Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755897AbaBFKSZ (ORCPT ); Thu, 6 Feb 2014 05:18:25 -0500 Received: from service87.mimecast.com ([91.220.42.44]:40389 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755537AbaBFKSU convert rfc822-to-8bit (ORCPT ); Thu, 6 Feb 2014 05:18:20 -0500 Date: Thu, 6 Feb 2014 10:18:15 +0000 From: Liviu Dudau To: Tanmay Inamdar Cc: Arnd Bergmann , "devicetree@vger.kernel.org" , linaro-kernel , linux-pci , Will Deacon , LKML , Catalin Marinas , Bjorn Helgaas , LAKML Subject: Re: [PATCH] pci: Add support for creating a generic host_bridge from device tree Message-ID: <20140206101814.GA4993@e106497-lin.cambridge.arm.com> Mail-Followup-To: Tanmay Inamdar , Arnd Bergmann , "devicetree@vger.kernel.org" , linaro-kernel , linux-pci , Will Deacon , LKML , Catalin Marinas , Bjorn Helgaas , LAKML References: <1391452428-22917-1-git-send-email-Liviu.Dudau@arm.com> <1391452428-22917-2-git-send-email-Liviu.Dudau@arm.com> <7398333.9L5KlyFggU@wuerfel> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 06 Feb 2014 10:18:15.0379 (UTC) FILETIME=[BF636230:01CF2324] X-MC-Unique: 114020610181702201 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, Feb 05, 2014 at 10:26:27PM +0000, Tanmay Inamdar wrote: > Hello Liviu, > > I did not get the first email of this particular patch on any of > subscribed mailing lists (don't know why), hence replying here. Strange, it shows in the MARC and GMANE archive for linux-pci, probably a hickup on your receiving side? > > +struct pci_host_bridge * > +pci_host_bridge_of_init(struct device *parent, int busno, struct pci_ops *ops, > + void *host_data, struct list_head *resources) > +{ > + struct pci_bus *root_bus; > + struct pci_host_bridge *bridge; > + > + /* first parse the host bridge bus ranges */ > + if (pci_host_bridge_of_get_ranges(parent->of_node, resources)) > + return NULL; > + > + /* then create the root bus */ > + root_bus = pci_create_root_bus(parent, busno, ops, host_data, resources); > + if (!root_bus) > + return NULL; > + > + bridge = to_pci_host_bridge(root_bus->bridge); > + > + return bridge; > +} > > You are keeping the domain_nr inside pci_host_bridge structure. In > above API, domain_nr is required in 'pci_find_bus' function called > from 'pci_create_root_bus'. Since the bridge is allocated after > creating root bus, 'pci_find_bus' always gets domain_nr as 0. This > will cause problem for scanning multiple domains. Good catch. I was switching between creating a pci_controller in arch/arm64 and adding the needed bits in pci_host_bridge. After internal review I've decided to add the domain_nr to pci_host_bridge, but forgot to update the code everywhere. Thanks for reviewing this, will fix in v2. Do you find porting to the new API straight forward? Best regards, Liviu > > > On Mon, Feb 3, 2014 at 10:46 AM, Arnd Bergmann wrote: > > On Monday 03 February 2014 18:33:48 Liviu Dudau wrote: > >> +/** > >> + * pci_host_bridge_of_get_ranges - Parse PCI host bridge resources from DT > >> + * @dev: device node of the host bridge having the range property > >> + * @resources: list where the range of resources will be added after DT parsing > >> + * > >> + * This function will parse the "ranges" property of a PCI host bridge device > >> + * node and setup the resource mapping based on its content. It is expected > >> + * that the property conforms with the Power ePAPR document. > >> + * > >> + * Each architecture will then apply their filtering based on the limitations > >> + * of each platform. One general restriction seems to be the number of IO space > >> + * ranges, the PCI framework makes intensive use of struct resource management, > >> + * and for IORESOURCE_IO types they can only be requested if they are contained > >> + * within the global ioport_resource, so that should be limited to one IO space > >> + * range. > > > > Actually we have quite a different set of restrictions around I/O space on ARM32 > > at the moment: Each host bridge can have its own 64KB range in an arbitrary > > location on MMIO space, and the total must not exceed 2MB of I/O space. > > > >> + */ > >> +static int pci_host_bridge_of_get_ranges(struct device_node *dev, > >> + struct list_head *resources) > >> +{ > >> + struct resource *res; > >> + struct of_pci_range range; > >> + struct of_pci_range_parser parser; > >> + int err; > >> + > >> + pr_info("PCI host bridge %s ranges:\n", dev->full_name); > >> + > >> + /* Check for ranges property */ > >> + err = of_pci_range_parser_init(&parser, dev); > >> + if (err) > >> + return err; > >> + > >> + pr_debug("Parsing ranges property...\n"); > >> + for_each_of_pci_range(&parser, &range) { > >> + /* Read next ranges element */ > >> + pr_debug("pci_space: 0x%08x pci_addr:0x%016llx ", > >> + range.pci_space, range.pci_addr); > >> + pr_debug("cpu_addr:0x%016llx size:0x%016llx\n", > >> + range.cpu_addr, range.size); > >> + > >> + /* If we failed translation or got a zero-sized region > >> + * (some FW try to feed us with non sensical zero sized regions > >> + * such as power3 which look like some kind of attempt > >> + * at exposing the VGA memory hole) then skip this range > >> + */ > >> + if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) > >> + continue; > >> + > >> + res = kzalloc(sizeof(struct resource), GFP_KERNEL); > >> + if (!res) { > >> + err = -ENOMEM; > >> + goto bridge_ranges_nomem; > >> + } > >> + > >> + of_pci_range_to_resource(&range, dev, res); > >> + > >> + pci_add_resource_offset(resources, res, > >> + range.cpu_addr - range.pci_addr); > >> + } > > > > I believe of_pci_range_to_resource() will return the MMIO aperture for the > > I/O space window here, which is not what you are supposed to pass into > > pci_add_resource_offset. > > > >> +EXPORT_SYMBOL(pci_host_bridge_of_init); > > > > EXPORT_SYMBOL_GPL > > > >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > >> index 6e34498..16febae 100644 > >> --- a/drivers/pci/probe.c > >> +++ b/drivers/pci/probe.c > >> @@ -1787,6 +1787,17 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > >> list_for_each_entry_safe(window, n, resources, list) { > >> list_move_tail(&window->list, &bridge->windows); > >> res = window->res; > >> + /* > >> + * IO resources are stored in the kernel with a CPU start > >> + * address of zero. Adjust the data accordingly and remember > >> + * the offset > >> + */ > >> + if (resource_type(res) == IORESOURCE_IO) { > >> + bridge->io_offset = res->start; > >> + res->end -= res->start; > >> + window->offset -= res->start; > >> + res->start = 0; > >> + } > >> offset = window->offset; > >> if (res->flags & IORESOURCE_BUS) > > > > Won't this break all existing host bridges? > > > > Arnd > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- ==================== | 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/