ionic: add Rx dropped packet counter

Add a counter for packets dropped by the driver, typically
for bad size or a receive error seen by the device.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic_lif.h

@@ -37,6 +37,7 @@ struct ionic_rx_stats {
 	u64 csum_complete;
 	u64 csum_error;
 	u64 buffers_posted;
+	u64 dropped;
 };
 
 #define IONIC_QCQ_F_INITED		BIT(0)

drivers/net/ethernet/pensando/ionic/ionic_stats.c

@@ -39,6 +39,7 @@ static const struct ionic_stat_desc ionic_rx_stats_desc[] = {
 	IONIC_RX_STAT_DESC(csum_none),
 	IONIC_RX_STAT_DESC(csum_complete),
 	IONIC_RX_STAT_DESC(csum_error),
+	IONIC_RX_STAT_DESC(dropped),
 };
 
 static const struct ionic_stat_desc ionic_txq_stats_desc[] = {

drivers/net/ethernet/pensando/ionic/ionic_txrx.c

@@ -152,12 +152,16 @@ static void ionic_rx_clean(struct ionic_queue *q, struct ionic_desc_info *desc_i
 	stats = q_to_rx_stats(q);
 	netdev = q->lif->netdev;
 
-	if (comp->status)
+	if (comp->status) {
+		stats->dropped++;
 		return;
+	}
 
 	/* no packet processing while resetting */
-	if (unlikely(test_bit(IONIC_LIF_QUEUE_RESET, q->lif->state)))
+	if (unlikely(test_bit(IONIC_LIF_QUEUE_RESET, q->lif->state))) {
+		stats->dropped++;
 		return;
+	}
 
 	stats->pkts++;
 	stats->bytes += le16_to_cpu(comp->len);
@@ -167,8 +171,10 @@ static void ionic_rx_clean(struct ionic_queue *q, struct ionic_desc_info *desc_i
 	else
 		skb = ionic_rx_frags(q, desc_info, cq_info);
 
-	if (unlikely(!skb))
+	if (unlikely(!skb)) {
+		stats->dropped++;
 		return;
+	}
 
 	skb_record_rx_queue(skb, q->index);