net: pse-pd: Introduce attached_phydev to pse control

In preparation for reporting PSE events via ethtool notifications,
introduce an attached_phydev field in the pse_control structure.
This field stores the phy_device associated with the PSE PI,
ensuring that notifications are sent to the correct network
interface.

The attached_phydev pointer is directly tied to the PHY lifecycle. It
is set when the PHY is registered and cleared when the PHY is removed.
There is no need to use a refcount, as doing so could interfere with
the PHY removal process.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-1-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 26 insertions, 17 deletions

diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c
index aea0f0357568..9b41d4697a40 100644
--- a/drivers/net/mdio/fwnode_mdio.c
+++ b/drivers/net/mdio/fwnode_mdio.c
@@ -18,7 +18,8 @@ MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("FWNODE MDIO bus (Ethernet PHY) accessors");
 
 static struct pse_control *
-fwnode_find_pse_control(struct fwnode_handle *fwnode)
+fwnode_find_pse_control(struct fwnode_handle *fwnode,
+			struct phy_device *phydev)
 {
 	struct pse_control *psec;
 	struct device_node *np;
@@ -30,7 +31,7 @@ fwnode_find_pse_control(struct fwnode_handle *fwnode)
 	if (!np)
 		return NULL;
 
-	psec = of_pse_control_get(np);
+	psec = of_pse_control_get(np, phydev);
 	if (PTR_ERR(psec) == -ENOENT)
 		return NULL;
 
@@ -128,15 +129,9 @@ int fwnode_mdiobus_register_phy(struct mii_bus *bus,
 	u32 phy_id;
 	int rc;
 
-	psec = fwnode_find_pse_control(child);
-	if (IS_ERR(psec))
-		return PTR_ERR(psec);
-
 	mii_ts = fwnode_find_mii_timestamper(child);
-	if (IS_ERR(mii_ts)) {
-		rc = PTR_ERR(mii_ts);
-		goto clean_pse;
-	}
+	if (IS_ERR(mii_ts))
+		return PTR_ERR(mii_ts);
 
 	is_c45 = fwnode_device_is_compatible(child, "ethernet-phy-ieee802.3-c45");
 	if (is_c45 || fwnode_get_phy_id(child, &phy_id))
@@ -169,6 +164,12 @@ int fwnode_mdiobus_register_phy(struct mii_bus *bus,
 			goto clean_phy;
 	}
 
+	psec = fwnode_find_pse_control(child, phy);
+	if (IS_ERR(psec)) {
+		rc = PTR_ERR(psec);
+		goto unregister_phy;
+	}
+
 	phy->psec = psec;
 
 	/* phy->mii_ts may already be defined by the PHY driver. A
@@ -180,12 +181,13 @@ int fwnode_mdiobus_register_phy(struct mii_bus *bus,
 
 	return 0;
 
+unregister_phy:
+	if (is_acpi_node(child) || is_of_node(child))
+		phy_device_remove(phy);
 clean_phy:
 	phy_device_free(phy);
 clean_mii_ts:
 	unregister_mii_timestamper(mii_ts);
-clean_pse:
-	pse_control_put(psec);
 
 	return rc;
 }
diff --git a/drivers/net/pse-pd/pse_core.c b/drivers/net/pse-pd/pse_core.c
index 4602e26eb8c8..4610c1f0ddd6 100644
--- a/drivers/net/pse-pd/pse_core.c
+++ b/drivers/net/pse-pd/pse_core.c
@@ -23,6 +23,7 @@ static LIST_HEAD(pse_controller_list);
  * @list: list entry for the pcdev's PSE controller list
  * @id: ID of the PSE line in the PSE controller device
  * @refcnt: Number of gets of this pse_control
+ * @attached_phydev: PHY device pointer attached by the PSE control
  */
 struct pse_control {
 	struct pse_controller_dev *pcdev;
@@ -30,6 +31,7 @@ struct pse_control {
 	struct list_head list;
 	unsigned int id;
 	struct kref refcnt;
+	struct phy_device *attached_phydev;
 };
 
 static int of_load_single_pse_pi_pairset(struct device_node *node,
@@ -599,7 +601,8 @@ void pse_control_put(struct pse_control *psec)
 EXPORT_SYMBOL_GPL(pse_control_put);
 
 static struct pse_control *
-pse_control_get_internal(struct pse_controller_dev *pcdev, unsigned int index)
+pse_control_get_internal(struct pse_controller_dev *pcdev, unsigned int index,
+			 struct phy_device *phydev)
 {
 	struct pse_control *psec;
 	int ret;
@@ -638,6 +641,7 @@ pse_control_get_internal(struct pse_controller_dev *pcdev, unsigned int index)
 	psec->pcdev = pcdev;
 	list_add(&psec->list, &pcdev->pse_control_head);
 	psec->id = index;
+	psec->attached_phydev = phydev;
 	kref_init(&psec->refcnt);
 
 	return psec;
@@ -693,7 +697,8 @@ static int psec_id_xlate(struct pse_controller_dev *pcdev,
 	return pse_spec->args[0];
 }
 
-struct pse_control *of_pse_control_get(struct device_node *node)
+struct pse_control *of_pse_control_get(struct device_node *node,
+				       struct phy_device *phydev)
 {
 	struct pse_controller_dev *r, *pcdev;
 	struct of_phandle_args args;
@@ -743,7 +748,7 @@ struct pse_control *of_pse_control_get(struct device_node *node)
 	}
 
 	/* pse_list_mutex also protects the pcdev's pse_control list */
-	psec = pse_control_get_internal(pcdev, psec_id);
+	psec = pse_control_get_internal(pcdev, psec_id, phydev);
 
 out:
 	mutex_unlock(&pse_list_mutex);
diff --git a/include/linux/pse-pd/pse.h b/include/linux/pse-pd/pse.h
index c773eeb92d04..8b0866fad2ad 100644
--- a/include/linux/pse-pd/pse.h
+++ b/include/linux/pse-pd/pse.h
@@ -250,7 +250,8 @@ struct device;
 int devm_pse_controller_register(struct device *dev,
 				 struct pse_controller_dev *pcdev);
 
-struct pse_control *of_pse_control_get(struct device_node *node);
+struct pse_control *of_pse_control_get(struct device_node *node,
+				       struct phy_device *phydev);
 void pse_control_put(struct pse_control *psec);
 
 int pse_ethtool_get_status(struct pse_control *psec,
@@ -268,7 +269,8 @@ bool pse_has_c33(struct pse_control *psec);
 
 #else
 
-static inline struct pse_control *of_pse_control_get(struct device_node *node)
+static inline struct pse_control *of_pse_control_get(struct device_node *node,
+						     struct phy_device *phydev)
 {
 	return ERR_PTR(-ENOENT);
 }