net: ethtool: plumb PHY stats to PHY drivers

Introduce support for standardized PHY statistics reporting in ethtool
by extending the PHYLIB framework. Add the functions
phy_ethtool_get_phy_stats() and phy_ethtool_get_link_ext_stats() to
provide a consistent interface for retrieving PHY-level and
link-specific statistics. These functions are used within the ethtool
implementation to avoid direct access to the phy_device structure
outside of the PHYLIB framework.

A new structure, ethtool_phy_stats, is introduced to standardize PHY
statistics such as packet counts, byte counts, and error counters.
Drivers are updated to include callbacks for retrieving PHY and
link-specific statistics, ensuring values are explicitly set only for
supported fields, initialized with ETHTOOL_STAT_NOT_SET to avoid
ambiguity.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index f711bfd75c4d..4bf70cfec826 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -412,6 +412,29 @@ struct ethtool_eth_phy_stats {
 	);
 };
 
+/**
+ * struct ethtool_phy_stats - PHY-level statistics counters
+ * @rx_packets: Total successfully received frames
+ * @rx_bytes: Total successfully received bytes
+ * @rx_errors: Total received frames with errors (e.g., CRC errors)
+ * @tx_packets: Total successfully transmitted frames
+ * @tx_bytes: Total successfully transmitted bytes
+ * @tx_errors: Total transmitted frames with errors
+ *
+ * This structure provides a standardized interface for reporting
+ * PHY-level statistics counters. It is designed to expose statistics
+ * commonly provided by PHYs but not explicitly defined in the IEEE
+ * 802.3 standard.
+ */
+struct ethtool_phy_stats {
+	u64 rx_packets;
+	u64 rx_bytes;
+	u64 rx_errors;
+	u64 tx_packets;
+	u64 tx_bytes;
+	u64 tx_errors;
+};
+
 /* Basic IEEE 802.3 MAC Ctrl statistics (30.3.3.*), not otherwise exposed
  * via a more targeted API.
  */