Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756547AbaKTCsA (ORCPT ); Wed, 19 Nov 2014 21:48:00 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:49490 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754289AbaKTCr4 (ORCPT ); Wed, 19 Nov 2014 21:47:56 -0500 Message-ID: <546D5647.8030401@huawei.com> Date: Thu, 20 Nov 2014 10:47:35 +0800 From: Yijing Wang User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Liviu Dudau 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() 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> In-Reply-To: <20141119163726.GW12037@e106497-lin.cambridge.arm.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.27.212] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020209.546D565A.003A,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 6c30e06b394fa6177a7b802026ca246b Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>> +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(). >>>> -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 ? And if we still use arch spec macros convert ssydata to pci_controller, so what's the greatest advantage ? If we move domain and msi_chip out of sysdata, what's other things in sysdata still need us to convert in PCI core ? > > 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 -- 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/