Merge branch 'add-fec-bins-histogram-report-via-ethtool'

Vadim Fedorenko says:

====================
add FEC bins histogram report via ethtool

IEEE 802.3ck-2022 defines counters for FEC bins and 802.3df-2024
clarifies it a bit further. Implement reporting interface through as
addition to FEC stats available in ethtool. NetDevSim driver has simple
implementation as an example while mlx5 has much more complex solution.

The example query is the same as usual FEC statistics while the answer
is a bit more verbose:

  $ ynl --family ethtool --do fec-get \
        --json '{"header":{"dev-index": 10, "flags": 4}}'
  {'auto': 0,
   'header': {'dev-index': 10, 'dev-name': 'eni10np1'},
   'modes': {'bits': {}, 'nomask': True, 'size': 121},
   'stats': {'corr-bits': [],
             'corrected': [123],
             'hist': [{'bin-high': 0,
                       'bin-low': 0,
                       'bin-val': 445,
                       'bin-val-per-lane': [125, 120, 100, 100]},
                      {'bin-high': 3, 'bin-low': 1, 'bin-val': 12},
                      {'bin-high': 7,
                       'bin-low': 4,
                       'bin-val': 2,
                       'bin-val-per-lane': [2, 0, 0, 0]}],
             'uncorr': [4]}}
====================

Link: https://patch.msgid.link/20250924124037.1508846-1-vadim.fedorenko@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

20 files changed, 351 insertions, 24 deletions

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 7a7594713f1f..6a0fb1974513 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -1220,6 +1220,30 @@ attribute-sets:
         type: nest
         nested-attributes: tunnel-udp
   -
+    name: fec-hist
+    attr-cnt-name: --ethtool-a-fec-hist-cnt
+    attributes:
+      -
+        name: pad
+        type: pad
+      -
+        name: bin-low
+        type: u32
+        doc: Low bound of FEC bin (inclusive)
+      -
+        name: bin-high
+        type: u32
+        doc: High bound of FEC bin (inclusive)
+      -
+        name: bin-val
+        type: uint
+        doc: Error count in the bin (optional if per-lane values exist)
+      -
+        name: bin-val-per-lane
+        type: binary
+        sub-type: u64
+        doc: An array of per-lane error counters in the bin (optional)
+  -
     name: fec-stat
     attr-cnt-name: __ethtool-a-fec-stat-cnt
     attributes:
@@ -1242,6 +1266,11 @@ attribute-sets:
         name: corr-bits
         type: binary
         sub-type: u64
+      -
+        name: hist
+        type: nest
+        multi-attr: True
+        nested-attributes: fec-hist
   -
     name: fec
     attr-cnt-name: __ethtool-a-fec-cnt
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index ab20c644af24..b270886c5f5d 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1541,6 +1541,11 @@ Drivers fill in the statistics in the following structure:
 .. kernel-doc:: include/linux/ethtool.h
     :identifiers: ethtool_fec_stats
 
+Statistics may have FEC bins histogram attribute ``ETHTOOL_A_FEC_STAT_HIST``
+as defined in IEEE 802.3ck-2022 and 802.3df-2024. Nested attributes will have
+the range of FEC errors in the bin (inclusive) and the amount of error events
+in the bin.
+
 FEC_SET
 =======
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index be32ef8f5c96..41686a6f84b5 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -3208,7 +3208,8 @@ static int bnxt_get_fecparam(struct net_device *dev,
 }
 
 static void bnxt_get_fec_stats(struct net_device *dev,
-			       struct ethtool_fec_stats *fec_stats)
+			       struct ethtool_fec_stats *fec_stats,
+			       struct ethtool_fec_hist *hist)
 {
 	struct bnxt *bp = netdev_priv(dev);
 	u64 *rx;
diff --git a/drivers/net/ethernet/fungible/funeth/funeth_ethtool.c b/drivers/net/ethernet/fungible/funeth/funeth_ethtool.c
index ba83dbf4ed22..1966dba512f8 100644
--- a/drivers/net/ethernet/fungible/funeth/funeth_ethtool.c
+++ b/drivers/net/ethernet/fungible/funeth/funeth_ethtool.c
@@ -930,7 +930,8 @@ static void fun_get_rmon_stats(struct net_device *netdev,
 }
 
 static void fun_get_fec_stats(struct net_device *netdev,
-			      struct ethtool_fec_stats *stats)
+			      struct ethtool_fec_stats *stats,
+			      struct ethtool_fec_hist *hist)
 {
 	const struct funeth_priv *fp = netdev_priv(netdev);
 
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
index a752d0e3db3a..a5eefa28454c 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
@@ -1659,7 +1659,8 @@ static void hns3_set_msglevel(struct net_device *netdev, u32 msg_level)
 }
 
 static void hns3_get_fec_stats(struct net_device *netdev,
-			       struct ethtool_fec_stats *fec_stats)
+			       struct ethtool_fec_stats *fec_stats,
+			       struct ethtool_fec_hist *hist)
 {
 	struct hnae3_handle *handle = hns3_get_handle(netdev);
 	struct hnae3_ae_dev *ae_dev = hns3_get_ae_dev(handle);
diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index 348acd46a0ef..dc131779d426 100644
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
@@ -4624,10 +4624,12 @@ static int ice_get_port_fec_stats(struct ice_hw *hw, u16 pcs_quad, u16 pcs_port,
  * ice_get_fec_stats - returns FEC correctable, uncorrectable stats per netdev
  * @netdev: network interface device structure
  * @fec_stats: buffer to hold FEC statistics for given port
+ * @hist: buffer to put FEC histogram statistics for given port
  *
  */
 static void ice_get_fec_stats(struct net_device *netdev,
-			      struct ethtool_fec_stats *fec_stats)
+			      struct ethtool_fec_stats *fec_stats,
+			      struct ethtool_fec_hist *hist)
 {
 	struct ice_netdev_priv *np = netdev_priv(netdev);
 	struct ice_port_topology port_topology;
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
index 998c734ff839..b90e23dc49de 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
@@ -1283,7 +1283,8 @@ end:
 }
 
 static void otx2_get_fec_stats(struct net_device *netdev,
-			       struct ethtool_fec_stats *fec_stats)
+			       struct ethtool_fec_stats *fec_stats,
+			       struct ethtool_fec_hist *hist)
 {
 	struct otx2_nic *pfvf = netdev_priv(netdev);
 	struct cgx_fw_data *rsp;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 4ffbc263d60f..14e3207b14e7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -956,6 +956,7 @@ struct mlx5e_priv {
 	struct mlx5e_mqprio_rl    *mqprio_rl;
 	struct dentry             *dfs_root;
 	struct mlx5_devcom_comp_dev *devcom;
+	struct ethtool_fec_hist_range *fec_ranges;
 };
 
 struct mlx5e_dev {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index d507366d773e..fd45384a855b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -1927,11 +1927,12 @@ static int mlx5e_set_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
 }
 
 static void mlx5e_get_fec_stats(struct net_device *netdev,
-				struct ethtool_fec_stats *fec_stats)
+				struct ethtool_fec_stats *fec_stats,
+				struct ethtool_fec_hist *hist)
 {
 	struct mlx5e_priv *priv = netdev_priv(netdev);
 
-	mlx5e_stats_fec_get(priv, fec_stats);
+	mlx5e_stats_fec_get(priv, fec_stats, hist);
 }
 
 static int mlx5e_get_fecparam(struct net_device *netdev,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 5e007bb3bad1..0c79c42ae538 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -6279,8 +6279,15 @@ int mlx5e_priv_init(struct mlx5e_priv *priv,
 	if (!priv->channel_stats)
 		goto err_free_tx_rates;
 
+	priv->fec_ranges = kcalloc(ETHTOOL_FEC_HIST_MAX,
+				   sizeof(*priv->fec_ranges), GFP_KERNEL);
+	if (!priv->fec_ranges)
+		goto err_free_channel_stats;
+
 	return 0;
 
+err_free_channel_stats:
+	kfree(priv->channel_stats);
 err_free_tx_rates:
 	kfree(priv->tx_rates);
 err_free_txq2sq_stats:
@@ -6304,6 +6311,7 @@ void mlx5e_priv_cleanup(struct mlx5e_priv *priv)
 	if (!priv->mdev)
 		return;
 
+	kfree(priv->fec_ranges);
 	for (i = 0; i < priv->stats_nch; i++)
 		kvfree(priv->channel_stats[i]);
 	kfree(priv->channel_stats);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
index c6185ddba04b..7c029a7d0fd7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
@@ -1446,16 +1446,13 @@ static void fec_set_rs_stats(struct ethtool_fec_stats *fec_stats, u32 *ppcnt)
 }
 
 static void fec_set_block_stats(struct mlx5e_priv *priv,
+				int mode,
 				struct ethtool_fec_stats *fec_stats)
 {
 	struct mlx5_core_dev *mdev = priv->mdev;
 	u32 out[MLX5_ST_SZ_DW(ppcnt_reg)] = {};
 	u32 in[MLX5_ST_SZ_DW(ppcnt_reg)] = {};
 	int sz = MLX5_ST_SZ_BYTES(ppcnt_reg);
-	int mode = fec_active_mode(mdev);
-
-	if (mode == MLX5E_FEC_NOFEC)
-		return;
 
 	MLX5_SET(ppcnt_reg, in, local_port, 1);
 	MLX5_SET(ppcnt_reg, in, grp, MLX5_PHYSICAL_LAYER_COUNTERS_GROUP);
@@ -1494,14 +1491,130 @@ static void fec_set_corrected_bits_total(struct mlx5e_priv *priv,
 				      phy_corrected_bits);
 }
 
+#define MLX5_RS_HISTOGRAM_ENTRIES \
+	(MLX5_FLD_SZ_BYTES(rs_histogram_cntrs, hist) / \
+	 MLX5_FLD_SZ_BYTES(rs_histogram_cntrs, hist[0]))
+
+enum {
+	MLX5E_HISTOGRAM_FEC_RS_544_514 = 1,
+	MLX5E_HISTOGRAM_FEC_LLRS = 2,
+	MLX5E_HISTOGRAM_FEC_RS_528_514 = 3,
+};
+
+static bool fec_rs_validate_hist_type(int mode, int hist_type)
+{
+	switch (mode) {
+	case MLX5E_FEC_RS_528_514:
+		return hist_type == MLX5E_HISTOGRAM_FEC_RS_528_514;
+	case MLX5E_FEC_RS_544_514_INTERLEAVED_QUAD:
+	case MLX5E_FEC_RS_544_514:
+		return hist_type == MLX5E_HISTOGRAM_FEC_RS_544_514;
+	case MLX5E_FEC_LLRS_272_257_1:
+		return hist_type == MLX5E_HISTOGRAM_FEC_LLRS;
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static u8
+fec_rs_histogram_fill_ranges(struct mlx5e_priv *priv, int mode,
+			     const struct ethtool_fec_hist_range **ranges)
+{
+	struct mlx5_core_dev *mdev = priv->mdev;
+	u32 out[MLX5_ST_SZ_DW(pphcr_reg)] = {0};
+	u32 in[MLX5_ST_SZ_DW(pphcr_reg)] = {0};
+	int sz = MLX5_ST_SZ_BYTES(pphcr_reg);
+	u8 hist_type, num_of_bins;
+
+	memset(priv->fec_ranges, 0,
+	       ETHTOOL_FEC_HIST_MAX * sizeof(*priv->fec_ranges));
+	MLX5_SET(pphcr_reg, in, local_port, 1);
+	if (mlx5_core_access_reg(mdev, in, sz, out, sz, MLX5_REG_PPHCR, 0, 0))
+		return 0;
+
+	hist_type = MLX5_GET(pphcr_reg, out, active_hist_type);
+	if (!fec_rs_validate_hist_type(mode, hist_type))
+		return 0;
+
+	num_of_bins = MLX5_GET(pphcr_reg, out, num_of_bins);
+	if (WARN_ON_ONCE(num_of_bins > MLX5_RS_HISTOGRAM_ENTRIES))
+		return 0;
+
+	for (int i = 0; i < num_of_bins; i++) {
+		void *bin_range = MLX5_ADDR_OF(pphcr_reg, out, bin_range[i]);
+
+		priv->fec_ranges[i].high = MLX5_GET(bin_range_layout, bin_range,
+						    high_val);
+		priv->fec_ranges[i].low = MLX5_GET(bin_range_layout, bin_range,
+						   low_val);
+	}
+	*ranges = priv->fec_ranges;
+
+	return num_of_bins;
+}
+
+static void fec_rs_histogram_fill_stats(struct mlx5e_priv *priv,
+					u8 num_of_bins,
+					struct ethtool_fec_hist *hist)
+{
+	struct mlx5_core_dev *mdev = priv->mdev;
+	u32 out[MLX5_ST_SZ_DW(ppcnt_reg)] = {0};
+	u32 in[MLX5_ST_SZ_DW(ppcnt_reg)] = {0};
+	int sz = MLX5_ST_SZ_BYTES(ppcnt_reg);
+	void *rs_histogram_cntrs;
+
+	MLX5_SET(ppcnt_reg, in, local_port, 1);
+	MLX5_SET(ppcnt_reg, in, grp, MLX5_RS_FEC_HISTOGRAM_GROUP);
+	if (mlx5_core_access_reg(mdev, in, sz, out, sz, MLX5_REG_PPCNT, 0, 0))
+		return;
+
+	rs_histogram_cntrs = MLX5_ADDR_OF(ppcnt_reg, out,
+					  counter_set.rs_histogram_cntrs);
+	/* Guaranteed that num_of_bins is less than MLX5E_FEC_RS_HIST_MAX
+	 * by fec_rs_histogram_fill_ranges().
+	 */
+	for (int i = 0; i < num_of_bins; i++)
+		hist->values[i].sum = MLX5_GET64(rs_histogram_cntrs,
+						 rs_histogram_cntrs,
+						 hist[i]);
+}
+
+static void fec_set_histograms_stats(struct mlx5e_priv *priv, int mode,
+				     struct ethtool_fec_hist *hist)
+{
+	u8 num_of_bins;
+
+	switch (mode) {
+	case MLX5E_FEC_RS_528_514:
+	case MLX5E_FEC_RS_544_514:
+	case MLX5E_FEC_LLRS_272_257_1:
+	case MLX5E_FEC_RS_544_514_INTERLEAVED_QUAD:
+		num_of_bins =
+			fec_rs_histogram_fill_ranges(priv, mode, &hist->ranges);
+		if (num_of_bins)
+			return fec_rs_histogram_fill_stats(priv, num_of_bins,
+							   hist);
+		break;
+	default:
+		return;
+	}
+}
+
 void mlx5e_stats_fec_get(struct mlx5e_priv *priv,
-			 struct ethtool_fec_stats *fec_stats)
+			 struct ethtool_fec_stats *fec_stats,
+			 struct ethtool_fec_hist *hist)
 {
-	if (!MLX5_CAP_PCAM_FEATURE(priv->mdev, ppcnt_statistical_group))
+	int mode = fec_active_mode(priv->mdev);
+
+	if (mode == MLX5E_FEC_NOFEC ||
+	    !MLX5_CAP_PCAM_FEATURE(priv->mdev, ppcnt_statistical_group))
 		return;
 
 	fec_set_corrected_bits_total(priv, fec_stats);
-	fec_set_block_stats(priv, fec_stats);
+	fec_set_block_stats(priv, mode, fec_stats);
+	fec_set_histograms_stats(priv, mode, hist);
 }
 
 #define PPORT_ETH_EXT_OFF(c) \
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
index 72dbcc1928ef..09f155acb461 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
@@ -117,7 +117,8 @@ void mlx5e_stats_update_ndo_stats(struct mlx5e_priv *priv);
 void mlx5e_stats_pause_get(struct mlx5e_priv *priv,
 			   struct ethtool_pause_stats *pause_stats);
 void mlx5e_stats_fec_get(struct mlx5e_priv *priv,
-			 struct ethtool_fec_stats *fec_stats);
+			 struct ethtool_fec_stats *fec_stats,
+			 struct ethtool_fec_hist *hist);
 
 void mlx5e_stats_eth_phy_get(struct mlx5e_priv *priv,
 			     struct ethtool_eth_phy_stats *phy_stats);
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index fecb8c602024..d55d2ac1c3b9 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -1718,7 +1718,8 @@ fbnic_get_pause_stats(struct net_device *netdev,
 
 static void
 fbnic_get_fec_stats(struct net_device *netdev,
-		    struct ethtool_fec_stats *fec_stats)
+		    struct ethtool_fec_stats *fec_stats,
+		    struct ethtool_fec_hist *hist)
 {
 	struct fbnic_net *fbn = netdev_priv(netdev);
 	struct fbnic_phy_stats *phy_stats;
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 23c6a7df78d0..18fe5850a978 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -217,7 +217,8 @@ static int efx_ethtool_set_wol(struct net_device *net_dev,
 }
 
 static void efx_ethtool_get_fec_stats(struct net_device *net_dev,
-				      struct ethtool_fec_stats *fec_stats)
+				      struct ethtool_fec_stats *fec_stats,
+				      struct ethtool_fec_hist *hist)
 {
 	struct efx_nic *efx = efx_netdev_priv(net_dev);
 
diff --git a/drivers/net/ethernet/sfc/siena/ethtool.c b/drivers/net/ethernet/sfc/siena/ethtool.c
index 994909789bfe..8c3ebd0617fb 100644
--- a/drivers/net/ethernet/sfc/siena/ethtool.c
+++ b/drivers/net/ethernet/sfc/siena/ethtool.c
@@ -217,7 +217,8 @@ static int efx_ethtool_set_wol(struct net_device *net_dev,
 }
 
 static void efx_ethtool_get_fec_stats(struct net_device *net_dev,
-				      struct ethtool_fec_stats *fec_stats)
+				      struct ethtool_fec_stats *fec_stats,
+				      struct ethtool_fec_hist *hist)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
 
diff --git a/drivers/net/netdevsim/ethtool.c b/drivers/net/netdevsim/ethtool.c
index f631d90c428a..36a201533aae 100644
--- a/drivers/net/netdevsim/ethtool.c
+++ b/drivers/net/netdevsim/ethtool.c
@@ -165,11 +165,34 @@ nsim_set_fecparam(struct net_device *dev, struct ethtool_fecparam *fecparam)
 	return 0;
 }
 
+static const struct ethtool_fec_hist_range netdevsim_fec_ranges[] = {
+	{ 0, 0},
+	{ 1, 3},
+	{ 4, 7},
+	{ 0, 0}
+};
+
 static void
-nsim_get_fec_stats(struct net_device *dev, struct ethtool_fec_stats *fec_stats)
+nsim_get_fec_stats(struct net_device *dev, struct ethtool_fec_stats *fec_stats,
+		   struct ethtool_fec_hist *hist)
 {
+	struct ethtool_fec_hist_value *values = hist->values;
+
+	hist->ranges = netdevsim_fec_ranges;
+
 	fec_stats->corrected_blocks.total = 123;
 	fec_stats->uncorrectable_blocks.total = 4;
+
+	values[0].per_lane[0] = 125;
+	values[0].per_lane[1] = 120;
+	values[0].per_lane[2] = 100;
+	values[0].per_lane[3] = 100;
+	values[1].sum = 12;
+	values[2].sum = 2;
+	values[2].per_lane[0] = 2;
+	values[2].per_lane[1] = 0;
+	values[2].per_lane[2] = 0;
+	values[2].per_lane[3] = 0;
 }
 
 static int nsim_get_ts_info(struct net_device *dev,
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index c869b7f8bce8..c2d8b4ec62eb 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -492,7 +492,29 @@ struct ethtool_pause_stats {
 };
 
 #define ETHTOOL_MAX_LANES	8
+/**
+ * IEEE 802.3ck/df defines 16 bins for FEC histogram plus one more for
+ * the end-of-list marker, total 17 items
+ */
+#define ETHTOOL_FEC_HIST_MAX	17
+/**
+ * struct ethtool_fec_hist_range - error bits range for FEC histogram
+ * statistics
+ * @low: low bound of the bin (inclusive)
+ * @high: high bound of the bin (inclusive)
+ */
+struct ethtool_fec_hist_range {
+	u16 low;
+	u16 high;
+};
 
+struct ethtool_fec_hist {
+	struct ethtool_fec_hist_value {
+		u64 sum;
+		u64 per_lane[ETHTOOL_MAX_LANES];
+	} values[ETHTOOL_FEC_HIST_MAX];
+	const struct ethtool_fec_hist_range *ranges;
+};
 /**
  * struct ethtool_fec_stats - statistics for IEEE 802.3 FEC
  * @corrected_blocks: number of received blocks corrected by FEC
@@ -1214,7 +1236,8 @@ struct ethtool_ops {
 	int	(*set_link_ksettings)(struct net_device *,
 				      const struct ethtool_link_ksettings *);
 	void	(*get_fec_stats)(struct net_device *dev,
-				 struct ethtool_fec_stats *fec_stats);
+				 struct ethtool_fec_stats *fec_stats,
+				 struct ethtool_fec_hist *hist);
 	int	(*get_fecparam)(struct net_device *,
 				      struct ethtool_fecparam *);
 	int	(*set_fecparam)(struct net_device *,
diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index e3b8813465d7..0e8ac0d974e2 100644
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -562,11 +562,23 @@ enum {
 };
 
 enum {
+	ETHTOOL_A_FEC_HIST_PAD = 1,
+	ETHTOOL_A_FEC_HIST_BIN_LOW,
+	ETHTOOL_A_FEC_HIST_BIN_HIGH,
+	ETHTOOL_A_FEC_HIST_BIN_VAL,
+	ETHTOOL_A_FEC_HIST_BIN_VAL_PER_LANE,
+
+	__ETHTOOL_A_FEC_HIST_CNT,
+	ETHTOOL_A_FEC_HIST_MAX = (__ETHTOOL_A_FEC_HIST_CNT - 1)
+};
+
+enum {
 	ETHTOOL_A_FEC_STAT_UNSPEC,
 	ETHTOOL_A_FEC_STAT_PAD,
 	ETHTOOL_A_FEC_STAT_CORRECTED,
 	ETHTOOL_A_FEC_STAT_UNCORR,
 	ETHTOOL_A_FEC_STAT_CORR_BITS,
+	ETHTOOL_A_FEC_STAT_HIST,
 
 	__ETHTOOL_A_FEC_STAT_CNT,
 	ETHTOOL_A_FEC_STAT_MAX = (__ETHTOOL_A_FEC_STAT_CNT - 1)
diff --git a/net/ethtool/fec.c b/net/ethtool/fec.c
index e7d3f2c352a3..4669e74cbcaa 100644
--- a/net/ethtool/fec.c
+++ b/net/ethtool/fec.c
@@ -17,6 +17,7 @@ struct fec_reply_data {
 		u64 stats[1 + ETHTOOL_MAX_LANES];
 		u8 cnt;
 	} corr, uncorr, corr_bits;
+	struct ethtool_fec_hist fec_stat_hist;
 };
 
 #define FEC_REPDATA(__reply_base) \
@@ -113,7 +114,10 @@ static int fec_prepare_data(const struct ethnl_req_info *req_base,
 		struct ethtool_fec_stats stats;
 
 		ethtool_stats_init((u64 *)&stats, sizeof(stats) / 8);
-		dev->ethtool_ops->get_fec_stats(dev, &stats);
+		ethtool_stats_init((u64 *)data->fec_stat_hist.values,
+				   sizeof(data->fec_stat_hist.values) / 8);
+		dev->ethtool_ops->get_fec_stats(dev, &stats,
+						&data->fec_stat_hist);
 
 		fec_stats_recalc(&data->corr, &stats.corrected_blocks);
 		fec_stats_recalc(&data->uncorr, &stats.uncorrectable_blocks);
@@ -157,13 +161,77 @@ static int fec_reply_size(const struct ethnl_req_info *req_base,
 	len += nla_total_size(sizeof(u8)) +	/* _FEC_AUTO */
 	       nla_total_size(sizeof(u32));	/* _FEC_ACTIVE */
 
-	if (req_base->flags & ETHTOOL_FLAG_STATS)
+	if (req_base->flags & ETHTOOL_FLAG_STATS) {
 		len += 3 * nla_total_size_64bit(sizeof(u64) *
 						(1 + ETHTOOL_MAX_LANES));
+		/* add FEC bins information */
+		len += (nla_total_size(0) +  /* _A_FEC_HIST */
+			nla_total_size(4) +  /* _A_FEC_HIST_BIN_LOW */
+			nla_total_size(4) +  /* _A_FEC_HIST_BIN_HI */
+			/* _A_FEC_HIST_BIN_VAL + per-lane values */
+			nla_total_size_64bit(sizeof(u64)) +
+			nla_total_size_64bit(sizeof(u64) * ETHTOOL_MAX_LANES)) *
+			ETHTOOL_FEC_HIST_MAX;
+	}
 
 	return len;
 }
 
+static int fec_put_hist(struct sk_buff *skb,
+			const struct ethtool_fec_hist *hist)
+{
+	const struct ethtool_fec_hist_range *ranges = hist->ranges;
+	const struct ethtool_fec_hist_value *values = hist->values;
+	struct nlattr *nest;
+	int i, j;
+	u64 sum;
+
+	if (!ranges)
+		return 0;
+
+	for (i = 0; i < ETHTOOL_FEC_HIST_MAX; i++) {
+		if (i && !ranges[i].low && !ranges[i].high)
+			break;
+
+		if (WARN_ON_ONCE(values[i].sum == ETHTOOL_STAT_NOT_SET &&
+				 values[i].per_lane[0] == ETHTOOL_STAT_NOT_SET))
+			break;
+
+		nest = nla_nest_start(skb, ETHTOOL_A_FEC_STAT_HIST);
+		if (!nest)
+			return -EMSGSIZE;
+
+		if (nla_put_u32(skb, ETHTOOL_A_FEC_HIST_BIN_LOW,
+				ranges[i].low) ||
+		    nla_put_u32(skb, ETHTOOL_A_FEC_HIST_BIN_HIGH,
+				ranges[i].high))
+			goto err_cancel_hist;
+		sum = 0;
+		for (j = 0; j < ETHTOOL_MAX_LANES; j++) {
+			if (values[i].per_lane[j] == ETHTOOL_STAT_NOT_SET)
+				break;
+			sum += values[i].per_lane[j];
+		}
+		if (nla_put_uint(skb, ETHTOOL_A_FEC_HIST_BIN_VAL,
+				 values[i].sum == ETHTOOL_STAT_NOT_SET ?
+				 sum : values[i].sum))
+			goto err_cancel_hist;
+		if (j && nla_put_64bit(skb, ETHTOOL_A_FEC_HIST_BIN_VAL_PER_LANE,
+				       sizeof(u64) * j,
+				       values[i].per_lane,
+				       ETHTOOL_A_FEC_HIST_PAD))
+			goto err_cancel_hist;
+
+		nla_nest_end(skb, nest);
+	}
+
+	return 0;
+
+err_cancel_hist:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
 static int fec_put_stats(struct sk_buff *skb, const struct fec_reply_data *data)
 {
 	struct nlattr *nest;
@@ -183,6 +251,9 @@ static int fec_put_stats(struct sk_buff *skb, const struct fec_reply_data *data)
 			  data->corr_bits.stats, ETHTOOL_A_FEC_STAT_PAD))
 		goto err_cancel;
 
+	if (fec_put_hist(skb, &data->fec_stat_hist))
+		goto err_cancel;
+
 	nla_nest_end(skb, nest);
 	return 0;
 
diff --git a/tools/testing/selftests/drivers/net/stats.py b/tools/testing/selftests/drivers/net/stats.py
index c2bb5d3f1ca1..04d0a2a13e73 100755
--- a/tools/testing/selftests/drivers/net/stats.py
+++ b/tools/testing/selftests/drivers/net/stats.py
@@ -57,6 +57,36 @@ def check_fec(cfg) -> None:
     ksft_true(data['stats'], "driver does not report stats")
 
 
+def check_fec_hist(cfg) -> None:
+    """
+    Check that drivers which support FEC histogram statistics report
+    reasonable values.
+    """
+
+    try:
+        data = ethnl.fec_get({"header": {"dev-index": cfg.ifindex,
+                                         "flags": {'stats'}}})
+    except NlError as e:
+        if e.error == errno.EOPNOTSUPP:
+            raise KsftSkipEx("FEC not supported by the device") from e
+        raise
+    if 'stats' not in data:
+        raise KsftSkipEx("FEC stats not supported by the device")
+    if 'hist' not in data['stats']:
+        raise KsftSkipEx("FEC histogram not supported by the device")
+
+    hist = data['stats']['hist']
+    for fec_bin in hist:
+        for key in ['bin-low', 'bin-high', 'bin-val']:
+            ksft_in(key, fec_bin,
+	            "Drivers should always report FEC bin range and value")
+        ksft_ge(fec_bin['bin-high'], fec_bin['bin-low'],
+                "FEC bin range should be valid")
+        if 'bin-val-per-lane' in fec_bin:
+            ksft_eq(sum(fec_bin['bin-val-per-lane']), fec_bin['bin-val'],
+                    "FEC bin value should be equal to sum of per-plane values")
+
+
 def pkt_byte_sum(cfg) -> None:
     """
     Check that qstat and interface stats match in value.
@@ -279,8 +309,9 @@ def main() -> None:
     """ Ksft boiler plate main """
 
     with NetDrvEnv(__file__, queue_count=100) as cfg:
-        ksft_run([check_pause, check_fec, pkt_byte_sum, qstat_by_ifindex,
-                  check_down, procfs_hammer, procfs_downup_hammer],
+        ksft_run([check_pause, check_fec, check_fec_hist, pkt_byte_sum,
+		  qstat_by_ifindex, check_down, procfs_hammer,
+		  procfs_downup_hammer],
                  args=(cfg, ))
     ksft_exit()