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Annotation of sys/arch/i386/include/atomic.h, Revision 1.1.1.1

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_ */