[linux-block.git] / include / linux / mutex.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Mutexes: blocking mutual exclusion locks
 *
 * started by Ingo Molnar:
 *
 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *
 * This file contains the main data structure and API definitions.
 */
#ifndef __LINUX_MUTEX_H
#define __LINUX_MUTEX_H

#include <asm/current.h>
#include <linux/list.h>
#include <linux/spinlock_types.h>
#include <linux/lockdep.h>
#include <linux/atomic.h>
#include <asm/processor.h>
#include <linux/osq_lock.h>
#include <linux/debug_locks.h>
#include <linux/cleanup.h>
#include <linux/mutex_types.h>

struct device;

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __DEP_MAP_MUTEX_INITIALIZER(lockname)			\
		, .dep_map = {					\
			.name = #lockname,			\
			.wait_type_inner = LD_WAIT_SLEEP,	\
		}
#else
# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
#endif

#ifdef CONFIG_DEBUG_MUTEXES

# define __DEBUG_MUTEX_INITIALIZER(lockname)				\
	, .magic = &lockname

extern void mutex_destroy(struct mutex *lock);

#else

# define __DEBUG_MUTEX_INITIALIZER(lockname)

static inline void mutex_destroy(struct mutex *lock) {}

#endif

/**
 * mutex_init - initialize the mutex
 * @mutex: the mutex to be initialized
 *
 * Initialize the mutex to unlocked state.
 *
 * It is not allowed to initialize an already locked mutex.
 */
#define mutex_init(mutex)						\
do {									\
	static struct lock_class_key __key;				\
									\
	__mutex_init((mutex), #mutex, &__key);				\
} while (0)

/**
 * mutex_init_with_key - initialize a mutex with a given lockdep key
 * @mutex: the mutex to be initialized
 * @key: the lockdep key to be associated with the mutex
 *
 * Initialize the mutex to the unlocked state.
 *
 * It is not allowed to initialize an already locked mutex.
 */
#define mutex_init_with_key(mutex, key) __mutex_init((mutex), #mutex, (key))

#ifndef CONFIG_PREEMPT_RT
#define __MUTEX_INITIALIZER(lockname) \
		{ .owner = ATOMIC_LONG_INIT(0) \
		, .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
		, .wait_list = LIST_HEAD_INIT(lockname.wait_list) \
		__DEBUG_MUTEX_INITIALIZER(lockname) \
		__DEP_MAP_MUTEX_INITIALIZER(lockname) }

#define DEFINE_MUTEX(mutexname) \
	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)

extern void __mutex_init(struct mutex *lock, const char *name,
			 struct lock_class_key *key);

/**
 * mutex_is_locked - is the mutex locked
 * @lock: the mutex to be queried
 *
 * Returns true if the mutex is locked, false if unlocked.
 */
extern bool mutex_is_locked(struct mutex *lock);

#else /* !CONFIG_PREEMPT_RT */
/*
 * Preempt-RT variant based on rtmutexes.
 */

#define __MUTEX_INITIALIZER(mutexname)					\
{									\
	.rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex)	\
	__DEP_MAP_MUTEX_INITIALIZER(mutexname)				\
}

#define DEFINE_MUTEX(mutexname)						\
	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)

extern void __mutex_rt_init(struct mutex *lock, const char *name,
			    struct lock_class_key *key);

#define mutex_is_locked(l)	rt_mutex_base_is_locked(&(l)->rtmutex)

#define __mutex_init(mutex, name, key)			\
do {							\
	rt_mutex_base_init(&(mutex)->rtmutex);		\
	__mutex_rt_init((mutex), name, key);		\
} while (0)

#endif /* CONFIG_PREEMPT_RT */

#ifdef CONFIG_DEBUG_MUTEXES

int __devm_mutex_init(struct device *dev, struct mutex *lock);

#else

static inline int __devm_mutex_init(struct device *dev, struct mutex *lock)
{
	/*
	 * When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so
	 * no really need to register it in the devm subsystem.
	 */
	return 0;
}

#endif

#define devm_mutex_init(dev, mutex)			\
({							\
	typeof(mutex) mutex_ = (mutex);			\
							\
	mutex_init(mutex_);				\
	__devm_mutex_init(dev, mutex_);			\
})

/*
 * See kernel/locking/mutex.c for detailed documentation of these APIs.
 * Also see Documentation/locking/mutex-design.rst.
 */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass);
extern void _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock,
					unsigned int subclass);
extern int __must_check _mutex_lock_killable(struct mutex *lock,
		unsigned int subclass, struct lockdep_map *nest_lock);
extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass);

#define mutex_lock(lock) mutex_lock_nested(lock, 0)
#define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0)
#define mutex_lock_killable(lock) _mutex_lock_killable(lock, 0, NULL)
#define mutex_lock_io(lock) mutex_lock_io_nested(lock, 0)

#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)

#define mutex_lock_killable_nest_lock(lock, nest_lock)			\
(									\
	typecheck(struct lockdep_map *, &(nest_lock)->dep_map),		\
	_mutex_lock_killable(lock, 0, &(nest_lock)->dep_map)		\
)

#define mutex_lock_killable_nested(lock, subclass) \
	_mutex_lock_killable(lock, subclass, NULL)

#else
extern void mutex_lock(struct mutex *lock);
extern int __must_check mutex_lock_interruptible(struct mutex *lock);
extern int __must_check mutex_lock_killable(struct mutex *lock);
extern void mutex_lock_io(struct mutex *lock);

# define mutex_lock_nested(lock, subclass) mutex_lock(lock)
# define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock)
# define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock)
# define mutex_lock_killable_nest_lock(lock, nest_lock) mutex_lock_killable(lock)
# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
# define mutex_lock_io_nested(lock, subclass) mutex_lock_io(lock)
#endif

/*
 * NOTE: mutex_trylock() follows the spin_trylock() convention,
 *       not the down_trylock() convention!
 *
 * Returns 1 if the mutex has been acquired successfully, and 0 on contention.
 */

#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern int _mutex_trylock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);

#define mutex_trylock_nest_lock(lock, nest_lock)		\
(								\
	typecheck(struct lockdep_map *, &(nest_lock)->dep_map),	\
	_mutex_trylock_nest_lock(lock, &(nest_lock)->dep_map)	\
)

#define mutex_trylock(lock) _mutex_trylock_nest_lock(lock, NULL)
#else
extern int mutex_trylock(struct mutex *lock);
#define mutex_trylock_nest_lock(lock, nest_lock) mutex_trylock(lock)
#endif

extern void mutex_unlock(struct mutex *lock);

extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);

DEFINE_GUARD(mutex, struct mutex *, mutex_lock(_T), mutex_unlock(_T))
DEFINE_GUARD_COND(mutex, _try, mutex_trylock(_T))
DEFINE_GUARD_COND(mutex, _intr, mutex_lock_interruptible(_T) == 0)

extern unsigned long mutex_get_owner(struct mutex *lock);

#endif /* __LINUX_MUTEX_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/*
	3	* Mutexes: blocking mutual exclusion locks
	4	*
	5	* started by Ingo Molnar:
	6	*
	7	* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
	8	*
	9	* This file contains the main data structure and API definitions.
	10	*/
	11	#ifndef __LINUX_MUTEX_H
	12	#define __LINUX_MUTEX_H
	13
	14	#include <asm/current.h>
	15	#include <linux/list.h>
	16	#include <linux/spinlock_types.h>
	17	#include <linux/lockdep.h>
	18	#include <linux/atomic.h>
	19	#include <asm/processor.h>
	20	#include <linux/osq_lock.h>
	21	#include <linux/debug_locks.h>
	22	#include <linux/cleanup.h>
	23	#include <linux/mutex_types.h>
	24
	25	struct device;
	26
	27	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	28	# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
	29	, .dep_map = { \
	30	.name = #lockname, \
	31	.wait_type_inner = LD_WAIT_SLEEP, \
	32	}
	33	#else
	34	# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
	35	#endif
	36
	37	#ifdef CONFIG_DEBUG_MUTEXES
	38
	39	# define __DEBUG_MUTEX_INITIALIZER(lockname) \
	40	, .magic = &lockname
	41
	42	extern void mutex_destroy(struct mutex *lock);
	43
	44	#else
	45
	46	# define __DEBUG_MUTEX_INITIALIZER(lockname)
	47
	48	static inline void mutex_destroy(struct mutex *lock) {}
	49
	50	#endif
	51
	52	/**
	53	* mutex_init - initialize the mutex
	54	* @mutex: the mutex to be initialized
	55	*
	56	* Initialize the mutex to unlocked state.
	57	*
	58	* It is not allowed to initialize an already locked mutex.
	59	*/
	60	#define mutex_init(mutex) \
	61	do { \
	62	static struct lock_class_key __key; \
	63	\
	64	__mutex_init((mutex), #mutex, &__key); \
	65	} while (0)
	66
	67	/**
	68	* mutex_init_with_key - initialize a mutex with a given lockdep key
	69	* @mutex: the mutex to be initialized
	70	* @key: the lockdep key to be associated with the mutex
	71	*
	72	* Initialize the mutex to the unlocked state.
	73	*
	74	* It is not allowed to initialize an already locked mutex.
	75	*/
	76	#define mutex_init_with_key(mutex, key) __mutex_init((mutex), #mutex, (key))
	77
	78	#ifndef CONFIG_PREEMPT_RT
	79	#define __MUTEX_INITIALIZER(lockname) \
	80	{ .owner = ATOMIC_LONG_INIT(0) \
	81	, .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
	82	, .wait_list = LIST_HEAD_INIT(lockname.wait_list) \
	83	__DEBUG_MUTEX_INITIALIZER(lockname) \
	84	__DEP_MAP_MUTEX_INITIALIZER(lockname) }
	85
	86	#define DEFINE_MUTEX(mutexname) \
	87	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
	88
	89	extern void __mutex_init(struct mutex lock, const char name,
	90	struct lock_class_key *key);
	91
	92	/**
	93	* mutex_is_locked - is the mutex locked
	94	* @lock: the mutex to be queried
	95	*
	96	* Returns true if the mutex is locked, false if unlocked.
	97	*/
	98	extern bool mutex_is_locked(struct mutex *lock);
	99
	100	#else /* !CONFIG_PREEMPT_RT */
	101	/*
	102	* Preempt-RT variant based on rtmutexes.
	103	*/
	104
	105	#define __MUTEX_INITIALIZER(mutexname) \
	106	{ \
	107	.rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex) \
	108	__DEP_MAP_MUTEX_INITIALIZER(mutexname) \
	109	}
	110
	111	#define DEFINE_MUTEX(mutexname) \
	112	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
	113
	114	extern void __mutex_rt_init(struct mutex lock, const char name,
	115	struct lock_class_key *key);
	116
	117	#define mutex_is_locked(l) rt_mutex_base_is_locked(&(l)->rtmutex)
	118
	119	#define __mutex_init(mutex, name, key) \
	120	do { \
	121	rt_mutex_base_init(&(mutex)->rtmutex); \
	122	__mutex_rt_init((mutex), name, key); \
	123	} while (0)
	124
	125	#endif /* CONFIG_PREEMPT_RT */
	126
	127	#ifdef CONFIG_DEBUG_MUTEXES
	128
	129	int __devm_mutex_init(struct device dev, struct mutex lock);
	130
	131	#else
	132
	133	static inline int __devm_mutex_init(struct device dev, struct mutex lock)
	134	{
	135	/*
	136	* When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so
	137	* no really need to register it in the devm subsystem.
	138	*/
	139	return 0;
	140	}
	141
	142	#endif
	143
	144	#define devm_mutex_init(dev, mutex) \
	145	({ \
	146	typeof(mutex) mutex_ = (mutex); \
	147	\
	148	mutex_init(mutex_); \
	149	__devm_mutex_init(dev, mutex_); \
	150	})
	151
	152	/*
	153	* See kernel/locking/mutex.c for detailed documentation of these APIs.
	154	* Also see Documentation/locking/mutex-design.rst.
	155	*/
	156	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	157	extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass);
	158	extern void _mutex_lock_nest_lock(struct mutex lock, struct lockdep_map nest_lock);
	159	extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock,
	160	unsigned int subclass);
	161	extern int __must_check _mutex_lock_killable(struct mutex *lock,
	162	unsigned int subclass, struct lockdep_map *nest_lock);
	163	extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass);
	164
	165	#define mutex_lock(lock) mutex_lock_nested(lock, 0)
	166	#define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0)
	167	#define mutex_lock_killable(lock) _mutex_lock_killable(lock, 0, NULL)
	168	#define mutex_lock_io(lock) mutex_lock_io_nested(lock, 0)
	169
	170	#define mutex_lock_nest_lock(lock, nest_lock) \
	171	do { \
	172	typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
	173	_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
	174	} while (0)
	175
	176	#define mutex_lock_killable_nest_lock(lock, nest_lock) \
	177	( \
	178	typecheck(struct lockdep_map *, &(nest_lock)->dep_map), \
	179	_mutex_lock_killable(lock, 0, &(nest_lock)->dep_map) \
	180	)
	181
	182	#define mutex_lock_killable_nested(lock, subclass) \
	183	_mutex_lock_killable(lock, subclass, NULL)
	184
	185	#else
	186	extern void mutex_lock(struct mutex *lock);
	187	extern int __must_check mutex_lock_interruptible(struct mutex *lock);
	188	extern int __must_check mutex_lock_killable(struct mutex *lock);
	189	extern void mutex_lock_io(struct mutex *lock);
	190
	191	# define mutex_lock_nested(lock, subclass) mutex_lock(lock)
	192	# define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock)
	193	# define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock)
	194	# define mutex_lock_killable_nest_lock(lock, nest_lock) mutex_lock_killable(lock)
	195	# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
	196	# define mutex_lock_io_nested(lock, subclass) mutex_lock_io(lock)
	197	#endif
	198
	199	/*
	200	* NOTE: mutex_trylock() follows the spin_trylock() convention,
	201	* not the down_trylock() convention!
	202	*
	203	* Returns 1 if the mutex has been acquired successfully, and 0 on contention.
	204	*/
	205
	206	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	207	extern int _mutex_trylock_nest_lock(struct mutex lock, struct lockdep_map nest_lock);
	208
	209	#define mutex_trylock_nest_lock(lock, nest_lock) \
	210	( \
	211	typecheck(struct lockdep_map *, &(nest_lock)->dep_map), \
	212	_mutex_trylock_nest_lock(lock, &(nest_lock)->dep_map) \
	213	)
	214
	215	#define mutex_trylock(lock) _mutex_trylock_nest_lock(lock, NULL)
	216	#else
	217	extern int mutex_trylock(struct mutex *lock);
	218	#define mutex_trylock_nest_lock(lock, nest_lock) mutex_trylock(lock)
	219	#endif
	220
	221	extern void mutex_unlock(struct mutex *lock);
	222
	223	extern int atomic_dec_and_mutex_lock(atomic_t cnt, struct mutex lock);
	224
	225	DEFINE_GUARD(mutex, struct mutex *, mutex_lock(_T), mutex_unlock(_T))
	226	DEFINE_GUARD_COND(mutex, _try, mutex_trylock(_T))
	227	DEFINE_GUARD_COND(mutex, _intr, mutex_lock_interruptible(_T) == 0)
	228
	229	extern unsigned long mutex_get_owner(struct mutex *lock);
	230
	231	#endif /* __LINUX_MUTEX_H */