c +++ linux-5.0.19-rt11/kernel/cgroup/cpuset.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:348 @ static struct cpuset top_cpuset = { */ static DEFINE_MUTEX(cpuset_mutex); -static DEFINE_SPINLOCK(callback_lock); +static DEFINE_RAW_SPINLOCK(callback_lock); static struct workqueue_struct *cpuset_migrate_mm_wq; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1223 @ static int update_parent_subparts_cpumas * Newly added CPUs will be removed from effective_cpus and * newly deleted ones will be added back to effective_cpus. */ - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); if (adding) { cpumask_or(parent->subparts_cpus, parent->subparts_cpus, tmp->addmask); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1242 @ static int update_parent_subparts_cpumas } parent->nr_subparts_cpus = cpumask_weight(parent->subparts_cpus); - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); return cmd == partcmd_update; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1347 @ static void update_cpumasks_hier(struct continue; rcu_read_unlock(); - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cpumask_copy(cp->effective_cpus, tmp->new_cpus); if (cp->nr_subparts_cpus && @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1378 @ static void update_cpumasks_hier(struct = cpumask_weight(cp->subparts_cpus); } } - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); WARN_ON(!is_in_v2_mode() && !cpumask_equal(cp->cpus_allowed, cp->effective_cpus)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1496 @ static int update_cpumask(struct cpuset return -EINVAL; } - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1507 @ static int update_cpumask(struct cpuset cs->cpus_allowed); cs->nr_subparts_cpus = cpumask_weight(cs->subparts_cpus); } - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); update_cpumasks_hier(cs, &tmp); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1701 @ static void update_nodemasks_hier(struct continue; rcu_read_unlock(); - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cp->effective_mems = *new_mems; - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); WARN_ON(!is_in_v2_mode() && !nodes_equal(cp->mems_allowed, cp->effective_mems)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1771 @ static int update_nodemask(struct cpuset if (retval < 0) goto done; - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cs->mems_allowed = trialcs->mems_allowed; - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); /* use trialcs->mems_allowed as a temp variable */ update_nodemasks_hier(cs, &trialcs->mems_allowed); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1864 @ static int update_flag(cpuset_flagbits_t spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs)) || (is_spread_page(cs) != is_spread_page(trialcs))); - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cs->flags = trialcs->flags; - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed) rebuild_sched_domains_locked(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2369 @ static int cpuset_common_seq_show(struct cpuset_filetype_t type = seq_cft(sf)->private; int ret = 0; - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); switch (type) { case FILE_CPULIST: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2391 @ static int cpuset_common_seq_show(struct ret = -EINVAL; } - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); return ret; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2701 @ static int cpuset_css_online(struct cgro cpuset_inc(); - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); if (is_in_v2_mode()) { cpumask_copy(cs->effective_cpus, parent->effective_cpus); cs->effective_mems = parent->effective_mems; cs->use_parent_ecpus = true; parent->child_ecpus_count++; } - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags)) goto out_unlock; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2735 @ static int cpuset_css_online(struct cgro } rcu_read_unlock(); - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cs->mems_allowed = parent->mems_allowed; cs->effective_mems = parent->mems_allowed; cpumask_copy(cs->cpus_allowed, parent->cpus_allowed); cpumask_copy(cs->effective_cpus, parent->cpus_allowed); - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); out_unlock: mutex_unlock(&cpuset_mutex); return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2793 @ static void cpuset_css_free(struct cgrou static void cpuset_bind(struct cgroup_subsys_state *root_css) { mutex_lock(&cpuset_mutex); - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); if (is_in_v2_mode()) { cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2804 @ static void cpuset_bind(struct cgroup_su top_cpuset.mems_allowed = top_cpuset.effective_mems; } - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); mutex_unlock(&cpuset_mutex); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2818 @ static void cpuset_fork(struct task_stru if (task_css_is_root(task, cpuset_cgrp_id)) return; - set_cpus_allowed_ptr(task, ¤t->cpus_allowed); + set_cpus_allowed_ptr(task, current->cpus_ptr); task->mems_allowed = current->mems_allowed; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2905 @ hotplug_update_tasks_legacy(struct cpuse { bool is_empty; - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cpumask_copy(cs->cpus_allowed, new_cpus); cpumask_copy(cs->effective_cpus, new_cpus); cs->mems_allowed = *new_mems; cs->effective_mems = *new_mems; - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); /* * Don't call update_tasks_cpumask() if the cpuset becomes empty, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2947 @ hotplug_update_tasks(struct cpuset *cs, if (nodes_empty(*new_mems)) *new_mems = parent_cs(cs)->effective_mems; - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cpumask_copy(cs->effective_cpus, new_cpus); cs->effective_mems = *new_mems; - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); if (cpus_updated) update_tasks_cpumask(cs); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3105 @ static void cpuset_hotplug_workfn(struct /* synchronize cpus_allowed to cpu_active_mask */ if (cpus_updated) { - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); if (!on_dfl) cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3125 @ static void cpuset_hotplug_workfn(struct } } cpumask_copy(top_cpuset.effective_cpus, &new_cpus); - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); /* we don't mess with cpumasks of tasks in top_cpuset */ } /* synchronize mems_allowed to N_MEMORY */ if (mems_updated) { - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); if (!on_dfl) top_cpuset.mems_allowed = new_mems; top_cpuset.effective_mems = new_mems; - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); update_tasks_nodemask(&top_cpuset); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3236 @ void cpuset_cpus_allowed(struct task_str { unsigned long flags; - spin_lock_irqsave(&callback_lock, flags); + raw_spin_lock_irqsave(&callback_lock, flags); rcu_read_lock(); guarantee_online_cpus(task_cs(tsk), pmask); rcu_read_unlock(); - spin_unlock_irqrestore(&callback_lock, flags); + raw_spin_unlock_irqrestore(&callback_lock, flags); } void cpuset_cpus_allowed_fallback(struct task_struct *tsk) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3288 @ nodemask_t cpuset_mems_allowed(struct ta nodemask_t mask; unsigned long flags; - spin_lock_irqsave(&callback_lock, flags); + raw_spin_lock_irqsave(&callback_lock, flags); rcu_read_lock(); guarantee_online_mems(task_cs(tsk), &mask); rcu_read_unlock(); - spin_unlock_irqrestore(&callback_lock, flags); + raw_spin_unlock_irqrestore(&callback_lock, flags); return mask; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3384 @ bool __cpuset_node_allowed(int node, gfp return true; /* Not hardwall and node outside mems_allowed: scan up cpusets */ - spin_lock_irqsave(&callback_lock, flags); + raw_spin_lock_irqsave(&callback_lock, flags); rcu_read_lock(); cs = nearest_hardwall_ancestor(task_cs(current)); allowed = node_isset(node, cs->mems_allowed); rcu_read_unlock(); - spin_unlock_irqrestore(&callback_lock, flags); + raw_spin_unlock_irqrestore(&callback_lock, flags); return allowed; } Index: linux-5.0.19-rt11/kernel/cgroup/rstat.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/cgroup/rstat.c +++ linux-5.0.19-rt11/kernel/cgroup/rstat.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:162 @ static void cgroup_rstat_flush_locked(st raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu); struct cgroup *pos = NULL; + unsigned long flags; - raw_spin_lock(cpu_lock); + raw_spin_lock_irqsave(cpu_lock, flags); while ((pos = cgroup_rstat_cpu_pop_updated(pos, cgrp, cpu))) { struct cgroup_subsys_state *css; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:176 @ static void cgroup_rstat_flush_locked(st css->ss->css_rstat_flush(css, cpu); rcu_read_unlock(); } - raw_spin_unlock(cpu_lock); + raw_spin_unlock_irqrestore(cpu_lock, flags); /* if @may_sleep, play nice and yield if necessary */ if (may_sleep && (need_resched() || Index: linux-5.0.19-rt11/kernel/cpu.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/cpu.c +++ linux-5.0.19-rt11/kernel/cpu.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:78 @ static DEFINE_PER_CPU(struct cpuhp_cpu_s .fail = CPUHP_INVALID, }; +#if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PREEMPT_RT_FULL) +static DEFINE_PER_CPU(struct rt_rw_lock, cpuhp_pin_lock) = \ + __RWLOCK_RT_INITIALIZER(cpuhp_pin_lock); +#endif + #if defined(CONFIG_LOCKDEP) && defined(CONFIG_SMP) static struct lockdep_map cpuhp_state_up_map = STATIC_LOCKDEP_MAP_INIT("cpuhp_state-up", &cpuhp_state_up_map); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:289 @ static int cpu_hotplug_disabled; #ifdef CONFIG_HOTPLUG_CPU +/** + * pin_current_cpu - Prevent the current cpu from being unplugged + */ +void pin_current_cpu(void) +{ +#ifdef CONFIG_PREEMPT_RT_FULL + struct rt_rw_lock *cpuhp_pin; + unsigned int cpu; + int ret; + +again: + cpuhp_pin = this_cpu_ptr(&cpuhp_pin_lock); + ret = __read_rt_trylock(cpuhp_pin); + if (ret) { + current->pinned_on_cpu = smp_processor_id(); + return; + } + cpu = smp_processor_id(); + preempt_lazy_enable(); + preempt_enable(); + + __read_rt_lock(cpuhp_pin); + + preempt_disable(); + preempt_lazy_disable(); + if (cpu != smp_processor_id()) { + __read_rt_unlock(cpuhp_pin); + goto again; + } + current->pinned_on_cpu = cpu; +#endif +} + +/** + * unpin_current_cpu - Allow unplug of current cpu + */ +void unpin_current_cpu(void) +{ +#ifdef CONFIG_PREEMPT_RT_FULL + struct rt_rw_lock *cpuhp_pin = this_cpu_ptr(&cpuhp_pin_lock); + + if (WARN_ON(current->pinned_on_cpu != smp_processor_id())) + cpuhp_pin = per_cpu_ptr(&cpuhp_pin_lock, current->pinned_on_cpu); + + current->pinned_on_cpu = -1; + __read_rt_unlock(cpuhp_pin); +#endif +} + DEFINE_STATIC_PERCPU_RWSEM(cpu_hotplug_lock); void cpus_read_lock(void) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:924 @ static int take_cpu_down(void *_param) static int takedown_cpu(unsigned int cpu) { +#ifdef CONFIG_PREEMPT_RT_FULL + struct rt_rw_lock *cpuhp_pin = per_cpu_ptr(&cpuhp_pin_lock, cpu); +#endif struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:939 @ static int takedown_cpu(unsigned int cpu */ irq_lock_sparse(); +#ifdef CONFIG_PREEMPT_RT_FULL + __write_rt_lock(cpuhp_pin); +#endif + /* * So now all preempt/rcu users must observe !cpu_active(). */ err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu)); if (err) { +#ifdef CONFIG_PREEMPT_RT_FULL + __write_rt_unlock(cpuhp_pin); +#endif /* CPU refused to die */ irq_unlock_sparse(); /* Unpark the hotplug thread so we can rollback there */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:969 @ static int takedown_cpu(unsigned int cpu wait_for_ap_thread(st, false); BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); +#ifdef CONFIG_PREEMPT_RT_FULL + __write_rt_unlock(cpuhp_pin); +#endif /* Interrupts are moved away from the dying cpu, reenable alloc/free */ irq_unlock_sparse(); Index: linux-5.0.19-rt11/kernel/events/core.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/events/core.c +++ linux-5.0.19-rt11/kernel/events/core.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1105 @ static void __perf_mux_hrtimer_init(stru cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); raw_spin_lock_init(&cpuctx->hrtimer_lock); - hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); + hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD); timer->function = perf_mux_hrtimer_handler; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:9248 @ static void perf_swevent_init_hrtimer(st if (!is_sampling_event(event)) return; - hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); hwc->hrtimer.function = perf_swevent_hrtimer; /* Index: linux-5.0.19-rt11/kernel/exit.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/exit.c +++ linux-5.0.19-rt11/kernel/exit.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:163 @ static void __exit_signal(struct task_st * Do this under ->siglock, we can race with another thread * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals. */ - flush_sigqueue(&tsk->pending); + flush_task_sigqueue(tsk); tsk->sighand = NULL; spin_unlock(&sighand->siglock); Index: linux-5.0.19-rt11/kernel/fork.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/fork.c +++ linux-5.0.19-rt11/kernel/fork.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:43 @ #include <linux/hmm.h> #include <linux/fs.h> #include <linux/mm.h> +#include <linux/kprobes.h> #include <linux/vmacache.h> #include <linux/nsproxy.h> #include <linux/capability.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:683 @ void __mmdrop(struct mm_struct *mm) } EXPORT_SYMBOL_GPL(__mmdrop); +#ifdef CONFIG_PREEMPT_RT_BASE +/* + * RCU callback for delayed mm drop. Not strictly rcu, but we don't + * want another facility to make this work. + */ +void __mmdrop_delayed(struct rcu_head *rhp) +{ + struct mm_struct *mm = container_of(rhp, struct mm_struct, delayed_drop); + + __mmdrop(mm); +} +#endif + static void mmdrop_async_fn(struct work_struct *work) { struct mm_struct *mm; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:730 @ static inline void put_signal_struct(str if (atomic_dec_and_test(&sig->sigcnt)) free_signal_struct(sig); } - +#ifdef CONFIG_PREEMPT_RT_BASE +static +#endif void __put_task_struct(struct task_struct *tsk) { WARN_ON(!tsk->exit_state); WARN_ON(atomic_read(&tsk->usage)); WARN_ON(tsk == current); + /* + * Remove function-return probe instances associated with this + * task and put them back on the free list. + */ + kprobe_flush_task(tsk); + + /* Task is done with its stack. */ + put_task_stack(tsk); + cgroup_free(tsk); task_numa_free(tsk); security_task_free(tsk); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:758 @ void __put_task_struct(struct task_struc if (!profile_handoff_task(tsk)) free_task(tsk); } +#ifndef CONFIG_PREEMPT_RT_BASE EXPORT_SYMBOL_GPL(__put_task_struct); +#else +void __put_task_struct_cb(struct rcu_head *rhp) +{ + struct task_struct *tsk = container_of(rhp, struct task_struct, put_rcu); + + __put_task_struct(tsk); + +} +EXPORT_SYMBOL_GPL(__put_task_struct_cb); +#endif void __init __weak arch_task_cache_init(void) { } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:930 @ static struct task_struct *dup_task_stru #ifdef CONFIG_STACKPROTECTOR tsk->stack_canary = get_random_canary(); #endif + if (orig->cpus_ptr == &orig->cpus_mask) + tsk->cpus_ptr = &tsk->cpus_mask; /* * One for us, one for whoever does the "release_task()" (usually @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:944 @ static struct task_struct *dup_task_stru tsk->splice_pipe = NULL; tsk->task_frag.page = NULL; tsk->wake_q.next = NULL; + tsk->wake_q_sleeper.next = NULL; account_kernel_stack(tsk, 1); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1671 @ static void rt_mutex_init_task(struct ta */ static void posix_cpu_timers_init(struct task_struct *tsk) { +#ifdef CONFIG_PREEMPT_RT_BASE + tsk->posix_timer_list = NULL; +#endif tsk->cputime_expires.prof_exp = 0; tsk->cputime_expires.virt_exp = 0; tsk->cputime_expires.sched_exp = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1876 @ static __latent_entropy struct task_stru spin_lock_init(&p->alloc_lock); init_sigpending(&p->pending); + p->sigqueue_cache = NULL; p->utime = p->stime = p->gtime = 0; #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME Index: linux-5.0.19-rt11/kernel/futex.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/futex.c +++ linux-5.0.19-rt11/kernel/futex.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:246 @ struct futex_q { struct plist_node list; struct task_struct *task; - spinlock_t *lock_ptr; + raw_spinlock_t *lock_ptr; union futex_key key; struct futex_pi_state *pi_state; struct rt_mutex_waiter *rt_waiter; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:267 @ static const struct futex_q futex_q_init */ struct futex_hash_bucket { atomic_t waiters; - spinlock_t lock; + raw_spinlock_t lock; struct plist_head chain; } ____cacheline_aligned_in_smp; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:833 @ static void get_pi_state(struct futex_pi * Drops a reference to the pi_state object and frees or caches it * when the last reference is gone. */ -static void put_pi_state(struct futex_pi_state *pi_state) +static struct futex_pi_state *__put_pi_state(struct futex_pi_state *pi_state) { if (!pi_state) - return; + return NULL; if (!atomic_dec_and_test(&pi_state->refcount)) - return; + return NULL; /* * If pi_state->owner is NULL, the owner is most probably dying @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:859 @ static void put_pi_state(struct futex_pi raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); } - if (current->pi_state_cache) { - kfree(pi_state); - } else { + if (!current->pi_state_cache) { /* * pi_state->list is already empty. * clear pi_state->owner. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:868 @ static void put_pi_state(struct futex_pi pi_state->owner = NULL; atomic_set(&pi_state->refcount, 1); current->pi_state_cache = pi_state; + pi_state = NULL; + } + return pi_state; +} + +static void put_pi_state(struct futex_pi_state *pi_state) +{ + kfree(__put_pi_state(pi_state)); +} + +static void put_pi_state_atomic(struct futex_pi_state *pi_state, + struct list_head *to_free) +{ + if (__put_pi_state(pi_state)) + list_add(&pi_state->list, to_free); +} + +static void free_pi_state_list(struct list_head *to_free) +{ + struct futex_pi_state *p, *next; + + list_for_each_entry_safe(p, next, to_free, list) { + list_del(&p->list); + kfree(p); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:908 @ void exit_pi_state_list(struct task_stru struct futex_pi_state *pi_state; struct futex_hash_bucket *hb; union futex_key key = FUTEX_KEY_INIT; + LIST_HEAD(to_free); if (!futex_cmpxchg_enabled) return; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:942 @ void exit_pi_state_list(struct task_stru } raw_spin_unlock_irq(&curr->pi_lock); - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); raw_spin_lock(&curr->pi_lock); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:952 @ void exit_pi_state_list(struct task_stru if (head->next != next) { /* retain curr->pi_lock for the loop invariant */ raw_spin_unlock(&pi_state->pi_mutex.wait_lock); - spin_unlock(&hb->lock); - put_pi_state(pi_state); + raw_spin_unlock(&hb->lock); + put_pi_state_atomic(pi_state, &to_free); continue; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:964 @ void exit_pi_state_list(struct task_stru raw_spin_unlock(&curr->pi_lock); raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); rt_mutex_futex_unlock(&pi_state->pi_mutex); put_pi_state(pi_state); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:972 @ void exit_pi_state_list(struct task_stru raw_spin_lock_irq(&curr->pi_lock); } raw_spin_unlock_irq(&curr->pi_lock); + + free_pi_state_list(&to_free); } #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1510 @ static int wake_futex_pi(u32 __user *uad struct task_struct *new_owner; bool postunlock = false; DEFINE_WAKE_Q(wake_q); + DEFINE_WAKE_Q(wake_sleeper_q); int ret = 0; new_owner = rt_mutex_next_owner(&pi_state->pi_mutex); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1570 @ static int wake_futex_pi(u32 __user *uad pi_state->owner = new_owner; raw_spin_unlock(&new_owner->pi_lock); - postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q); - + postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q, + &wake_sleeper_q); out_unlock: raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); if (postunlock) - rt_mutex_postunlock(&wake_q); + rt_mutex_postunlock(&wake_q, &wake_sleeper_q); return ret; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1588 @ static inline void double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) { if (hb1 <= hb2) { - spin_lock(&hb1->lock); + raw_spin_lock(&hb1->lock); if (hb1 < hb2) - spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); + raw_spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); } else { /* hb1 > hb2 */ - spin_lock(&hb2->lock); - spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); + raw_spin_lock(&hb2->lock); + raw_spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); } } static inline void double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) { - spin_unlock(&hb1->lock); + raw_spin_unlock(&hb1->lock); if (hb1 != hb2) - spin_unlock(&hb2->lock); + raw_spin_unlock(&hb2->lock); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1630 @ futex_wake(u32 __user *uaddr, unsigned i if (!hb_waiters_pending(hb)) goto out_put_key; - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); plist_for_each_entry_safe(this, next, &hb->chain, list) { if (match_futex (&this->key, &key)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1649 @ futex_wake(u32 __user *uaddr, unsigned i } } - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); wake_up_q(&wake_q); out_put_key: put_futex_key(&key); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1956 @ static int futex_requeue(u32 __user *uad struct futex_hash_bucket *hb1, *hb2; struct futex_q *this, *next; DEFINE_WAKE_Q(wake_q); + LIST_HEAD(to_free); if (nr_wake < 0 || nr_requeue < 0) return -EINVAL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2194 @ retry_private: * object. */ this->pi_state = NULL; - put_pi_state(pi_state); + put_pi_state_atomic(pi_state, &to_free); /* * We stop queueing more waiters and let user * space deal with the mess. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2211 @ retry_private: * in futex_proxy_trylock_atomic() or in lookup_pi_state(). We * need to drop it here again. */ - put_pi_state(pi_state); + put_pi_state_atomic(pi_state, &to_free); out_unlock: double_unlock_hb(hb1, hb2); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2232 @ out_put_keys: out_put_key1: put_futex_key(&key1); out: + free_pi_state_list(&to_free); return ret ? ret : task_count; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2256 @ static inline struct futex_hash_bucket * q->lock_ptr = &hb->lock; - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); return hb; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2264 @ static inline void queue_unlock(struct futex_hash_bucket *hb) __releases(&hb->lock) { - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); hb_waiters_dec(hb); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2303 @ static inline void queue_me(struct futex __releases(&hb->lock) { __queue_me(q, hb); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2319 @ static inline void queue_me(struct futex */ static int unqueue_me(struct futex_q *q) { - spinlock_t *lock_ptr; + raw_spinlock_t *lock_ptr; int ret = 0; /* In the common case we don't take the spinlock, which is nice. */ retry: /* - * q->lock_ptr can change between this read and the following spin_lock. - * Use READ_ONCE to forbid the compiler from reloading q->lock_ptr and - * optimizing lock_ptr out of the logic below. + * q->lock_ptr can change between this read and the following + * raw_spin_lock. Use READ_ONCE to forbid the compiler from reloading + * q->lock_ptr and optimizing lock_ptr out of the logic below. */ lock_ptr = READ_ONCE(q->lock_ptr); if (lock_ptr != NULL) { - spin_lock(lock_ptr); + raw_spin_lock(lock_ptr); /* * q->lock_ptr can change between reading it and - * spin_lock(), causing us to take the wrong lock. This + * raw_spin_lock(), causing us to take the wrong lock. This * corrects the race condition. * * Reasoning goes like this: if we have the wrong lock, * q->lock_ptr must have changed (maybe several times) - * between reading it and the spin_lock(). It can - * change again after the spin_lock() but only if it was - * already changed before the spin_lock(). It cannot, + * between reading it and the raw_spin_lock(). It can + * change again after the raw_spin_lock() but only if it was + * already changed before the raw_spin_lock(). It cannot, * however, change back to the original value. Therefore * we can detect whether we acquired the correct lock. */ if (unlikely(lock_ptr != q->lock_ptr)) { - spin_unlock(lock_ptr); + raw_spin_unlock(lock_ptr); goto retry; } __unqueue_futex(q); BUG_ON(q->pi_state); - spin_unlock(lock_ptr); + raw_spin_unlock(lock_ptr); ret = 1; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2369 @ retry: static void unqueue_me_pi(struct futex_q *q) __releases(q->lock_ptr) { + struct futex_pi_state *ps; + __unqueue_futex(q); BUG_ON(!q->pi_state); - put_pi_state(q->pi_state); + ps = __put_pi_state(q->pi_state); q->pi_state = NULL; - spin_unlock(q->lock_ptr); + raw_spin_unlock(q->lock_ptr); + kfree(ps); } static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2511 @ retry: */ handle_err: raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); - spin_unlock(q->lock_ptr); + raw_spin_unlock(q->lock_ptr); switch (err) { case -EFAULT: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2529 @ handle_err: break; } - spin_lock(q->lock_ptr); + raw_spin_lock(q->lock_ptr); raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2625 @ static void futex_wait_queue_me(struct f /* * The task state is guaranteed to be set before another task can * wake it. set_current_state() is implemented using smp_store_mb() and - * queue_me() calls spin_unlock() upon completion, both serializing + * queue_me() calls raw_spin_unlock() upon completion, both serializing * access to the hash list and forcing another memory barrier. */ set_current_state(TASK_INTERRUPTIBLE); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2743 @ static int futex_wait(u32 __user *uaddr, if (abs_time) { to = &timeout; - hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ? - CLOCK_REALTIME : CLOCK_MONOTONIC, - HRTIMER_MODE_ABS); - hrtimer_init_sleeper(to, current); + hrtimer_init_sleeper_on_stack(to, (flags & FLAGS_CLOCKRT) ? + CLOCK_REALTIME : CLOCK_MONOTONIC, + HRTIMER_MODE_ABS, current); hrtimer_set_expires_range_ns(&to->timer, *abs_time, current->timer_slack_ns); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2844 @ static int futex_lock_pi(u32 __user *uad if (time) { to = &timeout; - hrtimer_init_on_stack(&to->timer, CLOCK_REALTIME, - HRTIMER_MODE_ABS); - hrtimer_init_sleeper(to, current); + hrtimer_init_sleeper_on_stack(to, CLOCK_REALTIME, + HRTIMER_MODE_ABS, current); hrtimer_set_expires(&to->timer, *time); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2900 @ retry_private: goto no_block; } - rt_mutex_init_waiter(&rt_waiter); + rt_mutex_init_waiter(&rt_waiter, false); /* * On PREEMPT_RT_FULL, when hb->lock becomes an rt_mutex, we must not @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2916 @ retry_private: * before __rt_mutex_start_proxy_lock() is done. */ raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock); - spin_unlock(q.lock_ptr); + raw_spin_unlock(q.lock_ptr); /* * __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter * such that futex_unlock_pi() is guaranteed to observe the waiter when @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2937 @ retry_private: ret = rt_mutex_wait_proxy_lock(&q.pi_state->pi_mutex, to, &rt_waiter); cleanup: - spin_lock(q.lock_ptr); + raw_spin_lock(q.lock_ptr); /* * If we failed to acquire the lock (deadlock/signal/timeout), we must * first acquire the hb->lock before removing the lock from the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3038 @ retry: return ret; hb = hash_futex(&key); - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); /* * Check waiters first. We do not trust user space values at @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3072 @ retry: * rt_waiter. Also see the WARN in wake_futex_pi(). */ raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); /* drops pi_state->pi_mutex.wait_lock */ ret = wake_futex_pi(uaddr, uval, pi_state); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3111 @ retry: * owner. */ if ((ret = cmpxchg_futex_value_locked(&curval, uaddr, uval, 0))) { - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); switch (ret) { case -EFAULT: goto pi_faulted; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3131 @ retry: ret = (curval == uval) ? 0 : -EAGAIN; out_unlock: - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); out_putkey: put_futex_key(&key); return ret; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3263 @ static int futex_wait_requeue_pi(u32 __u if (abs_time) { to = &timeout; - hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ? - CLOCK_REALTIME : CLOCK_MONOTONIC, - HRTIMER_MODE_ABS); - hrtimer_init_sleeper(to, current); + hrtimer_init_sleeper_on_stack(to, (flags & FLAGS_CLOCKRT) ? + CLOCK_REALTIME : CLOCK_MONOTONIC, + HRTIMER_MODE_ABS, current); hrtimer_set_expires_range_ns(&to->timer, *abs_time, current->timer_slack_ns); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3274 @ static int futex_wait_requeue_pi(u32 __u * The waiter is allocated on our stack, manipulated by the requeue * code while we sleep on uaddr. */ - rt_mutex_init_waiter(&rt_waiter); + rt_mutex_init_waiter(&rt_waiter, false); ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE); if (unlikely(ret != 0)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3305 @ static int futex_wait_requeue_pi(u32 __u /* Queue the futex_q, drop the hb lock, wait for wakeup. */ futex_wait_queue_me(hb, &q, to); - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); if (ret) goto out_put_keys; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3327 @ static int futex_wait_requeue_pi(u32 __u * did a lock-steal - fix up the PI-state in that case. */ if (q.pi_state && (q.pi_state->owner != current)) { - spin_lock(q.lock_ptr); + struct futex_pi_state *ps_free; + + raw_spin_lock(q.lock_ptr); ret = fixup_pi_state_owner(uaddr2, &q, current); if (ret && rt_mutex_owner(&q.pi_state->pi_mutex) == current) { pi_state = q.pi_state; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3339 @ static int futex_wait_requeue_pi(u32 __u * Drop the reference to the pi state which * the requeue_pi() code acquired for us. */ - put_pi_state(q.pi_state); - spin_unlock(q.lock_ptr); + ps_free = __put_pi_state(q.pi_state); + raw_spin_unlock(q.lock_ptr); + kfree(ps_free); } } else { struct rt_mutex *pi_mutex; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3355 @ static int futex_wait_requeue_pi(u32 __u pi_mutex = &q.pi_state->pi_mutex; ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter); - spin_lock(q.lock_ptr); + raw_spin_lock(q.lock_ptr); if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter)) ret = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3980 @ static int __init futex_init(void) for (i = 0; i < futex_hashsize; i++) { atomic_set(&futex_queues[i].waiters, 0); plist_head_init(&futex_queues[i].chain); - spin_lock_init(&futex_queues[i].lock); + raw_spin_lock_init(&futex_queues[i].lock); } return 0; Index: linux-5.0.19-rt11/kernel/irq/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/kernel/irq/Kconfig +++ linux-5.0.19-rt11/kernel/irq/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:94 @ config GENERIC_MSI_IRQ_DOMAIN select IRQ_DOMAIN_HIERARCHY select GENERIC_MSI_IRQ +config IRQ_MSI_IOMMU + bool + config HANDLE_DOMAIN_IRQ bool Index: linux-5.0.19-rt11/kernel/irq/handle.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/irq/handle.c +++ linux-5.0.19-rt11/kernel/irq/handle.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:188 @ irqreturn_t handle_irq_event_percpu(stru { irqreturn_t retval; unsigned int flags = 0; + struct pt_regs *regs = get_irq_regs(); + u64 ip = regs ? instruction_pointer(regs) : 0; retval = __handle_irq_event_percpu(desc, &flags); - add_interrupt_randomness(desc->irq_data.irq, flags); +#ifdef CONFIG_PREEMPT_RT_FULL + desc->random_ip = ip; +#else + add_interrupt_randomness(desc->irq_data.irq, flags, ip); +#endif if (!noirqdebug) note_interrupt(desc, retval); Index: linux-5.0.19-rt11/kernel/irq/manage.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/irq/manage.c +++ linux-5.0.19-rt11/kernel/irq/manage.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:26 @ #include "internals.h" #ifdef CONFIG_IRQ_FORCED_THREADING +# ifndef CONFIG_PREEMPT_RT_BASE __read_mostly bool force_irqthreads; EXPORT_SYMBOL_GPL(force_irqthreads); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:36 @ static int __init setup_forced_irqthread return 0; } early_param("threadirqs", setup_forced_irqthreads); +# endif #endif static void __synchronize_hardirq(struct irq_desc *desc) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1039 @ static int irq_thread(void *data) if (action_ret == IRQ_WAKE_THREAD) irq_wake_secondary(desc, action); +#ifdef CONFIG_PREEMPT_RT_FULL + migrate_disable(); + add_interrupt_randomness(action->irq, 0, + desc->random_ip ^ (unsigned long) action); + migrate_enable(); +#endif wake_threads_waitq(desc); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2240 @ EXPORT_SYMBOL_GPL(irq_get_irqchip_state) * This call sets the internal irqchip state of an interrupt, * depending on the value of @which. * - * This function should be called with preemption disabled if the + * This function should be called with migration disabled if the * interrupt controller has per-cpu registers. */ int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, Index: linux-5.0.19-rt11/kernel/irq/spurious.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/irq/spurious.c +++ linux-5.0.19-rt11/kernel/irq/spurious.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:445 @ MODULE_PARM_DESC(noirqdebug, "Disable ir static int __init irqfixup_setup(char *str) { +#ifdef CONFIG_PREEMPT_RT_BASE + pr_warn("irqfixup boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n"); + return 1; +#endif irqfixup = 1; printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); printk(KERN_WARNING "This may impact system performance.\n"); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:461 @ module_param(irqfixup, int, 0644); static int __init irqpoll_setup(char *str) { +#ifdef CONFIG_PREEMPT_RT_BASE + pr_warn("irqpoll boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n"); + return 1; +#endif irqfixup = 2; printk(KERN_WARNING "Misrouted IRQ fixup and polling support " "enabled\n"); Index: linux-5.0.19-rt11/kernel/irq_work.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/irq_work.c +++ linux-5.0.19-rt11/kernel/irq_work.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:20 @ #include <linux/cpu.h> #include <linux/notifier.h> #include <linux/smp.h> +#include <linux/interrupt.h> #include <asm/processor.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:63 @ void __weak arch_irq_work_raise(void) /* Enqueue on current CPU, work must already be claimed and preempt disabled */ static void __irq_work_queue_local(struct irq_work *work) { + struct llist_head *list; + bool lazy_work, realtime = IS_ENABLED(CONFIG_PREEMPT_RT_FULL); + + lazy_work = work->flags & IRQ_WORK_LAZY; + /* If the work is "lazy", handle it from next tick if any */ - if (work->flags & IRQ_WORK_LAZY) { - if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) && - tick_nohz_tick_stopped()) - arch_irq_work_raise(); - } else { - if (llist_add(&work->llnode, this_cpu_ptr(&raised_list))) + if (lazy_work || (realtime && !(work->flags & IRQ_WORK_HARD_IRQ))) + list = this_cpu_ptr(&lazy_list); + else + list = this_cpu_ptr(&raised_list); + + if (llist_add(&work->llnode, list)) { + if (!lazy_work || tick_nohz_tick_stopped()) arch_irq_work_raise(); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:117 @ bool irq_work_queue_on(struct irq_work * preempt_disable(); if (cpu != smp_processor_id()) { + struct llist_head *list; + /* Arch remote IPI send/receive backend aren't NMI safe */ WARN_ON_ONCE(in_nmi()); - if (llist_add(&work->llnode, &per_cpu(raised_list, cpu))) + if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL) && !(work->flags & IRQ_WORK_HARD_IRQ)) + list = &per_cpu(lazy_list, cpu); + else + list = &per_cpu(raised_list, cpu); + + if (llist_add(&work->llnode, list)) arch_send_call_function_single_ipi(cpu); } else { __irq_work_queue_local(work); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:145 @ bool irq_work_needs_cpu(void) raised = this_cpu_ptr(&raised_list); lazy = this_cpu_ptr(&lazy_list); - if (llist_empty(raised) || arch_irq_work_has_interrupt()) - if (llist_empty(lazy)) - return false; + if (llist_empty(raised) && llist_empty(lazy)) + return false; /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:160 @ static void irq_work_run_list(struct lli struct llist_node *llnode; unsigned long flags; +#ifndef CONFIG_PREEMPT_RT_FULL + /* + * nort: On RT IRQ-work may run in SOFTIRQ context. + */ BUG_ON(!irqs_disabled()); - +#endif if (llist_empty(list)) return; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:197 @ static void irq_work_run_list(struct lli void irq_work_run(void) { irq_work_run_list(this_cpu_ptr(&raised_list)); - irq_work_run_list(this_cpu_ptr(&lazy_list)); + if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) { + /* + * NOTE: we raise softirq via IPI for safety, + * and execute in irq_work_tick() to move the + * overhead from hard to soft irq context. + */ + if (!llist_empty(this_cpu_ptr(&lazy_list))) + raise_softirq(TIMER_SOFTIRQ); + } else + irq_work_run_list(this_cpu_ptr(&lazy_list)); } EXPORT_SYMBOL_GPL(irq_work_run); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:216 @ void irq_work_tick(void) if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) irq_work_run_list(raised); + + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) + irq_work_run_list(this_cpu_ptr(&lazy_list)); +} + +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) +void irq_work_tick_soft(void) +{ irq_work_run_list(this_cpu_ptr(&lazy_list)); } +#endif /* * Synchronize against the irq_work @entry, ensures the entry is not Index: linux-5.0.19-rt11/kernel/kexec_core.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/kexec_core.c +++ linux-5.0.19-rt11/kernel/kexec_core.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:975 @ void crash_kexec(struct pt_regs *regs) old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); if (old_cpu == PANIC_CPU_INVALID) { /* This is the 1st CPU which comes here, so go ahead. */ - printk_safe_flush_on_panic(); __crash_kexec(regs); /* Index: linux-5.0.19-rt11/kernel/ksysfs.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/ksysfs.c +++ linux-5.0.19-rt11/kernel/ksysfs.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:143 @ KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_CRASH_CORE */ +#if defined(CONFIG_PREEMPT_RT_FULL) +static ssize_t realtime_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", 1); +} +KERNEL_ATTR_RO(realtime); +#endif + /* whether file capabilities are enabled */ static ssize_t fscaps_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:243 @ static struct attribute * kernel_attrs[] &rcu_expedited_attr.attr, &rcu_normal_attr.attr, #endif +#ifdef CONFIG_PREEMPT_RT_FULL + &realtime_attr.attr, +#endif NULL }; Index: linux-5.0.19-rt11/kernel/kthread.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/kthread.c +++ linux-5.0.19-rt11/kernel/kthread.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:602 @ void __kthread_init_worker(struct kthrea struct lock_class_key *key) { memset(worker, 0, sizeof(struct kthread_worker)); - spin_lock_init(&worker->lock); + raw_spin_lock_init(&worker->lock); lockdep_set_class_and_name(&worker->lock, key, name); INIT_LIST_HEAD(&worker->work_list); INIT_LIST_HEAD(&worker->delayed_work_list); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:644 @ repeat: if (kthread_should_stop()) { __set_current_state(TASK_RUNNING); - spin_lock_irq(&worker->lock); + raw_spin_lock_irq(&worker->lock); worker->task = NULL; - spin_unlock_irq(&worker->lock); + raw_spin_unlock_irq(&worker->lock); return 0; } work = NULL; - spin_lock_irq(&worker->lock); + raw_spin_lock_irq(&worker->lock); if (!list_empty(&worker->work_list)) { work = list_first_entry(&worker->work_list, struct kthread_work, node); list_del_init(&work->node); } worker->current_work = work; - spin_unlock_irq(&worker->lock); + raw_spin_unlock_irq(&worker->lock); if (work) { __set_current_state(TASK_RUNNING); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:815 @ bool kthread_queue_work(struct kthread_w bool ret = false; unsigned long flags; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); if (!queuing_blocked(worker, work)) { kthread_insert_work(worker, work, &worker->work_list); ret = true; } - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); return ret; } EXPORT_SYMBOL_GPL(kthread_queue_work); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:838 @ void kthread_delayed_work_timer_fn(struc struct kthread_delayed_work *dwork = from_timer(dwork, t, timer); struct kthread_work *work = &dwork->work; struct kthread_worker *worker = work->worker; + unsigned long flags; /* * This might happen when a pending work is reinitialized. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:847 @ void kthread_delayed_work_timer_fn(struc if (WARN_ON_ONCE(!worker)) return; - spin_lock(&worker->lock); + raw_spin_lock_irqsave(&worker->lock, flags); /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:856 @ void kthread_delayed_work_timer_fn(struc list_del_init(&work->node); kthread_insert_work(worker, work, &worker->work_list); - spin_unlock(&worker->lock); + raw_spin_unlock_irqrestore(&worker->lock, flags); } EXPORT_SYMBOL(kthread_delayed_work_timer_fn); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:912 @ bool kthread_queue_delayed_work(struct k unsigned long flags; bool ret = false; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); if (!queuing_blocked(worker, work)) { __kthread_queue_delayed_work(worker, dwork, delay); ret = true; } - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); return ret; } EXPORT_SYMBOL_GPL(kthread_queue_delayed_work); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:955 @ void kthread_flush_work(struct kthread_w if (!worker) return; - spin_lock_irq(&worker->lock); + raw_spin_lock_irq(&worker->lock); /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:967 @ void kthread_flush_work(struct kthread_w else noop = true; - spin_unlock_irq(&worker->lock); + raw_spin_unlock_irq(&worker->lock); if (!noop) wait_for_completion(&fwork.done); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1000 @ static bool __kthread_cancel_work(struct * any queuing is blocked by setting the canceling counter. */ work->canceling++; - spin_unlock_irqrestore(&worker->lock, *flags); + raw_spin_unlock_irqrestore(&worker->lock, *flags); del_timer_sync(&dwork->timer); - spin_lock_irqsave(&worker->lock, *flags); + raw_spin_lock_irqsave(&worker->lock, *flags); work->canceling--; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1049 @ bool kthread_mod_delayed_work(struct kth unsigned long flags; int ret = false; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); /* Do not bother with canceling when never queued. */ if (!work->worker) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1066 @ bool kthread_mod_delayed_work(struct kth fast_queue: __kthread_queue_delayed_work(worker, dwork, delay); out: - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); return ret; } EXPORT_SYMBOL_GPL(kthread_mod_delayed_work); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1080 @ static bool __kthread_cancel_work_sync(s if (!worker) goto out; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1094 @ static bool __kthread_cancel_work_sync(s * In the meantime, block any queuing by setting the canceling counter. */ work->canceling++; - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); kthread_flush_work(work); - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); work->canceling--; out_fast: - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); out: return ret; } Index: linux-5.0.19-rt11/kernel/locking/Makefile =================================================================== --- linux-5.0.19-rt11.orig/kernel/locking/Makefile +++ linux-5.0.19-rt11/kernel/locking/Makefile @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6 @ # and is generally not a function of system call inputs. KCOV_INSTRUMENT := n -obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o +obj-y += semaphore.o percpu-rwsem.o ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:15 @ CFLAGS_REMOVE_mutex-debug.o = $(CC_FLAGS CFLAGS_REMOVE_rtmutex-debug.o = $(CC_FLAGS_FTRACE) endif +ifneq ($(CONFIG_PREEMPT_RT_FULL),y) +obj-y += mutex.o obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o +endif +obj-y += rwsem.o obj-$(CONFIG_LOCKDEP) += lockdep.o ifeq ($(CONFIG_PROC_FS),y) obj-$(CONFIG_LOCKDEP) += lockdep_proc.o @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:32 @ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o +ifneq ($(CONFIG_PREEMPT_RT_FULL),y) obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o +endif +obj-$(CONFIG_PREEMPT_RT_FULL) += mutex-rt.o rwsem-rt.o rwlock-rt.o obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o obj-$(CONFIG_WW_MUTEX_SELFTEST) += test-ww_mutex.o Index: linux-5.0.19-rt11/kernel/locking/lockdep.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/locking/lockdep.c +++ linux-5.0.19-rt11/kernel/locking/lockdep.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:702 @ look_up_lock_class(const struct lockdep_ * Huh! same key, different name? Did someone trample * on some memory? We're most confused. */ - WARN_ON_ONCE(class->name != lock->name); + WARN_ON_ONCE(class->name != lock->name && + lock->key != &__lockdep_no_validate__); return class; } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3771 @ static void check_flags(unsigned long fl } } +#ifndef CONFIG_PREEMPT_RT_FULL /* * We dont accurately track softirq state in e.g. * hardirq contexts (such as on 4KSTACKS), so only @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3786 @ static void check_flags(unsigned long fl DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled); } } +#endif if (!debug_locks) print_irqtrace_events(current); Index: linux-5.0.19-rt11/kernel/locking/locktorture.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/locking/locktorture.c +++ linux-5.0.19-rt11/kernel/locking/locktorture.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:32 @ #include <linux/kthread.h> #include <linux/sched/rt.h> #include <linux/spinlock.h> -#include <linux/rwlock.h> #include <linux/mutex.h> #include <linux/rwsem.h> #include <linux/smp.h> Index: linux-5.0.19-rt11/kernel/locking/mutex-rt.c =================================================================== --- /dev/null +++ linux-5.0.19-rt11/kernel/locking/mutex-rt.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +/* + * kernel/rt.c + * + * Real-Time Preemption Support + * + * started by Ingo Molnar: + * + * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> + * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> + * + * historic credit for proving that Linux spinlocks can be implemented via + * RT-aware mutexes goes to many people: The Pmutex project (Dirk Grambow + * and others) who prototyped it on 2.4 and did lots of comparative + * research and analysis; TimeSys, for proving that you can implement a + * fully preemptible kernel via the use of IRQ threading and mutexes; + * Bill Huey for persuasively arguing on lkml that the mutex model is the + * right one; and to MontaVista, who ported pmutexes to 2.6. + * + * This code is a from-scratch implementation and is not based on pmutexes, + * but the idea of converting spinlocks to mutexes is used here too. + * + * lock debugging, locking tree, deadlock detection: + * + * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey + * Released under the General Public License (GPL). + * + * Includes portions of the generic R/W semaphore implementation from: + * + * Copyright (c) 2001 David Howells (dhowells@redhat.com). + * - Derived partially from idea by Andrea Arcangeli <andrea@suse.de> + * - Derived also from comments by Linus + * + * Pending ownership of locks and ownership stealing: + * + * Copyright (C) 2005, Kihon Technologies Inc., Steven Rostedt + * + * (also by Steven Rostedt) + * - Converted single pi_lock to individual task locks. + * + * By Esben Nielsen: + * Doing priority inheritance with help of the scheduler. + * + * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> + * - major rework based on Esben Nielsens initial patch + * - replaced thread_info references by task_struct refs + * - removed task->pending_owner dependency + * - BKL drop/reacquire for semaphore style locks to avoid deadlocks + * in the scheduler return path as discussed with Steven Rostedt + * + * Copyright (C) 2006, Kihon Technologies Inc. + * Steven Rostedt <rostedt@goodmis.org> + * - debugged and patched Thomas Gleixner's rework. + * - added back the cmpxchg to the rework. + * - turned atomic require back on for SMP. + */ + +#include <linux/spinlock.h> +#include <linux/rtmutex.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/kallsyms.h> +#include <linux/syscalls.h> +#include <linux/interrupt.h> +#include <linux/plist.h> +#include <linux/fs.h> +#include <linux/futex.h> +#include <linux/hrtimer.h> + +#include "rtmutex_common.h" + +/* + * struct mutex functions + */ +void __mutex_do_init(struct mutex *mutex, const char *name, + struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held lock: + */ + debug_check_no_locks_freed((void *)mutex, sizeof(*mutex)); + lockdep_init_map(&mutex->dep_map, name, key, 0); +#endif + mutex->lock.save_state = 0; +} +EXPORT_SYMBOL(__mutex_do_init); + +void __lockfunc _mutex_lock(struct mutex *lock) +{ + mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); + __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(_mutex_lock); + +void __lockfunc _mutex_lock_io(struct mutex *lock) +{ + int token; + + token = io_schedule_prepare(); + _mutex_lock(lock); + io_schedule_finish(token); +} +EXPORT_SYMBOL_GPL(_mutex_lock_io); + +int __lockfunc _mutex_lock_interruptible(struct mutex *lock) +{ + int ret; + + mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); + ret = __rt_mutex_lock_state(&lock->lock, TASK_INTERRUPTIBLE); + if (ret) + mutex_release(&lock->dep_map, 1, _RET_IP_); + return ret; +} +EXPORT_SYMBOL(_mutex_lock_interruptible); + +int __lockfunc _mutex_lock_killable(struct mutex *lock) +{ + int ret; + + mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); + ret = __rt_mutex_lock_state(&lock->lock, TASK_KILLABLE); + if (ret) + mutex_release(&lock->dep_map, 1, _RET_IP_); + return ret; +} +EXPORT_SYMBOL(_mutex_lock_killable); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass) +{ + mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_); + __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(_mutex_lock_nested); + +void __lockfunc _mutex_lock_io_nested(struct mutex *lock, int subclass) +{ + int token; + + token = io_schedule_prepare(); + + mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_); + __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE); + + io_schedule_finish(token); +} +EXPORT_SYMBOL_GPL(_mutex_lock_io_nested); + +void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest) +{ + mutex_acquire_nest(&lock->dep_map, 0, 0, nest, _RET_IP_); + __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(_mutex_lock_nest_lock); + +int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass) +{ + int ret; + + mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_); + ret = __rt_mutex_lock_state(&lock->lock, TASK_INTERRUPTIBLE); + if (ret) + mutex_release(&lock->dep_map, 1, _RET_IP_); + return ret; +} +EXPORT_SYMBOL(_mutex_lock_interruptible_nested); + +int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass) +{ + int ret; + + mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); + ret = __rt_mutex_lock_state(&lock->lock, TASK_KILLABLE); + if (ret) + mutex_release(&lock->dep_map, 1, _RET_IP_); + return ret; +} +EXPORT_SYMBOL(_mutex_lock_killable_nested); +#endif + +int __lockfunc _mutex_trylock(struct mutex *lock) +{ + int ret = __rt_mutex_trylock(&lock->lock); + + if (ret) + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + + return ret; +} +EXPORT_SYMBOL(_mutex_trylock); + +void __lockfunc _mutex_unlock(struct mutex *lock) +{ + mutex_release(&lock->dep_map, 1, _RET_IP_); + __rt_mutex_unlock(&lock->lock); +} +EXPORT_SYMBOL(_mutex_unlock); + +/** + * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0 + * @cnt: the atomic which we are to dec + * @lock: the mutex to return holding if we dec to 0 + * + * return true and hold lock if we dec to 0, return false otherwise + */ +int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock) +{ + /* dec if we can't possibly hit 0 */ + if (atomic_add_unless(cnt, -1, 1)) + return 0; + /* we might hit 0, so take the lock */ + mutex_lock(lock); + if (!atomic_dec_and_test(cnt)) { + /* when we actually did the dec, we didn't hit 0 */ + mutex_unlock(lock); + return 0; + } + /* we hit 0, and we hold the lock */ + return 1; +} +EXPORT_SYMBOL(atomic_dec_and_mutex_lock); Index: linux-5.0.19-rt11/kernel/locking/rtmutex.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/locking/rtmutex.c +++ linux-5.0.19-rt11/kernel/locking/rtmutex.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:10 @ * Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com> * Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt * Copyright (C) 2006 Esben Nielsen + * Adaptive Spinlocks: + * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich, + * and Peter Morreale, + * Adaptive Spinlocks simplification: + * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com> * * See Documentation/locking/rt-mutex-design.txt for details. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:26 @ #include <linux/sched/wake_q.h> #include <linux/sched/debug.h> #include <linux/timer.h> +#include <linux/ww_mutex.h> +#include <linux/blkdev.h> #include "rtmutex_common.h" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:238 @ static inline bool unlock_rt_mutex_safe( * Only use with rt_mutex_waiter_{less,equal}() */ #define task_to_waiter(p) \ - &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline } + &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline, .task = (p) } static inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:278 @ rt_mutex_waiter_equal(struct rt_mutex_wa return 1; } +#define STEAL_NORMAL 0 +#define STEAL_LATERAL 1 + +static inline int +rt_mutex_steal(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, int mode) +{ + struct rt_mutex_waiter *top_waiter = rt_mutex_top_waiter(lock); + + if (waiter == top_waiter || rt_mutex_waiter_less(waiter, top_waiter)) + return 1; + + /* + * Note that RT tasks are excluded from lateral-steals + * to prevent the introduction of an unbounded latency. + */ + if (mode == STEAL_NORMAL || rt_task(waiter->task)) + return 0; + + return rt_mutex_waiter_equal(waiter, top_waiter); +} + static void rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:403 @ static bool rt_mutex_cond_detect_deadloc return debug_rt_mutex_detect_deadlock(waiter, chwalk); } +static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter) +{ + if (waiter->savestate) + wake_up_lock_sleeper(waiter->task); + else + wake_up_process(waiter->task); +} + /* * Max number of times we'll walk the boosting chain: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:735 @ static int rt_mutex_adjust_prio_chain(st * follow here. This is the end of the chain we are walking. */ if (!rt_mutex_owner(lock)) { + struct rt_mutex_waiter *lock_top_waiter; + /* * If the requeue [7] above changed the top waiter, * then we need to wake the new top waiter up to try * to get the lock. */ - if (prerequeue_top_waiter != rt_mutex_top_waiter(lock)) - wake_up_process(rt_mutex_top_waiter(lock)->task); + lock_top_waiter = rt_mutex_top_waiter(lock); + if (prerequeue_top_waiter != lock_top_waiter) + rt_mutex_wake_waiter(lock_top_waiter); raw_spin_unlock_irq(&lock->wait_lock); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:846 @ static int rt_mutex_adjust_prio_chain(st * @task: The task which wants to acquire the lock * @waiter: The waiter that is queued to the lock's wait tree if the * callsite called task_blocked_on_lock(), otherwise NULL + * @mode: Lock steal mode (STEAL_NORMAL, STEAL_LATERAL) */ -static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, - struct rt_mutex_waiter *waiter) +static int __try_to_take_rt_mutex(struct rt_mutex *lock, + struct task_struct *task, + struct rt_mutex_waiter *waiter, int mode) { lockdep_assert_held(&lock->wait_lock); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:886 @ static int try_to_take_rt_mutex(struct r */ if (waiter) { /* - * If waiter is not the highest priority waiter of - * @lock, give up. + * If waiter is not the highest priority waiter of @lock, + * or its peer when lateral steal is allowed, give up. */ - if (waiter != rt_mutex_top_waiter(lock)) + if (!rt_mutex_steal(lock, waiter, mode)) return 0; - /* * We can acquire the lock. Remove the waiter from the * lock waiters tree. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:908 @ static int try_to_take_rt_mutex(struct r */ if (rt_mutex_has_waiters(lock)) { /* - * If @task->prio is greater than or equal to - * the top waiter priority (kernel view), - * @task lost. + * If @task->prio is greater than the top waiter + * priority (kernel view), or equal to it when a + * lateral steal is forbidden, @task lost. */ - if (!rt_mutex_waiter_less(task_to_waiter(task), - rt_mutex_top_waiter(lock))) + if (!rt_mutex_steal(lock, task_to_waiter(task), mode)) return 0; - /* * The current top waiter stays enqueued. We * don't have to change anything in the lock @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:960 @ takeit: return 1; } +#ifdef CONFIG_PREEMPT_RT_FULL +/* + * preemptible spin_lock functions: + */ +static inline void rt_spin_lock_fastlock(struct rt_mutex *lock, + void (*slowfn)(struct rt_mutex *lock)) +{ + might_sleep_no_state_check(); + + if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) + return; + else + slowfn(lock); +} + +static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock, + void (*slowfn)(struct rt_mutex *lock)) +{ + if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) + return; + else + slowfn(lock); +} +#ifdef CONFIG_SMP +/* + * Note that owner is a speculative pointer and dereferencing relies + * on rcu_read_lock() and the check against the lock owner. + */ +static int adaptive_wait(struct rt_mutex *lock, + struct task_struct *owner) +{ + int res = 0; + + rcu_read_lock(); + for (;;) { + if (owner != rt_mutex_owner(lock)) + break; + /* + * Ensure that owner->on_cpu is dereferenced _after_ + * checking the above to be valid. + */ + barrier(); + if (!owner->on_cpu) { + res = 1; + break; + } + cpu_relax(); + } + rcu_read_unlock(); + return res; +} +#else +static int adaptive_wait(struct rt_mutex *lock, + struct task_struct *orig_owner) +{ + return 1; +} +#endif + +static int task_blocks_on_rt_mutex(struct rt_mutex *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task, + enum rtmutex_chainwalk chwalk); +/* + * Slow path lock function spin_lock style: this variant is very + * careful not to miss any non-lock wakeups. + * + * We store the current state under p->pi_lock in p->saved_state and + * the try_to_wake_up() code handles this accordingly. + */ +void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock, + struct rt_mutex_waiter *waiter, + unsigned long flags) +{ + struct task_struct *lock_owner, *self = current; + struct rt_mutex_waiter *top_waiter; + int ret; + + if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL)) + return; + + BUG_ON(rt_mutex_owner(lock) == self); + + /* + * We save whatever state the task is in and we'll restore it + * after acquiring the lock taking real wakeups into account + * as well. We are serialized via pi_lock against wakeups. See + * try_to_wake_up(). + */ + raw_spin_lock(&self->pi_lock); + self->saved_state = self->state; + __set_current_state_no_track(TASK_UNINTERRUPTIBLE); + raw_spin_unlock(&self->pi_lock); + + ret = task_blocks_on_rt_mutex(lock, waiter, self, RT_MUTEX_MIN_CHAINWALK); + BUG_ON(ret); + + for (;;) { + /* Try to acquire the lock again. */ + if (__try_to_take_rt_mutex(lock, self, waiter, STEAL_LATERAL)) + break; + + top_waiter = rt_mutex_top_waiter(lock); + lock_owner = rt_mutex_owner(lock); + + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + + debug_rt_mutex_print_deadlock(waiter); + + if (top_waiter != waiter || adaptive_wait(lock, lock_owner)) + schedule(); + + raw_spin_lock_irqsave(&lock->wait_lock, flags); + + raw_spin_lock(&self->pi_lock); + __set_current_state_no_track(TASK_UNINTERRUPTIBLE); + raw_spin_unlock(&self->pi_lock); + } + + /* + * Restore the task state to current->saved_state. We set it + * to the original state above and the try_to_wake_up() code + * has possibly updated it when a real (non-rtmutex) wakeup + * happened while we were blocked. Clear saved_state so + * try_to_wakeup() does not get confused. + */ + raw_spin_lock(&self->pi_lock); + __set_current_state_no_track(self->saved_state); + self->saved_state = TASK_RUNNING; + raw_spin_unlock(&self->pi_lock); + + /* + * try_to_take_rt_mutex() sets the waiter bit + * unconditionally. We might have to fix that up: + */ + fixup_rt_mutex_waiters(lock); + + BUG_ON(rt_mutex_has_waiters(lock) && waiter == rt_mutex_top_waiter(lock)); + BUG_ON(!RB_EMPTY_NODE(&waiter->tree_entry)); +} + +static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock) +{ + struct rt_mutex_waiter waiter; + unsigned long flags; + + rt_mutex_init_waiter(&waiter, true); + + raw_spin_lock_irqsave(&lock->wait_lock, flags); + rt_spin_lock_slowlock_locked(lock, &waiter, flags); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + debug_rt_mutex_free_waiter(&waiter); +} + +static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock, + struct wake_q_head *wake_q, + struct wake_q_head *wq_sleeper); +/* + * Slow path to release a rt_mutex spin_lock style + */ +void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock) +{ + unsigned long flags; + DEFINE_WAKE_Q(wake_q); + DEFINE_WAKE_Q(wake_sleeper_q); + bool postunlock; + + raw_spin_lock_irqsave(&lock->wait_lock, flags); + postunlock = __rt_mutex_unlock_common(lock, &wake_q, &wake_sleeper_q); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + + if (postunlock) + rt_mutex_postunlock(&wake_q, &wake_sleeper_q); +} + +void __lockfunc rt_spin_lock(spinlock_t *lock) +{ + sleeping_lock_inc(); + migrate_disable(); + spin_acquire(&lock->dep_map, 0, 0, _RET_IP_); + rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock); +} +EXPORT_SYMBOL(rt_spin_lock); + +void __lockfunc __rt_spin_lock(struct rt_mutex *lock) +{ + rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock); +} + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass) +{ + sleeping_lock_inc(); + migrate_disable(); + spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); + rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock); +} +EXPORT_SYMBOL(rt_spin_lock_nested); +#endif + +void __lockfunc rt_spin_unlock(spinlock_t *lock) +{ + /* NOTE: we always pass in '1' for nested, for simplicity */ + spin_release(&lock->dep_map, 1, _RET_IP_); + rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock); + migrate_enable(); + sleeping_lock_dec(); +} +EXPORT_SYMBOL(rt_spin_unlock); + +void __lockfunc __rt_spin_unlock(struct rt_mutex *lock) +{ + rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock); +} +EXPORT_SYMBOL(__rt_spin_unlock); + +/* + * Wait for the lock to get unlocked: instead of polling for an unlock + * (like raw spinlocks do), we lock and unlock, to force the kernel to + * schedule if there's contention: + */ +void __lockfunc rt_spin_unlock_wait(spinlock_t *lock) +{ + spin_lock(lock); + spin_unlock(lock); +} +EXPORT_SYMBOL(rt_spin_unlock_wait); + +int __lockfunc rt_spin_trylock(spinlock_t *lock) +{ + int ret; + + sleeping_lock_inc(); + migrate_disable(); + ret = __rt_mutex_trylock(&lock->lock); + if (ret) { + spin_acquire(&lock->dep_map, 0, 1, _RET_IP_); + } else { + migrate_enable(); + sleeping_lock_dec(); + } + return ret; +} +EXPORT_SYMBOL(rt_spin_trylock); + +int __lockfunc rt_spin_trylock_bh(spinlock_t *lock) +{ + int ret; + + local_bh_disable(); + ret = __rt_mutex_trylock(&lock->lock); + if (ret) { + sleeping_lock_inc(); + migrate_disable(); + spin_acquire(&lock->dep_map, 0, 1, _RET_IP_); + } else + local_bh_enable(); + return ret; +} +EXPORT_SYMBOL(rt_spin_trylock_bh); + +int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags) +{ + int ret; + + *flags = 0; + ret = __rt_mutex_trylock(&lock->lock); + if (ret) { + sleeping_lock_inc(); + migrate_disable(); + spin_acquire(&lock->dep_map, 0, 1, _RET_IP_); + } + return ret; +} +EXPORT_SYMBOL(rt_spin_trylock_irqsave); + +void +__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held lock: + */ + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + lockdep_init_map(&lock->dep_map, name, key, 0); +#endif +} +EXPORT_SYMBOL(__rt_spin_lock_init); + +#endif /* PREEMPT_RT_FULL */ + +#ifdef CONFIG_PREEMPT_RT_FULL + static inline int __sched +__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx) +{ + struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock); + struct ww_acquire_ctx *hold_ctx = READ_ONCE(ww->ctx); + + if (!hold_ctx) + return 0; + + if (unlikely(ctx == hold_ctx)) + return -EALREADY; + + if (ctx->stamp - hold_ctx->stamp <= LONG_MAX && + (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) { +#ifdef CONFIG_DEBUG_MUTEXES + DEBUG_LOCKS_WARN_ON(ctx->contending_lock); + ctx->contending_lock = ww; +#endif + return -EDEADLK; + } + + return 0; +} +#else + static inline int __sched +__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx) +{ + BUG(); + return 0; +} + +#endif + +static inline int +try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, + struct rt_mutex_waiter *waiter) +{ + return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL); +} + /* * Task blocks on lock. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1389 @ static int task_blocks_on_rt_mutex(struc * Called with lock->wait_lock held and interrupts disabled. */ static void mark_wakeup_next_waiter(struct wake_q_head *wake_q, + struct wake_q_head *wake_sleeper_q, struct rt_mutex *lock) { struct rt_mutex_waiter *waiter; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1429 @ static void mark_wakeup_next_waiter(stru * Pairs with preempt_enable() in rt_mutex_postunlock(); */ preempt_disable(); - wake_q_add(wake_q, waiter->task); + if (waiter->savestate) + wake_q_add_sleeper(wake_sleeper_q, waiter->task); + else + wake_q_add(wake_q, waiter->task); raw_spin_unlock(¤t->pi_lock); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1514 @ void rt_mutex_adjust_pi(struct task_stru return; } next_lock = waiter->lock; - raw_spin_unlock_irqrestore(&task->pi_lock, flags); /* gets dropped in rt_mutex_adjust_prio_chain()! */ get_task_struct(task); + raw_spin_unlock_irqrestore(&task->pi_lock, flags); rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL, next_lock, NULL, task); } -void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) +void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate) { debug_rt_mutex_init_waiter(waiter); RB_CLEAR_NODE(&waiter->pi_tree_entry); RB_CLEAR_NODE(&waiter->tree_entry); waiter->task = NULL; + waiter->savestate = savestate; } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1545 @ void rt_mutex_init_waiter(struct rt_mute static int __sched __rt_mutex_slowlock(struct rt_mutex *lock, int state, struct hrtimer_sleeper *timeout, - struct rt_mutex_waiter *waiter) + struct rt_mutex_waiter *waiter, + struct ww_acquire_ctx *ww_ctx) { int ret = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1555 @ __rt_mutex_slowlock(struct rt_mutex *loc if (try_to_take_rt_mutex(lock, current, waiter)) break; - /* - * TASK_INTERRUPTIBLE checks for signals and - * timeout. Ignored otherwise. - */ - if (likely(state == TASK_INTERRUPTIBLE)) { - /* Signal pending? */ - if (signal_pending(current)) - ret = -EINTR; - if (timeout && !timeout->task) - ret = -ETIMEDOUT; + if (timeout && !timeout->task) { + ret = -ETIMEDOUT; + break; + } + if (signal_pending_state(state, current)) { + ret = -EINTR; + break; + } + + if (ww_ctx && ww_ctx->acquired > 0) { + ret = __mutex_lock_check_stamp(lock, ww_ctx); if (ret) break; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1604 @ static void rt_mutex_handle_deadlock(int } } -/* - * Slow path lock function: - */ -static int __sched -rt_mutex_slowlock(struct rt_mutex *lock, int state, - struct hrtimer_sleeper *timeout, - enum rtmutex_chainwalk chwalk) +static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww, + struct ww_acquire_ctx *ww_ctx) { - struct rt_mutex_waiter waiter; - unsigned long flags; - int ret = 0; +#ifdef CONFIG_DEBUG_MUTEXES + /* + * If this WARN_ON triggers, you used ww_mutex_lock to acquire, + * but released with a normal mutex_unlock in this call. + * + * This should never happen, always use ww_mutex_unlock. + */ + DEBUG_LOCKS_WARN_ON(ww->ctx); + + /* + * Not quite done after calling ww_acquire_done() ? + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire); - rt_mutex_init_waiter(&waiter); + if (ww_ctx->contending_lock) { + /* + * After -EDEADLK you tried to + * acquire a different ww_mutex? Bad! + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww); + + /* + * You called ww_mutex_lock after receiving -EDEADLK, + * but 'forgot' to unlock everything else first? + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0); + ww_ctx->contending_lock = NULL; + } /* - * Technically we could use raw_spin_[un]lock_irq() here, but this can - * be called in early boot if the cmpxchg() fast path is disabled - * (debug, no architecture support). In this case we will acquire the - * rtmutex with lock->wait_lock held. But we cannot unconditionally - * enable interrupts in that early boot case. So we need to use the - * irqsave/restore variants. + * Naughty, using a different class will lead to undefined behavior! */ - raw_spin_lock_irqsave(&lock->wait_lock, flags); + DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class); +#endif + ww_ctx->acquired++; +} + +#ifdef CONFIG_PREEMPT_RT_FULL +static void ww_mutex_account_lock(struct rt_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ + struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock); + struct rt_mutex_waiter *waiter, *n; + + /* + * This branch gets optimized out for the common case, + * and is only important for ww_mutex_lock. + */ + ww_mutex_lock_acquired(ww, ww_ctx); + ww->ctx = ww_ctx; + + /* + * Give any possible sleeping processes the chance to wake up, + * so they can recheck if they have to back off. + */ + rbtree_postorder_for_each_entry_safe(waiter, n, &lock->waiters.rb_root, + tree_entry) { + /* XXX debug rt mutex waiter wakeup */ + + BUG_ON(waiter->lock != lock); + rt_mutex_wake_waiter(waiter); + } +} + +#else + +static void ww_mutex_account_lock(struct rt_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ + BUG(); +} +#endif + +int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state, + struct hrtimer_sleeper *timeout, + enum rtmutex_chainwalk chwalk, + struct ww_acquire_ctx *ww_ctx, + struct rt_mutex_waiter *waiter) +{ + int ret; + +#ifdef CONFIG_PREEMPT_RT_FULL + if (ww_ctx) { + struct ww_mutex *ww; + + ww = container_of(lock, struct ww_mutex, base.lock); + if (unlikely(ww_ctx == READ_ONCE(ww->ctx))) + return -EALREADY; + } +#endif /* Try to acquire the lock again: */ if (try_to_take_rt_mutex(lock, current, NULL)) { - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + if (ww_ctx) + ww_mutex_account_lock(lock, ww_ctx); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1711 @ rt_mutex_slowlock(struct rt_mutex *lock, if (unlikely(timeout)) hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); - ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk); + ret = task_blocks_on_rt_mutex(lock, waiter, current, chwalk); - if (likely(!ret)) + if (likely(!ret)) { /* sleep on the mutex */ - ret = __rt_mutex_slowlock(lock, state, timeout, &waiter); + ret = __rt_mutex_slowlock(lock, state, timeout, waiter, + ww_ctx); + } else if (ww_ctx) { + /* ww_mutex received EDEADLK, let it become EALREADY */ + ret = __mutex_lock_check_stamp(lock, ww_ctx); + BUG_ON(!ret); + } if (unlikely(ret)) { __set_current_state(TASK_RUNNING); - remove_waiter(lock, &waiter); - rt_mutex_handle_deadlock(ret, chwalk, &waiter); + remove_waiter(lock, waiter); + /* ww_mutex wants to report EDEADLK/EALREADY, let it */ + if (!ww_ctx) + rt_mutex_handle_deadlock(ret, chwalk, waiter); + } else if (ww_ctx) { + ww_mutex_account_lock(lock, ww_ctx); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1738 @ rt_mutex_slowlock(struct rt_mutex *lock, * unconditionally. We might have to fix that up. */ fixup_rt_mutex_waiters(lock); + return ret; +} + +/* + * Slow path lock function: + */ +static int __sched +rt_mutex_slowlock(struct rt_mutex *lock, int state, + struct hrtimer_sleeper *timeout, + enum rtmutex_chainwalk chwalk, + struct ww_acquire_ctx *ww_ctx) +{ + struct rt_mutex_waiter waiter; + unsigned long flags; + int ret = 0; + + rt_mutex_init_waiter(&waiter, false); + + /* + * Technically we could use raw_spin_[un]lock_irq() here, but this can + * be called in early boot if the cmpxchg() fast path is disabled + * (debug, no architecture support). In this case we will acquire the + * rtmutex with lock->wait_lock held. But we cannot unconditionally + * enable interrupts in that early boot case. So we need to use the + * irqsave/restore variants. + */ + raw_spin_lock_irqsave(&lock->wait_lock, flags); + + ret = rt_mutex_slowlock_locked(lock, state, timeout, chwalk, ww_ctx, + &waiter); raw_spin_unlock_irqrestore(&lock->wait_lock, flags); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1828 @ static inline int rt_mutex_slowtrylock(s * Return whether the current task needs to call rt_mutex_postunlock(). */ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock, - struct wake_q_head *wake_q) + struct wake_q_head *wake_q, + struct wake_q_head *wake_sleeper_q) { unsigned long flags; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1883 @ static bool __sched rt_mutex_slowunlock( * * Queue the next waiter for wakeup once we release the wait_lock. */ - mark_wakeup_next_waiter(wake_q, lock); + mark_wakeup_next_waiter(wake_q, wake_sleeper_q, lock); raw_spin_unlock_irqrestore(&lock->wait_lock, flags); return true; /* call rt_mutex_postunlock() */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1897 @ static bool __sched rt_mutex_slowunlock( */ static inline int rt_mutex_fastlock(struct rt_mutex *lock, int state, + struct ww_acquire_ctx *ww_ctx, int (*slowfn)(struct rt_mutex *lock, int state, struct hrtimer_sleeper *timeout, - enum rtmutex_chainwalk chwalk)) + enum rtmutex_chainwalk chwalk, + struct ww_acquire_ctx *ww_ctx)) { if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) return 0; - return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK); + /* + * If rt_mutex blocks, the function sched_submit_work will not call + * blk_schedule_flush_plug (because tsk_is_pi_blocked would be true). + * We must call blk_schedule_flush_plug here, if we don't call it, + * a deadlock in I/O may happen. + */ + if (unlikely(blk_needs_flush_plug(current))) + blk_schedule_flush_plug(current); + + return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK, ww_ctx); } static inline int rt_mutex_timed_fastlock(struct rt_mutex *lock, int state, struct hrtimer_sleeper *timeout, enum rtmutex_chainwalk chwalk, + struct ww_acquire_ctx *ww_ctx, int (*slowfn)(struct rt_mutex *lock, int state, struct hrtimer_sleeper *timeout, - enum rtmutex_chainwalk chwalk)) + enum rtmutex_chainwalk chwalk, + struct ww_acquire_ctx *ww_ctx)) { if (chwalk == RT_MUTEX_MIN_CHAINWALK && likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) return 0; - return slowfn(lock, state, timeout, chwalk); + if (unlikely(blk_needs_flush_plug(current))) + blk_schedule_flush_plug(current); + + return slowfn(lock, state, timeout, chwalk, ww_ctx); } static inline int @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1951 @ rt_mutex_fasttrylock(struct rt_mutex *lo /* * Performs the wakeup of the the top-waiter and re-enables preemption. */ -void rt_mutex_postunlock(struct wake_q_head *wake_q) +void rt_mutex_postunlock(struct wake_q_head *wake_q, + struct wake_q_head *wake_sleeper_q) { wake_up_q(wake_q); + wake_up_q_sleeper(wake_sleeper_q); /* Pairs with preempt_disable() in rt_mutex_slowunlock() */ preempt_enable(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1964 @ void rt_mutex_postunlock(struct wake_q_h static inline void rt_mutex_fastunlock(struct rt_mutex *lock, bool (*slowfn)(struct rt_mutex *lock, - struct wake_q_head *wqh)) + struct wake_q_head *wqh, + struct wake_q_head *wq_sleeper)) { DEFINE_WAKE_Q(wake_q); + DEFINE_WAKE_Q(wake_sleeper_q); if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) return; - if (slowfn(lock, &wake_q)) - rt_mutex_postunlock(&wake_q); + if (slowfn(lock, &wake_q, &wake_sleeper_q)) + rt_mutex_postunlock(&wake_q, &wake_sleeper_q); } -static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass) +int __sched __rt_mutex_lock_state(struct rt_mutex *lock, int state) { might_sleep(); + return rt_mutex_fastlock(lock, state, NULL, rt_mutex_slowlock); +} + +/** + * rt_mutex_lock_state - lock a rt_mutex with a given state + * + * @lock: The rt_mutex to be locked + * @state: The state to set when blocking on the rt_mutex + */ +static inline int __sched rt_mutex_lock_state(struct rt_mutex *lock, + unsigned int subclass, int state) +{ + int ret; mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); - rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock); + ret = __rt_mutex_lock_state(lock, state); + if (ret) + mutex_release(&lock->dep_map, 1, _RET_IP_); + return ret; +} + +static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass) +{ + rt_mutex_lock_state(lock, subclass, TASK_UNINTERRUPTIBLE); } #ifdef CONFIG_DEBUG_LOCK_ALLOC @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2044 @ EXPORT_SYMBOL_GPL(rt_mutex_lock); */ int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock) { - int ret; - - might_sleep(); - - mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); - ret = rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock); - if (ret) - mutex_release(&lock->dep_map, 1, _RET_IP_); - - return ret; + return rt_mutex_lock_state(lock, 0, TASK_INTERRUPTIBLE); } EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2062 @ int __sched __rt_mutex_futex_trylock(str } /** + * rt_mutex_lock_killable - lock a rt_mutex killable + * + * @lock: the rt_mutex to be locked + * @detect_deadlock: deadlock detection on/off + * + * Returns: + * 0 on success + * -EINTR when interrupted by a signal + */ +int __sched rt_mutex_lock_killable(struct rt_mutex *lock) +{ + return rt_mutex_lock_state(lock, 0, TASK_KILLABLE); +} +EXPORT_SYMBOL_GPL(rt_mutex_lock_killable); + +/** * rt_mutex_timed_lock - lock a rt_mutex interruptible * the timeout structure is provided * by the caller @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2100 @ rt_mutex_timed_lock(struct rt_mutex *loc mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout, RT_MUTEX_MIN_CHAINWALK, + NULL, rt_mutex_slowlock); if (ret) mutex_release(&lock->dep_map, 1, _RET_IP_); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2109 @ rt_mutex_timed_lock(struct rt_mutex *loc } EXPORT_SYMBOL_GPL(rt_mutex_timed_lock); +int __sched __rt_mutex_trylock(struct rt_mutex *lock) +{ +#ifdef CONFIG_PREEMPT_RT_FULL + if (WARN_ON_ONCE(in_irq() || in_nmi())) +#else + if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq())) +#endif + return 0; + + return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock); +} + /** * rt_mutex_trylock - try to lock a rt_mutex * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2136 @ int __sched rt_mutex_trylock(struct rt_m { int ret; - if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq())) - return 0; - - ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock); + ret = __rt_mutex_trylock(lock); if (ret) mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2144 @ int __sched rt_mutex_trylock(struct rt_m } EXPORT_SYMBOL_GPL(rt_mutex_trylock); +void __sched __rt_mutex_unlock(struct rt_mutex *lock) +{ + rt_mutex_fastunlock(lock, rt_mutex_slowunlock); +} + /** * rt_mutex_unlock - unlock a rt_mutex * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2157 @ EXPORT_SYMBOL_GPL(rt_mutex_trylock); void __sched rt_mutex_unlock(struct rt_mutex *lock) { mutex_release(&lock->dep_map, 1, _RET_IP_); - rt_mutex_fastunlock(lock, rt_mutex_slowunlock); + __rt_mutex_unlock(lock); } EXPORT_SYMBOL_GPL(rt_mutex_unlock); -/** - * Futex variant, that since futex variants do not use the fast-path, can be - * simple and will not need to retry. - */ -bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wake_q) +static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock, + struct wake_q_head *wake_q, + struct wake_q_head *wq_sleeper) { lockdep_assert_held(&lock->wait_lock); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2180 @ bool __sched __rt_mutex_futex_unlock(str * avoid inversion prior to the wakeup. preempt_disable() * therein pairs with rt_mutex_postunlock(). */ - mark_wakeup_next_waiter(wake_q, lock); + mark_wakeup_next_waiter(wake_q, wq_sleeper, lock); return true; /* call postunlock() */ } +/** + * Futex variant, that since futex variants do not use the fast-path, can be + * simple and will not need to retry. + */ +bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock, + struct wake_q_head *wake_q, + struct wake_q_head *wq_sleeper) +{ + return __rt_mutex_unlock_common(lock, wake_q, wq_sleeper); +} + void __sched rt_mutex_futex_unlock(struct rt_mutex *lock) { DEFINE_WAKE_Q(wake_q); + DEFINE_WAKE_Q(wake_sleeper_q); unsigned long flags; bool postunlock; raw_spin_lock_irqsave(&lock->wait_lock, flags); - postunlock = __rt_mutex_futex_unlock(lock, &wake_q); + postunlock = __rt_mutex_futex_unlock(lock, &wake_q, &wake_sleeper_q); raw_spin_unlock_irqrestore(&lock->wait_lock, flags); if (postunlock) - rt_mutex_postunlock(&wake_q); + rt_mutex_postunlock(&wake_q, &wake_sleeper_q); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2247 @ void __rt_mutex_init(struct rt_mutex *lo if (name && key) debug_rt_mutex_init(lock, name, key); } -EXPORT_SYMBOL_GPL(__rt_mutex_init); +EXPORT_SYMBOL(__rt_mutex_init); /** * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2267 @ void rt_mutex_init_proxy_locked(struct r struct task_struct *proxy_owner) { __rt_mutex_init(lock, NULL, NULL); +#ifdef CONFIG_DEBUG_SPINLOCK + /* + * get another key class for the wait_lock. LOCK_PI and UNLOCK_PI is + * holding the ->wait_lock of the proxy_lock while unlocking a sleeping + * lock. + */ + raw_spin_lock_init(&lock->wait_lock); +#endif debug_rt_mutex_proxy_lock(lock, proxy_owner); rt_mutex_set_owner(lock, proxy_owner); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2422 @ int rt_mutex_wait_proxy_lock(struct rt_m struct hrtimer_sleeper *to, struct rt_mutex_waiter *waiter) { + struct task_struct *tsk = current; int ret; raw_spin_lock_irq(&lock->wait_lock); /* sleep on the mutex */ set_current_state(TASK_INTERRUPTIBLE); - ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter); + ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL); /* * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might * have to fix that up. */ fixup_rt_mutex_waiters(lock); + /* + * RT has a problem here when the wait got interrupted by a timeout + * or a signal. task->pi_blocked_on is still set. The task must + * acquire the hash bucket lock when returning from this function. + * + * If the hash bucket lock is contended then the + * BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on)) in + * task_blocks_on_rt_mutex() will trigger. This can be avoided by + * clearing task->pi_blocked_on which removes the task from the + * boosting chain of the rtmutex. That's correct because the task + * is not longer blocked on it. + */ + if (ret) { + raw_spin_lock(&tsk->pi_lock); + tsk->pi_blocked_on = NULL; + raw_spin_unlock(&tsk->pi_lock); + } + raw_spin_unlock_irq(&lock->wait_lock); return ret; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2513 @ bool rt_mutex_cleanup_proxy_lock(struct return cleanup; } + +static inline int +ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ +#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH + unsigned tmp; + + if (ctx->deadlock_inject_countdown-- == 0) { + tmp = ctx->deadlock_inject_interval; + if (tmp > UINT_MAX/4) + tmp = UINT_MAX; + else + tmp = tmp*2 + tmp + tmp/2; + + ctx->deadlock_inject_interval = tmp; + ctx->deadlock_inject_countdown = tmp; + ctx->contending_lock = lock; + + ww_mutex_unlock(lock); + + return -EDEADLK; + } +#endif + + return 0; +} + +#ifdef CONFIG_PREEMPT_RT_FULL +int __sched +ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + int ret; + + might_sleep(); + + mutex_acquire_nest(&lock->base.dep_map, 0, 0, + ctx ? &ctx->dep_map : NULL, _RET_IP_); + ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0, + ctx); + if (ret) + mutex_release(&lock->base.dep_map, 1, _RET_IP_); + else if (!ret && ctx && ctx->acquired > 1) + return ww_mutex_deadlock_injection(lock, ctx); + + return ret; +} +EXPORT_SYMBOL_GPL(ww_mutex_lock_interruptible); + +int __sched +ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + int ret; + + might_sleep(); + + mutex_acquire_nest(&lock->base.dep_map, 0, 0, + ctx ? &ctx->dep_map : NULL, _RET_IP_); + ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0, + ctx); + if (ret) + mutex_release(&lock->base.dep_map, 1, _RET_IP_); + else if (!ret && ctx && ctx->acquired > 1) + return ww_mutex_deadlock_injection(lock, ctx); + + return ret; +} +EXPORT_SYMBOL_GPL(ww_mutex_lock); + +void __sched ww_mutex_unlock(struct ww_mutex *lock) +{ + int nest = !!lock->ctx; + + /* + * The unlocking fastpath is the 0->1 transition from 'locked' + * into 'unlocked' state: + */ + if (nest) { +#ifdef CONFIG_DEBUG_MUTEXES + DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired); +#endif + if (lock->ctx->acquired > 0) + lock->ctx->acquired--; + lock->ctx = NULL; + } + + mutex_release(&lock->base.dep_map, nest, _RET_IP_); + __rt_mutex_unlock(&lock->base.lock); +} +EXPORT_SYMBOL(ww_mutex_unlock); + +int __rt_mutex_owner_current(struct rt_mutex *lock) +{ + return rt_mutex_owner(lock) == current; +} +EXPORT_SYMBOL(__rt_mutex_owner_current); +#endif Index: linux-5.0.19-rt11/kernel/locking/rtmutex_common.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/locking/rtmutex_common.h +++ linux-5.0.19-rt11/kernel/locking/rtmutex_common.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:18 @ #include <linux/rtmutex.h> #include <linux/sched/wake_q.h> +#include <linux/sched/debug.h> /* * This is the control structure for tasks blocked on a rt_mutex, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:33 @ struct rt_mutex_waiter { struct rb_node pi_tree_entry; struct task_struct *task; struct rt_mutex *lock; + bool savestate; #ifdef CONFIG_DEBUG_RT_MUTEXES unsigned long ip; struct pid *deadlock_task_pid; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:140 @ extern void rt_mutex_init_proxy_locked(s struct task_struct *proxy_owner); extern void rt_mutex_proxy_unlock(struct rt_mutex *lock, struct task_struct *proxy_owner); -extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter); +extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savetate); extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, struct task_struct *task); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:158 @ extern int __rt_mutex_futex_trylock(stru extern void rt_mutex_futex_unlock(struct rt_mutex *lock); extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wqh); + struct wake_q_head *wqh, + struct wake_q_head *wq_sleeper); -extern void rt_mutex_postunlock(struct wake_q_head *wake_q); +extern void rt_mutex_postunlock(struct wake_q_head *wake_q, + struct wake_q_head *wake_sleeper_q); + +/* RW semaphore special interface */ +struct ww_acquire_ctx; + +extern int __rt_mutex_lock_state(struct rt_mutex *lock, int state); +extern int __rt_mutex_trylock(struct rt_mutex *lock); +extern void __rt_mutex_unlock(struct rt_mutex *lock); +int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state, + struct hrtimer_sleeper *timeout, + enum rtmutex_chainwalk chwalk, + struct ww_acquire_ctx *ww_ctx, + struct rt_mutex_waiter *waiter); +void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock, + struct rt_mutex_waiter *waiter, + unsigned long flags); +void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock); #ifdef CONFIG_DEBUG_RT_MUTEXES # include "rtmutex-debug.h" Index: linux-5.0.19-rt11/kernel/locking/rwlock-rt.c =================================================================== --- /dev/null +++ linux-5.0.19-rt11/kernel/locking/rwlock-rt.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +/* + */ +#include <linux/sched/debug.h> +#include <linux/export.h> + +#include "rtmutex_common.h" +#include <linux/rwlock_types_rt.h> + +/* + * RT-specific reader/writer locks + * + * write_lock() + * 1) Lock lock->rtmutex + * 2) Remove the reader BIAS to force readers into the slow path + * 3) Wait until all readers have left the critical region + * 4) Mark it write locked + * + * write_unlock() + * 1) Remove the write locked marker + * 2) Set the reader BIAS so readers can use the fast path again + * 3) Unlock lock->rtmutex to release blocked readers + * + * read_lock() + * 1) Try fast path acquisition (reader BIAS is set) + * 2) Take lock->rtmutex.wait_lock which protects the writelocked flag + * 3) If !writelocked, acquire it for read + * 4) If writelocked, block on lock->rtmutex + * 5) unlock lock->rtmutex, goto 1) + * + * read_unlock() + * 1) Try fast path release (reader count != 1) + * 2) Wake the writer waiting in write_lock()#3 + * + * read_lock()#3 has the consequence, that rw locks on RT are not writer + * fair, but writers, which should be avoided in RT tasks (think tasklist + * lock), are subject to the rtmutex priority/DL inheritance mechanism. + * + * It's possible to make the rw locks writer fair by keeping a list of + * active readers. A blocked writer would force all newly incoming readers + * to block on the rtmutex, but the rtmutex would have to be proxy locked + * for one reader after the other. We can't use multi-reader inheritance + * because there is no way to support that with + * SCHED_DEADLINE. Implementing the one by one reader boosting/handover + * mechanism is a major surgery for a very dubious value. + * + * The risk of writer starvation is there, but the pathological use cases + * which trigger it are not necessarily the typical RT workloads. + */ + +void __rwlock_biased_rt_init(struct rt_rw_lock *lock, const char *name, + struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held semaphore: + */ + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + lockdep_init_map(&lock->dep_map, name, key, 0); +#endif + atomic_set(&lock->readers, READER_BIAS); + rt_mutex_init(&lock->rtmutex); + lock->rtmutex.save_state = 1; +} + +int __read_rt_trylock(struct rt_rw_lock *lock) +{ + int r, old; + + /* + * Increment reader count, if lock->readers < 0, i.e. READER_BIAS is + * set. + */ + for (r = atomic_read(&lock->readers); r < 0;) { + old = atomic_cmpxchg(&lock->readers, r, r + 1); + if (likely(old == r)) + return 1; + r = old; + } + return 0; +} + +void __sched __read_rt_lock(struct rt_rw_lock *lock) +{ + struct rt_mutex *m = &lock->rtmutex; + struct rt_mutex_waiter waiter; + unsigned long flags; + + if (__read_rt_trylock(lock)) + return; + + raw_spin_lock_irqsave(&m->wait_lock, flags); + /* + * Allow readers as long as the writer has not completely + * acquired the semaphore for write. + */ + if (atomic_read(&lock->readers) != WRITER_BIAS) { + atomic_inc(&lock->readers); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + return; + } + + /* + * Call into the slow lock path with the rtmutex->wait_lock + * held, so this can't result in the following race: + * + * Reader1 Reader2 Writer + * read_lock() + * write_lock() + * rtmutex_lock(m) + * swait() + * read_lock() + * unlock(m->wait_lock) + * read_unlock() + * swake() + * lock(m->wait_lock) + * lock->writelocked=true + * unlock(m->wait_lock) + * + * write_unlock() + * lock->writelocked=false + * rtmutex_unlock(m) + * read_lock() + * write_lock() + * rtmutex_lock(m) + * swait() + * rtmutex_lock(m) + * + * That would put Reader1 behind the writer waiting on + * Reader2 to call read_unlock() which might be unbound. + */ + rt_mutex_init_waiter(&waiter, true); + rt_spin_lock_slowlock_locked(m, &waiter, flags); + /* + * The slowlock() above is guaranteed to return with the rtmutex is + * now held, so there can't be a writer active. Increment the reader + * count and immediately drop the rtmutex again. + */ + atomic_inc(&lock->readers); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + rt_spin_lock_slowunlock(m); + + debug_rt_mutex_free_waiter(&waiter); +} + +void __read_rt_unlock(struct rt_rw_lock *lock) +{ + struct rt_mutex *m = &lock->rtmutex; + struct task_struct *tsk; + + /* + * sem->readers can only hit 0 when a writer is waiting for the + * active readers to leave the critical region. + */ + if (!atomic_dec_and_test(&lock->readers)) + return; + + raw_spin_lock_irq(&m->wait_lock); + /* + * Wake the writer, i.e. the rtmutex owner. It might release the + * rtmutex concurrently in the fast path, but to clean up the rw + * lock it needs to acquire m->wait_lock. The worst case which can + * happen is a spurious wakeup. + */ + tsk = rt_mutex_owner(m); + if (tsk) + wake_up_process(tsk); + + raw_spin_unlock_irq(&m->wait_lock); +} + +static void __write_unlock_common(struct rt_rw_lock *lock, int bias, + unsigned long flags) +{ + struct rt_mutex *m = &lock->rtmutex; + + atomic_add(READER_BIAS - bias, &lock->readers); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + rt_spin_lock_slowunlock(m); +} + +void __sched __write_rt_lock(struct rt_rw_lock *lock) +{ + struct rt_mutex *m = &lock->rtmutex; + struct task_struct *self = current; + unsigned long flags; + + /* Take the rtmutex as a first step */ + __rt_spin_lock(m); + + /* Force readers into slow path */ + atomic_sub(READER_BIAS, &lock->readers); + + raw_spin_lock_irqsave(&m->wait_lock, flags); + + raw_spin_lock(&self->pi_lock); + self->saved_state = self->state; + __set_current_state_no_track(TASK_UNINTERRUPTIBLE); + raw_spin_unlock(&self->pi_lock); + + for (;;) { + /* Have all readers left the critical region? */ + if (!atomic_read(&lock->readers)) { + atomic_set(&lock->readers, WRITER_BIAS); + raw_spin_lock(&self->pi_lock); + __set_current_state_no_track(self->saved_state); + self->saved_state = TASK_RUNNING; + raw_spin_unlock(&self->pi_lock); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + return; + } + + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + + if (atomic_read(&lock->readers) != 0) + schedule(); + + raw_spin_lock_irqsave(&m->wait_lock, flags); + + raw_spin_lock(&self->pi_lock); + __set_current_state_no_track(TASK_UNINTERRUPTIBLE); + raw_spin_unlock(&self->pi_lock); + } +} + +int __write_rt_trylock(struct rt_rw_lock *lock) +{ + struct rt_mutex *m = &lock->rtmutex; + unsigned long flags; + + if (!__rt_mutex_trylock(m)) + return 0; + + atomic_sub(READER_BIAS, &lock->readers); + + raw_spin_lock_irqsave(&m->wait_lock, flags); + if (!atomic_read(&lock->readers)) { + atomic_set(&lock->readers, WRITER_BIAS); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + return 1; + } + __write_unlock_common(lock, 0, flags); + return 0; +} + +void __write_rt_unlock(struct rt_rw_lock *lock) +{ + struct rt_mutex *m = &lock->rtmutex; + unsigned long flags; + + raw_spin_lock_irqsave(&m->wait_lock, flags); + __write_unlock_common(lock, WRITER_BIAS, flags); +} + +/* Map the reader biased implementation */ +static inline int do_read_rt_trylock(rwlock_t *rwlock) +{ + return __read_rt_trylock(rwlock); +} + +static inline int do_write_rt_trylock(rwlock_t *rwlock) +{ + return __write_rt_trylock(rwlock); +} + +static inline void do_read_rt_lock(rwlock_t *rwlock) +{ + __read_rt_lock(rwlock); +} + +static inline void do_write_rt_lock(rwlock_t *rwlock) +{ + __write_rt_lock(rwlock); +} + +static inline void do_read_rt_unlock(rwlock_t *rwlock) +{ + __read_rt_unlock(rwlock); +} + +static inline void do_write_rt_unlock(rwlock_t *rwlock) +{ + __write_rt_unlock(rwlock); +} + +static inline void do_rwlock_rt_init(rwlock_t *rwlock, const char *name, + struct lock_class_key *key) +{ + __rwlock_biased_rt_init(rwlock, name, key); +} + +int __lockfunc rt_read_can_lock(rwlock_t *rwlock) +{ + return atomic_read(&rwlock->readers) < 0; +} + +int __lockfunc rt_write_can_lock(rwlock_t *rwlock) +{ + return atomic_read(&rwlock->readers) == READER_BIAS; +} + +/* + * The common functions which get wrapped into the rwlock API. + */ +int __lockfunc rt_read_trylock(rwlock_t *rwlock) +{ + int ret; + + sleeping_lock_inc(); + migrate_disable(); + ret = do_read_rt_trylock(rwlock); + if (ret) { + rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_); + } else { + migrate_enable(); + sleeping_lock_dec(); + } + return ret; +} +EXPORT_SYMBOL(rt_read_trylock); + +int __lockfunc rt_write_trylock(rwlock_t *rwlock) +{ + int ret; + + sleeping_lock_inc(); + migrate_disable(); + ret = do_write_rt_trylock(rwlock); + if (ret) { + rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_); + } else { + migrate_enable(); + sleeping_lock_dec(); + } + return ret; +} +EXPORT_SYMBOL(rt_write_trylock); + +void __lockfunc rt_read_lock(rwlock_t *rwlock) +{ + sleeping_lock_inc(); + migrate_disable(); + rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_); + do_read_rt_lock(rwlock); +} +EXPORT_SYMBOL(rt_read_lock); + +void __lockfunc rt_write_lock(rwlock_t *rwlock) +{ + sleeping_lock_inc(); + migrate_disable(); + rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_); + do_write_rt_lock(rwlock); +} +EXPORT_SYMBOL(rt_write_lock); + +void __lockfunc rt_read_unlock(rwlock_t *rwlock) +{ + rwlock_release(&rwlock->dep_map, 1, _RET_IP_); + do_read_rt_unlock(rwlock); + migrate_enable(); + sleeping_lock_dec(); +} +EXPORT_SYMBOL(rt_read_unlock); + +void __lockfunc rt_write_unlock(rwlock_t *rwlock) +{ + rwlock_release(&rwlock->dep_map, 1, _RET_IP_); + do_write_rt_unlock(rwlock); + migrate_enable(); + sleeping_lock_dec(); +} +EXPORT_SYMBOL(rt_write_unlock); + +void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key) +{ + do_rwlock_rt_init(rwlock, name, key); +} +EXPORT_SYMBOL(__rt_rwlock_init); Index: linux-5.0.19-rt11/kernel/locking/rwsem-rt.c =================================================================== --- /dev/null +++ linux-5.0.19-rt11/kernel/locking/rwsem-rt.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +/* + */ +#include <linux/blkdev.h> +#include <linux/rwsem.h> +#include <linux/sched/debug.h> +#include <linux/sched/signal.h> +#include <linux/export.h> + +#include "rtmutex_common.h" + +/* + * RT-specific reader/writer semaphores + * + * down_write() + * 1) Lock sem->rtmutex + * 2) Remove the reader BIAS to force readers into the slow path + * 3) Wait until all readers have left the critical region + * 4) Mark it write locked + * + * up_write() + * 1) Remove the write locked marker + * 2) Set the reader BIAS so readers can use the fast path again + * 3) Unlock sem->rtmutex to release blocked readers + * + * down_read() + * 1) Try fast path acquisition (reader BIAS is set) + * 2) Take sem->rtmutex.wait_lock which protects the writelocked flag + * 3) If !writelocked, acquire it for read + * 4) If writelocked, block on sem->rtmutex + * 5) unlock sem->rtmutex, goto 1) + * + * up_read() + * 1) Try fast path release (reader count != 1) + * 2) Wake the writer waiting in down_write()#3 + * + * down_read()#3 has the consequence, that rw semaphores on RT are not writer + * fair, but writers, which should be avoided in RT tasks (think mmap_sem), + * are subject to the rtmutex priority/DL inheritance mechanism. + * + * It's possible to make the rw semaphores writer fair by keeping a list of + * active readers. A blocked writer would force all newly incoming readers to + * block on the rtmutex, but the rtmutex would have to be proxy locked for one + * reader after the other. We can't use multi-reader inheritance because there + * is no way to support that with SCHED_DEADLINE. Implementing the one by one + * reader boosting/handover mechanism is a major surgery for a very dubious + * value. + * + * The risk of writer starvation is there, but the pathological use cases + * which trigger it are not necessarily the typical RT workloads. + */ + +void __rwsem_init(struct rw_semaphore *sem, const char *name, + struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held semaphore: + */ + debug_check_no_locks_freed((void *)sem, sizeof(*sem)); + lockdep_init_map(&sem->dep_map, name, key, 0); +#endif + atomic_set(&sem->readers, READER_BIAS); +} +EXPORT_SYMBOL(__rwsem_init); + +int __down_read_trylock(struct rw_semaphore *sem) +{ + int r, old; + + /* + * Increment reader count, if sem->readers < 0, i.e. READER_BIAS is + * set. + */ + for (r = atomic_read(&sem->readers); r < 0;) { + old = atomic_cmpxchg(&sem->readers, r, r + 1); + if (likely(old == r)) + return 1; + r = old; + } + return 0; +} + +static int __sched __down_read_common(struct rw_semaphore *sem, int state) +{ + struct rt_mutex *m = &sem->rtmutex; + struct rt_mutex_waiter waiter; + int ret; + + if (__down_read_trylock(sem)) + return 0; + /* + * If rt_mutex blocks, the function sched_submit_work will not call + * blk_schedule_flush_plug (because tsk_is_pi_blocked would be true). + * We must call blk_schedule_flush_plug here, if we don't call it, + * a deadlock in I/O may happen. + */ + if (unlikely(blk_needs_flush_plug(current))) + blk_schedule_flush_plug(current); + + might_sleep(); + raw_spin_lock_irq(&m->wait_lock); + /* + * Allow readers as long as the writer has not completely + * acquired the semaphore for write. + */ + if (atomic_read(&sem->readers) != WRITER_BIAS) { + atomic_inc(&sem->readers); + raw_spin_unlock_irq(&m->wait_lock); + return 0; + } + + /* + * Call into the slow lock path with the rtmutex->wait_lock + * held, so this can't result in the following race: + * + * Reader1 Reader2 Writer + * down_read() + * down_write() + * rtmutex_lock(m) + * swait() + * down_read() + * unlock(m->wait_lock) + * up_read() + * swake() + * lock(m->wait_lock) + * sem->writelocked=true + * unlock(m->wait_lock) + * + * up_write() + * sem->writelocked=false + * rtmutex_unlock(m) + * down_read() + * down_write() + * rtmutex_lock(m) + * swait() + * rtmutex_lock(m) + * + * That would put Reader1 behind the writer waiting on + * Reader2 to call up_read() which might be unbound. + */ + rt_mutex_init_waiter(&waiter, false); + ret = rt_mutex_slowlock_locked(m, state, NULL, RT_MUTEX_MIN_CHAINWALK, + NULL, &waiter); + /* + * The slowlock() above is guaranteed to return with the rtmutex (for + * ret = 0) is now held, so there can't be a writer active. Increment + * the reader count and immediately drop the rtmutex again. + * For ret != 0 we don't hold the rtmutex and need unlock the wait_lock. + * We don't own the lock then. + */ + if (!ret) + atomic_inc(&sem->readers); + raw_spin_unlock_irq(&m->wait_lock); + if (!ret) + __rt_mutex_unlock(m); + + debug_rt_mutex_free_waiter(&waiter); + return ret; +} + +void __down_read(struct rw_semaphore *sem) +{ + int ret; + + ret = __down_read_common(sem, TASK_UNINTERRUPTIBLE); + WARN_ON_ONCE(ret); +} + +int __down_read_killable(struct rw_semaphore *sem) +{ + int ret; + + ret = __down_read_common(sem, TASK_KILLABLE); + if (likely(!ret)) + return ret; + WARN_ONCE(ret != -EINTR, "Unexpected state: %d\n", ret); + return -EINTR; +} + +void __up_read(struct rw_semaphore *sem) +{ + struct rt_mutex *m = &sem->rtmutex; + struct task_struct *tsk; + + /* + * sem->readers can only hit 0 when a writer is waiting for the + * active readers to leave the critical region. + */ + if (!atomic_dec_and_test(&sem->readers)) + return; + + might_sleep(); + raw_spin_lock_irq(&m->wait_lock); + /* + * Wake the writer, i.e. the rtmutex owner. It might release the + * rtmutex concurrently in the fast path (due to a signal), but to + * clean up the rwsem it needs to acquire m->wait_lock. The worst + * case which can happen is a spurious wakeup. + */ + tsk = rt_mutex_owner(m); + if (tsk) + wake_up_process(tsk); + + raw_spin_unlock_irq(&m->wait_lock); +} + +static void __up_write_unlock(struct rw_semaphore *sem, int bias, + unsigned long flags) +{ + struct rt_mutex *m = &sem->rtmutex; + + atomic_add(READER_BIAS - bias, &sem->readers); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + __rt_mutex_unlock(m); +} + +static int __sched __down_write_common(struct rw_semaphore *sem, int state) +{ + struct rt_mutex *m = &sem->rtmutex; + unsigned long flags; + + /* Take the rtmutex as a first step */ + if (__rt_mutex_lock_state(m, state)) + return -EINTR; + + /* Force readers into slow path */ + atomic_sub(READER_BIAS, &sem->readers); + might_sleep(); + + set_current_state(state); + for (;;) { + raw_spin_lock_irqsave(&m->wait_lock, flags); + /* Have all readers left the critical region? */ + if (!atomic_read(&sem->readers)) { + atomic_set(&sem->readers, WRITER_BIAS); + __set_current_state(TASK_RUNNING); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + return 0; + } + + if (signal_pending_state(state, current)) { + __set_current_state(TASK_RUNNING); + __up_write_unlock(sem, 0, flags); + return -EINTR; + } + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + + if (atomic_read(&sem->readers) != 0) { + schedule(); + set_current_state(state); + } + } +} + +void __sched __down_write(struct rw_semaphore *sem) +{ + __down_write_common(sem, TASK_UNINTERRUPTIBLE); +} + +int __sched __down_write_killable(struct rw_semaphore *sem) +{ + return __down_write_common(sem, TASK_KILLABLE); +} + +int __down_write_trylock(struct rw_semaphore *sem) +{ + struct rt_mutex *m = &sem->rtmutex; + unsigned long flags; + + if (!__rt_mutex_trylock(m)) + return 0; + + atomic_sub(READER_BIAS, &sem->readers); + + raw_spin_lock_irqsave(&m->wait_lock, flags); + if (!atomic_read(&sem->readers)) { + atomic_set(&sem->readers, WRITER_BIAS); + raw_spin_unlock_irqrestore(&m->wait_lock, flags); + return 1; + } + __up_write_unlock(sem, 0, flags); + return 0; +} + +void __up_write(struct rw_semaphore *sem) +{ + struct rt_mutex *m = &sem->rtmutex; + unsigned long flags; + + raw_spin_lock_irqsave(&m->wait_lock, flags); + __up_write_unlock(sem, WRITER_BIAS, flags); +} + +void __downgrade_write(struct rw_semaphore *sem) +{ + struct rt_mutex *m = &sem->rtmutex; + unsigned long flags; + + raw_spin_lock_irqsave(&m->wait_lock, flags); + /* Release it and account current as reader */ + __up_write_unlock(sem, WRITER_BIAS - 1, flags); +} Index: linux-5.0.19-rt11/kernel/locking/spinlock.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/locking/spinlock.c +++ linux-5.0.19-rt11/kernel/locking/spinlock.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:120 @ void __lockfunc __raw_##op##_lock_bh(loc * __[spin|read|write]_lock_bh() */ BUILD_LOCK_OPS(spin, raw_spinlock); + +#ifndef CONFIG_PREEMPT_RT_FULL BUILD_LOCK_OPS(read, rwlock); BUILD_LOCK_OPS(write, rwlock); +#endif #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:208 @ void __lockfunc _raw_spin_unlock_bh(raw_ EXPORT_SYMBOL(_raw_spin_unlock_bh); #endif +#ifndef CONFIG_PREEMPT_RT_FULL + #ifndef CONFIG_INLINE_READ_TRYLOCK int __lockfunc _raw_read_trylock(rwlock_t *lock) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:354 @ void __lockfunc _raw_write_unlock_bh(rwl EXPORT_SYMBOL(_raw_write_unlock_bh); #endif +#endif /* !PREEMPT_RT_FULL */ + #ifdef CONFIG_DEBUG_LOCK_ALLOC void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass) Index: linux-5.0.19-rt11/kernel/locking/spinlock_debug.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/locking/spinlock_debug.c +++ linux-5.0.19-rt11/kernel/locking/spinlock_debug.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:34 @ void __raw_spin_lock_init(raw_spinlock_t EXPORT_SYMBOL(__raw_spin_lock_init); +#ifndef CONFIG_PREEMPT_RT_FULL void __rwlock_init(rwlock_t *lock, const char *name, struct lock_class_key *key) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:52 @ void __rwlock_init(rwlock_t *lock, const } EXPORT_SYMBOL(__rwlock_init); +#endif static void spin_dump(raw_spinlock_t *lock, const char *msg) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:140 @ void do_raw_spin_unlock(raw_spinlock_t * arch_spin_unlock(&lock->raw_lock); } +#ifndef CONFIG_PREEMPT_RT_FULL static void rwlock_bug(rwlock_t *lock, const char *msg) { if (!debug_locks_off()) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:230 @ void do_raw_write_unlock(rwlock_t *lock) debug_write_unlock(lock); arch_write_unlock(&lock->raw_lock); } + +#endif Index: linux-5.0.19-rt11/kernel/panic.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/panic.c +++ linux-5.0.19-rt11/kernel/panic.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:226 @ void panic(const char *fmt, ...) * Bypass the panic_cpu check and call __crash_kexec directly. */ if (!_crash_kexec_post_notifiers) { - printk_safe_flush_on_panic(); __crash_kexec(NULL); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:249 @ void panic(const char *fmt, ...) */ atomic_notifier_call_chain(&panic_notifier_list, 0, buf); - /* Call flush even twice. It tries harder with a single online CPU */ - printk_safe_flush_on_panic(); kmsg_dump(KMSG_DUMP_PANIC); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:510 @ static u64 oops_id; static int init_oops_id(void) { +#ifndef CONFIG_PREEMPT_RT_FULL if (!oops_id) get_random_bytes(&oops_id, sizeof(oops_id)); else +#endif oops_id++; return 0; Index: linux-5.0.19-rt11/kernel/power/hibernate.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/power/hibernate.c +++ linux-5.0.19-rt11/kernel/power/hibernate.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:684 @ static int load_image_and_restore(void) return error; } +#ifndef CONFIG_SUSPEND +bool pm_in_action; +#endif + /** * hibernate - Carry out system hibernation, including saving the image. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:701 @ int hibernate(void) return -EPERM; } + pm_in_action = true; + lock_system_sleep(); /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:781 @ int hibernate(void) atomic_inc(&snapshot_device_available); Unlock: unlock_system_sleep(); + pm_in_action = false; pr_info("hibernation exit\n"); return error; Index: linux-5.0.19-rt11/kernel/power/suspend.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/power/suspend.c +++ linux-5.0.19-rt11/kernel/power/suspend.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:603 @ static int enter_state(suspend_state_t s return error; } +bool pm_in_action; + /** * pm_suspend - Externally visible function for suspending the system. * @state: System sleep state to enter. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:619 @ int pm_suspend(suspend_state_t state) if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX) return -EINVAL; + pm_in_action = true; pr_info("suspend entry (%s)\n", mem_sleep_labels[state]); error = enter_state(state); if (error) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:629 @ int pm_suspend(suspend_state_t state) suspend_stats.success++; } pr_info("suspend exit\n"); + pm_in_action = false; return error; } EXPORT_SYMBOL(pm_suspend); Index: linux-5.0.19-rt11/kernel/printk/Makefile =================================================================== --- linux-5.0.19-rt11.orig/kernel/printk/Makefile +++ linux-5.0.19-rt11/kernel/printk/Makefile @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1 @ obj-y = printk.o -obj-$(CONFIG_PRINTK) += printk_safe.o obj-$(CONFIG_A11Y_BRAILLE_CONSOLE) += braille.o Index: linux-5.0.19-rt11/kernel/printk/internal.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/printk/internal.h +++ /dev/null @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1 @ -/* - * internal.h - printk internal definitions - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see <http://www.gnu.org/licenses/>. - */ -#include <linux/percpu.h> - -#ifdef CONFIG_PRINTK - -#define PRINTK_SAFE_CONTEXT_MASK 0x3fffffff -#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x40000000 -#define PRINTK_NMI_CONTEXT_MASK 0x80000000 - -extern raw_spinlock_t logbuf_lock; - -__printf(5, 0) -int vprintk_store(int facility, int level, - const char *dict, size_t dictlen, - const char *fmt, va_list args); - -__printf(1, 0) int vprintk_default(const char *fmt, va_list args); -__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args); -__printf(1, 0) int vprintk_func(const char *fmt, va_list args); -void __printk_safe_enter(void); -void __printk_safe_exit(void); - -#define printk_safe_enter_irqsave(flags) \ - do { \ - local_irq_save(flags); \ - __printk_safe_enter(); \ - } while (0) - -#define printk_safe_exit_irqrestore(flags) \ - do { \ - __printk_safe_exit(); \ - local_irq_restore(flags); \ - } while (0) - -#define printk_safe_enter_irq() \ - do { \ - local_irq_disable(); \ - __printk_safe_enter(); \ - } while (0) - -#define printk_safe_exit_irq() \ - do { \ - __printk_safe_exit(); \ - local_irq_enable(); \ - } while (0) - -void defer_console_output(void); - -#else - -__printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; } - -/* - * In !PRINTK builds we still export logbuf_lock spin_lock, console_sem - * semaphore and some of console functions (console_unlock()/etc.), so - * printk-safe must preserve the existing local IRQ guarantees. - */ -#define printk_safe_enter_irqsave(flags) local_irq_save(flags) -#define printk_safe_exit_irqrestore(flags) local_irq_restore(flags) - -#define printk_safe_enter_irq() local_irq_disable() -#define printk_safe_exit_irq() local_irq_enable() - -#endif /* CONFIG_PRINTK */ Index: linux-5.0.19-rt11/kernel/printk/printk.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/printk/printk.c +++ linux-5.0.19-rt11/kernel/printk/printk.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:47 @ #include <linux/irq_work.h> #include <linux/ctype.h> #include <linux/uio.h> +#include <linux/kthread.h> +#include <linux/clocksource.h> +#include <linux/printk_ringbuffer.h> #include <linux/sched/clock.h> #include <linux/sched/debug.h> #include <linux/sched/task_stack.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:63 @ #include "console_cmdline.h" #include "braille.h" -#include "internal.h" -int console_printk[4] = { +int console_printk[5] = { CONSOLE_LOGLEVEL_DEFAULT, /* console_loglevel */ MESSAGE_LOGLEVEL_DEFAULT, /* default_message_loglevel */ CONSOLE_LOGLEVEL_MIN, /* minimum_console_loglevel */ CONSOLE_LOGLEVEL_DEFAULT, /* default_console_loglevel */ + CONSOLE_LOGLEVEL_EMERGENCY, /* emergency_console_loglevel */ }; atomic_t ignore_console_lock_warning __read_mostly = ATOMIC_INIT(0); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:213 @ static int nr_ext_console_drivers; static int __down_trylock_console_sem(unsigned long ip) { - int lock_failed; - unsigned long flags; - - /* - * Here and in __up_console_sem() we need to be in safe mode, - * because spindump/WARN/etc from under console ->lock will - * deadlock in printk()->down_trylock_console_sem() otherwise. - */ - printk_safe_enter_irqsave(flags); - lock_failed = down_trylock(&console_sem); - printk_safe_exit_irqrestore(flags); - - if (lock_failed) + if (down_trylock(&console_sem)) return 1; mutex_acquire(&console_lock_dep_map, 0, 1, ip); return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:222 @ static int __down_trylock_console_sem(un static void __up_console_sem(unsigned long ip) { - unsigned long flags; - mutex_release(&console_lock_dep_map, 1, ip); - printk_safe_enter_irqsave(flags); up(&console_sem); - printk_safe_exit_irqrestore(flags); } #define up_console_sem() __up_console_sem(_RET_IP_) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:239 @ static void __up_console_sem(unsigned lo static int console_locked, console_suspended; /* - * If exclusive_console is non-NULL then only this console is to be printed to. - */ -static struct console *exclusive_console; - -/* * Array of consoles built from command line options (console=) */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:335 @ enum log_flags { struct printk_log { u64 ts_nsec; /* timestamp in nanoseconds */ + u16 cpu; /* cpu that generated record */ u16 len; /* length of entire record */ u16 text_len; /* length of text buffer */ u16 dict_len; /* length of dictionary buffer */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:348 @ __packed __aligned(4) #endif ; -/* - * The logbuf_lock protects kmsg buffer, indices, counters. This can be taken - * within the scheduler's rq lock. It must be released before calling - * console_unlock() or anything else that might wake up a process. - */ -DEFINE_RAW_SPINLOCK(logbuf_lock); - -/* - * Helper macros to lock/unlock logbuf_lock and switch between - * printk-safe/unsafe modes. - */ -#define logbuf_lock_irq() \ - do { \ - printk_safe_enter_irq(); \ - raw_spin_lock(&logbuf_lock); \ - } while (0) - -#define logbuf_unlock_irq() \ - do { \ - raw_spin_unlock(&logbuf_lock); \ - printk_safe_exit_irq(); \ - } while (0) - -#define logbuf_lock_irqsave(flags) \ - do { \ - printk_safe_enter_irqsave(flags); \ - raw_spin_lock(&logbuf_lock); \ - } while (0) - -#define logbuf_unlock_irqrestore(flags) \ - do { \ - raw_spin_unlock(&logbuf_lock); \ - printk_safe_exit_irqrestore(flags); \ - } while (0) +DECLARE_STATIC_PRINTKRB_CPULOCK(printk_cpulock); #ifdef CONFIG_PRINTK -DECLARE_WAIT_QUEUE_HEAD(log_wait); -/* the next printk record to read by syslog(READ) or /proc/kmsg */ +/* record buffer */ +DECLARE_STATIC_PRINTKRB(printk_rb, CONFIG_LOG_BUF_SHIFT, &printk_cpulock); + +static DEFINE_MUTEX(syslog_lock); +DECLARE_STATIC_PRINTKRB_ITER(syslog_iter, &printk_rb); + +/* the last printk record read by syslog(READ) or /proc/kmsg */ static u64 syslog_seq; -static u32 syslog_idx; static size_t syslog_partial; static bool syslog_time; -/* index and sequence number of the first record stored in the buffer */ -static u64 log_first_seq; -static u32 log_first_idx; - -/* index and sequence number of the next record to store in the buffer */ -static u64 log_next_seq; -static u32 log_next_idx; - -/* the next printk record to write to the console */ -static u64 console_seq; -static u32 console_idx; -static u64 exclusive_console_stop_seq; - -/* the next printk record to read after the last 'clear' command */ +/* the last printk record at the last 'clear' command */ static u64 clear_seq; -static u32 clear_idx; #define PREFIX_MAX 32 #define LOG_LINE_MAX (1024 - PREFIX_MAX) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:371 @ static u32 clear_idx; #define LOG_LEVEL(v) ((v) & 0x07) #define LOG_FACILITY(v) ((v) >> 3 & 0xff) -/* record buffer */ -#define LOG_ALIGN __alignof__(struct printk_log) -#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT) -#define LOG_BUF_LEN_MAX (u32)(1 << 31) -static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN); -static char *log_buf = __log_buf; -static u32 log_buf_len = __LOG_BUF_LEN; - /* Return log buffer address */ char *log_buf_addr_get(void) { - return log_buf; + return printk_rb.buffer; } /* Return log buffer size */ u32 log_buf_len_get(void) { - return log_buf_len; + return (1 << printk_rb.size_bits); } /* human readable text of the record */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:395 @ static char *log_dict(const struct print return (char *)msg + sizeof(struct printk_log) + msg->text_len; } -/* get record by index; idx must point to valid msg */ -static struct printk_log *log_from_idx(u32 idx) -{ - struct printk_log *msg = (struct printk_log *)(log_buf + idx); - - /* - * A length == 0 record is the end of buffer marker. Wrap around and - * read the message at the start of the buffer. - */ - if (!msg->len) - return (struct printk_log *)log_buf; - return msg; -} - -/* get next record; idx must point to valid msg */ -static u32 log_next(u32 idx) -{ - struct printk_log *msg = (struct printk_log *)(log_buf + idx); - - /* length == 0 indicates the end of the buffer; wrap */ - /* - * A length == 0 record is the end of buffer marker. Wrap around and - * read the message at the start of the buffer as *this* one, and - * return the one after that. - */ - if (!msg->len) { - msg = (struct printk_log *)log_buf; - return msg->len; - } - return idx + msg->len; -} - -/* - * Check whether there is enough free space for the given message. - * - * The same values of first_idx and next_idx mean that the buffer - * is either empty or full. - * - * If the buffer is empty, we must respect the position of the indexes. - * They cannot be reset to the beginning of the buffer. - */ -static int logbuf_has_space(u32 msg_size, bool empty) -{ - u32 free; - - if (log_next_idx > log_first_idx || empty) - free = max(log_buf_len - log_next_idx, log_first_idx); - else - free = log_first_idx - log_next_idx; - - /* - * We need space also for an empty header that signalizes wrapping - * of the buffer. - */ - return free >= msg_size + sizeof(struct printk_log); -} - -static int log_make_free_space(u32 msg_size) -{ - while (log_first_seq < log_next_seq && - !logbuf_has_space(msg_size, false)) { - /* drop old messages until we have enough contiguous space */ - log_first_idx = log_next(log_first_idx); - log_first_seq++; - } - - if (clear_seq < log_first_seq) { - clear_seq = log_first_seq; - clear_idx = log_first_idx; - } - - /* sequence numbers are equal, so the log buffer is empty */ - if (logbuf_has_space(msg_size, log_first_seq == log_next_seq)) - return 0; - - return -ENOMEM; -} - -/* compute the message size including the padding bytes */ -static u32 msg_used_size(u16 text_len, u16 dict_len, u32 *pad_len) -{ - u32 size; - - size = sizeof(struct printk_log) + text_len + dict_len; - *pad_len = (-size) & (LOG_ALIGN - 1); - size += *pad_len; - - return size; -} - -/* - * Define how much of the log buffer we could take at maximum. The value - * must be greater than two. Note that only half of the buffer is available - * when the index points to the middle. - */ -#define MAX_LOG_TAKE_PART 4 -static const char trunc_msg[] = "<truncated>"; - -static u32 truncate_msg(u16 *text_len, u16 *trunc_msg_len, - u16 *dict_len, u32 *pad_len) -{ - /* - * The message should not take the whole buffer. Otherwise, it might - * get removed too soon. - */ - u32 max_text_len = log_buf_len / MAX_LOG_TAKE_PART; - if (*text_len > max_text_len) - *text_len = max_text_len; - /* enable the warning message */ - *trunc_msg_len = strlen(trunc_msg); - /* disable the "dict" completely */ - *dict_len = 0; - /* compute the size again, count also the warning message */ - return msg_used_size(*text_len + *trunc_msg_len, 0, pad_len); -} +static void printk_emergency(char *buffer, int level, u64 ts_nsec, u16 cpu, + char *text, u16 text_len); /* insert record into the buffer, discard old ones, update heads */ static int log_store(int facility, int level, - enum log_flags flags, u64 ts_nsec, + enum log_flags flags, u64 ts_nsec, u16 cpu, const char *dict, u16 dict_len, const char *text, u16 text_len) { struct printk_log *msg; - u32 size, pad_len; - u16 trunc_msg_len = 0; - - /* number of '\0' padding bytes to next message */ - size = msg_used_size(text_len, dict_len, &pad_len); + struct prb_handle h; + char *rbuf; + u32 size; - if (log_make_free_space(size)) { - /* truncate the message if it is too long for empty buffer */ - size = truncate_msg(&text_len, &trunc_msg_len, - &dict_len, &pad_len); - /* survive when the log buffer is too small for trunc_msg */ - if (log_make_free_space(size)) - return 0; - } + size = sizeof(*msg) + text_len + dict_len; - if (log_next_idx + size + sizeof(struct printk_log) > log_buf_len) { + rbuf = prb_reserve(&h, &printk_rb, size); + if (!rbuf) { /* - * This message + an additional empty header does not fit - * at the end of the buffer. Add an empty header with len == 0 - * to signify a wrap around. + * An emergency message would have been printed, but + * it cannot be stored in the log. */ - memset(log_buf + log_next_idx, 0, sizeof(struct printk_log)); - log_next_idx = 0; + prb_inc_lost(&printk_rb); + return 0; } /* fill message */ - msg = (struct printk_log *)(log_buf + log_next_idx); + msg = (struct printk_log *)rbuf; memcpy(log_text(msg), text, text_len); msg->text_len = text_len; - if (trunc_msg_len) { - memcpy(log_text(msg) + text_len, trunc_msg, trunc_msg_len); - msg->text_len += trunc_msg_len; - } memcpy(log_dict(msg), dict, dict_len); msg->dict_len = dict_len; msg->facility = facility; msg->level = level & 7; msg->flags = flags & 0x1f; - if (ts_nsec > 0) - msg->ts_nsec = ts_nsec; - else - msg->ts_nsec = local_clock(); - memset(log_dict(msg) + dict_len, 0, pad_len); + msg->ts_nsec = ts_nsec; + msg->cpu = cpu; msg->len = size; /* insert message */ - log_next_idx += msg->len; - log_next_seq++; + prb_commit(&h); return msg->text_len; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:496 @ static ssize_t msg_print_ext_header(char do_div(ts_usec, 1000); - return scnprintf(buf, size, "%u,%llu,%llu,%c;", + return scnprintf(buf, size, "%u,%llu,%llu,%c,%hu;", (msg->facility << 3) | msg->level, seq, ts_usec, - msg->flags & LOG_CONT ? 'c' : '-'); + msg->flags & LOG_CONT ? 'c' : '-', msg->cpu); } static ssize_t msg_print_ext_body(char *buf, size_t size, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:549 @ static ssize_t msg_print_ext_body(char * return p - buf; } +#define PRINTK_SPRINT_MAX (LOG_LINE_MAX + PREFIX_MAX) +#define PRINTK_RECORD_MAX (sizeof(struct printk_log) + \ + CONSOLE_EXT_LOG_MAX + PRINTK_SPRINT_MAX) + /* /dev/kmsg - userspace message inject/listen interface */ struct devkmsg_user { u64 seq; - u32 idx; + struct prb_iterator iter; struct ratelimit_state rs; struct mutex lock; char buf[CONSOLE_EXT_LOG_MAX]; + char msgbuf[PRINTK_RECORD_MAX]; }; static __printf(3, 4) __cold @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:643 @ static ssize_t devkmsg_read(struct file size_t count, loff_t *ppos) { struct devkmsg_user *user = file->private_data; + struct prb_iterator backup_iter; struct printk_log *msg; - size_t len; ssize_t ret; + size_t len; + u64 seq; if (!user) return -EBADF; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:656 @ static ssize_t devkmsg_read(struct file if (ret) return ret; - logbuf_lock_irq(); - while (user->seq == log_next_seq) { - if (file->f_flags & O_NONBLOCK) { - ret = -EAGAIN; - logbuf_unlock_irq(); - goto out; - } + /* make a backup copy in case there is a problem */ + prb_iter_copy(&backup_iter, &user->iter); - logbuf_unlock_irq(); - ret = wait_event_interruptible(log_wait, - user->seq != log_next_seq); - if (ret) - goto out; - logbuf_lock_irq(); + if (file->f_flags & O_NONBLOCK) { + ret = prb_iter_next(&user->iter, &user->msgbuf[0], + sizeof(user->msgbuf), &seq); + } else { + ret = prb_iter_wait_next(&user->iter, &user->msgbuf[0], + sizeof(user->msgbuf), &seq); } - - if (user->seq < log_first_seq) { - /* our last seen message is gone, return error and reset */ - user->idx = log_first_idx; - user->seq = log_first_seq; + if (ret == 0) { + /* end of list */ + ret = -EAGAIN; + goto out; + } else if (ret == -EINVAL) { + /* iterator invalid, return error and reset */ ret = -EPIPE; - logbuf_unlock_irq(); + prb_iter_init(&user->iter, &printk_rb, &user->seq); + goto out; + } else if (ret < 0) { + /* interrupted by signal */ goto out; } - msg = log_from_idx(user->idx); + if (user->seq == 0) { + user->seq = seq; + } else { + user->seq++; + if (user->seq < seq) { + ret = -EPIPE; + goto restore_out; + } + } + + msg = (struct printk_log *)&user->msgbuf[0]; len = msg_print_ext_header(user->buf, sizeof(user->buf), msg, user->seq); len += msg_print_ext_body(user->buf + len, sizeof(user->buf) - len, log_dict(msg), msg->dict_len, log_text(msg), msg->text_len); - user->idx = log_next(user->idx); - user->seq++; - logbuf_unlock_irq(); - if (len > count) { ret = -EINVAL; - goto out; + goto restore_out; } if (copy_to_user(buf, user->buf, len)) { ret = -EFAULT; - goto out; + goto restore_out; } + ret = len; + goto out; +restore_out: + /* + * There was an error, but this message should not be + * lost because of it. Restore the backup and setup + * seq so that it will work with the next read. + */ + prb_iter_copy(&user->iter, &backup_iter); + user->seq = seq - 1; out: mutex_unlock(&user->lock); return ret; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:725 @ out: static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence) { struct devkmsg_user *user = file->private_data; - loff_t ret = 0; + loff_t ret; + u64 seq; if (!user) return -EBADF; if (offset) return -ESPIPE; - logbuf_lock_irq(); + ret = mutex_lock_interruptible(&user->lock); + if (ret) + return ret; + switch (whence) { case SEEK_SET: /* the first record */ - user->idx = log_first_idx; - user->seq = log_first_seq; + prb_iter_init(&user->iter, &printk_rb, &user->seq); break; case SEEK_DATA: /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:748 @ static loff_t devkmsg_llseek(struct file * like issued by 'dmesg -c'. Reading /dev/kmsg itself * changes no global state, and does not clear anything. */ - user->idx = clear_idx; - user->seq = clear_seq; + for (;;) { + prb_iter_init(&user->iter, &printk_rb, &seq); + ret = prb_iter_seek(&user->iter, clear_seq); + if (ret > 0) { + /* seeked to clear seq */ + user->seq = clear_seq; + break; + } else if (ret == 0) { + /* + * The end of the list was hit without + * ever seeing the clear seq. Just + * seek to the beginning of the list. + */ + prb_iter_init(&user->iter, &printk_rb, + &user->seq); + break; + } + /* iterator invalid, start over */ + + /* reset clear_seq if it is no longer available */ + if (seq > clear_seq) + clear_seq = 0; + } + ret = 0; break; case SEEK_END: /* after the last record */ - user->idx = log_next_idx; - user->seq = log_next_seq; + for (;;) { + ret = prb_iter_next(&user->iter, NULL, 0, &user->seq); + if (ret == 0) + break; + else if (ret > 0) + continue; + /* iterator invalid, start over */ + prb_iter_init(&user->iter, &printk_rb, &user->seq); + } + ret = 0; break; default: ret = -EINVAL; } - logbuf_unlock_irq(); + + mutex_unlock(&user->lock); return ret; } +struct wait_queue_head *printk_wait_queue(void) +{ + /* FIXME: using prb internals! */ + return printk_rb.wq; +} + static __poll_t devkmsg_poll(struct file *file, poll_table *wait) { struct devkmsg_user *user = file->private_data; + struct prb_iterator iter; __poll_t ret = 0; + int rbret; + u64 seq; if (!user) return EPOLLERR|EPOLLNVAL; - poll_wait(file, &log_wait, wait); + poll_wait(file, printk_wait_queue(), wait); - logbuf_lock_irq(); - if (user->seq < log_next_seq) { - /* return error when data has vanished underneath us */ - if (user->seq < log_first_seq) - ret = EPOLLIN|EPOLLRDNORM|EPOLLERR|EPOLLPRI; - else - ret = EPOLLIN|EPOLLRDNORM; - } - logbuf_unlock_irq(); + mutex_lock(&user->lock); + + /* use copy so no actual iteration takes place */ + prb_iter_copy(&iter, &user->iter); + + rbret = prb_iter_next(&iter, &user->msgbuf[0], + sizeof(user->msgbuf), &seq); + if (rbret == 0) + goto out; + + ret = EPOLLIN|EPOLLRDNORM; + + if (rbret < 0 || (seq - user->seq) != 1) + ret |= EPOLLERR|EPOLLPRI; +out: + mutex_unlock(&user->lock); return ret; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:858 @ static int devkmsg_open(struct inode *in mutex_init(&user->lock); - logbuf_lock_irq(); - user->idx = log_first_idx; - user->seq = log_first_seq; - logbuf_unlock_irq(); + prb_iter_init(&user->iter, &printk_rb, &user->seq); file->private_data = user; return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:898 @ const struct file_operations kmsg_fops = */ void log_buf_vmcoreinfo_setup(void) { - VMCOREINFO_SYMBOL(log_buf); - VMCOREINFO_SYMBOL(log_buf_len); - VMCOREINFO_SYMBOL(log_first_idx); - VMCOREINFO_SYMBOL(clear_idx); - VMCOREINFO_SYMBOL(log_next_idx); /* * Export struct printk_log size and field offsets. User space tools can * parse it and detect any changes to structure down the line. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:910 @ void log_buf_vmcoreinfo_setup(void) } #endif +/* FIXME: no support for buffer resizing */ +#if 0 /* requested log_buf_len from kernel cmdline */ static unsigned long __initdata new_log_buf_len; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:977 @ static void __init log_buf_add_cpu(void) #else /* !CONFIG_SMP */ static inline void log_buf_add_cpu(void) {} #endif /* CONFIG_SMP */ +#endif /* 0 */ void __init setup_log_buf(int early) { +/* FIXME: no support for buffer resizing */ +#if 0 unsigned long flags; char *new_log_buf; unsigned int free; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1021 @ void __init setup_log_buf(int early) pr_info("log_buf_len: %u bytes\n", log_buf_len); pr_info("early log buf free: %u(%u%%)\n", free, (free * 100) / __LOG_BUF_LEN); +#endif } static bool __read_mostly ignore_loglevel; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1102 @ static inline void boot_delay_msec(int l static bool printk_time = IS_ENABLED(CONFIG_PRINTK_TIME); module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR); +static size_t print_cpu(u16 cpu, char *buf) +{ + return sprintf(buf, "%03hu: ", cpu); +} + static size_t print_syslog(unsigned int level, char *buf) { return sprintf(buf, "<%u>", level); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1129 @ static size_t print_prefix(const struct len = print_syslog((msg->facility << 3) | msg->level, buf); if (time) len += print_time(msg->ts_nsec, buf + len); + len += print_cpu(msg->cpu, buf + len); return len; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1174 @ static size_t msg_print_text(const struc return len; } -static int syslog_print(char __user *buf, int size) +static int syslog_print(char __user *buf, int size, char *text, + char *msgbuf, int *locked) { - char *text; + struct prb_iterator iter; struct printk_log *msg; int len = 0; - - text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); - if (!text) - return -ENOMEM; + u64 seq; + int ret; while (size > 0) { size_t n; size_t skip; - logbuf_lock_irq(); - if (syslog_seq < log_first_seq) { - /* messages are gone, move to first one */ - syslog_seq = log_first_seq; - syslog_idx = log_first_idx; - syslog_partial = 0; + for (;;) { + prb_iter_copy(&iter, &syslog_iter); + ret = prb_iter_next(&iter, msgbuf, + PRINTK_RECORD_MAX, &seq); + if (ret < 0) { + /* messages are gone, move to first one */ + prb_iter_init(&syslog_iter, &printk_rb, + &syslog_seq); + syslog_partial = 0; + continue; + } + break; } - if (syslog_seq == log_next_seq) { - logbuf_unlock_irq(); + if (ret == 0) break; + + /* + * If messages have been missed, the partial tracker + * is no longer valid and must be reset. + */ + if (syslog_seq > 0 && seq - 1 != syslog_seq) { + syslog_seq = seq - 1; + syslog_partial = 0; } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1219 @ static int syslog_print(char __user *buf if (!syslog_partial) syslog_time = printk_time; + msg = (struct printk_log *)msgbuf; + skip = syslog_partial; - msg = log_from_idx(syslog_idx); n = msg_print_text(msg, true, syslog_time, text, - LOG_LINE_MAX + PREFIX_MAX); + PRINTK_SPRINT_MAX); if (n - syslog_partial <= size) { /* message fits into buffer, move forward */ - syslog_idx = log_next(syslog_idx); - syslog_seq++; + prb_iter_next(&syslog_iter, NULL, 0, &syslog_seq); n -= syslog_partial; syslog_partial = 0; - } else if (!len){ + } else if (!len) { /* partial read(), remember position */ n = size; syslog_partial += n; } else n = 0; - logbuf_unlock_irq(); if (!n) break; + mutex_unlock(&syslog_lock); if (copy_to_user(buf, text + skip, n)) { if (!len) len = -EFAULT; + *locked = 0; break; } + ret = mutex_lock_interruptible(&syslog_lock); len += n; size -= n; buf += n; + + if (ret) { + if (!len) + len = ret; + *locked = 0; + break; + } } - kfree(text); return len; } -static int syslog_print_all(char __user *buf, int size, bool clear) +static int count_remaining(struct prb_iterator *iter, u64 until_seq, + char *msgbuf, int size, bool records, bool time) { - char *text; + struct prb_iterator local_iter; + struct printk_log *msg; int len = 0; - u64 next_seq; u64 seq; - u32 idx; + int ret; + + prb_iter_copy(&local_iter, iter); + for (;;) { + ret = prb_iter_next(&local_iter, msgbuf, size, &seq); + if (ret == 0) { + break; + } else if (ret < 0) { + /* the iter is invalid, restart from head */ + prb_iter_init(&local_iter, &printk_rb, NULL); + len = 0; + continue; + } + + if (until_seq && seq >= until_seq) + break; + + if (records) { + len++; + } else { + msg = (struct printk_log *)msgbuf; + len += msg_print_text(msg, true, time, NULL, 0); + } + } + + return len; +} + +static void syslog_clear(void) +{ + struct prb_iterator iter; + int ret; + + prb_iter_init(&iter, &printk_rb, &clear_seq); + for (;;) { + ret = prb_iter_next(&iter, NULL, 0, &clear_seq); + if (ret == 0) + break; + else if (ret < 0) + prb_iter_init(&iter, &printk_rb, &clear_seq); + } +} + +static int syslog_print_all(char __user *buf, int size, bool clear) +{ + struct prb_iterator iter; + struct printk_log *msg; + char *msgbuf = NULL; + char *text = NULL; + int textlen; + u64 seq = 0; + int len = 0; bool time; + int ret; - text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); + text = kmalloc(PRINTK_SPRINT_MAX, GFP_KERNEL); if (!text) return -ENOMEM; + msgbuf = kmalloc(PRINTK_RECORD_MAX, GFP_KERNEL); + if (!msgbuf) { + kfree(text); + return -ENOMEM; + } time = printk_time; - logbuf_lock_irq(); + /* - * Find first record that fits, including all following records, - * into the user-provided buffer for this dump. + * Setup iter to last event before clear. Clear may + * be lost, but keep going with a best effort. */ - seq = clear_seq; - idx = clear_idx; - while (seq < log_next_seq) { - struct printk_log *msg = log_from_idx(idx); - - len += msg_print_text(msg, true, time, NULL, 0); - idx = log_next(idx); - seq++; - } - - /* move first record forward until length fits into the buffer */ - seq = clear_seq; - idx = clear_idx; - while (len > size && seq < log_next_seq) { - struct printk_log *msg = log_from_idx(idx); + prb_iter_init(&iter, &printk_rb, NULL); + prb_iter_seek(&iter, clear_seq); + /* count the total bytes after clear */ + len = count_remaining(&iter, 0, msgbuf, PRINTK_RECORD_MAX, + false, time); + + /* move iter forward until length fits into the buffer */ + while (len > size) { + ret = prb_iter_next(&iter, msgbuf, + PRINTK_RECORD_MAX, &seq); + if (ret == 0) { + break; + } else if (ret < 0) { + /* + * The iter is now invalid so clear will + * also be invalid. Restart from the head. + */ + prb_iter_init(&iter, &printk_rb, NULL); + len = count_remaining(&iter, 0, msgbuf, + PRINTK_RECORD_MAX, false, time); + continue; + } + + msg = (struct printk_log *)msgbuf; len -= msg_print_text(msg, true, time, NULL, 0); - idx = log_next(idx); - seq++; - } - /* last message fitting into this dump */ - next_seq = log_next_seq; + if (clear) + clear_seq = seq; + } + /* copy messages to buffer */ len = 0; - while (len >= 0 && seq < next_seq) { - struct printk_log *msg = log_from_idx(idx); - int textlen = msg_print_text(msg, true, time, text, - LOG_LINE_MAX + PREFIX_MAX); + while (len >= 0 && len < size) { + if (clear) + clear_seq = seq; + + ret = prb_iter_next(&iter, msgbuf, + PRINTK_RECORD_MAX, &seq); + if (ret == 0) { + break; + } else if (ret < 0) { + /* + * The iter is now invalid. Make a best + * effort to grab the rest of the log + * from the new head. + */ + prb_iter_init(&iter, &printk_rb, NULL); + continue; + } - idx = log_next(idx); - seq++; + msg = (struct printk_log *)msgbuf; + textlen = msg_print_text(msg, true, time, text, + PRINTK_SPRINT_MAX); + if (textlen < 0) { + len = textlen; + break; + } - logbuf_unlock_irq(); if (copy_to_user(buf + len, text, textlen)) len = -EFAULT; else len += textlen; - logbuf_lock_irq(); - - if (seq < log_first_seq) { - /* messages are gone, move to next one */ - seq = log_first_seq; - idx = log_first_idx; - } } - if (clear) { - clear_seq = log_next_seq; - clear_idx = log_next_idx; - } - logbuf_unlock_irq(); + if (clear && !seq) + syslog_clear(); - kfree(text); + if (text) + kfree(text); + if (msgbuf) + kfree(msgbuf); return len; } -static void syslog_clear(void) -{ - logbuf_lock_irq(); - clear_seq = log_next_seq; - clear_idx = log_next_idx; - logbuf_unlock_irq(); -} - int do_syslog(int type, char __user *buf, int len, int source) { bool clear = false; static int saved_console_loglevel = LOGLEVEL_DEFAULT; + struct prb_iterator iter; + char *msgbuf = NULL; + char *text = NULL; + int locked; int error; + int ret; error = check_syslog_permissions(type, source); if (error) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1442 @ int do_syslog(int type, char __user *buf return 0; if (!access_ok(buf, len)) return -EFAULT; - error = wait_event_interruptible(log_wait, - syslog_seq != log_next_seq); + + text = kmalloc(PRINTK_SPRINT_MAX, GFP_KERNEL); + msgbuf = kmalloc(PRINTK_RECORD_MAX, GFP_KERNEL); + if (!text || !msgbuf) { + error = -ENOMEM; + goto out; + } + + error = mutex_lock_interruptible(&syslog_lock); if (error) - return error; - error = syslog_print(buf, len); + goto out; + + /* + * Wait until a first message is available. Use a copy + * because no iteration should occur for syslog now. + */ + for (;;) { + prb_iter_copy(&iter, &syslog_iter); + + mutex_unlock(&syslog_lock); + ret = prb_iter_wait_next(&iter, NULL, 0, NULL); + if (ret == -ERESTARTSYS) { + error = ret; + goto out; + } + error = mutex_lock_interruptible(&syslog_lock); + if (error) + goto out; + + if (ret == -EINVAL) { + prb_iter_init(&syslog_iter, &printk_rb, + &syslog_seq); + syslog_partial = 0; + continue; + } + break; + } + + /* print as much as will fit in the user buffer */ + locked = 1; + error = syslog_print(buf, len, text, msgbuf, &locked); + if (locked) + mutex_unlock(&syslog_lock); break; /* Read/clear last kernel messages */ case SYSLOG_ACTION_READ_CLEAR: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1529 @ int do_syslog(int type, char __user *buf break; /* Number of chars in the log buffer */ case SYSLOG_ACTION_SIZE_UNREAD: - logbuf_lock_irq(); - if (syslog_seq < log_first_seq) { - /* messages are gone, move to first one */ - syslog_seq = log_first_seq; - syslog_idx = log_first_idx; - syslog_partial = 0; - } + msgbuf = kmalloc(PRINTK_RECORD_MAX, GFP_KERNEL); + if (!msgbuf) + return -ENOMEM; + + error = mutex_lock_interruptible(&syslog_lock); + if (error) + goto out; + if (source == SYSLOG_FROM_PROC) { /* * Short-cut for poll(/"proc/kmsg") which simply checks * for pending data, not the size; return the count of * records, not the length. */ - error = log_next_seq - syslog_seq; + error = count_remaining(&syslog_iter, 0, msgbuf, + PRINTK_RECORD_MAX, true, + printk_time); } else { - u64 seq = syslog_seq; - u32 idx = syslog_idx; - bool time = syslog_partial ? syslog_time : printk_time; - - while (seq < log_next_seq) { - struct printk_log *msg = log_from_idx(idx); - - error += msg_print_text(msg, true, time, NULL, - 0); - time = printk_time; - idx = log_next(idx); - seq++; - } + error = count_remaining(&syslog_iter, 0, msgbuf, + PRINTK_RECORD_MAX, false, + printk_time); error -= syslog_partial; } - logbuf_unlock_irq(); + + mutex_unlock(&syslog_lock); break; /* Size of the log buffer */ case SYSLOG_ACTION_SIZE_BUFFER: - error = log_buf_len; + error = prb_buffer_size(&printk_rb); break; default: error = -EINVAL; break; } - +out: + if (msgbuf) + kfree(msgbuf); + if (text) + kfree(text); return error; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1576 @ SYSCALL_DEFINE3(syslog, int, type, char return do_syslog(type, buf, len, SYSLOG_FROM_READER); } -/* - * Special console_lock variants that help to reduce the risk of soft-lockups. - * They allow to pass console_lock to another printk() call using a busy wait. - */ +int printk_delay_msec __read_mostly; -#ifdef CONFIG_LOCKDEP -static struct lockdep_map console_owner_dep_map = { - .name = "console_owner" -}; -#endif +static inline void printk_delay(int level) +{ + boot_delay_msec(level); + if (unlikely(printk_delay_msec)) { + int m = printk_delay_msec; -static DEFINE_RAW_SPINLOCK(console_owner_lock); -static struct task_struct *console_owner; -static bool console_waiter; + while (m--) { + mdelay(1); + touch_nmi_watchdog(); + } + } +} -/** - * console_lock_spinning_enable - mark beginning of code where another - * thread might safely busy wait - * - * This basically converts console_lock into a spinlock. This marks - * the section where the console_lock owner can not sleep, because - * there may be a waiter spinning (like a spinlock). Also it must be - * ready to hand over the lock at the end of the section. - */ -static void console_lock_spinning_enable(void) -{ - raw_spin_lock(&console_owner_lock); - console_owner = current; - raw_spin_unlock(&console_owner_lock); +static void print_console_dropped(struct console *con, u64 count) +{ + char text[64]; + int len; - /* The waiter may spin on us after setting console_owner */ - spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_); + len = sprintf(text, "** %llu printk message%s dropped **\n", + count, count > 1 ? "s" : ""); + con->write(con, text, len); } -/** - * console_lock_spinning_disable_and_check - mark end of code where another - * thread was able to busy wait and check if there is a waiter - * - * This is called at the end of the section where spinning is allowed. - * It has two functions. First, it is a signal that it is no longer - * safe to start busy waiting for the lock. Second, it checks if - * there is a busy waiter and passes the lock rights to her. - * - * Important: Callers lose the lock if there was a busy waiter. - * They must not touch items synchronized by console_lock - * in this case. - * - * Return: 1 if the lock rights were passed, 0 otherwise. - */ -static int console_lock_spinning_disable_and_check(void) +static void format_text(struct printk_log *msg, u64 seq, + char *ext_text, size_t *ext_len, + char *text, size_t *len, bool time) { - int waiter; - - raw_spin_lock(&console_owner_lock); - waiter = READ_ONCE(console_waiter); - console_owner = NULL; - raw_spin_unlock(&console_owner_lock); + if (suppress_message_printing(msg->level)) { + /* + * Skip record that has level above the console + * loglevel and update each console's local seq. + */ + *len = 0; + *ext_len = 0; + return; + } - if (!waiter) { - spin_release(&console_owner_dep_map, 1, _THIS_IP_); - return 0; + *len = msg_print_text(msg, console_msg_format & MSG_FORMAT_SYSLOG, + time, text, PRINTK_SPRINT_MAX); + if (nr_ext_console_drivers) { + *ext_len = msg_print_ext_header(ext_text, CONSOLE_EXT_LOG_MAX, + msg, seq); + *ext_len += msg_print_ext_body(ext_text + *ext_len, + CONSOLE_EXT_LOG_MAX - *ext_len, + log_dict(msg), msg->dict_len, + log_text(msg), msg->text_len); + } else { + *ext_len = 0; } +} - /* The waiter is now free to continue */ - WRITE_ONCE(console_waiter, false); +static void printk_write_history(struct console *con, u64 master_seq) +{ + struct prb_iterator iter; + bool time = printk_time; + static char *ext_text; + static char *text; + static char *buf; + u64 seq; - spin_release(&console_owner_dep_map, 1, _THIS_IP_); + ext_text = kmalloc(CONSOLE_EXT_LOG_MAX, GFP_KERNEL); + text = kmalloc(PRINTK_SPRINT_MAX, GFP_KERNEL); + buf = kmalloc(PRINTK_RECORD_MAX, GFP_KERNEL); + if (!ext_text || !text || !buf) + return; - /* - * Hand off console_lock to waiter. The waiter will perform - * the up(). After this, the waiter is the console_lock owner. - */ - mutex_release(&console_lock_dep_map, 1, _THIS_IP_); - return 1; -} + if (!(con->flags & CON_ENABLED)) + goto out; -/** - * console_trylock_spinning - try to get console_lock by busy waiting - * - * This allows to busy wait for the console_lock when the current - * owner is running in specially marked sections. It means that - * the current owner is running and cannot reschedule until it - * is ready to lose the lock. - * - * Return: 1 if we got the lock, 0 othrewise - */ -static int console_trylock_spinning(void) -{ - struct task_struct *owner = NULL; - bool waiter; - bool spin = false; - unsigned long flags; + if (!con->write) + goto out; - if (console_trylock()) - return 1; + if (!cpu_online(raw_smp_processor_id()) && + !(con->flags & CON_ANYTIME)) + goto out; - printk_safe_enter_irqsave(flags); + prb_iter_init(&iter, &printk_rb, NULL); - raw_spin_lock(&console_owner_lock); - owner = READ_ONCE(console_owner); - waiter = READ_ONCE(console_waiter); - if (!waiter && owner && owner != current) { - WRITE_ONCE(console_waiter, true); - spin = true; - } - raw_spin_unlock(&console_owner_lock); - - /* - * If there is an active printk() writing to the - * consoles, instead of having it write our data too, - * see if we can offload that load from the active - * printer, and do some printing ourselves. - * Go into a spin only if there isn't already a waiter - * spinning, and there is an active printer, and - * that active printer isn't us (recursive printk?). - */ - if (!spin) { - printk_safe_exit_irqrestore(flags); - return 0; - } + for (;;) { + struct printk_log *msg; + size_t ext_len; + size_t len; + int ret; - /* We spin waiting for the owner to release us */ - spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_); - /* Owner will clear console_waiter on hand off */ - while (READ_ONCE(console_waiter)) - cpu_relax(); - spin_release(&console_owner_dep_map, 1, _THIS_IP_); + ret = prb_iter_next(&iter, buf, PRINTK_RECORD_MAX, &seq); + if (ret == 0) { + break; + } else if (ret < 0) { + prb_iter_init(&iter, &printk_rb, NULL); + continue; + } - printk_safe_exit_irqrestore(flags); - /* - * The owner passed the console lock to us. - * Since we did not spin on console lock, annotate - * this as a trylock. Otherwise lockdep will - * complain. - */ - mutex_acquire(&console_lock_dep_map, 0, 1, _THIS_IP_); + if (seq > master_seq) + break; - return 1; + con->printk_seq++; + if (con->printk_seq < seq) { + print_console_dropped(con, seq - con->printk_seq); + con->printk_seq = seq; + } + + msg = (struct printk_log *)buf; + format_text(msg, master_seq, ext_text, &ext_len, text, + &len, time); + + if (len == 0 && ext_len == 0) + continue; + + if (con->flags & CON_EXTENDED) + con->write(con, ext_text, ext_len); + else + con->write(con, text, len); + + printk_delay(msg->level); + } +out: + con->wrote_history = 1; + kfree(ext_text); + kfree(text); + kfree(buf); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1705 @ static int console_trylock_spinning(void * log_buf[start] to log_buf[end - 1]. * The console_lock must be held. */ -static void call_console_drivers(const char *ext_text, size_t ext_len, - const char *text, size_t len) +static void call_console_drivers(u64 seq, const char *ext_text, size_t ext_len, + const char *text, size_t len, int level, + int facility) { struct console *con; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1717 @ static void call_console_drivers(const c return; for_each_console(con) { - if (exclusive_console && con != exclusive_console) - continue; if (!(con->flags & CON_ENABLED)) continue; + if (!con->wrote_history) { + if (con->flags & CON_PRINTBUFFER) { + printk_write_history(con, seq); + continue; + } + con->wrote_history = 1; + con->printk_seq = seq - 1; + } + if (con->write_atomic && level < emergency_console_loglevel && + facility == 0) { + /* skip emergency messages, already printed */ + if (con->printk_seq < seq) + con->printk_seq = seq; + continue; + } + if (con->flags & CON_BOOT && facility == 0) { + /* skip emergency messages, already printed */ + if (con->printk_seq < seq) + con->printk_seq = seq; + continue; + } if (!con->write) continue; - if (!cpu_online(smp_processor_id()) && + if (!cpu_online(raw_smp_processor_id()) && !(con->flags & CON_ANYTIME)) continue; + if (con->printk_seq >= seq) + continue; + + con->printk_seq++; + if (con->printk_seq < seq) { + print_console_dropped(con, seq - con->printk_seq); + con->printk_seq = seq; + } + + /* for supressed messages, only seq is updated */ + if (len == 0 && ext_len == 0) + continue; + if (con->flags & CON_EXTENDED) con->write(con, ext_text, ext_len); else @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1765 @ static void call_console_drivers(const c } } -int printk_delay_msec __read_mostly; - -static inline void printk_delay(void) -{ - if (unlikely(printk_delay_msec)) { - int m = printk_delay_msec; - - while (m--) { - mdelay(1); - touch_nmi_watchdog(); - } - } -} - /* * Continuation lines are buffered, and not committed to the record buffer * until the line is complete, or a race forces it. The line fragments @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1774 @ static inline void printk_delay(void) static struct cont { char buf[LOG_LINE_MAX]; size_t len; /* length == 0 means unused buffer */ - struct task_struct *owner; /* task of first print*/ + int cpu_owner; /* cpu of first print*/ u64 ts_nsec; /* time of first print */ u8 level; /* log level of first message */ u8 facility; /* log facility of first message */ enum log_flags flags; /* prefix, newline flags */ -} cont; +} cont[2]; -static void cont_flush(void) +static void cont_flush(int ctx) { - if (cont.len == 0) + struct cont *c = &cont[ctx]; + + if (c->len == 0) return; - log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec, - NULL, 0, cont.buf, cont.len); - cont.len = 0; + log_store(c->facility, c->level, c->flags, c->ts_nsec, c->cpu_owner, + NULL, 0, c->buf, c->len); + c->len = 0; } -static bool cont_add(int facility, int level, enum log_flags flags, const char *text, size_t len) +static void cont_add(int ctx, int cpu, int facility, int level, + enum log_flags flags, const char *text, size_t len) { + struct cont *c = &cont[ctx]; + + if (cpu != c->cpu_owner || !(flags & LOG_CONT)) + cont_flush(ctx); + /* If the line gets too long, split it up in separate records. */ - if (cont.len + len > sizeof(cont.buf)) { - cont_flush(); - return false; - } + while (c->len + len > sizeof(c->buf)) + cont_flush(ctx); - if (!cont.len) { - cont.facility = facility; - cont.level = level; - cont.owner = current; - cont.ts_nsec = local_clock(); - cont.flags = flags; + if (!c->len) { + c->facility = facility; + c->level = level; + c->cpu_owner = cpu; + c->ts_nsec = local_clock(); + c->flags = flags; } - memcpy(cont.buf + cont.len, text, len); - cont.len += len; + memcpy(c->buf + c->len, text, len); + c->len += len; - // The original flags come from the first line, - // but later continuations can add a newline. + /* + * The original flags come from the first line, + * but later continuations can add a newline. + */ if (flags & LOG_NEWLINE) { - cont.flags |= LOG_NEWLINE; - cont_flush(); + c->flags |= LOG_NEWLINE; + cont_flush(ctx); } - - return true; } -static size_t log_output(int facility, int level, enum log_flags lflags, const char *dict, size_t dictlen, char *text, size_t text_len) +/* ring buffer used as memory allocator for temporary sprint buffers */ +DECLARE_STATIC_PRINTKRB(sprint_rb, + ilog2(PRINTK_RECORD_MAX + sizeof(struct prb_entry) + + sizeof(long)) + 2, &printk_cpulock); + +asmlinkage int vprintk_emit(int facility, int level, + const char *dict, size_t dictlen, + const char *fmt, va_list args) { - /* - * If an earlier line was buffered, and we're a continuation - * write from the same process, try to add it to the buffer. - */ - if (cont.len) { - if (cont.owner == current && (lflags & LOG_CONT)) { - if (cont_add(facility, level, lflags, text, text_len)) - return text_len; - } - /* Otherwise, make sure it's flushed */ - cont_flush(); - } + enum log_flags lflags = 0; + int ctx = !!in_nmi(); + int printed_len = 0; + struct prb_handle h; + size_t text_len; + u64 ts_nsec; + char *text; + char *rbuf; + int cpu; - /* Skip empty continuation lines that couldn't be added - they just flush */ - if (!text_len && (lflags & LOG_CONT)) - return 0; + ts_nsec = local_clock(); - /* If it doesn't end in a newline, try to buffer the current line */ - if (!(lflags & LOG_NEWLINE)) { - if (cont_add(facility, level, lflags, text, text_len)) - return text_len; + rbuf = prb_reserve(&h, &sprint_rb, PRINTK_SPRINT_MAX); + if (!rbuf) { + prb_inc_lost(&printk_rb); + return printed_len; } - /* Store it in the record log */ - return log_store(facility, level, lflags, 0, dict, dictlen, text, text_len); -} - -/* Must be called under logbuf_lock. */ -int vprintk_store(int facility, int level, - const char *dict, size_t dictlen, - const char *fmt, va_list args) -{ - static char textbuf[LOG_LINE_MAX]; - char *text = textbuf; - size_t text_len; - enum log_flags lflags = 0; + cpu = raw_smp_processor_id(); /* - * The printf needs to come first; we need the syslog - * prefix which might be passed-in as a parameter. + * If this turns out to be an emergency message, there + * may need to be a prefix added. Leave room for it. */ - text_len = vscnprintf(text, sizeof(textbuf), fmt, args); + text = rbuf + PREFIX_MAX; + text_len = vscnprintf(text, PRINTK_SPRINT_MAX - PREFIX_MAX, fmt, args); - /* mark and strip a trailing newline */ + /* strip and flag a trailing newline */ if (text_len && text[text_len-1] == '\n') { text_len--; lflags |= LOG_NEWLINE; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1896 @ int vprintk_store(int facility, int leve if (dict) lflags |= LOG_PREFIX|LOG_NEWLINE; - return log_output(facility, level, lflags, - dict, dictlen, text, text_len); -} - -asmlinkage int vprintk_emit(int facility, int level, - const char *dict, size_t dictlen, - const char *fmt, va_list args) -{ - int printed_len; - bool in_sched = false, pending_output; - unsigned long flags; - u64 curr_log_seq; - - if (level == LOGLEVEL_SCHED) { - level = LOGLEVEL_DEFAULT; - in_sched = true; + /* + * NOTE: + * - rbuf points to beginning of allocated buffer + * - text points to beginning of text + * - there is room before text for prefix + */ + if (facility == 0) { + /* only the kernel can create emergency messages */ + printk_emergency(rbuf, level & 7, ts_nsec, cpu, + text, text_len); } - boot_delay_msec(level); - printk_delay(); - - /* This stops the holder of console_sem just where we want him */ - logbuf_lock_irqsave(flags); - curr_log_seq = log_next_seq; - printed_len = vprintk_store(facility, level, dict, dictlen, fmt, args); - pending_output = (curr_log_seq != log_next_seq); - logbuf_unlock_irqrestore(flags); - - /* If called from the scheduler, we can not call up(). */ - if (!in_sched && pending_output) { - /* - * Disable preemption to avoid being preempted while holding - * console_sem which would prevent anyone from printing to - * console - */ - preempt_disable(); - /* - * Try to acquire and then immediately release the console - * semaphore. The release will print out buffers and wake up - * /dev/kmsg and syslog() users. - */ - if (console_trylock_spinning()) - console_unlock(); - preempt_enable(); + if ((lflags & LOG_CONT) || !(lflags & LOG_NEWLINE)) { + cont_add(ctx, cpu, facility, level, lflags, text, text_len); + printed_len = text_len; + } else { + if (cpu == cont[ctx].cpu_owner) + cont_flush(ctx); + printed_len = log_store(facility, level, lflags, ts_nsec, cpu, + dict, dictlen, text, text_len); } - if (pending_output) - wake_up_klogd(); + prb_commit(&h); return printed_len; } EXPORT_SYMBOL(vprintk_emit); +static __printf(1, 0) int vprintk_func(const char *fmt, va_list args) +{ + return vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args); +} + asmlinkage int vprintk(const char *fmt, va_list args) { return vprintk_func(fmt, args); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1984 @ asmlinkage __visible int printk(const ch return r; } EXPORT_SYMBOL(printk); - -#else /* CONFIG_PRINTK */ - -#define LOG_LINE_MAX 0 -#define PREFIX_MAX 0 -#define printk_time false - -static u64 syslog_seq; -static u32 syslog_idx; -static u64 console_seq; -static u32 console_idx; -static u64 exclusive_console_stop_seq; -static u64 log_first_seq; -static u32 log_first_idx; -static u64 log_next_seq; -static char *log_text(const struct printk_log *msg) { return NULL; } -static char *log_dict(const struct printk_log *msg) { return NULL; } -static struct printk_log *log_from_idx(u32 idx) { return NULL; } -static u32 log_next(u32 idx) { return 0; } -static ssize_t msg_print_ext_header(char *buf, size_t size, - struct printk_log *msg, - u64 seq) { return 0; } -static ssize_t msg_print_ext_body(char *buf, size_t size, - char *dict, size_t dict_len, - char *text, size_t text_len) { return 0; } -static void console_lock_spinning_enable(void) { } -static int console_lock_spinning_disable_and_check(void) { return 0; } -static void call_console_drivers(const char *ext_text, size_t ext_len, - const char *text, size_t len) {} -static size_t msg_print_text(const struct printk_log *msg, bool syslog, - bool time, char *buf, size_t size) { return 0; } -static bool suppress_message_printing(int level) { return false; } - #endif /* CONFIG_PRINTK */ #ifdef CONFIG_EARLY_PRINTK @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2214 @ int is_console_locked(void) } EXPORT_SYMBOL(is_console_locked); -/* - * Check if we have any console that is capable of printing while cpu is - * booting or shutting down. Requires console_sem. - */ -static int have_callable_console(void) -{ - struct console *con; - - for_each_console(con) - if ((con->flags & CON_ENABLED) && - (con->flags & CON_ANYTIME)) - return 1; - - return 0; -} - -/* - * Can we actually use the console at this time on this cpu? - * - * Console drivers may assume that per-cpu resources have been allocated. So - * unless they're explicitly marked as being able to cope (CON_ANYTIME) don't - * call them until this CPU is officially up. - */ -static inline int can_use_console(void) -{ - return cpu_online(raw_smp_processor_id()) || have_callable_console(); -} - /** * console_unlock - unlock the console system * * Releases the console_lock which the caller holds on the console system * and the console driver list. * - * While the console_lock was held, console output may have been buffered - * by printk(). If this is the case, console_unlock(); emits - * the output prior to releasing the lock. - * - * If there is output waiting, we wake /dev/kmsg and syslog() users. - * * console_unlock(); may be called from any context. */ void console_unlock(void) { - static char ext_text[CONSOLE_EXT_LOG_MAX]; - static char text[LOG_LINE_MAX + PREFIX_MAX]; - unsigned long flags; - bool do_cond_resched, retry; - if (console_suspended) { up_console_sem(); return; } - /* - * Console drivers are called with interrupts disabled, so - * @console_may_schedule should be cleared before; however, we may - * end up dumping a lot of lines, for example, if called from - * console registration path, and should invoke cond_resched() - * between lines if allowable. Not doing so can cause a very long - * scheduling stall on a slow console leading to RCU stall and - * softlockup warnings which exacerbate the issue with more - * messages practically incapacitating the system. - * - * console_trylock() is not able to detect the preemptive - * context reliably. Therefore the value must be stored before - * and cleared after the the "again" goto label. - */ - do_cond_resched = console_may_schedule; -again: - console_may_schedule = 0; - - /* - * We released the console_sem lock, so we need to recheck if - * cpu is online and (if not) is there at least one CON_ANYTIME - * console. - */ - if (!can_use_console()) { - console_locked = 0; - up_console_sem(); - return; - } - - for (;;) { - struct printk_log *msg; - size_t ext_len = 0; - size_t len; - - printk_safe_enter_irqsave(flags); - raw_spin_lock(&logbuf_lock); - if (console_seq < log_first_seq) { - len = sprintf(text, - "** %llu printk messages dropped **\n", - log_first_seq - console_seq); - - /* messages are gone, move to first one */ - console_seq = log_first_seq; - console_idx = log_first_idx; - } else { - len = 0; - } -skip: - if (console_seq == log_next_seq) - break; - - msg = log_from_idx(console_idx); - if (suppress_message_printing(msg->level)) { - /* - * Skip record we have buffered and already printed - * directly to the console when we received it, and - * record that has level above the console loglevel. - */ - console_idx = log_next(console_idx); - console_seq++; - goto skip; - } - - /* Output to all consoles once old messages replayed. */ - if (unlikely(exclusive_console && - console_seq >= exclusive_console_stop_seq)) { - exclusive_console = NULL; - } - - len += msg_print_text(msg, - console_msg_format & MSG_FORMAT_SYSLOG, - printk_time, text + len, sizeof(text) - len); - if (nr_ext_console_drivers) { - ext_len = msg_print_ext_header(ext_text, - sizeof(ext_text), - msg, console_seq); - ext_len += msg_print_ext_body(ext_text + ext_len, - sizeof(ext_text) - ext_len, - log_dict(msg), msg->dict_len, - log_text(msg), msg->text_len); - } - console_idx = log_next(console_idx); - console_seq++; - raw_spin_unlock(&logbuf_lock); - - /* - * While actively printing out messages, if another printk() - * were to occur on another CPU, it may wait for this one to - * finish. This task can not be preempted if there is a - * waiter waiting to take over. - */ - console_lock_spinning_enable(); - - stop_critical_timings(); /* don't trace print latency */ - call_console_drivers(ext_text, ext_len, text, len); - start_critical_timings(); - - if (console_lock_spinning_disable_and_check()) { - printk_safe_exit_irqrestore(flags); - return; - } - - printk_safe_exit_irqrestore(flags); - - if (do_cond_resched) - cond_resched(); - } - console_locked = 0; - - raw_spin_unlock(&logbuf_lock); - up_console_sem(); - - /* - * Someone could have filled up the buffer again, so re-check if there's - * something to flush. In case we cannot trylock the console_sem again, - * there's a new owner and the console_unlock() from them will do the - * flush, no worries. - */ - raw_spin_lock(&logbuf_lock); - retry = console_seq != log_next_seq; - raw_spin_unlock(&logbuf_lock); - printk_safe_exit_irqrestore(flags); - - if (retry && console_trylock()) - goto again; } EXPORT_SYMBOL(console_unlock); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2280 @ void console_unblank(void) void console_flush_on_panic(void) { /* - * If someone else is holding the console lock, trylock will fail - * and may_schedule may be set. Ignore and proceed to unlock so - * that messages are flushed out. As this can be called from any - * context and we don't want to get preempted while flushing, - * ensure may_schedule is cleared. + * FIXME: This is currently a NOP. Emergency messages will have been + * printed, but what about if write_atomic is not available on the + * console? What if the printk kthread is still alive? */ - console_trylock(); - console_may_schedule = 0; - console_unlock(); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2361 @ early_param("keep_bootcon", keep_bootcon void register_console(struct console *newcon) { int i; - unsigned long flags; struct console *bcon = NULL; struct console_cmdline *c; static bool has_preferred; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2476 @ void register_console(struct console *ne if (newcon->flags & CON_EXTENDED) nr_ext_console_drivers++; - if (newcon->flags & CON_PRINTBUFFER) { - /* - * console_unlock(); will print out the buffered messages - * for us. - */ - logbuf_lock_irqsave(flags); - console_seq = syslog_seq; - console_idx = syslog_idx; - /* - * We're about to replay the log buffer. Only do this to the - * just-registered console to avoid excessive message spam to - * the already-registered consoles. - * - * Set exclusive_console with disabled interrupts to reduce - * race window with eventual console_flush_on_panic() that - * ignores console_lock. - */ - exclusive_console = newcon; - exclusive_console_stop_seq = console_seq; - logbuf_unlock_irqrestore(flags); - } console_unlock(); console_sysfs_notify(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2485 @ void register_console(struct console *ne * boot consoles, real consoles, etc - this is to ensure that end * users know there might be something in the kernel's log buffer that * went to the bootconsole (that they do not see on the real console) + * + * This message is also important because it will trigger the + * printk kthread to begin dumping the log buffer to the newly + * registered console. */ pr_info("%sconsole [%s%d] enabled\n", (newcon->flags & CON_BOOT) ? "boot" : "" , @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2632 @ static int __init printk_late_init(void) late_initcall(printk_late_init); #if defined CONFIG_PRINTK -/* - * Delayed printk version, for scheduler-internal messages: - */ -#define PRINTK_PENDING_WAKEUP 0x01 -#define PRINTK_PENDING_OUTPUT 0x02 +static int printk_kthread_func(void *data) +{ + struct prb_iterator iter; + struct printk_log *msg; + size_t ext_len; + char *ext_text; + u64 master_seq; + size_t len; + char *text; + char *buf; + int ret; -static DEFINE_PER_CPU(int, printk_pending); + ext_text = kmalloc(CONSOLE_EXT_LOG_MAX, GFP_KERNEL); + text = kmalloc(PRINTK_SPRINT_MAX, GFP_KERNEL); + buf = kmalloc(PRINTK_RECORD_MAX, GFP_KERNEL); + if (!ext_text || !text || !buf) + return -1; -static void wake_up_klogd_work_func(struct irq_work *irq_work) -{ - int pending = __this_cpu_xchg(printk_pending, 0); + prb_iter_init(&iter, &printk_rb, NULL); - if (pending & PRINTK_PENDING_OUTPUT) { - /* If trylock fails, someone else is doing the printing */ - if (console_trylock()) - console_unlock(); + /* the printk kthread never exits */ + for (;;) { + ret = prb_iter_wait_next(&iter, buf, + PRINTK_RECORD_MAX, &master_seq); + if (ret == -ERESTARTSYS) { + continue; + } else if (ret < 0) { + /* iterator invalid, start over */ + prb_iter_init(&iter, &printk_rb, NULL); + continue; + } + + msg = (struct printk_log *)buf; + format_text(msg, master_seq, ext_text, &ext_len, text, + &len, printk_time); + + console_lock(); + call_console_drivers(master_seq, ext_text, ext_len, text, len, + msg->level, msg->facility); + if (len > 0 || ext_len > 0) + printk_delay(msg->level); + console_unlock(); } - if (pending & PRINTK_PENDING_WAKEUP) - wake_up_interruptible(&log_wait); -} + kfree(ext_text); + kfree(text); + kfree(buf); -static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = { - .func = wake_up_klogd_work_func, - .flags = IRQ_WORK_LAZY, -}; + return 0; +} -void wake_up_klogd(void) +static int __init init_printk_kthread(void) { - preempt_disable(); - if (waitqueue_active(&log_wait)) { - this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP); - irq_work_queue(this_cpu_ptr(&wake_up_klogd_work)); + struct task_struct *thread; + + thread = kthread_run(printk_kthread_func, NULL, "printk"); + if (IS_ERR(thread)) { + pr_err("printk: unable to create printing thread\n"); + return PTR_ERR(thread); } - preempt_enable(); -} -void defer_console_output(void) -{ - preempt_disable(); - __this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT); - irq_work_queue(this_cpu_ptr(&wake_up_klogd_work)); - preempt_enable(); + return 0; } +late_initcall(init_printk_kthread); -int vprintk_deferred(const char *fmt, va_list args) +static int vprintk_deferred(const char *fmt, va_list args) { - int r; - - r = vprintk_emit(0, LOGLEVEL_SCHED, NULL, 0, fmt, args); - defer_console_output(); - - return r; + return vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args); } int printk_deferred(const char *fmt, ...) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2821 @ module_param_named(always_kmsg_dump, alw */ void kmsg_dump(enum kmsg_dump_reason reason) { + struct kmsg_dumper dumper_local; struct kmsg_dumper *dumper; - unsigned long flags; if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump) return; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2832 @ void kmsg_dump(enum kmsg_dump_reason rea if (dumper->max_reason && reason > dumper->max_reason) continue; - /* initialize iterator with data about the stored records */ - dumper->active = true; + /* + * use a local copy to avoid modifying the + * iterator used by any other cpus/contexts + */ + memcpy(&dumper_local, dumper, sizeof(dumper_local)); - logbuf_lock_irqsave(flags); - dumper->cur_seq = clear_seq; - dumper->cur_idx = clear_idx; - dumper->next_seq = log_next_seq; - dumper->next_idx = log_next_idx; - logbuf_unlock_irqrestore(flags); + /* initialize iterator with data about the stored records */ + dumper_local.active = true; + kmsg_dump_rewind(&dumper_local); /* invoke dumper which will iterate over records */ - dumper->dump(dumper, reason); - - /* reset iterator */ - dumper->active = false; + dumper_local.dump(&dumper_local, reason); } rcu_read_unlock(); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2870 @ void kmsg_dump(enum kmsg_dump_reason rea bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog, char *line, size_t size, size_t *len) { + struct prb_iterator iter; struct printk_log *msg; - size_t l = 0; - bool ret = false; + struct prb_handle h; + bool cont = false; + char *msgbuf; + char *rbuf; + size_t l; + u64 seq; + int ret; if (!dumper->active) - goto out; + return cont; - if (dumper->cur_seq < log_first_seq) { - /* messages are gone, move to first available one */ - dumper->cur_seq = log_first_seq; - dumper->cur_idx = log_first_idx; + rbuf = prb_reserve(&h, &sprint_rb, PRINTK_RECORD_MAX); + if (!rbuf) + return cont; + msgbuf = rbuf; +retry: + for (;;) { + prb_iter_init(&iter, &printk_rb, &seq); + + if (dumper->line_seq == seq) { + /* already where we want to be */ + break; + } else if (dumper->line_seq < seq) { + /* messages are gone, move to first available one */ + dumper->line_seq = seq; + break; + } + + ret = prb_iter_seek(&iter, dumper->line_seq); + if (ret > 0) { + /* seeked to line_seq */ + break; + } else if (ret == 0) { + /* + * The end of the list was hit without ever seeing + * line_seq. Reset it to the beginning of the list. + */ + prb_iter_init(&iter, &printk_rb, &dumper->line_seq); + break; + } + /* iterator invalid, start over */ } - /* last entry */ - if (dumper->cur_seq >= log_next_seq) + ret = prb_iter_next(&iter, msgbuf, PRINTK_RECORD_MAX, + &dumper->line_seq); + if (ret == 0) goto out; + else if (ret < 0) + goto retry; - msg = log_from_idx(dumper->cur_idx); + msg = (struct printk_log *)msgbuf; l = msg_print_text(msg, syslog, printk_time, line, size); - dumper->cur_idx = log_next(dumper->cur_idx); - dumper->cur_seq++; - ret = true; -out: if (len) *len = l; - return ret; + cont = true; +out: + prb_commit(&h); + return cont; } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2953 @ out: bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog, char *line, size_t size, size_t *len) { - unsigned long flags; bool ret; - logbuf_lock_irqsave(flags); ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len); - logbuf_unlock_irqrestore(flags); return ret; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2983 @ EXPORT_SYMBOL_GPL(kmsg_dump_get_line); bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog, char *buf, size_t size, size_t *len) { - unsigned long flags; - u64 seq; - u32 idx; - u64 next_seq; - u32 next_idx; - size_t l = 0; - bool ret = false; + struct prb_iterator iter; bool time = printk_time; + struct printk_log *msg; + u64 new_end_seq = 0; + struct prb_handle h; + bool cont = false; + char *msgbuf; + u64 end_seq; + int textlen; + u64 seq = 0; + char *rbuf; + int l = 0; + int ret; if (!dumper->active) - goto out; + return cont; - logbuf_lock_irqsave(flags); - if (dumper->cur_seq < log_first_seq) { - /* messages are gone, move to first available one */ - dumper->cur_seq = log_first_seq; - dumper->cur_idx = log_first_idx; - } + rbuf = prb_reserve(&h, &sprint_rb, PRINTK_RECORD_MAX); + if (!rbuf) + return cont; + msgbuf = rbuf; - /* last entry */ - if (dumper->cur_seq >= dumper->next_seq) { - logbuf_unlock_irqrestore(flags); - goto out; - } + prb_iter_init(&iter, &printk_rb, NULL); - /* calculate length of entire buffer */ - seq = dumper->cur_seq; - idx = dumper->cur_idx; - while (seq < dumper->next_seq) { - struct printk_log *msg = log_from_idx(idx); + /* + * seek to the start record, which is set/modified + * by kmsg_dump_get_line_nolock() + */ + ret = prb_iter_seek(&iter, dumper->line_seq); + if (ret <= 0) + prb_iter_init(&iter, &printk_rb, &seq); - l += msg_print_text(msg, true, time, NULL, 0); - idx = log_next(idx); - seq++; + /* work with a local end seq to have a constant value */ + end_seq = dumper->buffer_end_seq; + if (!end_seq) { + /* initialize end seq to "infinity" */ + end_seq = -1; + dumper->buffer_end_seq = end_seq; } +retry: + if (seq >= end_seq) + goto out; - /* move first record forward until length fits into the buffer */ - seq = dumper->cur_seq; - idx = dumper->cur_idx; - while (l > size && seq < dumper->next_seq) { - struct printk_log *msg = log_from_idx(idx); + /* count the total bytes after seq */ + textlen = count_remaining(&iter, end_seq, msgbuf, + PRINTK_RECORD_MAX, 0, time); + + /* move iter forward until length fits into the buffer */ + while (textlen > size) { + ret = prb_iter_next(&iter, msgbuf, PRINTK_RECORD_MAX, &seq); + if (ret == 0) { + break; + } else if (ret < 0) { + prb_iter_init(&iter, &printk_rb, &seq); + goto retry; + } - l -= msg_print_text(msg, true, time, NULL, 0); - idx = log_next(idx); - seq++; + msg = (struct printk_log *)msgbuf; + textlen -= msg_print_text(msg, true, time, NULL, 0); } - /* last message in next interation */ - next_seq = seq; - next_idx = idx; + /* save end seq for the next interation */ + new_end_seq = seq + 1; + + /* copy messages to buffer */ + while (l < size) { + ret = prb_iter_next(&iter, msgbuf, PRINTK_RECORD_MAX, &seq); + if (ret == 0) { + break; + } else if (ret < 0) { + /* + * iterator (and thus also the start position) + * invalid, start over from beginning of list + */ + prb_iter_init(&iter, &printk_rb, NULL); + continue; + } - l = 0; - while (seq < dumper->next_seq) { - struct printk_log *msg = log_from_idx(idx); + if (seq >= end_seq) + break; - l += msg_print_text(msg, syslog, time, buf + l, size - l); - idx = log_next(idx); - seq++; + msg = (struct printk_log *)msgbuf; + textlen = msg_print_text(msg, syslog, time, buf + l, size - l); + if (textlen > 0) + l += textlen; + cont = true; } - dumper->next_seq = next_seq; - dumper->next_idx = next_idx; - ret = true; - logbuf_unlock_irqrestore(flags); -out: - if (len) + if (cont && len) *len = l; - return ret; +out: + prb_commit(&h); + if (new_end_seq) + dumper->buffer_end_seq = new_end_seq; + return cont; } EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3093 @ EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer); */ void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper) { - dumper->cur_seq = clear_seq; - dumper->cur_idx = clear_idx; - dumper->next_seq = log_next_seq; - dumper->next_idx = log_next_idx; + dumper->line_seq = 0; + dumper->buffer_end_seq = 0; } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3107 @ void kmsg_dump_rewind_nolock(struct kmsg */ void kmsg_dump_rewind(struct kmsg_dumper *dumper) { - unsigned long flags; - - logbuf_lock_irqsave(flags); kmsg_dump_rewind_nolock(dumper); - logbuf_unlock_irqrestore(flags); } EXPORT_SYMBOL_GPL(kmsg_dump_rewind); +static bool console_can_emergency(int level) +{ + struct console *con; + + for_each_console(con) { + if (!(con->flags & CON_ENABLED)) + continue; + if (con->write_atomic && level < emergency_console_loglevel) + return true; + if (con->write && (con->flags & CON_BOOT)) + return true; + } + return false; +} + +static void call_emergency_console_drivers(int level, const char *text, + size_t text_len) +{ + struct console *con; + + for_each_console(con) { + if (!(con->flags & CON_ENABLED)) + continue; + if (con->write_atomic && level < emergency_console_loglevel) { + con->write_atomic(con, text, text_len); + continue; + } + if (con->write && (con->flags & CON_BOOT)) { + con->write(con, text, text_len); + continue; + } + } +} + +static void printk_emergency(char *buffer, int level, u64 ts_nsec, u16 cpu, + char *text, u16 text_len) +{ + struct printk_log msg; + size_t prefix_len; + + if (!console_can_emergency(level)) + return; + + msg.level = level; + msg.ts_nsec = ts_nsec; + msg.cpu = cpu; + msg.facility = 0; + + /* "text" must have PREFIX_MAX preceding bytes available */ + + prefix_len = print_prefix(&msg, + console_msg_format & MSG_FORMAT_SYSLOG, + printk_time, buffer); + /* move the prefix forward to the beginning of the message text */ + text -= prefix_len; + memmove(text, buffer, prefix_len); + text_len += prefix_len; + + text[text_len++] = '\n'; + + call_emergency_console_drivers(level, text, text_len); + + touch_softlockup_watchdog_sync(); + clocksource_touch_watchdog(); + rcu_cpu_stall_reset(); + touch_nmi_watchdog(); + + printk_delay(level); +} #endif + +void console_atomic_lock(unsigned int *flags) +{ + prb_lock(&printk_cpulock, flags); +} +EXPORT_SYMBOL(console_atomic_lock); + +void console_atomic_unlock(unsigned int flags) +{ + prb_unlock(&printk_cpulock, flags); +} +EXPORT_SYMBOL(console_atomic_unlock); Index: linux-5.0.19-rt11/kernel/printk/printk_safe.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/printk/printk_safe.c +++ /dev/null @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1 @ -/* - * printk_safe.c - Safe printk for printk-deadlock-prone contexts - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see <http://www.gnu.org/licenses/>. - */ - -#include <linux/preempt.h> -#include <linux/spinlock.h> -#include <linux/debug_locks.h> -#include <linux/smp.h> -#include <linux/cpumask.h> -#include <linux/irq_work.h> -#include <linux/printk.h> - -#include "internal.h" - -/* - * printk() could not take logbuf_lock in NMI context. Instead, - * it uses an alternative implementation that temporary stores - * the strings into a per-CPU buffer. The content of the buffer - * is later flushed into the main ring buffer via IRQ work. - * - * The alternative implementation is chosen transparently - * by examinig current printk() context mask stored in @printk_context - * per-CPU variable. - * - * The implementation allows to flush the strings also from another CPU. - * There are situations when we want to make sure that all buffers - * were handled or when IRQs are blocked. - */ -static int printk_safe_irq_ready __read_mostly; - -#define SAFE_LOG_BUF_LEN ((1 << CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT) - \ - sizeof(atomic_t) - \ - sizeof(atomic_t) - \ - sizeof(struct irq_work)) - -struct printk_safe_seq_buf { - atomic_t len; /* length of written data */ - atomic_t message_lost; - struct irq_work work; /* IRQ work that flushes the buffer */ - unsigned char buffer[SAFE_LOG_BUF_LEN]; -}; - -static DEFINE_PER_CPU(struct printk_safe_seq_buf, safe_print_seq); -static DEFINE_PER_CPU(int, printk_context); - -#ifdef CONFIG_PRINTK_NMI -static DEFINE_PER_CPU(struct printk_safe_seq_buf, nmi_print_seq); -#endif - -/* Get flushed in a more safe context. */ -static void queue_flush_work(struct printk_safe_seq_buf *s) -{ - if (printk_safe_irq_ready) - irq_work_queue(&s->work); -} - -/* - * Add a message to per-CPU context-dependent buffer. NMI and printk-safe - * have dedicated buffers, because otherwise printk-safe preempted by - * NMI-printk would have overwritten the NMI messages. - * - * The messages are flushed from irq work (or from panic()), possibly, - * from other CPU, concurrently with printk_safe_log_store(). Should this - * happen, printk_safe_log_store() will notice the buffer->len mismatch - * and repeat the write. - */ -static __printf(2, 0) int printk_safe_log_store(struct printk_safe_seq_buf *s, - const char *fmt, va_list args) -{ - int add; - size_t len; - va_list ap; - -again: - len = atomic_read(&s->len); - - /* The trailing '\0' is not counted into len. */ - if (len >= sizeof(s->buffer) - 1) { - atomic_inc(&s->message_lost); - queue_flush_work(s); - return 0; - } - - /* - * Make sure that all old data have been read before the buffer - * was reset. This is not needed when we just append data. - */ - if (!len) - smp_rmb(); - - va_copy(ap, args); - add = vscnprintf(s->buffer + len, sizeof(s->buffer) - len, fmt, ap); - va_end(ap); - if (!add) - return 0; - - /* - * Do it once again if the buffer has been flushed in the meantime. - * Note that atomic_cmpxchg() is an implicit memory barrier that - * makes sure that the data were written before updating s->len. - */ - if (atomic_cmpxchg(&s->len, len, len + add) != len) - goto again; - - queue_flush_work(s); - return add; -} - -static inline void printk_safe_flush_line(const char *text, int len) -{ - /* - * Avoid any console drivers calls from here, because we may be - * in NMI or printk_safe context (when in panic). The messages - * must go only into the ring buffer at this stage. Consoles will - * get explicitly called later when a crashdump is not generated. - */ - printk_deferred("%.*s", len, text); -} - -/* printk part of the temporary buffer line by line */ -static int printk_safe_flush_buffer(const char *start, size_t len) -{ - const char *c, *end; - bool header; - - c = start; - end = start + len; - header = true; - - /* Print line by line. */ - while (c < end) { - if (*c == '\n') { - printk_safe_flush_line(start, c - start + 1); - start = ++c; - header = true; - continue; - } - - /* Handle continuous lines or missing new line. */ - if ((c + 1 < end) && printk_get_level(c)) { - if (header) { - c = printk_skip_level(c); - continue; - } - - printk_safe_flush_line(start, c - start); - start = c++; - header = true; - continue; - } - - header = false; - c++; - } - - /* Check if there was a partial line. Ignore pure header. */ - if (start < end && !header) { - static const char newline[] = KERN_CONT "\n"; - - printk_safe_flush_line(start, end - start); - printk_safe_flush_line(newline, strlen(newline)); - } - - return len; -} - -static void report_message_lost(struct printk_safe_seq_buf *s) -{ - int lost = atomic_xchg(&s->message_lost, 0); - - if (lost) - printk_deferred("Lost %d message(s)!\n", lost); -} - -/* - * Flush data from the associated per-CPU buffer. The function - * can be called either via IRQ work or independently. - */ -static void __printk_safe_flush(struct irq_work *work) -{ - static raw_spinlock_t read_lock = - __RAW_SPIN_LOCK_INITIALIZER(read_lock); - struct printk_safe_seq_buf *s = - container_of(work, struct printk_safe_seq_buf, work); - unsigned long flags; - size_t len; - int i; - - /* - * The lock has two functions. First, one reader has to flush all - * available message to make the lockless synchronization with - * writers easier. Second, we do not want to mix messages from - * different CPUs. This is especially important when printing - * a backtrace. - */ - raw_spin_lock_irqsave(&read_lock, flags); - - i = 0; -more: - len = atomic_read(&s->len); - - /* - * This is just a paranoid check that nobody has manipulated - * the buffer an unexpected way. If we printed something then - * @len must only increase. Also it should never overflow the - * buffer size. - */ - if ((i && i >= len) || len > sizeof(s->buffer)) { - const char *msg = "printk_safe_flush: internal error\n"; - - printk_safe_flush_line(msg, strlen(msg)); - len = 0; - } - - if (!len) - goto out; /* Someone else has already flushed the buffer. */ - - /* Make sure that data has been written up to the @len */ - smp_rmb(); - i += printk_safe_flush_buffer(s->buffer + i, len - i); - - /* - * Check that nothing has got added in the meantime and truncate - * the buffer. Note that atomic_cmpxchg() is an implicit memory - * barrier that makes sure that the data were copied before - * updating s->len. - */ - if (atomic_cmpxchg(&s->len, len, 0) != len) - goto more; - -out: - report_message_lost(s); - raw_spin_unlock_irqrestore(&read_lock, flags); -} - -/** - * printk_safe_flush - flush all per-cpu nmi buffers. - * - * The buffers are flushed automatically via IRQ work. This function - * is useful only when someone wants to be sure that all buffers have - * been flushed at some point. - */ -void printk_safe_flush(void) -{ - int cpu; - - for_each_possible_cpu(cpu) { -#ifdef CONFIG_PRINTK_NMI - __printk_safe_flush(&per_cpu(nmi_print_seq, cpu).work); -#endif - __printk_safe_flush(&per_cpu(safe_print_seq, cpu).work); - } -} - -/** - * printk_safe_flush_on_panic - flush all per-cpu nmi buffers when the system - * goes down. - * - * Similar to printk_safe_flush() but it can be called even in NMI context when - * the system goes down. It does the best effort to get NMI messages into - * the main ring buffer. - * - * Note that it could try harder when there is only one CPU online. - */ -void printk_safe_flush_on_panic(void) -{ - /* - * Make sure that we could access the main ring buffer. - * Do not risk a double release when more CPUs are up. - */ - if (raw_spin_is_locked(&logbuf_lock)) { - if (num_online_cpus() > 1) - return; - - debug_locks_off(); - raw_spin_lock_init(&logbuf_lock); - } - - printk_safe_flush(); -} - -#ifdef CONFIG_PRINTK_NMI -/* - * Safe printk() for NMI context. It uses a per-CPU buffer to - * store the message. NMIs are not nested, so there is always only - * one writer running. But the buffer might get flushed from another - * CPU, so we need to be careful. - */ -static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args) -{ - struct printk_safe_seq_buf *s = this_cpu_ptr(&nmi_print_seq); - - return printk_safe_log_store(s, fmt, args); -} - -void notrace printk_nmi_enter(void) -{ - this_cpu_or(printk_context, PRINTK_NMI_CONTEXT_MASK); -} - -void notrace printk_nmi_exit(void) -{ - this_cpu_and(printk_context, ~PRINTK_NMI_CONTEXT_MASK); -} - -/* - * Marks a code that might produce many messages in NMI context - * and the risk of losing them is more critical than eventual - * reordering. - * - * It has effect only when called in NMI context. Then printk() - * will try to store the messages into the main logbuf directly - * and use the per-CPU buffers only as a fallback when the lock - * is not available. - */ -void printk_nmi_direct_enter(void) -{ - if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK) - this_cpu_or(printk_context, PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -void printk_nmi_direct_exit(void) -{ - this_cpu_and(printk_context, ~PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -#else - -static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args) -{ - return 0; -} - -#endif /* CONFIG_PRINTK_NMI */ - -/* - * Lock-less printk(), to avoid deadlocks should the printk() recurse - * into itself. It uses a per-CPU buffer to store the message, just like - * NMI. - */ -static __printf(1, 0) int vprintk_safe(const char *fmt, va_list args) -{ - struct printk_safe_seq_buf *s = this_cpu_ptr(&safe_print_seq); - - return printk_safe_log_store(s, fmt, args); -} - -/* Can be preempted by NMI. */ -void __printk_safe_enter(void) -{ - this_cpu_inc(printk_context); -} - -/* Can be preempted by NMI. */ -void __printk_safe_exit(void) -{ - this_cpu_dec(printk_context); -} - -__printf(1, 0) int vprintk_func(const char *fmt, va_list args) -{ - /* - * Try to use the main logbuf even in NMI. But avoid calling console - * drivers that might have their own locks. - */ - if ((this_cpu_read(printk_context) & PRINTK_NMI_DIRECT_CONTEXT_MASK) && - raw_spin_trylock(&logbuf_lock)) { - int len; - - len = vprintk_store(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args); - raw_spin_unlock(&logbuf_lock); - defer_console_output(); - return len; - } - - /* Use extra buffer in NMI when logbuf_lock is taken or in safe mode. */ - if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK) - return vprintk_nmi(fmt, args); - - /* Use extra buffer to prevent a recursion deadlock in safe mode. */ - if (this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK) - return vprintk_safe(fmt, args); - - /* No obstacles. */ - return vprintk_default(fmt, args); -} - -void __init printk_safe_init(void) -{ - int cpu; - - for_each_possible_cpu(cpu) { - struct printk_safe_seq_buf *s; - - s = &per_cpu(safe_print_seq, cpu); - init_irq_work(&s->work, __printk_safe_flush); - -#ifdef CONFIG_PRINTK_NMI - s = &per_cpu(nmi_print_seq, cpu); - init_irq_work(&s->work, __printk_safe_flush); -#endif - } - - /* - * In the highly unlikely event that a NMI were to trigger at - * this moment. Make sure IRQ work is set up before this - * variable is set. - */ - barrier(); - printk_safe_irq_ready = 1; - - /* Flush pending messages that did not have scheduled IRQ works. */ - printk_safe_flush(); -} Index: linux-5.0.19-rt11/kernel/ptrace.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/ptrace.c +++ linux-5.0.19-rt11/kernel/ptrace.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:179 @ static bool ptrace_freeze_traced(struct spin_lock_irq(&task->sighand->siglock); if (task_is_traced(task) && !__fatal_signal_pending(task)) { - task->state = __TASK_TRACED; + unsigned long flags; + + raw_spin_lock_irqsave(&task->pi_lock, flags); + if (task->state & __TASK_TRACED) + task->state = __TASK_TRACED; + else + task->saved_state = __TASK_TRACED; + raw_spin_unlock_irqrestore(&task->pi_lock, flags); ret = true; } spin_unlock_irq(&task->sighand->siglock); Index: linux-5.0.19-rt11/kernel/rcu/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/kernel/rcu/Kconfig +++ linux-5.0.19-rt11/kernel/rcu/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:193 @ config RCU_FAST_NO_HZ config RCU_BOOST bool "Enable RCU priority boosting" - depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT - default n + depends on (RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT) || PREEMPT_RT_FULL + default y if PREEMPT_RT_FULL help This option boosts the priority of preempted RCU readers that block the current preemptible RCU grace period for too long. Index: linux-5.0.19-rt11/kernel/rcu/srcutree.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/rcu/srcutree.c +++ linux-5.0.19-rt11/kernel/rcu/srcutree.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:41 @ #include <linux/delay.h> #include <linux/module.h> #include <linux/srcu.h> +#include <linux/locallock.h> #include "rcu.h" #include "rcu_segcblist.h" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:62 @ static bool __read_mostly srcu_init_done static void srcu_invoke_callbacks(struct work_struct *work); static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay); static void process_srcu(struct work_struct *work); +static void srcu_delay_timer(struct timer_list *t); /* Wrappers for lock acquisition and release, see raw_spin_lock_rcu_node(). */ #define spin_lock_rcu_node(p) \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:161 @ static void init_srcu_struct_nodes(struc snp->grphi = cpu; } sdp->cpu = cpu; - INIT_DELAYED_WORK(&sdp->work, srcu_invoke_callbacks); + INIT_WORK(&sdp->work, srcu_invoke_callbacks); + timer_setup(&sdp->delay_work, srcu_delay_timer, 0); sdp->ssp = ssp; sdp->grpmask = 1 << (cpu - sdp->mynode->grplo); if (is_static) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:392 @ void _cleanup_srcu_struct(struct srcu_st } else { flush_delayed_work(&ssp->work); } - for_each_possible_cpu(cpu) + for_each_possible_cpu(cpu) { + struct srcu_data *sdp = per_cpu_ptr(ssp->sda, cpu); + if (quiesced) { - if (WARN_ON(delayed_work_pending(&per_cpu_ptr(ssp->sda, cpu)->work))) + if (WARN_ON(timer_pending(&sdp->delay_work))) + return; /* Just leak it! */ + if (WARN_ON(work_pending(&sdp->work))) return; /* Just leak it! */ } else { - flush_delayed_work(&per_cpu_ptr(ssp->sda, cpu)->work); + del_timer_sync(&sdp->delay_work); + flush_work(&sdp->work); } + } if (WARN_ON(rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)) != SRCU_STATE_IDLE) || WARN_ON(srcu_readers_active(ssp))) { pr_info("%s: Active srcu_struct %p state: %d\n", @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:475 @ static void srcu_gp_start(struct srcu_st WARN_ON_ONCE(state != SRCU_STATE_SCAN1); } -/* - * Track online CPUs to guide callback workqueue placement. - */ -DEFINE_PER_CPU(bool, srcu_online); -void srcu_online_cpu(unsigned int cpu) +static void srcu_delay_timer(struct timer_list *t) { - WRITE_ONCE(per_cpu(srcu_online, cpu), true); -} + struct srcu_data *sdp = container_of(t, struct srcu_data, delay_work); -void srcu_offline_cpu(unsigned int cpu) -{ - WRITE_ONCE(per_cpu(srcu_online, cpu), false); + queue_work_on(sdp->cpu, rcu_gp_wq, &sdp->work); } -/* - * Place the workqueue handler on the specified CPU if online, otherwise - * just run it whereever. This is useful for placing workqueue handlers - * that are to invoke the specified CPU's callbacks. - */ -static bool srcu_queue_delayed_work_on(int cpu, struct workqueue_struct *wq, - struct delayed_work *dwork, +static void srcu_queue_delayed_work_on(struct srcu_data *sdp, unsigned long delay) { - bool ret; + if (!delay) { + queue_work_on(sdp->cpu, rcu_gp_wq, &sdp->work); + return; + } - preempt_disable(); - if (READ_ONCE(per_cpu(srcu_online, cpu))) - ret = queue_delayed_work_on(cpu, wq, dwork, delay); - else - ret = queue_delayed_work(wq, dwork, delay); - preempt_enable(); - return ret; + timer_reduce(&sdp->delay_work, jiffies + delay); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:500 @ static bool srcu_queue_delayed_work_on(i */ static void srcu_schedule_cbs_sdp(struct srcu_data *sdp, unsigned long delay) { - srcu_queue_delayed_work_on(sdp->cpu, rcu_gp_wq, &sdp->work, delay); + srcu_queue_delayed_work_on(sdp, delay); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:756 @ static void srcu_flip(struct srcu_struct smp_mb(); /* D */ /* Pairs with C. */ } +static DEFINE_LOCAL_IRQ_LOCK(sp_llock); /* * If SRCU is likely idle, return true, otherwise return false. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:786 @ static bool srcu_might_be_idle(struct sr unsigned long t; /* If the local srcu_data structure has callbacks, not idle. */ - local_irq_save(flags); + local_lock_irqsave(sp_llock, flags); sdp = this_cpu_ptr(ssp->sda); if (rcu_segcblist_pend_cbs(&sdp->srcu_cblist)) { - local_irq_restore(flags); + local_unlock_irqrestore(sp_llock, flags); return false; /* Callbacks already present, so not idle. */ } - local_irq_restore(flags); + local_unlock_irqrestore(sp_llock, flags); /* * No local callbacks, so probabalistically probe global state. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:872 @ void __call_srcu(struct srcu_struct *ssp } rhp->func = func; idx = srcu_read_lock(ssp); - local_irq_save(flags); + local_lock_irqsave(sp_llock, flags); sdp = this_cpu_ptr(ssp->sda); spin_lock_rcu_node(sdp); rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp, false); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:888 @ void __call_srcu(struct srcu_struct *ssp sdp->srcu_gp_seq_needed_exp = s; needexp = true; } - spin_unlock_irqrestore_rcu_node(sdp, flags); + spin_unlock_rcu_node(sdp); + local_unlock_irqrestore(sp_llock, flags); if (needgp) srcu_funnel_gp_start(ssp, sdp, s, do_norm); else if (needexp) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1184 @ static void srcu_invoke_callbacks(struct struct srcu_data *sdp; struct srcu_struct *ssp; - sdp = container_of(work, struct srcu_data, work.work); + sdp = container_of(work, struct srcu_data, work); + ssp = sdp->ssp; rcu_cblist_init(&ready_cbs); spin_lock_irq_rcu_node(sdp); Index: linux-5.0.19-rt11/kernel/rcu/tree.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/rcu/tree.c +++ linux-5.0.19-rt11/kernel/rcu/tree.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:65 @ #include <linux/suspend.h> #include <linux/ftrace.h> #include <linux/tick.h> +#include <linux/gfp.h> +#include <linux/oom.h> +#include <linux/smpboot.h> +#include <linux/jiffies.h> +#include <linux/sched/isolation.h> +#include "../time/tick-internal.h" #include "tree.h" #include "rcu.h" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1155 @ static int rcu_implicit_dynticks_qs(stru !rdp->rcu_iw_pending && rdp->rcu_iw_gp_seq != rnp->gp_seq && (rnp->ffmask & rdp->grpmask)) { init_irq_work(&rdp->rcu_iw, rcu_iw_handler); + rdp->rcu_iw.flags = IRQ_WORK_HARD_IRQ; rdp->rcu_iw_pending = true; rdp->rcu_iw_gp_seq = rnp->gp_seq; irq_work_queue_on(&rdp->rcu_iw, rdp->cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2735 @ EXPORT_SYMBOL_GPL(rcu_fwd_progress_check * structures. This may be called only from the CPU to whom the rdp * belongs. */ -static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused) +static __latent_entropy void rcu_process_callbacks(void) { unsigned long flags; struct rcu_data *rdp = raw_cpu_ptr(&rcu_data); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2777 @ static __latent_entropy void rcu_process trace_rcu_utilization(TPS("End RCU core")); } +static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task); + /* * Schedule RCU callback invocation. If the running implementation of RCU * does not support RCU priority boosting, just do a direct call, otherwise @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2790 @ static void invoke_rcu_callbacks(struct { if (unlikely(!READ_ONCE(rcu_scheduler_fully_active))) return; - if (likely(!rcu_state.boost)) { - rcu_do_batch(rdp); + rcu_do_batch(rdp); +} + +static void rcu_wake_cond(struct task_struct *t, int status) +{ + /* + * If the thread is yielding, only wake it when this + * is invoked from idle + */ + if (t && (status != RCU_KTHREAD_YIELDING || is_idle_task(current))) + wake_up_process(t); +} + +/* + * Wake up this CPU's rcuc kthread to do RCU core processing. + */ +static void invoke_rcu_core(void) +{ + unsigned long flags; + struct task_struct *t; + + if (!cpu_online(smp_processor_id())) return; + local_irq_save(flags); + __this_cpu_write(rcu_cpu_has_work, 1); + t = __this_cpu_read(rcu_cpu_kthread_task); + if (t != NULL && current != t) + rcu_wake_cond(t, __this_cpu_read(rcu_cpu_kthread_status)); + local_irq_restore(flags); +} + +static void rcu_cpu_kthread_park(unsigned int cpu) +{ + per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU; +} + +static int rcu_cpu_kthread_should_run(unsigned int cpu) +{ + return __this_cpu_read(rcu_cpu_has_work); +} + +/* + * Per-CPU kernel thread that invokes RCU callbacks. This replaces + * the RCU softirq used in configurations of RCU that do not support RCU + * priority boosting. + */ +static void rcu_cpu_kthread(unsigned int cpu) +{ + unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status); + char work, *workp = this_cpu_ptr(&rcu_cpu_has_work); + int spincnt; + + for (spincnt = 0; spincnt < 10; spincnt++) { + trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait")); + local_bh_disable(); + *statusp = RCU_KTHREAD_RUNNING; + this_cpu_inc(rcu_cpu_kthread_loops); + local_irq_disable(); + work = *workp; + *workp = 0; + local_irq_enable(); + if (work) + rcu_process_callbacks(); + local_bh_enable(); + if (*workp == 0) { + trace_rcu_utilization(TPS("End CPU kthread@rcu_wait")); + *statusp = RCU_KTHREAD_WAITING; + return; + } } - invoke_rcu_callbacks_kthread(); + *statusp = RCU_KTHREAD_YIELDING; + trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield")); + schedule_timeout_interruptible(2); + trace_rcu_utilization(TPS("End CPU kthread@rcu_yield")); + *statusp = RCU_KTHREAD_WAITING; } -static void invoke_rcu_core(void) +static struct smp_hotplug_thread rcu_cpu_thread_spec = { + .store = &rcu_cpu_kthread_task, + .thread_should_run = rcu_cpu_kthread_should_run, + .thread_fn = rcu_cpu_kthread, + .thread_comm = "rcuc/%u", + .setup = rcu_cpu_kthread_setup, + .park = rcu_cpu_kthread_park, +}; + +/* + * Spawn per-CPU RCU core processing kthreads. + */ +static int __init rcu_spawn_core_kthreads(void) { - if (cpu_online(smp_processor_id())) - raise_softirq(RCU_SOFTIRQ); + int cpu; + + for_each_possible_cpu(cpu) + per_cpu(rcu_cpu_has_work, cpu) = 0; + WARN_ONCE(smpboot_register_percpu_thread(&rcu_cpu_thread_spec), "%s: Could not start rcub kthread, OOM is now expected behavior\n", __func__); + return 0; } +early_initcall(rcu_spawn_core_kthreads); /* * Handle any core-RCU processing required by a call_rcu() invocation. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3437 @ int rcutree_online_cpu(unsigned int cpu) raw_spin_lock_irqsave_rcu_node(rnp, flags); rnp->ffmask |= rdp->grpmask; raw_spin_unlock_irqrestore_rcu_node(rnp, flags); - if (IS_ENABLED(CONFIG_TREE_SRCU)) - srcu_online_cpu(cpu); if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE) return 0; /* Too early in boot for scheduler work. */ sync_sched_exp_online_cleanup(cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3461 @ int rcutree_offline_cpu(unsigned int cpu raw_spin_unlock_irqrestore_rcu_node(rnp, flags); rcutree_affinity_setting(cpu, cpu); - if (IS_ENABLED(CONFIG_TREE_SRCU)) - srcu_offline_cpu(cpu); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3881 @ void __init rcu_init(void) rcu_init_one(); if (dump_tree) rcu_dump_rcu_node_tree(); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); /* * We don't need protection against CPU-hotplug here because Index: linux-5.0.19-rt11/kernel/rcu/tree.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/rcu/tree.h +++ linux-5.0.19-rt11/kernel/rcu/tree.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:405 @ static const char *tp_rcu_varname __used int rcu_dynticks_snap(struct rcu_data *rdp); -#ifdef CONFIG_RCU_BOOST DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status); DECLARE_PER_CPU(int, rcu_cpu_kthread_cpu); DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); DECLARE_PER_CPU(char, rcu_cpu_has_work); -#endif /* #ifdef CONFIG_RCU_BOOST */ /* Forward declarations for rcutree_plugin.h */ static void rcu_bootup_announce(void); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:426 @ void call_rcu(struct rcu_head *head, rcu static void dump_blkd_tasks(struct rcu_node *rnp, int ncheck); static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); static void rcu_preempt_boost_start_gp(struct rcu_node *rnp); -static void invoke_rcu_callbacks_kthread(void); static bool rcu_is_callbacks_kthread(void); +static void rcu_cpu_kthread_setup(unsigned int cpu); static void __init rcu_spawn_boost_kthreads(void); static void rcu_prepare_kthreads(int cpu); static void rcu_cleanup_after_idle(void); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:463 @ static void rcu_bind_gp_kthread(void); static bool rcu_nohz_full_cpu(void); static void rcu_dynticks_task_enter(void); static void rcu_dynticks_task_exit(void); - -#ifdef CONFIG_SRCU -void srcu_online_cpu(unsigned int cpu); -void srcu_offline_cpu(unsigned int cpu); -#else /* #ifdef CONFIG_SRCU */ -void srcu_online_cpu(unsigned int cpu) { } -void srcu_offline_cpu(unsigned int cpu) { } -#endif /* #else #ifdef CONFIG_SRCU */ Index: linux-5.0.19-rt11/kernel/rcu/tree_plugin.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/rcu/tree_plugin.h +++ linux-5.0.19-rt11/kernel/rcu/tree_plugin.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:27 @ * Paul E. McKenney <paulmck@linux.vnet.ibm.com> */ -#include <linux/delay.h> -#include <linux/gfp.h> -#include <linux/oom.h> -#include <linux/sched/debug.h> -#include <linux/smpboot.h> -#include <linux/sched/isolation.h> -#include <uapi/linux/sched/types.h> -#include "../time/tick-internal.h" - -#ifdef CONFIG_RCU_BOOST - #include "../locking/rtmutex_common.h" /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:37 @ DEFINE_PER_CPU(unsigned int, rcu_cpu_kth DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); DEFINE_PER_CPU(char, rcu_cpu_has_work); -#else /* #ifdef CONFIG_RCU_BOOST */ - -/* - * Some architectures do not define rt_mutexes, but if !CONFIG_RCU_BOOST, - * all uses are in dead code. Provide a definition to keep the compiler - * happy, but add WARN_ON_ONCE() to complain if used in the wrong place. - * This probably needs to be excluded from -rt builds. - */ -#define rt_mutex_owner(a) ({ WARN_ON_ONCE(1); NULL; }) -#define rt_mutex_futex_unlock(x) WARN_ON_ONCE(1) - -#endif /* #else #ifdef CONFIG_RCU_BOOST */ - #ifdef CONFIG_RCU_NOCB_CPU static cpumask_var_t rcu_nocb_mask; /* CPUs to have callbacks offloaded. */ static bool __read_mostly rcu_nocb_poll; /* Offload kthread are to poll. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:309 @ void rcu_note_context_switch(bool preemp struct task_struct *t = current; struct rcu_data *rdp = this_cpu_ptr(&rcu_data); struct rcu_node *rnp; + int sleeping_l = 0; barrier(); /* Avoid RCU read-side critical sections leaking down. */ trace_rcu_utilization(TPS("Start context switch")); lockdep_assert_irqs_disabled(); - WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0); +#if defined(CONFIG_PREEMPT_RT_FULL) + sleeping_l = t->sleeping_lock; +#endif + WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0 && !sleeping_l); if (t->rcu_read_lock_nesting > 0 && !t->rcu_read_unlock_special.b.blocked) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:635 @ static void rcu_read_unlock_special(stru /* Need to defer quiescent state until everything is enabled. */ if (irqs_were_disabled) { /* Enabling irqs does not reschedule, so... */ - raise_softirq_irqoff(RCU_SOFTIRQ); + invoke_rcu_core(); } else { /* Enabling BH or preempt does reschedule, so... */ set_tsk_need_resched(current); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1133 @ dump_blkd_tasks(struct rcu_node *rnp, in #endif /* #else #ifdef CONFIG_PREEMPT_RCU */ +/* + * If boosting, set rcuc kthreads to realtime priority. + */ +static void rcu_cpu_kthread_setup(unsigned int cpu) +{ #ifdef CONFIG_RCU_BOOST + struct sched_param sp; -static void rcu_wake_cond(struct task_struct *t, int status) -{ - /* - * If the thread is yielding, only wake it when this - * is invoked from idle - */ - if (status != RCU_KTHREAD_YIELDING || is_idle_task(current)) - wake_up_process(t); + sp.sched_priority = kthread_prio; + sched_setscheduler_nocheck(current, SCHED_FIFO, &sp); +#endif /* #ifdef CONFIG_RCU_BOOST */ } +#ifdef CONFIG_RCU_BOOST + /* * Carry out RCU priority boosting on the task indicated by ->exp_tasks * or ->boost_tasks, advancing the pointer to the next task in the @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1286 @ static void rcu_initiate_boost(struct rc } /* - * Wake up the per-CPU kthread to invoke RCU callbacks. - */ -static void invoke_rcu_callbacks_kthread(void) -{ - unsigned long flags; - - local_irq_save(flags); - __this_cpu_write(rcu_cpu_has_work, 1); - if (__this_cpu_read(rcu_cpu_kthread_task) != NULL && - current != __this_cpu_read(rcu_cpu_kthread_task)) { - rcu_wake_cond(__this_cpu_read(rcu_cpu_kthread_task), - __this_cpu_read(rcu_cpu_kthread_status)); - } - local_irq_restore(flags); -} - -/* * Is the current CPU running the RCU-callbacks kthread? * Caller must have preemption disabled. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1338 @ static int rcu_spawn_one_boost_kthread(s return 0; } -static void rcu_kthread_do_work(void) -{ - rcu_do_batch(this_cpu_ptr(&rcu_data)); -} - -static void rcu_cpu_kthread_setup(unsigned int cpu) -{ - struct sched_param sp; - - sp.sched_priority = kthread_prio; - sched_setscheduler_nocheck(current, SCHED_FIFO, &sp); -} - -static void rcu_cpu_kthread_park(unsigned int cpu) -{ - per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU; -} - -static int rcu_cpu_kthread_should_run(unsigned int cpu) -{ - return __this_cpu_read(rcu_cpu_has_work); -} - -/* - * Per-CPU kernel thread that invokes RCU callbacks. This replaces - * the RCU softirq used in configurations of RCU that do not support RCU - * priority boosting. - */ -static void rcu_cpu_kthread(unsigned int cpu) -{ - unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status); - char work, *workp = this_cpu_ptr(&rcu_cpu_has_work); - int spincnt; - - for (spincnt = 0; spincnt < 10; spincnt++) { - trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait")); - local_bh_disable(); - *statusp = RCU_KTHREAD_RUNNING; - this_cpu_inc(rcu_cpu_kthread_loops); - local_irq_disable(); - work = *workp; - *workp = 0; - local_irq_enable(); - if (work) - rcu_kthread_do_work(); - local_bh_enable(); - if (*workp == 0) { - trace_rcu_utilization(TPS("End CPU kthread@rcu_wait")); - *statusp = RCU_KTHREAD_WAITING; - return; - } - } - *statusp = RCU_KTHREAD_YIELDING; - trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield")); - schedule_timeout_interruptible(2); - trace_rcu_utilization(TPS("End CPU kthread@rcu_yield")); - *statusp = RCU_KTHREAD_WAITING; -} - /* * Set the per-rcu_node kthread's affinity to cover all CPUs that are * served by the rcu_node in question. The CPU hotplug lock is still @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1368 @ static void rcu_boost_kthread_setaffinit free_cpumask_var(cm); } -static struct smp_hotplug_thread rcu_cpu_thread_spec = { - .store = &rcu_cpu_kthread_task, - .thread_should_run = rcu_cpu_kthread_should_run, - .thread_fn = rcu_cpu_kthread, - .thread_comm = "rcuc/%u", - .setup = rcu_cpu_kthread_setup, - .park = rcu_cpu_kthread_park, -}; - /* * Spawn boost kthreads -- called as soon as the scheduler is running. */ static void __init rcu_spawn_boost_kthreads(void) { struct rcu_node *rnp; - int cpu; - for_each_possible_cpu(cpu) - per_cpu(rcu_cpu_has_work, cpu) = 0; - if (WARN_ONCE(smpboot_register_percpu_thread(&rcu_cpu_thread_spec), "%s: Could not start rcub kthread, OOM is now expected behavior\n", __func__)) - return; rcu_for_each_leaf_node(rnp) (void)rcu_spawn_one_boost_kthread(rnp); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1397 @ static void rcu_initiate_boost(struct rc raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } -static void invoke_rcu_callbacks_kthread(void) -{ - WARN_ON_ONCE(1); -} - static bool rcu_is_callbacks_kthread(void) { return false; Index: linux-5.0.19-rt11/kernel/rcu/update.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/rcu/update.c +++ linux-5.0.19-rt11/kernel/rcu/update.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:71 @ extern int rcu_expedited; /* from sysctl module_param(rcu_expedited, int, 0); extern int rcu_normal; /* from sysctl */ module_param(rcu_normal, int, 0); -static int rcu_normal_after_boot; +static int rcu_normal_after_boot = IS_ENABLED(CONFIG_PREEMPT_RT_FULL); +#ifndef CONFIG_PREEMPT_RT_FULL module_param(rcu_normal_after_boot, int, 0); +#endif #endif /* #ifndef CONFIG_TINY_RCU */ #ifdef CONFIG_DEBUG_LOCK_ALLOC Index: linux-5.0.19-rt11/kernel/sched/completion.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/completion.c +++ linux-5.0.19-rt11/kernel/sched/completion.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:32 @ void complete(struct completion *x) { unsigned long flags; - spin_lock_irqsave(&x->wait.lock, flags); + raw_spin_lock_irqsave(&x->wait.lock, flags); if (x->done != UINT_MAX) x->done++; - __wake_up_locked(&x->wait, TASK_NORMAL, 1); - spin_unlock_irqrestore(&x->wait.lock, flags); + swake_up_locked(&x->wait); + raw_spin_unlock_irqrestore(&x->wait.lock, flags); } EXPORT_SYMBOL(complete); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:61 @ void complete_all(struct completion *x) { unsigned long flags; - spin_lock_irqsave(&x->wait.lock, flags); + raw_spin_lock_irqsave(&x->wait.lock, flags); x->done = UINT_MAX; - __wake_up_locked(&x->wait, TASK_NORMAL, 0); - spin_unlock_irqrestore(&x->wait.lock, flags); + swake_up_all_locked(&x->wait); + raw_spin_unlock_irqrestore(&x->wait.lock, flags); } EXPORT_SYMBOL(complete_all); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:73 @ do_wait_for_common(struct completion *x, long (*action)(long), long timeout, int state) { if (!x->done) { - DECLARE_WAITQUEUE(wait, current); + DECLARE_SWAITQUEUE(wait); - __add_wait_queue_entry_tail_exclusive(&x->wait, &wait); do { if (signal_pending_state(state, current)) { timeout = -ERESTARTSYS; break; } + __prepare_to_swait(&x->wait, &wait); __set_current_state(state); - spin_unlock_irq(&x->wait.lock); + raw_spin_unlock_irq(&x->wait.lock); timeout = action(timeout); - spin_lock_irq(&x->wait.lock); + raw_spin_lock_irq(&x->wait.lock); } while (!x->done && timeout); - __remove_wait_queue(&x->wait, &wait); + __finish_swait(&x->wait, &wait); if (!x->done) return timeout; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:103 @ __wait_for_common(struct completion *x, complete_acquire(x); - spin_lock_irq(&x->wait.lock); + raw_spin_lock_irq(&x->wait.lock); timeout = do_wait_for_common(x, action, timeout, state); - spin_unlock_irq(&x->wait.lock); + raw_spin_unlock_irq(&x->wait.lock); complete_release(x); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:294 @ bool try_wait_for_completion(struct comp if (!READ_ONCE(x->done)) return false; - spin_lock_irqsave(&x->wait.lock, flags); + raw_spin_lock_irqsave(&x->wait.lock, flags); if (!x->done) ret = false; else if (x->done != UINT_MAX) x->done--; - spin_unlock_irqrestore(&x->wait.lock, flags); + raw_spin_unlock_irqrestore(&x->wait.lock, flags); return ret; } EXPORT_SYMBOL(try_wait_for_completion); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:325 @ bool completion_done(struct completion * * otherwise we can end up freeing the completion before complete() * is done referencing it. */ - spin_lock_irqsave(&x->wait.lock, flags); - spin_unlock_irqrestore(&x->wait.lock, flags); + raw_spin_lock_irqsave(&x->wait.lock, flags); + raw_spin_unlock_irqrestore(&x->wait.lock, flags); return true; } EXPORT_SYMBOL(completion_done); Index: linux-5.0.19-rt11/kernel/sched/core.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/core.c +++ linux-5.0.19-rt11/kernel/sched/core.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:47 @ const_debug unsigned int sysctl_sched_fe * Number of tasks to iterate in a single balance run. * Limited because this is done with IRQs disabled. */ +#ifdef CONFIG_PREEMPT_RT_FULL +const_debug unsigned int sysctl_sched_nr_migrate = 8; +#else const_debug unsigned int sysctl_sched_nr_migrate = 32; +#endif /* * period over which we measure -rt task CPU usage in us. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:322 @ static void hrtick_rq_init(struct rq *rq rq->hrtick_csd.info = rq; #endif - hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); rq->hrtick_timer.function = hrtick; } #else /* CONFIG_SCHED_HRTICK */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:416 @ static bool set_nr_if_polling(struct tas * This function must be used as-if it were wake_up_process(); IOW the task * must be ready to be woken at this location. */ -void wake_q_add(struct wake_q_head *head, struct task_struct *task) +void __wake_q_add(struct wake_q_head *head, struct task_struct *task, + bool sleeper) { - struct wake_q_node *node = &task->wake_q; + struct wake_q_node *node; + + if (sleeper) + node = &task->wake_q_sleeper; + else + node = &task->wake_q; /* * Atomically grab the task, if ->wake_q is !nil already it means @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:447 @ void wake_q_add(struct wake_q_head *head head->lastp = &node->next; } -void wake_up_q(struct wake_q_head *head) +void __wake_up_q(struct wake_q_head *head, bool sleeper) { struct wake_q_node *node = head->first; while (node != WAKE_Q_TAIL) { struct task_struct *task; - task = container_of(node, struct task_struct, wake_q); + if (sleeper) + task = container_of(node, struct task_struct, wake_q_sleeper); + else + task = container_of(node, struct task_struct, wake_q); BUG_ON(!task); /* Task can safely be re-inserted now: */ node = node->next; - task->wake_q.next = NULL; - + if (sleeper) + task->wake_q_sleeper.next = NULL; + else + task->wake_q.next = NULL; /* * wake_up_process() executes a full barrier, which pairs with * the queueing in wake_q_add() so as not to miss wakeups. */ - wake_up_process(task); + if (sleeper) + wake_up_lock_sleeper(task); + else + wake_up_process(task); put_task_struct(task); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:508 @ void resched_curr(struct rq *rq) trace_sched_wake_idle_without_ipi(cpu); } +#ifdef CONFIG_PREEMPT_LAZY + +static int tsk_is_polling(struct task_struct *p) +{ +#ifdef TIF_POLLING_NRFLAG + return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG); +#else + return 0; +#endif +} + +void resched_curr_lazy(struct rq *rq) +{ + struct task_struct *curr = rq->curr; + int cpu; + + if (!sched_feat(PREEMPT_LAZY)) { + resched_curr(rq); + return; + } + + lockdep_assert_held(&rq->lock); + + if (test_tsk_need_resched(curr)) + return; + + if (test_tsk_need_resched_lazy(curr)) + return; + + set_tsk_need_resched_lazy(curr); + + cpu = cpu_of(rq); + if (cpu == smp_processor_id()) + return; + + /* NEED_RESCHED_LAZY must be visible before we test polling */ + smp_mb(); + if (!tsk_is_polling(curr)) + smp_send_reschedule(cpu); +} +#endif + void resched_cpu(int cpu) { struct rq *rq = cpu_rq(cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:959 @ static inline bool is_per_cpu_kthread(st */ static inline bool is_cpu_allowed(struct task_struct *p, int cpu) { - if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) + if (!cpumask_test_cpu(cpu, p->cpus_ptr)) return false; - if (is_per_cpu_kthread(p)) + if (is_per_cpu_kthread(p) || __migrate_disabled(p)) return cpu_online(cpu); return cpu_active(cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1054 @ static int migration_cpu_stop(void *data local_irq_disable(); /* * We need to explicitly wake pending tasks before running - * __migrate_task() such that we will not miss enforcing cpus_allowed + * __migrate_task() such that we will not miss enforcing cpus_ptr * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test. */ sched_ttwu_pending(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1085 @ static int migration_cpu_stop(void *data */ void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask) { - cpumask_copy(&p->cpus_allowed, new_mask); + cpumask_copy(&p->cpus_mask, new_mask); p->nr_cpus_allowed = cpumask_weight(new_mask); } -void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) +int __migrate_disabled(struct task_struct *p) +{ + return p->migrate_disable; +} +EXPORT_SYMBOL_GPL(__migrate_disabled); +#endif + +static void __do_set_cpus_allowed_tail(struct task_struct *p, + const struct cpumask *new_mask) { struct rq *rq = task_rq(p); bool queued, running; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1127 @ void do_set_cpus_allowed(struct task_str set_curr_task(rq, p); } +void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) +{ +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) + if (__migrate_disabled(p)) { + lockdep_assert_held(&p->pi_lock); + + cpumask_copy(&p->cpus_mask, new_mask); + p->migrate_disable_update = 1; + return; + } +#endif + __do_set_cpus_allowed_tail(p, new_mask); +} + /* * Change a given task's CPU affinity. Migrate the thread to a * proper CPU and schedule it away if the CPU it's executing on @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1178 @ static int __set_cpus_allowed_ptr(struct goto out; } - if (cpumask_equal(&p->cpus_allowed, new_mask)) + if (cpumask_equal(p->cpus_ptr, new_mask)) goto out; if (!cpumask_intersects(new_mask, cpu_valid_mask)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1199 @ static int __set_cpus_allowed_ptr(struct } /* Can the task run on the task's current CPU? If so, we're done */ - if (cpumask_test_cpu(task_cpu(p), new_mask)) + if (cpumask_test_cpu(task_cpu(p), new_mask) || __migrate_disabled(p)) + goto out; + +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) + if (__migrate_disabled(p)) { + p->migrate_disable_update = 1; goto out; + } +#endif dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask); if (task_running(rq, p) || p->state == TASK_WAKING) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1348 @ static int migrate_swap_stop(void *data) if (task_cpu(arg->src_task) != arg->src_cpu) goto unlock; - if (!cpumask_test_cpu(arg->dst_cpu, &arg->src_task->cpus_allowed)) + if (!cpumask_test_cpu(arg->dst_cpu, arg->src_task->cpus_ptr)) goto unlock; - if (!cpumask_test_cpu(arg->src_cpu, &arg->dst_task->cpus_allowed)) + if (!cpumask_test_cpu(arg->src_cpu, arg->dst_task->cpus_ptr)) goto unlock; __migrate_swap_task(arg->src_task, arg->dst_cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1393 @ int migrate_swap(struct task_struct *cur if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu)) goto out; - if (!cpumask_test_cpu(arg.dst_cpu, &arg.src_task->cpus_allowed)) + if (!cpumask_test_cpu(arg.dst_cpu, arg.src_task->cpus_ptr)) goto out; - if (!cpumask_test_cpu(arg.src_cpu, &arg.dst_task->cpus_allowed)) + if (!cpumask_test_cpu(arg.src_cpu, arg.dst_task->cpus_ptr)) goto out; trace_sched_swap_numa(cur, arg.src_cpu, p, arg.dst_cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1407 @ out: } #endif /* CONFIG_NUMA_BALANCING */ +static bool check_task_state(struct task_struct *p, long match_state) +{ + bool match = false; + + raw_spin_lock_irq(&p->pi_lock); + if (p->state == match_state || p->saved_state == match_state) + match = true; + raw_spin_unlock_irq(&p->pi_lock); + + return match; +} + /* * wait_task_inactive - wait for a thread to unschedule. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1463 @ unsigned long wait_task_inactive(struct * is actually now running somewhere else! */ while (task_running(rq, p)) { - if (match_state && unlikely(p->state != match_state)) + if (match_state && !check_task_state(p, match_state)) return 0; cpu_relax(); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1478 @ unsigned long wait_task_inactive(struct running = task_running(rq, p); queued = task_on_rq_queued(p); ncsw = 0; - if (!match_state || p->state == match_state) + if (!match_state || p->state == match_state || + p->saved_state == match_state) ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ task_rq_unlock(rq, p, &rf); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1554 @ void kick_process(struct task_struct *p) EXPORT_SYMBOL_GPL(kick_process); /* - * ->cpus_allowed is protected by both rq->lock and p->pi_lock + * ->cpus_ptr is protected by both rq->lock and p->pi_lock * * A few notes on cpu_active vs cpu_online: * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1594 @ static int select_fallback_rq(int cpu, s for_each_cpu(dest_cpu, nodemask) { if (!cpu_active(dest_cpu)) continue; - if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) + if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) return dest_cpu; } } for (;;) { /* Any allowed, online CPU? */ - for_each_cpu(dest_cpu, &p->cpus_allowed) { + for_each_cpu(dest_cpu, p->cpus_ptr) { if (!is_cpu_allowed(p, dest_cpu)) continue; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1645 @ out: } /* - * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. + * The caller (fork, wakeup) owns p->pi_lock, ->cpus_ptr is stable. */ static inline int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1655 @ int select_task_rq(struct task_struct *p if (p->nr_cpus_allowed > 1) cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags); else - cpu = cpumask_any(&p->cpus_allowed); + cpu = cpumask_any(p->cpus_ptr); /* * In order not to call set_task_cpu() on a blocking task we need - * to rely on ttwu() to place the task on a valid ->cpus_allowed + * to rely on ttwu() to place the task on a valid ->cpus_ptr * CPU. * * Since this is common to all placement strategies, this lives here. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1762 @ static inline void ttwu_activate(struct { activate_task(rq, p, en_flags); p->on_rq = TASK_ON_RQ_QUEUED; - - /* If a worker is waking up, notify the workqueue: */ - if (p->flags & PF_WQ_WORKER) - wq_worker_waking_up(p, cpu_of(rq)); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2080 @ try_to_wake_up(struct task_struct *p, un */ raw_spin_lock_irqsave(&p->pi_lock, flags); smp_mb__after_spinlock(); - if (!(p->state & state)) + if (!(p->state & state)) { + /* + * The task might be running due to a spinlock sleeper + * wakeup. Check the saved state and set it to running + * if the wakeup condition is true. + */ + if (!(wake_flags & WF_LOCK_SLEEPER)) { + if (p->saved_state & state) { + p->saved_state = TASK_RUNNING; + success = 1; + } + } goto out; + } + + /* + * If this is a regular wakeup, then we can unconditionally + * clear the saved state of a "lock sleeper". + */ + if (!(wake_flags & WF_LOCK_SLEEPER)) + p->saved_state = TASK_RUNNING; trace_sched_waking(p); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2199 @ out: } /** - * try_to_wake_up_local - try to wake up a local task with rq lock held - * @p: the thread to be awakened - * @rf: request-queue flags for pinning - * - * Put @p on the run-queue if it's not already there. The caller must - * ensure that this_rq() is locked, @p is bound to this_rq() and not - * the current task. - */ -static void try_to_wake_up_local(struct task_struct *p, struct rq_flags *rf) -{ - struct rq *rq = task_rq(p); - - if (WARN_ON_ONCE(rq != this_rq()) || - WARN_ON_ONCE(p == current)) - return; - - lockdep_assert_held(&rq->lock); - - if (!raw_spin_trylock(&p->pi_lock)) { - /* - * This is OK, because current is on_cpu, which avoids it being - * picked for load-balance and preemption/IRQs are still - * disabled avoiding further scheduler activity on it and we've - * not yet picked a replacement task. - */ - rq_unlock(rq, rf); - raw_spin_lock(&p->pi_lock); - rq_relock(rq, rf); - } - - if (!(p->state & TASK_NORMAL)) - goto out; - - trace_sched_waking(p); - - if (!task_on_rq_queued(p)) { - if (p->in_iowait) { - delayacct_blkio_end(p); - atomic_dec(&rq->nr_iowait); - } - ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK); - } - - ttwu_do_wakeup(rq, p, 0, rf); - ttwu_stat(p, smp_processor_id(), 0); -out: - raw_spin_unlock(&p->pi_lock); -} - -/** * wake_up_process - Wake up a specific process * @p: The process to be woken up. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2215 @ int wake_up_process(struct task_struct * } EXPORT_SYMBOL(wake_up_process); +/** + * wake_up_lock_sleeper - Wake up a specific process blocked on a "sleeping lock" + * @p: The process to be woken up. + * + * Same as wake_up_process() above, but wake_flags=WF_LOCK_SLEEPER to indicate + * the nature of the wakeup. + */ +int wake_up_lock_sleeper(struct task_struct *p) +{ + return try_to_wake_up(p, TASK_UNINTERRUPTIBLE, WF_LOCK_SLEEPER); +} + int wake_up_state(struct task_struct *p, unsigned int state) { return try_to_wake_up(p, state, 0); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2464 @ int sched_fork(unsigned long clone_flags p->on_cpu = 0; #endif init_task_preempt_count(p); +#ifdef CONFIG_HAVE_PREEMPT_LAZY + task_thread_info(p)->preempt_lazy_count = 0; +#endif #ifdef CONFIG_SMP plist_node_init(&p->pushable_tasks, MAX_PRIO); RB_CLEAR_NODE(&p->pushable_dl_tasks); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2507 @ void wake_up_new_task(struct task_struct #ifdef CONFIG_SMP /* * Fork balancing, do it here and not earlier because: - * - cpus_allowed can change in the fork path + * - cpus_ptr can change in the fork path * - any previously selected CPU might disappear through hotplug * * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2795 @ static struct rq *finish_task_switch(str * provided by mmdrop(), * - a sync_core for SYNC_CORE. */ + /* + * We use mmdrop_delayed() here so we don't have to do the + * full __mmdrop() when we are the last user. + */ if (mm) { membarrier_mm_sync_core_before_usermode(mm); - mmdrop(mm); + mmdrop_delayed(mm); } if (unlikely(prev_state == TASK_DEAD)) { if (prev->sched_class->task_dead) prev->sched_class->task_dead(prev); - /* - * Remove function-return probe instances associated with this - * task and put them back on the free list. - */ - kprobe_flush_task(prev); - - /* Task is done with its stack. */ - put_task_stack(prev); - put_task_struct(prev); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3521 @ static void __sched notrace __schedule(b atomic_inc(&rq->nr_iowait); delayacct_blkio_start(); } - - /* - * If a worker went to sleep, notify and ask workqueue - * whether it wants to wake up a task to maintain - * concurrency. - */ - if (prev->flags & PF_WQ_WORKER) { - struct task_struct *to_wakeup; - - to_wakeup = wq_worker_sleeping(prev); - if (to_wakeup) - try_to_wake_up_local(to_wakeup, &rf); - } } switch_count = &prev->nvcsw; } next = pick_next_task(rq, prev, &rf); clear_tsk_need_resched(prev); + clear_tsk_need_resched_lazy(prev); clear_preempt_need_resched(); if (likely(prev != next)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3579 @ void __noreturn do_task_dead(void) static inline void sched_submit_work(struct task_struct *tsk) { - if (!tsk->state || tsk_is_pi_blocked(tsk)) + if (!tsk->state) + return; + + /* + * If a worker went to sleep, notify and ask workqueue whether + * it wants to wake up a task to maintain concurrency. + * As this function is called inside the schedule() context, + * we disable preemption to avoid it calling schedule() again + * in the possible wakeup of a kworker. + */ + if (tsk->flags & PF_WQ_WORKER) { + preempt_disable(); + wq_worker_sleeping(tsk); + preempt_enable_no_resched(); + } + + if (tsk_is_pi_blocked(tsk)) return; + /* * If we are going to sleep and we have plugged IO queued, * make sure to submit it to avoid deadlocks. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3606 @ static inline void sched_submit_work(str blk_schedule_flush_plug(tsk); } +static void sched_update_worker(struct task_struct *tsk) +{ + if (tsk->flags & PF_WQ_WORKER) + wq_worker_running(tsk); +} + asmlinkage __visible void __sched schedule(void) { struct task_struct *tsk = current; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3622 @ asmlinkage __visible void __sched schedu __schedule(false); sched_preempt_enable_no_resched(); } while (need_resched()); + sched_update_worker(tsk); } EXPORT_SYMBOL(schedule); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3711 @ static void __sched notrace preempt_sche } while (need_resched()); } +#ifdef CONFIG_PREEMPT_LAZY +/* + * If TIF_NEED_RESCHED is then we allow to be scheduled away since this is + * set by a RT task. Oterwise we try to avoid beeing scheduled out as long as + * preempt_lazy_count counter >0. + */ +static __always_inline int preemptible_lazy(void) +{ + if (test_thread_flag(TIF_NEED_RESCHED)) + return 1; + if (current_thread_info()->preempt_lazy_count) + return 0; + return 1; +} + +#else + +static inline int preemptible_lazy(void) +{ + return 1; +} + +#endif + #ifdef CONFIG_PREEMPT /* * this is the entry point to schedule() from in-kernel preemption @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3749 @ asmlinkage __visible void __sched notrac */ if (likely(!preemptible())) return; - + if (!preemptible_lazy()) + return; preempt_schedule_common(); } NOKPROBE_SYMBOL(preempt_schedule); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3777 @ asmlinkage __visible void __sched notrac if (likely(!preemptible())) return; + if (!preemptible_lazy()) + return; + do { /* * Because the function tracer can trace preempt_count_sub() @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4408 @ change: * the entire root_domain to become SCHED_DEADLINE. We * will also fail if there's no bandwidth available. */ - if (!cpumask_subset(span, &p->cpus_allowed) || + if (!cpumask_subset(span, p->cpus_ptr) || rq->rd->dl_bw.bw == 0) { task_rq_unlock(rq, p, &rf); return -EPERM; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5007 @ long sched_getaffinity(pid_t pid, struct goto out_unlock; raw_spin_lock_irqsave(&p->pi_lock, flags); - cpumask_and(mask, &p->cpus_allowed, cpu_active_mask); + cpumask_and(mask, &p->cpus_mask, cpu_active_mask); raw_spin_unlock_irqrestore(&p->pi_lock, flags); out_unlock: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5546 @ void init_idle(struct task_struct *idle, /* Set the preempt count _outside_ the spinlocks! */ init_idle_preempt_count(idle, cpu); - +#ifdef CONFIG_HAVE_PREEMPT_LAZY + task_thread_info(idle)->preempt_lazy_count = 0; +#endif /* * The idle tasks have their own, simple scheduling class: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5587 @ int task_can_attach(struct task_struct * * allowed nodes is unnecessary. Thus, cpusets are not * applicable for such threads. This prevents checking for * success of set_cpus_allowed_ptr() on all attached tasks - * before cpus_allowed may be changed. + * before cpus_mask may be changed. */ if (p->flags & PF_NO_SETAFFINITY) { ret = -EINVAL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5614 @ int migrate_task_to(struct task_struct * if (curr_cpu == target_cpu) return 0; - if (!cpumask_test_cpu(target_cpu, &p->cpus_allowed)) + if (!cpumask_test_cpu(target_cpu, p->cpus_ptr)) return -EINVAL; /* TODO: This is not properly updating schedstats */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5653 @ void sched_setnuma(struct task_struct *p #endif /* CONFIG_NUMA_BALANCING */ #ifdef CONFIG_HOTPLUG_CPU +static DEFINE_PER_CPU(struct mm_struct *, idle_last_mm); + /* * Ensure that the idle task is using init_mm right before its CPU goes * offline. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5670 @ void idle_task_exit(void) current->active_mm = &init_mm; finish_arch_post_lock_switch(); } - mmdrop(mm); + /* + * Defer the cleanup to an alive cpu. On RT we can neither + * call mmdrop() nor mmdrop_delayed() from here. + */ + per_cpu(idle_last_mm, smp_processor_id()) = mm; } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5758 @ static void migrate_tasks(struct rq *dea put_prev_task(rq, next); /* - * Rules for changing task_struct::cpus_allowed are holding + * Rules for changing task_struct::cpus_mask are holding * both pi_lock and rq->lock, such that holding either * stabilizes the mask. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5986 @ int sched_cpu_dying(unsigned int cpu) update_max_interval(); nohz_balance_exit_idle(rq); hrtick_clear(rq); + if (per_cpu(idle_last_mm, cpu)) { + mmdrop_delayed(per_cpu(idle_last_mm, cpu)); + per_cpu(idle_last_mm, cpu) = NULL; + } return 0; } #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6226 @ void __init sched_init(void) #ifdef CONFIG_DEBUG_ATOMIC_SLEEP static inline int preempt_count_equals(int preempt_offset) { - int nested = preempt_count() + rcu_preempt_depth(); + int nested = preempt_count() + sched_rcu_preempt_depth(); return (nested == preempt_offset); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:7212 @ const u32 sched_prio_to_wmult[40] = { }; #undef CREATE_TRACE_POINTS + +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) + +static inline void +update_nr_migratory(struct task_struct *p, long delta) +{ + if (unlikely((p->sched_class == &rt_sched_class || + p->sched_class == &dl_sched_class) && + p->nr_cpus_allowed > 1)) { + if (p->sched_class == &rt_sched_class) + task_rq(p)->rt.rt_nr_migratory += delta; + else + task_rq(p)->dl.dl_nr_migratory += delta; + } +} + +static inline void +migrate_disable_update_cpus_allowed(struct task_struct *p) +{ + struct rq *rq; + struct rq_flags rf; + + p->cpus_ptr = cpumask_of(smp_processor_id()); + + rq = task_rq_lock(p, &rf); + update_nr_migratory(p, -1); + p->nr_cpus_allowed = 1; + task_rq_unlock(rq, p, &rf); +} + +static inline void +migrate_enable_update_cpus_allowed(struct task_struct *p) +{ + struct rq *rq; + struct rq_flags rf; + + p->cpus_ptr = &p->cpus_mask; + + rq = task_rq_lock(p, &rf); + p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask); + update_nr_migratory(p, 1); + task_rq_unlock(rq, p, &rf); +} + +void migrate_disable(void) +{ + struct task_struct *p = current; + + if (in_atomic() || irqs_disabled()) { +#ifdef CONFIG_SCHED_DEBUG + p->migrate_disable_atomic++; +#endif + return; + } +#ifdef CONFIG_SCHED_DEBUG + if (unlikely(p->migrate_disable_atomic)) { + tracing_off(); + WARN_ON_ONCE(1); + } +#endif + + if (p->migrate_disable) { + p->migrate_disable++; + return; + } + + preempt_disable(); + preempt_lazy_disable(); + pin_current_cpu(); + + migrate_disable_update_cpus_allowed(p); + p->migrate_disable = 1; + + preempt_enable(); +} +EXPORT_SYMBOL(migrate_disable); + +void migrate_enable(void) +{ + struct task_struct *p = current; + + if (in_atomic() || irqs_disabled()) { +#ifdef CONFIG_SCHED_DEBUG + p->migrate_disable_atomic--; +#endif + return; + } + +#ifdef CONFIG_SCHED_DEBUG + if (unlikely(p->migrate_disable_atomic)) { + tracing_off(); + WARN_ON_ONCE(1); + } +#endif + + WARN_ON_ONCE(p->migrate_disable <= 0); + if (p->migrate_disable > 1) { + p->migrate_disable--; + return; + } + + preempt_disable(); + + p->migrate_disable = 0; + migrate_enable_update_cpus_allowed(p); + + if (p->migrate_disable_update) { + struct rq *rq; + struct rq_flags rf; + + rq = task_rq_lock(p, &rf); + update_rq_clock(rq); + + __do_set_cpus_allowed_tail(p, &p->cpus_mask); + task_rq_unlock(rq, p, &rf); + + p->migrate_disable_update = 0; + + WARN_ON(smp_processor_id() != task_cpu(p)); + if (!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) { + const struct cpumask *cpu_valid_mask = cpu_active_mask; + struct migration_arg arg; + unsigned int dest_cpu; + + if (p->flags & PF_KTHREAD) { + /* + * Kernel threads are allowed on online && !active CPUs + */ + cpu_valid_mask = cpu_online_mask; + } + dest_cpu = cpumask_any_and(cpu_valid_mask, &p->cpus_mask); + arg.task = p; + arg.dest_cpu = dest_cpu; + + unpin_current_cpu(); + preempt_lazy_enable(); + preempt_enable(); + stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); + tlb_migrate_finish(p->mm); + + return; + } + } + unpin_current_cpu(); + preempt_lazy_enable(); + preempt_enable(); +} +EXPORT_SYMBOL(migrate_enable); + +#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) +void migrate_disable(void) +{ +#ifdef CONFIG_SCHED_DEBUG + struct task_struct *p = current; + + if (in_atomic() || irqs_disabled()) { + p->migrate_disable_atomic++; + return; + } + + if (unlikely(p->migrate_disable_atomic)) { + tracing_off(); + WARN_ON_ONCE(1); + } + + p->migrate_disable++; +#endif + barrier(); +} +EXPORT_SYMBOL(migrate_disable); + +void migrate_enable(void) +{ +#ifdef CONFIG_SCHED_DEBUG + struct task_struct *p = current; + + if (in_atomic() || irqs_disabled()) { + p->migrate_disable_atomic--; + return; + } + + if (unlikely(p->migrate_disable_atomic)) { + tracing_off(); + WARN_ON_ONCE(1); + } + + WARN_ON_ONCE(p->migrate_disable <= 0); + p->migrate_disable--; +#endif + barrier(); +} +EXPORT_SYMBOL(migrate_enable); +#endif Index: linux-5.0.19-rt11/kernel/sched/cpudeadline.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/cpudeadline.c +++ linux-5.0.19-rt11/kernel/sched/cpudeadline.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:127 @ int cpudl_find(struct cpudl *cp, struct const struct sched_dl_entity *dl_se = &p->dl; if (later_mask && - cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) { + cpumask_and(later_mask, cp->free_cpus, p->cpus_ptr)) { return 1; } else { int best_cpu = cpudl_maximum(cp); WARN_ON(best_cpu != -1 && !cpu_present(best_cpu)); - if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) && + if (cpumask_test_cpu(best_cpu, p->cpus_ptr) && dl_time_before(dl_se->deadline, cp->elements[0].dl)) { if (later_mask) cpumask_set_cpu(best_cpu, later_mask); Index: linux-5.0.19-rt11/kernel/sched/cpupri.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/cpupri.c +++ linux-5.0.19-rt11/kernel/sched/cpupri.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:101 @ int cpupri_find(struct cpupri *cp, struc if (skip) continue; - if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids) + if (cpumask_any_and(p->cpus_ptr, vec->mask) >= nr_cpu_ids) continue; if (lowest_mask) { - cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask); + cpumask_and(lowest_mask, p->cpus_ptr, vec->mask); /* * We have to ensure that we have at least one bit Index: linux-5.0.19-rt11/kernel/sched/deadline.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/deadline.c +++ linux-5.0.19-rt11/kernel/sched/deadline.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:541 @ static struct rq *dl_task_offline_migrat * If we cannot preempt any rq, fall back to pick any * online CPU: */ - cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed); + cpu = cpumask_any_and(cpu_active_mask, p->cpus_ptr); if (cpu >= nr_cpu_ids) { /* * Failed to find any suitable CPU. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1056 @ void init_dl_task_timer(struct sched_dl_ { struct hrtimer *timer = &dl_se->dl_timer; - hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); timer->function = dl_task_timer; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1827 @ static void set_curr_task_dl(struct rq * static int pick_dl_task(struct rq *rq, struct task_struct *p, int cpu) { if (!task_running(rq, p) && - cpumask_test_cpu(cpu, &p->cpus_allowed)) + cpumask_test_cpu(cpu, p->cpus_ptr)) return 1; return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1977 @ static struct rq *find_lock_later_rq(str /* Retry if something changed. */ if (double_lock_balance(rq, later_rq)) { if (unlikely(task_rq(task) != rq || - !cpumask_test_cpu(later_rq->cpu, &task->cpus_allowed) || + !cpumask_test_cpu(later_rq->cpu, task->cpus_ptr) || task_running(rq, task) || !dl_task(task) || !task_on_rq_queued(task))) { Index: linux-5.0.19-rt11/kernel/sched/debug.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/debug.c +++ linux-5.0.19-rt11/kernel/sched/debug.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:985 @ void proc_sched_show_task(struct task_st P(dl.runtime); P(dl.deadline); } +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE) + P(migrate_disable); +#endif + P(nr_cpus_allowed); #undef PN_SCHEDSTAT #undef PN #undef __PN Index: linux-5.0.19-rt11/kernel/sched/fair.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/fair.c +++ linux-5.0.19-rt11/kernel/sched/fair.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1611 @ static void task_numa_compare(struct tas * be incurred if the tasks were swapped. */ /* Skip this swap candidate if cannot move to the source cpu */ - if (!cpumask_test_cpu(env->src_cpu, &cur->cpus_allowed)) + if (!cpumask_test_cpu(env->src_cpu, cur->cpus_ptr)) goto unlock; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1708 @ static void task_numa_find_cpu(struct ta for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) { /* Skip this CPU if the source task cannot migrate */ - if (!cpumask_test_cpu(cpu, &env->p->cpus_allowed)) + if (!cpumask_test_cpu(cpu, env->p->cpus_ptr)) continue; env->dst_cpu = cpu; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4036 @ check_preempt_tick(struct cfs_rq *cfs_rq ideal_runtime = sched_slice(cfs_rq, curr); delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; if (delta_exec > ideal_runtime) { - resched_curr(rq_of(cfs_rq)); + resched_curr_lazy(rq_of(cfs_rq)); /* * The current task ran long enough, ensure it doesn't get * re-elected due to buddy favours. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4060 @ check_preempt_tick(struct cfs_rq *cfs_rq return; if (delta > ideal_runtime) - resched_curr(rq_of(cfs_rq)); + resched_curr_lazy(rq_of(cfs_rq)); } static void @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4202 @ entity_tick(struct cfs_rq *cfs_rq, struc * validating it and just reschedule. */ if (queued) { - resched_curr(rq_of(cfs_rq)); + resched_curr_lazy(rq_of(cfs_rq)); return; } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4386 @ static void __account_cfs_rq_runtime(str * hierarchy can be throttled */ if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr)) - resched_curr(rq_of(cfs_rq)); + resched_curr_lazy(rq_of(cfs_rq)); } static __always_inline @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4572 @ static u64 distribute_cfs_runtime(struct struct rq *rq = rq_of(cfs_rq); struct rq_flags rf; - rq_lock(rq, &rf); + rq_lock_irqsave(rq, &rf); if (!cfs_rq_throttled(cfs_rq)) goto next; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4589 @ static u64 distribute_cfs_runtime(struct unthrottle_cfs_rq(cfs_rq); next: - rq_unlock(rq, &rf); + rq_unlock_irqrestore(rq, &rf); if (!remaining) break; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4605 @ next: * period the timer is deactivated until scheduling resumes; cfs_b->idle is * used to track this state. */ -static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) +static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, unsigned long flags) { u64 runtime, runtime_expires; int throttled; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4647 @ static int do_sched_cfs_period_timer(str while (throttled && cfs_b->runtime > 0 && !cfs_b->distribute_running) { runtime = cfs_b->runtime; cfs_b->distribute_running = 1; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); /* we can't nest cfs_b->lock while distributing bandwidth */ runtime = distribute_cfs_runtime(cfs_b, runtime, runtime_expires); - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); cfs_b->distribute_running = 0; throttled = !list_empty(&cfs_b->throttled_cfs_rq); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4760 @ static __always_inline void return_cfs_r static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b) { u64 runtime = 0, slice = sched_cfs_bandwidth_slice(); + unsigned long flags; u64 expires; /* confirm we're still not at a refresh boundary */ - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); if (cfs_b->distribute_running) { - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); return; } if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) { - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); return; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4782 @ static void do_sched_cfs_slack_timer(str if (runtime) cfs_b->distribute_running = 1; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); if (!runtime) return; runtime = distribute_cfs_runtime(cfs_b, runtime, expires); - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); if (expires == cfs_b->runtime_expires) lsub_positive(&cfs_b->runtime, runtime); cfs_b->distribute_running = 0; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4873 @ static enum hrtimer_restart sched_cfs_pe { struct cfs_bandwidth *cfs_b = container_of(timer, struct cfs_bandwidth, period_timer); + unsigned long flags; int overrun; int idle = 0; int count = 0; - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); for (;;) { overrun = hrtimer_forward_now(timer, cfs_b->period); if (!overrun) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4906 @ static enum hrtimer_restart sched_cfs_pe count = 0; } - idle = do_sched_cfs_period_timer(cfs_b, overrun); + idle = do_sched_cfs_period_timer(cfs_b, overrun, flags); } if (idle) cfs_b->period_active = 0; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5082 @ static void hrtick_start_fair(struct rq if (delta < 0) { if (rq->curr == p) - resched_curr(rq); + resched_curr_lazy(rq); return; } hrtick_start(rq, delta); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5792 @ find_idlest_group(struct sched_domain *s /* Skip over this group if it has no CPUs allowed */ if (!cpumask_intersects(sched_group_span(group), - &p->cpus_allowed)) + p->cpus_ptr)) continue; local_group = cpumask_test_cpu(this_cpu, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5924 @ find_idlest_group_cpu(struct sched_group return cpumask_first(sched_group_span(group)); /* Traverse only the allowed CPUs */ - for_each_cpu_and(i, sched_group_span(group), &p->cpus_allowed) { + for_each_cpu_and(i, sched_group_span(group), p->cpus_ptr) { if (available_idle_cpu(i)) { struct rq *rq = cpu_rq(i); struct cpuidle_state *idle = idle_get_state(rq); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5964 @ static inline int find_idlest_cpu(struct { int new_cpu = cpu; - if (!cpumask_intersects(sched_domain_span(sd), &p->cpus_allowed)) + if (!cpumask_intersects(sched_domain_span(sd), p->cpus_ptr)) return prev_cpu; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6081 @ static int select_idle_core(struct task_ if (!test_idle_cores(target, false)) return -1; - cpumask_and(cpus, sched_domain_span(sd), &p->cpus_allowed); + cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); for_each_cpu_wrap(core, cpus, target) { bool idle = true; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6115 @ static int select_idle_smt(struct task_s return -1; for_each_cpu(cpu, cpu_smt_mask(target)) { - if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) + if (!cpumask_test_cpu(cpu, p->cpus_ptr)) continue; if (available_idle_cpu(cpu)) return cpu; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6178 @ static int select_idle_cpu(struct task_s for_each_cpu_wrap(cpu, sched_domain_span(sd), target) { if (!--nr) return -1; - if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) + if (!cpumask_test_cpu(cpu, p->cpus_ptr)) continue; if (available_idle_cpu(cpu)) break; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6215 @ static int select_idle_sibling(struct ta recent_used_cpu != target && cpus_share_cache(recent_used_cpu, target) && available_idle_cpu(recent_used_cpu) && - cpumask_test_cpu(p->recent_used_cpu, &p->cpus_allowed)) { + cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr)) { /* * Replace recent_used_cpu with prev as it is a potential * candidate for the next wake: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6561 @ static int find_energy_efficient_cpu(str int max_spare_cap_cpu = -1; for_each_cpu_and(cpu, perf_domain_span(pd), sched_domain_span(sd)) { - if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) + if (!cpumask_test_cpu(cpu, p->cpus_ptr)) continue; /* Skip CPUs that will be overutilized. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6650 @ select_task_rq_fair(struct task_struct * } want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) && - cpumask_test_cpu(cpu, &p->cpus_allowed); + cpumask_test_cpu(cpu, p->cpus_ptr); } rcu_read_lock(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6911 @ static void check_preempt_wakeup(struct return; preempt: - resched_curr(rq); + resched_curr_lazy(rq); /* * Only set the backward buddy when the current task is still * on the rq. This can happen when a wakeup gets interleaved @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:7400 @ int can_migrate_task(struct task_struct /* * We do not migrate tasks that are: * 1) throttled_lb_pair, or - * 2) cannot be migrated to this CPU due to cpus_allowed, or + * 2) cannot be migrated to this CPU due to cpus_ptr, or * 3) running (obviously), or * 4) are cache-hot on their current CPU. */ if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu)) return 0; - if (!cpumask_test_cpu(env->dst_cpu, &p->cpus_allowed)) { + if (!cpumask_test_cpu(env->dst_cpu, p->cpus_ptr)) { int cpu; schedstat_inc(p->se.statistics.nr_failed_migrations_affine); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:7427 @ int can_migrate_task(struct task_struct /* Prevent to re-select dst_cpu via env's CPUs: */ for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) { - if (cpumask_test_cpu(cpu, &p->cpus_allowed)) { + if (cpumask_test_cpu(cpu, p->cpus_ptr)) { env->flags |= LBF_DST_PINNED; env->new_dst_cpu = cpu; break; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8024 @ check_cpu_capacity(struct rq *rq, struct /* * Group imbalance indicates (and tries to solve) the problem where balancing - * groups is inadequate due to ->cpus_allowed constraints. + * groups is inadequate due to ->cpus_ptr constraints. * * Imagine a situation of two groups of 4 CPUs each and 4 tasks each with a * cpumask covering 1 CPU of the first group and 3 CPUs of the second group. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8695 @ static struct sched_group *find_busiest_ /* * If the busiest group is imbalanced the below checks don't * work because they assume all things are equal, which typically - * isn't true due to cpus_allowed constraints and the like. + * isn't true due to cpus_ptr constraints and the like. */ if (busiest->group_type == group_imbalanced) goto force_balance; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:9123 @ more_balance: * if the curr task on busiest CPU can't be * moved to this_cpu: */ - if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { + if (!cpumask_test_cpu(this_cpu, busiest->curr->cpus_ptr)) { raw_spin_unlock_irqrestore(&busiest->lock, flags); env.flags |= LBF_ALL_PINNED; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:10111 @ static void task_fork_fair(struct task_s * 'current' within the tree based on its new key value. */ swap(curr->vruntime, se->vruntime); - resched_curr(rq); + resched_curr_lazy(rq); } se->vruntime -= cfs_rq->min_vruntime; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:10135 @ prio_changed_fair(struct rq *rq, struct */ if (rq->curr == p) { if (p->prio > oldprio) - resched_curr(rq); + resched_curr_lazy(rq); } else check_preempt_curr(rq, p, 0); } Index: linux-5.0.19-rt11/kernel/sched/features.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/features.h +++ linux-5.0.19-rt11/kernel/sched/features.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:49 @ SCHED_FEAT(LB_BIAS, false) */ SCHED_FEAT(NONTASK_CAPACITY, true) +#ifdef CONFIG_PREEMPT_RT_FULL +SCHED_FEAT(TTWU_QUEUE, false) +# ifdef CONFIG_PREEMPT_LAZY +SCHED_FEAT(PREEMPT_LAZY, true) +# endif +#else + /* * Queue remote wakeups on the target CPU and process them * using the scheduler IPI. Reduces rq->lock contention/bounces. */ SCHED_FEAT(TTWU_QUEUE, true) +#endif /* * When doing wakeups, attempt to limit superfluous scans of the LLC domain. Index: linux-5.0.19-rt11/kernel/sched/rt.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/rt.c +++ linux-5.0.19-rt11/kernel/sched/rt.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:48 @ void init_rt_bandwidth(struct rt_bandwid raw_spin_lock_init(&rt_b->rt_runtime_lock); - hrtimer_init(&rt_b->rt_period_timer, - CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_HARD); rt_b->rt_period_timer.function = sched_rt_period_timer; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1617 @ static void put_prev_task_rt(struct rq * static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) { if (!task_running(rq, p) && - cpumask_test_cpu(cpu, &p->cpus_allowed)) + cpumask_test_cpu(cpu, p->cpus_ptr)) return 1; return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1754 @ static struct rq *find_lock_lowest_rq(st * Also make sure that it wasn't scheduled on its rq. */ if (unlikely(task_rq(task) != rq || - !cpumask_test_cpu(lowest_rq->cpu, &task->cpus_allowed) || + !cpumask_test_cpu(lowest_rq->cpu, task->cpus_ptr) || task_running(rq, task) || !rt_task(task) || !task_on_rq_queued(task))) { Index: linux-5.0.19-rt11/kernel/sched/sched.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/sched.h +++ linux-5.0.19-rt11/kernel/sched/sched.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1575 @ static inline int task_on_rq_migrating(s #define WF_SYNC 0x01 /* Waker goes to sleep after wakeup */ #define WF_FORK 0x02 /* Child wakeup after fork */ #define WF_MIGRATED 0x4 /* Internal use, task got migrated */ +#define WF_LOCK_SLEEPER 0x08 /* wakeup spinlock "sleeper" */ /* * To aid in avoiding the subversion of "niceness" due to uneven distribution @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1770 @ extern void reweight_task(struct task_st extern void resched_curr(struct rq *rq); extern void resched_cpu(int cpu); +#ifdef CONFIG_PREEMPT_LAZY +extern void resched_curr_lazy(struct rq *rq); +#else +static inline void resched_curr_lazy(struct rq *rq) +{ + resched_curr(rq); +} +#endif + extern struct rt_bandwidth def_rt_bandwidth; extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); Index: linux-5.0.19-rt11/kernel/sched/swait.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/swait.c +++ linux-5.0.19-rt11/kernel/sched/swait.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:35 @ void swake_up_locked(struct swait_queue_ } EXPORT_SYMBOL(swake_up_locked); +void swake_up_all_locked(struct swait_queue_head *q) +{ + struct swait_queue *curr; + int wakes = 0; + + while (!list_empty(&q->task_list)) { + + curr = list_first_entry(&q->task_list, typeof(*curr), + task_list); + wake_up_process(curr->task); + list_del_init(&curr->task_list); + wakes++; + } + if (pm_in_action) + return; + WARN(wakes > 2, "complete_all() with %d waiters\n", wakes); +} +EXPORT_SYMBOL(swake_up_all_locked); + void swake_up_one(struct swait_queue_head *q) { unsigned long flags; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:73 @ void swake_up_all(struct swait_queue_hea struct swait_queue *curr; LIST_HEAD(tmp); + WARN_ON(irqs_disabled()); raw_spin_lock_irq(&q->lock); list_splice_init(&q->task_list, &tmp); while (!list_empty(&tmp)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:92 @ void swake_up_all(struct swait_queue_hea } EXPORT_SYMBOL(swake_up_all); -static void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait) +void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait) { wait->task = current; if (list_empty(&wait->task_list)) Index: linux-5.0.19-rt11/kernel/sched/topology.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/sched/topology.c +++ linux-5.0.19-rt11/kernel/sched/topology.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:476 @ static int init_rootdomain(struct root_d rd->rto_cpu = -1; raw_spin_lock_init(&rd->rto_lock); init_irq_work(&rd->rto_push_work, rto_push_irq_work_func); + rd->rto_push_work.flags |= IRQ_WORK_HARD_IRQ; #endif init_dl_bw(&rd->dl_bw); Index: linux-5.0.19-rt11/kernel/signal.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/signal.c +++ linux-5.0.19-rt11/kernel/signal.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:22 @ #include <linux/sched/task.h> #include <linux/sched/task_stack.h> #include <linux/sched/cputime.h> +#include <linux/sched/rt.h> #include <linux/fs.h> #include <linux/tty.h> #include <linux/binfmts.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:397 @ void task_join_group_stop(struct task_st } } +static inline struct sigqueue *get_task_cache(struct task_struct *t) +{ + struct sigqueue *q = t->sigqueue_cache; + + if (cmpxchg(&t->sigqueue_cache, q, NULL) != q) + return NULL; + return q; +} + +static inline int put_task_cache(struct task_struct *t, struct sigqueue *q) +{ + if (cmpxchg(&t->sigqueue_cache, NULL, q) == NULL) + return 0; + return 1; +} + /* * allocate a new signal queue record * - this may be called without locks if and only if t == current, otherwise an * appropriate lock must be held to stop the target task from exiting */ static struct sigqueue * -__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit) +__sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags, + int override_rlimit, int fromslab) { struct sigqueue *q = NULL; struct user_struct *user; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:437 @ __sigqueue_alloc(int sig, struct task_st if (override_rlimit || atomic_read(&user->sigpending) <= task_rlimit(t, RLIMIT_SIGPENDING)) { - q = kmem_cache_alloc(sigqueue_cachep, flags); + if (!fromslab) + q = get_task_cache(t); + if (!q) + q = kmem_cache_alloc(sigqueue_cachep, flags); } else { print_dropped_signal(sig); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:457 @ __sigqueue_alloc(int sig, struct task_st return q; } +static struct sigqueue * +__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, + int override_rlimit) +{ + return __sigqueue_do_alloc(sig, t, flags, override_rlimit, 0); +} + static void __sigqueue_free(struct sigqueue *q) { if (q->flags & SIGQUEUE_PREALLOC) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:473 @ static void __sigqueue_free(struct sigqu kmem_cache_free(sigqueue_cachep, q); } +static void sigqueue_free_current(struct sigqueue *q) +{ + struct user_struct *up; + + if (q->flags & SIGQUEUE_PREALLOC) + return; + + up = q->user; + if (rt_prio(current->normal_prio) && !put_task_cache(current, q)) { + atomic_dec(&up->sigpending); + free_uid(up); + } else + __sigqueue_free(q); +} + void flush_sigqueue(struct sigpending *queue) { struct sigqueue *q; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:501 @ void flush_sigqueue(struct sigpending *q } /* + * Called from __exit_signal. Flush tsk->pending and + * tsk->sigqueue_cache + */ +void flush_task_sigqueue(struct task_struct *tsk) +{ + struct sigqueue *q; + + flush_sigqueue(&tsk->pending); + + q = get_task_cache(tsk); + if (q) + kmem_cache_free(sigqueue_cachep, q); +} + +/* * Flush all pending signals for this kthread. */ void flush_signals(struct task_struct *t) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:639 @ still_pending: (info->si_code == SI_TIMER) && (info->si_sys_private); - __sigqueue_free(first); + sigqueue_free_current(first); } else { /* * Ok, it wasn't in the queue. This must be @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:676 @ int dequeue_signal(struct task_struct *t bool resched_timer = false; int signr; + WARN_ON_ONCE(tsk != current); + /* We only dequeue private signals from ourselves, we don't let * signalfd steal them */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1331 @ int do_send_sig_info(int sig, struct ker * We don't want to have recursive SIGSEGV's etc, for example, * that is why we also clear SIGNAL_UNKILLABLE. */ -int -force_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *t) +static int +do_force_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *t) { unsigned long int flags; int ret, blocked, ignored; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1361 @ force_sig_info(int sig, struct kernel_si return ret; } +int force_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *t) +{ +/* + * On some archs, PREEMPT_RT has to delay sending a signal from a trap + * since it can not enable preemption, and the signal code's spin_locks + * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will + * send the signal on exit of the trap. + */ +#ifdef ARCH_RT_DELAYS_SIGNAL_SEND + if (in_atomic()) { + if (WARN_ON_ONCE(t != current)) + return 0; + if (WARN_ON_ONCE(t->forced_info.si_signo)) + return 0; + + if (is_si_special(info)) { + WARN_ON_ONCE(info != SEND_SIG_PRIV); + t->forced_info.si_signo = sig; + t->forced_info.si_errno = 0; + t->forced_info.si_code = SI_KERNEL; + t->forced_info.si_pid = 0; + t->forced_info.si_uid = 0; + } else { + t->forced_info = *info; + } + + set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); + return 0; + } +#endif + return do_force_sig_info(sig, info, t); +} + /* * Nuke all other threads in the group. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1813 @ EXPORT_SYMBOL(kill_pid); */ struct sigqueue *sigqueue_alloc(void) { - struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0); + /* Preallocated sigqueue objects always from the slabcache ! */ + struct sigqueue *q = __sigqueue_do_alloc(-1, current, GFP_KERNEL, 0, 1); if (q) q->flags |= SIGQUEUE_PREALLOC; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2194 @ static void ptrace_stop(int exit_code, i if (gstop_done && ptrace_reparented(current)) do_notify_parent_cldstop(current, false, why); - /* - * Don't want to allow preemption here, because - * sys_ptrace() needs this task to be inactive. - * - * XXX: implement read_unlock_no_resched(). - */ - preempt_disable(); read_unlock(&tasklist_lock); - preempt_enable_no_resched(); freezable_schedule(); } else { /* Index: linux-5.0.19-rt11/kernel/softirq.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/softirq.c +++ linux-5.0.19-rt11/kernel/softirq.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:29 @ #include <linux/smpboot.h> #include <linux/tick.h> #include <linux/irq.h> +#include <linux/locallock.h> #define CREATE_TRACE_POINTS #include <trace/events/irq.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:106 @ static bool ksoftirqd_running(unsigned l * softirq and whether we just have bh disabled. */ +#ifdef CONFIG_PREEMPT_RT_FULL +static DEFINE_LOCAL_IRQ_LOCK(bh_lock); +static DEFINE_PER_CPU(long, softirq_counter); + +void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) +{ + unsigned long __maybe_unused flags; + long soft_cnt; + + WARN_ON_ONCE(in_irq()); + if (!in_atomic()) + local_lock(bh_lock); + soft_cnt = this_cpu_inc_return(softirq_counter); + WARN_ON_ONCE(soft_cnt == 0); + current->softirq_count += SOFTIRQ_DISABLE_OFFSET; + +#ifdef CONFIG_TRACE_IRQFLAGS + local_irq_save(flags); + if (soft_cnt == 1) + trace_softirqs_off(ip); + local_irq_restore(flags); +#endif +} +EXPORT_SYMBOL(__local_bh_disable_ip); + +static void local_bh_disable_rt(void) +{ + local_bh_disable(); +} + +void _local_bh_enable(void) +{ + unsigned long __maybe_unused flags; + long soft_cnt; + + soft_cnt = this_cpu_dec_return(softirq_counter); + WARN_ON_ONCE(soft_cnt < 0); + +#ifdef CONFIG_TRACE_IRQFLAGS + local_irq_save(flags); + if (soft_cnt == 0) + trace_softirqs_on(_RET_IP_); + local_irq_restore(flags); +#endif + + current->softirq_count -= SOFTIRQ_DISABLE_OFFSET; + if (!in_atomic()) + local_unlock(bh_lock); +} + +void _local_bh_enable_rt(void) +{ + _local_bh_enable(); +} + +void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) +{ + u32 pending; + long count; + + WARN_ON_ONCE(in_irq()); + lockdep_assert_irqs_enabled(); + + local_irq_disable(); + count = this_cpu_read(softirq_counter); + + if (unlikely(count == 1)) { + pending = local_softirq_pending(); + if (pending && !ksoftirqd_running(pending)) { + if (!in_atomic()) + __do_softirq(); + else + wakeup_softirqd(); + } + trace_softirqs_on(ip); + } + count = this_cpu_dec_return(softirq_counter); + WARN_ON_ONCE(count < 0); + local_irq_enable(); + + if (!in_atomic()) + local_unlock(bh_lock); + + current->softirq_count -= SOFTIRQ_DISABLE_OFFSET; + preempt_check_resched(); +} +EXPORT_SYMBOL(__local_bh_enable_ip); + +#else +static void local_bh_disable_rt(void) { } +static void _local_bh_enable_rt(void) { } + /* * This one is for softirq.c-internal use, * where hardirqs are disabled legitimately: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:292 @ void __local_bh_enable_ip(unsigned long preempt_check_resched(); } EXPORT_SYMBOL(__local_bh_enable_ip); +#endif /* * We restart softirq processing for at most MAX_SOFTIRQ_RESTART times, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:363 @ asmlinkage __visible void __softirq_entr pending = local_softirq_pending(); account_irq_enter_time(current); +#ifdef CONFIG_PREEMPT_RT_FULL + current->softirq_count |= SOFTIRQ_OFFSET; +#else __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); +#endif in_hardirq = lockdep_softirq_start(); restart: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:401 @ restart: h++; pending >>= softirq_bit; } - +#ifndef CONFIG_PREEMPT_RT_FULL if (__this_cpu_read(ksoftirqd) == current) rcu_softirq_qs(); +#endif local_irq_disable(); pending = local_softirq_pending(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:418 @ restart: lockdep_softirq_end(in_hardirq); account_irq_exit_time(current); +#ifdef CONFIG_PREEMPT_RT_FULL + current->softirq_count &= ~SOFTIRQ_OFFSET; +#else __local_bh_enable(SOFTIRQ_OFFSET); +#endif WARN_ON_ONCE(in_interrupt()); current_restore_flags(old_flags, PF_MEMALLOC); } +#ifndef CONFIG_PREEMPT_RT_FULL asmlinkage __visible void do_softirq(void) { __u32 pending; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:445 @ asmlinkage __visible void do_softirq(voi local_irq_restore(flags); } +#endif /* * Enter an interrupt context. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:466 @ void irq_enter(void) __irq_enter(); } +#ifdef CONFIG_PREEMPT_RT_FULL + +static inline void invoke_softirq(void) +{ + if (this_cpu_read(softirq_counter) == 0) + wakeup_softirqd(); +} + +#else + static inline void invoke_softirq(void) { if (ksoftirqd_running(local_softirq_pending())) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:501 @ static inline void invoke_softirq(void) wakeup_softirqd(); } } +#endif static inline void tick_irq_exit(void) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:539 @ void irq_exit(void) /* * This function must run with irqs disabled! */ +#ifdef CONFIG_PREEMPT_RT_FULL +void raise_softirq_irqoff(unsigned int nr) +{ + __raise_softirq_irqoff(nr); + + /* + * If we're in an hard interrupt we let irq return code deal + * with the wakeup of ksoftirqd. + */ + if (in_irq()) + return; + /* + * If were are not in BH-disabled section then we have to wake + * ksoftirqd. + */ + if (this_cpu_read(softirq_counter) == 0) + wakeup_softirqd(); +} + +#else + inline void raise_softirq_irqoff(unsigned int nr) { __raise_softirq_irqoff(nr); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:577 @ inline void raise_softirq_irqoff(unsigne wakeup_softirqd(); } +#endif + void raise_softirq(unsigned int nr) { unsigned long flags; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:706 @ void tasklet_kill(struct tasklet_struct while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { do { - yield(); + local_bh_disable(); + local_bh_enable(); } while (test_bit(TASKLET_STATE_SCHED, &t->state)); } tasklet_unlock_wait(t); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:788 @ static int ksoftirqd_should_run(unsigned static void run_ksoftirqd(unsigned int cpu) { + local_bh_disable_rt(); local_irq_disable(); if (local_softirq_pending()) { /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:797 @ static void run_ksoftirqd(unsigned int c */ __do_softirq(); local_irq_enable(); + _local_bh_enable_rt(); cond_resched(); return; } local_irq_enable(); + _local_bh_enable_rt(); } #ifdef CONFIG_HOTPLUG_CPU @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:876 @ static struct smp_hotplug_thread softirq static __init int spawn_ksoftirqd(void) { +#ifdef CONFIG_PREEMPT_RT_FULL + int cpu; + + for_each_possible_cpu(cpu) + lockdep_set_novalidate_class(per_cpu_ptr(&bh_lock.lock, cpu)); +#endif + cpuhp_setup_state_nocalls(CPUHP_SOFTIRQ_DEAD, "softirq:dead", NULL, takeover_tasklets); BUG_ON(smpboot_register_percpu_thread(&softirq_threads)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:891 @ static __init int spawn_ksoftirqd(void) } early_initcall(spawn_ksoftirqd); +#ifdef CONFIG_PREEMPT_RT_FULL + +/* + * On preempt-rt a softirq running context might be blocked on a + * lock. There might be no other runnable task on this CPU because the + * lock owner runs on some other CPU. So we have to go into idle with + * the pending bit set. Therefor we need to check this otherwise we + * warn about false positives which confuses users and defeats the + * whole purpose of this test. + * + * This code is called with interrupts disabled. + */ +void softirq_check_pending_idle(void) +{ + struct task_struct *tsk = __this_cpu_read(ksoftirqd); + static int rate_limit; + bool okay = false; + u32 warnpending; + + if (rate_limit >= 10) + return; + + warnpending = local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK; + if (!warnpending) + return; + + if (!tsk) + return; + /* + * If ksoftirqd is blocked on a lock then we may go idle with pending + * softirq. + */ + raw_spin_lock(&tsk->pi_lock); + if (tsk->pi_blocked_on || tsk->state == TASK_RUNNING || + (tsk->state == TASK_UNINTERRUPTIBLE && tsk->sleeping_lock)) { + okay = true; + } + raw_spin_unlock(&tsk->pi_lock); + if (okay) + return; + /* + * The softirq lock is held in non-atomic context and the owner is + * blocking on a lock. It will schedule softirqs once the counter goes + * back to zero. + */ + if (this_cpu_read(softirq_counter) > 0) + return; + + printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n", + warnpending); + rate_limit++; +} + +#else + +void softirq_check_pending_idle(void) +{ + static int ratelimit; + + if (ratelimit < 10 && + (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) { + pr_warn("NOHZ: local_softirq_pending %02x\n", + (unsigned int) local_softirq_pending()); + ratelimit++; + } +} + +#endif + /* * [ These __weak aliases are kept in a separate compilation unit, so that * GCC does not inline them incorrectly. ] Index: linux-5.0.19-rt11/kernel/time/alarmtimer.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/alarmtimer.c +++ linux-5.0.19-rt11/kernel/time/alarmtimer.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:436 @ int alarm_cancel(struct alarm *alarm) int ret = alarm_try_to_cancel(alarm); if (ret >= 0) return ret; - cpu_relax(); + hrtimer_grab_expiry_lock(&alarm->timer); } } EXPORT_SYMBOL_GPL(alarm_cancel); Index: linux-5.0.19-rt11/kernel/time/hrtimer.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/hrtimer.c +++ linux-5.0.19-rt11/kernel/time/hrtimer.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:933 @ u64 hrtimer_forward(struct hrtimer *time } EXPORT_SYMBOL_GPL(hrtimer_forward); +void hrtimer_grab_expiry_lock(const struct hrtimer *timer) +{ + struct hrtimer_clock_base *base = timer->base; + + if (base && base->cpu_base) { + spin_lock(&base->cpu_base->softirq_expiry_lock); + spin_unlock(&base->cpu_base->softirq_expiry_lock); + } +} + /* * enqueue_hrtimer - internal function to (re)start a timer * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1112 @ void hrtimer_start_range_ns(struct hrtim * Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft * match. */ +#ifndef CONFIG_PREEMPT_RT_BASE WARN_ON_ONCE(!(mode & HRTIMER_MODE_SOFT) ^ !timer->is_soft); +#endif base = lock_hrtimer_base(timer, &flags); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1177 @ int hrtimer_cancel(struct hrtimer *timer if (ret >= 0) return ret; - cpu_relax(); + hrtimer_grab_expiry_lock(timer); } } EXPORT_SYMBOL_GPL(hrtimer_cancel); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1274 @ static inline int hrtimer_clockid_to_bas static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode) { - bool softtimer = !!(mode & HRTIMER_MODE_SOFT); - int base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0; + bool softtimer; + int base; struct hrtimer_cpu_base *cpu_base; + softtimer = !!(mode & HRTIMER_MODE_SOFT); +#ifdef CONFIG_PREEMPT_RT_FULL + if (!softtimer && !(mode & HRTIMER_MODE_HARD)) + softtimer = true; +#endif + base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0; + memset(timer, 0, sizeof(struct hrtimer)); cpu_base = raw_cpu_ptr(&hrtimer_bases); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1481 @ static __latent_entropy void hrtimer_run unsigned long flags; ktime_t now; + spin_lock(&cpu_base->softirq_expiry_lock); raw_spin_lock_irqsave(&cpu_base->lock, flags); now = hrtimer_update_base(cpu_base); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1491 @ static __latent_entropy void hrtimer_run hrtimer_update_softirq_timer(cpu_base, true); raw_spin_unlock_irqrestore(&cpu_base->lock, flags); + spin_unlock(&cpu_base->softirq_expiry_lock); } #ifdef CONFIG_HIGH_RES_TIMERS @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1663 @ static enum hrtimer_restart hrtimer_wake return HRTIMER_NORESTART; } -void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) -{ +static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl, + clockid_t clock_id, + enum hrtimer_mode mode, + struct task_struct *task) +{ +#ifdef CONFIG_PREEMPT_RT_FULL + if (!(mode & (HRTIMER_MODE_SOFT | HRTIMER_MODE_HARD))) { + if (task_is_realtime(current) || system_state != SYSTEM_RUNNING) + mode |= HRTIMER_MODE_HARD; + else + mode |= HRTIMER_MODE_SOFT; + } +#endif + __hrtimer_init(&sl->timer, clock_id, mode); sl->timer.function = hrtimer_wakeup; sl->task = task; } + +/** + * hrtimer_init_sleeper - initialize sleeper to the given clock + * @sl: sleeper to be initialized + * @clock_id: the clock to be used + * @mode: timer mode abs/rel + * @task: the task to wake up + */ +void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id, + enum hrtimer_mode mode, struct task_struct *task) +{ + debug_init(&sl->timer, clock_id, mode); + __hrtimer_init_sleeper(sl, clock_id, mode, task); + +} EXPORT_SYMBOL_GPL(hrtimer_init_sleeper); +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS +void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, + clockid_t clock_id, + enum hrtimer_mode mode, + struct task_struct *task) +{ + debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr); + __hrtimer_init_sleeper(sl, clock_id, mode, task); +} +EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack); +#endif + int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts) { switch(restart->nanosleep.type) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1732 @ static int __sched do_nanosleep(struct h { struct restart_block *restart; - hrtimer_init_sleeper(t, current); - do { set_current_state(TASK_INTERRUPTIBLE); hrtimer_start_expires(&t->timer, mode); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1739 @ static int __sched do_nanosleep(struct h if (likely(t->task)) freezable_schedule(); + __set_current_state(TASK_RUNNING); hrtimer_cancel(&t->timer); mode = HRTIMER_MODE_ABS; } while (t->task && !signal_pending(current)); - __set_current_state(TASK_RUNNING); if (!t->task) return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1768 @ static long __sched hrtimer_nanosleep_re struct hrtimer_sleeper t; int ret; - hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid, - HRTIMER_MODE_ABS); + hrtimer_init_sleeper_on_stack(&t, restart->nanosleep.clockid, + HRTIMER_MODE_ABS, current); hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); - ret = do_nanosleep(&t, HRTIMER_MODE_ABS); destroy_hrtimer_on_stack(&t.timer); return ret; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1788 @ long hrtimer_nanosleep(const struct time if (dl_task(current) || rt_task(current)) slack = 0; - hrtimer_init_on_stack(&t.timer, clockid, mode); + hrtimer_init_sleeper_on_stack(&t, clockid, mode, current); hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack); ret = do_nanosleep(&t, mode); if (ret != -ERESTART_RESTARTBLOCK) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1848 @ COMPAT_SYSCALL_DEFINE2(nanosleep, struct } #endif +#ifdef CONFIG_PREEMPT_RT_FULL +/* + * Sleep for 1 ms in hope whoever holds what we want will let it go. + */ +void cpu_chill(void) +{ + unsigned int freeze_flag = current->flags & PF_NOFREEZE; + struct task_struct *self = current; + ktime_t chill_time; + + raw_spin_lock_irq(&self->pi_lock); + self->saved_state = self->state; + __set_current_state_no_track(TASK_UNINTERRUPTIBLE); + raw_spin_unlock_irq(&self->pi_lock); + + chill_time = ktime_set(0, NSEC_PER_MSEC); + + current->flags |= PF_NOFREEZE; + sleeping_lock_inc(); + schedule_hrtimeout(&chill_time, HRTIMER_MODE_REL_HARD); + sleeping_lock_dec(); + if (!freeze_flag) + current->flags &= ~PF_NOFREEZE; + + raw_spin_lock_irq(&self->pi_lock); + __set_current_state_no_track(self->saved_state); + self->saved_state = TASK_RUNNING; + raw_spin_unlock_irq(&self->pi_lock); +} +EXPORT_SYMBOL(cpu_chill); +#endif + /* * Functions related to boot-time initialization: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1901 @ int hrtimers_prepare_cpu(unsigned int cp cpu_base->softirq_next_timer = NULL; cpu_base->expires_next = KTIME_MAX; cpu_base->softirq_expires_next = KTIME_MAX; + spin_lock_init(&cpu_base->softirq_expiry_lock); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2020 @ schedule_hrtimeout_range_clock(ktime_t * return -EINTR; } - hrtimer_init_on_stack(&t.timer, clock_id, mode); + hrtimer_init_sleeper_on_stack(&t, clock_id, mode, current); hrtimer_set_expires_range_ns(&t.timer, *expires, delta); - hrtimer_init_sleeper(&t, current); - hrtimer_start_expires(&t.timer, mode); if (likely(t.task)) Index: linux-5.0.19-rt11/kernel/time/itimer.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/itimer.c +++ linux-5.0.19-rt11/kernel/time/itimer.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:216 @ again: /* We are sharing ->siglock with it_real_fn() */ if (hrtimer_try_to_cancel(timer) < 0) { spin_unlock_irq(&tsk->sighand->siglock); + hrtimer_grab_expiry_lock(timer); goto again; } expires = timeval_to_ktime(value->it_value); Index: linux-5.0.19-rt11/kernel/time/jiffies.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/jiffies.c +++ linux-5.0.19-rt11/kernel/time/jiffies.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:61 @ static struct clocksource clocksource_ji .max_cycles = 10, }; -__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock); +__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock); +__cacheline_aligned_in_smp seqcount_t jiffies_seq; #if (BITS_PER_LONG < 64) u64 get_jiffies_64(void) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:71 @ u64 get_jiffies_64(void) u64 ret; do { - seq = read_seqbegin(&jiffies_lock); + seq = read_seqcount_begin(&jiffies_seq); ret = jiffies_64; - } while (read_seqretry(&jiffies_lock, seq)); + } while (read_seqcount_retry(&jiffies_seq, seq)); return ret; } EXPORT_SYMBOL(get_jiffies_64); Index: linux-5.0.19-rt11/kernel/time/posix-cpu-timers.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/posix-cpu-timers.c +++ linux-5.0.19-rt11/kernel/time/posix-cpu-timers.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6 @ * Implement CPU time clocks for the POSIX clock interface. */ +#include <uapi/linux/sched/types.h> #include <linux/sched/signal.h> #include <linux/sched/cputime.h> +#include <linux/sched/rt.h> #include <linux/posix-timers.h> #include <linux/errno.h> #include <linux/math64.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:20 @ #include <linux/workqueue.h> #include <linux/compat.h> #include <linux/sched/deadline.h> +#include <linux/smpboot.h> #include "posix-timers.h" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:792 @ check_timers_list(struct list_head *time return t->expires; t->firing = 1; + t->firing_cpu = smp_processor_id(); list_move_tail(&t->entry, firing); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1135 @ static inline int fastpath_timer_check(s return 0; } +static DEFINE_PER_CPU(spinlock_t, cpu_timer_expiry_lock) = __SPIN_LOCK_UNLOCKED(cpu_timer_expiry_lock); + +void cpu_timers_grab_expiry_lock(struct k_itimer *timer) +{ + int cpu = timer->it.cpu.firing_cpu; + + if (cpu >= 0) { + spinlock_t *expiry_lock = per_cpu_ptr(&cpu_timer_expiry_lock, cpu); + + spin_lock_irq(expiry_lock); + spin_unlock_irq(expiry_lock); + } +} + /* * This is called from the timer interrupt handler. The irq handler has * already updated our counts. We need to check if any timers fire now. * Interrupts are disabled. */ -void run_posix_cpu_timers(struct task_struct *tsk) +static void __run_posix_cpu_timers(struct task_struct *tsk) { LIST_HEAD(firing); struct k_itimer *timer, *next; unsigned long flags; - - lockdep_assert_irqs_disabled(); + spinlock_t *expiry_lock; /* * The fast path checks that there are no expired thread or thread @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1168 @ void run_posix_cpu_timers(struct task_st if (!fastpath_timer_check(tsk)) return; + expiry_lock = this_cpu_ptr(&cpu_timer_expiry_lock); + spin_lock(expiry_lock); + if (!lock_task_sighand(tsk, &flags)) return; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1205 @ void run_posix_cpu_timers(struct task_st list_del_init(&timer->it.cpu.entry); cpu_firing = timer->it.cpu.firing; timer->it.cpu.firing = 0; + timer->it.cpu.firing_cpu = -1; /* * The firing flag is -1 if we collided with a reset * of the timer, which already reported this @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1215 @ void run_posix_cpu_timers(struct task_st cpu_timer_fire(timer); spin_unlock(&timer->it_lock); } + spin_unlock(expiry_lock); } +#ifdef CONFIG_PREEMPT_RT_BASE +#include <linux/kthread.h> +#include <linux/cpu.h> +DEFINE_PER_CPU(struct task_struct *, posix_timer_task); +DEFINE_PER_CPU(struct task_struct *, posix_timer_tasklist); +DEFINE_PER_CPU(bool, posix_timer_th_active); + +static void posix_cpu_kthread_fn(unsigned int cpu) +{ + struct task_struct *tsk = NULL; + struct task_struct *next = NULL; + + BUG_ON(per_cpu(posix_timer_task, cpu) != current); + + /* grab task list */ + raw_local_irq_disable(); + tsk = per_cpu(posix_timer_tasklist, cpu); + per_cpu(posix_timer_tasklist, cpu) = NULL; + raw_local_irq_enable(); + + /* its possible the list is empty, just return */ + if (!tsk) + return; + + /* Process task list */ + while (1) { + /* save next */ + next = tsk->posix_timer_list; + + /* run the task timers, clear its ptr and + * unreference it + */ + __run_posix_cpu_timers(tsk); + tsk->posix_timer_list = NULL; + put_task_struct(tsk); + + /* check if this is the last on the list */ + if (next == tsk) + break; + tsk = next; + } +} + +static inline int __fastpath_timer_check(struct task_struct *tsk) +{ + /* tsk == current, ensure it is safe to use ->signal/sighand */ + if (unlikely(tsk->exit_state)) + return 0; + + if (!task_cputime_zero(&tsk->cputime_expires)) + return 1; + + if (!task_cputime_zero(&tsk->signal->cputime_expires)) + return 1; + + return 0; +} + +void run_posix_cpu_timers(struct task_struct *tsk) +{ + unsigned int cpu = smp_processor_id(); + struct task_struct *tasklist; + + BUG_ON(!irqs_disabled()); + + if (per_cpu(posix_timer_th_active, cpu) != true) + return; + + /* get per-cpu references */ + tasklist = per_cpu(posix_timer_tasklist, cpu); + + /* check to see if we're already queued */ + if (!tsk->posix_timer_list && __fastpath_timer_check(tsk)) { + get_task_struct(tsk); + if (tasklist) { + tsk->posix_timer_list = tasklist; + } else { + /* + * The list is terminated by a self-pointing + * task_struct + */ + tsk->posix_timer_list = tsk; + } + per_cpu(posix_timer_tasklist, cpu) = tsk; + + wake_up_process(per_cpu(posix_timer_task, cpu)); + } +} + +static int posix_cpu_kthread_should_run(unsigned int cpu) +{ + return __this_cpu_read(posix_timer_tasklist) != NULL; +} + +static void posix_cpu_kthread_park(unsigned int cpu) +{ + this_cpu_write(posix_timer_th_active, false); +} + +static void posix_cpu_kthread_unpark(unsigned int cpu) +{ + this_cpu_write(posix_timer_th_active, true); +} + +static void posix_cpu_kthread_setup(unsigned int cpu) +{ + struct sched_param sp; + + sp.sched_priority = MAX_RT_PRIO - 1; + sched_setscheduler_nocheck(current, SCHED_FIFO, &sp); + posix_cpu_kthread_unpark(cpu); +} + +static struct smp_hotplug_thread posix_cpu_thread = { + .store = &posix_timer_task, + .thread_should_run = posix_cpu_kthread_should_run, + .thread_fn = posix_cpu_kthread_fn, + .thread_comm = "posixcputmr/%u", + .setup = posix_cpu_kthread_setup, + .park = posix_cpu_kthread_park, + .unpark = posix_cpu_kthread_unpark, +}; + +static int __init posix_cpu_thread_init(void) +{ + /* Start one for boot CPU. */ + unsigned long cpu; + int ret; + + /* init the per-cpu posix_timer_tasklets */ + for_each_possible_cpu(cpu) + per_cpu(posix_timer_tasklist, cpu) = NULL; + + ret = smpboot_register_percpu_thread(&posix_cpu_thread); + WARN_ON(ret); + + return 0; +} +early_initcall(posix_cpu_thread_init); +#else /* CONFIG_PREEMPT_RT_BASE */ +void run_posix_cpu_timers(struct task_struct *tsk) +{ + lockdep_assert_irqs_disabled(); + __run_posix_cpu_timers(tsk); +} +#endif /* CONFIG_PREEMPT_RT_BASE */ + /* * Set one of the process-wide special case CPU timers or RLIMIT_CPU. * The tsk->sighand->siglock must be held by the caller. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1481 @ static int do_cpu_nanosleep(const clocki spin_unlock_irq(&timer.it_lock); while (error == TIMER_RETRY) { + + cpu_timers_grab_expiry_lock(&timer); /* * We need to handle case when timer was or is in the * middle of firing. In other cases we already freed Index: linux-5.0.19-rt11/kernel/time/posix-timers.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/posix-timers.c +++ linux-5.0.19-rt11/kernel/time/posix-timers.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:445 @ static struct k_itimer * alloc_posix_tim static void k_itimer_rcu_free(struct rcu_head *head) { - struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu); + struct k_itimer *tmr = container_of(head, struct k_itimer, rcu); kmem_cache_free(posix_timers_cache, tmr); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:462 @ static void release_posix_timer(struct k } put_pid(tmr->it_pid); sigqueue_free(tmr->sigq); - call_rcu(&tmr->it.rcu, k_itimer_rcu_free); + call_rcu(&tmr->rcu, k_itimer_rcu_free); } static int common_timer_create(struct k_itimer *new_timer) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:808 @ static int common_hrtimer_try_to_cancel( return hrtimer_try_to_cancel(&timr->it.real.timer); } +static void timer_wait_for_callback(const struct k_clock *kc, struct k_itimer *timer) +{ + if (kc->timer_arm == common_hrtimer_arm) + hrtimer_grab_expiry_lock(&timer->it.real.timer); + else if (kc == &alarm_clock) + hrtimer_grab_expiry_lock(&timer->it.alarm.alarmtimer.timer); + else + /* posix-cpu-timers */ + cpu_timers_grab_expiry_lock(timer); +} + /* Set a POSIX.1b interval timer. */ int common_timer_set(struct k_itimer *timr, int flags, struct itimerspec64 *new_setting, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:884 @ retry: else error = kc->timer_set(timr, flags, new_spec64, old_spec64); - unlock_timer(timr, flag); if (error == TIMER_RETRY) { + rcu_read_lock(); + unlock_timer(timr, flag); + timer_wait_for_callback(kc, timr); + rcu_read_unlock(); old_spec64 = NULL; // We already got the old time... goto retry; } + unlock_timer(timr, flag); return error; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:954 @ int common_timer_del(struct k_itimer *ti return 0; } -static inline int timer_delete_hook(struct k_itimer *timer) +static int timer_delete_hook(struct k_itimer *timer) { const struct k_clock *kc = timer->kclock; + int ret; if (WARN_ON_ONCE(!kc || !kc->timer_del)) return -EINVAL; - return kc->timer_del(timer); + ret = kc->timer_del(timer); + if (ret == TIMER_RETRY) { + rcu_read_lock(); + spin_unlock_irq(&timer->it_lock); + timer_wait_for_callback(kc, timer); + rcu_read_unlock(); + } + return ret; } /* Delete a POSIX.1b interval timer. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:982 @ retry_delete: if (!timer) return -EINVAL; - if (timer_delete_hook(timer) == TIMER_RETRY) { - unlock_timer(timer, flags); + if (timer_delete_hook(timer) == TIMER_RETRY) goto retry_delete; - } spin_lock(¤t->sighand->siglock); list_del(&timer->list); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1009 @ static void itimer_delete(struct k_itime retry_delete: spin_lock_irqsave(&timer->it_lock, flags); - if (timer_delete_hook(timer) == TIMER_RETRY) { - unlock_timer(timer, flags); + if (timer_delete_hook(timer) == TIMER_RETRY) goto retry_delete; - } + list_del(&timer->list); /* * This keeps any tasks waiting on the spin lock from thinking Index: linux-5.0.19-rt11/kernel/time/posix-timers.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/posix-timers.h +++ linux-5.0.19-rt11/kernel/time/posix-timers.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:35 @ extern const struct k_clock clock_proces extern const struct k_clock clock_thread; extern const struct k_clock alarm_clock; +extern void cpu_timers_grab_expiry_lock(struct k_itimer *timer); + int posix_timer_event(struct k_itimer *timr, int si_private); void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting); Index: linux-5.0.19-rt11/kernel/time/tick-broadcast-hrtimer.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/tick-broadcast-hrtimer.c +++ linux-5.0.19-rt11/kernel/time/tick-broadcast-hrtimer.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:107 @ static enum hrtimer_restart bc_handler(s void tick_setup_hrtimer_broadcast(void) { - hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); bctimer.function = bc_handler; clockevents_register_device(&ce_broadcast_hrtimer); } Index: linux-5.0.19-rt11/kernel/time/tick-common.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/tick-common.c +++ linux-5.0.19-rt11/kernel/time/tick-common.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:78 @ int tick_is_oneshot_available(void) static void tick_periodic(int cpu) { if (tick_do_timer_cpu == cpu) { - write_seqlock(&jiffies_lock); + raw_spin_lock(&jiffies_lock); + write_seqcount_begin(&jiffies_seq); /* Keep track of the next tick event */ tick_next_period = ktime_add(tick_next_period, tick_period); do_timer(1); - write_sequnlock(&jiffies_lock); + write_seqcount_end(&jiffies_seq); + raw_spin_unlock(&jiffies_lock); update_wall_time(); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:158 @ void tick_setup_periodic(struct clock_ev ktime_t next; do { - seq = read_seqbegin(&jiffies_lock); + seq = read_seqcount_begin(&jiffies_seq); next = tick_next_period; - } while (read_seqretry(&jiffies_lock, seq)); + } while (read_seqcount_retry(&jiffies_seq, seq)); clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT); Index: linux-5.0.19-rt11/kernel/time/tick-sched.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/tick-sched.c +++ linux-5.0.19-rt11/kernel/time/tick-sched.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:67 @ static void tick_do_update_jiffies64(kti return; /* Reevaluate with jiffies_lock held */ - write_seqlock(&jiffies_lock); + raw_spin_lock(&jiffies_lock); + write_seqcount_begin(&jiffies_seq); delta = ktime_sub(now, last_jiffies_update); if (delta >= tick_period) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:91 @ static void tick_do_update_jiffies64(kti /* Keep the tick_next_period variable up to date */ tick_next_period = ktime_add(last_jiffies_update, tick_period); } else { - write_sequnlock(&jiffies_lock); + write_seqcount_end(&jiffies_seq); + raw_spin_unlock(&jiffies_lock); return; } - write_sequnlock(&jiffies_lock); + write_seqcount_end(&jiffies_seq); + raw_spin_unlock(&jiffies_lock); update_wall_time(); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:107 @ static ktime_t tick_init_jiffy_update(vo { ktime_t period; - write_seqlock(&jiffies_lock); + raw_spin_lock(&jiffies_lock); + write_seqcount_begin(&jiffies_seq); /* Did we start the jiffies update yet ? */ if (last_jiffies_update == 0) last_jiffies_update = tick_next_period; period = last_jiffies_update; - write_sequnlock(&jiffies_lock); + write_seqcount_end(&jiffies_seq); + raw_spin_unlock(&jiffies_lock); return period; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:232 @ static void nohz_full_kick_func(struct i static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = { .func = nohz_full_kick_func, + .flags = IRQ_WORK_HARD_IRQ, }; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:658 @ static ktime_t tick_nohz_next_event(stru /* Read jiffies and the time when jiffies were updated last */ do { - seq = read_seqbegin(&jiffies_lock); + seq = read_seqcount_begin(&jiffies_seq); basemono = last_jiffies_update; basejiff = jiffies; - } while (read_seqretry(&jiffies_lock, seq)); + } while (read_seqcount_retry(&jiffies_seq, seq)); ts->last_jiffies = basejiff; ts->timer_expires_base = basemono; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:892 @ static bool can_stop_idle_tick(int cpu, return false; if (unlikely(local_softirq_pending())) { - static int ratelimit; - - if (ratelimit < 10 && - (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) { - pr_warn("NOHZ: local_softirq_pending %02x\n", - (unsigned int) local_softirq_pending()); - ratelimit++; - } + softirq_check_pending_idle(); return false; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1304 @ void tick_setup_sched_timer(void) /* * Emulate tick processing via per-CPU hrtimers: */ - hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); ts->sched_timer.function = tick_sched_timer; /* Get the next period (per-CPU) */ Index: linux-5.0.19-rt11/kernel/time/timekeeping.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/timekeeping.c +++ linux-5.0.19-rt11/kernel/time/timekeeping.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2383 @ EXPORT_SYMBOL(hardpps); */ void xtime_update(unsigned long ticks) { - write_seqlock(&jiffies_lock); + raw_spin_lock(&jiffies_lock); + write_seqcount_begin(&jiffies_seq); do_timer(ticks); - write_sequnlock(&jiffies_lock); + write_seqcount_end(&jiffies_seq); + raw_spin_unlock(&jiffies_lock); update_wall_time(); } Index: linux-5.0.19-rt11/kernel/time/timekeeping.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/timekeeping.h +++ linux-5.0.19-rt11/kernel/time/timekeeping.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:28 @ static inline void sched_clock_resume(vo extern void do_timer(unsigned long ticks); extern void update_wall_time(void); -extern seqlock_t jiffies_lock; +extern raw_spinlock_t jiffies_lock; +extern seqcount_t jiffies_seq; #define CS_NAME_LEN 32 Index: linux-5.0.19-rt11/kernel/time/timer.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/time/timer.c +++ linux-5.0.19-rt11/kernel/time/timer.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:199 @ EXPORT_SYMBOL(jiffies_64); struct timer_base { raw_spinlock_t lock; struct timer_list *running_timer; + spinlock_t expiry_lock; unsigned long clk; unsigned long next_expiry; unsigned int cpu; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1210 @ int del_timer(struct timer_list *timer) } EXPORT_SYMBOL(del_timer); -/** - * try_to_del_timer_sync - Try to deactivate a timer - * @timer: timer to delete - * - * This function tries to deactivate a timer. Upon successful (ret >= 0) - * exit the timer is not queued and the handler is not running on any CPU. - */ -int try_to_del_timer_sync(struct timer_list *timer) +static int __try_to_del_timer_sync(struct timer_list *timer, + struct timer_base **basep) { struct timer_base *base; unsigned long flags; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1219 @ int try_to_del_timer_sync(struct timer_l debug_assert_init(timer); - base = lock_timer_base(timer, &flags); + *basep = base = lock_timer_base(timer, &flags); if (base->running_timer != timer) ret = detach_if_pending(timer, base, true); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1228 @ int try_to_del_timer_sync(struct timer_l return ret; } + +/** + * try_to_del_timer_sync - Try to deactivate a timer + * @timer: timer to delete + * + * This function tries to deactivate a timer. Upon successful (ret >= 0) + * exit the timer is not queued and the handler is not running on any CPU. + */ +int try_to_del_timer_sync(struct timer_list *timer) +{ + struct timer_base *base; + + return __try_to_del_timer_sync(timer, &base); +} EXPORT_SYMBOL(try_to_del_timer_sync); -#ifdef CONFIG_SMP +#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL) +static int __del_timer_sync(struct timer_list *timer) +{ + struct timer_base *base; + int ret; + + for (;;) { + ret = __try_to_del_timer_sync(timer, &base); + if (ret >= 0) + return ret; + + /* + * When accessing the lock, timers of base are no longer expired + * and so timer is no longer running. + */ + spin_lock(&base->expiry_lock); + spin_unlock(&base->expiry_lock); + } +} + /** * del_timer_sync - deactivate a timer and wait for the handler to finish. * @timer: the timer to be deactivated @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1319 @ int del_timer_sync(struct timer_list *ti * could lead to deadlock. */ WARN_ON(in_irq() && !(timer->flags & TIMER_IRQSAFE)); - for (;;) { - int ret = try_to_del_timer_sync(timer); - if (ret >= 0) - return ret; - cpu_relax(); - } + + return __del_timer_sync(timer); } EXPORT_SYMBOL(del_timer_sync); #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1380 @ static void expire_timers(struct timer_b fn = timer->function; - if (timer->flags & TIMER_IRQSAFE) { + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL) && + timer->flags & TIMER_IRQSAFE) { raw_spin_unlock(&base->lock); call_timer_fn(timer, fn); + base->running_timer = NULL; + spin_unlock(&base->expiry_lock); + spin_lock(&base->expiry_lock); raw_spin_lock(&base->lock); } else { raw_spin_unlock_irq(&base->lock); call_timer_fn(timer, fn); + base->running_timer = NULL; + spin_unlock(&base->expiry_lock); + spin_lock(&base->expiry_lock); raw_spin_lock_irq(&base->lock); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1688 @ static inline void __run_timers(struct t if (!time_after_eq(jiffies, base->clk)) return; + spin_lock(&base->expiry_lock); raw_spin_lock_irq(&base->lock); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1715 @ static inline void __run_timers(struct t while (levels--) expire_timers(base, heads + levels); } - base->running_timer = NULL; raw_spin_unlock_irq(&base->lock); + spin_unlock(&base->expiry_lock); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1726 @ static __latent_entropy void run_timer_s { struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]); + irq_work_tick_soft(); + __run_timers(base); if (IS_ENABLED(CONFIG_NO_HZ_COMMON)) __run_timers(this_cpu_ptr(&timer_bases[BASE_DEF])); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1963 @ static void __init init_timer_cpu(int cp base->cpu = cpu; raw_spin_lock_init(&base->lock); base->clk = jiffies; + spin_lock_init(&base->expiry_lock); } } Index: linux-5.0.19-rt11/kernel/trace/trace.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/trace/trace.c +++ linux-5.0.19-rt11/kernel/trace/trace.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2140 @ tracing_generic_entry_update(struct trac struct task_struct *tsk = current; entry->preempt_count = pc & 0xff; + entry->preempt_lazy_count = preempt_lazy_count(); entry->pid = (tsk) ? tsk->pid : 0; entry->flags = #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2151 @ tracing_generic_entry_update(struct trac ((pc & NMI_MASK ) ? TRACE_FLAG_NMI : 0) | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | ((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) | - (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) | + (tif_need_resched_now() ? TRACE_FLAG_NEED_RESCHED : 0) | + (need_resched_lazy() ? TRACE_FLAG_NEED_RESCHED_LAZY : 0) | (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0); + + entry->migrate_disable = (tsk) ? __migrate_disabled(tsk) & 0xFF : 0; } EXPORT_SYMBOL_GPL(tracing_generic_entry_update); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3355 @ get_total_entries(struct trace_buffer *b static void print_lat_help_header(struct seq_file *m) { - seq_puts(m, "# _------=> CPU# \n" - "# / _-----=> irqs-off \n" - "# | / _----=> need-resched \n" - "# || / _---=> hardirq/softirq \n" - "# ||| / _--=> preempt-depth \n" - "# |||| / delay \n" - "# cmd pid ||||| time | caller \n" - "# \\ / ||||| \\ | / \n"); + seq_puts(m, "# _--------=> CPU# \n" + "# / _-------=> irqs-off \n" + "# | / _------=> need-resched \n" + "# || / _-----=> need-resched_lazy \n" + "# ||| / _----=> hardirq/softirq \n" + "# |||| / _---=> preempt-depth \n" + "# ||||| / _--=> preempt-lazy-depth\n" + "# |||||| / _-=> migrate-disable \n" + "# ||||||| / delay \n" + "# cmd pid |||||||| time | caller \n" + "# \\ / |||||||| \\ | / \n"); } static void print_event_info(struct trace_buffer *buf, struct seq_file *m) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3403 @ static void print_func_help_header_irq(s tgid ? tgid_space : space); seq_printf(m, "# %s / _----=> need-resched\n", tgid ? tgid_space : space); - seq_printf(m, "# %s| / _---=> hardirq/softirq\n", + seq_printf(m, "# %s| / _---=> need-resched_lazy\n", + tgid ? tgid_space : space); + seq_printf(m, "# %s|| / _--=> hardirq/softirq\n", tgid ? tgid_space : space); - seq_printf(m, "# %s|| / _--=> preempt-depth\n", + seq_printf(m, "# %s||| / preempt-depth\n", tgid ? tgid_space : space); - seq_printf(m, "# %s||| / delay\n", + seq_printf(m, "# %s|||| / delay\n", tgid ? tgid_space : space); - seq_printf(m, "# TASK-PID %sCPU# |||| TIMESTAMP FUNCTION\n", + seq_printf(m, "# TASK-PID %sCPU# ||||| TIMESTAMP FUNCTION\n", tgid ? " TGID " : space); - seq_printf(m, "# | | %s | |||| | |\n", + seq_printf(m, "# | | %s | ||||| | |\n", tgid ? " | " : space); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8385 @ void ftrace_dump(enum ftrace_dump_mode o tracing_off(); local_irq_save(flags); - printk_nmi_direct_enter(); /* Simulate the iterator */ trace_init_global_iter(&iter); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8465 @ void ftrace_dump(enum ftrace_dump_mode o atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); } atomic_dec(&dump_running); - printk_nmi_direct_exit(); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(ftrace_dump); Index: linux-5.0.19-rt11/kernel/trace/trace.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/trace/trace.h +++ linux-5.0.19-rt11/kernel/trace/trace.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:130 @ struct kretprobe_trace_entry_head { * NEED_RESCHED - reschedule is requested * HARDIRQ - inside an interrupt handler * SOFTIRQ - inside a softirq handler + * NEED_RESCHED_LAZY - lazy reschedule is requested */ enum trace_flag_type { TRACE_FLAG_IRQS_OFF = 0x01, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:140 @ enum trace_flag_type { TRACE_FLAG_SOFTIRQ = 0x10, TRACE_FLAG_PREEMPT_RESCHED = 0x20, TRACE_FLAG_NMI = 0x40, + TRACE_FLAG_NEED_RESCHED_LAZY = 0x80, }; #define TRACE_BUF_SIZE 1024 Index: linux-5.0.19-rt11/kernel/trace/trace_events.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/trace/trace_events.c +++ linux-5.0.19-rt11/kernel/trace/trace_events.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:191 @ static int trace_define_common_fields(vo __common_field(unsigned char, flags); __common_field(unsigned char, preempt_count); __common_field(int, pid); + __common_field(unsigned short, migrate_disable); + __common_field(unsigned short, padding); return ret; } Index: linux-5.0.19-rt11/kernel/trace/trace_hwlat.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/trace/trace_hwlat.c +++ linux-5.0.19-rt11/kernel/trace/trace_hwlat.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:280 @ static void move_to_next_cpu(void) * of this thread, than stop migrating for the duration * of the current test. */ - if (!cpumask_equal(current_mask, ¤t->cpus_allowed)) + if (!cpumask_equal(current_mask, current->cpus_ptr)) goto disable; get_online_cpus(); Index: linux-5.0.19-rt11/kernel/trace/trace_output.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/trace/trace_output.c +++ linux-5.0.19-rt11/kernel/trace/trace_output.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:429 @ int trace_print_lat_fmt(struct trace_seq { char hardsoft_irq; char need_resched; + char need_resched_lazy; char irqs_off; int hardirq; int softirq; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:460 @ int trace_print_lat_fmt(struct trace_seq break; } + need_resched_lazy = + (entry->flags & TRACE_FLAG_NEED_RESCHED_LAZY) ? 'L' : '.'; + hardsoft_irq = (nmi && hardirq) ? 'Z' : nmi ? 'z' : @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:471 @ int trace_print_lat_fmt(struct trace_seq softirq ? 's' : '.' ; - trace_seq_printf(s, "%c%c%c", - irqs_off, need_resched, hardsoft_irq); + trace_seq_printf(s, "%c%c%c%c", + irqs_off, need_resched, need_resched_lazy, + hardsoft_irq); if (entry->preempt_count) trace_seq_printf(s, "%x", entry->preempt_count); else trace_seq_putc(s, '.'); + if (entry->preempt_lazy_count) + trace_seq_printf(s, "%x", entry->preempt_lazy_count); + else + trace_seq_putc(s, '.'); + + if (entry->migrate_disable) + trace_seq_printf(s, "%x", entry->migrate_disable); + else + trace_seq_putc(s, '.'); + return !trace_seq_has_overflowed(s); } Index: linux-5.0.19-rt11/kernel/watchdog.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/watchdog.c +++ linux-5.0.19-rt11/kernel/watchdog.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:486 @ static void watchdog_enable(unsigned int * Start the timer first to prevent the NMI watchdog triggering * before the timer has a chance to fire. */ - hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); hrtimer->function = watchdog_timer_fn; hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL_PINNED); Index: linux-5.0.19-rt11/kernel/workqueue.c =================================================================== --- linux-5.0.19-rt11.orig/kernel/workqueue.c +++ linux-5.0.19-rt11/kernel/workqueue.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:130 @ enum { * * PL: wq_pool_mutex protected. * - * PR: wq_pool_mutex protected for writes. Sched-RCU protected for reads. + * PR: wq_pool_mutex protected for writes. RCU protected for reads. * * PW: wq_pool_mutex and wq->mutex protected for writes. Either for reads. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:139 @ enum { * * WQ: wq->mutex protected. * - * WR: wq->mutex protected for writes. Sched-RCU protected for reads. + * WR: wq->mutex protected for writes. RCU protected for reads. * * MD: wq_mayday_lock protected. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:147 @ enum { /* struct worker is defined in workqueue_internal.h */ struct worker_pool { - spinlock_t lock; /* the pool lock */ + raw_spinlock_t lock; /* the pool lock */ int cpu; /* I: the associated cpu */ int node; /* I: the associated node ID */ int id; /* I: pool ID */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:186 @ struct worker_pool { atomic_t nr_running ____cacheline_aligned_in_smp; /* - * Destruction of pool is sched-RCU protected to allow dereferences + * Destruction of pool is RCU protected to allow dereferences * from get_work_pool(). */ struct rcu_head rcu; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:215 @ struct pool_workqueue { /* * Release of unbound pwq is punted to system_wq. See put_pwq() * and pwq_unbound_release_workfn() for details. pool_workqueue - * itself is also sched-RCU protected so that the first pwq can be + * itself is also RCU protected so that the first pwq can be * determined without grabbing wq->mutex. */ struct work_struct unbound_release_work; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:300 @ static struct workqueue_attrs *wq_update static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */ static DEFINE_MUTEX(wq_pool_attach_mutex); /* protects worker attach/detach */ -static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ -static DECLARE_WAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */ +static DEFINE_RAW_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ +static DECLARE_SWAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */ static LIST_HEAD(workqueues); /* PR: list of all workqueues */ static bool workqueue_freezing; /* PL: have wqs started freezing? */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:360 @ static void workqueue_sysfs_unregister(s #include <trace/events/workqueue.h> #define assert_rcu_or_pool_mutex() \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&wq_pool_mutex), \ - "sched RCU or wq_pool_mutex should be held") + "RCU or wq_pool_mutex should be held") #define assert_rcu_or_wq_mutex(wq) \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&wq->mutex), \ - "sched RCU or wq->mutex should be held") + "RCU or wq->mutex should be held") #define assert_rcu_or_wq_mutex_or_pool_mutex(wq) \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&wq->mutex) && \ !lockdep_is_held(&wq_pool_mutex), \ - "sched RCU, wq->mutex or wq_pool_mutex should be held") + "RCU, wq->mutex or wq_pool_mutex should be held") #define for_each_cpu_worker_pool(pool, cpu) \ for ((pool) = &per_cpu(cpu_worker_pools, cpu)[0]; \ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:385 @ static void workqueue_sysfs_unregister(s * @pool: iteration cursor * @pi: integer used for iteration * - * This must be called either with wq_pool_mutex held or sched RCU read + * This must be called either with wq_pool_mutex held or RCU read * locked. If the pool needs to be used beyond the locking in effect, the * caller is responsible for guaranteeing that the pool stays online. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:417 @ static void workqueue_sysfs_unregister(s * @pwq: iteration cursor * @wq: the target workqueue * - * This must be called either with wq->mutex held or sched RCU read locked. + * This must be called either with wq->mutex held or RCU read locked. * If the pwq needs to be used beyond the locking in effect, the caller is * responsible for guaranteeing that the pwq stays online. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:553 @ static int worker_pool_assign_id(struct * @wq: the target workqueue * @node: the node ID * - * This must be called with any of wq_pool_mutex, wq->mutex or sched RCU + * This must be called with any of wq_pool_mutex, wq->mutex or RCU * read locked. * If the pwq needs to be used beyond the locking in effect, the caller is * responsible for guaranteeing that the pwq stays online. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:697 @ static struct pool_workqueue *get_work_p * @work: the work item of interest * * Pools are created and destroyed under wq_pool_mutex, and allows read - * access under sched-RCU read lock. As such, this function should be - * called under wq_pool_mutex or with preemption disabled. + * access under RCU read lock. As such, this function should be + * called under wq_pool_mutex or inside of a rcu_read_lock() region. * * All fields of the returned pool are accessible as long as the above * mentioned locking is in effect. If the returned pool needs to be used @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:831 @ static struct worker *first_idle_worker( * Wake up the first idle worker of @pool. * * CONTEXT: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void wake_up_worker(struct worker_pool *pool) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:842 @ static void wake_up_worker(struct worker } /** - * wq_worker_waking_up - a worker is waking up + * wq_worker_running - a worker is running again * @task: task waking up - * @cpu: CPU @task is waking up to * - * This function is called during try_to_wake_up() when a worker is - * being awoken. - * - * CONTEXT: - * spin_lock_irq(rq->lock) + * This function is called when a worker returns from schedule() */ -void wq_worker_waking_up(struct task_struct *task, int cpu) +void wq_worker_running(struct task_struct *task) { struct worker *worker = kthread_data(task); - if (!(worker->flags & WORKER_NOT_RUNNING)) { - WARN_ON_ONCE(worker->pool->cpu != cpu); + if (!worker->sleeping) + return; + if (!(worker->flags & WORKER_NOT_RUNNING)) atomic_inc(&worker->pool->nr_running); - } + worker->sleeping = 0; } /** * wq_worker_sleeping - a worker is going to sleep * @task: task going to sleep * - * This function is called during schedule() when a busy worker is - * going to sleep. Worker on the same cpu can be woken up by - * returning pointer to its task. - * - * CONTEXT: - * spin_lock_irq(rq->lock) - * - * Return: - * Worker task on @cpu to wake up, %NULL if none. + * This function is called from schedule() when a busy worker is + * going to sleep. */ -struct task_struct *wq_worker_sleeping(struct task_struct *task) +void wq_worker_sleeping(struct task_struct *task) { - struct worker *worker = kthread_data(task), *to_wakeup = NULL; + struct worker *next, *worker = kthread_data(task); struct worker_pool *pool; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:876 @ struct task_struct *wq_worker_sleeping(s * checking NOT_RUNNING. */ if (worker->flags & WORKER_NOT_RUNNING) - return NULL; + return; pool = worker->pool; - /* this can only happen on the local cpu */ - if (WARN_ON_ONCE(pool->cpu != raw_smp_processor_id())) - return NULL; + if (WARN_ON_ONCE(worker->sleeping)) + return; + + worker->sleeping = 1; + raw_spin_lock_irq(&pool->lock); /* * The counterpart of the following dec_and_test, implied mb, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:898 @ struct task_struct *wq_worker_sleeping(s * lock is safe. */ if (atomic_dec_and_test(&pool->nr_running) && - !list_empty(&pool->worklist)) - to_wakeup = first_idle_worker(pool); - return to_wakeup ? to_wakeup->task : NULL; + !list_empty(&pool->worklist)) { + next = first_idle_worker(pool); + if (next) + wake_up_process(next->task); + } + raw_spin_unlock_irq(&pool->lock); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:913 @ struct task_struct *wq_worker_sleeping(s * the scheduler to get a worker's last known identity. * * CONTEXT: - * spin_lock_irq(rq->lock) + * raw_spin_lock_irq(rq->lock) * * Return: * The last work function %current executed as a worker, NULL if it @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:934 @ work_func_t wq_worker_last_func(struct t * Set @flags in @worker->flags and adjust nr_running accordingly. * * CONTEXT: - * spin_lock_irq(pool->lock) + * raw_spin_lock_irq(pool->lock) */ static inline void worker_set_flags(struct worker *worker, unsigned int flags) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:959 @ static inline void worker_set_flags(stru * Clear @flags in @worker->flags and adjust nr_running accordingly. * * CONTEXT: - * spin_lock_irq(pool->lock) + * raw_spin_lock_irq(pool->lock) */ static inline void worker_clr_flags(struct worker *worker, unsigned int flags) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1007 @ static inline void worker_clr_flags(stru * actually occurs, it should be easy to locate the culprit work function. * * CONTEXT: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). * * Return: * Pointer to worker which is executing @work if found, %NULL @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1042 @ static struct worker *find_worker_execut * nested inside outer list_for_each_entry_safe(). * * CONTEXT: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void move_linked_works(struct work_struct *work, struct list_head *head, struct work_struct **nextp) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1117 @ static void put_pwq_unlocked(struct pool { if (pwq) { /* - * As both pwqs and pools are sched-RCU protected, the + * As both pwqs and pools are RCU protected, the * following lock operations are safe. */ - spin_lock_irq(&pwq->pool->lock); + raw_spin_lock_irq(&pwq->pool->lock); put_pwq(pwq); - spin_unlock_irq(&pwq->pool->lock); + raw_spin_unlock_irq(&pwq->pool->lock); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1155 @ static void pwq_activate_first_delayed(s * decrement nr_in_flight of its pwq and handle workqueue flushing. * * CONTEXT: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, int color) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1245 @ static int try_to_grab_pending(struct wo if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) return 0; + rcu_read_lock(); /* * The queueing is in progress, or it is already queued. Try to * steal it from ->worklist without clearing WORK_STRUCT_PENDING. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1254 @ static int try_to_grab_pending(struct wo if (!pool) goto fail; - spin_lock(&pool->lock); + raw_spin_lock(&pool->lock); /* * work->data is guaranteed to point to pwq only while the work * item is queued on pwq->wq, and both updating work->data to point @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1283 @ static int try_to_grab_pending(struct wo /* work->data points to pwq iff queued, point to pool */ set_work_pool_and_keep_pending(work, pool->id); - spin_unlock(&pool->lock); + raw_spin_unlock(&pool->lock); + rcu_read_unlock(); return 1; } - spin_unlock(&pool->lock); + raw_spin_unlock(&pool->lock); fail: + rcu_read_unlock(); local_irq_restore(*flags); if (work_is_canceling(work)) return -ENOENT; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1308 @ fail: * work_struct flags. * * CONTEXT: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void insert_work(struct pool_workqueue *pwq, struct work_struct *work, struct list_head *head, unsigned int extra_flags) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1403 @ static void __queue_work(int cpu, struct if (unlikely(wq->flags & __WQ_DRAINING) && WARN_ON_ONCE(!is_chained_work(wq))) return; + rcu_read_lock(); retry: if (req_cpu == WORK_CPU_UNBOUND) cpu = wq_select_unbound_cpu(raw_smp_processor_id()); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1423 @ retry: if (last_pool && last_pool != pwq->pool) { struct worker *worker; - spin_lock(&last_pool->lock); + raw_spin_lock(&last_pool->lock); worker = find_worker_executing_work(last_pool, work); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1431 @ retry: pwq = worker->current_pwq; } else { /* meh... not running there, queue here */ - spin_unlock(&last_pool->lock); - spin_lock(&pwq->pool->lock); + raw_spin_unlock(&last_pool->lock); + raw_spin_lock(&pwq->pool->lock); } } else { - spin_lock(&pwq->pool->lock); + raw_spin_lock(&pwq->pool->lock); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1448 @ retry: */ if (unlikely(!pwq->refcnt)) { if (wq->flags & WQ_UNBOUND) { - spin_unlock(&pwq->pool->lock); + raw_spin_unlock(&pwq->pool->lock); cpu_relax(); goto retry; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1460 @ retry: /* pwq determined, queue */ trace_workqueue_queue_work(req_cpu, pwq, work); - if (WARN_ON(!list_empty(&work->entry))) { - spin_unlock(&pwq->pool->lock); - return; - } + if (WARN_ON(!list_empty(&work->entry))) + goto out; pwq->nr_in_flight[pwq->work_color]++; work_flags = work_color_to_flags(pwq->work_color); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1479 @ retry: insert_work(pwq, work, worklist, work_flags); - spin_unlock(&pwq->pool->lock); +out: + raw_spin_unlock(&pwq->pool->lock); + rcu_read_unlock(); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1516 @ EXPORT_SYMBOL(queue_work_on); void delayed_work_timer_fn(struct timer_list *t) { struct delayed_work *dwork = from_timer(dwork, t, timer); + unsigned long flags; - /* should have been called from irqsafe timer with irq already off */ + local_irq_save(flags); __queue_work(dwork->cpu, dwork->wq, &dwork->work); + local_irq_restore(flags); } EXPORT_SYMBOL(delayed_work_timer_fn); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1667 @ EXPORT_SYMBOL(queue_rcu_work); * necessary. * * LOCKING: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void worker_enter_idle(struct worker *worker) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1707 @ static void worker_enter_idle(struct wor * @worker is leaving idle state. Update stats. * * LOCKING: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void worker_leave_idle(struct worker *worker) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1845 @ static struct worker *create_worker(stru worker_attach_to_pool(worker, pool); /* start the newly created worker */ - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); worker->pool->nr_workers++; worker_enter_idle(worker); wake_up_process(worker->task); - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); return worker; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1868 @ fail: * be idle. * * CONTEXT: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void destroy_worker(struct worker *worker) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1894 @ static void idle_worker_timeout(struct t { struct worker_pool *pool = from_timer(pool, t, idle_timer); - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); while (too_many_workers(pool)) { struct worker *worker; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1912 @ static void idle_worker_timeout(struct t destroy_worker(worker); } - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); } static void send_mayday(struct work_struct *work) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1943 @ static void pool_mayday_timeout(struct t struct worker_pool *pool = from_timer(pool, t, mayday_timer); struct work_struct *work; - spin_lock_irq(&pool->lock); - spin_lock(&wq_mayday_lock); /* for wq->maydays */ + raw_spin_lock_irq(&pool->lock); + raw_spin_lock(&wq_mayday_lock); /* for wq->maydays */ if (need_to_create_worker(pool)) { /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1957 @ static void pool_mayday_timeout(struct t send_mayday(work); } - spin_unlock(&wq_mayday_lock); - spin_unlock_irq(&pool->lock); + raw_spin_unlock(&wq_mayday_lock); + raw_spin_unlock_irq(&pool->lock); mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1977 @ static void pool_mayday_timeout(struct t * may_start_working() %true. * * LOCKING: - * spin_lock_irq(pool->lock) which may be released and regrabbed + * raw_spin_lock_irq(pool->lock) which may be released and regrabbed * multiple times. Does GFP_KERNEL allocations. Called only from * manager. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1986 @ __releases(&pool->lock) __acquires(&pool->lock) { restart: - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); /* if we don't make progress in MAYDAY_INITIAL_TIMEOUT, call for help */ mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2002 @ restart: } del_timer_sync(&pool->mayday_timer); - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); /* * This is necessary even after a new worker was just successfully * created as @pool->lock was dropped and the new worker might have @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2025 @ restart: * and may_start_working() is true. * * CONTEXT: - * spin_lock_irq(pool->lock) which may be released and regrabbed + * raw_spin_lock_irq(pool->lock) which may be released and regrabbed * multiple times. Does GFP_KERNEL allocations. * * Return: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2048 @ static bool manage_workers(struct worker pool->manager = NULL; pool->flags &= ~POOL_MANAGER_ACTIVE; - wake_up(&wq_manager_wait); + swake_up_one(&wq_manager_wait); return true; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2064 @ static bool manage_workers(struct worker * call this function to process a work. * * CONTEXT: - * spin_lock_irq(pool->lock) which is released and regrabbed. + * raw_spin_lock_irq(pool->lock) which is released and regrabbed. */ static void process_one_work(struct worker *worker, struct work_struct *work) __releases(&pool->lock) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2146 @ __acquires(&pool->lock) */ set_work_pool_and_clear_pending(work, pool->id); - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); lock_map_acquire(&pwq->wq->lockdep_map); lock_map_acquire(&lockdep_map); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2201 @ __acquires(&pool->lock) */ cond_resched(); - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); /* clear cpu intensive status */ if (unlikely(cpu_intensive)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2227 @ __acquires(&pool->lock) * fetches a work from the top and executes it. * * CONTEXT: - * spin_lock_irq(pool->lock) which may be released and regrabbed + * raw_spin_lock_irq(pool->lock) which may be released and regrabbed * multiple times. */ static void process_scheduled_works(struct worker *worker) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2269 @ static int worker_thread(void *__worker) /* tell the scheduler that this is a workqueue worker */ set_pf_worker(true); woke_up: - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); /* am I supposed to die? */ if (unlikely(worker->flags & WORKER_DIE)) { - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); WARN_ON_ONCE(!list_empty(&worker->entry)); set_pf_worker(false); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2339 @ sleep: */ worker_enter_idle(worker); __set_current_state(TASK_IDLE); - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); schedule(); goto woke_up; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2393 @ repeat: should_stop = kthread_should_stop(); /* see whether any pwq is asking for help */ - spin_lock_irq(&wq_mayday_lock); + raw_spin_lock_irq(&wq_mayday_lock); while (!list_empty(&wq->maydays)) { struct pool_workqueue *pwq = list_first_entry(&wq->maydays, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2405 @ repeat: __set_current_state(TASK_RUNNING); list_del_init(&pwq->mayday_node); - spin_unlock_irq(&wq_mayday_lock); + raw_spin_unlock_irq(&wq_mayday_lock); worker_attach_to_pool(rescuer, pool); - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); /* * Slurp in all works issued via this workqueue and @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2438 @ repeat: * incur MAYDAY_INTERVAL delay inbetween. */ if (need_to_create_worker(pool)) { - spin_lock(&wq_mayday_lock); + raw_spin_lock(&wq_mayday_lock); get_pwq(pwq); list_move_tail(&pwq->mayday_node, &wq->maydays); - spin_unlock(&wq_mayday_lock); + raw_spin_unlock(&wq_mayday_lock); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2459 @ repeat: if (need_more_worker(pool)) wake_up_worker(pool); - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); worker_detach_from_pool(rescuer); - spin_lock_irq(&wq_mayday_lock); + raw_spin_lock_irq(&wq_mayday_lock); } - spin_unlock_irq(&wq_mayday_lock); + raw_spin_unlock_irq(&wq_mayday_lock); if (should_stop) { __set_current_state(TASK_RUNNING); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2546 @ static void wq_barrier_func(struct work_ * underneath us, so we can't reliably determine pwq from @target. * * CONTEXT: - * spin_lock_irq(pool->lock). + * raw_spin_lock_irq(pool->lock). */ static void insert_wq_barrier(struct pool_workqueue *pwq, struct wq_barrier *barr, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2633 @ static bool flush_workqueue_prep_pwqs(st for_each_pwq(pwq, wq) { struct worker_pool *pool = pwq->pool; - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); if (flush_color >= 0) { WARN_ON_ONCE(pwq->flush_color != -1); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2650 @ static bool flush_workqueue_prep_pwqs(st pwq->work_color = work_color; } - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); } if (flush_color >= 0 && atomic_dec_and_test(&wq->nr_pwqs_to_flush)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2850 @ reflush: for_each_pwq(pwq, wq) { bool drained; - spin_lock_irq(&pwq->pool->lock); + raw_spin_lock_irq(&pwq->pool->lock); drained = !pwq->nr_active && list_empty(&pwq->delayed_works); - spin_unlock_irq(&pwq->pool->lock); + raw_spin_unlock_irq(&pwq->pool->lock); if (drained) continue; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2881 @ static bool start_flush_work(struct work might_sleep(); - local_irq_disable(); + rcu_read_lock(); pool = get_work_pool(work); if (!pool) { - local_irq_enable(); + rcu_read_unlock(); return false; } - spin_lock(&pool->lock); + raw_spin_lock_irq(&pool->lock); /* see the comment in try_to_grab_pending() with the same code */ pwq = get_work_pwq(work); if (pwq) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2904 @ static bool start_flush_work(struct work check_flush_dependency(pwq->wq, work); insert_wq_barrier(pwq, barr, work, worker); - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); /* * Force a lock recursion deadlock when using flush_work() inside a @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2920 @ static bool start_flush_work(struct work lock_map_acquire(&pwq->wq->lockdep_map); lock_map_release(&pwq->wq->lockdep_map); } - + rcu_read_unlock(); return true; already_gone: - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); + rcu_read_unlock(); return false; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3236 @ EXPORT_SYMBOL_GPL(execute_in_process_con * * Undo alloc_workqueue_attrs(). */ -void free_workqueue_attrs(struct workqueue_attrs *attrs) +static void free_workqueue_attrs(struct workqueue_attrs *attrs) { if (attrs) { free_cpumask_var(attrs->cpumask); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3246 @ void free_workqueue_attrs(struct workque /** * alloc_workqueue_attrs - allocate a workqueue_attrs - * @gfp_mask: allocation mask to use * * Allocate a new workqueue_attrs, initialize with default settings and * return it. * * Return: The allocated new workqueue_attr on success. %NULL on failure. */ -struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask) +static struct workqueue_attrs *alloc_workqueue_attrs(void) { struct workqueue_attrs *attrs; - attrs = kzalloc(sizeof(*attrs), gfp_mask); + attrs = kzalloc(sizeof(*attrs), GFP_KERNEL); if (!attrs) goto fail; - if (!alloc_cpumask_var(&attrs->cpumask, gfp_mask)) + if (!alloc_cpumask_var(&attrs->cpumask, GFP_KERNEL)) goto fail; cpumask_copy(attrs->cpumask, cpu_possible_mask); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3316 @ static bool wqattrs_equal(const struct w */ static int init_worker_pool(struct worker_pool *pool) { - spin_lock_init(&pool->lock); + raw_spin_lock_init(&pool->lock); pool->id = -1; pool->cpu = -1; pool->node = NUMA_NO_NODE; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3337 @ static int init_worker_pool(struct worke pool->refcnt = 1; /* shouldn't fail above this point */ - pool->attrs = alloc_workqueue_attrs(GFP_KERNEL); + pool->attrs = alloc_workqueue_attrs(); if (!pool->attrs) return -ENOMEM; return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3370 @ static void rcu_free_pool(struct rcu_hea * put_unbound_pool - put a worker_pool * @pool: worker_pool to put * - * Put @pool. If its refcnt reaches zero, it gets destroyed in sched-RCU + * Put @pool. If its refcnt reaches zero, it gets destroyed in RCU * safe manner. get_unbound_pool() calls this function on its failure path * and this function should be able to release pools which went through, * successfully or not, init_worker_pool(). @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3402 @ static void put_unbound_pool(struct work * @pool's workers from blocking on attach_mutex. We're the last * manager and @pool gets freed with the flag set. */ - spin_lock_irq(&pool->lock); - wait_event_lock_irq(wq_manager_wait, + raw_spin_lock_irq(&pool->lock); + swait_event_lock_irq(wq_manager_wait, !(pool->flags & POOL_MANAGER_ACTIVE), pool->lock); pool->flags |= POOL_MANAGER_ACTIVE; while ((worker = first_idle_worker(pool))) destroy_worker(worker); WARN_ON(pool->nr_workers || pool->nr_idle); - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); mutex_lock(&wq_pool_attach_mutex); if (!list_empty(&pool->workers)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3564 @ static void pwq_adjust_max_active(struct return; /* this function can be called during early boot w/ irq disabled */ - spin_lock_irqsave(&pwq->pool->lock, flags); + raw_spin_lock_irqsave(&pwq->pool->lock, flags); /* * During [un]freezing, the caller is responsible for ensuring that @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3587 @ static void pwq_adjust_max_active(struct pwq->max_active = 0; } - spin_unlock_irqrestore(&pwq->pool->lock, flags); + raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); } /* initialize newly alloced @pwq which is associated with @wq and @pool */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3760 @ apply_wqattrs_prepare(struct workqueue_s ctx = kzalloc(struct_size(ctx, pwq_tbl, nr_node_ids), GFP_KERNEL); - new_attrs = alloc_workqueue_attrs(GFP_KERNEL); - tmp_attrs = alloc_workqueue_attrs(GFP_KERNEL); + new_attrs = alloc_workqueue_attrs(); + tmp_attrs = alloc_workqueue_attrs(); if (!ctx || !new_attrs || !tmp_attrs) goto out_free; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3897 @ static int apply_workqueue_attrs_locked( * * Return: 0 on success and -errno on failure. */ -int apply_workqueue_attrs(struct workqueue_struct *wq, +static int apply_workqueue_attrs(struct workqueue_struct *wq, const struct workqueue_attrs *attrs) { int ret; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3908 @ int apply_workqueue_attrs(struct workque return ret; } -EXPORT_SYMBOL_GPL(apply_workqueue_attrs); /** * wq_update_unbound_numa - update NUMA affinity of a wq for CPU hot[un]plug @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3985 @ static void wq_update_unbound_numa(struc use_dfl_pwq: mutex_lock(&wq->mutex); - spin_lock_irq(&wq->dfl_pwq->pool->lock); + raw_spin_lock_irq(&wq->dfl_pwq->pool->lock); get_pwq(wq->dfl_pwq); - spin_unlock_irq(&wq->dfl_pwq->pool->lock); + raw_spin_unlock_irq(&wq->dfl_pwq->pool->lock); old_pwq = numa_pwq_tbl_install(wq, node, wq->dfl_pwq); out_unlock: mutex_unlock(&wq->mutex); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4106 @ struct workqueue_struct *__alloc_workque return NULL; if (flags & WQ_UNBOUND) { - wq->unbound_attrs = alloc_workqueue_attrs(GFP_KERNEL); + wq->unbound_attrs = alloc_workqueue_attrs(); if (!wq->unbound_attrs) goto err_free_wq; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4333 @ bool workqueue_congested(int cpu, struct struct pool_workqueue *pwq; bool ret; - rcu_read_lock_sched(); + rcu_read_lock(); + preempt_disable(); if (cpu == WORK_CPU_UNBOUND) cpu = smp_processor_id(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4345 @ bool workqueue_congested(int cpu, struct pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu)); ret = !list_empty(&pwq->delayed_works); - rcu_read_unlock_sched(); + preempt_enable(); + rcu_read_unlock(); return ret; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4372 @ unsigned int work_busy(struct work_struc if (work_pending(work)) ret |= WORK_BUSY_PENDING; - local_irq_save(flags); + rcu_read_lock(); pool = get_work_pool(work); if (pool) { - spin_lock(&pool->lock); + raw_spin_lock_irqsave(&pool->lock, flags); if (find_worker_executing_work(pool, work)) ret |= WORK_BUSY_RUNNING; - spin_unlock(&pool->lock); + raw_spin_unlock_irqrestore(&pool->lock, flags); } - local_irq_restore(flags); + rcu_read_unlock(); return ret; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4564 @ void show_workqueue_state(void) unsigned long flags; int pi; - rcu_read_lock_sched(); + rcu_read_lock(); pr_info("Showing busy workqueues and worker pools:\n"); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4584 @ void show_workqueue_state(void) pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags); for_each_pwq(pwq, wq) { - spin_lock_irqsave(&pwq->pool->lock, flags); + raw_spin_lock_irqsave(&pwq->pool->lock, flags); if (pwq->nr_active || !list_empty(&pwq->delayed_works)) show_pwq(pwq); - spin_unlock_irqrestore(&pwq->pool->lock, flags); + raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); /* * We could be printing a lot from atomic context, e.g. * sysrq-t -> show_workqueue_state(). Avoid triggering @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4601 @ void show_workqueue_state(void) struct worker *worker; bool first = true; - spin_lock_irqsave(&pool->lock, flags); + raw_spin_lock_irqsave(&pool->lock, flags); if (pool->nr_workers == pool->nr_idle) goto next_pool; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4620 @ void show_workqueue_state(void) } pr_cont("\n"); next_pool: - spin_unlock_irqrestore(&pool->lock, flags); + raw_spin_unlock_irqrestore(&pool->lock, flags); /* * We could be printing a lot from atomic context, e.g. * sysrq-t -> show_workqueue_state(). Avoid triggering @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4629 @ void show_workqueue_state(void) touch_nmi_watchdog(); } - rcu_read_unlock_sched(); + rcu_read_unlock(); } /* used to show worker information through /proc/PID/{comm,stat,status} */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4650 @ void wq_worker_comm(char *buf, size_t si struct worker_pool *pool = worker->pool; if (pool) { - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); /* * ->desc tracks information (wq name or * set_worker_desc()) for the latest execution. If @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4664 @ void wq_worker_comm(char *buf, size_t si scnprintf(buf + off, size - off, "-%s", worker->desc); } - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4695 @ static void unbind_workers(int cpu) for_each_cpu_worker_pool(pool, cpu) { mutex_lock(&wq_pool_attach_mutex); - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); /* * We've blocked all attach/detach operations. Make all workers @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4709 @ static void unbind_workers(int cpu) pool->flags |= POOL_DISASSOCIATED; - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); mutex_unlock(&wq_pool_attach_mutex); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4735 @ static void unbind_workers(int cpu) * worker blocking could lead to lengthy stalls. Kick off * unbound chain execution of currently pending work items. */ - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); wake_up_worker(pool); - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4764 @ static void rebind_workers(struct worker WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask) < 0); - spin_lock_irq(&pool->lock); + raw_spin_lock_irq(&pool->lock); pool->flags &= ~POOL_DISASSOCIATED; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4803 @ static void rebind_workers(struct worker WRITE_ONCE(worker->flags, worker_flags); } - spin_unlock_irq(&pool->lock); + raw_spin_unlock_irq(&pool->lock); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5016 @ bool freeze_workqueues_busy(void) * nr_active is monotonically decreasing. It's safe * to peek without lock. */ - rcu_read_lock_sched(); + rcu_read_lock(); for_each_pwq(pwq, wq) { WARN_ON_ONCE(pwq->nr_active < 0); if (pwq->nr_active) { busy = true; - rcu_read_unlock_sched(); + rcu_read_unlock(); goto out_unlock; } } - rcu_read_unlock_sched(); + rcu_read_unlock(); } out_unlock: mutex_unlock(&wq_pool_mutex); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5220 @ static ssize_t wq_pool_ids_show(struct d const char *delim = ""; int node, written = 0; - rcu_read_lock_sched(); + get_online_cpus(); + rcu_read_lock(); for_each_node(node) { written += scnprintf(buf + written, PAGE_SIZE - written, "%s%d:%d", delim, node, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5229 @ static ssize_t wq_pool_ids_show(struct d delim = " "; } written += scnprintf(buf + written, PAGE_SIZE - written, "\n"); - rcu_read_unlock_sched(); + rcu_read_unlock(); + put_online_cpus(); return written; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5255 @ static struct workqueue_attrs *wq_sysfs_ lockdep_assert_held(&wq_pool_mutex); - attrs = alloc_workqueue_attrs(GFP_KERNEL); + attrs = alloc_workqueue_attrs(); if (!attrs) return NULL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5677 @ static void __init wq_numa_init(void) return; } - wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs(GFP_KERNEL); + wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs(); BUG_ON(!wq_update_unbound_numa_attrs_buf); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5752 @ int __init workqueue_init_early(void) for (i = 0; i < NR_STD_WORKER_POOLS; i++) { struct workqueue_attrs *attrs; - BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL))); + BUG_ON(!(attrs = alloc_workqueue_attrs())); attrs->nice = std_nice[i]; unbound_std_wq_attrs[i] = attrs; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5761 @ int __init workqueue_init_early(void) * guaranteed by max_active which is enforced by pwqs. * Turn off NUMA so that dfl_pwq is used for all nodes. */ - BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL))); + BUG_ON(!(attrs = alloc_workqueue_attrs())); attrs->nice = std_nice[i]; attrs->no_numa = true; ordered_wq_attrs[i] = attrs; Index: linux-5.0.19-rt11/kernel/workqueue_internal.h =================================================================== --- linux-5.0.19-rt11.orig/kernel/workqueue_internal.h +++ linux-5.0.19-rt11/kernel/workqueue_internal.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:47 @ struct worker { unsigned long last_active; /* L: last active timestamp */ unsigned int flags; /* X: flags */ int id; /* I: worker id */ + int sleeping; /* None */ /* * Opaque string set with work_set_desc(). Printed out with task @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:76 @ static inline struct worker *current_wq_ * Scheduler hooks for concurrency managed workqueue. Only to be used from * sched/ and workqueue.c. */ -void wq_worker_waking_up(struct task_struct *task, int cpu); -struct task_struct *wq_worker_sleeping(struct task_struct *task); +void wq_worker_running(struct task_struct *task); +void wq_worker_sleeping(struct task_struct *task); work_func_t wq_worker_last_func(struct task_struct *task); #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */ Index: linux-5.0.19-rt11/lib/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/lib/Kconfig +++ linux-5.0.19-rt11/lib/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:455 @ config CHECK_SIGNATURE config CPUMASK_OFFSTACK bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS + depends on !PREEMPT_RT_FULL help Use dynamic allocation for cpumask_var_t, instead of putting them on the stack. This is a bit more expensive, but avoids Index: linux-5.0.19-rt11/lib/Kconfig.debug =================================================================== --- linux-5.0.19-rt11.orig/lib/Kconfig.debug +++ linux-5.0.19-rt11/lib/Kconfig.debug @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:46 @ config CONSOLE_LOGLEVEL_QUIET will be used as the loglevel. IOW passing "quiet" will be the equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>" +config CONSOLE_LOGLEVEL_EMERGENCY + int "Emergency console loglevel (1-15)" + range 1 15 + default "5" + help + The loglevel to determine if a console message is an emergency + message. + + If supported by the console driver, emergency messages will be + flushed to the console immediately. This can cause significant system + latencies so the value should be set such that only significant + messages are classified as emergency messages. + + Setting a default here is equivalent to passing in + emergency_loglevel=<x> in the kernel bootargs. emergency_loglevel=<x> + continues to override whatever value is specified here as well. + config MESSAGE_LOGLEVEL_DEFAULT int "Default message log level (1-7)" range 1 7 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1242 @ config DEBUG_ATOMIC_SLEEP config DEBUG_LOCKING_API_SELFTESTS bool "Locking API boot-time self-tests" - depends on DEBUG_KERNEL + depends on DEBUG_KERNEL && !PREEMPT_RT_FULL help Say Y here if you want the kernel to run a short self-test during bootup. The self-test checks whether common types of locking bugs Index: linux-5.0.19-rt11/lib/Makefile =================================================================== --- linux-5.0.19-rt11.orig/lib/Makefile +++ linux-5.0.19-rt11/lib/Makefile @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:33 @ endif lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o timerqueue.o xarray.o \ - idr.o int_sqrt.o extable.o \ + idr.o int_sqrt.o extable.o printk_ringbuffer.o \ sha1.o chacha.o irq_regs.o argv_split.o \ flex_proportions.o ratelimit.o show_mem.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \ Index: linux-5.0.19-rt11/lib/bust_spinlocks.c =================================================================== --- linux-5.0.19-rt11.orig/lib/bust_spinlocks.c +++ linux-5.0.19-rt11/lib/bust_spinlocks.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:29 @ void bust_spinlocks(int yes) unblank_screen(); #endif console_unblank(); - if (--oops_in_progress == 0) - wake_up_klogd(); + --oops_in_progress; } } Index: linux-5.0.19-rt11/lib/debugobjects.c =================================================================== --- linux-5.0.19-rt11.orig/lib/debugobjects.c +++ linux-5.0.19-rt11/lib/debugobjects.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:379 @ __debug_object_init(void *addr, struct d struct debug_obj *obj; unsigned long flags; - fill_pool(); +#ifdef CONFIG_PREEMPT_RT_FULL + if (preempt_count() == 0 && !irqs_disabled()) +#endif + fill_pool(); db = get_bucket((unsigned long) addr); Index: linux-5.0.19-rt11/lib/irq_poll.c =================================================================== --- linux-5.0.19-rt11.orig/lib/irq_poll.c +++ linux-5.0.19-rt11/lib/irq_poll.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:40 @ void irq_poll_sched(struct irq_poll *iop list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll)); __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ); local_irq_restore(flags); + preempt_check_resched_rt(); } EXPORT_SYMBOL(irq_poll_sched); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:76 @ void irq_poll_complete(struct irq_poll * local_irq_save(flags); __irq_poll_complete(iop); local_irq_restore(flags); + preempt_check_resched_rt(); } EXPORT_SYMBOL(irq_poll_complete); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:101 @ static void __latent_entropy irq_poll_so } local_irq_enable(); + preempt_check_resched_rt(); /* Even though interrupts have been re-enabled, this * access is safe because interrupts can only add new @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:139 @ static void __latent_entropy irq_poll_so __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ); local_irq_enable(); + preempt_check_resched_rt(); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:203 @ static int irq_poll_cpu_dead(unsigned in this_cpu_ptr(&blk_cpu_iopoll)); __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ); local_irq_enable(); + preempt_check_resched_rt(); return 0; } Index: linux-5.0.19-rt11/lib/locking-selftest.c =================================================================== --- linux-5.0.19-rt11.orig/lib/locking-selftest.c +++ linux-5.0.19-rt11/lib/locking-selftest.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:745 @ GENERATE_TESTCASE(init_held_rtmutex); #include "locking-selftest-spin-hardirq.h" GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_spin) +#ifndef CONFIG_PREEMPT_RT_FULL + #include "locking-selftest-rlock-hardirq.h" GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:762 @ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_ #include "locking-selftest-wlock-softirq.h" GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock) +#endif + #undef E1 #undef E2 +#ifndef CONFIG_PREEMPT_RT_FULL /* * Enabling hardirqs with a softirq-safe lock held: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:800 @ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A #undef E1 #undef E2 +#endif + /* * Enabling irqs with an irq-safe lock held: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:825 @ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A #include "locking-selftest-spin-hardirq.h" GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_spin) +#ifndef CONFIG_PREEMPT_RT_FULL + #include "locking-selftest-rlock-hardirq.h" GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:842 @ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B #include "locking-selftest-wlock-softirq.h" GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock) +#endif + #undef E1 #undef E2 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:875 @ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B #include "locking-selftest-spin-hardirq.h" GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_spin) +#ifndef CONFIG_PREEMPT_RT_FULL + #include "locking-selftest-rlock-hardirq.h" GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:892 @ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_ #include "locking-selftest-wlock-softirq.h" GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock) +#endif + #undef E1 #undef E2 #undef E3 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:927 @ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_ #include "locking-selftest-spin-hardirq.h" GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_spin) +#ifndef CONFIG_PREEMPT_RT_FULL + #include "locking-selftest-rlock-hardirq.h" GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:944 @ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_ #include "locking-selftest-wlock-softirq.h" GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock) +#endif + #undef E1 #undef E2 #undef E3 +#ifndef CONFIG_PREEMPT_RT_FULL + /* * read-lock / write-lock irq inversion. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1014 @ GENERATE_PERMUTATIONS_3_EVENTS(irq_inver #undef E2 #undef E3 +#endif + +#ifndef CONFIG_PREEMPT_RT_FULL + /* * read-lock / write-lock recursion that is actually safe. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1056 @ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_ #undef E2 #undef E3 +#endif + /* * read-lock / write-lock recursion that is unsafe. */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2087 @ void locking_selftest(void) printk(" --------------------------------------------------------------------------\n"); +#ifndef CONFIG_PREEMPT_RT_FULL /* * irq-context testcases: */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2100 @ void locking_selftest(void) DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion); // DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2); +#else + /* On -rt, we only do hardirq context test for raw spinlock */ + DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 12); + DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 21); + + DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 12); + DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 21); + + DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 123); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 132); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 213); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 231); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 312); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 321); + + DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 123); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 132); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 213); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 231); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 312); + DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 321); +#endif ww_tests(); Index: linux-5.0.19-rt11/lib/nmi_backtrace.c =================================================================== --- linux-5.0.19-rt11.orig/lib/nmi_backtrace.c +++ linux-5.0.19-rt11/lib/nmi_backtrace.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:78 @ void nmi_trigger_cpumask_backtrace(const touch_softlockup_watchdog(); } - /* - * Force flush any remote buffers that might be stuck in IRQ context - * and therefore could not run their irq_work. - */ - printk_safe_flush(); - clear_bit_unlock(0, &backtrace_flag); put_cpu(); } Index: linux-5.0.19-rt11/lib/printk_ringbuffer.c =================================================================== --- /dev/null +++ linux-5.0.19-rt11/lib/printk_ringbuffer.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4 @ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/sched.h> +#include <linux/smp.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/printk_ringbuffer.h> + +#define PRB_SIZE(rb) (1 << rb->size_bits) +#define PRB_SIZE_BITMASK(rb) (PRB_SIZE(rb) - 1) +#define PRB_INDEX(rb, lpos) (lpos & PRB_SIZE_BITMASK(rb)) +#define PRB_WRAPS(rb, lpos) (lpos >> rb->size_bits) +#define PRB_WRAP_LPOS(rb, lpos, xtra) \ + ((PRB_WRAPS(rb, lpos) + xtra) << rb->size_bits) +#define PRB_DATA_SIZE(e) (e->size - sizeof(struct prb_entry)) +#define PRB_DATA_ALIGN sizeof(long) + +static bool __prb_trylock(struct prb_cpulock *cpu_lock, + unsigned int *cpu_store) +{ + unsigned long *flags; + unsigned int cpu; + + cpu = get_cpu(); + + *cpu_store = atomic_read(&cpu_lock->owner); + /* memory barrier to ensure the current lock owner is visible */ + smp_rmb(); + if (*cpu_store == -1) { + flags = per_cpu_ptr(cpu_lock->irqflags, cpu); + local_irq_save(*flags); + if (atomic_try_cmpxchg_acquire(&cpu_lock->owner, + cpu_store, cpu)) { + return true; + } + local_irq_restore(*flags); + } else if (*cpu_store == cpu) { + return true; + } + + put_cpu(); + return false; +} + +/* + * prb_lock: Perform a processor-reentrant spin lock. + * @cpu_lock: A pointer to the lock object. + * @cpu_store: A "flags" pointer to store lock status information. + * + * If no processor has the lock, the calling processor takes the lock and + * becomes the owner. If the calling processor is already the owner of the + * lock, this function succeeds immediately. If lock is locked by another + * processor, this function spins until the calling processor becomes the + * owner. + * + * It is safe to call this function from any context and state. + */ +void prb_lock(struct prb_cpulock *cpu_lock, unsigned int *cpu_store) +{ + for (;;) { + if (__prb_trylock(cpu_lock, cpu_store)) + break; + cpu_relax(); + } +} + +/* + * prb_unlock: Perform a processor-reentrant spin unlock. + * @cpu_lock: A pointer to the lock object. + * @cpu_store: A "flags" object storing lock status information. + * + * Release the lock. The calling processor must be the owner of the lock. + * + * It is safe to call this function from any context and state. + */ +void prb_unlock(struct prb_cpulock *cpu_lock, unsigned int cpu_store) +{ + unsigned long *flags; + unsigned int cpu; + + cpu = atomic_read(&cpu_lock->owner); + atomic_set_release(&cpu_lock->owner, cpu_store); + + if (cpu_store == -1) { + flags = per_cpu_ptr(cpu_lock->irqflags, cpu); + local_irq_restore(*flags); + } + + put_cpu(); +} + +static struct prb_entry *to_entry(struct printk_ringbuffer *rb, + unsigned long lpos) +{ + char *buffer = rb->buffer; + buffer += PRB_INDEX(rb, lpos); + return (struct prb_entry *)buffer; +} + +static int calc_next(struct printk_ringbuffer *rb, unsigned long tail, + unsigned long lpos, int size, unsigned long *calced_next) +{ + unsigned long next_lpos; + int ret = 0; +again: + next_lpos = lpos + size; + if (next_lpos - tail > PRB_SIZE(rb)) + return -1; + + if (PRB_WRAPS(rb, lpos) != PRB_WRAPS(rb, next_lpos)) { + lpos = PRB_WRAP_LPOS(rb, next_lpos, 0); + ret |= 1; + goto again; + } + + *calced_next = next_lpos; + return ret; +} + +static bool push_tail(struct printk_ringbuffer *rb, unsigned long tail) +{ + unsigned long new_tail; + struct prb_entry *e; + unsigned long head; + + if (tail != atomic_long_read(&rb->tail)) + return true; + + e = to_entry(rb, tail); + if (e->size != -1) + new_tail = tail + e->size; + else + new_tail = PRB_WRAP_LPOS(rb, tail, 1); + + /* make sure the new tail does not overtake the head */ + head = atomic_long_read(&rb->head); + if (head - new_tail > PRB_SIZE(rb)) + return false; + + atomic_long_cmpxchg(&rb->tail, tail, new_tail); + return true; +} + +/* + * prb_commit: Commit a reserved entry to the ring buffer. + * @h: An entry handle referencing the data entry to commit. + * + * Commit data that has been reserved using prb_reserve(). Once the data + * block has been committed, it can be invalidated at any time. If a writer + * is interested in using the data after committing, the writer should make + * its own copy first or use the prb_iter_ reader functions to access the + * data in the ring buffer. + * + * It is safe to call this function from any context and state. + */ +void prb_commit(struct prb_handle *h) +{ + struct printk_ringbuffer *rb = h->rb; + bool changed = false; + struct prb_entry *e; + unsigned long head; + unsigned long res; + + for (;;) { + if (atomic_read(&rb->ctx) != 1) { + /* the interrupted context will fixup head */ + atomic_dec(&rb->ctx); + break; + } + /* assign sequence numbers before moving head */ + head = atomic_long_read(&rb->head); + res = atomic_long_read(&rb->reserve); + while (head != res) { + e = to_entry(rb, head); + if (e->size == -1) { + head = PRB_WRAP_LPOS(rb, head, 1); + continue; + } + while (atomic_long_read(&rb->lost)) { + atomic_long_dec(&rb->lost); + rb->seq++; + } + e->seq = ++rb->seq; + head += e->size; + changed = true; + } + atomic_long_set_release(&rb->head, res); + + atomic_dec(&rb->ctx); + + if (atomic_long_read(&rb->reserve) == res) + break; + atomic_inc(&rb->ctx); + } + + prb_unlock(rb->cpulock, h->cpu); + + if (changed) { + atomic_long_inc(&rb->wq_counter); + if (wq_has_sleeper(rb->wq)) { +#ifdef CONFIG_IRQ_WORK + irq_work_queue(rb->wq_work); +#else + if (!in_nmi()) + wake_up_interruptible_all(rb->wq); +#endif + } + } +} + +/* + * prb_reserve: Reserve an entry within a ring buffer. + * @h: An entry handle to be setup and reference an entry. + * @rb: A ring buffer to reserve data within. + * @size: The number of bytes to reserve. + * + * Reserve an entry of at least @size bytes to be used by the caller. If + * successful, the data region of the entry belongs to the caller and cannot + * be invalidated by any other task/context. For this reason, the caller + * should call prb_commit() as quickly as possible in order to avoid preventing + * other tasks/contexts from reserving data in the case that the ring buffer + * has wrapped. + * + * It is safe to call this function from any context and state. + * + * Returns a pointer to the reserved entry (and @h is setup to reference that + * entry) or NULL if it was not possible to reserve data. + */ +char *prb_reserve(struct prb_handle *h, struct printk_ringbuffer *rb, + unsigned int size) +{ + unsigned long tail, res1, res2; + int ret; + + if (size == 0) + return NULL; + size += sizeof(struct prb_entry); + size += PRB_DATA_ALIGN - 1; + size &= ~(PRB_DATA_ALIGN - 1); + if (size >= PRB_SIZE(rb)) + return NULL; + + h->rb = rb; + prb_lock(rb->cpulock, &h->cpu); + + atomic_inc(&rb->ctx); + + do { + for (;;) { + tail = atomic_long_read(&rb->tail); + res1 = atomic_long_read(&rb->reserve); + ret = calc_next(rb, tail, res1, size, &res2); + if (ret >= 0) + break; + if (!push_tail(rb, tail)) { + prb_commit(h); + return NULL; + } + } + } while (!atomic_long_try_cmpxchg_acquire(&rb->reserve, &res1, res2)); + + h->entry = to_entry(rb, res1); + + if (ret) { + /* handle wrap */ + h->entry->size = -1; + h->entry = to_entry(rb, PRB_WRAP_LPOS(rb, res2, 0)); + } + + h->entry->size = size; + + return &h->entry->data[0]; +} + +/* + * prb_iter_copy: Copy an iterator. + * @dest: The iterator to copy to. + * @src: The iterator to copy from. + * + * Make a deep copy of an iterator. This is particularly useful for making + * backup copies of an iterator in case a form of rewinding it needed. + * + * It is safe to call this function from any context and state. But + * note that this function is not atomic. Callers should not make copies + * to/from iterators that can be accessed by other tasks/contexts. + */ +void prb_iter_copy(struct prb_iterator *dest, struct prb_iterator *src) +{ + memcpy(dest, src, sizeof(*dest)); +} + +/* + * prb_iter_init: Initialize an iterator for a ring buffer. + * @iter: The iterator to initialize. + * @rb: A ring buffer to that @iter should iterate. + * @seq: The sequence number of the position preceding the first record. + * May be NULL. + * + * Initialize an iterator to be used with a specified ring buffer. If @seq + * is non-NULL, it will be set such that prb_iter_next() will provide a + * sequence value of "@seq + 1" if no records were missed. + * + * It is safe to call this function from any context and state. + */ +void prb_iter_init(struct prb_iterator *iter, struct printk_ringbuffer *rb, + u64 *seq) +{ + memset(iter, 0, sizeof(*iter)); + iter->rb = rb; + iter->lpos = PRB_INIT; + + if (!seq) + return; + + for (;;) { + struct prb_iterator tmp_iter; + int ret; + + prb_iter_copy(&tmp_iter, iter); + + ret = prb_iter_next(&tmp_iter, NULL, 0, seq); + if (ret < 0) + continue; + + if (ret == 0) + *seq = 0; + else + (*seq)--; + break; + } +} + +static bool is_valid(struct printk_ringbuffer *rb, unsigned long lpos) +{ + unsigned long head, tail; + + tail = atomic_long_read(&rb->tail); + head = atomic_long_read(&rb->head); + head -= tail; + lpos -= tail; + + if (lpos >= head) + return false; + return true; +} + +/* + * prb_iter_data: Retrieve the record data at the current position. + * @iter: Iterator tracking the current position. + * @buf: A buffer to store the data of the record. May be NULL. + * @size: The size of @buf. (Ignored if @buf is NULL.) + * @seq: The sequence number of the record. May be NULL. + * + * If @iter is at a record, provide the data and/or sequence number of that + * record (if specified by the caller). + * + * It is safe to call this function from any context and state. + * + * Returns >=0 if the current record contains valid data (returns 0 if @buf + * is NULL or returns the size of the data block if @buf is non-NULL) or + * -EINVAL if @iter is now invalid. + */ +int prb_iter_data(struct prb_iterator *iter, char *buf, int size, u64 *seq) +{ + struct printk_ringbuffer *rb = iter->rb; + unsigned long lpos = iter->lpos; + unsigned int datsize = 0; + struct prb_entry *e; + + if (buf || seq) { + e = to_entry(rb, lpos); + if (!is_valid(rb, lpos)) + return -EINVAL; + /* memory barrier to ensure valid lpos */ + smp_rmb(); + if (buf) { + datsize = PRB_DATA_SIZE(e); + /* memory barrier to ensure load of datsize */ + smp_rmb(); + if (!is_valid(rb, lpos)) + return -EINVAL; + if (PRB_INDEX(rb, lpos) + datsize > + PRB_SIZE(rb) - PRB_DATA_ALIGN) { + return -EINVAL; + } + if (size > datsize) + size = datsize; + memcpy(buf, &e->data[0], size); + } + if (seq) + *seq = e->seq; + /* memory barrier to ensure loads of entry data */ + smp_rmb(); + } + + if (!is_valid(rb, lpos)) + return -EINVAL; + + return datsize; +} + +/* + * prb_iter_next: Advance to the next record. + * @iter: Iterator tracking the current position. + * @buf: A buffer to store the data of the next record. May be NULL. + * @size: The size of @buf. (Ignored if @buf is NULL.) + * @seq: The sequence number of the next record. May be NULL. + * + * If a next record is available, @iter is advanced and (if specified) + * the data and/or sequence number of that record are provided. + * + * It is safe to call this function from any context and state. + * + * Returns 1 if @iter was advanced, 0 if @iter is at the end of the list, or + * -EINVAL if @iter is now invalid. + */ +int prb_iter_next(struct prb_iterator *iter, char *buf, int size, u64 *seq) +{ + struct printk_ringbuffer *rb = iter->rb; + unsigned long next_lpos; + struct prb_entry *e; + unsigned int esize; + + if (iter->lpos == PRB_INIT) { + next_lpos = atomic_long_read(&rb->tail); + } else { + if (!is_valid(rb, iter->lpos)) + return -EINVAL; + /* memory barrier to ensure valid lpos */ + smp_rmb(); + e = to_entry(rb, iter->lpos); + esize = e->size; + /* memory barrier to ensure load of size */ + smp_rmb(); + if (!is_valid(rb, iter->lpos)) + return -EINVAL; + next_lpos = iter->lpos + esize; + } + if (next_lpos == atomic_long_read(&rb->head)) + return 0; + if (!is_valid(rb, next_lpos)) + return -EINVAL; + /* memory barrier to ensure valid lpos */ + smp_rmb(); + + iter->lpos = next_lpos; + e = to_entry(rb, iter->lpos); + esize = e->size; + /* memory barrier to ensure load of size */ + smp_rmb(); + if (!is_valid(rb, iter->lpos)) + return -EINVAL; + if (esize == -1) + iter->lpos = PRB_WRAP_LPOS(rb, iter->lpos, 1); + + if (prb_iter_data(iter, buf, size, seq) < 0) + return -EINVAL; + + return 1; +} + +/* + * prb_iter_wait_next: Advance to the next record, blocking if none available. + * @iter: Iterator tracking the current position. + * @buf: A buffer to store the data of the next record. May be NULL. + * @size: The size of @buf. (Ignored if @buf is NULL.) + * @seq: The sequence number of the next record. May be NULL. + * + * If a next record is already available, this function works like + * prb_iter_next(). Otherwise block interruptible until a next record is + * available. + * + * When a next record is available, @iter is advanced and (if specified) + * the data and/or sequence number of that record are provided. + * + * This function might sleep. + * + * Returns 1 if @iter was advanced, -EINVAL if @iter is now invalid, or + * -ERESTARTSYS if interrupted by a signal. + */ +int prb_iter_wait_next(struct prb_iterator *iter, char *buf, int size, u64 *seq) +{ + unsigned long last_seen; + int ret; + + for (;;) { + last_seen = atomic_long_read(&iter->rb->wq_counter); + + ret = prb_iter_next(iter, buf, size, seq); + if (ret != 0) + break; + + ret = wait_event_interruptible(*iter->rb->wq, + last_seen != atomic_long_read(&iter->rb->wq_counter)); + if (ret < 0) + break; + } + + return ret; +} + +/* + * prb_iter_seek: Seek forward to a specific record. + * @iter: Iterator to advance. + * @seq: Record number to advance to. + * + * Advance @iter such that a following call to prb_iter_data() will provide + * the contents of the specified record. If a record is specified that does + * not yet exist, advance @iter to the end of the record list. + * + * Note that iterators cannot be rewound. So if a record is requested that + * exists but is previous to @iter in position, @iter is considered invalid. + * + * It is safe to call this function from any context and state. + * + * Returns 1 on succces, 0 if specified record does not yet exist (@iter is + * now at the end of the list), or -EINVAL if @iter is now invalid. + */ +int prb_iter_seek(struct prb_iterator *iter, u64 seq) +{ + u64 cur_seq; + int ret; + + /* first check if the iterator is already at the wanted seq */ + if (seq == 0) { + if (iter->lpos == PRB_INIT) + return 1; + else + return -EINVAL; + } + if (iter->lpos != PRB_INIT) { + if (prb_iter_data(iter, NULL, 0, &cur_seq) >= 0) { + if (cur_seq == seq) + return 1; + if (cur_seq > seq) + return -EINVAL; + } + } + + /* iterate to find the wanted seq */ + for (;;) { + ret = prb_iter_next(iter, NULL, 0, &cur_seq); + if (ret <= 0) + break; + + if (cur_seq == seq) + break; + + if (cur_seq > seq) { + ret = -EINVAL; + break; + } + } + + return ret; +} + +/* + * prb_buffer_size: Get the size of the ring buffer. + * @rb: The ring buffer to get the size of. + * + * Return the number of bytes used for the ring buffer entry storage area. + * Note that this area stores both entry header and entry data. Therefore + * this represents an upper bound to the amount of data that can be stored + * in the ring buffer. + * + * It is safe to call this function from any context and state. + * + * Returns the size in bytes of the entry storage area. + */ +int prb_buffer_size(struct printk_ringbuffer *rb) +{ + return PRB_SIZE(rb); +} + +/* + * prb_inc_lost: Increment the seq counter to signal a lost record. + * @rb: The ring buffer to increment the seq of. + * + * Increment the seq counter so that a seq number is intentially missing + * for the readers. This allows readers to identify that a record is + * missing. A writer will typically use this function if prb_reserve() + * fails. + * + * It is safe to call this function from any context and state. + */ +void prb_inc_lost(struct printk_ringbuffer *rb) +{ + atomic_long_inc(&rb->lost); +} Index: linux-5.0.19-rt11/lib/radix-tree.c =================================================================== --- linux-5.0.19-rt11.orig/lib/radix-tree.c +++ linux-5.0.19-rt11/lib/radix-tree.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:42 @ #include <linux/slab.h> #include <linux/string.h> #include <linux/xarray.h> - +#include <linux/locallock.h> /* * Radix tree node cache. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:88 @ struct radix_tree_preload { struct radix_tree_node *nodes; }; static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, }; +static DEFINE_LOCAL_IRQ_LOCK(radix_tree_preloads_lock); static inline struct radix_tree_node *entry_to_node(void *ptr) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:286 @ radix_tree_node_alloc(gfp_t gfp_mask, st * succeed in getting a node here (and never reach * kmem_cache_alloc) */ - rtp = this_cpu_ptr(&radix_tree_preloads); + rtp = &get_locked_var(radix_tree_preloads_lock, radix_tree_preloads); if (rtp->nr) { ret = rtp->nodes; rtp->nodes = ret->parent; rtp->nr--; } + put_locked_var(radix_tree_preloads_lock, radix_tree_preloads); /* * Update the allocation stack trace as this is more useful * for debugging. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:358 @ static __must_check int __radix_tree_pre */ gfp_mask &= ~__GFP_ACCOUNT; - preempt_disable(); + local_lock(radix_tree_preloads_lock); rtp = this_cpu_ptr(&radix_tree_preloads); while (rtp->nr < nr) { - preempt_enable(); + local_unlock(radix_tree_preloads_lock); node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); if (node == NULL) goto out; - preempt_disable(); + local_lock(radix_tree_preloads_lock); rtp = this_cpu_ptr(&radix_tree_preloads); if (rtp->nr < nr) { node->parent = rtp->nodes; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:407 @ int radix_tree_maybe_preload(gfp_t gfp_m if (gfpflags_allow_blocking(gfp_mask)) return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE); /* Preloading doesn't help anything with this gfp mask, skip it */ - preempt_disable(); + local_lock(radix_tree_preloads_lock); return 0; } EXPORT_SYMBOL(radix_tree_maybe_preload); +void radix_tree_preload_end(void) +{ + local_unlock(radix_tree_preloads_lock); +} +EXPORT_SYMBOL(radix_tree_preload_end); + static unsigned radix_tree_load_root(const struct radix_tree_root *root, struct radix_tree_node **nodep, unsigned long *maxindex) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1502 @ EXPORT_SYMBOL(radix_tree_tagged); void idr_preload(gfp_t gfp_mask) { if (__radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE)) - preempt_disable(); + local_lock(radix_tree_preloads_lock); } EXPORT_SYMBOL(idr_preload); +void idr_preload_end(void) +{ + local_unlock(radix_tree_preloads_lock); +} +EXPORT_SYMBOL(idr_preload_end); + void __rcu **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, unsigned long max) Index: linux-5.0.19-rt11/lib/scatterlist.c =================================================================== --- linux-5.0.19-rt11.orig/lib/scatterlist.c +++ linux-5.0.19-rt11/lib/scatterlist.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:779 @ void sg_miter_stop(struct sg_mapping_ite flush_kernel_dcache_page(miter->page); if (miter->__flags & SG_MITER_ATOMIC) { - WARN_ON_ONCE(preemptible()); + WARN_ON_ONCE(!pagefault_disabled()); kunmap_atomic(miter->addr); } else kunmap(miter->page); Index: linux-5.0.19-rt11/lib/smp_processor_id.c =================================================================== --- linux-5.0.19-rt11.orig/lib/smp_processor_id.c +++ linux-5.0.19-rt11/lib/smp_processor_id.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:25 @ notrace static unsigned int check_preemp * Kernel threads bound to a single CPU can safely use * smp_processor_id(): */ - if (cpumask_equal(¤t->cpus_allowed, cpumask_of(this_cpu))) + if (cpumask_equal(current->cpus_ptr, cpumask_of(this_cpu))) goto out; /* Index: linux-5.0.19-rt11/localversion-rt =================================================================== --- /dev/null +++ linux-5.0.19-rt11/localversion-rt @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1 @ +-rt16 Index: linux-5.0.19-rt11/mm/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/mm/Kconfig +++ linux-5.0.19-rt11/mm/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:375 @ config NOMMU_INITIAL_TRIM_EXCESS config TRANSPARENT_HUGEPAGE bool "Transparent Hugepage Support" - depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE + depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT_FULL select COMPACTION select XARRAY_MULTI help Index: linux-5.0.19-rt11/mm/compaction.c =================================================================== --- linux-5.0.19-rt11.orig/mm/compaction.c +++ linux-5.0.19-rt11/mm/compaction.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1661 @ check_drain: block_start_pfn(cc->migrate_pfn, cc->order); if (cc->last_migrated_pfn < current_block_start) { - cpu = get_cpu(); + cpu = get_cpu_light(); + local_lock_irq(swapvec_lock); lru_add_drain_cpu(cpu); + local_unlock_irq(swapvec_lock); drain_local_pages(zone); - put_cpu(); + put_cpu_light(); /* No more flushing until we migrate again */ cc->last_migrated_pfn = 0; } Index: linux-5.0.19-rt11/mm/highmem.c =================================================================== --- linux-5.0.19-rt11.orig/mm/highmem.c +++ linux-5.0.19-rt11/mm/highmem.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:33 @ #include <linux/kgdb.h> #include <asm/tlbflush.h> - +#ifndef CONFIG_PREEMPT_RT_FULL #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) DEFINE_PER_CPU(int, __kmap_atomic_idx); +EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx); +#endif #endif /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:113 @ static inline wait_queue_head_t *get_pkm atomic_long_t _totalhigh_pages __read_mostly; EXPORT_SYMBOL(_totalhigh_pages); -EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx); - unsigned int nr_free_highpages (void) { struct zone *zone; Index: linux-5.0.19-rt11/mm/kmemleak.c =================================================================== --- linux-5.0.19-rt11.orig/mm/kmemleak.c +++ linux-5.0.19-rt11/mm/kmemleak.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:29 @ * * The following locks and mutexes are used by kmemleak: * - * - kmemleak_lock (rwlock): protects the object_list modifications and + * - kmemleak_lock (raw spinlock): protects the object_list modifications and * accesses to the object_tree_root. The object_list is the main list * holding the metadata (struct kmemleak_object) for the allocated memory * blocks. The object_tree_root is a red black tree used to look-up @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:202 @ static LIST_HEAD(gray_list); /* search tree for object boundaries */ static struct rb_root object_tree_root = RB_ROOT; /* rw_lock protecting the access to object_list and object_tree_root */ -static DEFINE_RWLOCK(kmemleak_lock); +static DEFINE_RAW_SPINLOCK(kmemleak_lock); /* allocation caches for kmemleak internal data */ static struct kmem_cache *object_cache; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:518 @ static struct kmemleak_object *find_and_ struct kmemleak_object *object; rcu_read_lock(); - read_lock_irqsave(&kmemleak_lock, flags); + raw_spin_lock_irqsave(&kmemleak_lock, flags); object = lookup_object(ptr, alias); - read_unlock_irqrestore(&kmemleak_lock, flags); + raw_spin_unlock_irqrestore(&kmemleak_lock, flags); /* check whether the object is still available */ if (object && !get_object(object)) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:540 @ static struct kmemleak_object *find_and_ unsigned long flags; struct kmemleak_object *object; - write_lock_irqsave(&kmemleak_lock, flags); + raw_spin_lock_irqsave(&kmemleak_lock, flags); object = lookup_object(ptr, alias); if (object) { rb_erase(&object->rb_node, &object_tree_root); list_del_rcu(&object->object_list); } - write_unlock_irqrestore(&kmemleak_lock, flags); + raw_spin_unlock_irqrestore(&kmemleak_lock, flags); return object; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:621 @ static struct kmemleak_object *create_ob /* kernel backtrace */ object->trace_len = __save_stack_trace(object->trace); - write_lock_irqsave(&kmemleak_lock, flags); + raw_spin_lock_irqsave(&kmemleak_lock, flags); untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr); min_addr = min(min_addr, untagged_ptr); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:653 @ static struct kmemleak_object *create_ob list_add_tail_rcu(&object->object_list, &object_list); out: - write_unlock_irqrestore(&kmemleak_lock, flags); + raw_spin_unlock_irqrestore(&kmemleak_lock, flags); return object; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1340 @ static void scan_block(void *_start, voi unsigned long flags; unsigned long untagged_ptr; - read_lock_irqsave(&kmemleak_lock, flags); + raw_spin_lock_irqsave(&kmemleak_lock, flags); for (ptr = start; ptr < end; ptr++) { struct kmemleak_object *object; unsigned long pointer; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1398 @ static void scan_block(void *_start, voi spin_unlock(&object->lock); } } - read_unlock_irqrestore(&kmemleak_lock, flags); + raw_spin_unlock_irqrestore(&kmemleak_lock, flags); } /* Index: linux-5.0.19-rt11/mm/memcontrol.c =================================================================== --- linux-5.0.19-rt11.orig/mm/memcontrol.c +++ linux-5.0.19-rt11/mm/memcontrol.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:72 @ #include <net/sock.h> #include <net/ip.h> #include "slab.h" +#include <linux/locallock.h> #include <linux/uaccess.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:98 @ int do_swap_account __read_mostly; #define do_swap_account 0 #endif +static DEFINE_LOCAL_IRQ_LOCK(event_lock); + /* Whether legacy memory+swap accounting is active */ static bool do_memsw_account(void) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2078 @ static void drain_all_stock(struct mem_c * as well as workers from this path always operate on the local * per-cpu data. CPU up doesn't touch memcg_stock at all. */ - curcpu = get_cpu(); + curcpu = get_cpu_light(); for_each_online_cpu(cpu) { struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); struct mem_cgroup *memcg; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2098 @ static void drain_all_stock(struct mem_c } css_put(&memcg->css); } - put_cpu(); + put_cpu_light(); mutex_unlock(&percpu_charge_mutex); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4875 @ static int mem_cgroup_move_account(struc ret = 0; - local_irq_disable(); + local_lock_irq(event_lock); mem_cgroup_charge_statistics(to, page, compound, nr_pages); memcg_check_events(to, page); mem_cgroup_charge_statistics(from, page, compound, -nr_pages); memcg_check_events(from, page); - local_irq_enable(); + local_unlock_irq(event_lock); out_unlock: unlock_page(page); out: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5999 @ void mem_cgroup_commit_charge(struct pag commit_charge(page, memcg, lrucare); - local_irq_disable(); + local_lock_irq(event_lock); mem_cgroup_charge_statistics(memcg, page, compound, nr_pages); memcg_check_events(memcg, page); - local_irq_enable(); + local_unlock_irq(event_lock); if (do_memsw_account() && PageSwapCache(page)) { swp_entry_t entry = { .val = page_private(page) }; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6071 @ static void uncharge_batch(const struct memcg_oom_recover(ug->memcg); } - local_irq_save(flags); + local_lock_irqsave(event_lock, flags); __mod_memcg_state(ug->memcg, MEMCG_RSS, -ug->nr_anon); __mod_memcg_state(ug->memcg, MEMCG_CACHE, -ug->nr_file); __mod_memcg_state(ug->memcg, MEMCG_RSS_HUGE, -ug->nr_huge); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6079 @ static void uncharge_batch(const struct __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); __this_cpu_add(ug->memcg->stat_cpu->nr_page_events, nr_pages); memcg_check_events(ug->memcg, ug->dummy_page); - local_irq_restore(flags); + local_unlock_irqrestore(event_lock, flags); if (!mem_cgroup_is_root(ug->memcg)) css_put_many(&ug->memcg->css, nr_pages); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6242 @ void mem_cgroup_migrate(struct page *old commit_charge(newpage, memcg, false); - local_irq_save(flags); + local_lock_irqsave(event_lock, flags); mem_cgroup_charge_statistics(memcg, newpage, compound, nr_pages); memcg_check_events(memcg, newpage); - local_irq_restore(flags); + local_unlock_irqrestore(event_lock, flags); } DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6437 @ void mem_cgroup_swapout(struct page *pag struct mem_cgroup *memcg, *swap_memcg; unsigned int nr_entries; unsigned short oldid; + unsigned long flags; VM_BUG_ON_PAGE(PageLRU(page), page); VM_BUG_ON_PAGE(page_count(page), page); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6483 @ void mem_cgroup_swapout(struct page *pag * important here to have the interrupts disabled because it is the * only synchronisation we have for updating the per-CPU variables. */ + local_lock_irqsave(event_lock, flags); +#ifndef CONFIG_PREEMPT_RT_BASE VM_BUG_ON(!irqs_disabled()); +#endif mem_cgroup_charge_statistics(memcg, page, PageTransHuge(page), -nr_entries); memcg_check_events(memcg, page); if (!mem_cgroup_is_root(memcg)) css_put_many(&memcg->css, nr_entries); + local_unlock_irqrestore(event_lock, flags); } /** Index: linux-5.0.19-rt11/mm/mmu_context.c =================================================================== --- linux-5.0.19-rt11.orig/mm/mmu_context.c +++ linux-5.0.19-rt11/mm/mmu_context.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:28 @ void use_mm(struct mm_struct *mm) struct task_struct *tsk = current; task_lock(tsk); + preempt_disable_rt(); active_mm = tsk->active_mm; if (active_mm != mm) { mmgrab(mm); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:36 @ void use_mm(struct mm_struct *mm) } tsk->mm = mm; switch_mm(active_mm, mm, tsk); + preempt_enable_rt(); task_unlock(tsk); #ifdef finish_arch_post_lock_switch finish_arch_post_lock_switch(); Index: linux-5.0.19-rt11/mm/page_alloc.c =================================================================== --- linux-5.0.19-rt11.orig/mm/page_alloc.c +++ linux-5.0.19-rt11/mm/page_alloc.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:63 @ #include <linux/hugetlb.h> #include <linux/sched/rt.h> #include <linux/sched/mm.h> +#include <linux/locallock.h> #include <linux/page_owner.h> #include <linux/kthread.h> #include <linux/memcontrol.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:312 @ EXPORT_SYMBOL(nr_node_ids); EXPORT_SYMBOL(nr_online_nodes); #endif +static DEFINE_LOCAL_IRQ_LOCK(pa_lock); + +#ifdef CONFIG_PREEMPT_RT_BASE +# define cpu_lock_irqsave(cpu, flags) \ + local_lock_irqsave_on(pa_lock, flags, cpu) +# define cpu_unlock_irqrestore(cpu, flags) \ + local_unlock_irqrestore_on(pa_lock, flags, cpu) +#else +# define cpu_lock_irqsave(cpu, flags) local_irq_save(flags) +# define cpu_unlock_irqrestore(cpu, flags) local_irq_restore(flags) +#endif + int page_group_by_mobility_disabled __read_mostly; #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1141 @ static inline void prefetch_buddy(struct } /* - * Frees a number of pages from the PCP lists + * Frees a number of pages which have been collected from the pcp lists. * Assumes all pages on list are in same zone, and of same order. * count is the number of pages to free. * @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1151 @ static inline void prefetch_buddy(struct * And clear the zone's pages_scanned counter, to hold off the "all pages are * pinned" detection logic. */ -static void free_pcppages_bulk(struct zone *zone, int count, - struct per_cpu_pages *pcp) +static void free_pcppages_bulk(struct zone *zone, struct list_head *head, + bool zone_retry) +{ + bool isolated_pageblocks; + struct page *page, *tmp; + unsigned long flags; + + spin_lock_irqsave(&zone->lock, flags); + isolated_pageblocks = has_isolate_pageblock(zone); + + /* + * Use safe version since after __free_one_page(), + * page->lru.next will not point to original list. + */ + list_for_each_entry_safe(page, tmp, head, lru) { + int mt = get_pcppage_migratetype(page); + + if (page_zone(page) != zone) { + /* + * free_unref_page_list() sorts pages by zone. If we end + * up with pages from a different NUMA nodes belonging + * to the same ZONE index then we need to redo with the + * correct ZONE pointer. Skip the page for now, redo it + * on the next iteration. + */ + WARN_ON_ONCE(zone_retry == false); + if (zone_retry) + continue; + } + + /* MIGRATE_ISOLATE page should not go to pcplists */ + VM_BUG_ON_PAGE(is_migrate_isolate(mt), page); + /* Pageblock could have been isolated meanwhile */ + if (unlikely(isolated_pageblocks)) + mt = get_pageblock_migratetype(page); + + list_del(&page->lru); + __free_one_page(page, page_to_pfn(page), zone, 0, mt); + trace_mm_page_pcpu_drain(page, 0, mt); + } + spin_unlock_irqrestore(&zone->lock, flags); +} + +static void isolate_pcp_pages(int count, struct per_cpu_pages *pcp, + struct list_head *dst) + { int migratetype = 0; int batch_free = 0; int prefetch_nr = 0; - bool isolated_pageblocks; - struct page *page, *tmp; - LIST_HEAD(head); + struct page *page; while (count) { struct list_head *list; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1233 @ static void free_pcppages_bulk(struct zo if (bulkfree_pcp_prepare(page)) continue; - list_add_tail(&page->lru, &head); + list_add_tail(&page->lru, dst); /* * We are going to put the page back to the global @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1248 @ static void free_pcppages_bulk(struct zo prefetch_buddy(page); } while (--count && --batch_free && !list_empty(list)); } - - spin_lock(&zone->lock); - isolated_pageblocks = has_isolate_pageblock(zone); - - /* - * Use safe version since after __free_one_page(), - * page->lru.next will not point to original list. - */ - list_for_each_entry_safe(page, tmp, &head, lru) { - int mt = get_pcppage_migratetype(page); - /* MIGRATE_ISOLATE page should not go to pcplists */ - VM_BUG_ON_PAGE(is_migrate_isolate(mt), page); - /* Pageblock could have been isolated meanwhile */ - if (unlikely(isolated_pageblocks)) - mt = get_pageblock_migratetype(page); - - __free_one_page(page, page_to_pfn(page), zone, 0, mt); - trace_mm_page_pcpu_drain(page, 0, mt); - } - spin_unlock(&zone->lock); } static void free_one_page(struct zone *zone, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1348 @ static void __free_pages_ok(struct page return; migratetype = get_pfnblock_migratetype(page, pfn); - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); __count_vm_events(PGFREE, 1 << order); free_one_page(page_zone(page), page, pfn, order, migratetype); - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); } static void __init __free_pages_boot_core(struct page *page, unsigned int order) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2659 @ void drain_zone_pages(struct zone *zone, { unsigned long flags; int to_drain, batch; + LIST_HEAD(dst); - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); batch = READ_ONCE(pcp->batch); to_drain = min(pcp->count, batch); if (to_drain > 0) - free_pcppages_bulk(zone, to_drain, pcp); - local_irq_restore(flags); + isolate_pcp_pages(to_drain, pcp, &dst); + + local_unlock_irqrestore(pa_lock, flags); + + if (to_drain > 0) + free_pcppages_bulk(zone, &dst, false); } #endif @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2686 @ static void drain_pages_zone(unsigned in unsigned long flags; struct per_cpu_pageset *pset; struct per_cpu_pages *pcp; + LIST_HEAD(dst); + int count; - local_irq_save(flags); + cpu_lock_irqsave(cpu, flags); pset = per_cpu_ptr(zone->pageset, cpu); pcp = &pset->pcp; - if (pcp->count) - free_pcppages_bulk(zone, pcp->count, pcp); - local_irq_restore(flags); + count = pcp->count; + if (count) + isolate_pcp_pages(count, pcp, &dst); + + cpu_unlock_irqrestore(cpu, flags); + + if (count) + free_pcppages_bulk(zone, &dst, false); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2735 @ void drain_local_pages(struct zone *zone drain_pages(cpu); } +#ifndef CONFIG_PREEMPT_RT_BASE static void drain_local_pages_wq(struct work_struct *work) { struct pcpu_drain *drain; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2753 @ static void drain_local_pages_wq(struct drain_local_pages(drain->zone); preempt_enable(); } +#endif /* * Spill all the per-cpu pages from all CPUs back into the buddy allocator. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2821 @ void drain_all_pages(struct zone *zone) cpumask_clear_cpu(cpu, &cpus_with_pcps); } +#ifdef CONFIG_PREEMPT_RT_BASE + for_each_cpu(cpu, &cpus_with_pcps) { + if (zone) + drain_pages_zone(cpu, zone); + else + drain_pages(cpu); + } +#else for_each_cpu(cpu, &cpus_with_pcps) { struct pcpu_drain *drain = per_cpu_ptr(&pcpu_drain, cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2838 @ void drain_all_pages(struct zone *zone) } for_each_cpu(cpu, &cpus_with_pcps) flush_work(&per_cpu_ptr(&pcpu_drain, cpu)->work); +#endif mutex_unlock(&pcpu_drain_mutex); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2910 @ static bool free_unref_page_prepare(stru return true; } -static void free_unref_page_commit(struct page *page, unsigned long pfn) +static void free_unref_page_commit(struct page *page, unsigned long pfn, + struct list_head *dst) { struct zone *zone = page_zone(page); struct per_cpu_pages *pcp; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2940 @ static void free_unref_page_commit(struc pcp->count++; if (pcp->count >= pcp->high) { unsigned long batch = READ_ONCE(pcp->batch); - free_pcppages_bulk(zone, batch, pcp); + + isolate_pcp_pages(batch, pcp, dst); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2952 @ void free_unref_page(struct page *page) { unsigned long flags; unsigned long pfn = page_to_pfn(page); + struct zone *zone = page_zone(page); + LIST_HEAD(dst); if (!free_unref_page_prepare(page, pfn)) return; - local_irq_save(flags); - free_unref_page_commit(page, pfn); - local_irq_restore(flags); + local_lock_irqsave(pa_lock, flags); + free_unref_page_commit(page, pfn, &dst); + local_unlock_irqrestore(pa_lock, flags); + if (!list_empty(&dst)) + free_pcppages_bulk(zone, &dst, false); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2973 @ void free_unref_page_list(struct list_he struct page *page, *next; unsigned long flags, pfn; int batch_count = 0; + struct list_head dsts[__MAX_NR_ZONES]; + int i; + + for (i = 0; i < __MAX_NR_ZONES; i++) + INIT_LIST_HEAD(&dsts[i]); /* Prepare pages for freeing */ list_for_each_entry_safe(page, next, list, lru) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2987 @ void free_unref_page_list(struct list_he set_page_private(page, pfn); } - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); list_for_each_entry_safe(page, next, list, lru) { unsigned long pfn = page_private(page); + enum zone_type type; set_page_private(page, 0); trace_mm_page_free_batched(page); - free_unref_page_commit(page, pfn); + type = page_zonenum(page); + free_unref_page_commit(page, pfn, &dsts[type]); /* * Guard against excessive IRQ disabled times when we get * a large list of pages to free. */ if (++batch_count == SWAP_CLUSTER_MAX) { - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); batch_count = 0; - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); } } - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); + + for (i = 0; i < __MAX_NR_ZONES; ) { + struct page *page; + struct zone *zone; + + if (list_empty(&dsts[i])) { + i++; + continue; + } + + page = list_first_entry(&dsts[i], struct page, lru); + zone = page_zone(page); + + free_pcppages_bulk(zone, &dsts[i], true); + } } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3158 @ static struct page *rmqueue_pcplist(stru struct page *page; unsigned long flags; - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); pcp = &this_cpu_ptr(zone->pageset)->pcp; list = &pcp->lists[migratetype]; page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3166 @ static struct page *rmqueue_pcplist(stru __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); zone_statistics(preferred_zone, zone); } - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); return page; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3193 @ struct page *rmqueue(struct zone *prefer * allocate greater than order-1 page units with __GFP_NOFAIL. */ WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); - spin_lock_irqsave(&zone->lock, flags); + local_spin_lock_irqsave(pa_lock, &zone->lock, flags); do { page = NULL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3213 @ struct page *rmqueue(struct zone *prefer __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); zone_statistics(preferred_zone, zone); - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); out: /* Separate test+clear to avoid unnecessary atomics */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3226 @ out: return page; failed: - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); return NULL; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:7462 @ void __init free_area_init(unsigned long static int page_alloc_cpu_dead(unsigned int cpu) { - + local_lock_irq_on(swapvec_lock, cpu); lru_add_drain_cpu(cpu); + local_unlock_irq_on(swapvec_lock, cpu); drain_pages(cpu); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8397 @ void zone_pcp_reset(struct zone *zone) struct per_cpu_pageset *pset; /* avoid races with drain_pages() */ - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); if (zone->pageset != &boot_pageset) { for_each_online_cpu(cpu) { pset = per_cpu_ptr(zone->pageset, cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8406 @ void zone_pcp_reset(struct zone *zone) free_percpu(zone->pageset); zone->pageset = &boot_pageset; } - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); } #ifdef CONFIG_MEMORY_HOTREMOVE Index: linux-5.0.19-rt11/mm/slab.c =================================================================== --- linux-5.0.19-rt11.orig/mm/slab.c +++ linux-5.0.19-rt11/mm/slab.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:236 @ static void kmem_cache_node_init(struct parent->shared = NULL; parent->alien = NULL; parent->colour_next = 0; - spin_lock_init(&parent->list_lock); + raw_spin_lock_init(&parent->list_lock); parent->free_objects = 0; parent->free_touched = 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:590 @ static noinline void cache_free_pfmemall page_node = page_to_nid(page); n = get_node(cachep, page_node); - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); free_block(cachep, &objp, 1, page_node, &list); - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); slabs_destroy(cachep, &list); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:721 @ static void __drain_alien_cache(struct k struct kmem_cache_node *n = get_node(cachep, node); if (ac->avail) { - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); /* * Stuff objects into the remote nodes shared array first. * That way we could avoid the overhead of putting the objects @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:732 @ static void __drain_alien_cache(struct k free_block(cachep, ac->entry, ac->avail, node, list); ac->avail = 0; - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:805 @ static int __cache_free_alien(struct kme slabs_destroy(cachep, &list); } else { n = get_node(cachep, page_node); - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); free_block(cachep, &objp, 1, page_node, &list); - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); slabs_destroy(cachep, &list); } return 1; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:848 @ static int init_cache_node(struct kmem_c */ n = get_node(cachep, node); if (n) { - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num; - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:930 @ static int setup_kmem_cache_node(struct goto fail; n = get_node(cachep, node); - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); if (n->shared && force_change) { free_block(cachep, n->shared->entry, n->shared->avail, node, &list); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:948 @ static int setup_kmem_cache_node(struct new_alien = NULL; } - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); slabs_destroy(cachep, &list); /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:987 @ static void cpuup_canceled(long cpu) if (!n) continue; - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); /* Free limit for this kmem_cache_node */ n->free_limit -= cachep->batchcount; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1000 @ static void cpuup_canceled(long cpu) } if (!cpumask_empty(mask)) { - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); goto free_slab; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1014 @ static void cpuup_canceled(long cpu) alien = n->alien; n->alien = NULL; - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); kfree(shared); if (alien) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1198 @ static void __init init_list(struct kmem /* * Do not assume that spinlocks can be initialized via memcpy: */ - spin_lock_init(&ptr->list_lock); + raw_spin_lock_init(&ptr->list_lock); MAKE_ALL_LISTS(cachep, ptr, nodeid); cachep->node[nodeid] = ptr; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1369 @ slab_out_of_memory(struct kmem_cache *ca for_each_kmem_cache_node(cachep, node, n) { unsigned long total_slabs, free_slabs, free_objs; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); total_slabs = n->total_slabs; free_slabs = n->free_slabs; free_objs = n->free_objects; - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); pr_warn(" node %d: slabs: %ld/%ld, objs: %ld/%ld\n", node, total_slabs - free_slabs, total_slabs, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2168 @ static void check_spinlock_acquired(stru { #ifdef CONFIG_SMP check_irq_off(); - assert_spin_locked(&get_node(cachep, numa_mem_id())->list_lock); + assert_raw_spin_locked(&get_node(cachep, numa_mem_id())->list_lock); #endif } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2176 @ static void check_spinlock_acquired_node { #ifdef CONFIG_SMP check_irq_off(); - assert_spin_locked(&get_node(cachep, node)->list_lock); + assert_raw_spin_locked(&get_node(cachep, node)->list_lock); #endif } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2216 @ static void do_drain(void *arg) check_irq_off(); ac = cpu_cache_get(cachep); n = get_node(cachep, node); - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); free_block(cachep, ac->entry, ac->avail, node, &list); - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); slabs_destroy(cachep, &list); ac->avail = 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2236 @ static void drain_cpu_caches(struct kmem drain_alien_cache(cachep, n->alien); for_each_kmem_cache_node(cachep, node, n) { - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); drain_array_locked(cachep, n->shared, node, true, &list); - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); slabs_destroy(cachep, &list); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2260 @ static int drain_freelist(struct kmem_ca nr_freed = 0; while (nr_freed < tofree && !list_empty(&n->slabs_free)) { - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); p = n->slabs_free.prev; if (p == &n->slabs_free) { - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); goto out; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2276 @ static int drain_freelist(struct kmem_ca * to the cache. */ n->free_objects -= cache->num; - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); slab_destroy(cache, page); nr_freed++; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2730 @ static void cache_grow_end(struct kmem_c INIT_LIST_HEAD(&page->lru); n = get_node(cachep, page_to_nid(page)); - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); n->total_slabs++; if (!page->active) { list_add_tail(&page->lru, &(n->slabs_free)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2740 @ static void cache_grow_end(struct kmem_c STATS_INC_GROWN(cachep); n->free_objects += cachep->num - page->active; - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); fixup_objfreelist_debug(cachep, &list); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2908 @ static struct page *get_first_slab(struc { struct page *page; - assert_spin_locked(&n->list_lock); + assert_raw_spin_locked(&n->list_lock); page = list_first_entry_or_null(&n->slabs_partial, struct page, lru); if (!page) { n->free_touched = 1; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2934 @ static noinline void *cache_alloc_pfmema if (!gfp_pfmemalloc_allowed(flags)) return NULL; - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); page = get_first_slab(n, true); if (!page) { - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); return NULL; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2946 @ static noinline void *cache_alloc_pfmema fixup_slab_list(cachep, n, page, &list); - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); fixup_objfreelist_debug(cachep, &list); return obj; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3005 @ static void *cache_alloc_refill(struct k if (!n->free_objects && (!shared || !shared->avail)) goto direct_grow; - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); shared = READ_ONCE(n->shared); /* See if we can refill from the shared array */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3029 @ static void *cache_alloc_refill(struct k must_grow: n->free_objects -= ac->avail; alloc_done: - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); fixup_objfreelist_debug(cachep, &list); direct_grow: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3254 @ static void *____cache_alloc_node(struct BUG_ON(!n); check_irq_off(); - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); page = get_first_slab(n, false); if (!page) goto must_grow; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3272 @ static void *____cache_alloc_node(struct fixup_slab_list(cachep, n, page, &list); - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); fixup_objfreelist_debug(cachep, &list); return obj; must_grow: - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); page = cache_grow_begin(cachep, gfp_exact_node(flags), nodeid); if (page) { /* This slab isn't counted yet so don't update free_objects */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3453 @ static void cache_flusharray(struct kmem check_irq_off(); n = get_node(cachep, node); - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); if (n->shared) { struct array_cache *shared_array = n->shared; int max = shared_array->limit - shared_array->avail; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3482 @ free_done: STATS_SET_FREEABLE(cachep, i); } #endif - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); slabs_destroy(cachep, &list); ac->avail -= batchcount; memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3890 @ static int __do_tune_cpucache(struct kme node = cpu_to_mem(cpu); n = get_node(cachep, node); - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); free_block(cachep, ac->entry, ac->avail, node, &list); - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); slabs_destroy(cachep, &list); } free_percpu(prev); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4017 @ static void drain_array(struct kmem_cach return; } - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); drain_array_locked(cachep, ac, node, false, &list); - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); slabs_destroy(cachep, &list); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4103 @ void get_slabinfo(struct kmem_cache *cac for_each_kmem_cache_node(cachep, node, n) { check_irq_on(); - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); total_slabs += n->total_slabs; free_slabs += n->free_slabs; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4112 @ void get_slabinfo(struct kmem_cache *cac if (n->shared) shared_avail += n->shared->avail; - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); } num_objs = total_slabs * cachep->num; active_slabs = total_slabs - free_slabs; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4328 @ static int leaks_show(struct seq_file *m for_each_kmem_cache_node(cachep, node, n) { check_irq_on(); - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); list_for_each_entry(page, &n->slabs_full, lru) handle_slab(x, cachep, page); list_for_each_entry(page, &n->slabs_partial, lru) handle_slab(x, cachep, page); - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); } } while (!is_store_user_clean(cachep)); Index: linux-5.0.19-rt11/mm/slab.h =================================================================== --- linux-5.0.19-rt11.orig/mm/slab.h +++ linux-5.0.19-rt11/mm/slab.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:456 @ static inline void slab_post_alloc_hook( * The slab lists for all objects. */ struct kmem_cache_node { - spinlock_t list_lock; + raw_spinlock_t list_lock; #ifdef CONFIG_SLAB struct list_head slabs_partial; /* partial list first, better asm code */ Index: linux-5.0.19-rt11/mm/slub.c =================================================================== --- linux-5.0.19-rt11.orig/mm/slub.c +++ linux-5.0.19-rt11/mm/slub.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1187 @ static noinline int free_debug_processin unsigned long uninitialized_var(flags); int ret = 0; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); slab_lock(page); if (s->flags & SLAB_CONSISTENCY_CHECKS) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1222 @ out: bulk_cnt, cnt); slab_unlock(page); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); if (!ret) slab_fix(s, "Object at 0x%p not freed", object); return ret; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1390 @ static inline void dec_slabs_node(struct #endif /* CONFIG_SLUB_DEBUG */ +struct slub_free_list { + raw_spinlock_t lock; + struct list_head list; +}; +static DEFINE_PER_CPU(struct slub_free_list, slub_free_list); + /* * Hooks for other subsystems that check memory allocations. In a typical * production configuration these hooks all should produce no code at all. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1633 @ static struct page *allocate_slab(struct void *start, *p, *next; int idx, order; bool shuffle; + bool enableirqs = false; flags &= gfp_allowed_mask; if (gfpflags_allow_blocking(flags)) + enableirqs = true; + +#ifdef CONFIG_PREEMPT_RT_FULL + if (system_state > SYSTEM_BOOTING) + enableirqs = true; +#endif + if (enableirqs) local_irq_enable(); flags |= s->allocflags; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1704 @ static struct page *allocate_slab(struct page->frozen = 1; out: - if (gfpflags_allow_blocking(flags)) + if (enableirqs) local_irq_disable(); if (!page) return NULL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1762 @ static void __free_slab(struct kmem_cach __free_pages(page, order); } +static void free_delayed(struct list_head *h) +{ + while (!list_empty(h)) { + struct page *page = list_first_entry(h, struct page, lru); + + list_del(&page->lru); + __free_slab(page->slab_cache, page); + } +} + static void rcu_free_slab(struct rcu_head *h) { struct page *page = container_of(h, struct page, rcu_head); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1783 @ static void free_slab(struct kmem_cache { if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU)) { call_rcu(&page->rcu_head, rcu_free_slab); + } else if (irqs_disabled()) { + struct slub_free_list *f = this_cpu_ptr(&slub_free_list); + + raw_spin_lock(&f->lock); + list_add(&page->lru, &f->list); + raw_spin_unlock(&f->lock); } else __free_slab(s, page); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1896 @ static void *get_partial_node(struct kme if (!n || !n->nr_partial) return NULL; - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); list_for_each_entry_safe(page, page2, &n->partial, lru) { void *t; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1921 @ static void *get_partial_node(struct kme break; } - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); return object; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2167 @ redo: * that acquire_slab() will see a slab page that * is frozen */ - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); } } else { m = M_FULL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2178 @ redo: * slabs from diagnostic functions will not see * any frozen slabs. */ - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2202 @ redo: goto redo; if (lock) - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); if (m == M_PARTIAL) stat(s, tail); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2241 @ static void unfreeze_partials(struct kme n2 = get_node(s, page_to_nid(page)); if (n != n2) { if (n) - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); n = n2; - spin_lock(&n->list_lock); + raw_spin_lock(&n->list_lock); } do { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2273 @ static void unfreeze_partials(struct kme } if (n) - spin_unlock(&n->list_lock); + raw_spin_unlock(&n->list_lock); while (discard_page) { page = discard_page; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2310 @ static void put_cpu_partial(struct kmem_ pobjects = oldpage->pobjects; pages = oldpage->pages; if (drain && pobjects > s->cpu_partial) { + struct slub_free_list *f; unsigned long flags; + LIST_HEAD(tofree); /* * partial array is full. Move the existing * set to the per node partial list. */ local_irq_save(flags); unfreeze_partials(s, this_cpu_ptr(s->cpu_slab)); + f = this_cpu_ptr(&slub_free_list); + raw_spin_lock(&f->lock); + list_splice_init(&f->list, &tofree); + raw_spin_unlock(&f->lock); local_irq_restore(flags); + free_delayed(&tofree); oldpage = NULL; pobjects = 0; pages = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2392 @ static bool has_cpu_slab(int cpu, void * static void flush_all(struct kmem_cache *s) { + LIST_HEAD(tofree); + int cpu; + on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC); + for_each_online_cpu(cpu) { + struct slub_free_list *f; + + if (!has_cpu_slab(cpu, s)) + continue; + + f = &per_cpu(slub_free_list, cpu); + raw_spin_lock_irq(&f->lock); + list_splice_init(&f->list, &tofree); + raw_spin_unlock_irq(&f->lock); + free_delayed(&tofree); + } } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2462 @ static unsigned long count_partial(struc unsigned long x = 0; struct page *page; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); list_for_each_entry(page, &n->partial, lru) x += get_count(page); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); return x; } #endif /* CONFIG_SLUB_DEBUG || CONFIG_SYSFS */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2605 @ static inline void *get_freelist(struct * already disabled (which is the case for bulk allocation). */ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, - unsigned long addr, struct kmem_cache_cpu *c) + unsigned long addr, struct kmem_cache_cpu *c, + struct list_head *to_free) { + struct slub_free_list *f; void *freelist; struct page *page; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2664 @ load_freelist: VM_BUG_ON(!c->page->frozen); c->freelist = get_freepointer(s, freelist); c->tid = next_tid(c->tid); + +out: + f = this_cpu_ptr(&slub_free_list); + raw_spin_lock(&f->lock); + list_splice_init(&f->list, to_free); + raw_spin_unlock(&f->lock); + return freelist; new_slab: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2686 @ new_slab: if (unlikely(!freelist)) { slab_out_of_memory(s, gfpflags, node); - return NULL; + goto out; } page = c->page; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2699 @ new_slab: goto new_slab; /* Slab failed checks. Next slab needed */ deactivate_slab(s, page, get_freepointer(s, freelist), c); - return freelist; + goto out; } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2711 @ static void *__slab_alloc(struct kmem_ca { void *p; unsigned long flags; + LIST_HEAD(tofree); local_irq_save(flags); #ifdef CONFIG_PREEMPT @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2723 @ static void *__slab_alloc(struct kmem_ca c = this_cpu_ptr(s->cpu_slab); #endif - p = ___slab_alloc(s, gfpflags, node, addr, c); + p = ___slab_alloc(s, gfpflags, node, addr, c, &tofree); local_irq_restore(flags); + free_delayed(&tofree); return p; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2911 @ static void __slab_free(struct kmem_cach do { if (unlikely(n)) { - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); n = NULL; } prior = page->freelist; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2943 @ static void __slab_free(struct kmem_cach * Otherwise the list_lock will synchronize with * other processors updating the list of slabs. */ - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2985 @ static void __slab_free(struct kmem_cach add_partial(n, page, DEACTIVATE_TO_TAIL); stat(s, FREE_ADD_PARTIAL); } - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); return; slab_empty: @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3000 @ slab_empty: remove_full(s, n, page); } - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); stat(s, FREE_SLAB); discard_slab(s, page); } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3203 @ int kmem_cache_alloc_bulk(struct kmem_ca void **p) { struct kmem_cache_cpu *c; + LIST_HEAD(to_free); int i; /* memcg and kmem_cache debug support */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3227 @ int kmem_cache_alloc_bulk(struct kmem_ca * of re-populating per CPU c->freelist */ p[i] = ___slab_alloc(s, flags, NUMA_NO_NODE, - _RET_IP_, c); + _RET_IP_, c, &to_free); if (unlikely(!p[i])) goto error; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3239 @ int kmem_cache_alloc_bulk(struct kmem_ca } c->tid = next_tid(c->tid); local_irq_enable(); + free_delayed(&to_free); /* Clear memory outside IRQ disabled fastpath loop */ if (unlikely(flags & __GFP_ZERO)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3254 @ int kmem_cache_alloc_bulk(struct kmem_ca return i; error: local_irq_enable(); + free_delayed(&to_free); slab_post_alloc_hook(s, flags, i, p); __kmem_cache_free_bulk(s, i, p); return 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3390 @ static void init_kmem_cache_node(struct kmem_cache_node *n) { n->nr_partial = 0; - spin_lock_init(&n->list_lock); + raw_spin_lock_init(&n->list_lock); INIT_LIST_HEAD(&n->partial); #ifdef CONFIG_SLUB_DEBUG atomic_long_set(&n->nr_slabs, 0); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3743 @ static void list_slab_objects(struct kme const char *text) { #ifdef CONFIG_SLUB_DEBUG +#ifdef CONFIG_PREEMPT_RT_BASE + /* XXX move out of irq-off section */ + slab_err(s, page, text, s->name); +#else + void *addr = page_address(page); void *p; unsigned long *map = bitmap_zalloc(page->objects, GFP_ATOMIC); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3767 @ static void list_slab_objects(struct kme slab_unlock(page); bitmap_free(map); #endif +#endif } + /* * Attempt to free all partial slabs on a node. * This is called from __kmem_cache_shutdown(). We must take list_lock @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3782 @ static void free_partial(struct kmem_cac struct page *page, *h; BUG_ON(irqs_disabled()); - spin_lock_irq(&n->list_lock); + raw_spin_lock_irq(&n->list_lock); list_for_each_entry_safe(page, h, &n->partial, lru) { if (!page->inuse) { remove_partial(n, page); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3792 @ static void free_partial(struct kmem_cac "Objects remaining in %s on __kmem_cache_shutdown()"); } } - spin_unlock_irq(&n->list_lock); + raw_spin_unlock_irq(&n->list_lock); list_for_each_entry_safe(page, h, &discard, lru) discard_slab(s, page); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4066 @ int __kmem_cache_shrink(struct kmem_cach for (i = 0; i < SHRINK_PROMOTE_MAX; i++) INIT_LIST_HEAD(promote + i); - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); /* * Build lists of slabs to discard or promote. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4097 @ int __kmem_cache_shrink(struct kmem_cach for (i = SHRINK_PROMOTE_MAX - 1; i >= 0; i--) list_splice(promote + i, &n->partial); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); /* Release empty slabs */ list_for_each_entry_safe(page, t, &discard, lru) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4310 @ void __init kmem_cache_init(void) { static __initdata struct kmem_cache boot_kmem_cache, boot_kmem_cache_node; + int cpu; + + for_each_possible_cpu(cpu) { + raw_spin_lock_init(&per_cpu(slub_free_list, cpu).lock); + INIT_LIST_HEAD(&per_cpu(slub_free_list, cpu).list); + } if (debug_guardpage_minorder()) slub_max_order = 0; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4517 @ static int validate_slab_node(struct kme struct page *page; unsigned long flags; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); list_for_each_entry(page, &n->partial, lru) { validate_slab_slab(s, page, map); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4539 @ static int validate_slab_node(struct kme s->name, count, atomic_long_read(&n->nr_slabs)); out: - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); return count; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4725 @ static int list_locations(struct kmem_ca if (!atomic_long_read(&n->nr_slabs)) continue; - spin_lock_irqsave(&n->list_lock, flags); + raw_spin_lock_irqsave(&n->list_lock, flags); list_for_each_entry(page, &n->partial, lru) process_slab(&t, s, page, alloc, map); list_for_each_entry(page, &n->full, lru) process_slab(&t, s, page, alloc, map); - spin_unlock_irqrestore(&n->list_lock, flags); + raw_spin_unlock_irqrestore(&n->list_lock, flags); } for (i = 0; i < t.count; i++) { Index: linux-5.0.19-rt11/mm/swap.c =================================================================== --- linux-5.0.19-rt11.orig/mm/swap.c +++ linux-5.0.19-rt11/mm/swap.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:35 @ #include <linux/memcontrol.h> #include <linux/gfp.h> #include <linux/uio.h> +#include <linux/locallock.h> #include <linux/hugetlb.h> #include <linux/page_idle.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:54 @ static DEFINE_PER_CPU(struct pagevec, lr #ifdef CONFIG_SMP static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs); #endif +static DEFINE_LOCAL_IRQ_LOCK(rotate_lock); +DEFINE_LOCAL_IRQ_LOCK(swapvec_lock); /* * This path almost never happens for VM activity - pages are normally @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:258 @ void rotate_reclaimable_page(struct page unsigned long flags; get_page(page); - local_irq_save(flags); + local_lock_irqsave(rotate_lock, flags); pvec = this_cpu_ptr(&lru_rotate_pvecs); if (!pagevec_add(pvec, page) || PageCompound(page)) pagevec_move_tail(pvec); - local_irq_restore(flags); + local_unlock_irqrestore(rotate_lock, flags); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:312 @ void activate_page(struct page *page) { page = compound_head(page); if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { - struct pagevec *pvec = &get_cpu_var(activate_page_pvecs); + struct pagevec *pvec = &get_locked_var(swapvec_lock, + activate_page_pvecs); get_page(page); if (!pagevec_add(pvec, page) || PageCompound(page)) pagevec_lru_move_fn(pvec, __activate_page, NULL); - put_cpu_var(activate_page_pvecs); + put_locked_var(swapvec_lock, activate_page_pvecs); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:340 @ void activate_page(struct page *page) static void __lru_cache_activate_page(struct page *page) { - struct pagevec *pvec = &get_cpu_var(lru_add_pvec); + struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec); int i; /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:362 @ static void __lru_cache_activate_page(st } } - put_cpu_var(lru_add_pvec); + put_locked_var(swapvec_lock, lru_add_pvec); } /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:404 @ EXPORT_SYMBOL(mark_page_accessed); static void __lru_cache_add(struct page *page) { - struct pagevec *pvec = &get_cpu_var(lru_add_pvec); + struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec); get_page(page); if (!pagevec_add(pvec, page) || PageCompound(page)) __pagevec_lru_add(pvec); - put_cpu_var(lru_add_pvec); + put_locked_var(swapvec_lock, lru_add_pvec); } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:587 @ void lru_add_drain_cpu(int cpu) unsigned long flags; /* No harm done if a racing interrupt already did this */ - local_irq_save(flags); +#ifdef CONFIG_PREEMPT_RT_BASE + local_lock_irqsave_on(rotate_lock, flags, cpu); pagevec_move_tail(pvec); - local_irq_restore(flags); + local_unlock_irqrestore_on(rotate_lock, flags, cpu); +#else + local_lock_irqsave(rotate_lock, flags); + pagevec_move_tail(pvec); + local_unlock_irqrestore(rotate_lock, flags); +#endif } pvec = &per_cpu(lru_deactivate_file_pvecs, cpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:627 @ void deactivate_file_page(struct page *p return; if (likely(get_page_unless_zero(page))) { - struct pagevec *pvec = &get_cpu_var(lru_deactivate_file_pvecs); + struct pagevec *pvec = &get_locked_var(swapvec_lock, + lru_deactivate_file_pvecs); if (!pagevec_add(pvec, page) || PageCompound(page)) pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL); - put_cpu_var(lru_deactivate_file_pvecs); + put_locked_var(swapvec_lock, lru_deactivate_file_pvecs); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:647 @ void mark_page_lazyfree(struct page *pag { if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && !PageSwapCache(page) && !PageUnevictable(page)) { - struct pagevec *pvec = &get_cpu_var(lru_lazyfree_pvecs); + struct pagevec *pvec = &get_locked_var(swapvec_lock, + lru_lazyfree_pvecs); get_page(page); if (!pagevec_add(pvec, page) || PageCompound(page)) pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL); - put_cpu_var(lru_lazyfree_pvecs); + put_locked_var(swapvec_lock, lru_lazyfree_pvecs); } } void lru_add_drain(void) { - lru_add_drain_cpu(get_cpu()); - put_cpu(); + lru_add_drain_cpu(local_lock_cpu(swapvec_lock)); + local_unlock_cpu(swapvec_lock); } #ifdef CONFIG_SMP +#ifdef CONFIG_PREEMPT_RT_BASE +static inline void remote_lru_add_drain(int cpu, struct cpumask *has_work) +{ + local_lock_on(swapvec_lock, cpu); + lru_add_drain_cpu(cpu); + local_unlock_on(swapvec_lock, cpu); +} + +#else + static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); static void lru_add_drain_per_cpu(struct work_struct *dummy) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:682 @ static void lru_add_drain_per_cpu(struct lru_add_drain(); } +static inline void remote_lru_add_drain(int cpu, struct cpumask *has_work) +{ + struct work_struct *work = &per_cpu(lru_add_drain_work, cpu); + + INIT_WORK(work, lru_add_drain_per_cpu); + queue_work_on(cpu, mm_percpu_wq, work); + cpumask_set_cpu(cpu, has_work); +} +#endif + /* * Doesn't need any cpu hotplug locking because we do rely on per-cpu * kworkers being shut down before our page_alloc_cpu_dead callback is @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:716 @ void lru_add_drain_all(void) cpumask_clear(&has_work); for_each_online_cpu(cpu) { - struct work_struct *work = &per_cpu(lru_add_drain_work, cpu); if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) || pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) || pagevec_count(&per_cpu(lru_deactivate_file_pvecs, cpu)) || pagevec_count(&per_cpu(lru_lazyfree_pvecs, cpu)) || - need_activate_page_drain(cpu)) { - INIT_WORK(work, lru_add_drain_per_cpu); - queue_work_on(cpu, mm_percpu_wq, work); - cpumask_set_cpu(cpu, &has_work); - } + need_activate_page_drain(cpu)) + remote_lru_add_drain(cpu, &has_work); } +#ifndef CONFIG_PREEMPT_RT_BASE for_each_cpu(cpu, &has_work) flush_work(&per_cpu(lru_add_drain_work, cpu)); +#endif mutex_unlock(&lock); } Index: linux-5.0.19-rt11/mm/vmalloc.c =================================================================== --- linux-5.0.19-rt11.orig/mm/vmalloc.c +++ linux-5.0.19-rt11/mm/vmalloc.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:855 @ static void *new_vmap_block(unsigned int struct vmap_block *vb; struct vmap_area *va; unsigned long vb_idx; - int node, err; + int node, err, cpu; void *vaddr; node = numa_node_id(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:898 @ static void *new_vmap_block(unsigned int BUG_ON(err); radix_tree_preload_end(); - vbq = &get_cpu_var(vmap_block_queue); + cpu = get_cpu_light(); + vbq = this_cpu_ptr(&vmap_block_queue); spin_lock(&vbq->lock); list_add_tail_rcu(&vb->free_list, &vbq->free); spin_unlock(&vbq->lock); - put_cpu_var(vmap_block_queue); + put_cpu_light(); return vaddr; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:972 @ static void *vb_alloc(unsigned long size struct vmap_block *vb; void *vaddr = NULL; unsigned int order; + int cpu; BUG_ON(offset_in_page(size)); BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:987 @ static void *vb_alloc(unsigned long size order = get_order(size); rcu_read_lock(); - vbq = &get_cpu_var(vmap_block_queue); + cpu = get_cpu_light(); + vbq = this_cpu_ptr(&vmap_block_queue); list_for_each_entry_rcu(vb, &vbq->free, free_list) { unsigned long pages_off; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1011 @ static void *vb_alloc(unsigned long size break; } - put_cpu_var(vmap_block_queue); + put_cpu_light(); rcu_read_unlock(); /* Allocate new block if nothing was found */ Index: linux-5.0.19-rt11/mm/vmstat.c =================================================================== --- linux-5.0.19-rt11.orig/mm/vmstat.c +++ linux-5.0.19-rt11/mm/vmstat.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:323 @ void __mod_zone_page_state(struct zone * long x; long t; + preempt_disable_rt(); x = delta + __this_cpu_read(*p); t = __this_cpu_read(pcp->stat_threshold); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:333 @ void __mod_zone_page_state(struct zone * x = 0; } __this_cpu_write(*p, x); + preempt_enable_rt(); } EXPORT_SYMBOL(__mod_zone_page_state); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:345 @ void __mod_node_page_state(struct pglist long x; long t; + preempt_disable_rt(); x = delta + __this_cpu_read(*p); t = __this_cpu_read(pcp->stat_threshold); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:355 @ void __mod_node_page_state(struct pglist x = 0; } __this_cpu_write(*p, x); + preempt_enable_rt(); } EXPORT_SYMBOL(__mod_node_page_state); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:388 @ void __inc_zone_state(struct zone *zone, s8 __percpu *p = pcp->vm_stat_diff + item; s8 v, t; + preempt_disable_rt(); v = __this_cpu_inc_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v > t)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:397 @ void __inc_zone_state(struct zone *zone, zone_page_state_add(v + overstep, zone, item); __this_cpu_write(*p, -overstep); } + preempt_enable_rt(); } void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:406 @ void __inc_node_state(struct pglist_data s8 __percpu *p = pcp->vm_node_stat_diff + item; s8 v, t; + preempt_disable_rt(); v = __this_cpu_inc_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v > t)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:415 @ void __inc_node_state(struct pglist_data node_page_state_add(v + overstep, pgdat, item); __this_cpu_write(*p, -overstep); } + preempt_enable_rt(); } void __inc_zone_page_state(struct page *page, enum zone_stat_item item) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:436 @ void __dec_zone_state(struct zone *zone, s8 __percpu *p = pcp->vm_stat_diff + item; s8 v, t; + preempt_disable_rt(); v = __this_cpu_dec_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v < - t)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:445 @ void __dec_zone_state(struct zone *zone, zone_page_state_add(v - overstep, zone, item); __this_cpu_write(*p, overstep); } + preempt_enable_rt(); } void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:454 @ void __dec_node_state(struct pglist_data s8 __percpu *p = pcp->vm_node_stat_diff + item; s8 v, t; + preempt_disable_rt(); v = __this_cpu_dec_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v < - t)) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:463 @ void __dec_node_state(struct pglist_data node_page_state_add(v - overstep, pgdat, item); __this_cpu_write(*p, overstep); } + preempt_enable_rt(); } void __dec_zone_page_state(struct page *page, enum zone_stat_item item) Index: linux-5.0.19-rt11/mm/workingset.c =================================================================== --- linux-5.0.19-rt11.orig/mm/workingset.c +++ linux-5.0.19-rt11/mm/workingset.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:371 @ static struct list_lru shadow_nodes; void workingset_update_node(struct xa_node *node) { + struct address_space *mapping; + /* * Track non-empty nodes that contain only shadow entries; * unlink those that contain pages or are being freed. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:381 @ void workingset_update_node(struct xa_no * already where they should be. The list_empty() test is safe * as node->private_list is protected by the i_pages lock. */ - VM_WARN_ON_ONCE(!irqs_disabled()); /* For __inc_lruvec_page_state */ + mapping = container_of(node->array, struct address_space, i_pages); + lockdep_assert_held(&mapping->i_pages.xa_lock); if (node->count && node->count == node->nr_values) { if (list_empty(&node->private_list)) { Index: linux-5.0.19-rt11/mm/zsmalloc.c =================================================================== --- linux-5.0.19-rt11.orig/mm/zsmalloc.c +++ linux-5.0.19-rt11/mm/zsmalloc.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:58 @ #include <linux/migrate.h> #include <linux/pagemap.h> #include <linux/fs.h> +#include <linux/locallock.h> #define ZSPAGE_MAGIC 0x58 @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:76 @ */ #define ZS_MAX_ZSPAGE_ORDER 2 #define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) - #define ZS_HANDLE_SIZE (sizeof(unsigned long)) +#ifdef CONFIG_PREEMPT_RT_FULL + +struct zsmalloc_handle { + unsigned long addr; + struct mutex lock; +}; + +#define ZS_HANDLE_ALLOC_SIZE (sizeof(struct zsmalloc_handle)) + +#else + +#define ZS_HANDLE_ALLOC_SIZE (sizeof(unsigned long)) +#endif + /* * Object location (<PFN>, <obj_idx>) is encoded as * as single (unsigned long) handle value. @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:337 @ static void SetZsPageMovable(struct zs_p static int create_cache(struct zs_pool *pool) { - pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE, + pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_ALLOC_SIZE, 0, 0, NULL); if (!pool->handle_cachep) return 1; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:361 @ static void destroy_cache(struct zs_pool static unsigned long cache_alloc_handle(struct zs_pool *pool, gfp_t gfp) { - return (unsigned long)kmem_cache_alloc(pool->handle_cachep, - gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); + void *p; + + p = kmem_cache_alloc(pool->handle_cachep, + gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); +#ifdef CONFIG_PREEMPT_RT_FULL + if (p) { + struct zsmalloc_handle *zh = p; + + mutex_init(&zh->lock); + } +#endif + return (unsigned long)p; } +#ifdef CONFIG_PREEMPT_RT_FULL +static struct zsmalloc_handle *zs_get_pure_handle(unsigned long handle) +{ + return (void *)(handle &~((1 << OBJ_TAG_BITS) - 1)); +} +#endif + static void cache_free_handle(struct zs_pool *pool, unsigned long handle) { kmem_cache_free(pool->handle_cachep, (void *)handle); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:400 @ static void cache_free_zspage(struct zs_ static void record_obj(unsigned long handle, unsigned long obj) { +#ifdef CONFIG_PREEMPT_RT_FULL + struct zsmalloc_handle *zh = zs_get_pure_handle(handle); + + WRITE_ONCE(zh->addr, obj); +#else /* * lsb of @obj represents handle lock while other bits * represent object value the handle is pointing so * updating shouldn't do store tearing. */ WRITE_ONCE(*(unsigned long *)handle, obj); +#endif } /* zpool driver */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:493 @ MODULE_ALIAS("zpool-zsmalloc"); /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ static DEFINE_PER_CPU(struct mapping_area, zs_map_area); +static DEFINE_LOCAL_IRQ_LOCK(zs_map_area_lock); static bool is_zspage_isolated(struct zspage *zspage) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:923 @ static unsigned long location_to_obj(str static unsigned long handle_to_obj(unsigned long handle) { +#ifdef CONFIG_PREEMPT_RT_FULL + struct zsmalloc_handle *zh = zs_get_pure_handle(handle); + + return zh->addr; +#else return *(unsigned long *)handle; +#endif } static unsigned long obj_to_head(struct page *page, void *obj) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:943 @ static unsigned long obj_to_head(struct static inline int testpin_tag(unsigned long handle) { +#ifdef CONFIG_PREEMPT_RT_FULL + struct zsmalloc_handle *zh = zs_get_pure_handle(handle); + + return mutex_is_locked(&zh->lock); +#else return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle); +#endif } static inline int trypin_tag(unsigned long handle) { +#ifdef CONFIG_PREEMPT_RT_FULL + struct zsmalloc_handle *zh = zs_get_pure_handle(handle); + + return mutex_trylock(&zh->lock); +#else return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle); +#endif } static void pin_tag(unsigned long handle) { +#ifdef CONFIG_PREEMPT_RT_FULL + struct zsmalloc_handle *zh = zs_get_pure_handle(handle); + + return mutex_lock(&zh->lock); +#else bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle); +#endif } static void unpin_tag(unsigned long handle) { +#ifdef CONFIG_PREEMPT_RT_FULL + struct zsmalloc_handle *zh = zs_get_pure_handle(handle); + + return mutex_unlock(&zh->lock); +#else bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle); +#endif } static void reset_page(struct page *page) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1408 @ void *zs_map_object(struct zs_pool *pool class = pool->size_class[class_idx]; off = (class->size * obj_idx) & ~PAGE_MASK; - area = &get_cpu_var(zs_map_area); + area = &get_locked_var(zs_map_area_lock, zs_map_area); area->vm_mm = mm; if (off + class->size <= PAGE_SIZE) { /* this object is contained entirely within a page */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1462 @ void zs_unmap_object(struct zs_pool *poo __zs_unmap_object(area, pages, off, class->size); } - put_cpu_var(zs_map_area); + put_locked_var(zs_map_area_lock, zs_map_area); migrate_read_unlock(zspage); unpin_tag(handle); Index: linux-5.0.19-rt11/mm/zswap.c =================================================================== --- linux-5.0.19-rt11.orig/mm/zswap.c +++ linux-5.0.19-rt11/mm/zswap.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:30 @ #include <linux/highmem.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/locallock.h> #include <linux/types.h> #include <linux/atomic.h> #include <linux/frontswap.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:994 @ static void zswap_fill_page(void *ptr, u memset_l(page, value, PAGE_SIZE / sizeof(unsigned long)); } +/* protect zswap_dstmem from concurrency */ +static DEFINE_LOCAL_IRQ_LOCK(zswap_dstmem_lock); /********************************* * frontswap hooks **********************************/ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1072 @ static int zswap_frontswap_store(unsigne } /* compress */ - dst = get_cpu_var(zswap_dstmem); - tfm = *get_cpu_ptr(entry->pool->tfm); + dst = get_locked_var(zswap_dstmem_lock, zswap_dstmem); + tfm = *this_cpu_ptr(entry->pool->tfm); src = kmap_atomic(page); ret = crypto_comp_compress(tfm, src, PAGE_SIZE, dst, &dlen); kunmap_atomic(src); - put_cpu_ptr(entry->pool->tfm); if (ret) { ret = -EINVAL; goto put_dstmem; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1099 @ static int zswap_frontswap_store(unsigne memcpy(buf, &zhdr, hlen); memcpy(buf + hlen, dst, dlen); zpool_unmap_handle(entry->pool->zpool, handle); - put_cpu_var(zswap_dstmem); + put_locked_var(zswap_dstmem_lock, zswap_dstmem); /* populate entry */ entry->offset = offset; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1127 @ insert_entry: return 0; put_dstmem: - put_cpu_var(zswap_dstmem); + put_locked_var(zswap_dstmem_lock, zswap_dstmem); zswap_pool_put(entry->pool); freepage: zswap_entry_cache_free(entry); Index: linux-5.0.19-rt11/net/Kconfig =================================================================== --- linux-5.0.19-rt11.orig/net/Kconfig +++ linux-5.0.19-rt11/net/Kconfig @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:282 @ config CGROUP_NET_CLASSID config NET_RX_BUSY_POLL bool - default y + default y if !PREEMPT_RT_FULL config BQL bool Index: linux-5.0.19-rt11/net/core/dev.c =================================================================== --- linux-5.0.19-rt11.orig/net/core/dev.c +++ linux-5.0.19-rt11/net/core/dev.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:202 @ static unsigned int napi_gen_id = NR_CPU static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8); static seqcount_t devnet_rename_seq; +static DEFINE_MUTEX(devnet_rename_mutex); static inline void dev_base_seq_inc(struct net *net) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:225 @ static inline struct hlist_head *dev_ind static inline void rps_lock(struct softnet_data *sd) { #ifdef CONFIG_RPS - spin_lock(&sd->input_pkt_queue.lock); + raw_spin_lock(&sd->input_pkt_queue.raw_lock); #endif } static inline void rps_unlock(struct softnet_data *sd) { #ifdef CONFIG_RPS - spin_unlock(&sd->input_pkt_queue.lock); + raw_spin_unlock(&sd->input_pkt_queue.raw_lock); #endif } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:928 @ retry: strcpy(name, dev->name); rcu_read_unlock(); if (read_seqcount_retry(&devnet_rename_seq, seq)) { - cond_resched(); + mutex_lock(&devnet_rename_mutex); + mutex_unlock(&devnet_rename_mutex); goto retry; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1206 @ int dev_change_name(struct net_device *d likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK))) return -EBUSY; - write_seqcount_begin(&devnet_rename_seq); + mutex_lock(&devnet_rename_mutex); + __raw_write_seqcount_begin(&devnet_rename_seq); - if (strncmp(newname, dev->name, IFNAMSIZ) == 0) { - write_seqcount_end(&devnet_rename_seq); - return 0; - } + if (strncmp(newname, dev->name, IFNAMSIZ) == 0) + goto outunlock; memcpy(oldname, dev->name, IFNAMSIZ); err = dev_get_valid_name(net, dev, newname); - if (err < 0) { - write_seqcount_end(&devnet_rename_seq); - return err; - } + if (err < 0) + goto outunlock; if (oldname[0] && !strchr(oldname, '%')) netdev_info(dev, "renamed from %s\n", oldname); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1229 @ rollback: if (ret) { memcpy(dev->name, oldname, IFNAMSIZ); dev->name_assign_type = old_assign_type; - write_seqcount_end(&devnet_rename_seq); - return ret; + err = ret; + goto outunlock; } - write_seqcount_end(&devnet_rename_seq); + __raw_write_seqcount_end(&devnet_rename_seq); + mutex_unlock(&devnet_rename_mutex); netdev_adjacent_rename_links(dev, oldname); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1255 @ rollback: /* err >= 0 after dev_alloc_name() or stores the first errno */ if (err >= 0) { err = ret; - write_seqcount_begin(&devnet_rename_seq); + mutex_lock(&devnet_rename_mutex); + __raw_write_seqcount_begin(&devnet_rename_seq); memcpy(dev->name, oldname, IFNAMSIZ); memcpy(oldname, newname, IFNAMSIZ); dev->name_assign_type = old_assign_type; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1269 @ rollback: } return err; + +outunlock: + __raw_write_seqcount_end(&devnet_rename_seq); + mutex_unlock(&devnet_rename_mutex); + return err; } /** @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2763 @ static void __netif_reschedule(struct Qd sd->output_queue_tailp = &q->next_sched; raise_softirq_irqoff(NET_TX_SOFTIRQ); local_irq_restore(flags); + preempt_check_resched_rt(); } void __netif_schedule(struct Qdisc *q) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2826 @ void __dev_kfree_skb_irq(struct sk_buff __this_cpu_write(softnet_data.completion_queue, skb); raise_softirq_irqoff(NET_TX_SOFTIRQ); local_irq_restore(flags); + preempt_check_resched_rt(); } EXPORT_SYMBOL(__dev_kfree_skb_irq); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3509 @ static inline int __dev_xmit_skb(struct * This permits qdisc->running owner to get the lock more * often and dequeue packets faster. */ +#ifdef CONFIG_PREEMPT_RT_FULL + contended = true; +#else contended = qdisc_is_running(q); +#endif if (unlikely(contended)) spin_lock(&q->busylock); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3585 @ static void skb_update_prio(struct sk_bu #define skb_update_prio(skb) #endif +#ifndef CONFIG_PREEMPT_RT_FULL DEFINE_PER_CPU(int, xmit_recursion); EXPORT_SYMBOL(xmit_recursion); +#endif /** * dev_loopback_xmit - loop back @skb @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3879 @ static int __dev_queue_xmit(struct sk_bu if (dev->flags & IFF_UP) { int cpu = smp_processor_id(); /* ok because BHs are off */ +#ifdef CONFIG_PREEMPT_RT_FULL + if (txq->xmit_lock_owner != current) { +#else if (txq->xmit_lock_owner != cpu) { - if (unlikely(__this_cpu_read(xmit_recursion) > - XMIT_RECURSION_LIMIT)) +#endif + if (unlikely(xmit_rec_read() > XMIT_RECURSION_LIMIT)) goto recursion_alert; skb = validate_xmit_skb(skb, dev, &again); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:3894 @ static int __dev_queue_xmit(struct sk_bu HARD_TX_LOCK(dev, txq, cpu); if (!netif_xmit_stopped(txq)) { - __this_cpu_inc(xmit_recursion); + xmit_rec_inc(); skb = dev_hard_start_xmit(skb, dev, txq, &rc); - __this_cpu_dec(xmit_recursion); + xmit_rec_dec(); if (dev_xmit_complete(rc)) { HARD_TX_UNLOCK(dev, txq); goto out; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4315 @ drop: rps_unlock(sd); local_irq_restore(flags); + preempt_check_resched_rt(); atomic_long_inc(&skb->dev->rx_dropped); kfree_skb(skb); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4542 @ static int netif_rx_internal(struct sk_b struct rps_dev_flow voidflow, *rflow = &voidflow; int cpu; - preempt_disable(); + migrate_disable(); rcu_read_lock(); cpu = get_rps_cpu(skb->dev, skb, &rflow); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4552 @ static int netif_rx_internal(struct sk_b ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail); rcu_read_unlock(); - preempt_enable(); + migrate_enable(); } else #endif { unsigned int qtail; - ret = enqueue_to_backlog(skb, get_cpu(), &qtail); - put_cpu(); + ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail); + put_cpu_light(); } return ret; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:4598 @ int netif_rx_ni(struct sk_buff *skb) trace_netif_rx_ni_entry(skb); - preempt_disable(); + local_bh_disable(); err = netif_rx_internal(skb); - if (local_softirq_pending()) - do_softirq(); - preempt_enable(); + local_bh_enable(); trace_netif_rx_ni_exit(err); return err; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5341 @ static void flush_backlog(struct work_st skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) { if (skb->dev->reg_state == NETREG_UNREGISTERING) { __skb_unlink(skb, &sd->input_pkt_queue); - kfree_skb(skb); + __skb_queue_tail(&sd->tofree_queue, skb); input_queue_head_incr(sd); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5351 @ static void flush_backlog(struct work_st skb_queue_walk_safe(&sd->process_queue, skb, tmp) { if (skb->dev->reg_state == NETREG_UNREGISTERING) { __skb_unlink(skb, &sd->process_queue); - kfree_skb(skb); + __skb_queue_tail(&sd->tofree_queue, skb); input_queue_head_incr(sd); } } + if (!skb_queue_empty(&sd->tofree_queue)) + raise_softirq_irqoff(NET_RX_SOFTIRQ); local_bh_enable(); + } static void flush_all_backlogs(void) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5921 @ static void net_rps_action_and_irq_enabl sd->rps_ipi_list = NULL; local_irq_enable(); + preempt_check_resched_rt(); /* Send pending IPI's to kick RPS processing on remote cpus. */ net_rps_send_ipi(remsd); } else #endif local_irq_enable(); + preempt_check_resched_rt(); } static bool sd_has_rps_ipi_waiting(struct softnet_data *sd) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5958 @ static int process_backlog(struct napi_s while (again) { struct sk_buff *skb; + local_irq_disable(); while ((skb = __skb_dequeue(&sd->process_queue))) { + local_irq_enable(); rcu_read_lock(); __netif_receive_skb(skb); rcu_read_unlock(); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:5968 @ static int process_backlog(struct napi_s if (++work >= quota) return work; + local_irq_disable(); } - local_irq_disable(); rps_lock(sd); if (skb_queue_empty(&sd->input_pkt_queue)) { /* @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6008 @ void __napi_schedule(struct napi_struct local_irq_save(flags); ____napi_schedule(this_cpu_ptr(&softnet_data), n); local_irq_restore(flags); + preempt_check_resched_rt(); } EXPORT_SYMBOL(__napi_schedule); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6045 @ bool napi_schedule_prep(struct napi_stru } EXPORT_SYMBOL(napi_schedule_prep); +#ifndef CONFIG_PREEMPT_RT_FULL /** * __napi_schedule_irqoff - schedule for receive * @n: entry to schedule @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6057 @ void __napi_schedule_irqoff(struct napi_ ____napi_schedule(this_cpu_ptr(&softnet_data), n); } EXPORT_SYMBOL(__napi_schedule_irqoff); +#endif bool napi_complete_done(struct napi_struct *n, int work_done) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:6437 @ static __latent_entropy void net_rx_acti unsigned long time_limit = jiffies + usecs_to_jiffies(netdev_budget_usecs); int budget = netdev_budget; + struct sk_buff_head tofree_q; + struct sk_buff *skb; LIST_HEAD(list); LIST_HEAD(repoll); + __skb_queue_head_init(&tofree_q); + local_irq_disable(); + skb_queue_splice_init(&sd->tofree_queue, &tofree_q); list_splice_init(&sd->poll_list, &list); local_irq_enable(); + while ((skb = __skb_dequeue(&tofree_q))) + kfree_skb(skb); + for (;;) { struct napi_struct *n; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8521 @ static void netdev_init_one_queue(struct /* Initialize queue lock */ spin_lock_init(&queue->_xmit_lock); netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type); - queue->xmit_lock_owner = -1; + netdev_queue_clear_owner(queue); netdev_queue_numa_node_write(queue, NUMA_NO_NODE); queue->dev = dev; #ifdef CONFIG_BQL @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:9455 @ static int dev_cpu_dead(unsigned int old raise_softirq_irqoff(NET_TX_SOFTIRQ); local_irq_enable(); + preempt_check_resched_rt(); #ifdef CONFIG_RPS remsd = oldsd->rps_ipi_list; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:9469 @ static int dev_cpu_dead(unsigned int old netif_rx_ni(skb); input_queue_head_incr(oldsd); } - while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) { + while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx_ni(skb); input_queue_head_incr(oldsd); } + while ((skb = __skb_dequeue(&oldsd->tofree_queue))) { + kfree_skb(skb); + } return 0; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:9784 @ static int __init net_dev_init(void) INIT_WORK(flush, flush_backlog); - skb_queue_head_init(&sd->input_pkt_queue); - skb_queue_head_init(&sd->process_queue); + skb_queue_head_init_raw(&sd->input_pkt_queue); + skb_queue_head_init_raw(&sd->process_queue); + skb_queue_head_init_raw(&sd->tofree_queue); #ifdef CONFIG_XFRM_OFFLOAD skb_queue_head_init(&sd->xfrm_backlog); #endif Index: linux-5.0.19-rt11/net/core/filter.c =================================================================== --- linux-5.0.19-rt11.orig/net/core/filter.c +++ linux-5.0.19-rt11/net/core/filter.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2005 @ static inline int __bpf_tx_skb(struct ne { int ret; - if (unlikely(__this_cpu_read(xmit_recursion) > XMIT_RECURSION_LIMIT)) { + if (unlikely(xmit_rec_read() > XMIT_RECURSION_LIMIT)) { net_crit_ratelimited("bpf: recursion limit reached on datapath, buggy bpf program?\n"); kfree_skb(skb); return -ENETDOWN; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2013 @ static inline int __bpf_tx_skb(struct ne skb->dev = dev; - __this_cpu_inc(xmit_recursion); + xmit_rec_inc(); ret = dev_queue_xmit(skb); - __this_cpu_dec(xmit_recursion); + xmit_rec_dec(); return ret; } Index: linux-5.0.19-rt11/net/core/gen_estimator.c =================================================================== --- linux-5.0.19-rt11.orig/net/core/gen_estimator.c +++ linux-5.0.19-rt11/net/core/gen_estimator.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:49 @ struct net_rate_estimator { struct gnet_stats_basic_packed *bstats; spinlock_t *stats_lock; - seqcount_t *running; + net_seqlock_t *running; struct gnet_stats_basic_cpu __percpu *cpu_bstats; u8 ewma_log; u8 intvl_log; /* period : (250ms << intvl_log) */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:132 @ int gen_new_estimator(struct gnet_stats_ struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct net_rate_estimator __rcu **rate_est, spinlock_t *lock, - seqcount_t *running, + net_seqlock_t *running, struct nlattr *opt) { struct gnet_estimator *parm = nla_data(opt); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:230 @ int gen_replace_estimator(struct gnet_st struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct net_rate_estimator __rcu **rate_est, spinlock_t *lock, - seqcount_t *running, struct nlattr *opt) + net_seqlock_t *running, struct nlattr *opt) { return gen_new_estimator(bstats, cpu_bstats, rate_est, lock, running, opt); Index: linux-5.0.19-rt11/net/core/gen_stats.c =================================================================== --- linux-5.0.19-rt11.orig/net/core/gen_stats.c +++ linux-5.0.19-rt11/net/core/gen_stats.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:145 @ __gnet_stats_copy_basic_cpu(struct gnet_ } void -__gnet_stats_copy_basic(const seqcount_t *running, +__gnet_stats_copy_basic(net_seqlock_t *running, struct gnet_stats_basic_packed *bstats, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:158 @ __gnet_stats_copy_basic(const seqcount_t } do { if (running) - seq = read_seqcount_begin(running); + seq = net_seq_begin(running); bstats->bytes = b->bytes; bstats->packets = b->packets; - } while (running && read_seqcount_retry(running, seq)); + } while (running && net_seq_retry(running, seq)); } EXPORT_SYMBOL(__gnet_stats_copy_basic); static int -___gnet_stats_copy_basic(const seqcount_t *running, +___gnet_stats_copy_basic(net_seqlock_t *running, struct gnet_dump *d, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:207 @ ___gnet_stats_copy_basic(const seqcount_ * if the room in the socket buffer was not sufficient. */ int -gnet_stats_copy_basic(const seqcount_t *running, +gnet_stats_copy_basic(net_seqlock_t *running, struct gnet_dump *d, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:231 @ EXPORT_SYMBOL(gnet_stats_copy_basic); * if the room in the socket buffer was not sufficient. */ int -gnet_stats_copy_basic_hw(const seqcount_t *running, +gnet_stats_copy_basic_hw(net_seqlock_t *running, struct gnet_dump *d, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b) Index: linux-5.0.19-rt11/net/core/pktgen.c =================================================================== --- linux-5.0.19-rt11.orig/net/core/pktgen.c +++ linux-5.0.19-rt11/net/core/pktgen.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2163 @ static void spin(struct pktgen_dev *pkt_ s64 remaining; struct hrtimer_sleeper t; - hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + hrtimer_init_sleeper_on_stack(&t, CLOCK_MONOTONIC, HRTIMER_MODE_ABS, + current); hrtimer_set_expires(&t.timer, spin_until); remaining = ktime_to_ns(hrtimer_expires_remaining(&t.timer)); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:2179 @ static void spin(struct pktgen_dev *pkt_ } while (ktime_compare(end_time, spin_until) < 0); } else { /* see do_nanosleep */ - hrtimer_init_sleeper(&t, current); do { set_current_state(TASK_INTERRUPTIBLE); hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS); Index: linux-5.0.19-rt11/net/core/skbuff.c =================================================================== --- linux-5.0.19-rt11.orig/net/core/skbuff.c +++ linux-5.0.19-rt11/net/core/skbuff.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:66 @ #include <linux/errqueue.h> #include <linux/prefetch.h> #include <linux/if_vlan.h> +#include <linux/locallock.h> #include <net/protocol.h> #include <net/dst.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:337 @ struct napi_alloc_cache { static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache); static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache); +static DEFINE_LOCAL_IRQ_LOCK(netdev_alloc_lock); +static DEFINE_LOCAL_IRQ_LOCK(napi_alloc_cache_lock); static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) { @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:346 @ static void *__netdev_alloc_frag(unsigne unsigned long flags; void *data; - local_irq_save(flags); + local_lock_irqsave(netdev_alloc_lock, flags); nc = this_cpu_ptr(&netdev_alloc_cache); data = page_frag_alloc(nc, fragsz, gfp_mask); - local_irq_restore(flags); + local_unlock_irqrestore(netdev_alloc_lock, flags); return data; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:370 @ EXPORT_SYMBOL(netdev_alloc_frag); static void *__napi_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) { - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + struct napi_alloc_cache *nc; + void *data; - return page_frag_alloc(&nc->page, fragsz, gfp_mask); + nc = &get_locked_var(napi_alloc_cache_lock, napi_alloc_cache); + data = page_frag_alloc(&nc->page, fragsz, gfp_mask); + put_locked_var(napi_alloc_cache_lock, napi_alloc_cache); + return data; } void *napi_alloc_frag(unsigned int fragsz) @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:425 @ struct sk_buff *__netdev_alloc_skb(struc if (sk_memalloc_socks()) gfp_mask |= __GFP_MEMALLOC; - local_irq_save(flags); + local_lock_irqsave(netdev_alloc_lock, flags); nc = this_cpu_ptr(&netdev_alloc_cache); data = page_frag_alloc(nc, len, gfp_mask); pfmemalloc = nc->pfmemalloc; - local_irq_restore(flags); + local_unlock_irqrestore(netdev_alloc_lock, flags); if (unlikely(!data)) return NULL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:472 @ EXPORT_SYMBOL(__netdev_alloc_skb); struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, gfp_t gfp_mask) { - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + struct napi_alloc_cache *nc; struct sk_buff *skb; void *data; + bool pfmemalloc; len += NET_SKB_PAD + NET_IP_ALIGN; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:493 @ struct sk_buff *__napi_alloc_skb(struct if (sk_memalloc_socks()) gfp_mask |= __GFP_MEMALLOC; + nc = &get_locked_var(napi_alloc_cache_lock, napi_alloc_cache); data = page_frag_alloc(&nc->page, len, gfp_mask); + pfmemalloc = nc->page.pfmemalloc; + put_locked_var(napi_alloc_cache_lock, napi_alloc_cache); if (unlikely(!data)) return NULL; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:507 @ struct sk_buff *__napi_alloc_skb(struct } /* use OR instead of assignment to avoid clearing of bits in mask */ - if (nc->page.pfmemalloc) + if (pfmemalloc) skb->pfmemalloc = 1; skb->head_frag = 1; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:736 @ void __consume_stateless_skb(struct sk_b void __kfree_skb_flush(void) { - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + struct napi_alloc_cache *nc; + nc = &get_locked_var(napi_alloc_cache_lock, napi_alloc_cache); /* flush skb_cache if containing objects */ if (nc->skb_count) { kmem_cache_free_bulk(skbuff_head_cache, nc->skb_count, nc->skb_cache); nc->skb_count = 0; } + put_locked_var(napi_alloc_cache_lock, napi_alloc_cache); } static inline void _kfree_skb_defer(struct sk_buff *skb) { - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + struct napi_alloc_cache *nc; /* drop skb->head and call any destructors for packet */ skb_release_all(skb); + nc = &get_locked_var(napi_alloc_cache_lock, napi_alloc_cache); /* record skb to CPU local list */ nc->skb_cache[nc->skb_count++] = skb; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:770 @ static inline void _kfree_skb_defer(stru nc->skb_cache); nc->skb_count = 0; } + put_locked_var(napi_alloc_cache_lock, napi_alloc_cache); } void __kfree_skb_defer(struct sk_buff *skb) { Index: linux-5.0.19-rt11/net/netfilter/core.c =================================================================== --- linux-5.0.19-rt11.orig/net/netfilter/core.c +++ linux-5.0.19-rt11/net/netfilter/core.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:23 @ #include <linux/inetdevice.h> #include <linux/proc_fs.h> #include <linux/mutex.h> +#include <linux/locallock.h> #include <linux/mm.h> #include <linux/rcupdate.h> #include <net/net_namespace.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:31 @ #include "nf_internals.h" +#ifdef CONFIG_PREEMPT_RT_BASE +DEFINE_LOCAL_IRQ_LOCK(xt_write_lock); +EXPORT_PER_CPU_SYMBOL(xt_write_lock); +#endif + const struct nf_ipv6_ops __rcu *nf_ipv6_ops __read_mostly; EXPORT_SYMBOL_GPL(nf_ipv6_ops); Index: linux-5.0.19-rt11/net/packet/af_packet.c =================================================================== --- linux-5.0.19-rt11.orig/net/packet/af_packet.c +++ linux-5.0.19-rt11/net/packet/af_packet.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:66 @ #include <linux/if_packet.h> #include <linux/wireless.h> #include <linux/kernel.h> +#include <linux/delay.h> #include <linux/kmod.h> #include <linux/slab.h> #include <linux/vmalloc.h> @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:671 @ static void prb_retire_rx_blk_timer_expi if (BLOCK_NUM_PKTS(pbd)) { while (atomic_read(&pkc->blk_fill_in_prog)) { /* Waiting for skb_copy_bits to finish... */ - cpu_relax(); + cpu_chill(); } } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:933 @ static void prb_retire_current_block(str if (!(status & TP_STATUS_BLK_TMO)) { while (atomic_read(&pkc->blk_fill_in_prog)) { /* Waiting for skb_copy_bits to finish... */ - cpu_relax(); + cpu_chill(); } } prb_close_block(pkc, pbd, po, status); Index: linux-5.0.19-rt11/net/rds/ib_rdma.c =================================================================== --- linux-5.0.19-rt11.orig/net/rds/ib_rdma.c +++ linux-5.0.19-rt11/net/rds/ib_rdma.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:37 @ #include <linux/slab.h> #include <linux/rculist.h> #include <linux/llist.h> +#include <linux/delay.h> #include "rds_single_path.h" #include "ib_mr.h" @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:226 @ static inline void wait_clean_list_grace for_each_online_cpu(cpu) { flag = &per_cpu(clean_list_grace, cpu); while (test_bit(CLEAN_LIST_BUSY_BIT, flag)) - cpu_relax(); + cpu_chill(); } } Index: linux-5.0.19-rt11/net/sched/sch_api.c =================================================================== --- linux-5.0.19-rt11.orig/net/sched/sch_api.c +++ linux-5.0.19-rt11/net/sched/sch_api.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1245 @ static struct Qdisc *qdisc_create(struct rcu_assign_pointer(sch->stab, stab); } if (tca[TCA_RATE]) { - seqcount_t *running; + net_seqlock_t *running; err = -EOPNOTSUPP; if (sch->flags & TCQ_F_MQROOT) { Index: linux-5.0.19-rt11/net/sched/sch_generic.c =================================================================== --- linux-5.0.19-rt11.orig/net/sched/sch_generic.c +++ linux-5.0.19-rt11/net/sched/sch_generic.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:573 @ struct Qdisc noop_qdisc = { .ops = &noop_qdisc_ops, .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), .dev_queue = &noop_netdev_queue, +#ifdef CONFIG_PREEMPT_RT_BASE + .running = __SEQLOCK_UNLOCKED(noop_qdisc.running), +#else .running = SEQCNT_ZERO(noop_qdisc.running), +#endif .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock), .gso_skb = { .next = (struct sk_buff *)&noop_qdisc.gso_skb, @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:878 @ struct Qdisc *qdisc_alloc(struct netdev_ lockdep_set_class(&sch->busylock, dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); +#ifdef CONFIG_PREEMPT_RT_BASE + seqlock_init(&sch->running); + lockdep_set_class(&sch->running.seqcount, + dev->qdisc_running_key ?: &qdisc_running_key); + lockdep_set_class(&sch->running.lock, + dev->qdisc_running_key ?: &qdisc_running_key); +#else seqcount_init(&sch->running); lockdep_set_class(&sch->running, dev->qdisc_running_key ?: &qdisc_running_key); +#endif sch->ops = ops; sch->flags = ops->static_flags; @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:1238 @ void dev_deactivate_many(struct list_hea /* Wait for outstanding qdisc_run calls. */ list_for_each_entry(dev, head, close_list) { while (some_qdisc_is_busy(dev)) - yield(); + msleep(1); /* The new qdisc is assigned at this point so we can safely * unwind stale skb lists and qdisc statistics */ Index: linux-5.0.19-rt11/net/sunrpc/svc_xprt.c =================================================================== --- linux-5.0.19-rt11.orig/net/sunrpc/svc_xprt.c +++ linux-5.0.19-rt11/net/sunrpc/svc_xprt.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:395 @ void svc_xprt_do_enqueue(struct svc_xprt if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) return; - cpu = get_cpu(); + cpu = get_cpu_light(); pool = svc_pool_for_cpu(xprt->xpt_server, cpu); atomic_long_inc(&pool->sp_stats.packets); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:419 @ void svc_xprt_do_enqueue(struct svc_xprt rqstp = NULL; out_unlock: rcu_read_unlock(); - put_cpu(); + put_cpu_light(); trace_svc_xprt_do_enqueue(xprt, rqstp); } EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue); Index: linux-5.0.19-rt11/samples/trace_events/trace-events-sample.c =================================================================== --- linux-5.0.19-rt11.orig/samples/trace_events/trace-events-sample.c +++ linux-5.0.19-rt11/samples/trace_events/trace-events-sample.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:36 @ static void simple_thread_func(int cnt) /* Silly tracepoints */ trace_foo_bar("hello", cnt, array, random_strings[len], - ¤t->cpus_allowed); + current->cpus_ptr); trace_foo_with_template_simple("HELLO", cnt); Index: linux-5.0.19-rt11/scripts/mkcompile_h =================================================================== --- linux-5.0.19-rt11.orig/scripts/mkcompile_h +++ linux-5.0.19-rt11/scripts/mkcompile_h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:8 @ TARGET=$1 ARCH=$2 SMP=$3 PREEMPT=$4 -CC=$5 +RT=$5 +CC=$6 vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:57 @ UTS_VERSION="#$VERSION" CONFIG_FLAGS="" if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi +if [ -n "$RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS RT"; fi UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP" # Truncate to maximum length Index: linux-5.0.19-rt11/security/apparmor/include/path.h =================================================================== --- linux-5.0.19-rt11.orig/security/apparmor/include/path.h +++ linux-5.0.19-rt11/security/apparmor/include/path.h @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:43 @ struct aa_buffers { #include <linux/percpu.h> #include <linux/preempt.h> +#include <linux/locallock.h> DECLARE_PER_CPU(struct aa_buffers, aa_buffers); +DECLARE_LOCAL_IRQ_LOCK(aa_buffers_lock); #define ASSIGN(FN, A, X, N) ((X) = FN(A, N)) #define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:56 @ DECLARE_PER_CPU(struct aa_buffers, aa_bu #define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++) -#ifdef CONFIG_DEBUG_PREEMPT +#ifdef CONFIG_PREEMPT_RT_BASE +static inline void AA_BUG_PREEMPT_ENABLED(const char *s) +{ + struct local_irq_lock *lv; + + lv = this_cpu_ptr(&aa_buffers_lock); + WARN_ONCE(lv->owner != current, + "__get_buffer without aa_buffers_lock\n"); +} + +#elif defined(CONFIG_DEBUG_PREEMPT) #define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X) #else #define AA_BUG_PREEMPT_ENABLED(X) /* nop */ @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:82 @ DECLARE_PER_CPU(struct aa_buffers, aa_bu #define get_buffers(X...) \ do { \ - struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers); \ + struct aa_buffers *__cpu_var; \ + __cpu_var = get_locked_ptr(aa_buffers_lock, &aa_buffers); \ __get_buffers(__cpu_var, X); \ } while (0) #define put_buffers(X, Y...) \ do { \ __put_buffers(X, Y); \ - put_cpu_ptr(&aa_buffers); \ + put_locked_ptr(aa_buffers_lock, &aa_buffers); \ } while (0) #endif /* __AA_PATH_H */ Index: linux-5.0.19-rt11/security/apparmor/lsm.c =================================================================== --- linux-5.0.19-rt11.orig/security/apparmor/lsm.c +++ linux-5.0.19-rt11/security/apparmor/lsm.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:51 @ int apparmor_initialized; DEFINE_PER_CPU(struct aa_buffers, aa_buffers); - +DEFINE_LOCAL_IRQ_LOCK(aa_buffers_lock); /* * LSM hook functions Index: linux-5.0.19-rt11/virt/kvm/arm/arm.c =================================================================== --- linux-5.0.19-rt11.orig/virt/kvm/arm/arm.c +++ linux-5.0.19-rt11/virt/kvm/arm/arm.c @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:712 @ int kvm_arch_vcpu_ioctl_run(struct kvm_v * involves poking the GIC, which must be done in a * non-preemptible context. */ - preempt_disable(); + migrate_disable(); kvm_pmu_flush_hwstate(vcpu); @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:761 @ int kvm_arch_vcpu_ioctl_run(struct kvm_v kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); local_irq_enable(); - preempt_enable(); + migrate_enable(); continue; } @ linux-5.0.19-rt11/Documentation/preempt-locking.txt:839 @ int kvm_arch_vcpu_ioctl_run(struct kvm_v /* Exit types that need handling before we can be preempted */ handle_exit_early(vcpu, run, ret); - preempt_enable(); + migrate_enable(); ret = handle_exit(vcpu, run, ret); }