arch/x86/lib/atomic64_386_32.S

   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; \
  27 ENDPROC(atomic64_##op##_386); \
  28 .purgem endp; \
  29 .endm; \
  30 ENTRY(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
  44 BEGIN(read)
  45         movl  (v), %eax
  46         movl 4(v), %edx
  47 RET_ENDP
  48 #undef v
  49
  50 #define v %esi
  51 BEGIN(set)
  52         movl %ebx,  (v)
  53         movl %ecx, 4(v)
  54 RET_ENDP
  55 #undef v
  56
  57 #define v  %esi
  58 BEGIN(xchg)
  59         movl  (v), %eax
  60         movl 4(v), %edx
  61         movl %ebx,  (v)
  62         movl %ecx, 4(v)
  63 RET_ENDP
  64 #undef v
  65
  66 #define v %ecx
  67 BEGIN(add)
  68         addl %eax,  (v)
  69         adcl %edx, 4(v)
  70 RET_ENDP
  71 #undef v
  72
  73 #define v %ecx
  74 BEGIN(add_return)
  75         addl  (v), %eax
  76         adcl 4(v), %edx
  77         movl %eax,  (v)
  78         movl %edx, 4(v)
  79 RET_ENDP
  80 #undef v
  81
  82 #define v %ecx
  83 BEGIN(sub)
  84         subl %eax,  (v)
  85         sbbl %edx, 4(v)
  86 RET_ENDP
  87 #undef v
  88
  89 #define v %ecx
  90 BEGIN(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)
  98 RET_ENDP
  99 #undef v
 100
 101 #define v %esi
 102 BEGIN(inc)
 103         addl $1,  (v)
 104         adcl $0, 4(v)
 105 RET_ENDP
 106 #undef v
 107
 108 #define v %esi
 109 BEGIN(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)
 116 RET_ENDP
 117 #undef v
 118
 119 #define v %esi
 120 BEGIN(dec)
 121         subl $1,  (v)
 122         sbbl $0, 4(v)
 123 RET_ENDP
 124 #undef v
 125
 126 #define v %esi
 127 BEGIN(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)
 134 RET_ENDP
 135 #undef v
 136
 137 #define v %esi
 138 BEGIN(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
 145 1:
 146         movl %eax,  (v)
 147         movl %edx, 4(v)
 148         movl $1, %eax
 149 2:
 150         RET
 151 3:
 152         cmpl %edx, %edi
 153         jne 1b
 154         xorl %eax, %eax
 155         jmp 2b
 156 ENDP
 157 #undef v
 158
 159 #define v %esi
 160 BEGIN(inc_not_zero)
 161         movl  (v), %eax
 162         movl 4(v), %edx
 163         testl %eax, %eax
 164         je 3f
 165 1:
 166         addl $1, %eax
 167         adcl $0, %edx
 168         movl %eax,  (v)
 169         movl %edx, 4(v)
 170         movl $1, %eax
 171 2:
 172         RET
 173 3:
 174         testl %edx, %edx
 175         jne 1b
 176         jmp 2b
 177 ENDP
 178 #undef v
 179
 180 #define v %esi
 181 BEGIN(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)
 189 1:
 190 RET_ENDP
 191 #undef v