The previous attempt to augment carrier_down (see Link) was not met with much enthusiasm so let's do the simple thing of exposing what some devices already maintain. Add a common ethtool statistic for link going down. Currently users have to maintain per-driver mapping to extract the right stat from the vendor-specific ethtool -S stats. carrier_down does not fit the bill because it counts a lot of software related false positives. Add the statistic to the extended link state API to steer vendors towards implementing all of it. Implement for bnxt. mlx5 and (possibly) enic also have a counter for this but I leave the implementation to their maintainers. Link: https://lore.kernel.org/r/20220520004500.2250674-1-kuba@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> --- CC: corbet@xxxxxxx CC: michael.chan@xxxxxxxxxxxx CC: huangguangbin2@xxxxxxxxxx CC: chenhao288@xxxxxxxxxxxxx CC: moshet@xxxxxxxxxx CC: linux@xxxxxxxxxxxxxxxx CC: linux-doc@xxxxxxxxxxxxxxx --- Documentation/networking/ethtool-netlink.rst | 1 + .../net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 15 +++++++++++++++ include/linux/ethtool.h | 14 ++++++++++++++ include/uapi/linux/ethtool_netlink.h | 2 ++ net/ethtool/linkstate.c | 19 ++++++++++++++++++- 5 files changed, 50 insertions(+), 1 deletion(-) diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst index d578b8bcd8a4..5454aa6c013c 100644 --- a/Documentation/networking/ethtool-netlink.rst +++ b/Documentation/networking/ethtool-netlink.rst @@ -491,6 +491,7 @@ any attributes. ``ETHTOOL_A_LINKSTATE_SQI_MAX`` u32 Max support SQI value ``ETHTOOL_A_LINKSTATE_EXT_STATE`` u8 link extended state ``ETHTOOL_A_LINKSTATE_EXT_SUBSTATE`` u8 link extended substate + ``ETHTOOL_A_LINKSTATE_EXT_DOWN_CNT`` u64 count of link down events ==================================== ====== ============================ For most NIC drivers, the value of ``ETHTOOL_A_LINKSTATE_LINK`` returns diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c index cc89e5eabcb9..d5957ed00759 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c @@ -4112,6 +4112,20 @@ static void bnxt_get_rmon_stats(struct net_device *dev, *ranges = bnxt_rmon_ranges; } +static void bnxt_get_link_ext_stats(struct net_device *dev, + struct ethtool_link_ext_stats *stats) +{ + struct bnxt *bp = netdev_priv(dev); + u64 *rx; + + if (BNXT_VF(bp) || !(bp->flags & BNXT_FLAG_PORT_STATS_EXT)) + return; + + rx = bp->rx_port_stats_ext.sw_stats; + stats->LinkDownEvents = + *(rx + BNXT_RX_STATS_EXT_OFFSET(link_down_events)); +} + void bnxt_ethtool_free(struct bnxt *bp) { kfree(bp->test_info); @@ -4161,6 +4175,7 @@ const struct ethtool_ops bnxt_ethtool_ops = { .get_eeprom = bnxt_get_eeprom, .set_eeprom = bnxt_set_eeprom, .get_link = bnxt_get_link, + .get_link_ext_stats = bnxt_get_link_ext_stats, .get_eee = bnxt_get_eee, .set_eee = bnxt_set_eee, .get_module_info = bnxt_get_module_info, diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 99dc7bfbcd3c..3d8480da7896 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -125,6 +125,17 @@ struct ethtool_link_ext_state_info { }; }; +struct ethtool_link_ext_stats { + /* Custom Linux statistic for PHY level link down events. + * In a simpler world it should be equal to netdev->carrier_down_count + * unfortunately netdev also counts local reconfigurations which don't + * actually take the physical link down, not to mention NC-SI which, + * if present, keeps the link up regardless of host state. + * This statistic counts when PHY _actually_ went down, or lost link. + */ + u64 LinkDownEvents; +}; + /** * ethtool_rxfh_indir_default - get default value for RX flow hash indirection * @index: Index in RX flow hash indirection table @@ -481,6 +492,7 @@ struct ethtool_module_power_mode_params { * do not attach ext_substate attribute to netlink message). If link_ext_state * and link_ext_substate are unknown, return -ENODATA. If not implemented, * link_ext_state and link_ext_substate will not be sent to userspace. + * @get_link_ext_stats: Read extra link-related counters. * @get_eeprom_len: Read range of EEPROM addresses for validation of * @get_eeprom and @set_eeprom requests. * Returns 0 if device does not support EEPROM access. @@ -652,6 +664,8 @@ struct ethtool_ops { u32 (*get_link)(struct net_device *); int (*get_link_ext_state)(struct net_device *, struct ethtool_link_ext_state_info *); + void (*get_link_ext_stats)(struct net_device *, + struct ethtool_link_ext_stats *); int (*get_eeprom_len)(struct net_device *); int (*get_eeprom)(struct net_device *, struct ethtool_eeprom *, u8 *); diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h index bb57084ac524..8167848983d0 100644 --- a/include/uapi/linux/ethtool_netlink.h +++ b/include/uapi/linux/ethtool_netlink.h @@ -262,6 +262,8 @@ enum { ETHTOOL_A_LINKSTATE_SQI_MAX, /* u32 */ ETHTOOL_A_LINKSTATE_EXT_STATE, /* u8 */ ETHTOOL_A_LINKSTATE_EXT_SUBSTATE, /* u8 */ + ETHTOOL_A_LINKSTATE_PAD, + ETHTOOL_A_LINKSTATE_EXT_DOWN_CNT, /* u64 */ /* add new constants above here */ __ETHTOOL_A_LINKSTATE_CNT, diff --git a/net/ethtool/linkstate.c b/net/ethtool/linkstate.c index fb676f349455..c84d9b5afd53 100644 --- a/net/ethtool/linkstate.c +++ b/net/ethtool/linkstate.c @@ -13,6 +13,7 @@ struct linkstate_reply_data { int link; int sqi; int sqi_max; + struct ethtool_link_ext_stats link_stats; bool link_ext_state_provided; struct ethtool_link_ext_state_info ethtool_link_ext_state_info; }; @@ -22,7 +23,7 @@ struct linkstate_reply_data { const struct nla_policy ethnl_linkstate_get_policy[] = { [ETHTOOL_A_LINKSTATE_HEADER] = - NLA_POLICY_NESTED(ethnl_header_policy), + NLA_POLICY_NESTED(ethnl_header_policy_stats), }; static int linkstate_get_sqi(struct net_device *dev) @@ -107,6 +108,13 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base, goto out; } + ethtool_stats_init((u64 *)&data->link_stats, + sizeof(data->link_stats) / 8); + + if (req_base->flags & ETHTOOL_FLAG_STATS && + dev->ethtool_ops->get_link_ext_stats) + dev->ethtool_ops->get_link_ext_stats(dev, &data->link_stats); + ret = 0; out: ethnl_ops_complete(dev); @@ -134,6 +142,9 @@ static int linkstate_reply_size(const struct ethnl_req_info *req_base, if (data->ethtool_link_ext_state_info.__link_ext_substate) len += nla_total_size(sizeof(u8)); /* LINKSTATE_EXT_SUBSTATE */ + if (data->link_stats.LinkDownEvents != ETHTOOL_STAT_NOT_SET) + len += nla_total_size_64bit(sizeof(u64)); + return len; } @@ -166,6 +177,12 @@ static int linkstate_fill_reply(struct sk_buff *skb, return -EMSGSIZE; } + if (data->link_stats.LinkDownEvents != ETHTOOL_STAT_NOT_SET) + if (nla_put_u64_64bit(skb, ETHTOOL_A_LINKSTATE_EXT_DOWN_CNT, + data->link_stats.LinkDownEvents, + ETHTOOL_A_LINKSTATE_PAD)) + return -EMSGSIZE; + return 0; } -- 2.37.3
