From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753405Ab2LDJh1 (ORCPT ); Tue, 4 Dec 2012 04:37:27 -0500 Received: from eu1sys200aog116.obsmtp.com ([207.126.144.141]:57336 "EHLO eu1sys200aog116.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751880Ab2LDJhZ (ORCPT ); Tue, 4 Dec 2012 04:37:25 -0500 Message-ID: <50BDC437.1050701@st.com> Date: Tue, 4 Dec 2012 10:36:55 +0100 From: Armando Visconti User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.24) Gecko/20111108 Fedora/3.1.16-1.fc14 Lightning/1.0b3pre Thunderbird/3.1.16 MIME-Version: 1.0 To: Will Deacon , Russell King - ARM Linux Cc: "kgene.kim@samsung.com" , "swarren@nvidia.com" , "nico@linaro.org" , spear-devel , "linux-kernel@vger.kernel.org" , "hsweeten@visionengravers.com" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] nommu: Enable the strict alignment (CR_A) bit only if ARCH < v6 References: <1354187042-28568-1-git-send-email-armando.visconti@st.com> <50BCD6DB.2030200@st.com> <20121203172553.GC14363@n2100.arm.linux.org.uk> <20121203174617.GL20074@mudshark.cambridge.arm.com> In-Reply-To: <20121203174617.GL20074@mudshark.cambridge.arm.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/03/2012 06:46 PM, Will Deacon wrote: > On Mon, Dec 03, 2012 at 05:25:53PM +0000, Russell King - ARM Linux wrote: >> On Mon, Dec 03, 2012 at 05:44:11PM +0100, Armando Visconti wrote: >>> On 11/29/2012 12:04 PM, Armando VISCONTI wrote: >>>> This patch keeps disabled the strict alignment CP15 bit for >>>> all armv6 and armv7 processor without the mmu. This behaviour >>>> is now same as in the mmu case. >>>> >>>> Signed-off-by: Armando Visconti >>>> --- >>>> arch/arm/kernel/head-nommu.S | 2 +- >>>> 1 files changed, 1 insertions(+), 1 deletions(-) >>>> >>>> diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S >>>> index 278cfc1..2c228a0 100644 >>>> --- a/arch/arm/kernel/head-nommu.S >>>> +++ b/arch/arm/kernel/head-nommu.S >>>> @@ -68,7 +68,7 @@ __after_proc_init: >>>> * CP15 system control register value returned in r0 from >>>> * the CPU init function. >>>> */ >>>> -#ifdef CONFIG_ALIGNMENT_TRAP >>>> +#if defined(CONFIG_ALIGNMENT_TRAP)&& __LINUX_ARM_ARCH__< 6 >>>> orr r0, r0, #CR_A >>>> #else >>>> bic r0, r0, #CR_A >>> >>> Any feedback on this simple patch? >> >> Well, it brings the nommu version into line with the mmu version, so >> it's sensible. Please put it in the patch system, thanks. > Done! > In which case, I'll definitely dust-off the patches to prevent unaligned > accesses to strongly-ordered memory because that results in good ol' > UNPREDICTABLE behaviour. > Yes, we definetely need them. Thx, Arm