[mirror_ubuntu-artful-kernel.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>

#define SEMAPHORE_DEBUG		0

/*
 * 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;
#if SEMAPHORE_DEBUG
	unsigned		__magic;
#endif
};

#if SEMAPHORE_DEBUG
# 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)
#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)

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;

#if SEMAPHORE_DEBUG
	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;

#if SEMAPHORE_DEBUG
	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;

#if SEMAPHORE_DEBUG
	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;

#if SEMAPHORE_DEBUG
	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
8080f231	23	#define SEMAPHORE_DEBUG 0
1da177e4 LT	24
	25	/*
	26	* the semaphore definition
	27	* - if counter is >0 then there are tokens available on the semaphore for down to collect
	28	* - if counter is <=0 then there are no spare tokens, and anyone that wants one must wait
	29	* - if wait_list is not empty, then there are processes waiting for the semaphore
	30	*/
	31	struct semaphore {
	32	unsigned counter;
	33	spinlock_t wait_lock;
	34	struct list_head wait_list;
	35	#if SEMAPHORE_DEBUG
	36	unsigned __magic;
	37	#endif
	38	};
	39
	40	#if SEMAPHORE_DEBUG
	41	# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
	42	#else
	43	# define __SEM_DEBUG_INIT(name)
	44	#endif
	45
	46
	47	#define __SEMAPHORE_INITIALIZER(name,count) \
	48	{ count, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __SEM_DEBUG_INIT(name) }
	49
1da177e4 LT	50	#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
	51	struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
	52
	53	#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
	54	#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
	55
	56	static inline void sema_init (struct semaphore *sem, int val)
	57	{
	58	sem = (struct semaphore) __SEMAPHORE_INITIALIZER(sem, val);
	59	}
	60
	61	static inline void init_MUTEX (struct semaphore *sem)
	62	{
	63	sema_init(sem, 1);
	64	}
	65
	66	static inline void init_MUTEX_LOCKED (struct semaphore *sem)
	67	{
	68	sema_init(sem, 0);
	69	}
	70
	71	extern void __down(struct semaphore *sem, unsigned long flags);
	72	extern int __down_interruptible(struct semaphore *sem, unsigned long flags);
	73	extern void __up(struct semaphore *sem);
	74
	75	static inline void down(struct semaphore *sem)
	76	{
	77	unsigned long flags;
	78
	79	#if SEMAPHORE_DEBUG
	80	CHECK_MAGIC(sem->__magic);
	81	#endif
	82
	83	spin_lock_irqsave(&sem->wait_lock, flags);
	84	if (likely(sem->counter > 0)) {
	85	sem->counter--;
	86	spin_unlock_irqrestore(&sem->wait_lock, flags);
	87	}
	88	else {
	89	__down(sem, flags);
	90	}
	91	}
	92
	93	static inline int down_interruptible(struct semaphore *sem)
	94	{
	95	unsigned long flags;
	96	int ret = 0;
	97
	98	#if SEMAPHORE_DEBUG
	99	CHECK_MAGIC(sem->__magic);
	100	#endif
	101
	102	spin_lock_irqsave(&sem->wait_lock, flags);
	103	if (likely(sem->counter > 0)) {
	104	sem->counter--;
	105	spin_unlock_irqrestore(&sem->wait_lock, flags);
	106	}
	107	else {
	108	ret = __down_interruptible(sem, flags);
	109	}
	110	return ret;
	111	}
	112
	113	/*
114	* non-blockingly attempt to down() a semaphore.
115	* - returns zero if we acquired it
116	*/
117	static inline int down_trylock(struct semaphore *sem)
118	{
119	unsigned long flags;
120	int success = 0;
121
122	#if SEMAPHORE_DEBUG
123	CHECK_MAGIC(sem->__magic);
124	#endif
125
126	spin_lock_irqsave(&sem->wait_lock, flags);
127	if (sem->counter > 0) {
128	sem->counter--;
129	success = 1;
130	}
131	spin_unlock_irqrestore(&sem->wait_lock, flags);
132	return !success;
133	}
134
135	static inline void up(struct semaphore *sem)
136	{
137	unsigned long flags;
138
139	#if SEMAPHORE_DEBUG
140	CHECK_MAGIC(sem->__magic);
141	#endif
142
143	spin_lock_irqsave(&sem->wait_lock, flags);
144	if (!list_empty(&sem->wait_list))
145	__up(sem);
146	else
147	sem->counter++;
148	spin_unlock_irqrestore(&sem->wait_lock, flags);
149	}
150
151	static inline int sem_getcount(struct semaphore *sem)
152	{
153	return sem->counter;
154	}
155
156	#endif /* __ASSEMBLY__ */
157
158	#endif