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>

3 files changed, 101 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.
  */
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 4875465653ca..81d1612e7d35 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1144,6 +1144,35 @@ struct phy_driver {
 	int (*cable_test_get_status)(struct phy_device *dev, bool *finished);
 
 	/* Get statistics from the PHY using ethtool */
+	/**
+	 * @get_phy_stats: Retrieve PHY statistics.
+	 * @dev: The PHY device for which the statistics are retrieved.
+	 * @eth_stats: structure where Ethernet PHY stats will be stored.
+	 * @stats: structure where additional PHY-specific stats will be stored.
+	 *
+	 * Retrieves the supported PHY statistics and populates the provided
+	 * structures. The input structures are pre-initialized with
+	 * `ETHTOOL_STAT_NOT_SET`, and the driver must only modify members
+	 * corresponding to supported statistics. Unmodified members will remain
+	 * set to `ETHTOOL_STAT_NOT_SET` and will not be returned to userspace.
+	 */
+	void (*get_phy_stats)(struct phy_device *dev,
+			      struct ethtool_eth_phy_stats *eth_stats,
+			      struct ethtool_phy_stats *stats);
+
+	/**
+	 * @get_link_stats: Retrieve link statistics.
+	 * @dev: The PHY device for which the statistics are retrieved.
+	 * @link_stats: structure where link-specific stats will be stored.
+	 *
+	 * Retrieves link-related statistics for the given PHY device. The input
+	 * structure is pre-initialized with `ETHTOOL_STAT_NOT_SET`, and the
+	 * driver must only modify members corresponding to supported
+	 * statistics. Unmodified members will remain set to
+	 * `ETHTOOL_STAT_NOT_SET` and will not be returned to userspace.
+	 */
+	void (*get_link_stats)(struct phy_device *dev,
+			       struct ethtool_link_ext_stats *link_stats);
 	/** @get_sset_count: Number of statistic counters */
 	int (*get_sset_count)(struct phy_device *dev);
 	/** @get_strings: Names of the statistic counters */
@@ -2124,6 +2153,13 @@ int phy_ethtool_get_strings(struct phy_device *phydev, u8 *data);
 int phy_ethtool_get_sset_count(struct phy_device *phydev);
 int phy_ethtool_get_stats(struct phy_device *phydev,
 			  struct ethtool_stats *stats, u64 *data);
+
+void __phy_ethtool_get_phy_stats(struct phy_device *phydev,
+			 struct ethtool_eth_phy_stats *phy_stats,
+			 struct ethtool_phy_stats *phydev_stats);
+void __phy_ethtool_get_link_ext_stats(struct phy_device *phydev,
+				      struct ethtool_link_ext_stats *link_stats);
+
 int phy_ethtool_get_plca_cfg(struct phy_device *phydev,
 			     struct phy_plca_cfg *plca_cfg);
 int phy_ethtool_set_plca_cfg(struct phy_device *phydev,
diff --git a/include/linux/phylib_stubs.h b/include/linux/phylib_stubs.h
index 1279f48c8a70..9d2d6090c86d 100644
--- a/include/linux/phylib_stubs.h
+++ b/include/linux/phylib_stubs.h
@@ -5,6 +5,9 @@
 
 #include <linux/rtnetlink.h>
 
+struct ethtool_eth_phy_stats;
+struct ethtool_link_ext_stats;
+struct ethtool_phy_stats;
 struct kernel_hwtstamp_config;
 struct netlink_ext_ack;
 struct phy_device;
@@ -19,6 +22,11 @@ struct phylib_stubs {
 	int (*hwtstamp_set)(struct phy_device *phydev,
 			    struct kernel_hwtstamp_config *config,
 			    struct netlink_ext_ack *extack);
+	void (*get_phy_stats)(struct phy_device *phydev,
+			      struct ethtool_eth_phy_stats *phy_stats,
+			      struct ethtool_phy_stats *phydev_stats);
+	void (*get_link_ext_stats)(struct phy_device *phydev,
+				   struct ethtool_link_ext_stats *link_stats);
 };
 
 static inline int phy_hwtstamp_get(struct phy_device *phydev,
@@ -50,6 +58,29 @@ static inline int phy_hwtstamp_set(struct phy_device *phydev,
 	return phylib_stubs->hwtstamp_set(phydev, config, extack);
 }
 
+static inline void phy_ethtool_get_phy_stats(struct phy_device *phydev,
+					struct ethtool_eth_phy_stats *phy_stats,
+					struct ethtool_phy_stats *phydev_stats)
+{
+	ASSERT_RTNL();
+
+	if (!phylib_stubs)
+		return;
+
+	phylib_stubs->get_phy_stats(phydev, phy_stats, phydev_stats);
+}
+
+static inline void phy_ethtool_get_link_ext_stats(struct phy_device *phydev,
+				    struct ethtool_link_ext_stats *link_stats)
+{
+	ASSERT_RTNL();
+
+	if (!phylib_stubs)
+		return;
+
+	phylib_stubs->get_link_ext_stats(phydev, link_stats);
+}
+
 #else
 
 static inline int phy_hwtstamp_get(struct phy_device *phydev,
@@ -65,4 +96,15 @@ static inline int phy_hwtstamp_set(struct phy_device *phydev,
 	return -EOPNOTSUPP;
 }
 
+static inline void phy_ethtool_get_phy_stats(struct phy_device *phydev,
+					struct ethtool_eth_phy_stats *phy_stats,
+					struct ethtool_phy_stats *phydev_stats)
+{
+}
+
+static inline void phy_ethtool_get_link_ext_stats(struct phy_device *phydev,
+				    struct ethtool_link_ext_stats *link_stats)
+{
+}
+
 #endif