1 files changed, 18 insertions, 60 deletions

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index f379689dde30..9259a732e8a4 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -43,6 +43,9 @@
 #define XENVIF_QUEUE_LENGTH 32
 #define XENVIF_NAPI_WEIGHT  64
 
+/* Number of bytes allowed on the internal guest Rx queue. */
+#define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
+
 /* This function is used to set SKBTX_DEV_ZEROCOPY as well as
  * increasing the inflight counter. We need to increase the inflight
  * counter because core driver calls into xenvif_zerocopy_callback
@@ -60,20 +63,11 @@ void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
         atomic_dec(&queue->inflight_packets);
 }
 
-static inline void xenvif_stop_queue(struct xenvif_queue *queue)
-{
-        struct net_device *dev = queue->vif->dev;
-
-        if (!queue->vif->can_queue)
-                return;
-
-        netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
-}
-
 int xenvif_schedulable(struct xenvif *vif)
 {
         return netif_running(vif->dev) &&
-                test_bit(VIF_STATUS_CONNECTED, &vif->status);
+                test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
+                !vif->disabled;
 }
 
 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
@@ -114,16 +108,7 @@ int xenvif_poll(struct napi_struct *napi, int budget)
 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
 {
         struct xenvif_queue *queue = dev_id;
-        struct netdev_queue *net_queue =
-                netdev_get_tx_queue(queue->vif->dev, queue->id);
 
-        /* QUEUE_STATUS_RX_PURGE_EVENT is only set if either QDisc was off OR
-         * the carrier went down and this queue was previously blocked
-         */
-        if (unlikely(netif_tx_queue_stopped(net_queue) ||
-                     (!netif_carrier_ok(queue->vif->dev) &&
-                      test_bit(QUEUE_STATUS_RX_STALLED, &queue->status))))
-                set_bit(QUEUE_STATUS_RX_PURGE_EVENT, &queue->status);
         xenvif_kick_thread(queue);
 
         return IRQ_HANDLED;
@@ -151,24 +136,13 @@ void xenvif_wake_queue(struct xenvif_queue *queue)
         netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
 }
 
-/* Callback to wake the queue's thread and turn the carrier off on timeout */
-static void xenvif_rx_stalled(unsigned long data)
-{
-        struct xenvif_queue *queue = (struct xenvif_queue *)data;
-
-        if (xenvif_queue_stopped(queue)) {
-                set_bit(QUEUE_STATUS_RX_PURGE_EVENT, &queue->status);
-                xenvif_kick_thread(queue);
-        }
-}
-
 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
         struct xenvif_queue *queue = NULL;
         unsigned int num_queues = vif->num_queues;
         u16 index;
-        int min_slots_needed;
+        struct xenvif_rx_cb *cb;
 
         BUG_ON(skb->dev != dev);
 
@@ -191,30 +165,10 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
             !xenvif_schedulable(vif))
                 goto drop;
 
-        /* At best we'll need one slot for the header and one for each
-         * frag.
-         */
-        min_slots_needed = 1 + skb_shinfo(skb)->nr_frags;
-
-        /* If the skb is GSO then we'll also need an extra slot for the
-         * metadata.
-         */
-        if (skb_is_gso(skb))
-                min_slots_needed++;
-
-        /* If the skb can't possibly fit in the remaining slots
-         * then turn off the queue to give the ring a chance to
-         * drain.
-         */
-        if (!xenvif_rx_ring_slots_available(queue, min_slots_needed)) {
-                queue->rx_stalled.function = xenvif_rx_stalled;
-                queue->rx_stalled.data = (unsigned long)queue;
-                xenvif_stop_queue(queue);
-                mod_timer(&queue->rx_stalled,
-                          jiffies + rx_drain_timeout_jiffies);
-        }
+        cb = XENVIF_RX_CB(skb);
+        cb->expires = jiffies + vif->drain_timeout;
 
-        skb_queue_tail(&queue->rx_queue, skb);
+        xenvif_rx_queue_tail(queue, skb);
         xenvif_kick_thread(queue);
 
         return NETDEV_TX_OK;
@@ -281,10 +235,10 @@ static void xenvif_down(struct xenvif *vif)
 
         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
                 queue = &vif->queues[queue_index];
-                napi_disable(&queue->napi);
                 disable_irq(queue->tx_irq);
                 if (queue->tx_irq != queue->rx_irq)
                         disable_irq(queue->rx_irq);
+                napi_disable(&queue->napi);
                 del_timer_sync(&queue->credit_timeout);
         }
 }
@@ -460,11 +414,15 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
         vif->ip_csum = 1;
         vif->dev = dev;
         vif->disabled = false;
+        vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
+        vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
 
         /* Start out with no queues. */
         vif->queues = NULL;
         vif->num_queues = 0;
 
+        spin_lock_init(&vif->lock);
+
         dev->netdev_ops = &xenvif_netdev_ops;
         dev->hw_features = NETIF_F_SG |
                 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
@@ -508,6 +466,8 @@ int xenvif_init_queue(struct xenvif_queue *queue)
         init_timer(&queue->credit_timeout);
         queue->credit_window_start = get_jiffies_64();
 
+        queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
+
         skb_queue_head_init(&queue->rx_queue);
         skb_queue_head_init(&queue->tx_queue);
 
@@ -539,8 +499,6 @@ int xenvif_init_queue(struct xenvif_queue *queue)
                 queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
         }
 
-        init_timer(&queue->rx_stalled);
-
         return 0;
 }
 
@@ -551,7 +509,6 @@ void xenvif_carrier_on(struct xenvif *vif)
                 dev_set_mtu(vif->dev, ETH_DATA_LEN);
         netdev_update_features(vif->dev);
         set_bit(VIF_STATUS_CONNECTED, &vif->status);
-        netif_carrier_on(vif->dev);
         if (netif_running(vif->dev))
                 xenvif_up(vif);
         rtnl_unlock();
@@ -611,6 +568,8 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
                 disable_irq(queue->rx_irq);
         }
 
+        queue->stalled = true;
+
         task = kthread_create(xenvif_kthread_guest_rx,
                               (void *)queue, "%s-guest-rx", queue->name);
         if (IS_ERR(task)) {
@@ -674,7 +633,6 @@ void xenvif_disconnect(struct xenvif *vif)
                 netif_napi_del(&queue->napi);
 
                 if (queue->task) {
-                        del_timer_sync(&queue->rx_stalled);
                         kthread_stop(queue->task);
                         queue->task = NULL;
                 }