[PATCH net-next v1 1/2] ethtool: provide UAPI for PHY Signal Quality Index (SQI)

From: Oleksij Rempel
Date: Tue May 19 2020 - 03:52:17 EST


Signal Quality Index is a mandatory value required by "OPEN Alliance
SIG" for the 100Base-T1 PHYs [1]. This indicator can be used for cable
integrity diagnostic and investigating other noise sources and
implement by at least two vendors: NXP[2] and TI[3].

[1] http://www.opensig.org/download/document/218/Advanced_PHY_features_for_automotive_Ethernet_V1.0.pdf
[2] https://www.nxp.com/docs/en/data-sheet/TJA1100.pdf
[3] https://www.ti.com/product/DP83TC811R-Q1

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
Documentation/networking/ethtool-netlink.rst | 1 +
include/linux/phy.h | 1 +
include/uapi/linux/ethtool.h | 11 +++++++++
include/uapi/linux/ethtool_netlink.h | 1 +
net/ethtool/common.c | 10 ++++++++
net/ethtool/common.h | 1 +
net/ethtool/linkstate.c | 25 +++++++++++++++++++-
7 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index eed46b6aa07df..4485e622182fc 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -457,6 +457,7 @@ Kernel response contents:
==================================== ====== ==========================
``ETHTOOL_A_LINKSTATE_HEADER`` nested reply header
``ETHTOOL_A_LINKSTATE_LINK`` bool link state (up/down)
+ ``ETHTOOL_A_LINKSTATE_SQI`` u8 Current Signal Quality Index
==================================== ====== ==========================

For most NIC drivers, the value of ``ETHTOOL_A_LINKSTATE_LINK`` returns
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 59344db43fcb1..b2fd230460d77 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -706,6 +706,7 @@ struct phy_driver {
struct ethtool_tunable *tuna,
const void *data);
int (*set_loopback)(struct phy_device *dev, bool enable);
+ int (*get_sqi)(struct phy_device *dev);
};
#define to_phy_driver(d) container_of(to_mdio_common_driver(d), \
struct phy_driver, mdiodrv)
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index f4662b3a9e1ef..e55caacd1886c 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1678,6 +1678,17 @@ static inline int ethtool_validate_duplex(__u8 duplex)
#define MASTER_SLAVE_STATE_SLAVE 3
#define MASTER_SLAVE_STATE_ERR 4

+#define SQI_STATE_UNSUPPORTED 0
+#define SQI_STATE_0 1
+#define SQI_STATE_1 2
+#define SQI_STATE_2 3
+#define SQI_STATE_3 4
+#define SQI_STATE_4 5
+#define SQI_STATE_5 6
+#define SQI_STATE_6 7
+#define SQI_STATE_7 8
+#define SQI_STATE_8 9
+
/* Which connector port. */
#define PORT_TP 0x00
#define PORT_AUI 0x01
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 2881af411f761..1fd80ec0c952f 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -232,6 +232,7 @@ enum {
ETHTOOL_A_LINKSTATE_UNSPEC,
ETHTOOL_A_LINKSTATE_HEADER, /* nest - _A_HEADER_* */
ETHTOOL_A_LINKSTATE_LINK, /* u8 */
+ ETHTOOL_A_LINKSTATE_SQI, /* u8 */

/* add new constants above here */
__ETHTOOL_A_LINKSTATE_CNT,
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 423e640e3876d..f3c905e59124f 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -310,6 +310,16 @@ int __ethtool_get_link(struct net_device *dev)
return netif_running(dev) && dev->ethtool_ops->get_link(dev);
}

+int __ethtool_get_sqi(struct net_device *dev)
+{
+ struct phy_device *phydev = dev->phydev;
+
+ if (!phydev->drv->get_sqi)
+ return -EOPNOTSUPP;
+
+ return phydev->drv->get_sqi(phydev);
+}
+
int ethtool_get_max_rxfh_channel(struct net_device *dev, u32 *max)
{
u32 dev_size, current_max = 0;
diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index a62f68ccc43ab..a251040d967db 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -30,6 +30,7 @@ extern const char ts_tx_type_names[][ETH_GSTRING_LEN];
extern const char ts_rx_filter_names[][ETH_GSTRING_LEN];

int __ethtool_get_link(struct net_device *dev);
+int __ethtool_get_sqi(struct net_device *dev);

bool convert_legacy_settings_to_link_ksettings(
struct ethtool_link_ksettings *link_ksettings,
diff --git a/net/ethtool/linkstate.c b/net/ethtool/linkstate.c
index 2740cde0a182b..5013ee275176d 100644
--- a/net/ethtool/linkstate.c
+++ b/net/ethtool/linkstate.c
@@ -10,6 +10,7 @@ struct linkstate_req_info {
struct linkstate_reply_data {
struct ethnl_reply_data base;
int link;
+ u8 sqi;
};

#define LINKSTATE_REPDATA(__reply_base) \
@@ -20,6 +21,7 @@ linkstate_get_policy[ETHTOOL_A_LINKSTATE_MAX + 1] = {
[ETHTOOL_A_LINKSTATE_UNSPEC] = { .type = NLA_REJECT },
[ETHTOOL_A_LINKSTATE_HEADER] = { .type = NLA_NESTED },
[ETHTOOL_A_LINKSTATE_LINK] = { .type = NLA_REJECT },
+ [ETHTOOL_A_LINKSTATE_SQI] = { .type = NLA_REJECT },
};

static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
@@ -34,6 +36,15 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
if (ret < 0)
return ret;
data->link = __ethtool_get_link(dev);
+
+ ret = __ethtool_get_sqi(dev);
+ if (ret == -EOPNOTSUPP)
+ ret = SQI_STATE_UNSUPPORTED;
+ if (ret < 0)
+ return ret;
+
+ data->sqi = ret;
+
ethnl_ops_complete(dev);

return 0;
@@ -42,8 +53,16 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
static int linkstate_reply_size(const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
{
- return nla_total_size(sizeof(u8)) /* LINKSTATE_LINK */
+ struct linkstate_reply_data *data = LINKSTATE_REPDATA(reply_base);
+ int len;
+
+ len = nla_total_size(sizeof(u8)) /* LINKSTATE_LINK */
+ 0;
+
+ if (data->sqi != SQI_STATE_UNSUPPORTED)
+ len += nla_total_size(sizeof(u8));
+
+ return len;
}

static int linkstate_fill_reply(struct sk_buff *skb,
@@ -56,6 +75,10 @@ static int linkstate_fill_reply(struct sk_buff *skb,
nla_put_u8(skb, ETHTOOL_A_LINKSTATE_LINK, !!data->link))
return -EMSGSIZE;

+ if (data->sqi != SQI_STATE_UNSUPPORTED &&
+ nla_put_u8(skb, ETHTOOL_A_LINKSTATE_SQI, data->sqi))
+ return -EMSGSIZE;
+
return 0;
}

--
2.26.2