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 #define dma_rmb() barrier() 27 #define dma_wmb() barrier() 28 29 #include <asm-generic/barrier.h> 30 31 #endif 32