Annotation of sys/arch/powerpc/include/lock.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: lock.h,v 1.1 2007/03/20 20:59:53 kettenis Exp $ */
! 2: /* $NetBSD: lock.h,v 1.8 2005/12/28 19:09:29 perry Exp $ */
! 3:
! 4: /*-
! 5: * Copyright (c) 2000 The NetBSD Foundation, Inc.
! 6: * All rights reserved.
! 7: *
! 8: * This code is derived from software contributed to The NetBSD Foundation
! 9: * by Jason R. Thorpe.
! 10: *
! 11: * Redistribution and use in source and binary forms, with or without
! 12: * modification, are permitted provided that the following conditions
! 13: * are met:
! 14: * 1. Redistributions of source code must retain the above copyright
! 15: * notice, this list of conditions and the following disclaimer.
! 16: * 2. Redistributions in binary form must reproduce the above copyright
! 17: * notice, this list of conditions and the following disclaimer in the
! 18: * documentation and/or other materials provided with the distribution.
! 19: * 3. All advertising materials mentioning features or use of this software
! 20: * must display the following acknowledgement:
! 21: * This product includes software developed by the NetBSD
! 22: * Foundation, Inc. and its contributors.
! 23: * 4. Neither the name of The NetBSD Foundation nor the names of its
! 24: * contributors may be used to endorse or promote products derived
! 25: * from this software without specific prior written permission.
! 26: *
! 27: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
! 28: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
! 29: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
! 30: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
! 31: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
! 32: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
! 33: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
! 34: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
! 35: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
! 36: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
! 37: * POSSIBILITY OF SUCH DAMAGE.
! 38: */
! 39:
! 40: /*
! 41: * Machine-dependent spin lock operations.
! 42: */
! 43:
! 44: #ifndef _POWERPC_LOCK_H_
! 45: #define _POWERPC_LOCK_H_
! 46:
! 47: typedef __volatile int __cpu_simple_lock_t;
! 48:
! 49: #define __SIMPLELOCK_LOCKED 1
! 50: #define __SIMPLELOCK_UNLOCKED 0
! 51:
! 52: static __inline void
! 53: __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
! 54: {
! 55: *alp = __SIMPLELOCK_UNLOCKED;
! 56: __asm volatile ("sync");
! 57: }
! 58:
! 59: static __inline void
! 60: __cpu_simple_lock(__cpu_simple_lock_t *alp)
! 61: {
! 62: int old;
! 63:
! 64: __asm volatile (" \
! 65: \n\
! 66: 1: lwarx %0,0,%1 \n\
! 67: cmpwi %0,%2 \n\
! 68: beq+ 3f \n\
! 69: 2: lwzx %0,0,%1 \n\
! 70: cmpwi %0,%2 \n\
! 71: beq+ 1b \n\
! 72: b 2b \n\
! 73: 3: stwcx. %3,0,%1 \n\
! 74: bne- 1b \n\
! 75: isync \n\
! 76: \n"
! 77: : "=&r"(old)
! 78: : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED)
! 79: : "memory");
! 80: }
! 81:
! 82: static __inline int
! 83: __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
! 84: {
! 85: int old, dummy;
! 86:
! 87: __asm volatile (" \
! 88: \n\
! 89: 1: lwarx %0,0,%1 \n\
! 90: cmpwi %0,%2 \n\
! 91: bne 2f \n\
! 92: stwcx. %3,0,%1 \n\
! 93: bne- 1b \n\
! 94: 2: stwcx. %3,0,%4 \n\
! 95: isync \n\
! 96: \n"
! 97: : "=&r"(old)
! 98: : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED),
! 99: "r"(&dummy)
! 100: : "memory");
! 101:
! 102: return (old == __SIMPLELOCK_UNLOCKED);
! 103: }
! 104:
! 105: static __inline void
! 106: __cpu_simple_unlock(__cpu_simple_lock_t *alp)
! 107: {
! 108: __asm volatile ("sync");
! 109: *alp = __SIMPLELOCK_UNLOCKED;
! 110: }
! 111:
! 112: #endif /* _POWERPC_LOCK_H_ */
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