sfc: implement per-queue rx drop and overrun stats

Reviewed-by: Jacob Keller <[e-mail]>
Signed-off-by: Edward Cree <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/sfc/efx.c

···
 	rx_queue = efx_channel_get_rx_queue(channel);
 	/* Count only packets since last time datapath was started */
 	stats->packets = rx_queue->rx_packets - rx_queue->old_rx_packets;
+	stats->hw_drops = efx_get_queue_stat_rx_hw_drops(channel) -
+			  channel->old_n_rx_hw_drops;
+	stats->hw_drop_overruns = channel->n_rx_nodesc_trunc -
+				  channel->old_n_rx_hw_drop_overruns;
 }
 
 static void efx_get_queue_stats_tx(struct net_device *net_dev, int idx,
···
 	struct efx_channel *channel;
 
 	rx->packets = 0;
+	rx->hw_drops = 0;
+	rx->hw_drop_overruns = 0;
 	tx->packets = 0;
 	tx->bytes = 0;
 
···
 	 */
 	efx_for_each_channel(channel, efx) {
 		rx_queue = efx_channel_get_rx_queue(channel);
-		if (channel->channel >= net_dev->real_num_rx_queues)
+		if (channel->channel >= net_dev->real_num_rx_queues) {
 			rx->packets += rx_queue->rx_packets;
-		else
+			rx->hw_drops += efx_get_queue_stat_rx_hw_drops(channel);
+			rx->hw_drop_overruns += channel->n_rx_nodesc_trunc;
+		} else {
 			rx->packets += rx_queue->old_rx_packets;
+			rx->hw_drops += channel->old_n_rx_hw_drops;
+			rx->hw_drop_overruns += channel->old_n_rx_hw_drop_overruns;
+		}
 		efx_for_each_channel_tx_queue(tx_queue, channel) {
 			if (channel->channel < efx->tx_channel_offset ||
 			    channel->channel >= efx->tx_channel_offset +

drivers/net/ethernet/sfc/efx_channels.c

···
 			atomic_inc(&efx->active_queues);
 		}
 
+		/* reset per-queue stats */
+		channel->old_n_rx_hw_drops = efx_get_queue_stat_rx_hw_drops(channel);
+		channel->old_n_rx_hw_drop_overruns = channel->n_rx_nodesc_trunc;
+
 		efx_for_each_channel_rx_queue(rx_queue, channel) {
 			efx_init_rx_queue(rx_queue);
 			atomic_inc(&efx->active_queues);

drivers/net/ethernet/sfc/efx_channels.h

···
 void efx_start_channels(struct efx_nic *efx);
 void efx_stop_channels(struct efx_nic *efx);
 
+static inline u64 efx_get_queue_stat_rx_hw_drops(struct efx_channel *channel)
+{
+	return channel->n_rx_eth_crc_err + channel->n_rx_frm_trunc +
+	       channel->n_rx_overlength + channel->n_rx_nodesc_trunc +
+	       channel->n_rx_mport_bad;
+}
+
 void efx_init_napi_channel(struct efx_channel *channel);
 void efx_init_napi(struct efx_nic *efx);
 void efx_fini_napi_channel(struct efx_channel *channel);

drivers/net/ethernet/sfc/net_driver.h

···
  * @n_rx_xdp_redirect: Count of RX packets redirected to a different NIC by XDP
  * @n_rx_mport_bad: Count of RX packets dropped because their ingress mport was
  *	not recognised
+ * @old_n_rx_hw_drops: Count of all RX packets dropped for any reason as of last
+ *	efx_start_channels()
+ * @old_n_rx_hw_drop_overruns: Value of @n_rx_nodesc_trunc as of last
+ *	efx_start_channels()
  * @rx_pkt_n_frags: Number of fragments in next packet to be delivered by
  *	__efx_rx_packet(), or zero if there is none
  * @rx_pkt_index: Ring index of first buffer for next packet to be delivered
···
 	unsigned int n_rx_xdp_tx;
 	unsigned int n_rx_xdp_redirect;
 	unsigned int n_rx_mport_bad;
+
+	unsigned int old_n_rx_hw_drops;
+	unsigned int old_n_rx_hw_drop_overruns;
 
 	unsigned int rx_pkt_n_frags;
 	unsigned int rx_pkt_index;