Get network stats from accelerator plugin

diff -r 709db80c03c3 drivers/xen/netfront/accel.c
--- a/drivers/xen/netfront/accel.c	Mon Oct 22 14:29:07 2007 +0100
+++ b/drivers/xen/netfront/accel.c	Mon Oct 29 16:48:27 2007 +0000
@@ -529,6 +529,7 @@ static void accelerator_remove_hooks(str
 static void accelerator_remove_hooks(struct netfront_accelerator *accelerator,
 				     int remove_master)
 {
+	struct netfront_accel_hooks *hooks;
 	struct netfront_accel_vif_state *vif_state, *tmp;
 	unsigned flags;
 
@@ -537,6 +538,7 @@ static void accelerator_remove_hooks(str
 	list_for_each_entry_safe(vif_state, tmp,
 				 &accelerator->vif_states,
 				 link) {
+		hooks = vif_state->hooks;
 		accelerator_remove_single_hook(accelerator, vif_state);
 
 		/* 
@@ -544,7 +546,12 @@ static void accelerator_remove_hooks(str
 		 * were set, must be called without lock held
 		 */
 		spin_unlock_irqrestore(&accelerator->vif_states_lock, flags);
+
+		/* Last chance to get statistics from the accelerator */
+		hooks->get_stats(vif_state->np->netdev, &vif_state->np->stats);
+
 		kref_put(&vif_state->vif_kref, vif_kref_release);
+
 		spin_lock_irqsave(&accelerator->vif_states_lock, flags);
 	}
 	
@@ -663,7 +670,8 @@ int netfront_accelerator_call_remove(str
 		kref_get(&np->accel_vif_state.vif_kref);
 		spin_unlock_irqrestore
 			(&np->accelerator->vif_states_lock, flags);
-		
+		/* Last chance to get statistics from the accelerator */
+		vif_state->hooks->get_stats(np->netdev, &np->stats);
 		rc = np->accel_vif_state.hooks->remove(dev);
 		
 		kref_put(&np->accel_vif_state.vif_kref,
@@ -720,6 +728,9 @@ int netfront_accelerator_call_suspend(st
 			spin_unlock_irqrestore
 				(&np->accelerator->vif_states_lock, flags);
 
+			/* Last chance to get stats from the accelerator */
+			np->accel_vif_state.hooks->get_stats(dev, &np->stats);
+
 			rc = np->accel_vif_state.hooks->suspend(dev);
 
 			kref_put(&np->accel_vif_state.vif_kref,
@@ -869,6 +880,42 @@ void netfront_accelerator_call_stop_napi
 				(&np->accelerator->vif_states_lock, flags);
 		}
 	}
+}
+
+
+int netfront_accelerator_call_get_stats(struct netfront_info *np,
+					struct net_device *dev)
+{
+	struct netfront_accel_hooks *hooks;
+	unsigned flags;
+	int rc = 0;
+
+	/* 
+	 * Call the get_stats accelerator hook.  The use count for the
+	 * accelerator's hooks is incremented for the duration of the
+	 * call to prevent the accelerator being able to modify the
+	 * hooks in the middle (by, for example, unloading)
+	 */
+
+	if (np->accel_vif_state.hooks) {
+		spin_lock_irqsave(&np->accelerator->vif_states_lock, flags); 
+		hooks = np->accel_vif_state.hooks;
+		if (hooks) {
+			kref_get(&np->accel_vif_state.vif_kref);
+			spin_unlock_irqrestore
+				(&np->accelerator->vif_states_lock, flags);
+
+ 			rc = np->accel_vif_state.hooks->get_stats(dev,
+								  &np->stats);
+		
+			kref_put(&np->accel_vif_state.vif_kref,
+				 vif_kref_release);
+		} else {
+			spin_unlock_irqrestore
+				(&np->accelerator->vif_states_lock, flags);
+		}
+	}
+	return rc;
 }
 
 
diff -r 709db80c03c3 drivers/xen/netfront/netfront.c
--- a/drivers/xen/netfront/netfront.c	Mon Oct 22 14:29:07 2007 +0100
+++ b/drivers/xen/netfront/netfront.c	Mon Oct 29 16:28:47 2007 +0000
@@ -1674,6 +1674,8 @@ static struct net_device_stats *network_
 static struct net_device_stats *network_get_stats(struct net_device *dev)
 {
 	struct netfront_info *np = netdev_priv(dev);
+
+	netfront_accelerator_call_get_stats(np, dev);
 	return &np->stats;
 }
 
diff -r 709db80c03c3 drivers/xen/netfront/netfront.h
--- a/drivers/xen/netfront/netfront.h	Mon Oct 22 14:29:07 2007 +0100
+++ b/drivers/xen/netfront/netfront.h	Mon Oct 29 16:28:47 2007 +0000
@@ -96,12 +96,17 @@ struct netfront_accel_hooks {
 	 * path has slots too
 	 */
 	int (*check_busy)(struct net_device *dev);
+	/*
+	 * Get the fastpath network statistics
+	 */
+	int (*get_stats)(struct net_device *dev,
+			 struct net_device_stats *stats);
 };
 
 
 /* Version of API/protocol for communication between netfront and
    acceleration plugin supported */
-#define NETFRONT_ACCEL_VERSION 0x00010000
+#define NETFRONT_ACCEL_VERSION 0x00010001
 
 /* 
  * Per-netfront device state for the accelerator.  This is used to
@@ -295,7 +300,9 @@ extern
 extern
 void netfront_accelerator_call_stop_napi_irq(struct netfront_info *np,
 					     struct net_device *dev);
-
+extern
+int netfront_accelerator_call_get_stats(struct netfront_info *np,
+					struct net_device *dev);
 extern
 int netfront_load_accelerator(struct netfront_info *np, 
 			      struct xenbus_device *dev,