Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754274AbaGBOXJ (ORCPT ); Wed, 2 Jul 2014 10:23:09 -0400 Received: from service87.mimecast.com ([91.220.42.44]:40793 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753121AbaGBOXH convert rfc822-to-8bit (ORCPT ); Wed, 2 Jul 2014 10:23:07 -0400 Date: Wed, 2 Jul 2014 15:23:03 +0100 From: Liviu Dudau To: Arnd Bergmann Cc: "linux-arm-kernel@lists.infradead.org" , Liviu Dudau , Sinan Kaya , linaro-kernel , Benjamin Herrenschmidt , Device Tree ML , linux-pci , Jingoo Han , LKML , Will Deacon , Grant Likely , Kukjin Kim , Tanmay Inamdar , Suravee Suthikulanit , Catalin Marinas , Bjorn Helgaas Subject: Re: [PATCH v8 3/9] pci: Introduce pci_register_io_range() helper function. Message-ID: <20140702142303.GJ2173@e106497-lin.cambridge.arm.com> References: <1404240214-9804-1-git-send-email-Liviu.Dudau@arm.com> <8556461.i7qCGvGY5a@wuerfel> <20140701204508.GA19569@bart.dudau.co.uk> <7343032.WUqPgbXNQS@wuerfel> MIME-Version: 1.0 In-Reply-To: <7343032.WUqPgbXNQS@wuerfel> User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 02 Jul 2014 14:23:04.0868 (UTC) FILETIME=[23510640:01CF9601] X-MC-Unique: 114070215230410901 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 02, 2014 at 01:30:31PM +0100, Arnd Bergmann wrote: > On Tuesday 01 July 2014 21:45:09 Liviu Dudau wrote: > > On Tue, Jul 01, 2014 at 09:36:10PM +0200, Arnd Bergmann wrote: > > > On Tuesday 01 July 2014 19:43:28 Liviu Dudau wrote: > > > > > > This still conflicts with the other allocator you have in patch 9 > > > for pci_remap_iospace: nothing guarantees that the mapping is the > > > same for both. > > > > > > Also, this is a completely pointless exercise at this moment, because > > > nobody cares about the result of pci_address_to_pio on architectures > > > that don't already provide this function. If we ever get a proper > > > Open Firmware implementation that wants to put hardcoded PCI devices > > > into DT, we can add an implementation, but for now this seems overkill. > > > > > > The allocator in pci_register_io_range seems reasonable, why not merge > > > this function with pci_remap_iospace() as I have asked you multiple > > > times before? Just make it return the io_offset so the caller can > > > put that into the PCI host resources. > > > > Hi Arnd, > > > > While I agree with you that at some moment the allocators were inconsistent > > wrt each other, for this version I would respectfully disagree on this. > > The allocator in pci_register_io_range() only makes sure that the ranges > > are not overlapping, it doesn't do any mapping whatsoever, while > > pci_remap_iospace() does only an ioremap_page_range(). The idea is that > > you get the offset out of pci_address_to_pio() and apply it to > > pci_remap_iospace(). > > Ok, got it now, I'm sorry I didn't read this properly at first. > > Your solution looks correct to me, just using different > tradeoffs to what I was expecting: You get a working pci_address_to_pio() > function, which is probably never needed, but in turn you need to > keep the state of each host bridge in a global list. Just a reminder that with my patchset I *do* start using pci_address_to_pio() in order to correctly parse the IO ranges from DT. Best regards, Liviu > > Arnd > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ -- 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/