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/* $OpenBSD: lock.h,v 1.2 2008/06/26 05:42:12 ray Exp $ */
/* $NetBSD: lock.h,v 1.10 2006/01/03 01:29:46 uwe Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Gregory McGarry.
*
* 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/
/*
* Machine-dependent spin lock operations.
*/
#ifndef _SH_LOCK_H_
#define _SH_LOCK_H_
typedef volatile u_int8_t __cpu_simple_lock_t;
#define __SIMPLELOCK_LOCKED 0x80
#define __SIMPLELOCK_UNLOCKED 0x00
static __inline void
__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
{
*alp = __SIMPLELOCK_UNLOCKED;
}
static __inline void
__cpu_simple_lock(__cpu_simple_lock_t *alp)
{
__asm volatile(
"1: tas.b %0 \n"
" bf 1b \n"
: "=m" (*alp));
}
static __inline int
__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
{
int __rv;
__asm volatile(
" tas.b %0 \n"
" mov #0, %1 \n"
" rotcl %1 \n"
: "=m" (*alp), "=r" (__rv));
return (__rv);
}
static __inline void
__cpu_simple_unlock(__cpu_simple_lock_t *alp)
{
*alp = __SIMPLELOCK_UNLOCKED;
}
#endif /* !_SH_LOCK_H_ */
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