sfc: add statistics for ARFS

Report the number of successful and failed insertions, and also the
 current count of filters, to aid in tuning e.g. rps_flow_cnt.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

drivers/net/ethernet/sfc/ethtool.c

@@ -56,6 +56,9 @@ static u64 efx_get_atomic_stat(void *field)
 #define EFX_ETHTOOL_UINT_CHANNEL_STAT(field)			\
 	EFX_ETHTOOL_STAT(field, channel, n_##field,		\
 			 unsigned int, efx_get_uint_stat)
+#define EFX_ETHTOOL_UINT_CHANNEL_STAT_NO_N(field)		\
+	EFX_ETHTOOL_STAT(field, channel, field,			\
+			 unsigned int, efx_get_uint_stat)
 
 #define EFX_ETHTOOL_UINT_TXQ_STAT(field)			\
 	EFX_ETHTOOL_STAT(tx_##field, tx_queue, field,		\
@@ -87,6 +90,9 @@ static const struct efx_sw_stat_desc efx_sw_stat_desc[] = {
 	EFX_ETHTOOL_UINT_CHANNEL_STAT(rx_xdp_bad_drops),
 	EFX_ETHTOOL_UINT_CHANNEL_STAT(rx_xdp_tx),
 	EFX_ETHTOOL_UINT_CHANNEL_STAT(rx_xdp_redirect),
+	EFX_ETHTOOL_UINT_CHANNEL_STAT_NO_N(rfs_filter_count),
+	EFX_ETHTOOL_UINT_CHANNEL_STAT(rfs_succeeded),
+	EFX_ETHTOOL_UINT_CHANNEL_STAT(rfs_failed),
 };
 
 #define EFX_ETHTOOL_SW_STAT_COUNT ARRAY_SIZE(efx_sw_stat_desc)

drivers/net/ethernet/sfc/net_driver.h

@@ -444,6 +444,8 @@ enum efx_sync_events_state {
  * @rfs_last_expiry: value of jiffies last time some accelerated RFS filters
  *	were checked for expiry
  * @rfs_expire_index: next accelerated RFS filter ID to check for expiry
+ * @n_rfs_succeeded: number of successful accelerated RFS filter insertions
+ * @n_rfs_failed; number of failed accelerated RFS filter insertions
  * @filter_work: Work item for efx_filter_rfs_expire()
  * @rps_flow_id: Flow IDs of filters allocated for accelerated RFS,
  *      indexed by filter ID
@@ -497,6 +499,8 @@ struct efx_channel {
 	unsigned int rfs_filter_count;
 	unsigned int rfs_last_expiry;
 	unsigned int rfs_expire_index;
+	unsigned int n_rfs_succeeded;
+	unsigned int n_rfs_failed;
 	struct work_struct filter_work;
 #define RPS_FLOW_ID_INVALID 0xFFFFFFFF
 	u32 *rps_flow_id;

drivers/net/ethernet/sfc/rx.c

@@ -1032,6 +1032,7 @@ static void efx_filter_rfs_work(struct work_struct *data)
 				   req->spec.rem_host, ntohs(req->spec.rem_port),
 				   req->spec.loc_host, ntohs(req->spec.loc_port),
 				   req->rxq_index, req->flow_id, rc, arfs_id);
+		channel->n_rfs_succeeded++;
 	} else {
 		if (req->spec.ether_type == htons(ETH_P_IP))
 			netif_dbg(efx, rx_status, efx->net_dev,
@@ -1047,6 +1048,7 @@ static void efx_filter_rfs_work(struct work_struct *data)
 				  req->spec.rem_host, ntohs(req->spec.rem_port),
 				  req->spec.loc_host, ntohs(req->spec.loc_port),
 				  req->rxq_index, req->flow_id, rc, arfs_id);
+		channel->n_rfs_failed++;
 		/* We're overloading the NIC's filter tables, so let's do a
 		 * chunk of extra expiry work.
 		 */