root/tools/arch/alpha/include/asm/barrier.h 
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __TOOLS_LINUX_ASM_ALPHA_BARRIER_H
#define __TOOLS_LINUX_ASM_ALPHA_BARRIER_H

#define mb()    __asm__ __volatile__("mb": : :"memory")
#define rmb()   __asm__ __volatile__("mb": : :"memory")
#define wmb()   __asm__ __volatile__("wmb": : :"memory")

#endif          /* __TOOLS_LINUX_ASM_ALPHA_BARRIER_H */