neigh: Get rid of neigh_table->kmem_cachep

We are going to alloc for device specific private areas for
neighbour entries, and in order to do that we have to move
away from the fixed allocation size enforced by using
neigh_table->kmem_cachep

As a nice side effect we can now use kfree_rcu().

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 27d3fef..661ad12 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -288,7 +288,7 @@
 			goto out_entries;
 	}
 
-	n = kmem_cache_zalloc(tbl->kmem_cachep, GFP_ATOMIC);
+	n = kzalloc(tbl->entry_size, GFP_ATOMIC);
 	if (!n)
 		goto out_entries;
 
@@ -678,12 +678,6 @@
 		neigh_parms_destroy(parms);
 }
 
-static void neigh_destroy_rcu(struct rcu_head *head)
-{
-	struct neighbour *neigh = container_of(head, struct neighbour, rcu);
-
-	kmem_cache_free(neigh->tbl->kmem_cachep, neigh);
-}
 /*
  *	neighbour must already be out of the table;
  *
@@ -711,7 +705,7 @@
 	NEIGH_PRINTK2("neigh %p is destroyed.\n", neigh);
 
 	atomic_dec(&neigh->tbl->entries);
-	call_rcu(&neigh->rcu, neigh_destroy_rcu);
+	kfree_rcu(neigh, rcu);
 }
 EXPORT_SYMBOL(neigh_destroy);
 
@@ -1486,11 +1480,6 @@
 	tbl->parms.reachable_time =
 			  neigh_rand_reach_time(tbl->parms.base_reachable_time);
 
-	if (!tbl->kmem_cachep)
-		tbl->kmem_cachep =
-			kmem_cache_create(tbl->id, tbl->entry_size, 0,
-					  SLAB_HWCACHE_ALIGN|SLAB_PANIC,
-					  NULL);
 	tbl->stats = alloc_percpu(struct neigh_statistics);
 	if (!tbl->stats)
 		panic("cannot create neighbour cache statistics");
@@ -1575,9 +1564,6 @@
 	free_percpu(tbl->stats);
 	tbl->stats = NULL;
 
-	kmem_cache_destroy(tbl->kmem_cachep);
-	tbl->kmem_cachep = NULL;
-
 	return 0;
 }
 EXPORT_SYMBOL(neigh_table_clear);