From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261780AbULUQOj (ORCPT ); Tue, 21 Dec 2004 11:14:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261781AbULUQOj (ORCPT ); Tue, 21 Dec 2004 11:14:39 -0500 Received: from gate.crashing.org ([63.228.1.57]:27827 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S261780AbULUQOe (ORCPT ); Tue, 21 Dec 2004 11:14:34 -0500 Subject: Re: [PATCH] add PCI API to sysfs From: Benjamin Herrenschmidt To: Matthew Wilcox Cc: Jesse Barnes , linux-pci@atrey.karlin.mff.cuni.cz, Greg KH , Linux Kernel list , Bjorn Helgaas , willy@debian.org In-Reply-To: <20041221123146.GA16109@parcelfarce.linux.theplanet.co.uk> References: <200412201450.47952.jbarnes@engr.sgi.com> <20041220225817.GA21404@kroah.com> <200412201501.12575.jbarnes@engr.sgi.com> <1103613121.21771.28.camel@gaston> <20041221123146.GA16109@parcelfarce.linux.theplanet.co.uk> Content-Type: text/plain Date: Tue, 21 Dec 2004 17:13:58 +0100 Message-Id: <1103645638.28670.43.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2004-12-21 at 12:31 +0000, Matthew Wilcox wrote: > On Tue, Dec 21, 2004 at 08:12:01AM +0100, Benjamin Herrenschmidt wrote: > > treat all busses of a domain the same, but it leaves us with the > > necessary flexibility for setups with bridges that can remap the legacy > > space or that kind of thing. > > Do any such bridges exist? I've never heard of them. io space accesses > are implemented by the host bridge, so I think the most generic we need > to support is one per host bridge, ie root bus. I've seen PCI->ISA stuffs that could remap the legacy ISA memory space at some random place, though don't ask me the details, I forgot. Also, per-bus avoids the work of having to walk the tree up, etc... and doesn't make thing more complicated for the sysfs code so ... Ben