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1 | /* SPDX-License-Identifier: GPL-2.0 */ | |
2 | /* | |
3 | * RT Mutexes: blocking mutual exclusion locks with PI support | |
4 | * | |
5 | * started by Ingo Molnar and Thomas Gleixner: | |
6 | * | |
7 | * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> | |
8 | * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> | |
9 | * | |
10 | * This file contains the public data structure and API definitions. | |
11 | */ | |
12 | ||
13 | #ifndef __LINUX_RT_MUTEX_H | |
14 | #define __LINUX_RT_MUTEX_H | |
15 | ||
16 | #include <linux/linkage.h> | |
17 | #include <linux/rbtree.h> | |
18 | #include <linux/spinlock_types.h> | |
19 | ||
20 | extern int max_lock_depth; /* for sysctl */ | |
21 | ||
22 | /** | |
23 | * The rt_mutex structure | |
24 | * | |
25 | * @wait_lock: spinlock to protect the structure | |
26 | * @waiters: rbtree root to enqueue waiters in priority order; | |
27 | * caches top-waiter (leftmost node). | |
28 | * @owner: the mutex owner | |
29 | */ | |
30 | struct rt_mutex { | |
31 | raw_spinlock_t wait_lock; | |
32 | struct rb_root_cached waiters; | |
33 | struct task_struct *owner; | |
34 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
35 | int save_state; | |
36 | const char *name, *file; | |
37 | int line; | |
38 | void *magic; | |
39 | #endif | |
40 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
41 | struct lockdep_map dep_map; | |
42 | #endif | |
43 | }; | |
44 | ||
45 | struct rt_mutex_waiter; | |
46 | struct hrtimer_sleeper; | |
47 | ||
48 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
49 | extern int rt_mutex_debug_check_no_locks_freed(const void *from, | |
50 | unsigned long len); | |
51 | extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task); | |
52 | #else | |
53 | static inline int rt_mutex_debug_check_no_locks_freed(const void *from, | |
54 | unsigned long len) | |
55 | { | |
56 | return 0; | |
57 | } | |
58 | # define rt_mutex_debug_check_no_locks_held(task) do { } while (0) | |
59 | #endif | |
60 | ||
61 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
62 | # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ | |
63 | , .name = #mutexname, .file = __FILE__, .line = __LINE__ | |
64 | ||
65 | # define rt_mutex_init(mutex) \ | |
66 | do { \ | |
67 | static struct lock_class_key __key; \ | |
68 | __rt_mutex_init(mutex, __func__, &__key); \ | |
69 | } while (0) | |
70 | ||
71 | extern void rt_mutex_debug_task_free(struct task_struct *tsk); | |
72 | #else | |
73 | # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) | |
74 | # define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL, NULL) | |
75 | # define rt_mutex_debug_task_free(t) do { } while (0) | |
76 | #endif | |
77 | ||
78 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
79 | #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \ | |
80 | , .dep_map = { .name = #mutexname } | |
81 | #else | |
82 | #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) | |
83 | #endif | |
84 | ||
85 | #define __RT_MUTEX_INITIALIZER(mutexname) \ | |
86 | { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ | |
87 | , .waiters = RB_ROOT_CACHED \ | |
88 | , .owner = NULL \ | |
89 | __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ | |
90 | __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)} | |
91 | ||
92 | #define DEFINE_RT_MUTEX(mutexname) \ | |
93 | struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname) | |
94 | ||
95 | /** | |
96 | * rt_mutex_is_locked - is the mutex locked | |
97 | * @lock: the mutex to be queried | |
98 | * | |
99 | * Returns 1 if the mutex is locked, 0 if unlocked. | |
100 | */ | |
101 | static inline int rt_mutex_is_locked(struct rt_mutex *lock) | |
102 | { | |
103 | return lock->owner != NULL; | |
104 | } | |
105 | ||
106 | extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key); | |
107 | extern void rt_mutex_destroy(struct rt_mutex *lock); | |
108 | ||
109 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
110 | extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass); | |
111 | #define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0) | |
112 | #else | |
113 | extern void rt_mutex_lock(struct rt_mutex *lock); | |
114 | #define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock) | |
115 | #endif | |
116 | ||
117 | extern int rt_mutex_lock_interruptible(struct rt_mutex *lock); | |
118 | extern int rt_mutex_timed_lock(struct rt_mutex *lock, | |
119 | struct hrtimer_sleeper *timeout); | |
120 | ||
121 | extern int rt_mutex_trylock(struct rt_mutex *lock); | |
122 | ||
123 | extern void rt_mutex_unlock(struct rt_mutex *lock); | |
124 | ||
125 | #endif |