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#ifndef _ASM_IA64_SEMAPHORE_H
#define _ASM_IA64_SEMAPHORE_H
/*
* Copyright (C) 1998-2000 Hewlett-Packard Co
* Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/wait.h>
#include <linux/rwsem.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);
}
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);
extern int __down_interruptible (struct semaphore * sem);
extern int __down_trylock (struct semaphore * sem);
extern void __up (struct semaphore * sem);
/*
* Atomically decrement the semaphore's count. If it goes negative,
* block the calling thread in the TASK_UNINTERRUPTIBLE state.
*/
static inline void
down (struct semaphore *sem)
{
might_sleep();
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
/*
* Atomically decrement the semaphore's count. If it goes negative,
* block the calling thread in the TASK_INTERRUPTIBLE state.
*/
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;
}
static inline void
up (struct semaphore * sem)
{
if (atomic_inc_return(&sem->count) <= 0)
__up(sem);
}
#endif /* _ASM_IA64_SEMAPHORE_H */
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