From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D2E8C433E0 for ; Thu, 4 Feb 2021 09:56:18 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2A2F264DE1 for ; Thu, 4 Feb 2021 09:56:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2A2F264DE1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=b9etD2CBKbj+NQlTVea61LVIf+rP/5K5qU7YQv187U4=; b=lCtz0X92/KC81Exy61FeTEWdn AyvYYSUQCL7SeJVHjSCNSbC5JTHofU8rFAB2LumCYulkEbwQpTvpL9XcboirT1bvtsm2Uqbxj8YvL KG2/emuwpsre/YyQBogKgxtS8LazpLX9ghwP5j/cN5ui4ZnnvFnoNMfOSFyU8EKqaPmu1xYWgZbX2 xkQbYXBRlWGwXl6WlD2rQ7rn2CqhJl5Fq9QHfFOGq+tYeO4gb+wndGJ4DkHEh7GdEInXt9uzh6alH uv+XshrzBSK8U+6xeIsUi/w6PI9m9+hYL4VQM4L4mmc98ECC2W48D+vcy51faFMjsMeUd9tY/9tLG e3NOuoe0A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l7bLu-0002yq-OW; Thu, 04 Feb 2021 09:55:06 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l7bLs-0002yP-6i for linux-arm-kernel@lists.infradead.org; Thu, 04 Feb 2021 09:55:04 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id A997064F46; Thu, 4 Feb 2021 09:55:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612432502; bh=6GS1Oj2S2vEZKlcHYCYmO7hqCEnMei8WJEz2ukGolfo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qUnpTfZxIKo0TNU5CQyB0iCkXoynIR4R8UgFiBKvl40Gfsrgk24C/omXSuxDCLAm5 n8SFeSVZYu2SWodIYj2tuC2wOa0yx50tr4/iVSstpoUgzZ0sr966HKnatoQzJomiaO +JDhQyeljmJoruGeyocpNQY5QAGFmdIV0LpG5scewWxs1nI2lnZcjNNyXHYn7buNO/ fMXOlIHd2y+nAZMeZahi6Zbqup0MixDnCVyA3Hm4y5ZacZy/6jzlshVUJeGPQotPoe 3Mo4iFrzr+IR2IvAVvaa5lxtQRRdfvY7MNgzB+XyJCjb2KNROpo0JEv9adou8Cdl1K +7weHqr/r5jqg== Date: Thu, 4 Feb 2021 09:54:58 +0000 From: Will Deacon To: Suzuki K Poulose Subject: Re: [PATCH] arm64: Extend workaround for erratum 1024718 to all versions of Cortex-A55 Message-ID: <20210204095457.GA20361@willie-the-truck> References: <20210203230057.3961239-1-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210203230057.3961239-1-suzuki.poulose@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210204_045504_346486_AEABD071 X-CRM114-Status: GOOD ( 17.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: catalin.marinas@arm.com, Kunihiko Hayashi , James Morse , stable@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Suzuki, On Wed, Feb 03, 2021 at 11:00:57PM +0000, Suzuki K Poulose wrote: > The erratum 1024718 affects Cortex-A55 r0p0 to r2p0. However > we apply the work around for r0p0 - r1p0. Unfortunately this > won't be fixed for the future revisions for the CPU. Thus > extend the work around for all versions of A55, to cover > for r2p0 and any future revisions. > > Cc: stable@vger.kernel.org > Cc: Catalin Marinas > Cc: Will Deacon > Cc: James Morse > Cc: Kunihiko Hayashi > Signed-off-by: Suzuki K Poulose > --- > arch/arm64/kernel/cpufeature.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index e99eddec0a46..db400ca77427 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -1455,7 +1455,7 @@ static bool cpu_has_broken_dbm(void) > /* List of CPUs which have broken DBM support. */ > static const struct midr_range cpus[] = { > #ifdef CONFIG_ARM64_ERRATUM_1024718 > - MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0), // A55 r0p0 -r1p0 > + MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), I think we have bigger problems with this erratum, since cpu_has_hw_af() doesn't taken this erratum into account at all, meaning that arch_faults_on_old_pte() will return the wrong value on any system with an A55. Please can you fix that along with this patch? You'll need to pay extra attention to the stuff I've queued on for-next/faultaround, where we will actually want arch_wants_old_prefaulted_pte() to return 'true' if any of the CPUs have DBM, since it's a pure performance thing. Cheers, Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel