Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755083AbZDIG4M (ORCPT ); Thu, 9 Apr 2009 02:56:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752911AbZDIGz4 (ORCPT ); Thu, 9 Apr 2009 02:55:56 -0400 Received: from complete.lackof.org ([198.49.126.79]:45270 "EHLO complete.lackof.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753373AbZDIGzz (ORCPT ); Thu, 9 Apr 2009 02:55:55 -0400 Date: Thu, 9 Apr 2009 00:55:53 -0600 From: Grant Grundler To: Kumar Gala Cc: Jesse Barnes , Linux Kernel Mailing List , linux-pci@vger.kernel.org, Benjamin Herrenschmidt , Linux/PPC Development Subject: Re: tracking of PCI address space Message-ID: <20090409065553.GA14780@lackof.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Home-Page: http://www.parisc-linux.org/ User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1340 Lines: 32 On Wed, Apr 08, 2009 at 03:53:55PM -0500, Kumar Gala wrote: > I was wondering if we have anything that tracks regions associated with > the "inbound" side of a pci_bus. > > What I mean is on embedded PPC we have window/mapping registers for both > inbound (accessing memory on the SoC) and outbound (access PCI device > MMIO, IO etc). The combination of the inbound & outbound convey what > exists in the PCI address space vs CPU physical address space (and how to > map from one to the other). Most PCI Host bus controllers will negatively decode the outbound ranges for inbound traffic. PARISC and IA64 have extra registers to play some games with that. But routing between PCI bus controllers to make them look like a single PCI segment was the main intent of that. I've not found any other uses to subvert that. > Today in the PPC land we only attach > outbound windows to the pci_bus. So technically the inbound side > information (like what subset of physical memory is visible on the PCI > bus) seems to be lost. What did you need inbound "routing map" for? thanks, grant -- 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/