Index: linux-5.4.17-rt9/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.html
===================================================================
--- linux-5.4.17-rt9.orig/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.html
+++ linux-5.4.17-rt9/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.html
@@ -56,8 +56,8 @@ sections.
RCU-preempt Expedited Grace Periods
-CONFIG_PREEMPT=y kernels implement RCU-preempt.
-The overall flow of the handling of a given CPU by an RCU-preempt
+CONFIG_PREEMPT=y and CONFIG_PREEMPT_RT=y 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:
-CONFIG_PREEMPT=n kernels implement RCU-sched.
-The overall flow of the handling of a given CPU by an RCU-sched
+CONFIG_PREEMPT=n and CONFIG_PREEMPT_RT=n 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:
rcu_read_lock() and
rcu_read_unlock() are extremely lightweight, and in
fact have exactly zero overhead in Linux kernels built for production
-use with CONFIG_PREEMPT=n .
+use with CONFIG_PREEMPTION=n .
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
bloatwatch
efforts, memory footprint is critically important on single-CPU systems with
-non-preemptible (CONFIG_PREEMPT=n ) kernels, and thus
+non-preemptible (CONFIG_PREEMPTION=n ) kernels, and thus
tiny RCU
was born.
Josh Triplett has since taken over the small-memory banner with his
@@ -1887,7 +1887,7 @@ constructs, there are limitations.
Implementations of RCU for which rcu_read_lock()
and rcu_read_unlock() generate no code, such as
-Linux-kernel RCU when CONFIG_PREEMPT=n , can be
+Linux-kernel RCU when CONFIG_PREEMPTION=n , can be
nested arbitrarily deeply.
After all, there is no overhead.
Except that if all these instances of rcu_read_lock()
@@ -2229,7 +2229,7 @@ be a no-op.
However, once the scheduler has spawned its first kthread, this early
boot trick fails for synchronize_rcu() (as well as for
-synchronize_rcu_expedited() ) in CONFIG_PREEMPT=y
+synchronize_rcu_expedited() ) in CONFIG_PREEMPTION=y
kernels.
The reason is that an RCU read-side critical section might be preempted,
which means that a subsequent synchronize_rcu() really does have
@@ -2568,7 +2568,7 @@ the following:
If the compiler did make this transformation in a
-CONFIG_PREEMPT=n kernel build, and if get_user() did
+CONFIG_PREEMPTION=n kernel build, and if get_user() 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 CONFIG_PREEMPT=y therefore
+Kernels built with CONFIG_PREEMPTION=y 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
rcu_barrier_bh() , and
rcu_read_lock_bh_held() .
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.
@@ -3088,12 +3088,12 @@ of an RCU read-side critical section can
Therefore, RCU-sched 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 CONFIG_PREEMPT=n , the RCU and RCU-sched
+In kernels built with CONFIG_PREEMPTION=n , the RCU and RCU-sched
APIs have identical implementations, while kernels built with
-CONFIG_PREEMPT=y provide a separate implementation for each.
+CONFIG_PREEMPTION=y provide a separate implementation for each.
-Note well that in CONFIG_PREEMPT=y kernels,
+Note well that in CONFIG_PREEMPTION=y kernels,
rcu_read_lock_sched() and rcu_read_unlock_sched()
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, cons
call_rcu_tasks() ,
synchronize_rcu_tasks() , and
rcu_barrier_tasks() .
-In CONFIG_PREEMPT=n kernels, trampolines cannot be preempted,
+In CONFIG_PREEMPTION=n kernels, trampolines cannot be preempted,
so these APIs map to
call_rcu() ,
synchronize_rcu() , and
rcu_barrier() , respectively.
-In CONFIG_PREEMPT=y kernels, trampolines can be preempted,
+In CONFIG_PREEMPTION=y kernels, trampolines can be preempted,
and these three APIs are therefore implemented by separate functions
that check for voluntary context switches.
Index: linux-5.4.17-rt9/Documentation/RCU/checklist.txt
===================================================================
--- linux-5.4.17-rt9.orig/Documentation/RCU/checklist.txt
+++ linux-5.4.17-rt9/Documentation/RCU/checklist.txt
@@ -210,8 +210,8 @@ over a rather long period of time, but i
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,
Index: linux-5.4.17-rt9/Documentation/RCU/rcubarrier.txt
===================================================================
--- linux-5.4.17-rt9.orig/Documentation/RCU/rcubarrier.txt
+++ linux-5.4.17-rt9/Documentation/RCU/rcubarrier.txt
@@ -6,8 +6,8 @@ RCU (read-copy update) is a synchronizat
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 i
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
Index: linux-5.4.17-rt9/Documentation/RCU/stallwarn.txt
===================================================================
--- linux-5.4.17-rt9.orig/Documentation/RCU/stallwarn.txt
+++ linux-5.4.17-rt9/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-per
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,
Index: linux-5.4.17-rt9/Documentation/RCU/whatisRCU.txt
===================================================================
--- linux-5.4.17-rt9.orig/Documentation/RCU/whatisRCU.txt
+++ linux-5.4.17-rt9/Documentation/RCU/whatisRCU.txt
@@ -648,9 +648,10 @@ Quick Quiz #1: Why is this argument naiv
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) { }
Index: linux-5.4.17-rt9/Documentation/printk-ringbuffer.txt
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/Documentation/printk-ringbuffer.txt
@@ -0,0 +1,377 @@
+struct printk_ringbuffer
+------------------------
+John Ogness
+
+Overview
+~~~~~~~~
+As the name suggests, this ring buffer was implemented specifically to serve
+the needs of the printk() infrastructure. The ring buffer itself is not
+specific to printk and could be used for other purposes. _However_, the
+requirements and semantics of printk are rather unique. If you intend to use
+this ring buffer for anything other than printk, you need to be very clear on
+its features, behavior, and pitfalls.
+
+Features
+^^^^^^^^
+The printk ring buffer has the following features:
+
+- single global buffer
+- resides in initialized data section (available at early boot)
+- lockless readers
+- supports multiple writers
+- supports multiple non-consuming readers
+- safe from any context (including NMI)
+- groups bytes into variable length blocks (referenced by entries)
+- entries tagged with sequence numbers
+
+Behavior
+^^^^^^^^
+Since the printk ring buffer readers are lockless, there exists no
+synchronization between readers and writers. Basically writers are the tasks
+in control and may overwrite any and all committed data at any time and from
+any context. For this reason readers can miss entries if they are overwritten
+before the reader was able to access the data. The reader API implementation
+is such that reader access to entries is atomic, so there is no risk of
+readers having to deal with partial or corrupt data. Also, entries are
+tagged with sequence numbers so readers can recognize if entries were missed.
+
+Writing to the ring buffer consists of 2 steps. First a writer must reserve
+an entry of desired size. After this step the writer has exclusive access
+to the memory region. Once the data has been written to memory, it needs to
+be committed to the ring buffer. After this step the entry has been inserted
+into the ring buffer and assigned an appropriate sequence number.
+
+Once committed, a writer must no longer access the data directly. This is
+because the data may have been overwritten and no longer exists. If a
+writer must access the data, it should either keep a private copy before
+committing the entry or use the reader API to gain access to the data.
+
+Because of how the data backend is implemented, entries that have been
+reserved but not yet committed act as barriers, preventing future writers
+from filling the ring buffer beyond the location of the reserved but not
+yet committed entry region. For this reason it is *important* that writers
+perform both reserve and commit as quickly as possible. Also, be aware that
+preemption and local interrupts are disabled and writing to the ring buffer
+is processor-reentrant locked during the reserve/commit window. Writers in
+NMI contexts can still preempt any other writers, but as long as these
+writers do not write a large amount of data with respect to the ring buffer
+size, this should not become an issue.
+
+API
+~~~
+
+Declaration
+^^^^^^^^^^^
+The printk ring buffer can be instantiated as a static structure:
+
+ /* declare a static struct printk_ringbuffer */
+ #define DECLARE_STATIC_PRINTKRB(name, szbits, cpulockptr)
+
+The value of szbits specifies the size of the ring buffer in bits. The
+cpulockptr field is a pointer to a prb_cpulock struct that is used to
+perform processor-reentrant spin locking for the writers. It is specified
+externally because it may be used for multiple ring buffers (or other
+code) to synchronize writers without risk of deadlock.
+
+Here is an example of a declaration of a printk ring buffer specifying a
+32KB (2^15) ring buffer:
+
+....
+DECLARE_STATIC_PRINTKRB_CPULOCK(rb_cpulock);
+DECLARE_STATIC_PRINTKRB(rb, 15, &rb_cpulock);
+....
+
+If writers will be using multiple ring buffers and the ordering of that usage
+is not clear, the same prb_cpulock should be used for both ring buffers.
+
+Writer API
+^^^^^^^^^^
+The writer API consists of 2 functions. The first is to reserve an entry in
+the ring buffer, the second is to commit that data to the ring buffer. The
+reserved entry information is stored within a provided `struct prb_handle`.
+
+ /* reserve an entry */
+ char *prb_reserve(struct prb_handle *h, struct printk_ringbuffer *rb,
+ unsigned int size);
+
+ /* commit a reserved entry to the ring buffer */
+ void prb_commit(struct prb_handle *h);
+
+Here is an example of a function to write data to a ring buffer:
+
+....
+int write_data(struct printk_ringbuffer *rb, char *data, int size)
+{
+ struct prb_handle h;
+ char *buf;
+
+ buf = prb_reserve(&h, rb, size);
+ if (!buf)
+ return -1;
+ memcpy(buf, data, size);
+ prb_commit(&h);
+
+ return 0;
+}
+....
+
+Pitfalls
+++++++++
+Be aware that prb_reserve() can fail. A retry might be successful, but it
+depends entirely on whether or not the next part of the ring buffer to
+overwrite belongs to reserved but not yet committed entries of other writers.
+Writers can use the prb_inc_lost() function to allow readers to notice that a
+message was lost.
+
+Reader API
+^^^^^^^^^^
+The reader API utilizes a `struct prb_iterator` to track the reader's
+position in the ring buffer.
+
+ /* declare a pre-initialized static iterator for a ring buffer */
+ #define DECLARE_STATIC_PRINTKRB_ITER(name, rbaddr)
+
+ /* initialize iterator for a ring buffer (if static macro NOT used) */
+ void prb_iter_init(struct prb_iterator *iter,
+ struct printk_ringbuffer *rb, u64 *seq);
+
+ /* make a deep copy of an iterator */
+ void prb_iter_copy(struct prb_iterator *dest,
+ struct prb_iterator *src);
+
+ /* non-blocking, advance to next entry (and read the data) */
+ int prb_iter_next(struct prb_iterator *iter, char *buf,
+ int size, u64 *seq);
+
+ /* blocking, advance to next entry (and read the data) */
+ int prb_iter_wait_next(struct prb_iterator *iter, char *buf,
+ int size, u64 *seq);
+
+ /* position iterator at the entry seq */
+ int prb_iter_seek(struct prb_iterator *iter, u64 seq);
+
+ /* read data at current position */
+ int prb_iter_data(struct prb_iterator *iter, char *buf,
+ int size, u64 *seq);
+
+Typically prb_iter_data() is not needed because the data can be retrieved
+directly with prb_iter_next().
+
+Here is an example of a non-blocking function that will read all the data in
+a ring buffer:
+
+....
+void read_all_data(struct printk_ringbuffer *rb, char *buf, int size)
+{
+ struct prb_iterator iter;
+ u64 prev_seq = 0;
+ u64 seq;
+ int ret;
+
+ prb_iter_init(&iter, rb, NULL);
+
+ for (;;) {
+ ret = prb_iter_next(&iter, buf, size, &seq);
+ if (ret > 0) {
+ if (seq != ++prev_seq) {
+ /* "seq - prev_seq" entries missed */
+ prev_seq = seq;
+ }
+ /* process buf here */
+ } else if (ret == 0) {
+ /* hit the end, done */
+ break;
+ } else if (ret < 0) {
+ /*
+ * iterator is invalid, a writer overtook us, reset the
+ * iterator and keep going, entries were missed
+ */
+ prb_iter_init(&iter, rb, NULL);
+ }
+ }
+}
+....
+
+Pitfalls
+++++++++
+The reader's iterator can become invalid at any time because the reader was
+overtaken by a writer. Typically the reader should reset the iterator back
+to the current oldest entry (which will be newer than the entry the reader
+was at) and continue, noting the number of entries that were missed.
+
+Utility API
+^^^^^^^^^^^
+Several functions are available as convenience for external code.
+
+ /* query the size of the data buffer */
+ int prb_buffer_size(struct printk_ringbuffer *rb);
+
+ /* skip a seq number to signify a lost record */
+ void prb_inc_lost(struct printk_ringbuffer *rb);
+
+ /* processor-reentrant spin lock */
+ void prb_lock(struct prb_cpulock *cpu_lock, unsigned int *cpu_store);
+
+ /* processor-reentrant spin unlock */
+ void prb_lock(struct prb_cpulock *cpu_lock, unsigned int *cpu_store);
+
+Pitfalls
+++++++++
+Although the value returned by prb_buffer_size() does represent an absolute
+upper bound, the amount of data that can be stored within the ring buffer
+is actually less because of the additional storage space of a header for each
+entry.
+
+The prb_lock() and prb_unlock() functions can be used to synchronize between
+ring buffer writers and other external activities. The function of a
+processor-reentrant spin lock is to disable preemption and local interrupts
+and synchronize against other processors. It does *not* protect against
+multiple contexts of a single processor, i.e NMI.
+
+Implementation
+~~~~~~~~~~~~~~
+This section describes several of the implementation concepts and details to
+help developers better understand the code.
+
+Entries
+^^^^^^^
+All ring buffer data is stored within a single static byte array. The reason
+for this is to ensure that any pointers to the data (past and present) will
+always point to valid memory. This is important because the lockless readers
+may be preempted for long periods of time and when they resume may be working
+with expired pointers.
+
+Entries are identified by start index and size. (The start index plus size
+is the start index of the next entry.) The start index is not simply an
+offset into the byte array, but rather a logical position (lpos) that maps
+directly to byte array offsets.
+
+For example, for a byte array of 1000, an entry may have have a start index
+of 100. Another entry may have a start index of 1100. And yet another 2100.
+All of these entry are pointing to the same memory region, but only the most
+recent entry is valid. The other entries are pointing to valid memory, but
+represent entries that have been overwritten.
+
+Note that due to overflowing, the most recent entry is not necessarily the one
+with the highest lpos value. Indeed, the printk ring buffer initializes its
+data such that an overflow happens relatively quickly in order to validate the
+handling of this situation. The implementation assumes that an lpos (unsigned
+long) will never completely wrap while a reader is preempted. If this were to
+become an issue, the seq number (which never wraps) could be used to increase
+the robustness of handling this situation.
+
+Buffer Wrapping
+^^^^^^^^^^^^^^^
+If an entry starts near the end of the byte array but would extend beyond it,
+a special terminating entry (size = -1) is inserted into the byte array and
+the real entry is placed at the beginning of the byte array. This can waste
+space at the end of the byte array, but simplifies the implementation by
+allowing writers to always work with contiguous buffers.
+
+Note that the size field is the first 4 bytes of the entry header. Also note
+that calc_next() always ensures that there are at least 4 bytes left at the
+end of the byte array to allow room for a terminating entry.
+
+Ring Buffer Pointers
+^^^^^^^^^^^^^^^^^^^^
+Three pointers (lpos values) are used to manage the ring buffer:
+
+ - _tail_: points to the oldest entry
+ - _head_: points to where the next new committed entry will be
+ - _reserve_: points to where the next new reserved entry will be
+
+These pointers always maintain a logical ordering:
+
+ tail <= head <= reserve
+
+The reserve pointer moves forward when a writer reserves a new entry. The
+head pointer moves forward when a writer commits a new entry.
+
+The reserve pointer cannot overwrite the tail pointer in a wrap situation. In
+such a situation, the tail pointer must be "pushed forward", thus
+invalidating that oldest entry. Readers identify if they are accessing a
+valid entry by ensuring their entry pointer is `>= tail && < head`.
+
+If the tail pointer is equal to the head pointer, it cannot be pushed and any
+reserve operation will fail. The only resolution is for writers to commit
+their reserved entries.
+
+Processor-Reentrant Locking
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The purpose of the processor-reentrant locking is to limit the interruption
+scenarios of writers to 2 contexts. This allows for a simplified
+implementation where:
+
+- The reserve/commit window only exists on 1 processor at a time. A reserve
+ can never fail due to uncommitted entries of other processors.
+
+- When committing entries, it is trivial to handle the situation when
+ subsequent entries have already been committed, i.e. managing the head
+ pointer.
+
+Performance
+~~~~~~~~~~~
+Some basic tests were performed on a quad Intel(R) Xeon(R) CPU E5-2697 v4 at
+2.30GHz (36 cores / 72 threads). All tests involved writing a total of
+32,000,000 records at an average of 33 bytes each. Each writer was pinned to
+its own CPU and would write as fast as it could until a total of 32,000,000
+records were written. All tests involved 2 readers that were both pinned
+together to another CPU. Each reader would read as fast as it could and track
+how many of the 32,000,000 records it could read. All tests used a ring buffer
+of 16KB in size, which holds around 350 records (header + data for each
+entry).
+
+The only difference between the tests is the number of writers (and thus also
+the number of records per writer). As more writers are added, the time to
+write a record increases. This is because data pointers, modified via cmpxchg,
+and global data access in general become more contended.
+
+1 writer
+^^^^^^^^
+ runtime: 0m 18s
+ reader1: 16219900/32000000 (50%) records
+ reader2: 16141582/32000000 (50%) records
+
+2 writers
+^^^^^^^^^
+ runtime: 0m 32s
+ reader1: 16327957/32000000 (51%) records
+ reader2: 16313988/32000000 (50%) records
+
+4 writers
+^^^^^^^^^
+ runtime: 0m 42s
+ reader1: 16421642/32000000 (51%) records
+ reader2: 16417224/32000000 (51%) records
+
+8 writers
+^^^^^^^^^
+ runtime: 0m 43s
+ reader1: 16418300/32000000 (51%) records
+ reader2: 16432222/32000000 (51%) records
+
+16 writers
+^^^^^^^^^^
+ runtime: 0m 54s
+ reader1: 16539189/32000000 (51%) records
+ reader2: 16542711/32000000 (51%) records
+
+32 writers
+^^^^^^^^^^
+ runtime: 1m 13s
+ reader1: 16731808/32000000 (52%) records
+ reader2: 16735119/32000000 (52%) records
+
+Comments
+^^^^^^^^
+It is particularly interesting to compare/contrast the 1-writer and 32-writer
+tests. Despite the writing of the 32,000,000 records taking over 4 times
+longer, the readers (which perform no cmpxchg) were still unable to keep up.
+This shows that the memory contention between the increasing number of CPUs
+also has a dramatic effect on readers.
+
+It should also be noted that in all cases each reader was able to read >=50%
+of the records. This means that a single reader would have been able to keep
+up with the writer(s) in all cases, becoming slightly easier as more writers
+are added. This was the purpose of pinning 2 readers to 1 CPU: to observe how
+maximum reader performance changes.
Index: linux-5.4.17-rt9/Documentation/trace/ftrace-uses.rst
===================================================================
--- linux-5.4.17-rt9.orig/Documentation/trace/ftrace-uses.rst
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/alpha/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/alpha/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/arch/arc/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/arc/kernel/entry.S
+++ linux-5.4.17-rt9/arch/arc/kernel/entry.S
@@ -337,11 +337,11 @@ resume_user_mode_begin:
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
Index: linux-5.4.17-rt9/arch/arm/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/arm/include/asm/irq.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/include/asm/irq.h
+++ linux-5.4.17-rt9/arch/arm/include/asm/irq.h
@@ -23,6 +23,8 @@
#endif
#ifndef __ASSEMBLY__
+#include
+
struct irqaction;
struct pt_regs;
Index: linux-5.4.17-rt9/arch/arm/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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 {
Index: linux-5.4.17-rt9/arch/arm/include/asm/switch_to.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/include/asm/switch_to.h
+++ linux-5.4.17-rt9/arch/arm/include/asm/switch_to.h
@@ -4,13 +4,20 @@
#include
+#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(s
#define switch_to(prev,next,last) \
do { \
__complete_pending_tlbi(); \
+ switch_kmaps(prev, next); \
last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \
} while (0)
Index: linux-5.4.17-rt9/arch/arm/include/asm/thread_info.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/include/asm/thread_info.h
+++ linux-5.4.17-rt9/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(stru
#define TIF_SYSCALL_TRACE 4 /* syscall trace active */
#define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */
#define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */
-#define TIF_SECCOMP 7 /* seccomp syscall filtering active */
+#define TIF_SECCOMP 8 /* seccomp syscall filtering active */
+#define TIF_NEED_RESCHED_LAZY 7
#define TIF_NOHZ 12 /* in adaptive nohz mode */
#define TIF_USING_IWMMXT 17
@@ -149,6 +151,7 @@ extern int vfp_restore_user_hwstate(stru
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
#define _TIF_UPROBE (1 << TIF_UPROBE)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
@@ -164,7 +167,8 @@ extern int vfp_restore_user_hwstate(stru
* Change these and you break ASM code in entry-common.S
*/
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
- _TIF_NOTIFY_RESUME | _TIF_UPROBE)
+ _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
+ _TIF_NEED_RESCHED_LAZY)
#endif /* __KERNEL__ */
#endif /* __ASM_ARM_THREAD_INFO_H */
Index: linux-5.4.17-rt9/arch/arm/kernel/asm-offsets.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/kernel/asm-offsets.c
+++ linux-5.4.17-rt9/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));
Index: linux-5.4.17-rt9/arch/arm/kernel/entry-armv.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/kernel/entry-armv.S
+++ linux-5.4.17-rt9/arch/arm/kernel/entry-armv.S
@@ -211,13 +211,20 @@ __irq_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:
Index: linux-5.4.17-rt9/arch/arm/kernel/entry-common.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/kernel/entry-common.S
+++ linux-5.4.17-rt9/arch/arm/kernel/entry-common.S
@@ -53,7 +53,9 @@ __ret_fast_syscall:
cmp r2, #TASK_SIZE
blne addr_limit_check_failed
ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
- tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
+ tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
+ bne fast_work_pending
+ tst r1, #_TIF_SECCOMP
bne fast_work_pending
@@ -90,8 +92,11 @@ __ret_fast_syscall:
cmp r2, #TASK_SIZE
blne addr_limit_check_failed
ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
- tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
+ tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
+ bne do_slower_path
+ tst r1, #_TIF_SECCOMP
beq no_work_pending
+do_slower_path:
UNWIND(.fnend )
ENDPROC(ret_fast_syscall)
Index: linux-5.4.17-rt9/arch/arm/kernel/signal.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/kernel/signal.c
+++ linux-5.4.17-rt9/arch/arm/kernel/signal.c
@@ -649,7 +649,8 @@ do_work_pending(struct pt_regs *regs, un
*/
trace_hardirqs_off();
do {
- if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+ if (likely(thread_flags & (_TIF_NEED_RESCHED |
+ _TIF_NEED_RESCHED_LAZY))) {
schedule();
} else {
if (unlikely(!user_mode(regs)))
Index: linux-5.4.17-rt9/arch/arm/kernel/smp.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/kernel/smp.c
+++ linux-5.4.17-rt9/arch/arm/kernel/smp.c
@@ -682,11 +682,9 @@ void handle_IPI(int ipinr, struct pt_reg
break;
case IPI_CPU_BACKTRACE:
- printk_nmi_enter();
irq_enter();
nmi_cpu_backtrace(regs);
irq_exit();
- printk_nmi_exit();
break;
default:
Index: linux-5.4.17-rt9/arch/arm/kernel/traps.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/kernel/traps.c
+++ linux-5.4.17-rt9/arch/arm/kernel/traps.c
@@ -248,6 +248,8 @@ void show_stack(struct task_struct *tsk,
#ifdef CONFIG_PREEMPT
#define S_PREEMPT " PREEMPT"
+#elif defined(CONFIG_PREEMPT_RT)
+#define S_PREEMPT " PREEMPT_RT"
#else
#define S_PREEMPT ""
#endif
Index: linux-5.4.17-rt9/arch/arm/mm/cache-v7.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/mm/cache-v7.S
+++ linux-5.4.17-rt9/arch/arm/mm/cache-v7.S
@@ -135,13 +135,13 @@ flush_levels:
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
Index: linux-5.4.17-rt9/arch/arm/mm/cache-v7m.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/mm/cache-v7m.S
+++ linux-5.4.17-rt9/arch/arm/mm/cache-v7m.S
@@ -183,13 +183,13 @@ flush_levels:
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
Index: linux-5.4.17-rt9/arch/arm/mm/fault.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/mm/fault.c
+++ linux-5.4.17-rt9/arch/arm/mm/fault.c
@@ -414,6 +414,9 @@ do_translation_fault(unsigned long addr,
if (addr < TASK_SIZE)
return do_page_fault(addr, fsr, regs);
+ if (interrupts_enabled(regs))
+ local_irq_enable();
+
if (user_mode(regs))
goto bad_area;
@@ -481,6 +484,9 @@ do_translation_fault(unsigned long addr,
static int
do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
+ if (interrupts_enabled(regs))
+ local_irq_enable();
+
do_bad_area(addr, fsr, regs);
return 0;
}
Index: linux-5.4.17-rt9/arch/arm/mm/highmem.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm/mm/highmem.c
+++ linux-5.4.17-rt9/arch/arm/mm/highmem.c
@@ -31,6 +31,11 @@ static inline pte_t get_fixmap_pte(unsig
return *ptep;
}
+static unsigned int fixmap_idx(int type)
+{
+ return FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
+}
+
void *kmap(struct page *page)
{
might_sleep();
@@ -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
Index: linux-5.4.17-rt9/arch/arm64/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/arm64/crypto/sha256-glue.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/crypto/sha256-glue.c
+++ linux-5.4.17-rt9/arch/arm64/crypto/sha256-glue.c
@@ -97,7 +97,7 @@ static int sha256_update_neon(struct sha
* 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;
Index: linux-5.4.17-rt9/arch/arm64/include/asm/assembler.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/include/asm/assembler.h
+++ linux-5.4.17-rt9/arch/arm64/include/asm/assembler.h
@@ -699,8 +699,8 @@ USER(\label, ic ivau, \tmp2) // invali
* where 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) // invali
.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
Index: linux-5.4.17-rt9/arch/arm64/include/asm/kvm_mmu.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/include/asm/kvm_mmu.h
+++ linux-5.4.17-rt9/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)
{
Index: linux-5.4.17-rt9/arch/arm64/include/asm/preempt.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/include/asm/preempt.h
+++ linux-5.4.17-rt9/arch/arm64/include/asm/preempt.h
@@ -70,20 +70,43 @@ static inline bool __preempt_count_dec_a
* interrupt occurring between the non-atomic READ_ONCE/WRITE_ONCE
* pair.
*/
- return !pc || !READ_ONCE(ti->preempt_count);
+ if (!pc || !READ_ONCE(ti->preempt_count))
+ return true;
+#ifdef CONFIG_PREEMPT_LAZY
+ if ((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 */
Index: linux-5.4.17-rt9/arch/arm64/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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
#include
Index: linux-5.4.17-rt9/arch/arm64/include/asm/thread_info.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/include/asm/thread_info.h
+++ linux-5.4.17-rt9/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 tas
#define TIF_FOREIGN_FPSTATE 3 /* CPU's FP state is not current's */
#define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */
#define TIF_FSCHECK 5 /* Check FS is USER_DS on return */
+#define TIF_NEED_RESCHED_LAZY 6
#define TIF_NOHZ 7
#define TIF_SYSCALL_TRACE 8 /* syscall trace active */
#define TIF_SYSCALL_AUDIT 9 /* syscall auditing */
@@ -83,6 +85,7 @@ void arch_release_task_struct(struct tas
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_FOREIGN_FPSTATE (1 << TIF_FOREIGN_FPSTATE)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
#define _TIF_NOHZ (1 << TIF_NOHZ)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
@@ -96,8 +99,9 @@ void arch_release_task_struct(struct tas
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
_TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
- _TIF_UPROBE | _TIF_FSCHECK)
+ _TIF_UPROBE | _TIF_FSCHECK | _TIF_NEED_RESCHED_LAZY)
+#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
_TIF_NOHZ | _TIF_SYSCALL_EMU)
Index: linux-5.4.17-rt9/arch/arm64/kernel/asm-offsets.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/kernel/asm-offsets.c
+++ linux-5.4.17-rt9/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));
Index: linux-5.4.17-rt9/arch/arm64/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/kernel/entry.S
+++ linux-5.4.17-rt9/arch/arm64/kernel/entry.S
@@ -669,7 +669,7 @@ el1_irq:
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_MASKIN
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
Index: linux-5.4.17-rt9/arch/arm64/kernel/fpsimd.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/kernel/fpsimd.c
+++ linux-5.4.17-rt9/arch/arm64/kernel/fpsimd.c
@@ -213,6 +213,16 @@ static void sve_free(struct task_struct
__sve_free(task);
}
+static void *sve_free_atomic(struct task_struct *task)
+{
+ void *sve_state = task->thread.sve_state;
+
+ WARN_ON(test_tsk_thread_flag(task, TIF_SVE));
+
+ task->thread.sve_state = NULL;
+ return sve_state;
+}
+
/*
* TIF_SVE controls whether a task can use SVE without trapping while
* in userspace, and also the way a task's FPSIMD/SVE state is stored
@@ -1010,6 +1020,7 @@ void fpsimd_thread_switch(struct task_st
void fpsimd_flush_thread(void)
{
int vl, supported_vl;
+ void *mem = NULL;
if (!system_supports_fpsimd())
return;
@@ -1022,7 +1033,7 @@ 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.
@@ -1056,6 +1067,7 @@ void fpsimd_flush_thread(void)
}
put_cpu_fpsimd_context();
+ kfree(mem);
}
/*
Index: linux-5.4.17-rt9/arch/arm64/kernel/signal.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/kernel/signal.c
+++ linux-5.4.17-rt9/arch/arm64/kernel/signal.c
@@ -910,7 +910,7 @@ asmlinkage void do_notify_resume(struct
/* Check valid user FS if needed */
addr_limit_user_check();
- if (thread_flags & _TIF_NEED_RESCHED) {
+ if (thread_flags & _TIF_NEED_RESCHED_MASK) {
/* Unmask Debug and SError for the next task */
local_daif_restore(DAIF_PROCCTX_NOIRQ);
Index: linux-5.4.17-rt9/arch/arm64/kernel/smp.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/kernel/smp.c
+++ linux-5.4.17-rt9/arch/arm64/kernel/smp.c
@@ -31,6 +31,7 @@
#include
#include
#include
+#include
#include
#include
@@ -39,6 +40,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -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)
Index: linux-5.4.17-rt9/arch/arm64/kernel/traps.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/kernel/traps.c
+++ linux-5.4.17-rt9/arch/arm64/kernel/traps.c
@@ -143,9 +143,12 @@ void show_stack(struct task_struct *tsk,
#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)
Index: linux-5.4.17-rt9/arch/arm64/kvm/va_layout.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/arm64/kvm/va_layout.c
+++ linux-5.4.17-rt9/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 al
BUG_ON(nr_inst != 5);
- if (!has_vhe() && !va_mask)
- compute_layout();
-
for (i = 0; i < nr_inst; i++) {
u32 rd, rn, insn, oinsn;
@@ -156,9 +153,6 @@ void kvm_patch_vector_branch(struct alt_
return;
}
- if (!va_mask)
- compute_layout();
-
/*
* Compute HYP VA by using the same computation as kern_hyp_va()
*/
Index: linux-5.4.17-rt9/arch/c6x/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/c6x/kernel/entry.S
+++ linux-5.4.17-rt9/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 @@ work_notifysig:
;; 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 @@ preempt_schedule:
B .S2 preempt_schedule_irq
#endif
ADDKPC .S2 preempt_schedule,B3,4
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */
ENTRY(enable_exception)
DINT
Index: linux-5.4.17-rt9/arch/csky/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/csky/kernel/entry.S
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/h8300/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/h8300/kernel/entry.S
+++ linux-5.4.17-rt9/arch/h8300/kernel/entry.S
@@ -284,12 +284,12 @@ badsys:
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 @@ work_resched:
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
Index: linux-5.4.17-rt9/arch/hexagon/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/hexagon/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/arch/hexagon/kernel/vm_entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/hexagon/kernel/vm_entry.S
+++ linux-5.4.17-rt9/arch/hexagon/kernel/vm_entry.S
@@ -265,12 +265,12 @@ event_dispatch:
* 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
Index: linux-5.4.17-rt9/arch/ia64/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/ia64/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/arch/ia64/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/ia64/kernel/entry.S
+++ linux-5.4.17-rt9/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 @@ skip_rbs_switch:
/*
* 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
Index: linux-5.4.17-rt9/arch/ia64/kernel/kprobes.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/ia64/kernel/kprobes.c
+++ linux-5.4.17-rt9/arch/ia64/kernel/kprobes.c
@@ -841,7 +841,7 @@ static int __kprobes pre_kprobes_handler
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;
Index: linux-5.4.17-rt9/arch/m68k/coldfire/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/m68k/coldfire/entry.S
+++ linux-5.4.17-rt9/arch/m68k/coldfire/entry.S
@@ -108,7 +108,7 @@ ret_from_exception:
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
Index: linux-5.4.17-rt9/arch/microblaze/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/microblaze/kernel/entry.S
+++ linux-5.4.17-rt9/arch/microblaze/kernel/entry.S
@@ -728,7 +728,7 @@ no_intr_resched:
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;
Index: linux-5.4.17-rt9/arch/mips/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/mips/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/mips/include/asm/asmmacro.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/mips/include/asm/asmmacro.h
+++ linux-5.4.17-rt9/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)
Index: linux-5.4.17-rt9/arch/mips/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/mips/kernel/entry.S
+++ linux-5.4.17-rt9/arch/mips/kernel/entry.S
@@ -19,7 +19,7 @@
#include
#include
-#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 @@ resume_userspace:
bnez t0, work_pending
j restore_all
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
resume_kernel:
local_irq_disable
lw t0, TI_PRE_COUNT($28)
Index: linux-5.4.17-rt9/arch/nds32/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/nds32/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/nds32/kernel/ex-exit.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/nds32/kernel/ex-exit.S
+++ linux-5.4.17-rt9/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 @@ no_work_pending:
/*
* preemptive kernel
*/
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
resume_kernel:
gie_disable
lwi $t0, [tsk+#TSK_TI_PREEMPT]
Index: linux-5.4.17-rt9/arch/nios2/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/nios2/kernel/entry.S
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/parisc/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/parisc/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/parisc/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/parisc/kernel/entry.S
+++ linux-5.4.17-rt9/arch/parisc/kernel/entry.S
@@ -940,14 +940,14 @@ intr_restore:
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 @@ intr_do_resched:
* 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 @@ intr_do_preempt:
nop
b,n intr_restore /* ssm PSW_SM_I done by intr_restore */
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */
/*
* External interrupts.
Index: linux-5.4.17-rt9/arch/powerpc/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/Kconfig
+++ linux-5.4.17-rt9/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
select HAVE_MMU_GATHER_PAGE_SIZE
select HAVE_REGS_AND_STACK_ACCESS_API
@@ -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"
Index: linux-5.4.17-rt9/arch/powerpc/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/arch/powerpc/include/asm/stackprotector.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/include/asm/stackprotector.h
+++ linux-5.4.17-rt9/arch/powerpc/include/asm/stackprotector.h
@@ -24,7 +24,11 @@ static __always_inline void boot_init_st
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;
Index: linux-5.4.17-rt9/arch/powerpc/include/asm/thread_info.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/include/asm/thread_info.h
+++ linux-5.4.17-rt9/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<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 */
@@ -922,7 +931,7 @@ resume_kernel:
*/
bl trace_hardirqs_on
#endif
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */
restore_kuap:
kuap_restore r1, r2, r9, r10, r0
@@ -1225,7 +1234,7 @@ global_dbcr0:
#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
do_work: /* r10 contains MSR_KERNEL here */
- andi. r0,r9,_TIF_NEED_RESCHED
+ andi. r0,r9,_TIF_NEED_RESCHED_MASK
beq do_user_signal
do_resched: /* r10 contains MSR_KERNEL here */
@@ -1246,7 +1255,7 @@ recheck:
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
Index: linux-5.4.17-rt9/arch/powerpc/kernel/entry_64.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/kernel/entry_64.S
+++ linux-5.4.17-rt9/arch/powerpc/kernel/entry_64.S
@@ -240,7 +240,9 @@ system_call_exit:
ld r9,TI_FLAGS(r12)
li r11,-MAX_ERRNO
- andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
+ lis r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@h
+ ori r0,r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@l
+ and. r0,r9,r0
bne- .Lsyscall_exit_work
andi. r0,r8,MSR_FP
@@ -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 @@ resume_kernel:
bne- 0b
1:
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
/* Check if we need to preempt */
+ lwz r8,TI_PREEMPT(r9)
+ cmpwi 0,r8,0 /* if non-zero, just restore regs and return */
+ bne restore
andi. r0,r4,_TIF_NEED_RESCHED
+ bne+ check_count
+
+ andi. r0,r4,_TIF_NEED_RESCHED_LAZY
beq+ restore
+ lwz r8,TI_PREEMPT_LAZY(r9)
+
/* Check that preempt_count() == 0 and interrupts are enabled */
- lwz r8,TI_PREEMPT(r9)
+check_count:
cmpwi cr0,r8,0
bne restore
ld r0,SOFTE(r1)
@@ -877,7 +887,7 @@ resume_kernel:
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:
Index: linux-5.4.17-rt9/arch/powerpc/kernel/irq.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/kernel/irq.c
+++ linux-5.4.17-rt9/arch/powerpc/kernel/irq.c
@@ -679,10 +679,12 @@ void *mcheckirq_ctx[NR_CPUS] __read_most
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)
{
Index: linux-5.4.17-rt9/arch/powerpc/kernel/misc_32.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/kernel/misc_32.S
+++ linux-5.4.17-rt9/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);
Index: linux-5.4.17-rt9/arch/powerpc/kernel/misc_64.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/kernel/misc_64.S
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/powerpc/kernel/traps.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/kernel/traps.c
+++ linux-5.4.17-rt9/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" : "",
Index: linux-5.4.17-rt9/arch/powerpc/kernel/watchdog.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/kernel/watchdog.c
+++ linux-5.4.17-rt9/arch/powerpc/kernel/watchdog.c
@@ -181,11 +181,6 @@ static void watchdog_smp_panic(int cpu,
wd_smp_unlock(&flags);
- printk_safe_flush();
- /*
- * printk_safe_flush() seems to require another print
- * before anything actually goes out to console.
- */
if (sysctl_hardlockup_all_cpu_backtrace)
trigger_allbutself_cpu_backtrace();
Index: linux-5.4.17-rt9/arch/powerpc/kvm/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/kvm/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/powerpc/platforms/ps3/device-init.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/platforms/ps3/device-init.c
+++ linux-5.4.17-rt9/arch/powerpc/platforms/ps3/device-init.c
@@ -738,8 +738,8 @@ static int ps3_notification_read_write(s
}
pr_debug("%s:%u: notification %s issued\n", __func__, __LINE__, op);
- res = wait_event_interruptible(dev->done.wait,
- dev->done.done || kthread_should_stop());
+ res = swait_event_interruptible_exclusive(dev->done.wait,
+ dev->done.done || kthread_should_stop());
if (kthread_should_stop())
res = -EINTR;
if (res) {
Index: linux-5.4.17-rt9/arch/powerpc/platforms/pseries/iommu.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/powerpc/platforms/pseries/iommu.c
+++ linux-5.4.17-rt9/arch/powerpc/platforms/pseries/iommu.c
@@ -24,6 +24,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -177,6 +178,7 @@ static int tce_build_pSeriesLP(unsigned
}
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,
@@ -198,8 +200,8 @@ static int tce_buildmulti_pSeriesLP(stru
direction, attrs);
}
- local_irq_save(flags); /* to protect tcep and the page behind it */
-
+ /* to protect tcep and the page behind it */
+ local_lock_irqsave(tcp_page_lock, flags);
tcep = __this_cpu_read(tce_page);
/* This is safe to do since interrupts are off when we're called
@@ -209,7 +211,7 @@ static int tce_buildmulti_pSeriesLP(stru
tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
/* If allocation fails, fall back to the loop implementation */
if (!tcep) {
- local_irq_restore(flags);
+ local_unlock_irqrestore(tcp_page_lock, flags);
return tce_build_pSeriesLP(tbl->it_index, tcenum,
tbl->it_page_shift,
npages, uaddr, direction, attrs);
@@ -244,7 +246,7 @@ static int tce_buildmulti_pSeriesLP(stru
tcenum += limit;
} while (npages > 0 && !rc);
- local_irq_restore(flags);
+ local_unlock_irqrestore(tcp_page_lock, flags);
if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
ret = (int)rc;
@@ -415,13 +417,14 @@ static int tce_setrange_multi_pSeriesLP(
DMA_BIDIRECTIONAL, 0);
}
- 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);
@@ -467,7 +470,7 @@ static int tce_setrange_multi_pSeriesLP(
/* error cleanup: caller will clear whole range */
- local_irq_enable();
+ local_unlock_irq(tcp_page_lock);
return rc;
}
Index: linux-5.4.17-rt9/arch/riscv/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/riscv/kernel/entry.S
+++ linux-5.4.17-rt9/arch/riscv/kernel/entry.S
@@ -155,7 +155,7 @@ _save_context:
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 @@ restore_all:
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
Index: linux-5.4.17-rt9/arch/s390/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/s390/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/s390/include/asm/preempt.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/s390/include/asm/preempt.h
+++ linux-5.4.17-rt9/arch/s390/include/asm/preempt.h
@@ -130,11 +130,11 @@ static inline bool should_resched(int pr
#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 */
Index: linux-5.4.17-rt9/arch/s390/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/s390/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/arch/s390/kernel/dumpstack.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/s390/kernel/dumpstack.c
+++ linux-5.4.17-rt9/arch/s390/kernel/dumpstack.c
@@ -194,6 +194,8 @@ void die(struct pt_regs *regs, const cha
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())
Index: linux-5.4.17-rt9/arch/s390/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/s390/kernel/entry.S
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/sh/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/sh/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/sh/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/sh/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/arch/sh/kernel/cpu/sh5/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/sh/kernel/cpu/sh5/entry.S
+++ linux-5.4.17-rt9/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 @@ ret_from_exception:
/* Check softirqs */
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
pta ret_from_syscall, tr0
blink tr0, ZERO
Index: linux-5.4.17-rt9/arch/sh/kernel/entry-common.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/sh/kernel/entry-common.S
+++ linux-5.4.17-rt9/arch/sh/kernel/entry-common.S
@@ -41,7 +41,7 @@
*/
#include
-#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)
Index: linux-5.4.17-rt9/arch/sh/kernel/irq.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/sh/kernel/irq.c
+++ linux-5.4.17-rt9/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)
{
Index: linux-5.4.17-rt9/arch/sparc/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/sparc/Kconfig
+++ linux-5.4.17-rt9/arch/sparc/Kconfig
@@ -276,7 +276,7 @@ config US3_MC
config GENERIC_LOCKBREAK
bool
default y
- depends on SPARC64 && SMP && PREEMPT
+ depends on SPARC64 && SMP && PREEMPTION
config NUMA
bool "NUMA support"
Index: linux-5.4.17-rt9/arch/sparc/kernel/irq_64.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/sparc/kernel/irq_64.c
+++ linux-5.4.17-rt9/arch/sparc/kernel/irq_64.c
@@ -854,6 +854,7 @@ void __irq_entry handler_irq(int pil, st
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)
Index: linux-5.4.17-rt9/arch/sparc/kernel/rtrap_64.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/sparc/kernel/rtrap_64.S
+++ linux-5.4.17-rt9/arch/sparc/kernel/rtrap_64.S
@@ -310,7 +310,7 @@ kern_rtt_restore:
retry
to_kernel:
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
ldsw [%g6 + TI_PRE_COUNT], %l5
brnz %l5, kern_fpucheck
ldx [%g6 + TI_FLAGS], %l5
Index: linux-5.4.17-rt9/arch/x86/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/x86/crypto/aesni-intel_glue.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/crypto/aesni-intel_glue.c
+++ linux-5.4.17-rt9/arch/x86/crypto/aesni-intel_glue.c
@@ -387,14 +387,14 @@ static int ecb_encrypt(struct skcipher_r
err = skcipher_walk_virt(&walk, req, true);
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_ecb_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = skcipher_walk_done(&walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -409,14 +409,14 @@ static int ecb_decrypt(struct skcipher_r
err = skcipher_walk_virt(&walk, req, true);
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_ecb_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = skcipher_walk_done(&walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -431,14 +431,14 @@ static int cbc_encrypt(struct skcipher_r
err = skcipher_walk_virt(&walk, req, true);
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_cbc_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = skcipher_walk_done(&walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -453,14 +453,14 @@ static int cbc_decrypt(struct skcipher_r
err = skcipher_walk_virt(&walk, req, true);
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_cbc_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = skcipher_walk_done(&walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -510,18 +510,20 @@ static int ctr_crypt(struct skcipher_req
err = skcipher_walk_virt(&walk, req, true);
- kernel_fpu_begin();
while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
+ kernel_fpu_begin();
aesni_ctr_enc_tfm(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = skcipher_walk_done(&walk, nbytes);
}
if (walk.nbytes) {
+ kernel_fpu_begin();
ctr_crypt_final(ctx, &walk);
+ kernel_fpu_end();
err = skcipher_walk_done(&walk, 0);
}
- kernel_fpu_end();
return err;
}
Index: linux-5.4.17-rt9/arch/x86/crypto/cast5_avx_glue.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/crypto/cast5_avx_glue.c
+++ linux-5.4.17-rt9/arch/x86/crypto/cast5_avx_glue.c
@@ -46,7 +46,7 @@ static inline void cast5_fpu_end(bool fp
static int ecb_crypt(struct skcipher_request *req, bool enc)
{
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
@@ -61,7 +61,7 @@ static int ecb_crypt(struct skcipher_req
u8 *wsrc = walk.src.virt.addr;
u8 *wdst = walk.dst.virt.addr;
- fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, &walk, nbytes);
/* Process multi-block batch */
if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
@@ -90,10 +90,9 @@ static int ecb_crypt(struct skcipher_req
} while (nbytes >= bsize);
done:
+ cast5_fpu_end(fpu_enabled);
err = skcipher_walk_done(&walk, nbytes);
}
-
- cast5_fpu_end(fpu_enabled);
return err;
}
@@ -197,7 +196,7 @@ static int cbc_decrypt(struct skcipher_r
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm);
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct skcipher_walk walk;
unsigned int nbytes;
int err;
@@ -205,12 +204,11 @@ static int cbc_decrypt(struct skcipher_r
err = skcipher_walk_virt(&walk, req, false);
while ((nbytes = walk.nbytes)) {
- fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, &walk, nbytes);
nbytes = __cbc_decrypt(ctx, &walk);
+ cast5_fpu_end(fpu_enabled);
err = skcipher_walk_done(&walk, nbytes);
}
-
- cast5_fpu_end(fpu_enabled);
return err;
}
@@ -277,7 +275,7 @@ static int ctr_crypt(struct skcipher_req
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm);
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct skcipher_walk walk;
unsigned int nbytes;
int err;
@@ -285,13 +283,12 @@ static int ctr_crypt(struct skcipher_req
err = skcipher_walk_virt(&walk, req, false);
while ((nbytes = walk.nbytes) >= CAST5_BLOCK_SIZE) {
- fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, &walk, nbytes);
nbytes = __ctr_crypt(&walk, ctx);
+ cast5_fpu_end(fpu_enabled);
err = skcipher_walk_done(&walk, nbytes);
}
- cast5_fpu_end(fpu_enabled);
-
if (walk.nbytes) {
ctr_crypt_final(&walk, ctx);
err = skcipher_walk_done(&walk, 0);
Index: linux-5.4.17-rt9/arch/x86/crypto/chacha_glue.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/crypto/chacha_glue.c
+++ linux-5.4.17-rt9/arch/x86/crypto/chacha_glue.c
@@ -127,7 +127,6 @@ static int chacha_simd_stream_xor(struct
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
if (nbytes < walk->total) {
nbytes = round_down(nbytes, walk->stride);
- next_yield -= nbytes;
}
chacha_dosimd(state, walk->dst.virt.addr, walk->src.virt.addr,
nbytes, ctx->nrounds);
- if (next_yield <= 0) {
- /* temporarily allow preemption */
- kernel_fpu_end();
- kernel_fpu_begin();
- next_yield = 4096;
- }
-
+ kernel_fpu_end();
err = skcipher_walk_done(walk, walk->nbytes - nbytes);
+ kernel_fpu_begin();
}
return err;
Index: linux-5.4.17-rt9/arch/x86/crypto/glue_helper.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/crypto/glue_helper.c
+++ linux-5.4.17-rt9/arch/x86/crypto/glue_helper.c
@@ -24,7 +24,7 @@ int glue_ecb_req_128bit(const struct com
void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
const unsigned int bsize = 128 / 8;
struct skcipher_walk walk;
- bool fpu_enabled = false;
+ bool fpu_enabled;
unsigned int nbytes;
int err;
@@ -37,7 +37,7 @@ int glue_ecb_req_128bit(const struct com
unsigned int i;
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- &walk, fpu_enabled, nbytes);
+ &walk, false, nbytes);
for (i = 0; i < gctx->num_funcs; i++) {
func_bytes = bsize * gctx->funcs[i].num_blocks;
@@ -55,10 +55,9 @@ int glue_ecb_req_128bit(const struct com
if (nbytes < bsize)
break;
}
+ glue_fpu_end(fpu_enabled);
err = skcipher_walk_done(&walk, nbytes);
}
-
- glue_fpu_end(fpu_enabled);
return err;
}
EXPORT_SYMBOL_GPL(glue_ecb_req_128bit);
@@ -101,7 +100,7 @@ int glue_cbc_decrypt_req_128bit(const st
void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
const unsigned int bsize = 128 / 8;
struct skcipher_walk walk;
- bool fpu_enabled = false;
+ bool fpu_enabled;
unsigned int nbytes;
int err;
@@ -115,7 +114,7 @@ int glue_cbc_decrypt_req_128bit(const st
u128 last_iv;
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- &walk, fpu_enabled, nbytes);
+ &walk, false, nbytes);
/* Start of the last block. */
src += nbytes / bsize - 1;
dst += nbytes / bsize - 1;
@@ -147,10 +146,10 @@ int glue_cbc_decrypt_req_128bit(const st
done:
u128_xor(dst, dst, (u128 *)walk.iv);
*(u128 *)walk.iv = last_iv;
+ glue_fpu_end(fpu_enabled);
err = skcipher_walk_done(&walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
return err;
}
EXPORT_SYMBOL_GPL(glue_cbc_decrypt_req_128bit);
@@ -161,7 +160,7 @@ int glue_ctr_req_128bit(const struct com
void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
const unsigned int bsize = 128 / 8;
struct skcipher_walk walk;
- bool fpu_enabled = false;
+ bool fpu_enabled;
unsigned int nbytes;
int err;
@@ -175,7 +174,7 @@ int glue_ctr_req_128bit(const struct com
le128 ctrblk;
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- &walk, fpu_enabled, nbytes);
+ &walk, false, nbytes);
be128_to_le128(&ctrblk, (be128 *)walk.iv);
@@ -199,11 +198,10 @@ int glue_ctr_req_128bit(const struct com
}
le128_to_be128((be128 *)walk.iv, &ctrblk);
+ glue_fpu_end(fpu_enabled);
err = skcipher_walk_done(&walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
-
if (nbytes) {
le128 ctrblk;
u128 tmp;
@@ -301,8 +299,14 @@ int glue_xts_req_128bit(const struct com
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;
}
Index: linux-5.4.17-rt9/arch/x86/entry/common.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/entry/common.c
+++ linux-5.4.17-rt9/arch/x86/entry/common.c
@@ -130,7 +130,7 @@ static long syscall_trace_enter(struct p
#define EXIT_TO_USERMODE_LOOP_FLAGS \
(_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
- _TIF_NEED_RESCHED | _TIF_USER_RETURN_NOTIFY | _TIF_PATCH_PENDING)
+ _TIF_NEED_RESCHED_MASK | _TIF_USER_RETURN_NOTIFY | _TIF_PATCH_PENDING)
static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
{
@@ -145,9 +145,16 @@ static void exit_to_usermode_loop(struct
/* We have work to do. */
local_irq_enable();
- if (cached_flags & _TIF_NEED_RESCHED)
+ if (cached_flags & _TIF_NEED_RESCHED_MASK)
schedule();
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+ if (unlikely(current->forced_info.si_signo)) {
+ struct task_struct *t = current;
+ force_sig_info(&t->forced_info);
+ t->forced_info.si_signo = 0;
+ }
+#endif
if (cached_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
Index: linux-5.4.17-rt9/arch/x86/entry/entry_32.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/entry/entry_32.S
+++ linux-5.4.17-rt9/arch/x86/entry/entry_32.S
@@ -1106,8 +1106,26 @@ restore_all:
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
Index: linux-5.4.17-rt9/arch/x86/entry/entry_64.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/entry/entry_64.S
+++ linux-5.4.17-rt9/arch/x86/entry/entry_64.S
@@ -670,7 +670,23 @@ retint_kernel:
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
Index: linux-5.4.17-rt9/arch/x86/include/asm/fpu/api.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/include/asm/fpu/api.h
+++ linux-5.4.17-rt9/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.
Index: linux-5.4.17-rt9/arch/x86/include/asm/preempt.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/include/asm/preempt.h
+++ linux-5.4.17-rt9/arch/x86/include/asm/preempt.h
@@ -89,17 +89,48 @@ static __always_inline void __preempt_co
* a decrement which hits zero means we have no preempt_count and should
* reschedule.
*/
-static __always_inline bool __preempt_count_dec_and_test(void)
+static __always_inline bool ____preempt_count_dec_and_test(void)
{
return GEN_UNARY_RMWcc("decl", __preempt_count, e, __percpu_arg([var]));
}
+static __always_inline bool __preempt_count_dec_and_test(void)
+{
+ if (____preempt_count_dec_and_test())
+ return true;
+#ifdef CONFIG_PREEMPT_LAZY
+ if (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
Index: linux-5.4.17-rt9/arch/x86/include/asm/signal.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/include/asm/signal.h
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/arch/x86/include/asm/stackprotector.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/include/asm/stackprotector.h
+++ linux-5.4.17-rt9/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_st
* of randomness. The TSC only matters for very early init,
* there it already has some randomness on most systems. Later
* on during the bootup the random pool has true entropy too.
+ * For preempt-rt we need to weaken the randomness a bit, as
+ * we can't call into the random generator from atomic context
+ * due to locking constraints. We just leave canary
+ * uninitialized and use the TSC based randomness on top of it.
*/
+#ifndef CONFIG_PREEMPT_RT
get_random_bytes(&canary, sizeof(canary));
+#endif
tsc = rdtsc();
canary += tsc + (tsc << 32UL);
canary &= CANARY_MASK;
Index: linux-5.4.17-rt9/arch/x86/include/asm/thread_info.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/include/asm/thread_info.h
+++ linux-5.4.17-rt9/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
+#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)
/*
Index: linux-5.4.17-rt9/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-5.4.17-rt9/arch/x86/kernel/apic/io_apic.c
@@ -1725,7 +1725,7 @@ static bool io_apic_level_ack_pending(st
return false;
}
-static inline bool ioapic_irqd_mask(struct irq_data *data)
+static inline bool ioapic_prepare_move(struct irq_data *data)
{
/* If we are moving the IRQ we need to mask it */
if (unlikely(irqd_is_setaffinity_pending(data))) {
@@ -1736,9 +1736,9 @@ static inline bool ioapic_irqd_mask(stru
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(st
}
}
#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_
{
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_
eoi_ioapic_pin(cfg->vector, irq_data->chip_data);
}
- ioapic_irqd_unmask(irq_data, masked);
+ ioapic_finish_move(irq_data, moveit);
}
static void ioapic_ir_ack_level(struct irq_data *irq_data)
Index: linux-5.4.17-rt9/arch/x86/kernel/asm-offsets.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/kernel/asm-offsets.c
+++ linux-5.4.17-rt9/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);
Index: linux-5.4.17-rt9/arch/x86/kernel/cpu/mshyperv.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/kernel/cpu/mshyperv.c
+++ linux-5.4.17-rt9/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();
Index: linux-5.4.17-rt9/arch/x86/kernel/fpu/core.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/kernel/fpu/core.c
+++ linux-5.4.17-rt9/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):
*
Index: linux-5.4.17-rt9/arch/x86/kernel/irq_32.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/kernel/irq_32.c
+++ linux-5.4.17-rt9/arch/x86/kernel/irq_32.c
@@ -131,6 +131,7 @@ int irq_init_percpu_irqstack(unsigned in
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)
{
Index: linux-5.4.17-rt9/arch/x86/kernel/process_32.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/kernel/process_32.c
+++ linux-5.4.17-rt9/arch/x86/kernel/process_32.c
@@ -38,6 +38,7 @@
#include
#include
#include
+#include
#include
#include
@@ -196,6 +197,35 @@ start_thread(struct pt_regs *regs, unsig
}
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,
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
Index: linux-5.4.17-rt9/arch/x86/kvm/x86.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/kvm/x86.c
+++ linux-5.4.17-rt9/arch/x86/kvm/x86.c
@@ -7257,6 +7257,14 @@ 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,
Index: linux-5.4.17-rt9/arch/x86/mm/highmem_32.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/mm/highmem_32.c
+++ linux-5.4.17-rt9/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
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);
Index: linux-5.4.17-rt9/arch/x86/mm/iomap_32.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/mm/iomap_32.c
+++ linux-5.4.17-rt9/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
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();
}
Index: linux-5.4.17-rt9/arch/x86/mm/tlb.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/x86/mm/tlb.c
+++ linux-5.4.17-rt9/arch/x86/mm/tlb.c
@@ -708,7 +708,7 @@ void native_flush_tlb_others(const struc
(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);
}
/*
Index: linux-5.4.17-rt9/arch/xtensa/include/asm/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/arch/xtensa/include/asm/spinlock_types.h
+++ linux-5.4.17-rt9/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
#include
Index: linux-5.4.17-rt9/arch/xtensa/kernel/entry.S
===================================================================
--- linux-5.4.17-rt9.orig/arch/xtensa/kernel/entry.S
+++ linux-5.4.17-rt9/arch/xtensa/kernel/entry.S
@@ -520,7 +520,7 @@ common_exception_return:
call4 schedule # void schedule (void)
j 1b
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
6:
_bbci.l a4, TIF_NEED_RESCHED, 4f
Index: linux-5.4.17-rt9/arch/xtensa/kernel/traps.c
===================================================================
--- linux-5.4.17-rt9.orig/arch/xtensa/kernel/traps.c
+++ linux-5.4.17-rt9/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]);
Index: linux-5.4.17-rt9/block/blk-ioc.c
===================================================================
--- linux-5.4.17-rt9.orig/block/blk-ioc.c
+++ linux-5.4.17-rt9/block/blk-ioc.c
@@ -9,6 +9,7 @@
#include
#include
#include
+#include
#include "blk.h"
@@ -115,7 +116,7 @@ static void ioc_release_fn(struct work_s
spin_unlock(&q->queue_lock);
} else {
spin_unlock_irqrestore(&ioc->lock, flags);
- cpu_relax();
+ cpu_chill();
spin_lock_irqsave_nested(&ioc->lock, flags, 1);
}
}
Index: linux-5.4.17-rt9/block/blk-mq.c
===================================================================
--- linux-5.4.17-rt9.orig/block/blk-mq.c
+++ linux-5.4.17-rt9/block/blk-mq.c
@@ -611,9 +611,17 @@ static void __blk_mq_complete_request(st
return;
}
- cpu = get_cpu();
+ cpu = get_cpu_light();
+ /*
+ * Avoid SMP function calls for completions because they acquire
+ * sleeping spinlocks on RT.
+ */
+#ifdef CONFIG_PREEMPT_RT
+ 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(st
} else {
q->mq_ops->complete(rq);
}
- put_cpu();
+ put_cpu_light();
}
static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx)
@@ -1466,14 +1474,14 @@ static void __blk_mq_delay_run_hw_queue(
return;
if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
- int cpu = get_cpu();
+ int cpu = get_cpu_light();
if (cpumask_test_cpu(cpu, hctx->cpumask)) {
__blk_mq_run_hw_queue(hctx);
- put_cpu();
+ put_cpu_light();
return;
}
- put_cpu();
+ put_cpu_light();
}
kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work,
Index: linux-5.4.17-rt9/block/blk-softirq.c
===================================================================
--- linux-5.4.17-rt9.orig/block/blk-softirq.c
+++ linux-5.4.17-rt9/block/blk-softirq.c
@@ -42,17 +42,13 @@ static __latent_entropy void blk_done_so
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
this_cpu_ptr(&blk_cpu_done));
raise_softirq_irqoff(BLOCK_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
return 0;
}
@@ -142,6 +139,7 @@ do_local:
goto do_local;
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
static __init int blk_softirq_init(void)
Index: linux-5.4.17-rt9/crypto/cryptd.c
===================================================================
--- linux-5.4.17-rt9.orig/crypto/cryptd.c
+++ linux-5.4.17-rt9/crypto/cryptd.c
@@ -36,6 +36,7 @@ static struct workqueue_struct *cryptd_w
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 cryp
cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
INIT_WORK(&cpu_queue->work, cryptd_queue_worker);
+ spin_lock_init(&cpu_queue->qlock);
}
pr_info("cryptd: max_cpu_qlen set to %d\n", max_cpu_qlen);
return 0;
@@ -129,8 +131,10 @@ static int cryptd_enqueue_request(struct
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
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 w
cpu_queue = container_of(work, struct cryptd_cpu_queue, work);
/*
* Only handle one request at a time to avoid hogging crypto workqueue.
- * preempt_disable/enable is used to prevent being preempted by
- * cryptd_enqueue_request(). local_bh_disable/enable is used to prevent
- * cryptd_enqueue_request() being accessed from software interrupts.
*/
- local_bh_disable();
- preempt_disable();
+ spin_lock_bh(&cpu_queue->qlock);
backlog = crypto_get_backlog(&cpu_queue->queue);
req = crypto_dequeue_request(&cpu_queue->queue);
- preempt_enable();
- local_bh_enable();
+ spin_unlock_bh(&cpu_queue->qlock);
if (!req)
return;
Index: linux-5.4.17-rt9/drivers/block/zram/zcomp.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/block/zram/zcomp.c
+++ linux-5.4.17-rt9/drivers/block/zram/zcomp.c
@@ -113,12 +113,20 @@ ssize_t zcomp_available_show(const char
struct zcomp_strm *zcomp_stream_get(struct zcomp *comp)
{
- return *get_cpu_ptr(comp->stream);
+ struct zcomp_strm *zstrm;
+
+ zstrm = *get_local_ptr(comp->stream);
+ spin_lock(&zstrm->zcomp_lock);
+ return zstrm;
}
void zcomp_stream_put(struct zcomp *comp)
{
- put_cpu_ptr(comp->stream);
+ struct zcomp_strm *zstrm;
+
+ zstrm = *this_cpu_ptr(comp->stream);
+ spin_unlock(&zstrm->zcomp_lock);
+ put_local_ptr(zstrm);
}
int zcomp_compress(struct zcomp_strm *zstrm,
@@ -168,6 +176,7 @@ int zcomp_cpu_up_prepare(unsigned int cp
pr_err("Can't allocate a compression stream\n");
return -ENOMEM;
}
+ spin_lock_init(&zstrm->zcomp_lock);
*per_cpu_ptr(comp->stream, cpu) = zstrm;
return 0;
}
Index: linux-5.4.17-rt9/drivers/block/zram/zcomp.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/block/zram/zcomp.h
+++ linux-5.4.17-rt9/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 */
Index: linux-5.4.17-rt9/drivers/block/zram/zram_drv.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/block/zram/zram_drv.c
+++ linux-5.4.17-rt9/drivers/block/zram/zram_drv.c
@@ -55,6 +55,40 @@ static void zram_free_page(struct zram *
static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
u32 index, int offset, struct bio *bio);
+#ifdef CONFIG_PREEMPT_RT
+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
{
bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags);
}
+#endif
static inline bool init_done(struct zram *zram)
{
@@ -1154,6 +1189,7 @@ static bool zram_meta_alloc(struct zram
if (!huge_class_size)
huge_class_size = zs_huge_class_size(zram->mem_pool);
+ zram_meta_init_table_locks(zram, num_pages);
return true;
}
@@ -1216,6 +1252,7 @@ static int __zram_bvec_read(struct zram
unsigned long handle;
unsigned int size;
void *src, *dst;
+ struct zcomp_strm *zstrm;
zram_slot_lock(zram, index);
if (zram_test_flag(zram, index, ZRAM_WB)) {
@@ -1246,6 +1283,7 @@ static int __zram_bvec_read(struct zram
size = zram_get_obj_size(zram, index);
+ zstrm = zcomp_stream_get(zram->comp);
src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
if (size == PAGE_SIZE) {
dst = kmap_atomic(page);
@@ -1253,14 +1291,13 @@ static int __zram_bvec_read(struct zram
kunmap_atomic(dst);
ret = 0;
} else {
- struct zcomp_strm *zstrm = zcomp_stream_get(zram->comp);
dst = kmap_atomic(page);
ret = zcomp_decompress(zstrm, src, size, dst);
kunmap_atomic(dst);
- zcomp_stream_put(zram->comp);
}
zs_unmap_object(zram->mem_pool, handle);
+ zcomp_stream_put(zram->comp);
zram_slot_unlock(zram, index);
/* Should NEVER happen. Return bio error if it does. */
Index: linux-5.4.17-rt9/drivers/block/zram/zram_drv.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/block/zram/zram_drv.h
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/drivers/char/random.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/char/random.c
+++ linux-5.4.17-rt9/drivers/char/random.c
@@ -1305,28 +1305,27 @@ static __u32 get_reg(struct fast_pool *f
return *ptr;
}
-void add_interrupt_randomness(int irq, int irq_flags)
+void add_interrupt_randomness(int irq, int irq_flags, __u64 ip)
{
struct entropy_store *r;
struct fast_pool *fast_pool = this_cpu_ptr(&irq_randomness);
- struct pt_regs *regs = get_irq_regs();
unsigned long now = jiffies;
cycles_t cycles = random_get_entropy();
__u32 c_high, j_high;
- __u64 ip;
unsigned long seed;
int credit = 0;
if (cycles == 0)
- cycles = get_reg(fast_pool, regs);
+ cycles = get_reg(fast_pool, NULL);
c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0;
j_high = (sizeof(now) > 4) ? now >> 32 : 0;
fast_pool->pool[0] ^= cycles ^ j_high ^ irq;
fast_pool->pool[1] ^= now ^ c_high;
- ip = regs ? instruction_pointer(regs) : _RET_IP_;
+ if (!ip)
+ ip = _RET_IP_;
fast_pool->pool[2] ^= ip;
fast_pool->pool[3] ^= (sizeof(ip) > 4) ? ip >> 32 :
- get_reg(fast_pool, regs);
+ get_reg(fast_pool, NULL);
fast_mix(fast_pool);
add_interrupt_bench(cycles);
Index: linux-5.4.17-rt9/drivers/char/tpm/tpm-dev-common.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/char/tpm/tpm-dev-common.c
+++ linux-5.4.17-rt9/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)
Index: linux-5.4.17-rt9/drivers/char/tpm/tpm_tis.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/char/tpm/tpm_tis.c
+++ linux-5.4.17-rt9/drivers/char/tpm/tpm_tis.c
@@ -49,6 +49,31 @@ static inline struct tpm_tis_tcg_phy *to
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 tp
struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
while (len--)
- iowrite8(*value++, phy->iobase + addr);
+ tpm_tis_iowrite8(*value++, phy->iobase, addr);
return 0;
}
@@ -173,7 +198,7 @@ static int tpm_tcg_write32(struct tpm_ti
{
struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
- iowrite32(value, phy->iobase + addr);
+ tpm_tis_iowrite32(value, phy->iobase, addr);
return 0;
}
Index: linux-5.4.17-rt9/drivers/clocksource/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/drivers/clocksource/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/drivers/clocksource/timer-atmel-tcb.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/clocksource/timer-atmel-tcb.c
+++ linux-5.4.17-rt9/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_ti
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_cl
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_even
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_e
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_
/* 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
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
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
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
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
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;
Index: linux-5.4.17-rt9/drivers/connector/cn_proc.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/connector/cn_proc.c
+++ linux-5.4.17-rt9/drivers/connector/cn_proc.c
@@ -18,6 +18,7 @@
#include
#include
+#include
/*
* 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 = {
/* 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_ms
*/
cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
- preempt_enable();
+ local_unlock(send_msg_lock);
}
void proc_fork_connector(struct task_struct *task)
Index: linux-5.4.17-rt9/drivers/dma-buf/dma-buf.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/dma-buf/dma-buf.c
+++ linux-5.4.17-rt9/drivers/dma-buf/dma-buf.c
@@ -214,7 +214,7 @@ static __poll_t dma_buf_poll(struct file
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 @@ retry:
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
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();
}
Index: linux-5.4.17-rt9/drivers/dma-buf/dma-resv.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/dma-buf/dma-resv.c
+++ linux-5.4.17-rt9/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 dm
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 @@ replace:
/* 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_
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 @@ retry:
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_r
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_r
}
}
- 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 dm
retry:
shared_count = 0;
- seq = read_seqcount_begin(&obj->seq);
+ seq = read_seqbegin(&obj->seq);
rcu_read_lock();
i = -1;
@@ -553,7 +540,7 @@ retry:
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 d
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 @@ retry:
break;
}
- if (read_seqcount_retry(&obj->seq, seq))
+ if (read_seqretry(&obj->seq, seq))
goto retry;
}
@@ -639,7 +626,7 @@ retry:
if (ret < 0)
goto retry;
- if (read_seqcount_retry(&obj->seq, seq))
+ if (read_seqretry(&obj->seq, seq))
goto retry;
}
}
Index: linux-5.4.17-rt9/drivers/firmware/efi/efi.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/firmware/efi/efi.c
+++ linux-5.4.17-rt9/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
if (parse_option_str(str, "noruntime"))
disable_runtime = true;
+ if (parse_option_str(str, "runtime"))
+ disable_runtime = false;
+
return 0;
}
early_param("efi", parse_efi_cmdline);
Index: linux-5.4.17-rt9/drivers/gpu/drm/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -252,11 +252,9 @@ static int amdgpu_amdkfd_remove_eviction
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) {
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/display/intel_sprite.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/display/intel_sprite.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -38,6 +38,7 @@
#include
#include
#include
+#include
#include "i915_drv.h"
#include "i915_trace.h"
@@ -80,6 +81,8 @@ int intel_usecs_to_scanlines(const struc
#define VBLANK_EVASION_TIME_US 100
#endif
+static DEFINE_LOCAL_IRQ_LOCK(pipe_update_lock);
+
/**
* intel_pipe_update_start() - start update of a set of display registers
* @new_crtc_state: the new crtc state
@@ -129,7 +132,7 @@ void intel_pipe_update_start(const struc
DRM_ERROR("PSR idle timed out 0x%x, atomic update may fail\n",
psr_status);
- local_irq_disable();
+ local_lock_irq(pipe_update_lock);
crtc->debug.min_vbl = min;
crtc->debug.max_vbl = max;
@@ -153,11 +156,11 @@ void intel_pipe_update_start(const struc
break;
}
- local_irq_enable();
+ local_unlock_irq(pipe_update_lock);
timeout = schedule_timeout(timeout);
- local_irq_disable();
+ local_lock_irq(pipe_update_lock);
}
finish_wait(wq, &wait);
@@ -190,7 +193,7 @@ void intel_pipe_update_start(const struc
return;
irq_disable:
- local_irq_disable();
+ local_lock_irq(pipe_update_lock);
}
/**
@@ -226,7 +229,7 @@ void intel_pipe_update_end(struct intel_
new_crtc_state->base.event = NULL;
}
- local_irq_enable();
+ local_unlock_irq(pipe_update_lock);
if (intel_vgpu_active(dev_priv))
return;
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/gem/i915_gem_busy.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/gem/i915_gem_busy.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/gem/i915_gem_busy.c
@@ -75,7 +75,6 @@ busy_check_writer(const struct dma_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 *d
*
*/
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 @@ retry:
}
}
- 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;
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
@@ -120,7 +120,6 @@ __dma_fence_signal__notify(struct dma_fe
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
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
}
}
- 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(struc
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(stru
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
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_engine.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/gt/intel_engine.h
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -357,7 +357,6 @@ void intel_engine_init_execlists(struct
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
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_engine_pm.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/gt/intel_engine_pm.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -38,12 +38,15 @@ static int __engine_unpark(struct intel_
}
#if IS_ENABLED(CONFIG_LOCKDEP)
+#include
+
+static DEFINE_LOCAL_IRQ_LOCK(timeline_lock);
static inline unsigned long __timeline_mark_lock(struct intel_context *ce)
{
unsigned long flags;
- local_irq_save(flags);
+ local_lock_irqsave(timeline_lock, flags);
mutex_acquire(&ce->timeline->mutex.dep_map, 2, 0, _THIS_IP_);
return flags;
@@ -53,7 +56,7 @@ static inline void __timeline_mark_unloc
unsigned long flags)
{
mutex_release(&ce->timeline->mutex.dep_map, 0, _THIS_IP_);
- local_irq_restore(flags);
+ local_unlock_irqrestore(timeline_lock, flags);
}
#else
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_hangcheck.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/gt/intel_hangcheck.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_hangcheck.c
@@ -283,7 +283,7 @@ static void hangcheck_elapsed(struct wor
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);
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_reset.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/gt/intel_reset.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -695,7 +695,7 @@ static void reset_finish_engine(struct i
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)
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/i915_irq.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/i915_irq.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/i915_irq.c
@@ -983,6 +983,7 @@ bool i915_get_crtc_scanoutpos(struct drm
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
*etime = ktime_get();
/* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */
+ preempt_enable_rt();
spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/i915_request.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/i915_request.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/i915/i915_request.c
@@ -205,14 +205,14 @@ static void remove_from_engine(struct i9
* 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 i
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 i
*/
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 i
__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);
Index: linux-5.4.17-rt9/drivers/gpu/drm/i915/i915_trace.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/i915/i915_trace.h
+++ linux-5.4.17-rt9/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
#include
#include
@@ -721,7 +725,7 @@ DEFINE_EVENT(i915_request, i915_request_
TP_ARGS(rq)
);
-#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS)
+#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS) && !defined(NOTRACE)
DEFINE_EVENT(i915_request, i915_request_submit,
TP_PROTO(struct i915_request *rq),
TP_ARGS(rq)
Index: linux-5.4.17-rt9/drivers/gpu/drm/radeon/radeon_display.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/radeon/radeon_display.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/radeon/radeon_display.c
@@ -1821,6 +1821,7 @@ int radeon_get_crtc_scanoutpos(struct dr
struct radeon_device *rdev = dev->dev_private;
/* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */
+ preempt_disable_rt();
/* Get optional system timestamp before query. */
if (stime)
@@ -1913,6 +1914,7 @@ int radeon_get_crtc_scanoutpos(struct dr
*etime = ktime_get();
/* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */
+ preempt_enable_rt();
/* Decode into vertical and horizontal scanout position. */
*vpos = position & 0x1fff;
Index: linux-5.4.17-rt9/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
+++ linux-5.4.17-rt9/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
@@ -169,10 +169,8 @@ void vmw_fifo_ping_host(struct vmw_priva
{
u32 *fifo_mem = dev_priv->mmio_virt;
- preempt_disable();
if (cmpxchg(fifo_mem + SVGA_FIFO_BUSY, 0, 1) == 0)
vmw_write(dev_priv, SVGA_REG_SYNC, reason);
- preempt_enable();
}
void vmw_fifo_release(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
Index: linux-5.4.17-rt9/drivers/hv/hyperv_vmbus.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/hv/hyperv_vmbus.h
+++ linux-5.4.17-rt9/drivers/hv/hyperv_vmbus.h
@@ -18,6 +18,7 @@
#include
#include
#include
+#include
#include "hv_trace.h"
Index: linux-5.4.17-rt9/drivers/hv/vmbus_drv.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/hv/vmbus_drv.c
+++ linux-5.4.17-rt9/drivers/hv/vmbus_drv.c
@@ -22,6 +22,7 @@
#include
#include
#include
+#include
#include
#include
@@ -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);
}
/*
Index: linux-5.4.17-rt9/drivers/leds/trigger/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/drivers/leds/trigger/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/drivers/md/bcache/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/drivers/md/bcache/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/drivers/md/raid5.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/md/raid5.c
+++ linux-5.4.17-rt9/drivers/md/raid5.c
@@ -2058,8 +2058,9 @@ static void raid_run_ops(struct stripe_h
struct raid5_percpu *percpu;
unsigned long cpu;
- cpu = get_cpu();
+ cpu = get_cpu_light();
percpu = per_cpu_ptr(conf->percpu, cpu);
+ spin_lock(&percpu->lock);
if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
ops_run_biofill(sh);
overlap_clear++;
@@ -2118,7 +2119,8 @@ static void raid_run_ops(struct stripe_h
if (test_and_clear_bit(R5_Overlap, &dev->flags))
wake_up(&sh->raid_conf->wait_for_overlap);
}
- put_cpu();
+ spin_unlock(&percpu->lock);
+ put_cpu_light();
}
static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh)
@@ -6821,6 +6823,7 @@ static int raid456_cpu_up_prepare(unsign
__func__, cpu);
return -ENOMEM;
}
+ spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock);
return 0;
}
Index: linux-5.4.17-rt9/drivers/md/raid5.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/md/raid5.h
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/drivers/media/platform/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/drivers/media/platform/Kconfig
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
+++ linux-5.4.17-rt9/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
@@ -693,8 +693,8 @@ static void ezusb_req_ctx_wait(struct ez
while (!ctx->done.done && msecs--)
udelay(1000);
} else {
- wait_event_interruptible(ctx->done.wait,
- ctx->done.done);
+ swait_event_interruptible_exclusive(ctx->done.wait,
+ ctx->done.done);
}
break;
default:
Index: linux-5.4.17-rt9/drivers/of/base.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/of/base.c
+++ linux-5.4.17-rt9/drivers/of/base.c
@@ -123,115 +123,38 @@ int __weak of_node_to_nid(struct device_
}
#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];
-/*
- * Caller must hold devtree_lock.
- */
-static void __of_free_phandle_cache(void)
+static u32 of_phandle_cache_hash(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;
+ return hash_32(handle, OF_PHANDLE_CACHE_BITS);
}
-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)
+void __of_phandle_cache_inv_entry(phandle handle)
{
- phandle masked_handle;
+ u32 handle_hash;
struct device_node *np;
if (!handle)
return;
- masked_handle = handle & phandle_cache_mask;
-
- 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();
+ handle_hash = of_phandle_cache_hash(handle);
- 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_phan
{
struct device_node *np = NULL;
unsigned long flags;
- phandle masked_handle;
+ u32 handle_hash;
if (!handle)
return NULL;
- raw_spin_lock_irqsave(&devtree_lock, flags);
+ handle_hash = of_phandle_cache_hash(handle);
- masked_handle = handle & phandle_cache_mask;
+ raw_spin_lock_irqsave(&devtree_lock, flags);
- 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;
}
}
Index: linux-5.4.17-rt9/drivers/of/dynamic.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/of/dynamic.c
+++ linux-5.4.17-rt9/drivers/of/dynamic.c
@@ -276,7 +276,7 @@ void __of_detach_node(struct device_node
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);
}
/**
Index: linux-5.4.17-rt9/drivers/of/of_private.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/of/of_private.h
+++ linux-5.4.17-rt9/drivers/of/of_private.h
@@ -85,14 +85,12 @@ int of_resolve_phandles(struct device_no
#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) {};
Index: linux-5.4.17-rt9/drivers/of/overlay.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/of/overlay.c
+++ linux-5.4.17-rt9/drivers/of/overlay.c
@@ -974,8 +974,6 @@ static int of_overlay_apply(const void *
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;
Index: linux-5.4.17-rt9/drivers/pci/switch/switchtec.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/pci/switch/switchtec.c
+++ linux-5.4.17-rt9/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_cre
stuser->stdev = stdev;
kref_init(&stuser->kref);
INIT_LIST_HEAD(&stuser->list);
- init_completion(&stuser->comp);
+ init_waitqueue_head(&stuser->cmd_comp);
stuser->event_cnt = atomic_read(&stdev->event_cnt);
dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser);
@@ -175,7 +176,7 @@ static int mrpc_queue_cmd(struct switcht
kref_get(&stuser->kref);
stuser->read_len = sizeof(stuser->data);
stuser_set_state(stuser, MRPC_QUEUED);
- init_completion(&stuser->comp);
+ stuser->cmd_done = false;
list_add_tail(&stuser->list, &stdev->mrpc_queue);
mrpc_cmd_submit(stdev);
@@ -222,7 +223,8 @@ static void mrpc_complete_cmd(struct swi
memcpy_fromio(stuser->data, &stdev->mmio_mrpc->output_data,
stuser->read_len);
out:
- complete_all(&stuser->comp);
+ stuser->cmd_done = true;
+ wake_up_interruptible(&stuser->cmd_comp);
list_del_init(&stuser->list);
stuser_put(stuser);
stdev->mrpc_busy = 0;
@@ -494,10 +496,11 @@ static ssize_t switchtec_dev_read(struct
mutex_unlock(&stdev->mrpc_mutex);
if (filp->f_flags & O_NONBLOCK) {
- if (!try_wait_for_completion(&stuser->comp))
+ if (!READ_ONCE(stuser->cmd_done))
return -EAGAIN;
} else {
- rc = wait_for_completion_interruptible(&stuser->comp);
+ rc = wait_event_interruptible(stuser->cmd_comp,
+ stuser->cmd_done);
if (rc < 0)
return rc;
}
@@ -545,7 +548,7 @@ static __poll_t switchtec_dev_poll(struc
struct switchtec_dev *stdev = stuser->stdev;
__poll_t ret = 0;
- poll_wait(filp, &stuser->comp.wait, wait);
+ poll_wait(filp, &stuser->cmd_comp, wait);
poll_wait(filp, &stdev->event_wq, wait);
if (lock_mutex_and_test_alive(stdev))
@@ -553,7 +556,7 @@ static __poll_t switchtec_dev_poll(struc
mutex_unlock(&stdev->mrpc_mutex);
- if (try_wait_for_completion(&stuser->comp))
+ if (READ_ONCE(stuser->cmd_done))
ret |= EPOLLIN | EPOLLRDNORM;
if (stuser->event_cnt != atomic_read(&stdev->event_cnt))
@@ -1106,7 +1109,8 @@ static void stdev_kill(struct switchtec_
/* Wake up and kill any users waiting on an MRPC request */
list_for_each_entry_safe(stuser, tmpuser, &stdev->mrpc_queue, list) {
- complete_all(&stuser->comp);
+ stuser->cmd_done = true;
+ wake_up_interruptible(&stuser->cmd_comp);
list_del_init(&stuser->list);
stuser_put(stuser);
}
Index: linux-5.4.17-rt9/drivers/scsi/fcoe/fcoe.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/scsi/fcoe/fcoe.c
+++ linux-5.4.17-rt9/drivers/scsi/fcoe/fcoe.c
@@ -1452,11 +1452,11 @@ err2:
static int fcoe_alloc_paged_crc_eof(struct sk_buff *skb, int tlen)
{
struct fcoe_percpu_s *fps;
- int rc;
+ int rc, cpu = get_cpu_light();
- fps = &get_cpu_var(fcoe_percpu);
+ fps = &per_cpu(fcoe_percpu, cpu);
rc = fcoe_get_paged_crc_eof(skb, tlen, fps);
- put_cpu_var(fcoe_percpu);
+ put_cpu_light();
return rc;
}
@@ -1641,11 +1641,11 @@ static inline int fcoe_filter_frames(str
return 0;
}
- stats = per_cpu_ptr(lport->stats, get_cpu());
+ stats = per_cpu_ptr(lport->stats, get_cpu_light());
stats->InvalidCRCCount++;
if (stats->InvalidCRCCount < 5)
printk(KERN_WARNING "fcoe: dropping frame with CRC error\n");
- put_cpu();
+ put_cpu_light();
return -EINVAL;
}
@@ -1686,7 +1686,7 @@ static void fcoe_recv_frame(struct sk_bu
*/
hp = (struct fcoe_hdr *) skb_network_header(skb);
- stats = per_cpu_ptr(lport->stats, get_cpu());
+ stats = per_cpu_ptr(lport->stats, get_cpu_light());
if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
if (stats->ErrorFrames < 5)
printk(KERN_WARNING "fcoe: FCoE version "
@@ -1718,13 +1718,13 @@ static void fcoe_recv_frame(struct sk_bu
goto drop;
if (!fcoe_filter_frames(lport, fp)) {
- put_cpu();
+ put_cpu_light();
fc_exch_recv(lport, fp);
return;
}
drop:
stats->ErrorFrames++;
- put_cpu();
+ put_cpu_light();
kfree_skb(skb);
}
Index: linux-5.4.17-rt9/drivers/scsi/fcoe/fcoe_ctlr.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/scsi/fcoe/fcoe_ctlr.c
+++ linux-5.4.17-rt9/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -826,7 +826,7 @@ static unsigned long fcoe_ctlr_age_fcfs(
INIT_LIST_HEAD(&del_list);
- stats = per_cpu_ptr(fip->lp->stats, get_cpu());
+ stats = per_cpu_ptr(fip->lp->stats, get_cpu_light());
list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
@@ -862,7 +862,7 @@ static unsigned long fcoe_ctlr_age_fcfs(
sel_time = fcf->time;
}
}
- put_cpu();
+ put_cpu_light();
list_for_each_entry_safe(fcf, next, &del_list, list) {
/* Removes fcf from current list */
Index: linux-5.4.17-rt9/drivers/scsi/libfc/fc_exch.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/scsi/libfc/fc_exch.c
+++ linux-5.4.17-rt9/drivers/scsi/libfc/fc_exch.c
@@ -821,10 +821,10 @@ static struct fc_exch *fc_exch_em_alloc(
}
memset(ep, 0, sizeof(*ep));
- cpu = get_cpu();
+ cpu = get_cpu_light();
pool = per_cpu_ptr(mp->pool, cpu);
spin_lock_bh(&pool->lock);
- put_cpu();
+ put_cpu_light();
/* peek cache of free slot */
if (pool->left != FC_XID_UNKNOWN) {
Index: linux-5.4.17-rt9/drivers/thermal/intel/x86_pkg_temp_thermal.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/thermal/intel/x86_pkg_temp_thermal.c
+++ linux-5.4.17-rt9/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_w
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_w
}
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_va
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_va
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(u
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(unsig
}
/* 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(unsig
* 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(unsig
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)
Index: linux-5.4.17-rt9/drivers/tty/serial/8250/8250.h
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/8250/8250.h
+++ linux-5.4.17-rt9/drivers/tty/serial/8250/8250.h
@@ -130,12 +130,55 @@ static inline void serial_dl_write(struc
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
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;
}
Index: linux-5.4.17-rt9/drivers/tty/serial/8250/8250_core.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/8250/8250_core.c
+++ linux-5.4.17-rt9/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
/*
@@ -274,10 +283,8 @@ static void serial8250_backup_timeout(st
* Must disable interrupts or else we risk racing with the interrupt
* based handler.
*/
- if (up->port.irq) {
- ier = serial_in(up, UART_IER);
- serial_out(up, UART_IER, 0);
- }
+ if (up->port.irq)
+ ier = serial8250_clear_IER(up);
iir = serial_in(up, UART_IIR);
@@ -300,7 +307,7 @@ static void serial8250_backup_timeout(st
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);
@@ -578,6 +585,14 @@ serial8250_register_ports(struct uart_dr
#ifdef CONFIG_SERIAL_8250_CONSOLE
+static void univ8250_console_write_atomic(struct console *co, const char *s,
+ unsigned int count)
+{
+ struct uart_8250_port *up = &serial8250_ports[co->index];
+
+ serial8250_console_write_atomic(up, s, count);
+}
+
static void univ8250_console_write(struct console *co, const char *s,
unsigned int count)
{
@@ -663,6 +678,7 @@ static int univ8250_console_match(struct
static struct console univ8250_console = {
.name = "ttyS",
+ .write_atomic = univ8250_console_write_atomic,
.write = univ8250_console_write,
.device = uart_console_device,
.setup = univ8250_console_setup,
Index: linux-5.4.17-rt9/drivers/tty/serial/8250/8250_fsl.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/8250/8250_fsl.c
+++ linux-5.4.17-rt9/drivers/tty/serial/8250/8250_fsl.c
@@ -57,9 +57,18 @@ int fsl8250_handle_irq(struct uart_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 {
Index: linux-5.4.17-rt9/drivers/tty/serial/8250/8250_ingenic.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/8250/8250_ingenic.c
+++ linux-5.4.17-rt9/drivers/tty/serial/8250/8250_ingenic.c
@@ -146,6 +146,8 @@ OF_EARLYCON_DECLARE(x1000_uart, "ingenic
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(stru
* 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;
Index: linux-5.4.17-rt9/drivers/tty/serial/8250/8250_mtk.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/8250/8250_mtk.c
+++ linux-5.4.17-rt9/drivers/tty/serial/8250/8250_mtk.c
@@ -212,12 +212,37 @@ static void mtk8250_shutdown(struct uart
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)
Index: linux-5.4.17-rt9/drivers/tty/serial/8250/8250_port.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/8250/8250_port.c
+++ linux-5.4.17-rt9/drivers/tty/serial/8250/8250_port.c
@@ -721,7 +721,7 @@ static void serial8250_set_sleep(struct
serial_out(p, UART_EFR, UART_EFR_ECB);
serial_out(p, UART_LCR, 0);
}
- serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
+ 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 ua
up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
up->port.read_status_mask &= ~UART_LSR_DR;
- serial_port_out(port, UART_IER, up->ier);
+ serial8250_set_IER(up, up->ier);
serial8250_rpm_put(up);
}
@@ -1408,7 +1408,7 @@ static void __do_stop_tx_rs485(struct ua
serial8250_clear_and_reinit_fifos(p);
p->ier |= UART_IER_RLSI | UART_IER_RDI;
- serial_port_out(&p->port, UART_IER, p->ier);
+ 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
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
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(str
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(str
* 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);
}
@@ -2358,7 +2351,7 @@ void serial8250_do_shutdown(struct uart_
*/
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);
@@ -2643,7 +2636,7 @@ serial8250_do_set_termios(struct uart_po
if (up->capabilities & UART_CAP_RTOIE)
up->ier |= UART_IER_RTOIE;
- serial_port_out(port, UART_IER, up->ier);
+ serial8250_set_IER(up, up->ier);
if (up->capabilities & UART_CAP_EFR) {
unsigned char efr = 0;
@@ -3107,7 +3100,7 @@ EXPORT_SYMBOL_GPL(serial8250_set_default
#ifdef CONFIG_SERIAL_8250_CONSOLE
-static void serial8250_console_putchar(struct uart_port *port, int ch)
+static void serial8250_console_putchar_locked(struct uart_port *port, int ch)
{
struct uart_8250_port *up = up_to_u8250p(port);
@@ -3115,6 +3108,18 @@ static void serial8250_console_putchar(s
serial_port_out(port, UART_TX, ch);
}
+static void serial8250_console_putchar(struct uart_port *port, int ch)
+{
+ struct uart_8250_port *up = up_to_u8250p(port);
+ unsigned int flags;
+
+ wait_for_xmitr(up, UART_LSR_THRE);
+
+ console_atomic_lock(&flags);
+ serial8250_console_putchar_locked(port, ch);
+ console_atomic_unlock(flags);
+}
+
/*
* Restore serial console when h/w power-off detected
*/
@@ -3136,6 +3141,32 @@ static void serial8250_console_restore(s
serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);
}
+void serial8250_console_write_atomic(struct uart_8250_port *up,
+ const char *s, unsigned int count)
+{
+ struct uart_port *port = &up->port;
+ unsigned int flags;
+ 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...
@@ -3148,26 +3179,13 @@ void serial8250_console_write(struct uar
struct uart_port *port = &up->port;
unsigned long flags;
unsigned int ier;
- int locked = 1;
touch_nmi_watchdog();
serial8250_rpm_get(up);
+ spin_lock_irqsave(&port->lock, flags);
- if (oops_in_progress)
- locked = spin_trylock_irqsave(&port->lock, flags);
- else
- spin_lock_irqsave(&port->lock, flags);
-
- /*
- * First save the IER then disable the interrupts
- */
- ier = serial_port_in(port, UART_IER);
-
- if (up->capabilities & UART_CAP_UUE)
- serial_port_out(port, UART_IER, UART_IER_UUE);
- else
- serial_port_out(port, UART_IER, 0);
+ 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))) {
@@ -3175,14 +3193,16 @@ void serial8250_console_write(struct uar
up->canary = 0;
}
+ atomic_inc(&up->console_printing);
uart_console_write(port, s, count, serial8250_console_putchar);
+ atomic_dec(&up->console_printing);
/*
* Finally, wait for transmitter to become empty
* and restore the IER
*/
wait_for_xmitr(up, BOTH_EMPTY);
- serial_port_out(port, UART_IER, ier);
+ serial8250_set_IER(up, ier);
/*
* The receive handling will happen properly because the
@@ -3194,8 +3214,7 @@ void serial8250_console_write(struct uar
if (up->msr_saved_flags)
serial8250_modem_status(up);
- if (locked)
- spin_unlock_irqrestore(&port->lock, flags);
+ spin_unlock_irqrestore(&port->lock, flags);
serial8250_rpm_put(up);
}
@@ -3216,6 +3235,7 @@ static unsigned int probe_baud(struct ua
int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
{
+ struct uart_8250_port *up = up_to_u8250p(port);
int baud = 9600;
int bits = 8;
int parity = 'n';
@@ -3224,6 +3244,8 @@ int serial8250_console_setup(struct uart
if (!port->iobase && !port->membase)
return -ENODEV;
+ atomic_set(&up->console_printing, 0);
+
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else if (probe)
Index: linux-5.4.17-rt9/drivers/tty/serial/amba-pl011.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/amba-pl011.c
+++ linux-5.4.17-rt9/drivers/tty/serial/amba-pl011.c
@@ -2209,18 +2209,24 @@ pl011_console_write(struct console *co,
{
struct uart_amba_port *uap = amba_ports[co->index];
unsigned int old_cr = 0, new_cr;
- unsigned long flags;
+ unsigned long flags = 0;
int locked = 1;
clk_enable(uap->clk);
- local_irq_save(flags);
+ /*
+ * local_irq_save(flags);
+ *
+ * This local_irq_save() is nonsense. If we come in via sysrq
+ * handling then interrupts are already disabled. Aside of
+ * that the port.sysrq check is racy on SMP regardless.
+ */
if (uap->port.sysrq)
locked = 0;
else if (oops_in_progress)
- locked = spin_trylock(&uap->port.lock);
+ locked = spin_trylock_irqsave(&uap->port.lock, flags);
else
- spin_lock(&uap->port.lock);
+ spin_lock_irqsave(&uap->port.lock, flags);
/*
* First save the CR then disable the interrupts
@@ -2246,8 +2252,7 @@ pl011_console_write(struct console *co,
pl011_write(old_cr, uap, REG_CR);
if (locked)
- spin_unlock(&uap->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
clk_disable(uap->clk);
}
Index: linux-5.4.17-rt9/drivers/tty/serial/omap-serial.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/tty/serial/omap-serial.c
+++ linux-5.4.17-rt9/drivers/tty/serial/omap-serial.c
@@ -1307,13 +1307,10 @@ serial_omap_console_write(struct console
pm_runtime_get_sync(up->dev);
- local_irq_save(flags);
- if (up->port.sysrq)
- locked = 0;
- else if (oops_in_progress)
- locked = spin_trylock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
else
- spin_lock(&up->port.lock);
+ spin_lock_irqsave(&up->port.lock, flags);
/*
* First save the IER then disable the interrupts
@@ -1342,8 +1339,7 @@ serial_omap_console_write(struct console
pm_runtime_mark_last_busy(up->dev);
pm_runtime_put_autosuspend(up->dev);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static int __init
Index: linux-5.4.17-rt9/drivers/usb/gadget/function/f_fs.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/usb/gadget/function/f_fs.c
+++ linux-5.4.17-rt9/drivers/usb/gadget/function/f_fs.c
@@ -1717,7 +1717,7 @@ static void ffs_data_put(struct ffs_data
pr_info("%s(): freeing\n", __func__);
ffs_data_clear(ffs);
BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
- waitqueue_active(&ffs->ep0req_completion.wait) ||
+ swait_active(&ffs->ep0req_completion.wait) ||
waitqueue_active(&ffs->wait));
destroy_workqueue(ffs->io_completion_wq);
kfree(ffs->dev_name);
Index: linux-5.4.17-rt9/drivers/usb/gadget/legacy/inode.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/usb/gadget/legacy/inode.c
+++ linux-5.4.17-rt9/drivers/usb/gadget/legacy/inode.c
@@ -344,7 +344,7 @@ ep_io (struct ep_data *epdata, void *buf
spin_unlock_irq (&epdata->dev->lock);
if (likely (value == 0)) {
- value = wait_event_interruptible (done.wait, done.done);
+ value = swait_event_interruptible_exclusive(done.wait, done.done);
if (value != 0) {
spin_lock_irq (&epdata->dev->lock);
if (likely (epdata->ep != NULL)) {
@@ -353,7 +353,7 @@ ep_io (struct ep_data *epdata, void *buf
usb_ep_dequeue (epdata->ep, epdata->req);
spin_unlock_irq (&epdata->dev->lock);
- wait_event (done.wait, done.done);
+ swait_event_exclusive(done.wait, done.done);
if (epdata->status == -ECONNRESET)
epdata->status = -EINTR;
} else {
Index: linux-5.4.17-rt9/drivers/video/backlight/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/drivers/video/backlight/Kconfig
+++ linux-5.4.17-rt9/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,
Index: linux-5.4.17-rt9/drivers/xen/preempt.c
===================================================================
--- linux-5.4.17-rt9.orig/drivers/xen/preempt.c
+++ linux-5.4.17-rt9/drivers/xen/preempt.c
@@ -8,7 +8,7 @@
#include
#include
-#ifndef CONFIG_PREEMPT
+#ifndef CONFIG_PREEMPTION
/*
* Some hypercalls issued by the toolstack can take many 10s of
@@ -39,4 +39,4 @@ asmlinkage __visible void xen_maybe_pree
__this_cpu_write(xen_in_preemptible_hcall, true);
}
}
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */
Index: linux-5.4.17-rt9/fs/afs/dir_silly.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/afs/dir_silly.c
+++ linux-5.4.17-rt9/fs/afs/dir_silly.c
@@ -202,7 +202,7 @@ int afs_silly_iput(struct dentry *dentry
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);
Index: linux-5.4.17-rt9/fs/btrfs/volumes.h
===================================================================
--- linux-5.4.17-rt9.orig/fs/btrfs/volumes.h
+++ linux-5.4.17-rt9/fs/btrfs/volumes.h
@@ -179,7 +179,7 @@ btrfs_device_set_##name(struct btrfs_dev
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) \
Index: linux-5.4.17-rt9/fs/buffer.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/buffer.c
+++ linux-5.4.17-rt9/fs/buffer.c
@@ -275,8 +275,7 @@ static void end_buffer_async_read(struct
* decide that the page is now completely done.
*/
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ 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
}
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
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 buffe
}
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 buffe
}
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
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(gf
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();
Index: linux-5.4.17-rt9/fs/cifs/readdir.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/cifs/readdir.c
+++ linux-5.4.17-rt9/fs/cifs/readdir.c
@@ -80,7 +80,7 @@ cifs_prime_dcache(struct dentry *parent,
struct inode *inode;
struct super_block *sb = parent->d_sb;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
Index: linux-5.4.17-rt9/fs/dcache.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/dcache.c
+++ linux-5.4.17-rt9/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(str
static inline void end_dir_add(struct inode *dir, unsigned n)
{
- smp_store_release(&dir->i_dir_seq, n + 2);
+ smp_store_release(&dir->__i_dir_seq, n + 2);
+ preempt_enable_rt();
}
static void d_wait_lookup(struct dentry *dentry)
{
- if (d_in_lookup(dentry)) {
- DECLARE_WAITQUEUE(wait, current);
- add_wait_queue(dentry->d_wait, &wait);
- do {
- set_current_state(TASK_UNINTERRUPTIBLE);
- spin_unlock(&dentry->d_lock);
- schedule();
- spin_lock(&dentry->d_lock);
- } while (d_in_lookup(dentry));
- }
+ struct swait_queue __wait;
+
+ if (!d_in_lookup(dentry))
+ return;
+
+ INIT_LIST_HEAD(&__wait.task_list);
+ do {
+ prepare_to_swait_exclusive(dentry->d_wait, &__wait, TASK_UNINTERRUPTIBLE);
+ spin_unlock(&dentry->d_lock);
+ schedule();
+ spin_lock(&dentry->d_lock);
+ } while (d_in_lookup(dentry));
+ finish_swait(dentry->d_wait, &__wait);
}
struct dentry *d_alloc_parallel(struct dentry *parent,
const struct qstr *name,
- wait_queue_head_t *wq)
+ struct swait_queue_head *wq)
{
unsigned int hash = name->hash;
struct hlist_bl_head *b = in_lookup_hash(parent, hash);
@@ -2525,7 +2530,7 @@ struct dentry *d_alloc_parallel(struct d
retry:
rcu_read_lock();
- seq = smp_load_acquire(&parent->d_inode->i_dir_seq);
+ seq = smp_load_acquire(&parent->d_inode->__i_dir_seq);
r_seq = read_seqbegin(&rename_lock);
dentry = __d_lookup_rcu(parent, name, &d_seq);
if (unlikely(dentry)) {
@@ -2553,7 +2558,7 @@ retry:
}
hlist_bl_lock(b);
- if (unlikely(READ_ONCE(parent->d_inode->i_dir_seq) != seq)) {
+ if (unlikely(READ_ONCE(parent->d_inode->__i_dir_seq) != seq)) {
hlist_bl_unlock(b);
rcu_read_unlock();
goto retry;
@@ -2626,7 +2631,7 @@ void __d_lookup_done(struct dentry *dent
hlist_bl_lock(b);
dentry->d_flags &= ~DCACHE_PAR_LOOKUP;
__hlist_bl_del(&dentry->d_u.d_in_lookup_hash);
- wake_up_all(dentry->d_wait);
+ swake_up_all(dentry->d_wait);
dentry->d_wait = NULL;
hlist_bl_unlock(b);
INIT_HLIST_NODE(&dentry->d_u.d_alias);
@@ -3139,6 +3144,8 @@ __setup("dhash_entries=", set_dhash_entr
static void __init dcache_init_early(void)
{
+ unsigned int loop;
+
/* If hashes are distributed across NUMA nodes, defer
* hash allocation until vmalloc space is available.
*/
@@ -3155,11 +3162,16 @@ static void __init dcache_init_early(voi
NULL,
0,
0);
+
+ for (loop = 0; loop < (1U << d_hash_shift); loop++)
+ INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
+
d_hash_shift = 32 - d_hash_shift;
}
static void __init dcache_init(void)
{
+ unsigned int loop;
/*
* A constructor could be added for stable state like the lists,
* but it is probably not worth it because of the cache nature
@@ -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;
}
Index: linux-5.4.17-rt9/fs/eventpoll.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/eventpoll.c
+++ linux-5.4.17-rt9/fs/eventpoll.c
@@ -567,12 +567,12 @@ static int ep_poll_wakeup_proc(void *pri
static void ep_poll_safewake(wait_queue_head_t *wq)
{
- int this_cpu = get_cpu();
+ int this_cpu = get_cpu_light();
ep_call_nested(&poll_safewake_ncalls,
ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu);
- put_cpu();
+ put_cpu_light();
}
#else
Index: linux-5.4.17-rt9/fs/ext4/page-io.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/ext4/page-io.c
+++ linux-5.4.17-rt9/fs/ext4/page-io.c
@@ -87,11 +87,10 @@ static void ext4_finish_bio(struct 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 *
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);
Index: linux-5.4.17-rt9/fs/fscache/cookie.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/fscache/cookie.c
+++ linux-5.4.17-rt9/fs/fscache/cookie.c
@@ -958,3 +958,11 @@ inconsistent:
return -ESTALE;
}
EXPORT_SYMBOL(__fscache_check_consistency);
+
+void __init fscache_cookie_init(void)
+{
+ int i;
+
+ for (i = 0; i < (1 << fscache_cookie_hash_shift) - 1; i++)
+ INIT_HLIST_BL_HEAD(&fscache_cookie_hash[i]);
+}
Index: linux-5.4.17-rt9/fs/fscache/main.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/fscache/main.c
+++ linux-5.4.17-rt9/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)
Index: linux-5.4.17-rt9/fs/fuse/readdir.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/fuse/readdir.c
+++ linux-5.4.17-rt9/fs/fuse/readdir.c
@@ -158,7 +158,7 @@ static int fuse_direntplus_link(struct f
struct inode *dir = d_inode(parent);
struct fuse_conn *fc;
struct inode *inode;
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
if (!o->nodeid) {
/*
Index: linux-5.4.17-rt9/fs/inode.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/inode.c
+++ linux-5.4.17-rt9/fs/inode.c
@@ -156,7 +156,7 @@ int inode_init_always(struct super_block
inode->i_bdev = NULL;
inode->i_cdev = NULL;
inode->i_link = NULL;
- inode->i_dir_seq = 0;
+ inode->__i_dir_seq = 0;
inode->i_rdev = 0;
inode->dirtied_when = 0;
Index: linux-5.4.17-rt9/fs/jbd2/commit.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/jbd2/commit.c
+++ linux-5.4.17-rt9/fs/jbd2/commit.c
@@ -482,10 +482,10 @@ void jbd2_journal_commit_transaction(jou
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 @@ restart_loop:
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 @@ restart_loop:
* 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);
/*
@@ -1028,8 +1029,10 @@ restart_loop:
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
Index: linux-5.4.17-rt9/fs/jbd2/journal.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/jbd2/journal.c
+++ linux-5.4.17-rt9/fs/jbd2/journal.c
@@ -363,7 +363,7 @@ int jbd2_journal_write_metadata_buffer(t
/* 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 @@ repeat:
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 @@ repeat:
__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);
}
@@ -2407,6 +2407,8 @@ static struct journal_head *journal_allo
ret = kmem_cache_zalloc(jbd2_journal_head_cache,
GFP_NOFS | __GFP_NOFAIL);
}
+ if (ret)
+ spin_lock_init(&ret->b_state_lock);
return ret;
}
@@ -2526,17 +2528,23 @@ static void __journal_remove_journal_hea
J_ASSERT_BH(bh, buffer_jbd(bh));
J_ASSERT_BH(bh, jh2bh(jh) == bh);
BUFFER_TRACE(bh, "remove journal_head");
+
+ /* 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, bh->b_size);
+ 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, bh->b_size);
+ jbd2_free(jh->b_committed_data, b_size);
}
- bh->b_private = NULL;
- jh->b_bh = NULL; /* debug, really */
- clear_buffer_jbd(bh);
journal_free_journal_head(jh);
}
@@ -2554,9 +2562,11 @@ void jbd2_journal_put_journal_head(struc
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);
+ }
}
/*
Index: linux-5.4.17-rt9/fs/jbd2/transaction.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/jbd2/transaction.c
+++ linux-5.4.17-rt9/fs/jbd2/transaction.c
@@ -877,7 +877,7 @@ repeat:
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);
@@ -927,7 +927,7 @@ repeat:
error = -EROFS;
if (is_handle_aborted(handle)) {
- jbd_unlock_bh_state(bh);
+ spin_unlock(&jh->b_state_lock);
goto out;
}
error = 0;
@@ -991,7 +991,7 @@ repeat:
*/
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;
}
@@ -1012,7 +1012,7 @@ repeat:
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;
@@ -1031,7 +1031,7 @@ attach_next:
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
@@ -1173,7 +1173,7 @@ int jbd2_journal_get_create_access(handl
* 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 &&
@@ -1208,7 +1208,7 @@ int jbd2_journal_get_create_access(handl
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
@@ -1279,13 +1279,13 @@ repeat:
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;
}
@@ -1293,7 +1293,7 @@ repeat:
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))
@@ -1394,16 +1394,16 @@ int jbd2_journal_dirty_metadata(handle_t
*/
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 "
@@ -1413,13 +1413,13 @@ int jbd2_journal_dirty_metadata(handle_t
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) {
/*
@@ -1505,7 +1505,7 @@ int jbd2_journal_dirty_metadata(handle_t
__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;
@@ -1543,18 +1543,20 @@ int jbd2_journal_forget (handle_t *handl
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 */
@@ -1602,10 +1604,7 @@ int jbd2_journal_forget (handle_t *handl
__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) {
@@ -1647,7 +1646,7 @@ int jbd2_journal_forget (handle_t *handl
if (!jh->b_cp_transaction) {
JBUFFER_TRACE(jh, "belongs to none transaction");
spin_unlock(&journal->j_list_lock);
- goto not_jbd;
+ goto drop;
}
/*
@@ -1657,7 +1656,7 @@ int jbd2_journal_forget (handle_t *handl
if (!buffer_dirty(bh)) {
__jbd2_journal_remove_checkpoint(jh);
spin_unlock(&journal->j_list_lock);
- goto not_jbd;
+ goto drop;
}
/*
@@ -1670,20 +1669,15 @@ int jbd2_journal_forget (handle_t *handl
__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;
}
/**
@@ -1882,7 +1876,7 @@ free_and_exit:
*
* j_list_lock is held.
*
- * jbd_lock_bh_state(jh2bh(jh)) is held.
+ * jh->b_state_lock is held.
*/
static inline void
@@ -1906,7 +1900,7 @@ __blist_add_buffer(struct journal_head *
*
* 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
@@ -1938,7 +1932,7 @@ static void __jbd2_journal_temp_unlink_b
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);
@@ -1975,17 +1969,15 @@ static void __jbd2_journal_temp_unlink_b
}
/*
- * 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)
@@ -1994,18 +1986,19 @@ void jbd2_journal_unfile_buffer(journal_
/* 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)
@@ -2092,10 +2085,10 @@ int jbd2_journal_try_to_free_buffers(jou
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);
@@ -2116,7 +2109,7 @@ busy:
*
* 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)
{
@@ -2137,6 +2130,7 @@ static int __dispose_buffer(struct journ
} else {
JBUFFER_TRACE(jh, "on running transaction");
__jbd2_journal_unfile_buffer(jh);
+ jbd2_journal_put_journal_head(jh);
}
return may_free;
}
@@ -2203,18 +2197,15 @@ static int journal_unmap_buffer(journal_
* 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)
@@ -2293,10 +2284,10 @@ static int journal_unmap_buffer(journal_
* 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;
}
/*
@@ -2310,10 +2301,10 @@ static int journal_unmap_buffer(journal_
if (journal->j_running_transaction && buffer_jbddirty(bh))
jh->b_next_transaction = journal->j_running_transaction;
jh->b_modified = 0;
- 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.
@@ -2337,11 +2328,10 @@ zap_buffer:
* 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));
@@ -2428,7 +2418,7 @@ void __jbd2_journal_file_buffer(struct j
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);
@@ -2490,11 +2480,11 @@ void __jbd2_journal_file_buffer(struct j
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);
}
/*
@@ -2504,23 +2494,25 @@ void jbd2_journal_file_buffer(struct jou
* 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;
}
/*
@@ -2548,6 +2540,7 @@ void __jbd2_journal_refile_buffer(struct
if (was_dirty)
set_buffer_jbddirty(bh);
+ return false;
}
/*
@@ -2558,16 +2551,15 @@ void __jbd2_journal_refile_buffer(struct
*/
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);
}
/*
Index: linux-5.4.17-rt9/fs/namei.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/namei.c
+++ linux-5.4.17-rt9/fs/namei.c
@@ -1638,7 +1638,7 @@ static struct dentry *__lookup_slow(cons
{
struct dentry *dentry, *old;
struct inode *inode = dir->d_inode;
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
/* Don't go there if it's already dead */
if (unlikely(IS_DEADDIR(inode)))
@@ -3126,7 +3126,7 @@ static int lookup_open(struct nameidata
struct dentry *dentry;
int error, create_error = 0;
umode_t mode = op->mode;
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
if (unlikely(IS_DEADDIR(dir_inode)))
return -ENOENT;
Index: linux-5.4.17-rt9/fs/namespace.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/namespace.c
+++ linux-5.4.17-rt9/fs/namespace.c
@@ -14,6 +14,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -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
Index: linux-5.4.17-rt9/fs/nfs/delegation.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/nfs/delegation.c
+++ linux-5.4.17-rt9/fs/nfs/delegation.c
@@ -162,11 +162,11 @@ again:
sp = state->owner;
/* Block nfs4_proc_unlck */
mutex_lock(&sp->so_delegreturn_mutex);
- seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
+ seq = read_seqbegin(&sp->so_reclaim_seqlock);
err = nfs4_open_delegation_recall(ctx, state, stateid);
if (!err)
err = nfs_delegation_claim_locks(state, stateid);
- if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
+ if (!err && read_seqretry(&sp->so_reclaim_seqlock, seq))
err = -EAGAIN;
mutex_unlock(&sp->so_delegreturn_mutex);
put_nfs_open_context(ctx);
Index: linux-5.4.17-rt9/fs/nfs/dir.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/nfs/dir.c
+++ linux-5.4.17-rt9/fs/nfs/dir.c
@@ -457,7 +457,7 @@ 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);
@@ -1517,7 +1517,7 @@ int nfs_atomic_open(struct inode *dir, s
struct file *file, unsigned open_flags,
umode_t mode)
{
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
struct nfs_open_context *ctx;
struct dentry *res;
struct iattr attr = { .ia_valid = ATTR_OPEN };
@@ -1846,7 +1846,11 @@ int nfs_rmdir(struct inode *dir, struct
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) {
@@ -1856,7 +1860,11 @@ int nfs_rmdir(struct inode *dir, struct
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);
Index: linux-5.4.17-rt9/fs/nfs/inode.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/nfs/inode.c
+++ linux-5.4.17-rt9/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);
}
Index: linux-5.4.17-rt9/fs/nfs/nfs4_fs.h
===================================================================
--- linux-5.4.17-rt9.orig/fs/nfs/nfs4_fs.h
+++ linux-5.4.17-rt9/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;
};
Index: linux-5.4.17-rt9/fs/nfs/nfs4proc.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/nfs/nfs4proc.c
+++ linux-5.4.17-rt9/fs/nfs/nfs4proc.c
@@ -2967,7 +2967,7 @@ static int _nfs4_open_and_get_state(stru
unsigned int seq;
int ret;
- seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
+ seq = raw_seqcount_begin(&sp->so_reclaim_seqlock.seqcount);
dir_verifier = nfs_save_change_attribute(dir);
ret = _nfs4_proc_open(opendata, ctx);
@@ -3021,7 +3021,7 @@ static int _nfs4_open_and_get_state(stru
if (d_inode(dentry) == state->inode) {
nfs_inode_attach_open_context(ctx);
- if (read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
+ if (read_seqretry(&sp->so_reclaim_seqlock, seq))
nfs4_schedule_stateid_recovery(server, state);
}
Index: linux-5.4.17-rt9/fs/nfs/nfs4state.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/nfs/nfs4state.c
+++ linux-5.4.17-rt9/fs/nfs/nfs4state.c
@@ -508,7 +508,7 @@ nfs4_alloc_state_owner(struct nfs_server
nfs4_init_seqid_counter(&sp->so_seqid);
atomic_set(&sp->so_count, 1);
INIT_LIST_HEAD(&sp->so_lru);
- seqcount_init(&sp->so_reclaim_seqcount);
+ seqlock_init(&sp->so_reclaim_seqlock);
mutex_init(&sp->so_delegreturn_mutex);
return sp;
}
@@ -1616,8 +1616,12 @@ static int nfs4_reclaim_open_state(struc
* recovering after a network partition or a reboot from a
* server that doesn't support a grace period.
*/
+#ifdef CONFIG_PREEMPT_RT
+ 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))
@@ -1678,14 +1682,20 @@ restart:
spin_lock(&sp->so_lock);
goto restart;
}
- raw_write_seqcount_end(&sp->so_reclaim_seqcount);
spin_unlock(&sp->so_lock);
+#ifdef CONFIG_PREEMPT_RT
+ 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;
}
Index: linux-5.4.17-rt9/fs/nfs/unlink.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/nfs/unlink.c
+++ linux-5.4.17-rt9/fs/nfs/unlink.c
@@ -13,7 +13,7 @@
#include
#include
#include
-#include
+#include
#include
#include
@@ -53,6 +53,29 @@ static void nfs_async_unlink_done(struct
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(voi
struct dentry *dentry = data->dentry;
struct super_block *sb = dentry->d_sb;
- up_read_non_owner(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem);
+ nfs_up_anon(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem);
d_lookup_done(dentry);
nfs_free_unlinkdata(data);
dput(dentry);
@@ -119,10 +142,10 @@ static int nfs_call_unlink(struct dentry
struct inode *dir = d_inode(dentry->d_parent);
struct dentry *alias;
- down_read_non_owner(&NFS_I(dir)->rmdir_sem);
+ nfs_down_anon(&NFS_I(dir)->rmdir_sem);
alias = d_alloc_parallel(dentry->d_parent, &data->args.name, &data->wq);
if (IS_ERR(alias)) {
- up_read_non_owner(&NFS_I(dir)->rmdir_sem);
+ nfs_up_anon(&NFS_I(dir)->rmdir_sem);
return 0;
}
if (!d_in_lookup(alias)) {
@@ -144,7 +167,7 @@ static int nfs_call_unlink(struct dentry
ret = 0;
spin_unlock(&alias->d_lock);
dput(alias);
- up_read_non_owner(&NFS_I(dir)->rmdir_sem);
+ nfs_up_anon(&NFS_I(dir)->rmdir_sem);
/*
* If we'd displaced old cached devname, free it. At that
* point dentry is definitely not a root, so we won't need
@@ -180,7 +203,7 @@ nfs_async_unlink(struct dentry *dentry,
data->cred = get_current_cred();
data->res.dir_attr = &data->dir_attr;
- init_waitqueue_head(&data->wq);
+ init_swait_queue_head(&data->wq);
status = -EBUSY;
spin_lock(&dentry->d_lock);
Index: linux-5.4.17-rt9/fs/ntfs/aops.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/ntfs/aops.c
+++ linux-5.4.17-rt9/fs/ntfs/aops.c
@@ -92,8 +92,7 @@ static void ntfs_end_buffer_async_read(s
"0x%llx.", (unsigned long long)bh->b_blocknr);
}
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ 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(s
}
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(s
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;
}
Index: linux-5.4.17-rt9/fs/ocfs2/suballoc.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/ocfs2/suballoc.c
+++ linux-5.4.17-rt9/fs/ocfs2/suballoc.c
@@ -1252,6 +1252,7 @@ static int ocfs2_test_bg_bit_allocatable
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
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(
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(
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(
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(
}
if (undo_fn)
- jbd_unlock_bh_state(group_bh);
+ spin_unlock(&jh->b_state_lock);
ocfs2_journal_dirty(handle, group_bh);
bail:
Index: linux-5.4.17-rt9/fs/proc/base.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/proc/base.c
+++ linux-5.4.17-rt9/fs/proc/base.c
@@ -1891,7 +1891,7 @@ bool proc_fill_cache(struct file *file,
child = d_hash_and_lookup(dir, &qname);
if (!child) {
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
child = d_alloc_parallel(dir, &qname, &wq);
if (IS_ERR(child))
goto end_instantiate;
Index: linux-5.4.17-rt9/fs/proc/kmsg.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/proc/kmsg.c
+++ linux-5.4.17-rt9/fs/proc/kmsg.c
@@ -18,8 +18,6 @@
#include
#include
-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 *fi
static __poll_t kmsg_poll(struct file *file, poll_table *wait)
{
- poll_wait(file, &log_wait, wait);
+ poll_wait(file, printk_wait_queue(), wait);
if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
return EPOLLIN | EPOLLRDNORM;
return 0;
Index: linux-5.4.17-rt9/fs/proc/proc_sysctl.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/proc/proc_sysctl.c
+++ linux-5.4.17-rt9/fs/proc/proc_sysctl.c
@@ -702,7 +702,7 @@ static bool proc_sys_fill_cache(struct f
child = d_lookup(dir, &qname);
if (!child) {
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
child = d_alloc_parallel(dir, &qname, &wq);
if (IS_ERR(child))
return false;
Index: linux-5.4.17-rt9/fs/squashfs/decompressor_multi_percpu.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/squashfs/decompressor_multi_percpu.c
+++ linux-5.4.17-rt9/fs/squashfs/decompressor_multi_percpu.c
@@ -8,6 +8,7 @@
#include
#include
#include
+#include
#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_
{
struct squashfs_stream __percpu *percpu =
(struct squashfs_stream __percpu *) msblk->stream;
- struct squashfs_stream *stream = get_cpu_ptr(percpu);
- int res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
- offset, length, output);
- put_cpu_ptr(stream);
+ struct squashfs_stream *stream;
+ int res;
+
+ stream = get_locked_ptr(stream_lock, percpu);
+
+ res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
+ offset, length, output);
+
+ put_locked_ptr(stream_lock, stream);
if (res < 0)
ERROR("%s decompression failed, data probably corrupt\n",
Index: linux-5.4.17-rt9/fs/stack.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/stack.c
+++ linux-5.4.17-rt9/fs/stack.c
@@ -23,7 +23,7 @@ void fsstack_copy_inode_size(struct inod
/*
* 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 inod
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.
Index: linux-5.4.17-rt9/fs/userfaultfd.c
===================================================================
--- linux-5.4.17-rt9.orig/fs/userfaultfd.c
+++ linux-5.4.17-rt9/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(stru
* 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(stru
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_userfau
* 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(vo
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)
Index: linux-5.4.17-rt9/include/linux/bottom_half.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/bottom_half.h
+++ linux-5.4.17-rt9/include/linux/bottom_half.h
@@ -4,6 +4,10 @@
#include
+#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_d
barrier();
}
#endif
+#endif
static inline void local_bh_disable(void)
{
Index: linux-5.4.17-rt9/include/linux/bpf.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/bpf.h
+++ linux-5.4.17-rt9/include/linux/bpf.h
@@ -541,7 +541,7 @@ int bpf_prog_array_copy(struct bpf_prog_
struct bpf_prog *_prog; \
struct bpf_prog_array *_array; \
u32 _ret = 1; \
- preempt_disable(); \
+ migrate_disable(); \
rcu_read_lock(); \
_array = rcu_dereference(array); \
if (unlikely(check_non_null && !_array))\
@@ -554,7 +554,7 @@ int bpf_prog_array_copy(struct bpf_prog_
} \
_out: \
rcu_read_unlock(); \
- preempt_enable(); \
+ migrate_enable(); \
_ret; \
})
@@ -588,7 +588,7 @@ _out: \
u32 ret; \
u32 _ret = 1; \
u32 _cn = 0; \
- preempt_disable(); \
+ migrate_disable(); \
rcu_read_lock(); \
_array = rcu_dereference(array); \
_item = &_array->items[0]; \
@@ -600,7 +600,7 @@ _out: \
_item++; \
} \
rcu_read_unlock(); \
- preempt_enable(); \
+ migrate_enable(); \
if (_ret) \
_ret = (_cn ? NET_XMIT_CN : NET_XMIT_SUCCESS); \
else \
@@ -617,6 +617,36 @@ _out: \
#ifdef CONFIG_BPF_SYSCALL
DECLARE_PER_CPU(int, bpf_prog_active);
+/*
+ * Block execution of BPF programs attached to instrumentation (perf,
+ * kprobes, tracepoints) to prevent deadlocks on map operations as any of
+ * these events can happen inside a region which holds a map bucket lock
+ * and can deadlock on it.
+ *
+ * Use the preemption safe inc/dec variants on RT because migrate disable
+ * is preemptible on RT and preemption in the middle of the RMW operation
+ * might lead to inconsistent state. Use the raw variants for non RT
+ * kernels as migrate_disable() maps to preempt_disable() so the slightly
+ * more expensive save operation can be avoided.
+ */
+static inline void bpf_disable_instrumentation(void)
+{
+ migrate_disable();
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ this_cpu_inc(bpf_prog_active);
+ else
+ __this_cpu_inc(bpf_prog_active);
+}
+
+static inline void bpf_enable_instrumentation(void)
+{
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ this_cpu_dec(bpf_prog_active);
+ else
+ __this_cpu_dec(bpf_prog_active);
+ migrate_enable();
+}
+
extern const struct file_operations bpf_map_fops;
extern const struct file_operations bpf_prog_fops;
Index: linux-5.4.17-rt9/include/linux/buffer_head.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/buffer_head.h
+++ linux-5.4.17-rt9/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 */
};
/*
Index: linux-5.4.17-rt9/include/linux/cgroup-defs.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/cgroup-defs.h
+++ linux-5.4.17-rt9/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);
Index: linux-5.4.17-rt9/include/linux/cgroup.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/cgroup.h
+++ linux-5.4.17-rt9/include/linux/cgroup.h
@@ -750,9 +750,6 @@ static inline void cgroup_path_from_kern
*/
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.
Index: linux-5.4.17-rt9/include/linux/completion.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/completion.h
+++ linux-5.4.17-rt9/include/linux/completion.h
@@ -9,7 +9,7 @@
* See kernel/sched/completion.c for details.
*/
-#include
+#include
/*
* 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(stru
static inline void complete_release(struct completion *x) {}
#define COMPLETION_INITIALIZER(work) \
- { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+ { 0, __SWAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
#define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \
(*({ init_completion_map(&(work), &(map)); &(work); }))
@@ -85,7 +85,7 @@ static inline void complete_release(stru
static inline void __init_completion(struct completion *x)
{
x->done = 0;
- init_waitqueue_head(&x->wait);
+ init_swait_queue_head(&x->wait);
}
/**
Index: linux-5.4.17-rt9/include/linux/console.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/console.h
+++ linux-5.4.17-rt9/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 */
Index: linux-5.4.17-rt9/include/linux/dcache.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/dcache.h
+++ linux-5.4.17-rt9/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 *de
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 *);
Index: linux-5.4.17-rt9/include/linux/delay.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/delay.h
+++ linux-5.4.17-rt9/include/linux/delay.h
@@ -65,4 +65,10 @@ static inline void ssleep(unsigned int s
msleep(seconds * 1000);
}
+#ifdef CONFIG_PREEMPT_RT
+extern void cpu_chill(void);
+#else
+# define cpu_chill() cpu_relax()
+#endif
+
#endif /* defined(_LINUX_DELAY_H) */
Index: linux-5.4.17-rt9/include/linux/dma-resv.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/dma-resv.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/include/linux/filter.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/filter.h
+++ linux-5.4.17-rt9/include/linux/filter.h
@@ -555,7 +555,7 @@ DECLARE_STATIC_KEY_FALSE(bpf_stats_enabl
#define BPF_PROG_RUN(prog, ctx) ({ \
u32 ret; \
- cant_sleep(); \
+ cant_migrate(); \
if (static_branch_unlikely(&bpf_stats_enabled_key)) { \
struct bpf_prog_stats *stats; \
u64 start = sched_clock(); \
@@ -570,6 +570,28 @@ DECLARE_STATIC_KEY_FALSE(bpf_stats_enabl
} \
ret; })
+/*
+ * Use in preemptible and therefore migratable context to make sure that
+ * the execution of the BPF program runs on one CPU.
+ *
+ * This uses migrate_disable/enable() explicitly to document that the
+ * invocation of a BPF program does not require reentrancy protection
+ * against a BPF program which is invoked from a preempting task.
+ *
+ * For non RT enabled kernels migrate_disable/enable() maps to
+ * preempt_disable/enable(), i.e. it disables also preemption.
+ */
+static inline u32 bpf_prog_run_pin_on_cpu(const struct bpf_prog *prog,
+ const void *ctx)
+{
+ u32 ret;
+
+ migrate_disable();
+ ret = BPF_PROG_RUN(prog, ctx);
+ migrate_enable();
+ return ret;
+}
+
#define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
struct bpf_skb_data_end {
@@ -647,6 +669,7 @@ static inline u8 *bpf_skb_cb(struct sk_b
return qdisc_skb_cb(skb)->data;
}
+/* Must be invoked with migration disabled */
static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog,
struct sk_buff *skb)
{
@@ -672,9 +695,9 @@ static inline u32 bpf_prog_run_save_cb(c
{
u32 res;
- preempt_disable();
+ migrate_disable();
res = __bpf_prog_run_save_cb(prog, skb);
- preempt_enable();
+ migrate_enable();
return res;
}
@@ -687,9 +710,7 @@ static inline u32 bpf_prog_run_clear_cb(
if (unlikely(prog->cb_access))
memset(cb_data, 0, BPF_SKB_CB_LEN);
- preempt_disable();
- res = BPF_PROG_RUN(prog, skb);
- preempt_enable();
+ res = bpf_prog_run_pin_on_cpu(prog, skb);
return res;
}
Index: linux-5.4.17-rt9/include/linux/fs.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/fs.h
+++ linux-5.4.17-rt9/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 s
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 i
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();
Index: linux-5.4.17-rt9/include/linux/fscache.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/fscache.h
+++ linux-5.4.17-rt9/include/linux/fscache.h
@@ -226,6 +226,7 @@ extern void __fscache_readpages_cancel(s
extern void __fscache_disable_cookie(struct fscache_cookie *, const void *, bool);
extern void __fscache_enable_cookie(struct fscache_cookie *, const void *, loff_t,
bool (*)(void *), void *);
+extern void fscache_cookie_init(void);
/**
* fscache_register_netfs - Register a filesystem as desiring caching services
Index: linux-5.4.17-rt9/include/linux/genhd.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/genhd.h
+++ linux-5.4.17-rt9/include/linux/genhd.h
@@ -717,7 +717,7 @@ static inline void hd_free_part(struct h
* 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_rea
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(s
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();
Index: linux-5.4.17-rt9/include/linux/gfp.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/gfp.h
+++ linux-5.4.17-rt9/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);
Index: linux-5.4.17-rt9/include/linux/hardirq.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/hardirq.h
+++ linux-5.4.17-rt9/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)
Index: linux-5.4.17-rt9/include/linux/highmem.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/highmem.h
+++ linux-5.4.17-rt9/include/linux/highmem.h
@@ -8,6 +8,7 @@
#include
#include
#include
+#include
#include
@@ -90,7 +91,7 @@ static inline void kunmap(struct page *p
static inline void *kmap_atomic(struct page *page)
{
- preempt_disable();
+ preempt_disable_nort();
pagefault_disable();
return page_address(page);
}
@@ -99,7 +100,7 @@ static inline void *kmap_atomic(struct p
static inline void __kunmap_atomic(void *addr)
{
pagefault_enable();
- preempt_enable();
+ preempt_enable_nort();
}
#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
@@ -111,32 +112,51 @@ static inline void __kunmap_atomic(void
#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
}
Index: linux-5.4.17-rt9/include/linux/idr.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/idr.h
+++ linux-5.4.17-rt9/include/linux/idr.h
@@ -169,10 +169,7 @@ static inline bool idr_is_empty(const st
* Each idr_preload() should be matched with an invocation of this
* function. See idr_preload() for details.
*/
-static inline void idr_preload_end(void)
-{
- preempt_enable();
-}
+void idr_preload_end(void);
/**
* idr_for_each_entry() - Iterate over an IDR's elements of a given type.
Index: linux-5.4.17-rt9/include/linux/interrupt.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/interrupt.h
+++ linux-5.4.17-rt9/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(unsig
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
+extern void softirq_check_pending_idle(void);
DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
@@ -625,7 +626,10 @@ static inline void tasklet_unlock(struct
static inline void tasklet_unlock_wait(struct tasklet_struct *t)
{
- while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
+ while (test_bit(TASKLET_STATE_RUN, &(t)->state)) {
+ local_bh_disable();
+ local_bh_enable();
+ }
}
#else
#define tasklet_trylock(t) 1
Index: linux-5.4.17-rt9/include/linux/irq_work.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/irq_work.h
+++ linux-5.4.17-rt9/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(vo
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 */
Index: linux-5.4.17-rt9/include/linux/irqdesc.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/irqdesc.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/include/linux/irqflags.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/irqflags.h
+++ linux-5.4.17-rt9/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)
@@ -63,6 +55,21 @@ do { \
# define lockdep_softirq_enter() do { } while (0)
# define lockdep_softirq_exit() do { } while (0)
#endif
+
+#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT)
+# define lockdep_softirq_enter() \
+do { \
+ current->softirq_context++; \
+} while (0)
+# define lockdep_softirq_exit() \
+do { \
+ current->softirq_context--; \
+} while (0)
+
+#else
+# define lockdep_softirq_enter() do { } while (0)
+# define lockdep_softirq_exit() do { } while (0)
+#endif
#if defined(CONFIG_IRQSOFF_TRACER) || \
defined(CONFIG_PREEMPT_TRACER)
Index: linux-5.4.17-rt9/include/linux/jbd2.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/jbd2.h
+++ linux-5.4.17-rt9/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
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
/* 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);
Index: linux-5.4.17-rt9/include/linux/journal-head.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/journal-head.h
+++ linux-5.4.17-rt9/include/linux/journal-head.h
@@ -11,6 +11,8 @@
#ifndef JOURNAL_HEAD_H_INCLUDED
#define JOURNAL_HEAD_H_INCLUDED
+#include
+
typedef unsigned int tid_t; /* Unique transaction ID */
typedef struct transaction_s transaction_t; /* Compound transaction type */
@@ -24,13 +26,18 @@ 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()]
*/
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;
Index: linux-5.4.17-rt9/include/linux/kernel.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/kernel.h
+++ linux-5.4.17-rt9/include/linux/kernel.h
@@ -227,6 +227,10 @@ extern void __cant_sleep(const char *fil
*/
# 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 *fil
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)
@@ -266,6 +271,13 @@ extern void __cant_sleep(const char *fil
#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
+#ifndef CONFIG_PREEMPT_RT
+# define cant_migrate() cant_sleep()
+#else
+ /* Placeholder for now */
+# define cant_migrate() do { } while (0)
+#endif
+
/**
* abs - return absolute value of an argument
* @x: the value. If it is unsigned type, it is converted to signed type first.
Index: linux-5.4.17-rt9/include/linux/kmsg_dump.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/kmsg_dump.h
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/include/linux/list_bl.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/list_bl.h
+++ linux-5.4.17-rt9/include/linux/list_bl.h
@@ -3,6 +3,7 @@
#define _LINUX_LIST_BL_H
#include
+#include
#include
/*
@@ -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(str
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)
Index: linux-5.4.17-rt9/include/linux/locallock.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/include/linux/locallock.h
@@ -0,0 +1,282 @@
+#ifndef _LINUX_LOCALLOCK_H
+#define _LINUX_LOCALLOCK_H
+
+#include
+#include
+#include
+
+#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
Index: linux-5.4.17-rt9/include/linux/mm_types.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/mm_types.h
+++ linux-5.4.17-rt9/include/linux/mm_types.h
@@ -12,6 +12,7 @@
#include
#include
#include
+#include
#include
#include
@@ -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
Index: linux-5.4.17-rt9/include/linux/mutex.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/mutex.h
+++ linux-5.4.17-rt9/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
+#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 */
Index: linux-5.4.17-rt9/include/linux/mutex_rt.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
+
+/* FIXME: Just for __lockfunc */
+#include
+
+struct mutex {
+ struct rt_mutex lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
+
+#define __MUTEX_INITIALIZER(mutexname) \
+ { \
+ .lock = __RT_MUTEX_INITIALIZER(mutexname.lock) \
+ __DEP_MAP_MUTEX_INITIALIZER(mutexname) \
+ }
+
+#define DEFINE_MUTEX(mutexname) \
+ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
+
+extern void __mutex_do_init(struct mutex *lock, const char *name, struct lock_class_key *key);
+extern void __lockfunc _mutex_lock(struct mutex *lock);
+extern void __lockfunc _mutex_lock_io(struct mutex *lock);
+extern void __lockfunc _mutex_lock_io_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_lock_interruptible(struct mutex *lock);
+extern int __lockfunc _mutex_lock_killable(struct mutex *lock);
+extern void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass);
+extern void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
+extern int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_trylock(struct mutex *lock);
+extern void __lockfunc _mutex_unlock(struct mutex *lock);
+
+#define mutex_is_locked(l) rt_mutex_is_locked(&(l)->lock)
+#define mutex_lock(l) _mutex_lock(l)
+#define mutex_lock_interruptible(l) _mutex_lock_interruptible(l)
+#define mutex_lock_killable(l) _mutex_lock_killable(l)
+#define mutex_trylock(l) _mutex_trylock(l)
+#define mutex_unlock(l) _mutex_unlock(l)
+#define mutex_lock_io(l) _mutex_lock_io(l);
+
+#define __mutex_owner(l) ((l)->lock.owner)
+
+#ifdef CONFIG_DEBUG_MUTEXES
+#define mutex_destroy(l) rt_mutex_destroy(&(l)->lock)
+#else
+static inline void mutex_destroy(struct mutex *lock) {}
+#endif
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define mutex_lock_nested(l, s) _mutex_lock_nested(l, s)
+# define mutex_lock_interruptible_nested(l, s) \
+ _mutex_lock_interruptible_nested(l, s)
+# define mutex_lock_killable_nested(l, s) \
+ _mutex_lock_killable_nested(l, s)
+# define mutex_lock_io_nested(l, s) _mutex_lock_io_nested(l, s)
+
+# define mutex_lock_nest_lock(lock, nest_lock) \
+do { \
+ typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
+ _mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
+} while (0)
+
+#else
+# define mutex_lock_nested(l, s) _mutex_lock(l)
+# define mutex_lock_interruptible_nested(l, s) \
+ _mutex_lock_interruptible(l)
+# define mutex_lock_killable_nested(l, s) \
+ _mutex_lock_killable(l)
+# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
+# define mutex_lock_io_nested(l, s) _mutex_lock_io(l)
+#endif
+
+# define mutex_init(mutex) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(mutex)->lock); \
+ __mutex_do_init((mutex), #mutex, &__key); \
+} while (0)
+
+# define __mutex_init(mutex, name, key) \
+do { \
+ rt_mutex_init(&(mutex)->lock); \
+ __mutex_do_init((mutex), name, key); \
+} while (0)
+
+/**
+ * These values are chosen such that FAIL and SUCCESS match the
+ * values of the regular mutex_trylock().
+ */
+enum mutex_trylock_recursive_enum {
+ MUTEX_TRYLOCK_FAILED = 0,
+ MUTEX_TRYLOCK_SUCCESS = 1,
+ MUTEX_TRYLOCK_RECURSIVE,
+};
+/**
+ * mutex_trylock_recursive - trylock variant that allows recursive locking
+ * @lock: mutex to be locked
+ *
+ * This function should not be used, _ever_. It is purely for hysterical GEM
+ * raisins, and once those are gone this will be removed.
+ *
+ * Returns:
+ * MUTEX_TRYLOCK_FAILED - trylock failed,
+ * MUTEX_TRYLOCK_SUCCESS - lock acquired,
+ * MUTEX_TRYLOCK_RECURSIVE - we already owned the lock.
+ */
+int __rt_mutex_owner_current(struct rt_mutex *lock);
+
+static inline /* __deprecated */ __must_check enum mutex_trylock_recursive_enum
+mutex_trylock_recursive(struct mutex *lock)
+{
+ if (unlikely(__rt_mutex_owner_current(&lock->lock)))
+ return MUTEX_TRYLOCK_RECURSIVE;
+
+ return mutex_trylock(lock);
+}
+
+extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
+
+#endif
Index: linux-5.4.17-rt9/include/linux/netdevice.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/netdevice.h
+++ linux-5.4.17-rt9/include/linux/netdevice.h
@@ -3018,6 +3018,7 @@ struct softnet_data {
unsigned int dropped;
struct sk_buff_head input_pkt_queue;
struct napi_struct backlog;
+ struct sk_buff_head tofree_queue;
};
Index: linux-5.4.17-rt9/include/linux/nfs_fs.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/nfs_fs.h
+++ linux-5.4.17-rt9/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)
Index: linux-5.4.17-rt9/include/linux/nfs_xdr.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/nfs_xdr.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/include/linux/percpu-refcount.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/percpu-refcount.h
+++ linux-5.4.17-rt9/include/linux/percpu-refcount.h
@@ -186,14 +186,14 @@ static inline void percpu_ref_get_many(s
{
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(str
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(str
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_liv
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_liv
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(s
{
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();
}
/**
Index: linux-5.4.17-rt9/include/linux/percpu-rwsem.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/percpu-rwsem.h
+++ linux-5.4.17-rt9/include/linux/percpu-rwsem.h
@@ -3,41 +3,52 @@
#define _LINUX_PERCPU_RWSEM_H
#include
-#include
#include
#include
+#include
#include
#include
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(stru
* 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(stru
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_trylo
*/
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 per
__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
Index: linux-5.4.17-rt9/include/linux/percpu.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/percpu.h
+++ linux-5.4.17-rt9/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)
Index: linux-5.4.17-rt9/include/linux/pid.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/pid.h
+++ linux-5.4.17-rt9/include/linux/pid.h
@@ -3,6 +3,7 @@
#define _LINUX_PID_H
#include
+#include
#include
#include
Index: linux-5.4.17-rt9/include/linux/posix-timers.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/posix-timers.h
+++ linux-5.4.17-rt9/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_wa
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 { };
Index: linux-5.4.17-rt9/include/linux/preempt.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/preempt.h
+++ linux-5.4.17-rt9/include/linux/preempt.h
@@ -78,10 +78,8 @@
#include
#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;
Index: linux-5.4.17-rt9/include/linux/printk.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/printk.h
+++ linux-5.4.17-rt9/include/linux/printk.h
@@ -58,6 +58,7 @@ static inline const char *printk_skip_he
*/
#define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT
#define CONSOLE_LOGLEVEL_QUIET CONFIG_CONSOLE_LOGLEVEL_QUIET
+#define CONSOLE_LOGLEVEL_EMERGENCY CONFIG_CONSOLE_LOGLEVEL_EMERGENCY
extern int console_printk[];
@@ -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_
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(
static inline void dump_stack(void)
{
}
-
-static inline void printk_safe_init(void)
-{
-}
-
-static inline void printk_safe_flush(void)
-{
-}
-
-static inline void printk_safe_flush_on_panic(void)
-{
-}
#endif
extern int kptr_restrict;
Index: linux-5.4.17-rt9/include/linux/printk_ringbuffer.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
+#include
+#include
+#include
+
+struct prb_cpulock {
+ atomic_t owner;
+ unsigned long __percpu *irqflags;
+};
+
+struct printk_ringbuffer {
+ void *buffer;
+ unsigned int size_bits;
+
+ u64 seq;
+ atomic_long_t lost;
+
+ atomic_long_t tail;
+ atomic_long_t head;
+ atomic_long_t reserve;
+
+ struct prb_cpulock *cpulock;
+ atomic_t ctx;
+
+ struct wait_queue_head *wq;
+ atomic_long_t wq_counter;
+ struct irq_work *wq_work;
+};
+
+struct prb_entry {
+ unsigned int size;
+ u64 seq;
+ char data[0];
+};
+
+struct prb_handle {
+ struct printk_ringbuffer *rb;
+ unsigned int cpu;
+ struct prb_entry *entry;
+};
+
+#define DECLARE_STATIC_PRINTKRB_CPULOCK(name) \
+static DEFINE_PER_CPU(unsigned long, _##name##_percpu_irqflags); \
+static struct prb_cpulock name = { \
+ .owner = ATOMIC_INIT(-1), \
+ .irqflags = &_##name##_percpu_irqflags, \
+}
+
+#define PRB_INIT ((unsigned long)-1)
+
+#define DECLARE_STATIC_PRINTKRB_ITER(name, rbaddr) \
+static struct prb_iterator name = { \
+ .rb = rbaddr, \
+ .lpos = PRB_INIT, \
+}
+
+struct prb_iterator {
+ struct printk_ringbuffer *rb;
+ unsigned long lpos;
+};
+
+#define DECLARE_STATIC_PRINTKRB(name, szbits, cpulockptr) \
+static char _##name##_buffer[1 << (szbits)] \
+ __aligned(__alignof__(long)); \
+static DECLARE_WAIT_QUEUE_HEAD(_##name##_wait); \
+static void _##name##_wake_work_func(struct irq_work *irq_work) \
+{ \
+ wake_up_interruptible_all(&_##name##_wait); \
+} \
+static struct irq_work _##name##_wake_work = { \
+ .func = _##name##_wake_work_func, \
+ .flags = IRQ_WORK_LAZY, \
+}; \
+static struct printk_ringbuffer name = { \
+ .buffer = &_##name##_buffer[0], \
+ .size_bits = szbits, \
+ .seq = 0, \
+ .lost = ATOMIC_LONG_INIT(0), \
+ .tail = ATOMIC_LONG_INIT(-111 * sizeof(long)), \
+ .head = ATOMIC_LONG_INIT(-111 * sizeof(long)), \
+ .reserve = ATOMIC_LONG_INIT(-111 * sizeof(long)), \
+ .cpulock = cpulockptr, \
+ .ctx = ATOMIC_INIT(0), \
+ .wq = &_##name##_wait, \
+ .wq_counter = ATOMIC_LONG_INIT(0), \
+ .wq_work = &_##name##_wake_work, \
+}
+
+/* writer interface */
+char *prb_reserve(struct prb_handle *h, struct printk_ringbuffer *rb,
+ unsigned int size);
+void prb_commit(struct prb_handle *h);
+
+/* reader interface */
+void prb_iter_init(struct prb_iterator *iter, struct printk_ringbuffer *rb,
+ u64 *seq);
+void prb_iter_copy(struct prb_iterator *dest, struct prb_iterator *src);
+int prb_iter_next(struct prb_iterator *iter, char *buf, int size, u64 *seq);
+int prb_iter_wait_next(struct prb_iterator *iter, char *buf, int size,
+ u64 *seq);
+int prb_iter_seek(struct prb_iterator *iter, u64 seq);
+int prb_iter_data(struct prb_iterator *iter, char *buf, int size, u64 *seq);
+
+/* utility functions */
+int prb_buffer_size(struct printk_ringbuffer *rb);
+void prb_inc_lost(struct printk_ringbuffer *rb);
+void prb_lock(struct prb_cpulock *cpu_lock, unsigned int *cpu_store);
+void prb_unlock(struct prb_cpulock *cpu_lock, unsigned int cpu_store);
+
+#endif /*_LINUX_PRINTK_RINGBUFFER_H */
Index: linux-5.4.17-rt9/include/linux/radix-tree.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/radix-tree.h
+++ linux-5.4.17-rt9/include/linux/radix-tree.h
@@ -226,6 +226,7 @@ unsigned int radix_tree_gang_lookup(cons
unsigned int max_items);
int radix_tree_preload(gfp_t gfp_mask);
int radix_tree_maybe_preload(gfp_t gfp_mask);
+void radix_tree_preload_end(void);
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *,
unsigned long index, unsigned int tag);
@@ -243,11 +244,6 @@ unsigned int radix_tree_gang_lookup_tag_
unsigned int max_items, unsigned int tag);
int radix_tree_tagged(const struct radix_tree_root *, unsigned int tag);
-static inline void radix_tree_preload_end(void)
-{
- preempt_enable();
-}
-
void __rcu **idr_get_free(struct radix_tree_root *root,
struct radix_tree_iter *iter, gfp_t gfp,
unsigned long max);
Index: linux-5.4.17-rt9/include/linux/random.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/random.h
+++ linux-5.4.17-rt9/include/linux/random.h
@@ -33,7 +33,7 @@ static inline void add_latent_entropy(vo
extern void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value) __latent_entropy;
-extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
+extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip) __latent_entropy;
extern void get_random_bytes(void *buf, int nbytes);
extern int wait_for_random_bytes(void);
Index: linux-5.4.17-rt9/include/linux/ratelimit.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/ratelimit.h
+++ linux-5.4.17-rt9/include/linux/ratelimit.h
@@ -59,7 +59,7 @@ static inline void ratelimit_state_exit(
return;
if (rs->missed) {
- pr_warn("%s: %d output lines suppressed due to ratelimiting\n",
+ pr_info("%s: %d output lines suppressed due to ratelimiting\n",
current->comm, rs->missed);
rs->missed = 0;
}
Index: linux-5.4.17-rt9/include/linux/rbtree.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/rbtree.h
+++ linux-5.4.17-rt9/include/linux/rbtree.h
@@ -19,7 +19,7 @@
#include
#include
-#include
+#include
struct rb_node {
unsigned long __rb_parent_color;
Index: linux-5.4.17-rt9/include/linux/rcu_assign_pointer.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
+#include
+
+#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
Index: linux-5.4.17-rt9/include/linux/rcupdate.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/rcupdate.h
+++ linux-5.4.17-rt9/include/linux/rcupdate.h
@@ -29,6 +29,7 @@
#include
#include
#include
+#include
#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
*
* 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_che
#define rcu_sleep_check() \
do { \
rcu_preempt_sleep_check(); \
- RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map), \
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) \
+ 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_che
* (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); \
@@ -335,54 +337,6 @@ static inline void rcu_preempt_sleep_che
})
/**
- * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
- * @v: The value to statically initialize with.
- */
-#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
-
-/**
- * rcu_assign_pointer() - assign to RCU-protected pointer
- * @p: pointer to assign to
- * @v: value to assign (publish)
- *
- * Assigns the specified value to the specified RCU-protected
- * pointer, ensuring that any concurrent RCU readers will see
- * any prior initialization.
- *
- * Inserts memory barriers on architectures that require them
- * (which is most of them), and also prevents the compiler from
- * reordering the code that initializes the structure after the pointer
- * assignment. More importantly, this call documents which pointers
- * will be dereferenced by RCU read-side code.
- *
- * In some special cases, you may use RCU_INIT_POINTER() instead
- * of rcu_assign_pointer(). RCU_INIT_POINTER() is a bit faster due
- * to the fact that it does not constrain either the CPU or the compiler.
- * That said, using RCU_INIT_POINTER() when you should have used
- * rcu_assign_pointer() is a very bad thing that results in
- * impossible-to-diagnose memory corruption. So please be careful.
- * See the RCU_INIT_POINTER() comment header for details.
- *
- * Note that rcu_assign_pointer() evaluates each of its arguments only
- * once, appearances notwithstanding. One of the "extra" evaluations
- * is in typeof() and the other visible only to sparse (__CHECKER__),
- * neither of which actually execute the argument. As with most cpp
- * macros, this execute-arguments-only-once property is important, so
- * please be careful when making changes to rcu_assign_pointer() and the
- * other macros that it invokes.
- */
-#define rcu_assign_pointer(p, v) \
-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
* @ptr: regular 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),
Index: linux-5.4.17-rt9/include/linux/rtmutex.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/rtmutex.h
+++ linux-5.4.17-rt9/include/linux/rtmutex.h
@@ -14,11 +14,15 @@
#define __LINUX_RT_MUTEX_H
#include
+#include
#include
-#include
extern int max_lock_depth; /* for sysctl */
+#ifdef CONFIG_DEBUG_MUTEXES
+#include
+#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_mute
#endif
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
extern int rt_mutex_timed_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *timeout);
Index: linux-5.4.17-rt9/include/linux/rwlock_rt.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/include/linux/rwlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/rwlock_types.h
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/include/linux/rwlock_types_rt.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/include/linux/rwsem-rt.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
+#include
+
+#define READER_BIAS (1U << 31)
+#define WRITER_BIAS (1U << 30)
+
+struct rw_semaphore {
+ atomic_t readers;
+ struct rt_mutex rtmutex;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
+
+#define __RWSEM_INITIALIZER(name) \
+{ \
+ .readers = ATOMIC_INIT(READER_BIAS), \
+ .rtmutex = __RT_MUTEX_INITIALIZER(name.rtmutex), \
+ RW_DEP_MAP_INIT(name) \
+}
+
+#define DECLARE_RWSEM(lockname) \
+ struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname)
+
+extern void __rwsem_init(struct rw_semaphore *rwsem, const char *name,
+ struct lock_class_key *key);
+
+#define __init_rwsem(sem, name, key) \
+do { \
+ rt_mutex_init(&(sem)->rtmutex); \
+ __rwsem_init((sem), (name), (key)); \
+} while (0)
+
+#define init_rwsem(sem) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __init_rwsem((sem), #sem, &__key); \
+} while (0)
+
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+ return atomic_read(&sem->readers) != READER_BIAS;
+}
+
+static inline int rwsem_is_contended(struct rw_semaphore *sem)
+{
+ return atomic_read(&sem->readers) > 0;
+}
+
+extern void __down_read(struct rw_semaphore *sem);
+extern int __down_read_killable(struct rw_semaphore *sem);
+extern int __down_read_trylock(struct rw_semaphore *sem);
+extern void __down_write(struct rw_semaphore *sem);
+extern int __must_check __down_write_killable(struct rw_semaphore *sem);
+extern int __down_write_trylock(struct rw_semaphore *sem);
+extern void __up_read(struct rw_semaphore *sem);
+extern void __up_write(struct rw_semaphore *sem);
+extern void __downgrade_write(struct rw_semaphore *sem);
+
+#endif
Index: linux-5.4.17-rt9/include/linux/rwsem.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/rwsem.h
+++ linux-5.4.17-rt9/include/linux/rwsem.h
@@ -16,6 +16,11 @@
#include
#include
#include
+
+#ifdef CONFIG_PREEMPT_RT
+#include
+#else /* PREEMPT_RT */
+
#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
#include
#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(str
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
*/
Index: linux-5.4.17-rt9/include/linux/sched.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/sched.h
+++ linux-5.4.17-rt9/include/linux/sched.h
@@ -31,6 +31,7 @@
#include
#include
#include
+#include
/* 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
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(
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
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
Index: linux-5.4.17-rt9/include/linux/sched/mm.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/sched/mm.h
+++ linux-5.4.17-rt9/include/linux/sched/mm.h
@@ -49,6 +49,17 @@ static inline void mmdrop(struct mm_stru
__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
Index: linux-5.4.17-rt9/include/linux/sched/wake_q.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/sched/wake_q.h
+++ linux-5.4.17-rt9/include/linux/sched/wake_q.h
@@ -58,6 +58,17 @@ static inline bool wake_q_empty(struct w
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 */
Index: linux-5.4.17-rt9/include/linux/seqlock.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/seqlock.h
+++ linux-5.4.17-rt9/include/linux/seqlock.h
@@ -221,20 +221,30 @@ static inline int read_seqcount_retry(co
return __read_seqcount_retry(s, start);
}
-
-
-static inline void raw_write_seqcount_begin(seqcount_t *s)
+static inline void __raw_write_seqcount_begin(seqcount_t *s)
{
s->sequence++;
smp_wmb();
}
-static inline void raw_write_seqcount_end(seqcount_t *s)
+static inline void raw_write_seqcount_begin(seqcount_t *s)
+{
+ preempt_disable_rt();
+ __raw_write_seqcount_begin(s);
+}
+
+static inline void __raw_write_seqcount_end(seqcount_t *s)
{
smp_wmb();
s->sequence++;
}
+static inline void raw_write_seqcount_end(seqcount_t *s)
+{
+ __raw_write_seqcount_end(s);
+ preempt_enable_rt();
+}
+
/**
* raw_write_seqcount_barrier - do a seq write barrier
* @s: pointer to seqcount_t
@@ -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(con
static inline void write_seqlock(seqlock_t *sl)
{
spin_lock(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __raw_write_seqcount_begin(&sl->seqcount);
+}
+
+static inline int try_write_seqlock(seqlock_t *sl)
+{
+ if (spin_trylock(&sl->lock)) {
+ __raw_write_seqcount_begin(&sl->seqcount);
+ return 1;
+ }
+ return 0;
}
static inline void write_sequnlock(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __raw_write_seqcount_end(&sl->seqcount);
spin_unlock(&sl->lock);
}
static inline void write_seqlock_bh(seqlock_t *sl)
{
spin_lock_bh(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __raw_write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock_bh(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __raw_write_seqcount_end(&sl->seqcount);
spin_unlock_bh(&sl->lock);
}
static inline void write_seqlock_irq(seqlock_t *sl)
{
spin_lock_irq(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __raw_write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock_irq(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __raw_write_seqcount_end(&sl->seqcount);
spin_unlock_irq(&sl->lock);
}
@@ -484,7 +526,7 @@ static inline unsigned long __write_seql
unsigned long flags;
spin_lock_irqsave(&sl->lock, flags);
- write_seqcount_begin(&sl->seqcount);
+ __raw_write_seqcount_begin(&sl->seqcount);
return flags;
}
@@ -494,7 +536,7 @@ static inline unsigned long __write_seql
static inline void
write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags)
{
- write_seqcount_end(&sl->seqcount);
+ __raw_write_seqcount_end(&sl->seqcount);
spin_unlock_irqrestore(&sl->lock, flags);
}
Index: linux-5.4.17-rt9/include/linux/serial_8250.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/serial_8250.h
+++ linux-5.4.17-rt9/include/linux/serial_8250.h
@@ -7,6 +7,7 @@
#ifndef _LINUX_SERIAL_8250_H
#define _LINUX_SERIAL_8250_H
+#include
#include
#include
#include
@@ -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_82
void serial8250_set_defaults(struct uart_8250_port *up);
void serial8250_console_write(struct uart_8250_port *up, const char *s,
unsigned int count);
+void serial8250_console_write_atomic(struct uart_8250_port *up, const char *s,
+ unsigned int count);
int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
extern void serial8250_set_isa_configurator(void (*v)
Index: linux-5.4.17-rt9/include/linux/signal.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/signal.h
+++ linux-5.4.17-rt9/include/linux/signal.h
@@ -255,6 +255,7 @@ static inline void init_sigpending(struc
}
extern void flush_sigqueue(struct sigpending *queue);
+extern void flush_task_sigqueue(struct task_struct *tsk);
/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
static inline int valid_signal(unsigned long sig)
Index: linux-5.4.17-rt9/include/linux/skbuff.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/skbuff.h
+++ linux-5.4.17-rt9/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(s
__skb_queue_head_init(list);
}
+static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
+{
+ raw_spin_lock_init(&list->raw_lock);
+ __skb_queue_head_init(list);
+}
+
static inline void skb_queue_head_init_class(struct sk_buff_head *list,
struct lock_class_key *class)
{
Index: linux-5.4.17-rt9/include/linux/smp.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/smp.h
+++ linux-5.4.17-rt9/include/linux/smp.h
@@ -15,6 +15,7 @@
#include
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 cpuma
* 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_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(smp_cond_func_t cond_func, smp_call_func_t func,
+ void *info, bool wait);
+
+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:
Index: linux-5.4.17-rt9/include/linux/spinlock.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/spinlock.h
+++ linux-5.4.17-rt9/include/linux/spinlock.h
@@ -307,7 +307,11 @@ static inline void do_raw_spin_unlock(ra
})
/* Include rwlock functions */
-#include
+#ifdef CONFIG_PREEMPT_RT
+# include
+#else
+# include
+#endif
/*
* Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
@@ -318,6 +322,10 @@ static inline void do_raw_spin_unlock(ra
# include
#endif
+#ifdef CONFIG_PREEMPT_RT
+# include
+#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_conte
#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)
Index: linux-5.4.17-rt9/include/linux/spinlock_api_smp.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/spinlock_api_smp.h
+++ linux-5.4.17-rt9/include/linux/spinlock_api_smp.h
@@ -187,6 +187,8 @@ static inline int __raw_spin_trylock_bh(
return 0;
}
-#include
+#ifndef CONFIG_PREEMPT_RT
+# include
+#endif
#endif /* __LINUX_SPINLOCK_API_SMP_H */
Index: linux-5.4.17-rt9/include/linux/spinlock_rt.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
+
+extern void
+__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key);
+
+#define spin_lock_init(slock) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(slock)->lock); \
+ __rt_spin_lock_init(slock, #slock, &__key); \
+} while (0)
+
+extern void __lockfunc rt_spin_lock(spinlock_t *lock);
+extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
+extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
+extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
+extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock(spinlock_t *lock);
+extern int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock);
+
+/*
+ * lockdep-less calls, for derived types like rwlock:
+ * (for trylock they can use rt_mutex_trylock() directly.
+ * Migrate disable handling must be done at the call site.
+ */
+extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock);
+extern void __lockfunc __rt_spin_trylock(struct rt_mutex *lock);
+extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock);
+
+#define spin_lock(lock) rt_spin_lock(lock)
+
+#define spin_lock_bh(lock) \
+ do { \
+ local_bh_disable(); \
+ rt_spin_lock(lock); \
+ } while (0)
+
+#define spin_lock_irq(lock) spin_lock(lock)
+
+#define spin_do_trylock(lock) __cond_lock(lock, rt_spin_trylock(lock))
+
+#define spin_trylock(lock) \
+({ \
+ int __locked; \
+ __locked = spin_do_trylock(lock); \
+ __locked; \
+})
+
+#ifdef CONFIG_LOCKDEP
+# define spin_lock_nested(lock, subclass) \
+ do { \
+ rt_spin_lock_nested(lock, subclass); \
+ } while (0)
+
+#define spin_lock_bh_nested(lock, subclass) \
+ do { \
+ local_bh_disable(); \
+ rt_spin_lock_nested(lock, subclass); \
+ } while (0)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ rt_spin_lock_nested(lock, subclass); \
+ } while (0)
+#else
+# define spin_lock_nested(lock, subclass) spin_lock(lock)
+# define spin_lock_bh_nested(lock, subclass) spin_lock_bh(lock)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ spin_lock(lock); \
+ } while (0)
+#endif
+
+#define spin_lock_irqsave(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ spin_lock(lock); \
+ } while (0)
+
+static inline unsigned long spin_lock_trace_flags(spinlock_t *lock)
+{
+ unsigned long flags = 0;
+#ifdef CONFIG_TRACE_IRQFLAGS
+ flags = rt_spin_lock_trace_flags(lock);
+#else
+ spin_lock(lock); /* lock_local */
+#endif
+ return flags;
+}
+
+/* FIXME: we need rt_spin_lock_nest_lock */
+#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0)
+
+#define spin_unlock(lock) rt_spin_unlock(lock)
+
+#define spin_unlock_bh(lock) \
+ do { \
+ rt_spin_unlock(lock); \
+ local_bh_enable(); \
+ } while (0)
+
+#define spin_unlock_irq(lock) spin_unlock(lock)
+
+#define spin_unlock_irqrestore(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ (void) flags; \
+ spin_unlock(lock); \
+ } while (0)
+
+#define spin_trylock_bh(lock) __cond_lock(lock, rt_spin_trylock_bh(lock))
+#define spin_trylock_irq(lock) spin_trylock(lock)
+
+#define spin_trylock_irqsave(lock, flags) \
+ rt_spin_trylock_irqsave(lock, &(flags))
+
+#define spin_unlock_wait(lock) rt_spin_unlock_wait(lock)
+
+#ifdef CONFIG_GENERIC_LOCKBREAK
+# define spin_is_contended(lock) ((lock)->break_lock)
+#else
+# define spin_is_contended(lock) (((void)(lock), 0))
+#endif
+
+static inline int spin_can_lock(spinlock_t *lock)
+{
+ return !rt_mutex_is_locked(&lock->lock);
+}
+
+static inline int spin_is_locked(spinlock_t *lock)
+{
+ return rt_mutex_is_locked(&lock->lock);
+}
+
+static inline void assert_spin_locked(spinlock_t *lock)
+{
+ BUG_ON(!spin_is_locked(lock));
+}
+
+#endif
Index: linux-5.4.17-rt9/include/linux/spinlock_types.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/spinlock_types.h
+++ linux-5.4.17-rt9/include/linux/spinlock_types.h
@@ -9,77 +9,15 @@
* Released under the General Public License (GPL).
*/
-#if defined(CONFIG_SMP)
-# include
-#else
-# include
-#endif
-
-#include
-
-typedef struct raw_spinlock {
- arch_spinlock_t raw_lock;
-#ifdef CONFIG_DEBUG_SPINLOCK
- unsigned int magic, owner_cpu;
- void *owner;
-#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- struct lockdep_map dep_map;
-#endif
-} raw_spinlock_t;
-
-#define SPINLOCK_MAGIC 0xdead4ead
-
-#define SPINLOCK_OWNER_INIT ((void *)-1L)
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
-#else
-# define SPIN_DEP_MAP_INIT(lockname)
-#endif
+#include
-#ifdef CONFIG_DEBUG_SPINLOCK
-# define SPIN_DEBUG_INIT(lockname) \
- .magic = SPINLOCK_MAGIC, \
- .owner_cpu = -1, \
- .owner = SPINLOCK_OWNER_INIT,
+#ifndef CONFIG_PREEMPT_RT
+# include
+# include
#else
-# define SPIN_DEBUG_INIT(lockname)
+# include
+# include
+# include
#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
-
#endif /* __LINUX_SPINLOCK_TYPES_H */
Index: linux-5.4.17-rt9/include/linux/spinlock_types_nort.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/include/linux/spinlock_types_raw.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/include/linux/spinlock_types_raw.h
@@ -0,0 +1,55 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
+#define __LINUX_SPINLOCK_TYPES_RAW_H
+
+#include
+
+#if defined(CONFIG_SMP)
+# include
+#else
+# include
+#endif
+
+#include
+
+typedef struct raw_spinlock {
+ arch_spinlock_t raw_lock;
+#ifdef CONFIG_DEBUG_SPINLOCK
+ unsigned int magic, owner_cpu;
+ void *owner;
+#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} raw_spinlock_t;
+
+#define SPINLOCK_MAGIC 0xdead4ead
+
+#define SPINLOCK_OWNER_INIT ((void *)-1L)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
+#else
+# define SPIN_DEP_MAP_INIT(lockname)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define SPIN_DEBUG_INIT(lockname) \
+ .magic = SPINLOCK_MAGIC, \
+ .owner_cpu = -1, \
+ .owner = SPINLOCK_OWNER_INIT,
+#else
+# define SPIN_DEBUG_INIT(lockname)
+#endif
+
+#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \
+ { \
+ .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \
+ SPIN_DEBUG_INIT(lockname) \
+ SPIN_DEP_MAP_INIT(lockname) }
+
+#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \
+ (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
+
+#endif
Index: linux-5.4.17-rt9/include/linux/spinlock_types_rt.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
+
+/*
+ * PREEMPT_RT: spinlocks - an RT mutex plus lock-break field:
+ */
+typedef struct spinlock {
+ struct rt_mutex lock;
+ unsigned int break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} spinlock_t;
+
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+# define __RT_SPIN_INITIALIZER(name) \
+ { \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+ .save_state = 1, \
+ .file = __FILE__, \
+ .line = __LINE__ , \
+ }
+#else
+# define __RT_SPIN_INITIALIZER(name) \
+ { \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+ .save_state = 1, \
+ }
+#endif
+
+/*
+.wait_list = PLIST_HEAD_INIT_RAW((name).lock.wait_list, (name).lock.wait_lock)
+*/
+
+#define __SPIN_LOCK_UNLOCKED(name) \
+ { .lock = __RT_SPIN_INITIALIZER(name.lock), \
+ SPIN_DEP_MAP_INIT(name) }
+
+#define DEFINE_SPINLOCK(name) \
+ spinlock_t name = __SPIN_LOCK_UNLOCKED(name)
+
+#endif
Index: linux-5.4.17-rt9/include/linux/spinlock_types_up.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/spinlock_types_up.h
+++ linux-5.4.17-rt9/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
*
Index: linux-5.4.17-rt9/include/linux/stop_machine.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/stop_machine.h
+++ linux-5.4.17-rt9/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);
Index: linux-5.4.17-rt9/include/linux/suspend.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/suspend.h
+++ linux-5.4.17-rt9/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;
Index: linux-5.4.17-rt9/include/linux/swait.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/swait.h
+++ linux-5.4.17-rt9/include/linux/swait.h
@@ -160,7 +160,9 @@ static inline bool swq_has_sleeper(struc
extern void swake_up_one(struct swait_queue_head *q);
extern void swake_up_all(struct swait_queue_head *q);
extern void swake_up_locked(struct swait_queue_head *q);
+extern void swake_up_all_locked(struct swait_queue_head *q);
+extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
extern void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state);
extern long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state);
@@ -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 */
Index: linux-5.4.17-rt9/include/linux/thread_info.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/thread_info.h
+++ linux-5.4.17-rt9/include/linux/thread_info.h
@@ -97,7 +97,17 @@ static inline int test_ti_thread_flag(st
#define test_thread_flag(flag) \
test_ti_thread_flag(current_thread_info(), flag)
-#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+#ifdef CONFIG_PREEMPT_LAZY
+#define tif_need_resched() (test_thread_flag(TIF_NEED_RESCHED) || \
+ test_thread_flag(TIF_NEED_RESCHED_LAZY))
+#define tif_need_resched_now() (test_thread_flag(TIF_NEED_RESCHED))
+#define tif_need_resched_lazy() test_thread_flag(TIF_NEED_RESCHED_LAZY))
+
+#else
+#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_now() test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_lazy() 0
+#endif
#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
static inline int arch_within_stack_frames(const void * const stack,
Index: linux-5.4.17-rt9/include/linux/trace_events.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/trace_events.h
+++ linux-5.4.17-rt9/include/linux/trace_events.h
@@ -62,6 +62,8 @@ struct trace_entry {
unsigned char flags;
unsigned char preempt_count;
int pid;
+ unsigned char migrate_disable;
+ unsigned char preempt_lazy_count;
};
#define TRACE_EVENT_TYPE_MAX \
Index: linux-5.4.17-rt9/include/linux/uaccess.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/uaccess.h
+++ linux-5.4.17-rt9/include/linux/uaccess.h
@@ -182,6 +182,7 @@ static __always_inline void pagefault_di
*/
static inline void pagefault_disable(void)
{
+ migrate_disable();
pagefault_disabled_inc();
/*
* make sure to have issued the store before a pagefault
@@ -198,6 +199,7 @@ static inline void pagefault_enable(void
*/
barrier();
pagefault_disabled_dec();
+ migrate_enable();
}
/*
Index: linux-5.4.17-rt9/include/linux/vmstat.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/vmstat.h
+++ linux-5.4.17-rt9/include/linux/vmstat.h
@@ -54,7 +54,9 @@ DECLARE_PER_CPU(struct vm_event_state, v
*/
static inline void __count_vm_event(enum vm_event_item item)
{
+ preempt_disable_rt();
raw_cpu_inc(vm_event_states.event[item]);
+ preempt_enable_rt();
}
static inline void count_vm_event(enum vm_event_item item)
@@ -64,7 +66,9 @@ static inline void count_vm_event(enum v
static inline void __count_vm_events(enum vm_event_item item, long delta)
{
+ preempt_disable_rt();
raw_cpu_add(vm_event_states.event[item], delta);
+ preempt_enable_rt();
}
static inline void count_vm_events(enum vm_event_item item, long delta)
Index: linux-5.4.17-rt9/include/linux/wait.h
===================================================================
--- linux-5.4.17-rt9.orig/include/linux/wait.h
+++ linux-5.4.17-rt9/include/linux/wait.h
@@ -10,6 +10,7 @@
#include
#include
+#include
typedef struct wait_queue_entry wait_queue_entry_t;
@@ -20,6 +21,7 @@ int default_wake_function(struct wait_qu
#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:
Index: linux-5.4.17-rt9/include/net/gen_stats.h
===================================================================
--- linux-5.4.17-rt9.orig/include/net/gen_stats.h
+++ linux-5.4.17-rt9/include/net/gen_stats.h
@@ -6,6 +6,7 @@
#include
#include
#include
+#include
struct gnet_stats_basic_cpu {
struct gnet_stats_basic_packed bstats;
@@ -36,15 +37,15 @@ int gnet_stats_start_copy_compat(struct
spinlock_t *lock, struct gnet_dump *d,
int padattr);
-int gnet_stats_copy_basic(const seqcount_t *running,
+int gnet_stats_copy_basic(net_seqlock_t *running,
struct gnet_dump *d,
struct gnet_stats_basic_cpu __percpu *cpu,
struct gnet_stats_basic_packed *b);
-void __gnet_stats_copy_basic(const seqcount_t *running,
+void __gnet_stats_copy_basic(net_seqlock_t *running,
struct gnet_stats_basic_packed *bstats,
struct gnet_stats_basic_cpu __percpu *cpu,
struct gnet_stats_basic_packed *b);
-int gnet_stats_copy_basic_hw(const seqcount_t *running,
+int gnet_stats_copy_basic_hw(net_seqlock_t *running,
struct gnet_dump *d,
struct gnet_stats_basic_cpu __percpu *cpu,
struct gnet_stats_basic_packed *b);
@@ -64,13 +65,13 @@ int gen_new_estimator(struct gnet_stats_
struct gnet_stats_basic_cpu __percpu *cpu_bstats,
struct net_rate_estimator __rcu **rate_est,
spinlock_t *lock,
- seqcount_t *running, struct nlattr *opt);
+ net_seqlock_t *running, struct nlattr *opt);
void gen_kill_estimator(struct net_rate_estimator __rcu **ptr);
int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_basic_cpu __percpu *cpu_bstats,
struct net_rate_estimator __rcu **ptr,
spinlock_t *lock,
- seqcount_t *running, struct nlattr *opt);
+ net_seqlock_t *running, struct nlattr *opt);
bool gen_estimator_active(struct net_rate_estimator __rcu **ptr);
bool gen_estimator_read(struct net_rate_estimator __rcu **ptr,
struct gnet_stats_rate_est64 *sample);
Index: linux-5.4.17-rt9/include/net/neighbour.h
===================================================================
--- linux-5.4.17-rt9.orig/include/net/neighbour.h
+++ linux-5.4.17-rt9/include/net/neighbour.h
@@ -459,7 +459,7 @@ static inline int neigh_hh_bridge(struct
}
#endif
-static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
+static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
{
unsigned int hh_alen = 0;
unsigned int seq;
@@ -502,7 +502,7 @@ static inline int neigh_hh_output(const
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;
Index: linux-5.4.17-rt9/include/net/net_seq_lock.h
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/include/net/sch_generic.h
===================================================================
--- linux-5.4.17-rt9.orig/include/net/sch_generic.h
+++ linux-5.4.17-rt9/include/net/sch_generic.h
@@ -10,6 +10,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -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(stru
{
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(struc
} 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_sle
return qdisc_lock(root);
}
-static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
+static inline net_seqlock_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
{
struct Qdisc *root = qdisc_root_sleeping(qdisc);
Index: linux-5.4.17-rt9/include/xen/xen-ops.h
===================================================================
--- linux-5.4.17-rt9.orig/include/xen/xen-ops.h
+++ linux-5.4.17-rt9/include/xen/xen-ops.h
@@ -215,7 +215,7 @@ bool xen_running_on_version_or_later(uns
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
__this_cpu_write(xen_in_preemptible_hcall, false);
}
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */
#endif /* INCLUDE_XEN_OPS_H */
Index: linux-5.4.17-rt9/init/Kconfig
===================================================================
--- linux-5.4.17-rt9.orig/init/Kconfig
+++ linux-5.4.17-rt9/init/Kconfig
@@ -904,6 +904,7 @@ 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
@@ -1785,6 +1786,7 @@ 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
@@ -1805,6 +1807,7 @@ 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
@@ -1870,7 +1873,7 @@ 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
Index: linux-5.4.17-rt9/init/init_task.c
===================================================================
--- linux-5.4.17-rt9.orig/init/init_task.c
+++ linux-5.4.17-rt9/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 = {
Index: linux-5.4.17-rt9/init/main.c
===================================================================
--- linux-5.4.17-rt9.orig/init/main.c
+++ linux-5.4.17-rt9/init/main.c
@@ -694,7 +694,6 @@ asmlinkage __visible void __init start_k
boot_init_stack_canary();
time_init();
- printk_safe_init();
perf_event_init();
profile_init();
call_function_init();
Index: linux-5.4.17-rt9/kernel/Kconfig.locks
===================================================================
--- linux-5.4.17-rt9.orig/kernel/Kconfig.locks
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/kernel/Kconfig.preempt
===================================================================
--- linux-5.4.17-rt9.orig/kernel/Kconfig.preempt
+++ linux-5.4.17-rt9/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
Index: linux-5.4.17-rt9/kernel/bpf/hashtab.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/bpf/hashtab.c
+++ linux-5.4.17-rt9/kernel/bpf/hashtab.c
@@ -17,9 +17,62 @@
(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE | \
BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED)
+/*
+ * The bucket lock has two protection scopes:
+ *
+ * 1) Serializing concurrent operations from BPF programs on differrent
+ * CPUs
+ *
+ * 2) Serializing concurrent operations from BPF programs and sys_bpf()
+ *
+ * BPF programs can execute in any context including perf, kprobes and
+ * tracing. As there are almost no limits where perf, kprobes and tracing
+ * can be invoked from the lock operations need to be protected against
+ * deadlocks. Deadlocks can be caused by recursion and by an invocation in
+ * the lock held section when functions which acquire this lock are invoked
+ * from sys_bpf(). BPF recursion is prevented by incrementing the per CPU
+ * variable bpf_prog_active, which prevents BPF programs attached to perf
+ * events, kprobes and tracing to be invoked before the prior invocation
+ * from one of these contexts completed. sys_bpf() uses the same mechanism
+ * by pinning the task to the current CPU and incrementing the recursion
+ * protection accross the map operation.
+ *
+ * This has subtle implications on PREEMPT_RT. PREEMPT_RT forbids certain
+ * operations like memory allocations (even with GFP_ATOMIC) from atomic
+ * contexts. This is required because even with GFP_ATOMIC the memory
+ * allocator calls into code pathes which acquire locks with long held lock
+ * sections. To ensure the deterministic behaviour these locks are regular
+ * spinlocks, which are converted to 'sleepable' spinlocks on RT. The only
+ * true atomic contexts on an RT kernel are the low level hardware
+ * handling, scheduling, low level interrupt handling, NMIs etc. None of
+ * these contexts should ever do memory allocations.
+ *
+ * As regular device interrupt handlers and soft interrupts are forced into
+ * thread context, the existing code which does
+ * spin_lock*(); alloc(GPF_ATOMIC); spin_unlock*();
+ * just works.
+ *
+ * In theory the BPF locks could be converted to regular spinlocks as well,
+ * but the bucket locks and percpu_freelist locks can be taken from
+ * arbitrary contexts (perf, kprobes, tracepoints) which are required to be
+ * atomic contexts even on RT. These mechanisms require preallocated maps,
+ * so there is no need to invoke memory allocations within the lock held
+ * sections.
+ *
+ * BPF maps which need dynamic allocation are only used from (forced)
+ * thread context on RT and can therefore use regular spinlocks which in
+ * turn allows to invoke memory allocations from the lock held section.
+ *
+ * On a non RT kernel this distinction is neither possible nor required.
+ * spinlock maps to raw_spinlock and the extra code is optimized out by the
+ * compiler.
+ */
struct bucket {
struct hlist_nulls_head head;
- raw_spinlock_t lock;
+ union {
+ raw_spinlock_t raw_lock;
+ spinlock_t lock;
+ };
};
struct bpf_htab {
@@ -57,6 +110,51 @@ struct htab_elem {
char key[0] __aligned(8);
};
+static inline bool htab_is_prealloc(const struct bpf_htab *htab)
+{
+ return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
+}
+
+static inline bool htab_use_raw_lock(const struct bpf_htab *htab)
+{
+ return (!IS_ENABLED(CONFIG_PREEMPT_RT) || htab_is_prealloc(htab));
+}
+
+static void htab_init_buckets(struct bpf_htab *htab)
+{
+ unsigned i;
+
+ for (i = 0; i < htab->n_buckets; i++) {
+ INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
+ if (htab_use_raw_lock(htab))
+ raw_spin_lock_init(&htab->buckets[i].raw_lock);
+ else
+ spin_lock_init(&htab->buckets[i].lock);
+ }
+}
+
+static inline unsigned long htab_lock_bucket(const struct bpf_htab *htab,
+ struct bucket *b)
+{
+ unsigned long flags;
+
+ if (htab_use_raw_lock(htab))
+ raw_spin_lock_irqsave(&b->raw_lock, flags);
+ else
+ spin_lock_irqsave(&b->lock, flags);
+ return flags;
+}
+
+static inline void htab_unlock_bucket(const struct bpf_htab *htab,
+ struct bucket *b,
+ unsigned long flags)
+{
+ if (htab_use_raw_lock(htab))
+ raw_spin_unlock_irqrestore(&b->raw_lock, flags);
+ else
+ spin_unlock_irqrestore(&b->lock, flags);
+}
+
static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
static bool htab_is_lru(const struct bpf_htab *htab)
@@ -71,11 +169,6 @@ static bool htab_is_percpu(const struct
htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
}
-static bool htab_is_prealloc(const struct bpf_htab *htab)
-{
- return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
-}
-
static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
void __percpu *pptr)
{
@@ -306,8 +399,8 @@ static struct bpf_map *htab_map_alloc(un
bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
struct bpf_htab *htab;
- int err, i;
u64 cost;
+ int err;
htab = kzalloc(sizeof(*htab), GFP_USER);
if (!htab)
@@ -369,10 +462,7 @@ static struct bpf_map *htab_map_alloc(un
else
htab->hashrnd = get_random_int();
- for (i = 0; i < htab->n_buckets; i++) {
- INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
- raw_spin_lock_init(&htab->buckets[i].lock);
- }
+ htab_init_buckets(htab);
if (prealloc) {
err = prealloc_init(htab);
@@ -580,7 +670,7 @@ static bool htab_lru_map_delete_node(voi
b = __select_bucket(htab, tgt_l->hash);
head = &b->head;
- raw_spin_lock_irqsave(&b->lock, flags);
+ flags = htab_lock_bucket(htab, b);
hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
if (l == tgt_l) {
@@ -588,7 +678,7 @@ static bool htab_lru_map_delete_node(voi
break;
}
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ htab_unlock_bucket(htab, b, flags);
return l == tgt_l;
}
@@ -664,15 +754,7 @@ static void htab_elem_free_rcu(struct rc
struct htab_elem *l = container_of(head, struct htab_elem, rcu);
struct bpf_htab *htab = l->htab;
- /* must increment bpf_prog_active to avoid kprobe+bpf triggering while
- * we're calling kfree, otherwise deadlock is possible if kprobes
- * are placed somewhere inside of slub
- */
- preempt_disable();
- __this_cpu_inc(bpf_prog_active);
htab_elem_free(htab, l);
- __this_cpu_dec(bpf_prog_active);
- preempt_enable();
}
static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
@@ -862,8 +944,7 @@ static int htab_map_update_elem(struct b
*/
}
- /* bpf_map_update_elem() can be called in_irq() */
- raw_spin_lock_irqsave(&b->lock, flags);
+ flags = htab_lock_bucket(htab, b);
l_old = lookup_elem_raw(head, hash, key, key_size);
@@ -904,7 +985,7 @@ static int htab_map_update_elem(struct b
}
ret = 0;
err:
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ htab_unlock_bucket(htab, b, flags);
return ret;
}
@@ -942,8 +1023,7 @@ static int htab_lru_map_update_elem(stru
return -ENOMEM;
memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size);
- /* bpf_map_update_elem() can be called in_irq() */
- raw_spin_lock_irqsave(&b->lock, flags);
+ flags = htab_lock_bucket(htab, b);
l_old = lookup_elem_raw(head, hash, key, key_size);
@@ -962,7 +1042,7 @@ static int htab_lru_map_update_elem(stru
ret = 0;
err:
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ htab_unlock_bucket(htab, b, flags);
if (ret)
bpf_lru_push_free(&htab->lru, &l_new->lru_node);
@@ -997,8 +1077,7 @@ static int __htab_percpu_map_update_elem
b = __select_bucket(htab, hash);
head = &b->head;
- /* bpf_map_update_elem() can be called in_irq() */
- raw_spin_lock_irqsave(&b->lock, flags);
+ flags = htab_lock_bucket(htab, b);
l_old = lookup_elem_raw(head, hash, key, key_size);
@@ -1021,7 +1100,7 @@ static int __htab_percpu_map_update_elem
}
ret = 0;
err:
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ htab_unlock_bucket(htab, b, flags);
return ret;
}
@@ -1061,8 +1140,7 @@ static int __htab_lru_percpu_map_update_
return -ENOMEM;
}
- /* bpf_map_update_elem() can be called in_irq() */
- raw_spin_lock_irqsave(&b->lock, flags);
+ flags = htab_lock_bucket(htab, b);
l_old = lookup_elem_raw(head, hash, key, key_size);
@@ -1084,7 +1162,7 @@ static int __htab_lru_percpu_map_update_
}
ret = 0;
err:
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ htab_unlock_bucket(htab, b, flags);
if (l_new)
bpf_lru_push_free(&htab->lru, &l_new->lru_node);
return ret;
@@ -1122,7 +1200,7 @@ static int htab_map_delete_elem(struct b
b = __select_bucket(htab, hash);
head = &b->head;
- raw_spin_lock_irqsave(&b->lock, flags);
+ flags = htab_lock_bucket(htab, b);
l = lookup_elem_raw(head, hash, key, key_size);
@@ -1132,7 +1210,7 @@ static int htab_map_delete_elem(struct b
ret = 0;
}
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ htab_unlock_bucket(htab, b, flags);
return ret;
}
@@ -1154,7 +1232,7 @@ static int htab_lru_map_delete_elem(stru
b = __select_bucket(htab, hash);
head = &b->head;
- raw_spin_lock_irqsave(&b->lock, flags);
+ flags = htab_lock_bucket(htab, b);
l = lookup_elem_raw(head, hash, key, key_size);
@@ -1163,7 +1241,7 @@ static int htab_lru_map_delete_elem(stru
ret = 0;
}
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ htab_unlock_bucket(htab, b, flags);
if (l)
bpf_lru_push_free(&htab->lru, &l->lru_node);
return ret;
Index: linux-5.4.17-rt9/kernel/bpf/lpm_trie.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/bpf/lpm_trie.c
+++ linux-5.4.17-rt9/kernel/bpf/lpm_trie.c
@@ -34,7 +34,7 @@ struct lpm_trie {
size_t n_entries;
size_t max_prefixlen;
size_t data_size;
- raw_spinlock_t lock;
+ spinlock_t lock;
};
/* This trie implements a longest prefix match algorithm that can be used to
@@ -315,7 +315,7 @@ static int trie_update_elem(struct bpf_m
if (key->prefixlen > trie->max_prefixlen)
return -EINVAL;
- raw_spin_lock_irqsave(&trie->lock, irq_flags);
+ spin_lock_irqsave(&trie->lock, irq_flags);
/* Allocate and fill a new node */
@@ -422,7 +422,7 @@ out:
kfree(im_node);
}
- raw_spin_unlock_irqrestore(&trie->lock, irq_flags);
+ spin_unlock_irqrestore(&trie->lock, irq_flags);
return ret;
}
@@ -442,7 +442,7 @@ static int trie_delete_elem(struct bpf_m
if (key->prefixlen > trie->max_prefixlen)
return -EINVAL;
- raw_spin_lock_irqsave(&trie->lock, irq_flags);
+ spin_lock_irqsave(&trie->lock, irq_flags);
/* Walk the tree looking for an exact key/length match and keeping
* track of the path we traverse. We will need to know the node
@@ -518,7 +518,7 @@ static int trie_delete_elem(struct bpf_m
kfree_rcu(node, rcu);
out:
- raw_spin_unlock_irqrestore(&trie->lock, irq_flags);
+ spin_unlock_irqrestore(&trie->lock, irq_flags);
return ret;
}
@@ -575,7 +575,7 @@ static struct bpf_map *trie_alloc(union
if (ret)
goto out_err;
- raw_spin_lock_init(&trie->lock);
+ spin_lock_init(&trie->lock);
return &trie->map;
out_err:
Index: linux-5.4.17-rt9/kernel/bpf/percpu_freelist.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/bpf/percpu_freelist.c
+++ linux-5.4.17-rt9/kernel/bpf/percpu_freelist.c
@@ -25,12 +25,18 @@ void pcpu_freelist_destroy(struct pcpu_f
free_percpu(s->freelist);
}
+static inline void pcpu_freelist_push_node(struct pcpu_freelist_head *head,
+ struct pcpu_freelist_node *node)
+{
+ node->next = head->first;
+ head->first = node;
+}
+
static inline void ___pcpu_freelist_push(struct pcpu_freelist_head *head,
struct pcpu_freelist_node *node)
{
raw_spin_lock(&head->lock);
- node->next = head->first;
- head->first = node;
+ pcpu_freelist_push_node(head, node);
raw_spin_unlock(&head->lock);
}
@@ -56,21 +62,16 @@ void pcpu_freelist_populate(struct pcpu_
u32 nr_elems)
{
struct pcpu_freelist_head *head;
- unsigned long flags;
int i, cpu, pcpu_entries;
pcpu_entries = nr_elems / num_possible_cpus() + 1;
i = 0;
- /* disable irq to workaround lockdep false positive
- * in bpf usage pcpu_freelist_populate() will never race
- * with pcpu_freelist_push()
- */
- local_irq_save(flags);
for_each_possible_cpu(cpu) {
again:
head = per_cpu_ptr(s->freelist, cpu);
- ___pcpu_freelist_push(head, buf);
+ /* No locking required as this is not visible yet. */
+ pcpu_freelist_push_node(head, buf);
i++;
buf += elem_size;
if (i == nr_elems)
@@ -78,7 +79,6 @@ again:
if (i % pcpu_entries)
goto again;
}
- local_irq_restore(flags);
}
struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
Index: linux-5.4.17-rt9/kernel/bpf/stackmap.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/bpf/stackmap.c
+++ linux-5.4.17-rt9/kernel/bpf/stackmap.c
@@ -40,6 +40,9 @@ static void do_up_read(struct irq_work *
{
struct stack_map_irq_work *work;
+ if (WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_RT)))
+ return;
+
work = container_of(entry, struct stack_map_irq_work, irq_work);
up_read_non_owner(work->sem);
work->sem = NULL;
@@ -288,10 +291,18 @@ static void stack_map_get_build_id_offse
struct stack_map_irq_work *work = NULL;
if (irqs_disabled()) {
- work = this_cpu_ptr(&up_read_work);
- if (work->irq_work.flags & IRQ_WORK_BUSY)
- /* cannot queue more up_read, fallback */
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ work = this_cpu_ptr(&up_read_work);
+ if (work->irq_work.flags & IRQ_WORK_BUSY)
+ /* cannot queue more up_read, fallback */
+ irq_work_busy = true;
+ } else {
+ /*
+ * PREEMPT_RT does not allow to trylock mmap sem in
+ * interrupt disabled context. Force the fallback code.
+ */
irq_work_busy = true;
+ }
}
/*
Index: linux-5.4.17-rt9/kernel/bpf/syscall.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/bpf/syscall.c
+++ linux-5.4.17-rt9/kernel/bpf/syscall.c
@@ -794,8 +794,7 @@ static int map_lookup_elem(union bpf_att
goto done;
}
- preempt_disable();
- this_cpu_inc(bpf_prog_active);
+ bpf_disable_instrumentation();
if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
err = bpf_percpu_hash_copy(map, key, value);
@@ -836,8 +835,7 @@ static int map_lookup_elem(union bpf_att
}
rcu_read_unlock();
}
- this_cpu_dec(bpf_prog_active);
- preempt_enable();
+ bpf_enable_instrumentation();
done:
if (err)
@@ -934,11 +932,7 @@ static int map_update_elem(union bpf_att
goto out;
}
- /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
- * inside bpf map update or delete otherwise deadlocks are possible
- */
- preempt_disable();
- __this_cpu_inc(bpf_prog_active);
+ bpf_disable_instrumentation();
if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
err = bpf_percpu_hash_update(map, key, value, attr->flags);
@@ -969,8 +963,7 @@ static int map_update_elem(union bpf_att
err = map->ops->map_update_elem(map, key, value, attr->flags);
rcu_read_unlock();
}
- __this_cpu_dec(bpf_prog_active);
- preempt_enable();
+ bpf_enable_instrumentation();
maybe_wait_bpf_programs(map);
out:
free_value:
@@ -1016,13 +1009,11 @@ static int map_delete_elem(union bpf_att
goto out;
}
- preempt_disable();
- __this_cpu_inc(bpf_prog_active);
+ bpf_disable_instrumentation();
rcu_read_lock();
err = map->ops->map_delete_elem(map, key);
rcu_read_unlock();
- __this_cpu_dec(bpf_prog_active);
- preempt_enable();
+ bpf_enable_instrumentation();
maybe_wait_bpf_programs(map);
out:
kfree(key);
Index: linux-5.4.17-rt9/kernel/bpf/verifier.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/bpf/verifier.c
+++ linux-5.4.17-rt9/kernel/bpf/verifier.c
@@ -7874,26 +7874,48 @@ static bool is_tracing_prog_type(enum bp
}
}
+static bool is_preallocated_map(struct bpf_map *map)
+{
+ if (!check_map_prealloc(map))
+ return false;
+ if (map->inner_map_meta && !check_map_prealloc(map->inner_map_meta))
+ return false;
+ return true;
+}
+
static int check_map_prog_compatibility(struct bpf_verifier_env *env,
struct bpf_map *map,
struct bpf_prog *prog)
{
- /* Make sure that BPF_PROG_TYPE_PERF_EVENT programs only use
- * preallocated hash maps, since doing memory allocation
- * in overflow_handler can crash depending on where nmi got
- * triggered.
+ /*
+ * Validate that trace type programs use preallocated hash maps.
+ *
+ * For programs attached to PERF events this is mandatory as the
+ * perf NMI can hit any arbitrary code sequence.
+ *
+ * All other trace types using preallocated hash maps are unsafe as
+ * well because tracepoint or kprobes can be inside locked regions
+ * of the memory allocator or at a place where a recursion into the
+ * memory allocator would see inconsistent state.
+ *
+ * On RT enabled kernels run-time allocation of all trace type
+ * programs is strictly prohibited due to lock type constraints. On
+ * !RT kernels it is allowed for backwards compatibility reasons for
+ * now, but warnings are emitted so developers are made aware of
+ * the unsafety and can fix their programs before this is enforced.
*/
- if (prog->type == BPF_PROG_TYPE_PERF_EVENT) {
- if (!check_map_prealloc(map)) {
+ if (is_tracing_prog_type(prog->type) && !is_preallocated_map(map)) {
+ if (prog->type == BPF_PROG_TYPE_PERF_EVENT) {
verbose(env, "perf_event programs can only use preallocated hash map\n");
return -EINVAL;
}
- if (map->inner_map_meta &&
- !check_map_prealloc(map->inner_map_meta)) {
- verbose(env, "perf_event programs can only use preallocated inner hash map\n");
+ if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ verbose(env, "trace type programs can only use preallocated hash map\n");
return -EINVAL;
}
+ WARN_ONCE(1, "trace type BPF program uses run-time allocation\n");
+ verbose(env, "trace type programs with run-time allocated hash maps are unsafe. Switch to preallocated hash maps.\n");
}
if ((is_tracing_prog_type(prog->type) ||
Index: linux-5.4.17-rt9/kernel/cgroup/cgroup.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/cgroup/cgroup.c
+++ linux-5.4.17-rt9/kernel/cgroup/cgroup.c
@@ -1957,7 +1957,6 @@ static void init_cgroup_housekeeping(str
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)
@@ -5014,12 +5013,6 @@ static void css_release_work_fn(struct w
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);
@@ -5081,7 +5074,6 @@ static void init_and_link_css(struct cgr
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);
@@ -5090,9 +5082,6 @@ static void init_and_link_css(struct cgr
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));
}
@@ -5194,7 +5183,6 @@ static struct cgroup_subsys_state *css_c
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);
Index: linux-5.4.17-rt9/kernel/cgroup/cpuset.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/cgroup/cpuset.c
+++ linux-5.4.17-rt9/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_cpumas
* Newly added CPUs will be removed from effective_cpus and
* newly deleted ones will be added back to effective_cpus.
*/
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
if (adding) {
cpumask_or(parent->subparts_cpus,
parent->subparts_cpus, tmp->addmask);
@@ -1274,7 +1274,7 @@ static int update_parent_subparts_cpumas
}
parent->nr_subparts_cpus = cpumask_weight(parent->subparts_cpus);
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
return cmd == partcmd_update;
}
@@ -1379,7 +1379,7 @@ static void update_cpumasks_hier(struct
continue;
rcu_read_unlock();
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
cpumask_copy(cp->effective_cpus, tmp->new_cpus);
if (cp->nr_subparts_cpus &&
@@ -1410,7 +1410,7 @@ static void update_cpumasks_hier(struct
= cpumask_weight(cp->subparts_cpus);
}
}
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
WARN_ON(!is_in_v2_mode() &&
!cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
@@ -1528,7 +1528,7 @@ static int update_cpumask(struct cpuset
return -EINVAL;
}
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
/*
@@ -1539,7 +1539,7 @@ static int update_cpumask(struct cpuset
cs->cpus_allowed);
cs->nr_subparts_cpus = cpumask_weight(cs->subparts_cpus);
}
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
update_cpumasks_hier(cs, &tmp);
@@ -1733,9 +1733,9 @@ static void update_nodemasks_hier(struct
continue;
rcu_read_unlock();
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
cp->effective_mems = *new_mems;
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
WARN_ON(!is_in_v2_mode() &&
!nodes_equal(cp->mems_allowed, cp->effective_mems));
@@ -1803,9 +1803,9 @@ static int update_nodemask(struct cpuset
if (retval < 0)
goto done;
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
cs->mems_allowed = trialcs->mems_allowed;
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
/* use trialcs->mems_allowed as a temp variable */
update_nodemasks_hier(cs, &trialcs->mems_allowed);
@@ -1896,9 +1896,9 @@ static int update_flag(cpuset_flagbits_t
spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs))
|| (is_spread_page(cs) != is_spread_page(trialcs)));
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
cs->flags = trialcs->flags;
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
rebuild_sched_domains_locked();
@@ -2407,7 +2407,7 @@ static int cpuset_common_seq_show(struct
cpuset_filetype_t type = seq_cft(sf)->private;
int ret = 0;
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
switch (type) {
case FILE_CPULIST:
@@ -2429,7 +2429,7 @@ static int cpuset_common_seq_show(struct
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 cgro
cpuset_inc();
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
if (is_in_v2_mode()) {
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
cs->effective_mems = parent->effective_mems;
cs->use_parent_ecpus = true;
parent->child_ecpus_count++;
}
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))
goto out_unlock;
@@ -2776,12 +2776,12 @@ static int cpuset_css_online(struct cgro
}
rcu_read_unlock();
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
cs->mems_allowed = parent->mems_allowed;
cs->effective_mems = parent->mems_allowed;
cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
out_unlock:
percpu_up_write(&cpuset_rwsem);
put_online_cpus();
@@ -2837,7 +2837,7 @@ static void cpuset_css_free(struct cgrou
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_su
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 cpuse
{
bool is_empty;
- spin_lock_irq(&callback_lock);
+ raw_spin_lock_irq(&callback_lock);
cpumask_copy(cs->cpus_allowed, new_cpus);
cpumask_copy(cs->effective_cpus, new_cpus);
cs->mems_allowed = *new_mems;
cs->effective_mems = *new_mems;
- spin_unlock_irq(&callback_lock);
+ raw_spin_unlock_irq(&callback_lock);
/*
* Don't call update_tasks_cpumask() if the cpuset becomes empty,
@@ -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
/* 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
}
}
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_str
{
unsigned long flags;
- spin_lock_irqsave(&callback_lock, flags);
+ raw_spin_lock_irqsave(&callback_lock, flags);
rcu_read_lock();
guarantee_online_cpus(task_cs(tsk), pmask);
rcu_read_unlock();
- spin_unlock_irqrestore(&callback_lock, flags);
+ raw_spin_unlock_irqrestore(&callback_lock, flags);
}
/**
@@ -3341,11 +3341,11 @@ nodemask_t cpuset_mems_allowed(struct ta
nodemask_t mask;
unsigned long flags;
- spin_lock_irqsave(&callback_lock, flags);
+ raw_spin_lock_irqsave(&callback_lock, flags);
rcu_read_lock();
guarantee_online_mems(task_cs(tsk), &mask);
rcu_read_unlock();
- spin_unlock_irqrestore(&callback_lock, flags);
+ raw_spin_unlock_irqrestore(&callback_lock, flags);
return mask;
}
@@ -3437,14 +3437,14 @@ bool __cpuset_node_allowed(int node, gfp
return true;
/* Not hardwall and node outside mems_allowed: scan up cpusets */
- spin_lock_irqsave(&callback_lock, flags);
+ raw_spin_lock_irqsave(&callback_lock, flags);
rcu_read_lock();
cs = nearest_hardwall_ancestor(task_cs(current));
allowed = node_isset(node, cs->mems_allowed);
rcu_read_unlock();
- spin_unlock_irqrestore(&callback_lock, flags);
+ raw_spin_unlock_irqrestore(&callback_lock, flags);
return allowed;
}
Index: linux-5.4.17-rt9/kernel/cgroup/rstat.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/cgroup/rstat.c
+++ linux-5.4.17-rt9/kernel/cgroup/rstat.c
@@ -149,7 +149,7 @@ static struct cgroup *cgroup_rstat_cpu_p
}
/* 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(st
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 *c
{
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 c
*
* 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)
Index: linux-5.4.17-rt9/kernel/cpu.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/cpu.c
+++ linux-5.4.17-rt9/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_);
}
/*
@@ -848,6 +848,15 @@ 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)
@@ -877,6 +886,10 @@ 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);
@@ -891,11 +904,39 @@ 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 */
@@ -914,6 +955,9 @@ 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();
Index: linux-5.4.17-rt9/kernel/events/core.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/events/core.c
+++ linux-5.4.17-rt9/kernel/events/core.c
@@ -8966,7 +8966,6 @@ static void bpf_overflow_handler(struct
int ret = 0;
ctx.regs = perf_arch_bpf_user_pt_regs(regs);
- preempt_disable();
if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
goto out;
rcu_read_lock();
@@ -8974,7 +8973,6 @@ static void bpf_overflow_handler(struct
rcu_read_unlock();
out:
__this_cpu_dec(bpf_prog_active);
- preempt_enable();
if (!ret)
return;
@@ -10264,7 +10262,7 @@ static struct pmu *perf_init_event(struc
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;
Index: linux-5.4.17-rt9/kernel/exit.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/exit.c
+++ linux-5.4.17-rt9/kernel/exit.c
@@ -161,7 +161,7 @@ static void __exit_signal(struct task_st
* Do this under ->siglock, we can race with another thread
* doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
*/
- flush_sigqueue(&tsk->pending);
+ flush_task_sigqueue(tsk);
tsk->sighand = NULL;
spin_unlock(&sighand->siglock);
@@ -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
Index: linux-5.4.17-rt9/kernel/fork.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/fork.c
+++ linux-5.4.17-rt9/kernel/fork.c
@@ -43,6 +43,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -289,7 +290,7 @@ static inline void free_thread_stack(str
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_struc
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_stru
tsk->splice_pipe = NULL;
tsk->task_frag.page = NULL;
tsk->wake_q.next = NULL;
+ tsk->wake_q_sleeper.next = NULL;
account_kernel_stack(tsk, 1);
@@ -1900,6 +1924,7 @@ static __latent_entropy struct task_stru
spin_lock_init(&p->alloc_lock);
init_sigpending(&p->pending);
+ p->sigqueue_cache = NULL;
p->utime = p->stime = p->gtime = 0;
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
Index: linux-5.4.17-rt9/kernel/futex.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/futex.c
+++ linux-5.4.17-rt9/kernel/futex.c
@@ -945,7 +945,9 @@ static void exit_pi_state_list(struct ta
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 *uad
struct task_struct *new_owner;
bool postunlock = false;
DEFINE_WAKE_Q(wake_q);
+ DEFINE_WAKE_Q(wake_sleeper_q);
int ret = 0;
new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
@@ -1613,13 +1616,13 @@ static int wake_futex_pi(u32 __user *uad
pi_state->owner = new_owner;
raw_spin_unlock(&new_owner->pi_lock);
- postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q);
-
+ postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q,
+ &wake_sleeper_q);
out_unlock:
raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
if (postunlock)
- rt_mutex_postunlock(&wake_q);
+ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
return ret;
}
@@ -2243,6 +2246,16 @@ retry_private:
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 @@ retry_private:
goto no_block;
}
- rt_mutex_init_waiter(&rt_waiter);
+ rt_mutex_init_waiter(&rt_waiter, false);
/*
* On PREEMPT_RT_FULL, when hb->lock becomes an rt_mutex, we must not
@@ -2967,6 +2980,14 @@ retry_private:
* 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 @@ retry_private:
*/
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 @@ retry:
* 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 __u
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 __u
* The waiter is allocated on our stack, manipulated by the requeue
* code while we sleep on uaddr.
*/
- rt_mutex_init_waiter(&rt_waiter);
+ rt_mutex_init_waiter(&rt_waiter, false);
ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE);
if (unlikely(ret != 0))
@@ -3350,20 +3381,55 @@ static int futex_wait_requeue_pi(u32 __u
/* Queue the futex_q, drop the hb lock, wait for wakeup. */
futex_wait_queue_me(hb, &q, to);
- spin_lock(&hb->lock);
- 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 __u
* did a lock-steal - fix up the PI-state in that case.
*/
if (q.pi_state && (q.pi_state->owner != current)) {
- spin_lock(q.lock_ptr);
+ 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 __u
* 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 __u
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;
Index: linux-5.4.17-rt9/kernel/irq/handle.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/irq/handle.c
+++ linux-5.4.17-rt9/kernel/irq/handle.c
@@ -185,10 +185,16 @@ irqreturn_t handle_irq_event_percpu(stru
{
irqreturn_t retval;
unsigned int flags = 0;
+ struct pt_regs *regs = get_irq_regs();
+ u64 ip = regs ? instruction_pointer(regs) : 0;
retval = __handle_irq_event_percpu(desc, &flags);
- add_interrupt_randomness(desc->irq_data.irq, flags);
+#ifdef CONFIG_PREEMPT_RT
+ desc->random_ip = ip;
+#else
+ add_interrupt_randomness(desc->irq_data.irq, flags, ip);
+#endif
if (!noirqdebug)
note_interrupt(desc, retval);
Index: linux-5.4.17-rt9/kernel/irq/manage.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/irq/manage.c
+++ linux-5.4.17-rt9/kernel/irq/manage.c
@@ -1085,6 +1085,12 @@ 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);
}
@@ -2667,7 +2673,7 @@ 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,
Index: linux-5.4.17-rt9/kernel/irq/spurious.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/irq/spurious.c
+++ linux-5.4.17-rt9/kernel/irq/spurious.c
@@ -442,6 +442,10 @@ MODULE_PARM_DESC(noirqdebug, "Disable ir
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");
Index: linux-5.4.17-rt9/kernel/irq_work.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/irq_work.c
+++ linux-5.4.17-rt9/kernel/irq_work.c
@@ -18,6 +18,7 @@
#include
#include
#include
+#include
#include
@@ -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 *
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 lli
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 lli
void irq_work_run(void)
{
irq_work_run_list(this_cpu_ptr(&raised_list));
- irq_work_run_list(this_cpu_ptr(&lazy_list));
+ if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ /*
+ * 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
Index: linux-5.4.17-rt9/kernel/kexec_core.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/kexec_core.c
+++ linux-5.4.17-rt9/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);
/*
Index: linux-5.4.17-rt9/kernel/ksysfs.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/ksysfs.c
+++ linux-5.4.17-rt9/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)
@@ -229,6 +238,9 @@ static struct attribute * kernel_attrs[]
&rcu_expedited_attr.attr,
&rcu_normal_attr.attr,
#endif
+#ifdef CONFIG_PREEMPT_RT
+ &realtime_attr.attr,
+#endif
NULL
};
Index: linux-5.4.17-rt9/kernel/locking/Makefile
===================================================================
--- linux-5.4.17-rt9.orig/kernel/locking/Makefile
+++ linux-5.4.17-rt9/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
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
Index: linux-5.4.17-rt9/kernel/locking/lockdep.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/locking/lockdep.c
+++ linux-5.4.17-rt9/kernel/locking/lockdep.c
@@ -4409,6 +4409,7 @@ static void check_flags(unsigned long fl
}
}
+#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 fl
DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
}
}
+#endif
if (!debug_locks)
print_irqtrace_events(current);
Index: linux-5.4.17-rt9/kernel/locking/locktorture.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/locking/locktorture.c
+++ linux-5.4.17-rt9/kernel/locking/locktorture.c
@@ -16,7 +16,6 @@
#include
#include
#include
-#include
#include
#include
#include
Index: linux-5.4.17-rt9/kernel/locking/mutex-rt.c
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/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
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner
+ *
+ * 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
+ * - 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
+ * - 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
+ * - debugged and patched Thomas Gleixner's rework.
+ * - added back the cmpxchg to the rework.
+ * - turned atomic require back on for SMP.
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include "rtmutex_common.h"
+
+/*
+ * struct mutex functions
+ */
+void __mutex_do_init(struct mutex *mutex, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)mutex, sizeof(*mutex));
+ lockdep_init_map(&mutex->dep_map, name, key, 0);
+#endif
+ mutex->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__mutex_do_init);
+
+void __lockfunc _mutex_lock(struct mutex *lock)
+{
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(_mutex_lock);
+
+void __lockfunc _mutex_lock_io(struct mutex *lock)
+{
+ int token;
+
+ token = io_schedule_prepare();
+ _mutex_lock(lock);
+ io_schedule_finish(token);
+}
+EXPORT_SYMBOL_GPL(_mutex_lock_io);
+
+int __lockfunc _mutex_lock_interruptible(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = __rt_mutex_lock_state(&lock->lock, TASK_INTERRUPTIBLE);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible);
+
+int __lockfunc _mutex_lock_killable(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = __rt_mutex_lock_state(&lock->lock, TASK_KILLABLE);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass)
+{
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(_mutex_lock_nested);
+
+void __lockfunc _mutex_lock_io_nested(struct mutex *lock, int subclass)
+{
+ int token;
+
+ token = io_schedule_prepare();
+
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+
+ io_schedule_finish(token);
+}
+EXPORT_SYMBOL_GPL(_mutex_lock_io_nested);
+
+void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
+{
+ mutex_acquire_nest(&lock->dep_map, 0, 0, nest, _RET_IP_);
+ __rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(_mutex_lock_nest_lock);
+
+int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ ret = __rt_mutex_lock_state(&lock->lock, TASK_INTERRUPTIBLE);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible_nested);
+
+int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ ret = __rt_mutex_lock_state(&lock->lock, TASK_KILLABLE);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable_nested);
+#endif
+
+int __lockfunc _mutex_trylock(struct mutex *lock)
+{
+ int ret = __rt_mutex_trylock(&lock->lock);
+
+ if (ret)
+ mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_trylock);
+
+void __lockfunc _mutex_unlock(struct mutex *lock)
+{
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ __rt_mutex_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_unlock);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+ /* dec if we can't possibly hit 0 */
+ if (atomic_add_unless(cnt, -1, 1))
+ return 0;
+ /* we might hit 0, so take the lock */
+ mutex_lock(lock);
+ if (!atomic_dec_and_test(cnt)) {
+ /* when we actually did the dec, we didn't hit 0 */
+ mutex_unlock(lock);
+ return 0;
+ }
+ /* we hit 0, and we hold the lock */
+ return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
Index: linux-5.4.17-rt9/kernel/locking/percpu-rwsem.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/locking/percpu-rwsem.c
+++ linux-5.4.17-rt9/kernel/locking/percpu-rwsem.c
@@ -1,27 +1,29 @@
// SPDX-License-Identifier: GPL-2.0-only
#include
-#include
#include
+#include
#include
#include
#include
#include
+#include
#include
-#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_
}
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);
+ __this_cpu_dec(*sem->read_count);
- if (try)
- return 0;
+ /* Prod writer to re-evaluate readers_active_check() */
+ rcuwait_wake_up(&sem->writer);
- /*
- * 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();
+ return false;
+}
- /*
- * 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);
+static inline bool __percpu_down_write_trylock(struct percpu_rw_semaphore *sem)
+{
+ if (atomic_read(&sem->block))
+ return false;
- preempt_disable();
- return 1;
+ 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 */
}
-EXPORT_SYMBOL_GPL(__percpu_down_read);
-void __percpu_up_read(struct percpu_rw_semaphore *sem)
+static void percpu_rwsem_wait(struct percpu_rw_semaphore *sem, bool reader)
{
- smp_mb(); /* B matches C */
+ DEFINE_WAIT_FUNC(wq_entry, percpu_rwsem_wake_function);
+ bool wait;
+
+ spin_lock_irq(&sem->waiters.lock);
/*
- * 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.
+ * Serialize against the wakeup in percpu_up_write(), if we fail
+ * the trylock, the wakeup must see us on the list.
*/
- __this_cpu_dec(*sem->read_count);
+ 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);
+}
- /* Prod writer to recheck readers_active */
- rcuwait_wake_up(&sem->writer);
+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_up_read);
+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
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);
-
/*
- * Notify new readers to block; up until now, and thus throughout the
- * longish rcu_sync_enter() above, new readers could still come in.
+ * Try set sem->block; this provides writer-writer exclusion.
+ * Having sem->block set makes new readers block.
*/
- WRITE_ONCE(sem->readers_block, 1);
+ if (!__percpu_down_write_trylock(sem))
+ percpu_rwsem_wait(sem, /* .reader = */ false);
- smp_mb(); /* D matches A */
+ /* smp_mb() implied by __percpu_down_write_trylock() on success -- 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_se
* 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
Index: linux-5.4.17-rt9/kernel/locking/rtmutex.c
===================================================================
--- linux-5.4.17-rt9.orig/kernel/locking/rtmutex.c
+++ linux-5.4.17-rt9/kernel/locking/rtmutex.c
@@ -8,6 +8,11 @@
* Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner
* 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
*
* See Documentation/locking/rt-mutex-design.rst for details.
*/
@@ -19,6 +24,8 @@
#include
#include
#include
+#include
+#include
#include "rtmutex_common.h"
@@ -136,6 +143,12 @@ static void fixup_rt_mutex_waiters(struc
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(
* 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_wa
return 1;
}
+#define STEAL_NORMAL 0
+#define STEAL_LATERAL 1
+
+static inline int
+rt_mutex_steal(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, int mode)
+{
+ struct rt_mutex_waiter *top_waiter = rt_mutex_top_waiter(lock);
+
+ if (waiter == top_waiter || rt_mutex_waiter_less(waiter, top_waiter))
+ return 1;
+
+ /*
+ * Note that RT tasks are excluded from lateral-steals
+ * to prevent the introduction of an unbounded latency.
+ */
+ if (mode == STEAL_NORMAL || rt_task(waiter->task))
+ return 0;
+
+ return rt_mutex_waiter_equal(waiter, top_waiter);
+}
+
static void
rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
{
@@ -373,6 +407,14 @@ static bool rt_mutex_cond_detect_deadloc
return debug_rt_mutex_detect_deadlock(waiter, chwalk);
}
+static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
+{
+ if (waiter->savestate)
+ wake_up_lock_sleeper(waiter->task);
+ else
+ wake_up_process(waiter->task);
+}
+
/*
* Max number of times we'll walk the boosting chain:
*/
@@ -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(st
* 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(st
* follow here. This is the end of the chain we are walking.
*/
if (!rt_mutex_owner(lock)) {
+ struct rt_mutex_waiter *lock_top_waiter;
+
/*
* If the requeue [7] above changed the top waiter,
* then we need to wake the new top waiter up to try
* to get the lock.
*/
- if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
- wake_up_process(rt_mutex_top_waiter(lock)->task);
+ lock_top_waiter = rt_mutex_top_waiter(lock);
+ if (prerequeue_top_waiter != lock_top_waiter)
+ rt_mutex_wake_waiter(lock_top_waiter);
raw_spin_unlock_irq(&lock->wait_lock);
return 0;
}
@@ -803,9 +849,11 @@ static int rt_mutex_adjust_prio_chain(st
* @task: The task which wants to acquire the lock
* @waiter: The waiter that is queued to the lock's wait tree if the
* callsite called task_blocked_on_lock(), otherwise NULL
+ * @mode: Lock steal mode (STEAL_NORMAL, STEAL_LATERAL)
*/
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
- struct rt_mutex_waiter *waiter)
+static int __try_to_take_rt_mutex(struct rt_mutex *lock,
+ struct task_struct *task,
+ struct rt_mutex_waiter *waiter, int mode)
{
lockdep_assert_held(&lock->wait_lock);
@@ -841,12 +889,11 @@ static int try_to_take_rt_mutex(struct r
*/
if (waiter) {
/*
- * If waiter is not the highest priority waiter of
- * @lock, give up.
+ * If waiter is not the highest priority waiter of @lock,
+ * or its peer when lateral steal is allowed, give up.
*/
- if (waiter != rt_mutex_top_waiter(lock))
+ if (!rt_mutex_steal(lock, waiter, mode))
return 0;
-
/*
* We can acquire the lock. Remove the waiter from the
* lock waiters tree.
@@ -864,14 +911,12 @@ static int try_to_take_rt_mutex(struct r
*/
if (rt_mutex_has_waiters(lock)) {
/*
- * If @task->prio is greater than or equal to
- * the top waiter priority (kernel view),
- * @task lost.
+ * If @task->prio is greater than the top waiter
+ * priority (kernel view), or equal to it when a
+ * lateral steal is forbidden, @task lost.
*/
- if (!rt_mutex_waiter_less(task_to_waiter(task),
- rt_mutex_top_waiter(lock)))
+ if (!rt_mutex_steal(lock, task_to_waiter(task), mode))
return 0;
-
/*
* The current top waiter stays enqueued. We
* don't have to change anything in the lock
@@ -918,6 +963,344 @@ takeit:
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(struc
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(struc
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(struc
* Called with lock->wait_lock held and interrupts disabled.
*/
static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q,
struct rt_mutex *lock)
{
struct rt_mutex_waiter *waiter;
@@ -1054,7 +1454,10 @@ static void mark_wakeup_next_waiter(stru
* Pairs with preempt_enable() in rt_mutex_postunlock();
*/
preempt_disable();
- wake_q_add(wake_q, waiter->task);
+ if (waiter->savestate)
+ wake_q_add_sleeper(wake_sleeper_q, waiter->task);
+ else
+ wake_q_add(wake_q, waiter->task);
raw_spin_unlock(¤t->pi_lock);
}
@@ -1069,7 +1472,7 @@ static void remove_waiter(struct rt_mute
{
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_mute
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_stru
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_mute
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- struct rt_mutex_waiter *waiter)
+ struct rt_mutex_waiter *waiter,
+ struct ww_acquire_ctx *ww_ctx)
{
int ret = 0;
@@ -1175,16 +1582,17 @@ __rt_mutex_slowlock(struct rt_mutex *loc
if (try_to_take_rt_mutex(lock, current, waiter))
break;
- /*
- * TASK_INTERRUPTIBLE checks for signals and
- * timeout. Ignored otherwise.
- */
- if (likely(state == TASK_INTERRUPTIBLE)) {
- /* Signal pending? */
- if (signal_pending(current))
- ret = -EINTR;
- if (timeout && !timeout->task)
- ret = -ETIMEDOUT;
+ if (timeout && !timeout->task) {
+ ret = -ETIMEDOUT;
+ break;
+ }
+ if (signal_pending_state(state, current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ if (ww_ctx && ww_ctx->acquired > 0) {
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
break;
}
@@ -1223,33 +1631,104 @@ static void rt_mutex_handle_deadlock(int
}
}
-/*
- * Slow path lock function:
- */
-static int __sched
-rt_mutex_slowlock(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk)
+static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
+ struct ww_acquire_ctx *ww_ctx)
{
- struct rt_mutex_waiter waiter;
- unsigned long flags;
- int ret = 0;
+#ifdef CONFIG_DEBUG_MUTEXES
+ /*
+ * If this WARN_ON triggers, you used ww_mutex_lock to acquire,
+ * but released with a normal mutex_unlock in this call.
+ *
+ * This should never happen, always use ww_mutex_unlock.
+ */
+ DEBUG_LOCKS_WARN_ON(ww->ctx);
- rt_mutex_init_waiter(&waiter);
+ /*
+ * 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;
+ }
/*
- * Technically we could use raw_spin_[un]lock_irq() here, but this can
- * be called in early boot if the cmpxchg() fast path is disabled
- * (debug, no architecture support). In this case we will acquire the
- * rtmutex with lock->wait_lock held. But we cannot unconditionally
- * enable interrupts in that early boot case. So we need to use the
- * irqsave/restore variants.
+ * Naughty, using a different class will lead to undefined behavior!
*/
- raw_spin_lock_irqsave(&lock->wait_lock, flags);
+ DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class);
+#endif
+ ww_ctx->acquired++;
+}
+
+#ifdef CONFIG_PREEMPT_RT
+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)) {
- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ if (ww_ctx)
+ ww_mutex_account_lock(lock, ww_ctx);
return 0;
}
@@ -1259,16 +1738,26 @@ rt_mutex_slowlock(struct rt_mutex *lock,
if (unlikely(timeout))
hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
- ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk);
+ ret = task_blocks_on_rt_mutex(lock, waiter, current, chwalk);
- if (likely(!ret))
+ if (likely(!ret)) {
/* sleep on the mutex */
- ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
+ ret = __rt_mutex_slowlock(lock, state, timeout, waiter,
+ ww_ctx);
+ } else if (ww_ctx) {
+ /* ww_mutex received EDEADLK, let it become EALREADY */
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
+ BUG_ON(!ret);
+ }
if (unlikely(ret)) {
__set_current_state(TASK_RUNNING);
- remove_waiter(lock, &waiter);
- rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+ remove_waiter(lock, waiter);
+ /* ww_mutex wants to report EDEADLK/EALREADY, let it */
+ if (!ww_ctx)
+ rt_mutex_handle_deadlock(ret, chwalk, waiter);
+ } else if (ww_ctx) {
+ ww_mutex_account_lock(lock, ww_ctx);
}
/*
@@ -1276,6 +1765,36 @@ rt_mutex_slowlock(struct rt_mutex *lock,
* unconditionally. We might have to fix that up.
*/
fixup_rt_mutex_waiters(lock);
+ return ret;
+}
+
+/*
+ * Slow path lock function:
+ */
+static int __sched
+rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ struct rt_mutex_waiter waiter;
+ unsigned long flags;
+ int ret = 0;
+
+ rt_mutex_init_waiter(&waiter, false);
+
+ /*
+ * Technically we could use raw_spin_[un]lock_irq() here, but this can
+ * be called in early boot if the cmpxchg() fast path is disabled
+ * (debug, no architecture support). In this case we will acquire the
+ * rtmutex with lock->wait_lock held. But we cannot unconditionally
+ * enable interrupts in that early boot case. So we need to use the
+ * irqsave/restore variants.
+ */
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+ ret = rt_mutex_slowlock_locked(lock, state, timeout, chwalk, ww_ctx,
+ &waiter);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
@@ -1336,7 +1855,8 @@ static inline int rt_mutex_slowtrylock(s
* Return whether the current task needs to call rt_mutex_postunlock().
*/
static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
- struct wake_q_head *wake_q)
+ struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q)
{
unsigned long flags;
@@ -1390,7 +1910,7 @@ static bool __sched rt_mutex_slowunlock(
*
* Queue the next waiter for wakeup once we release the wait_lock.
*/
- mark_wakeup_next_waiter(wake_q, lock);
+ mark_wakeup_next_waiter(wake_q, wake_sleeper_q, lock);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return true; /* call rt_mutex_postunlock() */
@@ -1404,29 +1924,45 @@ static bool __sched rt_mutex_slowunlock(
*/
static inline int
rt_mutex_fastlock(struct rt_mutex *lock, int state,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 0;
- return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
+ /*
+ * If rt_mutex blocks, the function sched_submit_work will not call
+ * blk_schedule_flush_plug (because tsk_is_pi_blocked would be true).
+ * We must call blk_schedule_flush_plug here, if we don't call it,
+ * a deadlock in I/O may happen.
+ */
+ if (unlikely(blk_needs_flush_plug(current)))
+ blk_schedule_flush_plug(current);
+
+ return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK, ww_ctx);
}
static inline int
rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 0;
- return slowfn(lock, state, timeout, chwalk);
+ if (unlikely(blk_needs_flush_plug(current)))
+ blk_schedule_flush_plug(current);
+
+ return slowfn(lock, state, timeout, chwalk, ww_ctx);
}
static inline int
@@ -1442,9 +1978,11 @@ rt_mutex_fasttrylock(struct rt_mutex *lo
/*
* Performs the wakeup of the the top-waiter and re-enables preemption.
*/
-void rt_mutex_postunlock(struct wake_q_head *wake_q)
+void rt_mutex_postunlock(struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q)
{
wake_up_q(wake_q);
+ wake_up_q_sleeper(wake_sleeper_q);
/* Pairs with preempt_disable() in rt_mutex_slowunlock() */
preempt_enable();
@@ -1453,23 +1991,46 @@ void rt_mutex_postunlock(struct wake_q_h
static inline void
rt_mutex_fastunlock(struct rt_mutex *lock,
bool (*slowfn)(struct rt_mutex *lock,
- struct wake_q_head *wqh))
+ struct wake_q_head *wqh,
+ struct wake_q_head *wq_sleeper))
{
DEFINE_WAKE_Q(wake_q);
+ DEFINE_WAKE_Q(wake_sleeper_q);
if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
return;
- if (slowfn(lock, &wake_q))
- rt_mutex_postunlock(&wake_q);
+ if (slowfn(lock, &wake_q, &wake_sleeper_q))
+ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
}
-static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
+int __sched __rt_mutex_lock_state(struct rt_mutex *lock, int state)
{
might_sleep();
+ return rt_mutex_fastlock(lock, state, NULL, rt_mutex_slowlock);
+}
+
+/**
+ * rt_mutex_lock_state - lock a rt_mutex with a given state
+ *
+ * @lock: The rt_mutex to be locked
+ * @state: The state to set when blocking on the rt_mutex
+ */
+static inline int __sched rt_mutex_lock_state(struct rt_mutex *lock,
+ unsigned int subclass, int state)
+{
+ int ret;
mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
- rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
+ ret = __rt_mutex_lock_state(lock, state);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+
+static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
+{
+ rt_mutex_lock_state(lock, subclass, TASK_UNINTERRUPTIBLE);
}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -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);
@@ -1537,6 +2089,22 @@ int __sched __rt_mutex_futex_trylock(str
}
/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock: the rt_mutex to be locked
+ * @detect_deadlock: deadlock detection on/off
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+ return rt_mutex_lock_state(lock, 0, TASK_KILLABLE);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
+/**
* rt_mutex_timed_lock - lock a rt_mutex interruptible
* the timeout structure is provided
* by the caller
@@ -1559,6 +2127,7 @@ rt_mutex_timed_lock(struct rt_mutex *loc
mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
RT_MUTEX_MIN_CHAINWALK,
+ NULL,
rt_mutex_slowlock);
if (ret)
mutex_release(&lock->dep_map, 1, _RET_IP_);
@@ -1567,6 +2136,18 @@ rt_mutex_timed_lock(struct rt_mutex *loc
}
EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
+int __sched __rt_mutex_trylock(struct rt_mutex *lock)
+{
+#ifdef CONFIG_PREEMPT_RT
+ 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_m
{
int ret;
- if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
- return 0;
-
- ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+ ret = __rt_mutex_trylock(lock);
if (ret)
mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
@@ -1593,6 +2171,11 @@ int __sched rt_mutex_trylock(struct rt_m
}
EXPORT_SYMBOL_GPL(rt_mutex_trylock);
+void __sched __rt_mutex_unlock(struct rt_mutex *lock)
+{
+ rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
+}
+
/**
* rt_mutex_unlock - unlock a rt_mutex
*
@@ -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(str
* avoid inversion prior to the wakeup. preempt_disable()
* therein pairs with rt_mutex_postunlock().
*/
- mark_wakeup_next_waiter(wake_q, lock);
+ mark_wakeup_next_waiter(wake_q, wq_sleeper, lock);
return true; /* call postunlock() */
}
+/**
+ * Futex variant, that since futex variants do not use the fast-path, can be
+ * simple and will not need to retry.
+ */
+bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
+ struct wake_q_head *wake_q,
+ struct wake_q_head *wq_sleeper)
+{
+ return __rt_mutex_unlock_common(lock, wake_q, wq_sleeper);
+}
+
void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
{
DEFINE_WAKE_Q(wake_q);
+ DEFINE_WAKE_Q(wake_sleeper_q);
unsigned long flags;
bool postunlock;
raw_spin_lock_irqsave(&lock->wait_lock, flags);
- postunlock = __rt_mutex_futex_unlock(lock, &wake_q);
+ postunlock = __rt_mutex_futex_unlock(lock, &wake_q, &wake_sleeper_q);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
if (postunlock)
- rt_mutex_postunlock(&wake_q);
+ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
}
/**
@@ -1682,7 +2274,7 @@ void __rt_mutex_init(struct rt_mutex *lo
if (name && key)
debug_rt_mutex_init(lock, name, key);
}
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
+EXPORT_SYMBOL(__rt_mutex_init);
/**
* rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
@@ -1702,6 +2294,14 @@ void rt_mutex_init_proxy_locked(struct r
struct task_struct *proxy_owner)
{
__rt_mutex_init(lock, NULL, NULL);
+#ifdef CONFIG_DEBUG_SPINLOCK
+ /*
+ * get another key class for the wait_lock. LOCK_PI and UNLOCK_PI is
+ * holding the ->wait_lock of the proxy_lock while unlocking a sleeping
+ * lock.
+ */
+ raw_spin_lock_init(&lock->wait_lock);
+#endif
debug_rt_mutex_proxy_lock(lock, proxy_owner);
rt_mutex_set_owner(lock, proxy_owner);
}
@@ -1725,6 +2325,26 @@ void rt_mutex_proxy_unlock(struct rt_mut
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 r
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 r
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_m
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
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
Index: linux-5.4.17-rt9/kernel/locking/rtmutex_common.h
===================================================================
--- linux-5.4.17-rt9.orig/kernel/locking/rtmutex_common.h
+++ linux-5.4.17-rt9/kernel/locking/rtmutex_common.h
@@ -15,6 +15,7 @@
#include
#include
+#include
/*
* 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(stru
extern void rt_mutex_futex_unlock(struct rt_mutex *lock);
extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock,
- struct wake_q_head *wqh);
+ struct wake_q_head *wqh,
+ struct wake_q_head *wq_sleeper);
+
+extern void rt_mutex_postunlock(struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q);
+
+/* RW semaphore special interface */
+struct ww_acquire_ctx;
-extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
+extern int __rt_mutex_lock_state(struct rt_mutex *lock, int state);
+extern int __rt_mutex_trylock(struct rt_mutex *lock);
+extern void __rt_mutex_unlock(struct rt_mutex *lock);
+int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx,
+ struct rt_mutex_waiter *waiter);
+void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ unsigned long flags);
+void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock);
#ifdef CONFIG_DEBUG_RT_MUTEXES
# include "rtmutex-debug.h"
Index: linux-5.4.17-rt9/kernel/locking/rwlock-rt.c
===================================================================
--- /dev/null
+++ linux-5.4.17-rt9/kernel/locking/rwlock-rt.c
@@ -0,0 +1,384 @@
+/*
+ */
+#include
@@ -140,8 +140,8 @@ or offline, among other things.
RCU-sched Expedited Grace Periods
Index: linux-5.4.17-rt9/Documentation/RCU/Design/Requirements/Requirements.html
===================================================================
--- linux-5.4.17-rt9.orig/Documentation/RCU/Design/Requirements/Requirements.html
+++ linux-5.4.17-rt9/Documentation/RCU/Design/Requirements/Requirements.html
@@ -106,7 +106,7 @@ big RCU read-side critical section.
Production-quality implementations of rcu_read_lock() and
rcu_read_unlock() are extremely lightweight, and in
fact have exactly zero overhead in Linux kernels built for production
-use with CONFIG_PREEMPT=n.
+use with CONFIG_PREEMPTION=n.