107 lines
2.4 KiB
C
107 lines
2.4 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 __MUTEX_INITIALIZER(name) __SEMAPHORE_INIT(name,1)
|
|
|
|
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
|
|
struct semaphore name = __SEMAPHORE_INIT(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);
|
|
}
|
|
|
|
static inline int sema_count(struct semaphore *sem)
|
|
{
|
|
return atomic_read(&sem->count);
|
|
}
|
|
|
|
/*
|
|
* 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
|