Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752641AbcLFBBY (ORCPT ); Mon, 5 Dec 2016 20:01:24 -0500 Received: from mail.kernel.org ([198.145.29.136]:51362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752548AbcLFBBU (ORCPT ); Mon, 5 Dec 2016 20:01:20 -0500 From: Andy Lutomirski To: x86@kernel.org Cc: One Thousand Gnomes , Borislav Petkov , "linux-kernel@vger.kernel.org" , Brian Gerst , Matthew Whitehead , Borislav Petkov , Andy Lutomirski Subject: [RFC PATCH 1/6] x86/CPU: Add X86_FEATURE_CPUID Date: Mon, 5 Dec 2016 17:01:10 -0800 Message-Id: <64c7a16c0c56df35e33b16fec30b69a73a0b96d7.1480985979.git.luto@kernel.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2224 Lines: 58 From: Borislav Petkov Add a synthetic CPUID flag denoting whether the CPU sports the CPUID instruction or not. This will come useful later when accomodating CPUID-less CPUs. Signed-off-by: Borislav Petkov Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/cpufeatures.h | 2 +- arch/x86/kernel/cpu/common.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index a4f9aee62217..e6be43b2679a 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -100,7 +100,7 @@ #define X86_FEATURE_XTOPOLOGY ( 3*32+22) /* cpu topology enum extensions */ #define X86_FEATURE_TSC_RELIABLE ( 3*32+23) /* TSC is known to be reliable */ #define X86_FEATURE_NONSTOP_TSC ( 3*32+24) /* TSC does not stop in C states */ -/* free, was #define X86_FEATURE_CLFLUSH_MONITOR ( 3*32+25) * "" clflush reqd with monitor */ +#define X86_FEATURE_CPUID ( 3*32+25) /* CPU has CPUID instruction itself */ #define X86_FEATURE_EXTD_APICID ( 3*32+26) /* has extended APICID (8 bits) */ #define X86_FEATURE_AMD_DCM ( 3*32+27) /* multi-node processor */ #define X86_FEATURE_APERFMPERF ( 3*32+28) /* APERFMPERF */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index cc9e980c68ec..37f031f39e27 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -800,14 +800,12 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) memset(&c->x86_capability, 0, sizeof c->x86_capability); c->extended_cpuid_level = 0; - if (!have_cpuid_p()) - identify_cpu_without_cpuid(c); - /* cyrix could have cpuid enabled via c_identify()*/ if (have_cpuid_p()) { cpu_detect(c); get_cpu_vendor(c); get_cpu_cap(c); + setup_force_cpu_cap(X86_FEATURE_CPUID); if (this_cpu->c_early_init) this_cpu->c_early_init(c); @@ -817,6 +815,9 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) if (this_cpu->c_bsp_init) this_cpu->c_bsp_init(c); + } else { + identify_cpu_without_cpuid(c); + setup_clear_cpu_cap(X86_FEATURE_CPUID); } setup_force_cpu_cap(X86_FEATURE_ALWAYS); -- 2.9.3