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#ifndef _ASM_M32R_SEMAPHORE_H
#define _ASM_M32R_SEMAPHORE_H
#include <linux/linkage.h>
#ifdef __KERNEL__
/*
* SMP- and interrupt-safe semaphores..
*
* Copyright (C) 1996 Linus Torvalds
* Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
*/
#include <linux/wait.h>
#include <linux/rwsem.h>
#include <asm/assembler.h>
#include <asm/system.h>
#include <asm/atomic.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)
{
/*
* *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
*
* i'd rather use the more flexible initialization above, but sadly
* GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well.
*/
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_failed(void /* special register calling convention */);
asmlinkage int __down_failed_interruptible(void /* params in registers */);
asmlinkage int __down_failed_trylock(void /* params in registers */);
asmlinkage void __up_wakeup(void /* special register calling convention */);
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);
/*
* Atomically decrement the semaphore's count. If it goes negative,
* block the calling thread in the TASK_UNINTERRUPTIBLE state.
*/
static inline void down(struct semaphore * sem)
{
might_sleep();
if (unlikely(atomic_dec_return(&sem->count) < 0))
__down(sem);
}
/*
* Interruptible try to acquire a semaphore. If we obtained
* it, return zero. If we were interrupted, returns -EINTR
*/
static inline int down_interruptible(struct semaphore * sem)
{
int result = 0;
might_sleep();
if (unlikely(atomic_dec_return(&sem->count) < 0))
result = __down_interruptible(sem);
return result;
}
/*
* Non-blockingly attempt to down() a semaphore.
* Returns zero if we acquired it
*/
static inline int down_trylock(struct semaphore * sem)
{
unsigned long flags;
long count;
int result = 0;
local_irq_save(flags);
__asm__ __volatile__ (
"# down_trylock \n\t"
DCACHE_CLEAR("%0", "r4", "%1")
M32R_LOCK" %0, @%1; \n\t"
"addi %0, #-1; \n\t"
M32R_UNLOCK" %0, @%1; \n\t"
: "=&r" (count)
: "r" (&sem->count)
: "memory"
#ifdef CONFIG_CHIP_M32700_TS1
, "r4"
#endif /* CONFIG_CHIP_M32700_TS1 */
);
local_irq_restore(flags);
if (unlikely(count < 0))
result = __down_trylock(sem);
return result;
}
/*
* 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)
{
if (unlikely(atomic_inc_return(&sem->count) <= 0))
__up(sem);
}
#endif /* __KERNEL__ */
#endif /* _ASM_M32R_SEMAPHORE_H */
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