Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752700AbcL2MEZ (ORCPT ); Thu, 29 Dec 2016 07:04:25 -0500 Received: from fllnx209.ext.ti.com ([198.47.19.16]:48891 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752474AbcL2MEY (ORCPT ); Thu, 29 Dec 2016 07:04:24 -0500 Subject: Re: [PATCH] pci: rename *host* directory to *controller* To: Joao Pinto , Bjorn Helgaas References: <1482912577-31356-1-git-send-email-kishon@ti.com> <20161228092228.GA14025@infradead.org> <20161228164118.GB19653@bhelgaas-glaptop.roam.corp.google.com> <1ee66ce2-c321-2341-c964-c8b32218ca7e@synopsys.com> <426f0cb8-b9d4-7c0d-5eea-0ae0d4b01668@synopsys.com> <5864A335.9000203@ti.com> CC: Christoph Hellwig , Bjorn Helgaas , , , , Linus Torvalds From: Kishon Vijay Abraham I Message-ID: <5864F812.5050605@ti.com> Date: Thu, 29 Dec 2016 17:18:34 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4560 Lines: 110 Hi, On Thursday 29 December 2016 04:08 PM, Joao Pinto wrote: > > Hi, > > ?s 5:46 AM de 12/29/2016, Kishon Vijay Abraham I escreveu: >> Hi, >> >> On Wednesday 28 December 2016 10:50 PM, Joao Pinto wrote: >>> ?s 5:17 PM de 12/28/2016, Joao Pinto escreveu: >>>> ?s 4:41 PM de 12/28/2016, Bjorn Helgaas escreveu: >>>>> On Wed, Dec 28, 2016 at 01:57:13PM +0000, Joao Pinto wrote: >>>>>> ?s 9:22 AM de 12/28/2016, Christoph Hellwig escreveu: >>>>>>> On Wed, Dec 28, 2016 at 01:39:37PM +0530, Kishon Vijay Abraham I wrote: >>>>>>>> As discussed during our LPC discussions, I'm posting the rename patch >>>>>>>> here. I'll post the rest of EP series before the next merge window. >>>>>>>> >>>>>>>> There might be hiccups because of this renaming but feel this is >>>>>>>> necessary for long-term maintenance. >>>>>>> >>>>>>> if we do this rename it would be great to get it to Linus NOW after >>>>>>> -rc1 as that minimizes the impact on the 4.11 merge window. >>>>>> >>>>>> Rename it to controller is a bit vague I thing since we have the PCI Endpoint IP >>>>>> also. Wouldn't be better to name it rc_controller? >>>>> >>>>> I think Kishon's whole goal is to add PCI Endpoint IP, so he wants a >>>>> neutral name that can cover both RC and Endpoint. >> >> right. >>>>> >>>>> I'm not a huge fan of "controller" because it feels a little bit long >>>>> and while I suppose it technically does include the concept of the PCI >>>>> interface of an endpoint, it still suggests more of the host side to >>>>> me. >>>>> >>>>> Doesn't USB have a similar situation? I see there's a >>>>> drivers/usb/host/ (probably where we copied from in the first place). >>>>> Is a USB gadget the USB analog of what you're doing? How do they >>>>> share code between the master/slave sides? >>>>> >>>> >>>> The usb/host contains the implemnentations by the spec of the several >>>> *hci (USB Host) and then you can have for example the USB 3.0 Designware >>>> Host specific ops in dwc3 and for USB 2.0 in dwc2/. >> >> right, each IP have a separate directory in USB. I thought of doing something >> similar for PCI but decided against it since that would involve identifying all >> the PCI IPs used and eventually result in more directories. >>>> For device purposes it uses the core/ and then some of the device functions >>>> are extended from the gadget/ package in which you can use mass_storage and >>>> other types of functions. >> >> That would be similar for PCI endpoint. All endpoint specific core >> functionality will be added in drivers/pci/endpoint (see RFC [1]). >>>> >>>> In our case in PCI we have the core functions inside /drivers/pci and the host >>>> mangled inside host. I suggest: >>>> >>>> drivers/pci >>>> drivers/pci/core/ >>>> drivers/pci/core/hotplug >>>> drivers/pci/core/pcie >>>> drivers/pci/core/ >>>> drivers/pci/host >>>> drivers/pci/dwc -> here would be pcie-designware and the specific vendor drivers >>> >>> Correction: >>> drivers/pci/host/dwc -> here would be pcie-designware and the specific vendor >>> drivers >>> >>>> drivers/pci/ -> here would be the drivers for vendorN controller >>> >>> Correction: >>> drivers/pci/host/ -> here would be the drivers for vendorN controller >>> >>>> drivers/pci/endpoint -> common code >>>> drivers/pci/endpoint/dwc -> implementation of Synopsys specific endpoint ops >>>> drivers/pci/ -> implementation of other vendors specific endpoint ops >> >> There are some parts of the dwc driver that is common to both root complex and >> endpoint. Where should that be? I'm sure no one wants to duplicate the common >> piece in both root complex and endpoint. > > You are right, the config space is almost the same and some ops also common. > I would suggest: > > drivers/pci > drivers/pci/core/ > drivers/pci/core/hotplug > drivers/pci/core/pcie > drivers/pci/core/ > drivers/pci/dwc > drivers/pci/dwc/common.c -> common ops and registers between RC and endpoint > drivers/pci/dwc/host/ > drivers/pci/dwc/endpoint/ > > What do you think? I don't think we should have sub-directories within dwc (USB too doesn't have sub-directories). Where should the platform specific driver be kept? For example pci-dra7xx.c (which use dwc) has both rc and ep specific parts but the changes are so minimal that splitting the file won't make much sense. And such a change would also mean we create a separate directory for every other driver present right now in pci/host. Thanks Kishon