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#include <asm/dwarf2.h>
  15
  16/* if you want SMP support, implement these with real spinlocks */
  17.macro LOCK reg
  18        pushfl_cfi
  19        cli
  20.endm
  21
  22.macro UNLOCK reg
  23        popfl_cfi
  24.endm
  25
  26#define BEGIN(op) \
  27.macro endp; \
  28        CFI_ENDPROC; \
  29ENDPROC(atomic64_##op##_386); \
  30.purgem endp; \
  31.endm; \
  32ENTRY(atomic64_##op##_386); \
  33        CFI_STARTPROC; \
  34        LOCK v;
  35
  36#define ENDP endp
  37
  38#define RET \
  39        UNLOCK v; \
  40        ret
  41
  42#define RET_ENDP \
  43        RET; \
  44        ENDP
  45
  46#define v %ecx
  47BEGIN(read)
  48        movl  (v), %eax
  49        movl 4(v), %edx
  50RET_ENDP
  51#undef v
  52
  53#define v %esi
  54BEGIN(set)
  55        movl %ebx,  (v)
  56        movl %ecx, 4(v)
  57RET_ENDP
  58#undef v
  59
  60#define v  %esi
  61BEGIN(xchg)
  62        movl  (v), %eax
  63        movl 4(v), %edx
  64        movl %ebx,  (v)
  65        movl %ecx, 4(v)
  66RET_ENDP
  67#undef v
  68
  69#define v %ecx
  70BEGIN(add)
  71        addl %eax,  (v)
  72        adcl %edx, 4(v)
  73RET_ENDP
  74#undef v
  75
  76#define v %ecx
  77BEGIN(add_return)
  78        addl  (v), %eax
  79        adcl 4(v), %edx
  80        movl %eax,  (v)
  81        movl %edx, 4(v)
  82RET_ENDP
  83#undef v
  84
  85#define v %ecx
  86BEGIN(sub)
  87        subl %eax,  (v)
  88        sbbl %edx, 4(v)
  89RET_ENDP
  90#undef v
  91
  92#define v %ecx
  93BEGIN(sub_return)
  94        negl %edx
  95        negl %eax
  96        sbbl $0, %edx
  97        addl  (v), %eax
  98        adcl 4(v), %edx
  99        movl %eax,  (v)
 100        movl %edx, 4(v)
 101RET_ENDP
 102#undef v
 103
 104#define v %esi
 105BEGIN(inc)
 106        addl $1,  (v)
 107        adcl $0, 4(v)
 108RET_ENDP
 109#undef v
 110
 111#define v %esi
 112BEGIN(inc_return)
 113        movl  (v), %eax
 114        movl 4(v), %edx
 115        addl $1, %eax
 116        adcl $0, %edx
 117        movl %eax,  (v)
 118        movl %edx, 4(v)
 119RET_ENDP
 120#undef v
 121
 122#define v %esi
 123BEGIN(dec)
 124        subl $1,  (v)
 125        sbbl $0, 4(v)
 126RET_ENDP
 127#undef v
 128
 129#define v %esi
 130BEGIN(dec_return)
 131        movl  (v), %eax
 132        movl 4(v), %edx
 133        subl $1, %eax
 134        sbbl $0, %edx
 135        movl %eax,  (v)
 136        movl %edx, 4(v)
 137RET_ENDP
 138#undef v
 139
 140#define v %esi
 141BEGIN(add_unless)
 142        addl %eax, %ecx
 143        adcl %edx, %edi
 144        addl  (v), %eax
 145        adcl 4(v), %edx
 146        cmpl %eax, %ecx
 147        je 3f
 1481:
 149        movl %eax,  (v)
 150        movl %edx, 4(v)
 151        movl $1, %eax
 1522:
 153        RET
 1543:
 155        cmpl %edx, %edi
 156        jne 1b
 157        xorl %eax, %eax
 158        jmp 2b
 159ENDP
 160#undef v
 161
 162#define v %esi
 163BEGIN(inc_not_zero)
 164        movl  (v), %eax
 165        movl 4(v), %edx
 166        testl %eax, %eax
 167        je 3f
 1681:
 169        addl $1, %eax
 170        adcl $0, %edx
 171        movl %eax,  (v)
 172        movl %edx, 4(v)
 173        movl $1, %eax
 1742:
 175        RET
 1763:
 177        testl %edx, %edx
 178        jne 1b
 179        jmp 2b
 180ENDP
 181#undef v
 182
 183#define v %esi
 184BEGIN(dec_if_positive)
 185        movl  (v), %eax
 186        movl 4(v), %edx
 187        subl $1, %eax
 188        sbbl $0, %edx
 189        js 1f
 190        movl %eax,  (v)
 191        movl %edx, 4(v)
 1921:
 193RET_ENDP
 194#undef v
 195