ethtool: add FEC bins histogram report

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. Drivers can leave bin
counter uninitialized if per-lane values are provided. In this case the
core will recalculate summ for the bin.

Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Link: https://patch.msgid.link/20250924124037.1508846-2-vadim.fedorenko@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 73 insertions, 2 deletions

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;