From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754420AbZEXHT0 (ORCPT ); Sun, 24 May 2009 03:19:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751843AbZEXHTT (ORCPT ); Sun, 24 May 2009 03:19:19 -0400 Received: from ganesha.gnumonks.org ([213.95.27.120]:42386 "EHLO ganesha.gnumonks.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751256AbZEXHTT (ORCPT ); Sun, 24 May 2009 03:19:19 -0400 Date: Sun, 24 May 2009 14:49:05 +0800 From: Harald Welte To: "H. Peter Anvin" Cc: lkml@morethan.org, Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, Alan Cox Subject: Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic Message-ID: <20090524064905.GH20452@prithivi.gnumonks.org> References: <200905221139.26941.lkml@morethan.org> <200905221946.01808.lkml@morethan.org> <4A1748A9.1020306@zytor.com> <200905231304.55973.lkml@morethan.org> <4A188A48.5000208@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A188A48.5000208@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 Dear hpa, and others, On Sat, May 23, 2009 at 04:44:08PM -0700, H. Peter Anvin wrote: > It looks like there might be a problem with the C7-M ... Michael reports > that if he sets LOCK_PREFIX to "lock;" it works, but that shouldn't be > necessary for a uniprocessor. > I will try my best to help, though I have to admit I'm far from being a x86 expert, and particularly not with regard to low-level bits such as atomic operations. So please give me some time to research some background about that, and read up all the details on the currently reported/described problem. Once I understand it in full detail, I can talk to the right people inside CentaurLabs (VIA's CPU division). If somebody (optionally) can phrase a precise technical question that I can directly forward to somebody with low-level x86 knowledge but no Linux background, it would definitely help speeding up the process. > I'm wondering if we have to revive the OOSTORE hack, or some other > workaround. It is of course hard for me to track this down since (a) I > don't have access to the CPU documentation, As far as I know, there really is no such documentation.. all documentation that I've ever seen internally is electrical data sheets and high-level feature set descriptiosn, CPUID, MSR and padlock. There are no actual x86 instruction set documents... Centaur is < 100 people, they don't have the resources to work on documents along the lines of what Intel has... > and (b) I work for Intel now, which limits the amount of time I can > realistically spend on this. Sure, thanks for letting me know. -- - Harald Welte http://linux.via.com.tw/ ============================================================================ VIA Open Source Liaison