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#ifndef _M68K_SEMAPHORE_H
#define _M68K_SEMAPHORE_H
#include <linux/linkage.h>
#include <asm/system.h>
#include <asm/atomic.h>
#include <asm/spinlock.h>
/*
* SMP- and interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*/
struct semaphore {
atomic_t count;
atomic_t waking;
struct wait_queue * wait;
};
#define MUTEX ((struct semaphore) { ATOMIC_INIT(1), ATOMIC_INIT(0), NULL })
#define MUTEX_LOCKED ((struct semaphore) { ATOMIC_INIT(0), ATOMIC_INIT(0), NULL })
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);
#define sema_init(sem, val) atomic_set(&((sem)->count), val)
/*
* 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)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
__asm__ __volatile__(
"| atomic down operation\n\t"
"subql #1,%0@\n\t"
"jmi 2f\n\t"
"1:\n"
".section .text.lock,\"ax\"\n"
".even\n"
"2:\tpea 1b\n\t"
"jbra __down_failed\n"
".previous"
: /* no outputs */
: "a" (sem1)
: "memory");
}
extern inline int down_interruptible(struct semaphore * sem)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
register int result __asm__ ("%d0");
__asm__ __volatile__(
"| atomic interruptible down 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_interruptible\n"
".previous"
: "=d" (result)
: "a" (sem1)
: "%d0", "memory");
return result;
}
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)
: "%d0", "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)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
__asm__ __volatile__(
"| atomic up operation\n\t"
"addql #1,%0@\n\t"
"jle 2f\n"
"1:\n"
".section .text.lock,\"ax\"\n"
".even\n"
"2:\t"
"pea 1b\n\t"
"jbra __up_wakeup\n"
".previous"
: /* no outputs */
: "a" (sem1)
: "memory");
}
#endif
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