ethtool: add FEC statistics

Similarly to pause statistics add stats for FEC.

The IEEE standard mandates two sets of counters:
 - 30.5.1.1.17 aFECCorrectedBlocks
 - 30.5.1.1.18 aFECUncorrectableBlocks
where block is a block of bits FEC operates on.
Each of these counters is defined per lane (PCS instance).

Multiple vendors provide number of corrected _bits_ rather
than/as well as blocks.

This set adds the 2 standard-based block counters and a extra
one for corrected bits.

Counters are exposed to user space via netlink in new attributes.
Each attribute carries an array of u64s, first element is
the total count, and the following ones are a per-lane break down.

Much like with pause stats the operation will not fail when driver
does not implement the get_fec_stats callback (nor can the driver
fail the operation by returning an error). If stats can't be
reported the relevant attributes will be empty.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 72 insertions, 1 deletions

diff --git a/net/ethtool/fec.c b/net/ethtool/fec.c
index 3e7d091ee7aaf6..8738dafd541722 100644
--- a/net/ethtool/fec.c
+++ b/net/ethtool/fec.c
@@ -13,6 +13,10 @@ struct fec_reply_data {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(fec_link_modes);
 	u32 active_fec;
 	u8 fec_auto;
+	struct fec_stat_grp {
+		u64 stats[1 + ETHTOOL_MAX_LANES];
+		u8 cnt;
+	} corr, uncorr, corr_bits;
 };
 
 #define FEC_REPDATA(__reply_base) \
@@ -21,7 +25,7 @@ struct fec_reply_data {
 #define ETHTOOL_FEC_MASK	((ETHTOOL_FEC_LLRS << 1) - 1)
 
 const struct nla_policy ethnl_fec_get_policy[ETHTOOL_A_FEC_HEADER + 1] = {
-	[ETHTOOL_A_FEC_HEADER]	= NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_FEC_HEADER]	= NLA_POLICY_NESTED(ethnl_header_policy_stats),
 };
 
 static void
@@ -64,6 +68,28 @@ ethtool_link_modes_to_fecparam(struct ethtool_fecparam *fec,
 	return 0;
 }
 
+static void
+fec_stats_recalc(struct fec_stat_grp *grp, struct ethtool_fec_stat *stats)
+{
+	int i;
+
+	if (stats->lanes[0] == ETHTOOL_STAT_NOT_SET) {
+		grp->stats[0] = stats->total;
+		grp->cnt = stats->total != ETHTOOL_STAT_NOT_SET;
+		return;
+	}
+
+	grp->cnt = 1;
+	grp->stats[0] = 0;
+	for (i = 0; i < ETHTOOL_MAX_LANES; i++) {
+		if (stats->lanes[i] == ETHTOOL_STAT_NOT_SET)
+			break;
+
+		grp->stats[0] += stats->lanes[i];
+		grp->stats[grp->cnt++] = stats->lanes[i];
+	}
+}
+
 static int fec_prepare_data(const struct ethnl_req_info *req_base,
 			    struct ethnl_reply_data *reply_base,
 			    struct genl_info *info)
@@ -82,6 +108,17 @@ static int fec_prepare_data(const struct ethnl_req_info *req_base,
 	ret = dev->ethtool_ops->get_fecparam(dev, &fec);
 	if (ret)
 		goto out_complete;
+	if (req_base->flags & ETHTOOL_FLAG_STATS &&
+	    dev->ethtool_ops->get_fec_stats) {
+		struct ethtool_fec_stats stats;
+
+		ethtool_stats_init((u64 *)&stats, sizeof(stats) / 8);
+		dev->ethtool_ops->get_fec_stats(dev, &stats);
+
+		fec_stats_recalc(&data->corr, &stats.corrected_blocks);
+		fec_stats_recalc(&data->uncorr, &stats.uncorrectable_blocks);
+		fec_stats_recalc(&data->corr_bits, &stats.corrected_bits);
+	}
 
 	WARN_ON_ONCE(fec.reserved);
 
@@ -120,9 +157,40 @@ 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)
+		len += 3 * nla_total_size_64bit(sizeof(u64) *
+						(1 + ETHTOOL_MAX_LANES));
+
 	return len;
 }
 
+static int fec_put_stats(struct sk_buff *skb, const struct fec_reply_data *data)
+{
+	struct nlattr *nest;
+
+	nest = nla_nest_start(skb, ETHTOOL_A_FEC_STATS);
+	if (!nest)
+		return -EMSGSIZE;
+
+	if (nla_put_64bit(skb, ETHTOOL_A_FEC_STAT_CORRECTED,
+			  sizeof(u64) * data->corr.cnt,
+			  data->corr.stats, ETHTOOL_A_FEC_STAT_PAD) ||
+	    nla_put_64bit(skb, ETHTOOL_A_FEC_STAT_UNCORR,
+			  sizeof(u64) * data->uncorr.cnt,
+			  data->uncorr.stats, ETHTOOL_A_FEC_STAT_PAD) ||
+	    nla_put_64bit(skb, ETHTOOL_A_FEC_STAT_CORR_BITS,
+			  sizeof(u64) * data->corr_bits.cnt,
+			  data->corr_bits.stats, ETHTOOL_A_FEC_STAT_PAD))
+		goto err_cancel;
+
+	nla_nest_end(skb, nest);
+	return 0;
+
+err_cancel:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
 static int fec_fill_reply(struct sk_buff *skb,
 			  const struct ethnl_req_info *req_base,
 			  const struct ethnl_reply_data *reply_base)
@@ -143,6 +211,9 @@ static int fec_fill_reply(struct sk_buff *skb,
 	     nla_put_u32(skb, ETHTOOL_A_FEC_ACTIVE, data->active_fec)))
 		return -EMSGSIZE;
 
+	if (req_base->flags & ETHTOOL_FLAG_STATS && fec_put_stats(skb, data))
+		return -EMSGSIZE;
+
 	return 0;
 }