1 /* SPDX-License-Identifier: GPL-2.0 */ 1
2 /*
3 * RT Mutexes: blocking mutual exclusion locks
4 *
5 * started by Ingo Molnar and Thomas Gleixner:
6 *
7 * Copyright (C) 2004-2006 Red Hat, Inc., Ing
8 * Copyright (C) 2006, Timesys Corp., Thomas
9 *
10 * This file contains the public data structur
11 */
12
13 #ifndef __LINUX_RT_MUTEX_H
14 #define __LINUX_RT_MUTEX_H
15
16 #include <linux/compiler.h>
17 #include <linux/linkage.h>
18 #include <linux/rbtree_types.h>
19 #include <linux/spinlock_types_raw.h>
20
21 extern int max_lock_depth; /* for sysctl */
22
23 struct rt_mutex_base {
24 raw_spinlock_t wait_lock;
25 struct rb_root_cached waiters;
26 struct task_struct *owner;
27 };
28
29 #define __RT_MUTEX_BASE_INITIALIZER(rtbasename
30 {
31 .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(
32 .waiters = RB_ROOT_CACHED,
33 .owner = NULL
34 }
35
36 /**
37 * rt_mutex_base_is_locked - is the rtmutex lo
38 * @lock: the mutex to be queried
39 *
40 * Returns true if the mutex is locked, false
41 */
42 static inline bool rt_mutex_base_is_locked(str
43 {
44 return READ_ONCE(lock->owner) != NULL;
45 }
46
47 extern void rt_mutex_base_init(struct rt_mutex
48
49 /**
50 * The rt_mutex structure
51 *
52 * @wait_lock: spinlock to protect the struct
53 * @waiters: rbtree root to enqueue waiters
54 * caches top-waiter (leftmost no
55 * @owner: the mutex owner
56 */
57 struct rt_mutex {
58 struct rt_mutex_base rtmutex;
59 #ifdef CONFIG_DEBUG_LOCK_ALLOC
60 struct lockdep_map dep_map;
61 #endif
62 };
63
64 struct rt_mutex_waiter;
65 struct hrtimer_sleeper;
66
67 #ifdef CONFIG_DEBUG_RT_MUTEXES
68 extern void rt_mutex_debug_task_free(struct ta
69 #else
70 static inline void rt_mutex_debug_task_free(st
71 #endif
72
73 #define rt_mutex_init(mutex) \
74 do { \
75 static struct lock_class_key __key; \
76 __rt_mutex_init(mutex, __func__, &__ke
77 } while (0)
78
79 #ifdef CONFIG_DEBUG_LOCK_ALLOC
80 #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexna
81 .dep_map = {
82 .name = #mutexname,
83 .wait_type_inner = LD_WAIT_SLE
84 }
85 #else
86 #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexna
87 #endif
88
89 #define __RT_MUTEX_INITIALIZER(mutexname)
90 {
91 .rtmutex = __RT_MUTEX_BASE_INITIALIZER
92 __DEP_MAP_RT_MUTEX_INITIALIZER(mutexna
93 }
94
95 #define DEFINE_RT_MUTEX(mutexname) \
96 struct rt_mutex mutexname = __RT_MUTEX
97
98 extern void __rt_mutex_init(struct rt_mutex *l
99
100 #ifdef CONFIG_DEBUG_LOCK_ALLOC
101 extern void rt_mutex_lock_nested(struct rt_mut
102 extern void _rt_mutex_lock_nest_lock(struct rt
103 #define rt_mutex_lock(lock) rt_mutex_lock_nest
104 #define rt_mutex_lock_nest_lock(lock, nest_loc
105 do {
106 typecheck(struct lockdep_map *
107 _rt_mutex_lock_nest_lock(lock,
108 } while (0)
109
110 #else
111 extern void rt_mutex_lock(struct rt_mutex *loc
112 #define rt_mutex_lock_nested(lock, subclass) r
113 #define rt_mutex_lock_nest_lock(lock, nest_loc
114 #endif
115
116 extern int rt_mutex_lock_interruptible(struct
117 extern int rt_mutex_lock_killable(struct rt_mu
118 extern int rt_mutex_trylock(struct rt_mutex *l
119
120 extern void rt_mutex_unlock(struct rt_mutex *l
121
122 #endif
123
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