netdev: Move queue_lock into struct netdev_queue.

The lock is now an attribute of the device queue.

One thing to notice is that "suspicious" places
emerge which will need specific training about
multiple queue handling.  They are so marked with
explicit "netdev->rx_queue" and "netdev->tx_queue"
references.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 11 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 9b281c906eb..05011048b86 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1667,6 +1667,7 @@ out_kfree_skb:
 int dev_queue_xmit(struct sk_buff *skb)
 {
 	struct net_device *dev = skb->dev;
+	struct netdev_queue *txq;
 	struct Qdisc *q;
 	int rc = -ENOMEM;
 
@@ -1699,14 +1700,15 @@ int dev_queue_xmit(struct sk_buff *skb)
 	}
 
 gso:
-	spin_lock_prefetch(&dev->queue_lock);
+	txq = &dev->tx_queue;
+	spin_lock_prefetch(&txq->lock);
 
 	/* Disable soft irqs for various locks below. Also
 	 * stops preemption for RCU.
 	 */
 	rcu_read_lock_bh();
 
-	/* Updates of qdisc are serialized by queue_lock.
+	/* Updates of qdisc are serialized by queue->lock.
 	 * The struct Qdisc which is pointed to by qdisc is now a
 	 * rcu structure - it may be accessed without acquiring
 	 * a lock (but the structure may be stale.) The freeing of the
@@ -1714,7 +1716,7 @@ gso:
 	 * more references to it.
 	 *
 	 * If the qdisc has an enqueue function, we still need to
-	 * hold the queue_lock before calling it, since queue_lock
+	 * hold the queue->lock before calling it, since queue->lock
 	 * also serializes access to the device queue.
 	 */
 
@@ -1724,19 +1726,19 @@ gso:
 #endif
 	if (q->enqueue) {
 		/* Grab device queue */
-		spin_lock(&dev->queue_lock);
+		spin_lock(&txq->lock);
 		q = dev->qdisc;
 		if (q->enqueue) {
 			/* reset queue_mapping to zero */
 			skb_set_queue_mapping(skb, 0);
 			rc = q->enqueue(skb, q);
 			qdisc_run(dev);
-			spin_unlock(&dev->queue_lock);
+			spin_unlock(&txq->lock);
 
 			rc = rc == NET_XMIT_BYPASS ? NET_XMIT_SUCCESS : rc;
 			goto out;
 		}
-		spin_unlock(&dev->queue_lock);
+		spin_unlock(&txq->lock);
 	}
 
 	/* The device has no queue. Common case for software devices:
@@ -1919,14 +1921,17 @@ static void net_tx_action(struct softirq_action *h)
 
 		while (head) {
 			struct net_device *dev = head;
+			struct netdev_queue *txq;
 			head = head->next_sched;
 
+			txq = &dev->tx_queue;
+
 			smp_mb__before_clear_bit();
 			clear_bit(__LINK_STATE_SCHED, &dev->state);
 
-			if (spin_trylock(&dev->queue_lock)) {
+			if (spin_trylock(&txq->lock)) {
 				qdisc_run(dev);
-				spin_unlock(&dev->queue_lock);
+				spin_unlock(&txq->lock);
 			} else {
 				netif_schedule(dev);
 			}
@@ -3787,7 +3792,6 @@ int register_netdevice(struct net_device *dev)
 	BUG_ON(!dev_net(dev));
 	net = dev_net(dev);
 
-	spin_lock_init(&dev->queue_lock);
 	spin_lock_init(&dev->_xmit_lock);
 	netdev_set_lockdep_class(&dev->_xmit_lock, dev->type);
 	dev->xmit_lock_owner = -1;
@@ -4072,10 +4076,17 @@ static struct net_device_stats *internal_stats(struct net_device *dev)
 	return &dev->stats;
 }
 
+static void netdev_init_one_queue(struct net_device *dev,
+				  struct netdev_queue *queue)
+{
+	spin_lock_init(&queue->lock);
+	queue->dev = dev;
+}
+
 static void netdev_init_queues(struct net_device *dev)
 {
-	dev->rx_queue.dev = dev;
-	dev->tx_queue.dev = dev;
+	netdev_init_one_queue(dev, &dev->rx_queue);
+	netdev_init_one_queue(dev, &dev->tx_queue);
 }
 
 /**