1 /* $OpenBSD: atomic.h,v 1.11 2012/11/19 15:18:06 pirofti 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 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #ifndef _MACHINE_ATOMIC_H_ 36 #define _MACHINE_ATOMIC_H_ 37 38 /* 39 * Perform atomic operations on memory. Should be atomic with respect 40 * to interrupts and multiple processors. 41 * 42 * void atomic_setbits_int(volatile u_int *a, u_int mask) { *a |= mask; } 43 * void atomic_clearbits_int(volatile u_int *a, u_int mas) { *a &= ~mask; } 44 */ 45 #if defined(_KERNEL) && !defined(_LOCORE) 46 47 #ifdef MULTIPROCESSOR 48 #define LOCK "lock" 49 #else 50 #define LOCK 51 #endif 52 53 static __inline u_int64_t 54 i386_atomic_testset_uq(volatile u_int64_t *ptr, u_int64_t val) 55 { 56 __asm__ volatile ("\n1:\t" LOCK " cmpxchg8b (%1); jnz 1b" : "+A" (val) : 57 "r" (ptr), "b" ((u_int32_t)val), "c" ((u_int32_t)(val >> 32))); 58 return val; 59 } 60 61 static __inline u_int32_t 62 i386_atomic_testset_ul(volatile u_int32_t *ptr, unsigned long val) 63 { 64 __asm__ volatile ("xchgl %0,(%2)" :"=r" (val):"0" (val),"r" (ptr)); 65 return val; 66 } 67 68 static __inline int 69 i386_atomic_testset_i(volatile int *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 void 76 i386_atomic_setbits_l(volatile u_int32_t *ptr, unsigned long bits) 77 { 78 __asm __volatile(LOCK " orl %1,%0" : "=m" (*ptr) : "ir" (bits)); 79 } 80 81 static __inline void 82 i386_atomic_clearbits_l(volatile u_int32_t *ptr, unsigned long bits) 83 { 84 bits = ~bits; 85 __asm __volatile(LOCK " andl %1,%0" : "=m" (*ptr) : "ir" (bits)); 86 } 87 88 /* 89 * cas = compare and set 90 */ 91 static __inline int 92 i486_atomic_cas_int(volatile u_int *ptr, u_int expect, u_int set) 93 { 94 int res; 95 96 __asm volatile(LOCK " cmpxchgl %2, %1" : "=a" (res), "=m" (*ptr) 97 : "r" (set), "a" (expect), "m" (*ptr) : "memory"); 98 99 return (res); 100 } 101 102 static __inline int 103 i386_atomic_cas_int32(volatile int32_t *ptr, int32_t expect, int32_t set) 104 { 105 int res; 106 107 __asm volatile(LOCK " cmpxchgl %2, %1" : "=a" (res), "=m" (*ptr) 108 : "r" (set), "a" (expect), "m" (*ptr) : "memory"); 109 110 return (res); 111 } 112 113 int ucas_32(volatile int32_t *, int32_t, int32_t); 114 #define futex_atomic_ucas_int32 ucas_32 115 116 #define atomic_setbits_int i386_atomic_setbits_l 117 #define atomic_clearbits_int i386_atomic_clearbits_l 118 119 #undef LOCK 120 121 #endif /* defined(_KERNEL) && !defined(_LOCORE) */ 122 #endif /* _MACHINE_ATOMIC_H_ */ 123