Jiang Liu
2013-May-16 15:50 UTC
[RFC PATCH v2, part3 07/11] PCI, xen-pcifront: use new PCI interfaces to simplify implementation
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 <jiang.liu at huawei.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Cc: Jeremy Fitzhardinge <jeremy at goop.org> Cc: xen-devel at lists.xensource.com Cc: virtualization at lists.linux-foundation.org Cc: linux-pci at vger.kernel.org Cc: linux-kernel at 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
Konrad Rzeszutek Wilk
2013-Jun-07 14:50 UTC
[RFC PATCH v2, part3 07/11] PCI, xen-pcifront: use new PCI interfaces to simplify implementation
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 <jiang.liu at huawei.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> > Cc: Jeremy Fitzhardinge <jeremy at goop.org> > Cc: xen-devel at lists.xensource.com > Cc: virtualization at lists.linux-foundation.org > Cc: linux-pci at vger.kernel.org > Cc: linux-kernel at 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 >
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