From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755229Ab0DZU2E (ORCPT ); Mon, 26 Apr 2010 16:28:04 -0400 Received: from g5t0007.atlanta.hp.com ([15.192.0.44]:1370 "EHLO g5t0007.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755206Ab0DZU2A (ORCPT ); Mon, 26 Apr 2010 16:28:00 -0400 From: Bjorn Helgaas To: Jesse Barnes Subject: Re: [PATCH] x86/PCI: never allocate PCI MMIO resources below BIOS_END Date: Mon, 26 Apr 2010 14:27:56 -0600 User-Agent: KMail/1.9.10 Cc: Andy Isaacson , "R. Andrew Bailey" , Yinghai , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , guenter.roeck@ericsson.com, Linus Torvalds , "linux-pci@vger.kernel.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Thomas Renninger , yaneti@declera.com References: <4BC4E55B.7000103@oracle.com> <20100426183436.GV11130@hexapodia.org> <20100426123135.5d095d2f@virtuousgeek.org> In-Reply-To: <20100426123135.5d095d2f@virtuousgeek.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <201004261427.57229.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 26 April 2010 01:31:35 pm Jesse Barnes wrote: > On Mon, 26 Apr 2010 11:34:36 -0700 > Andy Isaacson wrote: > > On Fri, Apr 23, 2010 at 05:05:24PM -0600, Bjorn Helgaas wrote: > > > commit 7fb707eb97fdf6dc4fa4b127f127f8d00223afc7 > > > Author: Bjorn Helgaas > > > Date: Fri Apr 23 15:22:10 2010 -0600 > > > > > > x86/PCI: never allocate PCI MMIO resources below BIOS_END > > > > > > When we move a PCI device or assign resources to a device not configured > > > by the BIOS, we want to avoid the BIOS region below 1MB. Note that if the > > > BIOS places devices below 1MB, we leave them there. > > > > Works for me. dmesg at > > https://bugzilla.kernel.org/attachment.cgi?id=26150 > > Great, thanks for testing. Applied this one to my for-linus tree. Thanks! > I still think Yinghai's patches should go in as well (marking regions as > busy seems like good housekeeping), but with this fixed they're a better > fit for -next. I'm a little concerned that those patches are a sledgehammer approach. Previously, IORESOURCE_BUSY has basically been used for mutual exclusion between drivers that would otherwise claim the same resource. It hasn't been used to guide resource assignment in the PCI/PNP/etc core. Maybe it's a good idea to also use IORESOURCE_BUSY there, but I'm not sure. Right now it feels like undesirable overloading to me. I think it also leads to at least one problem: Guenter's machine has no VGA but has a PCI device that lives at 0xa0000. The driver for that device won't be able to request that region if the arch code has marked it busy. Bjorn