openvswitch: change the data type of error status to atomic_long_t

Change the date type of error status from u64 to atomic_long_t, and use atomic
operation, then remove the lock which is used to protect the error status.

The operation of atomic maybe faster than spin lock.

Cc: Pravin Shelar <pshelar@nicira.com>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/vport.h b/net/openvswitch/vport.h
index 35f89d8..0d95b9f 100644
--- a/net/openvswitch/vport.h
+++ b/net/openvswitch/vport.h
@@ -62,10 +62,10 @@
 /* The following definitions are for implementers of vport devices: */
 
 struct vport_err_stats {
-	u64 rx_dropped;
-	u64 rx_errors;
-	u64 tx_dropped;
-	u64 tx_errors;
+	atomic_long_t rx_dropped;
+	atomic_long_t rx_errors;
+	atomic_long_t tx_dropped;
+	atomic_long_t tx_errors;
 };
 /**
  * struct vport_portids - array of netlink portids of a vport.
@@ -93,7 +93,6 @@
  * @dp_hash_node: Element in @datapath->ports hash table in datapath.c.
  * @ops: Class structure.
  * @percpu_stats: Points to per-CPU statistics used and maintained by vport
- * @stats_lock: Protects @err_stats;
  * @err_stats: Points to error statistics used and maintained by vport
  */
 struct vport {
@@ -108,7 +107,6 @@
 
 	struct pcpu_sw_netstats __percpu *percpu_stats;
 
-	spinlock_t stats_lock;
 	struct vport_err_stats err_stats;
 };