From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757394AbYEVSGV (ORCPT ); Thu, 22 May 2008 14:06:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755727AbYEVSGH (ORCPT ); Thu, 22 May 2008 14:06:07 -0400 Received: from mx1.redhat.com ([66.187.233.31]:47298 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755202AbYEVSGF (ORCPT ); Thu, 22 May 2008 14:06:05 -0400 Date: Thu, 22 May 2008 13:02:23 -0400 From: Dave Jones To: "H. Peter Anvin" Cc: Yinghai Lu , Linux Kernel , Ingo Molnar , Thomas Gleixner Subject: Re: [X86] Add recent Centaur CPUs to PAT whitelist Message-ID: <20080522170223.GA32314@redhat.com> Mail-Followup-To: Dave Jones , "H. Peter Anvin" , Yinghai Lu , Linux Kernel , Ingo Molnar , Thomas Gleixner References: <200805200409.m4K49V3G024332@gelk.kernelslacker.org> <86802c440805192249y77e78918u8392f5a43331365@mail.gmail.com> <20080520131943.GA4843@redhat.com> <4834B6AC.9090503@zytor.com> <20080522140753.GB20613@redhat.com> <4835A3EC.1030307@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4835A3EC.1030307@zytor.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 22, 2008 at 09:48:44AM -0700, H. Peter Anvin wrote: > Dave Jones wrote: > > On Wed, May 21, 2008 at 04:56:28PM -0700, H. Peter Anvin wrote: > > > Dave Jones wrote: > > > > > > > > From conversation with Centaur engineers, both the newer generations > > > > of the VIA C7, and their future CPUs support PAT, with no known errata. > > > > > > > > Signed-off-by: Dave Jones > > > > > > > > > > Question: are there any VIA CPUs that display the PAT CPUID flag that > > > aren't covered by the above? > > > > No. They only added PAT support with the current Esther (C7) generation iirc. > > > > OK, so we should just enable VIA unconditionally as long as PAT is > displayed and not worry about generation numbers; same with Transmeta > (only the Transmeta Efficeon supported PAT, and it had a > strictly-coherent memory system.) Like so? Unconditionally enable PAT support on Centaur and Transmeta CPUs. All known models that advertise PAT have no known errata. Signed-off-by: Dave Jones --- linux-2.6/arch/x86/kernel/cpu/addon_cpuid_features.c~ 2008-05-22 12:59:07.000000000 -0400 +++ linux-2.6/arch/x86/kernel/cpu/addon_cpuid_features.c 2008-05-22 12:59:36.000000000 -0400 @@ -62,6 +62,9 @@ void __cpuinit validate_pat_support(stru if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15)) return; break; + case X86_VENDOR_CENTAUR: + case X86_VENDOR_TRANSMETA: + return; } pat_disable(cpu_has_pat ? -- http://www.codemonkey.org.uk