xen-netback: Using a new state bit instead of carrier

This patch introduces a new state bit VIF_STATUS_CONNECTED to track whether the
vif is in a connected state. Using carrier will not work with the next patch
in this series, which aims to turn the carrier temporarily off if the guest
doesn't seem to be able to receive packets.

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org

v2:
- rename the bitshift type to "enum state_bit_shift" here, not in the next patch
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 8 deletions

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index bd59d9dbf27b..fbdadb3d8220 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -55,7 +55,8 @@ static inline void xenvif_stop_queue(struct xenvif_queue *queue)
 
 int xenvif_schedulable(struct xenvif *vif)
 {
-        return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
+        return netif_running(vif->dev) &&
+                test_bit(VIF_STATUS_CONNECTED, &vif->status);
 }
 
 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
@@ -267,7 +268,7 @@ static void xenvif_down(struct xenvif *vif)
 static int xenvif_open(struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
-        if (netif_carrier_ok(dev))
+        if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
                 xenvif_up(vif);
         netif_tx_start_all_queues(dev);
         return 0;
@@ -276,7 +277,7 @@ static int xenvif_open(struct net_device *dev)
 static int xenvif_close(struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
-        if (netif_carrier_ok(dev))
+        if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
                 xenvif_down(vif);
         netif_tx_stop_all_queues(dev);
         return 0;
@@ -528,6 +529,7 @@ void xenvif_carrier_on(struct xenvif *vif)
         if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
                 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);
@@ -625,9 +627,11 @@ void xenvif_carrier_off(struct xenvif *vif)
         struct net_device *dev = vif->dev;
 
         rtnl_lock();
-        netif_carrier_off(dev); /* discard queued packets */
-        if (netif_running(dev))
-                xenvif_down(vif);
+        if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
+                netif_carrier_off(dev); /* discard queued packets */
+                if (netif_running(dev))
+                        xenvif_down(vif);
+        }
         rtnl_unlock();
 }
 
@@ -656,8 +660,7 @@ void xenvif_disconnect(struct xenvif *vif)
         unsigned int num_queues = vif->num_queues;
         unsigned int queue_index;
 
-        if (netif_carrier_ok(vif->dev))
-                xenvif_carrier_off(vif);
+        xenvif_carrier_off(vif);
 
         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
                 queue = &vif->queues[queue_index];