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-rw-r--r--debian/patches-rt/0172-locking-rtmutex-add-mutex-implementation-based-on-rt.patch385
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
+