projects/linux·blob assoc-array-fixes · refs

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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 <[email protected]>
8 * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <[email protected]>
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/compiler.h>
17#include <linux/linkage.h>
18#include <linux/rbtree_types.h>
19#include <linux/spinlock_types_raw.h>
20
21extern int max_lock_depth;
22
23struct rt_mutex_base {
24 raw_spinlock_t wait_lock;
25 struct rb_root_cached waiters __guarded_by(&wait_lock);
26 struct task_struct *owner __guarded_by(&wait_lock);
27};
28
29#define __RT_MUTEX_BASE_INITIALIZER(rtbasename) \
30{ \
31 .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(rtbasename.wait_lock), \
32 .waiters = RB_ROOT_CACHED, \
33 .owner = NULL \
34}
35
36/**
37 * rt_mutex_base_is_locked - is the rtmutex locked
38 * @lock: the mutex to be queried
39 *
40 * Returns true if the mutex is locked, false if unlocked.
41 */
42static inline bool rt_mutex_base_is_locked(struct rt_mutex_base *lock)
43{
44 return data_race(READ_ONCE(lock->owner) != NULL);
45}
46
47#ifdef CONFIG_RT_MUTEXES
48#define RT_MUTEX_HAS_WAITERS 1UL
49
50static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock)
51{
52 unsigned long owner = (unsigned long) data_race(READ_ONCE(lock->owner));
53
54 return (struct task_struct *) (owner & ~RT_MUTEX_HAS_WAITERS);
55}
56#endif
57extern void rt_mutex_base_init(struct rt_mutex_base *rtb);
58
59context_lock_struct(rt_mutex);
60
61/**
62 * The rt_mutex structure
63 *
64 * @wait_lock: spinlock to protect the structure
65 * @waiters: rbtree root to enqueue waiters in priority order;
66 * caches top-waiter (leftmost node).
67 * @owner: the mutex owner
68 */
69struct rt_mutex {
70 struct rt_mutex_base rtmutex;
71#ifdef CONFIG_DEBUG_LOCK_ALLOC
72 struct lockdep_map dep_map;
73#endif
74};
75
76struct rt_mutex_waiter;
77struct hrtimer_sleeper;
78
79#ifdef CONFIG_DEBUG_RT_MUTEXES
80extern void rt_mutex_debug_task_free(struct task_struct *tsk);
81#else
82static inline void rt_mutex_debug_task_free(struct task_struct *tsk) { }
83#endif
84
85#define rt_mutex_init(mutex) \
86do { \
87 static struct lock_class_key __key; \
88 __rt_mutex_init(mutex, __func__, &__key); \
89} while (0)
90
91#ifdef CONFIG_DEBUG_LOCK_ALLOC
92#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
93 .dep_map = { \
94 .name = #mutexname, \
95 .wait_type_inner = LD_WAIT_SLEEP, \
96 }
97#else
98#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
99#endif
100
101#define __RT_MUTEX_INITIALIZER(mutexname) \
102{ \
103 .rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex), \
104 __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
105}
106
107#define DEFINE_RT_MUTEX(mutexname) \
108 struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
109
110extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
111
112#ifdef CONFIG_DEBUG_LOCK_ALLOC
113extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass)
114 __acquires(lock);
115extern void _rt_mutex_lock_nest_lock(struct rt_mutex *lock, struct lockdep_map *nest_lock)
116 __acquires(lock);
117#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
118#define rt_mutex_lock_nest_lock(lock, nest_lock) \
119 do { \
120 typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
121 _rt_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
122 } while (0)
123
124#else
125extern void rt_mutex_lock(struct rt_mutex *lock) __acquires(lock);
126#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
127#define rt_mutex_lock_nest_lock(lock, nest_lock) rt_mutex_lock(lock)
128#endif
129
130extern int rt_mutex_lock_interruptible(struct rt_mutex *lock)
131 __cond_acquires(0, lock);
132extern int rt_mutex_lock_killable(struct rt_mutex *lock)
133 __cond_acquires(0, lock);
134extern int rt_mutex_trylock(struct rt_mutex *lock)
135 __cond_acquires(true, lock);
136
137extern void rt_mutex_unlock(struct rt_mutex *lock)
138 __releases(lock);
139
140#endif