netdev: Create netdev_queue abstraction.

A netdev_queue is an entity managed by a qdisc.

Currently there is one RX and one TX queue, and a netdev_queue merely
contains a backpointer to the net_device.

The Qdisc struct is augmented with a netdev_queue pointer as well.

Eventually the 'dev' Qdisc member will go away and we will have the
resulting hierarchy:

	net_device --> netdev_queue --> Qdisc

Also, qdisc_alloc() and qdisc_create_dflt() now take a netdev_queue
pointer argument.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 7593393..9b281c9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4072,6 +4072,12 @@
 	return &dev->stats;
 }
 
+static void netdev_init_queues(struct net_device *dev)
+{
+	dev->rx_queue.dev = dev;
+	dev->tx_queue.dev = dev;
+}
+
 /**
  *	alloc_netdev_mq - allocate network device
  *	@sizeof_priv:	size of private data to allocate space for
@@ -4124,6 +4130,8 @@
 	dev->egress_subqueue_count = queue_count;
 	dev->gso_max_size = GSO_MAX_SIZE;
 
+	netdev_init_queues(dev);
+
 	dev->get_stats = internal_stats;
 	netpoll_netdev_init(dev);
 	setup(dev);