/* SPDX-License-Identifier: GPL-2.0-only */ | |
#include <linux/linkage.h> | |
#include <asm/export.h> | |
.text | |
/* | |
* Inputs: | |
* %esi : memory location to compare | |
* %eax : low 32 bits of old value | |
* %edx : high 32 bits of old value | |
* %ebx : low 32 bits of new value | |
* %ecx : high 32 bits of new value | |
*/ | |
SYM_FUNC_START(cmpxchg8b_emu) | |
# | |
# Emulate 'cmpxchg8b (%esi)' on UP except we don't | |
# set the whole ZF thing (caller will just compare | |
# eax:edx with the expected value) | |
# | |
pushfl | |
cli | |
cmpl (%esi), %eax | |
jne .Lnot_same | |
cmpl 4(%esi), %edx | |
jne .Lhalf_same | |
movl %ebx, (%esi) | |
movl %ecx, 4(%esi) | |
popfl | |
ret | |
.Lnot_same: | |
movl (%esi), %eax | |
.Lhalf_same: | |
movl 4(%esi), %edx | |
popfl | |
ret | |
SYM_FUNC_END(cmpxchg8b_emu) | |
EXPORT_SYMBOL(cmpxchg8b_emu) |