diff options
author | Matthew Wilcox <matthew@wil.cx> | 2008-03-08 02:55:58 (GMT) |
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committer | Matthew Wilcox <willy@linux.intel.com> | 2008-04-17 14:42:34 (GMT) |
commit | 64ac24e738823161693bf791f87adc802cf529ff (patch) | |
tree | 19c0b0cf314d4394ca580c05b86cdf874ce0a167 /include/asm-v850 | |
parent | e48b3deee475134585eed03e7afebe4bf9e0dba9 (diff) | |
download | linux-64ac24e738823161693bf791f87adc802cf529ff.tar.xz |
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-v850')
-rw-r--r-- | include/asm-v850/semaphore.h | 85 |
1 files changed, 1 insertions, 84 deletions
diff --git a/include/asm-v850/semaphore.h b/include/asm-v850/semaphore.h index 10ed0cc..d9b2034 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 <linux/linkage.h> -#include <linux/spinlock.h> -#include <linux/wait.h> -#include <linux/rwsem.h> - -#include <asm/atomic.h> - -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 <linux/semaphore.h> |