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Diffstat (limited to 'include/asm-cris/semaphore-helper.h')
-rw-r--r-- | include/asm-cris/semaphore-helper.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/include/asm-cris/semaphore-helper.h b/include/asm-cris/semaphore-helper.h new file mode 100644 index 000000000000..dbd0f30b85b6 --- /dev/null +++ b/include/asm-cris/semaphore-helper.h @@ -0,0 +1,81 @@ +/* $Id: semaphore-helper.h,v 1.3 2001/03/26 15:00:33 orjanf Exp $ + * + * SMP- and interrupt-safe semaphores helper functions. Generic versions, no + * optimizations whatsoever... + * + */ + +#ifndef _ASM_SEMAPHORE_HELPER_H +#define _ASM_SEMAPHORE_HELPER_H + +#include <asm/atomic.h> +#include <linux/errno.h> + +#define read(a) ((a)->counter) +#define inc(a) (((a)->counter)++) +#define dec(a) (((a)->counter)--) + +#define count_inc(a) ((*(a))++) + +/* + * These two _must_ execute atomically wrt each other. + */ +extern inline void wake_one_more(struct semaphore * sem) +{ + atomic_inc(&sem->waking); +} + +extern inline int waking_non_zero(struct semaphore *sem) +{ + unsigned long flags; + int ret = 0; + + local_save_flags(flags); + local_irq_disable(); + if (read(&sem->waking) > 0) { + dec(&sem->waking); + ret = 1; + } + local_irq_restore(flags); + return ret; +} + +extern inline int waking_non_zero_interruptible(struct semaphore *sem, + struct task_struct *tsk) +{ + int ret = 0; + unsigned long flags; + + local_save_flags(flags); + local_irq_disable(); + if (read(&sem->waking) > 0) { + dec(&sem->waking); + ret = 1; + } else if (signal_pending(tsk)) { + inc(&sem->count); + ret = -EINTR; + } + local_irq_restore(flags); + return ret; +} + +extern inline int waking_non_zero_trylock(struct semaphore *sem) +{ + int ret = 1; + unsigned long flags; + + local_save_flags(flags); + local_irq_disable(); + if (read(&sem->waking) <= 0) + inc(&sem->count); + else { + dec(&sem->waking); + ret = 0; + } + local_irq_restore(flags); + return ret; +} + +#endif /* _ASM_SEMAPHORE_HELPER_H */ + + |