99 lines
3.2 KiB
C
99 lines
3.2 KiB
C
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/* $NetBSD: lock.h,v 1.1 2001/06/19 00:20:11 fvdl 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 _X86_64_LOCK_H_
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#define _X86_64_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 __cpu_simple_lock_init __P((__cpu_simple_lock_t *))
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__attribute__((__unused__));
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static __inline void __cpu_simple_lock __P((__cpu_simple_lock_t *))
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__attribute__((__unused__));
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static __inline int __cpu_simple_lock_try __P((__cpu_simple_lock_t *))
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__attribute__((__unused__));
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static __inline void __cpu_simple_unlock __P((__cpu_simple_lock_t *))
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__attribute__((__unused__));
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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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}
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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 __val = __SIMPLELOCK_LOCKED;
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do {
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__asm __volatile("xchgl %0, %2"
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: "=r" (__val)
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: "0" (__val), "m" (*alp));
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} while (__val != __SIMPLELOCK_UNLOCKED);
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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 __val = __SIMPLELOCK_LOCKED;
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__asm __volatile("xchgl %0, %2"
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: "=r" (__val)
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: "0" (__val), "m" (*alp));
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return ((__val == __SIMPLELOCK_UNLOCKED) ? 1 : 0);
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}
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void
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__cpu_simple_unlock(__cpu_simple_lock_t *alp)
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{
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*alp = __SIMPLELOCK_UNLOCKED;
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}
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#endif /* _X86_64_LOCK_H_ */
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