From patchwork Wed Apr 3 21:22:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884511 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 87B1D1708 for ; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7243328450 for ; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6616C285B7; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0989028450 for ; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726606AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726562AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754277" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:12 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 17/20] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Date: Wed, 3 Apr 2019 14:22:03 -0700 Message-Id: <1554326526-172295-18-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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); }