[PATCH net-next v6 0/7] Introduce unified and structured PHY

[PATCH net-next v6 0/7] Introduce unified and structured PHY

[Oleksij Rempel]

This patch set introduces a unified and well-structured interface for
reporting PHY statistics. Instead of relying on arbitrary strings in PHY
drivers, this interface provides a consistent and structured way to
expose PHY statistics to userspace via ethtool.

The initial groundwork for this effort was laid by Jakub Kicinski, who
contributed patches to plumb PHY statistics to drivers and added support
for structured statistics in ethtool. Building on Jakub's work, I tested
the implementation with several PHYs, addressed a few issues, and added
support for statistics in two specific PHY drivers.

Most of changes are tracked in separate patches.
changes v6:
- drop ethtool_stat_add patch
changes v5:
- rebase against latest net-next

Jakub Kicinski (2):
  net: ethtool: plumb PHY stats to PHY drivers
  net: ethtool: add support for structured PHY statistics

Oleksij Rempel (5):
  ethtool: linkstate: migrate linkstate functions to support multi-PHY
    setups
  Documentation: networking: update PHY error counter diagnostics in
    twisted pair guide
  net: phy: introduce optional polling interface for PHY statistics
  net: phy: dp83td510: add statistics support
  net: phy: dp83tg720: add statistics support

 .../twisted_pair_layer1_diagnostics.rst       |  39 +++--
 Documentation/networking/ethtool-netlink.rst  |   1 +
 drivers/net/phy/dp83td510.c                   | 112 ++++++++++++
 drivers/net/phy/dp83tg720.c                   | 161 ++++++++++++++++++
 drivers/net/phy/phy.c                         |  63 +++++++
 drivers/net/phy/phy_device.c                  |   2 +
 include/linux/ethtool.h                       |  23 +++
 include/linux/phy.h                           |  57 +++++++
 include/linux/phylib_stubs.h                  |  42 +++++
 include/uapi/linux/ethtool.h                  |   2 +
 include/uapi/linux/ethtool_netlink.h          |  14 ++
 net/ethtool/linkstate.c                       |  26 ++-
 net/ethtool/netlink.h                         |   1 +
 net/ethtool/stats.c                           |  55 ++++++
 net/ethtool/strset.c                          |   5 +
 15 files changed, 583 insertions(+), 20 deletions(-)

--
2.39.5

[PATCH net-next v6 1/7] ethtool: linkstate: migrate linkstate functions to support multi-PHY setups

[Oleksij Rempel]

Adapt linkstate_get_sqi() and linkstate_get_sqi_max() to take a
phy_device argument directly, enabling support for setups with
multiple PHYs. The previous assumption of a single PHY attached to
a net_device no longer holds.

Use ethnl_req_get_phydev() to identify the appropriate PHY device
for the operation. Update linkstate_prepare_data() and related
logic to accommodate this change, ensuring compatibility with
multi-PHY configurations.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v3:
- s/ETHTOOL_A_PLCA_HEADER/ETHTOOL_A_LINKSTATE_HEADER
---
 net/ethtool/linkstate.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/net/ethtool/linkstate.c b/net/ethtool/linkstate.c
index 34d76e87847d..459cfea7652d 100644
--- a/net/ethtool/linkstate.c
+++ b/net/ethtool/linkstate.c
@@ -26,9 +26,8 @@ const struct nla_policy ethnl_linkstate_get_policy[] = {
 		NLA_POLICY_NESTED(ethnl_header_policy_stats),
 };
 
-static int linkstate_get_sqi(struct net_device *dev)
+static int linkstate_get_sqi(struct phy_device *phydev)
 {
-	struct phy_device *phydev = dev->phydev;
 	int ret;
 
 	if (!phydev)
@@ -46,9 +45,8 @@ static int linkstate_get_sqi(struct net_device *dev)
 	return ret;
 }
 
-static int linkstate_get_sqi_max(struct net_device *dev)
+static int linkstate_get_sqi_max(struct phy_device *phydev)
 {
-	struct phy_device *phydev = dev->phydev;
 	int ret;
 
 	if (!phydev)
@@ -100,19 +98,28 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
 {
 	struct linkstate_reply_data *data = LINKSTATE_REPDATA(reply_base);
 	struct net_device *dev = reply_base->dev;
+	struct nlattr **tb = info->attrs;
+	struct phy_device *phydev;
 	int ret;
 
+	phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_LINKSTATE_HEADER],
+				      info->extack);
+	if (IS_ERR(phydev)) {
+		ret = PTR_ERR(phydev);
+		goto out;
+	}
+
 	ret = ethnl_ops_begin(dev);
 	if (ret < 0)
 		return ret;
 	data->link = __ethtool_get_link(dev);
 
-	ret = linkstate_get_sqi(dev);
+	ret = linkstate_get_sqi(phydev);
 	if (linkstate_sqi_critical_error(ret))
 		goto out;
 	data->sqi = ret;
 
-	ret = linkstate_get_sqi_max(dev);
+	ret = linkstate_get_sqi_max(phydev);
 	if (linkstate_sqi_critical_error(ret))
 		goto out;
 	data->sqi_max = ret;
@@ -127,9 +134,9 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
 			   sizeof(data->link_stats) / 8);
 
 	if (req_base->flags & ETHTOOL_FLAG_STATS) {
-		if (dev->phydev)
+		if (phydev)
 			data->link_stats.link_down_events =
-				READ_ONCE(dev->phydev->link_down_events);
+				READ_ONCE(phydev->link_down_events);
 
 		if (dev->ethtool_ops->get_link_ext_stats)
 			dev->ethtool_ops->get_link_ext_stats(dev,
-- 
2.39.5

[PATCH net-next v6 2/7] net: ethtool: plumb PHY stats to PHY drivers

[Oleksij Rempel]

From: Jakub Kicinski <kuba@kernel.org>

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>
---
changes v6:
- correct documentation, return for void functions.
- move phy_ethtool_get_phy_stats() and phy_ethtool_get_link_ext_stats()
  to phylib_stubs
changes v4:
- fix "make htmldocs" warnings
changes v3:
- fix ./scripts/kernel-doc warning
- move phy_ethtool_get_phy_stats() and phy_ethtool_get_link_ext_stats()
  to the headers.
- - s/ETHTOOL_A_PLCA_HEADER/ETHTOOL_A_STATS_HEADER
changes v2:
- move 'struct ethtool_phy_stats' to this patch
- add comments
---
 drivers/net/phy/phy.c        | 43 ++++++++++++++++++++++++++++++++++++
 drivers/net/phy/phy_device.c |  2 ++
 include/linux/ethtool.h      | 23 +++++++++++++++++++
 include/linux/phy.h          | 36 ++++++++++++++++++++++++++++++
 include/linux/phylib_stubs.h | 42 +++++++++++++++++++++++++++++++++++
 net/ethtool/linkstate.c      |  5 +++--
 net/ethtool/stats.c          | 18 +++++++++++++++
 7 files changed, 167 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e4b04cdaa995..e629c3b1a940 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -615,6 +615,49 @@ int phy_ethtool_get_stats(struct phy_device *phydev,
 }
 EXPORT_SYMBOL(phy_ethtool_get_stats);
 
+/**
+ * phy_ethtool_get_phy_stats - Retrieve standardized PHY statistics
+ * @phydev: Pointer to the PHY device
+ * @phy_stats: Pointer to ethtool_eth_phy_stats structure
+ * @phydev_stats: Pointer to ethtool_phy_stats structure
+ *
+ * Fetches PHY statistics using a kernel-defined interface for consistent
+ * diagnostics. Unlike phy_ethtool_get_stats(), which allows custom stats,
+ * this function enforces a standardized format for better interoperability.
+ */
+void __phy_ethtool_get_phy_stats(struct phy_device *phydev,
+				 struct ethtool_eth_phy_stats *phy_stats,
+				 struct ethtool_phy_stats *phydev_stats)
+{
+	if (!phydev->drv || !phydev->drv->get_phy_stats)
+		return;
+
+	mutex_lock(&phydev->lock);
+	phydev->drv->get_phy_stats(phydev, phy_stats, phydev_stats);
+	mutex_unlock(&phydev->lock);
+}
+
+/**
+ * phy_ethtool_get_link_ext_stats - Retrieve extended link statistics for a PHY
+ * @phydev: Pointer to the PHY device
+ * @link_stats: Pointer to the structure to store extended link statistics
+ *
+ * Populates the ethtool_link_ext_stats structure with link down event counts
+ * and additional driver-specific link statistics, if available.
+ */
+void __phy_ethtool_get_link_ext_stats(struct phy_device *phydev,
+				      struct ethtool_link_ext_stats *link_stats)
+{
+	link_stats->link_down_events = READ_ONCE(phydev->link_down_events);
+
+	if (!phydev->drv || !phydev->drv->get_link_stats)
+		return;
+
+	mutex_lock(&phydev->lock);
+	phydev->drv->get_link_stats(phydev, link_stats);
+	mutex_unlock(&phydev->lock);
+}
+
 /**
  * phy_ethtool_get_plca_cfg - Get PLCA RS configuration
  * @phydev: the phy_device struct
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index bdc997f59779..5b34d39d1d52 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -3800,6 +3800,8 @@ static const struct ethtool_phy_ops phy_ethtool_phy_ops = {
 static const struct phylib_stubs __phylib_stubs = {
 	.hwtstamp_get = __phy_hwtstamp_get,
 	.hwtstamp_set = __phy_hwtstamp_set,
+	.get_phy_stats = __phy_ethtool_get_phy_stats,
+	.get_link_ext_stats = __phy_ethtool_get_link_ext_stats,
 };
 
 static void phylib_register_stubs(void)
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 5bc71d59910c..2fcaf96d3aed 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 */
@@ -2123,6 +2152,13 @@ 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
diff --git a/net/ethtool/linkstate.c b/net/ethtool/linkstate.c
index 459cfea7652d..af19e1bed303 100644
--- a/net/ethtool/linkstate.c
+++ b/net/ethtool/linkstate.c
@@ -3,6 +3,7 @@
 #include "netlink.h"
 #include "common.h"
 #include <linux/phy.h>
+#include <linux/phylib_stubs.h>
 
 struct linkstate_req_info {
 	struct ethnl_req_info		base;
@@ -135,8 +136,8 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
 
 	if (req_base->flags & ETHTOOL_FLAG_STATS) {
 		if (phydev)
-			data->link_stats.link_down_events =
-				READ_ONCE(phydev->link_down_events);
+			phy_ethtool_get_link_ext_stats(phydev,
+						       &data->link_stats);
 
 		if (dev->ethtool_ops->get_link_ext_stats)
 			dev->ethtool_ops->get_link_ext_stats(dev,
diff --git a/net/ethtool/stats.c b/net/ethtool/stats.c
index 912f0c4fff2f..f4d822c225db 100644
--- a/net/ethtool/stats.c
+++ b/net/ethtool/stats.c
@@ -1,5 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
+#include <linux/phy.h>
+#include <linux/phylib_stubs.h>
+
 #include "netlink.h"
 #include "common.h"
 #include "bitset.h"
@@ -20,6 +23,7 @@ struct stats_reply_data {
 		struct ethtool_eth_mac_stats	mac_stats;
 		struct ethtool_eth_ctrl_stats	ctrl_stats;
 		struct ethtool_rmon_stats	rmon_stats;
+		struct ethtool_phy_stats	phydev_stats;
 	);
 	const struct ethtool_rmon_hist_range	*rmon_ranges;
 };
@@ -120,8 +124,15 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base,
 	struct stats_reply_data *data = STATS_REPDATA(reply_base);
 	enum ethtool_mac_stats_src src = req_info->src;
 	struct net_device *dev = reply_base->dev;
+	struct nlattr **tb = info->attrs;
+	struct phy_device *phydev;
 	int ret;
 
+	phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_STATS_HEADER],
+				      info->extack);
+	if (IS_ERR(phydev))
+		return PTR_ERR(phydev);
+
 	ret = ethnl_ops_begin(dev);
 	if (ret < 0)
 		return ret;
@@ -145,6 +156,13 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base,
 	data->ctrl_stats.src = src;
 	data->rmon_stats.src = src;
 
+	if (test_bit(ETHTOOL_STATS_ETH_PHY, req_info->stat_mask) &&
+	    src == ETHTOOL_MAC_STATS_SRC_AGGREGATE) {
+		if (phydev)
+			phy_ethtool_get_phy_stats(phydev, &data->phy_stats,
+						  &data->phydev_stats);
+	}
+
 	if (test_bit(ETHTOOL_STATS_ETH_PHY, req_info->stat_mask) &&
 	    dev->ethtool_ops->get_eth_phy_stats)
 		dev->ethtool_ops->get_eth_phy_stats(dev, &data->phy_stats);
-- 
2.39.5

[PATCH net-next v6 3/7] net: ethtool: add support for structured PHY statistics

[Oleksij Rempel]

From: Jakub Kicinski <kuba@kernel.org>

Introduce a new way to report PHY statistics in a structured and
standardized format using the netlink API. This new method does not
replace the old driver-specific stats, which can still be accessed with
`ethtool -S <eth name>`. The structured stats are available with
`ethtool -S <eth name> --all-groups`.

This new method makes it easier to diagnose problems by organizing stats
in a consistent and documented way.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v2:
- move 'struct ethtool_phy_stats' to this patch
---
 Documentation/networking/ethtool-netlink.rst |  1 +
 include/uapi/linux/ethtool.h                 |  2 +
 include/uapi/linux/ethtool_netlink.h         | 14 +++++++
 net/ethtool/netlink.h                        |  1 +
 net/ethtool/stats.c                          | 39 +++++++++++++++++++-
 net/ethtool/strset.c                         |  5 +++
 6 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index a7ba6368a4d5..da846f1d998e 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1616,6 +1616,7 @@ the ``ETHTOOL_A_STATS_GROUPS`` bitset. Currently defined values are:
  ETHTOOL_STATS_ETH_PHY  eth-phy  Basic IEEE 802.3 PHY statistics (30.3.2.1.*)
  ETHTOOL_STATS_ETH_CTRL eth-ctrl Basic IEEE 802.3 MAC Ctrl statistics (30.3.3.*)
  ETHTOOL_STATS_RMON     rmon     RMON (RFC 2819) statistics
+ ETHTOOL_STATS_PHY      phy      Additional PHY statistics, not defined by IEEE
  ====================== ======== ===============================================
 
 Each group should have a corresponding ``ETHTOOL_A_STATS_GRP`` in the reply.
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 7e1b3820f91f..d1089b88efc7 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -681,6 +681,7 @@ enum ethtool_link_ext_substate_module {
  * @ETH_SS_STATS_ETH_MAC: names of IEEE 802.3 MAC statistics
  * @ETH_SS_STATS_ETH_CTRL: names of IEEE 802.3 MAC Control statistics
  * @ETH_SS_STATS_RMON: names of RMON statistics
+ * @ETH_SS_STATS_PHY: names of PHY(dev) statistics
  *
  * @ETH_SS_COUNT: number of defined string sets
  */
@@ -706,6 +707,7 @@ enum ethtool_stringset {
 	ETH_SS_STATS_ETH_MAC,
 	ETH_SS_STATS_ETH_CTRL,
 	ETH_SS_STATS_RMON,
+	ETH_SS_STATS_PHY,
 
 	/* add new constants above here */
 	ETH_SS_COUNT
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 9c909ce733a5..9ff72cfb2e98 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -99,6 +99,7 @@ enum {
 	ETHTOOL_STATS_ETH_MAC,
 	ETHTOOL_STATS_ETH_CTRL,
 	ETHTOOL_STATS_RMON,
+	ETHTOOL_STATS_PHY,
 
 	/* add new constants above here */
 	__ETHTOOL_STATS_CNT
@@ -193,6 +194,19 @@ enum {
 	ETHTOOL_A_STATS_RMON_MAX = (__ETHTOOL_A_STATS_RMON_CNT - 1)
 };
 
+enum {
+	/* Basic packet counters if PHY has separate counters from the MAC */
+	ETHTOOL_A_STATS_PHY_RX_PKTS,
+	ETHTOOL_A_STATS_PHY_RX_BYTES,
+	ETHTOOL_A_STATS_PHY_RX_ERRORS,
+	ETHTOOL_A_STATS_PHY_TX_PKTS,
+	ETHTOOL_A_STATS_PHY_TX_BYTES,
+	ETHTOOL_A_STATS_PHY_TX_ERRORS,
+
+	/* add new constants above here */
+	__ETHTOOL_A_STATS_PHY_CNT,
+	ETHTOOL_A_STATS_PHY_MAX = (__ETHTOOL_A_STATS_PHY_CNT - 1)
+};
 
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 0a09298fff92..1ce0a3de1430 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -511,5 +511,6 @@ extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING
 extern const char stats_eth_mac_names[__ETHTOOL_A_STATS_ETH_MAC_CNT][ETH_GSTRING_LEN];
 extern const char stats_eth_ctrl_names[__ETHTOOL_A_STATS_ETH_CTRL_CNT][ETH_GSTRING_LEN];
 extern const char stats_rmon_names[__ETHTOOL_A_STATS_RMON_CNT][ETH_GSTRING_LEN];
+extern const char stats_phy_names[__ETHTOOL_A_STATS_PHY_CNT][ETH_GSTRING_LEN];
 
 #endif /* _NET_ETHTOOL_NETLINK_H */
diff --git a/net/ethtool/stats.c b/net/ethtool/stats.c
index f4d822c225db..038a2558f052 100644
--- a/net/ethtool/stats.c
+++ b/net/ethtool/stats.c
@@ -36,6 +36,7 @@ const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN] = {
 	[ETHTOOL_STATS_ETH_MAC]			= "eth-mac",
 	[ETHTOOL_STATS_ETH_CTRL]		= "eth-ctrl",
 	[ETHTOOL_STATS_RMON]			= "rmon",
+	[ETHTOOL_STATS_PHY]			= "phydev",
 };
 
 const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN] = {
@@ -80,6 +81,15 @@ const char stats_rmon_names[__ETHTOOL_A_STATS_RMON_CNT][ETH_GSTRING_LEN] = {
 	[ETHTOOL_A_STATS_RMON_JABBER]		= "etherStatsJabbers",
 };
 
+const char stats_phy_names[__ETHTOOL_A_STATS_PHY_CNT][ETH_GSTRING_LEN] = {
+	[ETHTOOL_A_STATS_PHY_RX_PKTS]		= "RxFrames",
+	[ETHTOOL_A_STATS_PHY_RX_BYTES]		= "RxOctets",
+	[ETHTOOL_A_STATS_PHY_RX_ERRORS]		= "RxErrors",
+	[ETHTOOL_A_STATS_PHY_TX_PKTS]		= "TxFrames",
+	[ETHTOOL_A_STATS_PHY_TX_BYTES]		= "TxOctets",
+	[ETHTOOL_A_STATS_PHY_TX_ERRORS]		= "TxErrors",
+};
+
 const struct nla_policy ethnl_stats_get_policy[ETHTOOL_A_STATS_SRC + 1] = {
 	[ETHTOOL_A_STATS_HEADER]	=
 		NLA_POLICY_NESTED(ethnl_header_policy),
@@ -156,7 +166,8 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base,
 	data->ctrl_stats.src = src;
 	data->rmon_stats.src = src;
 
-	if (test_bit(ETHTOOL_STATS_ETH_PHY, req_info->stat_mask) &&
+	if ((test_bit(ETHTOOL_STATS_PHY, req_info->stat_mask) ||
+	     test_bit(ETHTOOL_STATS_ETH_PHY, req_info->stat_mask)) &&
 	    src == ETHTOOL_MAC_STATS_SRC_AGGREGATE) {
 		if (phydev)
 			phy_ethtool_get_phy_stats(phydev, &data->phy_stats,
@@ -212,6 +223,10 @@ static int stats_reply_size(const struct ethnl_req_info *req_base,
 			nla_total_size(4)) *	/* _A_STATS_GRP_HIST_BKT_HI */
 			ETHTOOL_RMON_HIST_MAX * 2;
 	}
+	if (test_bit(ETHTOOL_STATS_PHY, req_info->stat_mask)) {
+		n_stats += sizeof(struct ethtool_phy_stats) / sizeof(u64);
+		n_grps++;
+	}
 
 	len += n_grps * (nla_total_size(0) + /* _A_STATS_GRP */
 			 nla_total_size(4) + /* _A_STATS_GRP_ID */
@@ -265,6 +280,25 @@ static int stats_put_phy_stats(struct sk_buff *skb,
 	return 0;
 }
 
+static int stats_put_phydev_stats(struct sk_buff *skb,
+				  const struct stats_reply_data *data)
+{
+	if (stat_put(skb, ETHTOOL_A_STATS_PHY_RX_PKTS,
+		     data->phydev_stats.rx_packets) ||
+	    stat_put(skb, ETHTOOL_A_STATS_PHY_RX_BYTES,
+		     data->phydev_stats.rx_bytes) ||
+	    stat_put(skb, ETHTOOL_A_STATS_PHY_RX_ERRORS,
+		     data->phydev_stats.rx_errors) ||
+	    stat_put(skb, ETHTOOL_A_STATS_PHY_TX_PKTS,
+		     data->phydev_stats.tx_packets) ||
+	    stat_put(skb, ETHTOOL_A_STATS_PHY_TX_BYTES,
+		     data->phydev_stats.tx_bytes) ||
+	    stat_put(skb, ETHTOOL_A_STATS_PHY_TX_ERRORS,
+		     data->phydev_stats.tx_errors))
+		return -EMSGSIZE;
+	return 0;
+}
+
 static int stats_put_mac_stats(struct sk_buff *skb,
 			       const struct stats_reply_data *data)
 {
@@ -441,6 +475,9 @@ static int stats_fill_reply(struct sk_buff *skb,
 	if (!ret && test_bit(ETHTOOL_STATS_RMON, req_info->stat_mask))
 		ret = stats_put_stats(skb, data, ETHTOOL_STATS_RMON,
 				      ETH_SS_STATS_RMON, stats_put_rmon_stats);
+	if (!ret && test_bit(ETHTOOL_STATS_PHY, req_info->stat_mask))
+		ret = stats_put_stats(skb, data, ETHTOOL_STATS_PHY,
+				      ETH_SS_STATS_PHY, stats_put_phydev_stats);
 
 	return ret;
 }
diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c
index b3382b3cf325..818cf01f0911 100644
--- a/net/ethtool/strset.c
+++ b/net/ethtool/strset.c
@@ -105,6 +105,11 @@ static const struct strset_info info_template[] = {
 		.count		= __ETHTOOL_A_STATS_RMON_CNT,
 		.strings	= stats_rmon_names,
 	},
+	[ETH_SS_STATS_PHY] = {
+		.per_dev	= false,
+		.count		= __ETHTOOL_A_STATS_PHY_CNT,
+		.strings	= stats_phy_names,
+	},
 };
 
 struct strset_req_info {
-- 
2.39.5

[PATCH net-next v6 4/7] Documentation: networking: update PHY error counter diagnostics in twisted pair guide

[Oleksij Rempel]

Replace generic instructions for monitoring error counters with a
procedure using the unified PHY statistics interface (`--all-groups`).

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 .../twisted_pair_layer1_diagnostics.rst       | 39 +++++++++++++------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/Documentation/networking/diagnostic/twisted_pair_layer1_diagnostics.rst b/Documentation/networking/diagnostic/twisted_pair_layer1_diagnostics.rst
index c9be5cc7e113..079e17effadf 100644
--- a/Documentation/networking/diagnostic/twisted_pair_layer1_diagnostics.rst
+++ b/Documentation/networking/diagnostic/twisted_pair_layer1_diagnostics.rst
@@ -713,17 +713,23 @@ driver supports reporting such events.
 
 - **Monitor Error Counters**:
 
-  - While some NIC drivers and PHYs provide error counters, there is no unified
-    set of PHY-specific counters across all hardware. Additionally, not all
-    PHYs provide useful information related to errors like CRC errors, frame
-    drops, or link flaps. Therefore, this step is dependent on the specific
-    hardware and driver support.
-
-  - **Next Steps**: Use `ethtool -S <interface>` to check if your driver
-    provides useful error counters. In some cases, counters may provide
-    information about errors like link flaps or physical layer problems (e.g.,
-    excessive CRC errors), but results can vary significantly depending on the
-    PHY.
+  - Use `ethtool -S <interface> --all-groups` to retrieve standardized interface
+    statistics if the driver supports the unified interface:
+
+  - **Command:** `ethtool -S <interface> --all-groups`
+
+  - **Example Output (if supported)**:
+
+    .. code-block:: bash
+
+      phydev-RxFrames: 100391
+      phydev-RxErrors: 0
+      phydev-TxFrames: 9
+      phydev-TxErrors: 0
+
+  - If the unified interface is not supported, use `ethtool -S <interface>` to
+    retrieve MAC and PHY counters. Note that non-standardized PHY counter names
+    vary by driver and must be interpreted accordingly:
 
   - **Command:** `ethtool -S <interface>`
 
@@ -740,6 +746,17 @@ driver supports reporting such events.
     condition) or kernel log messages (e.g., link up/down events) to further
     diagnose the issue.
 
+  - **Compare Counters**:
+
+    - Compare the egress and ingress frame counts reported by the PHY and MAC.
+
+    - A small difference may occur due to sampling rate differences between the
+      MAC and PHY drivers, or if the PHY and MAC are not always fully
+      synchronized in their UP or DOWN states.
+
+    - Significant discrepancies indicate potential issues in the data path
+      between the MAC and PHY.
+
 When All Else Fails...
 ~~~~~~~~~~~~~~~~~~~~~~
 
-- 
2.39.5

[PATCH net-next v6 5/7] net: phy: introduce optional polling interface for PHY statistics

[Oleksij Rempel]

Add an optional polling interface for PHY statistics to simplify driver
implementation.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v3:
- update commit message
changes v2:
- drop PHY_POLL_STATS
- add function comments
---
 drivers/net/phy/phy.c | 20 ++++++++++++++++++++
 include/linux/phy.h   | 21 +++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e629c3b1a940..e570e6bf85cc 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1441,6 +1441,23 @@ static int phy_enable_interrupts(struct phy_device *phydev)
 	return phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
 }
 
+/**
+ * phy_update_stats - Update PHY device statistics if supported.
+ * @phydev: Pointer to the PHY device structure.
+ *
+ * If the PHY driver provides an update_stats callback, this function
+ * invokes it to update the PHY statistics. If not, it returns 0.
+ *
+ * Return: 0 on success, or a negative error code if the callback fails.
+ */
+static int phy_update_stats(struct phy_device *phydev)
+{
+	if (!phydev->drv->update_stats)
+		return 0;
+
+	return phydev->drv->update_stats(phydev);
+}
+
 /**
  * phy_request_interrupt - request and enable interrupt for a PHY device
  * @phydev: target phy_device struct
@@ -1510,6 +1527,9 @@ static enum phy_state_work _phy_state_machine(struct phy_device *phydev)
 	case PHY_RUNNING:
 		err = phy_check_link_status(phydev);
 		func = &phy_check_link_status;
+
+		if (!err)
+			err = phy_update_stats(phydev);
 		break;
 	case PHY_CABLETEST:
 		err = phydev->drv->cable_test_get_status(phydev, &finished);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 2fcaf96d3aed..6e368a9fb801 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1173,6 +1173,24 @@ struct phy_driver {
 	 */
 	void (*get_link_stats)(struct phy_device *dev,
 			       struct ethtool_link_ext_stats *link_stats);
+
+	/**
+	 * @update_stats: Trigger periodic statistics updates.
+	 * @dev: The PHY device for which statistics updates are triggered.
+	 *
+	 * Periodically gathers statistics from the PHY device to update locally
+	 * maintained 64-bit counters. This is necessary for PHYs that implement
+	 * reduced-width counters (e.g., 16-bit or 32-bit) which can overflow
+	 * more frequently compared to 64-bit counters. By invoking this
+	 * callback, drivers can fetch the current counter values, handle
+	 * overflow detection, and accumulate the results into local 64-bit
+	 * counters for accurate reporting through the `get_phy_stats` and
+	 * `get_link_stats` interfaces.
+	 *
+	 * Return: 0 on success or a negative error code on failure.
+	 */
+	int (*update_stats)(struct phy_device *dev);
+
 	/** @get_sset_count: Number of statistic counters */
 	int (*get_sset_count)(struct phy_device *dev);
 	/** @get_strings: Names of the statistic counters */
@@ -1663,6 +1681,9 @@ static inline bool phy_polling_mode(struct phy_device *phydev)
 		if (phydev->drv->flags & PHY_POLL_CABLE_TEST)
 			return true;
 
+	if (phydev->drv->update_stats)
+		return true;
+
 	return phydev->irq == PHY_POLL;
 }
 
-- 
2.39.5

[PATCH net-next v6 6/7] net: phy: dp83td510: add statistics support

[Oleksij Rempel]

Add support for reporting PHY statistics in the DP83TD510 driver. This
includes cumulative tracking of transmit/receive packet counts, and
error counts. Implemented functions to update and provide statistics via
ethtool, with optional polling support enabled through `PHY_POLL_STATS`.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v6:
- drop ethtool_stat_add() support
changes v2:
- drop use of FIELD_GET
- add comments
---
 drivers/net/phy/dp83td510.c | 112 ++++++++++++++++++++++++++++++++++++
 1 file changed, 112 insertions(+)

diff --git a/drivers/net/phy/dp83td510.c b/drivers/net/phy/dp83td510.c
index 92aa3a2b9744..1abeacca7441 100644
--- a/drivers/net/phy/dp83td510.c
+++ b/drivers/net/phy/dp83td510.c
@@ -34,6 +34,29 @@
 #define DP83TD510E_CTRL_HW_RESET		BIT(15)
 #define DP83TD510E_CTRL_SW_RESET		BIT(14)
 
+/*
+ * DP83TD510E_PKT_STAT_x registers correspond to similarly named registers
+ * in the datasheet (PKT_STAT_1 through PKT_STAT_6). These registers store
+ * 32-bit or 16-bit counters for TX and RX statistics and must be read in
+ * sequence to ensure the counters are cleared correctly.
+ *
+ * - DP83TD510E_PKT_STAT_1: Contains TX packet count bits [15:0].
+ * - DP83TD510E_PKT_STAT_2: Contains TX packet count bits [31:16].
+ * - DP83TD510E_PKT_STAT_3: Contains TX error packet count.
+ * - DP83TD510E_PKT_STAT_4: Contains RX packet count bits [15:0].
+ * - DP83TD510E_PKT_STAT_5: Contains RX packet count bits [31:16].
+ * - DP83TD510E_PKT_STAT_6: Contains RX error packet count.
+ *
+ * Keeping the register names as defined in the datasheet helps maintain
+ * clarity and alignment with the documentation.
+ */
+#define DP83TD510E_PKT_STAT_1			0x12b
+#define DP83TD510E_PKT_STAT_2			0x12c
+#define DP83TD510E_PKT_STAT_3			0x12d
+#define DP83TD510E_PKT_STAT_4			0x12e
+#define DP83TD510E_PKT_STAT_5			0x12f
+#define DP83TD510E_PKT_STAT_6			0x130
+
 #define DP83TD510E_AN_STAT_1			0x60c
 #define DP83TD510E_MASTER_SLAVE_RESOL_FAIL	BIT(15)
 
@@ -58,8 +81,16 @@ static const u16 dp83td510_mse_sqi_map[] = {
 	0x0000  /* 24dB =< SNR */
 };
 
+struct dp83td510_stats {
+	u64 tx_pkt_cnt;
+	u64 tx_err_pkt_cnt;
+	u64 rx_pkt_cnt;
+	u64 rx_err_pkt_cnt;
+};
+
 struct dp83td510_priv {
 	bool alcd_test_active;
+	struct dp83td510_stats stats;
 };
 
 /* Time Domain Reflectometry (TDR) Functionality of DP83TD510 PHY
@@ -177,6 +208,85 @@ struct dp83td510_priv {
 #define DP83TD510E_ALCD_COMPLETE			BIT(15)
 #define DP83TD510E_ALCD_CABLE_LENGTH			GENMASK(10, 0)
 
+/**
+ * dp83td510_update_stats - Update the PHY statistics for the DP83TD510 PHY.
+ * @phydev: Pointer to the phy_device structure.
+ *
+ * The function reads the PHY statistics registers and updates the statistics
+ * structure.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+static int dp83td510_update_stats(struct phy_device *phydev)
+{
+	struct dp83td510_priv *priv = phydev->priv;
+	u32 count;
+	int ret;
+
+	/* The DP83TD510E_PKT_STAT registers are divided into two groups:
+	 * - Group 1 (TX stats): DP83TD510E_PKT_STAT_1 to DP83TD510E_PKT_STAT_3
+	 * - Group 2 (RX stats): DP83TD510E_PKT_STAT_4 to DP83TD510E_PKT_STAT_6
+	 *
+	 * Registers in each group are cleared only after reading them in a
+	 * plain sequence (e.g., 1, 2, 3 for Group 1 or 4, 5, 6 for Group 2).
+	 * Any deviation from the sequence, such as reading 1, 2, 1, 2, 3, will
+	 * prevent the group from being cleared. Additionally, the counters
+	 * for a group are frozen as soon as the first register in that group
+	 * is accessed.
+	 */
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_PKT_STAT_1);
+	if (ret < 0)
+		return ret;
+	/* tx_pkt_cnt_15_0 */
+	count = ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_PKT_STAT_2);
+	if (ret < 0)
+		return ret;
+	/* tx_pkt_cnt_31_16 */
+	count |= ret << 16;
+	priv->stats.tx_pkt_cnt += count;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_PKT_STAT_3);
+	if (ret < 0)
+		return ret;
+	/* tx_err_pkt_cnt */
+	priv->stats.tx_err_pkt_cnt += ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_PKT_STAT_4);
+	if (ret < 0)
+		return ret;
+	/* rx_pkt_cnt_15_0 */
+	count = ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_PKT_STAT_5);
+	if (ret < 0)
+		return ret;
+	/* rx_pkt_cnt_31_16 */
+	count |= ret << 16;
+	priv->stats.rx_pkt_cnt += count;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_PKT_STAT_6);
+	if (ret < 0)
+		return ret;
+	/* rx_err_pkt_cnt */
+	priv->stats.rx_err_pkt_cnt += ret;
+
+	return 0;
+}
+
+static void dp83td510_get_phy_stats(struct phy_device *phydev,
+				    struct ethtool_eth_phy_stats *eth_stats,
+				    struct ethtool_phy_stats *stats)
+{
+	struct dp83td510_priv *priv = phydev->priv;
+
+	stats->tx_packets = priv->stats.tx_pkt_cnt;
+	stats->tx_errors = priv->stats.tx_err_pkt_cnt;
+	stats->rx_packets = priv->stats.rx_pkt_cnt;
+	stats->rx_errors = priv->stats.rx_err_pkt_cnt;
+}
+
 static int dp83td510_config_intr(struct phy_device *phydev)
 {
 	int ret;
@@ -599,6 +709,8 @@ static struct phy_driver dp83td510_driver[] = {
 	.get_sqi_max	= dp83td510_get_sqi_max,
 	.cable_test_start = dp83td510_cable_test_start,
 	.cable_test_get_status = dp83td510_cable_test_get_status,
+	.get_phy_stats	= dp83td510_get_phy_stats,
+	.update_stats	= dp83td510_update_stats,
 
 	.suspend	= genphy_suspend,
 	.resume		= genphy_resume,
-- 
2.39.5

[PATCH net-next v6 7/7] net: phy: dp83tg720: add statistics support

[Oleksij Rempel]

Add support for reporting PHY statistics in the DP83TG720 driver. This
includes cumulative tracking of link loss events, transmit/receive
packet counts, and error counts. Implemented functions to update and
provide statistics via ethtool, with optional polling support enabled
through `PHY_POLL_STATS`.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v6:
- drop ethtool_stat_add() support
changes v2:
- drop use of FIELD_GET
- add comments
---
 drivers/net/phy/dp83tg720.c | 161 ++++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)

diff --git a/drivers/net/phy/dp83tg720.c b/drivers/net/phy/dp83tg720.c
index 0ef4d7dba065..4ea752131b8c 100644
--- a/drivers/net/phy/dp83tg720.c
+++ b/drivers/net/phy/dp83tg720.c
@@ -51,6 +51,9 @@
 /* Register 0x0405: Unknown Register */
 #define DP83TG720S_UNKNOWN_0405			0x405
 
+#define DP83TG720S_LINK_QUAL_3			0x547
+#define DP83TG720S_LINK_LOSS_CNT_MASK		GENMASK(15, 10)
+
 /* Register 0x0576: TDR Master Link Down Control */
 #define DP83TG720S_TDR_MASTER_LINK_DOWN		0x576
 
@@ -60,6 +63,29 @@
 /* In RGMII mode, Enable or disable the internal delay for TXD */
 #define DP83TG720S_RGMII_TX_CLK_SEL		BIT(0)
 
+/*
+ * DP83TG720S_PKT_STAT_x registers correspond to similarly named registers
+ * in the datasheet (PKT_STAT_1 through PKT_STAT_6). These registers store
+ * 32-bit or 16-bit counters for TX and RX statistics and must be read in
+ * sequence to ensure the counters are cleared correctly.
+ *
+ * - DP83TG720S_PKT_STAT_1: Contains TX packet count bits [15:0].
+ * - DP83TG720S_PKT_STAT_2: Contains TX packet count bits [31:16].
+ * - DP83TG720S_PKT_STAT_3: Contains TX error packet count.
+ * - DP83TG720S_PKT_STAT_4: Contains RX packet count bits [15:0].
+ * - DP83TG720S_PKT_STAT_5: Contains RX packet count bits [31:16].
+ * - DP83TG720S_PKT_STAT_6: Contains RX error packet count.
+ *
+ * Keeping the register names as defined in the datasheet helps maintain
+ * clarity and alignment with the documentation.
+ */
+#define DP83TG720S_PKT_STAT_1			0x639
+#define DP83TG720S_PKT_STAT_2			0x63a
+#define DP83TG720S_PKT_STAT_3			0x63b
+#define DP83TG720S_PKT_STAT_4			0x63c
+#define DP83TG720S_PKT_STAT_5			0x63d
+#define DP83TG720S_PKT_STAT_6			0x63e
+
 /* Register 0x083F: Unknown Register */
 #define DP83TG720S_UNKNOWN_083F			0x83f
 
@@ -69,6 +95,113 @@
 
 #define DP83TG720_SQI_MAX			7
 
+struct dp83tg720_stats {
+	u64 link_loss_cnt;
+	u64 tx_pkt_cnt;
+	u64 tx_err_pkt_cnt;
+	u64 rx_pkt_cnt;
+	u64 rx_err_pkt_cnt;
+};
+
+struct dp83tg720_priv {
+	struct dp83tg720_stats stats;
+};
+
+/**
+ * dp83tg720_update_stats - Update the PHY statistics for the DP83TD510 PHY.
+ * @phydev: Pointer to the phy_device structure.
+ *
+ * The function reads the PHY statistics registers and updates the statistics
+ * structure.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+static int dp83tg720_update_stats(struct phy_device *phydev)
+{
+	struct dp83tg720_priv *priv = phydev->priv;
+	u32 count;
+	int ret;
+
+	/* Read the link loss count */
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TG720S_LINK_QUAL_3);
+	if (ret < 0)
+		return ret;
+	/* link_loss_cnt */
+	count = FIELD_GET(DP83TG720S_LINK_LOSS_CNT_MASK, ret);
+	priv->stats.link_loss_cnt += count;
+
+	/* The DP83TG720S_PKT_STAT registers are divided into two groups:
+	 * - Group 1 (TX stats): DP83TG720S_PKT_STAT_1 to DP83TG720S_PKT_STAT_3
+	 * - Group 2 (RX stats): DP83TG720S_PKT_STAT_4 to DP83TG720S_PKT_STAT_6
+	 *
+	 * Registers in each group are cleared only after reading them in a
+	 * plain sequence (e.g., 1, 2, 3 for Group 1 or 4, 5, 6 for Group 2).
+	 * Any deviation from the sequence, such as reading 1, 2, 1, 2, 3, will
+	 * prevent the group from being cleared. Additionally, the counters
+	 * for a group are frozen as soon as the first register in that group
+	 * is accessed.
+	 */
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TG720S_PKT_STAT_1);
+	if (ret < 0)
+		return ret;
+	/* tx_pkt_cnt_15_0 */
+	count = ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TG720S_PKT_STAT_2);
+	if (ret < 0)
+		return ret;
+	/* tx_pkt_cnt_31_16 */
+	count |= ret << 16;
+	priv->stats.tx_pkt_cnt += count;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TG720S_PKT_STAT_3);
+	if (ret < 0)
+		return ret;
+	/* tx_err_pkt_cnt */
+	priv->stats.tx_err_pkt_cnt += ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TG720S_PKT_STAT_4);
+	if (ret < 0)
+		return ret;
+	/* rx_pkt_cnt_15_0 */
+	count = ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TG720S_PKT_STAT_5);
+	if (ret < 0)
+		return ret;
+	/* rx_pkt_cnt_31_16 */
+	count |= ret << 16;
+	priv->stats.rx_pkt_cnt += count;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TG720S_PKT_STAT_6);
+	if (ret < 0)
+		return ret;
+	/* rx_err_pkt_cnt */
+	priv->stats.rx_err_pkt_cnt += ret;
+
+	return 0;
+}
+
+static void dp83tg720_get_link_stats(struct phy_device *phydev,
+				     struct ethtool_link_ext_stats *link_stats)
+{
+	struct dp83tg720_priv *priv = phydev->priv;
+
+	link_stats->link_down_events = priv->stats.link_loss_cnt;
+}
+
+static void dp83tg720_get_phy_stats(struct phy_device *phydev,
+				    struct ethtool_eth_phy_stats *eth_stats,
+				    struct ethtool_phy_stats *stats)
+{
+	struct dp83tg720_priv *priv = phydev->priv;
+
+	stats->tx_packets = priv->stats.tx_pkt_cnt;
+	stats->tx_errors = priv->stats.tx_err_pkt_cnt;
+	stats->rx_packets = priv->stats.rx_pkt_cnt;
+	stats->rx_errors = priv->stats.rx_err_pkt_cnt;
+}
+
 /**
  * dp83tg720_cable_test_start - Start the cable test for the DP83TG720 PHY.
  * @phydev: Pointer to the phy_device structure.
@@ -182,6 +315,11 @@ static int dp83tg720_cable_test_get_status(struct phy_device *phydev,
 
 	ethnl_cable_test_result(phydev, ETHTOOL_A_CABLE_PAIR_A, stat);
 
+	/* save the current stats before resetting the PHY */
+	ret = dp83tg720_update_stats(phydev);
+	if (ret)
+		return ret;
+
 	return phy_init_hw(phydev);
 }
 
@@ -217,6 +355,11 @@ static int dp83tg720_read_status(struct phy_device *phydev)
 	phy_sts = phy_read(phydev, DP83TG720S_MII_REG_10);
 	phydev->link = !!(phy_sts & DP83TG720S_LINK_STATUS);
 	if (!phydev->link) {
+		/* save the current stats before resetting the PHY */
+		ret = dp83tg720_update_stats(phydev);
+		if (ret)
+			return ret;
+
 		/* According to the "DP83TC81x, DP83TG72x Software
 		 * Implementation Guide", the PHY needs to be reset after a
 		 * link loss or if no link is created after at least 100ms.
@@ -341,12 +484,27 @@ static int dp83tg720_config_init(struct phy_device *phydev)
 	return genphy_c45_pma_baset1_read_master_slave(phydev);
 }
 
+static int dp83tg720_probe(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->mdio.dev;
+	struct dp83tg720_priv *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	phydev->priv = priv;
+
+	return 0;
+}
+
 static struct phy_driver dp83tg720_driver[] = {
 {
 	PHY_ID_MATCH_MODEL(DP83TG720S_PHY_ID),
 	.name		= "TI DP83TG720S",
 
 	.flags          = PHY_POLL_CABLE_TEST,
+	.probe		= dp83tg720_probe,
 	.config_aneg	= dp83tg720_config_aneg,
 	.read_status	= dp83tg720_read_status,
 	.get_features	= genphy_c45_pma_read_ext_abilities,
@@ -355,6 +513,9 @@ static struct phy_driver dp83tg720_driver[] = {
 	.get_sqi_max	= dp83tg720_get_sqi_max,
 	.cable_test_start = dp83tg720_cable_test_start,
 	.cable_test_get_status = dp83tg720_cable_test_get_status,
+	.get_link_stats	= dp83tg720_get_link_stats,
+	.get_phy_stats	= dp83tg720_get_phy_stats,
+	.update_stats	= dp83tg720_update_stats,
 
 	.suspend	= genphy_suspend,
 	.resume		= genphy_resume,
-- 
2.39.5

Re: [PATCH net-next v6 2/7] net: ethtool: plumb PHY stats to PHY drivers

[Simon Horman]

On Thu, Jan 09, 2025 at 10:44:52AM +0100, Oleksij Rempel wrote:
> From: Jakub Kicinski <kuba@kernel.org>
> 
> 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>

...

> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index e4b04cdaa995..e629c3b1a940 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -615,6 +615,49 @@ int phy_ethtool_get_stats(struct phy_device *phydev,
>  }
>  EXPORT_SYMBOL(phy_ethtool_get_stats);
>  
> +/**
> + * phy_ethtool_get_phy_stats - Retrieve standardized PHY statistics

nit: __phy_ethtool_get_phy_stats

> + * @phydev: Pointer to the PHY device
> + * @phy_stats: Pointer to ethtool_eth_phy_stats structure
> + * @phydev_stats: Pointer to ethtool_phy_stats structure
> + *
> + * Fetches PHY statistics using a kernel-defined interface for consistent
> + * diagnostics. Unlike phy_ethtool_get_stats(), which allows custom stats,
> + * this function enforces a standardized format for better interoperability.
> + */
> +void __phy_ethtool_get_phy_stats(struct phy_device *phydev,
> +				 struct ethtool_eth_phy_stats *phy_stats,
> +				 struct ethtool_phy_stats *phydev_stats)
> +{
> +	if (!phydev->drv || !phydev->drv->get_phy_stats)
> +		return;
> +
> +	mutex_lock(&phydev->lock);
> +	phydev->drv->get_phy_stats(phydev, phy_stats, phydev_stats);
> +	mutex_unlock(&phydev->lock);
> +}
> +
> +/**
> + * phy_ethtool_get_link_ext_stats - Retrieve extended link statistics for a PHY

nit: __phy_ethtool_get_link_ext_stats

> + * @phydev: Pointer to the PHY device
> + * @link_stats: Pointer to the structure to store extended link statistics
> + *
> + * Populates the ethtool_link_ext_stats structure with link down event counts
> + * and additional driver-specific link statistics, if available.
> + */
> +void __phy_ethtool_get_link_ext_stats(struct phy_device *phydev,
> +				      struct ethtool_link_ext_stats *link_stats)
> +{
> +	link_stats->link_down_events = READ_ONCE(phydev->link_down_events);
> +
> +	if (!phydev->drv || !phydev->drv->get_link_stats)
> +		return;
> +
> +	mutex_lock(&phydev->lock);
> +	phydev->drv->get_link_stats(phydev, link_stats);
> +	mutex_unlock(&phydev->lock);
> +}
> +
>  /**
>   * phy_ethtool_get_plca_cfg - Get PLCA RS configuration
>   * @phydev: the phy_device struct

...

Re: [PATCH net-next v6 2/7] net: ethtool: plumb PHY stats to PHY drivers

[Jakub Kicinski]

On Thu,  9 Jan 2025 10:44:52 +0100 Oleksij Rempel wrote:
> +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);
> +}

So we traded on set of static inlines for another?
What's wrong with adding a C source which is always built in?
Like drivers/net/phy/stubs.c, maybe call it drivers/net/phy/accessors.c
or drivers/net/phy/helpers.c

Re: [PATCH net-next v6 2/7] net: ethtool: plumb PHY stats to PHY drivers

[Oleksij Rempel]

On Thu, Jan 09, 2025 at 08:07:58AM -0800, Jakub Kicinski wrote:
> On Thu,  9 Jan 2025 10:44:52 +0100 Oleksij Rempel wrote:
> > +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);
> > +}
> 
> So we traded on set of static inlines for another?
> What's wrong with adding a C source which is always built in?
> Like drivers/net/phy/stubs.c, maybe call it drivers/net/phy/accessors.c
> or drivers/net/phy/helpers.c

I chose the current stubs approach based on existing examples like
hw_timestamps. Any implementation, including the current one, will have
zero kernel size impact because each function is only used once. While
moving them to a C source file is an option, it doesn't seem necessary
given the current usage pattern. Do we really want to spend more time on
this for something that won’t impact functionality or size? :)

-- 
Pengutronix e.K.                           |                             |
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Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH net-next v6 2/7] net: ethtool: plumb PHY stats to PHY drivers

[Jakub Kicinski]

On Thu, 9 Jan 2025 18:27:44 +0100 Oleksij Rempel wrote:
> > So we traded on set of static inlines for another?
> > What's wrong with adding a C source which is always built in?
> > Like drivers/net/phy/stubs.c, maybe call it drivers/net/phy/accessors.c
> > or drivers/net/phy/helpers.c  
> 
> I chose the current stubs approach based on existing examples like
> hw_timestamps. Any implementation, including the current one, will have
> zero kernel size impact because each function is only used once. While
> moving them to a C source file is an option, it doesn't seem necessary
> given the current usage pattern. Do we really want to spend more time on
> this for something that won’t impact functionality or size? :)

If we keep following existing approaches we'll not have any chance 
to improve :/

But if you feel strongly it's fine. You do need to respin to fix what
Simon pointed out tho, either way.

Re: [PATCH net-next v6 2/7] net: ethtool: plumb PHY stats to PHY drivers

[kernel test robot]

Hi Oleksij,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Oleksij-Rempel/ethtool-linkstate-migrate-linkstate-functions-to-support-multi-PHY-setups/20250109-174927
base:   net-next/main
patch link:    https://lore.kernel.org/r/20250109094457.97466-3-o.rempel%40pengutronix.de
patch subject: [PATCH net-next v6 2/7] net: ethtool: plumb PHY stats to PHY drivers
config: arc-axs101_defconfig (https://download.01.org/0day-ci/archive/20250110/202501101219.XbI23MZj-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250110/202501101219.XbI23MZj-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501101219.XbI23MZj-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/net/phy/phy.c:631: warning: expecting prototype for phy_ethtool_get_phy_stats(). Prototype was for __phy_ethtool_get_phy_stats() instead
>> drivers/net/phy/phy.c:650: warning: expecting prototype for phy_ethtool_get_link_ext_stats(). Prototype was for __phy_ethtool_get_link_ext_stats() instead


vim +631 drivers/net/phy/phy.c

   617	
   618	/**
   619	 * phy_ethtool_get_phy_stats - Retrieve standardized PHY statistics
   620	 * @phydev: Pointer to the PHY device
   621	 * @phy_stats: Pointer to ethtool_eth_phy_stats structure
   622	 * @phydev_stats: Pointer to ethtool_phy_stats structure
   623	 *
   624	 * Fetches PHY statistics using a kernel-defined interface for consistent
   625	 * diagnostics. Unlike phy_ethtool_get_stats(), which allows custom stats,
   626	 * this function enforces a standardized format for better interoperability.
   627	 */
   628	void __phy_ethtool_get_phy_stats(struct phy_device *phydev,
   629					 struct ethtool_eth_phy_stats *phy_stats,
   630					 struct ethtool_phy_stats *phydev_stats)
 > 631	{
   632		if (!phydev->drv || !phydev->drv->get_phy_stats)
   633			return;
   634	
   635		mutex_lock(&phydev->lock);
   636		phydev->drv->get_phy_stats(phydev, phy_stats, phydev_stats);
   637		mutex_unlock(&phydev->lock);
   638	}
   639	
   640	/**
   641	 * phy_ethtool_get_link_ext_stats - Retrieve extended link statistics for a PHY
   642	 * @phydev: Pointer to the PHY device
   643	 * @link_stats: Pointer to the structure to store extended link statistics
   644	 *
   645	 * Populates the ethtool_link_ext_stats structure with link down event counts
   646	 * and additional driver-specific link statistics, if available.
   647	 */
   648	void __phy_ethtool_get_link_ext_stats(struct phy_device *phydev,
   649					      struct ethtool_link_ext_stats *link_stats)
 > 650	{
   651		link_stats->link_down_events = READ_ONCE(phydev->link_down_events);
   652	
   653		if (!phydev->drv || !phydev->drv->get_link_stats)
   654			return;
   655	
   656		mutex_lock(&phydev->lock);
   657		phydev->drv->get_link_stats(phydev, link_stats);
   658		mutex_unlock(&phydev->lock);
   659	}
   660	

-- 
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https://github.com/intel/lkp-tests/wiki