Add the isolate status information to the ETHTOOL_PHY_GET
netlink command attributes, and allow changing this parameter from a
newly-introduced ETHTOOL_PHY_SET command.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
V2 : Dropped loopback mode

 Documentation/networking/ethtool-netlink.rst |  1 +
 include/uapi/linux/ethtool_netlink.h         |  2 +
 net/ethtool/netlink.c                        |  8 +++
 net/ethtool/netlink.h                        |  1 +
 net/ethtool/phy.c                            | 68 ++++++++++++++++++++
 5 files changed, 80 insertions(+)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 295563e91082..800a8812a760 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -2235,6 +2235,7 @@ Kernel response contents:
                                                 bus, the name of this sfp bus
   ``ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME`` string  if the phy controls an sfp bus,
                                                 the name of the sfp bus
+  ``ETHTOOL_A_PHY_ISOLATE``             u8      The PHY Isolate status
   ===================================== ======  ===============================
 
 When ``ETHTOOL_A_PHY_UPSTREAM_TYPE`` is PHY_UPSTREAM_PHY, the PHY's parent is
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 283305f6b063..bee5bf7ef90d 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -59,6 +59,7 @@ enum {
 	ETHTOOL_MSG_MM_SET,
 	ETHTOOL_MSG_MODULE_FW_FLASH_ACT,
 	ETHTOOL_MSG_PHY_GET,
+	ETHTOOL_MSG_PHY_SET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -1079,6 +1080,7 @@ enum {
 	ETHTOOL_A_PHY_UPSTREAM_INDEX,		/* u32 */
 	ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,	/* string */
 	ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,	/* string */
+	ETHTOOL_A_PHY_ISOLATE,			/* u8 */
 
 	/* add new constants above here */
 	__ETHTOOL_A_PHY_CNT,
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index e3f0ef6b851b..26982f47a934 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -394,6 +394,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_PLCA_GET_STATUS]	= &ethnl_plca_status_request_ops,
 	[ETHTOOL_MSG_MM_GET]		= &ethnl_mm_request_ops,
 	[ETHTOOL_MSG_MM_SET]		= &ethnl_mm_request_ops,
+	[ETHTOOL_MSG_PHY_SET]		= &ethnl_phy_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -1243,6 +1244,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.policy = ethnl_phy_get_policy,
 		.maxattr = ARRAY_SIZE(ethnl_phy_get_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_PHY_SET,
+		.flags	= GENL_UNS_ADMIN_PERM,
+		.doit	= ethnl_default_set_doit,
+		.policy = ethnl_phy_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_phy_set_policy) - 1,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 203b08eb6c6f..7ae73e2eab32 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -485,6 +485,7 @@ extern const struct nla_policy ethnl_mm_get_policy[ETHTOOL_A_MM_HEADER + 1];
 extern const struct nla_policy ethnl_mm_set_policy[ETHTOOL_A_MM_MAX + 1];
 extern const struct nla_policy ethnl_module_fw_flash_act_policy[ETHTOOL_A_MODULE_FW_FLASH_PASSWORD + 1];
 extern const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1];
+extern const struct nla_policy ethnl_phy_set_policy[ETHTOOL_A_PHY_MAX + 1];
 
 int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
 int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);
diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
index ed8f690f6bac..b211bd83a3a0 100644
--- a/net/ethtool/phy.c
+++ b/net/ethtool/phy.c
@@ -30,10 +30,13 @@ ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
 	struct phy_req_info *req_info = PHY_REQINFO(req_base);
 	struct phy_device_node *pdn = req_info->pdn;
 	struct phy_device *phydev = pdn->phy;
+	const struct ethtool_phy_ops *ops;
 	size_t size = 0;
 
 	ASSERT_RTNL();
 
+	ops = ethtool_phy_ops;
+
 	/* ETHTOOL_A_PHY_INDEX */
 	size += nla_total_size(sizeof(u32));
 
@@ -66,6 +69,10 @@ ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
 			size += nla_total_size(strlen(sfp_name) + 1);
 	}
 
+	/* ETHTOOL_A_PHY_ISOLATE */
+	if (ops && ops->get_config)
+		size += nla_total_size(sizeof(u8));
+
 	return size;
 }
 
@@ -75,10 +82,20 @@ ethnl_phy_fill_reply(const struct ethnl_req_info *req_base, struct sk_buff *skb)
 	struct phy_req_info *req_info = PHY_REQINFO(req_base);
 	struct phy_device_node *pdn = req_info->pdn;
 	struct phy_device *phydev = pdn->phy;
+	const struct ethtool_phy_ops *ops;
+	struct phy_device_config cfg;
 	enum phy_upstream ptype;
+	int ret;
 
 	ptype = pdn->upstream_type;
 
+	ops = ethtool_phy_ops;
+	if (ops && ops->get_config) {
+		ret = ops->get_config(phydev, &cfg);
+		if (ret)
+			return ret;
+	}
+
 	if (nla_put_u32(skb, ETHTOOL_A_PHY_INDEX, phydev->phyindex) ||
 	    nla_put_string(skb, ETHTOOL_A_PHY_NAME, dev_name(&phydev->mdio.dev)) ||
 	    nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_TYPE, ptype))
@@ -114,6 +131,13 @@ ethnl_phy_fill_reply(const struct ethnl_req_info *req_base, struct sk_buff *skb)
 			return -EMSGSIZE;
 	}
 
+	/* Append PHY configuration, if possible */
+	if (!ops || !ops->get_config)
+		return 0;
+
+	if (nla_put_u8(skb, ETHTOOL_A_PHY_ISOLATE, cfg.isolate))
+		return -EMSGSIZE;
+
 	return 0;
 }
 
@@ -304,3 +328,47 @@ int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 
 	return ret;
 }
+
+const struct nla_policy ethnl_phy_set_policy[] = {
+	[ETHTOOL_A_PHY_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy_phy),
+	[ETHTOOL_A_PHY_ISOLATE]		= NLA_POLICY_MAX(NLA_U8, 1),
+};
+
+static int ethnl_set_phy(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+	struct netlink_ext_ack *extack = info->extack;
+	const struct ethtool_phy_ops *ops;
+	struct nlattr **tb = info->attrs;
+	struct phy_device_config cfg;
+	struct phy_device *phydev;
+	bool mod = false;
+	int ret;
+
+	ops = ethtool_phy_ops;
+	if (!ops || !ops->set_config || !ops->get_config)
+		return -EOPNOTSUPP;
+
+	/* We're running under rtnl */
+	phydev = ethnl_req_get_phydev(req_info, tb[ETHTOOL_A_PHY_HEADER],
+				      extack);
+	if (IS_ERR_OR_NULL(phydev))
+		return -ENODEV;
+
+	ret = ops->get_config(phydev, &cfg);
+	if (ret)
+		return ret;
+
+	ethnl_update_bool(&cfg.isolate, tb[ETHTOOL_A_PHY_ISOLATE], &mod);
+
+	if (!mod)
+		return 0;
+
+	/* Returning 0 is fine as we don't have a notification */
+	return ops->set_config(phydev, &cfg, extack);
+}
+
+const struct ethnl_request_ops ethnl_phy_request_ops = {
+	.hdr_attr		= ETHTOOL_A_PHY_HEADER,
+	.set			= ethnl_set_phy,
+};
-- 
2.46.1