From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261960AbULPRoA (ORCPT ); Thu, 16 Dec 2004 12:44:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261961AbULPRng (ORCPT ); Thu, 16 Dec 2004 12:43:36 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:59825 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S261963AbULPRmo (ORCPT ); Thu, 16 Dec 2004 12:42:44 -0500 From: Jesse Barnes To: linux-pci@atrey.karlin.mff.cuni.cz Subject: Re: [PATCH] add legacy I/O port & memory APIs to /proc/bus/pci Date: Thu, 16 Dec 2004 09:42:20 -0800 User-Agent: KMail/1.7.1 Cc: Bjorn Helgaas , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, willy@debian.org References: <200412160850.20223.jbarnes@engr.sgi.com> <200412161037.55293.bjorn.helgaas@hp.com> In-Reply-To: <200412161037.55293.bjorn.helgaas@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200412160942.20678.jbarnes@engr.sgi.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, December 16, 2004 9:37 am, Bjorn Helgaas wrote: > On Thursday 16 December 2004 9:50 am, Jesse Barnes wrote: > > This patch documents the /proc/bus/pci interface and adds some optional > > architecture specific APIs for accessing legacy I/O port and memory > > space. This is necessary on platforms where legacy I/O port space doesn't > > 'soft fail' like it does on PCs, and is useful for systems that can route > > legacy space to different PCI busses. > > But we didn't resolve anything with respect to multiple PCI domains, > did we? As far as I can see, /proc/bus/pci currently doesn't support > multiple domains at all. I don't like the idea of adding new stuff > that we already know is insufficient for machines in the very near > future. True, it's just extending an existing interface, but it > seems like if we're going to the trouble of changing X, we might as > well address multiple domains at the same time. The problem with adding domain support is that it'll break existing users, unless it's added on the side somehow. One thought I had was to document that /proc/bus/pci/ contains only busses from domain 0. Machines with more than 1 domain could create /proc/bus/pci/domain/DDDD directories with busses in the DDDD domain underneath. That wouldn't break existing applications, and would let you get at domains other than 0 if you needed to. Jesse