USB: core: Add hub_get() and hub_put() routines

Create hub_get() and hub_put() routines to encapsulate the kref_get()
and kref_put() calls in hub.c.  The new routines will be used by the
next patch in this series.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/604da420-ae8a-4a9e-91a4-2d511ff404fb@rowland.harvard.edu
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hub.c

@@ -130,7 +130,6 @@ EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
 #define HUB_DEBOUNCE_STEP	  25
 #define HUB_DEBOUNCE_STABLE	 100
 
-static void hub_release(struct kref *kref);
 static int usb_reset_and_verify_device(struct usb_device *udev);
 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state);
 static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
@@ -720,14 +719,14 @@ static void kick_hub_wq(struct usb_hub *hub)
 	 */
 	intf = to_usb_interface(hub->intfdev);
 	usb_autopm_get_interface_no_resume(intf);
-	kref_get(&hub->kref);
+	hub_get(hub);
 
 	if (queue_work(hub_wq, &hub->events))
 		return;
 
 	/* the work has already been scheduled */
 	usb_autopm_put_interface_async(intf);
-	kref_put(&hub->kref, hub_release);
+	hub_put(hub);
 }
 
 void usb_kick_hub_wq(struct usb_device *hdev)
@@ -1095,7 +1094,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 			goto init2;
 		goto init3;
 	}
-	kref_get(&hub->kref);
+	hub_get(hub);
 
 	/* The superspeed hub except for root hub has to use Hub Depth
 	 * value as an offset into the route string to locate the bits
@@ -1343,7 +1342,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 		device_unlock(&hdev->dev);
 	}
 
-	kref_put(&hub->kref, hub_release);
+	hub_put(hub);
 }
 
 /* Implement the continuations for the delays above */
@@ -1759,6 +1758,16 @@ static void hub_release(struct kref *kref)
 	kfree(hub);
 }
 
+void hub_get(struct usb_hub *hub)
+{
+	kref_get(&hub->kref);
+}
+
+void hub_put(struct usb_hub *hub)
+{
+	kref_put(&hub->kref, hub_release);
+}
+
 static unsigned highspeed_hubs;
 
 static void hub_disconnect(struct usb_interface *intf)
@@ -1807,7 +1816,7 @@ static void hub_disconnect(struct usb_interface *intf)
 
 	onboard_hub_destroy_pdevs(&hub->onboard_hub_devs);
 
-	kref_put(&hub->kref, hub_release);
+	hub_put(hub);
 }
 
 static bool hub_descriptor_is_sane(struct usb_host_interface *desc)
@@ -5934,7 +5943,7 @@ static void hub_event(struct work_struct *work)
 
 	/* Balance the stuff in kick_hub_wq() and allow autosuspend */
 	usb_autopm_put_interface(intf);
-	kref_put(&hub->kref, hub_release);
+	hub_put(hub);
 
 	kcov_remote_stop();
 }

drivers/usb/core/hub.h

@@ -129,6 +129,8 @@ extern void usb_hub_remove_port_device(struct usb_hub *hub,
 extern int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
 		int port1, bool set);
 extern struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev);
+extern void hub_get(struct usb_hub *hub);
+extern void hub_put(struct usb_hub *hub);
 extern int hub_port_debounce(struct usb_hub *hub, int port1,
 		bool must_be_connected);
 extern int usb_clear_port_feature(struct usb_device *hdev,