From patchwork Tue Jul 10 07:59:13 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiejun Chen X-Patchwork-Id: 170075 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 300692C03A8 for ; Tue, 10 Jul 2012 18:03:33 +1000 (EST) Received: from mail.windriver.com (mail.windriver.com [147.11.1.11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.windriver.com", Issuer "Intel External Basic Issuing CA 3A" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 108AE2C007E for ; Tue, 10 Jul 2012 18:02:55 +1000 (EST) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca [147.11.189.40]) by mail.windriver.com (8.14.3/8.14.3) with ESMTP id q6A82pwi002983 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Tue, 10 Jul 2012 01:02:51 -0700 (PDT) Received: from localhost.localdomain (128.224.162.71) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server id 14.1.255.0; Tue, 10 Jul 2012 01:02:50 -0700 From: Tiejun Chen To: Subject: [PATCH 1/1] powerpc: add "memory" attribute for mfmsr() Date: Tue, 10 Jul 2012 15:59:13 +0800 Message-ID: <1341907153-20516-1-git-send-email-tiejun.chen@windriver.com> X-Mailer: git-send-email 1.5.6 MIME-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 --- 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")