Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759002Ab3EWRya (ORCPT ); Thu, 23 May 2013 13:54:30 -0400 Received: from wolverine01.qualcomm.com ([199.106.114.254]:13036 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758057Ab3EWRy0 (ORCPT ); Thu, 23 May 2013 13:54:26 -0400 X-IronPort-AV: E=Sophos;i="4.87,729,1363158000"; d="scan'208";a="50058159" Message-ID: <519E57D2.3050000@codeaurora.org> Date: Thu, 23 May 2013 10:54:26 -0700 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Russell King CC: Brian Swetland , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM: avoid mis-detecting some V7 cores in the decompressor References: <1368049671-22879-1-git-send-email-sboyd@codeaurora.org> <5193E424.9090605@codeaurora.org> In-Reply-To: <5193E424.9090605@codeaurora.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2020 Lines: 60 On 05/15/13 12:38, Stephen Boyd wrote: > On 05/08/13 14:47, Stephen Boyd wrote: >> From: Brian Swetland >> >> Currently v7 CPUs with an MIDR that has no bits set in the range >> [16:12] will be detected as old ARM CPUs with no caches and so >> the cache will never be turned on during decompression. ARM's >> Cortex chips have an 0xC in the range [16:12] so they never match >> this entry, but Qualcomm's Scorpion and Krait processors never >> set these bits to anything besides 0 so they always match. >> >> Skip this entry if we've compiled in support for v7 CPUs. This >> allows kernel decompression to happen nearly instantly instead of >> taking over 20 seconds. >> >> Signed-off-by: Brian Swetland >> [sboyd: Clarified and extended commit text] >> Signed-off-by: Stephen Boyd >> --- > Ping? Russell, shall I add this to the patch tracker? > >> arch/arm/boot/compressed/head.S | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S >> index fe4d9c3..a236190 100644 >> --- a/arch/arm/boot/compressed/head.S >> +++ b/arch/arm/boot/compressed/head.S >> @@ -805,6 +805,8 @@ call_cache_fn: adr r12, proc_types >> .align 2 >> .type proc_types,#object >> proc_types: >> +#if !defined(CONFIG_CPU_V7) >> + /* This collides with some V7 IDs, preventing correct detection */ >> .word 0x00000000 @ old ARM ID >> .word 0x0000f000 >> mov pc, lr >> @@ -813,6 +815,7 @@ proc_types: >> THUMB( nop ) >> mov pc, lr >> THUMB( nop ) >> +#endif >> >> .word 0x41007000 @ ARM7/710 >> .word 0xfff8fe00 > -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/