From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755461Ab2FEFE7 (ORCPT ); Tue, 5 Jun 2012 01:04:59 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:54329 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751731Ab2FEFE5 convert rfc822-to-8bit (ORCPT ); Tue, 5 Jun 2012 01:04:57 -0400 MIME-Version: 1.0 In-Reply-To: References: <1337754877-19759-1-git-send-email-yinghai@kernel.org> <20120525043651.GA1391@google.com> <20120525193716.GA8817@google.com> <4FC50E09.4000204@zytor.com> <4FC51D79.6010804@zytor.com> <4FC536A5.6020600@zytor.com> Date: Mon, 4 Jun 2012 22:04:57 -0700 X-Google-Sender-Auth: rLPGDYABzhz30qo0V0TxxZ_BEG4 Message-ID: Subject: Re: [PATCH 02/11] PCI: Try to allocate mem64 above 4G at first From: Yinghai Lu To: Bjorn Helgaas Cc: "H. Peter Anvin" , David Miller , Tony Luck , Linus Torvalds , Steven Newbury , Andrew Morton , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 4, 2012 at 9:50 PM, Bjorn Helgaas wrote: > On Mon, Jun 4, 2012 at 7:37 PM, Yinghai Lu wrote: >> On Sun, Jun 3, 2012 at 6:05 PM, Bjorn Helgaas wrote: >>> On Fri, Jun 1, 2012 at 4:30 PM, Yinghai Lu wrote: >>>> On Tue, May 29, 2012 at 1:50 PM, H. Peter Anvin wrote: >>>>> >>>>> The bus-side address space should not be more than 32 bits no matter >>>>> what.  As Bjorn indicates, you seem to be mixing up bus and cpu >>>>> addresses all over the place. >>>> >>>> please check update patches that is using converted pci bus address >>>> for boundary checking. >>> >>> What problem does this fix?  There's significant risk that this >>> allocation change  will make us trip over something, so it must fix >>> something to make it worth considering. >> >> If we do not enable that, we would not find the problem. > > Sorry, that didn't make any sense to me.  I'm hoping you will point us > to a bug report that is fixed by this patch. current it only help Steve's test case. > >> On one my test setup that _CRS does state 64bit resource range, >> but when I clear some device resource manually and let kernel allocate >> high, just then find out those devices does not work with drivers. >> It turns out _CRS have more big range than what the chipset setting states. >> with fixing in BIOS, allocate high is working now on that platform. > > I didn't understand this either, sorry.  Are you saying that this > patch helps us work around a BIOS defect? Help us find out one BIOS defect. > >> yeah, how about >> >> pci=alloc_high >> >> and default to disabled ? > > I was actually thinking of something more specific, e.g., a way to > place one device at an exact address.  I've implemented that a couple > times already for testing various things.  But maybe a more general > option like "pci=alloc_high" would make sense, too. yeah. > .... > Linux has a long history of allocating bottom-up.  Windows has a long > history of allocating top-down.  You're proposing a third alternative, > allocating bottom-up starting at 4GB for 64-bit BARs.  If we change > this area, I would prefer something that follows Windows because I > think it will be closer to what's been tested by Windows.  Do you > think your alternative is better? hope we can figure out how windows is making it work. Steve, Can you check if Windows is working with your test case ? If it works, we may try do the same thing from Linux, so you will not need to append "pci=nocrs pci=alloc_high"... Thanks Yinghai