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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 37103C38A29 for ; Wed, 15 Apr 2020 10:34:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18156206D9 for ; Wed, 15 Apr 2020 10:34:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408693AbgDOKdz (ORCPT ); Wed, 15 Apr 2020 06:33:55 -0400 Received: from foss.arm.com ([217.140.110.172]:41798 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408651AbgDOKcB (ORCPT ); Wed, 15 Apr 2020 06:32:01 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7D90B1063; Wed, 15 Apr 2020 03:32:00 -0700 (PDT) Received: from [10.37.12.1] (unknown [10.37.12.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A70563F68F; Wed, 15 Apr 2020 03:31:58 -0700 (PDT) Subject: Re: [PATCH 5/8] arm64: cpufeature: Factor out checking of AArch32 features To: will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Cc: linux-kernel@vger.kernel.org, mark.rutland@arm.com, maz@kernel.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, saiprakash.ranjan@codeaurora.org, dianders@chromium.org, kernel-team@android.com References: <20200414213114.2378-1-will@kernel.org> <20200414213114.2378-6-will@kernel.org> From: Suzuki K Poulose Message-ID: <95817087-122e-0392-9474-c17ad1f926d2@arm.com> Date: Wed, 15 Apr 2020 11:36:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20200414213114.2378-6-will@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/14/2020 10:31 PM, Will Deacon wrote: > update_cpu_features() is pretty large, so split out the checking of the > AArch32 features into a separate function and call it after checking the > AArch64 features. > > Signed-off-by: Will Deacon > --- > arch/arm64/kernel/cpufeature.c | 108 +++++++++++++++++++-------------- > 1 file changed, 61 insertions(+), 47 deletions(-) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 7dfcdd9e75c1..32828a77acc3 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -715,6 +715,65 @@ static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot) > return 1; > } > > +static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info, > + struct cpuinfo_arm64 *boot) > +{ ... > - > if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) { > taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu, > info->reg_zcr, boot->reg_zcr); > @@ -845,6 +857,8 @@ void update_cpu_features(int cpu, > sve_update_vq_map(); > } > > + taint |= update_32bit_cpu_features(cpu, info, boot); > + This relies on the assumption that the id_aa64pfr0 has been sanitised. It may be worth adding a comment to make sure people (hacking the kernel) don't move this around and break that dependency. Either ways: Reviewed-by: Suzuki K Poulose