root/arch/x86/lib/atomic64_386_32.S

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * atomic64_t for 386/486
   4  *
   5  * Copyright © 2010  Luca Barbieri
   6  */
   7 
   8 #include <linux/linkage.h>
   9 #include <asm/alternative-asm.h>
  10 
  11 /* if you want SMP support, implement these with real spinlocks */
  12 .macro LOCK reg
  13         pushfl
  14         cli
  15 .endm
  16 
  17 .macro UNLOCK reg
  18         popfl
  19 .endm
  20 
  21 #define BEGIN(op) \
  22 .macro endp; \
  23 ENDPROC(atomic64_##op##_386); \
  24 .purgem endp; \
  25 .endm; \
  26 ENTRY(atomic64_##op##_386); \
  27         LOCK v;
  28 
  29 #define ENDP endp
  30 
  31 #define RET \
  32         UNLOCK v; \
  33         ret
  34 
  35 #define RET_ENDP \
  36         RET; \
  37         ENDP
  38 
  39 #define v %ecx
  40 BEGIN(read)
  41         movl  (v), %eax
  42         movl 4(v), %edx
  43 RET_ENDP
  44 #undef v
  45 
  46 #define v %esi
  47 BEGIN(set)
  48         movl %ebx,  (v)
  49         movl %ecx, 4(v)
  50 RET_ENDP
  51 #undef v
  52 
  53 #define v  %esi
  54 BEGIN(xchg)
  55         movl  (v), %eax
  56         movl 4(v), %edx
  57         movl %ebx,  (v)
  58         movl %ecx, 4(v)
  59 RET_ENDP
  60 #undef v
  61 
  62 #define v %ecx
  63 BEGIN(add)
  64         addl %eax,  (v)
  65         adcl %edx, 4(v)
  66 RET_ENDP
  67 #undef v
  68 
  69 #define v %ecx
  70 BEGIN(add_return)
  71         addl  (v), %eax
  72         adcl 4(v), %edx
  73         movl %eax,  (v)
  74         movl %edx, 4(v)
  75 RET_ENDP
  76 #undef v
  77 
  78 #define v %ecx
  79 BEGIN(sub)
  80         subl %eax,  (v)
  81         sbbl %edx, 4(v)
  82 RET_ENDP
  83 #undef v
  84 
  85 #define v %ecx
  86 BEGIN(sub_return)
  87         negl %edx
  88         negl %eax
  89         sbbl $0, %edx
  90         addl  (v), %eax
  91         adcl 4(v), %edx
  92         movl %eax,  (v)
  93         movl %edx, 4(v)
  94 RET_ENDP
  95 #undef v
  96 
  97 #define v %esi
  98 BEGIN(inc)
  99         addl $1,  (v)
 100         adcl $0, 4(v)
 101 RET_ENDP
 102 #undef v
 103 
 104 #define v %esi
 105 BEGIN(inc_return)
 106         movl  (v), %eax
 107         movl 4(v), %edx
 108         addl $1, %eax
 109         adcl $0, %edx
 110         movl %eax,  (v)
 111         movl %edx, 4(v)
 112 RET_ENDP
 113 #undef v
 114 
 115 #define v %esi
 116 BEGIN(dec)
 117         subl $1,  (v)
 118         sbbl $0, 4(v)
 119 RET_ENDP
 120 #undef v
 121 
 122 #define v %esi
 123 BEGIN(dec_return)
 124         movl  (v), %eax
 125         movl 4(v), %edx
 126         subl $1, %eax
 127         sbbl $0, %edx
 128         movl %eax,  (v)
 129         movl %edx, 4(v)
 130 RET_ENDP
 131 #undef v
 132 
 133 #define v %esi
 134 BEGIN(add_unless)
 135         addl %eax, %ecx
 136         adcl %edx, %edi
 137         addl  (v), %eax
 138         adcl 4(v), %edx
 139         cmpl %eax, %ecx
 140         je 3f
 141 1:
 142         movl %eax,  (v)
 143         movl %edx, 4(v)
 144         movl $1, %eax
 145 2:
 146         RET
 147 3:
 148         cmpl %edx, %edi
 149         jne 1b
 150         xorl %eax, %eax
 151         jmp 2b
 152 ENDP
 153 #undef v
 154 
 155 #define v %esi
 156 BEGIN(inc_not_zero)
 157         movl  (v), %eax
 158         movl 4(v), %edx
 159         testl %eax, %eax
 160         je 3f
 161 1:
 162         addl $1, %eax
 163         adcl $0, %edx
 164         movl %eax,  (v)
 165         movl %edx, 4(v)
 166         movl $1, %eax
 167 2:
 168         RET
 169 3:
 170         testl %edx, %edx
 171         jne 1b
 172         jmp 2b
 173 ENDP
 174 #undef v
 175 
 176 #define v %esi
 177 BEGIN(dec_if_positive)
 178         movl  (v), %eax
 179         movl 4(v), %edx
 180         subl $1, %eax
 181         sbbl $0, %edx
 182         js 1f
 183         movl %eax,  (v)
 184         movl %edx, 4(v)
 185 1:
 186 RET_ENDP
 187 #undef v