/* 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 <mingo@redhat.com>
* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
*
* This file contains the public data structure and API definitions.
*/
#ifndef __LINUX_RT_MUTEX_H
#define __LINUX_RT_MUTEX_H
#include <linux/linkage.h>
#include <linux/rbtree.h>
#include <linux/spinlock_types.h>
extern int max_lock_depth; /* for sysctl */
/**
* 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 {
raw_spinlock_t wait_lock;
struct rb_root_cached waiters;
struct task_struct *owner;
#ifdef CONFIG_DEBUG_RT_MUTEXES
int save_state;
const char *name, *file;
int line;
void *magic;
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
struct rt_mutex_waiter;
struct hrtimer_sleeper;
#ifdef CONFIG_DEBUG_RT_MUTEXES
extern int rt_mutex_debug_check_no_locks_freed(const void *from,
unsigned long len);
extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
#else
static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
unsigned long len)
{
return 0;
}
# define rt_mutex_debug_check_no_locks_held(task) do { } while (0)
#endif
#ifdef CONFIG_DEBUG_RT_MUTEXES
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
, .name = #mutexname, .file = __FILE__, .line = __LINE__
# define rt_mutex_init(mutex) \
do { \
static struct lock_class_key __key; \
__rt_mutex_init(mutex, __func__, &__key); \
} while (0)
extern void rt_mutex_debug_task_free(struct task_struct *tsk);
#else
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL, NULL)
# define rt_mutex_debug_task_free(t) do { } while (0)
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
, .dep_map = { .name = #mutexname }
#else
#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
#endif
#define __RT_MUTEX_INITIALIZER(mutexname) \
{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
, .waiters = RB_ROOT_CACHED \
, .owner = NULL \
__DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)}
#define DEFINE_RT_MUTEX(mutexname) \
struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
/**
* rt_mutex_is_locked - is the mutex locked
* @lock: the mutex to be queried
*
* Returns 1 if the mutex is locked, 0 if unlocked.
*/
static inline int rt_mutex_is_locked(struct rt_mutex *lock)
{
return lock->owner != NULL;
}
extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
extern void rt_mutex_destroy(struct rt_mutex *lock);
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass);
#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
#else
extern void rt_mutex_lock(struct rt_mutex *lock);
#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
#endif
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
extern int rt_mutex_timed_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *timeout);
extern int rt_mutex_trylock(struct rt_mutex *lock);
extern void rt_mutex_unlock(struct rt_mutex *lock);
#endif
