From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753147Ab0JDHbg (ORCPT ); Mon, 4 Oct 2010 03:31:36 -0400 Received: from mail.skyhub.de ([78.46.96.112]:53200 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752624Ab0JDHbf (ORCPT ); Mon, 4 Oct 2010 03:31:35 -0400 Date: Mon, 4 Oct 2010 09:31:27 +0200 From: Borislav Petkov To: "H. Peter Anvin" Cc: Ingo Molnar , Thomas Gleixner , lkml Subject: [PATCH] x86, cpu: Fix X86_FEATURE_NOPL Message-ID: <20101004073127.GA20305@liondog.tnic> Mail-Followup-To: Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , lkml References: <20101003093701.GB3733@liondog.tnic> <4CA89681.8000202@zytor.com> <20101003152212.GA13233@liondog.tnic> <20101003201139.GA16532@liondog.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ba0593bf553c450a03dbc5f8c1f0ff58b778a0c8 cleared the aforementioned cpuid bit only on 32-bit due to various problems with Virtual PC. This somehow got lost during the 32- + 64-bit merge so restore the feature bit on 64-bit. For that, set it explicitly for non-constant arguments of cpu_has(). Update comment for future reference. Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/common.c | 15 ++++++++++----- 1 files changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index caa967d..4b68bda 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -704,16 +704,21 @@ void __init early_cpu_init(void) } /* - * The NOPL instruction is supposed to exist on all CPUs with - * family >= 6; unfortunately, that's not true in practice because - * of early VIA chips and (more importantly) broken virtualizers that - * are not easy to detect. In the latter case it doesn't even *fail* - * reliably, so probing for it doesn't even work. Disable it completely + * The NOPL instruction is supposed to exist on all CPUs of family >= 6; + * unfortunately, that's not true in practice because of early VIA + * chips and (more importantly) broken virtualizers that are not easy + * to detect. In the latter case it doesn't even *fail* reliably, so + * probing for it doesn't even work. Disable it completely on 32-bit * unless we can find a reliable way to detect all the broken cases. + * Enable it explicitly on 64-bit for non-constant inputs of cpu_has(). */ static void __cpuinit detect_nopl(struct cpuinfo_x86 *c) { +#ifdef CONFIG_X86_32 clear_cpu_cap(c, X86_FEATURE_NOPL); +#else + set_cpu_cap(c, X86_FEATURE_NOPL); +#endif } static void __cpuinit generic_identify(struct cpuinfo_x86 *c) -- 1.7.2.3 -- Regards/Gruss, Boris.