PCI: hotplug: Use global PCI rescan-remove locking

Multiple race conditions are possible between PCI hotplug and the generic
PCI bus rescan and device removal that can be triggered via sysfs.

To avoid those race conditions make PCI hotplug use global PCI
rescan-remove locking.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/hotplug/cpqphp_pci.c

@@ -86,6 +86,8 @@ int cpqhp_configure_device (struct controller* ctrl, struct pci_func* func)
 	struct pci_bus *child;
 	int num;
 
+	pci_lock_rescan_remove();
+
 	if (func->pci_dev == NULL)
 		func->pci_dev = pci_get_bus_and_slot(func->bus,PCI_DEVFN(func->device, func->function));
 
@@ -100,7 +102,7 @@ int cpqhp_configure_device (struct controller* ctrl, struct pci_func* func)
 		func->pci_dev = pci_get_bus_and_slot(func->bus, PCI_DEVFN(func->device, func->function));
 		if (func->pci_dev == NULL) {
 			dbg("ERROR: pci_dev still null\n");
-			return 0;
+			goto out;
 		}
 	}
 
@@ -113,6 +115,8 @@ int cpqhp_configure_device (struct controller* ctrl, struct pci_func* func)
 
 	pci_dev_put(func->pci_dev);
 
+ out:
+	pci_unlock_rescan_remove();
 	return 0;
 }
 
@@ -123,6 +127,7 @@ int cpqhp_unconfigure_device(struct pci_func* func)
 
 	dbg("%s: bus/dev/func = %x/%x/%x\n", __func__, func->bus, func->device, func->function);
 
+	pci_lock_rescan_remove();
 	for (j=0; j<8 ; j++) {
 		struct pci_dev* temp = pci_get_bus_and_slot(func->bus, PCI_DEVFN(func->device, j));
 		if (temp) {
@@ -130,6 +135,7 @@ int cpqhp_unconfigure_device(struct pci_func* func)
 			pci_stop_and_remove_bus_device(temp);
 		}
 	}
+	pci_unlock_rescan_remove();
 	return 0;
 }