diff --git a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.html b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.html index 57300db4b5ff6..31c99382994e0 100644 --- a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.html +++ b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.html @@ -56,8 +56,8 @@ sections. RCU-preempt Expedited Grace Periods</a></h2> <p> -<tt>CONFIG_PREEMPT=y</tt> kernels implement RCU-preempt. -The overall flow of the handling of a given CPU by an RCU-preempt +<tt>CONFIG_PREEMPT=y</tt> and <tt>CONFIG_PREEMPT_RT=y</tt> kernels implement +RCU-preempt. The overall flow of the handling of a given CPU by an RCU-preempt expedited grace period is shown in the following diagram: <p><img src="ExpRCUFlow.svg" alt="ExpRCUFlow.svg" width="55%"> @@ -140,8 +140,8 @@ or offline, among other things. RCU-sched Expedited Grace Periods</a></h2> <p> -<tt>CONFIG_PREEMPT=n</tt> kernels implement RCU-sched. -The overall flow of the handling of a given CPU by an RCU-sched +<tt>CONFIG_PREEMPT=n</tt> and <tt>CONFIG_PREEMPT_RT=n</tt> kernels implement +RCU-sched. The overall flow of the handling of a given CPU by an RCU-sched expedited grace period is shown in the following diagram: <p><img src="ExpSchedFlow.svg" alt="ExpSchedFlow.svg" width="55%"> diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html index 467251f7fef69..348c5db1ff2bb 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.html +++ b/Documentation/RCU/Design/Requirements/Requirements.html @@ -106,7 +106,7 @@ big RCU read-side critical section. Production-quality implementations of <tt>rcu_read_lock()</tt> and <tt>rcu_read_unlock()</tt> are extremely lightweight, and in fact have exactly zero overhead in Linux kernels built for production -use with <tt>CONFIG_PREEMPT=n</tt>. +use with <tt>CONFIG_PREEMPTION=n</tt>. <p> This guarantee allows ordering to be enforced with extremely low @@ -1499,7 +1499,7 @@ costs have plummeted. However, as I learned from Matt Mackall's <a href="http://elinux.org/Linux_Tiny-FAQ">bloatwatch</a> efforts, memory footprint is critically important on single-CPU systems with -non-preemptible (<tt>CONFIG_PREEMPT=n</tt>) kernels, and thus +non-preemptible (<tt>CONFIG_PREEMPTION=n</tt>) kernels, and thus <a href="https://lkml.kernel.org/g/20090113221724.GA15307@linux.vnet.ibm.com">tiny RCU</a> was born. Josh Triplett has since taken over the small-memory banner with his @@ -1887,7 +1887,7 @@ constructs, there are limitations. <p> Implementations of RCU for which <tt>rcu_read_lock()</tt> and <tt>rcu_read_unlock()</tt> generate no code, such as -Linux-kernel RCU when <tt>CONFIG_PREEMPT=n</tt>, can be +Linux-kernel RCU when <tt>CONFIG_PREEMPTION=n</tt>, can be nested arbitrarily deeply. After all, there is no overhead. Except that if all these instances of <tt>rcu_read_lock()</tt> @@ -2229,7 +2229,7 @@ be a no-op. <p> However, once the scheduler has spawned its first kthread, this early boot trick fails for <tt>synchronize_rcu()</tt> (as well as for -<tt>synchronize_rcu_expedited()</tt>) in <tt>CONFIG_PREEMPT=y</tt> +<tt>synchronize_rcu_expedited()</tt>) in <tt>CONFIG_PREEMPTION=y</tt> kernels. The reason is that an RCU read-side critical section might be preempted, which means that a subsequent <tt>synchronize_rcu()</tt> really does have @@ -2568,7 +2568,7 @@ The compiler must not be permitted to transform this source code into <p> If the compiler did make this transformation in a -<tt>CONFIG_PREEMPT=n</tt> kernel build, and if <tt>get_user()</tt> did +<tt>CONFIG_PREEMPTION=n</tt> kernel build, and if <tt>get_user()</tt> did page fault, the result would be a quiescent state in the middle of an RCU read-side critical section. This misplaced quiescent state could result in line 4 being @@ -2906,7 +2906,7 @@ in conjunction with the The real-time-latency response requirements are such that the traditional approach of disabling preemption across RCU read-side critical sections is inappropriate. -Kernels built with <tt>CONFIG_PREEMPT=y</tt> therefore +Kernels built with <tt>CONFIG_PREEMPTION=y</tt> therefore use an RCU implementation that allows RCU read-side critical sections to be preempted. This requirement made its presence known after users made it @@ -3064,7 +3064,7 @@ includes <tt>rcu_barrier_bh()</tt>, and <tt>rcu_read_lock_bh_held()</tt>. However, the update-side APIs are now simple wrappers for other RCU -flavors, namely RCU-sched in CONFIG_PREEMPT=n kernels and RCU-preempt +flavors, namely RCU-sched in CONFIG_PREEMPTION=n kernels and RCU-preempt otherwise. <h3><a name="Sched Flavor">Sched Flavor (Historical)</a></h3> @@ -3088,12 +3088,12 @@ of an RCU read-side critical section can be a quiescent state. Therefore, <i>RCU-sched</i> was created, which follows “classic” RCU in that an RCU-sched grace period waits for for pre-existing interrupt and NMI handlers. -In kernels built with <tt>CONFIG_PREEMPT=n</tt>, the RCU and RCU-sched +In kernels built with <tt>CONFIG_PREEMPTION=n</tt>, the RCU and RCU-sched APIs have identical implementations, while kernels built with -<tt>CONFIG_PREEMPT=y</tt> provide a separate implementation for each. +<tt>CONFIG_PREEMPTION=y</tt> provide a separate implementation for each. <p> -Note well that in <tt>CONFIG_PREEMPT=y</tt> kernels, +Note well that in <tt>CONFIG_PREEMPTION=y</tt> kernels, <tt>rcu_read_lock_sched()</tt> and <tt>rcu_read_unlock_sched()</tt> disable and re-enable preemption, respectively. This means that if there was a preemption attempt during the @@ -3302,12 +3302,12 @@ The tasks-RCU API is quite compact, consisting only of <tt>call_rcu_tasks()</tt>, <tt>synchronize_rcu_tasks()</tt>, and <tt>rcu_barrier_tasks()</tt>. -In <tt>CONFIG_PREEMPT=n</tt> kernels, trampolines cannot be preempted, +In <tt>CONFIG_PREEMPTION=n</tt> kernels, trampolines cannot be preempted, so these APIs map to <tt>call_rcu()</tt>, <tt>synchronize_rcu()</tt>, and <tt>rcu_barrier()</tt>, respectively. -In <tt>CONFIG_PREEMPT=y</tt> kernels, trampolines can be preempted, +In <tt>CONFIG_PREEMPTION=y</tt> kernels, trampolines can be preempted, and these three APIs are therefore implemented by separate functions that check for voluntary context switches. diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt index e98ff261a438b..087dc6c22c37c 100644 --- a/Documentation/RCU/checklist.txt +++ b/Documentation/RCU/checklist.txt @@ -210,8 +210,8 @@ over a rather long period of time, but improvements are always welcome! the rest of the system. 7. As of v4.20, a given kernel implements only one RCU flavor, - which is RCU-sched for PREEMPT=n and RCU-preempt for PREEMPT=y. - If the updater uses call_rcu() or synchronize_rcu(), + which is RCU-sched for PREEMPTION=n and RCU-preempt for + PREEMPTION=y. If the updater uses call_rcu() or synchronize_rcu(), then the corresponding readers my use rcu_read_lock() and rcu_read_unlock(), rcu_read_lock_bh() and rcu_read_unlock_bh(), or any pair of primitives that disables and re-enables preemption, diff --git a/Documentation/RCU/rcubarrier.txt b/Documentation/RCU/rcubarrier.txt index a2782df697328..5aa93c215af46 100644 --- a/Documentation/RCU/rcubarrier.txt +++ b/Documentation/RCU/rcubarrier.txt @@ -6,8 +6,8 @@ RCU (read-copy update) is a synchronization mechanism that can be thought of as a replacement for read-writer locking (among other things), but with very low-overhead readers that are immune to deadlock, priority inversion, and unbounded latency. RCU read-side critical sections are delimited -by rcu_read_lock() and rcu_read_unlock(), which, in non-CONFIG_PREEMPT -kernels, generate no code whatsoever. +by rcu_read_lock() and rcu_read_unlock(), which, in +non-CONFIG_PREEMPTION kernels, generate no code whatsoever. This means that RCU writers are unaware of the presence of concurrent readers, so that RCU updates to shared data must be undertaken quite @@ -303,10 +303,10 @@ Answer: This cannot happen. The reason is that on_each_cpu() has its last to smp_call_function() and further to smp_call_function_on_cpu(), causing this latter to spin until the cross-CPU invocation of rcu_barrier_func() has completed. This by itself would prevent - a grace period from completing on non-CONFIG_PREEMPT kernels, + a grace period from completing on non-CONFIG_PREEMPTION kernels, since each CPU must undergo a context switch (or other quiescent state) before the grace period can complete. However, this is - of no use in CONFIG_PREEMPT kernels. + of no use in CONFIG_PREEMPTION kernels. Therefore, on_each_cpu() disables preemption across its call to smp_call_function() and also across the local call to diff --git a/Documentation/RCU/stallwarn.txt b/Documentation/RCU/stallwarn.txt index f48f4621ccbc2..bd510771b75ec 100644 --- a/Documentation/RCU/stallwarn.txt +++ b/Documentation/RCU/stallwarn.txt @@ -20,7 +20,7 @@ o A CPU looping with preemption disabled. o A CPU looping with bottom halves disabled. -o For !CONFIG_PREEMPT kernels, a CPU looping anywhere in the kernel +o For !CONFIG_PREEMPTION kernels, a CPU looping anywhere in the kernel without invoking schedule(). If the looping in the kernel is really expected and desirable behavior, you might need to add some calls to cond_resched(). @@ -39,7 +39,7 @@ o Anything that prevents RCU's grace-period kthreads from running. result in the "rcu_.*kthread starved for" console-log message, which will include additional debugging information. -o A CPU-bound real-time task in a CONFIG_PREEMPT kernel, which might +o A CPU-bound real-time task in a CONFIG_PREEMPTION kernel, which might happen to preempt a low-priority task in the middle of an RCU read-side critical section. This is especially damaging if that low-priority task is not permitted to run on any other CPU, diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 7e1a8721637ab..7e03e8f80b293 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -648,9 +648,10 @@ Quick Quiz #1: Why is this argument naive? How could a deadlock This section presents a "toy" RCU implementation that is based on "classic RCU". It is also short on performance (but only for updates) and -on features such as hotplug CPU and the ability to run in CONFIG_PREEMPT -kernels. The definitions of rcu_dereference() and rcu_assign_pointer() -are the same as those shown in the preceding section, so they are omitted. +on features such as hotplug CPU and the ability to run in +CONFIG_PREEMPTION kernels. The definitions of rcu_dereference() and +rcu_assign_pointer() are the same as those shown in the preceding +section, so they are omitted. void rcu_read_lock(void) { } diff --git a/Documentation/printk-ringbuffer.txt b/Documentation/printk-ringbuffer.txt new file mode 100644 index 0000000000000..6bde5dbd8545b --- /dev/null +++ b/Documentation/printk-ringbuffer.txt @@ -0,0 +1,377 @@ +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. diff --git a/Documentation/trace/ftrace-uses.rst b/Documentation/trace/ftrace-uses.rst index 1fbc69894eed0..1e0020b0bc745 100644 --- a/Documentation/trace/ftrace-uses.rst +++ b/Documentation/trace/ftrace-uses.rst @@ -146,7 +146,7 @@ FTRACE_OPS_FL_RECURSION_SAFE itself or any nested functions that those functions call. If this flag is set, it is possible that the callback will also - be called with preemption enabled (when CONFIG_PREEMPT is set), + be called with preemption enabled (when CONFIG_PREEMPTION is set), but this is not guaranteed. FTRACE_OPS_FL_IPMODIFY diff --git a/arch/Kconfig b/arch/Kconfig index 5f8a5d84dbbe9..d71dd2b76c988 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -31,6 +31,7 @@ config OPROFILE tristate "OProfile system profiling" depends on PROFILING depends on HAVE_OPROFILE + depends on !PREEMPT_RT select RING_BUFFER select RING_BUFFER_ALLOW_SWAP help diff --git a/arch/alpha/include/asm/spinlock_types.h b/arch/alpha/include/asm/spinlock_types.h index 1d5716bc060be..6883bc952d224 100644 --- a/arch/alpha/include/asm/spinlock_types.h +++ b/arch/alpha/include/asm/spinlock_types.h @@ -2,10 +2,6 @@ #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; diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 72be01270e246..1f6bb184a44db 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -337,11 +337,11 @@ ENTRY(ret_from_exception) resume_kernel_mode: ; Disable Interrupts from this point on - ; CONFIG_PREEMPT: This is a must for preempt_schedule_irq() - ; !CONFIG_PREEMPT: To ensure restore_regs is intr safe + ; CONFIG_PREEMPTION: This is a must for preempt_schedule_irq() + ; !CONFIG_PREEMPTION: To ensure restore_regs is intr safe IRQ_DISABLE r9 -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION ; Can't preempt if preemption disabled GET_CURR_THR_INFO_FROM_SP r10 diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 39002d769d956..9bb4351b19ed7 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -32,6 +32,7 @@ config ARM select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7 select ARCH_SUPPORTS_ATOMIC_RMW + select ARCH_SUPPORTS_RT select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU @@ -64,7 +65,7 @@ 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 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 @@ -103,6 +104,7 @@ 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 diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h index 46d41140df27d..c421b5b81946e 100644 --- a/arch/arm/include/asm/irq.h +++ b/arch/arm/include/asm/irq.h @@ -23,6 +23,8 @@ #endif #ifndef __ASSEMBLY__ +#include <linux/cpumask.h> + struct irqaction; struct pt_regs; diff --git a/arch/arm/include/asm/spinlock_types.h b/arch/arm/include/asm/spinlock_types.h index 5976958647fe1..a37c0803954ba 100644 --- a/arch/arm/include/asm/spinlock_types.h +++ b/arch/arm/include/asm/spinlock_types.h @@ -2,10 +2,6 @@ #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 { diff --git a/arch/arm/include/asm/switch_to.h b/arch/arm/include/asm/switch_to.h index d3e937dcee4d0..285e6248454fc 100644 --- a/arch/arm/include/asm/switch_to.h +++ b/arch/arm/include/asm/switch_to.h @@ -4,13 +4,20 @@ #include <linux/thread_info.h> +#if defined CONFIG_PREEMPT_RT && 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 * to ensure that the maintenance completes in case we migrate to another * CPU. */ -#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7) +#if defined(CONFIG_PREEMPTION) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7) #define __complete_pending_tlbi() dsb(ish) #else #define __complete_pending_tlbi() @@ -26,6 +33,7 @@ extern struct task_struct *__switch_to(struct task_struct *, struct thread_info #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) diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 0d0d5178e2c32..13be9c2137e26 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -46,6 +46,7 @@ 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 */ @@ -139,7 +140,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp *, #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 @@ -149,6 +151,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp *, #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) @@ -164,7 +167,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp *, * 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 */ diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index c773b829ee8ee..f3a0e1cd1f048 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -53,6 +53,7 @@ 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)); diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 858d4e5415326..e917b3da4b28a 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -211,13 +211,20 @@ ENDPROC(__dabt_svc) svc_entry irq_handler -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION 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 @@ -226,14 +233,20 @@ ENDPROC(__irq_svc) .ltorg -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION svc_preempt: mov r8, lr 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: diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 271cb8a1eba1e..fd039b1b37319 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -53,7 +53,9 @@ saved_pc .req lr 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 @@ -90,8 +92,11 @@ ENDPROC(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) diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index ab2568996ddb0..50d43ce823bfb 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -649,7 +649,8 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) */ 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))) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 46e1be9e57a81..581caf6493a94 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -682,11 +682,9 @@ void handle_IPI(int ipinr, struct pt_regs *regs) break; case IPI_CPU_BACKTRACE: - printk_nmi_enter(); irq_enter(); nmi_cpu_backtrace(regs); irq_exit(); - printk_nmi_exit(); break; default: diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index c053abd1fb539..abb7dd7e656fd 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -248,6 +248,8 @@ void show_stack(struct task_struct *tsk, unsigned long *sp) #ifdef CONFIG_PREEMPT #define S_PREEMPT " PREEMPT" +#elif defined(CONFIG_PREEMPT_RT) +#define S_PREEMPT " PREEMPT_RT" #else #define S_PREEMPT "" #endif diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S index 0ee8fc4b4672c..dc8f152f35566 100644 --- a/arch/arm/mm/cache-v7.S +++ b/arch/arm/mm/cache-v7.S @@ -135,13 +135,13 @@ ENTRY(v7_flush_dcache_all) and r1, r1, #7 @ mask of the bits for current cache only cmp r1, #2 @ see what cache we have at this level blt skip @ skip if no cache, or just i-cache -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION save_and_disable_irqs_notrace r9 @ make cssr&csidr read atomic #endif mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr isb @ isb to sych the new cssr&csidr mrc p15, 1, r1, c0, c0, 0 @ read the new csidr -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION restore_irqs_notrace r9 #endif and r2, r1, #7 @ extract the length of the cache lines diff --git a/arch/arm/mm/cache-v7m.S b/arch/arm/mm/cache-v7m.S index a0035c426ce63..1bc3a0a507539 100644 --- a/arch/arm/mm/cache-v7m.S +++ b/arch/arm/mm/cache-v7m.S @@ -183,13 +183,13 @@ ENTRY(v7m_flush_dcache_all) and r1, r1, #7 @ mask of the bits for current cache only cmp r1, #2 @ see what cache we have at this level blt skip @ skip if no cache, or just i-cache -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION save_and_disable_irqs_notrace r9 @ make cssr&csidr read atomic #endif write_csselr r10, r1 @ set current cache level isb @ isb to sych the new cssr&csidr read_ccsidr r1 @ read the new csidr -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION restore_irqs_notrace r9 #endif and r2, r1, #7 @ extract the length of the cache lines diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index bd0f4821f7e11..865fd8fbfe59c 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -414,6 +414,9 @@ do_translation_fault(unsigned long addr, unsigned int fsr, 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; @@ -481,6 +484,9 @@ do_translation_fault(unsigned long addr, unsigned int fsr, 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; } diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index a76f8ace9ce66..eb4a361d47d7b 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -31,6 +31,11 @@ static inline pte_t get_fixmap_pte(unsigned long vaddr) 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(); @@ -51,12 +56,13 @@ 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); @@ -76,7 +82,7 @@ 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 /* @@ -90,7 +96,10 @@ 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 + current->kmap_pte[type] = pte; +#endif + set_fixmap_pte(idx, pte); return (void *)vaddr; } @@ -103,44 +112,75 @@ 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 + 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 + current->kmap_pte[type] = pte; +#endif + set_fixmap_pte(idx, pte); return (void *)vaddr; } +#if defined CONFIG_PREEMPT_RT +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 diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 6ccd2ed309631..5eb2bec5aaab1 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -35,32 +35,32 @@ config ARM64 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAVE_NMI_SAFE_CMPXCHG - select ARCH_INLINE_READ_LOCK if !PREEMPT - select ARCH_INLINE_READ_LOCK_BH if !PREEMPT - select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT - select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT - select ARCH_INLINE_READ_UNLOCK if !PREEMPT - select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT - select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT - select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT - select ARCH_INLINE_WRITE_LOCK if !PREEMPT - select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT - select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT - select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT - select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT - select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT - select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT - select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT - select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT - select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT - select ARCH_INLINE_SPIN_LOCK if !PREEMPT - select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT - select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT - select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT - select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT - select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT - select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT - select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT + select ARCH_INLINE_READ_LOCK if !PREEMPTION + select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION + select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION + select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION + select ARCH_INLINE_READ_UNLOCK if !PREEMPTION + select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION + select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION + select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION + select ARCH_INLINE_WRITE_LOCK if !PREEMPTION + select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION + select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION + select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION + select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION + select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION + select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION + select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION + select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION + select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION + select ARCH_INLINE_SPIN_LOCK if !PREEMPTION + select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION + select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION + select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION + select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION + select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION + select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION + select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION select ARCH_KEEP_MEMBLOCK select ARCH_USE_CMPXCHG_LOCKREF select ARCH_USE_QUEUED_RWLOCKS @@ -69,6 +69,7 @@ config ARM64 select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG select ARCH_SUPPORTS_NUMA_BALANCING + select ARCH_SUPPORTS_RT select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT select ARCH_WANT_FRAME_POINTERS @@ -159,6 +160,7 @@ 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_FUNCTION_ARG_ACCESS_API select HAVE_RCU_TABLE_FREE diff --git a/arch/arm64/crypto/sha256-glue.c b/arch/arm64/crypto/sha256-glue.c index e273faca924f9..999da59f03a9d 100644 --- a/arch/arm64/crypto/sha256-glue.c +++ b/arch/arm64/crypto/sha256-glue.c @@ -97,7 +97,7 @@ static int sha256_update_neon(struct shash_desc *desc, const u8 *data, * input when running on a preemptible kernel, but process the * data block by block instead. */ - if (IS_ENABLED(CONFIG_PREEMPT) && + if (IS_ENABLED(CONFIG_PREEMPTION) && chunk + sctx->count % SHA256_BLOCK_SIZE > SHA256_BLOCK_SIZE) chunk = SHA256_BLOCK_SIZE - sctx->count % SHA256_BLOCK_SIZE; diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index b8cf7c85ffa2a..2cc0dd8bd9f78 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -699,8 +699,8 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU * where <label> is optional, and marks the point where execution will resume * after a yield has been performed. If omitted, execution resumes right after * the endif_yield_neon invocation. Note that the entire sequence, including - * the provided patchup code, will be omitted from the image if CONFIG_PREEMPT - * is not defined. + * the provided patchup code, will be omitted from the image if + * CONFIG_PREEMPTION is not defined. * * As a convenience, in the case where no patchup code is required, the above * sequence may be abbreviated to @@ -728,7 +728,7 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU .endm .macro if_will_cond_yield_neon -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION get_current_task x0 ldr x0, [x0, #TSK_TI_PREEMPT] sub x0, x0, #PREEMPT_DISABLE_OFFSET diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index befe37d4bc0e5..53d846f1bfe70 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -91,6 +91,7 @@ alternative_cb_end void kvm_update_va_mask(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst); +void kvm_compute_layout(void); static inline unsigned long __kern_hyp_va(unsigned long v) { diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h index d499516470149..3b19db2db1ed0 100644 --- a/arch/arm64/include/asm/preempt.h +++ b/arch/arm64/include/asm/preempt.h @@ -70,20 +70,43 @@ static inline bool __preempt_count_dec_and_test(void) * 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 ((pc & ~PREEMPT_NEED_RESCHED)) + return false; + 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 +#ifdef CONFIG_PREEMPTION void preempt_schedule(void); #define __preempt_schedule() preempt_schedule() void preempt_schedule_notrace(void); #define __preempt_schedule_notrace() preempt_schedule_notrace() -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ #endif /* __ASM_PREEMPT_H */ diff --git a/arch/arm64/include/asm/spinlock_types.h b/arch/arm64/include/asm/spinlock_types.h index 18782f0c47212..6672b05350b4e 100644 --- a/arch/arm64/include/asm/spinlock_types.h +++ b/arch/arm64/include/asm/spinlock_types.h @@ -5,10 +5,6 @@ #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> diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index f0cec4160136e..33328454d531e 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -29,6 +29,7 @@ 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 { @@ -63,6 +64,7 @@ void arch_release_task_struct(struct task_struct *tsk); #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 /* syscall trace active */ #define TIF_SYSCALL_AUDIT 9 /* syscall auditing */ @@ -83,6 +85,7 @@ void arch_release_task_struct(struct task_struct *tsk); #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) @@ -96,8 +99,9 @@ void arch_release_task_struct(struct task_struct *tsk); #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 | _TIF_SYSCALL_EMU) diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 214685760e1c3..f7975b079551e 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -30,6 +30,7 @@ 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)); diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index cf3bd2976e574..b25f633650809 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -669,7 +669,7 @@ ENDPROC(el1_sync) irq_handler -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION ldr x24, [tsk, #TSK_TI_PREEMPT] // get preempt count alternative_if ARM64_HAS_IRQ_PRIO_MASKING /* @@ -679,9 +679,18 @@ alternative_if ARM64_HAS_IRQ_PRIO_MASKING mrs x0, daif orr x24, x24, x0 alternative_else_nop_endif - cbnz x24, 1f // preempt count != 0 || NMI return path - bl arm64_preempt_schedule_irq // irq en/disable is done inside + + cbz x24, 1f // (need_resched + count) == 0 + cbnz w24, 2f // 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 arm64_preempt_schedule_irq // irq en/disable is done inside +2: #endif #ifdef CONFIG_ARM64_PSEUDO_NMI diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 37d3912cfe06f..ac326cac8b939 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -213,6 +213,16 @@ static void sve_free(struct task_struct *task) __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 @@ -1008,6 +1018,7 @@ void fpsimd_thread_switch(struct task_struct *next) void fpsimd_flush_thread(void) { int vl, supported_vl; + void *mem = NULL; if (!system_supports_fpsimd()) return; @@ -1020,7 +1031,7 @@ 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. @@ -1054,6 +1065,7 @@ void fpsimd_flush_thread(void) } put_cpu_fpsimd_context(); + kfree(mem); } /* diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index dd2cdc0d5be20..94dbce6b27195 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -910,7 +910,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, /* 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); diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index dc9fe879c2793..02d41eae3da86 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -31,6 +31,7 @@ #include <linux/of.h> #include <linux/irq_work.h> #include <linux/kexec.h> +#include <linux/kvm_host.h> #include <asm/alternative.h> #include <asm/atomic.h> @@ -39,6 +40,7 @@ #include <asm/cputype.h> #include <asm/cpu_ops.h> #include <asm/daifflags.h> +#include <asm/kvm_mmu.h> #include <asm/mmu_context.h> #include <asm/numa.h> #include <asm/pgtable.h> @@ -408,6 +410,8 @@ static void __init hyp_mode_check(void) "CPU: CPUs started in inconsistent modes"); else pr_info("CPU: All CPU(s) started at EL1\n"); + if (IS_ENABLED(CONFIG_KVM_ARM_HOST)) + kvm_compute_layout(); } void __init smp_cpus_done(unsigned int max_cpus) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 34739e80211bc..0bf934257744d 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -143,9 +143,12 @@ void show_stack(struct task_struct *tsk, unsigned long *sp) #ifdef CONFIG_PREEMPT #define S_PREEMPT " PREEMPT" +#elif defined(CONFIG_PREEMPT_RT) +#define S_PREEMPT " PREEMPT_RT" #else #define S_PREEMPT "" #endif + #define S_SMP " SMP" static int __die(const char *str, int err, struct pt_regs *regs) diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c index 2cf7d4b606c38..dab1fea4752aa 100644 --- a/arch/arm64/kvm/va_layout.c +++ b/arch/arm64/kvm/va_layout.c @@ -22,7 +22,7 @@ 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; @@ -110,9 +110,6 @@ void __init kvm_update_va_mask(struct alt_instr *alt, BUG_ON(nr_inst != 5); - if (!has_vhe() && !va_mask) - compute_layout(); - for (i = 0; i < nr_inst; i++) { u32 rd, rn, insn, oinsn; @@ -156,9 +153,6 @@ void kvm_patch_vector_branch(struct alt_instr *alt, return; } - if (!va_mask) - compute_layout(); - /* * Compute HYP VA by using the same computation as kern_hyp_va() */ diff --git a/arch/c6x/kernel/entry.S b/arch/c6x/kernel/entry.S index 4332a10aec6c7..fb154d19625bc 100644 --- a/arch/c6x/kernel/entry.S +++ b/arch/c6x/kernel/entry.S @@ -18,7 +18,7 @@ #define DP B14 #define SP B15 -#ifndef CONFIG_PREEMPT +#ifndef CONFIG_PREEMPTION #define resume_kernel restore_all #endif @@ -287,7 +287,7 @@ ;; is a little bit different ;; ENTRY(ret_from_exception) -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION MASK_INT B2 #endif @@ -557,7 +557,7 @@ ENDPROC(_nmi_handler) ;; ;; Jump to schedule() then return to ret_from_isr ;; -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION resume_kernel: GET_THREAD_INFO A12 LDW .D1T1 *+A12(THREAD_INFO_PREEMPT_COUNT),A1 @@ -582,7 +582,7 @@ ENDPROC(_nmi_handler) B .S2 preempt_schedule_irq #endif ADDKPC .S2 preempt_schedule,B3,4 -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ ENTRY(enable_exception) DINT diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S index a7a5b67df8989..0077063280000 100644 --- a/arch/csky/kernel/entry.S +++ b/arch/csky/kernel/entry.S @@ -277,7 +277,7 @@ ENTRY(csky_irq) zero_fp psrset ee -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION mov r9, sp /* Get current stack pointer */ bmaski r10, THREAD_SHIFT andn r9, r10 /* Get thread_info */ @@ -294,7 +294,7 @@ ENTRY(csky_irq) mov a0, sp jbsr csky_do_IRQ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION subi r12, 1 stw r12, (r9, TINFO_PREEMPT) cmpnei r12, 0 diff --git a/arch/h8300/kernel/entry.S b/arch/h8300/kernel/entry.S index 4ade5f8299bae..c6e289b5f1f28 100644 --- a/arch/h8300/kernel/entry.S +++ b/arch/h8300/kernel/entry.S @@ -284,12 +284,12 @@ INTERRUPTS = 128 mov.l er0,@(LER0:16,sp) bra resume_userspace -#if !defined(CONFIG_PREEMPT) +#if !defined(CONFIG_PREEMPTION) #define resume_kernel restore_all #endif ret_from_exception: -#if defined(CONFIG_PREEMPT) +#if defined(CONFIG_PREEMPTION) orc #0xc0,ccr #endif ret_from_interrupt: @@ -319,7 +319,7 @@ INTERRUPTS = 128 restore_all: RESTORE_ALL /* Does RTE */ -#if defined(CONFIG_PREEMPT) +#if defined(CONFIG_PREEMPTION) resume_kernel: mov.l @(TI_PRE_COUNT:16,er4),er0 bne restore_all:8 diff --git a/arch/hexagon/include/asm/spinlock_types.h b/arch/hexagon/include/asm/spinlock_types.h index 19d233497ba52..de72fb23016dc 100644 --- a/arch/hexagon/include/asm/spinlock_types.h +++ b/arch/hexagon/include/asm/spinlock_types.h @@ -8,10 +8,6 @@ #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; diff --git a/arch/hexagon/kernel/vm_entry.S b/arch/hexagon/kernel/vm_entry.S index 4023fdbea4902..554371d92bed6 100644 --- a/arch/hexagon/kernel/vm_entry.S +++ b/arch/hexagon/kernel/vm_entry.S @@ -265,12 +265,12 @@ * should be in the designated register (usually R19) * * If we were in kernel mode, we don't need to check scheduler - * or signals if CONFIG_PREEMPT is not set. If set, then it has + * or signals if CONFIG_PREEMPTION is not set. If set, then it has * to jump to a need_resched kind of block. - * BTW, CONFIG_PREEMPT is not supported yet. + * BTW, CONFIG_PREEMPTION is not supported yet. */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION R0 = #VM_INT_DISABLE trap1(#HVM_TRAP1_VMSETIE) #endif diff --git a/arch/ia64/include/asm/spinlock_types.h b/arch/ia64/include/asm/spinlock_types.h index 6e345fefcdcab..681408d6816fb 100644 --- a/arch/ia64/include/asm/spinlock_types.h +++ b/arch/ia64/include/asm/spinlock_types.h @@ -2,10 +2,6 @@ #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; diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S index a9992be5718b8..2ac9263315000 100644 --- a/arch/ia64/kernel/entry.S +++ b/arch/ia64/kernel/entry.S @@ -670,12 +670,12 @@ GLOBAL_ENTRY(ia64_leave_syscall) * * p6 controls whether current_thread_info()->flags needs to be check for * extra work. We always check for extra work when returning to user-level. - * With CONFIG_PREEMPT, we also check for extra work when the preempt_count + * With CONFIG_PREEMPTION, we also check for extra work when the preempt_count * is 0. After extra work processing has been completed, execution * resumes at ia64_work_processed_syscall with p6 set to 1 if the extra-work-check * needs to be redone. */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION RSM_PSR_I(p0, r2, r18) // disable interrupts cmp.eq pLvSys,p0=r0,r0 // pLvSys=1: leave from syscall (pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13 @@ -685,7 +685,7 @@ GLOBAL_ENTRY(ia64_leave_syscall) (pUStk) mov r21=0 // r21 <- 0 ;; cmp.eq p6,p0=r21,r0 // p6 <- pUStk || (preempt_count == 0) -#else /* !CONFIG_PREEMPT */ +#else /* !CONFIG_PREEMPTION */ RSM_PSR_I(pUStk, r2, r18) cmp.eq pLvSys,p0=r0,r0 // pLvSys=1: leave from syscall (pUStk) cmp.eq.unc p6,p0=r0,r0 // p6 <- pUStk @@ -814,12 +814,12 @@ GLOBAL_ENTRY(ia64_leave_kernel) * * p6 controls whether current_thread_info()->flags needs to be check for * extra work. We always check for extra work when returning to user-level. - * With CONFIG_PREEMPT, we also check for extra work when the preempt_count + * With CONFIG_PREEMPTION, we also check for extra work when the preempt_count * is 0. After extra work processing has been completed, execution * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check * needs to be redone. */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION RSM_PSR_I(p0, r17, r31) // disable interrupts cmp.eq p0,pLvSys=r0,r0 // pLvSys=0: leave from kernel (pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13 @@ -1120,7 +1120,7 @@ GLOBAL_ENTRY(ia64_leave_kernel) /* * On entry: - * r20 = ¤t->thread_info->pre_count (if CONFIG_PREEMPT) + * r20 = ¤t->thread_info->pre_count (if CONFIG_PREEMPTION) * r31 = current->thread_info->flags * On exit: * p6 = TRUE if work-pending-check needs to be redone diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index b8356edbde659..a6d6a0556f089 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -841,7 +841,7 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) return 1; } -#if !defined(CONFIG_PREEMPT) +#if !defined(CONFIG_PREEMPTION) if (p->ainsn.inst_flag == INST_FLAG_BOOSTABLE && !p->post_handler) { /* Boost up -- we can execute copied instructions directly */ ia64_psr(regs)->ri = p->ainsn.slot; diff --git a/arch/m68k/coldfire/entry.S b/arch/m68k/coldfire/entry.S index 52d312d5b4d4f..d43a02795a4a4 100644 --- a/arch/m68k/coldfire/entry.S +++ b/arch/m68k/coldfire/entry.S @@ -108,7 +108,7 @@ ENTRY(system_call) btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */ jeq Luser_return /* if so, skip resched, signals */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION movel %sp,%d1 /* get thread_info pointer */ andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ movel %d1,%a0 diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S index 4e1b567becd6a..253f2b702b4c0 100644 --- a/arch/microblaze/kernel/entry.S +++ b/arch/microblaze/kernel/entry.S @@ -728,7 +728,7 @@ irq_call:rtbd r0, do_IRQ; bri 6f; /* MS: Return to kernel state. */ 2: -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get preempt_count from thread info */ lwi r5, r11, TI_PREEMPT_COUNT; diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index e5c2d47608feb..4c8e303dcaeae 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2586,7 +2586,7 @@ 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 config CPU_SUPPORTS_HIGHMEM bool diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h index feb069cbf44e8..655f40ddb6d1e 100644 --- a/arch/mips/include/asm/asmmacro.h +++ b/arch/mips/include/asm/asmmacro.h @@ -63,7 +63,7 @@ .endm .macro local_irq_disable reg=t0 -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION lw \reg, TI_PRE_COUNT($28) addi \reg, \reg, 1 sw \reg, TI_PRE_COUNT($28) @@ -73,7 +73,7 @@ xori \reg, \reg, 1 mtc0 \reg, CP0_STATUS irq_disable_hazard -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION lw \reg, TI_PRE_COUNT($28) addi \reg, \reg, -1 sw \reg, TI_PRE_COUNT($28) diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S index 5469d43b69668..4849a48afc0f8 100644 --- a/arch/mips/kernel/entry.S +++ b/arch/mips/kernel/entry.S @@ -19,7 +19,7 @@ #include <asm/thread_info.h> #include <asm/war.h> -#ifndef CONFIG_PREEMPT +#ifndef CONFIG_PREEMPTION #define resume_kernel restore_all #else #define __ret_from_irq ret_from_exception @@ -27,7 +27,7 @@ .text .align 5 -#ifndef CONFIG_PREEMPT +#ifndef CONFIG_PREEMPTION FEXPORT(ret_from_exception) local_irq_disable # preempt stop b __ret_from_irq @@ -53,7 +53,7 @@ FEXPORT(__ret_from_irq) bnez t0, work_pending j restore_all -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION resume_kernel: local_irq_disable lw t0, TI_PRE_COUNT($28) diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig index fbd68329737f4..abbb74e46f054 100644 --- a/arch/nds32/Kconfig +++ b/arch/nds32/Kconfig @@ -61,7 +61,7 @@ config GENERIC_HWEIGHT config GENERIC_LOCKBREAK def_bool y - depends on PREEMPT + depends on PREEMPTION config TRACE_IRQFLAGS_SUPPORT def_bool y diff --git a/arch/nds32/kernel/ex-exit.S b/arch/nds32/kernel/ex-exit.S index 1df02a7933641..6a2966c2d8c8f 100644 --- a/arch/nds32/kernel/ex-exit.S +++ b/arch/nds32/kernel/ex-exit.S @@ -72,7 +72,7 @@ restore_user_regs_last .endm -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION .macro preempt_stop .endm #else @@ -158,7 +158,7 @@ ENTRY(ret_slow_syscall) /* * preemptive kernel */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION resume_kernel: gie_disable lwi $t0, [tsk+#TSK_TI_PREEMPT] diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S index 1e515ccd698e3..3d8d1d0bcb64b 100644 --- a/arch/nios2/kernel/entry.S +++ b/arch/nios2/kernel/entry.S @@ -365,7 +365,7 @@ ENTRY(ret_from_interrupt) ldw r1, PT_ESTATUS(sp) /* check if returning to kernel */ TSTBNZ r1, r1, ESTATUS_EU, Luser_return -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION GET_THREAD_INFO r1 ldw r4, TI_PREEMPT_COUNT(r1) bne r4, r0, restore_all diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 0c29d6cb2c8df..9b44f06b263ef 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -82,7 +82,7 @@ config STACK_GROWSUP config GENERIC_LOCKBREAK bool default y - depends on SMP && PREEMPT + depends on SMP && PREEMPTION config ARCH_HAS_ILOG2_U32 bool diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index b96d744969779..9a03e29c87330 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -940,14 +940,14 @@ ENTRY(intr_return) rfi nop -#ifndef CONFIG_PREEMPT +#ifndef CONFIG_PREEMPTION # define intr_do_preempt intr_restore -#endif /* !CONFIG_PREEMPT */ +#endif /* !CONFIG_PREEMPTION */ .import schedule,code intr_do_resched: /* Only call schedule on return to userspace. If we're returning - * to kernel space, we may schedule if CONFIG_PREEMPT, otherwise + * to kernel space, we may schedule if CONFIG_PREEMPTION, otherwise * we jump back to intr_restore. */ LDREG PT_IASQ0(%r16), %r20 @@ -979,7 +979,7 @@ ENTRY(intr_return) * and preempt_count is 0. otherwise, we continue on * our merry way back to the current running task. */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION .import preempt_schedule_irq,code intr_do_preempt: rsm PSW_SM_I, %r0 /* disable interrupts */ @@ -999,7 +999,7 @@ ENTRY(intr_return) nop b,n intr_restore /* ssm PSW_SM_I done by intr_restore */ -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ /* * External interrupts. diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 3e56c9c2f16ee..2ee24d22d575a 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -106,7 +106,7 @@ config LOCKDEP_SUPPORT config GENERIC_LOCKBREAK bool default y - depends on SMP && PREEMPT + depends on SMP && PREEMPTION config GENERIC_HWEIGHT bool @@ -144,6 +144,7 @@ config PPC select ARCH_MIGHT_HAVE_PC_SERIO select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_SUPPORTS_ATOMIC_RMW + select ARCH_SUPPORTS_RT select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF if PPC64 select ARCH_WANT_IPC_PARSE_VERSION @@ -221,6 +222,7 @@ 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_RCU_TABLE_NO_INVALIDATE if HAVE_RCU_TABLE_FREE select HAVE_MMU_GATHER_PAGE_SIZE @@ -398,7 +400,7 @@ menu "Kernel options" config HIGHMEM bool "High memory support" - depends on PPC32 + depends on PPC32 && !PREEMPT_RT source "kernel/Kconfig.hz" diff --git a/arch/powerpc/include/asm/spinlock_types.h b/arch/powerpc/include/asm/spinlock_types.h index 87adaf13b7e84..7305cb6a53e47 100644 --- a/arch/powerpc/include/asm/spinlock_types.h +++ b/arch/powerpc/include/asm/spinlock_types.h @@ -2,10 +2,6 @@ #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; diff --git a/arch/powerpc/include/asm/stackprotector.h b/arch/powerpc/include/asm/stackprotector.h index 1c8460e235838..b1653c160bab9 100644 --- a/arch/powerpc/include/asm/stackprotector.h +++ b/arch/powerpc/include/asm/stackprotector.h @@ -24,7 +24,11 @@ static __always_inline void boot_init_stack_canary(void) unsigned long canary; /* Try to get a semi random initial value. */ +#ifdef CONFIG_PREEMPT_RT + canary = (unsigned long)&canary; +#else canary = get_random_canary(); +#endif canary ^= mftb(); canary ^= LINUX_VERSION_CODE; canary &= CANARY_MASK; diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 8e1d0195ac366..594fdb569e540 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -30,6 +30,8 @@ struct thread_info { 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; @@ -80,11 +82,12 @@ 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 */ @@ -93,6 +96,9 @@ 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) @@ -112,6 +118,7 @@ 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 | \ @@ -121,8 +128,9 @@ 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 */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 5c0a1e17219b7..b28cd3acd6743 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -167,6 +167,7 @@ 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); #ifdef CONFIG_PPC64 OFFSET(DCACHEL1BLOCKSIZE, ppc64_caches, l1d.block_size); diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index d60908ea37fb9..940de56e90d19 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -400,7 +400,9 @@ _GLOBAL(DoSyscall) MTMSRD(r10) lwz r9,TI_FLAGS(r2) 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 @@ -515,13 +517,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) 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 @@ -530,12 +532,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) 1: stw r6,RESULT(r1) /* Save result */ stw r3,GPR3(r1) /* Update return value */ -2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) +2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)@h beq 4f /* Clear per-syscall TIF flags if any are set. */ - li r11,_TIF_PERSYSCALL_MASK + li r11,_TIF_PERSYSCALL_MASK@h addi r12,r2,TI_FLAGS 3: lwarx r8,0,r12 andc r8,r8,r11 @@ -897,13 +899,20 @@ user_exc_return: /* r10 contains MSR_KERNEL here */ bne- 0b 1: -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION /* check current_thread_info->preempt_count */ lwz r0,TI_PREEMPT(r2) cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ bne restore_kuap andi. r8,r8,_TIF_NEED_RESCHED + bne+ 1f + lwz r0,TI_PREEMPT_LAZY(r2) + cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ + bne restore_kuap + lwz r0,TI_FLAGS(r2) + andi. r0,r0,_TIF_NEED_RESCHED_LAZY beq+ restore_kuap +1: lwz r3,_MSR(r1) andi. r0,r3,MSR_EE /* interrupts off? */ beq restore_kuap /* don't schedule if so */ @@ -921,7 +930,7 @@ user_exc_return: /* r10 contains MSR_KERNEL here */ */ bl trace_hardirqs_on #endif -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ restore_kuap: kuap_restore r1, r2, r9, r10, r0 @@ -1224,7 +1233,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) #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 */ @@ -1245,7 +1254,7 @@ do_resched: /* r10 contains MSR_KERNEL here */ SYNC MTMSRD(r10) /* disable interrupts */ lwz r9,TI_FLAGS(r2) - 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 diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 3fd3ef352e3fd..dfd96e87d7b6c 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -240,7 +240,9 @@ system_call: /* label this so stack traces look sane */ 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 @@ -363,25 +365,25 @@ 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 @@ -786,7 +788,7 @@ _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 @@ -846,12 +848,20 @@ _GLOBAL(ret_from_except_lite) bne- 0b 1: -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION /* Check if we need to preempt */ - andi. r0,r4,_TIF_NEED_RESCHED - beq+ restore - /* Check that preempt_count() == 0 and interrupts are enabled */ 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 */ +check_count: cmpwi cr0,r8,0 bne restore ld r0,SOFTE(r1) @@ -877,7 +887,7 @@ _GLOBAL(ret_from_except_lite) li r10,MSR_RI mtmsrd r10,1 /* Update machine state */ #endif /* CONFIG_PPC_BOOK3E */ -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ .globl fast_exc_return_irq fast_exc_return_irq: diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index add67498c126b..201ddd5d3f156 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -679,10 +679,12 @@ void *mcheckirq_ctx[NR_CPUS] __read_mostly; void *softirq_ctx[NR_CPUS] __read_mostly; void *hardirq_ctx[NR_CPUS] __read_mostly; +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { call_do_softirq(softirq_ctx[smp_processor_id()]); } +#endif irq_hw_number_t virq_to_hw(unsigned int virq) { diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 82df4b09e79f4..4af2ef8783619 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -37,6 +37,7 @@ * We store the saved ksp_limit in the unused part * of the STACK_FRAME_OVERHEAD */ +#ifndef CONFIG_PREEMPT_RT _GLOBAL(call_do_softirq) mflr r0 stw r0,4(r1) @@ -52,6 +53,7 @@ _GLOBAL(call_do_softirq) stw r10,THREAD+KSP_LIMIT(r2) mtlr r0 blr +#endif /* * void call_do_irq(struct pt_regs *regs, void *sp); diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 9bc0aa9aeb654..9bce8e23f33eb 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -27,6 +27,7 @@ .text +#ifndef CONFIG_PREEMPT_RT _GLOBAL(call_do_softirq) mflr r0 std r0,16(r1) @@ -37,6 +38,7 @@ _GLOBAL(call_do_softirq) ld r0,16(r1) mtlr r0 blr +#endif _GLOBAL(call_do_irq) mflr r0 diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 014ff0701f245..b98d5bc68a886 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -171,7 +171,6 @@ 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(); @@ -261,12 +260,17 @@ static char *get_mmu_str(void) static int __die(const char *str, struct pt_regs *regs, long err) { + const char *pr = ""; + printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); + if (IS_ENABLED(CONFIG_PREEMPTION)) + pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT"; + printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n", IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE", PAGE_SIZE / 1024, get_mmu_str(), - IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", + pr, IS_ENABLED(CONFIG_SMP) ? " SMP" : "", IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "", debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c index af3c15a1d41eb..8ae46c5945d07 100644 --- a/arch/powerpc/kernel/watchdog.c +++ b/arch/powerpc/kernel/watchdog.c @@ -181,11 +181,6 @@ static void watchdog_smp_panic(int cpu, u64 tb) 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(); diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index 711fca9bc6f0c..dd3babcb3b16a 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -178,6 +178,7 @@ config KVM_E500MC config KVM_MPIC bool "KVM in-kernel MPIC emulation" depends on KVM && E500 + depends on !PREEMPT_RT select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQFD select HAVE_KVM_IRQ_ROUTING diff --git a/arch/powerpc/platforms/ps3/device-init.c b/arch/powerpc/platforms/ps3/device-init.c index 2735ec90414dc..359231cea8cd7 100644 --- a/arch/powerpc/platforms/ps3/device-init.c +++ b/arch/powerpc/platforms/ps3/device-init.c @@ -738,8 +738,8 @@ static int ps3_notification_read_write(struct ps3_notification_device *dev, } 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) { diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 6ba081dd61c93..60d060ba9fea7 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -24,6 +24,7 @@ #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> @@ -178,6 +179,7 @@ static int tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum, } 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, @@ -198,7 +200,8 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum, 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); @@ -209,7 +212,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum, 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); } @@ -243,7 +246,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum, 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; @@ -401,13 +404,14 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn, 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); @@ -453,7 +457,7 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn, /* error cleanup: caller will clear whole range */ - local_irq_enable(); + local_unlock_irq(tcp_page_lock); return rc; } diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 8ca4798311429..8f482313e5601 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -155,7 +155,7 @@ REG_L x2, PT_SP(sp) .endm -#if !IS_ENABLED(CONFIG_PREEMPT) +#if !IS_ENABLED(CONFIG_PREEMPTION) .set resume_kernel, restore_all #endif @@ -269,7 +269,7 @@ ENTRY(handle_exception) RESTORE_ALL sret -#if IS_ENABLED(CONFIG_PREEMPT) +#if IS_ENABLED(CONFIG_PREEMPTION) resume_kernel: REG_L s0, TASK_TI_PREEMPT_COUNT(tp) bnez s0, restore_all diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 43a81d0ad5074..33d968175038e 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -30,7 +30,7 @@ config GENERIC_BUG_RELATIVE_POINTERS def_bool y config GENERIC_LOCKBREAK - def_bool y if PREEMPT + def_bool y if PREEMPTTION config PGSTE def_bool y if KVM diff --git a/arch/s390/include/asm/preempt.h b/arch/s390/include/asm/preempt.h index b5ea9e14c017a..6ede29907fbf7 100644 --- a/arch/s390/include/asm/preempt.h +++ b/arch/s390/include/asm/preempt.h @@ -130,11 +130,11 @@ static inline bool should_resched(int preempt_offset) #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION extern asmlinkage void preempt_schedule(void); #define __preempt_schedule() preempt_schedule() extern asmlinkage void preempt_schedule_notrace(void); #define __preempt_schedule_notrace() preempt_schedule_notrace() -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ #endif /* __ASM_PREEMPT_H */ diff --git a/arch/s390/include/asm/spinlock_types.h b/arch/s390/include/asm/spinlock_types.h index cfed272e4fd59..8e28e8176ec88 100644 --- a/arch/s390/include/asm/spinlock_types.h +++ b/arch/s390/include/asm/spinlock_types.h @@ -2,10 +2,6 @@ #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; diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index 34bdc60c0b11d..8e38447be4653 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -194,6 +194,8 @@ void die(struct pt_regs *regs, const char *str) regs->int_code >> 17, ++die_counter); #ifdef CONFIG_PREEMPT pr_cont("PREEMPT "); +#elif defined(CONFIG_PREEMPT_RT) + pr_cont("PREEMPT_RT "); #endif pr_cont("SMP "); if (debug_pagealloc_enabled()) diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 270d1d145761b..9205add8481d5 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -790,7 +790,7 @@ ENTRY(io_int_handler) .Lio_work: tm __PT_PSW+1(%r11),0x01 # returning to user ? jo .Lio_work_user # yes -> do resched & signal -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION # check for preemptive scheduling icm %r0,15,__LC_PREEMPT_COUNT jnz .Lio_restore # preemption is disabled diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index f356ee674d89b..9ece111b02548 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -108,7 +108,7 @@ config GENERIC_CALIBRATE_DELAY config GENERIC_LOCKBREAK def_bool y - depends on SMP && PREEMPT + depends on SMP && PREEMPTION config ARCH_SUSPEND_POSSIBLE def_bool n diff --git a/arch/sh/include/asm/spinlock_types.h b/arch/sh/include/asm/spinlock_types.h index e82369f286a20..22ca9a98bbb8b 100644 --- a/arch/sh/include/asm/spinlock_types.h +++ b/arch/sh/include/asm/spinlock_types.h @@ -2,10 +2,6 @@ #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; diff --git a/arch/sh/kernel/cpu/sh5/entry.S b/arch/sh/kernel/cpu/sh5/entry.S index de68ffdfffbf5..81c8b64b977ff 100644 --- a/arch/sh/kernel/cpu/sh5/entry.S +++ b/arch/sh/kernel/cpu/sh5/entry.S @@ -86,7 +86,7 @@ andi r6, ~0xf0, r6; \ putcon r6, SR; -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION # define preempt_stop() CLI() #else # define preempt_stop() @@ -884,7 +884,7 @@ LRESVEC_block_end: /* Marker. Unused. */ /* Check softirqs */ -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION pta ret_from_syscall, tr0 blink tr0, ZERO diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S index d31f66e82ce51..956a7a03b0c83 100644 --- a/arch/sh/kernel/entry-common.S +++ b/arch/sh/kernel/entry-common.S @@ -41,7 +41,7 @@ */ #include <asm/dwarf.h> -#if defined(CONFIG_PREEMPT) +#if defined(CONFIG_PREEMPTION) # define preempt_stop() cli ; TRACE_IRQS_OFF #else # define preempt_stop() @@ -84,7 +84,7 @@ ENTRY(ret_from_irq) get_current_thread_info r8, r0 bt resume_kernel ! Yes, it's from kernel, go back soon -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION bra resume_userspace nop ENTRY(resume_kernel) diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c index 5717c7cbdd97a..c4e46252377ed 100644 --- a/arch/sh/kernel/irq.c +++ b/arch/sh/kernel/irq.c @@ -148,6 +148,7 @@ void irq_ctx_exit(int cpu) hardirq_ctx[cpu] = NULL; } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { struct thread_info *curctx; @@ -175,6 +176,7 @@ 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) { diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index eb24cb1afc11f..e8c3ea01c12f6 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -277,7 +277,7 @@ config US3_MC config GENERIC_LOCKBREAK bool default y - depends on SPARC64 && SMP && PREEMPT + depends on SPARC64 && SMP && PREEMPTION config NUMA bool "NUMA support" diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c index 3ec9f1402aad3..eb21682abfcb1 100644 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -854,6 +854,7 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs) set_irq_regs(old_regs); } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { void *orig_sp, *sp = softirq_stack[smp_processor_id()]; @@ -868,6 +869,7 @@ void do_softirq_own_stack(void) __asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp)); } +#endif #ifdef CONFIG_HOTPLUG_CPU void fixup_irqs(void) diff --git a/arch/sparc/kernel/rtrap_64.S b/arch/sparc/kernel/rtrap_64.S index 29aa34f11720c..c5fd4b450d9b6 100644 --- a/arch/sparc/kernel/rtrap_64.S +++ b/arch/sparc/kernel/rtrap_64.S @@ -310,7 +310,7 @@ kern_rtt: rdpr %canrestore, %g1 retry to_kernel: -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION ldsw [%g6 + TI_PRE_COUNT], %l5 brnz %l5, kern_fpucheck ldx [%g6 + TI_FLAGS], %l5 diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8ef85139553f5..4b77b3273051e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -90,6 +90,7 @@ config X86 select ARCH_SUPPORTS_ACPI select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 + select ARCH_SUPPORTS_RT select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS @@ -132,8 +133,8 @@ config X86 select HAVE_ALIGNED_STRUCT_PAGE if SLUB select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE - select HAVE_ARCH_JUMP_LABEL - select HAVE_ARCH_JUMP_LABEL_RELATIVE + select HAVE_ARCH_JUMP_LABEL if !PREEMPT_RT + select HAVE_ARCH_JUMP_LABEL_RELATIVE if !PREEMPT_RT select HAVE_ARCH_KASAN if X86_64 select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS if MMU @@ -199,6 +200,7 @@ 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_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index 3e707e81afdb4..0e80da8190be1 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -387,14 +387,14 @@ static int ecb_encrypt(struct skcipher_request *req) 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; } @@ -409,14 +409,14 @@ static int ecb_decrypt(struct skcipher_request *req) 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; } @@ -431,14 +431,14 @@ static int cbc_encrypt(struct skcipher_request *req) 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; } @@ -453,14 +453,14 @@ static int cbc_decrypt(struct skcipher_request *req) 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; } @@ -510,18 +510,20 @@ static int ctr_crypt(struct skcipher_request *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; } diff --git a/arch/x86/crypto/cast5_avx_glue.c b/arch/x86/crypto/cast5_avx_glue.c index 384ccb00f9e15..2f8df8ef8644e 100644 --- a/arch/x86/crypto/cast5_avx_glue.c +++ b/arch/x86/crypto/cast5_avx_glue.c @@ -46,7 +46,7 @@ static inline void cast5_fpu_end(bool fpu_enabled) 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; @@ -61,7 +61,7 @@ static int ecb_crypt(struct skcipher_request *req, bool enc) 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) { @@ -90,10 +90,9 @@ static int ecb_crypt(struct skcipher_request *req, bool enc) } while (nbytes >= bsize); done: + cast5_fpu_end(fpu_enabled); err = skcipher_walk_done(&walk, nbytes); } - - cast5_fpu_end(fpu_enabled); return err; } @@ -197,7 +196,7 @@ static int cbc_decrypt(struct skcipher_request *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; @@ -205,12 +204,11 @@ static int cbc_decrypt(struct skcipher_request *req) 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; } @@ -277,7 +275,7 @@ static int ctr_crypt(struct skcipher_request *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; @@ -285,13 +283,12 @@ static int ctr_crypt(struct skcipher_request *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); diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c index 388f95a4ec240..f8e9ee81c39dd 100644 --- a/arch/x86/crypto/chacha_glue.c +++ b/arch/x86/crypto/chacha_glue.c @@ -127,7 +127,6 @@ static int chacha_simd_stream_xor(struct skcipher_walk *walk, const struct chacha_ctx *ctx, const 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); @@ -140,20 +139,14 @@ static int chacha_simd_stream_xor(struct skcipher_walk *walk, 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; diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c index d15b99397480b..36c28b295b8e3 100644 --- a/arch/x86/crypto/glue_helper.c +++ b/arch/x86/crypto/glue_helper.c @@ -24,7 +24,7 @@ int glue_ecb_req_128bit(const struct common_glue_ctx *gctx, 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; @@ -37,7 +37,7 @@ int glue_ecb_req_128bit(const struct common_glue_ctx *gctx, 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; @@ -55,10 +55,9 @@ int glue_ecb_req_128bit(const struct common_glue_ctx *gctx, 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); @@ -101,7 +100,7 @@ int glue_cbc_decrypt_req_128bit(const struct common_glue_ctx *gctx, 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; @@ -115,7 +114,7 @@ int glue_cbc_decrypt_req_128bit(const struct common_glue_ctx *gctx, 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; @@ -147,10 +146,10 @@ int glue_cbc_decrypt_req_128bit(const struct common_glue_ctx *gctx, 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); @@ -161,7 +160,7 @@ int glue_ctr_req_128bit(const struct common_glue_ctx *gctx, 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; @@ -175,7 +174,7 @@ int glue_ctr_req_128bit(const struct common_glue_ctx *gctx, 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); @@ -199,11 +198,10 @@ int glue_ctr_req_128bit(const struct common_glue_ctx *gctx, } 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; @@ -301,8 +299,14 @@ int glue_xts_req_128bit(const struct common_glue_ctx *gctx, 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; } diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 3f8e22615812b..26934d55c14a0 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -130,7 +130,7 @@ static long syscall_trace_enter(struct pt_regs *regs) #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) { @@ -145,9 +145,16 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags) /* 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); + t->forced_info.si_signo = 0; + } +#endif if (cached_flags & _TIF_UPROBE) uprobe_notify_resume(regs); diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index f07baf0388bce..69049e32b4fa1 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1106,8 +1106,26 @@ ENTRY(entry_INT80_32) restore_all_kernel: #ifdef CONFIG_PREEMPTION DISABLE_INTERRUPTS(CLBR_ANY) + # preempt count == 0 + NEED_RS set? cmpl $0, PER_CPU_VAR(__preempt_count) +#ifndef CONFIG_PREEMPT_LAZY jnz .Lno_preempt +#else + jz test_int_off + + # atleast preempt count == 0 ? + cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count) + jne .Lno_preempt + + movl PER_CPU_VAR(current_task), %ebp + cmpl $0,TASK_TI_preempt_lazy_count(%ebp) # non-zero preempt_lazy_count ? + jnz .Lno_preempt + + testl $_TIF_NEED_RESCHED_LAZY, TASK_TI_flags(%ebp) + jz .Lno_preempt + +test_int_off: +#endif testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ? jz .Lno_preempt call preempt_schedule_irq diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index b7c3ea4cb19d4..ce564dc48647f 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -670,7 +670,23 @@ GLOBAL(swapgs_restore_regs_and_return_to_usermode) btl $9, EFLAGS(%rsp) /* were interrupts off? */ jnc 1f 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 1: #endif @@ -1074,6 +1090,7 @@ EXPORT_SYMBOL(native_load_gs_index) jmp 2b .previous +#ifndef CONFIG_PREEMPT_RT /* Call softirq on interrupt stack. Interrupts are off. */ ENTRY(do_softirq_own_stack) pushq %rbp @@ -1084,6 +1101,7 @@ 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 diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index b774c52e5411f..1786e4d9f70e8 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -23,6 +23,7 @@ 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. diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index 3d4cb83a88284..1f28e9f3dc8e2 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -89,17 +89,48 @@ static __always_inline void __preempt_count_sub(int val) * 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 (preempt_count()) + return false; + 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; + /* XXX PREEMPT_LOCK_OFFSET */ + 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_PREEMPTION diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h index 33d3c88a7225f..65b9a5d4132b7 100644 --- a/arch/x86/include/asm/signal.h +++ b/arch/x86/include/asm/signal.h @@ -28,6 +28,19 @@ 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 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) +#define ARCH_RT_DELAYS_SIGNAL_SEND +#endif + #ifndef CONFIG_COMPAT typedef sigset_t compat_sigset_t; #endif diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index 91e29b6a86a5e..1ef821537da8f 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -60,7 +60,7 @@ */ static __always_inline void boot_init_stack_canary(void) { - u64 canary; + u64 uninitialized_var(canary); u64 tsc; #ifdef CONFIG_X86_64 @@ -71,8 +71,14 @@ static __always_inline void boot_init_stack_canary(void) * 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 get_random_bytes(&canary, sizeof(canary)); +#endif tsc = rdtsc(); canary += tsc + (tsc << 32UL); canary &= CANARY_MASK; diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index f9453536f9bbc..f346f24140be9 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -56,17 +56,24 @@ 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 /* @@ -92,6 +99,7 @@ struct thread_info { #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 */ @@ -122,6 +130,7 @@ struct thread_info { #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) @@ -159,6 +168,8 @@ 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) /* diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index f0262cb5657a7..913c88617848b 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1725,7 +1725,7 @@ static bool io_apic_level_ack_pending(struct mp_chip_data *data) 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))) { @@ -1736,9 +1736,9 @@ static inline bool ioapic_irqd_mask(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) { - 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 @@ -1773,11 +1773,11 @@ static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked) } } #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 @@ -1786,11 +1786,11 @@ static void ioapic_ack_level(struct irq_data *irq_data) { 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 @@ -1845,7 +1845,7 @@ static void ioapic_ack_level(struct irq_data *irq_data) 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) diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 5c7ee3df4d0b0..24bcc28f68d4b 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -38,6 +38,10 @@ static void __used common(void) #endif BLANK(); +#ifdef CONFIG_PREEMPT_LAZY + OFFSET(TASK_TI_flags, task_struct, thread_info.flags); + OFFSET(TASK_TI_preempt_lazy_count, task_struct, thread_info.preempt_lazy_count); +#endif OFFSET(TASK_addr_limit, task_struct, thread.addr_limit); BLANK(); @@ -92,6 +96,7 @@ 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); diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index c656d92cd708f..de56d671bc7fd 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -77,12 +77,13 @@ EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq); __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); + u64 ip = regs ? instruction_pointer(regs) : 0; entering_irq(); inc_irq_stat(hyperv_stimer0_count); if (hv_stimer0_handler) hv_stimer0_handler(); - add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0); + add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0, ip); ack_APIC_irq(); exiting_irq(); diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 12c70840980e4..6909468cc7a04 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -113,6 +113,18 @@ 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): * diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index a759ca97cd01c..a74a7606806c1 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -131,6 +131,7 @@ int irq_init_percpu_irqstack(unsigned int cpu) return 0; } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { struct irq_stack *irqstk; @@ -147,6 +148,7 @@ void do_softirq_own_stack(void) call_on_stack(__do_softirq, isp); } +#endif void handle_irq(struct irq_desc *desc, struct pt_regs *regs) { diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index b8ceec4974fe3..39510443d996e 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -38,6 +38,7 @@ #include <linux/io.h> #include <linux/kdebug.h> #include <linux/syscalls.h> +#include <linux/highmem.h> #include <asm/pgtable.h> #include <asm/ldt.h> @@ -196,6 +197,35 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) } EXPORT_SYMBOL_GPL(start_thread); +#ifdef CONFIG_PREEMPT_RT +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. @@ -266,6 +296,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_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 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8d82ec0482fc2..4511110d43e11 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7207,6 +7207,14 @@ int kvm_arch_init(void *opaque) goto out; } +#ifdef CONFIG_PREEMPT_RT + 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, diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c index 0a1898b8552e2..8606f17582073 100644 --- a/arch/x86/mm/highmem_32.c +++ b/arch/x86/mm/highmem_32.c @@ -33,10 +33,11 @@ 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)) @@ -46,7 +47,10 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot) 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 + current->kmap_pte[type] = pte; +#endif + set_pte(kmap_pte-idx, pte); arch_flush_lazy_mmu_mode(); return (void *)vaddr; @@ -89,6 +93,9 @@ 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 + current->kmap_pte[type] = __pte(0); +#endif kpte_clear_flush(kmap_pte-idx, vaddr); kmap_atomic_idx_pop(); arch_flush_lazy_mmu_mode(); @@ -101,7 +108,7 @@ void __kunmap_atomic(void *kvaddr) #endif pagefault_enable(); - preempt_enable(); + preempt_enable_nort(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index 6748b4c2baff3..54e2f28fe1897 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -46,6 +46,7 @@ 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; @@ -55,7 +56,12 @@ void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) 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 + current->kmap_pte[type] = pte; +#endif + set_pte(kmap_pte - idx, pte); arch_flush_lazy_mmu_mode(); return (void *)vaddr; @@ -106,6 +112,9 @@ 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 + current->kmap_pte[type] = __pte(0); +#endif kpte_clear_flush(kmap_pte-idx, vaddr); kmap_atomic_idx_pop(); } diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index e6a9edc5baaf0..66f96f21a7b60 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -708,7 +708,7 @@ void native_flush_tlb_others(const struct cpumask *cpumask, (void *)info, 1); else on_each_cpu_cond_mask(tlb_is_not_lazy, flush_tlb_func_remote, - (void *)info, 1, GFP_ATOMIC, cpumask); + (void *)info, 1, cpumask); } /* diff --git a/arch/xtensa/include/asm/spinlock_types.h b/arch/xtensa/include/asm/spinlock_types.h index 64c9389254f13..dc846323b1cd7 100644 --- a/arch/xtensa/include/asm/spinlock_types.h +++ b/arch/xtensa/include/asm/spinlock_types.h @@ -2,10 +2,6 @@ #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> diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 9e3676879168a..a6434813df6c8 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -520,7 +520,7 @@ ENTRY(kernel_exception) call4 schedule # void schedule (void) j 1b -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION 6: _bbci.l a4, TIF_NEED_RESCHED, 4f diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index 4a6c495ce9b6d..2e7cf56412a05 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -524,12 +524,15 @@ DEFINE_SPINLOCK(die_lock); void die(const char * str, struct pt_regs * regs, long err) { static int die_counter; + const char *pr = ""; + + if (IS_ENABLED(CONFIG_PREEMPTION)) + pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT"; console_verbose(); spin_lock_irq(&die_lock); - pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter, - IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : ""); + pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter, pr); show_regs(regs); if (!user_mode(regs)) show_stack(NULL, (unsigned long*)regs->areg[1]); diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 5ed59ac6ae58b..b1da5f1592eb5 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -9,6 +9,7 @@ #include <linux/blkdev.h> #include <linux/slab.h> #include <linux/sched/task.h> +#include <linux/delay.h> #include "blk.h" @@ -115,7 +116,7 @@ static void ioc_release_fn(struct work_struct *work) spin_unlock(&q->queue_lock); } else { spin_unlock_irqrestore(&ioc->lock, flags); - cpu_relax(); + cpu_chill(); spin_lock_irqsave_nested(&ioc->lock, flags, 1); } } diff --git a/block/blk-mq.c b/block/blk-mq.c index ec791156e9ccd..3811881ff624e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -611,9 +611,17 @@ static void __blk_mq_complete_request(struct request *rq) 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 + 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; @@ -623,7 +631,7 @@ static void __blk_mq_complete_request(struct request *rq) } else { q->mq_ops->complete(rq); } - put_cpu(); + put_cpu_light(); } static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) @@ -1466,14 +1474,14 @@ static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, 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, diff --git a/block/blk-softirq.c b/block/blk-softirq.c index 457d9ba3eb204..4debe1124b990 100644 --- a/block/blk-softirq.c +++ b/block/blk-softirq.c @@ -42,17 +42,13 @@ static __latent_entropy void blk_done_softirq(struct softirq_action *h) static void trigger_softirq(void *data) { struct request *rq = data; - unsigned long flags; struct list_head *list; - local_irq_save(flags); list = this_cpu_ptr(&blk_cpu_done); list_add_tail(&rq->ipi_list, list); if (list->next == &rq->ipi_list) raise_softirq_irqoff(BLOCK_SOFTIRQ); - - local_irq_restore(flags); } /* @@ -91,6 +87,7 @@ static int blk_softirq_cpu_dead(unsigned int cpu) this_cpu_ptr(&blk_cpu_done)); raise_softirq_irqoff(BLOCK_SOFTIRQ); local_irq_enable(); + preempt_check_resched_rt(); return 0; } @@ -142,6 +139,7 @@ void __blk_complete_request(struct request *req) goto do_local; local_irq_restore(flags); + preempt_check_resched_rt(); } static __init int blk_softirq_init(void) diff --git a/crypto/cryptd.c b/crypto/cryptd.c index 927760b316a4d..fb1e305aa3984 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -36,6 +36,7 @@ static struct workqueue_struct *cryptd_wq; struct cryptd_cpu_queue { struct crypto_queue queue; struct work_struct work; + spinlock_t qlock; }; struct cryptd_queue { @@ -105,6 +106,7 @@ static int cryptd_init_queue(struct cryptd_queue *queue, 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; @@ -129,8 +131,10 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue, struct cryptd_cpu_queue *cpu_queue; refcount_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); @@ -146,7 +150,7 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue, refcount_inc(refcnt); out_put_cpu: - put_cpu(); + spin_unlock_bh(&cpu_queue->qlock); return err; } @@ -162,16 +166,11 @@ static void cryptd_queue_worker(struct work_struct *work) 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; diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index 1a8564a79d8dc..9dc3cc8beb2a6 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -113,12 +113,20 @@ ssize_t zcomp_available_show(const char *comp, char *buf) 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, @@ -168,6 +176,7 @@ int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node) 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; } diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h index 1806475b919df..b2c1db8a75ecb 100644 --- a/drivers/block/zram/zcomp.h +++ b/drivers/block/zram/zcomp.h @@ -10,6 +10,7 @@ struct zcomp_strm { /* compression/decompression buffer */ void *buffer; struct crypto_comp *tfm; + spinlock_t zcomp_lock; }; /* dynamic per-device compression frontend */ diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 4285e75e52c34..1699e84c9fce3 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -55,6 +55,40 @@ static void zram_free_page(struct zram *zram, size_t index); static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, struct bio *bio); +#ifdef CONFIG_PREEMPT_RT +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) { @@ -70,6 +104,7 @@ static void zram_slot_unlock(struct zram *zram, u32 index) { bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags); } +#endif static inline bool init_done(struct zram *zram) { @@ -1155,6 +1190,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize) if (!huge_class_size) huge_class_size = zs_huge_class_size(zram->mem_pool); + zram_meta_init_table_locks(zram, num_pages); return true; } @@ -1217,6 +1253,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index, 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)) { @@ -1247,6 +1284,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index, 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); @@ -1254,14 +1292,13 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index, 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. */ diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index f2fd46daa7604..7e4dd447e1ddd 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -63,6 +63,7 @@ struct zram_table_entry { unsigned long element; }; unsigned long flags; + spinlock_t lock; #ifdef CONFIG_ZRAM_MEMORY_TRACKING ktime_t ac_time; #endif diff --git a/drivers/char/random.c b/drivers/char/random.c index 01b8868b9bed2..d5ac183bf39c9 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1305,28 +1305,27 @@ static __u32 get_reg(struct fast_pool *f, struct pt_regs *regs) 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); diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index 87f4493402021..06a3a1fed42f6 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -20,7 +20,6 @@ #include "tpm-dev.h" static struct workqueue_struct *tpm_dev_wq; -static DEFINE_MUTEX(tpm_dev_wq_lock); static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space, u8 *buf, size_t bufsiz) diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index e7df342a317d6..f89057fdc0536 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -49,6 +49,31 @@ static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *da return container_of(data, struct tpm_tis_tcg_phy, priv); } +#ifdef CONFIG_PREEMPT_RT +/* + * 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"); @@ -146,7 +171,7 @@ static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len, 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; } @@ -173,7 +198,7 @@ static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value) { 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; } diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index f35a53ce8988a..d02f9c8d28487 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -434,6 +434,13 @@ config ATMEL_TCB_CLKSRC 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 diff --git a/drivers/clocksource/timer-atmel-tcb.c b/drivers/clocksource/timer-atmel-tcb.c index 7427b07495a89..ce6627ee161fe 100644 --- a/drivers/clocksource/timer-atmel-tcb.c +++ b/drivers/clocksource/timer-atmel-tcb.c @@ -28,8 +28,7 @@ * 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. + * 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, @@ -143,6 +142,8 @@ static unsigned long notrace tc_delay_timer_read32(void) struct tc_clkevt_device { struct clock_event_device clkevt; struct clk *clk; + bool clk_enabled; + u32 freq; void __iomem *regs; }; @@ -151,15 +152,26 @@ 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 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); @@ -167,8 +179,14 @@ static int tc_shutdown(struct clock_event_device *d) 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)) - clk_disable(tcd->clk); + tc_clk_disable(d); return 0; } @@ -181,9 +199,9 @@ static int tc_set_oneshot(struct clock_event_device *d) if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) tc_shutdown(d); - clk_enable(tcd->clk); + tc_clk_enable(d); - /* slow clock, count up to RC, then irq and stop */ + /* 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)); @@ -203,12 +221,12 @@ static int tc_set_periodic(struct clock_event_device *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); + tc_clk_enable(d); - /* slow clock, count up to RC, then irq and restart */ + /* 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)); + 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)); @@ -234,9 +252,13 @@ static struct tc_clkevt_device 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, + .set_state_shutdown = tc_shutdown_clk_off, .set_state_periodic = tc_set_periodic, .set_state_oneshot = tc_set_oneshot, }, @@ -256,8 +278,11 @@ static irqreturn_t ch2_irq(int irq, void *handle) return IRQ_NONE; } -static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) +static const u8 atmel_tcb_divisors[5] = { 2, 8, 32, 128, 0, }; + +static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx) { + unsigned divisor = atmel_tcb_divisors[divisor_idx]; int ret; struct clk *t2_clk = tc->clk[2]; int irq = tc->irq[2]; @@ -278,7 +303,11 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) clkevt.regs = tc->regs; clkevt.clk = t2_clk; - timer_clock = clk32k_divisor_idx; + timer_clock = divisor_idx; + if (!divisor) + clkevt.freq = 32768; + else + clkevt.freq = clk_get_rate(t2_clk) / divisor; clkevt.clkevt.cpumask = cpumask_of(0); @@ -289,7 +318,7 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) return ret; } - clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff); + clockevents_config_and_register(&clkevt.clkevt, clkevt.freq, 1, 0xffff); return ret; } @@ -346,8 +375,6 @@ static void __init tcb_setup_single_chan(struct atmel_tc *tc, int mck_divisor_id 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, }, @@ -467,7 +494,11 @@ static int __init tcb_clksrc_init(struct device_node *node) 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; diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c index d58ce664da843..1b2e9f19c98df 100644 --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -18,6 +18,7 @@ #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 @@ -40,10 +41,11 @@ static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; /* 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(); @@ -56,7 +58,7 @@ static inline void send_msg(struct cn_msg *msg) */ 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) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 433d91d710e4e..03d216e3dc548 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -214,7 +214,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) return 0; retry: - seq = read_seqcount_begin(&resv->seq); + seq = read_seqbegin(&resv->seq); rcu_read_lock(); fobj = rcu_dereference(resv->fence); @@ -223,7 +223,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) else shared_count = 0; fence_excl = rcu_dereference(resv->fence_excl); - if (read_seqcount_retry(&resv->seq, seq)) { + if (read_seqretry(&resv->seq, seq)) { rcu_read_unlock(); goto retry; } @@ -1189,12 +1189,12 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) robj = buf_obj->resv; while (true) { - seq = read_seqcount_begin(&robj->seq); + seq = read_seqbegin(&robj->seq); rcu_read_lock(); fobj = rcu_dereference(robj->fence); shared_count = fobj ? fobj->shared_count : 0; fence = rcu_dereference(robj->fence_excl); - if (!read_seqcount_retry(&robj->seq, seq)) + if (!read_seqretry(&robj->seq, seq)) break; rcu_read_unlock(); } diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 709002515550c..b0c0d4fe0b331 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -49,12 +49,6 @@ DEFINE_WD_CLASS(reservation_ww_class); EXPORT_SYMBOL(reservation_ww_class); -struct lock_class_key reservation_seqcount_class; -EXPORT_SYMBOL(reservation_seqcount_class); - -const char reservation_seqcount_string[] = "reservation_seqcount"; -EXPORT_SYMBOL(reservation_seqcount_string); - /** * dma_resv_list_alloc - allocate fence list * @shared_max: number of fences we need space for @@ -103,8 +97,7 @@ void dma_resv_init(struct dma_resv *obj) { ww_mutex_init(&obj->lock, &reservation_ww_class); - __seqcount_init(&obj->seq, reservation_seqcount_string, - &reservation_seqcount_class); + seqlock_init(&obj->seq); RCU_INIT_POINTER(obj->fence, NULL); RCU_INIT_POINTER(obj->fence_excl, NULL); } @@ -234,8 +227,7 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence) fobj = dma_resv_get_list(obj); count = fobj->shared_count; - preempt_disable(); - write_seqcount_begin(&obj->seq); + write_seqlock(&obj->seq); for (i = 0; i < count; ++i) { @@ -255,8 +247,7 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence) /* pointer update must be visible before we extend the shared_count */ smp_store_mb(fobj->shared_count, count); - write_seqcount_end(&obj->seq); - preempt_enable(); + write_sequnlock(&obj->seq); dma_fence_put(old); } EXPORT_SYMBOL(dma_resv_add_shared_fence); @@ -283,14 +274,12 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence) if (fence) dma_fence_get(fence); - preempt_disable(); - write_seqcount_begin(&obj->seq); - /* write_seqcount_begin provides the necessary memory barrier */ + write_seqlock(&obj->seq); + /* write_seqlock provides the necessary memory barrier */ RCU_INIT_POINTER(obj->fence_excl, fence); if (old) old->shared_count = 0; - write_seqcount_end(&obj->seq); - preempt_enable(); + write_sequnlock(&obj->seq); /* inplace update, no shared fences */ while (i--) @@ -368,13 +357,11 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src) src_list = dma_resv_get_list(dst); old = dma_resv_get_excl(dst); - preempt_disable(); - write_seqcount_begin(&dst->seq); - /* write_seqcount_begin provides the necessary memory barrier */ + write_seqlock(&dst->seq); + /* write_seqlock provides the necessary memory barrier */ RCU_INIT_POINTER(dst->fence_excl, new); RCU_INIT_POINTER(dst->fence, dst_list); - write_seqcount_end(&dst->seq); - preempt_enable(); + write_sequnlock(&dst->seq); dma_resv_list_free(src_list); dma_fence_put(old); @@ -414,7 +401,7 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, shared_count = i = 0; rcu_read_lock(); - seq = read_seqcount_begin(&obj->seq); + seq = read_seqbegin(&obj->seq); fence_excl = rcu_dereference(obj->fence_excl); if (fence_excl && !dma_fence_get_rcu(fence_excl)) @@ -456,7 +443,7 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, } } - if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) { + if (i != shared_count || read_seqretry(&obj->seq, seq)) { while (i--) dma_fence_put(shared[i]); dma_fence_put(fence_excl); @@ -507,7 +494,7 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj, retry: shared_count = 0; - seq = read_seqcount_begin(&obj->seq); + seq = read_seqbegin(&obj->seq); rcu_read_lock(); i = -1; @@ -553,7 +540,7 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj, rcu_read_unlock(); if (fence) { - if (read_seqcount_retry(&obj->seq, seq)) { + if (read_seqretry(&obj->seq, seq)) { dma_fence_put(fence); goto retry; } @@ -607,7 +594,7 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all) retry: ret = true; shared_count = 0; - seq = read_seqcount_begin(&obj->seq); + seq = read_seqbegin(&obj->seq); if (test_all) { unsigned i; @@ -627,7 +614,7 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all) break; } - if (read_seqcount_retry(&obj->seq, seq)) + if (read_seqretry(&obj->seq, seq)) goto retry; } @@ -639,7 +626,7 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all) if (ret < 0) goto retry; - if (read_seqcount_retry(&obj->seq, seq)) + if (read_seqretry(&obj->seq, seq)) goto retry; } } diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 34d41f67b54d1..2ee32b046f260 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -68,7 +68,7 @@ struct mm_struct efi_mm = { struct workqueue_struct *efi_rts_wq; -static bool disable_runtime; +static bool disable_runtime = IS_ENABLED(CONFIG_PREEMPT_RT); static int __init setup_noefi(char *arg) { disable_runtime = true; @@ -94,6 +94,9 @@ static int __init parse_efi_cmdline(char *str) 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); diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index e67c194c2acad..5f6dcbbeb0c1b 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -397,7 +397,7 @@ config DRM_R128 config DRM_I810 tristate "Intel I810" - # !PREEMPT because of missing ioctl locking + # !PREEMPTION because of missing ioctl locking depends on DRM && AGP && AGP_INTEL && (!PREEMPTION || BROKEN) help Choose this option if you have an Intel I810 graphics card. If M is diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index 6d021ecc8d598..52f77b7701c03 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -252,11 +252,9 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo, new->shared_count = k; /* Install the new fence list, seqcount provides the barriers */ - preempt_disable(); - write_seqcount_begin(&resv->seq); + write_seqlock(&resv->seq); RCU_INIT_POINTER(resv->fence, new); - write_seqcount_end(&resv->seq); - preempt_enable(); + write_sequnlock(&resv->seq); /* Drop the references to the removed fences or move them to ef_list */ for (i = j, k = 0; i < old->shared_count; ++i) { diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c index cae25e493128d..da71ac8dea356 100644 --- a/drivers/gpu/drm/i915/display/intel_sprite.c +++ b/drivers/gpu/drm/i915/display/intel_sprite.c @@ -38,6 +38,7 @@ #include <drm/drm_plane_helper.h> #include <drm/drm_rect.h> #include <drm/i915_drm.h> +#include <linux/locallock.h> #include "i915_drv.h" #include "i915_trace.h" @@ -80,6 +81,8 @@ int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode, #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 @@ -129,7 +132,7 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state) 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; @@ -153,11 +156,11 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state) 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); @@ -190,7 +193,7 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state) return; irq_disable: - local_irq_disable(); + local_lock_irq(pipe_update_lock); } /** @@ -226,7 +229,7 @@ void intel_pipe_update_end(struct intel_crtc_state *new_crtc_state) new_crtc_state->base.event = NULL; } - local_irq_enable(); + local_unlock_irq(pipe_update_lock); if (intel_vgpu_active(dev_priv)) return; diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c index 25235ef630c10..eaa8735aabee2 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c @@ -75,7 +75,6 @@ busy_check_writer(const struct dma_fence *fence) return __busy_set_if_active(fence, __busy_write_id); } - int i915_gem_busy_ioctl(struct drm_device *dev, void *data, struct drm_file *file) @@ -110,7 +109,8 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, * */ retry: - seq = raw_read_seqcount(&obj->base.resv->seq); + /* XXX raw_read_seqcount() does not wait for the WRTIE to finish */ + seq = read_seqbegin(&obj->base.resv->seq); /* Translate the exclusive fence to the READ *and* WRITE engine */ args->busy = @@ -129,7 +129,7 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, } } - if (args->busy && read_seqcount_retry(&obj->base.resv->seq, seq)) + if (args->busy && read_seqretry(&obj->base.resv->seq, seq)) goto retry; err = 0; diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c index 09c68dda20988..55317081d48b0 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -120,7 +120,6 @@ __dma_fence_signal__notify(struct dma_fence *fence, struct dma_fence_cb *cur, *tmp; lockdep_assert_held(fence->lock); - lockdep_assert_irqs_disabled(); list_for_each_entry_safe(cur, tmp, list, node) { INIT_LIST_HEAD(&cur->node); @@ -134,9 +133,10 @@ void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine) const ktime_t timestamp = ktime_get(); struct intel_context *ce, *cn; struct list_head *pos, *next; + unsigned long flags; LIST_HEAD(signal); - spin_lock(&b->irq_lock); + spin_lock_irqsave(&b->irq_lock, flags); if (b->irq_armed && list_empty(&b->signalers)) __intel_breadcrumbs_disarm_irq(b); @@ -182,30 +182,23 @@ void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine) } } - spin_unlock(&b->irq_lock); + spin_unlock_irqrestore(&b->irq_lock, flags); list_for_each_safe(pos, next, &signal) { struct i915_request *rq = list_entry(pos, typeof(*rq), signal_link); struct list_head cb_list; - spin_lock(&rq->lock); + spin_lock_irqsave(&rq->lock, flags); list_replace(&rq->fence.cb_list, &cb_list); __dma_fence_signal__timestamp(&rq->fence, timestamp); __dma_fence_signal__notify(&rq->fence, &cb_list); - spin_unlock(&rq->lock); + spin_unlock_irqrestore(&rq->lock, flags); i915_request_put(rq); } } -void intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine) -{ - local_irq_disable(); - intel_engine_breadcrumbs_irq(engine); - local_irq_enable(); -} - static void signal_irq_work(struct irq_work *work) { struct intel_engine_cs *engine = @@ -275,7 +268,6 @@ void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine) bool i915_request_enable_breadcrumb(struct i915_request *rq) { lockdep_assert_held(&rq->lock); - lockdep_assert_irqs_disabled(); if (test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags)) { struct intel_breadcrumbs *b = &rq->engine->breadcrumbs; @@ -325,7 +317,6 @@ void i915_request_cancel_breadcrumb(struct i915_request *rq) struct intel_breadcrumbs *b = &rq->engine->breadcrumbs; lockdep_assert_held(&rq->lock); - lockdep_assert_irqs_disabled(); /* * We must wait for b->irq_lock so that we know the interrupt handler diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h index 22aab8593abfa..316dccb41da80 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine.h +++ b/drivers/gpu/drm/i915/gt/intel_engine.h @@ -349,7 +349,6 @@ void intel_engine_init_execlists(struct intel_engine_cs *engine); void intel_engine_init_breadcrumbs(struct intel_engine_cs *engine); void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine); -void intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine); void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine); static inline void diff --git a/drivers/gpu/drm/i915/gt/intel_hangcheck.c b/drivers/gpu/drm/i915/gt/intel_hangcheck.c index 05d042cdefe24..7ca67aac27d4d 100644 --- a/drivers/gpu/drm/i915/gt/intel_hangcheck.c +++ b/drivers/gpu/drm/i915/gt/intel_hangcheck.c @@ -283,7 +283,7 @@ static void hangcheck_elapsed(struct work_struct *work) for_each_engine(engine, gt->i915, id) { struct hangcheck hc; - intel_engine_signal_breadcrumbs(engine); + intel_engine_breadcrumbs_irq(engine); hangcheck_load_sample(engine, &hc); hangcheck_accumulate_sample(engine, &hc); diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c index 8cea42379dd79..05f965e2e132e 100644 --- a/drivers/gpu/drm/i915/gt/intel_reset.c +++ b/drivers/gpu/drm/i915/gt/intel_reset.c @@ -695,7 +695,7 @@ static void reset_finish_engine(struct intel_engine_cs *engine) engine->reset.finish(engine); intel_uncore_forcewake_put(engine->uncore, FORCEWAKE_ALL); - intel_engine_signal_breadcrumbs(engine); + intel_engine_breadcrumbs_irq(engine); } static void reset_finish(struct intel_gt *gt, intel_engine_mask_t awake) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 37e3dd3c1a9dc..9a482fb0f4afa 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -983,6 +983,7 @@ bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe, 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) @@ -1034,6 +1035,7 @@ bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe, *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); diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 1c5506822dc72..cf10246fb01ad 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -205,14 +205,14 @@ static void remove_from_engine(struct i915_request *rq) * check that the rq still belongs to the newly locked engine. */ locked = READ_ONCE(rq->engine); - spin_lock(&locked->active.lock); + spin_lock_irq(&locked->active.lock); while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) { spin_unlock(&locked->active.lock); spin_lock(&engine->active.lock); locked = engine; } list_del(&rq->sched.link); - spin_unlock(&locked->active.lock); + spin_unlock_irq(&locked->active.lock); } static bool i915_request_retire(struct i915_request *rq) @@ -272,8 +272,6 @@ static bool i915_request_retire(struct i915_request *rq) active->retire(active, rq); } - local_irq_disable(); - /* * We only loosely track inflight requests across preemption, * and so we may find ourselves attempting to retire a _completed_ @@ -282,7 +280,7 @@ static bool i915_request_retire(struct i915_request *rq) */ remove_from_engine(rq); - spin_lock(&rq->lock); + spin_lock_irq(&rq->lock); i915_request_mark_complete(rq); if (!i915_request_signaled(rq)) dma_fence_signal_locked(&rq->fence); @@ -297,9 +295,7 @@ static bool i915_request_retire(struct i915_request *rq) __notify_execute_cb(rq); } GEM_BUG_ON(!list_empty(&rq->execute_cb)); - spin_unlock(&rq->lock); - - local_irq_enable(); + spin_unlock_irq(&rq->lock); remove_from_client(rq); list_del(&rq->link); diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h index 24f2944da09de..b8ee3cd14323d 100644 --- a/drivers/gpu/drm/i915/i915_trace.h +++ b/drivers/gpu/drm/i915/i915_trace.h @@ -2,6 +2,10 @@ #if !defined(_I915_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ) #define _I915_TRACE_H_ +#ifdef CONFIG_PREEMPT_RT +#define NOTRACE +#endif + #include <linux/stringify.h> #include <linux/types.h> #include <linux/tracepoint.h> @@ -721,7 +725,7 @@ DEFINE_EVENT(i915_request, i915_request_add, 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) diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c index e81b01f8db90e..b07e4684c2c40 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -1819,6 +1819,7 @@ int radeon_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe, 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) @@ -1911,6 +1912,7 @@ int radeon_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe, *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; diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index af9379a3bf899..0b1ef04302d4a 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -18,6 +18,7 @@ #include <linux/atomic.h> #include <linux/hyperv.h> #include <linux/interrupt.h> +#include <linux/irq.h> #include "hv_trace.h" diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 05ead1735c6e3..1bf1f1acc18c1 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -22,6 +22,7 @@ #include <linux/clockchips.h> #include <linux/cpu.h> #include <linux/sched/task_stack.h> +#include <linux/irq.h> #include <asm/mshyperv.h> #include <linux/delay.h> @@ -1199,6 +1200,8 @@ 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)) @@ -1243,7 +1246,7 @@ 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); } /* diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig index ce9429ca6ddea..29ccbd6acf43f 100644 --- a/drivers/leds/trigger/Kconfig +++ b/drivers/leds/trigger/Kconfig @@ -64,6 +64,7 @@ config LEDS_TRIGGER_BACKLIGHT config LEDS_TRIGGER_CPU bool "LED CPU Trigger" + depends on !PREEMPT_RT 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 diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig index 6dfa653d30db7..29c35eb524148 100644 --- a/drivers/md/bcache/Kconfig +++ b/drivers/md/bcache/Kconfig @@ -2,6 +2,7 @@ config BCACHE tristate "Block device as cache" + depends on !PREEMPT_RT select CRC64 help Allows a block device to be used as cache for other devices; uses diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 36cd7c2fbf408..aa66d14036e75 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2058,8 +2058,9 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 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++; @@ -2118,7 +2119,8 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 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) @@ -6821,6 +6823,7 @@ static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node) __func__, cpu); return -ENOMEM; } + spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock); return 0; } diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index f90e0704bed99..cca69edd669da 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -634,6 +634,7 @@ 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 */ void *scribble; /* space for constructing buffer * lists and performing address diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig index f1f61419fd292..56d4c1e91c276 100644 --- a/drivers/media/platform/Kconfig +++ b/drivers/media/platform/Kconfig @@ -585,7 +585,7 @@ config VIDEO_MESON_G12A_AO_CEC config CEC_GPIO tristate "Generic GPIO-based CEC driver" - depends on PREEMPT || COMPILE_TEST + depends on PREEMPTION || COMPILE_TEST select CEC_CORE select CEC_PIN select GPIOLIB diff --git a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c index 8c79b963bcffb..d000528b9e011 100644 --- a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c +++ b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c @@ -693,8 +693,8 @@ static void ezusb_req_ctx_wait(struct ezusb_priv *upriv, 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: diff --git a/drivers/of/base.c b/drivers/of/base.c index 1d667eb730e19..a82b8c05169e7 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -123,115 +123,38 @@ int __weak of_node_to_nid(struct device_node *np) } #endif -/* - * Assumptions behind phandle_cache implementation: - * - phandle property values are in a contiguous range of 1..n - * - * If the assumptions do not hold, then - * - the phandle lookup overhead reduction provided by the cache - * will likely be less - */ +#define OF_PHANDLE_CACHE_BITS 7 +#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS) -static struct device_node **phandle_cache; -static u32 phandle_cache_mask; +static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ]; + +static u32 of_phandle_cache_hash(phandle handle) +{ + return hash_32(handle, OF_PHANDLE_CACHE_BITS); +} /* * Caller must hold devtree_lock. */ -static void __of_free_phandle_cache(void) +void __of_phandle_cache_inv_entry(phandle handle) { - u32 cache_entries = phandle_cache_mask + 1; - u32 k; - - if (!phandle_cache) - return; - - for (k = 0; k < cache_entries; k++) - of_node_put(phandle_cache[k]); - - kfree(phandle_cache); - phandle_cache = NULL; -} - -int of_free_phandle_cache(void) -{ - unsigned long flags; - - raw_spin_lock_irqsave(&devtree_lock, flags); - - __of_free_phandle_cache(); - - raw_spin_unlock_irqrestore(&devtree_lock, flags); - - return 0; -} -#if !defined(CONFIG_MODULES) -late_initcall_sync(of_free_phandle_cache); -#endif - -/* - * Caller must hold devtree_lock. - */ -void __of_free_phandle_cache_entry(phandle handle) -{ - phandle masked_handle; + u32 handle_hash; struct device_node *np; if (!handle) return; - masked_handle = handle & phandle_cache_mask; + handle_hash = of_phandle_cache_hash(handle); - if (phandle_cache) { - np = phandle_cache[masked_handle]; - if (np && handle == np->phandle) { - of_node_put(np); - phandle_cache[masked_handle] = NULL; - } - } -} - -void of_populate_phandle_cache(void) -{ - unsigned long flags; - u32 cache_entries; - struct device_node *np; - u32 phandles = 0; - - raw_spin_lock_irqsave(&devtree_lock, flags); - - __of_free_phandle_cache(); - - for_each_of_allnodes(np) - if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) - phandles++; - - if (!phandles) - goto out; - - cache_entries = roundup_pow_of_two(phandles); - phandle_cache_mask = cache_entries - 1; - - phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache), - GFP_ATOMIC); - if (!phandle_cache) - goto out; - - for_each_of_allnodes(np) - if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) { - of_node_get(np); - phandle_cache[np->phandle & phandle_cache_mask] = np; - } - -out: - raw_spin_unlock_irqrestore(&devtree_lock, flags); + np = phandle_cache[handle_hash]; + if (np && handle == np->phandle) + phandle_cache[handle_hash] = NULL; } void __init of_core_init(void) { struct device_node *np; - of_populate_phandle_cache(); /* Create the kset, and register existing nodes */ mutex_lock(&of_mutex); @@ -241,8 +164,11 @@ void __init of_core_init(void) pr_err("failed to register existing nodes\n"); return; } - for_each_of_allnodes(np) + for_each_of_allnodes(np) { __of_attach_node_sysfs(np); + if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)]) + phandle_cache[of_phandle_cache_hash(np->phandle)] = np; + } mutex_unlock(&of_mutex); /* Symlink in /proc as required by userspace ABI */ @@ -1223,36 +1149,29 @@ struct device_node *of_find_node_by_phandle(phandle handle) { struct device_node *np = NULL; unsigned long flags; - phandle masked_handle; + u32 handle_hash; if (!handle) return NULL; + handle_hash = of_phandle_cache_hash(handle); + raw_spin_lock_irqsave(&devtree_lock, flags); - masked_handle = handle & phandle_cache_mask; - - if (phandle_cache) { - if (phandle_cache[masked_handle] && - handle == phandle_cache[masked_handle]->phandle) - np = phandle_cache[masked_handle]; - if (np && of_node_check_flag(np, OF_DETACHED)) { - WARN_ON(1); /* did not uncache np on node removal */ - of_node_put(np); - phandle_cache[masked_handle] = NULL; - np = NULL; - } + if (phandle_cache[handle_hash] && + handle == phandle_cache[handle_hash]->phandle) + np = phandle_cache[handle_hash]; + if (np && of_node_check_flag(np, OF_DETACHED)) { + WARN_ON(1); /* did not uncache np on node removal */ + phandle_cache[handle_hash] = NULL; + np = NULL; } if (!np) { for_each_of_allnodes(np) if (np->phandle == handle && !of_node_check_flag(np, OF_DETACHED)) { - if (phandle_cache) { - /* will put when removed from cache */ - of_node_get(np); - phandle_cache[masked_handle] = np; - } + phandle_cache[handle_hash] = np; break; } } diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 49b16f76d78e8..08fd823edac9d 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -276,7 +276,7 @@ void __of_detach_node(struct device_node *np) of_node_set_flag(np, OF_DETACHED); /* race with of_find_node_by_phandle() prevented by devtree_lock */ - __of_free_phandle_cache_entry(np->phandle); + __of_phandle_cache_inv_entry(np->phandle); } /** diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index 24786818e32e5..de0042bc77015 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -85,14 +85,12 @@ int of_resolve_phandles(struct device_node *tree); #endif #if defined(CONFIG_OF_DYNAMIC) -void __of_free_phandle_cache_entry(phandle handle); +void __of_phandle_cache_inv_entry(phandle handle); #endif #if defined(CONFIG_OF_OVERLAY) void of_overlay_mutex_lock(void); void of_overlay_mutex_unlock(void); -int of_free_phandle_cache(void); -void of_populate_phandle_cache(void); #else static inline void of_overlay_mutex_lock(void) {}; static inline void of_overlay_mutex_unlock(void) {}; diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 9617b7df7c4da..97fe92c1f1d24 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -974,8 +974,6 @@ static int of_overlay_apply(const void *fdt, struct device_node *tree, goto err_free_overlay_changeset; } - of_populate_phandle_cache(); - ret = __of_changeset_apply_notify(&ovcs->cset); if (ret) pr_err("overlay apply changeset entry notify error %d\n", ret); @@ -1218,17 +1216,9 @@ int of_overlay_remove(int *ovcs_id) list_del(&ovcs->ovcs_list); - /* - * Disable phandle cache. Avoids race condition that would arise - * from removing cache entry when the associated node is deleted. - */ - of_free_phandle_cache(); - ret_apply = 0; ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply); - of_populate_phandle_cache(); - if (ret) { if (ret_apply) devicetree_state_flags |= DTSF_REVERT_FAIL; diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index 465d6afd826e8..059f1e566bf65 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -52,10 +52,11 @@ 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; @@ -77,7 +78,7 @@ static struct switchtec_user *stuser_create(struct switchtec_dev *stdev) 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); @@ -175,7 +176,7 @@ static int mrpc_queue_cmd(struct switchtec_user *stuser) 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); @@ -222,7 +223,8 @@ static void mrpc_complete_cmd(struct switchtec_dev *stdev) 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; @@ -494,10 +496,11 @@ static ssize_t switchtec_dev_read(struct file *filp, char __user *data, 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; } @@ -545,7 +548,7 @@ static __poll_t switchtec_dev_poll(struct file *filp, poll_table *wait) 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)) @@ -553,7 +556,7 @@ static __poll_t switchtec_dev_poll(struct file *filp, poll_table *wait) 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)) @@ -1106,7 +1109,8 @@ static void stdev_kill(struct switchtec_dev *stdev) /* 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); } diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 25dae9f0b2055..2acc1f6da9020 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1452,11 +1452,11 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, 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; } @@ -1641,11 +1641,11 @@ static inline int fcoe_filter_frames(struct fc_lport *lport, 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; } @@ -1686,7 +1686,7 @@ static void fcoe_recv_frame(struct sk_buff *skb) */ 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 " @@ -1718,13 +1718,13 @@ static void fcoe_recv_frame(struct sk_buff *skb) 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); } diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c index 1791a393795da..8fdfae2b8782f 100644 --- a/drivers/scsi/fcoe/fcoe_ctlr.c +++ b/drivers/scsi/fcoe/fcoe_ctlr.c @@ -826,7 +826,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip) 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; @@ -862,7 +862,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip) sel_time = fcf->time; } } - put_cpu(); + put_cpu_light(); list_for_each_entry_safe(fcf, next, &del_list, list) { /* Removes fcf from current list */ diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c index 52e8666598531..78c75a2314228 100644 --- a/drivers/scsi/libfc/fc_exch.c +++ b/drivers/scsi/libfc/fc_exch.c @@ -821,10 +821,10 @@ static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport, } 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) { diff --git a/drivers/thermal/intel/x86_pkg_temp_thermal.c b/drivers/thermal/intel/x86_pkg_temp_thermal.c index ddb4a973c6986..e18758a8e911a 100644 --- a/drivers/thermal/intel/x86_pkg_temp_thermal.c +++ b/drivers/thermal/intel/x86_pkg_temp_thermal.c @@ -63,7 +63,7 @@ static int max_id __read_mostly; /* Array of zone pointers */ static struct zone_device **zones; /* Serializes interrupt notification, work and hotplug */ -static DEFINE_SPINLOCK(pkg_temp_lock); +static DEFINE_RAW_SPINLOCK(pkg_temp_lock); /* Protects zone operation in the work function against hotplug removal */ static DEFINE_MUTEX(thermal_zone_mutex); @@ -266,12 +266,12 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work) u64 msr_val, wr_val; mutex_lock(&thermal_zone_mutex); - spin_lock_irq(&pkg_temp_lock); + raw_spin_lock_irq(&pkg_temp_lock); ++pkg_work_cnt; zonedev = pkg_temp_thermal_get_dev(cpu); if (!zonedev) { - spin_unlock_irq(&pkg_temp_lock); + raw_spin_unlock_irq(&pkg_temp_lock); mutex_unlock(&thermal_zone_mutex); return; } @@ -285,7 +285,7 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work) } enable_pkg_thres_interrupt(); - spin_unlock_irq(&pkg_temp_lock); + raw_spin_unlock_irq(&pkg_temp_lock); /* * If tzone is not NULL, then thermal_zone_mutex will prevent the @@ -310,7 +310,7 @@ static int pkg_thermal_notify(u64 msr_val) struct zone_device *zonedev; unsigned long flags; - spin_lock_irqsave(&pkg_temp_lock, flags); + raw_spin_lock_irqsave(&pkg_temp_lock, flags); ++pkg_interrupt_cnt; disable_pkg_thres_interrupt(); @@ -322,7 +322,7 @@ static int pkg_thermal_notify(u64 msr_val) pkg_thermal_schedule_work(zonedev->cpu, &zonedev->work); } - spin_unlock_irqrestore(&pkg_temp_lock, flags); + raw_spin_unlock_irqrestore(&pkg_temp_lock, flags); return 0; } @@ -368,9 +368,9 @@ static int pkg_temp_thermal_device_add(unsigned int cpu) zonedev->msr_pkg_therm_high); cpumask_set_cpu(cpu, &zonedev->cpumask); - spin_lock_irq(&pkg_temp_lock); + raw_spin_lock_irq(&pkg_temp_lock); zones[id] = zonedev; - spin_unlock_irq(&pkg_temp_lock); + raw_spin_unlock_irq(&pkg_temp_lock); return 0; } @@ -407,7 +407,7 @@ static int pkg_thermal_cpu_offline(unsigned int cpu) } /* Protect against work and interrupts */ - spin_lock_irq(&pkg_temp_lock); + raw_spin_lock_irq(&pkg_temp_lock); /* * Check whether this cpu was the current target and store the new @@ -439,9 +439,9 @@ static int pkg_thermal_cpu_offline(unsigned int cpu) * To cancel the work we need to drop the lock, otherwise * we might deadlock if the work needs to be flushed. */ - spin_unlock_irq(&pkg_temp_lock); + raw_spin_unlock_irq(&pkg_temp_lock); cancel_delayed_work_sync(&zonedev->work); - spin_lock_irq(&pkg_temp_lock); + raw_spin_lock_irq(&pkg_temp_lock); /* * If this is not the last cpu in the package and the work * did not run after we dropped the lock above, then we @@ -452,7 +452,7 @@ static int pkg_thermal_cpu_offline(unsigned int cpu) pkg_thermal_schedule_work(target, &zonedev->work); } - spin_unlock_irq(&pkg_temp_lock); + raw_spin_unlock_irq(&pkg_temp_lock); /* Final cleanup if this is the last cpu */ if (lastcpu) diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h index 33ad9d6de5323..b29aed97a54dc 100644 --- a/drivers/tty/serial/8250/8250.h +++ b/drivers/tty/serial/8250/8250.h @@ -130,12 +130,55 @@ static inline void serial_dl_write(struct uart_8250_port *up, int value) up->dl_write(up, value); } +static inline void serial8250_set_IER(struct uart_8250_port *up, + unsigned char ier) +{ + struct uart_port *port = &up->port; + unsigned int flags; + bool is_console; + + is_console = uart_console(port); + + if (is_console) + console_atomic_lock(&flags); + + serial_out(up, UART_IER, ier); + + if (is_console) + console_atomic_unlock(flags); +} + +static inline unsigned char serial8250_clear_IER(struct uart_8250_port *up) +{ + struct uart_port *port = &up->port; + unsigned int clearval = 0; + unsigned int prior; + unsigned int flags; + bool is_console; + + is_console = uart_console(port); + + if (up->capabilities & UART_CAP_UUE) + clearval = UART_IER_UUE; + + if (is_console) + console_atomic_lock(&flags); + + prior = serial_port_in(port, UART_IER); + serial_port_out(port, UART_IER, clearval); + + if (is_console) + console_atomic_unlock(flags); + + return prior; +} + static inline bool serial8250_set_THRI(struct uart_8250_port *up) { if (up->ier & UART_IER_THRI) return false; up->ier |= UART_IER_THRI; - serial_out(up, UART_IER, up->ier); + serial8250_set_IER(up, up->ier); return true; } @@ -144,7 +187,7 @@ static inline bool serial8250_clear_THRI(struct uart_8250_port *up) if (!(up->ier & UART_IER_THRI)) return false; up->ier &= ~UART_IER_THRI; - serial_out(up, UART_IER, up->ier); + serial8250_set_IER(up, up->ier); return true; } diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index e682390ce0dea..eabb9274c0a9d 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -55,7 +55,16 @@ 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 +# define PASS_LIMIT 1000000 +#else +# define PASS_LIMIT 512 +#endif #include <asm/serial.h> /* @@ -275,10 +284,8 @@ static void serial8250_backup_timeout(struct timer_list *t) * 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) + ier = serial8250_clear_IER(up); iir = serial_in(up, UART_IIR); @@ -301,7 +308,7 @@ static void serial8250_backup_timeout(struct timer_list *t) serial8250_tx_chars(up); if (up->port.irq) - serial_out(up, UART_IER, ier); + serial8250_set_IER(up, ier); spin_unlock_irqrestore(&up->port.lock, flags); @@ -579,6 +586,14 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev) #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) { @@ -664,6 +679,7 @@ static int univ8250_console_match(struct console *co, char *name, int idx, 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, diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c index aa0e216d5eadb..8f711afadd4b5 100644 --- a/drivers/tty/serial/8250/8250_fsl.c +++ b/drivers/tty/serial/8250/8250_fsl.c @@ -57,9 +57,18 @@ int fsl8250_handle_irq(struct uart_port *port) /* Stop processing interrupts on input overrun */ if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) { + unsigned int ca_flags; unsigned long delay; + bool is_console; + is_console = uart_console(port); + + if (is_console) + console_atomic_lock(&ca_flags); up->ier = port->serial_in(port, UART_IER); + if (is_console) + console_atomic_unlock(ca_flags); + if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) { port->ops->stop_rx(port); } else { diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c index 424c07c5f6299..47f1482bd818a 100644 --- a/drivers/tty/serial/8250/8250_ingenic.c +++ b/drivers/tty/serial/8250/8250_ingenic.c @@ -146,6 +146,8 @@ OF_EARLYCON_DECLARE(x1000_uart, "ingenic,x1000-uart", static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value) { + unsigned int flags; + bool is_console; int ier; switch (offset) { @@ -167,7 +169,12 @@ static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value) * If we have enabled modem status IRQs we should enable * modem mode. */ + is_console = uart_console(p); + if (is_console) + console_atomic_lock(&flags); ier = p->serial_in(p, UART_IER); + if (is_console) + console_atomic_unlock(flags); if (ier & UART_IER_MSI) value |= UART_MCR_MDCE | UART_MCR_FCM; diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index 4d067f515f748..b509c3de0301f 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -212,12 +212,37 @@ static void mtk8250_shutdown(struct uart_port *port) static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask) { - serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask)); + struct uart_port *port = &up->port; + unsigned int flags; + unsigned int ier; + bool is_console; + + is_console = uart_console(port); + + if (is_console) + console_atomic_lock(&flags); + + ier = serial_in(up, UART_IER); + serial_out(up, UART_IER, ier & (~mask)); + + if (is_console) + console_atomic_unlock(flags); } static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask) { - serial_out(up, UART_IER, serial_in(up, UART_IER) | mask); + struct uart_port *port = &up->port; + unsigned int flags; + unsigned int ier; + + if (uart_console(port)) + console_atomic_lock(&flags); + + ier = serial_in(up, UART_IER); + serial_out(up, UART_IER, ier | mask); + + if (uart_console(port)) + console_atomic_unlock(flags); } static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 8407166610ce7..7767701122236 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -721,7 +721,7 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) serial_out(p, UART_EFR, UART_EFR_ECB); serial_out(p, UART_LCR, 0); } - serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0); + serial8250_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); @@ -1390,7 +1390,7 @@ static void serial8250_stop_rx(struct uart_port *port) up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); up->port.read_status_mask &= ~UART_LSR_DR; - serial_port_out(port, UART_IER, up->ier); + serial8250_set_IER(up, up->ier); serial8250_rpm_put(up); } @@ -1408,7 +1408,7 @@ static void __do_stop_tx_rs485(struct uart_8250_port *p) serial8250_clear_and_reinit_fifos(p); p->ier |= UART_IER_RLSI | UART_IER_RDI; - serial_port_out(&p->port, UART_IER, p->ier); + serial8250_set_IER(p, p->ier); } } static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t) @@ -1616,7 +1616,7 @@ static void serial8250_disable_ms(struct uart_port *port) mctrl_gpio_disable_ms(up->gpios); up->ier &= ~UART_IER_MSI; - serial_port_out(port, UART_IER, up->ier); + serial8250_set_IER(up, up->ier); } static void serial8250_enable_ms(struct uart_port *port) @@ -1632,7 +1632,7 @@ static void serial8250_enable_ms(struct uart_port *port) up->ier |= UART_IER_MSI; serial8250_rpm_get(up); - serial_port_out(port, UART_IER, up->ier); + serial8250_set_IER(up, up->ier); serial8250_rpm_put(up); } @@ -2026,14 +2026,7 @@ static void serial8250_put_poll_char(struct uart_port *port, 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); + ier = serial8250_clear_IER(up); wait_for_xmitr(up, BOTH_EMPTY); /* @@ -2046,7 +2039,7 @@ static void serial8250_put_poll_char(struct uart_port *port, * and restore the IER */ wait_for_xmitr(up, BOTH_EMPTY); - serial_port_out(port, UART_IER, ier); + serial8250_set_IER(up, ier); serial8250_rpm_put(up); } @@ -2354,7 +2347,7 @@ void serial8250_do_shutdown(struct uart_port *port) */ spin_lock_irqsave(&port->lock, flags); up->ier = 0; - serial_port_out(port, UART_IER, 0); + serial8250_set_IER(up, 0); spin_unlock_irqrestore(&port->lock, flags); synchronize_irq(port->irq); @@ -2639,7 +2632,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, if (up->capabilities & UART_CAP_RTOIE) up->ier |= UART_IER_RTOIE; - serial_port_out(port, UART_IER, up->ier); + serial8250_set_IER(up, up->ier); if (up->capabilities & UART_CAP_EFR) { unsigned char efr = 0; @@ -3103,7 +3096,7 @@ EXPORT_SYMBOL_GPL(serial8250_set_defaults); #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); @@ -3111,6 +3104,18 @@ static void serial8250_console_putchar(struct uart_port *port, int ch) 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 */ @@ -3132,6 +3137,32 @@ static void serial8250_console_restore(struct uart_8250_port *up) 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; + unsigned int ier; + + console_atomic_lock(&flags); + + touch_nmi_watchdog(); + + ier = serial8250_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); + serial8250_set_IER(up, ier); + + console_atomic_unlock(flags); +} + /* * Print a string to the serial port trying not to disturb * any possible real use of the port... @@ -3144,26 +3175,13 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s, 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); + ier = serial8250_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))) { @@ -3171,14 +3189,16 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s, 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); + serial8250_set_IER(up, ier); /* * The receive handling will happen properly because the @@ -3190,8 +3210,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s, 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); } @@ -3212,6 +3231,7 @@ static unsigned int probe_baud(struct uart_port *port) 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'; @@ -3220,6 +3240,8 @@ int serial8250_console_setup(struct uart_port *port, char *options, bool probe) 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) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index b0b6895463952..3cd2687cbb8d0 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2209,18 +2209,24 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) { 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 @@ -2246,8 +2252,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) 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); } diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 6420ae581a802..0f4f41ed9ffa5 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1307,13 +1307,10 @@ serial_omap_console_write(struct console *co, const char *s, 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 @@ -1342,8 +1339,7 @@ serial_omap_console_write(struct console *co, const char *s, 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 diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 59d9d512dcdac..1ee8637a232ab 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1715,7 +1715,7 @@ static void ffs_data_put(struct ffs_data *ffs) 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); diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index b47938dff1a22..e5141c1136e47 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -344,7 +344,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len) 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)) { @@ -353,7 +353,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len) 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 { diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 40676be2e46aa..d09396393724b 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -99,7 +99,7 @@ config LCD_TOSA config LCD_HP700 tristate "HP Jornada 700 series LCD Driver" - depends on SA1100_JORNADA720_SSP && !PREEMPT + depends on SA1100_JORNADA720_SSP && !PREEMPTION default y help If you have an HP Jornada 700 series handheld (710/720/728) @@ -228,7 +228,7 @@ config BACKLIGHT_HP680 config BACKLIGHT_HP700 tristate "HP Jornada 700 series Backlight Driver" - depends on SA1100_JORNADA720_SSP && !PREEMPT + depends on SA1100_JORNADA720_SSP && !PREEMPTION default y help If you have an HP Jornada 700 series, diff --git a/drivers/xen/preempt.c b/drivers/xen/preempt.c index 8b9919c26095d..70650b248de5d 100644 --- a/drivers/xen/preempt.c +++ b/drivers/xen/preempt.c @@ -8,7 +8,7 @@ #include <linux/sched.h> #include <xen/xen-ops.h> -#ifndef CONFIG_PREEMPT +#ifndef CONFIG_PREEMPTION /* * Some hypercalls issued by the toolstack can take many 10s of @@ -37,4 +37,4 @@ asmlinkage __visible void xen_maybe_preempt_hcall(void) __this_cpu_write(xen_in_preemptible_hcall, true); } } -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ diff --git a/fs/afs/dir_silly.c b/fs/afs/dir_silly.c index 361088a5edb98..c1b1a51eb7297 100644 --- a/fs/afs/dir_silly.c +++ b/fs/afs/dir_silly.c @@ -202,7 +202,7 @@ int afs_silly_iput(struct dentry *dentry, struct inode *inode) struct dentry *alias; int ret; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); _enter("%p{%pd},%llx", dentry, dentry, vnode->fid.vnode); diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 5acf5c507ec2e..ad1ccf94e4b87 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -179,7 +179,7 @@ btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \ write_seqcount_end(&dev->data_seqcount); \ preempt_enable(); \ } -#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) #define BTRFS_DEVICE_GETSET_FUNCS(name) \ static inline u64 \ btrfs_device_get_##name(const struct btrfs_device *dev) \ diff --git a/fs/buffer.c b/fs/buffer.c index 91ceca52d14f9..0d374ff8ff69b 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -275,8 +275,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) * 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); + spin_lock_irqsave(&first->b_uptodate_lock, flags); clear_buffer_async_read(bh); unlock_buffer(bh); tmp = bh; @@ -289,8 +288,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } while (tmp != bh); - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + spin_unlock_irqrestore(&first->b_uptodate_lock, flags); /* * If none of the buffers had errors and they are all @@ -302,8 +300,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) return; still_busy: - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + spin_unlock_irqrestore(&first->b_uptodate_lock, flags); return; } @@ -331,8 +328,7 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) } first = page_buffers(page); - local_irq_save(flags); - bit_spin_lock(BH_Uptodate_Lock, &first->b_state); + spin_lock_irqsave(&first->b_uptodate_lock, flags); clear_buffer_async_write(bh); unlock_buffer(bh); @@ -344,14 +340,12 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + spin_unlock_irqrestore(&first->b_uptodate_lock, flags); end_page_writeback(page); return; still_busy: - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + spin_unlock_irqrestore(&first->b_uptodate_lock, flags); return; } EXPORT_SYMBOL(end_buffer_async_write); @@ -1393,7 +1387,7 @@ static bool has_bh_in_lru(int cpu, void *dummy) void invalidate_bh_lrus(void) { - on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1, GFP_KERNEL); + on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1); } EXPORT_SYMBOL_GPL(invalidate_bh_lrus); @@ -3345,6 +3339,7 @@ struct buffer_head *alloc_buffer_head(gfp_t gfp_flags) struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags); if (ret) { INIT_LIST_HEAD(&ret->b_assoc_buffers); + spin_lock_init(&ret->b_uptodate_lock); preempt_disable(); __this_cpu_inc(bh_accounting.nr); recalc_bh_state(); diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c index 3925a7bfc74d6..33f7723fb83e9 100644 --- a/fs/cifs/readdir.c +++ b/fs/cifs/readdir.c @@ -80,7 +80,7 @@ cifs_prime_dcache(struct dentry *parent, struct qstr *name, 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); diff --git a/fs/dcache.c b/fs/dcache.c index e88cf0554e659..5699176ed169c 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2482,9 +2482,10 @@ 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(); } @@ -2492,26 +2493,30 @@ static inline unsigned start_dir_add(struct inode *dir) 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); @@ -2525,7 +2530,7 @@ struct dentry *d_alloc_parallel(struct dentry *parent, 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)) { @@ -2553,7 +2558,7 @@ struct dentry *d_alloc_parallel(struct dentry *parent, } 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; @@ -2626,7 +2631,7 @@ void __d_lookup_done(struct dentry *dentry) 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); @@ -3139,6 +3144,8 @@ __setup("dhash_entries=", set_dhash_entries); 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. */ @@ -3155,11 +3162,16 @@ static void __init dcache_init_early(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; } 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 @@ -3183,6 +3195,10 @@ 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; } diff --git a/fs/eventpoll.c b/fs/eventpoll.c index c4159bcc05d9a..9ba07cb3cb524 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -567,12 +567,12 @@ static int ep_poll_wakeup_proc(void *priv, void *cookie, int call_nests) 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 diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 12ceadef32c5a..64d4c06fbf836 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -87,11 +87,10 @@ static void ext4_finish_bio(struct bio *bio) } bh = head = page_buffers(page); /* - * We check all buffers in the page under BH_Uptodate_Lock + * We check all buffers in the page under b_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); + spin_lock_irqsave(&head->b_uptodate_lock, flags); do { if (bh_offset(bh) < bio_start || bh_offset(bh) + bh->b_size > bio_end) { @@ -103,8 +102,7 @@ static void ext4_finish_bio(struct bio *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); + spin_unlock_irqrestore(&head->b_uptodate_lock, flags); if (!under_io) { fscrypt_free_bounce_page(bounce_page); end_page_writeback(page); diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c index 0ce39658a6200..5508d92e3f8fc 100644 --- a/fs/fscache/cookie.c +++ b/fs/fscache/cookie.c @@ -958,3 +958,11 @@ int __fscache_check_consistency(struct fscache_cookie *cookie, 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]); +} diff --git a/fs/fscache/main.c b/fs/fscache/main.c index 59c2494efda34..f9625eb898530 100644 --- a/fs/fscache/main.c +++ b/fs/fscache/main.c @@ -145,6 +145,7 @@ 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) diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c index 6a40f75a0d25e..6e813ecf8f512 100644 --- a/fs/fuse/readdir.c +++ b/fs/fuse/readdir.c @@ -158,7 +158,7 @@ static int fuse_direntplus_link(struct file *file, 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) { /* diff --git a/fs/inode.c b/fs/inode.c index 96d62d97694ef..e1fe4723ff80e 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -156,7 +156,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode) 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; diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index c43591cd70f1c..41b7602718d0c 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -482,10 +482,10 @@ void jbd2_journal_commit_transaction(journal_t *journal) if (jh->b_committed_data) { struct buffer_head *bh = jh2bh(jh); - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); jbd2_free(jh->b_committed_data, bh->b_size); jh->b_committed_data = NULL; - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); } jbd2_journal_refile_buffer(journal, jh); } @@ -920,6 +920,7 @@ void jbd2_journal_commit_transaction(journal_t *journal) transaction_t *cp_transaction; struct buffer_head *bh; int try_to_free = 0; + bool drop_ref; jh = commit_transaction->t_forget; spin_unlock(&journal->j_list_lock); @@ -929,7 +930,7 @@ void jbd2_journal_commit_transaction(journal_t *journal) * done with it. */ get_bh(bh); - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); J_ASSERT_JH(jh, jh->b_transaction == commit_transaction); /* @@ -1024,8 +1025,10 @@ void jbd2_journal_commit_transaction(journal_t *journal) try_to_free = 1; } JBUFFER_TRACE(jh, "refile or unfile buffer"); - __jbd2_journal_refile_buffer(jh); - jbd_unlock_bh_state(bh); + drop_ref = __jbd2_journal_refile_buffer(jh); + spin_unlock(&jh->b_state_lock); + if (drop_ref) + jbd2_journal_put_journal_head(jh); if (try_to_free) release_buffer_page(bh); /* Drops bh reference */ else diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 1c58859aa5924..f6034ce4a1073 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -363,7 +363,7 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, /* keep subsequent assertions sane */ atomic_set(&new_bh->b_count, 1); - jbd_lock_bh_state(bh_in); + spin_lock(&jh_in->b_state_lock); repeat: /* * If a new transaction has already done a buffer copy-out, then @@ -405,13 +405,13 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, if (need_copy_out && !done_copy_out) { char *tmp; - jbd_unlock_bh_state(bh_in); + spin_unlock(&jh_in->b_state_lock); tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); if (!tmp) { brelse(new_bh); return -ENOMEM; } - jbd_lock_bh_state(bh_in); + spin_lock(&jh_in->b_state_lock); if (jh_in->b_frozen_data) { jbd2_free(tmp, bh_in->b_size); goto repeat; @@ -464,7 +464,7 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); spin_unlock(&journal->j_list_lock); set_buffer_shadow(bh_in); - jbd_unlock_bh_state(bh_in); + spin_unlock(&jh_in->b_state_lock); return do_escape | (done_copy_out << 1); } @@ -2410,6 +2410,8 @@ static struct journal_head *journal_alloc_journal_head(void) ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS | __GFP_NOFAIL); } + if (ret) + spin_lock_init(&ret->b_state_lock); return ret; } @@ -2529,17 +2531,23 @@ static void __journal_remove_journal_head(struct buffer_head *bh) J_ASSERT_BH(bh, buffer_jbd(bh)); J_ASSERT_BH(bh, jh2bh(jh) == bh); BUFFER_TRACE(bh, "remove journal_head"); - if (jh->b_frozen_data) { - printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); - jbd2_free(jh->b_frozen_data, bh->b_size); - } - if (jh->b_committed_data) { - printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); - jbd2_free(jh->b_committed_data, bh->b_size); - } + + /* Unlink before dropping the lock */ bh->b_private = NULL; jh->b_bh = NULL; /* debug, really */ clear_buffer_jbd(bh); +} + +static void journal_release_journal_head(struct journal_head *jh, size_t b_size) +{ + if (jh->b_frozen_data) { + printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); + jbd2_free(jh->b_frozen_data, b_size); + } + if (jh->b_committed_data) { + printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); + jbd2_free(jh->b_committed_data, b_size); + } journal_free_journal_head(jh); } @@ -2557,9 +2565,11 @@ void jbd2_journal_put_journal_head(struct journal_head *jh) if (!jh->b_jcount) { __journal_remove_journal_head(bh); jbd_unlock_bh_journal_head(bh); + journal_release_journal_head(jh, bh->b_size); __brelse(bh); - } else + } else { jbd_unlock_bh_journal_head(bh); + } } /* diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index bee8498d77929..7c11afe605320 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -879,7 +879,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, start_lock = jiffies; lock_buffer(bh); - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); /* If it takes too long to lock the buffer, trace it */ time_lock = jbd2_time_diff(start_lock, jiffies); @@ -929,7 +929,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, error = -EROFS; if (is_handle_aborted(handle)) { - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); goto out; } error = 0; @@ -993,7 +993,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, */ if (buffer_shadow(bh)) { JBUFFER_TRACE(jh, "on shadow: sleep"); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); wait_on_bit_io(&bh->b_state, BH_Shadow, TASK_UNINTERRUPTIBLE); goto repeat; } @@ -1014,7 +1014,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, JBUFFER_TRACE(jh, "generate frozen data"); if (!frozen_buffer) { JBUFFER_TRACE(jh, "allocate memory for buffer"); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); frozen_buffer = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS | __GFP_NOFAIL); goto repeat; @@ -1033,7 +1033,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, jh->b_next_transaction = transaction; done: - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); /* * If we are about to journal a buffer, then any revoke pending on it is @@ -1172,7 +1172,7 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) * that case: the transaction must have deleted the buffer for it to be * reused here. */ - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); J_ASSERT_JH(jh, (jh->b_transaction == transaction || jh->b_transaction == NULL || (jh->b_transaction == journal->j_committing_transaction && @@ -1207,7 +1207,7 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) jh->b_next_transaction = transaction; spin_unlock(&journal->j_list_lock); } - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); /* * akpm: I added this. ext3_alloc_branch can pick up new indirect @@ -1275,13 +1275,13 @@ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS|__GFP_NOFAIL); - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); if (!jh->b_committed_data) { /* Copy out the current buffer contents into the * preserved, committed copy. */ JBUFFER_TRACE(jh, "generate b_committed data"); if (!committed_data) { - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); goto repeat; } @@ -1289,7 +1289,7 @@ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) committed_data = NULL; memcpy(jh->b_committed_data, bh->b_data, bh->b_size); } - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); out: jbd2_journal_put_journal_head(jh); if (unlikely(committed_data)) @@ -1390,16 +1390,16 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) */ if (jh->b_transaction != transaction && jh->b_next_transaction != transaction) { - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); J_ASSERT_JH(jh, jh->b_transaction == transaction || jh->b_next_transaction == transaction); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); } if (jh->b_modified == 1) { /* If it's in our transaction it must be in BJ_Metadata list. */ if (jh->b_transaction == transaction && jh->b_jlist != BJ_Metadata) { - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); if (jh->b_transaction == transaction && jh->b_jlist != BJ_Metadata) pr_err("JBD2: assertion failure: h_type=%u " @@ -1409,13 +1409,13 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) jh->b_jlist); J_ASSERT_JH(jh, jh->b_transaction != transaction || jh->b_jlist == BJ_Metadata); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); } goto out; } journal = transaction->t_journal; - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); if (jh->b_modified == 0) { /* @@ -1501,7 +1501,7 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) __jbd2_journal_file_buffer(jh, transaction, BJ_Metadata); spin_unlock(&journal->j_list_lock); out_unlock_bh: - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); out: JBUFFER_TRACE(jh, "exit"); return ret; @@ -1539,18 +1539,20 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) BUFFER_TRACE(bh, "entry"); - jbd_lock_bh_state(bh); + jh = jbd2_journal_grab_journal_head(bh); + if (!jh) { + __bforget(bh); + return 0; + } - if (!buffer_jbd(bh)) - goto not_jbd; - jh = bh2jh(bh); + spin_lock(&jh->b_state_lock); /* Critical error: attempting to delete a bitmap buffer, maybe? * Don't do any jbd operations, and return an error. */ if (!J_EXPECT_JH(jh, !jh->b_committed_data, "inconsistent data on disk")) { err = -EIO; - goto not_jbd; + goto drop; } /* keep track of whether or not this transaction modified us */ @@ -1598,10 +1600,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); } else { __jbd2_journal_unfile_buffer(jh); - if (!buffer_jbd(bh)) { - spin_unlock(&journal->j_list_lock); - goto not_jbd; - } + jbd2_journal_put_journal_head(jh); } spin_unlock(&journal->j_list_lock); } else if (jh->b_transaction) { @@ -1643,7 +1642,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) if (!jh->b_cp_transaction) { JBUFFER_TRACE(jh, "belongs to none transaction"); spin_unlock(&journal->j_list_lock); - goto not_jbd; + goto drop; } /* @@ -1653,7 +1652,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) if (!buffer_dirty(bh)) { __jbd2_journal_remove_checkpoint(jh); spin_unlock(&journal->j_list_lock); - goto not_jbd; + goto drop; } /* @@ -1666,20 +1665,15 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); spin_unlock(&journal->j_list_lock); } - - jbd_unlock_bh_state(bh); - __brelse(bh); drop: + __brelse(bh); + spin_unlock(&jh->b_state_lock); + jbd2_journal_put_journal_head(jh); if (drop_reserve) { /* no need to reserve log space for this block -bzzz */ handle->h_buffer_credits++; } return err; - -not_jbd: - jbd_unlock_bh_state(bh); - __bforget(bh); - goto drop; } /** @@ -1878,7 +1872,7 @@ int jbd2_journal_stop(handle_t *handle) * * j_list_lock is held. * - * jbd_lock_bh_state(jh2bh(jh)) is held. + * jh->b_state_lock is held. */ static inline void @@ -1902,7 +1896,7 @@ __blist_add_buffer(struct journal_head **list, struct journal_head *jh) * * Called with j_list_lock held, and the journal may not be locked. * - * jbd_lock_bh_state(jh2bh(jh)) is held. + * jh->b_state_lock is held. */ static inline void @@ -1934,7 +1928,7 @@ static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) transaction_t *transaction; struct buffer_head *bh = jh2bh(jh); - J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); + lockdep_assert_held(&jh->b_state_lock); transaction = jh->b_transaction; if (transaction) assert_spin_locked(&transaction->t_journal->j_list_lock); @@ -1971,17 +1965,15 @@ static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) } /* - * Remove buffer from all transactions. + * Remove buffer from all transactions. The caller is responsible for dropping + * the jh reference that belonged to the transaction. * * Called with bh_state lock and j_list_lock - * - * jh and bh may be already freed when this function returns. */ static void __jbd2_journal_unfile_buffer(struct journal_head *jh) { __jbd2_journal_temp_unlink_buffer(jh); jh->b_transaction = NULL; - jbd2_journal_put_journal_head(jh); } void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) @@ -1990,18 +1982,19 @@ void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) /* Get reference so that buffer cannot be freed before we unlock it */ get_bh(bh); - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); spin_lock(&journal->j_list_lock); __jbd2_journal_unfile_buffer(jh); spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); + jbd2_journal_put_journal_head(jh); __brelse(bh); } /* * Called from jbd2_journal_try_to_free_buffers(). * - * Called under jbd_lock_bh_state(bh) + * Called under jh->b_state_lock */ static void __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) @@ -2088,10 +2081,10 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal, if (!jh) continue; - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); __journal_try_to_free_buffer(journal, bh); + spin_unlock(&jh->b_state_lock); jbd2_journal_put_journal_head(jh); - jbd_unlock_bh_state(bh); if (buffer_jbd(bh)) goto busy; } while ((bh = bh->b_this_page) != head); @@ -2112,7 +2105,7 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal, * * Called under j_list_lock. * - * Called under jbd_lock_bh_state(bh). + * Called under jh->b_state_lock. */ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) { @@ -2133,6 +2126,7 @@ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) } else { JBUFFER_TRACE(jh, "on running transaction"); __jbd2_journal_unfile_buffer(jh); + jbd2_journal_put_journal_head(jh); } return may_free; } @@ -2199,18 +2193,15 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, * holding the page lock. --sct */ - if (!buffer_jbd(bh)) + jh = jbd2_journal_grab_journal_head(bh); + if (!jh) goto zap_buffer_unlocked; /* OK, we have data buffer in journaled mode */ write_lock(&journal->j_state_lock); - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); spin_lock(&journal->j_list_lock); - jh = jbd2_journal_grab_journal_head(bh); - if (!jh) - goto zap_buffer_no_jh; - /* * We cannot remove the buffer from checkpoint lists until the * transaction adding inode to orphan list (let's call it T) @@ -2289,10 +2280,10 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, * for commit and try again. */ if (partial_page) { - jbd2_journal_put_journal_head(jh); spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); write_unlock(&journal->j_state_lock); + jbd2_journal_put_journal_head(jh); return -EBUSY; } /* @@ -2304,10 +2295,10 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, set_buffer_freed(bh); if (journal->j_running_transaction && buffer_jbddirty(bh)) jh->b_next_transaction = journal->j_running_transaction; - jbd2_journal_put_journal_head(jh); spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); write_unlock(&journal->j_state_lock); + jbd2_journal_put_journal_head(jh); return 0; } else { /* Good, the buffer belongs to the running transaction. @@ -2331,11 +2322,10 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, * here. */ jh->b_modified = 0; - jbd2_journal_put_journal_head(jh); -zap_buffer_no_jh: spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); + spin_unlock(&jh->b_state_lock); write_unlock(&journal->j_state_lock); + jbd2_journal_put_journal_head(jh); zap_buffer_unlocked: clear_buffer_dirty(bh); J_ASSERT_BH(bh, !buffer_jbddirty(bh)); @@ -2422,7 +2412,7 @@ void __jbd2_journal_file_buffer(struct journal_head *jh, int was_dirty = 0; struct buffer_head *bh = jh2bh(jh); - J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); + lockdep_assert_held(&jh->b_state_lock); assert_spin_locked(&transaction->t_journal->j_list_lock); J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); @@ -2484,11 +2474,11 @@ void __jbd2_journal_file_buffer(struct journal_head *jh, void jbd2_journal_file_buffer(struct journal_head *jh, transaction_t *transaction, int jlist) { - jbd_lock_bh_state(jh2bh(jh)); + spin_lock(&jh->b_state_lock); spin_lock(&transaction->t_journal->j_list_lock); __jbd2_journal_file_buffer(jh, transaction, jlist); spin_unlock(&transaction->t_journal->j_list_lock); - jbd_unlock_bh_state(jh2bh(jh)); + spin_unlock(&jh->b_state_lock); } /* @@ -2498,23 +2488,25 @@ void jbd2_journal_file_buffer(struct journal_head *jh, * buffer on that transaction's metadata list. * * Called under j_list_lock - * Called under jbd_lock_bh_state(jh2bh(jh)) + * Called under jh->b_state_lock * - * jh and bh may be already free when this function returns + * When this function returns true, there's no next transaction to refile to + * and the caller has to drop jh reference through + * jbd2_journal_put_journal_head(). */ -void __jbd2_journal_refile_buffer(struct journal_head *jh) +bool __jbd2_journal_refile_buffer(struct journal_head *jh) { int was_dirty, jlist; struct buffer_head *bh = jh2bh(jh); - J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); + lockdep_assert_held(&jh->b_state_lock); if (jh->b_transaction) assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); /* If the buffer is now unused, just drop it. */ if (jh->b_next_transaction == NULL) { __jbd2_journal_unfile_buffer(jh); - return; + return true; } /* @@ -2542,6 +2534,7 @@ void __jbd2_journal_refile_buffer(struct journal_head *jh) if (was_dirty) set_buffer_jbddirty(bh); + return false; } /* @@ -2552,16 +2545,15 @@ void __jbd2_journal_refile_buffer(struct journal_head *jh) */ void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) { - struct buffer_head *bh = jh2bh(jh); + bool drop; - /* Get reference so that buffer cannot be freed before we unlock it */ - get_bh(bh); - jbd_lock_bh_state(bh); + spin_lock(&jh->b_state_lock); spin_lock(&journal->j_list_lock); - __jbd2_journal_refile_buffer(jh); - jbd_unlock_bh_state(bh); + drop = __jbd2_journal_refile_buffer(jh); + spin_unlock(&jh->b_state_lock); spin_unlock(&journal->j_list_lock); - __brelse(bh); + if (drop) + jbd2_journal_put_journal_head(jh); } /* diff --git a/fs/namei.c b/fs/namei.c index e81521c87f985..cd74b3f7eae05 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1638,7 +1638,7 @@ static struct dentry *__lookup_slow(const struct qstr *name, { 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))) @@ -3126,7 +3126,7 @@ static int lookup_open(struct nameidata *nd, struct path *path, 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; diff --git a/fs/namespace.c b/fs/namespace.c index 2adfe7b166a3e..e67f6e405f366 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -14,6 +14,7 @@ #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> @@ -321,8 +322,11 @@ 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 diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index af549d70ec507..86a72d0d38177 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -162,11 +162,11 @@ static int nfs_delegation_claim_opens(struct inode *inode, 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); 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); diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index e180033e35cf1..d30412299573c 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -445,7 +445,7 @@ 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); @@ -1496,7 +1496,7 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry, 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 }; @@ -1825,7 +1825,11 @@ int nfs_rmdir(struct inode *dir, struct dentry *dentry) trace_nfs_rmdir_enter(dir, dentry); if (d_really_is_positive(dentry)) { +#ifdef CONFIG_PREEMPT_RT + 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) { @@ -1835,7 +1839,11 @@ int nfs_rmdir(struct inode *dir, struct dentry *dentry) case -ENOENT: nfs_dentry_handle_enoent(dentry); } +#ifdef CONFIG_PREEMPT_RT + 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); diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 2a03bfeec10a4..785e4c4aa8fd6 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -2105,7 +2105,11 @@ 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 + sema_init(&nfsi->rmdir_sem, 1); +#else init_rwsem(&nfsi->rmdir_sem); +#endif mutex_init(&nfsi->commit_mutex); nfs4_init_once(nfsi); } diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 16b2e5cc3e94a..23b9cf27f4b95 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -115,7 +115,7 @@ 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; }; diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index f26d714f9f28a..2a1e066da9132 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2965,7 +2965,7 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata, 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) @@ -3007,7 +3007,7 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata, 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); } diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 0c6d53dc3672a..8ed95c22ead32 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -510,7 +510,7 @@ nfs4_alloc_state_owner(struct nfs_server *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; } @@ -1618,8 +1618,12 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs * recovering after a network partition or a reboot from a * server that doesn't support a grace period. */ +#ifdef CONFIG_PREEMPT_RT + 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)) @@ -1680,14 +1684,20 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs spin_lock(&sp->so_lock); goto restart; } - raw_write_seqcount_end(&sp->so_reclaim_seqcount); spin_unlock(&sp->so_lock); +#ifdef CONFIG_PREEMPT_RT + 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 + write_sequnlock(&sp->so_reclaim_seqlock); +#else + write_seqcount_end(&sp->so_reclaim_seqlock.seqcount); +#endif return status; } diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c index 0effeee28352f..efa5adce9b309 100644 --- a/fs/nfs/unlink.c +++ b/fs/nfs/unlink.c @@ -13,7 +13,7 @@ #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> @@ -53,6 +53,29 @@ static void nfs_async_unlink_done(struct rpc_task *task, void *calldata) rpc_restart_call_prepare(task); } +#ifdef CONFIG_PREEMPT_RT +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. * @calldata: struct nfs_unlinkdata to release @@ -66,7 +89,7 @@ static void nfs_async_unlink_release(void *calldata) 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); @@ -119,10 +142,10 @@ static int nfs_call_unlink(struct dentry *dentry, struct inode *inode, struct nf 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)) { @@ -144,7 +167,7 @@ static int nfs_call_unlink(struct dentry *dentry, struct inode *inode, struct nf 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 @@ -180,7 +203,7 @@ nfs_async_unlink(struct dentry *dentry, const struct qstr *name) 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); diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index 7202a1e39d70c..554b744f41bf8 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -92,8 +92,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate) "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); + spin_lock_irqsave(&first->b_uptodate_lock, flags); clear_buffer_async_read(bh); unlock_buffer(bh); tmp = bh; @@ -108,8 +107,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } while (tmp != bh); - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + spin_unlock_irqrestore(&first->b_uptodate_lock, 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 @@ -142,8 +140,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate) unlock_page(page); return; still_busy: - bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); - local_irq_restore(flags); + spin_unlock_irqrestore(&first->b_uptodate_lock, flags); return; } diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 69c21a3843af8..4180c3ef0a68c 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -1252,6 +1252,7 @@ static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh, int nr) { struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data; + struct journal_head *jh; int ret; if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap)) @@ -1260,13 +1261,14 @@ static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh, if (!buffer_jbd(bg_bh)) return 1; - jbd_lock_bh_state(bg_bh); - bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data; + jh = bh2jh(bg_bh); + spin_lock(&jh->b_state_lock); + bg = (struct ocfs2_group_desc *) jh->b_committed_data; if (bg) ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap); else ret = 1; - jbd_unlock_bh_state(bg_bh); + spin_unlock(&jh->b_state_lock); return ret; } @@ -2387,6 +2389,7 @@ static int ocfs2_block_group_clear_bits(handle_t *handle, int status; unsigned int tmp; struct ocfs2_group_desc *undo_bg = NULL; + struct journal_head *jh; /* The caller got this descriptor from * ocfs2_read_group_descriptor(). Any corruption is a code bug. */ @@ -2405,10 +2408,10 @@ static int ocfs2_block_group_clear_bits(handle_t *handle, goto bail; } + jh = bh2jh(group_bh); if (undo_fn) { - jbd_lock_bh_state(group_bh); - undo_bg = (struct ocfs2_group_desc *) - bh2jh(group_bh)->b_committed_data; + spin_lock(&jh->b_state_lock); + undo_bg = (struct ocfs2_group_desc *) jh->b_committed_data; BUG_ON(!undo_bg); } @@ -2423,7 +2426,7 @@ static int ocfs2_block_group_clear_bits(handle_t *handle, le16_add_cpu(&bg->bg_free_bits_count, num_bits); if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) { if (undo_fn) - jbd_unlock_bh_state(group_bh); + spin_unlock(&jh->b_state_lock); return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n", (unsigned long long)le64_to_cpu(bg->bg_blkno), le16_to_cpu(bg->bg_bits), @@ -2432,7 +2435,7 @@ static int ocfs2_block_group_clear_bits(handle_t *handle, } if (undo_fn) - jbd_unlock_bh_state(group_bh); + spin_unlock(&jh->b_state_lock); ocfs2_journal_dirty(handle, group_bh); bail: diff --git a/fs/proc/base.c b/fs/proc/base.c index ebea9501afb84..2dcd8fb3abb58 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1891,7 +1891,7 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx, 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; diff --git a/fs/proc/kmsg.c b/fs/proc/kmsg.c index 4f4a2abb225eb..4e62963a87ca8 100644 --- a/fs/proc/kmsg.c +++ b/fs/proc/kmsg.c @@ -18,8 +18,6 @@ #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); @@ -42,7 +40,7 @@ static ssize_t kmsg_read(struct file *file, char __user *buf, 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; diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index d80989b6c3448..b5921f996e86d 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -702,7 +702,7 @@ static bool proc_sys_fill_cache(struct file *file, 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; diff --git a/fs/squashfs/decompressor_multi_percpu.c b/fs/squashfs/decompressor_multi_percpu.c index 2a2a2d106440e..f8dd256763284 100644 --- a/fs/squashfs/decompressor_multi_percpu.c +++ b/fs/squashfs/decompressor_multi_percpu.c @@ -8,6 +8,7 @@ #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" @@ -23,6 +24,8 @@ struct squashfs_stream { void *stream; }; +static DEFINE_LOCAL_IRQ_LOCK(stream_lock); + void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, void *comp_opts) { @@ -77,10 +80,15 @@ int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh, { 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", diff --git a/fs/stack.c b/fs/stack.c index 4ef2c056269d5..c9830924eb125 100644 --- a/fs/stack.c +++ b/fs/stack.c @@ -23,7 +23,7 @@ void fsstack_copy_inode_size(struct inode *dst, struct inode *src) /* * But on 32-bit, we ought to make an effort to keep the two halves of - * i_blocks in sync despite SMP or PREEMPT - though stat's + * i_blocks in sync despite SMP or PREEMPTION - though stat's * generic_fillattr() doesn't bother, and we won't be applying quotas * (where i_blocks does become important) at the upper level. * @@ -38,14 +38,14 @@ void fsstack_copy_inode_size(struct inode *dst, struct inode *src) spin_unlock(&src->i_lock); /* - * If CONFIG_SMP or CONFIG_PREEMPT on 32-bit, it's vital for + * If CONFIG_SMP or CONFIG_PREEMPTION on 32-bit, it's vital for * fsstack_copy_inode_size() to hold some lock around * i_size_write(), otherwise i_size_read() may spin forever (see * include/linux/fs.h). We don't necessarily hold i_mutex when this * is called, so take i_lock for that case. * * And if on 32-bit, continue our effort to keep the two halves of - * i_blocks in sync despite SMP or PREEMPT: use i_lock for that case + * i_blocks in sync despite SMP or PREEMPTION: use i_lock for that case * too, and do both at once by combining the tests. * * There is none of this locking overhead in the 64-bit case. diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d99d166fd8926..2deffbc812ee8 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -61,7 +61,7 @@ struct userfaultfd_ctx { /* waitqueue head for events */ wait_queue_head_t event_wqh; /* a refile sequence protected by fault_pending_wqh lock */ - struct seqcount refile_seq; + seqlock_t refile_seq; /* pseudo fd refcounting */ refcount_t refcount; /* userfaultfd syscall flags */ @@ -1063,7 +1063,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait, * waitqueue could become empty if this is the * only userfault. */ - write_seqcount_begin(&ctx->refile_seq); + write_seqlock(&ctx->refile_seq); /* * The fault_pending_wqh.lock prevents the uwq @@ -1089,7 +1089,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait, list_del(&uwq->wq.entry); add_wait_queue(&ctx->fault_wqh, &uwq->wq); - write_seqcount_end(&ctx->refile_seq); + write_sequnlock(&ctx->refile_seq); /* careful to always initialize msg if ret == 0 */ *msg = uwq->msg; @@ -1262,11 +1262,11 @@ static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx, * sure we've userfaults to wake. */ do { - seq = read_seqcount_begin(&ctx->refile_seq); + seq = read_seqbegin(&ctx->refile_seq); need_wakeup = waitqueue_active(&ctx->fault_pending_wqh) || waitqueue_active(&ctx->fault_wqh); cond_resched(); - } while (read_seqcount_retry(&ctx->refile_seq, seq)); + } while (read_seqretry(&ctx->refile_seq, seq)); if (need_wakeup) __wake_userfault(ctx, range); } @@ -1939,7 +1939,7 @@ static void init_once_userfaultfd_ctx(void *mem) init_waitqueue_head(&ctx->fault_wqh); init_waitqueue_head(&ctx->event_wqh); init_waitqueue_head(&ctx->fd_wqh); - seqcount_init(&ctx->refile_seq); + seqlock_init(&ctx->refile_seq); } SYSCALL_DEFINE1(userfaultfd, int, flags) diff --git a/include/Kbuild b/include/Kbuild index ffba79483cc5e..95b4105a6186f 100644 --- a/include/Kbuild +++ b/include/Kbuild @@ -1158,8 +1158,15 @@ header-test- += xen/xenbus.h # Do not include directly header-test- += linux/compiler-clang.h header-test- += linux/compiler-gcc.h +header-test- += linux/mutex_rt.h header-test- += linux/patchkey.h header-test- += linux/rwlock_api_smp.h +header-test- += linux/rwlock_rt.h +header-test- += linux/rwlock_types_rt.h +header-test- += linux/rwsem-rt.h +header-test- += linux/spinlock_rt.h +header-test- += linux/spinlock_types_nort.h +header-test- += linux/spinlock_types_rt.h header-test- += linux/spinlock_types_up.h header-test- += linux/spinlock_up.h header-test- += linux/wimax/debug.h diff --git a/include/linux/bottom_half.h b/include/linux/bottom_half.h index a19519f4241dc..ef2366a65ba2a 100644 --- a/include/linux/bottom_half.h +++ b/include/linux/bottom_half.h @@ -4,6 +4,10 @@ #include <linux/preempt.h> +#ifdef CONFIG_PREEMPT_RT +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 @@ -13,6 +17,7 @@ static __always_inline void __local_bh_disable_ip(unsigned long ip, unsigned int barrier(); } #endif +#endif static inline void local_bh_disable(void) { diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 7b73ef7f902d4..e0b020eaf32e2 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -22,9 +22,6 @@ enum bh_state_bits { BH_Dirty, /* Is dirty */ BH_Lock, /* Is locked */ BH_Req, /* Has been submitted for I/O */ - BH_Uptodate_Lock,/* Used by the first bh in a page, to serialise - * IO completion of other buffers in the page - */ BH_Mapped, /* Has a disk mapping */ BH_New, /* Disk mapping was newly created by get_block */ @@ -76,6 +73,9 @@ struct buffer_head { struct address_space *b_assoc_map; /* mapping this buffer is associated with */ atomic_t b_count; /* users using this buffer_head */ + spinlock_t b_uptodate_lock; /* Used by the first bh in a page, to + * serialise IO completion of other + * buffers in the page */ }; /* diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 430e219e3abaf..5708205542bf8 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -144,9 +144,6 @@ struct cgroup_subsys_state { struct list_head sibling; struct list_head children; - /* flush target list anchored at cgrp->rstat_css_list */ - struct list_head rstat_css_node; - /* * PI: Subsys-unique ID. 0 is unused and root is always 1. The * matching css can be looked up using css_from_id(). @@ -455,7 +452,6 @@ struct cgroup { /* per-cpu recursive resource statistics */ struct cgroup_rstat_cpu __percpu *rstat_cpu; - struct list_head rstat_css_list; /* cgroup basic resource statistics */ struct cgroup_base_stat pending_bstat; /* pending from children */ @@ -633,7 +629,6 @@ struct cgroup_subsys { void (*css_released)(struct cgroup_subsys_state *css); void (*css_free)(struct cgroup_subsys_state *css); void (*css_reset)(struct cgroup_subsys_state *css); - void (*css_rstat_flush)(struct cgroup_subsys_state *css, int cpu); int (*css_extra_stat_show)(struct seq_file *seq, struct cgroup_subsys_state *css); diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 3ba3e6da13a6f..affa3798c9f52 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -750,9 +750,6 @@ static inline void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, */ void cgroup_rstat_updated(struct cgroup *cgrp, int cpu); void cgroup_rstat_flush(struct cgroup *cgrp); -void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp); -void cgroup_rstat_flush_hold(struct cgroup *cgrp); -void cgroup_rstat_flush_release(void); /* * Basic resource stats. diff --git a/include/linux/completion.h b/include/linux/completion.h index 519e94915d185..bf8e77001f18f 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -9,7 +9,7 @@ * 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" @@ -25,7 +25,7 @@ */ struct completion { unsigned int done; - wait_queue_head_t wait; + struct swait_queue_head wait; }; #define init_completion_map(x, m) __init_completion(x) @@ -34,7 +34,7 @@ static inline void complete_acquire(struct completion *x) {} 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); })) @@ -85,7 +85,7 @@ static inline void complete_release(struct completion *x) {} static inline void __init_completion(struct completion *x) { x->done = 0; - init_waitqueue_head(&x->wait); + init_swait_queue_head(&x->wait); } /** diff --git a/include/linux/console.h b/include/linux/console.h index d09951d5a94e4..39d1bb43b4f25 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -145,6 +145,7 @@ 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); @@ -153,6 +154,8 @@ struct console { short flags; short index; int cflag; + unsigned long printk_seq; + int wrote_history; void *data; struct console *next; }; @@ -234,4 +237,7 @@ 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 */ diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 10090f11ab954..ac021d808c71d 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -106,7 +106,7 @@ 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 */ @@ -236,7 +236,7 @@ extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op extern struct dentry * d_alloc(struct dentry *, const struct qstr *); extern struct dentry * d_alloc_anon(struct super_block *); 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 *); diff --git a/include/linux/delay.h b/include/linux/delay.h index 8e6828094c1ee..7f2df975a53e2 100644 --- a/include/linux/delay.h +++ b/include/linux/delay.h @@ -65,4 +65,10 @@ static inline void ssleep(unsigned int seconds) msleep(seconds * 1000); } +#ifdef CONFIG_PREEMPT_RT +extern void cpu_chill(void); +#else +# define cpu_chill() cpu_relax() +#endif + #endif /* defined(_LINUX_DELAY_H) */ diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index ee50d10f052b5..81272ca122ee5 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -65,13 +65,13 @@ struct dma_resv_list { /** * struct dma_resv - a reservation object manages fences for a buffer * @lock: update side lock - * @seq: sequence count for managing RCU read-side synchronization + * @seq: sequence lock for managing RCU read-side synchronization * @fence_excl: the exclusive fence, if there is one currently * @fence: list of current shared fences */ struct dma_resv { struct ww_mutex lock; - seqcount_t seq; + seqlock_t seq; struct dma_fence __rcu *fence_excl; struct dma_resv_list __rcu *fence; diff --git a/include/linux/fs.h b/include/linux/fs.h index 0b4d8fc79e0f3..ab03c913559c3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -716,7 +716,7 @@ 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; @@ -855,7 +855,7 @@ static inline loff_t i_size_read(const struct inode *inode) i_size = inode->i_size; } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); return i_size; -#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) loff_t i_size; preempt_disable(); @@ -880,7 +880,7 @@ static inline void i_size_write(struct inode *inode, loff_t i_size) inode->i_size = i_size; write_seqcount_end(&inode->i_size_seqcount); preempt_enable(); -#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) preempt_disable(); inode->i_size = i_size; preempt_enable(); diff --git a/include/linux/fscache.h b/include/linux/fscache.h index ad044c0cb1f3b..164bfe4d207d0 100644 --- a/include/linux/fscache.h +++ b/include/linux/fscache.h @@ -226,6 +226,7 @@ extern void __fscache_readpages_cancel(struct fscache_cookie *cookie, 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 diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 8b5330dd5ac09..c1583357e9cd4 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -717,7 +717,7 @@ static inline void hd_free_part(struct hd_struct *part) * accessor function. * * Code written along the lines of i_size_read() and i_size_write(). - * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption + * CONFIG_PREEMPTION case optimizes the case of UP kernel with preemption * on. */ static inline sector_t part_nr_sects_read(struct hd_struct *part) @@ -730,7 +730,7 @@ static inline sector_t part_nr_sects_read(struct hd_struct *part) nr_sects = part->nr_sects; } while (read_seqcount_retry(&part->nr_sects_seq, seq)); return nr_sects; -#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) sector_t nr_sects; preempt_disable(); @@ -753,7 +753,7 @@ static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) write_seqcount_begin(&part->nr_sects_seq); part->nr_sects = size; write_seqcount_end(&part->nr_sects_seq); -#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) preempt_disable(); part->nr_sects = size; preempt_enable(); diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 61f2f6ff94673..6ce61770ef343 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -580,6 +580,7 @@ extern void page_frag_free(void *addr); void page_alloc_init(void); void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp); void drain_all_pages(struct zone *zone); +void drain_cpu_pages(unsigned int cpu, struct zone *zone); void drain_local_pages(struct zone *zone); void page_alloc_init_late(void); diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index da0af631ded5b..8d7bb3c0ff061 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -68,7 +68,6 @@ extern void irq_exit(void); #define nmi_enter() \ do { \ arch_nmi_enter(); \ - printk_nmi_enter(); \ lockdep_off(); \ ftrace_nmi_enter(); \ BUG_ON(in_nmi()); \ @@ -85,7 +84,6 @@ 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) diff --git a/include/linux/highmem.h b/include/linux/highmem.h index ea5cdbd8c2c32..4191b158c66a0 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -8,6 +8,7 @@ #include <linux/mm.h> #include <linux/uaccess.h> #include <linux/hardirq.h> +#include <linux/sched.h> #include <asm/cacheflush.h> @@ -90,7 +91,7 @@ static inline void kunmap(struct page *page) static inline void *kmap_atomic(struct page *page) { - preempt_disable(); + preempt_disable_nort(); pagefault_disable(); return page_address(page); } @@ -99,7 +100,7 @@ static inline void *kmap_atomic(struct page *page) 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)) @@ -111,32 +112,51 @@ static inline void __kunmap_atomic(void *addr) #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) +#ifndef CONFIG_PREEMPT_RT DECLARE_PER_CPU(int, __kmap_atomic_idx); +#endif static inline int kmap_atomic_idx_push(void) { +#ifndef CONFIG_PREEMPT_RT 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 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 +# 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 } diff --git a/include/linux/idr.h b/include/linux/idr.h index ac6e946b6767b..839da8f2f6f13 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -169,10 +169,7 @@ static inline bool idr_is_empty(const struct idr *idr) * 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. diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 89fc59dab57d2..029042f474c69 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -546,7 +546,7 @@ 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) void do_softirq_own_stack(void); #else static inline void do_softirq_own_stack(void) @@ -561,6 +561,7 @@ extern void __raise_softirq_irqoff(unsigned int nr); 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); @@ -625,7 +626,10 @@ static inline void tasklet_unlock(struct tasklet_struct *t) 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 diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index b11fcdfd07707..2964f4526f79e 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -18,6 +18,8 @@ /* 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) @@ -52,4 +54,10 @@ static inline bool irq_work_needs_cpu(void) { return false; } static inline void irq_work_run(void) { } #endif +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT) +void irq_work_tick_soft(void); +#else +static inline void irq_work_tick_soft(void) { } +#endif + #endif /* _LINUX_IRQ_WORK_H */ diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index d6e2ab538ef27..1e7fc375c36da 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -72,6 +72,7 @@ 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; diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 21619c92c3770..5304de2f78386 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -43,14 +43,6 @@ 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) @@ -64,6 +56,21 @@ do { \ # define lockdep_softirq_exit() do { } while (0) #endif +#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT) +# 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) extern void stop_critical_timings(void); diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 10e6049c0ba91..b56dbe515ad73 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -313,7 +313,6 @@ enum jbd_state_bits { BH_Revoked, /* Has been revoked from the log */ BH_RevokeValid, /* Revoked flag is valid */ BH_JBDDirty, /* Is dirty but journaled */ - BH_State, /* Pins most journal_head state */ BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ BH_Shadow, /* IO on shadow buffer is running */ BH_Verified, /* Metadata block has been verified ok */ @@ -342,26 +341,6 @@ static inline struct journal_head *bh2jh(struct buffer_head *bh) return bh->b_private; } -static inline void jbd_lock_bh_state(struct buffer_head *bh) -{ - bit_spin_lock(BH_State, &bh->b_state); -} - -static inline int jbd_trylock_bh_state(struct buffer_head *bh) -{ - return bit_spin_trylock(BH_State, &bh->b_state); -} - -static inline int jbd_is_locked_bh_state(struct buffer_head *bh) -{ - return bit_spin_is_locked(BH_State, &bh->b_state); -} - -static inline void jbd_unlock_bh_state(struct buffer_head *bh) -{ - bit_spin_unlock(BH_State, &bh->b_state); -} - static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) { bit_spin_lock(BH_JournalHead, &bh->b_state); @@ -556,9 +535,9 @@ struct transaction_chp_stats_s { * ->jbd_lock_bh_journal_head() (This is "innermost") * * j_state_lock - * ->jbd_lock_bh_state() + * ->b_state_lock * - * jbd_lock_bh_state() + * b_state_lock * ->j_list_lock * * j_state_lock @@ -1257,7 +1236,7 @@ JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3) /* Filing buffers */ extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); -extern void __jbd2_journal_refile_buffer(struct journal_head *); +extern bool __jbd2_journal_refile_buffer(struct journal_head *); extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); extern void __journal_free_buffer(struct journal_head *bh); diff --git a/include/linux/journal-head.h b/include/linux/journal-head.h index 9fb8705243145..75bc56109031f 100644 --- a/include/linux/journal-head.h +++ b/include/linux/journal-head.h @@ -11,6 +11,8 @@ #ifndef JOURNAL_HEAD_H_INCLUDED #define JOURNAL_HEAD_H_INCLUDED +#include <linux/spinlock.h> + typedef unsigned int tid_t; /* Unique transaction ID */ typedef struct transaction_s transaction_t; /* Compound transaction type */ @@ -23,6 +25,11 @@ struct journal_head { */ struct buffer_head *b_bh; + /* + * Protect the buffer head state + */ + spinlock_t b_state_lock; + /* * Reference count - see description in journal.c * [jbd_lock_bh_journal_head()] @@ -30,7 +37,7 @@ struct journal_head { int b_jcount; /* - * Journalling list for this buffer [jbd_lock_bh_state()] + * Journalling list for this buffer [b_state_lock] * NOTE: We *cannot* combine this with b_modified into a bitfield * as gcc would then (which the C standard allows but which is * very unuseful) make 64-bit accesses to the bitfield and clobber @@ -41,20 +48,20 @@ struct journal_head { /* * This flag signals the buffer has been modified by * the currently running transaction - * [jbd_lock_bh_state()] + * [b_state_lock] */ unsigned b_modified; /* * Copy of the buffer data frozen for writing to the log. - * [jbd_lock_bh_state()] + * [b_state_lock] */ char *b_frozen_data; /* * Pointer to a saved copy of the buffer containing no uncommitted * deallocation references, so that allocations can avoid overwriting - * uncommitted deletes. [jbd_lock_bh_state()] + * uncommitted deletes. [b_state_lock] */ char *b_committed_data; @@ -63,7 +70,7 @@ struct journal_head { * metadata: either the running transaction or the committing * transaction (if there is one). Only applies to buffers on a * transaction's data or metadata journaling list. - * [j_list_lock] [jbd_lock_bh_state()] + * [j_list_lock] [b_state_lock] * Either of these locks is enough for reading, both are needed for * changes. */ @@ -73,13 +80,13 @@ struct journal_head { * Pointer to the running compound transaction which is currently * modifying the buffer's metadata, if there was already a transaction * committing it when the new transaction touched it. - * [t_list_lock] [jbd_lock_bh_state()] + * [t_list_lock] [b_state_lock] */ transaction_t *b_next_transaction; /* * Doubly-linked list of buffers on a transaction's data, metadata or - * forget queue. [t_list_lock] [jbd_lock_bh_state()] + * forget queue. [t_list_lock] [b_state_lock] */ struct journal_head *b_tnext, *b_tprev; diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d83d403dac2ea..2f9abc6aab0be 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -227,6 +227,10 @@ extern void __cant_sleep(const char *file, int line, int preempt_offset); */ # 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) + /** * cant_sleep - annotation for functions that cannot sleep * @@ -258,6 +262,7 @@ extern void __cant_sleep(const char *file, int line, int preempt_offset); 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 cant_sleep() do { } while (0) # define sched_annotate_sleep() do { } while (0) # define non_block_start() do { } while (0) diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index 2e7a1e032c71a..ede5066663b92 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -46,10 +46,8 @@ 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 diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h index ae1b541446c90..83e0ec90ed0d5 100644 --- a/include/linux/list_bl.h +++ b/include/linux/list_bl.h @@ -3,6 +3,7 @@ #define _LINUX_LIST_BL_H #include <linux/list.h> +#include <linux/spinlock.h> #include <linux/bit_spinlock.h> /* @@ -33,13 +34,24 @@ struct hlist_bl_head { struct hlist_bl_node *first; +#ifdef CONFIG_PREEMPT_RT + 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 +#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) { @@ -145,12 +157,26 @@ static inline void hlist_bl_del_init(struct hlist_bl_node *n) static inline void hlist_bl_lock(struct hlist_bl_head *b) { +#ifndef CONFIG_PREEMPT_RT 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 __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) diff --git a/include/linux/locallock.h b/include/linux/locallock.h new file mode 100644 index 0000000000000..9b6b4def52d49 --- /dev/null +++ b/include/linux/locallock.h @@ -0,0 +1,282 @@ +#ifndef _LINUX_LOCALLOCK_H +#define _LINUX_LOCALLOCK_H + +#include <linux/percpu.h> +#include <linux/spinlock.h> +#include <asm/current.h> + +#ifdef CONFIG_PREEMPT_RT + +#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 */ + +#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 diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 270aa8fd2800b..497440fe047c0 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -12,6 +12,7 @@ #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> @@ -520,6 +521,9 @@ struct mm_struct { bool tlb_flush_batched; #endif struct uprobes_state uprobes_state; +#ifdef CONFIG_PREEMPT_RT + struct rcu_head delayed_drop; +#endif #ifdef CONFIG_HUGETLB_PAGE atomic_long_t hugetlb_usage; #endif diff --git a/include/linux/mutex.h b/include/linux/mutex.h index aca8f36dfac9a..2b72473ded555 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -22,6 +22,17 @@ 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 +# include <linux/mutex_rt.h> +#else + /* * Simple, straightforward mutexes with strict semantics: * @@ -108,13 +119,6 @@ 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) \ @@ -210,4 +214,6 @@ enum mutex_trylock_recursive_enum { extern /* __deprecated */ __must_check enum mutex_trylock_recursive_enum mutex_trylock_recursive(struct mutex *lock); +#endif /* !PREEMPT_RT */ + #endif /* __LINUX_MUTEX_H */ diff --git a/include/linux/mutex_rt.h b/include/linux/mutex_rt.h new file mode 100644 index 0000000000000..3fcb5edb1d2b4 --- /dev/null +++ b/include/linux/mutex_rt.h @@ -0,0 +1,130 @@ +#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 diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f8fde9fa479c8..b4aeead9104c2 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3016,6 +3016,7 @@ struct softnet_data { unsigned int dropped; struct sk_buff_head input_pkt_queue; struct napi_struct backlog; + struct sk_buff_head tofree_queue; }; diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 570a60c2f4f48..8e7f60827ecd9 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -165,7 +165,11 @@ struct nfs_inode { /* Readers: in-flight sillydelete RPC calls */ /* Writers: rmdir */ +#ifdef CONFIG_PREEMPT_RT + struct semaphore rmdir_sem; +#else struct rw_semaphore rmdir_sem; +#endif struct mutex commit_mutex; #if IS_ENABLED(CONFIG_NFS_V4) diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 9b8324ec08f31..c805cd551337a 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -1594,7 +1594,7 @@ 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; diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 7aef0abc194a2..390031e816dcd 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -186,14 +186,14 @@ static inline void percpu_ref_get_many(struct percpu_ref *ref, unsigned long nr) { unsigned long __percpu *percpu_count; - rcu_read_lock_sched(); + rcu_read_lock(); if (__ref_is_percpu(ref, &percpu_count)) this_cpu_add(*percpu_count, nr); else atomic_long_add(nr, &ref->count); - rcu_read_unlock_sched(); + rcu_read_unlock(); } /** @@ -223,7 +223,7 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref) unsigned long __percpu *percpu_count; bool ret; - rcu_read_lock_sched(); + rcu_read_lock(); if (__ref_is_percpu(ref, &percpu_count)) { this_cpu_inc(*percpu_count); @@ -232,7 +232,7 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref) ret = atomic_long_inc_not_zero(&ref->count); } - rcu_read_unlock_sched(); + rcu_read_unlock(); return ret; } @@ -257,7 +257,7 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) unsigned long __percpu *percpu_count; bool ret = false; - rcu_read_lock_sched(); + rcu_read_lock(); if (__ref_is_percpu(ref, &percpu_count)) { this_cpu_inc(*percpu_count); @@ -266,7 +266,7 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) ret = atomic_long_inc_not_zero(&ref->count); } - rcu_read_unlock_sched(); + rcu_read_unlock(); return ret; } @@ -285,14 +285,14 @@ static inline void percpu_ref_put_many(struct percpu_ref *ref, unsigned long nr) { unsigned long __percpu *percpu_count; - rcu_read_lock_sched(); + rcu_read_lock(); if (__ref_is_percpu(ref, &percpu_count)) this_cpu_sub(*percpu_count, nr); else if (unlikely(atomic_long_sub_and_test(nr, &ref->count))) ref->release(ref); - rcu_read_unlock_sched(); + rcu_read_unlock(); } /** diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 3998cdf9cd148..6e8d3871450a4 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -3,41 +3,52 @@ #define _LINUX_PERCPU_RWSEM_H #include <linux/atomic.h> -#include <linux/rwsem.h> #include <linux/percpu.h> #include <linux/rcuwait.h> +#include <linux/wait.h> #include <linux/rcu_sync.h> #include <linux/lockdep.h> struct percpu_rw_semaphore { struct rcu_sync rss; unsigned int __percpu *read_count; - struct rw_semaphore rw_sem; /* slowpath */ - struct rcuwait writer; /* blocked writer */ - int readers_block; + struct rcuwait writer; + wait_queue_head_t waiters; + atomic_t block; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif }; +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define __PERCPU_RWSEM_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }, +#else +#define __PERCPU_RWSEM_DEP_MAP_INIT(lockname) +#endif + #define __DEFINE_PERCPU_RWSEM(name, is_static) \ static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name); \ is_static struct percpu_rw_semaphore name = { \ .rss = __RCU_SYNC_INITIALIZER(name.rss), \ .read_count = &__percpu_rwsem_rc_##name, \ - .rw_sem = __RWSEM_INITIALIZER(name.rw_sem), \ .writer = __RCUWAIT_INITIALIZER(name.writer), \ + .waiters = __WAIT_QUEUE_HEAD_INITIALIZER(name.waiters), \ + .block = ATOMIC_INIT(0), \ + __PERCPU_RWSEM_DEP_MAP_INIT(name) \ } + #define DEFINE_PERCPU_RWSEM(name) \ __DEFINE_PERCPU_RWSEM(name, /* not static */) #define DEFINE_STATIC_PERCPU_RWSEM(name) \ __DEFINE_PERCPU_RWSEM(name, static) -extern int __percpu_down_read(struct percpu_rw_semaphore *, int); -extern void __percpu_up_read(struct percpu_rw_semaphore *); +extern bool __percpu_down_read(struct percpu_rw_semaphore *, bool); static inline void percpu_down_read(struct percpu_rw_semaphore *sem) { might_sleep(); - rwsem_acquire_read(&sem->rw_sem.dep_map, 0, 0, _RET_IP_); + rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_); preempt_disable(); /* @@ -48,8 +59,9 @@ static inline void percpu_down_read(struct percpu_rw_semaphore *sem) * and that once the synchronize_rcu() is done, the writer will see * anything we did within this RCU-sched read-size critical section. */ - __this_cpu_inc(*sem->read_count); - if (unlikely(!rcu_sync_is_idle(&sem->rss))) + if (likely(rcu_sync_is_idle(&sem->rss))) + __this_cpu_inc(*sem->read_count); + else __percpu_down_read(sem, false); /* Unconditional memory barrier */ /* * The preempt_enable() prevents the compiler from @@ -58,16 +70,17 @@ static inline void percpu_down_read(struct percpu_rw_semaphore *sem) preempt_enable(); } -static inline int percpu_down_read_trylock(struct percpu_rw_semaphore *sem) +static inline bool percpu_down_read_trylock(struct percpu_rw_semaphore *sem) { - int ret = 1; + bool ret = true; preempt_disable(); /* * Same as in percpu_down_read(). */ - __this_cpu_inc(*sem->read_count); - if (unlikely(!rcu_sync_is_idle(&sem->rss))) + if (likely(rcu_sync_is_idle(&sem->rss))) + __this_cpu_inc(*sem->read_count); + else ret = __percpu_down_read(sem, true); /* Unconditional memory barrier */ preempt_enable(); /* @@ -76,24 +89,36 @@ static inline int percpu_down_read_trylock(struct percpu_rw_semaphore *sem) */ if (ret) - rwsem_acquire_read(&sem->rw_sem.dep_map, 0, 1, _RET_IP_); + rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_); return ret; } static inline void percpu_up_read(struct percpu_rw_semaphore *sem) { + rwsem_release(&sem->dep_map, 1, _RET_IP_); + preempt_disable(); /* * Same as in percpu_down_read(). */ - if (likely(rcu_sync_is_idle(&sem->rss))) + if (likely(rcu_sync_is_idle(&sem->rss))) { __this_cpu_dec(*sem->read_count); - else - __percpu_up_read(sem); /* Unconditional memory barrier */ + } else { + /* + * slowpath; reader will only ever wake a single blocked + * writer. + */ + smp_mb(); /* B matches C */ + /* + * In other words, if they see our decrement (presumably to + * aggregate zero, as that is the only time it matters) they + * will also see our critical section. + */ + __this_cpu_dec(*sem->read_count); + rcuwait_wake_up(&sem->writer); + } preempt_enable(); - - rwsem_release(&sem->rw_sem.dep_map, 1, _RET_IP_); } extern void percpu_down_write(struct percpu_rw_semaphore *); @@ -110,29 +135,19 @@ extern void percpu_free_rwsem(struct percpu_rw_semaphore *); __percpu_init_rwsem(sem, #sem, &rwsem_key); \ }) -#define percpu_rwsem_is_held(sem) lockdep_is_held(&(sem)->rw_sem) - -#define percpu_rwsem_assert_held(sem) \ - lockdep_assert_held(&(sem)->rw_sem) +#define percpu_rwsem_is_held(sem) lockdep_is_held(sem) +#define percpu_rwsem_assert_held(sem) lockdep_assert_held(sem) static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem, bool read, unsigned long ip) { - lock_release(&sem->rw_sem.dep_map, 1, ip); -#ifdef CONFIG_RWSEM_SPIN_ON_OWNER - if (!read) - atomic_long_set(&sem->rw_sem.owner, RWSEM_OWNER_UNKNOWN); -#endif + lock_release(&sem->dep_map, 1, ip); } static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem, bool read, unsigned long ip) { - lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip); -#ifdef CONFIG_RWSEM_SPIN_ON_OWNER - if (!read) - atomic_long_set(&sem->rw_sem.owner, (long)current); -#endif + lock_acquire(&sem->dep_map, 0, 1, read, 1, NULL, ip); } #endif diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 5e76af742c807..3d0d9873de61e 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -19,6 +19,35 @@ #define PERCPU_MODULE_RESERVE 0 #endif +#ifdef CONFIG_PREEMPT_RT + +#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) diff --git a/include/linux/pid.h b/include/linux/pid.h index 9645b1194c981..916c1d0e42c22 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -3,6 +3,7 @@ #define _LINUX_PID_H #include <linux/rculist.h> +#include <linux/atomic.h> #include <linux/wait.h> #include <linux/refcount.h> diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h index 3d10c84a97a94..bad09364b20a1 100644 --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -72,6 +72,7 @@ struct cpu_timer { struct task_struct *task; struct list_head elist; int firing; + int firing_cpu; }; static inline bool cpu_timer_enqueue(struct timerqueue_head *head, @@ -123,6 +124,9 @@ struct posix_cputimers { struct posix_cputimer_base bases[CPUCLOCK_MAX]; unsigned int timers_active; unsigned int expiry_active; +#ifdef CONFIG_PREEMPT_RT + struct task_struct *posix_timer_list; +#endif }; static inline void posix_cputimers_init(struct posix_cputimers *pct) @@ -152,9 +156,16 @@ static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, INIT_CPU_TIMERBASE(b[2]), \ } +#ifdef CONFIG_PREEMPT_RT +# define INIT_TIMER_LIST .posix_timer_list = NULL, +#else +# define INIT_TIMER_LIST +#endif + #define INIT_CPU_TIMERS(s) \ .posix_cputimers = { \ .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \ + INIT_TIMER_LIST \ }, #else struct posix_cputimers { }; diff --git a/include/linux/preempt.h b/include/linux/preempt.h index bbb68dba37cc8..adb085fe31e43 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -78,10 +78,8 @@ #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? * @@ -96,12 +94,23 @@ * 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 + +#define softirq_count() ((long)current->softirq_count) +#define in_softirq() (softirq_count()) +#define in_serving_softirq() (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(); @@ -115,7 +124,11 @@ /* * The preempt_count offset after spin_lock() */ +#if !defined(CONFIG_PREEMPT_RT) #define PREEMPT_LOCK_OFFSET PREEMPT_DISABLE_OFFSET +#else +#define PREEMPT_LOCK_OFFSET 0 +#endif /* * The preempt_count offset needed for things like: @@ -164,6 +177,20 @@ 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() \ @@ -172,16 +199,53 @@ 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 +# 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) + +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) + +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_PREEMPTION #define preempt_enable() \ do { \ @@ -203,6 +267,13 @@ do { \ __preempt_schedule(); \ } while (0) +#define preempt_lazy_enable() \ +do { \ + dec_preempt_lazy_count(); \ + barrier(); \ + preempt_check_resched(); \ +} while (0) + #else /* !CONFIG_PREEMPTION */ #define preempt_enable() \ do { \ @@ -210,6 +281,12 @@ do { \ preempt_count_dec(); \ } while (0) +#define preempt_lazy_enable() \ +do { \ + dec_preempt_lazy_count(); \ + barrier(); \ +} while (0) + #define preempt_enable_notrace() \ do { \ barrier(); \ @@ -248,8 +325,16 @@ 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 @@ -268,10 +353,22 @@ 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 +# 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; diff --git a/include/linux/printk.h b/include/linux/printk.h index c09d67edda3a1..1fe8068100c25 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -58,6 +58,7 @@ static inline const char *printk_skip_headers(const char *buffer) */ #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[]; @@ -65,6 +66,7 @@ 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) { @@ -146,18 +148,6 @@ 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, @@ -202,9 +192,7 @@ __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...); 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) @@ -268,18 +256,6 @@ static inline void show_regs_print_info(const char *log_lvl) 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; diff --git a/include/linux/printk_ringbuffer.h b/include/linux/printk_ringbuffer.h new file mode 100644 index 0000000000000..ec3d7ceec378e --- /dev/null +++ b/include/linux/printk_ringbuffer.h @@ -0,0 +1,114 @@ +/* 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 */ diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 63e62372443a5..040b1fd0ab940 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -226,6 +226,7 @@ unsigned int radix_tree_gang_lookup(const struct radix_tree_root *, 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); @@ -243,11 +244,6 @@ unsigned int radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *, 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); diff --git a/include/linux/random.h b/include/linux/random.h index f189c927fdea5..62d8caa3b0b12 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -33,7 +33,7 @@ static inline void add_latent_entropy(void) {} 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); diff --git a/include/linux/ratelimit.h b/include/linux/ratelimit.h index 8ddf79e9207a9..51e90cea9c455 100644 --- a/include/linux/ratelimit.h +++ b/include/linux/ratelimit.h @@ -59,7 +59,7 @@ static inline void ratelimit_state_exit(struct ratelimit_state *rs) 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; } diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h index 1fd61a9af45cd..c667ec871abb5 100644 --- a/include/linux/rbtree.h +++ b/include/linux/rbtree.h @@ -19,7 +19,7 @@ #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; diff --git a/include/linux/rcu_assign_pointer.h b/include/linux/rcu_assign_pointer.h new file mode 100644 index 0000000000000..78c05f606a73d --- /dev/null +++ b/include/linux/rcu_assign_pointer.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#ifndef __LINUX_RCU_ASSIGN_POINTER_H__ +#define __LINUX_RCU_ASSIGN_POINTER_H__ +#include <linux/compiler.h> +#include <asm/barrier.h> + +#ifdef __CHECKER__ +#define rcu_check_sparse(p, space) \ + ((void)(((typeof(*p) space *)p) == p)) +#else /* #ifdef __CHECKER__ */ +#define rcu_check_sparse(p, space) +#endif /* #else #ifdef __CHECKER__ */ + +/** + * 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) \ +do { \ + uintptr_t _r_a_p__v = (uintptr_t)(v); \ + rcu_check_sparse(p, __rcu); \ + \ + 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)); \ +} while (0) + +#endif diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 75a2eded7aa2c..4b7c52128409d 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -29,6 +29,7 @@ #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)) @@ -51,6 +52,11 @@ 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 +#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 */ @@ -69,6 +75,8 @@ 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 */ @@ -154,7 +162,7 @@ static inline void exit_tasks_rcu_finish(void) { } * * This macro resembles cond_resched(), except that it is defined to * report potential quiescent states to RCU-tasks even if the cond_resched() - * machinery were to be shut off, as some advocate for PREEMPT kernels. + * machinery were to be shut off, as some advocate for PREEMPTION kernels. */ #define cond_resched_tasks_rcu_qs() \ do { \ @@ -279,7 +287,8 @@ static inline void rcu_preempt_sleep_check(void) { } #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)) \ + 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"); \ @@ -300,13 +309,6 @@ static inline void rcu_preempt_sleep_check(void) { } * (e.g., __srcu), should this make sense in the future. */ -#ifdef __CHECKER__ -#define rcu_check_sparse(p, space) \ - ((void)(((typeof(*p) space *)p) == p)) -#else /* #ifdef __CHECKER__ */ -#define rcu_check_sparse(p, space) -#endif /* #else #ifdef __CHECKER__ */ - #define __rcu_access_pointer(p, space) \ ({ \ typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ @@ -334,54 +336,6 @@ static inline void rcu_preempt_sleep_check(void) { } ((typeof(*p) __force __kernel *)(________p1)); \ }) -/** - * 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) \ -do { \ - uintptr_t _r_a_p__v = (uintptr_t)(v); \ - rcu_check_sparse(p, __rcu); \ - \ - 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)); \ -} while (0) - /** * rcu_swap_protected() - swap an RCU and a regular pointer * @rcu_ptr: RCU pointer @@ -580,7 +534,7 @@ do { \ * * You can avoid reading and understanding the next paragraph by * following this rule: don't put anything in an rcu_read_lock() RCU - * read-side critical section that would block in a !PREEMPT kernel. + * read-side critical section that would block in a !PREEMPTION kernel. * But if you want the full story, read on! * * In non-preemptible RCU implementations (TREE_RCU and TINY_RCU), diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h index 6fd615a0eea94..138bd1e183e09 100644 --- a/include/linux/rtmutex.h +++ b/include/linux/rtmutex.h @@ -14,11 +14,15 @@ #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 * @@ -31,8 +35,8 @@ 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; @@ -82,16 +86,23 @@ 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 @@ -115,6 +126,7 @@ extern void rt_mutex_lock(struct rt_mutex *lock); #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); diff --git a/include/linux/rwlock_rt.h b/include/linux/rwlock_rt.h new file mode 100644 index 0000000000000..a9c4c2ac4d1fa --- /dev/null +++ b/include/linux/rwlock_rt.h @@ -0,0 +1,119 @@ +#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 diff --git a/include/linux/rwlock_types.h b/include/linux/rwlock_types.h index 857a72ceb7942..c21683f3e14af 100644 --- a/include/linux/rwlock_types.h +++ b/include/linux/rwlock_types.h @@ -1,6 +1,10 @@ #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 diff --git a/include/linux/rwlock_types_rt.h b/include/linux/rwlock_types_rt.h new file mode 100644 index 0000000000000..546a1f8f12748 --- /dev/null +++ b/include/linux/rwlock_types_rt.h @@ -0,0 +1,55 @@ +#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 diff --git a/include/linux/rwsem-rt.h b/include/linux/rwsem-rt.h new file mode 100644 index 0000000000000..2018ff77904ad --- /dev/null +++ b/include/linux/rwsem-rt.h @@ -0,0 +1,68 @@ +#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 diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 00d6054687dd2..393f4520befc9 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -16,6 +16,11 @@ #include <linux/spinlock.h> #include <linux/atomic.h> #include <linux/err.h> + +#ifdef CONFIG_PREEMPT_RT +#include <linux/rwsem-rt.h> +#else /* PREEMPT_RT */ + #ifdef CONFIG_RWSEM_SPIN_ON_OWNER #include <linux/osq_lock.h> #endif @@ -53,12 +58,6 @@ struct rw_semaphore { #endif }; -/* - * Setting all bits of the owner field except bit 0 will indicate - * that the rwsem is writer-owned with an unknown owner. - */ -#define RWSEM_OWNER_UNKNOWN (-2L) - /* In all implementations count != 0 means locked */ static inline int rwsem_is_locked(struct rw_semaphore *sem) { @@ -121,6 +120,13 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem) return !list_empty(&sem->wait_list); } +#endif /* !PREEMPT_RT */ + +/* + * The functions below are the same for all rwsem implementations including + * the RT specific variant. + */ + /* * lock for reading */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 775503573ed70..c9e3aa38ce349 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -31,6 +31,7 @@ #include <linux/task_io_accounting.h> #include <linux/posix-timers.h> #include <linux/rseq.h> +#include <asm/kmap_types.h> /* task_struct member predeclarations (sorted alphabetically): */ struct audit_context; @@ -107,12 +108,8 @@ 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) @@ -140,6 +137,9 @@ 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 */ \ @@ -149,6 +149,7 @@ 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 @@ -193,6 +194,9 @@ 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 @@ -230,6 +234,8 @@ extern void io_schedule_finish(int token); extern long io_schedule_timeout(long timeout); extern void io_schedule(void); +int cpu_nr_pinned(int cpu); + /** * struct prev_cputime - snapshot of system and user cputime * @utime: time spent in user mode @@ -631,6 +637,8 @@ 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 @@ -700,6 +708,20 @@ struct task_struct { int nr_cpus_allowed; const cpumask_t *cpus_ptr; cpumask_t cpus_mask; +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT) + int migrate_disable; + bool migrate_disable_scheduled; +# ifdef CONFIG_SCHED_DEBUG + int pinned_on_cpu; +# endif +#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT) +# ifdef CONFIG_SCHED_DEBUG + int migrate_disable; +# endif +#endif +#ifdef CONFIG_PREEMPT_RT + int sleeping_lock; +#endif #ifdef CONFIG_PREEMPT_RCU int rcu_read_lock_nesting; @@ -913,11 +935,17 @@ 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 + /* 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; @@ -944,6 +972,7 @@ 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: */ @@ -978,6 +1007,9 @@ struct task_struct { int softirqs_enabled; int softirq_context; #endif +#ifdef CONFIG_PREEMPT_RT + int softirq_count; +#endif #ifdef CONFIG_LOCKDEP # define MAX_LOCK_DEPTH 48UL @@ -1241,6 +1273,12 @@ struct task_struct { unsigned int sequential_io; unsigned int sequential_io_avg; #endif +#ifdef CONFIG_PREEMPT_RT +# 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 @@ -1672,6 +1710,7 @@ extern struct task_struct *find_get_task_by_vpid(pid_t nr); 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 @@ -1754,6 +1793,89 @@ static inline int test_tsk_need_resched(struct task_struct *tsk) 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 + 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 + 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 + /* 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 @@ -1806,6 +1928,23 @@ static __always_inline bool need_resched(void) return unlikely(tif_need_resched()); } +#ifdef CONFIG_PREEMPT_RT +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. */ @@ -1997,4 +2136,6 @@ int sched_trace_rq_cpu(struct rq *rq); const struct cpumask *sched_trace_rd_span(struct root_domain *rd); +extern struct task_struct *takedown_cpu_task; + #endif diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index c49257a3b5108..2a498fc3d949f 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -49,6 +49,17 @@ static inline void mmdrop(struct mm_struct *mm) __mmdrop(mm); } +#ifdef CONFIG_PREEMPT_RT +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 diff --git a/include/linux/sched/wake_q.h b/include/linux/sched/wake_q.h index 26a2013ac39c4..6e2dff721547c 100644 --- a/include/linux/sched/wake_q.h +++ b/include/linux/sched/wake_q.h @@ -58,6 +58,17 @@ static inline bool wake_q_empty(struct wake_q_head *head) extern void wake_q_add(struct wake_q_head *head, struct task_struct *task); extern void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task); -extern void wake_up_q(struct wake_q_head *head); +extern void wake_q_add_sleeper(struct wake_q_head *head, struct task_struct *task); +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 */ diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index bcf4cf26b8c89..bc458c2658e4d 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -221,20 +221,30 @@ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) 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 @@ -428,10 +438,33 @@ typedef struct { /* * Read side functions for starting and finalizing a read side section. */ +#ifndef CONFIG_PREEMPT_RT 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) { @@ -446,36 +479,45 @@ static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) 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); } @@ -484,7 +526,7 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) unsigned long flags; spin_lock_irqsave(&sl->lock, flags); - write_seqcount_begin(&sl->seqcount); + __raw_write_seqcount_begin(&sl->seqcount); return flags; } @@ -494,7 +536,7 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) 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); } diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h index bb2bc99388cae..be74bb7cae64f 100644 --- a/include/linux/serial_8250.h +++ b/include/linux/serial_8250.h @@ -7,6 +7,7 @@ #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> @@ -123,6 +124,8 @@ 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; @@ -174,6 +177,8 @@ void serial8250_init_port(struct uart_8250_port *up); 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) diff --git a/include/linux/signal.h b/include/linux/signal.h index 1a5f88316b081..1870c233799ee 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -255,6 +255,7 @@ static inline void init_sigpending(struct sigpending *sig) } 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) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 6ae88b0c1c31d..e0178d7b775e7 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -293,6 +293,7 @@ struct sk_buff_head { __u32 qlen; spinlock_t lock; + raw_spinlock_t raw_lock; }; struct sk_buff; @@ -1844,6 +1845,12 @@ static inline void skb_queue_head_init(struct sk_buff_head *list) __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) { diff --git a/include/linux/smp.h b/include/linux/smp.h index 6fc856c9eda58..01ff6ed61591f 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -15,6 +15,7 @@ #include <linux/llist.h> typedef void (*smp_call_func_t)(void *info); +typedef bool (*smp_cond_func_t)(int cpu, void *info); struct __call_single_data { struct llist_node llist; smp_call_func_t func; @@ -49,13 +50,11 @@ void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, * cond_func returns a positive value. This may include the local * processor. */ -void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), - smp_call_func_t func, void *info, bool wait, - gfp_t gfp_flags); +void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func, + void *info, bool wait); -void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info), - smp_call_func_t func, void *info, bool wait, - gfp_t gfp_flags, const struct cpumask *mask); +void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func, + void *info, bool wait, const struct cpumask *mask); int smp_call_function_single_async(int cpu, call_single_data_t *csd); @@ -222,6 +221,9 @@ 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: diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 031ce8617df8f..826ddd48e6059 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -307,7 +307,11 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) }) /* Include rwlock functions */ -#include <linux/rwlock.h> +#ifdef CONFIG_PREEMPT_RT +# include <linux/rwlock_rt.h> +#else +# include <linux/rwlock.h> +#endif /* * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: @@ -318,6 +322,10 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) # include <linux/spinlock_api_up.h> #endif +#ifdef CONFIG_PREEMPT_RT +# include <linux/spinlock_rt.h> +#else /* PREEMPT_RT */ + /* * Map the spin_lock functions to the raw variants for PREEMPT_RT=n */ @@ -438,6 +446,8 @@ static __always_inline int spin_is_contended(spinlock_t *lock) #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) +#endif /* !PREEMPT_RT */ + /* * Pull the atomic_t declaration: * (asm-mips/atomic.h needs above definitions) diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h index b762eaba4cdf4..60f593969fe13 100644 --- a/include/linux/spinlock_api_smp.h +++ b/include/linux/spinlock_api_smp.h @@ -187,6 +187,8 @@ static inline int __raw_spin_trylock_bh(raw_spinlock_t *lock) return 0; } -#include <linux/rwlock_api_smp.h> +#ifndef CONFIG_PREEMPT_RT +# include <linux/rwlock_api_smp.h> +#endif #endif /* __LINUX_SPINLOCK_API_SMP_H */ diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h new file mode 100644 index 0000000000000..3696a77fa77d6 --- /dev/null +++ b/include/linux/spinlock_rt.h @@ -0,0 +1,156 @@ +#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 diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h index 24b4e6f2c1a22..8d896d3e1a017 100644 --- a/include/linux/spinlock_types.h +++ b/include/linux/spinlock_types.h @@ -9,77 +9,15 @@ * Released under the General Public License (GPL). */ -#if defined(CONFIG_SMP) -# include <asm/spinlock_types.h> +#include <linux/spinlock_types_raw.h> + +#ifndef CONFIG_PREEMPT_RT +# include <linux/spinlock_types_nort.h> +# include <linux/rwlock_types.h> #else -# include <linux/spinlock_types_up.h> +# include <linux/rtmutex.h> +# include <linux/spinlock_types_rt.h> +# include <linux/rwlock_types_rt.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) - -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 */ diff --git a/include/linux/spinlock_types_nort.h b/include/linux/spinlock_types_nort.h new file mode 100644 index 0000000000000..f1dac1fb1d6ac --- /dev/null +++ b/include/linux/spinlock_types_nort.h @@ -0,0 +1,33 @@ +#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 diff --git a/include/linux/spinlock_types_raw.h b/include/linux/spinlock_types_raw.h new file mode 100644 index 0000000000000..822bf64a61d3b --- /dev/null +++ b/include/linux/spinlock_types_raw.h @@ -0,0 +1,55 @@ +#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 diff --git a/include/linux/spinlock_types_rt.h b/include/linux/spinlock_types_rt.h new file mode 100644 index 0000000000000..3e3d8c5f7a9ad --- /dev/null +++ b/include/linux/spinlock_types_rt.h @@ -0,0 +1,48 @@ +#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 diff --git a/include/linux/spinlock_types_up.h b/include/linux/spinlock_types_up.h index c09b6407ae1b3..b0243ba07fb78 100644 --- a/include/linux/spinlock_types_up.h +++ b/include/linux/spinlock_types_up.h @@ -1,10 +1,6 @@ #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 * diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index f9a0c6189852e..27d32887103dd 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -26,6 +26,8 @@ struct cpu_stop_work { cpu_stop_fn_t fn; void *arg; struct cpu_stop_done *done; + /* Did not run due to disabled stopper; for nowait debug checks */ + bool disabled; }; int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg); diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 6fc8843f1c9e9..dd0c894fb1090 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -197,6 +197,12 @@ 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; diff --git a/include/linux/swait.h b/include/linux/swait.h index 73e06e9986d4b..21ae66cd41d30 100644 --- a/include/linux/swait.h +++ b/include/linux/swait.h @@ -160,7 +160,9 @@ static inline bool swq_has_sleeper(struct swait_queue_head *wq) 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); @@ -297,4 +299,18 @@ 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 */ diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index e93e249a4e9bf..c88b9cecc78aa 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -97,7 +97,17 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag) #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, diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 30a8cdcfd4a4f..f3b1ef07e4a5f 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -62,6 +62,9 @@ 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 \ diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 38555435a64a3..e2777169c5399 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -182,6 +182,7 @@ static __always_inline void pagefault_disabled_dec(void) */ static inline void pagefault_disable(void) { + migrate_disable(); pagefault_disabled_inc(); /* * make sure to have issued the store before a pagefault @@ -198,6 +199,7 @@ static inline void pagefault_enable(void) */ barrier(); pagefault_disabled_dec(); + migrate_enable(); } /* diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index bdeda4b079fe8..dec95902b138c 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -54,7 +54,9 @@ DECLARE_PER_CPU(struct vm_event_state, vm_event_states); */ 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) @@ -64,7 +66,9 @@ static inline void count_vm_event(enum vm_event_item item) 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) diff --git a/include/linux/wait.h b/include/linux/wait.h index 3eb7cae8206c3..1781c47d81f0b 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -10,6 +10,7 @@ #include <asm/current.h> #include <uapi/linux/wait.h> +#include <linux/atomic.h> typedef struct wait_queue_entry wait_queue_entry_t; @@ -20,6 +21,7 @@ int default_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int #define WQ_FLAG_EXCLUSIVE 0x01 #define WQ_FLAG_WOKEN 0x02 #define WQ_FLAG_BOOKMARK 0x04 +#define WQ_FLAG_CUSTOM 0x08 /* * A single wait-queue entry structure: diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h index ca23860adbb95..599572f9dcd1d 100644 --- a/include/net/gen_stats.h +++ b/include/net/gen_stats.h @@ -6,6 +6,7 @@ #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; @@ -36,15 +37,15 @@ int gnet_stats_start_copy_compat(struct sk_buff *skb, int type, 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); @@ -64,13 +65,13 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats, 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); diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 8ec77bfdc1a41..6cdf3a0741974 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -459,7 +459,7 @@ static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) } #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; @@ -502,7 +502,7 @@ static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb static inline int neigh_output(struct neighbour *n, struct sk_buff *skb, bool skip_cache) { - const struct hh_cache *hh = &n->hh; + struct hh_cache *hh = &n->hh; if ((n->nud_state & NUD_CONNECTED) && hh->hh_len && !skip_cache) return neigh_hh_output(hh, skb); @@ -543,7 +543,7 @@ 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; diff --git a/include/net/net_seq_lock.h b/include/net/net_seq_lock.h new file mode 100644 index 0000000000000..67710bace7418 --- /dev/null +++ b/include/net/net_seq_lock.h @@ -0,0 +1,15 @@ +#ifndef __NET_NET_SEQ_LOCK_H__ +#define __NET_NET_SEQ_LOCK_H__ + +#ifdef CONFIG_PREEMPT_RT +# 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 diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index d334e4609dd41..d50ddd90a77bc 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -10,6 +10,7 @@ #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 <linux/mutex.h> @@ -100,7 +101,7 @@ 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; @@ -138,7 +139,11 @@ static inline bool qdisc_is_running(struct Qdisc *qdisc) { if (qdisc->flags & TCQ_F_NOLOCK) return spin_is_locked(&qdisc->seqlock); +#ifdef CONFIG_PREEMPT_RT + return spin_is_locked(&qdisc->running.lock) ? true : false; +#else return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; +#endif } static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) @@ -162,17 +167,27 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc) } else if (qdisc_is_running(qdisc)) { return false; } +#ifdef CONFIG_PREEMPT_RT + 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 + write_sequnlock(&qdisc->running); +#else write_seqcount_end(&qdisc->running); +#endif if (qdisc->flags & TCQ_F_NOLOCK) spin_unlock(&qdisc->seqlock); } @@ -541,7 +556,7 @@ static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 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); diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index d89969aa9942c..095be1d66f31c 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -215,7 +215,7 @@ bool xen_running_on_version_or_later(unsigned int major, unsigned int minor); void xen_efi_runtime_setup(void); -#ifdef CONFIG_PREEMPT +#ifdef CONFIG_PREEMPTION static inline void xen_preemptible_hcall_begin(void) { @@ -239,6 +239,6 @@ static inline void xen_preemptible_hcall_end(void) __this_cpu_write(xen_in_preemptible_hcall, false); } -#endif /* CONFIG_PREEMPT */ +#endif /* CONFIG_PREEMPTION */ #endif /* INCLUDE_XEN_OPS_H */ diff --git a/init/Kconfig b/init/Kconfig index 0328b53d09ad7..c9e5274d3704a 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -924,6 +924,7 @@ config CFS_BANDWIDTH config RT_GROUP_SCHED bool "Group scheduling for SCHED_RR/FIFO" depends on CGROUP_SCHED + depends on !PREEMPT_RT default n help This feature lets you explicitly allocate real CPU bandwidth @@ -1630,6 +1631,7 @@ config KALLSYMS_BASE_RELATIVE # syscall, maps, verifier config BPF_SYSCALL bool "Enable bpf() system call" + depends on !PREEMPT_RT select BPF select IRQ_WORK default n @@ -1805,6 +1807,7 @@ choice config SLAB bool "SLAB" + depends on !PREEMPT_RT select HAVE_HARDENED_USERCOPY_ALLOCATOR help The regular slab allocator that is established and known to work @@ -1825,6 +1828,7 @@ config SLUB config SLOB depends on EXPERT bool "SLOB (Simple Allocator)" + depends on !PREEMPT_RT help SLOB replaces the stock allocator with a drastically simpler allocator. SLOB is generally more space efficient but @@ -1890,7 +1894,7 @@ config SHUFFLE_PAGE_ALLOCATOR config SLUB_CPU_PARTIAL default y - depends on SLUB && SMP + depends on SLUB && SMP && !PREEMPT_RT bool "SLUB per cpu partial cache" help Per cpu partial caches accelerate objects allocation and freeing diff --git a/init/init_task.c b/init/init_task.c index 9e5cbe5eab7b1..1539bfba1bef8 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -73,6 +73,10 @@ struct task_struct init_task .cpus_ptr = &init_task.cpus_mask, .cpus_mask = CPU_MASK_ALL, .nr_cpus_allowed= NR_CPUS, +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT) && \ + defined(CONFIG_SCHED_DEBUG) + .pinned_on_cpu = -1, +#endif .mm = NULL, .active_mm = &init_mm, .restart_block = { diff --git a/init/main.c b/init/main.c index c0206c507eba9..5cbb9fe937e0b 100644 --- a/init/main.c +++ b/init/main.c @@ -694,7 +694,6 @@ asmlinkage __visible void __init start_kernel(void) boot_init_stack_canary(); time_init(); - printk_safe_init(); perf_event_init(); profile_init(); call_function_init(); diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index e0852dc333acd..3de8fd11873b4 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -101,7 +101,7 @@ config UNINLINE_SPIN_UNLOCK # unlock and unlock_irq functions are inlined when: # - DEBUG_SPINLOCK=n and ARCH_INLINE_*LOCK=y # or -# - DEBUG_SPINLOCK=n and PREEMPT=n +# - DEBUG_SPINLOCK=n and PREEMPTION=n # # unlock_bh and unlock_irqrestore functions are inlined when: # - DEBUG_SPINLOCK=n and ARCH_INLINE_*LOCK=y @@ -139,7 +139,7 @@ config INLINE_SPIN_UNLOCK_BH config INLINE_SPIN_UNLOCK_IRQ def_bool y - depends on !PREEMPT || ARCH_INLINE_SPIN_UNLOCK_IRQ + depends on !PREEMPTION || ARCH_INLINE_SPIN_UNLOCK_IRQ config INLINE_SPIN_UNLOCK_IRQRESTORE def_bool y @@ -168,7 +168,7 @@ config INLINE_READ_LOCK_IRQSAVE config INLINE_READ_UNLOCK def_bool y - depends on !PREEMPT || ARCH_INLINE_READ_UNLOCK + depends on !PREEMPTION || ARCH_INLINE_READ_UNLOCK config INLINE_READ_UNLOCK_BH def_bool y @@ -176,7 +176,7 @@ config INLINE_READ_UNLOCK_BH config INLINE_READ_UNLOCK_IRQ def_bool y - depends on !PREEMPT || ARCH_INLINE_READ_UNLOCK_IRQ + depends on !PREEMPTION || ARCH_INLINE_READ_UNLOCK_IRQ config INLINE_READ_UNLOCK_IRQRESTORE def_bool y @@ -205,7 +205,7 @@ config INLINE_WRITE_LOCK_IRQSAVE config INLINE_WRITE_UNLOCK def_bool y - depends on !PREEMPT || ARCH_INLINE_WRITE_UNLOCK + depends on !PREEMPTION || ARCH_INLINE_WRITE_UNLOCK config INLINE_WRITE_UNLOCK_BH def_bool y @@ -213,7 +213,7 @@ config INLINE_WRITE_UNLOCK_BH config INLINE_WRITE_UNLOCK_IRQ def_bool y - depends on !PREEMPT || ARCH_INLINE_WRITE_UNLOCK_IRQ + depends on !PREEMPTION || ARCH_INLINE_WRITE_UNLOCK_IRQ config INLINE_WRITE_UNLOCK_IRQRESTORE def_bool y diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index deff972174967..7871ec3c9a02a 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -1,5 +1,11 @@ # SPDX-License-Identifier: GPL-2.0-only +config HAVE_PREEMPT_LAZY + bool + +config PREEMPT_LAZY + def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT + choice prompt "Preemption Model" default PREEMPT_NONE diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index ef4242e5d4bc6..82061b4f3ebcb 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1957,7 +1957,6 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) cgrp->dom_cgrp = cgrp; cgrp->max_descendants = INT_MAX; cgrp->max_depth = INT_MAX; - INIT_LIST_HEAD(&cgrp->rstat_css_list); prev_cputime_init(&cgrp->prev_cputime); for_each_subsys(ss, ssid) @@ -5013,12 +5012,6 @@ static void css_release_work_fn(struct work_struct *work) list_del_rcu(&css->sibling); if (ss) { - /* css release path */ - if (!list_empty(&css->rstat_css_node)) { - cgroup_rstat_flush(cgrp); - list_del_rcu(&css->rstat_css_node); - } - cgroup_idr_replace(&ss->css_idr, NULL, css->id); if (ss->css_released) ss->css_released(css); @@ -5080,7 +5073,6 @@ static void init_and_link_css(struct cgroup_subsys_state *css, css->id = -1; INIT_LIST_HEAD(&css->sibling); INIT_LIST_HEAD(&css->children); - INIT_LIST_HEAD(&css->rstat_css_node); css->serial_nr = css_serial_nr_next++; atomic_set(&css->online_cnt, 0); @@ -5089,9 +5081,6 @@ static void init_and_link_css(struct cgroup_subsys_state *css, css_get(css->parent); } - if (cgroup_on_dfl(cgrp) && ss->css_rstat_flush) - list_add_rcu(&css->rstat_css_node, &cgrp->rstat_css_list); - BUG_ON(cgroup_css(cgrp, ss)); } @@ -5193,7 +5182,6 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, err_list_del: list_del_rcu(&css->sibling); err_free_css: - list_del_rcu(&css->rstat_css_node); INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn); queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork); return ERR_PTR(err); diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index c87ee6412b36a..680034721002b 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -345,7 +345,7 @@ void cpuset_read_unlock(void) percpu_up_read(&cpuset_rwsem); } -static DEFINE_SPINLOCK(callback_lock); +static DEFINE_RAW_SPINLOCK(callback_lock); static struct workqueue_struct *cpuset_migrate_mm_wq; @@ -1255,7 +1255,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, * 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); @@ -1274,7 +1274,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, } parent->nr_subparts_cpus = cpumask_weight(parent->subparts_cpus); - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); return cmd == partcmd_update; } @@ -1379,7 +1379,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp) 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 && @@ -1410,7 +1410,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp) = 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)); @@ -1528,7 +1528,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, return -EINVAL; } - spin_lock_irq(&callback_lock); + raw_spin_lock_irq(&callback_lock); cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed); /* @@ -1539,7 +1539,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, 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); @@ -1733,9 +1733,9 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems) 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)); @@ -1803,9 +1803,9 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs, 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); @@ -1896,9 +1896,9 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, 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(); @@ -2407,7 +2407,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v) 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: @@ -2429,7 +2429,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v) ret = -EINVAL; } - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); return ret; } @@ -2742,14 +2742,14 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) 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; @@ -2776,12 +2776,12 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) } 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: percpu_up_write(&cpuset_rwsem); put_online_cpus(); @@ -2837,7 +2837,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css) static void cpuset_bind(struct cgroup_subsys_state *root_css) { percpu_down_write(&cpuset_rwsem); - 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); @@ -2848,7 +2848,7 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css) top_cpuset.mems_allowed = top_cpuset.effective_mems; } - spin_unlock_irq(&callback_lock); + raw_spin_unlock_irq(&callback_lock); percpu_up_write(&cpuset_rwsem); } @@ -2945,12 +2945,12 @@ hotplug_update_tasks_legacy(struct cpuset *cs, { 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, @@ -2987,10 +2987,10 @@ 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); @@ -3145,7 +3145,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) /* 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); /* @@ -3165,17 +3165,17 @@ static void cpuset_hotplug_workfn(struct work_struct *work) } } 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); } @@ -3276,11 +3276,11 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) { 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); } /** @@ -3341,11 +3341,11 @@ nodemask_t cpuset_mems_allowed(struct task_struct *tsk) 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; } @@ -3437,14 +3437,14 @@ bool __cpuset_node_allowed(int node, gfp_t gfp_mask) 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; } diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index ca19b4c8acf53..a59962e66aea1 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -149,7 +149,7 @@ static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos, } /* see cgroup_rstat_flush() */ -static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep) +static void cgroup_rstat_flush_locked(struct cgroup *cgrp) __releases(&cgroup_rstat_lock) __acquires(&cgroup_rstat_lock) { int cpu; @@ -161,27 +161,17 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep) cpu); struct cgroup *pos = NULL; - raw_spin_lock(cpu_lock); - while ((pos = cgroup_rstat_cpu_pop_updated(pos, cgrp, cpu))) { - struct cgroup_subsys_state *css; - + raw_spin_lock_irq(cpu_lock); + while ((pos = cgroup_rstat_cpu_pop_updated(pos, cgrp, cpu))) cgroup_base_stat_flush(pos, cpu); - rcu_read_lock(); - list_for_each_entry_rcu(css, &pos->rstat_css_list, - rstat_css_node) - css->ss->css_rstat_flush(css, cpu); - rcu_read_unlock(); - } - raw_spin_unlock(cpu_lock); + raw_spin_unlock_irq(cpu_lock); - /* if @may_sleep, play nice and yield if necessary */ - if (may_sleep && (need_resched() || - spin_needbreak(&cgroup_rstat_lock))) { - spin_unlock_irq(&cgroup_rstat_lock); + if (need_resched() || spin_needbreak(&cgroup_rstat_lock)) { + spin_unlock(&cgroup_rstat_lock); if (!cond_resched()) cpu_relax(); - spin_lock_irq(&cgroup_rstat_lock); + spin_lock(&cgroup_rstat_lock); } } } @@ -203,24 +193,9 @@ void cgroup_rstat_flush(struct cgroup *cgrp) { might_sleep(); - spin_lock_irq(&cgroup_rstat_lock); - cgroup_rstat_flush_locked(cgrp, true); - spin_unlock_irq(&cgroup_rstat_lock); -} - -/** - * cgroup_rstat_flush_irqsafe - irqsafe version of cgroup_rstat_flush() - * @cgrp: target cgroup - * - * This function can be called from any context. - */ -void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp) -{ - unsigned long flags; - - spin_lock_irqsave(&cgroup_rstat_lock, flags); - cgroup_rstat_flush_locked(cgrp, false); - spin_unlock_irqrestore(&cgroup_rstat_lock, flags); + spin_lock(&cgroup_rstat_lock); + cgroup_rstat_flush_locked(cgrp); + spin_unlock(&cgroup_rstat_lock); } /** @@ -232,21 +207,21 @@ void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp) * * This function may block. */ -void cgroup_rstat_flush_hold(struct cgroup *cgrp) +static void cgroup_rstat_flush_hold(struct cgroup *cgrp) __acquires(&cgroup_rstat_lock) { might_sleep(); - spin_lock_irq(&cgroup_rstat_lock); - cgroup_rstat_flush_locked(cgrp, true); + spin_lock(&cgroup_rstat_lock); + cgroup_rstat_flush_locked(cgrp); } /** * cgroup_rstat_flush_release - release cgroup_rstat_flush_hold() */ -void cgroup_rstat_flush_release(void) +static void cgroup_rstat_flush_release(void) __releases(&cgroup_rstat_lock) { - spin_unlock_irq(&cgroup_rstat_lock); + spin_unlock(&cgroup_rstat_lock); } int cgroup_rstat_init(struct cgroup *cgrp) diff --git a/kernel/cpu.c b/kernel/cpu.c index 116825437cd61..368309e9a1f52 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -331,12 +331,12 @@ void lockdep_assert_cpus_held(void) static void lockdep_acquire_cpus_lock(void) { - rwsem_acquire(&cpu_hotplug_lock.rw_sem.dep_map, 0, 0, _THIS_IP_); + rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_); } static void lockdep_release_cpus_lock(void) { - rwsem_release(&cpu_hotplug_lock.rw_sem.dep_map, 1, _THIS_IP_); + rwsem_release(&cpu_hotplug_lock.dep_map, 1, _THIS_IP_); } /* @@ -849,6 +849,15 @@ static int take_cpu_down(void *_param) int err, cpu = smp_processor_id(); int ret; +#ifdef CONFIG_PREEMPT_RT + /* + * If any tasks disabled migration before we got here, + * go back and sleep again. + */ + if (cpu_nr_pinned(cpu)) + return -EAGAIN; +#endif + /* Ensure this CPU doesn't handle any more interrupts. */ err = __cpu_disable(); if (err < 0) @@ -878,6 +887,10 @@ static int take_cpu_down(void *_param) return 0; } +#ifdef CONFIG_PREEMPT_RT +struct task_struct *takedown_cpu_task; +#endif + static int takedown_cpu(unsigned int cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); @@ -892,11 +905,39 @@ static int takedown_cpu(unsigned int cpu) */ irq_lock_sparse(); +#ifdef CONFIG_PREEMPT_RT + WARN_ON_ONCE(takedown_cpu_task); + takedown_cpu_task = current; + +again: + /* + * If a task pins this CPU after we pass this check, take_cpu_down + * will return -EAGAIN. + */ + for (;;) { + int nr_pinned; + + set_current_state(TASK_UNINTERRUPTIBLE); + nr_pinned = cpu_nr_pinned(cpu); + if (nr_pinned == 0) + break; + schedule(); + } + set_current_state(TASK_RUNNING); +#endif + /* * So now all preempt/rcu users must observe !cpu_active(). */ err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu)); +#ifdef CONFIG_PREEMPT_RT + if (err == -EAGAIN) + goto again; +#endif if (err) { +#ifdef CONFIG_PREEMPT_RT + takedown_cpu_task = NULL; +#endif /* CPU refused to die */ irq_unlock_sparse(); /* Unpark the hotplug thread so we can rollback there */ @@ -915,6 +956,9 @@ 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 + takedown_cpu_task = NULL; +#endif /* Interrupts are moved away from the dying cpu, reenable alloc/free */ irq_unlock_sparse(); diff --git a/kernel/events/core.c b/kernel/events/core.c index 6c829e22bad35..16bd0c08aa2af 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10256,7 +10256,7 @@ static struct pmu *perf_init_event(struct perf_event *event) goto unlock; } - list_for_each_entry_rcu(pmu, &pmus, entry) { + list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) { ret = perf_try_init_event(pmu, event); if (!ret) goto unlock; diff --git a/kernel/exit.c b/kernel/exit.c index 22dfaac9e48c5..dcb1f1182101e 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -161,7 +161,7 @@ static void __exit_signal(struct task_struct *tsk) * 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); @@ -258,6 +258,7 @@ void rcuwait_wake_up(struct rcuwait *w) wake_up_process(task); rcu_read_unlock(); } +EXPORT_SYMBOL_GPL(rcuwait_wake_up); /* * Determine if a process group is "orphaned", according to the POSIX diff --git a/kernel/fork.c b/kernel/fork.c index 755d8160e0012..44e95c5207a46 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -43,6 +43,7 @@ #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> @@ -289,7 +290,7 @@ static inline void free_thread_stack(struct task_struct *tsk) return; } - vfree_atomic(tsk->stack); + vfree(tsk->stack); return; } #endif @@ -696,6 +697,19 @@ void __mmdrop(struct mm_struct *mm) } EXPORT_SYMBOL_GPL(__mmdrop); +#ifdef CONFIG_PREEMPT_RT +/* + * 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; @@ -737,6 +751,15 @@ void __put_task_struct(struct task_struct *tsk) WARN_ON(refcount_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, true); security_task_free(tsk); @@ -927,6 +950,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) 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); @@ -1900,6 +1924,7 @@ static __latent_entropy struct task_struct *copy_process( 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 diff --git a/kernel/futex.c b/kernel/futex.c index afbf928d6a6b0..58c0c77fda797 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -945,7 +945,9 @@ static void exit_pi_state_list(struct task_struct *curr) if (head->next != next) { /* retain curr->pi_lock for the loop invariant */ raw_spin_unlock(&pi_state->pi_mutex.wait_lock); + raw_spin_unlock_irq(&curr->pi_lock); spin_unlock(&hb->lock); + raw_spin_lock_irq(&curr->pi_lock); put_pi_state(pi_state); continue; } @@ -1554,6 +1556,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ 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); @@ -1613,13 +1616,13 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ 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; } @@ -2243,6 +2246,16 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, requeue_pi_wake_futex(this, &key2, hb2); drop_count++; continue; + } else if (ret == -EAGAIN) { + /* + * Waiter was woken by timeout or + * signal and has set pi_blocked_on to + * PI_WAKEUP_INPROGRESS before we + * tried to enqueue it on the rtmutex. + */ + this->pi_state = NULL; + put_pi_state(pi_state); + continue; } else if (ret) { /* * rt_mutex_start_proxy_lock() detected a @@ -2951,7 +2964,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, 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 @@ -2967,6 +2980,14 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, * before __rt_mutex_start_proxy_lock() is done. */ raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock); + /* + * the migrate_disable() here disables migration in the in_atomic() fast + * path which is enabled again in the following spin_unlock(). We have + * one migrate_disable() pending in the slow-path which is reversed + * after the raw_spin_unlock_irq() where we leave the atomic context. + */ + migrate_disable(); + spin_unlock(q.lock_ptr); /* * __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter @@ -2975,6 +2996,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, */ ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current); raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock); + migrate_enable(); if (ret) { if (ret == 1) @@ -3123,10 +3145,19 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) * rt_waiter. Also see the WARN in wake_futex_pi(). */ raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); + /* + * Magic trickery for now to make the RT migrate disable + * logic happy. The following spin_unlock() happens with + * interrupts disabled so the internal migrate_enable() + * won't undo the migrate_disable() which was issued when + * locking hb->lock. + */ + migrate_disable(); spin_unlock(&hb->lock); /* drops pi_state->pi_mutex.wait_lock */ ret = wake_futex_pi(uaddr, uval, pi_state); + migrate_enable(); put_pi_state(pi_state); @@ -3298,7 +3329,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, struct hrtimer_sleeper timeout, *to; struct futex_pi_state *pi_state = NULL; struct rt_mutex_waiter rt_waiter; - struct futex_hash_bucket *hb; + struct futex_hash_bucket *hb, *hb2; union futex_key key2 = FUTEX_KEY_INIT; struct futex_q q = futex_q_init; int res, ret; @@ -3319,7 +3350,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * 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)) @@ -3350,20 +3381,55 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, /* Queue the futex_q, drop the hb lock, wait for wakeup. */ futex_wait_queue_me(hb, &q, to); - spin_lock(&hb->lock); - ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); - spin_unlock(&hb->lock); - if (ret) - goto out_put_keys; + /* + * On RT we must avoid races with requeue and trying to block + * on two mutexes (hb->lock and uaddr2's rtmutex) by + * serializing access to pi_blocked_on with pi_lock. + */ + raw_spin_lock_irq(¤t->pi_lock); + if (current->pi_blocked_on) { + /* + * We have been requeued or are in the process of + * being requeued. + */ + raw_spin_unlock_irq(¤t->pi_lock); + } else { + /* + * Setting pi_blocked_on to PI_WAKEUP_INPROGRESS + * prevents a concurrent requeue from moving us to the + * uaddr2 rtmutex. After that we can safely acquire + * (and possibly block on) hb->lock. + */ + current->pi_blocked_on = PI_WAKEUP_INPROGRESS; + raw_spin_unlock_irq(¤t->pi_lock); + + spin_lock(&hb->lock); + + /* + * Clean up pi_blocked_on. We might leak it otherwise + * when we succeeded with the hb->lock in the fast + * path. + */ + raw_spin_lock_irq(¤t->pi_lock); + current->pi_blocked_on = NULL; + raw_spin_unlock_irq(¤t->pi_lock); + + ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); + spin_unlock(&hb->lock); + if (ret) + goto out_put_keys; + } /* - * In order for us to be here, we know our q.key == key2, and since - * we took the hb->lock above, we also know that futex_requeue() has - * completed and we no longer have to concern ourselves with a wakeup - * race with the atomic proxy lock acquisition by the requeue code. The - * futex_requeue dropped our key1 reference and incremented our key2 - * reference count. + * In order to be here, we have either been requeued, are in + * the process of being requeued, or requeue successfully + * acquired uaddr2 on our behalf. If pi_blocked_on was + * non-null above, we may be racing with a requeue. Do not + * rely on q->lock_ptr to be hb2->lock until after blocking on + * hb->lock or hb2->lock. The futex_requeue dropped our key1 + * reference and incremented our key2 reference count. */ + hb2 = hash_futex(&key2); /* Check if the requeue code acquired the second futex for us. */ if (!q.rt_waiter) { @@ -3372,7 +3438,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * 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); + spin_lock(&hb2->lock); + BUG_ON(&hb2->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; @@ -3383,7 +3450,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * the requeue_pi() code acquired for us. */ put_pi_state(q.pi_state); - spin_unlock(q.lock_ptr); + spin_unlock(&hb2->lock); } } else { struct rt_mutex *pi_mutex; @@ -3397,7 +3464,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, pi_mutex = &q.pi_state->pi_mutex; ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter); - spin_lock(q.lock_ptr); + spin_lock(&hb2->lock); + BUG_ON(&hb2->lock != q.lock_ptr); if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter)) ret = 0; diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index a4ace611f47fe..3306fabed2217 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -185,10 +185,16 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc) { 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 + desc->random_ip = ip; +#else + add_interrupt_randomness(desc->irq_data.irq, flags, ip); +#endif if (!noirqdebug) note_interrupt(desc, retval); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 1753486b440cb..665a1dd59e5fc 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1099,6 +1099,12 @@ static int irq_thread(void *data) if (action_ret == IRQ_WAKE_THREAD) irq_wake_secondary(desc, action); +#ifdef CONFIG_PREEMPT_RT + migrate_disable(); + add_interrupt_randomness(action->irq, 0, + desc->random_ip ^ (unsigned long) action); + migrate_enable(); +#endif wake_threads_waitq(desc); } @@ -2681,7 +2687,7 @@ 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, diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 2ed97a7c9b2a6..9e97124946a6a 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -442,6 +442,10 @@ MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true"); static int __init irqfixup_setup(char *str) { +#ifdef CONFIG_PREEMPT_RT + pr_warn("irqfixup boot option not supported w/ CONFIG_PREEMPT_RT\n"); + return 1; +#endif irqfixup = 1; printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); printk(KERN_WARNING "This may impact system performance.\n"); @@ -454,6 +458,10 @@ module_param(irqfixup, int, 0644); static int __init irqpoll_setup(char *str) { +#ifdef CONFIG_PREEMPT_RT + pr_warn("irqpoll boot option not supported w/ CONFIG_PREEMPT_RT\n"); + return 1; +#endif irqfixup = 2; printk(KERN_WARNING "Misrouted IRQ fixup and polling support " "enabled\n"); diff --git a/kernel/irq_work.c b/kernel/irq_work.c index d42acaf818861..aab68fdbcb8d2 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -18,6 +18,7 @@ #include <linux/cpu.h> #include <linux/notifier.h> #include <linux/smp.h> +#include <linux/interrupt.h> #include <asm/processor.h> @@ -60,13 +61,19 @@ 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); + + 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(); } } @@ -108,9 +115,16 @@ bool irq_work_queue_on(struct irq_work *work, int cpu) 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) && !(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); @@ -129,9 +143,8 @@ 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())); @@ -145,8 +158,12 @@ static void irq_work_run_list(struct llist_head *list) struct llist_node *llnode; unsigned long flags; +#ifndef CONFIG_PREEMPT_RT + /* + * nort: On RT IRQ-work may run in SOFTIRQ context. + */ BUG_ON(!irqs_disabled()); - +#endif if (llist_empty(list)) return; @@ -178,7 +195,16 @@ static void irq_work_run_list(struct llist_head *list) 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)) { + /* + * 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); @@ -188,8 +214,17 @@ 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)) + irq_work_run_list(this_cpu_ptr(&lazy_list)); +} + +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT) +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 diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 15d70a90b50dc..e7cef4e2e01f9 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -972,7 +972,6 @@ 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); /* diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 35859da8bd4f7..dfff31ed644a6 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -138,6 +138,15 @@ KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_CRASH_CORE */ +#if defined(CONFIG_PREEMPT_RT) +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) @@ -228,6 +237,9 @@ static struct attribute * kernel_attrs[] = { #ifndef CONFIG_TINY_RCU &rcu_expedited_attr.attr, &rcu_normal_attr.attr, +#endif +#ifdef CONFIG_PREEMPT_RT + &realtime_attr.attr, #endif NULL }; diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index 45452facff3b4..fa253e0db7515 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile @@ -3,7 +3,7 @@ # 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 rwsem.o percpu-rwsem.o ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE) @@ -12,19 +12,23 @@ CFLAGS_REMOVE_mutex-debug.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_rtmutex-debug.o = $(CC_FLAGS_FTRACE) endif -obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o obj-$(CONFIG_LOCKDEP) += lockdep.o ifeq ($(CONFIG_PROC_FS),y) obj-$(CONFIG_LOCKDEP) += lockdep_proc.o endif obj-$(CONFIG_SMP) += spinlock.o -obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o obj-$(CONFIG_QUEUED_SPINLOCKS) += qspinlock.o obj-$(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),y) +obj-y += mutex.o +obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o +obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o +endif +obj-$(CONFIG_PREEMPT_RT) += mutex-rt.o rwsem-rt.o rwlock-rt.o obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o obj-$(CONFIG_WW_MUTEX_SELFTEST) += test-ww_mutex.o diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 35d3b6925b1ee..eed015cf5fc4a 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -4409,6 +4409,7 @@ static void check_flags(unsigned long flags) } } +#ifndef CONFIG_PREEMPT_RT /* * We dont accurately track softirq state in e.g. * hardirq contexts (such as on 4KSTACKS), so only @@ -4423,6 +4424,7 @@ static void check_flags(unsigned long flags) DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled); } } +#endif if (!debug_locks) print_irqtrace_events(current); diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index c513031cd7e33..9fb042d610d23 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -16,7 +16,6 @@ #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> diff --git a/kernel/locking/mutex-rt.c b/kernel/locking/mutex-rt.c new file mode 100644 index 0000000000000..4f81595c0f521 --- /dev/null +++ b/kernel/locking/mutex-rt.c @@ -0,0 +1,223 @@ +/* + * 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); diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c index 364d38a0c4441..e4a4a56037bb2 100644 --- a/kernel/locking/percpu-rwsem.c +++ b/kernel/locking/percpu-rwsem.c @@ -1,27 +1,29 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/atomic.h> -#include <linux/rwsem.h> #include <linux/percpu.h> +#include <linux/wait.h> #include <linux/lockdep.h> #include <linux/percpu-rwsem.h> #include <linux/rcupdate.h> #include <linux/sched.h> +#include <linux/sched/task.h> #include <linux/errno.h> -#include "rwsem.h" - int __percpu_init_rwsem(struct percpu_rw_semaphore *sem, - const char *name, struct lock_class_key *rwsem_key) + const char *name, struct lock_class_key *key) { sem->read_count = alloc_percpu(int); if (unlikely(!sem->read_count)) return -ENOMEM; - /* ->rw_sem represents the whole percpu_rw_semaphore for lockdep */ rcu_sync_init(&sem->rss); - __init_rwsem(&sem->rw_sem, name, rwsem_key); rcuwait_init(&sem->writer); - sem->readers_block = 0; + init_waitqueue_head(&sem->waiters); + atomic_set(&sem->block, 0); +#ifdef CONFIG_DEBUG_LOCK_ALLOC + debug_check_no_locks_freed((void *)sem, sizeof(*sem)); + lockdep_init_map(&sem->dep_map, name, key, 0); +#endif return 0; } EXPORT_SYMBOL_GPL(__percpu_init_rwsem); @@ -41,73 +43,139 @@ void percpu_free_rwsem(struct percpu_rw_semaphore *sem) } EXPORT_SYMBOL_GPL(percpu_free_rwsem); -int __percpu_down_read(struct percpu_rw_semaphore *sem, int try) +static bool __percpu_down_read_trylock(struct percpu_rw_semaphore *sem) { + __this_cpu_inc(*sem->read_count); + /* * Due to having preemption disabled the decrement happens on * the same CPU as the increment, avoiding the * increment-on-one-CPU-and-decrement-on-another problem. * - * If the reader misses the writer's assignment of readers_block, then - * the writer is guaranteed to see the reader's increment. + * If the reader misses the writer's assignment of sem->block, then the + * writer is guaranteed to see the reader's increment. * * Conversely, any readers that increment their sem->read_count after - * the writer looks are guaranteed to see the readers_block value, - * which in turn means that they are guaranteed to immediately - * decrement their sem->read_count, so that it doesn't matter that the - * writer missed them. + * the writer looks are guaranteed to see the sem->block value, which + * in turn means that they are guaranteed to immediately decrement + * their sem->read_count, so that it doesn't matter that the writer + * missed them. */ smp_mb(); /* A matches D */ /* - * If !readers_block the critical section starts here, matched by the + * If !sem->block the critical section starts here, matched by the * release in percpu_up_write(). */ - if (likely(!smp_load_acquire(&sem->readers_block))) - return 1; + if (likely(!atomic_read_acquire(&sem->block))) + return true; - /* - * Per the above comment; we still have preemption disabled and - * will thus decrement on the same CPU as we incremented. - */ - __percpu_up_read(sem); - - if (try) - return 0; - - /* - * We either call schedule() in the wait, or we'll fall through - * and reschedule on the preempt_enable() in percpu_down_read(). - */ - preempt_enable_no_resched(); - - /* - * Avoid lockdep for the down/up_read() we already have them. - */ - __down_read(&sem->rw_sem); - this_cpu_inc(*sem->read_count); - __up_read(&sem->rw_sem); - - preempt_disable(); - return 1; -} -EXPORT_SYMBOL_GPL(__percpu_down_read); - -void __percpu_up_read(struct percpu_rw_semaphore *sem) -{ - smp_mb(); /* B matches C */ - /* - * In other words, if they see our decrement (presumably to aggregate - * zero, as that is the only time it matters) they will also see our - * critical section. - */ __this_cpu_dec(*sem->read_count); - /* Prod writer to recheck readers_active */ + /* Prod writer to re-evaluate readers_active_check() */ rcuwait_wake_up(&sem->writer); + + return false; } -EXPORT_SYMBOL_GPL(__percpu_up_read); + +static inline bool __percpu_down_write_trylock(struct percpu_rw_semaphore *sem) +{ + if (atomic_read(&sem->block)) + return false; + + return atomic_xchg(&sem->block, 1) == 0; +} + +static bool __percpu_rwsem_trylock(struct percpu_rw_semaphore *sem, bool reader) +{ + if (reader) { + bool ret; + + preempt_disable(); + ret = __percpu_down_read_trylock(sem); + preempt_enable(); + + return ret; + } + return __percpu_down_write_trylock(sem); +} + +/* + * The return value of wait_queue_entry::func means: + * + * <0 - error, wakeup is terminated and the error is returned + * 0 - no wakeup, a next waiter is tried + * >0 - woken, if EXCLUSIVE, counted towards @nr_exclusive. + * + * We use EXCLUSIVE for both readers and writers to preserve FIFO order, + * and play games with the return value to allow waking multiple readers. + * + * Specifically, we wake readers until we've woken a single writer, or until a + * trylock fails. + */ +static int percpu_rwsem_wake_function(struct wait_queue_entry *wq_entry, + unsigned int mode, int wake_flags, + void *key) +{ + struct task_struct *p = get_task_struct(wq_entry->private); + bool reader = wq_entry->flags & WQ_FLAG_CUSTOM; + struct percpu_rw_semaphore *sem = key; + + /* concurrent against percpu_down_write(), can get stolen */ + if (!__percpu_rwsem_trylock(sem, reader)) + return 1; + + list_del_init(&wq_entry->entry); + smp_store_release(&wq_entry->private, NULL); + + wake_up_process(p); + put_task_struct(p); + + return !reader; /* wake (readers until) 1 writer */ +} + +static void percpu_rwsem_wait(struct percpu_rw_semaphore *sem, bool reader) +{ + DEFINE_WAIT_FUNC(wq_entry, percpu_rwsem_wake_function); + bool wait; + + spin_lock_irq(&sem->waiters.lock); + /* + * Serialize against the wakeup in percpu_up_write(), if we fail + * the trylock, the wakeup must see us on the list. + */ + wait = !__percpu_rwsem_trylock(sem, reader); + if (wait) { + wq_entry.flags |= WQ_FLAG_EXCLUSIVE | reader * WQ_FLAG_CUSTOM; + __add_wait_queue_entry_tail(&sem->waiters, &wq_entry); + } + spin_unlock_irq(&sem->waiters.lock); + + while (wait) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (!smp_load_acquire(&wq_entry.private)) + break; + schedule(); + } + __set_current_state(TASK_RUNNING); +} + +bool __percpu_down_read(struct percpu_rw_semaphore *sem, bool try) +{ + if (__percpu_down_read_trylock(sem)) + return true; + + if (try) + return false; + + preempt_enable(); + percpu_rwsem_wait(sem, /* .reader = */ true); + preempt_disable(); + + return true; +} +EXPORT_SYMBOL_GPL(__percpu_down_read); #define per_cpu_sum(var) \ ({ \ @@ -124,6 +192,8 @@ EXPORT_SYMBOL_GPL(__percpu_up_read); * zero. If this sum is zero, then it is stable due to the fact that if any * newly arriving readers increment a given counter, they will immediately * decrement that same counter. + * + * Assumes sem->block is set. */ static bool readers_active_check(struct percpu_rw_semaphore *sem) { @@ -142,32 +212,36 @@ static bool readers_active_check(struct percpu_rw_semaphore *sem) void percpu_down_write(struct percpu_rw_semaphore *sem) { + might_sleep(); + rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); + /* Notify readers to take the slow path. */ rcu_sync_enter(&sem->rss); - down_write(&sem->rw_sem); + /* + * Try set sem->block; this provides writer-writer exclusion. + * Having sem->block set makes new readers block. + */ + if (!__percpu_down_write_trylock(sem)) + percpu_rwsem_wait(sem, /* .reader = */ false); + + /* smp_mb() implied by __percpu_down_write_trylock() on success -- D matches A */ /* - * Notify new readers to block; up until now, and thus throughout the - * longish rcu_sync_enter() above, new readers could still come in. - */ - WRITE_ONCE(sem->readers_block, 1); - - smp_mb(); /* D matches A */ - - /* - * If they don't see our writer of readers_block, then we are - * guaranteed to see their sem->read_count increment, and therefore - * will wait for them. + * If they don't see our store of sem->block, then we are guaranteed to + * see their sem->read_count increment, and therefore will wait for + * them. */ - /* Wait for all now active readers to complete. */ + /* Wait for all active readers to complete. */ rcuwait_wait_event(&sem->writer, readers_active_check(sem)); } EXPORT_SYMBOL_GPL(percpu_down_write); void percpu_up_write(struct percpu_rw_semaphore *sem) { + rwsem_release(&sem->dep_map, 1, _RET_IP_); + /* * Signal the writer is done, no fast path yet. * @@ -178,12 +252,12 @@ void percpu_up_write(struct percpu_rw_semaphore *sem) * Therefore we force it through the slow path which guarantees an * acquire and thereby guarantees the critical section's consistency. */ - smp_store_release(&sem->readers_block, 0); + atomic_set_release(&sem->block, 0); /* - * Release the write lock, this will allow readers back in the game. + * Prod any pending reader/writer to make progress. */ - up_write(&sem->rw_sem); + __wake_up(&sem->waiters, TASK_NORMAL, 1, sem); /* * Once this completes (at least one RCU-sched grace period hence) the diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 2874bf5561620..602eb7821a1b1 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -8,6 +8,11 @@ * 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.rst for details. */ @@ -19,6 +24,8 @@ #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" @@ -136,6 +143,12 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock) WRITE_ONCE(*p, owner & ~RT_MUTEX_HAS_WAITERS); } +static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter) +{ + return waiter && waiter != PI_WAKEUP_INPROGRESS && + waiter != PI_REQUEUE_INPROGRESS; +} + /* * We can speed up the acquire/release, if there's no debugging state to be * set up. @@ -229,7 +242,7 @@ static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, * 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, @@ -269,6 +282,27 @@ rt_mutex_waiter_equal(struct rt_mutex_waiter *left, 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) { @@ -373,6 +407,14 @@ static bool rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter, 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: */ @@ -380,7 +422,8 @@ int max_lock_depth = 1024; static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p) { - return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL; + return rt_mutex_real_waiter(p->pi_blocked_on) ? + p->pi_blocked_on->lock : NULL; } /* @@ -516,7 +559,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, * reached or the state of the chain has changed while we * dropped the locks. */ - if (!waiter) + if (!rt_mutex_real_waiter(waiter)) goto out_unlock_pi; /* @@ -696,13 +739,16 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, * 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; } @@ -803,9 +849,11 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, * @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); @@ -841,12 +889,11 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, */ 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. @@ -864,14 +911,12 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, */ 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 @@ -918,6 +963,344 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, return 1; } +#ifdef CONFIG_PREEMPT_RT +/* + * 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(); + rcu_read_lock(); + 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(); + rcu_read_lock(); + 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(); + rcu_read_unlock(); + 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_); + rcu_read_lock(); + } 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(); + rcu_read_lock(); + 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(); + rcu_read_lock(); + 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 */ + +#ifdef CONFIG_PREEMPT_RT + 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. * @@ -950,6 +1333,22 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, return -EDEADLK; raw_spin_lock(&task->pi_lock); + /* + * In the case of futex requeue PI, this will be a proxy + * lock. The task will wake unaware that it is enqueueed on + * this lock. Avoid blocking on two locks and corrupting + * pi_blocked_on via the PI_WAKEUP_INPROGRESS + * flag. futex_wait_requeue_pi() sets this when it wakes up + * before requeue (due to a signal or timeout). Do not enqueue + * the task if PI_WAKEUP_INPROGRESS is set. + */ + if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) { + raw_spin_unlock(&task->pi_lock); + return -EAGAIN; + } + + BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on)); + waiter->task = task; waiter->lock = lock; waiter->prio = task->prio; @@ -973,7 +1372,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, rt_mutex_enqueue_pi(owner, waiter); rt_mutex_adjust_prio(owner); - if (owner->pi_blocked_on) + if (rt_mutex_real_waiter(owner->pi_blocked_on)) chain_walk = 1; } else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) { chain_walk = 1; @@ -1015,6 +1414,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, * 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; @@ -1054,7 +1454,10 @@ static void mark_wakeup_next_waiter(struct wake_q_head *wake_q, * 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); } @@ -1069,7 +1472,7 @@ static void remove_waiter(struct rt_mutex *lock, { bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); - struct rt_mutex *next_lock; + struct rt_mutex *next_lock = NULL; lockdep_assert_held(&lock->wait_lock); @@ -1095,7 +1498,8 @@ static void remove_waiter(struct rt_mutex *lock, rt_mutex_adjust_prio(owner); /* Store the lock on which owner is blocked or NULL */ - next_lock = task_blocked_on_lock(owner); + if (rt_mutex_real_waiter(owner->pi_blocked_on)) + next_lock = task_blocked_on_lock(owner); raw_spin_unlock(&owner->pi_lock); @@ -1131,26 +1535,28 @@ void rt_mutex_adjust_pi(struct task_struct *task) raw_spin_lock_irqsave(&task->pi_lock, flags); waiter = task->pi_blocked_on; - if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { + if (!rt_mutex_real_waiter(waiter) || + rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { raw_spin_unlock_irqrestore(&task->pi_lock, flags); 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; } /** @@ -1166,7 +1572,8 @@ void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) 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; @@ -1175,16 +1582,17 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state, 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; } @@ -1223,19 +1631,157 @@ static void rt_mutex_handle_deadlock(int res, int detect_deadlock, } } +static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww, + struct ww_acquire_ctx *ww_ctx) +{ +#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); + + 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; + } + + /* + * Naughty, using a different class will lead to undefined behavior! + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class); +#endif + ww_ctx->acquired++; +} + +#ifdef CONFIG_PREEMPT_RT +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 + 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)) { + if (ww_ctx) + ww_mutex_account_lock(lock, ww_ctx); + return 0; + } + + set_current_state(state); + + /* Setup the timer, when timeout != NULL */ + if (unlikely(timeout)) + hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); + + ret = task_blocks_on_rt_mutex(lock, waiter, current, chwalk); + + if (likely(!ret)) { + /* sleep on the mutex */ + 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); + /* 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); + } + + /* + * try_to_take_rt_mutex() sets the waiter bit + * 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) + 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); + rt_mutex_init_waiter(&waiter, false); /* * Technically we could use raw_spin_[un]lock_irq() here, but this can @@ -1247,35 +1793,8 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state, */ raw_spin_lock_irqsave(&lock->wait_lock, flags); - /* Try to acquire the lock again: */ - if (try_to_take_rt_mutex(lock, current, NULL)) { - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); - return 0; - } - - set_current_state(state); - - /* Setup the timer, when timeout != NULL */ - if (unlikely(timeout)) - hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); - - ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk); - - if (likely(!ret)) - /* sleep on the mutex */ - ret = __rt_mutex_slowlock(lock, state, timeout, &waiter); - - if (unlikely(ret)) { - __set_current_state(TASK_RUNNING); - remove_waiter(lock, &waiter); - rt_mutex_handle_deadlock(ret, chwalk, &waiter); - } - - /* - * try_to_take_rt_mutex() sets the waiter bit - * unconditionally. We might have to fix that up. - */ - fixup_rt_mutex_waiters(lock); + ret = rt_mutex_slowlock_locked(lock, state, timeout, chwalk, ww_ctx, + &waiter); raw_spin_unlock_irqrestore(&lock->wait_lock, flags); @@ -1336,7 +1855,8 @@ static inline int rt_mutex_slowtrylock(struct rt_mutex *lock) * 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; @@ -1390,7 +1910,7 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock, * * 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() */ @@ -1404,29 +1924,45 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock, */ 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 @@ -1442,9 +1978,11 @@ rt_mutex_fasttrylock(struct rt_mutex *lock, /* * 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(); @@ -1453,23 +1991,46 @@ void rt_mutex_postunlock(struct wake_q_head *wake_q) 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); +} + +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_); + 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) { - might_sleep(); - - mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); - rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock); + rt_mutex_lock_state(lock, subclass, TASK_UNINTERRUPTIBLE); } #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -1510,16 +2071,7 @@ 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); @@ -1536,6 +2088,22 @@ int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock) return __rt_mutex_slowtrylock(lock); } +/** + * 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 @@ -1559,6 +2127,7 @@ rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout) 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_); @@ -1567,6 +2136,18 @@ rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout) } EXPORT_SYMBOL_GPL(rt_mutex_timed_lock); +int __sched __rt_mutex_trylock(struct rt_mutex *lock) +{ +#ifdef CONFIG_PREEMPT_RT + 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 * @@ -1582,10 +2163,7 @@ int __sched rt_mutex_trylock(struct rt_mutex *lock) { 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_); @@ -1593,6 +2171,11 @@ int __sched rt_mutex_trylock(struct rt_mutex *lock) } 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 * @@ -1601,16 +2184,13 @@ 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); @@ -1627,23 +2207,35 @@ bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock, * 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); } /** @@ -1682,7 +2274,7 @@ void __rt_mutex_init(struct rt_mutex *lock, const char *name, 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 @@ -1702,6 +2294,14 @@ void rt_mutex_init_proxy_locked(struct rt_mutex *lock, 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); } @@ -1725,6 +2325,26 @@ void rt_mutex_proxy_unlock(struct rt_mutex *lock, rt_mutex_set_owner(lock, NULL); } +static void fixup_rt_mutex_blocked(struct rt_mutex *lock) +{ + struct task_struct *tsk = current; + /* + * 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. + */ + raw_spin_lock(&tsk->pi_lock); + tsk->pi_blocked_on = NULL; + raw_spin_unlock(&tsk->pi_lock); +} + /** * __rt_mutex_start_proxy_lock() - Start lock acquisition for another task * @lock: the rt_mutex to take @@ -1755,6 +2375,34 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, if (try_to_take_rt_mutex(lock, task, NULL)) return 1; +#ifdef CONFIG_PREEMPT_RT + /* + * In PREEMPT_RT there's an added race. + * If the task, that we are about to requeue, times out, + * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue + * to skip this task. But right after the task sets + * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then + * block on the spin_lock(&hb->lock), which in RT is an rtmutex. + * This will replace the PI_WAKEUP_INPROGRESS with the actual + * lock that it blocks on. We *must not* place this task + * on this proxy lock in that case. + * + * To prevent this race, we first take the task's pi_lock + * and check if it has updated its pi_blocked_on. If it has, + * we assume that it woke up and we return -EAGAIN. + * Otherwise, we set the task's pi_blocked_on to + * PI_REQUEUE_INPROGRESS, so that if the task is waking up + * it will know that we are in the process of requeuing it. + */ + raw_spin_lock(&task->pi_lock); + if (task->pi_blocked_on) { + raw_spin_unlock(&task->pi_lock); + return -EAGAIN; + } + task->pi_blocked_on = PI_REQUEUE_INPROGRESS; + raw_spin_unlock(&task->pi_lock); +#endif + /* We enforce deadlock detection for futexes */ ret = task_blocks_on_rt_mutex(lock, waiter, task, RT_MUTEX_FULL_CHAINWALK); @@ -1769,6 +2417,9 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, ret = 0; } + if (ret) + fixup_rt_mutex_blocked(lock); + debug_rt_mutex_print_deadlock(waiter); return ret; @@ -1854,12 +2505,15 @@ int rt_mutex_wait_proxy_lock(struct rt_mutex *lock, 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); + if (ret) + fixup_rt_mutex_blocked(lock); + raw_spin_unlock_irq(&lock->wait_lock); return ret; @@ -1921,3 +2575,99 @@ bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock, 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 +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 diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index d1d62f942be22..546aaf058b9ec 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -15,6 +15,7 @@ #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, @@ -29,6 +30,7 @@ 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; @@ -130,12 +132,15 @@ enum rtmutex_chainwalk { /* * PI-futex support (proxy locking functions, etc.): */ +#define PI_WAKEUP_INPROGRESS ((struct rt_mutex_waiter *) 1) +#define PI_REQUEUE_INPROGRESS ((struct rt_mutex_waiter *) 2) + extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock); extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, 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); @@ -153,9 +158,27 @@ extern int __rt_mutex_futex_trylock(struct rt_mutex *l); 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" diff --git a/kernel/locking/rwlock-rt.c b/kernel/locking/rwlock-rt.c new file mode 100644 index 0000000000000..0ae8c62ea8320 --- /dev/null +++ b/kernel/locking/rwlock-rt.c @@ -0,0 +1,384 @@ +/* + */ +#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_); + rcu_read_lock(); + } 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_); + rcu_read_lock(); + } else { + migrate_enable(); + sleeping_lock_dec(); + } + return ret; +} +EXPORT_SYMBOL(rt_write_trylock); + +void __lockfunc rt_read_lock(rwlock_t *rwlock) +{ + sleeping_lock_inc(); + rcu_read_lock(); + 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(); + rcu_read_lock(); + 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(); + rcu_read_unlock(); + 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(); + rcu_read_unlock(); + 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); diff --git a/kernel/locking/rwsem-rt.c b/kernel/locking/rwsem-rt.c new file mode 100644 index 0000000000000..f518495bd6ccd --- /dev/null +++ b/kernel/locking/rwsem-rt.c @@ -0,0 +1,302 @@ +/* + */ +#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); +} diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index baafa1dd9fcc4..0d11ba11a32ac 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -28,7 +28,7 @@ #include <linux/rwsem.h> #include <linux/atomic.h> -#include "rwsem.h" +#ifndef CONFIG_PREEMPT_RT #include "lock_events.h" /* @@ -660,8 +660,6 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem, unsigned long flags; bool ret = true; - BUILD_BUG_ON(!(RWSEM_OWNER_UNKNOWN & RWSEM_NONSPINNABLE)); - if (need_resched()) { lockevent_inc(rwsem_opt_fail); return false; @@ -1335,10 +1333,11 @@ static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem) return sem; } + /* * lock for reading */ -inline void __down_read(struct rw_semaphore *sem) +static inline void __down_read(struct rw_semaphore *sem) { if (!rwsem_read_trylock(sem)) { rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE); @@ -1426,7 +1425,7 @@ static inline int __down_write_trylock(struct rw_semaphore *sem) /* * unlock after reading */ -inline void __up_read(struct rw_semaphore *sem) +static inline void __up_read(struct rw_semaphore *sem) { long tmp; @@ -1485,6 +1484,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem) if (tmp & RWSEM_FLAG_WAITERS) rwsem_downgrade_wake(sem); } +#endif /* * lock for reading @@ -1616,6 +1616,7 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) } EXPORT_SYMBOL(_down_write_nest_lock); +#ifndef CONFIG_PREEMPT_RT void down_read_non_owner(struct rw_semaphore *sem) { might_sleep(); @@ -1623,6 +1624,7 @@ void down_read_non_owner(struct rw_semaphore *sem) __rwsem_set_reader_owned(sem, NULL); } EXPORT_SYMBOL(down_read_non_owner); +#endif void down_write_nested(struct rw_semaphore *sem, int subclass) { @@ -1647,11 +1649,13 @@ int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass) } EXPORT_SYMBOL(down_write_killable_nested); +#ifndef CONFIG_PREEMPT_RT void up_read_non_owner(struct rw_semaphore *sem) { DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); __up_read(sem); } EXPORT_SYMBOL(up_read_non_owner); +#endif #endif diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h index 2534ce49f6480..e69de29bb2d1d 100644 --- a/kernel/locking/rwsem.h +++ b/kernel/locking/rwsem.h @@ -1,10 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - -#ifndef __INTERNAL_RWSEM_H -#define __INTERNAL_RWSEM_H -#include <linux/rwsem.h> - -extern void __down_read(struct rw_semaphore *sem); -extern void __up_read(struct rw_semaphore *sem); - -#endif /* __INTERNAL_RWSEM_H */ diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c index 0ff08380f5318..45445a2f1799a 100644 --- a/kernel/locking/spinlock.c +++ b/kernel/locking/spinlock.c @@ -124,8 +124,11 @@ void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \ * __[spin|read|write]_lock_bh() */ BUILD_LOCK_OPS(spin, raw_spinlock); + +#ifndef CONFIG_PREEMPT_RT BUILD_LOCK_OPS(read, rwlock); BUILD_LOCK_OPS(write, rwlock); +#endif #endif @@ -209,6 +212,8 @@ void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock) EXPORT_SYMBOL(_raw_spin_unlock_bh); #endif +#ifndef CONFIG_PREEMPT_RT + #ifndef CONFIG_INLINE_READ_TRYLOCK int __lockfunc _raw_read_trylock(rwlock_t *lock) { @@ -353,6 +358,8 @@ void __lockfunc _raw_write_unlock_bh(rwlock_t *lock) EXPORT_SYMBOL(_raw_write_unlock_bh); #endif +#endif /* !PREEMPT_RT */ + #ifdef CONFIG_DEBUG_LOCK_ALLOC void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass) diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c index 472dd462a40ca..82915146c92ce 100644 --- a/kernel/locking/spinlock_debug.c +++ b/kernel/locking/spinlock_debug.c @@ -31,6 +31,7 @@ void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, EXPORT_SYMBOL(__raw_spin_lock_init); +#ifndef CONFIG_PREEMPT_RT void __rwlock_init(rwlock_t *lock, const char *name, struct lock_class_key *key) { @@ -48,6 +49,7 @@ void __rwlock_init(rwlock_t *lock, const char *name, } EXPORT_SYMBOL(__rwlock_init); +#endif static void spin_dump(raw_spinlock_t *lock, const char *msg) { @@ -139,6 +141,7 @@ void do_raw_spin_unlock(raw_spinlock_t *lock) arch_spin_unlock(&lock->raw_lock); } +#ifndef CONFIG_PREEMPT_RT static void rwlock_bug(rwlock_t *lock, const char *msg) { if (!debug_locks_off()) @@ -228,3 +231,5 @@ void do_raw_write_unlock(rwlock_t *lock) debug_write_unlock(lock); arch_write_unlock(&lock->raw_lock); } + +#endif diff --git a/kernel/panic.c b/kernel/panic.c index f470a038b05bd..cf00fca838174 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -237,7 +237,6 @@ 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); /* @@ -261,8 +260,6 @@ 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); /* @@ -524,9 +521,11 @@ static u64 oops_id; static int init_oops_id(void) { +#ifndef CONFIG_PREEMPT_RT if (!oops_id) get_random_bytes(&oops_id, sizeof(oops_id)); else +#endif oops_id++; return 0; diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 3c0a5a8170b02..c8713bbc44810 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -689,6 +689,10 @@ 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. */ @@ -702,6 +706,8 @@ 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)) { @@ -778,6 +784,7 @@ int hibernate(void) atomic_inc(&snapshot_device_available); Unlock: unlock_system_sleep(); + pm_in_action = false; pr_info("hibernation exit\n"); return error; diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index f3b7239f1892f..3205c45155eee 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -594,6 +594,8 @@ static int enter_state(suspend_state_t state) return error; } +bool pm_in_action; + /** * pm_suspend - Externally visible function for suspending the system. * @state: System sleep state to enter. @@ -608,6 +610,7 @@ 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) { @@ -617,6 +620,7 @@ 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); diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile index 4d052fc6bcde7..7b219d824c0fb 100644 --- a/kernel/printk/Makefile +++ b/kernel/printk/Makefile @@ -1,4 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only obj-y = printk.o -obj-$(CONFIG_PRINTK) += printk_safe.o obj-$(CONFIG_A11Y_BRAILLE_CONSOLE) += braille.o diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h deleted file mode 100644 index c8e6ab689d42f..0000000000000 --- a/kernel/printk/internal.h +++ /dev/null @@ -1,67 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * internal.h - printk internal definitions - */ -#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 */ diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index ca65327a6de8c..0605a74ad76b9 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -45,6 +45,9 @@ #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> @@ -58,13 +61,13 @@ #include "console_cmdline.h" #include "braille.h" -#include "internal.h" -int console_printk[4] = {