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, 32 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.h
index 72e55f6926b9..8c386571afce 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.h
@@ -59,6 +59,11 @@ void mlxsw_sp1_ptp_shaper_work(struct work_struct *work);
 int mlxsw_sp1_ptp_get_ts_info(struct mlxsw_sp *mlxsw_sp,
 			      struct ethtool_ts_info *info);
 
+int mlxsw_sp1_get_stats_count(void);
+void mlxsw_sp1_get_stats_strings(u8 **p);
+void mlxsw_sp1_get_stats(struct mlxsw_sp_port *mlxsw_sp_port,
+			 u64 *data, int data_index);
+
 #else
 
 static inline struct mlxsw_sp_ptp_clock *
@@ -125,6 +130,19 @@ static inline int mlxsw_sp1_ptp_get_ts_info(struct mlxsw_sp *mlxsw_sp,
 	return mlxsw_sp_ptp_get_ts_info_noptp(info);
 }
 
+static inline int mlxsw_sp1_get_stats_count(void)
+{
+	return 0;
+}
+
+static inline void mlxsw_sp1_get_stats_strings(u8 **p)
+{
+}
+
+static inline void mlxsw_sp1_get_stats(struct mlxsw_sp_port *mlxsw_sp_port,
+				       u64 *data, int data_index)
+{
+}
 #endif
 
 static inline struct mlxsw_sp_ptp_clock *
@@ -183,4 +201,18 @@ static inline int mlxsw_sp2_ptp_get_ts_info(struct mlxsw_sp *mlxsw_sp,
 	return mlxsw_sp_ptp_get_ts_info_noptp(info);
 }
 
+static inline int mlxsw_sp2_get_stats_count(void)
+{
+	return 0;
+}
+
+static inline void mlxsw_sp2_get_stats_strings(u8 **p)
+{
+}
+
+static inline void mlxsw_sp2_get_stats(struct mlxsw_sp_port *mlxsw_sp_port,
+				       u64 *data, int data_index)
+{
+}
+
 #endif