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10#ifndef __LINUX_MUTEX_H
11#define __LINUX_MUTEX_H
12
13#include <asm/current.h>
14#include <linux/list.h>
15#include <linux/spinlock_types.h>
16#include <linux/linkage.h>
17#include <linux/lockdep.h>
18#include <linux/atomic.h>
19#include <asm/processor.h>
20#include <linux/osq_lock.h>
21#include <linux/debug_locks.h>
22
23struct ww_acquire_ctx;
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53struct mutex {
54 atomic_long_t owner;
55 spinlock_t wait_lock;
56#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
57 struct optimistic_spin_queue osq;
58#endif
59 struct list_head wait_list;
60#ifdef CONFIG_DEBUG_MUTEXES
61 void *magic;
62#endif
63#ifdef CONFIG_DEBUG_LOCK_ALLOC
64 struct lockdep_map dep_map;
65#endif
66};
67
68static inline struct task_struct *__mutex_owner(struct mutex *lock)
69{
70 return (struct task_struct *)(atomic_long_read(&lock->owner) & ~0x07);
71}
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77struct mutex_waiter {
78 struct list_head list;
79 struct task_struct *task;
80 struct ww_acquire_ctx *ww_ctx;
81#ifdef CONFIG_DEBUG_MUTEXES
82 void *magic;
83#endif
84};
85
86#ifdef CONFIG_DEBUG_MUTEXES
87
88#define __DEBUG_MUTEX_INITIALIZER(lockname) \
89 , .magic = &lockname
90
91extern void mutex_destroy(struct mutex *lock);
92
93#else
94
95# define __DEBUG_MUTEX_INITIALIZER(lockname)
96
97static inline void mutex_destroy(struct mutex *lock) {}
98
99#endif
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109#define mutex_init(mutex) \
110do { \
111 static struct lock_class_key __key; \
112 \
113 __mutex_init((mutex), #mutex, &__key); \
114} while (0)
115
116#ifdef CONFIG_DEBUG_LOCK_ALLOC
117# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
118 , .dep_map = { .name = #lockname }
119#else
120# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
121#endif
122
123#define __MUTEX_INITIALIZER(lockname) \
124 { .owner = ATOMIC_LONG_INIT(0) \
125 , .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
126 , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \
127 __DEBUG_MUTEX_INITIALIZER(lockname) \
128 __DEP_MAP_MUTEX_INITIALIZER(lockname) }
129
130#define DEFINE_MUTEX(mutexname) \
131 struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
132
133extern void __mutex_init(struct mutex *lock, const char *name,
134 struct lock_class_key *key);
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142static inline int mutex_is_locked(struct mutex *lock)
143{
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147 return __mutex_owner(lock) != NULL;
148}
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154#ifdef CONFIG_DEBUG_LOCK_ALLOC
155extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass);
156extern void _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
157
158extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock,
159 unsigned int subclass);
160extern int __must_check mutex_lock_killable_nested(struct mutex *lock,
161 unsigned int subclass);
162extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass);
163
164#define mutex_lock(lock) mutex_lock_nested(lock, 0)
165#define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0)
166#define mutex_lock_killable(lock) mutex_lock_killable_nested(lock, 0)
167#define mutex_lock_io(lock) mutex_lock_io_nested(lock, 0)
168
169#define mutex_lock_nest_lock(lock, nest_lock) \
170do { \
171 typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
172 _mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
173} while (0)
174
175#else
176extern void mutex_lock(struct mutex *lock);
177extern int __must_check mutex_lock_interruptible(struct mutex *lock);
178extern int __must_check mutex_lock_killable(struct mutex *lock);
179extern void mutex_lock_io(struct mutex *lock);
180
181# define mutex_lock_nested(lock, subclass) mutex_lock(lock)
182# define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock)
183# define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock)
184# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
185# define mutex_lock_io_nested(lock, subclass) mutex_lock(lock)
186#endif
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194extern int mutex_trylock(struct mutex *lock);
195extern void mutex_unlock(struct mutex *lock);
196
197extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
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203enum mutex_trylock_recursive_enum {
204 MUTEX_TRYLOCK_FAILED = 0,
205 MUTEX_TRYLOCK_SUCCESS = 1,
206 MUTEX_TRYLOCK_RECURSIVE,
207};
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221static inline __must_check enum mutex_trylock_recursive_enum
222mutex_trylock_recursive(struct mutex *lock)
223{
224 if (unlikely(__mutex_owner(lock) == current))
225 return MUTEX_TRYLOCK_RECURSIVE;
226
227 return mutex_trylock(lock);
228}
229
230#endif
231