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#ifndef _PPC_SEMAPHORE_H
#define _PPC_SEMAPHORE_H
/*
* SMP- and interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
* Adapted for PowerPC by Gary Thomas and Paul Mackerras
*/
#include <asm/atomic.h>
struct semaphore {
atomic_t count;
atomic_t waking;
struct wait_queue *wait;
};
#define sema_init(sem, val) atomic_set(&((sem)->count), (val))
#define MUTEX ((struct semaphore) \
{ ATOMIC_INIT(1), ATOMIC_INIT(0), NULL })
#define MUTEX_LOCKED ((struct semaphore) \
{ ATOMIC_INIT(0), ATOMIC_INIT(0), NULL })
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);
extern inline void down(struct semaphore * sem)
{
if (atomic_dec_return(&sem->count) >= 0)
wmb();
else
__down(sem);
}
extern inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
if (atomic_dec_return(&sem->count) >= 0)
wmb();
else
ret = __down_interruptible(sem);
return ret;
}
extern inline int down_trylock(struct semaphore * sem)
{
int ret = 0;
if (atomic_dec_return(&sem->count) >= 0)
wmb();
else
ret = __down_trylock(sem);
return ret;
}
extern inline void up(struct semaphore * sem)
{
mb();
if (atomic_inc_return(&sem->count) <= 0)
__up(sem);
}
#endif /* !(_PPC_SEMAPHORE_H) */
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