1 files changed, 47 insertions, 31 deletions

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 2329cccf1fa6..b9de31ea7fc4 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -34,6 +34,7 @@
 #include <linux/ethtool.h>
 #include <linux/rtnetlink.h>
 #include <linux/if_vlan.h>
+#include <linux/vmalloc.h>
 
 #include <xen/events.h>
 #include <asm/xen/hypercall.h>
@@ -46,11 +47,6 @@ int xenvif_schedulable(struct xenvif *vif)
         return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
 }
 
-static int xenvif_rx_schedulable(struct xenvif *vif)
-{
-        return xenvif_schedulable(vif) && !xenvif_rx_ring_full(vif);
-}
-
 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
 {
         struct xenvif *vif = dev_id;
@@ -104,8 +100,8 @@ static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
 {
         struct xenvif *vif = dev_id;
 
-        if (xenvif_rx_schedulable(vif))
-                netif_wake_queue(vif->dev);
+        vif->rx_event = true;
+        xenvif_kick_thread(vif);
 
         return IRQ_HANDLED;
 }
@@ -121,24 +117,35 @@ static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
+        int min_slots_needed;
 
         BUG_ON(skb->dev != dev);
 
         /* Drop the packet if vif is not ready */
-        if (vif->task == NULL)
+        if (vif->task == NULL || !xenvif_schedulable(vif))
                 goto drop;
 
-        /* Drop the packet if the target domain has no receive buffers. */
-        if (!xenvif_rx_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;
 
-        /* Reserve ring slots for the worst-case number of fragments. */
-        vif->rx_req_cons_peek += xenvif_count_skb_slots(vif, skb);
+        /* If the skb is GSO then we'll also need an extra slot for the
+         * metadata.
+         */
+        if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 ||
+            skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+                min_slots_needed++;
 
-        if (vif->can_queue && xenvif_must_stop_queue(vif))
-                netif_stop_queue(dev);
+        /* 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(vif, min_slots_needed))
+                xenvif_stop_queue(vif);
 
-        xenvif_queue_tx_skb(vif, skb);
+        skb_queue_tail(&vif->rx_queue, skb);
+        xenvif_kick_thread(vif);
 
         return NETDEV_TX_OK;
 
@@ -148,12 +155,6 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
         return NETDEV_TX_OK;
 }
 
-void xenvif_notify_tx_completion(struct xenvif *vif)
-{
-        if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
-                netif_wake_queue(vif->dev);
-}
-
 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
@@ -307,6 +308,15 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
         SET_NETDEV_DEV(dev, parent);
 
         vif = netdev_priv(dev);
+
+        vif->grant_copy_op = vmalloc(sizeof(struct gnttab_copy) *
+                                     MAX_GRANT_COPY_OPS);
+        if (vif->grant_copy_op == NULL) {
+                pr_warn("Could not allocate grant copy space for %s\n", name);
+                free_netdev(dev);
+                return ERR_PTR(-ENOMEM);
+        }
+
         vif->domid  = domid;
         vif->handle = handle;
         vif->can_sg = 1;
@@ -368,16 +378,18 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
                    unsigned long rx_ring_ref, unsigned int tx_evtchn,
                    unsigned int rx_evtchn)
 {
+        struct task_struct *task;
         int err = -ENOMEM;
 
-        /* Already connected through? */
-        if (vif->tx_irq)
-                return 0;
+        BUG_ON(vif->tx_irq);
+        BUG_ON(vif->task);
 
         err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
         if (err < 0)
                 goto err;
 
+        init_waitqueue_head(&vif->wq);
+
         if (tx_evtchn == rx_evtchn) {
                 /* feature-split-event-channels == 0 */
                 err = bind_interdomain_evtchn_to_irqhandler(
@@ -410,15 +422,16 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
                 disable_irq(vif->rx_irq);
         }
 
-        init_waitqueue_head(&vif->wq);
-        vif->task = kthread_create(xenvif_kthread,
-                                   (void *)vif, "%s", vif->dev->name);
-        if (IS_ERR(vif->task)) {
+        task = kthread_create(xenvif_kthread,
+                              (void *)vif, "%s", vif->dev->name);
+        if (IS_ERR(task)) {
                 pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
-                err = PTR_ERR(vif->task);
+                err = PTR_ERR(task);
                 goto err_rx_unbind;
         }
 
+        vif->task = task;
+
         rtnl_lock();
         if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
                 dev_set_mtu(vif->dev, ETH_DATA_LEN);
@@ -461,8 +474,10 @@ void xenvif_disconnect(struct xenvif *vif)
         if (netif_carrier_ok(vif->dev))
                 xenvif_carrier_off(vif);
 
-        if (vif->task)
+        if (vif->task) {
                 kthread_stop(vif->task);
+                vif->task = NULL;
+        }
 
         if (vif->tx_irq) {
                 if (vif->tx_irq == vif->rx_irq)
@@ -483,6 +498,7 @@ void xenvif_free(struct xenvif *vif)
 
         unregister_netdev(vif->dev);
 
+        vfree(vif->grant_copy_op);
         free_netdev(vif->dev);
 
         module_put(THIS_MODULE);