mlxsw: spectrum_ptp: Add counters for GC events

On Spectrum-1, timestamped PTP packets and the corresponding timestamps need to
be kept in caches until both are available, at which point they are matched up
and packets forwarded as appropriate. However, not all packets will ever see
their timestamp, and not all timestamps will ever see their packet. It is
necessary to dispose of such abandoned entries, so a garbage collector was
introduced in commit 5d23e4159772 ("mlxsw: spectrum: PTP: Garbage-collect
unmatched entries").

If these GC events happen often, it is a sign of a problem. However because this
whole mechanism is taking place behind the scenes, there is no direct way to
determine whether garbage collection took place.

Therefore to fix this, on Spectrum-1 only, expose four artificial ethtool
counters for the GC events: GCd timestamps and packets, in TX and RX directions.

Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 1 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index dd3ae46e5eca..91e4792bb7e7 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -175,6 +175,10 @@ struct mlxsw_sp_ptp_ops {
 	void (*shaper_work)(struct work_struct *work);
 	int (*get_ts_info)(struct mlxsw_sp *mlxsw_sp,
 			   struct ethtool_ts_info *info);
+	int (*get_stats_count)(void);
+	void (*get_stats_strings)(u8 **p);
+	void (*get_stats)(struct mlxsw_sp_port *mlxsw_sp_port,
+			  u64 *data, int data_index);
 };
 
 static int mlxsw_sp_component_query(struct mlxfw_dev *mlxfw_dev,
@@ -2329,6 +2333,7 @@ static void mlxsw_sp_port_get_tc_strings(u8 **p, int tc)
 static void mlxsw_sp_port_get_strings(struct net_device *dev,
 				      u32 stringset, u8 *data)
 {
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
 	u8 *p = data;
 	int i;
 
@@ -2370,6 +2375,7 @@ static void mlxsw_sp_port_get_strings(struct net_device *dev,
 		for (i = 0; i < TC_MAX_QUEUE; i++)
 			mlxsw_sp_port_get_tc_strings(&p, i);
 
+		mlxsw_sp_port->mlxsw_sp->ptp_ops->get_stats_strings(&p);
 		break;
 	}
 }
@@ -2464,6 +2470,7 @@ static void __mlxsw_sp_port_get_stats(struct net_device *dev,
 static void mlxsw_sp_port_get_stats(struct net_device *dev,
 				    struct ethtool_stats *stats, u64 *data)
 {
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
 	int i, data_index = 0;
 
 	/* IEEE 802.3 Counters */
@@ -2504,13 +2511,21 @@ static void mlxsw_sp_port_get_stats(struct net_device *dev,
 					  data, data_index);
 		data_index += MLXSW_SP_PORT_HW_TC_STATS_LEN;
 	}
+
+	/* PTP counters */
+	mlxsw_sp_port->mlxsw_sp->ptp_ops->get_stats(mlxsw_sp_port,
+						    data, data_index);
+	data_index += mlxsw_sp_port->mlxsw_sp->ptp_ops->get_stats_count();
 }
 
 static int mlxsw_sp_port_get_sset_count(struct net_device *dev, int sset)
 {
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
+
 	switch (sset) {
 	case ETH_SS_STATS:
-		return MLXSW_SP_PORT_ETHTOOL_STATS_LEN;
+		return MLXSW_SP_PORT_ETHTOOL_STATS_LEN +
+		       mlxsw_sp_port->mlxsw_sp->ptp_ops->get_stats_count();
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -4643,6 +4658,9 @@ static const struct mlxsw_sp_ptp_ops mlxsw_sp1_ptp_ops = {
 	.hwtstamp_set	= mlxsw_sp1_ptp_hwtstamp_set,
 	.shaper_work	= mlxsw_sp1_ptp_shaper_work,
 	.get_ts_info	= mlxsw_sp1_ptp_get_ts_info,
+	.get_stats_count = mlxsw_sp1_get_stats_count,
+	.get_stats_strings = mlxsw_sp1_get_stats_strings,
+	.get_stats	= mlxsw_sp1_get_stats,
 };
 
 static const struct mlxsw_sp_ptp_ops mlxsw_sp2_ptp_ops = {
@@ -4656,6 +4674,9 @@ static const struct mlxsw_sp_ptp_ops mlxsw_sp2_ptp_ops = {
 	.hwtstamp_set	= mlxsw_sp2_ptp_hwtstamp_set,
 	.shaper_work	= mlxsw_sp2_ptp_shaper_work,
 	.get_ts_info	= mlxsw_sp2_ptp_get_ts_info,
+	.get_stats_count = mlxsw_sp2_get_stats_count,
+	.get_stats_strings = mlxsw_sp2_get_stats_strings,
+	.get_stats	= mlxsw_sp2_get_stats,
 };
 
 static int mlxsw_sp_netdevice_event(struct notifier_block *unused,