net: dsa: mv88e6xxx: Add "rmon" counter group support

Report the applicable subset of an mv88e6xxx port's counters using
ethtool's standardized "rmon" counter group.
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -1369,6 +1369,47 @@ static void mv88e6xxx_get_eth_mac_stats(struct dsa_switch *ds, int port,
 	mac_stats->stats.FramesReceivedOK += mac_stats->stats.BroadcastFramesReceivedOK;
 }
 
+static void mv88e6xxx_get_rmon_stats(struct dsa_switch *ds, int port,
+				     struct ethtool_rmon_stats *rmon_stats,
+				     const struct ethtool_rmon_hist_range **ranges)
+{
+	static const struct ethtool_rmon_hist_range rmon_ranges[] = {
+		{   64,    64 },
+		{   65,   127 },
+		{  128,   255 },
+		{  256,   511 },
+		{  512,  1023 },
+		{ 1024, 65535 },
+		{}
+	};
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int ret;
+
+	ret = mv88e6xxx_stats_snapshot(chip, port);
+	if (ret < 0)
+		return;
+
+#define MV88E6XXX_RMON_STAT_MAP(_id, _member)				\
+	mv88e6xxx_stats_get_stat(chip, port,				\
+				 &mv88e6xxx_hw_stats[MV88E6XXX_HW_STAT_ID_ ## _id], \
+				 &rmon_stats->stats._member)
+
+	MV88E6XXX_RMON_STAT_MAP(in_undersize, undersize_pkts);
+	MV88E6XXX_RMON_STAT_MAP(in_oversize, oversize_pkts);
+	MV88E6XXX_RMON_STAT_MAP(in_fragments, fragments);
+	MV88E6XXX_RMON_STAT_MAP(in_jabber, jabbers);
+	MV88E6XXX_RMON_STAT_MAP(hist_64bytes, hist[0]);
+	MV88E6XXX_RMON_STAT_MAP(hist_65_127bytes, hist[1]);
+	MV88E6XXX_RMON_STAT_MAP(hist_128_255bytes, hist[2]);
+	MV88E6XXX_RMON_STAT_MAP(hist_256_511bytes, hist[3]);
+	MV88E6XXX_RMON_STAT_MAP(hist_512_1023bytes, hist[4]);
+	MV88E6XXX_RMON_STAT_MAP(hist_1024_max_bytes, hist[5]);
+
+#undef MV88E6XXX_RMON_STAT_MAP
+
+	*ranges = rmon_ranges;
+}
+
 static int mv88e6xxx_get_regs_len(struct dsa_switch *ds, int port)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
@@ -6891,6 +6932,7 @@ static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
 	.get_strings		= mv88e6xxx_get_strings,
 	.get_ethtool_stats	= mv88e6xxx_get_ethtool_stats,
 	.get_eth_mac_stats	= mv88e6xxx_get_eth_mac_stats,
+	.get_rmon_stats		= mv88e6xxx_get_rmon_stats,
 	.get_sset_count		= mv88e6xxx_get_sset_count,
 	.port_max_mtu		= mv88e6xxx_get_max_mtu,
 	.port_change_mtu	= mv88e6xxx_change_mtu,