net: mscc: ocelot: add TX timestamping statistics

Add an u64 hardware timestamping statistics structure for each ocelot
port. Export a function from the common switch library for reporting
them to ethtool. This is called by the ocelot switchdev front-end for
now.

Note that for the switchdev driver, we report the one-step PTP packets
as unconfirmed, even though in principle, for some transmission
mechanisms like FDMA, we may be able to confirm transmission and bump
the "pkts" counter in ocelot_fdma_tx_cleanup() instead. I don't have
access to hardware which uses the switchdev front-end, and I've kept the
implementation simple.

Signed-off-by: Vladimir Oltean <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: vladimiroltean

drivers/net/ethernet/mscc/ocelot_net.c

@@ -993,13 +993,24 @@ static int ocelot_port_get_ts_info(struct net_device *dev,
 	return ocelot_get_ts_info(ocelot, port, info);
 }
 
+static void ocelot_port_ts_stats(struct net_device *dev,
+				 struct ethtool_ts_stats *ts_stats)
+{
+	struct ocelot_port_private *priv = netdev_priv(dev);
+	struct ocelot *ocelot = priv->port.ocelot;
+	int port = priv->port.index;
+
+	ocelot_port_get_ts_stats(ocelot, port, ts_stats);
+}
+
 static const struct ethtool_ops ocelot_ethtool_ops = {
 	.get_strings		= ocelot_port_get_strings,
 	.get_ethtool_stats	= ocelot_port_get_ethtool_stats,
 	.get_sset_count		= ocelot_port_get_sset_count,
 	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
 	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
 	.get_ts_info		= ocelot_port_get_ts_info,
+	.get_ts_stats		= ocelot_port_ts_stats,
 };
 
 static void ocelot_port_attr_stp_state_set(struct ocelot *ocelot, int port,

drivers/net/ethernet/mscc/ocelot_ptp.c

@@ -680,9 +680,14 @@ static int ocelot_port_queue_ptp_tx_skb(struct ocelot *ocelot, int port,
 	skb_queue_walk_safe(&ocelot_port->tx_skbs, skb, skb_tmp) {
 		if (time_before(OCELOT_SKB_CB(skb)->ptp_tx_time +
 				OCELOT_PTP_TX_TSTAMP_TIMEOUT, jiffies)) {
-			dev_warn_ratelimited(ocelot->dev,
-					     "port %d invalidating stale timestamp ID %u which seems lost\n",
-					     port, OCELOT_SKB_CB(skb)->ts_id);
+			u64_stats_update_begin(&ocelot_port->ts_stats->syncp);
+			ocelot_port->ts_stats->lost++;
+			u64_stats_update_end(&ocelot_port->ts_stats->syncp);
+
+			dev_dbg_ratelimited(ocelot->dev,
+					    "port %d invalidating stale timestamp ID %u which seems lost\n",
+					    port, OCELOT_SKB_CB(skb)->ts_id);
+
 			__skb_unlink(skb, &ocelot_port->tx_skbs);
 			kfree_skb(skb);
 			ocelot->ptp_skbs_in_flight--;
@@ -748,13 +753,20 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
 		return 0;
 
 	ptp_class = ptp_classify_raw(skb);
-	if (ptp_class == PTP_CLASS_NONE)
-		return -EINVAL;
+	if (ptp_class == PTP_CLASS_NONE) {
+		err = -EINVAL;
+		goto error;
+	}
 
 	/* Store ptp_cmd in OCELOT_SKB_CB(skb)->ptp_cmd */
 	if (ptp_cmd == IFH_REW_OP_ORIGIN_PTP) {
 		if (ocelot_ptp_is_onestep_sync(skb, ptp_class)) {
 			OCELOT_SKB_CB(skb)->ptp_cmd = ptp_cmd;
+
+			u64_stats_update_begin(&ocelot_port->ts_stats->syncp);
+			ocelot_port->ts_stats->onestep_pkts_unconfirmed++;
+			u64_stats_update_end(&ocelot_port->ts_stats->syncp);
+
 			return 0;
 		}
 
@@ -764,14 +776,16 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
 
 	if (ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
 		*clone = skb_clone_sk(skb);
-		if (!(*clone))
-			return -ENOMEM;
+		if (!(*clone)) {
+			err = -ENOMEM;
+			goto error;
+		}
 
 		/* Store timestamp ID in OCELOT_SKB_CB(clone)->ts_id */
 		err = ocelot_port_queue_ptp_tx_skb(ocelot, port, *clone);
 		if (err) {
 			kfree_skb(*clone);
-			return err;
+			goto error;
 		}
 
 		skb_shinfo(*clone)->tx_flags |= SKBTX_IN_PROGRESS;
@@ -780,6 +794,12 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
 	}
 
 	return 0;
+
+error:
+	u64_stats_update_begin(&ocelot_port->ts_stats->syncp);
+	ocelot_port->ts_stats->err++;
+	u64_stats_update_end(&ocelot_port->ts_stats->syncp);
+	return err;
 }
 EXPORT_SYMBOL(ocelot_port_txtstamp_request);
 
@@ -816,6 +836,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 
 	while (budget--) {
 		struct skb_shared_hwtstamps shhwtstamps;
+		struct ocelot_port *ocelot_port;
 		u32 val, id, seqid, txport;
 		struct sk_buff *skb_match;
 		struct timespec64 ts;
@@ -832,17 +853,27 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 		id = SYS_PTP_STATUS_PTP_MESS_ID_X(val);
 		txport = SYS_PTP_STATUS_PTP_MESS_TXPORT_X(val);
 		seqid = SYS_PTP_STATUS_PTP_MESS_SEQ_ID(val);
+		ocelot_port = ocelot->ports[txport];
 
 		/* Retrieve its associated skb */
 		skb_match = ocelot_port_dequeue_ptp_tx_skb(ocelot, txport, id,
 							   seqid);
 		if (!skb_match) {
-			dev_warn_ratelimited(ocelot->dev,
-					     "port %d received TX timestamp (seqid %d, ts id %u) for packet previously declared stale\n",
-					     txport, seqid, id);
+			u64_stats_update_begin(&ocelot_port->ts_stats->syncp);
+			ocelot_port->ts_stats->err++;
+			u64_stats_update_end(&ocelot_port->ts_stats->syncp);
+
+			dev_dbg_ratelimited(ocelot->dev,
+					    "port %d received TX timestamp (seqid %d, ts id %u) for packet previously declared stale\n",
+					    txport, seqid, id);
+
 			goto next_ts;
 		}
 
+		u64_stats_update_begin(&ocelot_port->ts_stats->syncp);
+		ocelot_port->ts_stats->pkts++;
+		u64_stats_update_end(&ocelot_port->ts_stats->syncp);
+
 		/* Get the h/w timestamp */
 		ocelot_get_hwtimestamp(ocelot, &ts);
 

drivers/net/ethernet/mscc/ocelot_stats.c

@@ -821,6 +821,26 @@ void ocelot_port_get_eth_phy_stats(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL_GPL(ocelot_port_get_eth_phy_stats);
 
+void ocelot_port_get_ts_stats(struct ocelot *ocelot, int port,
+			      struct ethtool_ts_stats *ts_stats)
+{
+	struct ocelot_port *ocelot_port = ocelot->ports[port];
+	struct ocelot_ts_stats *stats = ocelot_port->ts_stats;
+	unsigned int start;
+
+	if (!ocelot->ptp)
+		return;
+
+	do {
+		start = u64_stats_fetch_begin(&stats->syncp);
+		ts_stats->pkts = stats->pkts;
+		ts_stats->onestep_pkts_unconfirmed = stats->onestep_pkts_unconfirmed;
+		ts_stats->lost = stats->lost;
+		ts_stats->err = stats->err;
+	} while (u64_stats_fetch_retry(&stats->syncp, start));
+}
+EXPORT_SYMBOL_GPL(ocelot_port_get_ts_stats);
+
 void ocelot_port_get_stats64(struct ocelot *ocelot, int port,
 			     struct rtnl_link_stats64 *stats)
 {
@@ -960,6 +980,23 @@ int ocelot_stats_init(struct ocelot *ocelot)
 	if (!ocelot->stats)
 		return -ENOMEM;
 
+	if (ocelot->ptp) {
+		for (int port = 0; port < ocelot->num_phys_ports; port++) {
+			struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+			if (!ocelot_port)
+				continue;
+
+			ocelot_port->ts_stats = devm_kzalloc(ocelot->dev,
+							     sizeof(*ocelot_port->ts_stats),
+							     GFP_KERNEL);
+			if (!ocelot_port->ts_stats)
+				return -ENOMEM;
+
+			u64_stats_init(&ocelot_port->ts_stats->syncp);
+		}
+	}
+
 	snprintf(queue_name, sizeof(queue_name), "%s-stats",
 		 dev_name(ocelot->dev));
 	ocelot->stats_queue = create_singlethread_workqueue(queue_name);

include/soc/mscc/ocelot.h

@@ -759,6 +759,14 @@ struct ocelot_mm_state {
 	u8 active_preemptible_tcs;
 };
 
+struct ocelot_ts_stats {
+	u64 pkts;
+	u64 onestep_pkts_unconfirmed;
+	u64 lost;
+	u64 err;
+	struct u64_stats_sync syncp;
+};
+
 struct ocelot_port;
 
 struct ocelot_port {
@@ -778,6 +786,7 @@ struct ocelot_port {
 
 	phy_interface_t			phy_mode;
 
+	struct ocelot_ts_stats		*ts_stats;
 	struct sk_buff_head		tx_skbs;
 
 	unsigned int			trap_proto;
@@ -1023,6 +1032,8 @@ void ocelot_port_get_eth_mac_stats(struct ocelot *ocelot, int port,
 				   struct ethtool_eth_mac_stats *mac_stats);
 void ocelot_port_get_eth_phy_stats(struct ocelot *ocelot, int port,
 				   struct ethtool_eth_phy_stats *phy_stats);
+void ocelot_port_get_ts_stats(struct ocelot *ocelot, int port,
+			      struct ethtool_ts_stats *ts_stats);
 int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 		       struct kernel_ethtool_ts_info *info);
 void ocelot_set_ageing_time(struct ocelot *ocelot, unsigned int msecs);