diff options
author | Stephen Rothwell <sfr@canb.auug.org.au> | 2008-03-19 19:04:24 +1100 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2008-03-19 19:04:24 +1100 |
commit | 80ec4961c83f7e186c80fffd47bc03c14b512841 (patch) | |
tree | f1ac3304eaccbed68e770779cc558c1ff5362a37 /include/asm-powerpc/semaphore.h | |
parent | 44bf27f5929b96ded7d70a2ffec440f12441d7a3 (diff) | |
parent | b1619dbd79aa25354f9049979029ce172792f0f0 (diff) |
Merge commit 'semaphore/semaphore-20080314'
Diffstat (limited to 'include/asm-powerpc/semaphore.h')
-rw-r--r-- | include/asm-powerpc/semaphore.h | 95 |
1 files changed, 1 insertions, 94 deletions
diff --git a/include/asm-powerpc/semaphore.h b/include/asm-powerpc/semaphore.h index 48dd32e07749..d9b2034ed1d2 100644 --- a/include/asm-powerpc/semaphore.h +++ b/include/asm-powerpc/semaphore.h @@ -1,94 +1 @@ -#ifndef _ASM_POWERPC_SEMAPHORE_H -#define _ASM_POWERPC_SEMAPHORE_H - -/* - * Remove spinlock-based RW semaphores; RW semaphore definitions are - * now in rwsem.h and we use the generic lib/rwsem.c implementation. - * Rework semaphores to use atomic_dec_if_positive. - * -- Paul Mackerras (paulus@samba.org) - */ - -#ifdef __KERNEL__ - -#include <asm/atomic.h> -#include <asm/system.h> -#include <linux/wait.h> -#include <linux/rwsem.h> - -struct semaphore { - /* - * Note that any negative value of count is equivalent to 0, - * but additionally indicates that some process(es) might be - * sleeping on `wait'. - */ - atomic_t count; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INITIALIZER(name, n) \ -{ \ - .count = ATOMIC_INIT(n), \ - .wait = __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) -{ - atomic_set(&sem->count, val); - init_waitqueue_head(&sem->wait); -} - -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); -} - -extern void __down(struct semaphore * sem); -extern int __down_interruptible(struct semaphore * sem); -extern void __up(struct semaphore * sem); - -static inline void down(struct semaphore * sem) -{ - might_sleep(); - - /* - * Try to get the semaphore, take the slow path if we fail. - */ - if (unlikely(atomic_dec_return(&sem->count) < 0)) - __down(sem); -} - -static inline int down_interruptible(struct semaphore * sem) -{ - int ret = 0; - - might_sleep(); - - if (unlikely(atomic_dec_return(&sem->count) < 0)) - ret = __down_interruptible(sem); - return ret; -} - -static inline int down_trylock(struct semaphore * sem) -{ - return atomic_dec_if_positive(&sem->count) < 0; -} - -static inline void up(struct semaphore * sem) -{ - if (unlikely(atomic_inc_return(&sem->count) <= 0)) - __up(sem); -} - -#endif /* __KERNEL__ */ - -#endif /* _ASM_POWERPC_SEMAPHORE_H */ +#include <linux/semaphore.h> |