[linux-2.6-block.git] / include / asm-h8300 / semaphore-helper.h

#ifndef _H8300_SEMAPHORE_HELPER_H
#define _H8300_SEMAPHORE_HELPER_H

/*
 * SMP- and interrupt-safe semaphores helper functions.
 *
 * (C) Copyright 1996 Linus Torvalds
 *
 * based on
 * m68k version by Andreas Schwab
 */

#include <linux/errno.h>

/*
 * These two _must_ execute atomically wrt each other.
 */
static inline void wake_one_more(struct semaphore * sem)
{
	atomic_inc((atomic_t *)&sem->sleepers);
}

static inline int waking_non_zero(struct semaphore *sem)
{
	int ret;
	unsigned long flags;

	spin_lock_irqsave(&semaphore_wake_lock, flags);
	ret = 0;
	if (sem->sleepers > 0) {
		sem->sleepers--;
		ret = 1;
	}
	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
	return ret;
}

/*
 * waking_non_zero_interruptible:
 *	1	got the lock
 *	0	go to sleep
 *	-EINTR	interrupted
 */
static inline int waking_non_zero_interruptible(struct semaphore *sem,
						struct task_struct *tsk)
{
	int ret;
	unsigned long flags;

	spin_lock_irqsave(&semaphore_wake_lock, flags);
	ret = 0;
	if (sem->sleepers > 0) {
		sem->sleepers--;
		ret = 1;
	} else if (signal_pending(tsk)) {
		atomic_inc(&sem->count);
		ret = -EINTR;
	}
	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
	return ret;
}

/*
 * waking_non_zero_trylock:
 *	1	failed to lock
 *	0	got the lock
 */
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
	int ret;
	unsigned long flags;

	spin_lock_irqsave(&semaphore_wake_lock, flags);
	ret = 1;
	if (sem->sleepers <= 0)
		atomic_inc(&sem->count);
	else {
		sem->sleepers--;
		ret = 0;
	}
	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
	return ret;
}

#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _H8300_SEMAPHORE_HELPER_H
	2	#define _H8300_SEMAPHORE_HELPER_H
	3
	4	/*
	5	* SMP- and interrupt-safe semaphores helper functions.
	6	*
	7	* (C) Copyright 1996 Linus Torvalds
	8	*
	9	* based on
	10	* m68k version by Andreas Schwab
	11	*/
	12
1da177e4 LT	13	#include <linux/errno.h>
	14
	15	/*
	16	* These two _must_ execute atomically wrt each other.
	17	*/
	18	static inline void wake_one_more(struct semaphore * sem)
	19	{
	20	atomic_inc((atomic_t *)&sem->sleepers);
	21	}
	22
	23	static inline int waking_non_zero(struct semaphore *sem)
	24	{
	25	int ret;
	26	unsigned long flags;
	27
	28	spin_lock_irqsave(&semaphore_wake_lock, flags);
	29	ret = 0;
	30	if (sem->sleepers > 0) {
	31	sem->sleepers--;
	32	ret = 1;
	33	}
	34	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
	35	return ret;
	36	}
	37
	38	/*
	39	* waking_non_zero_interruptible:
	40	* 1 got the lock
	41	* 0 go to sleep
	42	* -EINTR interrupted
	43	*/
	44	static inline int waking_non_zero_interruptible(struct semaphore *sem,
	45	struct task_struct *tsk)
	46	{
	47	int ret;
	48	unsigned long flags;
	49
	50	spin_lock_irqsave(&semaphore_wake_lock, flags);
	51	ret = 0;
	52	if (sem->sleepers > 0) {
	53	sem->sleepers--;
	54	ret = 1;
	55	} else if (signal_pending(tsk)) {
	56	atomic_inc(&sem->count);
	57	ret = -EINTR;
	58	}
	59	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
	60	return ret;
	61	}
	62
	63	/*
	64	* waking_non_zero_trylock:
	65	* 1 failed to lock
	66	* 0 got the lock
	67	*/
	68	static inline int waking_non_zero_trylock(struct semaphore *sem)
	69	{
	70	int ret;
	71	unsigned long flags;
	72
	73	spin_lock_irqsave(&semaphore_wake_lock, flags);
	74	ret = 1;
	75	if (sem->sleepers <= 0)
	76	atomic_inc(&sem->count);
77	else {
78	sem->sleepers--;
79	ret = 0;
80	}
81	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
82	return ret;
83	}
84
85	#endif