Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755928Ab3FGOuz (ORCPT ); Fri, 7 Jun 2013 10:50:55 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:28867 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753911Ab3FGOux (ORCPT ); Fri, 7 Jun 2013 10:50:53 -0400 Date: Fri, 7 Jun 2013 10:50:24 -0400 From: Konrad Rzeszutek Wilk To: Jiang Liu Cc: Bjorn Helgaas , Yinghai Lu , Jiang Liu , "Rafael J . Wysocki" , Greg Kroah-Hartman , Gu Zheng , Toshi Kani , Myron Stowe , Yijing Wang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Jeremy Fitzhardinge , xen-devel@lists.xensource.com, virtualization@lists.linux-foundation.org Subject: Re: [RFC PATCH v2, part3 07/11] PCI, xen-pcifront: use new PCI interfaces to simplify implementation Message-ID: <20130607145024.GA16631@phenom.dumpdata.com> References: <1368719459-24800-1-git-send-email-jiang.liu@huawei.com> <1368719459-24800-8-git-send-email-jiang.liu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1368719459-24800-8-git-send-email-jiang.liu@huawei.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6608 Lines: 217 On Thu, May 16, 2013 at 11:50:55PM +0800, Jiang Liu wrote: > 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. That is incorrect. There are two types of backends - one of them will start at zero, but the other might not. > + * 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; > } > + Stray > 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); > } > + Stray > 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/