semaphore.h
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#ifndef _M68K_SEMAPHORE_H
#define _M68K_SEMAPHORE_H
#define RW_LOCK_BIAS 0x01000000
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <asm/system.h>
#include <asm/atomic.h>
/*
* Interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*/
struct semaphore {
atomic_t count;
atomic_t waking;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.waking = ATOMIC_INIT(0), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __MUTEX_INITIALIZER(name) \
__SEMAPHORE_INITIALIZER(name,1)
#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)
extern inline void sema_init (struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
}
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);
extern spinlock_t semaphore_wake_lock;
/*
* This is ugly, but we want the default case to fall through.
* "down_failed" is a special asm handler that calls the C
* routine that actually waits. See arch/m68k/lib/semaphore.S
*/
extern inline void down(struct semaphore * sem)
{
might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"movel %0, %%a1\n\t"
"lea %%pc@(1f), %%a0\n\t"
"subql #1, %%a1@\n\t"
"jmi __down_failed\n"
"1:"
: /* no outputs */
: "g" (sem)
: "cc", "%a0", "%a1", "memory");
}
extern inline int down_interruptible(struct semaphore * sem)
{
int ret;
might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"movel %1, %%a1\n\t"
"lea %%pc@(1f), %%a0\n\t"
"subql #1, %%a1@\n\t"
"jmi __down_failed_interruptible\n\t"
"clrl %%d0\n"
"1: movel %%d0, %0\n"
: "=d" (ret)
: "g" (sem)
: "cc", "%d0", "%a0", "%a1", "memory");
return(ret);
}
extern inline int down_trylock(struct semaphore * sem)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
register int result __asm__ ("%d0");
__asm__ __volatile__(
"| atomic down trylock operation\n\t"
"subql #1,%1@\n\t"
"jmi 2f\n\t"
"clrl %0\n"
"1:\n"
".section .text.lock,\"ax\"\n"
".even\n"
"2:\tpea 1b\n\t"
"jbra __down_failed_trylock\n"
".previous"
: "=d" (result)
: "a" (sem1)
: "memory");
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().
*/
extern inline void up(struct semaphore * sem)
{
__asm__ __volatile__(
"| atomic up operation\n\t"
"movel %0, %%a1\n\t"
"lea %%pc@(1f), %%a0\n\t"
"addql #1, %%a1@\n\t"
"jle __up_wakeup\n"
"1:"
: /* no outputs */
: "g" (sem)
: "cc", "%a0", "%a1", "memory");
}
#endif /* __ASSEMBLY__ */
#endif