From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:43840 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750933AbaEGOyH (ORCPT ); Wed, 7 May 2014 10:54:07 -0400 Date: Wed, 7 May 2014 15:53:27 +0100 From: Will Deacon To: Arnd Bergmann Cc: Srikanth Thokala , "linux-arm-kernel@lists.infradead.org" , Bjorn Helgaas , Michal Simek , "grant.likely@linaro.org" , Rob Herring , "devicetree@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Jason Gunthorpe , marc.zyngier@arm.com Subject: Re: [PATCH v3] pcie: Add Xilinx PCIe Host Bridge IP driver Message-ID: <20140507145327.GB2563@arm.com> References: <1397561911-11647-1-git-send-email-sthokal@xilinx.com> <201404301734.14478.arnd@arndb.de> <4288313.uDFYZQS3W7@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4288313.uDFYZQS3W7@wuerfel> Sender: linux-pci-owner@vger.kernel.org List-ID: Hi all, Thanks for CC'ing me, Arnd. On Wed, May 07, 2014 at 03:35:48PM +0100, Arnd Bergmann wrote: > On Wednesday 07 May 2014 17:21:13 Srikanth Thokala wrote: > > On Wed, Apr 30, 2014 at 9:04 PM, Arnd Bergmann wrote: > > > Would it be possible to split the config space access out into > > > a separate file? It would be nice to share that with the generic > > > ECAM driver that Will Deacon has sent. > > > > Yes, it should be possible. Is it ok, if I work on top of this driver? > > Do you mean as a follow-on patch? My feeling is that since we are trying > to merge both for 3.16, it would be good to get it done right away if > it doesn't cause too much extra work. Do you mean something as simple as a helper for base + offset ECAM addressing, or something more involved that handles the mapping as well? The latter would need some alignment on sys->private_data, I think. Srikanth: I'll CC you on the next version of my patches (I'll send them now). > > > As a general comment about the MSI implementation, I wonder if this is actually > > > generic enough to be shared with other host controllers. It could be moved > > > into a separate file like the config space access in that case. > > > > I feel the MSI implementation is not generic by looking into the other > > host controllers, > > it is more specific to the hardware. Correct me, if am wrong. > > The other host controllers are certainly incompatible, but this one looks > like it could be used on other controllers easily. > > Splitting it out would also make it easier to use another MSI implementation > like the one in the GIC. Actually, MarcZ and I already have my driver working with GICv3 + MSI. The code basically amounts to implementing {add,remove}_bus callbacks to set the msi_chip for the pci_bus, based on what we got out of the devicetree. I don't think we needed anything else... Marc? Will