Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754798Ab3EPPvt (ORCPT ); Thu, 16 May 2013 11:51:49 -0400 Received: from mail-da0-f42.google.com ([209.85.210.42]:60023 "EHLO mail-da0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754769Ab3EPPvp (ORCPT ); Thu, 16 May 2013 11:51:45 -0400 From: Jiang Liu To: Bjorn Helgaas , Yinghai Lu Cc: Jiang Liu , "Rafael J . Wysocki" , Greg Kroah-Hartman , Gu Zheng , Toshi Kani , Myron Stowe , Yijing Wang , Jiang Liu , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Konrad Rzeszutek Wilk , Jeremy Fitzhardinge , xen-devel@lists.xensource.com, virtualization@lists.linux-foundation.org Subject: [RFC PATCH v2, part3 07/11] PCI, xen-pcifront: use new PCI interfaces to simplify implementation Date: Thu, 16 May 2013 23:50:55 +0800 Message-Id: <1368719459-24800-8-git-send-email-jiang.liu@huawei.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1368719459-24800-1-git-send-email-jiang.liu@huawei.com> References: <1368719459-24800-1-git-send-email-jiang.liu@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6017 Lines: 208 Use new PCI interfaces to simplify xen-pcifront implementation: 1) Use pci_create_root_bus() instead of pci_scan_bus_parented() because pci_scan_bus_parented() is marked as __deprecated.This also gets rid of a duplicated call of pci_bus_start_devices(). 2) Use pci_stop_root_bus() and pci_remove_root_bus() instead of open-coded private implementation. 3) Use pci_set_host_bridge_release() to release data structures associated with PCI root buses. 4) Use pci_bus_get()/pci_bus_put() to manage PCI root bus reference count. This is also a preparation for coming PCI bus lock enhancement. Signed-off-by: Jiang Liu Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Cc: linux-pci@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- drivers/pci/xen-pcifront.c | 81 ++++++++++++++++++++++------------------------ 1 file changed, 39 insertions(+), 42 deletions(-) diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index 816cf94..6aa2c0f 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -25,11 +25,6 @@ #define INVALID_GRANT_REF (0) #define INVALID_EVTCHN (-1) -struct pci_bus_entry { - struct list_head list; - struct pci_bus *bus; -}; - #define _PDEVB_op_active (0) #define PDEVB_op_active (1 << (_PDEVB_op_active)) @@ -47,12 +42,12 @@ struct pcifront_device { struct xen_pci_sharedinfo *sh_info; struct work_struct op_work; unsigned long flags; - }; struct pcifront_sd { int domain; struct pcifront_device *pdev; + struct resource busn_res; }; static inline struct pcifront_device * @@ -67,6 +62,12 @@ static inline void pcifront_init_sd(struct pcifront_sd *sd, { sd->domain = domain; sd->pdev = pdev; + + /* Xen pci-backend doesn't export P2P bridges */ + sd->busn_res.start = bus; + sd->busn_res.end = bus; + sd->busn_res.flags = IORESOURCE_BUS; + sd->busn_res.name = "PCI busn"; } static DEFINE_SPINLOCK(pcifront_dev_lock); @@ -441,12 +442,19 @@ static int pcifront_scan_bus(struct pcifront_device *pdev, return 0; } +static void pcifront_release_sd(struct pci_host_bridge *bridge) +{ + struct pcifront_sd *sd = bridge->release_data; + + kfree(sd); +} + static int pcifront_scan_root(struct pcifront_device *pdev, unsigned int domain, unsigned int bus) { struct pci_bus *b; struct pcifront_sd *sd = NULL; - struct pci_bus_entry *bus_entry = NULL; + LIST_HEAD(resources); int err = 0; #ifndef CONFIG_PCI_DOMAINS @@ -463,16 +471,18 @@ static int pcifront_scan_root(struct pcifront_device *pdev, dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n", domain, bus); - bus_entry = kmalloc(sizeof(*bus_entry), GFP_KERNEL); - sd = kmalloc(sizeof(*sd), GFP_KERNEL); - if (!bus_entry || !sd) { + sd = kzalloc(sizeof(*sd), GFP_KERNEL); + if (!sd) { err = -ENOMEM; goto err_out; } pcifront_init_sd(sd, domain, bus, pdev); - b = pci_scan_bus_parented(&pdev->xdev->dev, bus, - &pcifront_bus_ops, sd); + pci_add_resource(&resources, &ioport_resource); + pci_add_resource(&resources, &iomem_resource); + pci_add_resource(&resources, &sd->busn_res); + b = pci_create_root_bus(&pdev->xdev->dev, bus, &pcifront_bus_ops, + sd, &resources); if (!b) { dev_err(&pdev->xdev->dev, "Error creating PCI Frontend Bus!\n"); @@ -480,12 +490,14 @@ static int pcifront_scan_root(struct pcifront_device *pdev, goto err_out; } - bus_entry->bus = b; + pci_set_host_bridge_release(to_pci_host_bridge(b->bridge), + pcifront_release_sd, sd); - list_add(&bus_entry->list, &pdev->root_buses); - - /* pci_scan_bus_parented skips devices which do not have a have - * devfn==0. The pcifront_scan_bus enumerates all devfn. */ + /* + * Every PCI physical device should have function 0, but that's not + * true for xen. + * So use pcifront_scan_bus() instead of pci_scan_child_bus(). + */ err = pcifront_scan_bus(pdev, domain, bus, b); /* Claim resources before going "live" with our devices */ @@ -497,7 +509,6 @@ static int pcifront_scan_root(struct pcifront_device *pdev, return err; err_out: - kfree(bus_entry); kfree(sd); return err; @@ -539,35 +550,19 @@ static int pcifront_rescan_root(struct pcifront_device *pdev, return err; } -static void free_root_bus_devs(struct pci_bus *bus) -{ - struct pci_dev *dev; - - while (!list_empty(&bus->devices)) { - dev = container_of(bus->devices.next, struct pci_dev, - bus_list); - dev_dbg(&dev->dev, "removing device\n"); - pci_stop_and_remove_bus_device(dev); - } -} - static void pcifront_free_roots(struct pcifront_device *pdev) { - struct pci_bus_entry *bus_entry, *t; + struct pcifront_sd *sd; + struct pci_bus *bus; dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n"); - list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) { - list_del(&bus_entry->list); - - free_root_bus_devs(bus_entry->bus); - - kfree(bus_entry->bus->sysdata); - - device_unregister(bus_entry->bus->bridge); - pci_remove_bus(bus_entry->bus); - - kfree(bus_entry); + for_each_pci_root_bus(bus) { + sd = bus->sysdata; + if (sd->pdev == pdev) { + pci_stop_root_bus(bus); + pci_remove_root_bus(bus); + } } } @@ -670,6 +665,7 @@ static irqreturn_t pcifront_handler_aer(int irq, void *dev) schedule_pcifront_aer_op(pdev); return IRQ_HANDLED; } + static int pcifront_connect_and_init_dma(struct pcifront_device *pdev) { int err = 0; @@ -705,6 +701,7 @@ static void pcifront_disconnect(struct pcifront_device *pdev) spin_unlock(&pcifront_dev_lock); } + static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev) { struct pcifront_device *pdev; -- 1.8.1.2 -- 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/