Annotation of sys/arch/i386/include/atomic.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: atomic.h,v 1.6 2007/05/25 15:55:27 art Exp $ */
! 2: /* $NetBSD: atomic.h,v 1.1.2.2 2000/02/21 18:54:07 sommerfeld 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 RedBack Networks Inc.
! 10: *
! 11: * Author: Bill Sommerfeld
! 12: *
! 13: * Redistribution and use in source and binary forms, with or without
! 14: * modification, are permitted provided that the following conditions
! 15: * are met:
! 16: * 1. Redistributions of source code must retain the above copyright
! 17: * notice, this list of conditions and the following disclaimer.
! 18: * 2. Redistributions in binary form must reproduce the above copyright
! 19: * notice, this list of conditions and the following disclaimer in the
! 20: * documentation and/or other materials provided with the distribution.
! 21: * 3. All advertising materials mentioning features or use of this software
! 22: * must display the following acknowledgement:
! 23: * This product includes software developed by the NetBSD
! 24: * Foundation, Inc. and its contributors.
! 25: * 4. Neither the name of The NetBSD Foundation nor the names of its
! 26: * contributors may be used to endorse or promote products derived
! 27: * from this software without specific prior written permission.
! 28: *
! 29: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
! 30: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
! 31: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
! 32: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
! 33: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
! 34: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
! 35: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
! 36: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
! 37: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
! 38: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
! 39: * POSSIBILITY OF SUCH DAMAGE.
! 40: */
! 41:
! 42: #ifndef _I386_ATOMIC_H_
! 43: #define _I386_ATOMIC_H_
! 44:
! 45: /*
! 46: * Perform atomic operations on memory. Should be atomic with respect
! 47: * to interrupts and multiple processors.
! 48: *
! 49: * void atomic_setbits_int(volatile u_int *a, u_int mask) { *a |= mask; }
! 50: * void atomic_clearbits_int(volatile u_int *a, u_int mas) { *a &= ~mask; }
! 51: */
! 52: #if defined(_KERNEL) && !defined(_LOCORE)
! 53:
! 54: #ifdef MULTIPROCESSOR
! 55: #define LOCK "lock"
! 56: #else
! 57: #define LOCK
! 58: #endif
! 59:
! 60: static __inline u_int64_t
! 61: i386_atomic_testset_uq(volatile u_int64_t *ptr, u_int64_t val)
! 62: {
! 63: __asm__ volatile ("\n1:\t" LOCK " cmpxchg8b (%1); jnz 1b" : "+A" (val) :
! 64: "r" (ptr), "b" ((u_int32_t)val), "c" ((u_int32_t)(val >> 32)));
! 65: return val;
! 66: }
! 67:
! 68: static __inline u_int32_t
! 69: i386_atomic_testset_ul(volatile u_int32_t *ptr, unsigned long val)
! 70: {
! 71: __asm__ volatile ("xchgl %0,(%2)" :"=r" (val):"0" (val),"r" (ptr));
! 72: return val;
! 73: }
! 74:
! 75: static __inline int
! 76: i386_atomic_testset_i(volatile int *ptr, unsigned long val)
! 77: {
! 78: __asm__ volatile ("xchgl %0,(%2)" :"=r" (val):"0" (val),"r" (ptr));
! 79: return val;
! 80: }
! 81:
! 82: static __inline void
! 83: i386_atomic_setbits_l(volatile u_int32_t *ptr, unsigned long bits)
! 84: {
! 85: __asm __volatile(LOCK " orl %1,%0" : "=m" (*ptr) : "ir" (bits));
! 86: }
! 87:
! 88: static __inline void
! 89: i386_atomic_clearbits_l(volatile u_int32_t *ptr, unsigned long bits)
! 90: {
! 91: bits = ~bits;
! 92: __asm __volatile(LOCK " andl %1,%0" : "=m" (*ptr) : "ir" (bits));
! 93: }
! 94:
! 95: /*
! 96: * cas = compare and set
! 97: */
! 98: static __inline int
! 99: i486_atomic_cas_int(volatile u_int *ptr, u_int expect, u_int set)
! 100: {
! 101: int res;
! 102:
! 103: __asm volatile(LOCK " cmpxchgl %2, %1" : "=a" (res), "=m" (*ptr)
! 104: : "r" (set), "a" (expect), "m" (*ptr) : "memory");
! 105:
! 106: return (res);
! 107: }
! 108:
! 109: #define atomic_setbits_int i386_atomic_setbits_l
! 110: #define atomic_clearbits_int i386_atomic_clearbits_l
! 111:
! 112: #undef LOCK
! 113:
! 114: #endif /* defined(_KERNEL) && !defined(_LOCORE) */
! 115: #endif /* _I386_ATOMIC_H_ */
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