1/* SPDX-License-Identifier: GPL-2.0-only */ 2 3#include <linux/linkage.h> 4#include <asm/export.h> 5 6.text 7 8/* 9 * Inputs: 10 * %esi : memory location to compare 11 * %eax : low 32 bits of old value 12 * %edx : high 32 bits of old value 13 * %ebx : low 32 bits of new value 14 * %ecx : high 32 bits of new value 15 */ 16SYM_FUNC_START(cmpxchg8b_emu) 17 18# 19# Emulate 'cmpxchg8b (%esi)' on UP except we don't 20# set the whole ZF thing (caller will just compare 21# eax:edx with the expected value) 22# 23 pushfl 24 cli 25 26 cmpl (%esi), %eax 27 jne .Lnot_same 28 cmpl 4(%esi), %edx 29 jne .Lhalf_same 30 31 movl %ebx, (%esi) 32 movl %ecx, 4(%esi) 33 34 popfl 35 ret 36 37.Lnot_same: 38 movl (%esi), %eax 39.Lhalf_same: 40 movl 4(%esi), %edx 41 42 popfl 43 ret 44 45SYM_FUNC_END(cmpxchg8b_emu) 46EXPORT_SYMBOL(cmpxchg8b_emu) 47