From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liviu Dudau Subject: Re: [RFC] Architecture independent pcibios? Date: Wed, 9 Oct 2013 11:45:54 +0100 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1381315068.4330.1.camel@pasglop> Content-Disposition: inline Sender: linux-pci-owner@vger.kernel.org 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" List-Id: devicetree@vger.kernel.org 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 wr= ote: > > > On Tue, 2013-10-08 at 11:55 -0500, Rob Herring wrote: > > > > > > > > I wonder if pci_process_bridge_OF_ranges() would fit somewher= e in > > > > > drivers/of? The implementations I looked at are mostly conce= rned 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 cour= se had > > > no time to actually implement yet :-) > >=20 > > In order to avoid any confusion, could you please point me again to= the > > relevant message(s) where you proposed your approach? >=20 > The one pointed to by the above URL ? >=20 > > > 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 mean= s the > > > pci_controller structure with its resources will have to become g= eneric > > > which somewhat overlaps with the pci_host_bridge that Bjorn intro= duced, > > > so that's really not great. > > > > > > I still think an arch with DT and simpler PCI code that powerpc c= ould > > > start looking at the transition to a better model that I hinted a= t... > >=20 > > As tempting as it is to start anew and with a cleaner code, I am wa= ry > > that porting the existing platforms to the new code will take longe= r > > 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 guarante= e > > that new ones will have an easier job. >=20 > It still makes little sense to generalize a pci_controller with > resources & offset on top of the generic pci_host_bridge with apertur= es. 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_contr= oller 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 >=20 > Ben. >=20 > > Best regards, > > Liviu > >=20 > > > > > > Cheers, > > > Ben. > > > > > > > > > > >=20 --=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- =C2=AF\_(=E3=83=84)_/=C2=AF