Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755302AbXICSSq (ORCPT ); Mon, 3 Sep 2007 14:18:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753106AbXICSSg (ORCPT ); Mon, 3 Sep 2007 14:18:36 -0400 Received: from outbound-sin.frontbridge.com ([207.46.51.80]:8124 "EHLO outbound9-sin-R.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751069AbXICSSf (ORCPT ); Mon, 3 Sep 2007 14:18:35 -0400 X-BigFish: VP X-MS-Exchange-Organization-Antispam-Report: OrigIP: 163.181.251.8;Service: EHS X-Server-Uuid: 8C3DB987-180B-4465-9446-45C15473FD3E Date: Mon, 3 Sep 2007 20:18:06 +0200 From: "Robert Richter" To: "dean gaudet" cc: "Andi Kleen" , patches@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [patch 5/5] x86: Set PCI config space size to extended for AMD Barcelona Message-ID: <20070903181805.GB4758@erda.amd.com> References: <20070903081736.288288000@amd.com> <20070903081736.805623000@amd.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) X-OriginalArrivalTime: 03 Sep 2007 18:18:06.0201 (UTC) FILETIME=[C6212E90:01C7EE56] X-WSS-ID: 6AC290670X86435142-01-01 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1461 Lines: 40 On 03.09.07 09:48:15, dean gaudet wrote: > it's so very unfortunate the PCI standard has no feature bit to indicate > the presence of ECS. Right. Not nice. > FWIW in my testing on a range of machines spanning 7 or 8 years i could > read config space reg 256... and get 0xffffffff when the device didn't > support ECS, and get valid data when the device did support ECS... granted > there may be some system out there which behaves really badly when you do > this. > > perhaps someone could write a userspace program and test that concept on a > far wider range of machines. A user space programm could map the config space (if MMCONFIG is usable) and scan the PCI devices directly using memory access. This patch sets pcidev->cfg_size to 4096 for certain devices so that the ECS is also available using proc/sys fs or lspci -xxxx. In this case the Kernel access functions are used. This works with both methods, CF8 and MMCONFIG. For CF8, all patches of these series must be used. Note also, that ECS access is not only for CPU devices available, but also of other PCI Express devices on the bus. -Robert -- AMD Saxony, Dresden, Germany Operating System Research Center email: robert.richter@amd.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/