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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 0B5A2C282DA for ; Wed, 17 Apr 2019 21:43:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD11421850 for ; Wed, 17 Apr 2019 21:43:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387796AbfDQVnW (ORCPT ); Wed, 17 Apr 2019 17:43:22 -0400 Received: from mga12.intel.com ([192.55.52.136]:20176 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387633AbfDQVma (ORCPT ); Wed, 17 Apr 2019 17:42:30 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441217" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:29 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 18/21] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Date: Wed, 17 Apr 2019 14:34:08 -0700 Message-Id: <1555536851-17462-19-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel option clearcpuid currently only takes feature bit which can be changed from kernel to kernel. Extend clearcpuid to use cap flag string, which is defined in x86_cap_flags[] and won't be changed from kernel to kernel. And user can easily get the cap flag string from /proc/cpuinfo. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/cpuid-deps.c | 26 ++++++++++++++++++++++++++ arch/x86/kernel/fpu/init.c | 3 ++- 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 0e56ff7e4848..823c4ab82e12 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -133,6 +133,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; extern void setup_clear_cpu_cap(unsigned int bit); extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); +bool find_cpu_cap(char *cap_flag, unsigned int *pfeature); #define setup_force_cpu_cap(bit) do { \ set_cpu_cap(&boot_cpu_data, bit); \ diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 3d633f67fbd7..1a71434f7b46 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -120,3 +120,29 @@ void setup_clear_cpu_cap(unsigned int feature) { do_clear_cpu_cap(NULL, feature); } + +/** + * find_cpu_cap - Given a cap flag string, find its corresponding feature bit. + * @cap_flag: cap flag string as defined in x86_cap_flags[] + * @pfeature: feature bit + * + * Return: true if the feature is found. false if not found + */ +bool find_cpu_cap(char *cap_flag, unsigned int *pfeature) +{ +#ifdef CONFIG_X86_FEATURE_NAMES + unsigned int feature; + + for (feature = 0; feature < NCAPINTS * 32; feature++) { + if (!x86_cap_flags[feature]) + continue; + + if (strcmp(cap_flag, x86_cap_flags[feature]) == 0) { + *pfeature = feature; + + return true; + } + } +#endif + return false; +} diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 88bbba7ee96a..99b895eea166 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -256,7 +256,8 @@ static void __init clear_cpuid(void) /* Chang command line range for next search. */ cmdline_size = option_pos - boot_command_line + 1; argptr = arg; - if (get_option(&argptr, &bit) && + /* cpu cap can be specified by either feature bit or string */ + if ((get_option(&argptr, &bit) || find_cpu_cap(arg, &bit)) && bit >= 0 && bit < NCAPINTS * 32) setup_clear_cpu_cap(bit); } -- 2.19.1