net: dsa: Provide additional RMON statistics

Display sw_in_discards, sw_in_filtered, and sw_out_filtered for chips
supported by mv88e6123_61_65 and mv88e6352 drivers.

The variables are provided in port registers, not the normal status registers.
Mark by adding 0x100 to the register offset and add special handling code
to mv88e6xxx_get_ethtool_stats.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 5 deletions

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index c071fde21f4..da558d887da 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -485,17 +485,33 @@ void mv88e6xxx_get_ethtool_stats(struct dsa_switch *ds,
 	for (i = 0; i < nr_stats; i++) {
 		struct mv88e6xxx_hw_stat *s = stats + i;
 		u32 low;
-		u32 high;
-
+		u32 high = 0;
+
+		if (s->reg >= 0x100) {
+			int ret;
+
+			ret = mv88e6xxx_reg_read(ds, REG_PORT(port),
+						 s->reg - 0x100);
+			if (ret < 0)
+				goto error;
+			low = ret;
+			if (s->sizeof_stat == 4) {
+				ret = mv88e6xxx_reg_read(ds, REG_PORT(port),
+							 s->reg - 0x100 + 1);
+				if (ret < 0)
+					goto error;
+				high = ret;
+			}
+			data[i] = (((u64)high) << 16) | low;
+			continue;
+		}
 		mv88e6xxx_stats_read(ds, s->reg, &low);
 		if (s->sizeof_stat == 8)
 			mv88e6xxx_stats_read(ds, s->reg + 1, &high);
-		else
-			high = 0;
 
 		data[i] = (((u64)high) << 32) | low;
 	}
-
+error:
 	mutex_unlock(&ps->stats_mutex);
 }