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/* SPDX-License-Identifier: GPL-2.0 */
/*
* RT Mutexes: blocking mutual exclusion locks with PI support
*
* started by Ingo Molnar and Thomas Gleixner:
*
* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <[email protected]>
* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <[email protected]>
*
* This file contains the public data structure and API definitions.
*/
#ifndef __LINUX_RT_MUTEX_H
#define __LINUX_RT_MUTEX_H
#include <linux/compiler.h>
#include <linux/linkage.h>
#include <linux/rbtree_types.h>
#include <linux/spinlock_types_raw.h>
extern int max_lock_depth; /* for sysctl */
struct rt_mutex_base {
raw_spinlock_t wait_lock;
struct rb_root_cached waiters;
struct task_struct *owner;
};
#define __RT_MUTEX_BASE_INITIALIZER(rtbasename) \
{ \
.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(rtbasename.wait_lock), \
.waiters = RB_ROOT_CACHED, \
.owner = NULL \
}
/**
* rt_mutex_base_is_locked - is the rtmutex locked
* @lock: the mutex to be queried
*
* Returns true if the mutex is locked, false if unlocked.
*/
static inline bool rt_mutex_base_is_locked(struct rt_mutex_base *lock)
{
return READ_ONCE(lock->owner) != NULL;
}
extern void rt_mutex_base_init(struct rt_mutex_base *rtb);
/**
* The rt_mutex structure
*
* @wait_lock: spinlock to protect the structure
* @waiters: rbtree root to enqueue waiters in priority order;
* caches top-waiter (leftmost node).
* @owner: the mutex owner
*/
struct rt_mutex {
struct rt_mutex_base rtmutex;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
struct rt_mutex_waiter;
struct hrtimer_sleeper;
#ifdef CONFIG_DEBUG_RT_MUTEXES
extern void rt_mutex_debug_task_free(struct task_struct *tsk);
#else
static inline void rt_mutex_debug_task_free(struct task_struct *tsk) { }
#endif
#define rt_mutex_init(mutex) \
do { \
static struct lock_class_key __key; \
__rt_mutex_init(mutex, __func__, &__key); \
} while (0)
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
.dep_map = { \
.name = #mutexname, \
.wait_type_inner = LD_WAIT_SLEEP, \
}
#else
#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
#endif
#define __RT_MUTEX_INITIALIZER(mutexname) \
{ \
.rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex), \
__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
}
#define DEFINE_RT_MUTEX(mutexname) \
struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass);
extern void _rt_mutex_lock_nest_lock(struct rt_mutex *lock, struct lockdep_map *nest_lock);
#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
#define rt_mutex_lock_nest_lock(lock, nest_lock) \
do { \
typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
_rt_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
} while (0)
#else
extern void rt_mutex_lock(struct rt_mutex *lock);
#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
#define rt_mutex_lock_nest_lock(lock, nest_lock) rt_mutex_lock(lock)
#endif
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
extern int rt_mutex_lock_killable(struct rt_mutex *lock);
extern int rt_mutex_trylock(struct rt_mutex *lock);
extern void rt_mutex_unlock(struct rt_mutex *lock);
#endif
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