From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760035Ab0ENWsJ (ORCPT ); Fri, 14 May 2010 18:48:09 -0400 Received: from cpoproxy2-pub.bluehost.com ([67.222.39.38]:53578 "HELO outbound-mail-158.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753825Ab0ENWsH (ORCPT ); Fri, 14 May 2010 18:48:07 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=virtuousgeek.org; h=Received:Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=XgKGSwFLQ/mrBHePFbLPRwZ+1FbTWVwtziqpOWoEvEyIS7te1C1yU0kYigm6bdxPIUljT5fLuKeRuL9zKb3CSTcUaQ7u6QCbDkUxJBKJ5yS7XRIo610SOrSyogtOLc+7; Date: Fri, 14 May 2010 15:47:06 -0700 From: Jesse Barnes To: Mike Travis Cc: Bjorn Helgaas , Mike Habeck , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, Jacob Pan , Tejun Heo , LKML , Yinghai , "linux-pci@vger.kernel.org" , Myron Stowe Subject: Re: [Patch 1/1] x86 pci: Add option to not assign BAR's if not already assigned Message-ID: <20100514154706.4f36f4ed@virtuousgeek.org> In-Reply-To: <4BEDCFD9.7020202@sgi.com> References: <4BEAF008.9030805@sgi.com> <201005131256.17997.bjorn.helgaas@hp.com> <4BEC5530.1000008@sgi.com> <201005131402.30759.bjorn.helgaas@hp.com> <20100514152509.3aeb37b4@virtuousgeek.org> <4BEDCFD9.7020202@sgi.com> X-Mailer: Claws Mail 3.7.5 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Identified-User: {10642:box514.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 75.110.194.140 authed with jbarnes@virtuousgeek.org} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 14 May 2010 15:34:01 -0700 Mike Travis wrote: > > > Jesse Barnes wrote: > > On Thu, 13 May 2010 14:02:30 -0600 > > Bjorn Helgaas wrote: > >>>> This issue is not specific to x86, so I don't really like having > >>>> the implementation be x86-specific. > >>> I agree this isn't a x86 specific issue but given the 'norom' > >>> cmdline option is basically doing the same thing (but for pci > >>> Expansion ROM BARs) this code was modeled after it. > > >> IMHO, we should fix both. > > > > Yeah, that would be good. Mike, have you looked at this at all? > > > > Also, to clarify, this isn't affecting users today, right? Or do you > > need all this I/O space for multiple IOHs and the drivers that bind to > > them in current UV systems? > > We have customers that want to install more than 16 PCI-e cards right > now. Our window of opportunity closes very soon (days), so either this > patch makes it in as is (or something close), or we wait for another > release cycle. UV shipments start this month. > > [I wouldn't mind working on an improvement for later.] Wow and they're using cards that want to use I/O space? Funky. It's too late to get this into 2.6.34, but that can't be what you were expecting... I don't see a problem with getting something like this in for 2.6.35. > > Fundamentally, until we have real dynamic PCI resource management (i.e. > > driver hooks for handling relocation, lazy allocation of resources at > > driver bind time, etc.) we're going to continue to need hacks like > > this. However, we could make them slightly more automated by making > > "nobar" and "norom" the default on systems that typically need them, > > maybe with a DMI table. > > It seems that BIOS changes are much more difficult. The real solution > to this problem is for Card Vendors to not request I/O Bars if they > won't be using them. But that's the hardest option of all to accomplish. Right. -- Jesse Barnes, Intel Open Source Technology Center