84 lines
1.6 KiB
C
84 lines
1.6 KiB
C
#ifndef _M68K_SEMAPHORE_HELPER_H
|
|
#define _M68K_SEMAPHORE_HELPER_H
|
|
|
|
/*
|
|
* SMP- and interrupt-safe semaphores helper functions.
|
|
*
|
|
* (C) Copyright 1996 Linus Torvalds
|
|
*
|
|
* m68k version by Andreas Schwab
|
|
*/
|
|
|
|
#include <linux/config.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;
|
|
|
|
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;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&semaphore_wake_lock, flags);
|
|
ret = 0;
|
|
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;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&semaphore_wake_lock, flags);
|
|
ret = 1;
|
|
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
|