net: Simplify RX queue allocation

This patch move RX queue allocation to alloc_netdev_mq and freeing of
the queues to free_netdev (symmetric to TX queue allocation).  Each
kobject RX queue takes a reference to the queue's device so that the
device can't be freed before all the kobjects have been released-- this
obviates the need for reference counts specific to RX queues.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 7549067..8725d16 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5051,12 +5051,8 @@
 	}
 	dev->_rx = rx;
 
-	/*
-	 * Set a pointer to first element in the array which holds the
-	 * reference count.
-	 */
 	for (i = 0; i < count; i++)
-		rx[i].first = rx;
+		rx[i].dev = dev;
 #endif
 	return 0;
 }
@@ -5132,10 +5128,6 @@
 
 	dev->iflink = -1;
 
-	ret = netif_alloc_rx_queues(dev);
-	if (ret)
-		goto out;
-
 	netdev_init_queues(dev);
 
 	/* Init, if this function is available */
@@ -5601,6 +5593,8 @@
 #ifdef CONFIG_RPS
 	dev->num_rx_queues = queue_count;
 	dev->real_num_rx_queues = queue_count;
+	if (netif_alloc_rx_queues(dev))
+		goto free_pcpu;
 #endif
 
 	dev->gso_max_size = GSO_MAX_SIZE;
@@ -5618,6 +5612,10 @@
 free_pcpu:
 	free_percpu(dev->pcpu_refcnt);
 	kfree(dev->_tx);
+#ifdef CONFIG_RPS
+	kfree(dev->_rx);
+#endif
+
 free_p:
 	kfree(p);
 	return NULL;
@@ -5639,6 +5637,9 @@
 	release_net(dev_net(dev));
 
 	kfree(dev->_tx);
+#ifdef CONFIG_RPS
+	kfree(dev->_rx);
+#endif
 
 	kfree(rcu_dereference_raw(dev->ingress_queue));