From 64ac24e738823161693bf791f87adc802cf529ff Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Fri, 7 Mar 2008 21:55:58 -0500 Subject: 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 Acked-by: Ingo Molnar --- include/asm-v850/semaphore.h | 85 +------------------------------------------- 1 file changed, 1 insertion(+), 84 deletions(-) (limited to 'include/asm-v850') diff --git a/include/asm-v850/semaphore.h b/include/asm-v850/semaphore.h index 10ed0ccf37df..d9b2034ed1d2 100644 --- a/include/asm-v850/semaphore.h +++ b/include/asm-v850/semaphore.h @@ -1,84 +1 @@ -#ifndef __V850_SEMAPHORE_H__ -#define __V850_SEMAPHORE_H__ - -#include -#include -#include -#include - -#include - -struct semaphore { - atomic_t count; - int sleepers; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INITIALIZER(name,count) \ - { ATOMIC_INIT (count), 0, \ - __WAIT_QUEUE_HEAD_INITIALIZER ((name).wait) } - -#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ - struct semaphore name = __SEMAPHORE_INITIALIZER (name,count) - -#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC (name,1) - -static inline void sema_init (struct semaphore *sem, int val) -{ - *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); -} - -static inline void init_MUTEX (struct semaphore *sem) -{ - sema_init (sem, 1); -} - -static inline void init_MUTEX_LOCKED (struct semaphore *sem) -{ - sema_init (sem, 0); -} - -/* - * special register calling convention - */ -asmlinkage void __down_failed (void); -asmlinkage int __down_interruptible_failed (void); -asmlinkage int __down_trylock_failed (void); -asmlinkage void __up_wakeup (void); - -extern void __down (struct semaphore * sem); -extern int __down_interruptible (struct semaphore * sem); -extern int __down_trylock (struct semaphore * sem); -extern void __up (struct semaphore * sem); - -static inline void down (struct semaphore * sem) -{ - might_sleep(); - if (atomic_dec_return (&sem->count) < 0) - __down (sem); -} - -static inline int down_interruptible (struct semaphore * sem) -{ - int ret = 0; - might_sleep(); - if (atomic_dec_return (&sem->count) < 0) - ret = __down_interruptible (sem); - return ret; -} - -static inline int down_trylock (struct semaphore *sem) -{ - int ret = 0; - if (atomic_dec_return (&sem->count) < 0) - ret = __down_trylock (sem); - return ret; -} - -static inline void up (struct semaphore * sem) -{ - if (atomic_inc_return (&sem->count) <= 0) - __up (sem); -} - -#endif /* __V850_SEMAPHORE_H__ */ +#include -- cgit v1.2.3