linux-sg2042/arch/x86/um/asm/barrier.h

42 lines
1.0 KiB
C

#ifndef _ASM_UM_BARRIER_H_
#define _ASM_UM_BARRIER_H_
#include <asm/asm.h>
#include <asm/segment.h>
#include <asm/cpufeatures.h>
#include <asm/cmpxchg.h>
#include <asm/nops.h>
#include <linux/kernel.h>
#include <linux/irqflags.h>
/*
* Force strict CPU ordering.
* And yes, this is required on UP too when we're talking
* to devices.
*/
#ifdef CONFIG_X86_32
#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
#else /* CONFIG_X86_32 */
#define mb() asm volatile("mfence" : : : "memory")
#define rmb() asm volatile("lfence" : : : "memory")
#define wmb() asm volatile("sfence" : : : "memory")
#endif /* CONFIG_X86_32 */
#ifdef CONFIG_X86_PPRO_FENCE
#define dma_rmb() rmb()
#else /* CONFIG_X86_PPRO_FENCE */
#define dma_rmb() barrier()
#endif /* CONFIG_X86_PPRO_FENCE */
#define dma_wmb() barrier()
#include <asm-generic/barrier.h>
#endif