1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _ASM_UM_BARRIER_H_
 3#define _ASM_UM_BARRIER_H_
 4
 5#include <asm/alternative.h>
 6
 7/*
 8 * Force strict CPU ordering.
 9 * And yes, this is required on UP too when we're talking
10 * to devices.
11 */
12#ifdef CONFIG_X86_32
13
14#define mb()	alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
15#define rmb()	alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
16#define wmb()	alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
17
18#else /* CONFIG_X86_32 */
19
20#define mb()	asm volatile("mfence" : : : "memory")
21#define rmb()	asm volatile("lfence" : : : "memory")
22#define wmb()	asm volatile("sfence" : : : "memory")
23
24#endif /* CONFIG_X86_32 */
25
26#include <asm-generic/barrier.h>
27
28#endif