[RFC PATCH v5] ethtool: add FEC bins histogramm report
From: Vadim Fedorenko <hidden>
Date: 2025-08-15 13:28:00
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.
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
---
With this RFC I would like to get early feedback from the community
about implementing FEC histogram statistics while we are waiting for
some vendors to actually implement it in their drivers. I implemented
the simplest solution in netdevsim driver to show how API looks like.
The example query is the same as usual FEC statistics while the answer
is a bit more verbose:
[vmuser@archvm9 linux]$ ./tools/net/ynl/pyynl/cli.py --spec Documentation/netlink/specs/ethtool.yaml --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}],
'uncorr': [4]}}
RFC v5:
- fix reply size calculation
- change per-lane statistics to be added to the reply as an array of
u64 values, the same way it's done for other FEC statistics. The
aggregated value is still put as a separate value
RFC v4:
- re-arrange data structures to avoid overrun of stack frame
- add WARN_ON_ONCE on no value for defined bin
RFC v3 (actually re-send of v2 with committed changes):
- adjust yaml spec to avoid nesting histogram attributes and use
flexible types
- add support for per-lane histogram together with total values
- remove sentinel (-1, -1) and use (0, 0) as common array break.
bin (0, 0) is still possible but only as a first element of
ranges array
---
Documentation/netlink/specs/ethtool.yaml | 26 +++++++
Documentation/networking/ethtool-netlink.rst | 5 ++
.../net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 3 +-
.../ethernet/fungible/funeth/funeth_ethtool.c | 3 +-
.../ethernet/hisilicon/hns3/hns3_ethtool.c | 3 +-
drivers/net/ethernet/intel/ice/ice_ethtool.c | 4 +-
.../marvell/octeontx2/nic/otx2_ethtool.c | 3 +-
.../ethernet/mellanox/mlx5/core/en_ethtool.c | 3 +-
drivers/net/ethernet/sfc/ethtool.c | 3 +-
drivers/net/ethernet/sfc/siena/ethtool.c | 3 +-
drivers/net/netdevsim/ethtool.c | 22 +++++-
include/linux/ethtool.h | 21 +++++-
.../uapi/linux/ethtool_netlink_generated.h | 12 ++++
net/ethtool/fec.c | 69 ++++++++++++++++++-
14 files changed, 168 insertions(+), 12 deletions(-)
diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 7a7594713f1f0..fba0e23ffbeda 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml@@ -1219,6 +1219,27 @@ attribute-sets: name: udp-ports type: nest nested-attributes: tunnel-udp + - + name: fec-hist + attr-cnt-name: __ethtool-a-fec-hist-cnt + attributes: + - + name: unspec + type: unused + value: 0 + - + name: bin-low + type: u32 + - + name: bin-high + type: u32 + - + name: bin-val + type: uint + - + name: bin-val-per-lane + type: uint + multi-attr: True - name: fec-stat attr-cnt-name: __ethtool-a-fec-stat-cnt
@@ -1242,6 +1263,11 @@ 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 ab20c644af248..b270886c5f5d5 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 68a4ee9f69b1a..7c5bacb0f5348 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c@@ -3197,7 +3197,8 @@ 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 ba83dbf4ed222..1966dba512f8a 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 d5454e126c856..aec0c4646b7ee 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 55e0f2c6af9e5..62d3cfca350c6 100644
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c@@ -4620,10 +4620,12 @@ 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 998c734ff8399..b90e23dc49de9 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 @@ static int otx2_set_link_ksettings(struct net_device *netdev, } 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_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index d507366d773e1..bcc3bbb78cc95 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c@@ -1927,7 +1927,8 @@ 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);
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 23c6a7df78d03..18fe5850a9786 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 994909789bfea..8c3ebd0617fb1 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 f631d90c428ac..6ef163847d134 100644
--- a/drivers/net/netdevsim/ethtool.c
+++ b/drivers/net/netdevsim/ethtool.c@@ -165,11 +165,31 @@ 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].bin_value = 445; + values[1].bin_value = 12; + values[2].bin_value = 2; + values[0].bin_value_per_lane[0] = 125; + values[0].bin_value_per_lane[1] = 120; + values[0].bin_value_per_lane[2] = 100; + values[0].bin_value_per_lane[3] = 100; } static int nsim_get_ts_info(struct net_device *dev,
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index de5bd76a400ca..6c0dc6ae080a8 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h@@ -492,7 +492,25 @@ struct ethtool_pause_stats { }; #define ETHTOOL_MAX_LANES 8 +#define ETHTOOL_FEC_HIST_MAX 18 +/** + * struct ethtool_fec_hist_range - error bits range for FEC bins histogram + * statistics + * @low: low bound of the bin (inclusive) + * @high: high bound of the bin (inclusive) + */ +struct ethtool_fec_hist_range { + s16 low; + s16 high; +}; +struct ethtool_fec_hist { + struct ethtool_fec_hist_value { + u64 bin_value; + u64 bin_value_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
@@ -1212,7 +1230,8 @@ 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 e3b8813465d73..984190097729f 100644
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h@@ -561,12 +561,24 @@ enum { ETHTOOL_A_TUNNEL_INFO_MAX = (__ETHTOOL_A_TUNNEL_INFO_CNT - 1) }; +enum { + ETHTOOL_A_FEC_HIST_UNSPEC, + 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 e7d3f2c352a34..9313bd17544fd 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 +114,11 @@ 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, + ETHTOOL_MAX_LANES * + sizeof(struct ethtool_fec_hist_value) / 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 +162,70 @@ 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; + + 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].bin_value == 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) || + nla_put_uint(skb, ETHTOOL_A_FEC_HIST_BIN_VAL, + values[i].bin_value)) + goto err_cancel_hist; + for (j = 0; j < ETHTOOL_MAX_LANES; j++) { + if (values[i].bin_value_per_lane[j] == ETHTOOL_STAT_NOT_SET) + break; + } + if (j && nla_put_64bit(skb, ETHTOOL_A_FEC_HIST_BIN_VAL_PER_LANE, + sizeof(u64) * j, + values[i].bin_value_per_lane, + ETHTOOL_A_FEC_STAT_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 +245,9 @@ 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;
--
2.47.3