Merge branch 'Ethernet-Cable-test-support'

Andrew Lunn says:

====================
Ethernet Cable test support

any copper Ethernet PHY have support for performing diagnostics of
the cable. Are the cable shorted, broken, not plugged into anything at
the other end? And they can report roughly how far along the cable any
fault is.

Add infrastructure in ethtool and phylib support for triggering a
cable test and reporting the results. The Marvell 1G PHY driver is
then extended to make use of this infrastructure.

For testing, a modified ethtool(1) can be found here:
https://github.com/lunn/ethtool.git feature/cable-test-v4. This also
contains extra code for TDR dump, which will be added to the kernel in
a later patch series.

Thanks to Chris Healy for extensive testing.

v2:
See individual patches but:

Remove _REPLY messages
Change length into a u32
Grammar fixes
Rename functions for consistency
Extack for cable test already running
Remove ethnl_cable_test_act_ops
Add status attributes
Rename pairs from numbers to letters

v3:

See individual patches but:
Remove ETHTOOL_MSG_CABLE_TEST_ACT_REPLY from documentation
Remove unused cable_test_get_policy
Fixed example in document
Add ETHTOOL_A_CABLE_NEST_* enum
Add ETHTOOL_MSG_CABLE_TEST_NTF to documentation
Poison phydev->skb
Return -EMSGSIZE when ethnl_bcastmsg_put() fails
Return valid error code when nla_nest_start() fails
Use u8 for results
Actually put u32 length into message
s/mavell/marvell/g
Remove include of <uapi/linux/ethtool_netlink.h>
EMSGSIZE when ethnl_bcastmsg_put() fails
Print an error message on failure, since this is a void function.

v4:
See individual patches but:
Remove unwanted blank line
ENOTSUPP->EOPNOTSUPP
Move EINVAL->EMSGSIZE fix to correct patch
====================

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 213 insertions, 3 deletions

diff --git a/net/Kconfig b/net/Kconfig
index c5ba2d180c43..5c524c6ee75d 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -455,6 +455,7 @@ config FAILOVER
 config ETHTOOL_NETLINK
 	bool "Netlink interface for ethtool"
 	default y
+	depends on PHYLIB=y || PHYLIB=n
 	help
 	  An alternative userspace interface for ethtool based on generic
 	  netlink. It provides better extensibility and some new features,
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 6c360c9c9370..0c2b94f20499 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -6,4 +6,4 @@ obj-$(CONFIG_ETHTOOL_NETLINK)	+= ethtool_nl.o
 
 ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o \
 		   linkstate.o debug.o wol.o features.o privflags.o rings.o \
-		   channels.o coalesce.o pause.o eee.o tsinfo.o
+		   channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o
diff --git a/net/ethtool/cabletest.c b/net/ethtool/cabletest.c
new file mode 100644
index 000000000000..5ba06eabe8c2
--- /dev/null
+++ b/net/ethtool/cabletest.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/phy.h>
+#include <linux/ethtool_netlink.h>
+#include "netlink.h"
+#include "common.h"
+
+/* CABLE_TEST_ACT */
+
+static const struct nla_policy
+cable_test_act_policy[ETHTOOL_A_CABLE_TEST_MAX + 1] = {
+	[ETHTOOL_A_CABLE_TEST_UNSPEC]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_CABLE_TEST_HEADER]		= { .type = NLA_NESTED },
+};
+
+static int ethnl_cable_test_started(struct phy_device *phydev)
+{
+	struct sk_buff *skb;
+	int err = -ENOMEM;
+	void *ehdr;
+
+	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb)
+		goto out;
+
+	ehdr = ethnl_bcastmsg_put(skb, ETHTOOL_MSG_CABLE_TEST_NTF);
+	if (!ehdr) {
+		err = -EMSGSIZE;
+		goto out;
+	}
+
+	err = ethnl_fill_reply_header(skb, phydev->attached_dev,
+				      ETHTOOL_A_CABLE_TEST_NTF_HEADER);
+	if (err)
+		goto out;
+
+	err = nla_put_u8(skb, ETHTOOL_A_CABLE_TEST_NTF_STATUS,
+			 ETHTOOL_A_CABLE_TEST_NTF_STATUS_STARTED);
+	if (err)
+		goto out;
+
+	genlmsg_end(skb, ehdr);
+
+	return ethnl_multicast(skb, phydev->attached_dev);
+
+out:
+	nlmsg_free(skb);
+	phydev_err(phydev, "%s: Error %pe\n", __func__, ERR_PTR(err));
+
+	return err;
+}
+
+int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *tb[ETHTOOL_A_CABLE_TEST_MAX + 1];
+	struct ethnl_req_info req_info = {};
+	struct net_device *dev;
+	int ret;
+
+	ret = nlmsg_parse(info->nlhdr, GENL_HDRLEN, tb,
+			  ETHTOOL_A_CABLE_TEST_MAX,
+			  cable_test_act_policy, info->extack);
+	if (ret < 0)
+		return ret;
+
+	ret = ethnl_parse_header_dev_get(&req_info,
+					 tb[ETHTOOL_A_CABLE_TEST_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
+	if (ret < 0)
+		return ret;
+
+	dev = req_info.dev;
+	if (!dev->phydev) {
+		ret = -EOPNOTSUPP;
+		goto out_dev_put;
+	}
+
+	rtnl_lock();
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		goto out_rtnl;
+
+	ret = phy_start_cable_test(dev->phydev, info->extack);
+
+	ethnl_ops_complete(dev);
+
+	if (!ret)
+		ethnl_cable_test_started(dev->phydev);
+
+out_rtnl:
+	rtnl_unlock();
+out_dev_put:
+	dev_put(dev);
+	return ret;
+}
+
+int ethnl_cable_test_alloc(struct phy_device *phydev)
+{
+	int err = -ENOMEM;
+
+	phydev->skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!phydev->skb)
+		goto out;
+
+	phydev->ehdr = ethnl_bcastmsg_put(phydev->skb,
+					  ETHTOOL_MSG_CABLE_TEST_NTF);
+	if (!phydev->ehdr) {
+		err = -EMSGSIZE;
+		goto out;
+	}
+
+	err = ethnl_fill_reply_header(phydev->skb, phydev->attached_dev,
+				      ETHTOOL_A_CABLE_TEST_NTF_HEADER);
+	if (err)
+		goto out;
+
+	err = nla_put_u8(phydev->skb, ETHTOOL_A_CABLE_TEST_NTF_STATUS,
+			 ETHTOOL_A_CABLE_TEST_NTF_STATUS_COMPLETED);
+	if (err)
+		goto out;
+
+	phydev->nest = nla_nest_start(phydev->skb,
+				      ETHTOOL_A_CABLE_TEST_NTF_NEST);
+	if (!phydev->nest) {
+		err = -EMSGSIZE;
+		goto out;
+	}
+
+	return 0;
+
+out:
+	nlmsg_free(phydev->skb);
+	phydev->skb = NULL;
+	return err;
+}
+EXPORT_SYMBOL_GPL(ethnl_cable_test_alloc);
+
+void ethnl_cable_test_free(struct phy_device *phydev)
+{
+	nlmsg_free(phydev->skb);
+	phydev->skb = NULL;
+}
+EXPORT_SYMBOL_GPL(ethnl_cable_test_free);
+
+void ethnl_cable_test_finished(struct phy_device *phydev)
+{
+	nla_nest_end(phydev->skb, phydev->nest);
+
+	genlmsg_end(phydev->skb, phydev->ehdr);
+
+	ethnl_multicast(phydev->skb, phydev->attached_dev);
+}
+EXPORT_SYMBOL_GPL(ethnl_cable_test_finished);
+
+int ethnl_cable_test_result(struct phy_device *phydev, u8 pair, u8 result)
+{
+	struct nlattr *nest;
+	int ret = -EMSGSIZE;
+
+	nest = nla_nest_start(phydev->skb, ETHTOOL_A_CABLE_NEST_RESULT);
+	if (!nest)
+		return -EMSGSIZE;
+
+	if (nla_put_u8(phydev->skb, ETHTOOL_A_CABLE_RESULT_PAIR, pair))
+		goto err;
+	if (nla_put_u8(phydev->skb, ETHTOOL_A_CABLE_RESULT_CODE, result))
+		goto err;
+
+	nla_nest_end(phydev->skb, nest);
+	return 0;
+
+err:
+	nla_nest_cancel(phydev->skb, nest);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ethnl_cable_test_result);
+
+int ethnl_cable_test_fault_length(struct phy_device *phydev, u8 pair, u32 cm)
+{
+	struct nlattr *nest;
+	int ret = -EMSGSIZE;
+
+	nest = nla_nest_start(phydev->skb,
+			      ETHTOOL_A_CABLE_NEST_FAULT_LENGTH);
+	if (!nest)
+		return -EMSGSIZE;
+
+	if (nla_put_u8(phydev->skb, ETHTOOL_A_CABLE_FAULT_LENGTH_PAIR, pair))
+		goto err;
+	if (nla_put_u32(phydev->skb, ETHTOOL_A_CABLE_FAULT_LENGTH_CM, cm))
+		goto err;
+
+	nla_nest_end(phydev->skb, nest);
+	return 0;
+
+err:
+	nla_nest_cancel(phydev->skb, nest);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ethnl_cable_test_fault_length);
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 0c772318c023..87bc02da74bc 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -181,13 +181,13 @@ err:
 	return NULL;
 }
 
-static void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd)
+void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd)
 {
 	return genlmsg_put(skb, 0, ++ethnl_bcast_seq, &ethtool_genl_family, 0,
 			   cmd);
 }
 
-static int ethnl_multicast(struct sk_buff *skb, struct net_device *dev)
+int ethnl_multicast(struct sk_buff *skb, struct net_device *dev)
 {
 	return genlmsg_multicast_netns(&ethtool_genl_family, dev_net(dev), skb,
 				       0, ETHNL_MCGRP_MONITOR, GFP_KERNEL);
@@ -839,6 +839,11 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_CABLE_TEST_ACT,
+		.flags	= GENL_UNS_ADMIN_PERM,
+		.doit	= ethnl_act_cable_test,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 81b8fa020bcb..b0eb5d920099 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -19,6 +19,8 @@ int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
 struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
 				 u16 hdr_attrtype, struct genl_info *info,
 				 void **ehdrp);
+void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd);
+int ethnl_multicast(struct sk_buff *skb, struct net_device *dev);
 
 /**
  * ethnl_strz_size() - calculate attribute length for fixed size string
@@ -357,5 +359,6 @@ int ethnl_set_channels(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_coalesce(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_pause(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_eee(struct sk_buff *skb, struct genl_info *info);
+int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);
 
 #endif /* _NET_ETHTOOL_NETLINK_H */