112 lines
3.2 KiB
C
112 lines
3.2 KiB
C
/* $NetBSD: lock.h,v 1.4 2000/07/08 04:36:56 tsubai Exp $ */
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/*-
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* Copyright (c) 2000 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Jason R. Thorpe.
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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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Machine-dependent spin lock operations.
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*/
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#ifndef _POWERPC_LOCK_H_
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#define _POWERPC_LOCK_H_
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typedef __volatile int __cpu_simple_lock_t;
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#define __SIMPLELOCK_LOCKED 1
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#define __SIMPLELOCK_UNLOCKED 0
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static __inline void
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__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
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{
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*alp = __SIMPLELOCK_UNLOCKED;
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__asm __volatile ("sync");
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}
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static __inline void
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__cpu_simple_lock(__cpu_simple_lock_t *alp)
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{
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int old;
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__asm __volatile (" \
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\n\
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1: lwarx %0,0,%1 \n\
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cmpwi %0,%2 \n\
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beq+ 3f \n\
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2: lwzx %0,0,%1 \n\
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cmpwi %0,%2 \n\
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beq+ 1b \n\
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b 2b \n\
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3: stwcx. %3,0,%1 \n\
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bne- 1b \n\
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isync \n\
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\n"
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: "=&r"(old)
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: "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED)
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: "memory");
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}
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static __inline int
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__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
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{
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int old, dummy;
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__asm __volatile (" \
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\n\
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1: lwarx %0,0,%1 \n\
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cmpwi %0,%2 \n\
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bne 2f \n\
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stwcx. %3,0,%1 \n\
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bne- 1b \n\
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2: stwcx. %3,0,%4 \n\
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isync \n\
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\n"
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: "=&r"(old)
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: "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED),
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"r"(&dummy)
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: "memory");
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return (old == __SIMPLELOCK_UNLOCKED);
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}
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static __inline void
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__cpu_simple_unlock(__cpu_simple_lock_t *alp)
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{
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__asm __volatile ("sync");
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*alp = __SIMPLELOCK_UNLOCKED;
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}
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#endif /* _POWERPC_LOCK_H_ */
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