From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752493AbaBYGCB (ORCPT ); Tue, 25 Feb 2014 01:02:01 -0500 Received: from mail-pb0-f50.google.com ([209.85.160.50]:65262 "EHLO mail-pb0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751439AbaBYGCA (ORCPT ); Tue, 25 Feb 2014 01:02:00 -0500 Date: Tue, 25 Feb 2014 13:01:47 +0700 From: Chris Bainbridge To: x86@kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH] x86: set Pentium M as PAE capable Message-ID: <20140225060146.GA4339@debian.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pentium M is PAE capable but does not indicate so in the CPUID response. This is an issue now that some distributions are no longer shipping non-PAE kernels (those distributions no longer boot on Pentium M). This small patch fixes the issue by forcing the PAE capability on Pentium M. For more discussion see https://bugs.launchpad.net/baltix/+bug/930447 Signed-off-by: Chris Bainbridge --- diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index bbe1b8b..97996aa 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -226,6 +226,12 @@ static void intel_workarounds(struct cpuinfo_x86 *c) clear_cpu_cap(c, X86_FEATURE_SEP); /* + * PAE CPUID bug: Pentium M reports no PAE but has PAE + */ + if ((c->x86 == 6) && ((c->x86_model == 9) || (c->x86_model == 13))) + set_cpu_cap(c, X86_FEATURE_PAE); + + /* * P4 Xeon errata 037 workaround. * Hardware prefetcher may cause stale data to be loaded into the cache. */