netdev: network device operations infrastructure

This patch changes the network device internal API to move adminstrative
operations out of the network device structure and into a separate structure.

This patch involves some hackery to maintain compatablity between the
new and old model, so all 300+ drivers don't have to be changed at once.
For drivers that aren't converted yet, the netdevice_ops virt function list
still resides in the net_device structure. For old protocols, the new
net_device_ops are copied out to the old net_device pointers.

After the transistion is completed the nag message can be changed to
an WARN_ON, and the compatiablity code can be made configurable.

Some function pointers aren't moved:
* destructor can't be in net_device_ops because
  it may need to be referenced after the module is unloaded.
* neighbor setup is manipulated in a couple of places that need special
  consideration
* hard_start_xmit is in the fast path for transmit.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index fc4e28e..630df60 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -172,12 +172,13 @@
 void netpoll_poll(struct netpoll *np)
 {
 	struct net_device *dev = np->dev;
+	const struct net_device_ops *ops = dev->netdev_ops;
 
-	if (!dev || !netif_running(dev) || !dev->poll_controller)
+	if (!dev || !netif_running(dev) || !ops->ndo_poll_controller)
 		return;
 
 	/* Process pending work on NIC */
-	dev->poll_controller(dev);
+	ops->ndo_poll_controller(dev);
 
 	poll_napi(dev);
 
@@ -694,7 +695,7 @@
 		atomic_inc(&npinfo->refcnt);
 	}
 
-	if (!ndev->poll_controller) {
+	if (!ndev->netdev_ops->ndo_poll_controller) {
 		printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
 		       np->name, np->dev_name);
 		err = -ENOTSUPP;