/*
* Copyright (c) 2008 Intel Corporation
* Author: Matthew Wilcox <[email protected]>
*
* 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 {
raw_spinlock_t lock;
unsigned int count;
struct list_head wait_list;
};

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

#define DEFINE_SEMAPHORE(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);
}

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 */