sfc: add extra RX drop counters for nodesc_trunc and noskb_drop

Added a counter rx_noskb_drop for failure to allocate an skb.
Summed the per-channel rx_nodesc_trunc counters earlier so that they can
 be included in rx_dropped.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 2d86224..4b80c0b 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -2724,6 +2724,17 @@
 	}
 }
 
+void efx_update_sw_stats(struct efx_nic *efx, u64 *stats)
+{
+	u64 n_rx_nodesc_trunc = 0;
+	struct efx_channel *channel;
+
+	efx_for_each_channel(channel, efx)
+		n_rx_nodesc_trunc += channel->n_rx_nodesc_trunc;
+	stats[GENERIC_STAT_rx_nodesc_trunc] = n_rx_nodesc_trunc;
+	stats[GENERIC_STAT_rx_noskb_drops] = atomic_read(&efx->n_rx_noskb_drops);
+}
+
 /**************************************************************************
  *
  * PCI interface