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 extern int max_lock_depth; /* for sysctl */ 20 21 /** 22 * The rt_mutex structure 23 * 24 * @wait_lock: spinlock to protect the structure 25 * @wait_list: pilist head to enqueue waiters in priority order 26 * @owner: the mutex owner 27 */ 28 struct rt_mutex { 29 raw_spinlock_t wait_lock; 30 struct plist_head wait_list; 31 struct task_struct *owner; 32 #ifdef CONFIG_DEBUG_RT_MUTEXES 33 int save_state; 34 const char *name, *file; 35 int line; 36 void *magic; 37 #endif 38 }; 39 40 struct rt_mutex_waiter; 41 struct hrtimer_sleeper; 42 43 #ifdef CONFIG_DEBUG_RT_MUTEXES 44 extern int rt_mutex_debug_check_no_locks_freed(const void *from, 45 unsigned long len); 46 extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task); 47 #else 48 static inline int rt_mutex_debug_check_no_locks_freed(const void *from, 49 unsigned long len) 50 { 51 return 0; 52 } 53 # define rt_mutex_debug_check_no_locks_held(task) do { } while (0) 54 #endif 55 56 #ifdef CONFIG_DEBUG_RT_MUTEXES 57 # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ 58 , .name = #mutexname, .file = __FILE__, .line = __LINE__ 59 # define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__) 60 extern void rt_mutex_debug_task_free(struct task_struct *tsk); 61 #else 62 # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) 63 # define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL) 64 # define rt_mutex_debug_task_free(t) do { } while (0) 65 #endif 66 67 #define __RT_MUTEX_INITIALIZER(mutexname) \ 68 { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ 69 , .wait_list = PLIST_HEAD_INIT(mutexname.wait_list) \ 70 , .owner = NULL \ 71 __DEBUG_RT_MUTEX_INITIALIZER(mutexname)} 72 73 #define DEFINE_RT_MUTEX(mutexname) \ 74 struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname) 75 76 /** 77 * rt_mutex_is_locked - is the mutex locked 78 * @lock: the mutex to be queried 79 * 80 * Returns 1 if the mutex is locked, 0 if unlocked. 81 */ 82 static inline int rt_mutex_is_locked(struct rt_mutex *lock) 83 { 84 return lock->owner != NULL; 85 } 86 87 extern void __rt_mutex_init(struct rt_mutex *lock, const char *name); 88 extern void rt_mutex_destroy(struct rt_mutex *lock); 89 90 extern void rt_mutex_lock(struct rt_mutex *lock); 91 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock, 92 int detect_deadlock); 93 extern int rt_mutex_timed_lock(struct rt_mutex *lock, 94 struct hrtimer_sleeper *timeout, 95 int detect_deadlock); 96 97 extern int rt_mutex_trylock(struct rt_mutex *lock); 98 99 extern void rt_mutex_unlock(struct rt_mutex *lock); 100 101 #ifdef CONFIG_RT_MUTEXES 102 # define INIT_RT_MUTEXES(tsk) \ 103 .pi_waiters = PLIST_HEAD_INIT(tsk.pi_waiters), \ 104 INIT_RT_MUTEX_DEBUG(tsk) 105 #else 106 # define INIT_RT_MUTEXES(tsk) 107 #endif 108 109 #endif 110