1 files changed, 51 insertions, 78 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index bf2744e1e3db..6ffc482550c1 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -57,6 +57,7 @@
 #include <xen/interface/grant_table.h>
 
 /* Module parameters */
+#define MAX_QUEUES_DEFAULT 8
 static unsigned int xennet_max_queues;
 module_param_named(max_queues, xennet_max_queues, uint, 0644);
 MODULE_PARM_DESC(max_queues,
@@ -281,6 +282,7 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 {
 	RING_IDX req_prod = queue->rx.req_prod_pvt;
 	int notify;
+	int err = 0;
 
 	if (unlikely(!netif_carrier_ok(queue->info->netdev)))
 		return;
@@ -295,8 +297,10 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 		struct xen_netif_rx_request *req;
 
 		skb = xennet_alloc_one_rx_buffer(queue);
-		if (!skb)
+		if (!skb) {
+			err = -ENOMEM;
 			break;
+		}
 
 		id = xennet_rxidx(req_prod);
 
@@ -320,8 +324,13 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 
 	queue->rx.req_prod_pvt = req_prod;
 
-	/* Not enough requests? Try again later. */
-	if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
+	/* Try again later if there are not enough requests or skb allocation
+	 * failed.
+	 * Enough requests is quantified as the sum of newly created slots and
+	 * the unconsumed slots at the backend.
+	 */
+	if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
+	    unlikely(err)) {
 		mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
 		return;
 	}
@@ -1051,7 +1060,7 @@ err:
 	if (work_done < budget) {
 		int more_to_do = 0;
 
-		napi_complete(napi);
+		napi_complete_done(napi, work_done);
 
 		RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
 		if (more_to_do)
@@ -1073,8 +1082,8 @@ static int xennet_change_mtu(struct net_device *dev, int mtu)
 	return 0;
 }
 
-static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
-						    struct rtnl_link_stats64 *tot)
+static void xennet_get_stats64(struct net_device *dev,
+			       struct rtnl_link_stats64 *tot)
 {
 	struct netfront_info *np = netdev_priv(dev);
 	int cpu;
@@ -1105,8 +1114,6 @@ static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
 
 	tot->rx_errors  = dev->stats.rx_errors;
 	tot->tx_dropped = dev->stats.tx_dropped;
-
-	return tot;
 }
 
 static void xennet_release_tx_bufs(struct netfront_queue *queue)
@@ -1169,43 +1176,23 @@ static netdev_features_t xennet_fix_features(struct net_device *dev,
 	netdev_features_t features)
 {
 	struct netfront_info *np = netdev_priv(dev);
-	int val;
-
-	if (features & NETIF_F_SG) {
-		if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
-				 "%d", &val) < 0)
-			val = 0;
-
-		if (!val)
-			features &= ~NETIF_F_SG;
-	}
-
-	if (features & NETIF_F_IPV6_CSUM) {
-		if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
-				 "feature-ipv6-csum-offload", "%d", &val) < 0)
-			val = 0;
-
-		if (!val)
-			features &= ~NETIF_F_IPV6_CSUM;
-	}
 
-	if (features & NETIF_F_TSO) {
-		if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
-				 "feature-gso-tcpv4", "%d", &val) < 0)
-			val = 0;
+	if (features & NETIF_F_SG &&
+	    !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
+		features &= ~NETIF_F_SG;
 
-		if (!val)
-			features &= ~NETIF_F_TSO;
-	}
+	if (features & NETIF_F_IPV6_CSUM &&
+	    !xenbus_read_unsigned(np->xbdev->otherend,
+				  "feature-ipv6-csum-offload", 0))
+		features &= ~NETIF_F_IPV6_CSUM;
 
-	if (features & NETIF_F_TSO6) {
-		if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
-				 "feature-gso-tcpv6", "%d", &val) < 0)
-			val = 0;
+	if (features & NETIF_F_TSO &&
+	    !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
+		features &= ~NETIF_F_TSO;
 
-		if (!val)
-			features &= ~NETIF_F_TSO6;
-	}
+	if (features & NETIF_F_TSO6 &&
+	    !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
+		features &= ~NETIF_F_TSO6;
 
 	return features;
 }
@@ -1329,6 +1316,8 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
 	netdev->features |= netdev->hw_features;
 
 	netdev->ethtool_ops = &xennet_ethtool_ops;
+	netdev->min_mtu = 0;
+	netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
 	SET_NETDEV_DEV(netdev, &dev->dev);
 
 	np->netdev = netdev;
@@ -1397,6 +1386,8 @@ static void xennet_disconnect_backend(struct netfront_info *info)
 	for (i = 0; i < num_queues && info->queues; ++i) {
 		struct netfront_queue *queue = &info->queues[i];
 
+		del_timer_sync(&queue->rx_refill_timer);
+
 		if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
 			unbind_from_irqhandler(queue->tx_irq, queue);
 		if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
@@ -1751,7 +1742,6 @@ static void xennet_destroy_queues(struct netfront_info *info)
 
 		if (netif_running(info->netdev))
 			napi_disable(&queue->napi);
-		del_timer_sync(&queue->rx_refill_timer);
 		netif_napi_del(&queue->napi);
 	}
 
@@ -1821,18 +1811,13 @@ static int talk_to_netback(struct xenbus_device *dev,
 	info->netdev->irq = 0;
 
 	/* Check if backend supports multiple queues */
-	err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
-			   "multi-queue-max-queues", "%u", &max_queues);
-	if (err < 0)
-		max_queues = 1;
+	max_queues = xenbus_read_unsigned(info->xbdev->otherend,
+					  "multi-queue-max-queues", 1);
 	num_queues = min(max_queues, xennet_max_queues);
 
 	/* Check feature-split-event-channels */
-	err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
-			   "feature-split-event-channels", "%u",
-			   &feature_split_evtchn);
-	if (err < 0)
-		feature_split_evtchn = 0;
+	feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
+					"feature-split-event-channels", 0);
 
 	/* Read mac addr. */
 	err = xen_net_read_mac(dev, info->netdev->dev_addr);
@@ -1845,27 +1830,19 @@ static int talk_to_netback(struct xenbus_device *dev,
 		xennet_destroy_queues(info);
 
 	err = xennet_create_queues(info, &num_queues);
-	if (err < 0)
-		goto destroy_ring;
+	if (err < 0) {
+		xenbus_dev_fatal(dev, err, "creating queues");
+		kfree(info->queues);
+		info->queues = NULL;
+		goto out;
+	}
 
 	/* Create shared ring, alloc event channel -- for each queue */
 	for (i = 0; i < num_queues; ++i) {
 		queue = &info->queues[i];
 		err = setup_netfront(dev, queue, feature_split_evtchn);
-		if (err) {
-			/* setup_netfront() will tidy up the current
-			 * queue on error, but we need to clean up
-			 * those already allocated.
-			 */
-			if (i > 0) {
-				rtnl_lock();
-				netif_set_real_num_tx_queues(info->netdev, i);
-				rtnl_unlock();
-				goto destroy_ring;
-			} else {
-				goto out;
-			}
-		}
+		if (err)
+			goto destroy_ring;
 	}
 
 again:
@@ -1955,9 +1932,10 @@ abort_transaction_no_dev_fatal:
 	xenbus_transaction_end(xbt, 1);
  destroy_ring:
 	xennet_disconnect_backend(info);
-	kfree(info->queues);
-	info->queues = NULL;
+	xennet_destroy_queues(info);
  out:
+	unregister_netdev(info->netdev);
+	xennet_free_netdev(info->netdev);
 	return err;
 }
 
@@ -1966,16 +1944,10 @@ static int xennet_connect(struct net_device *dev)
 	struct netfront_info *np = netdev_priv(dev);
 	unsigned int num_queues = 0;
 	int err;
-	unsigned int feature_rx_copy;
 	unsigned int j = 0;
 	struct netfront_queue *queue = NULL;
 
-	err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
-			   "feature-rx-copy", "%u", &feature_rx_copy);
-	if (err != 1)
-		feature_rx_copy = 0;
-
-	if (!feature_rx_copy) {
+	if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
 		dev_info(&dev->dev,
 			 "backend does not support copying receive path\n");
 		return -ENODEV;
@@ -2193,11 +2165,12 @@ static int __init netif_init(void)
 
 	pr_info("Initialising Xen virtual ethernet driver\n");
 
-	/* Allow as many queues as there are CPUs if user has not
+	/* Allow as many queues as there are CPUs inut max. 8 if user has not
 	 * specified a value.
 	 */
 	if (xennet_max_queues == 0)
-		xennet_max_queues = num_online_cpus();
+		xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
+					  num_online_cpus());
 
 	return xenbus_register_frontend(&netfront_driver);
 }