sys/cpu/i386/include/atomic.h

   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: src/sys/i386/include/atomic.h,v 1.9.2.1 2000/07/07 00:38:47 obrien Exp $
  27  * $DragonFly: src/sys/cpu/i386/include/atomic.h,v 1.3 2003/07/10 04:47:53 dillon Exp $
  28  */
  29 #ifndef _MACHINE_ATOMIC_H_
  30 #define _MACHINE_ATOMIC_H_
  31
  32 /*
  33  * Various simple arithmetic on memory which is atomic in the presence
  34  * of interrupts and multiple processors.
  35  *
  36  * atomic_set_char(P, V)        (*(u_char*)(P) |= (V))
  37  * atomic_clear_char(P, V)      (*(u_char*)(P) &= ~(V))
  38  * atomic_add_char(P, V)        (*(u_char*)(P) += (V))
  39  * atomic_subtract_char(P, V)   (*(u_char*)(P) -= (V))
  40  *
  41  * atomic_set_short(P, V)       (*(u_short*)(P) |= (V))
  42  * atomic_clear_short(P, V)     (*(u_short*)(P) &= ~(V))
  43  * atomic_add_short(P, V)       (*(u_short*)(P) += (V))
  44  * atomic_subtract_short(P, V)  (*(u_short*)(P) -= (V))
  45  *
  46  * atomic_set_int(P, V)         (*(u_int*)(P) |= (V))
  47  * atomic_clear_int(P, V)       (*(u_int*)(P) &= ~(V))
  48  * atomic_add_int(P, V)         (*(u_int*)(P) += (V))
  49  * atomic_subtract_int(P, V)    (*(u_int*)(P) -= (V))
  50  *
  51  * atomic_set_long(P, V)        (*(u_long*)(P) |= (V))
  52  * atomic_clear_long(P, V)      (*(u_long*)(P) &= ~(V))
  53  * atomic_add_long(P, V)        (*(u_long*)(P) += (V))
  54  * atomic_subtract_long(P, V)   (*(u_long*)(P) -= (V))
  55  */
  56
  57 /*
  58  * The above functions are expanded inline in the statically-linked
  59  * kernel.  Lock prefixes are generated if an SMP kernel is being
  60  * built.
  61  *
  62  * Kernel modules call real functions which are built into the kernel.
  63  * This allows kernel modules to be portable between UP and SMP systems.
  64  */
  65 #if defined(KLD_MODULE)
  66 #define ATOMIC_ASM(NAME, TYPE, OP, V)                   \
  67         extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v);
  68
  69 #else /* !KLD_MODULE */
  70 #if defined(SMP)
  71 #define MPLOCKED        "lock ; "
  72 #else
  73 #define MPLOCKED
  74 #endif
  75
  76 /*
  77  * The assembly is volatilized to demark potential before-and-after side
  78  * effects if an interrupt or SMP collision were to occur.  The primary
  79  * atomic instructions are MP safe, the nonlocked instructions are
  80  * local-interrupt-safe (so we don't depend on C 'X |= Y' generating an
  81  * atomic instruction).
  82  */
  83 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 9)
  84
  85 /* egcs 1.1.2+ version */
  86 #define ATOMIC_ASM(NAME, TYPE, OP, V)                   \
  87 static __inline void                                    \
  88 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
  89 {                                                       \
  90         __asm __volatile(MPLOCKED OP                    \
  91                          : "=m" (*p)                    \
  92                          :  "0" (*p), "ir" (V));        \
  93 }                                                       \
  94 static __inline void                                    \
  95 atomic_##NAME##_##TYPE##_nonlocked(volatile u_##TYPE *p, u_##TYPE v)\
  96 {                                                       \
  97         __asm __volatile(MPLOCKED OP                    \
  98                          : "=m" (*p)                    \
  99                          :  "0" (*p), "ir" (V));        \
 100 }
 101
 102 #else
 103
 104 /* gcc <= 2.8 version */
 105 #define ATOMIC_ASM(NAME, TYPE, OP, V)                   \
 106 static __inline void                                    \
 107 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 108 {                                                       \
 109         __asm __volatile(MPLOCKED OP                    \
 110                          : "=m" (*p)                    \
 111                          : "ir" (V));                   \
 112 }                                                       \
 113 static __inline void                                    \
 114 atomic_##NAME##_##TYPE##_nonlocked(volatile u_##TYPE *p, u_##TYPE v)\
 115 {                                                       \
 116         __asm __volatile(OP                             \
 117                          : "=m" (*p)                    \
 118                          : "ir" (V));                   \
 119 }
 120 #endif
 121 #endif /* KLD_MODULE */
 122
 123 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 9)
 124
 125 /* egcs 1.1.2+ version */
 126 ATOMIC_ASM(set,      char,  "orb %b2,%0",   v)
 127 ATOMIC_ASM(clear,    char,  "andb %b2,%0", ~v)
 128 ATOMIC_ASM(add,      char,  "addb %b2,%0",  v)
 129 ATOMIC_ASM(subtract, char,  "subb %b2,%0",  v)
 130
 131 ATOMIC_ASM(set,      short, "orw %w2,%0",   v)
 132 ATOMIC_ASM(clear,    short, "andw %w2,%0", ~v)
 133 ATOMIC_ASM(add,      short, "addw %w2,%0",  v)
 134 ATOMIC_ASM(subtract, short, "subw %w2,%0",  v)
 135
 136 ATOMIC_ASM(set,      int,   "orl %2,%0",   v)
 137 ATOMIC_ASM(clear,    int,   "andl %2,%0", ~v)
 138 ATOMIC_ASM(add,      int,   "addl %2,%0",  v)
 139 ATOMIC_ASM(subtract, int,   "subl %2,%0",  v)
 140
 141 ATOMIC_ASM(set,      long,  "orl %2,%0",   v)
 142 ATOMIC_ASM(clear,    long,  "andl %2,%0", ~v)
 143 ATOMIC_ASM(add,      long,  "addl %2,%0",  v)
 144 ATOMIC_ASM(subtract, long,  "subl %2,%0",  v)
 145
 146 #else
 147
 148 /* gcc <= 2.8 version */
 149 ATOMIC_ASM(set,      char,  "orb %1,%0",   v)
 150 ATOMIC_ASM(clear,    char,  "andb %1,%0", ~v)
 151 ATOMIC_ASM(add,      char,  "addb %1,%0",  v)
 152 ATOMIC_ASM(subtract, char,  "subb %1,%0",  v)
 153
 154 ATOMIC_ASM(set,      short, "orw %1,%0",   v)
 155 ATOMIC_ASM(clear,    short, "andw %1,%0", ~v)
 156 ATOMIC_ASM(add,      short, "addw %1,%0",  v)
 157 ATOMIC_ASM(subtract, short, "subw %1,%0",  v)
 158
 159 ATOMIC_ASM(set,      int,   "orl %1,%0",   v)
 160 ATOMIC_ASM(clear,    int,   "andl %1,%0", ~v)
 161 ATOMIC_ASM(add,      int,   "addl %1,%0",  v)
 162 ATOMIC_ASM(subtract, int,   "subl %1,%0",  v)
 163
 164 ATOMIC_ASM(set,      long,  "orl %1,%0",   v)
 165 ATOMIC_ASM(clear,    long,  "andl %1,%0", ~v)
 166 ATOMIC_ASM(add,      long,  "addl %1,%0",  v)
 167 ATOMIC_ASM(subtract, long,  "subl %1,%0",  v)
 168
 169 #endif
 170
 171 #endif /* ! _MACHINE_ATOMIC_H_ */