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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 F1C98C43331 for ; Tue, 12 Nov 2019 23:51:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD6E3214E0 for ; Tue, 12 Nov 2019 23:51:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727513AbfKLXvx (ORCPT ); Tue, 12 Nov 2019 18:51:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57316 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726977AbfKLXuf (ORCPT ); Tue, 12 Nov 2019 18:50:35 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iUfvc-0008I2-Vv; Tue, 12 Nov 2019 23:50:33 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iUfvc-00056e-FR; Tue, 12 Nov 2019 23:50:32 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Mark Gross" , "Borislav Petkov" , "Thomas Gleixner" , "Neelima Krishnan" , "Josh Poimboeuf" , "Pawan Gupta" , "Tony Luck" Date: Tue, 12 Nov 2019 23:48:01 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 04/25] x86/cpu: Add a helper function x86_read_arch_cap_msr() In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.77-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Pawan Gupta commit 286836a70433fb64131d2590f4bf512097c255e1 upstream. Add a helper function to read the IA32_ARCH_CAPABILITIES MSR. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Tested-by: Neelima Krishnan Reviewed-by: Mark Gross Reviewed-by: Tony Luck Reviewed-by: Josh Poimboeuf Signed-off-by: Ben Hutchings --- arch/x86/kernel/cpu/common.c | 15 +++++++++++---- arch/x86/kernel/cpu/cpu.h | 2 ++ 2 files changed, 13 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -878,19 +878,26 @@ static bool __init cpu_matches(unsigned return m && !!(m->driver_data & which); } -static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) +u64 x86_read_arch_cap_msr(void) { u64 ia32_cap = 0; + if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap); + + return ia32_cap; +} + +static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) +{ + u64 ia32_cap = x86_read_arch_cap_msr(); + if (cpu_matches(NO_SPECULATION)) return; setup_force_cpu_bug(X86_BUG_SPECTRE_V1); setup_force_cpu_bug(X86_BUG_SPECTRE_V2); - if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES)) - rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap); - if (!cpu_matches(NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) && !cpu_has(c, X86_FEATURE_AMD_SSB_NO)) setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS); --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -48,4 +48,6 @@ extern void cpu_detect_cache_sizes(struc extern void x86_spec_ctrl_setup_ap(void); +extern u64 x86_read_arch_cap_msr(void); + #endif /* ARCH_X86_CPU_H */