From b416c9a10baae6a177b4f9ee858b8d309542fbef Mon Sep 17 00:00:00 2001 From: Tiejun Chen Date: Wed, 11 Jul 2012 14:22:46 +1000 Subject: [PATCH] powerpc: Add "memory" attribute for mfmsr() Add "memory" attribute in inline assembly language as a compiler barrier to make sure 4.6.x GCC don't reorder mfmsr(). Signed-off-by: Tiejun Chen Signed-off-by: Benjamin Herrenschmidt CC: stable@vger.kernel.org --- arch/powerpc/include/asm/reg.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 2baeb7c..6386086 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1025,7 +1025,8 @@ /* Macros for setting and retrieving special purpose registers */ #ifndef __ASSEMBLY__ #define mfmsr() ({unsigned long rval; \ - asm volatile("mfmsr %0" : "=r" (rval)); rval;}) + asm volatile("mfmsr %0" : "=r" (rval) : \ + : "memory"); rval;}) #ifdef CONFIG_PPC_BOOK3S_64 #define __mtmsrd(v, l) asm volatile("mtmsrd %0," __stringify(l) \ : : "r" (v) : "memory") -- 2.7.4