mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
90 lines
2.1 KiB
C
90 lines
2.1 KiB
C
#ifndef _ASM_PARISC_SEMAPHORE_HELPER_H
|
|
#define _ASM_PARISC_SEMAPHORE_HELPER_H
|
|
|
|
/*
|
|
* SMP- and interrupt-safe semaphores helper functions.
|
|
*
|
|
* (C) Copyright 1996 Linus Torvalds
|
|
* (C) Copyright 1999 Andrea Arcangeli
|
|
*/
|
|
|
|
/*
|
|
* These two _must_ execute atomically wrt each other.
|
|
*
|
|
* This is trivially done with load_locked/store_cond,
|
|
* which we have. Let the rest of the losers suck eggs.
|
|
*/
|
|
static __inline__ void wake_one_more(struct semaphore * sem)
|
|
{
|
|
atomic_inc((atomic_t *)&sem->waking);
|
|
}
|
|
|
|
static __inline__ int waking_non_zero(struct semaphore *sem)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
spin_lock_irqsave(&semaphore_wake_lock, flags);
|
|
if (sem->waking > 0) {
|
|
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
|
|
*
|
|
* We must undo the sem->count down_interruptible() increment while we are
|
|
* protected by the spinlock in order to make atomic this atomic_inc() with the
|
|
* atomic_read() in wake_one_more(), otherwise we can race. -arca
|
|
*/
|
|
static __inline__ int waking_non_zero_interruptible(struct semaphore *sem,
|
|
struct task_struct *tsk)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
spin_lock_irqsave(&semaphore_wake_lock, flags);
|
|
if (sem->waking > 0) {
|
|
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
|
|
*
|
|
* We must undo the sem->count down_trylock() increment while we are
|
|
* protected by the spinlock in order to make atomic this atomic_inc() with the
|
|
* atomic_read() in wake_one_more(), otherwise we can race. -arca
|
|
*/
|
|
static __inline__ int waking_non_zero_trylock(struct semaphore *sem)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 1;
|
|
|
|
spin_lock_irqsave(&semaphore_wake_lock, flags);
|
|
if (sem->waking <= 0)
|
|
atomic_inc(&sem->count);
|
|
else {
|
|
sem->waking--;
|
|
ret = 0;
|
|
}
|
|
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
#endif /* _ASM_PARISC_SEMAPHORE_HELPER_H */
|