/* 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)

#ifdef CONFIG_DEBUG_LOCK_ALLOC
void mutex_init_lockep(struct mutex *lock, const char *name, struct lock_class_key *key);

static inline void __mutex_init(struct mutex *lock, const char *name,
                                struct lock_class_key *key)
{
        mutex_init_lockep(lock, name, key);
}
#else
extern void mutex_init_generic(struct mutex *lock);

static inline void __mutex_init(struct mutex *lock, const char *name,
                                struct lock_class_key *key)
{
        mutex_init_generic(lock);
}
#endif /* !CONFIG_DEBUG_LOCK_ALLOC */

/**
 * 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)

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

#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern void mutex_rt_init_lockdep(struct mutex *mutex, const char *name,
                             struct lock_class_key *key);

static inline void __mutex_init(struct mutex *lock, const char *name,
                                struct lock_class_key *key)
{
        mutex_rt_init_lockdep(lock, name, key);
}

#else
extern void mutex_rt_init_generic(struct mutex *mutex);

static inline void __mutex_init(struct mutex *lock, const char *name,
                                struct lock_class_key *key)
{
        mutex_rt_init_generic(lock);
}
#endif /* !CONFIG_LOCKDEP */
#endif /* CONFIG_PREEMPT_RT */

#ifdef CONFIG_DEBUG_MUTEXES

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

#else

static inline int __must_check __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 __mutex_init_ret(mutex)                         \
({                                                      \
        typeof(mutex) mutex_ = (mutex);                 \
                                                        \
        mutex_init(mutex_);                             \
        mutex_;                                         \
})

#define devm_mutex_init(dev, mutex) \
        __devm_mutex_init(dev, __mutex_init_ret(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) __acquires(lock);
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) __cond_acquires(0, lock);
extern int __must_check _mutex_lock_killable(struct mutex *lock,
                unsigned int subclass, struct lockdep_map *nest_lock) __cond_acquires(0, lock);
extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass) __acquires(lock);

#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) __acquires(lock);
extern int __must_check mutex_lock_interruptible(struct mutex *lock) __cond_acquires(0, lock);
extern int __must_check mutex_lock_killable(struct mutex *lock) __cond_acquires(0, lock);
extern void mutex_lock_io(struct mutex *lock) __acquires(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) __cond_acquires(true, 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) __cond_acquires(true, lock);
#define mutex_trylock_nest_lock(lock, nest_lock) mutex_trylock(lock)
#endif

extern void mutex_unlock(struct mutex *lock) __releases(lock);

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

DEFINE_LOCK_GUARD_1(mutex, struct mutex, mutex_lock(_T->lock), mutex_unlock(_T->lock))
DEFINE_LOCK_GUARD_1_COND(mutex, _try, mutex_trylock(_T->lock))
DEFINE_LOCK_GUARD_1_COND(mutex, _intr, mutex_lock_interruptible(_T->lock), _RET == 0)
DEFINE_LOCK_GUARD_1(mutex_init, struct mutex, mutex_init(_T->lock), /* */)

DECLARE_LOCK_GUARD_1_ATTRS(mutex,       __acquires(_T), __releases(*(struct mutex **)_T))
#define class_mutex_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(mutex, _T)
DECLARE_LOCK_GUARD_1_ATTRS(mutex_try,   __acquires(_T), __releases(*(struct mutex **)_T))
#define class_mutex_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(mutex_try, _T)
DECLARE_LOCK_GUARD_1_ATTRS(mutex_intr,  __acquires(_T), __releases(*(struct mutex **)_T))
#define class_mutex_intr_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(mutex_intr, _T)
DECLARE_LOCK_GUARD_1_ATTRS(mutex_init,  __acquires(_T), __releases(*(struct mutex **)_T))
#define class_mutex_init_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(mutex_init, _T)

extern unsigned long mutex_get_owner(struct mutex *lock);

#endif /* __LINUX_MUTEX_H */