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/* Based on M68K version, Lineo Inc. May 2001 */
#ifndef _BFIN_SEMAPHORE_HELPER_H
#define _BFIN_SEMAPHORE_HELPER_H
/*
* SMP- and interrupt-safe semaphores helper functions.
*
* (C) Copyright 1996 Linus Torvalds
*
*/
#include <asm/errno.h>
/*
* These two _must_ execute atomically wrt each other.
*/
static inline void wake_one_more(struct semaphore *sem)
{
atomic_inc(&sem->waking);
}
static inline int waking_non_zero(struct semaphore *sem)
{
int ret;
unsigned long flags = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*/
static inline int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
int ret = 0;
unsigned long flags = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*/
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
int ret = 1;
unsigned long flags = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 0;
} else
atomic_inc(&sem->count);
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
#endif /* _BFIN_SEMAPHORE_HELPER_H */
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