[deliverable/linux.git] / include / asm-frv / semaphore.h

/* semaphore.h: semaphores for the FR-V
 *
 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#ifndef _ASM_SEMAPHORE_H
#define _ASM_SEMAPHORE_H

#define RW_LOCK_BIAS		 0x01000000

#ifndef __ASSEMBLY__

#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>

/*
 * the semaphore definition
 * - if counter is >0 then there are tokens available on the semaphore for down to collect
 * - if counter is <=0 then there are no spare tokens, and anyone that wants one must wait
 * - if wait_list is not empty, then there are processes waiting for the semaphore
 */
struct semaphore {
	unsigned		counter;
	spinlock_t		wait_lock;
	struct list_head	wait_list;
#ifdef CONFIG_DEBUG_SEMAPHORE
	unsigned		__magic;
#endif
};

#ifdef CONFIG_DEBUG_SEMAPHORE
# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
#else
# define __SEM_DEBUG_INIT(name)
#endif


#define __SEMAPHORE_INITIALIZER(name,count) \
{ count, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __SEM_DEBUG_INIT(name) }

#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
	struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)

#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)

static inline void sema_init (struct semaphore *sem, int val)
{
	*sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
}

static inline void init_MUTEX (struct semaphore *sem)
{
	sema_init(sem, 1);
}

static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
	sema_init(sem, 0);
}

extern void __down(struct semaphore *sem, unsigned long flags);
extern int  __down_interruptible(struct semaphore *sem, unsigned long flags);
extern void __up(struct semaphore *sem);

static inline void down(struct semaphore *sem)
{
	unsigned long flags;

#ifdef CONFIG_DEBUG_SEMAPHORE
	CHECK_MAGIC(sem->__magic);
#endif

	spin_lock_irqsave(&sem->wait_lock, flags);
	if (likely(sem->counter > 0)) {
		sem->counter--;
		spin_unlock_irqrestore(&sem->wait_lock, flags);
	}
	else {
		__down(sem, flags);
	}
}

static inline int down_interruptible(struct semaphore *sem)
{
	unsigned long flags;
	int ret = 0;

#ifdef CONFIG_DEBUG_SEMAPHORE
	CHECK_MAGIC(sem->__magic);
#endif

	spin_lock_irqsave(&sem->wait_lock, flags);
	if (likely(sem->counter > 0)) {
		sem->counter--;
		spin_unlock_irqrestore(&sem->wait_lock, flags);
	}
	else {
		ret = __down_interruptible(sem, flags);
	}
	return ret;
}

/*
 * non-blockingly attempt to down() a semaphore.
 * - returns zero if we acquired it
 */
static inline int down_trylock(struct semaphore *sem)
{
	unsigned long flags;
	int success = 0;

#ifdef CONFIG_DEBUG_SEMAPHORE
	CHECK_MAGIC(sem->__magic);
#endif

	spin_lock_irqsave(&sem->wait_lock, flags);
	if (sem->counter > 0) {
		sem->counter--;
		success = 1;
	}
	spin_unlock_irqrestore(&sem->wait_lock, flags);
	return !success;
}

static inline void up(struct semaphore *sem)
{
	unsigned long flags;

#ifdef CONFIG_DEBUG_SEMAPHORE
	CHECK_MAGIC(sem->__magic);
#endif

	spin_lock_irqsave(&sem->wait_lock, flags);
	if (!list_empty(&sem->wait_list))
		__up(sem);
	else
		sem->counter++;
	spin_unlock_irqrestore(&sem->wait_lock, flags);
}

static inline int sem_getcount(struct semaphore *sem)
{
	return sem->counter;
}

#endif /* __ASSEMBLY__ */

#endif
Commit	Line	Data
1da177e4 LT	1	/* semaphore.h: semaphores for the FR-V
	2	*
	3	* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11	#ifndef _ASM_SEMAPHORE_H
	12	#define _ASM_SEMAPHORE_H
	13
	14	#define RW_LOCK_BIAS 0x01000000
	15
	16	#ifndef __ASSEMBLY__
	17
	18	#include <linux/linkage.h>
	19	#include <linux/wait.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/rwsem.h>
	22
1da177e4 LT	23	/*
	24	* the semaphore definition
	25	* - if counter is >0 then there are tokens available on the semaphore for down to collect
	26	* - if counter is <=0 then there are no spare tokens, and anyone that wants one must wait
	27	* - if wait_list is not empty, then there are processes waiting for the semaphore
	28	*/
	29	struct semaphore {
	30	unsigned counter;
	31	spinlock_t wait_lock;
	32	struct list_head wait_list;
c761c841	33	#ifdef CONFIG_DEBUG_SEMAPHORE
1da177e4 LT	34	unsigned __magic;
	35	#endif
	36	};
	37
c761c841	38	#ifdef CONFIG_DEBUG_SEMAPHORE
1da177e4 LT	39	# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
	40	#else
	41	# define __SEM_DEBUG_INIT(name)
	42	#endif
	43
	44
	45	#define __SEMAPHORE_INITIALIZER(name,count) \
	46	{ count, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __SEM_DEBUG_INIT(name) }
	47
1da177e4 LT	48	#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
	49	struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
	50
	51	#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
1da177e4 LT	52
	53	static inline void sema_init (struct semaphore *sem, int val)
	54	{
	55	sem = (struct semaphore) __SEMAPHORE_INITIALIZER(sem, val);
	56	}
	57
	58	static inline void init_MUTEX (struct semaphore *sem)
	59	{
	60	sema_init(sem, 1);
	61	}
	62
	63	static inline void init_MUTEX_LOCKED (struct semaphore *sem)
	64	{
	65	sema_init(sem, 0);
	66	}
	67
	68	extern void __down(struct semaphore *sem, unsigned long flags);
	69	extern int __down_interruptible(struct semaphore *sem, unsigned long flags);
	70	extern void __up(struct semaphore *sem);
	71
	72	static inline void down(struct semaphore *sem)
	73	{
	74	unsigned long flags;
	75
c761c841	76	#ifdef CONFIG_DEBUG_SEMAPHORE
1da177e4 LT	77	CHECK_MAGIC(sem->__magic);
	78	#endif
	79
	80	spin_lock_irqsave(&sem->wait_lock, flags);
	81	if (likely(sem->counter > 0)) {
	82	sem->counter--;
	83	spin_unlock_irqrestore(&sem->wait_lock, flags);
	84	}
	85	else {
	86	__down(sem, flags);
	87	}
	88	}
	89
	90	static inline int down_interruptible(struct semaphore *sem)
	91	{
	92	unsigned long flags;
	93	int ret = 0;
	94
c761c841	95	#ifdef CONFIG_DEBUG_SEMAPHORE
1da177e4 LT	96	CHECK_MAGIC(sem->__magic);
	97	#endif
	98
	99	spin_lock_irqsave(&sem->wait_lock, flags);
	100	if (likely(sem->counter > 0)) {
	101	sem->counter--;
	102	spin_unlock_irqrestore(&sem->wait_lock, flags);
	103	}
	104	else {
	105	ret = __down_interruptible(sem, flags);
	106	}
	107	return ret;
	108	}
	109
	110	/*
	111	* non-blockingly attempt to down() a semaphore.
	112	* - returns zero if we acquired it
	113	*/
	114	static inline int down_trylock(struct semaphore *sem)
	115	{
	116	unsigned long flags;
	117	int success = 0;
	118
c761c841	119	#ifdef CONFIG_DEBUG_SEMAPHORE
1da177e4 LT	120	CHECK_MAGIC(sem->__magic);
	121	#endif
	122
	123	spin_lock_irqsave(&sem->wait_lock, flags);
	124	if (sem->counter > 0) {
	125	sem->counter--;
	126	success = 1;
	127	}
	128	spin_unlock_irqrestore(&sem->wait_lock, flags);
	129	return !success;
	130	}
	131
	132	static inline void up(struct semaphore *sem)
	133	{
	134	unsigned long flags;
	135
c761c841	136	#ifdef CONFIG_DEBUG_SEMAPHORE
1da177e4 LT	137	CHECK_MAGIC(sem->__magic);
	138	#endif
	139
	140	spin_lock_irqsave(&sem->wait_lock, flags);
	141	if (!list_empty(&sem->wait_list))
	142	__up(sem);
	143	else
	144	sem->counter++;
	145	spin_unlock_irqrestore(&sem->wait_lock, flags);
	146	}
	147
	148	static inline int sem_getcount(struct semaphore *sem)
	149	{
	150	return sem->counter;
	151	}
	152
	153	#endif /* __ASSEMBLY__ */
	154
	155	#endif