1 #ifndef _ASM_UM_BARRIER_H_
2 #define _ASM_UM_BARRIER_H_
5 #include <asm/segment.h>
6 #include <asm/cpufeatures.h>
7 #include <asm/cmpxchg.h>
10 #include <linux/kernel.h>
11 #include <linux/irqflags.h>
14 * Force strict CPU ordering.
15 * And yes, this is required on UP too when we're talking
20 #define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
21 #define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
22 #define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
24 #else /* CONFIG_X86_32 */
26 #define mb() asm volatile("mfence" : : : "memory")
27 #define rmb() asm volatile("lfence" : : : "memory")
28 #define wmb() asm volatile("sfence" : : : "memory")
30 #endif /* CONFIG_X86_32 */
32 #ifdef CONFIG_X86_PPRO_FENCE
33 #define dma_rmb() rmb()
34 #else /* CONFIG_X86_PPRO_FENCE */
35 #define dma_rmb() barrier()
36 #endif /* CONFIG_X86_PPRO_FENCE */
37 #define dma_wmb() barrier()
39 #include <asm-generic/barrier.h>