x86 maps mmiowb() to barrier(), but this is superfluous because a compiler barrier is already implied by spin_unlock(). Since x86 also includes asm-generic/io.h in its asm/io.h file, we can remove the definition entirely and pick up the dummy definition from core code. Signed-off-by: Will Deacon <will.deacon@xxxxxxx> --- arch/x86/include/asm/io.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 686247db3106..a06a9f8294ea 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -90,8 +90,6 @@ build_mmio_write(__writel, "l", unsigned int, "r", ) #define __raw_writew __writew #define __raw_writel __writel -#define mmiowb() barrier() - #ifdef CONFIG_X86_64 build_mmio_read(readq, "q", u64, "=r", :"memory") -- 2.11.0