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 |
126 | |