/* * linux/include/asm-xtensa/semaphore.h * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2001 - 2005 Tensilica Inc. */ #ifndef _XTENSA_SEMAPHORE_H#define _XTENSA_SEMAPHORE_H #include <asm/atomic.h>#include <asm/system.h>#include <linux/wait.h>#include <linux/rwsem.h> struct semaphore {	atomic_t count;	int sleepers;	wait_queue_head_t wait;}; #define __SEMAPHORE_INITIALIZER(name,n)					\{									\	.count		= ATOMIC_INIT(n),				\	.sleepers	= 0,						\	.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)#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) static inline void sema_init (struct semaphore *sem, int val){	atomic_set(&sem->count, val);	sem->sleepers = 0;	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);} asmlinkage void __down(struct semaphore * sem);asmlinkage int  __down_interruptible(struct semaphore * sem);asmlinkage int  __down_trylock(struct semaphore * sem);asmlinkage void __up(struct semaphore * sem); extern spinlock_t semaphore_wake_lock; static inline void down(struct semaphore * sem){	might_sleep(); 	if (atomic_sub_return(1, &sem->count) < 0)		__down(sem);} static inline int down_interruptible(struct semaphore * sem){	int ret = 0; 	might_sleep(); 	if (atomic_sub_return(1, &sem->count) < 0)		ret = __down_interruptible(sem);	return ret;} static inline int down_trylock(struct semaphore * sem){	int ret = 0; 	if (atomic_sub_return(1, &sem->count) < 0)		ret = __down_trylock(sem);	return ret;} /* * Note! This is subtle. We jump to wake people up only if * the semaphore was negative (== somebody was waiting on it). */static inline void up(struct semaphore * sem){	if (atomic_add_return(1, &sem->count) <= 0)		__up(sem);} #endif /* _XTENSA_SEMAPHORE_H */