a3b98398cb
- The MD functions critical_enter/exit are renamed to start with a cpu_ prefix. - MI wrapper functions critical_enter/exit maintain a per-thread nesting count and a per-thread critical section saved state set when entering a critical section while at nesting level 0 and restored when exiting to nesting level 0. This moves the saved state out of spin mutexes so that interlocking spin mutexes works properly. - Most low-level MD code that used critical_enter/exit now use cpu_critical_enter/exit. MI code such as device drivers and spin mutexes use the MI wrappers. Note that since the MI wrappers store the state in the current thread, they do not have any return values or arguments. - mtx_intr_enable() is replaced with a constant CRITICAL_FORK which is assigned to curthread->td_savecrit during fork_exit(). Tested on: i386, alpha
66 lines
2.6 KiB
C
66 lines
2.6 KiB
C
/*-
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* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Berkeley Software Design Inc's name may not be used to endorse or
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* promote products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
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* $FreeBSD$
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*/
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#ifndef _MACHINE_MUTEX_H_
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#define _MACHINE_MUTEX_H_
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#ifdef LOCORE
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/*
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* Simple assembly macros to get and release non-recursive spin locks
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*/
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#define MTX_ENTER(lck) \
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mfmsr r10; \ /* disable interrupts */
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rlwinm r0, r10, 0, 17, 15; \
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mtmsr r0; \
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1: li r11, MTX_LOCK; \ /* MTX_LOCK offset */
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lwarx r0, r11, lck; \ /* load current lock value */
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cmplwi r0, r1, MTX_UNOWNED; \ /* compare with unowned */
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beq 1; \ /* if owned, loop */
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lwz r0, PC_CURPROC(pcpup); \ /* load curproc */
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stwcx. r0, r11, lck; \ /* attempt to store */
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beq 1; \ /* loop if failed */
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sync; \ /* sync */
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eieio; \ /* sync */
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stw r10, MTX_SAVEINTR(lck) /* save flags */
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#define MTX_EXIT(lck) \
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sync; \ /* sync */
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eieio; \ /* sync */
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li r0, MTX_UNOWNED; \ /* load in unowned */
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stw r0, MTX_LOCK(lck); \ /* store to lock */
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lwz r0, MTX_SAVEINTR(lck); \ /* load saved flags */
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mtmsr r0 /* enable interrupts */
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#endif /* !LOCORE */
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#endif /* __MACHINE_MUTEX_H */
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