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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0172-locking-rtmutex-add-mutex-implementation-based-on-rt.patch | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/debian/patches-rt/0172-locking-rtmutex-add-mutex-implementation-based-on-rt.patch b/debian/patches-rt/0172-locking-rtmutex-add-mutex-implementation-based-on-rt.patch new file mode 100644 index 000000000..655fd8534 --- /dev/null +++ b/debian/patches-rt/0172-locking-rtmutex-add-mutex-implementation-based-on-rt.patch @@ -0,0 +1,385 @@ +From c363a86a2fab38d43a50a8841e2b6d64b87ae69b Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 12 Oct 2017 17:17:03 +0200 +Subject: [PATCH 172/323] locking/rtmutex: add mutex implementation based on + rtmutex +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + include/linux/mutex_rt.h | 130 ++++++++++++++++++++++ + kernel/locking/mutex-rt.c | 224 ++++++++++++++++++++++++++++++++++++++ + 2 files changed, 354 insertions(+) + create mode 100644 include/linux/mutex_rt.h + create mode 100644 kernel/locking/mutex-rt.c + +diff --git a/include/linux/mutex_rt.h b/include/linux/mutex_rt.h +new file mode 100644 +index 000000000000..f0b2e07cd5c5 +--- /dev/null ++++ b/include/linux/mutex_rt.h +@@ -0,0 +1,130 @@ ++// SPDX-License-Identifier: GPL-2.0-only ++#ifndef __LINUX_MUTEX_RT_H ++#define __LINUX_MUTEX_RT_H ++ ++#ifndef __LINUX_MUTEX_H ++#error "Please include mutex.h" ++#endif ++ ++#include <linux/rtmutex.h> ++ ++/* FIXME: Just for __lockfunc */ ++#include <linux/spinlock.h> ++ ++struct mutex { ++ struct rt_mutex lock; ++#ifdef CONFIG_DEBUG_LOCK_ALLOC ++ struct lockdep_map dep_map; ++#endif ++}; ++ ++#define __MUTEX_INITIALIZER(mutexname) \ ++ { \ ++ .lock = __RT_MUTEX_INITIALIZER(mutexname.lock) \ ++ __DEP_MAP_MUTEX_INITIALIZER(mutexname) \ ++ } ++ ++#define DEFINE_MUTEX(mutexname) \ ++ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) ++ ++extern void __mutex_do_init(struct mutex *lock, const char *name, struct lock_class_key *key); ++extern void __lockfunc _mutex_lock(struct mutex *lock); ++extern void __lockfunc _mutex_lock_io_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_nested(l, 0); ++ ++#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_nested(l, s) ++#endif ++ ++# define mutex_init(mutex) \ ++do { \ ++ static struct lock_class_key __key; \ ++ \ ++ rt_mutex_init(&(mutex)->lock); \ ++ __mutex_do_init((mutex), #mutex, &__key); \ ++} while (0) ++ ++# define __mutex_init(mutex, name, key) \ ++do { \ ++ rt_mutex_init(&(mutex)->lock); \ ++ __mutex_do_init((mutex), name, key); \ ++} while (0) ++ ++/** ++ * These values are chosen such that FAIL and SUCCESS match the ++ * values of the regular mutex_trylock(). ++ */ ++enum mutex_trylock_recursive_enum { ++ MUTEX_TRYLOCK_FAILED = 0, ++ MUTEX_TRYLOCK_SUCCESS = 1, ++ MUTEX_TRYLOCK_RECURSIVE, ++}; ++/** ++ * mutex_trylock_recursive - trylock variant that allows recursive locking ++ * @lock: mutex to be locked ++ * ++ * This function should not be used, _ever_. It is purely for hysterical GEM ++ * raisins, and once those are gone this will be removed. ++ * ++ * Returns: ++ * MUTEX_TRYLOCK_FAILED - trylock failed, ++ * MUTEX_TRYLOCK_SUCCESS - lock acquired, ++ * MUTEX_TRYLOCK_RECURSIVE - we already owned the lock. ++ */ ++int __rt_mutex_owner_current(struct rt_mutex *lock); ++ ++static inline /* __deprecated */ __must_check enum mutex_trylock_recursive_enum ++mutex_trylock_recursive(struct mutex *lock) ++{ ++ if (unlikely(__rt_mutex_owner_current(&lock->lock))) ++ return MUTEX_TRYLOCK_RECURSIVE; ++ ++ return mutex_trylock(lock); ++} ++ ++extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); ++ ++#endif +diff --git a/kernel/locking/mutex-rt.c b/kernel/locking/mutex-rt.c +new file mode 100644 +index 000000000000..2b849e6b9b4a +--- /dev/null ++++ b/kernel/locking/mutex-rt.c +@@ -0,0 +1,224 @@ ++// SPDX-License-Identifier: GPL-2.0-only ++/* ++ * Real-Time Preemption Support ++ * ++ * started by Ingo Molnar: ++ * ++ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> ++ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> ++ * ++ * historic credit for proving that Linux spinlocks can be implemented via ++ * RT-aware mutexes goes to many people: The Pmutex project (Dirk Grambow ++ * and others) who prototyped it on 2.4 and did lots of comparative ++ * research and analysis; TimeSys, for proving that you can implement a ++ * fully preemptible kernel via the use of IRQ threading and mutexes; ++ * Bill Huey for persuasively arguing on lkml that the mutex model is the ++ * right one; and to MontaVista, who ported pmutexes to 2.6. ++ * ++ * This code is a from-scratch implementation and is not based on pmutexes, ++ * but the idea of converting spinlocks to mutexes is used here too. ++ * ++ * lock debugging, locking tree, deadlock detection: ++ * ++ * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey ++ * Released under the General Public License (GPL). ++ * ++ * Includes portions of the generic R/W semaphore implementation from: ++ * ++ * Copyright (c) 2001 David Howells (dhowells@redhat.com). ++ * - Derived partially from idea by Andrea Arcangeli <andrea@suse.de> ++ * - Derived also from comments by Linus ++ * ++ * Pending ownership of locks and ownership stealing: ++ * ++ * Copyright (C) 2005, Kihon Technologies Inc., Steven Rostedt ++ * ++ * (also by Steven Rostedt) ++ * - Converted single pi_lock to individual task locks. ++ * ++ * By Esben Nielsen: ++ * Doing priority inheritance with help of the scheduler. ++ * ++ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> ++ * - major rework based on Esben Nielsens initial patch ++ * - replaced thread_info references by task_struct refs ++ * - removed task->pending_owner dependency ++ * - BKL drop/reacquire for semaphore style locks to avoid deadlocks ++ * in the scheduler return path as discussed with Steven Rostedt ++ * ++ * Copyright (C) 2006, Kihon Technologies Inc. ++ * Steven Rostedt <rostedt@goodmis.org> ++ * - debugged and patched Thomas Gleixner's rework. ++ * - added back the cmpxchg to the rework. ++ * - turned atomic require back on for SMP. ++ */ ++ ++#include <linux/spinlock.h> ++#include <linux/rtmutex.h> ++#include <linux/sched.h> ++#include <linux/delay.h> ++#include <linux/module.h> ++#include <linux/kallsyms.h> ++#include <linux/syscalls.h> ++#include <linux/interrupt.h> ++#include <linux/plist.h> ++#include <linux/fs.h> ++#include <linux/futex.h> ++#include <linux/hrtimer.h> ++#include <linux/blkdev.h> ++ ++#include "rtmutex_common.h" ++ ++/* ++ * struct mutex functions ++ */ ++void __mutex_do_init(struct mutex *mutex, const char *name, ++ struct lock_class_key *key) ++{ ++#ifdef CONFIG_DEBUG_LOCK_ALLOC ++ /* ++ * Make sure we are not reinitializing a held lock: ++ */ ++ debug_check_no_locks_freed((void *)mutex, sizeof(*mutex)); ++ lockdep_init_map(&mutex->dep_map, name, key, 0); ++#endif ++ mutex->lock.save_state = 0; ++} ++EXPORT_SYMBOL(__mutex_do_init); ++ ++static int _mutex_lock_blk_flush(struct mutex *lock, int state) ++{ ++ /* ++ * Flush blk before ->pi_blocked_on is set. At schedule() time it is too ++ * late if one of the callbacks needs to acquire a sleeping lock. ++ */ ++ if (blk_needs_flush_plug(current)) ++ blk_schedule_flush_plug(current); ++ return __rt_mutex_lock_state(&lock->lock, state); ++} ++ ++void __lockfunc _mutex_lock(struct mutex *lock) ++{ ++ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); ++ _mutex_lock_blk_flush(lock, TASK_UNINTERRUPTIBLE); ++} ++EXPORT_SYMBOL(_mutex_lock); ++ ++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); ++ ++int __lockfunc _mutex_lock_interruptible(struct mutex *lock) ++{ ++ int ret; ++ ++ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); ++ ret = _mutex_lock_blk_flush(lock, TASK_INTERRUPTIBLE); ++ if (ret) ++ mutex_release(&lock->dep_map, _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 = _mutex_lock_blk_flush(lock, TASK_KILLABLE); ++ if (ret) ++ mutex_release(&lock->dep_map, _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_); ++ _mutex_lock_blk_flush(lock, TASK_UNINTERRUPTIBLE); ++} ++EXPORT_SYMBOL(_mutex_lock_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_); ++ _mutex_lock_blk_flush(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 = _mutex_lock_blk_flush(lock, TASK_INTERRUPTIBLE); ++ if (ret) ++ mutex_release(&lock->dep_map, _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 = _mutex_lock_blk_flush(lock, TASK_KILLABLE); ++ if (ret) ++ mutex_release(&lock->dep_map, _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, _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); +-- +2.43.0 + |