PCI/cpcihp: Use hotplug-safe pci_get_domain_bus_and_slot()

Following code has a race window between pci_find_bus() and pci_get_slot()
if PCI hotplug operation happens between them which removes the pci_bus.
So use PCI hotplug safe interface pci_get_domain_bus_and_slot() instead,
which also reduces code complexity.

    struct pci_bus *pci_bus = pci_find_bus(domain, busno);
    struct pci_dev *pci_dev = pci_get_slot(pci_bus, devfn);

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/hotplug/cpcihp_generic.c b/drivers/pci/hotplug/cpcihp_generic.c
index 81af764c629b6d34573fc2bb9297b26316fa79c6..a6a71c41cdf8cab3e69f5436456cca36fdf0b5a7 100644 (file)
--- a/drivers/pci/hotplug/cpcihp_generic.c
+++ b/drivers/pci/hotplug/cpcihp_generic.c
@@ -154,12 +154,8 @@ static int __init cpcihp_generic_init(void)
        if(!r)
                return -EBUSY;
 
-       bus = pci_find_bus(0, bridge_busnr);
-       if (!bus) {
-               err("Invalid bus number %d", bridge_busnr);
-               return -EINVAL;
-       }
-       dev = pci_get_slot(bus, PCI_DEVFN(bridge_slot, 0));
+       dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
+                                         PCI_DEVFN(bridge_slot, 0));
        if(!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
                err("Invalid bridge device %s", bridge);
                pci_dev_put(dev);