[deliverable/linux.git] / include / linux / semaphore.h

/*
 * Copyright (c) 2008 Intel Corporation
 * Author: Matthew Wilcox <willy@linux.intel.com>
 *
 * Distributed under the terms of the GNU GPL, version 2
 *
 * Please see kernel/semaphore.c for documentation of these functions
 */
#ifndef __LINUX_SEMAPHORE_H
#define __LINUX_SEMAPHORE_H

#include <linux/list.h>
#include <linux/spinlock.h>

/* Please don't access any members of this structure directly */
struct semaphore {
	spinlock_t		lock;
	unsigned int		count;
	struct list_head	wait_list;
};

#define __SEMAPHORE_INITIALIZER(name, n)				\
{									\
	.lock		= __SPIN_LOCK_UNLOCKED((name).lock),		\
	.count		= n,						\
	.wait_list	= LIST_HEAD_INIT((name).wait_list),		\
}

#define DECLARE_MUTEX(name)	\
	struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)

static inline void sema_init(struct semaphore *sem, int val)
{
	static struct lock_class_key __key;
	*sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
	lockdep_init_map(&sem->lock.dep_map, "semaphore->lock", &__key, 0);
}

#define init_MUTEX(sem)		sema_init(sem, 1)
#define init_MUTEX_LOCKED(sem)	sema_init(sem, 0)

extern void down(struct semaphore *sem);
extern int __must_check down_interruptible(struct semaphore *sem);
extern int __must_check down_killable(struct semaphore *sem);
extern int __must_check down_trylock(struct semaphore *sem);
extern int __must_check down_timeout(struct semaphore *sem, long jiffies);
extern void up(struct semaphore *sem);

#endif /* __LINUX_SEMAPHORE_H */
Commit	Line	Data
	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	*
	7	* Please see kernel/semaphore.c for documentation of these functions
	8	*/
	9	#ifndef __LINUX_SEMAPHORE_H
	10	#define __LINUX_SEMAPHORE_H
	11
	12	#include <linux/list.h>
	13	#include <linux/spinlock.h>
	14
	15	/* Please don't access any members of this structure directly */
	16	struct semaphore {
	17	spinlock_t lock;
	18	unsigned int count;
	19	struct list_head wait_list;
	20	};
	21
	22	#define __SEMAPHORE_INITIALIZER(name, n) \
	23	{ \
	24	.lock = __SPIN_LOCK_UNLOCKED((name).lock), \
	25	.count = n, \
	26	.wait_list = LIST_HEAD_INIT((name).wait_list), \
	27	}
	28
	29	#define DECLARE_MUTEX(name) \
	30	struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)
	31
	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
	39	#define init_MUTEX(sem) sema_init(sem, 1)
	40	#define init_MUTEX_LOCKED(sem) sema_init(sem, 0)
	41
	42	extern void down(struct semaphore *sem);
	43	extern int __must_check down_interruptible(struct semaphore *sem);
	44	extern int __must_check down_killable(struct semaphore *sem);
	45	extern int __must_check down_trylock(struct semaphore *sem);
	46	extern int __must_check down_timeout(struct semaphore *sem, long jiffies);
	47	extern void up(struct semaphore *sem);
	48
	49	#endif /* __LINUX_SEMAPHORE_H */