1 /*- 2 * Copyright (c) 1998 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 #ifndef _MACHINE_ATOMIC_H_ 29 #define _MACHINE_ATOMIC_H_ 30 31 /* 32 * Various simple arithmetic on memory which is atomic in the presence 33 * of interrupts and multiple processors. 34 * 35 * atomic_set_char(P, V) (*(u_char*)(P) |= (V)) 36 * atomic_clear_char(P, V) (*(u_char*)(P) &= ~(V)) 37 * atomic_add_char(P, V) (*(u_char*)(P) += (V)) 38 * atomic_subtract_char(P, V) (*(u_char*)(P) -= (V)) 39 * 40 * atomic_set_short(P, V) (*(u_short*)(P) |= (V)) 41 * atomic_clear_short(P, V) (*(u_short*)(P) &= ~(V)) 42 * atomic_add_short(P, V) (*(u_short*)(P) += (V)) 43 * atomic_subtract_short(P, V) (*(u_short*)(P) -= (V)) 44 * 45 * atomic_set_int(P, V) (*(u_int*)(P) |= (V)) 46 * atomic_clear_int(P, V) (*(u_int*)(P) &= ~(V)) 47 * atomic_add_int(P, V) (*(u_int*)(P) += (V)) 48 * atomic_subtract_int(P, V) (*(u_int*)(P) -= (V)) 49 * 50 * atomic_set_long(P, V) (*(u_long*)(P) |= (V)) 51 * atomic_clear_long(P, V) (*(u_long*)(P) &= ~(V)) 52 * atomic_add_long(P, V) (*(u_long*)(P) += (V)) 53 * atomic_subtract_long(P, V) (*(u_long*)(P) -= (V)) 54 */ 55 56 /* 57 * The above functions are expanded inline in the statically-linked 58 * kernel. Lock prefixes are generated if an SMP kernel is being 59 * built. 60 * 61 * Kernel modules call real functions which are built into the kernel. 62 * This allows kernel modules to be portable between UP and SMP systems. 63 */ 64 #if defined(KLD_MODULE) 65 #define ATOMIC_ASM(NAME, TYPE, OP, V) \ 66 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v); 67 68 #else /* !KLD_MODULE */ 69 #if defined(SMP) 70 #define MPLOCKED "lock ; " 71 #else 72 #define MPLOCKED 73 #endif 74 75 /* 76 * The assembly is volatilized to demark potential before-and-after side 77 * effects if an interrupt or SMP collision were to occur. 78 */ 79 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 9) 80 /* egcs 1.1.2+ version */ 81 #define ATOMIC_ASM(NAME, TYPE, OP, V) \ 82 static __inline void \ 83 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ 84 { \ 85 __asm __volatile(MPLOCKED OP \ 86 : "=m" (*p) \ 87 : "0" (*p), "ir" (V)); \ 88 } 89 90 #else 91 /* gcc <= 2.8 version */ 92 #define ATOMIC_ASM(NAME, TYPE, OP, V) \ 93 static __inline void \ 94 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ 95 { \ 96 __asm __volatile(MPLOCKED OP \ 97 : "=m" (*p) \ 98 : "ir" (V)); \ 99 } 100 #endif 101 #endif /* KLD_MODULE */ 102 103 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 9) 104 105 /* egcs 1.1.2+ version */ 106 ATOMIC_ASM(set, char, "orb %2,%0", v) 107 ATOMIC_ASM(clear, char, "andb %2,%0", ~v) 108 ATOMIC_ASM(add, char, "addb %2,%0", v) 109 ATOMIC_ASM(subtract, char, "subb %2,%0", v) 110 111 ATOMIC_ASM(set, short, "orw %2,%0", v) 112 ATOMIC_ASM(clear, short, "andw %2,%0", ~v) 113 ATOMIC_ASM(add, short, "addw %2,%0", v) 114 ATOMIC_ASM(subtract, short, "subw %2,%0", v) 115 116 ATOMIC_ASM(set, int, "orl %2,%0", v) 117 ATOMIC_ASM(clear, int, "andl %2,%0", ~v) 118 ATOMIC_ASM(add, int, "addl %2,%0", v) 119 ATOMIC_ASM(subtract, int, "subl %2,%0", v) 120 121 ATOMIC_ASM(set, long, "orl %2,%0", v) 122 ATOMIC_ASM(clear, long, "andl %2,%0", ~v) 123 ATOMIC_ASM(add, long, "addl %2,%0", v) 124 ATOMIC_ASM(subtract, long, "subl %2,%0", v) 125 126 #else 127 128 /* gcc <= 2.8 version */ 129 ATOMIC_ASM(set, char, "orb %1,%0", v) 130 ATOMIC_ASM(clear, char, "andb %1,%0", ~v) 131 ATOMIC_ASM(add, char, "addb %1,%0", v) 132 ATOMIC_ASM(subtract, char, "subb %1,%0", v) 133 134 ATOMIC_ASM(set, short, "orw %1,%0", v) 135 ATOMIC_ASM(clear, short, "andw %1,%0", ~v) 136 ATOMIC_ASM(add, short, "addw %1,%0", v) 137 ATOMIC_ASM(subtract, short, "subw %1,%0", v) 138 139 ATOMIC_ASM(set, int, "orl %1,%0", v) 140 ATOMIC_ASM(clear, int, "andl %1,%0", ~v) 141 ATOMIC_ASM(add, int, "addl %1,%0", v) 142 ATOMIC_ASM(subtract, int, "subl %1,%0", v) 143 144 ATOMIC_ASM(set, long, "orl %1,%0", v) 145 ATOMIC_ASM(clear, long, "andl %1,%0", ~v) 146 ATOMIC_ASM(add, long, "addl %1,%0", v) 147 ATOMIC_ASM(subtract, long, "subl %1,%0", v) 148 149 #endif 150 151 #endif /* ! _MACHINE_ATOMIC_H_ */ 152