From: Tiejun Chen <tiejun.chen@windriver.com>
To: <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 1/1] powerpc: add "memory" attribute for mfmsr()
Date: Tue, 10 Jul 2012 15:59:13 +0800 [thread overview]
Message-ID: <1341907153-20516-1-git-send-email-tiejun.chen@windriver.com> (raw)
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 <tiejun.chen@windriver.com>
---
arch/powerpc/include/asm/reg.h | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 559da19..578e5a0 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1016,7 +1016,8 @@
/* 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")
--
1.5.6
next reply other threads:[~2012-07-10 8:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-10 7:59 Tiejun Chen [this message]
2012-07-10 8:19 ` [PATCH 1/1] powerpc: add "memory" attribute for mfmsr() Benjamin Herrenschmidt
2012-07-10 8:22 ` tiejun.chen
2012-07-10 8:27 ` tiejun.chen
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