/* $OpenBSD: lock.h,v 1.1 2007/05/01 18:56:31 miod Exp $ */
/* public domain */
#ifndef _SPARC_LOCK_H_
#define _SPARC_LOCK_H_
typedef volatile u_int8_t __cpu_simple_lock_t;
#define __SIMPLELOCK_LOCKED 0xff
#define __SIMPLELOCK_UNLOCKED 0x00
static __inline__ void
__cpu_simple_lock_init(__cpu_simple_lock_t *l)
{
*l = __SIMPLELOCK_UNLOCKED;
}
static __inline__ void
__cpu_simple_lock(__cpu_simple_lock_t *l)
{
__cpu_simple_lock_t old;
do {
old = __SIMPLELOCK_LOCKED;
__asm__ __volatile__
("ldstub %0, %1" : "=m" (*l), "=r" (old) : "0" (*l));
} while (old != __SIMPLELOCK_UNLOCKED);
}
static __inline__ int
__cpu_simple_lock_try(__cpu_simple_lock_t *l)
{
__cpu_simple_lock_t old = __SIMPLELOCK_LOCKED;
__asm__ __volatile__
("ldstub %0, %1" : "=m" (*l), "=r" (old) : "0" (*l));
return (old == __SIMPLELOCK_UNLOCKED);
}
static __inline__ void
__cpu_simple_unlock(__cpu_simple_lock_t *l)
{
*l = __SIMPLELOCK_UNLOCKED;
}
#endif /* _SPARC_LOCK_H_ */