From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from service87.mimecast.com ([91.220.42.44]:52494 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751718Ab3JIKp6 convert rfc822-to-8bit (ORCPT ); Wed, 9 Oct 2013 06:45:58 -0400 Date: Wed, 9 Oct 2013 11:45:54 +0100 From: Liviu Dudau To: Benjamin Herrenschmidt Cc: Rob Herring , Bjorn Helgaas , "linux-pci@vger.kernel.org" , Catalin Marinas , Olof Johansson , Arnd Bergmann , Michal Simek , "grant.likely@linaro.org" , "devicetree@vger.kernel.org" Subject: Re: [RFC] Architecture independent pcibios? Message-ID: <20131009104553.GI25606@e102652-lin.cambridge.arm.com> References: <20131008144211.GA25231@e102652-lin.cambridge.arm.com> <525438F6.3090600@gmail.com> <1381264135.645.230.camel@pasglop> <20131009090923.GE25606@e102652-lin.cambridge.arm.com> <1381315068.4330.1.camel@pasglop> MIME-Version: 1.0 In-Reply-To: <1381315068.4330.1.camel@pasglop> Content-Type: text/plain; charset=UTF-8 Sender: linux-pci-owner@vger.kernel.org List-ID: On Wed, Oct 09, 2013 at 11:37:48AM +0100, Benjamin Herrenschmidt wrote: > On Wed, 2013-10-09 at 10:09 +0100, Liviu Dudau wrote: > > On Tue, Oct 08, 2013 at 09:28:55PM +0100, Benjamin Herrenschmidt wrote: > > > On Tue, 2013-10-08 at 11:55 -0500, Rob Herring wrote: > > > > > > > > I wonder if pci_process_bridge_OF_ranges() would fit somewhere in > > > > > drivers/of? The implementations I looked at are mostly concerned with > > > > > parsing OF resources, and they don't have much to do with PCI > > > > > directly. > > > > > > > > This was being done until Ben weighed in: > > > > > > > > https://lkml.org/lkml/2013/5/4/103 > > > > > > Well, I proposed an alternative (better) approach which I of course had > > > no time to actually implement yet :-) > > > > In order to avoid any confusion, could you please point me again to the > > relevant message(s) where you proposed your approach? > > The one pointed to by the above URL ? > > > > I have done the changes I needed to do to powerpc > > > pci_process_bridge_OF_ranges so it would be possible to move that now to > > > a generic place, but I still think it's not a great idea. It means the > > > pci_controller structure with its resources will have to become generic > > > which somewhat overlaps with the pci_host_bridge that Bjorn introduced, > > > so that's really not great. > > > > > > I still think an arch with DT and simpler PCI code that powerpc could > > > start looking at the transition to a better model that I hinted at... > > > > As tempting as it is to start anew and with a cleaner code, I am wary > > that porting the existing platforms to the new code will take longer > > that way. My intentions are to make the (probably infrequent) task of > > adding a new architecture to the PCI infrastructure a simple and > > straighforward task. But adding code for my platform is no guarantee > > that new ones will have an easier job. > > It still makes little sense to generalize a pci_controller with > resources & offset on top of the generic pci_host_bridge with apertures. Agreed. I'm looking on how to move functions that use pci_controller to use pci_host_bridge. Semantic question: what is the perceived difference between a pci_controller and a pci_host_bridge? Are they just historical naming artifacts of the same concept? (person A deciding to do a cleanup of the code and picks a new name in order not to upset the old APIs) Best regards, Liviu > > Ben. > > > Best regards, > > Liviu > > > > > > > > Cheers, > > > Ben. > > > > > > > > > > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯