Drivers: hv: Make the vmbus driver unloadable

It turns out that the vmbus driver can be made unloadable. Make it
unloadable.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index b91af50..36484db 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -223,6 +223,17 @@
 	vmbus_device_unregister(channel->device_obj);
 }
 
+void vmbus_free_channels(void)
+{
+	struct vmbus_channel *channel;
+
+	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
+		vmbus_device_unregister(channel->device_obj);
+		kfree(channel->device_obj);
+		free_channel(channel);
+	}
+}
+
 /*
  * vmbus_process_offer - Process the offer by creating a channel/device
  * associated with this offer