/*
* atomic64_t for 386/486
*
* Copyright © 2010 Luca Barbieri
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/linkage.h>
#include <asm/alternative-asm.h>
#include <asm/dwarf2.h>
/* if you want SMP support, implement these with real spinlocks */
.macro LOCK reg
pushfl
CFI_ADJUST_CFA_OFFSET 4
cli
.endm
.macro UNLOCK reg
popfl
CFI_ADJUST_CFA_OFFSET -4
.endm
#define BEGIN(op) \
.macro endp; \
CFI_ENDPROC; \
ENDPROC(atomic64_##op##_386); \
.purgem endp; \
.endm; \
ENTRY(atomic64_##op##_386); \
CFI_STARTPROC; \
LOCK v;
#define ENDP endp
#define RET \
UNLOCK v; \
ret
#define RET_ENDP \
RET; \
ENDP
#define v %ecx
BEGIN(read)
movl (v), %eax
movl 4(v), %edx
RET_ENDP
#undef v
#define v %esi
BEGIN(set)
movl %ebx, (v)
movl %ecx, 4(v)
RET_ENDP
#undef v
#define v %esi
BEGIN(xchg)
movl (v), %eax
movl 4(v), %edx
movl %ebx, (v)
movl %ecx, 4(v)
RET_ENDP
#undef v
#define v %ecx
BEGIN(add)
addl %eax, (v)
adcl %edx, 4(v)
RET_ENDP
#undef v
#define v %ecx
BEGIN(add_return)
addl (v), %eax
adcl 4(v), %edx
movl %eax, (v)
movl %edx, 4(v)
RET_ENDP
#undef v
#define v %ecx
BEGIN(sub)
subl %eax, (v)
sbbl %edx, 4(v)
RET_ENDP
#undef v
#define v %ecx
BEGIN(sub_return)
negl %edx
negl %eax
sbbl $0, %edx
addl (v), %eax
adcl 4(v), %edx
movl %eax, (v)
movl %edx, 4(v)
RET_ENDP
#undef v
#define v %esi
BEGIN(inc)
addl $1, (v)
adcl $0, 4(v)
RET_ENDP
#undef v
#define v %esi
BEGIN(inc_return)
movl (v), %eax
movl 4(v), %edx
addl $1, %eax
adcl $0, %edx
movl %eax, (v)
movl %edx, 4(v)
RET_ENDP
#undef v
#define v %esi
BEGIN(dec)
subl $1, (v)
sbbl $0, 4(v)
RET_ENDP
#undef v
#define v %esi
BEGIN(dec_return)
movl (v), %eax
movl 4(v), %edx
subl $1, %eax
sbbl $0, %edx
movl %eax, (v)
movl %edx, 4(v)
RET_ENDP
#undef v
#define v %ecx
BEGIN(add_unless)
addl %eax, %esi
adcl %edx, %edi
addl (v), %eax
adcl 4(v), %edx
cmpl %eax, %esi
je 3f
1:
movl %eax, (v)
movl %edx, 4(v)
movl $1, %eax
2:
RET
3:
cmpl %edx, %edi
jne 1b
xorl %eax, %eax
jmp 2b
ENDP
#undef v
#define v %esi
BEGIN(inc_not_zero)
movl (v), %eax
movl 4(v), %edx
testl %eax, %eax
je 3f
1:
addl $1, %eax
adcl $0, %edx
movl %eax, (v)
movl %edx, 4(v)
movl $1, %eax
2:
RET
3:
testl %edx, %edx
jne 1b
jmp 2b
ENDP
#undef v
#define v %esi
BEGIN(dec_if_positive)
movl (v), %eax
movl 4(v), %edx
subl $1, %eax
sbbl $0, %edx
js 1f
movl %eax, (v)
movl %edx, 4(v)
1:
RET_ENDP
#undef v
