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/siena.c b/drivers/net/ethernet/sfc/siena.c
index 50ffefe..ae69685 100644
--- a/drivers/net/ethernet/sfc/siena.c
+++ b/drivers/net/ethernet/sfc/siena.c
@@ -424,6 +424,8 @@
 	{ #ext_name, 64, 8 * MC_CMD_MAC_ ## mcdi_name }
 #define SIENA_OTHER_STAT(ext_name)				\
 	[SIENA_STAT_ ## ext_name] = { #ext_name, 0, 0 }
+#define GENERIC_SW_STAT(ext_name)				\
+	[GENERIC_STAT_ ## ext_name] = { #ext_name, 0, 0 }
 
 static const struct efx_hw_stat_desc siena_stat_desc[SIENA_STAT_COUNT] = {
 	SIENA_DMA_STAT(tx_bytes, TX_BYTES),
@@ -483,6 +485,8 @@
 	SIENA_DMA_STAT(rx_length_error, RX_LENGTH_ERROR_PKTS),
 	SIENA_DMA_STAT(rx_internal_error, RX_INTERNAL_ERROR_PKTS),
 	SIENA_DMA_STAT(rx_nodesc_drop_cnt, RX_NODESC_DROPS),
+	GENERIC_SW_STAT(rx_nodesc_trunc),
+	GENERIC_SW_STAT(rx_noskb_drops),
 };
 static const unsigned long siena_stat_mask[] = {
 	[0 ... BITS_TO_LONGS(SIENA_STAT_COUNT) - 1] = ~0UL,
@@ -528,6 +532,7 @@
 	efx_update_diff_stat(&stats[SIENA_STAT_rx_good_bytes],
 			     stats[SIENA_STAT_rx_bytes] -
 			     stats[SIENA_STAT_rx_bad_bytes]);
+	efx_update_sw_stats(efx, stats);
 	return 0;
 }
 
@@ -554,7 +559,9 @@
 		core_stats->tx_packets = stats[SIENA_STAT_tx_packets];
 		core_stats->rx_bytes = stats[SIENA_STAT_rx_bytes];
 		core_stats->tx_bytes = stats[SIENA_STAT_tx_bytes];
-		core_stats->rx_dropped = stats[SIENA_STAT_rx_nodesc_drop_cnt];
+		core_stats->rx_dropped = stats[SIENA_STAT_rx_nodesc_drop_cnt] +
+					 stats[GENERIC_STAT_rx_nodesc_trunc] +
+					 stats[GENERIC_STAT_rx_noskb_drops];
 		core_stats->multicast = stats[SIENA_STAT_rx_multicast];
 		core_stats->collisions = stats[SIENA_STAT_tx_collision];
 		core_stats->rx_length_errors =