net: ena: update driver's rx drop statistics

BugLink: http://bugs.launchpad.net/bugs/1701575

rx drop counter is reported by the device in the keep-alive
event.
update the driver's counter with the device counter.
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 11a9a460 net-next)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>

drivers/net/ethernet/amazon/ena/ena_netdev.c

@@ -3464,8 +3464,17 @@ static void ena_keep_alive_wd(void *adapter_data,
 			      struct ena_admin_aenq_entry *aenq_e)
 {
 	struct ena_adapter *adapter = (struct ena_adapter *)adapter_data;
+	struct ena_admin_aenq_keep_alive_desc *desc;
+	u64 rx_drops;
 
+	desc = (struct ena_admin_aenq_keep_alive_desc *)aenq_e;
 	adapter->last_keep_alive_jiffies = jiffies;
+
+	rx_drops = ((u64)desc->rx_drops_high << 32) | desc->rx_drops_low;
+
+	u64_stats_update_begin(&adapter->syncp);
+	adapter->dev_stats.rx_drops = rx_drops;
+	u64_stats_update_end(&adapter->syncp);
 }
 
 static void ena_notification(void *adapter_data,