net/mlx5e: Expose FEC counters via ethtool

Add FEC counters' statistics of corrected_blocks and
uncorrectable_blocks, along with their lanes via ethtool.

HW supports corrected_blocks and uncorrectable_blocks counters both for
RS-FEC mode and FC-FEC mode. In FC mode these counters are accumulated
per lane, while in RS mode the correction method crosses lanes, thus
only total corrected_blocks and uncorrectable_blocks are reported in
this mode.
Signed-off-by: Lama Kayal <lkayal@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en_stats.c

@@ -35,6 +35,7 @@
 #include "en_accel/tls.h"
 #include "en_accel/en_accel.h"
 #include "en/ptp.h"
+#include "en/port.h"
 
 static unsigned int stats_grps_num(struct mlx5e_priv *priv)
 {
@@ -1158,12 +1159,99 @@ static MLX5E_DECLARE_STATS_GRP_OP_UPDATE_STATS(phy)
 	mlx5_core_access_reg(mdev, in, sz, out, sz, MLX5_REG_PPCNT, 0, 0);
 }
 
-void mlx5e_stats_fec_get(struct mlx5e_priv *priv,
-			 struct ethtool_fec_stats *fec_stats)
+static int fec_num_lanes(struct mlx5_core_dev *dev)
+{
+	u32 out[MLX5_ST_SZ_DW(pmlp_reg)] = {};
+	u32 in[MLX5_ST_SZ_DW(pmlp_reg)] = {};
+	int err;
+
+	MLX5_SET(pmlp_reg, in, local_port, 1);
+	err = mlx5_core_access_reg(dev, in, sizeof(in), out, sizeof(out),
+				   MLX5_REG_PMLP, 0, 0);
+	if (err)
+		return 0;
+
+	return MLX5_GET(pmlp_reg, out, width);
+}
+
+static int fec_active_mode(struct mlx5_core_dev *mdev)
+{
+	unsigned long fec_active_long;
+	u32 fec_active;
+
+	if (mlx5e_get_fec_mode(mdev, &fec_active, NULL))
+		return MLX5E_FEC_NOFEC;
+
+	fec_active_long = fec_active;
+	return find_first_bit(&fec_active_long, sizeof(unsigned long) * BITS_PER_BYTE);
+}
+
+#define MLX5E_STATS_SET_FEC_BLOCK(idx) ({ \
+	fec_stats->corrected_blocks.lanes[(idx)] = \
+		MLX5E_READ_CTR64_BE_F(ppcnt, phys_layer_cntrs, \
+				      fc_fec_corrected_blocks_lane##idx); \
+	fec_stats->uncorrectable_blocks.lanes[(idx)] = \
+		MLX5E_READ_CTR64_BE_F(ppcnt, phys_layer_cntrs, \
+				      fc_fec_uncorrectable_blocks_lane##idx); \
+})
+
+static void fec_set_fc_stats(struct ethtool_fec_stats *fec_stats,
+			     u32 *ppcnt, u8 lanes)
+{
+	if (lanes > 3) { /* 4 lanes */
+		MLX5E_STATS_SET_FEC_BLOCK(3);
+		MLX5E_STATS_SET_FEC_BLOCK(2);
+	}
+	if (lanes > 1) /* 2 lanes */
+		MLX5E_STATS_SET_FEC_BLOCK(1);
+	if (lanes > 0) /* 1 lane */
+		MLX5E_STATS_SET_FEC_BLOCK(0);
+}
+
+static void fec_set_rs_stats(struct ethtool_fec_stats *fec_stats, u32 *ppcnt)
+{
+	fec_stats->corrected_blocks.total =
+		MLX5E_READ_CTR64_BE_F(ppcnt, phys_layer_cntrs,
+				      rs_fec_corrected_blocks);
+	fec_stats->uncorrectable_blocks.total =
+		MLX5E_READ_CTR64_BE_F(ppcnt, phys_layer_cntrs,
+				      rs_fec_uncorrectable_blocks);
+}
+
+static void fec_set_block_stats(struct mlx5e_priv *priv,
+				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);
+	if (mlx5_core_access_reg(mdev, in, sz, outl, sz, MLX5_REG_PPCNT, 0, 0))
+		return;
+
+	switch (mode) {
+	case MLX5E_FEC_RS_528_514:
+	case MLX5E_FEC_RS_544_514:
+	case MLX5E_FEC_LLRS_272_257_1:
+		fec_set_rs_stats(fec_stats, out);
+		return;
+	case MLX5E_FEC_FIRECODE:
+		fec_set_fc_stats(fec_stats, out, fec_num_lanes(mdev));
+	}
+}
+
+static void fec_set_corrected_bits_total(struct mlx5e_priv *priv,
+					 struct ethtool_fec_stats *fec_stats)
 {
 	u32 ppcnt_phy_statistical[MLX5_ST_SZ_DW(ppcnt_reg)];
 	struct mlx5_core_dev *mdev = priv->mdev;
-	u32 in[MLX5_ST_SZ_DW(ppcnt_reg)] = {0};
+	u32 in[MLX5_ST_SZ_DW(ppcnt_reg)] = {};
 	int sz = MLX5_ST_SZ_BYTES(ppcnt_reg);
 
 	if (!MLX5_CAP_PCAM_FEATURE(mdev, ppcnt_statistical_group))
@@ -1181,6 +1269,13 @@ void mlx5e_stats_fec_get(struct mlx5e_priv *priv,
 				      phy_corrected_bits);
 }
 
+void mlx5e_stats_fec_get(struct mlx5e_priv *priv,
+			 struct ethtool_fec_stats *fec_stats)
+{
+	fec_set_corrected_bits_total(priv, fec_stats);
+	fec_set_block_stats(priv, fec_stats);
+}
+
 #define PPORT_ETH_EXT_OFF(c) \
 	MLX5_BYTE_OFF(ppcnt_reg, \
 		      counter_set.eth_extended_cntrs_grp_data_layout.c##_high)