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 * $Id: atomic.h,v 1.2 1999/07/13 03:32:17 alc Exp $ 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 * Make kernel modules portable between UP and SMP. 58 */ 59 #if defined(SMP) || defined(KLD_MODULE) 60 #define MPLOCKED "lock ; " 61 #else 62 #define MPLOCKED 63 #endif 64 65 /* 66 * The assembly is volatilized to demark potential before-and-after side 67 * effects if an interrupt or SMP collision were to occur. 68 */ 69 #define ATOMIC_ASM(NAME, TYPE, OP, V) \ 70 static __inline void \ 71 atomic_##NAME##_##TYPE(void *p, u_##TYPE v) \ 72 { \ 73 __asm __volatile(MPLOCKED OP \ 74 : "=m" (*(u_##TYPE *)p) \ 75 : "0" (*(u_##TYPE *)p), "ir" (V)); \ 76 } 77 78 ATOMIC_ASM(set, char, "orb %2,%0", v) 79 ATOMIC_ASM(clear, char, "andb %2,%0", ~v) 80 ATOMIC_ASM(add, char, "addb %2,%0", v) 81 ATOMIC_ASM(subtract, char, "subb %2,%0", v) 82 83 ATOMIC_ASM(set, short, "orw %2,%0", v) 84 ATOMIC_ASM(clear, short, "andw %2,%0", ~v) 85 ATOMIC_ASM(add, short, "addw %2,%0", v) 86 ATOMIC_ASM(subtract, short, "subw %2,%0", v) 87 88 ATOMIC_ASM(set, int, "orl %2,%0", v) 89 ATOMIC_ASM(clear, int, "andl %2,%0", ~v) 90 ATOMIC_ASM(add, int, "addl %2,%0", v) 91 ATOMIC_ASM(subtract, int, "subl %2,%0", v) 92 93 ATOMIC_ASM(set, long, "orl %2,%0", v) 94 ATOMIC_ASM(clear, long, "andl %2,%0", ~v) 95 ATOMIC_ASM(add, long, "addl %2,%0", v) 96 ATOMIC_ASM(subtract, long, "subl %2,%0", v) 97 98 #endif /* ! _MACHINE_ATOMIC_H_ */ 99