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