LXR linux/arch/x86/lib/atomic64_386

   1/*
   2 * atomic64_t for 386/486
   3 *
   4 * Copyright © 2010  Luca Barbieri
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 */
  11
  12#include <linux/linkage.h>
  13#include <asm/alternative-asm.h>
  14
  15/* if you want SMP support, implement these with real spinlocks */
  16.macro LOCK reg
  17        pushfl
  18        cli
  19.endm
  20
  21.macro UNLOCK reg
  22        popfl
  23.endm
  24
  25#define BEGIN(op) \
  26.macro endp; \
  27ENDPROC(atomic64_##op##_386); \
  28.purgem endp; \
  29.endm; \
  30ENTRY(atomic64_##op##_386); \
  31        LOCK v;
  32
  33#define ENDP endp
  34
  35#define RET \
  36        UNLOCK v; \
  37        ret
  38
  39#define RET_ENDP \
  40        RET; \
  41        ENDP
  42
  43#define v %ecx
  44BEGIN(read)
  45        movl  (v), %eax
  46        movl 4(v), %edx
  47RET_ENDP
  48#undef v
  49
  50#define v %esi
  51BEGIN(set)
  52        movl %ebx,  (v)
  53        movl %ecx, 4(v)
  54RET_ENDP
  55#undef v
  56
  57#define v  %esi
  58BEGIN(xchg)
  59        movl  (v), %eax
  60        movl 4(v), %edx
  61        movl %ebx,  (v)
  62        movl %ecx, 4(v)
  63RET_ENDP
  64#undef v
  65
  66#define v %ecx
  67BEGIN(add)
  68        addl %eax,  (v)
  69        adcl %edx, 4(v)
  70RET_ENDP
  71#undef v
  72
  73#define v %ecx
  74BEGIN(add_return)
  75        addl  (v), %eax
  76        adcl 4(v), %edx
  77        movl %eax,  (v)
  78        movl %edx, 4(v)
  79RET_ENDP
  80#undef v
  81
  82#define v %ecx
  83BEGIN(sub)
  84        subl %eax,  (v)
  85        sbbl %edx, 4(v)
  86RET_ENDP
  87#undef v
  88
  89#define v %ecx
  90BEGIN(sub_return)
  91        negl %edx
  92        negl %eax
  93        sbbl $0, %edx
  94        addl  (v), %eax
  95        adcl 4(v), %edx
  96        movl %eax,  (v)
  97        movl %edx, 4(v)
  98RET_ENDP
  99#undef v
 100
 101#define v %esi
 102BEGIN(inc)
 103        addl $1,  (v)
 104        adcl $0, 4(v)
 105RET_ENDP
 106#undef v
 107
 108#define v %esi
 109BEGIN(inc_return)
 110        movl  (v), %eax
 111        movl 4(v), %edx
 112        addl $1, %eax
 113        adcl $0, %edx
 114        movl %eax,  (v)
 115        movl %edx, 4(v)
 116RET_ENDP
 117#undef v
 118
 119#define v %esi
 120BEGIN(dec)
 121        subl $1,  (v)
 122        sbbl $0, 4(v)
 123RET_ENDP
 124#undef v
 125
 126#define v %esi
 127BEGIN(dec_return)
 128        movl  (v), %eax
 129        movl 4(v), %edx
 130        subl $1, %eax
 131        sbbl $0, %edx
 132        movl %eax,  (v)
 133        movl %edx, 4(v)
 134RET_ENDP
 135#undef v
 136
 137#define v %esi
 138BEGIN(add_unless)
 139        addl %eax, %ecx
 140        adcl %edx, %edi
 141        addl  (v), %eax
 142        adcl 4(v), %edx
 143        cmpl %eax, %ecx
 144        je 3f
 1451:
 146        movl %eax,  (v)
 147        movl %edx, 4(v)
 148        movl $1, %eax
 1492:
 150        RET
 1513:
 152        cmpl %edx, %edi
 153        jne 1b
 154        xorl %eax, %eax
 155        jmp 2b
 156ENDP
 157#undef v
 158
 159#define v %esi
 160BEGIN(inc_not_zero)
 161        movl  (v), %eax
 162        movl 4(v), %edx
 163        testl %eax, %eax
 164        je 3f
 1651:
 166        addl $1, %eax
 167        adcl $0, %edx
 168        movl %eax,  (v)
 169        movl %edx, 4(v)
 170        movl $1, %eax
 1712:
 172        RET
 1733:
 174        testl %edx, %edx
 175        jne 1b
 176        jmp 2b
 177ENDP
 178#undef v
 179
 180#define v %esi
 181BEGIN(dec_if_positive)
 182        movl  (v), %eax
 183        movl 4(v), %edx
 184        subl $1, %eax
 185        sbbl $0, %edx
 186        js 1f
 187        movl %eax,  (v)
 188        movl %edx, 4(v)
 1891:
 190RET_ENDP
 191#undef v
 192