1 /* 2 * RT Mutexes: blocking mutual exclusion locks with PI support 3 * 4 * started by Ingo Molnar and Thomas Gleixner: 5 * 6 * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> 7 * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> 8 * 9 * This file contains the public data structure and API definitions. 10 */ 11 12 #ifndef __LINUX_RT_MUTEX_H 13 #define __LINUX_RT_MUTEX_H 14 15 #include <linux/linkage.h> 16 #include <linux/plist.h> 17 #include <linux/spinlock_types.h> 18 19 /** 20 * The rt_mutex structure 21 * 22 * @wait_lock: spinlock to protect the structure 23 * @wait_list: pilist head to enqueue waiters in priority order 24 * @owner: the mutex owner 25 */ 26 struct rt_mutex { 27 spinlock_t wait_lock; 28 struct plist_head wait_list; 29 struct task_struct *owner; 30 #ifdef CONFIG_DEBUG_RT_MUTEXES 31 int save_state; 32 const char *name, *file; 33 int line; 34 void *magic; 35 #endif 36 }; 37 38 struct rt_mutex_waiter; 39 struct hrtimer_sleeper; 40 41 #ifdef CONFIG_DEBUG_RT_MUTEXES 42 extern int rt_mutex_debug_check_no_locks_freed(const void *from, 43 unsigned long len); 44 extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task); 45 #else 46 static inline int rt_mutex_debug_check_no_locks_freed(const void *from, 47 unsigned long len) 48 { 49 return 0; 50 } 51 # define rt_mutex_debug_check_no_locks_held(task) do { } while (0) 52 #endif 53 54 #ifdef CONFIG_DEBUG_RT_MUTEXES 55 # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ 56 , .name = #mutexname, .file = __FILE__, .line = __LINE__ 57 # define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__) 58 extern void rt_mutex_debug_task_free(struct task_struct *tsk); 59 #else 60 # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) 61 # define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL) 62 # define rt_mutex_debug_task_free(t) do { } while (0) 63 #endif 64 65 #define __RT_MUTEX_INITIALIZER(mutexname) \ 66 { .wait_lock = __SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ 67 , .wait_list = PLIST_HEAD_INIT(mutexname.wait_list, mutexname.wait_lock) \ 68 , .owner = NULL \ 69 __DEBUG_RT_MUTEX_INITIALIZER(mutexname)} 70 71 #define DEFINE_RT_MUTEX(mutexname) \ 72 struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname) 73 74 /** 75 * rt_mutex_is_locked - is the mutex locked 76 * @lock: the mutex to be queried 77 * 78 * Returns 1 if the mutex is locked, 0 if unlocked. 79 */ 80 static inline int rt_mutex_is_locked(struct rt_mutex *lock) 81 { 82 return lock->owner != NULL; 83 } 84 85 extern void __rt_mutex_init(struct rt_mutex *lock, const char *name); 86 extern void rt_mutex_destroy(struct rt_mutex *lock); 87 88 extern void rt_mutex_lock(struct rt_mutex *lock); 89 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock, 90 int detect_deadlock); 91 extern int rt_mutex_timed_lock(struct rt_mutex *lock, 92 struct hrtimer_sleeper *timeout, 93 int detect_deadlock); 94 95 extern int rt_mutex_trylock(struct rt_mutex *lock); 96 97 extern void rt_mutex_unlock(struct rt_mutex *lock); 98 99 #ifdef CONFIG_RT_MUTEXES 100 # define INIT_RT_MUTEXES(tsk) \ 101 .pi_waiters = PLIST_HEAD_INIT(tsk.pi_waiters, tsk.pi_lock), \ 102 INIT_RT_MUTEX_DEBUG(tsk) 103 #else 104 # define INIT_RT_MUTEXES(tsk) 105 #endif 106 107 #endif 108
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