[mirror_ubuntu-artful-kernel.git] / include / asm-sh / semaphore.h

#ifndef __ASM_SH_SEMAPHORE_H
#define __ASM_SH_SEMAPHORE_H

#include <linux/linkage.h>

#ifdef __KERNEL__
/*
 * SMP- and interrupt-safe semaphores.
 *
 * (C) Copyright 1996 Linus Torvalds
 *
 * SuperH verison by Niibe Yutaka
 *  (Currently no asm implementation but generic C code...)
 */

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

#include <asm/system.h>
#include <asm/atomic.h>

struct semaphore {
	atomic_t count;
	int sleepers;
	wait_queue_head_t wait;
};

#define __SEMAPHORE_INITIALIZER(name, n)				\
{									\
	.count		= ATOMIC_INIT(n),				\
	.sleepers	= 0,						\
	.wait		= __WAIT_QUEUE_HEAD_INITIALIZER((name).wait)	\
}

#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);
 *
 * i'd rather use the more flexible initialization above, but sadly
 * GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well.
 */
	atomic_set(&sem->count, val);
	sem->sleepers = 0;
	init_waitqueue_head(&sem->wait);
}

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);
}

#if 0
asmlinkage void __down_failed(void /* special register calling convention */);
asmlinkage int  __down_failed_interruptible(void  /* params in registers */);
asmlinkage int  __down_failed_trylock(void  /* params in registers */);
asmlinkage void __up_wakeup(void /* special register calling convention */);
#endif

asmlinkage void __down(struct semaphore * sem);
asmlinkage int  __down_interruptible(struct semaphore * sem);
asmlinkage int  __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);

extern spinlock_t semaphore_wake_lock;

static inline void down(struct semaphore * sem)
{
	might_sleep();
	if (atomic_dec_return(&sem->count) < 0)
		__down(sem);
}

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

	might_sleep();
	if (atomic_dec_return(&sem->count) < 0)
		ret = __down_interruptible(sem);
	return ret;
}

static inline int down_trylock(struct semaphore * sem)
{
	int ret = 0;

	if (atomic_dec_return(&sem->count) < 0)
		ret = __down_trylock(sem);
	return ret;
}

/*
 * Note! This is subtle. We jump to wake people up only if
 * the semaphore was negative (== somebody was waiting on it).
 */
static inline void up(struct semaphore * sem)
{
	if (atomic_inc_return(&sem->count) <= 0)
		__up(sem);
}

#endif
#endif /* __ASM_SH_SEMAPHORE_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef __ASM_SH_SEMAPHORE_H
	2	#define __ASM_SH_SEMAPHORE_H
	3
	4	#include <linux/linkage.h>
	5
	6	#ifdef __KERNEL__
	7	/*
	8	* SMP- and interrupt-safe semaphores.
	9	*
	10	* (C) Copyright 1996 Linus Torvalds
	11	*
	12	* SuperH verison by Niibe Yutaka
	13	* (Currently no asm implementation but generic C code...)
	14	*/
	15
	16	#include <linux/spinlock.h>
	17	#include <linux/rwsem.h>
	18	#include <linux/wait.h>
	19
	20	#include <asm/system.h>
	21	#include <asm/atomic.h>
	22
	23	struct semaphore {
	24	atomic_t count;
	25	int sleepers;
	26	wait_queue_head_t wait;
	27	};
	28
	29	#define __SEMAPHORE_INITIALIZER(name, n) \
	30	{ \
	31	.count = ATOMIC_INIT(n), \
	32	.sleepers = 0, \
	33	.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
	34	}
	35
1da177e4 LT	36	#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
	37	struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
	38
	39	#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
	40	#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
	41
	42	static inline void sema_init (struct semaphore *sem, int val)
	43	{
	44	/*
	45	* sem = (struct semaphore)__SEMAPHORE_INITIALIZER((sem),val);
	46	*
	47	* i'd rather use the more flexible initialization above, but sadly
	48	* GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well.
	49	*/
	50	atomic_set(&sem->count, val);
	51	sem->sleepers = 0;
	52	init_waitqueue_head(&sem->wait);
	53	}
	54
	55	static inline void init_MUTEX (struct semaphore *sem)
	56	{
	57	sema_init(sem, 1);
	58	}
	59
	60	static inline void init_MUTEX_LOCKED (struct semaphore *sem)
	61	{
	62	sema_init(sem, 0);
	63	}
	64
	65	#if 0
	66	asmlinkage void __down_failed(void /* special register calling convention */);
	67	asmlinkage int __down_failed_interruptible(void /* params in registers */);
	68	asmlinkage int __down_failed_trylock(void /* params in registers */);
	69	asmlinkage void __up_wakeup(void /* special register calling convention */);
	70	#endif
	71
	72	asmlinkage void __down(struct semaphore * sem);
	73	asmlinkage int __down_interruptible(struct semaphore * sem);
	74	asmlinkage int __down_trylock(struct semaphore * sem);
	75	asmlinkage void __up(struct semaphore * sem);
	76
	77	extern spinlock_t semaphore_wake_lock;
	78
	79	static inline void down(struct semaphore * sem)
	80	{
	81	might_sleep();
	82	if (atomic_dec_return(&sem->count) < 0)
	83	__down(sem);
	84	}
	85
	86	static inline int down_interruptible(struct semaphore * sem)
	87	{
	88	int ret = 0;
	89
	90	might_sleep();
	91	if (atomic_dec_return(&sem->count) < 0)
	92	ret = __down_interruptible(sem);
	93	return ret;
	94	}
	95
	96	static inline int down_trylock(struct semaphore * sem)
	97	{
	98	int ret = 0;
	99
100	if (atomic_dec_return(&sem->count) < 0)
101	ret = __down_trylock(sem);
102	return ret;
103	}
104
105	/*
106	* Note! This is subtle. We jump to wake people up only if
107	* the semaphore was negative (== somebody was waiting on it).
108	*/
109	static inline void up(struct semaphore * sem)
110	{
111	if (atomic_inc_return(&sem->count) <= 0)
112	__up(sem);
113	}
114
115	#endif
116	#endif /* __ASM_SH_SEMAPHORE_H */