[PATCH net-next v2 00/12] net: phy_port: SFP modules representation and phy_port listing

[PATCH net-next v2 00/12] net: phy_port: SFP modules representation and phy_port listing

[Maxime Chevallier]

Hello everyone,

Here's V2 of the second phy_port series, this time bringing support for
more phy_port use especially for SFP, as well as the beggining of a
ethnl uAPI. That's a quick repost, but with the build issues and AI
review, I think it's worth getting this version out there for review.

It builds on the recent addition of phy_port representation to enable
listing the front-facing ports of an interface. For now, we don't control
these ports, we merely list their presence and their capabilities.

As the most common use-case of multi-port interfaces is combo-ports that
provide both RJ45 and SFP connectors on a single MAC, there's a lot of
SFP stuff in this series.

This series is in 2 main parts. The first one aims at representing the
SFP cages and modules using phy_port, as combo-ports with RJ45 + SFP are
by far the most common cases for multi-connector setups.

The second part is the netlink interface to list those ports, now that
most use-cases are covered.

Let's see what we can do with some examples of the new ethtool API :

- Get MII interfaces supported by an empty SFP cage :

# ethtool --show-ports eth3

Port for eth3:
	Port id: 1
	Occupied: no
	Supported MII interfaces : sgmii, 1000base-x, 2500base-x
	Port type: sfp


- Get Combo-ports supported modes, on each port :

# ethtool --show-ports eth0

Port for eth0:
	Port id: 1
	Occupied: no
	Supported link modes:  10baseT/Half 10baseT/Full
	                       100baseT/Half 100baseT/Full
	                       1000baseT/Half 1000baseT/Full
	                       10000baseT/Full
	                       2500baseT/Full
	                       5000baseT/Full
	Port type: mdi

Port for eth0:
	Port id: 2
	Occupied: no
	Supported MII interfaces : 10gbase-r
	Port type: sfp
	

- Get Achievable linkmodes on a SFP module (combo port with a DAC in the
SFP cage)

# ethtool --show-ports eth1

Port for eth1:
	Port id: 1
	Occupied: no
	Supported link modes:  10baseT/Half 10baseT/Full
	                       100baseT/Half 100baseT/Full
	                       1000baseT/Half 1000baseT/Full
	                       10000baseT/Full
	                       2500baseT/Full
	                       5000baseT/Full
	Port type: mdi

Port for eth1:
	Port id: 2
	Occupied: yes
	Supported MII interfaces : 10gbase-r
	Port type: sfp

Port for eth1:
	Port id: 3
	Occupied: no
	Supported link modes:  10000baseCR/Full
	Port type: mdi

Note that here, we have 3 ports :
 - The Copper port
 - The SFP Cage itself, marked as 'occupied'
 - The SFP module

This series builds on top of phy_port and phy_link_topology to allow
tracking the ports of an interface. We maintain a list of supported
linkmodes/interfaces on each port, which allows for fine-grained
reporting of each port's capability.

What this series doesn't do :
 - We don't support selecting which port is active. This is the next step.
 - We only support PHY-driven combo ports. The end-goal of this whole
   journey that started with phy_link_topology is to get support for MII
   muxes, such as the one we have on the Turris Omnia. This will eventually
   be upstreamed as well.

If you want to play around with it, here's [1] the patched ethtool that I've
been using to produce the outputs above.

Thanks !

Maxime

[1] : https://github.com/minimaxwell/ethtool/tree/mc/ethtool_port

Changelog :

Changes in V2:
 - Fix the cleanup path of phy_link_topo_add_phy, as per AI review
 - Fix the cleanup path of phy_sfp_probe, as per AI review
 - Fix the call-site of the disconnect_nophy sfp bus ops, per AI review
 - Fix the netdev-less case uin phylink, per AI review
 - Fix the prototype of phy_link_topo_get_port for the stubs
 - Dropped patch 11. It ended-up breaking 'allnoconfig', so instead we
   built a phy_interface_names array in net/ethtool/netlink.c
 - Fix an ethool-netlink spec discrepancy with the type of an attribute
 - Fix the size computation in the netlink port API
 - Fix the cleanup path in the netlink port API

Maxime Chevallier (12):
  net: phy: phy_port: Correctly recompute the port's linkmodes
  net: phy: phy_link_topology: Add a helper for opportunistic alloc
  net: phy: phy_link_topology: Track ports in phy_link_topology
  net: phylink: Register a phy_port for MAC-driven SFP busses
  net: phy: Create SFP phy_port before registering usptream
  net: sfp: Add a sfp-bus ops when connecting a module without PHY
  net: phy: Represent PHY-less SFP modules with phy_port
  net: phylink: Represent PHY-less SFP modules with phy_port
  net: phy: phy_port: Store information about a MII port's occupancy
  net: phy: phy_link_topology: Add a helper to retrieve ports
  netlink: specs: Add ethernet port listing with ethtool
  net: ethtool: Introduce ethtool command to list ports

 Documentation/netlink/specs/ethtool.yaml      |  50 +++
 Documentation/networking/ethtool-netlink.rst  |  35 ++
 MAINTAINERS                                   |   1 +
 drivers/net/phy/phy-caps.h                    |   2 +
 drivers/net/phy/phy_caps.c                    |  26 ++
 drivers/net/phy/phy_device.c                  | 106 ++++-
 drivers/net/phy/phy_link_topology.c           |  82 +++-
 drivers/net/phy/phy_port.c                    |   9 +-
 drivers/net/phy/phylink.c                     | 124 ++++++
 drivers/net/phy/sfp-bus.c                     |  20 +
 drivers/net/phy/sfp.c                         |  14 +
 drivers/net/phy/sfp.h                         |   2 +
 include/linux/phy.h                           |   4 +
 include/linux/phy_link_topology.h             |  35 ++
 include/linux/phy_port.h                      |   5 +
 include/linux/sfp.h                           |   5 +
 .../uapi/linux/ethtool_netlink_generated.h    |  19 +
 net/ethtool/Makefile                          |   2 +-
 net/ethtool/netlink.c                         |  26 ++
 net/ethtool/netlink.h                         |   8 +
 net/ethtool/port.c                            | 376 ++++++++++++++++++
 21 files changed, 925 insertions(+), 26 deletions(-)
 create mode 100644 net/ethtool/port.c

-- 
2.49.0

[PATCH net-next v2 01/12] net: phy: phy_port: Correctly recompute the port's linkmodes

[Maxime Chevallier]

a PHY-driven phy_port contains a 'supported' field containing the
linkmodes available on this port. This is populated based on :
 - The PHY's reported features
 - The DT representation of the connector
 - The PHY's attach_mdi() callback

As these different attrbution methods work in conjunction, the helper
phy_port_update_supported() recomputes the final 'supported' value based
on the populated mediums, linkmodes and pairs.

However this recompute wasn't correctly implemented, and added more
modes than necessary by or'ing the medium-specific modes to the existing
support. Let's fix this and properly filter the modes.

Fixes: 589e934d2735 ("net: phy: Introduce PHY ports representation")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phy_port.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/phy_port.c b/drivers/net/phy/phy_port.c
index ec93c8ca051e..68a0068220ed 100644
--- a/drivers/net/phy/phy_port.c
+++ b/drivers/net/phy/phy_port.c
@@ -118,11 +118,14 @@ void phy_port_update_supported(struct phy_port *port)
 	int i;
 
 	for_each_set_bit(i, &port->mediums, __ETHTOOL_LINK_MEDIUM_LAST) {
-		linkmode_zero(supported);
-		phy_caps_medium_get_supported(supported, i, port->pairs);
-		linkmode_or(port->supported, port->supported, supported);
+		__ETHTOOL_DECLARE_LINK_MODE_MASK(med_supported) = {0};
+
+		phy_caps_medium_get_supported(med_supported, i, port->pairs);
+		linkmode_or(supported, supported, med_supported);
 	}
 
+	linkmode_and(port->supported, port->supported, supported);
+
 	/* If there's no pairs specified, we grab the default number of
 	 * pairs as the max of the default pairs for each linkmode
 	 */
-- 
2.49.0

Re: [net-next,v2,01/12] net: phy: phy_port: Correctly recompute the port's linkmodes

[Jakub Kicinski]

This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.

For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html
---
net: phy: phy_port: Correctly recompute the port's linkmodes

This patch changes phy_port_update_supported() from OR'ing medium-specific
modes into port->supported to AND'ing (filtering) port->supported against
the accumulated medium modes.

Fixes: 589e934d2735 ("net: phy: Introduce PHY ports representation")

> diff --git a/drivers/net/phy/phy_port.c b/drivers/net/phy/phy_port.c
> index ec93c8ca051e..68a0068220ed 100644
> --- a/drivers/net/phy/phy_port.c
> +++ b/drivers/net/phy/phy_port.c
> @@ -118,11 +118,14 @@ void phy_port_update_supported(struct phy_port *port)
>  	int i;
>
>  	for_each_set_bit(i, &port->mediums, __ETHTOOL_LINK_MEDIUM_LAST) {
> -		linkmode_zero(supported);
> -		phy_caps_medium_get_supported(supported, i, port->pairs);
> -		linkmode_or(port->supported, port->supported, supported);
> +		__ETHTOOL_DECLARE_LINK_MODE_MASK(med_supported) = {0};
> +
> +		phy_caps_medium_get_supported(med_supported, i, port->pairs);
> +		linkmode_or(supported, supported, med_supported);
>  	}
>
> +	linkmode_and(port->supported, port->supported, supported);

When port->supported starts empty (all zeros), this AND operation will
always produce an empty result regardless of what modes are in supported.

Tracing the call path of_phy_ports() -> phy_of_parse_port() -> phy_add_port()
-> phy_port_update_supported(): phy_of_parse_port() creates the port via
phy_port_alloc() which zeros port->supported, and phy_of_parse_port()
only sets port->mediums and port->pairs without populating port->supported.

The attach_mdi_port() callbacks for drivers like dp83822 and marvell10g
also do not set port->supported before phy_port_update_supported() runs.

Does this leave port->supported empty for ports described in device tree?

The docstring above this function at line 112 states "Any mode that was
manually set in the port's supported list remains set" - but for the DT
path where port->supported starts at zero, the AND with zero produces
zero regardless of what medium modes were computed.
-- 
pw-bot: cr

[PATCH net-next v2 02/12] net: phy: phy_link_topology: Add a helper for opportunistic alloc

[Maxime Chevallier]

The phy_link_topology structure stores information about the PHY-related
components connected to a net_device. It is opportunistically allocated,
when we add the first item to the topology, as this is not relevant for
all kinds of net_devices.

In preparation for the addition of phy_port tracking in the topology,
let's make a dedicated helper for that allocation sequence.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phy_link_topology.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/net/phy/phy_link_topology.c b/drivers/net/phy/phy_link_topology.c
index 0e9e987f37dd..7dc2ff10c74a 100644
--- a/drivers/net/phy/phy_link_topology.c
+++ b/drivers/net/phy/phy_link_topology.c
@@ -27,21 +27,34 @@ static int netdev_alloc_phy_link_topology(struct net_device *dev)
 	return 0;
 }
 
+static struct phy_link_topology *phy_link_topo_get_or_alloc(struct net_device *dev)
+{
+	int ret;
+
+	if (dev->link_topo)
+		return dev->link_topo;
+
+	/* The topology is allocated the first time we add an object to it.
+	 * It is freed alongside the netdev.
+	 */
+	ret = netdev_alloc_phy_link_topology(dev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return dev->link_topo;
+}
+
 int phy_link_topo_add_phy(struct net_device *dev,
 			  struct phy_device *phy,
 			  enum phy_upstream upt, void *upstream)
 {
-	struct phy_link_topology *topo = dev->link_topo;
+	struct phy_link_topology *topo;
 	struct phy_device_node *pdn;
 	int ret;
 
-	if (!topo) {
-		ret = netdev_alloc_phy_link_topology(dev);
-		if (ret)
-			return ret;
-
-		topo = dev->link_topo;
-	}
+	topo = phy_link_topo_get_or_alloc(dev);
+	if (IS_ERR(topo))
+		return PTR_ERR(topo);
 
 	pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
 	if (!pdn)
-- 
2.49.0

[PATCH net-next v2 03/12] net: phy: phy_link_topology: Track ports in phy_link_topology

[Maxime Chevallier]

phy_port is aimed at representing the various physical interfaces of a
net_device. They can be controlled by various components in the link,
such as the Ethernet PHY, the Ethernet MAC, and SFP module, etc.

Let's therefore make so we keep track of all the ports connected to a
netdev in phy_link_topology. The only ports added for now are phy-driven
ports.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phy_link_topology.c | 53 +++++++++++++++++++++++++++++
 include/linux/phy_link_topology.h   | 18 ++++++++++
 include/linux/phy_port.h            |  2 ++
 3 files changed, 73 insertions(+)

diff --git a/drivers/net/phy/phy_link_topology.c b/drivers/net/phy/phy_link_topology.c
index 7dc2ff10c74a..456f1144e83e 100644
--- a/drivers/net/phy/phy_link_topology.c
+++ b/drivers/net/phy/phy_link_topology.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/phy_link_topology.h>
+#include <linux/phy_port.h>
 #include <linux/phy.h>
 #include <linux/rtnetlink.h>
 #include <linux/xarray.h>
@@ -22,6 +23,9 @@ static int netdev_alloc_phy_link_topology(struct net_device *dev)
 	xa_init_flags(&topo->phys, XA_FLAGS_ALLOC1);
 	topo->next_phy_index = 1;
 
+	xa_init_flags(&topo->ports, XA_FLAGS_ALLOC1);
+	topo->next_port_index = 1;
+
 	dev->link_topo = topo;
 
 	return 0;
@@ -44,12 +48,45 @@ static struct phy_link_topology *phy_link_topo_get_or_alloc(struct net_device *d
 	return dev->link_topo;
 }
 
+int phy_link_topo_add_port(struct net_device *dev, struct phy_port *port)
+{
+	struct phy_link_topology *topo;
+	int ret;
+
+	topo = phy_link_topo_get_or_alloc(dev);
+	if (IS_ERR(topo))
+		return PTR_ERR(topo);
+
+	/* Attempt to re-use a previously allocated port_id */
+	if (port->id)
+		ret = xa_insert(&topo->ports, port->id, port, GFP_KERNEL);
+	else
+		ret = xa_alloc_cyclic(&topo->ports, &port->id, port,
+				      xa_limit_32b, &topo->next_port_index,
+				      GFP_KERNEL);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_link_topo_add_port);
+
+void phy_link_topo_del_port(struct net_device *dev, struct phy_port *port)
+{
+	struct phy_link_topology *topo = dev->link_topo;
+
+	if (!topo)
+		return;
+
+	xa_erase(&topo->ports, port->id);
+}
+EXPORT_SYMBOL_GPL(phy_link_topo_del_port);
+
 int phy_link_topo_add_phy(struct net_device *dev,
 			  struct phy_device *phy,
 			  enum phy_upstream upt, void *upstream)
 {
 	struct phy_link_topology *topo;
 	struct phy_device_node *pdn;
+	struct phy_port *port;
 	int ret;
 
 	topo = phy_link_topo_get_or_alloc(dev);
@@ -89,8 +126,20 @@ int phy_link_topo_add_phy(struct net_device *dev,
 	if (ret < 0)
 		goto err;
 
+	/* Add all the PHY's ports to the topology */
+	list_for_each_entry(port, &phy->ports, head) {
+		ret = phy_link_topo_add_port(dev, port);
+		if (ret)
+			goto del_ports;
+	}
+
 	return 0;
 
+del_ports:
+	list_for_each_entry_from_reverse(port, &phy->ports, head)
+		phy_link_topo_del_port(dev, port);
+
+	xa_erase(&topo->phys, phy->phyindex);
 err:
 	kfree(pdn);
 	return ret;
@@ -102,10 +151,14 @@ void phy_link_topo_del_phy(struct net_device *dev,
 {
 	struct phy_link_topology *topo = dev->link_topo;
 	struct phy_device_node *pdn;
+	struct phy_port *port;
 
 	if (!topo)
 		return;
 
+	list_for_each_entry(port, &phy->ports, head)
+		phy_link_topo_del_port(dev, port);
+
 	pdn = xa_erase(&topo->phys, phy->phyindex);
 
 	/* We delete the PHY from the topology, however we don't re-set the
diff --git a/include/linux/phy_link_topology.h b/include/linux/phy_link_topology.h
index 68a59e25821c..66bceff72b19 100644
--- a/include/linux/phy_link_topology.h
+++ b/include/linux/phy_link_topology.h
@@ -16,11 +16,15 @@
 
 struct xarray;
 struct phy_device;
+struct phy_port;
 struct sfp_bus;
 
 struct phy_link_topology {
 	struct xarray phys;
 	u32 next_phy_index;
+
+	struct xarray ports;
+	u32 next_port_index;
 };
 
 struct phy_device_node {
@@ -43,6 +47,9 @@ int phy_link_topo_add_phy(struct net_device *dev,
 
 void phy_link_topo_del_phy(struct net_device *dev, struct phy_device *phy);
 
+int phy_link_topo_add_port(struct net_device *dev, struct phy_port *port);
+void phy_link_topo_del_port(struct net_device *dev, struct phy_port *port);
+
 static inline struct phy_device *
 phy_link_topo_get_phy(struct net_device *dev, u32 phyindex)
 {
@@ -72,6 +79,17 @@ static inline void phy_link_topo_del_phy(struct net_device *dev,
 {
 }
 
+static inline int phy_link_topo_add_port(struct net_device *dev,
+					 struct phy_port *port)
+{
+	return 0;
+}
+
+static inline void phy_link_topo_del_port(struct net_device *dev,
+					  struct phy_port *port)
+{
+}
+
 static inline struct phy_device *
 phy_link_topo_get_phy(struct net_device *dev, u32 phyindex)
 {
diff --git a/include/linux/phy_port.h b/include/linux/phy_port.h
index 0ef0f5ce4709..4e2a3fdd2f2e 100644
--- a/include/linux/phy_port.h
+++ b/include/linux/phy_port.h
@@ -36,6 +36,7 @@ struct phy_port_ops {
 /**
  * struct phy_port - A representation of a network device physical interface
  *
+ * @id: Unique identifier for the port within the topology
  * @head: Used by the port's parent to list ports
  * @parent_type: The type of device this port is directly connected to
  * @phy: If the parent is PHY_PORT_PHYDEV, the PHY controlling that port
@@ -52,6 +53,7 @@ struct phy_port_ops {
  * @is_sfp: Indicates if this port drives an SFP cage.
  */
 struct phy_port {
+	u32 id;
 	struct list_head head;
 	enum phy_port_parent parent_type;
 	union {
-- 
2.49.0

Re: [net-next,v2,03/12] net: phy: phy_link_topology: Track ports in phy_link_topology

[Jakub Kicinski]

This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.

For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html
---
    net: phy: phy_link_topology: Track ports in phy_link_topology

This commit adds a new ports xarray to phy_link_topology to track
phy_port structures alongside PHY devices. The ports are added when
a PHY is added and removed when a PHY is removed.

> diff --git a/drivers/net/phy/phy_link_topology.c b/drivers/net/phy/phy_link_topology.c
> index 7dc2ff10c74a..456f1144e83e 100644
> --- a/drivers/net/phy/phy_link_topology.c
> +++ b/drivers/net/phy/phy_link_topology.c

[ ... ]

> @@ -22,6 +23,9 @@ static int netdev_alloc_phy_link_topology(struct net_device *dev)
> 	xa_init_flags(&topo->phys, XA_FLAGS_ALLOC1);
> 	topo->next_phy_index = 1;
>
> +	xa_init_flags(&topo->ports, XA_FLAGS_ALLOC1);
> +	topo->next_port_index = 1;
> +
> 	dev->link_topo = topo;
>
> 	return 0;

The ports xarray is initialized here, but netdev_free_phy_link_topology()
in net/core/dev.c only calls xa_destroy() on topo->phys:

    static void netdev_free_phy_link_topology(struct net_device *dev)
    {
        struct phy_link_topology *topo = dev->link_topo;

        if (IS_ENABLED(CONFIG_PHYLIB) && topo) {
            xa_destroy(&topo->phys);
            kfree(topo);
            dev->link_topo = NULL;
        }
    }

Should xa_destroy(&topo->ports) be added before the kfree(topo) to avoid
leaking memory allocated by the ports xarray?

[PATCH net-next v2 04/12] net: phylink: Register a phy_port for MAC-driven SFP busses

[Maxime Chevallier]

phy_port tracks the interfaces that a netdevice feeds into. SFP cages are
such ports, but so far we are only tracking the ones that are driven by
PHYs acting as media-converters.

Let's populate a phy_port for MAC driver SFP cages, handled by phylink.

This phy_port represents the SFP cage itself, and not the module that
may be plugged into it. It's therefore not an MDI interface, so only the
'interfaces' field is relevant here.

The phy_port is only populated for 'NETDEV' phylink instances, as
otherwise we don't have any topology to attach the port to.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phylink.c | 53 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 7641f1f41e39..310af33d49a0 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -14,6 +14,8 @@
 #include <linux/of_mdio.h>
 #include <linux/phy.h>
 #include <linux/phy_fixed.h>
+#include <linux/phy_link_topology.h>
+#include <linux/phy_port.h>
 #include <linux/phylink.h>
 #include <linux/rtnetlink.h>
 #include <linux/spinlock.h>
@@ -93,6 +95,7 @@ struct phylink {
 	DECLARE_PHY_INTERFACE_MASK(sfp_interfaces);
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);
 	u8 sfp_port;
+	struct phy_port *sfp_bus_port;
 
 	struct eee_config eee_cfg;
 
@@ -1757,6 +1760,46 @@ static void phylink_fixed_poll(struct timer_list *t)
 
 static const struct sfp_upstream_ops sfp_phylink_ops;
 
+static int phylink_create_sfp_port(struct phylink *pl)
+{
+	struct phy_port *port;
+	int ret = 0;
+
+	if (!pl->netdev || !pl->sfp_bus)
+		return 0;
+
+	port = phy_port_alloc();
+	if (!port)
+		return -ENOMEM;
+
+	port->is_sfp = true;
+	port->is_mii = true;
+	port->active = true;
+
+	phy_interface_and(port->interfaces, pl->config->supported_interfaces,
+			  phylink_sfp_interfaces);
+	phy_port_update_supported(port);
+
+	ret = phy_link_topo_add_port(pl->netdev, port);
+	if (ret)
+		phy_port_destroy(port);
+	else
+		pl->sfp_bus_port = port;
+
+	return ret;
+}
+
+static void phylink_destroy_sfp_port(struct phylink *pl)
+{
+	if (pl->netdev && pl->sfp_bus_port)
+		phy_link_topo_del_port(pl->netdev, pl->sfp_bus_port);
+
+	if (pl->sfp_bus_port)
+		phy_port_destroy(pl->sfp_bus_port);
+
+	pl->sfp_bus_port = NULL;
+}
+
 static int phylink_register_sfp(struct phylink *pl,
 				const struct fwnode_handle *fwnode)
 {
@@ -1774,9 +1817,18 @@ static int phylink_register_sfp(struct phylink *pl,
 
 	pl->sfp_bus = bus;
 
+	ret = phylink_create_sfp_port(pl);
+	if (ret) {
+		sfp_bus_put(bus);
+		return ret;
+	}
+
 	ret = sfp_bus_add_upstream(bus, pl, &sfp_phylink_ops);
 	sfp_bus_put(bus);
 
+	if (ret)
+		phylink_destroy_sfp_port(pl);
+
 	return ret;
 }
 
@@ -1938,6 +1990,7 @@ EXPORT_SYMBOL_GPL(phylink_create);
 void phylink_destroy(struct phylink *pl)
 {
 	sfp_bus_del_upstream(pl->sfp_bus);
+	phylink_destroy_sfp_port(pl);
 	if (pl->link_gpio)
 		gpiod_put(pl->link_gpio);
 
-- 
2.49.0

[PATCH net-next v2 05/12] net: phy: Create SFP phy_port before registering usptream

[Maxime Chevallier]

When dealing with PHY-driver SFP, we create a phy_port representing the
SFP bus when we know we have such a bus.

We can move the port creation before registering the sfp upstream ops,
as long as we know the SFP bus is there. This will allow passing the
phy_port along with the upstream information to the SFP bus.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phy_device.c | 42 ++++++++++++++++++++++++------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8a3eb1839a3d..49696b1a2f13 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1665,13 +1665,13 @@ static void phy_del_port(struct phy_device *phydev, struct phy_port *port)
 	phydev->n_ports--;
 }
 
-static int phy_setup_sfp_port(struct phy_device *phydev)
+static struct phy_port *phy_setup_sfp_port(struct phy_device *phydev)
 {
 	struct phy_port *port = phy_port_alloc();
 	int ret;
 
 	if (!port)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	port->parent_type = PHY_PORT_PHY;
 	port->phy = phydev;
@@ -1686,10 +1686,12 @@ static int phy_setup_sfp_port(struct phy_device *phydev)
 	 * when attaching the port to the phydev.
 	 */
 	ret = phy_add_port(phydev, port);
-	if (ret)
+	if (ret) {
 		phy_port_destroy(port);
+		return ERR_PTR(ret);
+	}
 
-	return ret;
+	return port;
 }
 
 /**
@@ -1698,22 +1700,34 @@ static int phy_setup_sfp_port(struct phy_device *phydev)
  */
 static int phy_sfp_probe(struct phy_device *phydev)
 {
+	struct phy_port *port;
 	struct sfp_bus *bus;
-	int ret = 0;
+	int ret;
 
-	if (phydev->mdio.dev.fwnode) {
-		bus = sfp_bus_find_fwnode(phydev->mdio.dev.fwnode);
-		if (IS_ERR(bus))
-			return PTR_ERR(bus);
+	if (!phydev->mdio.dev.fwnode)
+		return 0;
+
+	bus = sfp_bus_find_fwnode(phydev->mdio.dev.fwnode);
+	if (IS_ERR(bus))
+		return PTR_ERR(bus);
 
-		phydev->sfp_bus = bus;
+	phydev->sfp_bus = bus;
 
-		ret = sfp_bus_add_upstream(bus, phydev, &sfp_phydev_ops);
-		sfp_bus_put(bus);
+	if (bus) {
+		port = phy_setup_sfp_port(phydev);
+		if (IS_ERR(port)) {
+			sfp_bus_put(bus);
+			return PTR_ERR(port);
+		}
 	}
 
-	if (!ret && phydev->sfp_bus)
-		ret = phy_setup_sfp_port(phydev);
+	ret = sfp_bus_add_upstream(bus, phydev, &sfp_phydev_ops);
+	sfp_bus_put(bus);
+
+	if (ret && port) {
+		phy_del_port(phydev, port);
+		phy_port_destroy(port);
+	}
 
 	return ret;
 }
-- 
2.49.0

[PATCH net-next v2 06/12] net: sfp: Add a sfp-bus ops when connecting a module without PHY

[Maxime Chevallier]

The SFP bus infrastructure notifies its upstream when a PHY device was
discovered on the module. However, we don't have any indication when a
module with no PHY was inserted, except for the .insert() and .start()
notifications.

We want to keep track of the SFP module's capabilities using phy_port.
When the module contains an embedded PHY, the PHY driver will expose a
phy_port for it. However when there's no PHY, we have no hook to
populate the phy_port, so let's introduce one. It is called when we
have parsed the module's caps, applied the fixups, tried and failed to
probe for a PHY.

This will allow the bus' upstream to create the corresponding port, and
register it to the topology.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/sfp-bus.c | 20 ++++++++++++++++++++
 drivers/net/phy/sfp.c     | 14 ++++++++++++++
 drivers/net/phy/sfp.h     |  2 ++
 include/linux/sfp.h       |  5 +++++
 4 files changed, 41 insertions(+)

diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index b945d75966d5..a3d9e28badd0 100644
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -753,6 +753,26 @@ void sfp_remove_phy(struct sfp_bus *bus)
 }
 EXPORT_SYMBOL_GPL(sfp_remove_phy);
 
+int sfp_module_connect_nophy(struct sfp_bus *bus)
+{
+	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
+
+	if (ops && ops->connect_nophy)
+		return ops->connect_nophy(bus->upstream);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sfp_module_connect_nophy);
+
+void sfp_module_disconnect_nophy(struct sfp_bus *bus)
+{
+	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
+
+	if (ops && ops->disconnect_nophy)
+		ops->disconnect_nophy(bus->upstream);
+}
+EXPORT_SYMBOL_GPL(sfp_module_disconnect_nophy);
+
 void sfp_link_up(struct sfp_bus *bus)
 {
 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 47f095bd91ce..050952bc7bce 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -1918,6 +1918,11 @@ static int sfp_sm_probe_phy(struct sfp *sfp, int addr, bool is_c45)
 	return 0;
 }
 
+static int sfp_sm_connect_nophy(struct sfp *sfp)
+{
+	return sfp_module_connect_nophy(sfp->sfp_bus);
+}
+
 static void sfp_sm_link_up(struct sfp *sfp)
 {
 	sfp_link_up(sfp->sfp_bus);
@@ -2646,6 +2651,8 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event)
 			sfp_module_stop(sfp->sfp_bus);
 		if (sfp->mod_phy)
 			sfp_sm_phy_detach(sfp);
+		else
+			sfp_module_disconnect_nophy(sfp->sfp_bus);
 		if (sfp->i2c_mii)
 			sfp_i2c_mdiobus_destroy(sfp);
 		sfp_module_tx_disable(sfp);
@@ -2749,6 +2756,13 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event)
 			sfp_sm_next(sfp, SFP_S_FAIL, 0);
 			break;
 		}
+		if (!sfp->mod_phy) {
+			ret = sfp_sm_connect_nophy(sfp);
+			if (ret) {
+				sfp_sm_next(sfp, SFP_S_FAIL, 0);
+				break;
+			}
+		}
 		if (sfp_module_start(sfp->sfp_bus)) {
 			sfp_sm_next(sfp, SFP_S_FAIL, 0);
 			break;
diff --git a/drivers/net/phy/sfp.h b/drivers/net/phy/sfp.h
index 879dff7afe6a..02f3814aac84 100644
--- a/drivers/net/phy/sfp.h
+++ b/drivers/net/phy/sfp.h
@@ -37,6 +37,8 @@ int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 void sfp_module_remove(struct sfp_bus *bus);
 int sfp_module_start(struct sfp_bus *bus);
 void sfp_module_stop(struct sfp_bus *bus);
+int sfp_module_connect_nophy(struct sfp_bus *bus);
+void sfp_module_disconnect_nophy(struct sfp_bus *bus);
 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
 				    const struct sfp_socket_ops *ops);
 void sfp_unregister_socket(struct sfp_bus *bus);
diff --git a/include/linux/sfp.h b/include/linux/sfp.h
index 5c71945a5e4d..1c18de1eb268 100644
--- a/include/linux/sfp.h
+++ b/include/linux/sfp.h
@@ -561,6 +561,9 @@ struct sfp_module_caps {
  *   on the module.
  * @disconnect_phy: called when a module with an I2C accessible PHY has
  *   been removed.
+ * @connect_nophy: called when it was established that the connected module
+ *		   doesn't have an I2C PHY accessible.
+ * @disconnect_nophy: called when the PHY-less module has been removed.
  */
 struct sfp_upstream_ops {
 	void (*attach)(void *priv, struct sfp_bus *bus);
@@ -573,6 +576,8 @@ struct sfp_upstream_ops {
 	void (*link_up)(void *priv);
 	int (*connect_phy)(void *priv, struct phy_device *);
 	void (*disconnect_phy)(void *priv, struct phy_device *);
+	int (*connect_nophy)(void *priv);
+	void (*disconnect_nophy)(void *priv);
 };
 
 #if IS_ENABLED(CONFIG_SFP)
-- 
2.49.0

[PATCH net-next v2 07/12] net: phy: Represent PHY-less SFP modules with phy_port

[Maxime Chevallier]

Now that th SFP bus infrastructure notifies when PHY-less modules are
connected, we can create a phy_port to represent it. Instead of letting
the SFP subsystem handle that, the Bus' upstream is in charge of
maintaining that phy_port and register it to the topology, as the
upstream (in this case a phy device) is directly interacting with the
underlying net_device.

Add a phy_caps helper alongside to get the achievable modes on this
module based on what the phy_port representing the bus supports.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phy-caps.h   |  2 ++
 drivers/net/phy/phy_caps.c   | 26 +++++++++++++++
 drivers/net/phy/phy_device.c | 62 +++++++++++++++++++++++++++++++++++-
 include/linux/phy.h          |  4 +++
 4 files changed, 93 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/phy-caps.h b/drivers/net/phy/phy-caps.h
index 421088e6f6e8..ec3d39a0ae06 100644
--- a/drivers/net/phy/phy-caps.h
+++ b/drivers/net/phy/phy-caps.h
@@ -66,5 +66,7 @@ void phy_caps_medium_get_supported(unsigned long *supported,
 				   enum ethtool_link_medium medium,
 				   int lanes);
 u32 phy_caps_mediums_from_linkmodes(unsigned long *linkmodes);
+void phy_caps_linkmode_filter_ifaces(unsigned long *to, const unsigned long *from,
+				     const unsigned long *interfaces);
 
 #endif /* __PHY_CAPS_H */
diff --git a/drivers/net/phy/phy_caps.c b/drivers/net/phy/phy_caps.c
index 942d43191561..558e4df4d63c 100644
--- a/drivers/net/phy/phy_caps.c
+++ b/drivers/net/phy/phy_caps.c
@@ -445,3 +445,29 @@ u32 phy_caps_mediums_from_linkmodes(unsigned long *linkmodes)
 	return mediums;
 }
 EXPORT_SYMBOL_GPL(phy_caps_mediums_from_linkmodes);
+
+/**
+ * phy_caps_linkmode_filter_ifaces() - Filter linkmodes with an interface list
+ * @to: Stores the filtered linkmodes
+ * @from: Linkmodes to filter
+ * @interfaces: Bitfield of phy_interface_t that we use for filtering
+ *
+ * Filter the provided linkmodes, only to keep the ones we can possibly achieve
+ * when using any of the provided MII interfaces.
+ */
+void phy_caps_linkmode_filter_ifaces(unsigned long *to,
+				     const unsigned long *from,
+				     const unsigned long *interfaces)
+{
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(ifaces_supported) = {};
+	unsigned int ifaces_caps = 0;
+	phy_interface_t interface;
+
+	for_each_set_bit(interface, interfaces, PHY_INTERFACE_MODE_MAX)
+		ifaces_caps |= phy_caps_from_interface(interface);
+
+	phy_caps_linkmodes(ifaces_caps, ifaces_supported);
+
+	linkmode_and(to, from, ifaces_supported);
+}
+EXPORT_SYMBOL_GPL(phy_caps_linkmode_filter_ifaces);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 49696b1a2f13..b3125cf30bf3 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1609,6 +1609,53 @@ static void phy_sfp_link_down(void *upstream)
 		port->ops->link_down(port);
 }
 
+static int phy_sfp_connect_nophy(void *upstream)
+{
+	struct phy_device *phydev = upstream;
+	const struct sfp_module_caps *caps;
+	struct phy_port *port;
+	int ret = 0;
+
+	/* Create mod port */
+	port = phy_port_alloc();
+	if (!port)
+		return -ENOMEM;
+
+	port->active = true;
+
+	caps = sfp_get_module_caps(phydev->sfp_bus);
+
+	phy_caps_linkmode_filter_ifaces(port->supported, caps->link_modes,
+					phydev->sfp_bus_port->interfaces);
+
+	if (phydev->attached_dev) {
+		ret = phy_link_topo_add_port(phydev->attached_dev, port);
+		if (ret) {
+			phy_port_destroy(port);
+			return ret;
+		}
+	}
+
+	/* we don't use phy_add_port() here as the module port isn't a direct
+	 * interface from the PHY, but rather an extension to the sfp-bus, that
+	 * is already represented by its own phy_port
+	 */
+	phydev->mod_port = port;
+
+	return 0;
+}
+
+static void phy_sfp_disconnect_nophy(void *upstream)
+{
+	struct phy_device *phydev = upstream;
+
+	if (phydev->attached_dev)
+		phy_link_topo_del_port(phydev->attached_dev, phydev->mod_port);
+
+	phy_port_destroy(phydev->mod_port);
+	phydev->mod_port = NULL;
+}
+
 static const struct sfp_upstream_ops sfp_phydev_ops = {
 	.attach = phy_sfp_attach,
 	.detach = phy_sfp_detach,
@@ -1618,6 +1665,8 @@ static const struct sfp_upstream_ops sfp_phydev_ops = {
 	.link_down = phy_sfp_link_down,
 	.connect_phy = phy_sfp_connect_phy,
 	.disconnect_phy = phy_sfp_disconnect_phy,
+	.connect_nophy = phy_sfp_connect_nophy,
+	.disconnect_nophy = phy_sfp_disconnect_nophy,
 };
 
 static int phy_add_port(struct phy_device *phydev, struct phy_port *port)
@@ -1700,7 +1749,7 @@ static struct phy_port *phy_setup_sfp_port(struct phy_device *phydev)
  */
 static int phy_sfp_probe(struct phy_device *phydev)
 {
-	struct phy_port *port;
+	struct phy_port *port = NULL;
 	struct sfp_bus *bus;
 	int ret;
 
@@ -1729,6 +1778,8 @@ static int phy_sfp_probe(struct phy_device *phydev)
 		phy_port_destroy(port);
 	}
 
+	phydev->sfp_bus_port = port;
+
 	return ret;
 }
 
@@ -1818,6 +1869,12 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 		err = phy_link_topo_add_phy(dev, phydev, PHY_UPSTREAM_MAC, dev);
 		if (err)
 			goto error;
+
+		if (phydev->mod_port) {
+			err = phy_link_topo_add_port(dev, phydev->mod_port);
+			if (err)
+				goto error;
+		}
 	}
 
 	/* Some Ethernet drivers try to connect to a PHY device before
@@ -1991,6 +2048,8 @@ void phy_detach(struct phy_device *phydev)
 		phydev->attached_dev->phydev = NULL;
 		phydev->attached_dev = NULL;
 		phy_link_topo_del_phy(dev, phydev);
+		if (phydev->mod_port)
+			phy_link_topo_del_port(dev, phydev->mod_port);
 	}
 
 	phydev->phy_link_change = NULL;
@@ -3818,6 +3877,7 @@ static int phy_remove(struct device *dev)
 
 	sfp_bus_del_upstream(phydev->sfp_bus);
 	phydev->sfp_bus = NULL;
+	phydev->sfp_bus_port = NULL;
 
 	if (phydev->drv && phydev->drv->remove)
 		phydev->drv->remove(phydev);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 6f9979a26892..dc788ae4da64 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -594,6 +594,8 @@ struct phy_oatc14_sqi_capability {
  * @phylink: Pointer to phylink instance for this PHY
  * @sfp_bus_attached: Flag indicating whether the SFP bus has been attached
  * @sfp_bus: SFP bus attached to this PHY's fiber port
+ * @sfp_bus_port: The phy_port connected to the downstream SFP bus
+ * @mod_port: phy_port representing the SFP module, if it is phy-less
  * @attached_dev: The attached enet driver's device instance ptr
  * @adjust_link: Callback for the enet controller to respond to changes: in the
  *               link state.
@@ -782,6 +784,8 @@ struct phy_device {
 	/* This may be modified under the rtnl lock */
 	bool sfp_bus_attached;
 	struct sfp_bus *sfp_bus;
+	struct phy_port *sfp_bus_port;
+	struct phy_port *mod_port;
 	struct phylink *phylink;
 	struct net_device *attached_dev;
 	struct mii_timestamper *mii_ts;
-- 
2.49.0

[PATCH net-next v2 08/12] net: phylink: Represent PHY-less SFP modules with phy_port

[Maxime Chevallier]

Let phylink handle the phy_port for PHY-less modules, and register it to
the topology.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phylink.c | 71 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 69 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 310af33d49a0..21af1dffa837 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -96,6 +96,7 @@ struct phylink {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);
 	u8 sfp_port;
 	struct phy_port *sfp_bus_port;
+	struct phy_port *mod_port;
 
 	struct eee_config eee_cfg;
 
@@ -1786,13 +1787,31 @@ static int phylink_create_sfp_port(struct phylink *pl)
 	else
 		pl->sfp_bus_port = port;
 
+	if (pl->mod_port) {
+		ret = phy_link_topo_add_port(pl->netdev, pl->mod_port);
+		if (ret)
+			goto out_bus_port;
+	}
+
+	return 0;
+out_bus_port:
+	phy_link_topo_del_port(pl->netdev, port);
+	phy_port_destroy(port);
 	return ret;
 }
 
 static void phylink_destroy_sfp_port(struct phylink *pl)
 {
-	if (pl->netdev && pl->sfp_bus_port)
-		phy_link_topo_del_port(pl->netdev, pl->sfp_bus_port);
+	if (pl->netdev) {
+		if (pl->sfp_bus_port)
+			phy_link_topo_del_port(pl->netdev, pl->sfp_bus_port);
+
+		/* Only remove it from the topology, it will be destroyed at
+		 * module removal.
+		 */
+		if (pl->mod_port)
+			phy_link_topo_del_port(pl->netdev, pl->mod_port);
+	}
 
 	if (pl->sfp_bus_port)
 		phy_port_destroy(pl->sfp_bus_port);
@@ -3998,6 +4017,52 @@ static void phylink_sfp_disconnect_phy(void *upstream,
 	phylink_disconnect_phy(upstream);
 }
 
+static int phylink_sfp_connect_nophy(void *upstream)
+{
+	const struct sfp_module_caps *caps;
+	struct phylink *pl = upstream;
+	struct phy_port *port;
+	int ret = 0;
+
+	if (!pl->sfp_bus_port)
+		return 0;
+
+	/* Create mod port */
+	port = phy_port_alloc();
+	if (!port)
+		return -ENOMEM;
+
+	port->active = true;
+
+	caps = sfp_get_module_caps(pl->sfp_bus);
+
+	phy_caps_linkmode_filter_ifaces(port->supported, caps->link_modes,
+					pl->sfp_bus_port->interfaces);
+
+	if (pl->netdev) {
+		ret = phy_link_topo_add_port(pl->netdev, port);
+		if (ret) {
+			phy_port_destroy(port);
+			return ret;
+		}
+	}
+
+	pl->mod_port = port;
+
+	return 0;
+}
+
+static void phylink_sfp_disconnect_nophy(void *upstream)
+{
+	struct phylink *pl = upstream;
+
+	if (pl->netdev)
+		phy_link_topo_del_port(pl->netdev, pl->mod_port);
+
+	phy_port_destroy(pl->mod_port);
+	pl->mod_port = NULL;
+}
+
 static const struct sfp_upstream_ops sfp_phylink_ops = {
 	.attach = phylink_sfp_attach,
 	.detach = phylink_sfp_detach,
@@ -4009,6 +4074,8 @@ static const struct sfp_upstream_ops sfp_phylink_ops = {
 	.link_down = phylink_sfp_link_down,
 	.connect_phy = phylink_sfp_connect_phy,
 	.disconnect_phy = phylink_sfp_disconnect_phy,
+	.connect_nophy = phylink_sfp_connect_nophy,
+	.disconnect_nophy = phylink_sfp_disconnect_nophy,
 };
 
 /* Helpers for MAC drivers */
-- 
2.49.0

Re: [net-next,v2,08/12] net: phylink: Represent PHY-less SFP modules with phy_port

[Jakub Kicinski]

This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.

For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html
---
net: phylink: Represent PHY-less SFP modules with phy_port

This patch adds support for representing PHY-less SFP modules using
phy_port by implementing connect_nophy and disconnect_nophy callbacks
for phylink.

> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index 310af33d49a0..21af1dffa837 100644

[ ... ]

> +static int phylink_sfp_connect_nophy(void *upstream)
> +{
> +	const struct sfp_module_caps *caps;
> +	struct phylink *pl = upstream;
> +	struct phy_port *port;
> +	int ret = 0;
> +
> +	if (!pl->sfp_bus_port)
> +		return 0;

This early return guards against sfp_bus_port being NULL, which prevents
mod_port from being allocated in that case.

> +
> +	/* Create mod port */
> +	port = phy_port_alloc();

[ ... ]

> +	pl->mod_port = port;
> +
> +	return 0;
> +}
> +
> +static void phylink_sfp_disconnect_nophy(void *upstream)
> +{
> +	struct phylink *pl = upstream;
> +
> +	if (pl->netdev)
> +		phy_link_topo_del_port(pl->netdev, pl->mod_port);
                                                     ^^^^^^^^^

Can pl->mod_port be NULL here? Looking at the SFP state machine in
sfp.c, sfp_module_disconnect_nophy() is called from the global cleanup
block when !sfp->mod_phy. This cleanup runs whenever the state machine
is not in SFP_S_DOWN and the module state changes.

If the module is removed while the state machine is in an early state
like SFP_S_WAIT or SFP_S_INIT (before PHY probing completes),
sfp_module_disconnect_nophy() will be called even though
phylink_sfp_connect_nophy() was never invoked. In that case, pl->mod_port
is still NULL.

The phy_link_topo_del_port() function dereferences port->id without a
NULL check, which would cause a NULL pointer dereference.

Should this check for pl->mod_port before calling phy_link_topo_del_port,
similar to how phylink_destroy_sfp_port() does?

> +
> +	phy_port_destroy(pl->mod_port);
> +	pl->mod_port = NULL;
> +}

[PATCH net-next v2 09/12] net: phy: phy_port: Store information about a MII port's occupancy

[Maxime Chevallier]

MII phy_ports are not meant to be connected directly to a link partner.
They are meant to feed into some media converter devices, so far we only
support SFP modules for that.

We have information about what MII they can handle, however we don't
store anything about whether they are currently connected to an SFP
module or not. As phy_port aims at listing the front-facing ports, let's
store an "occupied" bit to know whether or not a MII port is currently
front-facing (i.e. there's no module in the SFP cage), or occupied (i.e.
there's an SFP module).

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phy_device.c | 4 ++++
 drivers/net/phy/phylink.c    | 4 ++++
 include/linux/phy_port.h     | 3 +++
 3 files changed, 11 insertions(+)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index b3125cf30bf3..9dba31b9cb86 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1636,6 +1636,8 @@ static int phy_sfp_connect_nophy(void *upstream)
 		}
 	}
 
+	phydev->sfp_bus_port->occupied = true;
+
 	/* we don't use phy_add_port() here as the module port isn't a direct
 	 * interface from the PHY, but rather an extension to the sfp-bus, that
 	 * is already represented by its own phy_port
@@ -1649,6 +1651,8 @@ static void phy_sfp_disconnect_nophy(void *upstream)
 {
 	struct phy_device *phydev = upstream;
 
+	phydev->sfp_bus_port->occupied = false;
+
 	if (phydev->attached_dev)
 		phy_link_topo_del_port(phydev->attached_dev, phydev->mod_port);
 
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 21af1dffa837..bb257e91cdf6 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -4047,6 +4047,8 @@ static int phylink_sfp_connect_nophy(void *upstream)
 		}
 	}
 
+	pl->sfp_bus_port->occupied = true;
+
 	pl->mod_port = port;
 
 	return 0;
@@ -4056,6 +4058,8 @@ static void phylink_sfp_disconnect_nophy(void *upstream)
 {
 	struct phylink *pl = upstream;
 
+	pl->sfp_bus_port->occupied = false;
+
 	if (pl->netdev)
 		phy_link_topo_del_port(pl->netdev, pl->mod_port);
 
diff --git a/include/linux/phy_port.h b/include/linux/phy_port.h
index 4e2a3fdd2f2e..8d4f20bfd9dd 100644
--- a/include/linux/phy_port.h
+++ b/include/linux/phy_port.h
@@ -51,6 +51,8 @@ struct phy_port_ops {
  * @is_mii: Indicates if this port is MII (Media Independent Interface),
  *          or MDI (Media Dependent Interface).
  * @is_sfp: Indicates if this port drives an SFP cage.
+ * @occupied: Indicates if this port feeds into an another component that has
+ *	      a front-facing interface.
  */
 struct phy_port {
 	u32 id;
@@ -71,6 +73,7 @@ struct phy_port {
 	unsigned int active:1;
 	unsigned int is_mii:1;
 	unsigned int is_sfp:1;
+	unsigned int occupied:1;
 };
 
 struct phy_port *phy_port_alloc(void);
-- 
2.49.0

Re: [net-next,v2,09/12] net: phy: phy_port: Store information about a MII port's occupancy

[Jakub Kicinski]

This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.

For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html
---
net: phy: phy_port: Store information about a MII port's occupancy

This patch adds an "occupied" bitfield to struct phy_port to track
whether an MII port has an SFP module inserted. The field is set in
connect_nophy callbacks and cleared in disconnect_nophy callbacks.

> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index 21af1dffa837..bb257e91cdf6 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c

[ ... ]

> @@ -4047,6 +4047,8 @@ static int phylink_sfp_connect_nophy(void *upstream)
>  		}
>  	}
>
> +	pl->sfp_bus_port->occupied = true;

Note that phylink_sfp_connect_nophy() has a NULL check for sfp_bus_port
at the start of the function that returns early if it is NULL.

> +
>  	pl->mod_port = port;
>
>  	return 0;
> @@ -4056,6 +4058,8 @@ static void phylink_sfp_disconnect_nophy(void *upstream)
>  {
>  	struct phylink *pl = upstream;
>
> +	pl->sfp_bus_port->occupied = false;

Can this dereference a NULL pointer? When phylink is created with
PHYLINK_DEV type (rather than PHYLINK_NETDEV), pl->netdev is NULL and
phylink_create_sfp_port() returns early without setting sfp_bus_port.
The callbacks are still registered via sfp_bus_add_upstream(), so when
a PHY-less SFP module is later inserted and removed, this function
would be called with sfp_bus_port being NULL.

The connect function checks for NULL sfp_bus_port, but the disconnect
function does not. Should this have a similar guard?

> +
>  	if (pl->netdev)
>  		phy_link_topo_del_port(pl->netdev, pl->mod_port);

[PATCH net-next v2 10/12] net: phy: phy_link_topology: Add a helper to retrieve ports

[Maxime Chevallier]

In order to allow netlink access to phy_ports, let's add a helper to
retrieve them. When handling a port coming from phy_link_topology, the
caller must hold rtnl until it's done with it.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 include/linux/phy_link_topology.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/linux/phy_link_topology.h b/include/linux/phy_link_topology.h
index 66bceff72b19..b05858086e42 100644
--- a/include/linux/phy_link_topology.h
+++ b/include/linux/phy_link_topology.h
@@ -66,6 +66,17 @@ phy_link_topo_get_phy(struct net_device *dev, u32 phyindex)
 	return NULL;
 }
 
+static inline struct phy_port *
+phy_link_topo_get_port(struct net_device *dev, u32 port_id)
+{
+	struct phy_link_topology *topo = dev->link_topo;
+
+	if (!topo)
+		return NULL;
+
+	return xa_load(&topo->ports, port_id);
+}
+
 #else
 static inline int phy_link_topo_add_phy(struct net_device *dev,
 					struct phy_device *phy,
@@ -95,6 +106,12 @@ phy_link_topo_get_phy(struct net_device *dev, u32 phyindex)
 {
 	return NULL;
 }
+
+static inline struct phy_port *
+phy_link_topo_get_port(struct net_device *dev, u32 port_id)
+{
+	return NULL;
+}
 #endif
 
 #endif /* __PHY_LINK_TOPOLOGY_H */
-- 
2.49.0

[PATCH net-next v2 11/12] netlink: specs: Add ethernet port listing with ethtool

[Maxime Chevallier]

Ethernet network interfaces may have more than one front-facing port.
The phy_port infrastructure was introduced to keep track of
these ports, and allow userspace to know about the presence and
capability of these ports. Add a ethnl netlink message to report this
information.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 Documentation/netlink/specs/ethtool.yaml      | 50 +++++++++++++++++++
 Documentation/networking/ethtool-netlink.rst  | 35 +++++++++++++
 .../uapi/linux/ethtool_netlink_generated.h    | 19 +++++++
 3 files changed, 104 insertions(+)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 0a2d2343f79a..f0f424009fb0 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -210,6 +210,10 @@ definitions:
       -
         name: discard
         value: 31
+  -
+    name: port-type
+    type: enum
+    entries: [mdi, sfp]
 
 attribute-sets:
   -
@@ -1890,6 +1894,32 @@ attribute-sets:
         name: link
         type: nest
         nested-attributes: mse-snapshot
+  -
+    name: port
+    attr-cnt-name: --ethtool-a-port-cnt
+    attributes:
+      -
+        name: header
+        type: nest
+        nested-attributes: header
+      -
+        name: id
+        type: u32
+      -
+        name: supported-modes
+        type: nest
+        nested-attributes: bitset
+      -
+        name: supported-interfaces
+        type: nest
+        nested-attributes: bitset
+      -
+        name: type
+        type: u8
+        enum: port-type
+      -
+        name: occupied
+        type: u8
 
 operations:
   enum-model: directional
@@ -2842,6 +2872,26 @@ operations:
             - worst-channel
             - link
       dump: *mse-get-op
+    -
+      name: port-get
+      doc: Get ports attached to an interface
+
+      attribute-set: port
+
+      do: &port-get-op
+        request:
+          attributes:
+            - header
+            - id
+        reply:
+          attributes:
+            - header
+            - id
+            - supported-modes
+            - supported-interfaces
+            - type
+            - occupied
+      dump: *port-get-op
 
 mcast-groups:
   list:
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index af56c304cef4..68c447eaeb7a 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -2522,6 +2522,40 @@ Within each channel nest, only the metrics supported by the PHY will be present.
 See ``struct phy_mse_snapshot`` kernel documentation in
 ``include/linux/phy.h``.
 
+PORT_GET
+========
+
+Retrieve information about the physical connection points of a network device,
+referred to as "ports". User needs to specify a PORT_ID for the DO operation,
+in which case the DO request returns information about that specific port.
+
+As there can be more than one port, the DUMP operation can be used to list the
+ports present on a given interface, by passing an interface index or name in
+the dump request.
+
+Request contents:
+
+====================================  ======  =================================
+  ``ETHTOOL_A_PORT_HEADER``             nested  request header
+  ``ETHTOOL_A_PORT_ID``                 u32     port id
+  ====================================  ======  ===============================
+
+Kernel response contents:
+
+  =====================================   ======  =============================
+  ``ETHTOOL_A_PORT_HEADER``               nested  request header
+  ``ETHTOOL_A_PORT_ID``                   u32     the port's unique identifier,
+                                                  per netdevice.
+  ``ETHTOOL_A_PORT_SUPPORTED_MODES``      bitset  bitset of supported linkmodes
+  ``ETHTOOL_A_PORT_SUPPORTED_INTERFACES`` bitset  bitset of supported MII
+                                                  interfaces
+  ``ETHTOOL_A_PORT_TYPE``                 u8      the port type
+  ``ETHTOOL_A_PORT_OCCUPIED``             u8      for non-mdi ports, indicates
+                                                  if the port is connected to
+                                                  another device that could
+                                                  expose a MDI
+  =====================================   ======  =============================
+
 Request translation
 ===================
 
@@ -2632,4 +2666,5 @@ are netlink only.
   n/a                                 ``ETHTOOL_MSG_PHY_GET``
   ``SIOCGHWTSTAMP``                   ``ETHTOOL_MSG_TSCONFIG_GET``
   ``SIOCSHWTSTAMP``                   ``ETHTOOL_MSG_TSCONFIG_SET``
+  n/a                                 ``ETHTOOL_MSG_PORT_GET``
   =================================== =====================================
diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index 556a0c834df5..7ccd864a6e38 100644
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -78,6 +78,11 @@ enum ethtool_pse_event {
 	ETHTOOL_PSE_EVENT_SW_PW_CONTROL_ERROR = 64,
 };
 
+enum ethtool_port_type {
+	ETHTOOL_PORT_TYPE_MDI,
+	ETHTOOL_PORT_TYPE_SFP,
+};
+
 enum {
 	ETHTOOL_A_HEADER_UNSPEC,
 	ETHTOOL_A_HEADER_DEV_INDEX,
@@ -837,6 +842,18 @@ enum {
 	ETHTOOL_A_MSE_MAX = (__ETHTOOL_A_MSE_CNT - 1)
 };
 
+enum {
+	ETHTOOL_A_PORT_HEADER = 1,
+	ETHTOOL_A_PORT_ID,
+	ETHTOOL_A_PORT_SUPPORTED_MODES,
+	ETHTOOL_A_PORT_SUPPORTED_INTERFACES,
+	ETHTOOL_A_PORT_TYPE,
+	ETHTOOL_A_PORT_OCCUPIED,
+
+	__ETHTOOL_A_PORT_CNT,
+	ETHTOOL_A_PORT_MAX = (__ETHTOOL_A_PORT_CNT - 1)
+};
+
 enum {
 	ETHTOOL_MSG_USER_NONE = 0,
 	ETHTOOL_MSG_STRSET_GET = 1,
@@ -890,6 +907,7 @@ enum {
 	ETHTOOL_MSG_RSS_CREATE_ACT,
 	ETHTOOL_MSG_RSS_DELETE_ACT,
 	ETHTOOL_MSG_MSE_GET,
+	ETHTOOL_MSG_PORT_GET,
 
 	__ETHTOOL_MSG_USER_CNT,
 	ETHTOOL_MSG_USER_MAX = (__ETHTOOL_MSG_USER_CNT - 1)
@@ -951,6 +969,7 @@ enum {
 	ETHTOOL_MSG_RSS_CREATE_NTF,
 	ETHTOOL_MSG_RSS_DELETE_NTF,
 	ETHTOOL_MSG_MSE_GET_REPLY,
+	ETHTOOL_MSG_PORT_GET_REPLY,
 
 	__ETHTOOL_MSG_KERNEL_CNT,
 	ETHTOOL_MSG_KERNEL_MAX = (__ETHTOOL_MSG_KERNEL_CNT - 1)
-- 
2.49.0

[PATCH net-next v2 12/12] net: ethtool: Introduce ethtool command to list ports

[Maxime Chevallier]

Expose the phy_port information to userspace, so that we can know how
many ports are available on a given interface, as well as their
capabilities. For MDI ports, we report the list of supported linkmodes
based on what the PHY that drives this port says.
For MII ports, i.e. empty SFP cages, we report the MII linkmodes that we
can output on this port.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 MAINTAINERS           |   1 +
 net/ethtool/Makefile  |   2 +-
 net/ethtool/netlink.c |  26 +++
 net/ethtool/netlink.h |   8 +
 net/ethtool/port.c    | 376 ++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 412 insertions(+), 1 deletion(-)
 create mode 100644 net/ethtool/port.c

diff --git a/MAINTAINERS b/MAINTAINERS
index c3df85fd5acd..a8272e169888 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18226,6 +18226,7 @@ F:	Documentation/devicetree/bindings/net/ethernet-connector.yaml
 F:	Documentation/networking/phy-port.rst
 F:	drivers/net/phy/phy_port.c
 F:	include/linux/phy_port.h
+F:	net/ethtool/port.c
 K:	struct\s+phy_port|phy_port_
 
 NETWORKING [GENERAL]
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 629c10916670..9b5b09670008 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -9,4 +9,4 @@ ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o rss.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 cmis_fw_update.o cmis_cdb.o pse-pd.o plca.o \
-		   phy.o tsconfig.o mse.o
+		   phy.o tsconfig.o mse.o port.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 6e5f0f4f815a..90674aed7777 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -18,6 +18,8 @@ static u32 ethnl_bcast_seq;
 			     ETHTOOL_FLAG_OMIT_REPLY)
 #define ETHTOOL_FLAGS_STATS (ETHTOOL_FLAGS_BASIC | ETHTOOL_FLAG_STATS)
 
+char phy_interface_names[PHY_INTERFACE_MODE_MAX][ETH_GSTRING_LEN] __ro_after_init;
+
 const struct nla_policy ethnl_header_policy[] = {
 	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
 	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
@@ -421,6 +423,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_TSCONFIG_SET]	= &ethnl_tsconfig_request_ops,
 	[ETHTOOL_MSG_PHY_GET]		= &ethnl_phy_request_ops,
 	[ETHTOOL_MSG_MSE_GET]		= &ethnl_mse_request_ops,
+	[ETHTOOL_MSG_PORT_GET]		= &ethnl_port_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -1544,6 +1547,16 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.policy = ethnl_mse_get_policy,
 		.maxattr = ARRAY_SIZE(ethnl_mse_get_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_PORT_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_port_dump_start,
+		.dumpit	= ethnl_port_dumpit,
+		.done	= ethnl_port_dump_done,
+		.policy = ethnl_port_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_port_get_policy) - 1,
+	},
+
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
@@ -1566,10 +1579,23 @@ static struct genl_family ethtool_genl_family __ro_after_init = {
 
 /* module setup */
 
+static void __init ethnl_phy_names_populate(void)
+{
+	const char *name;
+	int i;
+
+	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++) {
+		name = phy_modes(i);
+		strscpy(phy_interface_names[i], name, ETH_GSTRING_LEN);
+	}
+}
+
 static int __init ethnl_init(void)
 {
 	int ret;
 
+	ethnl_phy_names_populate();
+
 	ret = genl_register_family(&ethtool_genl_family);
 	if (WARN(ret < 0, "ethtool: genetlink family registration failed"))
 		return ret;
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 89010eaa67df..e849bc63ac58 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -5,11 +5,14 @@
 
 #include <linux/ethtool_netlink.h>
 #include <linux/netdevice.h>
+#include <linux/phy.h>
 #include <net/genetlink.h>
 #include <net/sock.h>
 
 struct ethnl_req_info;
 
+extern char phy_interface_names[PHY_INTERFACE_MODE_MAX][ETH_GSTRING_LEN];
+
 u32 ethnl_bcast_seq_next(void);
 int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
 			       const struct nlattr *nest, struct net *net,
@@ -443,6 +446,7 @@ extern const struct ethnl_request_ops ethnl_mm_request_ops;
 extern const struct ethnl_request_ops ethnl_phy_request_ops;
 extern const struct ethnl_request_ops ethnl_tsconfig_request_ops;
 extern const struct ethnl_request_ops ethnl_mse_request_ops;
+extern const struct ethnl_request_ops ethnl_port_request_ops;
 
 extern const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_FLAGS + 1];
 extern const struct nla_policy ethnl_header_policy_stats[ETHTOOL_A_HEADER_FLAGS + 1];
@@ -499,6 +503,7 @@ extern const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1];
 extern const struct nla_policy ethnl_tsconfig_get_policy[ETHTOOL_A_TSCONFIG_HEADER + 1];
 extern const struct nla_policy ethnl_tsconfig_set_policy[ETHTOOL_A_TSCONFIG_MAX + 1];
 extern const struct nla_policy ethnl_mse_get_policy[ETHTOOL_A_MSE_HEADER + 1];
+extern const struct nla_policy ethnl_port_get_policy[ETHTOOL_A_PORT_ID + 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);
@@ -514,6 +519,9 @@ int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_tsinfo_done(struct netlink_callback *cb);
 int ethnl_rss_create_doit(struct sk_buff *skb, struct genl_info *info);
 int ethnl_rss_delete_doit(struct sk_buff *skb, struct genl_info *info);
+int ethnl_port_dump_start(struct netlink_callback *cb);
+int ethnl_port_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int ethnl_port_dump_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/port.c b/net/ethtool/port.c
new file mode 100644
index 000000000000..d9315355241b
--- /dev/null
+++ b/net/ethtool/port.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2026 Bootlin
+ *
+ */
+#include "common.h"
+#include "bitset.h"
+#include "netlink.h"
+
+#include <linux/phy.h>
+#include <linux/phy_link_topology.h>
+#include <linux/phy_port.h>
+#include <net/netdev_lock.h>
+
+struct port_req_info {
+	struct ethnl_req_info base;
+	u32 port_id;
+};
+
+struct port_reply_data {
+	struct ethnl_reply_data	base;
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
+	DECLARE_PHY_INTERFACE_MASK(interfaces);
+	u32 port_id;
+	bool mii;
+	bool sfp;
+	bool occupied;
+};
+
+#define PORT_REQINFO(__req_base) \
+	container_of(__req_base, struct port_req_info, base)
+
+#define PORT_REPDATA(__reply_base) \
+	container_of(__reply_base, struct port_reply_data, base)
+
+const struct nla_policy ethnl_port_get_policy[ETHTOOL_A_PORT_ID + 1] = {
+	[ETHTOOL_A_PORT_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_PORT_ID] = { .type = NLA_U32},
+};
+
+static int port_parse_request(struct ethnl_req_info *req_info,
+			      struct nlattr **tb,
+			      struct netlink_ext_ack *extack)
+{
+	struct port_req_info *request = PORT_REQINFO(req_info);
+
+	/* PORT id is required for GET requests */
+	if (tb[ETHTOOL_A_PORT_ID])
+		request->port_id = nla_get_u32(tb[ETHTOOL_A_PORT_ID]);
+
+	if (!request->port_id) {
+		NL_SET_ERR_MSG(extack, "port id missing");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int port_prepare_data(const struct ethnl_req_info *req_info,
+			     struct ethnl_reply_data *reply_data,
+			     const struct genl_info *info)
+{
+	struct port_reply_data *reply = PORT_REPDATA(reply_data);
+	struct port_req_info *request = PORT_REQINFO(req_info);
+	struct phy_port *port;
+
+	/* RTNL must be held while holding a ref to the phy_port. Here, caller
+	 * holds RTNL.
+	 */
+	port = phy_link_topo_get_port(req_info->dev, request->port_id);
+	if (!port)
+		return -ENODEV;
+
+	linkmode_copy(reply->supported, port->supported);
+	phy_interface_copy(reply->interfaces, port->interfaces);
+	reply->port_id = port->id;
+	reply->mii = port->is_mii;
+	reply->sfp = port->is_sfp;
+	reply->occupied = port->occupied;
+
+	return 0;
+}
+
+static int port_reply_size(const struct ethnl_req_info *req_info,
+			   const struct ethnl_reply_data *reply_data)
+{
+	bool compact = req_info->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	struct port_reply_data *reply = PORT_REPDATA(reply_data);
+	size_t size = 0;
+	int ret;
+
+	/* ETHTOOL_A_PORT_ID */
+	size += nla_total_size(sizeof(u32));
+
+	if (!reply->mii) {
+		/* ETHTOOL_A_PORT_SUPPORTED_MODES */
+		ret = ethnl_bitset_size(reply->supported, NULL,
+					__ETHTOOL_LINK_MODE_MASK_NBITS,
+					link_mode_names, compact);
+		if (ret < 0)
+			return ret;
+
+		size += ret;
+	} else {
+		/* ETHTOOL_A_PORT_SUPPORTED_INTERFACES */
+		ret = ethnl_bitset_size(reply->interfaces, NULL,
+					PHY_INTERFACE_MODE_MAX,
+					phy_interface_names, compact);
+		if (ret < 0)
+			return ret;
+
+		size += ret;
+	}
+
+	/* ETHTOOL_A_PORT_TYPE */
+	size += nla_total_size(sizeof(u8));
+
+	/* ETHTOOL_A_PORT_OCCUPIED */
+	size += nla_total_size(sizeof(u8));
+
+	return size;
+}
+
+static int port_fill_reply(struct sk_buff *skb,
+			   const struct ethnl_req_info *req_info,
+			   const struct ethnl_reply_data *reply_data)
+{
+	bool compact = req_info->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	struct port_reply_data *reply = PORT_REPDATA(reply_data);
+	int ret, port_type = ETHTOOL_PORT_TYPE_MDI;
+
+	if (nla_put_u32(skb, ETHTOOL_A_PORT_ID, reply->port_id))
+		return -EMSGSIZE;
+
+	if (!reply->mii) {
+		ret = ethnl_put_bitset(skb, ETHTOOL_A_PORT_SUPPORTED_MODES,
+				       reply->supported, NULL,
+				       __ETHTOOL_LINK_MODE_MASK_NBITS,
+				       link_mode_names, compact);
+		if (ret < 0)
+			return -EMSGSIZE;
+	} else {
+		ret = ethnl_put_bitset(skb, ETHTOOL_A_PORT_SUPPORTED_INTERFACES,
+				       reply->interfaces, NULL,
+				       PHY_INTERFACE_MODE_MAX,
+				       phy_interface_names, compact);
+		if (ret < 0)
+			return -EMSGSIZE;
+	}
+
+	if (reply->mii || reply->sfp)
+		port_type = ETHTOOL_PORT_TYPE_SFP;
+
+	if (nla_put_u8(skb, ETHTOOL_A_PORT_TYPE, port_type) ||
+	    nla_put_u8(skb, ETHTOOL_A_PORT_OCCUPIED, reply->occupied))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+struct port_dump_ctx {
+	struct port_req_info	*req_info;
+	struct port_reply_data	*reply_data;
+	unsigned long		ifindex;
+	unsigned long		pos_portid;
+};
+
+static struct port_dump_ctx *
+port_dump_ctx_get(struct netlink_callback *cb)
+{
+	return (struct port_dump_ctx *)cb->ctx;
+}
+
+int ethnl_port_dump_start(struct netlink_callback *cb)
+{
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
+	struct port_dump_ctx *ctx = port_dump_ctx_get(cb);
+	struct nlattr **tb = info->info.attrs;
+	struct port_reply_data *reply_data;
+	struct port_req_info *req_info;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+
+	req_info = kzalloc(sizeof(*req_info), GFP_KERNEL);
+	if (!req_info)
+		return -ENOMEM;
+
+	reply_data = kmalloc(sizeof(*reply_data), GFP_KERNEL);
+	if (!reply_data) {
+		ret = -ENOMEM;
+		goto free_req_info;
+	}
+
+	ret = ethnl_parse_header_dev_get(&req_info->base, tb[ETHTOOL_A_PORT_HEADER],
+					 genl_info_net(&info->info),
+					 info->info.extack, false);
+	if (ret < 0)
+		goto free_rep_data;
+
+	ctx->ifindex = 0;
+
+	/* For filtered DUMP requests, let's just store the ifindex. We'll check
+	 * again if the netdev is still there when looping over the netdev list
+	 * in the DUMP loop.
+	 */
+	if (req_info->base.dev) {
+		ctx->ifindex = req_info->base.dev->ifindex;
+		netdev_put(req_info->base.dev, &req_info->base.dev_tracker);
+		req_info->base.dev = NULL;
+	}
+
+	ctx->req_info = req_info;
+	ctx->reply_data = reply_data;
+
+	return 0;
+
+free_rep_data:
+	kfree(reply_data);
+free_req_info:
+	kfree(req_info);
+
+	return ret;
+}
+
+static int port_dump_one(struct sk_buff *skb, struct net_device *dev,
+			 struct netlink_callback *cb)
+{
+	struct port_dump_ctx *ctx = port_dump_ctx_get(cb);
+	void *ehdr;
+	int ret;
+
+	ehdr = ethnl_dump_put(skb, cb, ETHTOOL_A_PORT_HEADER);
+	if (!ehdr)
+		return -EMSGSIZE;
+
+	memset(ctx->reply_data, 0, sizeof(struct port_reply_data));
+	ctx->reply_data->base.dev = dev;
+
+	rtnl_lock();
+	netdev_lock_ops(dev);
+
+	ret = port_prepare_data(&ctx->req_info->base, &ctx->reply_data->base,
+				genl_info_dump(cb));
+
+	netdev_unlock_ops(dev);
+	rtnl_unlock();
+
+	if (ret < 0)
+		goto out;
+
+	ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_PORT_HEADER);
+	if (ret < 0)
+		goto out;
+
+	ret = port_fill_reply(skb, &ctx->req_info->base, &ctx->reply_data->base);
+
+out:
+	ctx->reply_data->base.dev = NULL;
+	if (ret < 0)
+		genlmsg_cancel(skb, ehdr);
+	else
+		genlmsg_end(skb, ehdr);
+
+	return ret;
+}
+
+static int port_dump_one_dev(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct port_dump_ctx *ctx = port_dump_ctx_get(cb);
+	struct net_device *dev;
+	struct phy_port *port;
+	int ret;
+
+	dev = ctx->req_info->base.dev;
+
+	if (!dev->link_topo)
+		return 0;
+
+	xa_for_each_start(&dev->link_topo->ports, ctx->pos_portid, port,
+			  ctx->pos_portid) {
+		ctx->req_info->port_id = ctx->pos_portid;
+
+		ret = port_dump_one(skb, dev, cb);
+		if (ret)
+			return ret;
+	}
+
+	ctx->pos_portid = 0;
+
+	return 0;
+}
+
+static int port_dump_all_dev(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct port_dump_ctx *ctx = port_dump_ctx_get(cb);
+	struct net *net = sock_net(skb->sk);
+	netdevice_tracker dev_tracker;
+	struct net_device *dev;
+	int ret = 0;
+
+	rcu_read_lock();
+	for_each_netdev_dump(net, dev, ctx->ifindex) {
+		netdev_hold(dev, &dev_tracker, GFP_ATOMIC);
+		rcu_read_unlock();
+
+		ctx->req_info->base.dev = dev;
+		ret = port_dump_one_dev(skb, cb);
+
+		rcu_read_lock();
+		netdev_put(dev, &dev_tracker);
+		ctx->req_info->base.dev = NULL;
+
+		if (ret < 0 && ret != -EOPNOTSUPP) {
+			if (likely(skb->len))
+				ret = skb->len;
+			break;
+		}
+		ret = 0;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+int ethnl_port_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
+	struct port_dump_ctx *ctx = port_dump_ctx_get(cb);
+	int ret = 0;
+
+	if (ctx->ifindex) {
+		netdevice_tracker dev_tracker;
+		struct net_device *dev;
+
+		dev = netdev_get_by_index(genl_info_net(&info->info),
+					  ctx->ifindex, &dev_tracker,
+					  GFP_KERNEL);
+		if (!dev)
+			return -ENODEV;
+
+		ctx->req_info->base.dev = dev;
+		ret = port_dump_one_dev(skb, cb);
+		if (ret < 0 && ret != -EOPNOTSUPP && likely(skb->len))
+			ret = skb->len;
+
+		netdev_put(dev, &dev_tracker);
+	} else {
+		ret = port_dump_all_dev(skb, cb);
+	}
+
+	return ret;
+}
+
+int ethnl_port_dump_done(struct netlink_callback *cb)
+{
+	struct port_dump_ctx *ctx = port_dump_ctx_get(cb);
+
+	kfree(ctx->req_info);
+	kfree(ctx->reply_data);
+
+	return 0;
+}
+
+const struct ethnl_request_ops ethnl_port_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_PORT_GET,
+	.reply_cmd		= ETHTOOL_MSG_PORT_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_PORT_HEADER,
+	.req_info_size		= sizeof(struct port_req_info),
+	.reply_data_size	= sizeof(struct port_reply_data),
+
+	.parse_request		= port_parse_request,
+	.prepare_data		= port_prepare_data,
+	.reply_size		= port_reply_size,
+	.fill_reply		= port_fill_reply,
+};
-- 
2.49.0

Re: [PATCH net-next v2 00/12] net: phy_port: SFP modules representation and phy_port listing

[Jakub Kicinski]

On Wed, 28 Jan 2026 21:45:13 +0100 Maxime Chevallier wrote:
> Here's V2 of the second phy_port series, this time bringing support for
> more phy_port use especially for SFP, as well as the beggining of a
> ethnl uAPI. That's a quick repost, but with the build issues and AI
> review, I think it's worth getting this version out there for review.
> 
> It builds on the recent addition of phy_port representation to enable
> listing the front-facing ports of an interface. For now, we don't control
> these ports, we merely list their presence and their capabilities.
> 
> As the most common use-case of multi-port interfaces is combo-ports that
> provide both RJ45 and SFP connectors on a single MAC, there's a lot of
> SFP stuff in this series.
> 
> This series is in 2 main parts. The first one aims at representing the
> SFP cages and modules using phy_port, as combo-ports with RJ45 + SFP are
> by far the most common cases for multi-connector setups.
> 
> The second part is the netlink interface to list those ports, now that
> most use-cases are covered.

I'll send out the AI code review. The one on patch 9 looks plausible,
not sure about the rest. LMK if none of them in fact make sense.

Re: [PATCH net-next v2 00/12] net: phy_port: SFP modules representation and phy_port listing

[Maxime Chevallier]

Hi Jakub,

On 30/01/2026 04:59, Jakub Kicinski wrote:
> On Wed, 28 Jan 2026 21:45:13 +0100 Maxime Chevallier wrote:
>> Here's V2 of the second phy_port series, this time bringing support for
>> more phy_port use especially for SFP, as well as the beggining of a
>> ethnl uAPI. That's a quick repost, but with the build issues and AI
>> review, I think it's worth getting this version out there for review.
>>
>> It builds on the recent addition of phy_port representation to enable
>> listing the front-facing ports of an interface. For now, we don't control
>> these ports, we merely list their presence and their capabilities.
>>
>> As the most common use-case of multi-port interfaces is combo-ports that
>> provide both RJ45 and SFP connectors on a single MAC, there's a lot of
>> SFP stuff in this series.
>>
>> This series is in 2 main parts. The first one aims at representing the
>> SFP cages and modules using phy_port, as combo-ports with RJ45 + SFP are
>> by far the most common cases for multi-connector setups.
>>
>> The second part is the netlink interface to list those ports, now that
>> most use-cases are covered.
> 
> I'll send out the AI code review. The one on patch 9 looks plausible,
> not sure about the rest. LMK if none of them in fact make sense.

Thanks, I'll look carefully into that :)

Maxime