cmpxchg8b_emu.S
/*
* 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; version 2
* of the License.
*
*/
#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
*/
ENTRY(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
ENDPROC(cmpxchg8b_emu)
EXPORT_SYMBOL(cmpxchg8b_emu)