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#ifndef _M88K_LOCK_H_
#define _M88K_LOCK_H_
/* $OpenBSD: lock.h,v 1.5 2007/10/27 20:36:17 miod Exp $ */
/*
* Copyright (c) 2005, Miodrag Vallat.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <m88k/asm.h>
typedef volatile u_int __cpu_simple_lock_t;
/* do not change these - code below assumes r0 == __SIMPLELOCK_UNLOCKED */
#define __SIMPLELOCK_LOCKED 1
#define __SIMPLELOCK_UNLOCKED 0
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)
{
/*
* The local __cpu_simple_lock_t is not declared volatile, so that
* stores to it can be optimized away, since we will use a register
* and only spin on it. xmem will do the right thing regardless of
* the volatile qualifier.
*/
u_int old;
do {
old = __SIMPLELOCK_LOCKED;
__asm__ __volatile__
("xmem %0, %2, r0" : "+r"(old), "+m"(*l) : "r"(l));
} while (old != __SIMPLELOCK_UNLOCKED);
}
static __inline__ int
__cpu_simple_lock_try(__cpu_simple_lock_t *l)
{
/*
* The local __cpu_simple_lock_t is not declared volatile, so that
* there are not pipeline synchronization around stores to it.
* xmem will do the right thing regardless of the volatile qualifier.
*/
u_int old = __SIMPLELOCK_LOCKED;
__asm__ __volatile__
("xmem %0, %2, r0" : "+r"(old), "+m"(*l) : "r"(l));
return (old == __SIMPLELOCK_UNLOCKED);
}
static __inline__ void
__cpu_simple_unlock(__cpu_simple_lock_t *l)
{
*l = __SIMPLELOCK_UNLOCKED;
}
#endif /* _M88K_LOCK_H_ */
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