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

/*
 * linux/include/asm-arm/semaphore.h
 */
#ifndef __ASM_ARM_SEMAPHORE_H
#define __ASM_ARM_SEMAPHORE_H

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

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

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

#define __SEMAPHORE_INIT(name, cnt)				\
{								\
	.count	= ATOMIC_INIT(cnt),				\
	.wait	= __WAIT_QUEUE_HEAD_INITIALIZER((name).wait),	\
}

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

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

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

/*
 * special register calling convention
 */
asmlinkage void __down_failed(void);
asmlinkage int  __down_interruptible_failed(void);
asmlinkage int  __down_trylock_failed(void);
asmlinkage void __up_wakeup(void);

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

/*
 * This is ugly, but we want the default case to fall through.
 * "__down" is the actual routine that waits...
 */
static inline void down(struct semaphore * sem)
{
	might_sleep();
	__down_op(sem, __down_failed);
}

/*
 * This is ugly, but we want the default case to fall through.
 * "__down_interruptible" is the actual routine that waits...
 */
static inline int down_interruptible (struct semaphore * sem)
{
	might_sleep();
	return __down_op_ret(sem, __down_interruptible_failed);
}

static inline int down_trylock(struct semaphore *sem)
{
	return __down_op_ret(sem, __down_trylock_failed);
}

/*
 * Note! This is subtle. We jump to wake people up only if
 * the semaphore was negative (== somebody was waiting on it).
 * The default case (no contention) will result in NO
 * jumps for both down() and up().
 */
static inline void up(struct semaphore * sem)
{
	__up_op(sem, __up_wakeup);
}

#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/include/asm-arm/semaphore.h
	3	*/
	4	#ifndef __ASM_ARM_SEMAPHORE_H
	5	#define __ASM_ARM_SEMAPHORE_H
	6
	7	#include <linux/linkage.h>
	8	#include <linux/spinlock.h>
	9	#include <linux/wait.h>
	10	#include <linux/rwsem.h>
	11
	12	#include <asm/atomic.h>
	13	#include <asm/locks.h>
	14
	15	struct semaphore {
	16	atomic_t count;
	17	int sleepers;
	18	wait_queue_head_t wait;
	19	};
	20
	21	#define __SEMAPHORE_INIT(name, cnt) \
	22	{ \
	23	.count = ATOMIC_INIT(cnt), \
	24	.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \
	25	}
	26
1da177e4 LT	27	#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
	28	struct semaphore name = __SEMAPHORE_INIT(name,count)
	29
	30	#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
1da177e4 LT	31
	32	static inline void sema_init(struct semaphore *sem, int val)
	33	{
	34	atomic_set(&sem->count, val);
	35	sem->sleepers = 0;
	36	init_waitqueue_head(&sem->wait);
	37	}
	38
	39	static inline void init_MUTEX(struct semaphore *sem)
	40	{
	41	sema_init(sem, 1);
	42	}
	43
	44	static inline void init_MUTEX_LOCKED(struct semaphore *sem)
	45	{
	46	sema_init(sem, 0);
	47	}
	48
1da177e4 LT	49	/*
	50	* special register calling convention
	51	*/
	52	asmlinkage void __down_failed(void);
	53	asmlinkage int __down_interruptible_failed(void);
	54	asmlinkage int __down_trylock_failed(void);
	55	asmlinkage void __up_wakeup(void);
	56
	57	extern void __down(struct semaphore * sem);
	58	extern int __down_interruptible(struct semaphore * sem);
	59	extern int __down_trylock(struct semaphore * sem);
	60	extern void __up(struct semaphore * sem);
	61
	62	/*
	63	* This is ugly, but we want the default case to fall through.
	64	* "__down" is the actual routine that waits...
	65	*/
	66	static inline void down(struct semaphore * sem)
	67	{
	68	might_sleep();
	69	__down_op(sem, __down_failed);
	70	}
	71
	72	/*
	73	* This is ugly, but we want the default case to fall through.
	74	* "__down_interruptible" is the actual routine that waits...
	75	*/
	76	static inline int down_interruptible (struct semaphore * sem)
	77	{
	78	might_sleep();
	79	return __down_op_ret(sem, __down_interruptible_failed);
	80	}
	81
	82	static inline int down_trylock(struct semaphore *sem)
	83	{
	84	return __down_op_ret(sem, __down_trylock_failed);
	85	}
	86
	87	/*
	88	* Note! This is subtle. We jump to wake people up only if
	89	* the semaphore was negative (== somebody was waiting on it).
	90	* The default case (no contention) will result in NO
	91	* jumps for both down() and up().
	92	*/
	93	static inline void up(struct semaphore * sem)
	94	{
	95	__up_op(sem, __up_wakeup);
	96	}
	97
	98	#endif