PCI: Stop all children first, before removing all children

This restores the previous behavior of stopping all child devices before
removing any of them.  The current SR-IOV design, where removing the PF
also drops references on all the VFs, depends on having the VFs continue
to exist after having been stopped.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/remove.c

@@ -56,25 +56,13 @@ void pci_remove_bus(struct pci_bus *bus)
 }
 EXPORT_SYMBOL(pci_remove_bus);
 
-/**
- * pci_stop_and_remove_bus_device - remove a PCI device and any children
- * @dev: the device to remove
- *
- * Remove a PCI device from the device lists, informing the drivers
- * that the device has been removed.  We also remove any subordinate
- * buses and children in a depth-first manner.
- *
- * For each device we remove, delete the device structure from the
- * device lists, remove the /proc entry, and notify userspace
- * (/sbin/hotplug).
- */
-void pci_stop_and_remove_bus_device(struct pci_dev *dev)
+static void pci_stop_bus_device(struct pci_dev *dev)
 {
 	struct pci_bus *bus = dev->subordinate;
 	struct pci_dev *child, *tmp;
 
 	/*
-	 * Removing an SR-IOV PF device removes all the associated VFs,
+	 * Stopping an SR-IOV PF device removes all the associated VFs,
 	 * which will update the bus->devices list and confuse the
 	 * iterator.  Therefore, iterate in reverse so we remove the VFs
 	 * first, then the PF.
@@ -82,13 +70,44 @@ void pci_stop_and_remove_bus_device(struct pci_dev *dev)
 	if (bus) {
 		list_for_each_entry_safe_reverse(child, tmp,
 						 &bus->devices, bus_list)
-			pci_stop_and_remove_bus_device(child);
+			pci_stop_bus_device(child);
+	}
+
+	pci_stop_dev(dev);
+}
+
+static void pci_remove_bus_device(struct pci_dev *dev)
+{
+	struct pci_bus *bus = dev->subordinate;
+	struct pci_dev *child, *tmp;
+
+	if (bus) {
+		list_for_each_entry_safe(child, tmp,
+					 &bus->devices, bus_list)
+			pci_remove_bus_device(child);
 
 		pci_remove_bus(bus);
 		dev->subordinate = NULL;
 	}
 
-	pci_stop_dev(dev);
 	pci_destroy_dev(dev);
 }
+
+/**
+ * pci_stop_and_remove_bus_device - remove a PCI device and any children
+ * @dev: the device to remove
+ *
+ * Remove a PCI device from the device lists, informing the drivers
+ * that the device has been removed.  We also remove any subordinate
+ * buses and children in a depth-first manner.
+ *
+ * For each device we remove, delete the device structure from the
+ * device lists, remove the /proc entry, and notify userspace
+ * (/sbin/hotplug).
+ */
+void pci_stop_and_remove_bus_device(struct pci_dev *dev)
+{
+	pci_stop_bus_device(dev);
+	pci_remove_bus_device(dev);
+}
 EXPORT_SYMBOL(pci_stop_and_remove_bus_device);