From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Arnd Bergmann To: linux-pci@vger.kernel.org, Bjorn Helgaas Cc: linux-kernel@vger.kernel.org, Christoph Hellwig , Lorenzo Pieralisi , Benjamin Herrenschmidt , linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, Arnd Bergmann Subject: [RFC 09/15] PCI: xenfront: clean up pcifront_scan_root() Date: Fri, 17 Aug 2018 12:26:39 +0200 Message-Id: <20180817102645.3839621-10-arnd@arndb.de> In-Reply-To: <20180817102645.3839621-1-arnd@arndb.de> References: <20180817102645.3839621-1-arnd@arndb.de> Sender: linux-acpi-owner@vger.kernel.org List-ID: Merging pci_scan_root_bus() into pcifront_scan_root() simplifies the implementation and makes it more readable. We can allocate the pcifront_sd structure along with the bridge structure, which helps manage its lifetime rules so we don't free it before the device has been released. There are two small issues that I noticed that could be improved: - It seems we unregister the 'bus' device that is a child of the 'pci_host_bridge' device after we unregister its parent in pcifront_free_roots(), which seems odd. - We probably don't need an extra pci_bus_entry list at all, but could instead walk the children of the pcifront_device, which are all pci_host_bridge devices. Signed-off-by: Arnd Bergmann --- drivers/pci/xen-pcifront.c | 67 ++++++++++++-------------------------- 1 file changed, 21 insertions(+), 46 deletions(-) diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index 24070e1c5f22..a5eb6cb02bec 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -443,40 +443,12 @@ static int pcifront_scan_bus(struct pcifront_device *pdev, return 0; } -static struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, - struct pci_ops *ops, void *sysdata, struct list_head *resources) -{ - struct pci_host_bridge *bridge; - int error; - - bridge = pci_alloc_host_bridge(0); - if (!bridge) - return NULL; - - list_splice_init(resources, &bridge->windows); - bridge->dev.parent = parent; - bridge->sysdata = sysdata; - bridge->busnr = bus; - bridge->ops = ops; - - error = pci_scan_root_bus_bridge(bridge); - if (error < 0) - goto err_out; - - return bridge->bus; - -err_out: - kfree(bridge); - return NULL; -} - static int pcifront_scan_root(struct pcifront_device *pdev, unsigned int domain, unsigned int bus) { - struct pci_bus *b; - LIST_HEAD(resources); struct pcifront_sd *sd = NULL; struct pci_bus_entry *bus_entry = NULL; + struct pci_host_bridge *bridge; int err = 0; static struct resource busn_res = { .start = 0, @@ -498,50 +470,55 @@ static int pcifront_scan_root(struct pcifront_device *pdev, dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n", domain, bus); + bridge = pci_alloc_host_bridge(sizeof(*sd)); + if (!bridge) + return -ENOMEM; + bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL); - sd = kzalloc(sizeof(*sd), GFP_KERNEL); - if (!bus_entry || !sd) { + sd = pci_host_bridge_priv(bridge); + if (!bus_entry) { err = -ENOMEM; goto err_out; } - pci_add_resource(&resources, &ioport_resource); - pci_add_resource(&resources, &iomem_resource); - pci_add_resource(&resources, &busn_res); + pci_add_resource(&bridge->windows, &ioport_resource); + pci_add_resource(&bridge->windows, &iomem_resource); + pci_add_resource(&bridge->windows, &busn_res); pcifront_init_sd(sd, domain, bus, pdev); + bridge->dev.parent = &pdev->xdev->dev; + bridge->sysdata = sd; + bridge->busnr = bus; + bridge->ops = &pcifront_bus_ops; pci_lock_rescan_remove(); - b = pci_scan_root_bus(&pdev->xdev->dev, bus, - &pcifront_bus_ops, sd, &resources); - if (!b) { + err = pci_scan_root_bus_bridge(bridge); + if (err < 0) { dev_err(&pdev->xdev->dev, "Error creating PCI Frontend Bus!\n"); - err = -ENOMEM; pci_unlock_rescan_remove(); - pci_free_resource_list(&resources); goto err_out; } - bus_entry->bus = b; + bus_entry->bus = bridge->bus; list_add(&bus_entry->list, &pdev->root_buses); /* pci_scan_root_bus skips devices which do not have a * devfn==0. The pcifront_scan_bus enumerates all devfn. */ - err = pcifront_scan_bus(pdev, domain, bus, b); + err = pcifront_scan_bus(pdev, domain, bus, bridge->bus); /* Claim resources before going "live" with our devices */ - pci_walk_bus(b, pcifront_claim_resource, pdev); + pci_walk_bus(bridge->bus, pcifront_claim_resource, pdev); /* Create SysFS and notify udev of the devices. Aka: "going live" */ - pci_bus_add_devices(b); + pci_bus_add_devices(bridge->bus); pci_unlock_rescan_remove(); return err; err_out: + pci_free_host_bridge(bridge); kfree(bus_entry); - kfree(sd); return err; } @@ -605,8 +582,6 @@ static void pcifront_free_roots(struct pcifront_device *pdev) free_root_bus_devs(bus_entry->bus); - kfree(bus_entry->bus->sysdata); - device_unregister(bus_entry->bus->bridge); pci_remove_bus(bus_entry->bus); -- 2.18.0