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 and all Linux-controlled PHYs. 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> --- The Linux PHY part is compile-tested only. Could anyone (who's not at netdev conf?) help testing it? v2: - add the support for all Linux-driven PHYs - LinkDownEvents -> link_down_events v1: https://lore.kernel.org/all/20221026020948.1913777-1-kuba@xxxxxxxxxx/ --- CC: corbet@xxxxxxx CC: michael.chan@xxxxxxxxxxxx CC: andrew@xxxxxxx CC: hkallweit1@xxxxxxxxx CC: linux@xxxxxxxxxxxxxxx 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 +++++++++++ drivers/net/phy/phy.c | 1 + include/linux/ethtool.h | 14 +++++++++++ include/linux/phy.h | 3 +++ include/uapi/linux/ethtool_netlink.h | 2 ++ net/ethtool/linkstate.c | 25 ++++++++++++++++++- 7 files changed, 60 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..d8f0351df954 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->link_down_events = + *(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/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index e741d8aebffe..e5b6cb1a77f9 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -67,6 +67,7 @@ static void phy_link_down(struct phy_device *phydev) { phydev->phy_link_change(phydev, false); phy_led_trigger_change_speed(phydev); + WRITE_ONCE(phydev->link_down_events, phydev->link_down_events + 1); } static const char *phy_pause_str(struct phy_device *phydev) diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 99dc7bfbcd3c..fa8e0d52dd30 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 link_down_events; +}; + /** * 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/linux/phy.h b/include/linux/phy.h index ddf66198f751..9a3752c0c444 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -600,6 +600,7 @@ struct macsec_ops; * @psec: Pointer to Power Sourcing Equipment control struct * @lock: Mutex for serialization access to PHY * @state_queue: Work queue for state machine + * @link_down_events: Number of times link was lost * @shared: Pointer to private data shared by phys in one package * @priv: Pointer to driver private data * @@ -723,6 +724,8 @@ struct phy_device { int pma_extable; + unsigned int link_down_events; + void (*phy_link_change)(struct phy_device *phydev, bool up); void (*adjust_link)(struct net_device *dev); 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..7276ff752b80 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 +108,19 @@ 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) { + if (dev->phydev) + data->link_stats.link_down_events = + READ_ONCE(dev->phydev->link_down_events); + + if (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 +148,9 @@ 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.link_down_events != ETHTOOL_STAT_NOT_SET) + len += nla_total_size_64bit(sizeof(u64)); + return len; } @@ -166,6 +183,12 @@ static int linkstate_fill_reply(struct sk_buff *skb, return -EMSGSIZE; } + if (data->link_stats.link_down_events != ETHTOOL_STAT_NOT_SET) + if (nla_put_u64_64bit(skb, ETHTOOL_A_LINKSTATE_EXT_DOWN_CNT, + data->link_stats.link_down_events, + ETHTOOL_A_LINKSTATE_PAD)) + return -EMSGSIZE; + return 0; } -- 2.37.3
