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/*-
* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
*
* 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.
* 3. Berkeley Software Design Inc's name may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``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 BERKELEY SOFTWARE DESIGN INC 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.
*
* from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
* $FreeBSD$
*/
#ifndef _MACHINE_MUTEX_H_
#define _MACHINE_MUTEX_H_
#ifdef LOCORE
/*
* Simple assembly macros to get and release non-recursive spin locks
*/
#define MTX_ENTER(lck) \
mfmsr r10; \ /* disable interrupts */
rlwinm r0, r10, 0, 17, 15; \
mtmsr r0; \
1: li r11, MTX_LOCK; \ /* MTX_LOCK offset */
lwarx r0, r11, lck; \ /* load current lock value */
cmplwi r0, r1, MTX_UNOWNED; \ /* compare with unowned */
beq 1; \ /* if owned, loop */
lwz r0, PC_CURPROC(pcpup); \ /* load curproc */
stwcx. r0, r11, lck; \ /* attempt to store */
beq 1; \ /* loop if failed */
sync; \ /* sync */
eieio; \ /* sync */
stw r10, MTX_SAVEINTR(lck) /* save flags */
#define MTX_EXIT(lck) \
sync; \ /* sync */
eieio; \ /* sync */
li r0, MTX_UNOWNED; \ /* load in unowned */
stw r0, MTX_LOCK(lck); \ /* store to lock */
lwz r0, MTX_SAVEINTR(lck); \ /* load saved flags */
mtmsr r0 /* enable interrupts */
#endif /* !LOCORE */
#endif /* __MACHINE_MUTEX_H */
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