ethtool: Add link extended state

Currently, drivers can only tell whether the link is up/down using
LINKSTATE_GET, but no additional information is given.

Add attributes to LINKSTATE_GET command in order to allow drivers
to expose the user more information in addition to link state to ease
the debug process, for example, reason for link down state.

Extended state consists of two attributes - link_ext_state and
link_ext_substate. The idea is to avoid 'vendor specific' states in order
to prevent drivers to use specific link_ext_state that can be in the future
common link_ext_state.

The substates allows drivers to add more information to the common
link_ext_state. For example, vendor can expose 'Autoneg' as link_ext_state
and add 'No partner detected during force mode' as link_ext_substate.

If a driver cannot pinpoint the extended state with the substate
accuracy, it is free to expose only the extended state and omit the
substate attribute.

Signed-off-by: Amit Cohen <amitc@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index a23b26eab479..48ad3b6a0150 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -86,6 +86,22 @@ struct net_device;
 u32 ethtool_op_get_link(struct net_device *dev);
 int ethtool_op_get_ts_info(struct net_device *dev, struct ethtool_ts_info *eti);
 
+
+/**
+ * struct ethtool_link_ext_state_info - link extended state and substate.
+ */
+struct ethtool_link_ext_state_info {
+	enum ethtool_link_ext_state link_ext_state;
+	union {
+		enum ethtool_link_ext_substate_autoneg autoneg;
+		enum ethtool_link_ext_substate_link_training link_training;
+		enum ethtool_link_ext_substate_link_logical_mismatch link_logical_mismatch;
+		enum ethtool_link_ext_substate_bad_signal_integrity bad_signal_integrity;
+		enum ethtool_link_ext_substate_cable_issue cable_issue;
+		u8 __link_ext_substate;
+	};
+};
+
 /**
  * ethtool_rxfh_indir_default - get default value for RX flow hash indirection
  * @index: Index in RX flow hash indirection table
@@ -245,6 +261,11 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 *legacy_u32,
  * @get_link: Report whether physical link is up.  Will only be called if
  *	the netdev is up.  Should usually be set to ethtool_op_get_link(),
  *	which uses netif_carrier_ok().
+ * @get_link_ext_state: Report link extended state. Should set link_ext_state and
+ *	link_ext_substate (link_ext_substate of 0 means link_ext_substate is unknown,
+ *	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_eeprom: Read data from the device EEPROM.
  *	Should fill in the magic field.  Don't need to check len for zero
  *	or wraparound.  Fill in the data argument with the eeprom values
@@ -384,6 +405,8 @@ struct ethtool_ops {
 	void	(*set_msglevel)(struct net_device *, u32);
 	int	(*nway_reset)(struct net_device *);
 	u32	(*get_link)(struct net_device *);
+	int	(*get_link_ext_state)(struct net_device *,
+				      struct ethtool_link_ext_state_info *);
 	int	(*get_eeprom_len)(struct net_device *);
 	int	(*get_eeprom)(struct net_device *,
 			      struct ethtool_eeprom *, u8 *);