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>

1 files changed, 2 insertions, 6 deletions

diff --git a/drivers/pci/hotplug/cpcihp_generic.c b/drivers/pci/hotplug/cpcihp_generic.c
index 81af764c629b..a6a71c41cdf8 100644
--- 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);