1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _ASM_UM_BARRIER_H_ 3#define _ASM_UM_BARRIER_H_ 4 5#include <asm/cpufeatures.h> 6#include <asm/alternative.h> 7 8/* 9 * Force strict CPU ordering. 10 * And yes, this is required on UP too when we're talking 11 * to devices. 12 */ 13#ifdef CONFIG_X86_32 14 15#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) 16#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) 17#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) 18 19#else /* CONFIG_X86_32 */ 20 21#define mb() asm volatile("mfence" : : : "memory") 22#define rmb() asm volatile("lfence" : : : "memory") 23#define wmb() asm volatile("sfence" : : : "memory") 24 25#endif /* CONFIG_X86_32 */ 26 27#include <asm-generic/barrier.h> 28 29#endif 30