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1 | /* |
2 | * Copyright (c) 2008 Intel Corporation | |
3 | * Author: Matthew Wilcox <willy@linux.intel.com> | |
4 | * | |
5 | * Distributed under the terms of the GNU GPL, version 2 | |
6 | * | |
714493cd | 7 | * Please see kernel/semaphore.c for documentation of these functions |
64ac24e7 MW |
8 | */ |
9 | #ifndef __LINUX_SEMAPHORE_H | |
10 | #define __LINUX_SEMAPHORE_H | |
11 | ||
12 | #include <linux/list.h> | |
13 | #include <linux/spinlock.h> | |
14 | ||
714493cd | 15 | /* Please don't access any members of this structure directly */ |
64ac24e7 | 16 | struct semaphore { |
8292c9e1 | 17 | raw_spinlock_t lock; |
b17170b2 | 18 | unsigned int count; |
64ac24e7 MW |
19 | struct list_head wait_list; |
20 | }; | |
21 | ||
22 | #define __SEMAPHORE_INITIALIZER(name, n) \ | |
23 | { \ | |
8292c9e1 | 24 | .lock = __RAW_SPIN_LOCK_UNLOCKED((name).lock), \ |
64ac24e7 MW |
25 | .count = n, \ |
26 | .wait_list = LIST_HEAD_INIT((name).wait_list), \ | |
27 | } | |
28 | ||
febc88c5 TG |
29 | #define DEFINE_SEMAPHORE(name) \ |
30 | struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1) | |
31 | ||
64ac24e7 MW |
32 | static inline void sema_init(struct semaphore *sem, int val) |
33 | { | |
34 | static struct lock_class_key __key; | |
35 | *sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val); | |
36 | lockdep_init_map(&sem->lock.dep_map, "semaphore->lock", &__key, 0); | |
37 | } | |
38 | ||
64ac24e7 | 39 | extern void down(struct semaphore *sem); |
64ac24e7 | 40 | extern int __must_check down_interruptible(struct semaphore *sem); |
f06d9686 | 41 | extern int __must_check down_killable(struct semaphore *sem); |
64ac24e7 | 42 | extern int __must_check down_trylock(struct semaphore *sem); |
f1241c87 | 43 | extern int __must_check down_timeout(struct semaphore *sem, long jiffies); |
64ac24e7 MW |
44 | extern void up(struct semaphore *sem); |
45 | ||
46 | #endif /* __LINUX_SEMAPHORE_H */ |