Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757505AbaKTJsR (ORCPT ); Thu, 20 Nov 2014 04:48:17 -0500 Received: from service87.mimecast.com ([91.220.42.44]:33681 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757482AbaKTJrt convert rfc822-to-8bit (ORCPT ); Thu, 20 Nov 2014 04:47:49 -0500 Date: Thu, 20 Nov 2014 09:47:41 +0000 From: Liviu Dudau To: Yijing Wang Cc: Bjorn Helgaas , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "huxinwei@huawei.com" , Wuyun , "linux-arm-kernel@lists.infradead.org" , Russell King , "x86@kernel.org" , Thomas Gleixner , Benjamin Herrenschmidt , "linuxppc-dev@lists.ozlabs.org" , Tony Luck , "linux-ia64@vger.kernel.org" , Thierry Reding , Liviu Dudau , "suravee.suthikulpanit@amd.com" Subject: Re: [RFC PATCH 07/16] PCI: Separate pci_host_bridge creation out of pci_create_root_bus() Message-ID: <20141120094741.GA17214@e106497-lin.cambridge.arm.com> References: <1416219710-26088-1-git-send-email-wangyijing@huawei.com> <1416219710-26088-8-git-send-email-wangyijing@huawei.com> <20141118153020.GL12037@e106497-lin.cambridge.arm.com> <546BF59C.8060203@huawei.com> <20141119163726.GW12037@e106497-lin.cambridge.arm.com> <546D5647.8030401@huawei.com> MIME-Version: 1.0 In-Reply-To: <546D5647.8030401@huawei.com> User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 20 Nov 2014 09:47:43.0242 (UTC) FILETIME=[07E7B6A0:01D004A7] X-MC-Unique: 114112009474500701 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 Thu, Nov 20, 2014 at 02:47:35AM +0000, Yijing Wang wrote: > >>>> +static void pci_release_host_bridge_dev(struct device *dev) > >>>> +{ > >>>> + struct pci_host_bridge *bridge = to_pci_host_bridge(dev); > >>>> + > >>>> + if (bridge->release_fn) > >>>> + bridge->release_fn(bridge); > >>>> + pci_free_resource_list(&bridge->windows); > >>>> + kfree(bridge); > >>>> +} > >>>> + > >>>> +struct pci_host_bridge *pci_create_host_bridge( > >>>> + struct device *parent, u32 db, > >>>> + struct pci_ops *ops, void *sysdata, > >>> > >>> I don't thinks it is worth moving the buses' pci_ops into pci_host_bridge. It > >>> might be more useful to have pci_host_bridge specific ops here. > >> > >> Because we want to create pci_host_bridge before pci root bus creation, > >> so when we scan the root bus and child buses, we use pci_host_bridge as > >> the only argument, and another pci_host_info will be addes in later patch, > >> which one support carry the pci_host_bridge ops. > > > > But pci_create_root_bus() already has a pci_ops argument, I don't see the reason > > to drop that. > > > > pci_create_host_bridge() can get pci_host_bridge ops while pci_create_root_bus() gets > > the bus ops. For find out the MSI controller, the domain number and any other HB > > specific stuff, you use the HB ops. For config R/W acceses you use bus ops. > > > > I want to unexport pci_create_root_bus() if we have pci_create_host_bridge(). That's fine, but the function signature doesn't change, right? And I think we should keep pci_scan_root_bus() with the current signature as well (except change sysdata into a struct pci_host_bridge *). We create the host bridge in one step, stuff it with all the data that we need for scanning the root and associated busses, and then call pci_scan_root_bus(). pci_host_bridge has the ops from pci_create_host_bridge() and the root bus from pci_scan_root_bus(). Hope this makes sense. > > > >>>> -struct pci_bus *pci_create_root_bus(struct device *parent, u32 db, > >>>> - struct pci_ops *ops, void *sysdata, struct list_head *resources) > >>>> +struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *bridge) > >>>> { > >>>> int error; > >>>> - struct pci_host_bridge *bridge; > >>>> struct pci_bus *b, *b2; > >>>> - struct pci_host_bridge_window *window, *n; > >>>> + struct pci_host_bridge_window *window; > >>>> struct resource *res; > >>>> resource_size_t offset; > >>>> char bus_addr[64]; > >>>> char *fmt; > >>>> - u8 bus = PCI_BUSNUM(db); > >>>> + struct device *parent = bridge->dev.parent; > >>>> > >>>> b = pci_alloc_bus(NULL); > >>>> if (!b) > >>>> return NULL; > >>>> > >>>> - b->sysdata = sysdata; > >>>> - b->ops = ops; > >>>> - b->number = b->busn_res.start = bus; > >>>> + b->sysdata = bridge->sysdata; > >>> > >>> I think bridge should be the b->sysdata here. > >> > >> ? what's the meaning? > > > > Currently, bus->sysdata holds a pointer to the arch/driver host bridge structure, as passed > > in pci_create_root_bus(). If you agree with my idea of wrapping the host bridge driver > > structure around the pci_host_bridge, then we will always have a way of retrieving that > > information; but for backwards compatibility we could set bus->sysdata to be the bridge. > > Then existing macros that convert sysdata to pci_controller can be reused after being > > updated. > > I think wrapping the host bridge driver structure around the pci_host_bridge could help > us to find the private pci_controller, but in this case, pci_host_bridge is not a pointer > so we put all pci_host_bridge init stuff in host drivers ? Of course we put pci_host_bridge init *calls* in the host drivers because we need to do host driver specific initialisation there anyway. > And if we still use arch spec > macros convert ssydata to pci_controller, so what's the greatest advantage ? Agree, the macro is not useful unless we have a common pci_controller structure. Sorry about the noise. > > If we move domain and msi_chip out of sysdata, what's other things in sysdata still need us > to convert in PCI core ? I've never said we need to keep sysdata. From my discussion with Bjorn a year ago the idea was to put the sysdata members into pci_host_bridge structure and remove sysdata member from pci_bus. pci_scan_root_bus() can still get a parameter called sysdata if we want, but it will be a struct pci_host_bridge * type. Best regards, Liviu > > > > > > > Best regards, > > Liviu > > > >> > >>> > >>>> + b->ops = bridge->ops; > >>> > >>> See comment above why I don't think this is necessary. > >>> > >>>> + b->number = b->busn_res.start = bridge->busnum; > >>>> pci_bus_assign_domain_nr(b, parent); > >>>> - b2 = pci_find_bus(pci_domain_nr(b), bus); > >>>> + bridge->domain = pci_domain_nr(b); > >>> > >>> Do you really want to overwrite the bridge's domain with the one from a bus that > >>> could possibly be rejected a couple of lines further down? > >>> > >>> As an asside: if we are doing the split of pci_host_bridge from root bus creation > >>> it is worth in my opinion to move the domain setup in pci_create_host_bridge() > >>> and stop fiddling with it here. > >> > >> > >> Hi Liviu, these lines just temporary, I will remove it after all host drivers > >> save its domain in pci_host_bridge. > >> > >> > >>> > >>> Otherwise it looks to me like you are heading in the right direction. > >> > >> Thanks! > >> Yijing. > >> > >>> > >>> Best regards, > >>> Liviu > >>> > >>>> + b2 = pci_find_bus(pci_domain_nr(b), bridge->busnum); > >>>> if (b2) { > >>>> /* If we already got to this bus through a different bridge, ignore it */ > >>>> dev_dbg(&b2->dev, "bus already known\n"); > >>>> goto err_out; > >>>> } > >>>> > >>>> - bridge = pci_alloc_host_bridge(b); > >>>> - if (!bridge) > >>>> - goto err_out; > >>>> - > >>>> - bridge->dev.parent = parent; > >>>> - bridge->dev.release = pci_release_host_bridge_dev; > >>>> - dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); > >>>> - error = pcibios_root_bridge_prepare(bridge); > >>>> - if (error) { > >>>> - kfree(bridge); > >>>> - goto err_out; > >>>> - } > >>>> - > >>>> - error = device_register(&bridge->dev); > >>>> - if (error) { > >>>> - put_device(&bridge->dev); > >>>> - goto err_out; > >>>> - } > >>>> b->bridge = get_device(&bridge->dev); > >>>> device_enable_async_suspend(b->bridge); > >>>> pci_set_bus_of_node(b); > >>>> @@ -1950,7 +1899,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db, > >>>> > >>>> b->dev.class = &pcibus_class; > >>>> b->dev.parent = b->bridge; > >>>> - dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus); > >>>> + dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), b->number); > >>>> error = device_register(&b->dev); > >>>> if (error) > >>>> goto class_dev_reg_err; > >>>> @@ -1966,12 +1915,11 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db, > >>>> printk(KERN_INFO "PCI host bridge to bus %s\n", dev_name(&b->dev)); > >>>> > >>>> /* Add initial resources to the bus */ > >>>> - list_for_each_entry_safe(window, n, resources, list) { > >>>> - list_move_tail(&window->list, &bridge->windows); > >>>> + list_for_each_entry(window, &bridge->windows, list) { > >>>> res = window->res; > >>>> offset = window->offset; > >>>> if (res->flags & IORESOURCE_BUS) > >>>> - pci_bus_insert_busn_res(b, bus, res->end); > >>>> + pci_bus_insert_busn_res(b, b->number, res->end); > >>>> else > >>>> pci_bus_add_resource(b, res, 0); > >>>> if (offset) { > >>>> @@ -2001,6 +1949,25 @@ err_out: > >>>> return NULL; > >>>> } > >>>> > >>>> +struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus, > >>>> + struct pci_ops *ops, void *sysdata, struct list_head *resources) > >>>> +{ > >>>> + struct pci_host_bridge *host; > >>>> + > >>>> + host = pci_create_host_bridge(parent, bus, ops, > >>>> + sysdata ,resources); > >>>> + if (!host) > >>>> + return NULL; > >>>> + > >>>> + host->bus = __pci_create_root_bus(host); > >>>> + if (!host->bus) { > >>>> + pci_free_host_bridge(host); > >>>> + return NULL; > >>>> + } > >>>> + > >>>> + return host->bus; > >>>> +} > >>>> + > >>>> int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) > >>>> { > >>>> struct resource *res = &b->busn_res; > >>>> @@ -2069,40 +2036,37 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db, > >>>> { > >>>> struct pci_host_bridge_window *window; > >>>> bool found = false; > >>>> - struct pci_bus *b; > >>>> - LIST_HEAD(default_res); > >>>> + struct pci_host_bridge *host; > >>>> int max; > >>>> > >>>> - if (!resources) { > >>>> - pci_add_resource(&default_res, &ioport_resource); > >>>> - pci_add_resource(&default_res, &iomem_resource); > >>>> - pci_add_resource(&default_res, &busn_resource); > >>>> - } else { > >>>> - list_for_each_entry(window, resources, list) > >>>> - if (window->res->flags & IORESOURCE_BUS) { > >>>> - found = true; > >>>> - break; > >>>> - } > >>>> - } > >>>> + host = pci_create_host_bridge(parent, db, ops, sysdata, resources); > >>>> + if (!host) > >>>> + return NULL; > >>>> > >>>> - b = pci_create_root_bus(parent, db, ops, sysdata, > >>>> - resources ? resources : &default_res); > >>>> - if (!b) > >>>> + list_for_each_entry(window, &host->windows, list) > >>>> + if (window->res->flags & IORESOURCE_BUS) { > >>>> + found = true; > >>>> + break; > >>>> + } > >>>> + > >>>> + host->bus = __pci_create_root_bus(host); > >>>> + if (!host->bus) { > >>>> + pci_free_host_bridge(host); > >>>> return NULL; > >>>> + } > >>>> > >>>> if (!found) { > >>>> - dev_info(&b->dev, > >>>> + dev_info(&host->bus->dev, > >>>> "No busn resource found for root bus, will use [bus %02x-ff]\n", > >>>> PCI_BUSNUM(db)); > >>>> - pci_bus_insert_busn_res(b, PCI_BUSNUM(db), 255); > >>>> + pci_bus_insert_busn_res(host->bus, PCI_BUSNUM(db), 255); > >>>> } > >>>> > >>>> - max = pci_scan_child_bus(b); > >>>> - > >>>> + max = pci_scan_child_bus(host->bus); > >>>> if (!found) > >>>> - pci_bus_update_busn_res_end(b, max); > >>>> + pci_bus_update_busn_res_end(host->bus, max); > >>>> > >>>> - return b; > >>>> + return host->bus; > >>>> } > >>>> EXPORT_SYMBOL(pci_scan_root_bus); > >>>> > >>>> diff --git a/include/linux/pci.h b/include/linux/pci.h > >>>> index 8b11b38..daa7f40 100644 > >>>> --- a/include/linux/pci.h > >>>> +++ b/include/linux/pci.h > >>>> @@ -402,7 +402,12 @@ struct pci_host_bridge_window { > >>>> struct pci_host_bridge { > >>>> struct device dev; > >>>> struct pci_bus *bus; /* root bus */ > >>>> + struct list_head list; > >>>> struct list_head windows; /* pci_host_bridge_windows */ > >>>> + int busnum; > >>>> + int domain; > >>>> + void *sysdata; > >>>> + struct pci_ops *ops; > >>>> void (*release_fn)(struct pci_host_bridge *); > >>>> void *release_data; > >>>> }; > >>>> @@ -413,7 +418,9 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge, > >>>> void *release_data); > >>>> > >>>> int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge); > >>>> - > >>>> +struct pci_host_bridge *pci_create_host_bridge( > >>>> + struct device *parent, u32 db, struct pci_ops *ops, > >>>> + void *sys, struct list_head *resources); > >>>> /* > >>>> * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond > >>>> * to P2P or CardBus bridge windows) go in a table. Additional ones (for > >>>> @@ -770,6 +777,8 @@ void pci_bus_add_devices(const struct pci_bus *bus); > >>>> struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus, > >>>> struct pci_ops *ops, void *sysdata, > >>>> struct list_head *resources); > >>>> +struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *host); > >>>> +void pci_free_host_bridge(struct pci_host_bridge *host); > >>>> int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax); > >>>> int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax); > >>>> void pci_bus_release_busn_res(struct pci_bus *b); > >>>> -- > >>>> 1.7.1 > >>>> > >>>> -- > >>>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in > >>>> the body of a message to majordomo@vger.kernel.org > >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html > >>>> > >>> > >> > >> > >> -- > >> Thanks! > >> Yijing > >> > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in > >> the body of a message to majordomo@vger.kernel.org > >> More majordomo info at http://vger.kernel.org/majordomo-info.html > >> > > > > > -- > Thanks! > Yijing > > -- ==================== | 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/