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 <arnd@xxxxxxxx>
---
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
