cmpxchg8b_emu.S
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/* 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)