IPoIB: Consolidate private neighbour data handling

Consolidate IPoIB's private neighbour data handling into
ipoib_neigh_alloc() and ipoib_neigh_free(). This will make it easier
to keep track of the neighbour structures that IPoIB is handling, and
is a nice cleanup of the code:

add/remove: 2/1 grow/shrink: 1/8 up/down: 100/-178 (-78)
function old new delta
ipoib_neigh_alloc - 61 +61
ipoib_neigh_free - 36 +36
ipoib_mcast_join_finish 1288 1291 +3
path_rec_completion 575 573 -2
ipoib_mcast_join_task 664 660 -4
ipoib_neigh_destructor 101 92 -9
ipoib_neigh_setup_dev 14 3 -11
ipoib_neigh_setup 17 - -17
path_free 238 215 -23
ipoib_mcast_free 329 306 -23
ipoib_mcast_send 718 684 -34
neigh_add_path 705 650 -55

Signed-off-by: Michael S. Tsirkin <[e-mail]>
Signed-off-by: Roland Dreier <[e-mail]>

drivers/infiniband/ulp/ipoib/ipoib.h

···
 				     INFINIBAND_ALEN, sizeof(void *));
 }
 
+struct ipoib_neigh *ipoib_neigh_alloc(struct neighbour *neigh);
+void ipoib_neigh_free(struct ipoib_neigh *neigh);
+
 extern struct workqueue_struct *ipoib_workqueue;
 
 /* functions */

drivers/infiniband/ulp/ipoib/ipoib_main.c

···
 		 */
 		if (neigh->ah)
 			ipoib_put_ah(neigh->ah);
-		*to_ipoib_neigh(neigh->neighbour) = NULL;
-		kfree(neigh);
+
+		ipoib_neigh_free(neigh);
 	}
 
 	spin_unlock_irqrestore(&priv->lock, flags);
···
 	struct ipoib_path *path;
 	struct ipoib_neigh *neigh;
 
-	neigh = kmalloc(sizeof *neigh, GFP_ATOMIC);
+	neigh = ipoib_neigh_alloc(skb->dst->neighbour);
 	if (!neigh) {
 		++priv->stats.tx_dropped;
 		dev_kfree_skb_any(skb);
···
 	}
 
 	skb_queue_head_init(&neigh->queue);
-	neigh->neighbour = skb->dst->neighbour;
-	*to_ipoib_neigh(skb->dst->neighbour) = neigh;
 
 	/*
 	 * We can only be called from ipoib_start_xmit, so we're
···
 		path = path_rec_create(dev,
 				       (union ib_gid *) (skb->dst->neighbour->ha + 4));
 		if (!path)
-			goto err;
+			goto err_path;
 
 		__path_add(dev, path);
 	}
···
 		__skb_queue_tail(&neigh->queue, skb);
 
 		if (!path->query && path_rec_start(dev, path))
-			goto err;
+			goto err_list;
 	}
 
 	spin_unlock(&priv->lock);
 	return;
 
-err:
-	*to_ipoib_neigh(skb->dst->neighbour) = NULL;
+err_list:
 	list_del(&neigh->list);
-	kfree(neigh);
 
+err_path:
+	ipoib_neigh_free(neigh);
 	++priv->stats.tx_dropped;
 	dev_kfree_skb_any(skb);
 
···
 		if (neigh->ah)
 			ah = neigh->ah;
 		list_del(&neigh->list);
-		*to_ipoib_neigh(n) = NULL;
-		kfree(neigh);
+		ipoib_neigh_free(neigh);
 	}
 
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	if (ah)
 		ipoib_put_ah(ah);
+}
+
+struct ipoib_neigh *ipoib_neigh_alloc(struct neighbour *neighbour)
+{
+	struct ipoib_neigh *neigh;
+
+	neigh = kmalloc(sizeof *neigh, GFP_ATOMIC);
+	if (!neigh)
+		return NULL;
+
+	neigh->neighbour = neighbour;
+	*to_ipoib_neigh(neighbour) = neigh;
+
+	return neigh;
+}
+
+void ipoib_neigh_free(struct ipoib_neigh *neigh)
+{
+	*to_ipoib_neigh(neigh->neighbour) = NULL;
+	kfree(neigh);
 }
 
 static int ipoib_neigh_setup_dev(struct net_device *dev, struct neigh_parms *parms)

drivers/infiniband/ulp/ipoib/ipoib_multicast.c

···
 		 */
 		if (neigh->ah)
 			ipoib_put_ah(neigh->ah);
-		*to_ipoib_neigh(neigh->neighbour) = NULL;
-		kfree(neigh);
+		ipoib_neigh_free(neigh);
 	}
 
 	spin_unlock_irqrestore(&priv->lock, flags);
···
 		if (skb->dst            &&
 		    skb->dst->neighbour &&
 		    !*to_ipoib_neigh(skb->dst->neighbour)) {
-			struct ipoib_neigh *neigh = kmalloc(sizeof *neigh, GFP_ATOMIC);
+			struct ipoib_neigh *neigh = ipoib_neigh_alloc(skb->dst->neighbour);
 
 			if (neigh) {
 				kref_get(&mcast->ah->ref);
 				neigh->ah  	= mcast->ah;
-				neigh->neighbour = skb->dst->neighbour;
-				*to_ipoib_neigh(skb->dst->neighbour) = neigh;
 				list_add_tail(&neigh->list, &mcast->neigh_list);
 			}
 		}