diff options
author | Matthew Wilcox <matthew@wil.cx> | 2008-03-07 21:55:58 -0500 |
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committer | Matthew Wilcox <willy@linux.intel.com> | 2008-04-17 10:42:34 -0400 |
commit | 64ac24e738823161693bf791f87adc802cf529ff (patch) | |
tree | 19c0b0cf314d4394ca580c05b86cdf874ce0a167 /include/asm-cris/semaphore-helper.h | |
parent | e48b3deee475134585eed03e7afebe4bf9e0dba9 (diff) |
Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/asm-cris/semaphore-helper.h')
-rw-r--r-- | include/asm-cris/semaphore-helper.h | 78 |
1 files changed, 0 insertions, 78 deletions
diff --git a/include/asm-cris/semaphore-helper.h b/include/asm-cris/semaphore-helper.h deleted file mode 100644 index 27bfeca1b98..00000000000 --- a/include/asm-cris/semaphore-helper.h +++ /dev/null @@ -1,78 +0,0 @@ -/* $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. - */ -static inline void wake_one_more(struct semaphore * sem) -{ - atomic_inc(&sem->waking); -} - -static inline int waking_non_zero(struct semaphore *sem) -{ - unsigned long flags; - int ret = 0; - - local_irq_save(flags); - if (read(&sem->waking) > 0) { - dec(&sem->waking); - ret = 1; - } - local_irq_restore(flags); - return ret; -} - -static inline int waking_non_zero_interruptible(struct semaphore *sem, - struct task_struct *tsk) -{ - int ret = 0; - unsigned long flags; - - local_irq_save(flags); - 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; -} - -static inline int waking_non_zero_trylock(struct semaphore *sem) -{ - int ret = 1; - unsigned long flags; - - local_irq_save(flags); - 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 */ - - |