Line data Source code
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 : raw_spinlock_t wait_lock;
28 : struct plist_head wait_list;
29 : struct task_struct *owner;
30 : #ifdef CONFIG_DEBUG_RT_MUTEXES
31 1 : 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 = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
67 : , .wait_list = PLIST_HEAD_INIT_RAW(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 1 :
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
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