linux/include/asm-arm/semaphore.h
Christoph Hellwig 04fc8bbcf5 kill DECLARE_MUTEX_LOCKED
DECLARE_MUTEX_LOCKED was used for semaphores used as completions and we've
got rid of them.  Well, except for one in libusual that the maintainer
explicitly wants to keep as semaphore.  So convert that useage to an
explicit sema_init and kill of DECLARE_MUTEX_LOCKED so that new code is
reminded to use a completion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: "Satyam Sharma" <satyam.sharma@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:47 -07:00

99 lines
2.2 KiB
C

/*
* linux/include/asm-arm/semaphore.h
*/
#ifndef __ASM_ARM_SEMAPHORE_H
#define __ASM_ARM_SEMAPHORE_H
#include <linux/linkage.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
#include <asm/atomic.h>
#include <asm/locks.h>
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INIT(name, cnt) \
{ \
.count = ATOMIC_INIT(cnt), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INIT(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);
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);
}
/*
* 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);
/*
* This is ugly, but we want the default case to fall through.
* "__down" is the actual routine that waits...
*/
static inline void down(struct semaphore * sem)
{
might_sleep();
__down_op(sem, __down_failed);
}
/*
* This is ugly, but we want the default case to fall through.
* "__down_interruptible" is the actual routine that waits...
*/
static inline int down_interruptible (struct semaphore * sem)
{
might_sleep();
return __down_op_ret(sem, __down_interruptible_failed);
}
static inline int down_trylock(struct semaphore *sem)
{
return __down_op_ret(sem, __down_trylock_failed);
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
__up_op(sem, __up_wakeup);
}
#endif