[PATCH net-next 0/8] net: Allow targeting specific PHYs through netlink

[PATCH net-next 0/8] net: Allow targeting specific PHYs through netlink

[Maxime Chevallier]

Hi everyone,

This series is a resend of the las 8 patches of the link_topology series:
https://lore.kernel.org/netdev/20240404093004.2552221-1-maxime.chevallier@bootlin.com/

There were a some conflicts on the netlink specs, which I guess made the
series fail to apply.

All patches of this series allow accessing and using the PHYs from the
topology through netlink commands such as PLCA, PSE-PD, Cable testing
and strsets, and introduces a dedicated command to list said PHYs.

This re-send is simply rebased on net-next, with the addition of
Andrew's Reviewed-by tags.

Thanks,

Maxime

Maxime Chevallier (8):
  netlink: specs: add phy-index as a header parameter
  net: ethtool: Introduce a command to list PHYs on an interface
  netlink: specs: add ethnl PHY_GET command set
  net: ethtool: plca: Target the command to the requested PHY
  net: ethtool: pse-pd: Target the command to the requested PHY
  net: ethtool: cable-test: Target the command to the requested PHY
  net: ethtool: strset: Allow querying phy stats by index
  Documentation: networking: document phy_link_topology

 Documentation/netlink/specs/ethtool.yaml      |  62 ++++
 Documentation/networking/ethtool-netlink.rst  |  45 +++
 Documentation/networking/index.rst            |   1 +
 .../networking/phy-link-topology.rst          | 120 +++++++
 include/uapi/linux/ethtool_netlink.h          |  20 ++
 net/ethtool/Makefile                          |   2 +-
 net/ethtool/cabletest.c                       |  16 +-
 net/ethtool/netlink.c                         |   9 +
 net/ethtool/netlink.h                         |   5 +
 net/ethtool/phy.c                             | 300 ++++++++++++++++++
 net/ethtool/plca.c                            |  19 +-
 net/ethtool/pse-pd.c                          |  13 +-
 net/ethtool/strset.c                          |  17 +-
 13 files changed, 594 insertions(+), 35 deletions(-)
 create mode 100644 Documentation/networking/phy-link-topology.rst
 create mode 100644 net/ethtool/phy.c

-- 
2.44.0

[PATCH net-next 1/8] netlink: specs: add phy-index as a header parameter

[Maxime Chevallier]

Update the spec to take the newly introduced phy-index as a generic
request parameter.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 Documentation/netlink/specs/ethtool.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 87ae7b397984..e8bdad790e3d 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -35,6 +35,9 @@ attribute-sets:
         name: flags
         type: u32
         enum: header-flags
+      -
+        name: phy-index
+        type: u32
 
   -
     name: bitset-bit
-- 
2.44.0

[PATCH net-next 2/8] net: ethtool: Introduce a command to list PHYs on an interface

[Maxime Chevallier]

As we have the ability to track the PHYs connected to a net_device
through the link_topology, we can expose this list to userspace. This
allows userspace to use these identifiers for phy-specific commands and
take the decision of which PHY to target by knowing the link topology.

Add PHY_GET and PHY_DUMP, which can be a filtered DUMP operation to list
devices on only one interface.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 Documentation/networking/ethtool-netlink.rst |  42 +++
 include/uapi/linux/ethtool_netlink.h         |  20 ++
 net/ethtool/Makefile                         |   2 +-
 net/ethtool/netlink.c                        |   9 +
 net/ethtool/netlink.h                        |   5 +
 net/ethtool/phy.c                            | 300 +++++++++++++++++++
 6 files changed, 377 insertions(+), 1 deletion(-)
 create mode 100644 net/ethtool/phy.c

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 5dc42f7ce429..b89a3d562018 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -2020,6 +2020,47 @@ The attributes are propagated to the driver through the following structure:
 .. kernel-doc:: include/linux/ethtool.h
     :identifiers: ethtool_mm_cfg
 
+PHY_GET
+=======
+
+Retrieve information about a given Ethernet PHY sitting on the link. The DO
+operation returns all available information about dev->phydev. User can also
+specify a PHY_INDEX, in which case the DO request returns information about that
+specific PHY.
+As there can be more than one PHY, the DUMP operation can be used to list the PHYs
+present on a given interface, by passing an interface index or name in
+the dump request.
+
+Request contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_PHY_HEADER``              nested  request header
+  ====================================  ======  ==========================
+
+Kernel response contents:
+
+  ===================================== ======  ===============================
+  ``ETHTOOL_A_PHY_HEADER``              nested  request header
+  ``ETHTOOL_A_PHY_INDEX``               u32     the phy's unique index, that can
+                                                be used for phy-specific
+                                                requests
+  ``ETHTOOL_A_PHY_DRVNAME``             string  the phy driver name
+  ``ETHTOOL_A_PHY_NAME``                string  the phy device name
+  ``ETHTOOL_A_PHY_UPSTREAM_TYPE``       u32     the type of device this phy is
+                                                connected to
+  ``ETHTOOL_A_PHY_UPSTREAM_INDEX``      u32     the PHY index of the upstream
+                                                PHY
+  ``ETHTOOL_A_PHY_UPSTREAM_SFP_NAME``   string  if this PHY is connected to
+                                                it's parent PHY through an SFP
+                                                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_ID``                  u32     the phy id if the phy is C22
+  ===================================== ======  ===============================
+
+When ``ETHTOOL_A_PHY_UPSTREAM_TYPE`` is PHY_UPSTREAM_PHY, the PHY's parent is
+another PHY.
+
 Request translation
 ===================
 
@@ -2126,4 +2167,5 @@ are netlink only.
   n/a                                 ``ETHTOOL_MSG_PLCA_GET_STATUS``
   n/a                                 ``ETHTOOL_MSG_MM_GET``
   n/a                                 ``ETHTOOL_MSG_MM_SET``
+  n/a                                 ``ETHTOOL_MSG_PHY_GET``
   =================================== =====================================
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 23e225f00fb0..c53b11877390 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -57,6 +57,7 @@ enum {
 	ETHTOOL_MSG_PLCA_GET_STATUS,
 	ETHTOOL_MSG_MM_GET,
 	ETHTOOL_MSG_MM_SET,
+	ETHTOOL_MSG_PHY_GET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -109,6 +110,8 @@ enum {
 	ETHTOOL_MSG_PLCA_NTF,
 	ETHTOOL_MSG_MM_GET_REPLY,
 	ETHTOOL_MSG_MM_NTF,
+	ETHTOOL_MSG_PHY_GET_REPLY,
+	ETHTOOL_MSG_PHY_NTF,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,
@@ -994,6 +997,23 @@ enum {
 	ETHTOOL_A_MM_MAX = (__ETHTOOL_A_MM_CNT - 1)
 };
 
+enum {
+	ETHTOOL_A_PHY_UNSPEC,
+	ETHTOOL_A_PHY_HEADER,			/* nest - _A_HEADER_* */
+	ETHTOOL_A_PHY_INDEX,			/* u32 */
+	ETHTOOL_A_PHY_DRVNAME,			/* string */
+	ETHTOOL_A_PHY_NAME,			/* string */
+	ETHTOOL_A_PHY_UPSTREAM_TYPE,		/* u32 */
+	ETHTOOL_A_PHY_UPSTREAM_INDEX,		/* u32 */
+	ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,	/* string */
+	ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,	/* string */
+	ETHTOOL_A_PHY_ID,			/* u32 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_PHY_CNT,
+	ETHTOOL_A_PHY_MAX = (__ETHTOOL_A_PHY_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 504f954a1b28..0ccd0e9afd3f 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -8,4 +8,4 @@ ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o rss.o \
 		   linkstate.o debug.o wol.o features.o privflags.o rings.o \
 		   channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o \
 		   tunnels.o fec.o eeprom.o stats.o phc_vclocks.o mm.o \
-		   module.o pse-pd.o plca.o mm.o
+		   module.o pse-pd.o plca.o mm.o phy.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 563e94e0cbd8..9847d2ee8402 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -1169,6 +1169,15 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.policy = ethnl_mm_set_policy,
 		.maxattr = ARRAY_SIZE(ethnl_mm_set_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_PHY_GET,
+		.doit	= ethnl_phy_doit,
+		.start	= ethnl_phy_start,
+		.dumpit	= ethnl_phy_dumpit,
+		.done	= ethnl_phy_done,
+		.policy = ethnl_phy_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_phy_get_policy) - 1,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index d57a890b5d9e..0e71b53bdb1c 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -446,6 +446,7 @@ extern const struct nla_policy ethnl_plca_set_cfg_policy[ETHTOOL_A_PLCA_MAX + 1]
 extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADER + 1];
 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_phy_get_policy[ETHTOOL_A_PHY_HEADER + 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);
@@ -453,6 +454,10 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info);
 int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info);
 int ethnl_tunnel_info_start(struct netlink_callback *cb);
 int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int ethnl_phy_start(struct netlink_callback *cb);
+int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info);
+int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int ethnl_phy_done(struct netlink_callback *cb);
 
 extern const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN];
 extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN];
diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
new file mode 100644
index 000000000000..0f6cb297dce2
--- /dev/null
+++ b/net/ethtool/phy.c
@@ -0,0 +1,300 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Bootlin
+ *
+ */
+#include "common.h"
+#include "netlink.h"
+
+#include <linux/phy.h>
+#include <linux/phy_link_topology.h>
+#include <linux/sfp.h>
+
+struct phy_req_info {
+	struct ethnl_req_info		base;
+	struct phy_device_node		pdn;
+};
+
+#define PHY_REQINFO(__req_base) \
+	container_of(__req_base, struct phy_req_info, base)
+
+const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1] = {
+	[ETHTOOL_A_PHY_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+/* Caller holds rtnl */
+static ssize_t
+ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
+		     struct netlink_ext_ack *extack)
+{
+	struct phy_req_info *req_info = PHY_REQINFO(req_base);
+	struct phy_device_node *pdn = &req_info->pdn;
+	struct phy_device *phydev = pdn->phy;
+	size_t size = 0;
+
+	ASSERT_RTNL();
+
+	/* ETHTOOL_A_PHY_INDEX */
+	size += nla_total_size(sizeof(u32));
+
+	/* ETHTOOL_A_DRVNAME */
+	if (phydev->drv)
+		size += nla_total_size(strlen(phydev->drv->name) + 1);
+
+	/* ETHTOOL_A_NAME */
+	size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)) + 1);
+
+	/* ETHTOOL_A_PHY_UPSTREAM_TYPE */
+	size += nla_total_size(sizeof(u32));
+
+	/* ETHTOOL_A_PHY_ID */
+	size += nla_total_size(sizeof(u32));
+
+	if (phy_on_sfp(phydev)) {
+		const char *upstream_sfp_name = sfp_get_name(pdn->parent_sfp_bus);
+
+		/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
+		if (upstream_sfp_name)
+			size += nla_total_size(strlen(upstream_sfp_name) + 1);
+
+		/* ETHTOOL_A_PHY_UPSTREAM_INDEX */
+		size += nla_total_size(sizeof(u32));
+	}
+
+	/* ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME */
+	if (phydev->sfp_bus) {
+		const char *sfp_name = sfp_get_name(phydev->sfp_bus);
+
+		if (sfp_name)
+			size += nla_total_size(strlen(sfp_name) + 1);
+	}
+
+	return size;
+}
+
+static int
+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;
+	enum phy_upstream ptype;
+
+	ptype = pdn->upstream_type;
+
+	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) ||
+	    nla_put_u32(skb, ETHTOOL_A_PHY_ID, phydev->phy_id))
+		return -EMSGSIZE;
+
+	if (phydev->drv &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, phydev->drv->name))
+		return -EMSGSIZE;
+
+	if (ptype == PHY_UPSTREAM_PHY) {
+		struct phy_device *upstream = pdn->upstream.phydev;
+		const char *sfp_upstream_name;
+
+		/* Parent index */
+		if (nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX, upstream->phyindex))
+			return -EMSGSIZE;
+
+		if (pdn->parent_sfp_bus) {
+			sfp_upstream_name = sfp_get_name(pdn->parent_sfp_bus);
+			if (sfp_upstream_name &&
+			    nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
+					   sfp_upstream_name))
+				return -EMSGSIZE;
+		}
+	}
+
+	if (phydev->sfp_bus) {
+		const char *sfp_name = sfp_get_name(phydev->sfp_bus);
+
+		if (sfp_name &&
+		    nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
+				   sfp_name))
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+
+static int ethnl_phy_parse_request(struct ethnl_req_info *req_base,
+				   struct nlattr **tb)
+{
+	struct phy_link_topology *topo = req_base->dev->link_topo;
+	struct phy_req_info *req_info = PHY_REQINFO(req_base);
+	struct phy_device_node *pdn;
+
+	if (!req_base->phydev)
+		return 0;
+
+	pdn = xa_load(&topo->phys, req_base->phydev->phyindex);
+	memcpy(&req_info->pdn, pdn, sizeof(*pdn));
+
+	return 0;
+}
+
+int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct phy_req_info req_info = {};
+	struct nlattr **tb = info->attrs;
+	struct sk_buff *rskb;
+	void *reply_payload;
+	int reply_len;
+	int ret;
+
+	ret = ethnl_parse_header_dev_get(&req_info.base,
+					 tb[ETHTOOL_A_PHY_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
+	if (ret < 0)
+		return ret;
+
+	rtnl_lock();
+
+	ret = ethnl_phy_parse_request(&req_info.base, tb);
+	if (ret < 0)
+		goto err_unlock_rtnl;
+
+	/* No PHY, return early */
+	if (!req_info.pdn.phy)
+		goto err_unlock_rtnl;
+
+	ret = ethnl_phy_reply_size(&req_info.base, info->extack);
+	if (ret < 0)
+		goto err_unlock_rtnl;
+	reply_len = ret + ethnl_reply_header_size();
+
+	rskb = ethnl_reply_init(reply_len, req_info.base.dev,
+				ETHTOOL_MSG_PHY_GET_REPLY,
+				ETHTOOL_A_PHY_HEADER,
+				info, &reply_payload);
+	if (!rskb) {
+		ret = -ENOMEM;
+		goto err_unlock_rtnl;
+	}
+
+	ret = ethnl_phy_fill_reply(&req_info.base, rskb);
+	if (ret)
+		goto err_free_msg;
+
+	rtnl_unlock();
+	ethnl_parse_header_dev_put(&req_info.base);
+	genlmsg_end(rskb, reply_payload);
+
+	return genlmsg_reply(rskb, info);
+
+err_free_msg:
+	nlmsg_free(rskb);
+err_unlock_rtnl:
+	rtnl_unlock();
+	ethnl_parse_header_dev_put(&req_info.base);
+	return ret;
+}
+
+struct ethnl_phy_dump_ctx {
+	struct phy_req_info	*phy_req_info;
+	unsigned long ifindex;
+	unsigned long phy_index;
+};
+
+int ethnl_phy_start(struct netlink_callback *cb)
+{
+	const struct genl_info *info = genl_info_dump(cb);
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+
+	ctx->phy_req_info = kzalloc(sizeof(*ctx->phy_req_info), GFP_KERNEL);
+	if (!ctx->phy_req_info)
+		return -ENOMEM;
+
+	ret = ethnl_parse_header_dev_get(&ctx->phy_req_info->base,
+					 info->attrs[ETHTOOL_A_PHY_HEADER],
+					 sock_net(cb->skb->sk), cb->extack,
+					 false);
+	ctx->ifindex = 0;
+	ctx->phy_index = 0;
+
+	if (ret)
+		kfree(ctx->phy_req_info);
+
+	return ret;
+}
+
+int ethnl_phy_done(struct netlink_callback *cb)
+{
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+
+	ethnl_parse_header_dev_put(&ctx->phy_req_info->base);
+	kfree(ctx->phy_req_info);
+
+	return 0;
+}
+
+static int ethnl_phy_dump_one_dev(struct sk_buff *skb, struct net_device *dev,
+				  struct netlink_callback *cb)
+{
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	struct phy_req_info *pri = ctx->phy_req_info;
+	struct phy_device_node *pdn;
+	int ret = 0;
+	void *ehdr;
+
+	pri->base.dev = dev;
+
+	xa_for_each_start(&dev->link_topo->phys, ctx->phy_index, pdn, ctx->phy_index) {
+		ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_PHY_GET_REPLY);
+		if (!ehdr) {
+			ret = -EMSGSIZE;
+			break;
+		}
+
+		ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_PHY_HEADER);
+		if (ret < 0) {
+			genlmsg_cancel(skb, ehdr);
+			break;
+		}
+
+		memcpy(&pri->pdn, pdn, sizeof(*pdn));
+		ret = ethnl_phy_fill_reply(&pri->base, skb);
+		if (ret < 0) {
+			genlmsg_cancel(skb, ehdr);
+			break;
+		}
+
+		genlmsg_end(skb, ehdr);
+	}
+
+	return ret;
+}
+
+int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	struct net *net = sock_net(skb->sk);
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+
+	if (ctx->phy_req_info->base.dev) {
+		ret = ethnl_phy_dump_one_dev(skb, ctx->phy_req_info->base.dev, cb);
+	} else {
+		for_each_netdev_dump(net, dev, ctx->ifindex) {
+			ret = ethnl_phy_dump_one_dev(skb, dev, cb);
+			if (ret)
+				break;
+
+			ctx->phy_index = 0;
+		}
+	}
+	rtnl_unlock();
+
+	return ret;
+}
+
-- 
2.44.0

[PATCH net-next 3/8] netlink: specs: add ethnl PHY_GET command set

[Maxime Chevallier]

The PHY_GET command, supporting both DUMP and GET operations, is used to
retrieve the list of PHYs connected to a netdevice, and get topology
information to know where exactly it sits on the physical link.

Add the netlink specs corresponding to that command.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 Documentation/netlink/specs/ethtool.yaml | 59 ++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index e8bdad790e3d..e33b74e9aea9 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -20,6 +20,11 @@ definitions:
     name: header-flags
     type: flags
     entries: [ compact-bitsets, omit-reply, stats ]
+  -
+    name: phy-upstream-type
+    enum-name:
+    type: enum
+    entries: [ mac, phy ]
 
 attribute-sets:
   -
@@ -966,6 +971,38 @@ attribute-sets:
       -
         name: burst-tmr
         type: u32
+  -
+    name: phy
+    attributes:
+      -
+        name: header
+        type: nest
+        nested-attributes: header
+      -
+        name: index
+        type: u32
+      -
+        name: drvname
+        type: string
+      -
+        name: name
+        type: string
+      -
+        name: upstream-type
+        type: u32
+        enum: phy-upstream-type
+      -
+        name: upstream-index
+        type: u32
+      -
+        name: upstream-sfp-name
+        type: string
+      -
+        name: downstream-sfp-name
+        type: string
+      -
+        name: id
+        type: u32
 
 operations:
   enum-model: directional
@@ -1718,3 +1755,25 @@ operations:
       name: mm-ntf
       doc: Notification for change in MAC Merge configuration.
       notify: mm-get
+    -
+      name: phy-get
+      doc: Get PHY devices attached to an interface
+
+      attribute-set: phy
+
+      do: &phy-get-op
+        request:
+          attributes:
+            - header
+        reply:
+          attributes:
+            - header
+            - index
+            - drvname
+            - name
+            - upstream-type
+            - upstream-index
+            - upstream-sfp-name
+            - downstream-sfp-name
+            - id
+      dump: *phy-get-op
-- 
2.44.0

[PATCH net-next 4/8] net: ethtool: plca: Target the command to the requested PHY

[Maxime Chevallier]

PLCA is a PHY-specific command. Instead of targeting the command
towards dev->phydev, use the request to pick the targeted PHY.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 net/ethtool/plca.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/net/ethtool/plca.c b/net/ethtool/plca.c
index b1e2e3b5027f..43b31a4a164e 100644
--- a/net/ethtool/plca.c
+++ b/net/ethtool/plca.c
@@ -25,7 +25,7 @@ struct plca_reply_data {
 
 const struct nla_policy ethnl_plca_get_cfg_policy[] = {
 	[ETHTOOL_A_PLCA_HEADER]		=
-		NLA_POLICY_NESTED(ethnl_header_policy),
+		NLA_POLICY_NESTED(ethnl_header_policy_phy),
 };
 
 static void plca_update_sint(int *dst, struct nlattr **tb, u32 attrid,
@@ -61,7 +61,7 @@ static int plca_get_cfg_prepare_data(const struct ethnl_req_info *req_base,
 	int ret;
 
 	// check that the PHY device is available and connected
-	if (!dev->phydev) {
+	if (!req_base->phydev) {
 		ret = -EOPNOTSUPP;
 		goto out;
 	}
@@ -80,7 +80,7 @@ static int plca_get_cfg_prepare_data(const struct ethnl_req_info *req_base,
 	memset(&data->plca_cfg, 0xff,
 	       sizeof_field(struct plca_reply_data, plca_cfg));
 
-	ret = ops->get_plca_cfg(dev->phydev, &data->plca_cfg);
+	ret = ops->get_plca_cfg(req_base->phydev, &data->plca_cfg);
 	ethnl_ops_complete(dev);
 
 out:
@@ -129,7 +129,7 @@ static int plca_get_cfg_fill_reply(struct sk_buff *skb,
 
 const struct nla_policy ethnl_plca_set_cfg_policy[] = {
 	[ETHTOOL_A_PLCA_HEADER]		=
-		NLA_POLICY_NESTED(ethnl_header_policy),
+		NLA_POLICY_NESTED(ethnl_header_policy_phy),
 	[ETHTOOL_A_PLCA_ENABLED]	= NLA_POLICY_MAX(NLA_U8, 1),
 	[ETHTOOL_A_PLCA_NODE_ID]	= NLA_POLICY_MAX(NLA_U32, 255),
 	[ETHTOOL_A_PLCA_NODE_CNT]	= NLA_POLICY_RANGE(NLA_U32, 1, 255),
@@ -141,7 +141,6 @@ const struct nla_policy ethnl_plca_set_cfg_policy[] = {
 static int
 ethnl_set_plca(struct ethnl_req_info *req_info, struct genl_info *info)
 {
-	struct net_device *dev = req_info->dev;
 	const struct ethtool_phy_ops *ops;
 	struct nlattr **tb = info->attrs;
 	struct phy_plca_cfg plca_cfg;
@@ -149,7 +148,7 @@ ethnl_set_plca(struct ethnl_req_info *req_info, struct genl_info *info)
 	int ret;
 
 	// check that the PHY device is available and connected
-	if (!dev->phydev)
+	if (!req_info->phydev)
 		return -EOPNOTSUPP;
 
 	ops = ethtool_phy_ops;
@@ -168,7 +167,7 @@ ethnl_set_plca(struct ethnl_req_info *req_info, struct genl_info *info)
 	if (!mod)
 		return 0;
 
-	ret = ops->set_plca_cfg(dev->phydev, &plca_cfg, info->extack);
+	ret = ops->set_plca_cfg(req_info->phydev, &plca_cfg, info->extack);
 	return ret < 0 ? ret : 1;
 }
 
@@ -191,7 +190,7 @@ const struct ethnl_request_ops ethnl_plca_cfg_request_ops = {
 
 const struct nla_policy ethnl_plca_get_status_policy[] = {
 	[ETHTOOL_A_PLCA_HEADER]		=
-		NLA_POLICY_NESTED(ethnl_header_policy),
+		NLA_POLICY_NESTED(ethnl_header_policy_phy),
 };
 
 static int plca_get_status_prepare_data(const struct ethnl_req_info *req_base,
@@ -204,7 +203,7 @@ static int plca_get_status_prepare_data(const struct ethnl_req_info *req_base,
 	int ret;
 
 	// check that the PHY device is available and connected
-	if (!dev->phydev) {
+	if (!req_base->phydev) {
 		ret = -EOPNOTSUPP;
 		goto out;
 	}
@@ -223,7 +222,7 @@ static int plca_get_status_prepare_data(const struct ethnl_req_info *req_base,
 	memset(&data->plca_st, 0xff,
 	       sizeof_field(struct plca_reply_data, plca_st));
 
-	ret = ops->get_plca_status(dev->phydev, &data->plca_st);
+	ret = ops->get_plca_status(req_base->phydev, &data->plca_st);
 	ethnl_ops_complete(dev);
 out:
 	return ret;
-- 
2.44.0

[PATCH net-next 5/8] net: ethtool: pse-pd: Target the command to the requested PHY

[Maxime Chevallier]

PSE and PD configuration is a PHY-specific command. Instead of targeting
the command towards dev->phydev, use the request to pick the targeted
PHY device.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 net/ethtool/pse-pd.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/net/ethtool/pse-pd.c b/net/ethtool/pse-pd.c
index cc478af77111..be50d79122c4 100644
--- a/net/ethtool/pse-pd.c
+++ b/net/ethtool/pse-pd.c
@@ -28,15 +28,13 @@ struct pse_reply_data {
 /* PSE_GET */
 
 const struct nla_policy ethnl_pse_get_policy[ETHTOOL_A_PSE_HEADER + 1] = {
-	[ETHTOOL_A_PSE_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_PSE_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy_phy),
 };
 
-static int pse_get_pse_attributes(struct net_device *dev,
+static int pse_get_pse_attributes(struct phy_device *phydev,
 				  struct netlink_ext_ack *extack,
 				  struct pse_reply_data *data)
 {
-	struct phy_device *phydev = dev->phydev;
-
 	if (!phydev) {
 		NL_SET_ERR_MSG(extack, "No PHY is attached");
 		return -EOPNOTSUPP;
@@ -64,7 +62,7 @@ static int pse_prepare_data(const struct ethnl_req_info *req_base,
 	if (ret < 0)
 		return ret;
 
-	ret = pse_get_pse_attributes(dev, info->extack, data);
+	ret = pse_get_pse_attributes(req_base->phydev, info->extack, data);
 
 	ethnl_ops_complete(dev);
 
@@ -109,7 +107,7 @@ static int pse_fill_reply(struct sk_buff *skb,
 /* PSE_SET */
 
 const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1] = {
-	[ETHTOOL_A_PSE_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_PSE_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy_phy),
 	[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL] =
 		NLA_POLICY_RANGE(NLA_U32, ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED,
 				 ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED),
@@ -124,7 +122,6 @@ ethnl_set_pse_validate(struct ethnl_req_info *req_info, struct genl_info *info)
 static int
 ethnl_set_pse(struct ethnl_req_info *req_info, struct genl_info *info)
 {
-	struct net_device *dev = req_info->dev;
 	struct pse_control_config config = {};
 	struct nlattr **tb = info->attrs;
 	struct phy_device *phydev;
@@ -132,7 +129,7 @@ ethnl_set_pse(struct ethnl_req_info *req_info, struct genl_info *info)
 	/* this values are already validated by the ethnl_pse_set_policy */
 	config.admin_cotrol = nla_get_u32(tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL]);
 
-	phydev = dev->phydev;
+	phydev = req_info->phydev;
 	if (!phydev) {
 		NL_SET_ERR_MSG(info->extack, "No PHY is attached");
 		return -EOPNOTSUPP;
-- 
2.44.0

[PATCH net-next 6/8] net: ethtool: cable-test: Target the command to the requested PHY

[Maxime Chevallier]

Cable testing is a PHY-specific command. Instead of targeting the command
towards dev->phydev, use the request to pick the targeted PHY.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 net/ethtool/cabletest.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/ethtool/cabletest.c b/net/ethtool/cabletest.c
index 06a151165c31..536800bbc379 100644
--- a/net/ethtool/cabletest.c
+++ b/net/ethtool/cabletest.c
@@ -13,7 +13,7 @@
 
 const struct nla_policy ethnl_cable_test_act_policy[] = {
 	[ETHTOOL_A_CABLE_TEST_HEADER]		=
-		NLA_POLICY_NESTED(ethnl_header_policy),
+		NLA_POLICY_NESTED(ethnl_header_policy_phy),
 };
 
 static int ethnl_cable_test_started(struct phy_device *phydev, u8 cmd)
@@ -69,7 +69,7 @@ int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info)
 		return ret;
 
 	dev = req_info.dev;
-	if (!dev->phydev) {
+	if (!req_info.phydev) {
 		ret = -EOPNOTSUPP;
 		goto out_dev_put;
 	}
@@ -85,12 +85,12 @@ int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info)
 	if (ret < 0)
 		goto out_rtnl;
 
-	ret = ops->start_cable_test(dev->phydev, info->extack);
+	ret = ops->start_cable_test(req_info.phydev, info->extack);
 
 	ethnl_ops_complete(dev);
 
 	if (!ret)
-		ethnl_cable_test_started(dev->phydev,
+		ethnl_cable_test_started(req_info.phydev,
 					 ETHTOOL_MSG_CABLE_TEST_NTF);
 
 out_rtnl:
@@ -220,7 +220,7 @@ static const struct nla_policy cable_test_tdr_act_cfg_policy[] = {
 
 const struct nla_policy ethnl_cable_test_tdr_act_policy[] = {
 	[ETHTOOL_A_CABLE_TEST_TDR_HEADER]	=
-		NLA_POLICY_NESTED(ethnl_header_policy),
+		NLA_POLICY_NESTED(ethnl_header_policy_phy),
 	[ETHTOOL_A_CABLE_TEST_TDR_CFG]		= { .type = NLA_NESTED },
 };
 
@@ -321,7 +321,7 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info)
 		return ret;
 
 	dev = req_info.dev;
-	if (!dev->phydev) {
+	if (!req_info.phydev) {
 		ret = -EOPNOTSUPP;
 		goto out_dev_put;
 	}
@@ -342,12 +342,12 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info)
 	if (ret < 0)
 		goto out_rtnl;
 
-	ret = ops->start_cable_test_tdr(dev->phydev, info->extack, &cfg);
+	ret = ops->start_cable_test_tdr(req_info.phydev, info->extack, &cfg);
 
 	ethnl_ops_complete(dev);
 
 	if (!ret)
-		ethnl_cable_test_started(dev->phydev,
+		ethnl_cable_test_started(req_info.phydev,
 					 ETHTOOL_MSG_CABLE_TEST_TDR_NTF);
 
 out_rtnl:
-- 
2.44.0

[PATCH net-next 7/8] net: ethtool: strset: Allow querying phy stats by index

[Maxime Chevallier]

The ETH_SS_PHY_STATS command gets PHY statistics. Use the phydev pointer
from the ethnl request to allow query phy stats from each PHY on the
link.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 net/ethtool/strset.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c
index c678b484a079..edc826407564 100644
--- a/net/ethtool/strset.c
+++ b/net/ethtool/strset.c
@@ -126,7 +126,7 @@ struct strset_reply_data {
 
 const struct nla_policy ethnl_strset_get_policy[] = {
 	[ETHTOOL_A_STRSET_HEADER]	=
-		NLA_POLICY_NESTED(ethnl_header_policy),
+		NLA_POLICY_NESTED(ethnl_header_policy_phy),
 	[ETHTOOL_A_STRSET_STRINGSETS]	= { .type = NLA_NESTED },
 	[ETHTOOL_A_STRSET_COUNTS_ONLY]	= { .type = NLA_FLAG },
 };
@@ -233,17 +233,18 @@ static void strset_cleanup_data(struct ethnl_reply_data *reply_base)
 }
 
 static int strset_prepare_set(struct strset_info *info, struct net_device *dev,
-			      unsigned int id, bool counts_only)
+			      struct phy_device *phydev, unsigned int id,
+			      bool counts_only)
 {
 	const struct ethtool_phy_ops *phy_ops = ethtool_phy_ops;
 	const struct ethtool_ops *ops = dev->ethtool_ops;
 	void *strings;
 	int count, ret;
 
-	if (id == ETH_SS_PHY_STATS && dev->phydev &&
+	if (id == ETH_SS_PHY_STATS && phydev &&
 	    !ops->get_ethtool_phy_stats && phy_ops &&
 	    phy_ops->get_sset_count)
-		ret = phy_ops->get_sset_count(dev->phydev);
+		ret = phy_ops->get_sset_count(phydev);
 	else if (ops->get_sset_count && ops->get_strings)
 		ret = ops->get_sset_count(dev, id);
 	else
@@ -258,10 +259,10 @@ static int strset_prepare_set(struct strset_info *info, struct net_device *dev,
 		strings = kcalloc(count, ETH_GSTRING_LEN, GFP_KERNEL);
 		if (!strings)
 			return -ENOMEM;
-		if (id == ETH_SS_PHY_STATS && dev->phydev &&
+		if (id == ETH_SS_PHY_STATS && phydev &&
 		    !ops->get_ethtool_phy_stats && phy_ops &&
 		    phy_ops->get_strings)
-			phy_ops->get_strings(dev->phydev, strings);
+			phy_ops->get_strings(phydev, strings);
 		else
 			ops->get_strings(dev, id, strings);
 		info->strings = strings;
@@ -305,8 +306,8 @@ static int strset_prepare_data(const struct ethnl_req_info *req_base,
 		    !data->sets[i].per_dev)
 			continue;
 
-		ret = strset_prepare_set(&data->sets[i], dev, i,
-					 req_info->counts_only);
+		ret = strset_prepare_set(&data->sets[i], dev, req_base->phydev,
+					 i, req_info->counts_only);
 		if (ret < 0)
 			goto err_ops;
 	}
-- 
2.44.0

[PATCH net-next 8/8] Documentation: networking: document phy_link_topology

[Maxime Chevallier]

The newly introduced phy_link_topology tracks all ethernet PHYs that are
attached to a netdevice. Document the base principle, internal and
external APIs. As the phy_link_topology is expected to be extended, this
documentation will hold any further improvements and additions made
relative to topology handling.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 Documentation/networking/ethtool-netlink.rst  |   3 +
 Documentation/networking/index.rst            |   1 +
 .../networking/phy-link-topology.rst          | 120 ++++++++++++++++++
 3 files changed, 124 insertions(+)
 create mode 100644 Documentation/networking/phy-link-topology.rst

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index b89a3d562018..1ae3bfd805ce 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -2027,10 +2027,13 @@ Retrieve information about a given Ethernet PHY sitting on the link. The DO
 operation returns all available information about dev->phydev. User can also
 specify a PHY_INDEX, in which case the DO request returns information about that
 specific PHY.
+
 As there can be more than one PHY, the DUMP operation can be used to list the PHYs
 present on a given interface, by passing an interface index or name in
 the dump request.
 
+For more information, refer to :ref:`Documentation/networking/phy-link-topology.rst`
+
 Request contents:
 
   ====================================  ======  ==========================
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 473d72c36d61..c29bc5179d8a 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -89,6 +89,7 @@ Contents:
    operstates
    packet_mmap
    phonet
+   phy-link-topology
    pktgen
    plip
    ppp_generic
diff --git a/Documentation/networking/phy-link-topology.rst b/Documentation/networking/phy-link-topology.rst
new file mode 100644
index 000000000000..1f021419ae8c
--- /dev/null
+++ b/Documentation/networking/phy-link-topology.rst
@@ -0,0 +1,120 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+PHY link topology
+=================
+
+Overview
+========
+
+The PHY link topology representation in the networking stack aims at representing
+the hardware layout for any given Ethernet link.
+
+An Ethernet interface from userspace's point of view is nothing but a
+:c:type:`struct net_device <net_device>`, which exposes configuration options
+through the legacy ioctls and the ethtool netlink commands. The base assumption
+when designing these configuration APIs were that the link looks something like ::
+
+  +-----------------------+        +----------+      +--------------+
+  | Ethernet Controller / |        | Ethernet |      | Connector /  |
+  |       MAC             | ------ |   PHY    | ---- |    Port      | ---... to LP
+  +-----------------------+        +----------+      +--------------+
+  struct net_device               struct phy_device
+
+Commands that needs to configure the PHY will go through the net_device.phydev
+field to reach the PHY and perform the relevant configuration.
+
+This assumption falls apart in more complex topologies that can arise when,
+for example, using SFP transceivers (although that's not the only specific case).
+
+Here, we have 2 basic scenarios. Either the MAC is able to output a serialized
+interface, that can directly be fed to an SFP cage, such as SGMII, 1000BaseX,
+10GBaseR, etc.
+
+The link topology then looks like this (when an SFP module is inserted) ::
+
+  +-----+  SGMII  +------------+
+  | MAC | ------- | SFP Module |
+  +-----+         +------------+
+
+Knowing that some modules embed a PHY, the actual link is more like ::
+
+  +-----+  SGMII   +--------------+
+  | MAC | -------- | PHY (on SFP) |
+  +-----+          +--------------+
+
+In this case, the SFP PHY is handled by phylib, and registered by phylink through
+its SFP upstream ops.
+
+Now some Ethernet controllers aren't able to output a serialized interface, so
+we can't directly connect them to an SFP cage. However, some PHYs can be used
+as media-converters, to translate the non-serialized MAC MII interface to a
+serialized MII interface fed to the SFP ::
+
+  +-----+  RGMII  +-----------------------+  SGMII  +--------------+
+  | MAC | ------- | PHY (media converter) | ------- | PHY (on SFP) |
+  +-----+         +-----------------------+         +--------------+
+
+This is where the model of having a single net_device.phydev pointer shows its
+limitations, as we now have 2 PHYs on the link.
+
+The phy_link topology framework aims at providing a way to keep track of every
+PHY on the link, for use by both kernel drivers and subsystems, but also to
+report the topology to userspace, allowing to target individual PHYs in configuration
+commands.
+
+API
+===
+
+The :c:type:`struct phy_link_topology <phy_link_topology>` is a per-netdevice
+resource, that gets initialized at netdevice creation. Once it's initialized,
+it is then possible to register PHYs to the topology through :
+
+:c:func:`phy_link_topo_add_phy`
+
+Besides registering the PHY to the topology, this call will also assign a unique
+index to the PHY, which can then be reported to userspace to refer to this PHY
+(akin to the ifindex). This index is a u32, ranging from 1 to U32_MAX. The value
+0 is reserved to indicate the PHY doesn't belong to any topology yet.
+
+The PHY can then be removed from the topology through
+
+:c:func:`phy_link_topo_del_phy`
+
+These function are already hooked into the phylib subsystem, so all PHYs that
+are linked to a net_device through :c:func:`phy_attach_direct` will automatically
+join the netdev's topology.
+
+PHYs that are on a SFP module will also be automatically registered IF the SFP
+upstream is phylink (so, no media-converter).
+
+PHY drivers that can be used as SFP upstream need to call :c:func:`phy_sfp_attach_phy`
+and :c:func:`phy_sfp_detach_phy`, which can be used as a
+.attach_phy / .detach_phy implementation for the
+:c:type:`struct sfp_upstream_ops <sfp_upstream_ops>`.
+
+UAPI
+====
+
+There exist a set of netlink commands to query the link topology from userspace,
+see ``Documentation/networking/ethtool-netlink.rst``.
+
+The whole point of having a topology representation is to assign the phyindex
+field in :c:type:`struct phy_device <phy_device>`. This index is reported to
+userspace using the ``ETHTOOL_MSG_PHY_GET`` ethtnl command. Performing a DUMP operation
+will result in all PHYs from all net_device being listed. The DUMP command
+accepts either a ``ETHTOOL_A_HEADER_DEV_INDEX`` or ``ETHTOOL_A_HEADER_DEV_NAME``
+to be passed in the request to filter the DUMP to a single net_device.
+
+The retrieved index can then be passed as a request parameter using the
+``ETHTOOL_A_HEADER_PHY_INDEX`` field in the following ethnl commands :
+
+* ``ETHTOOL_MSG_STRSET_GET`` to get the stats string set from a given PHY
+* ``ETHTOOL_MSG_CABLE_TEST_ACT`` and ``ETHTOOL_MSG_CABLE_TEST_ACT``, to perform
+  cable testing on a given PHY on the link (most likely the outermost PHY)
+* ``ETHTOOL_MSG_PSE_SET`` and ``ETHTOOL_MSG_PSE_GET`` for PHY-controlled PoE and PSE settings
+* ``ETHTOOL_MSG_PLCA_GET_CFG``, ``ETHTOOL_MSG_PLCA_SET_CFG`` and ``ETHTOOL_MSG_PLCA_GET_STATUS``
+  to set the PLCA (Physical Layer Collision Avoidance) parameters
+
+Note that the PHY index can be passed to other requests, which will silently
+ignore it if present and irrelevant.
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2.44.0

Re: [PATCH net-next 8/8] Documentation: networking: document phy_link_topology

[Jakub Kicinski]

On Tue,  9 Apr 2024 12:58:46 +0200 Maxime Chevallier wrote:
> +For more information, refer to :ref:`Documentation/networking/phy-link-topology.rst`

make htmldocs seems upset by this:

WARNING: undefined label: 'documentation/networking/phy-link-topology.rst'

I always struggle with the cross-file links TBH :S
-- 
pw-bot: cr