/* * 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/plist.h> #include <linux/spinlock_types.h> extern int max_lock_depth; /* for sysctl */ /** * The rt_mutex structure * * @wait_lock: spinlock to protect the structure * @wait_list: pilist head to enqueue waiters in priority order * @owner: the mutex owner */ struct rt_mutex { raw_spinlock_t wait_lock; struct plist_head wait_list; struct task_struct *owner; #ifdef CONFIG_DEBUG_RT_MUTEXES int save_state; const char *name, *file; int line; void *magic; #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) __rt_mutex_init(mutex, __func__) 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) # define rt_mutex_debug_task_free(t) do { } while (0) #endif #define __RT_MUTEX_INITIALIZER(mutexname) \ { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ , .wait_list = PLIST_HEAD_INIT(mutexname.wait_list) \ , .owner = NULL \ __DEBUG_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); extern void rt_mutex_destroy(struct rt_mutex *lock); extern void rt_mutex_lock(struct rt_mutex *lock); extern int rt_mutex_lock_interruptible(struct rt_mutex *lock, int detect_deadlock); extern int rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout, int detect_deadlock); extern int rt_mutex_trylock(struct rt_mutex *lock); extern void rt_mutex_unlock(struct rt_mutex *lock); #ifdef CONFIG_RT_MUTEXES # define INIT_RT_MUTEXES(tsk) \ .pi_waiters = PLIST_HEAD_INIT(tsk.pi_waiters), \ INIT_RT_MUTEX_DEBUG(tsk) #else # define INIT_RT_MUTEXES(tsk) #endif #endif