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, 48 insertions, 4 deletions

diff --git a/net/ethtool/linkstate.c b/net/ethtool/linkstate.c
index afe5ac8a0f00..4834091ec24c 100644
--- a/net/ethtool/linkstate.c
+++ b/net/ethtool/linkstate.c
@@ -9,10 +9,12 @@ struct linkstate_req_info {
 };
 
 struct linkstate_reply_data {
-	struct ethnl_reply_data		base;
-	int				link;
-	int				sqi;
-	int				sqi_max;
+	struct ethnl_reply_data			base;
+	int					link;
+	int					sqi;
+	int					sqi_max;
+	bool					link_ext_state_provided;
+	struct ethtool_link_ext_state_info	ethtool_link_ext_state_info;
 };
 
 #define LINKSTATE_REPDATA(__reply_base) \
@@ -25,6 +27,8 @@ linkstate_get_policy[ETHTOOL_A_LINKSTATE_MAX + 1] = {
 	[ETHTOOL_A_LINKSTATE_LINK]		= { .type = NLA_REJECT },
 	[ETHTOOL_A_LINKSTATE_SQI]		= { .type = NLA_REJECT },
 	[ETHTOOL_A_LINKSTATE_SQI_MAX]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_LINKSTATE_EXT_STATE]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_LINKSTATE_EXT_SUBSTATE]	= { .type = NLA_REJECT },
 };
 
 static int linkstate_get_sqi(struct net_device *dev)
@@ -61,6 +65,23 @@ static int linkstate_get_sqi_max(struct net_device *dev)
 	mutex_unlock(&phydev->lock);
 
 	return ret;
+};
+
+static int linkstate_get_link_ext_state(struct net_device *dev,
+					struct linkstate_reply_data *data)
+{
+	int err;
+
+	if (!dev->ethtool_ops->get_link_ext_state)
+		return -EOPNOTSUPP;
+
+	err = dev->ethtool_ops->get_link_ext_state(dev, &data->ethtool_link_ext_state_info);
+	if (err)
+		return err;
+
+	data->link_ext_state_provided = true;
+
+	return 0;
 }
 
 static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
@@ -86,6 +107,12 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
 		goto out;
 	data->sqi_max = ret;
 
+	if (dev->flags & IFF_UP) {
+		ret = linkstate_get_link_ext_state(dev, data);
+		if (ret < 0 && ret != -EOPNOTSUPP && ret != -ENODATA)
+			goto out;
+	}
+
 	ret = 0;
 out:
 	ethnl_ops_complete(dev);
@@ -107,6 +134,12 @@ static int linkstate_reply_size(const struct ethnl_req_info *req_base,
 	if (data->sqi_max != -EOPNOTSUPP)
 		len += nla_total_size(sizeof(u32));
 
+	if (data->link_ext_state_provided)
+		len += nla_total_size(sizeof(u8)); /* LINKSTATE_EXT_STATE */
+
+	if (data->ethtool_link_ext_state_info.__link_ext_substate)
+		len += nla_total_size(sizeof(u8)); /* LINKSTATE_EXT_SUBSTATE */
+
 	return len;
 }
 
@@ -128,6 +161,17 @@ static int linkstate_fill_reply(struct sk_buff *skb,
 	    nla_put_u32(skb, ETHTOOL_A_LINKSTATE_SQI_MAX, data->sqi_max))
 		return -EMSGSIZE;
 
+	if (data->link_ext_state_provided) {
+		if (nla_put_u8(skb, ETHTOOL_A_LINKSTATE_EXT_STATE,
+			       data->ethtool_link_ext_state_info.link_ext_state))
+			return -EMSGSIZE;
+
+		if (data->ethtool_link_ext_state_info.__link_ext_substate &&
+		    nla_put_u8(skb, ETHTOOL_A_LINKSTATE_EXT_SUBSTATE,
+			       data->ethtool_link_ext_state_info.__link_ext_substate))
+			return -EMSGSIZE;
+	}
+
 	return 0;
 }