diff mbox series

[RFC,net-next,v2,06/10] net: ethtool: Introduce a command to list PHYs on an interface

Message ID 20231117162323.626979-7-maxime.chevallier@bootlin.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series Introduce PHY listing and link_topology tracking | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 71 this patch: 1137
netdev/cc_maintainers warning 7 maintainers not CCed: leon@kernel.org sdf@google.com linux-doc@vger.kernel.org piergiorgio.beruto@gmail.com corbet@lwn.net sudheer.mogilappagari@intel.com horms@kernel.org
netdev/build_clang fail Errors and warnings before: 94 this patch: 1162
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 72 this patch: 1165
netdev/checkpatch warning WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? WARNING: line length of 83 exceeds 80 columns WARNING: line length of 86 exceeds 80 columns WARNING: line length of 87 exceeds 80 columns WARNING: line length of 98 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Maxime Chevallier Nov. 17, 2023, 4:23 p.m. UTC
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>
---
 Documentation/netlink/specs/ethtool.yaml     |  69 ++++-
 Documentation/networking/ethtool-netlink.rst |  51 ++++
 include/linux/ethtool_netlink.h              |   5 +
 include/uapi/linux/ethtool_netlink.h         |  29 ++
 net/ethtool/Makefile                         |   2 +-
 net/ethtool/netlink.c                        |   8 +
 net/ethtool/netlink.h                        |   3 +
 net/ethtool/phy.c                            | 279 +++++++++++++++++++
 8 files changed, 444 insertions(+), 2 deletions(-)
 create mode 100644 net/ethtool/phy.c

Comments

Andrew Lunn Nov. 21, 2023, 1:34 a.m. UTC | #1
> diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
> index 2540c70952ff..29ef675f45c0 100644
> --- a/Documentation/networking/ethtool-netlink.rst
> +++ b/Documentation/networking/ethtool-netlink.rst
> @@ -57,6 +57,7 @@ Structure of this header is
>    ``ETHTOOL_A_HEADER_DEV_INDEX``  u32     device ifindex
>    ``ETHTOOL_A_HEADER_DEV_NAME``   string  device name
>    ``ETHTOOL_A_HEADER_FLAGS``      u32     flags common for all requests
> +  ``ETHTOOL_A_HEADER_PHY_INDEX``  u32     phy device index
>    ==============================  ======  =============================
>  
>  ``ETHTOOL_A_HEADER_DEV_INDEX`` and ``ETHTOOL_A_HEADER_DEV_NAME`` identify the
> @@ -81,6 +82,12 @@ the behaviour is backward compatible, i.e. requests from old clients not aware
>  of the flag should be interpreted the way the client expects. A client must
>  not set flags it does not understand.
>  
> +``ETHTOOL_A_HEADER_PHY_INDEX`` identify the ethernet PHY the message relates to.
> +As there are numerous commands that are related to PHY configuration, and because
> +we can have more than one PHY on the link, the PHY index can be passed in the
> +request for the commands that needs it. It is however not mandatory, and if it
> +is not passed for commands that target a PHY, the net_device.phydev pointer
> +is used, as a fallback that keeps the legacy behaviour.

O.K, you did document it :-)

But i would make this part of the previous patch.

> +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_PHY``        nested  if the phy is connected to another
> +                                                phy, this nest contains info on
> +                                                that connection
> +  ``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

Maybe a future extension. We could make phy_bus_match() set
phydev->phy_id to the ID it matched to the driver when doing C45. We
would then always have a value here.

> --- a/include/linux/ethtool_netlink.h
> +++ b/include/linux/ethtool_netlink.h
> @@ -118,5 +118,10 @@ static inline bool ethtool_dev_mm_supported(struct net_device *dev)
>  	return false;
>  }
>  
> +int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
> +{
> +	return -EOPNOTSUPP;
> +}

This is a header file, so should probably be static inline.

     Andrew
Andrew Lunn Nov. 21, 2023, 1:40 a.m. UTC | #2
> +ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
> +		     struct netlink_ext_ack *extack)
> +{
> +	struct phy_device_node *pdn;
> +	struct phy_device *phydev;
> +	struct link_topology *lt;
> +	unsigned long index;
> +	size_t size;
> +
> +	lt = &req_base->dev->link_topo;
> +
> +	size = nla_total_size(0);
> +
> +	xa_for_each(&lt->phys, index, pdn) {
> +		phydev = pdn->phy;
> +
> +		/* ETHTOOL_A_PHY_INDEX */
> +		size += nla_total_size(sizeof(u32));
> +
> +		/* ETHTOOL_A_DRVNAME */
> +		size += nla_total_size(strlen(phydev->drv->name));
> +
> +		/* ETHTOOL_A_NAME */
> +		size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)));
> +
> +		/* ETHTOOL_A_PHY_UPSTREAM_TYPE */
> +		size += nla_total_size(sizeof(u8));
> +
> +		/* ETHTOOL_A_PHY_ID */
> +		size += nla_total_size(sizeof(u32));
> +
> +		if (phy_on_sfp(phydev)) {
> +			/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
> +			if (sfp_get_name(pdn->parent_sfp_bus))
> +				size += nla_total_size(strlen(sfp_get_name(pdn->parent_sfp_bus)));

Have you tried a modular build?

sfp_get_name() could be in a module, and then you will get linker
errors. It is all a bit messy calling into phylib from ethtool :-(

This might actually be the only function you need? If so, its small
enough you can move it into a header as a static inline function.

       Andrew
Maxime Chevallier Nov. 23, 2023, 1:40 p.m. UTC | #3
On Tue, 21 Nov 2023 02:40:27 +0100
Andrew Lunn <andrew@lunn.ch> wrote:

> > +ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
> > +		     struct netlink_ext_ack *extack)
> > +{
> > +	struct phy_device_node *pdn;
> > +	struct phy_device *phydev;
> > +	struct link_topology *lt;
> > +	unsigned long index;
> > +	size_t size;
> > +
> > +	lt = &req_base->dev->link_topo;
> > +
> > +	size = nla_total_size(0);
> > +
> > +	xa_for_each(&lt->phys, index, pdn) {
> > +		phydev = pdn->phy;
> > +
> > +		/* ETHTOOL_A_PHY_INDEX */
> > +		size += nla_total_size(sizeof(u32));
> > +
> > +		/* ETHTOOL_A_DRVNAME */
> > +		size += nla_total_size(strlen(phydev->drv->name));
> > +
> > +		/* ETHTOOL_A_NAME */
> > +		size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)));
> > +
> > +		/* ETHTOOL_A_PHY_UPSTREAM_TYPE */
> > +		size += nla_total_size(sizeof(u8));
> > +
> > +		/* ETHTOOL_A_PHY_ID */
> > +		size += nla_total_size(sizeof(u32));
> > +
> > +		if (phy_on_sfp(phydev)) {
> > +			/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
> > +			if (sfp_get_name(pdn->parent_sfp_bus))
> > +				size += nla_total_size(strlen(sfp_get_name(pdn->parent_sfp_bus)));  
> 
> Have you tried a modular build?

Now that you mention it, no. I did try with CONFIG_SFP disabled, but
not as a module, I'll add it to my test suite.

> 
> sfp_get_name() could be in a module, and then you will get linker
> errors. It is all a bit messy calling into phylib from ethtool :-(
> 
> This might actually be the only function you need? If so, its small
> enough you can move it into a header as a static inline function.

It's the only one indeed, so as add it as a header function then.

Thanks,

Maxime

>        Andrew
diff mbox series

Patch

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 5c7a65b009b4..ac9352d8ef57 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -16,6 +16,11 @@  definitions:
     name: stringset
     type: enum
     entries: []
+  -
+    name: phy-upstream-type
+    enum-name:
+    type: enum
+    entries: [ mac, sfp, phy ]
 
 attribute-sets:
   -
@@ -30,7 +35,9 @@  attribute-sets:
       -
         name: flags
         type: u32
-
+      -
+        name: phy-index
+        type: u32
   -
     name: bitset-bit
     attributes:
@@ -939,6 +946,45 @@  attribute-sets:
       -
         name: burst-tmr
         type: u32
+  -
+    name: phy-upstream
+    attributes:
+      -
+        name: index
+        type: u32
+      -
+        name: sfp-name
+        type: string
+  -
+    name: phy
+    attributes:
+      -
+        name: header
+        type: nest
+        nested-attributes: header
+      -
+        name: phy-index
+        type: u32
+      -
+        name: drvname
+        type: string
+      -
+        name: name
+        type: string
+      -
+        name: upstream-type
+        type: u8
+        enum: phy-upstream-type
+      -
+        name: upstream
+        type: nest
+        nested-attributes: phy-upstream
+      -
+        name: downstream-sfp-name
+        type: string
+      -
+        name: id
+        type: u32
 
 operations:
   enum-model: directional
@@ -1689,3 +1735,24 @@  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
+            - downstream-sfp-name
+            - id
+      dump: *phy-get-op
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 2540c70952ff..29ef675f45c0 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -57,6 +57,7 @@  Structure of this header is
   ``ETHTOOL_A_HEADER_DEV_INDEX``  u32     device ifindex
   ``ETHTOOL_A_HEADER_DEV_NAME``   string  device name
   ``ETHTOOL_A_HEADER_FLAGS``      u32     flags common for all requests
+  ``ETHTOOL_A_HEADER_PHY_INDEX``  u32     phy device index
   ==============================  ======  =============================
 
 ``ETHTOOL_A_HEADER_DEV_INDEX`` and ``ETHTOOL_A_HEADER_DEV_NAME`` identify the
@@ -81,6 +82,12 @@  the behaviour is backward compatible, i.e. requests from old clients not aware
 of the flag should be interpreted the way the client expects. A client must
 not set flags it does not understand.
 
+``ETHTOOL_A_HEADER_PHY_INDEX`` identify the ethernet PHY the message relates to.
+As there are numerous commands that are related to PHY configuration, and because
+we can have more than one PHY on the link, the PHY index can be passed in the
+request for the commands that needs it. It is however not mandatory, and if it
+is not passed for commands that target a PHY, the net_device.phydev pointer
+is used, as a fallback that keeps the legacy behaviour.
 
 Bit sets
 ========
@@ -1994,6 +2001,49 @@  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. 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_PHY``        nested  if the phy is connected to another
+                                                phy, this nest contains info on
+                                                that connection
+  ``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. Information on the parent PHY will be set in the
+``ETHTOOL_A_PHY_UPSTREAM_PHY`` nest, which has the following structure :
+
+  =================================     ======  ==========================
+  ``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
+  =================================     ======  ==========================
+
 Request translation
 ===================
 
@@ -2100,4 +2150,5 @@  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/linux/ethtool_netlink.h b/include/linux/ethtool_netlink.h
index fae0dfb9a9c8..b4c40f1cc854 100644
--- a/include/linux/ethtool_netlink.h
+++ b/include/linux/ethtool_netlink.h
@@ -118,5 +118,10 @@  static inline bool ethtool_dev_mm_supported(struct net_device *dev)
 	return false;
 }
 
+int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	return -EOPNOTSUPP;
+}
+
 #endif /* IS_ENABLED(CONFIG_ETHTOOL_NETLINK) */
 #endif /* _LINUX_ETHTOOL_NETLINK_H_ */
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index e557cf35250e..7d621963698a 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,
@@ -976,6 +979,32 @@  enum {
 	ETHTOOL_A_MM_MAX = (__ETHTOOL_A_MM_CNT - 1)
 };
 
+enum {
+	ETHTOOL_A_PHY_UPSTREAM_UNSPEC,
+	ETHTOOL_A_PHY_UPSTREAM_INDEX,			/* u32 */
+	ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,		/* string */
+
+	/* add new constants above here */
+	__ETHTOOL_A_PHY_UPSTREAM_CNT,
+	ETHTOOL_A_PHY_UPSTREAM_MAX = (__ETHTOOL_A_PHY_UPSTREAM_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,		/* u8 */
+	ETHTOOL_A_PHY_UPSTREAM,			/* nest - _A_PHY_UPSTREAM_* */
+	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 e83ee844b60f..80c8c312a584 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -1150,6 +1150,14 @@  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,
+		.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 3f5eb60bdf0b..844c83c2ec7f 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -452,6 +452,9 @@  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);
 
 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..ac6b4612301c
--- /dev/null
+++ b/net/ethtool/phy.c
@@ -0,0 +1,279 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Bootlin
+ *
+ */
+#include "common.h"
+#include "netlink.h"
+
+#include <linux/link_topology.h>
+#include <linux/phy.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_device_node *pdn;
+	struct phy_device *phydev;
+	struct link_topology *lt;
+	unsigned long index;
+	size_t size;
+
+	lt = &req_base->dev->link_topo;
+
+	size = nla_total_size(0);
+
+	xa_for_each(&lt->phys, index, pdn) {
+		phydev = pdn->phy;
+
+		/* ETHTOOL_A_PHY_INDEX */
+		size += nla_total_size(sizeof(u32));
+
+		/* ETHTOOL_A_DRVNAME */
+		size += nla_total_size(strlen(phydev->drv->name));
+
+		/* ETHTOOL_A_NAME */
+		size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)));
+
+		/* ETHTOOL_A_PHY_UPSTREAM_TYPE */
+		size += nla_total_size(sizeof(u8));
+
+		/* ETHTOOL_A_PHY_ID */
+		size += nla_total_size(sizeof(u32));
+
+		if (phy_on_sfp(phydev)) {
+			/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
+			if (sfp_get_name(pdn->parent_sfp_bus))
+				size += nla_total_size(strlen(sfp_get_name(pdn->parent_sfp_bus)));
+
+			/* ETHTOOL_A_PHY_UPSTREAM_INDEX */
+			size += nla_total_size(sizeof(u32));
+		}
+
+		/* ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME */
+		if (phydev->sfp_bus)
+			size += nla_total_size(strlen(sfp_get_name(phydev->sfp_bus)));
+	}
+
+	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;
+	struct nlattr *nest;
+
+	ptype = pdn->upstream_type;
+
+	if (nla_put_u32(skb, ETHTOOL_A_PHY_INDEX, phydev->phyindex) ||
+	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, phydev->drv->name) ||
+	    nla_put_string(skb, ETHTOOL_A_PHY_NAME, dev_name(&phydev->mdio.dev)) ||
+	    nla_put_u8(skb, ETHTOOL_A_PHY_UPSTREAM_TYPE, ptype) ||
+	    nla_put_u32(skb, ETHTOOL_A_PHY_ID, phydev->phy_id))
+		return -EMSGSIZE;
+
+	if (ptype == PHY_UPSTREAM_PHY) {
+		struct phy_device *upstream = pdn->upstream.phydev;
+
+		nest = nla_nest_start(skb, ETHTOOL_A_PHY_UPSTREAM);
+		if (!nest)
+			return -EMSGSIZE;
+
+		/* Parent index */
+		if (nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX, upstream->phyindex))
+			return -EMSGSIZE;
+
+		if (pdn->parent_sfp_bus && sfp_get_name(pdn->parent_sfp_bus) &&
+		    nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
+				   sfp_get_name(pdn->parent_sfp_bus)))
+			return -EMSGSIZE;
+
+		nla_nest_end(skb, nest);
+	}
+
+	if (phydev->sfp_bus &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
+			   sfp_get_name(phydev->sfp_bus)))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int ethnl_phy_parse_request(struct ethnl_req_info *req_base,
+				   struct nlattr **tb)
+{
+	struct phy_req_info *req_info = PHY_REQINFO(req_base);
+	struct link_topology *lt = &req_base->dev->link_topo;
+	struct phy_device_node *pdn;
+
+	if (!req_base->phydev)
+		return 0;
+
+	pdn = xa_load(&lt->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 ethnl_req_info	req_info;
+};
+
+int ethnl_phy_start(struct netlink_callback *cb)
+{
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	struct nlattr **tb = info->info.attrs;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+
+	memset(ctx, 0, sizeof(*ctx));
+
+	ret = ethnl_parse_header_dev_get(&ctx->req_info,
+					 tb[ETHTOOL_A_PHY_HEADER],
+					 sock_net(cb->skb->sk), cb->extack,
+					 false);
+	return ret;
+}
+
+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 = PHY_REQINFO(&ctx->req_info);
+	struct phy_device_node *pdn;
+	unsigned long index = 1;
+	void *ehdr;
+	int ret;
+
+	ctx->req_info.dev = dev;
+
+	xa_for_each(&dev->link_topo.phys, index, pdn) {
+		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(&ctx->req_info, skb);
+
+		genlmsg_end(skb, ehdr);
+	}
+
+	ctx->req_info.dev = NULL;
+
+	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);
+	unsigned long ifindex = 1;
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+
+	if (ctx->req_info.dev) {
+		ret = ethnl_phy_dump_one_dev(skb, ctx->req_info.dev, cb);
+	} else {
+		for_each_netdev_dump(net, dev, ifindex) {
+			ret = ethnl_phy_dump_one_dev(skb, dev, cb);
+			if (ret)
+				break;
+		}
+	}
+	rtnl_unlock();
+
+	if (ret == -EMSGSIZE && skb->len)
+		return skb->len;
+	return ret;
+}
+