1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_UM_BARRIER_H_
3 #define _ASM_UM_BARRIER_H_
5 #include <asm/cpufeatures.h>
6 #include <asm/alternative.h>
9 * Force strict CPU ordering.
10 * And yes, this is required on UP too when we're talking
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)
19 #else /* CONFIG_X86_32 */
21 #define mb() asm volatile("mfence" : : : "memory")
22 #define rmb() asm volatile("lfence" : : : "memory")
23 #define wmb() asm volatile("sfence" : : : "memory")
25 #endif /* CONFIG_X86_32 */
27 #include <asm-generic/barrier.h>