Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266298AbUA2RZY (ORCPT ); Thu, 29 Jan 2004 12:25:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266274AbUA2RZY (ORCPT ); Thu, 29 Jan 2004 12:25:24 -0500 Received: from zcars04e.nortelnetworks.com ([47.129.242.56]:42644 "EHLO zcars04e.nortelnetworks.com") by vger.kernel.org with ESMTP id S266298AbUA2RYb (ORCPT ); Thu, 29 Jan 2004 12:24:31 -0500 Message-ID: <401941C4.4070502@nortelnetworks.com> Date: Thu, 29 Jan 2004 12:24:20 -0500 X-Sybari-Space: 00000000 00000000 00000000 00000000 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.8) Gecko/20020204 X-Accept-Language: en-us MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, mj@ucw.cz Subject: question about PCI setup with multiple CPUs on the PCI bus(es) Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2149 Lines: 49 We have an interesting scenario thats causing us some headaches, and before we go and re-invent the wheel, I've been asked to see if there's any others that have had to do something similar. We have a main board with a processor on it and a number of PCI buses connected via bridges, with various devices on the buses. There are a number of PMC slots on two of the buses two which are connected PMC processor boards, each of which has a cpu, memory, various devices, and a PCI bridge. The problem we are running into is as follows: 1) the main board boots up, enumerates and configures the pci device space, and boots the daughterboards 2) the daughterboards boot up, enumerate and (re)configure the pci device space (differently than the cpu on the mainboard), and screw everything up We changed to kernel on the daughterboards to not touch PCI at all, and everything worked fine. However, one of the daughterboards (which is on its own pci bus separate from the others) needs to control two PCI devices. We tried to modify the PCI code to just go out and discover what was in PCI space, not configure any of it. However, as it did this it reprogrammed the PCI bridges, wrecking the configuration that the cpu on the main board expected. Surely we aren't the only people that want to put multiple CPUs on a single PCI space. How have people handled this in the past? Ideally what I'm looking for is a CONFIG_NO_MANGLE_PCI or something to that effect. As a last resort we are considering hardcoding the bus/device topology for the two drivers on special daughterboard, but this seems really kludgy. Anyone have any advice? Chris -- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.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/