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Ingo Molnar23f78d42006-06-27 02:54:53 -07001/*
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
Dave Young4f0e0562010-03-10 15:24:09 -080019extern int max_lock_depth; /* for sysctl */
20
Robert P. J. Day45f8bde2007-01-26 00:57:09 -080021/**
Ingo Molnar23f78d42006-06-27 02:54:53 -070022 * 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 */
28struct rt_mutex {
Thomas Gleixnerd209d742009-11-17 18:22:11 +010029 raw_spinlock_t wait_lock;
Ingo Molnar23f78d42006-06-27 02:54:53 -070030 struct plist_head wait_list;
31 struct task_struct *owner;
32#ifdef CONFIG_DEBUG_RT_MUTEXES
33 int save_state;
Ingo Molnar23f78d42006-06-27 02:54:53 -070034 const char *name, *file;
35 int line;
36 void *magic;
37#endif
38};
39
40struct rt_mutex_waiter;
41struct hrtimer_sleeper;
42
43#ifdef CONFIG_DEBUG_RT_MUTEXES
Ingo Molnare7eebaf2006-06-27 02:54:55 -070044 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
Ingo Molnar23f78d42006-06-27 02:54:53 -070057# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
58 , .name = #mutexname, .file = __FILE__, .line = __LINE__
Harvey Harrisond5c003b2008-10-15 22:01:24 -070059# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__)
Ingo Molnar23f78d42006-06-27 02:54:53 -070060 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)
Ingo Molnare7eebaf2006-06-27 02:54:55 -070064# define rt_mutex_debug_task_free(t) do { } while (0)
Ingo Molnar23f78d42006-06-27 02:54:53 -070065#endif
66
67#define __RT_MUTEX_INITIALIZER(mutexname) \
Thomas Gleixnerd209d742009-11-17 18:22:11 +010068 { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
69 , .wait_list = PLIST_HEAD_INIT_RAW(mutexname.wait_list, mutexname.wait_lock) \
Ingo Molnar23f78d42006-06-27 02:54:53 -070070 , .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
Robert P. J. Day45f8bde2007-01-26 00:57:09 -080076/**
Ingo Molnar23f78d42006-06-27 02:54:53 -070077 * 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 */
82static inline int rt_mutex_is_locked(struct rt_mutex *lock)
83{
84 return lock->owner != NULL;
85}
86
87extern void __rt_mutex_init(struct rt_mutex *lock, const char *name);
88extern void rt_mutex_destroy(struct rt_mutex *lock);
89
90extern void rt_mutex_lock(struct rt_mutex *lock);
91extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
92 int detect_deadlock);
93extern int rt_mutex_timed_lock(struct rt_mutex *lock,
94 struct hrtimer_sleeper *timeout,
95 int detect_deadlock);
96
97extern int rt_mutex_trylock(struct rt_mutex *lock);
98
99extern void rt_mutex_unlock(struct rt_mutex *lock);
100
Ingo Molnar23f78d42006-06-27 02:54:53 -0700101#ifdef CONFIG_RT_MUTEXES
102# define INIT_RT_MUTEXES(tsk) \
103 .pi_waiters = PLIST_HEAD_INIT(tsk.pi_waiters, tsk.pi_lock), \
104 INIT_RT_MUTEX_DEBUG(tsk)
105#else
106# define INIT_RT_MUTEXES(tsk)
107#endif
108
109#endif