diff --git a/MAINTAINERS b/MAINTAINERS
index cfe44a876d8a..ee9052bb6eb9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7953,6 +7953,8 @@ F:	include/linux/mii.h
 F:	include/linux/of_net.h
 F:	include/linux/phy.h
 F:	include/linux/phy_fixed.h
+F:	include/linux/phy_link_topology.h
+F:	include/linux/phy_link_topology_core.h
 F:	include/linux/phylib_stubs.h
 F:	include/linux/platform_data/mdio-bcm-unimac.h
 F:	include/linux/platform_data/mdio-gpio.h
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 197acfa0b412..9dff825145e4 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -2,7 +2,7 @@
 # Makefile for Linux PHY drivers
 
 libphy-y			:= phy.o phy-c45.o phy-core.o phy_device.o \
-				   linkmode.o
+				   linkmode.o phy_link_topology.o
 mdio-bus-y			+= mdio_bus.o mdio_device.o
 
 ifdef CONFIG_MDIO_DEVICE
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 2eefee970851..8478199f2d89 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -29,6 +29,7 @@
 #include <linux/phy.h>
 #include <linux/phylib_stubs.h>
 #include <linux/phy_led_triggers.h>
+#include <linux/phy_link_topology.h>
 #include <linux/pse-pd/pse.h>
 #include <linux/property.h>
 #include <linux/rtnetlink.h>
@@ -1511,6 +1512,11 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 
 		if (phydev->sfp_bus_attached)
 			dev->sfp_bus = phydev->sfp_bus;
+
+		err = phy_link_topo_add_phy(dev->link_topo, phydev,
+					    PHY_UPSTREAM_MAC, dev);
+		if (err)
+			goto error;
 	}
 
 	/* Some Ethernet drivers try to connect to a PHY device before
@@ -1938,6 +1944,7 @@ void phy_detach(struct phy_device *phydev)
 	if (dev) {
 		phydev->attached_dev->phydev = NULL;
 		phydev->attached_dev = NULL;
+		phy_link_topo_del_phy(dev->link_topo, phydev);
 	}
 	phydev->phylink = NULL;
 
diff --git a/drivers/net/phy/phy_link_topology.c b/drivers/net/phy/phy_link_topology.c
new file mode 100644
index 000000000000..985941c5c558
--- /dev/null
+++ b/drivers/net/phy/phy_link_topology.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Infrastructure to handle all PHY devices connected to a given netdev,
+ * either directly or indirectly attached.
+ *
+ * Copyright (c) 2023 Maxime Chevallier<maxime.chevallier@bootlin.com>
+ */
+
+#include <linux/phy_link_topology.h>
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+#include <linux/rtnetlink.h>
+#include <linux/xarray.h>
+
+struct phy_link_topology *phy_link_topo_create(struct net_device *dev)
+{
+	struct phy_link_topology *topo;
+
+	topo = kzalloc(sizeof(*topo), GFP_KERNEL);
+	if (!topo)
+		return ERR_PTR(-ENOMEM);
+
+	xa_init_flags(&topo->phys, XA_FLAGS_ALLOC1);
+	topo->next_phy_index = 1;
+
+	return topo;
+}
+
+void phy_link_topo_destroy(struct phy_link_topology *topo)
+{
+	if (!topo)
+		return;
+
+	xa_destroy(&topo->phys);
+	kfree(topo);
+}
+
+int phy_link_topo_add_phy(struct phy_link_topology *topo,
+			  struct phy_device *phy,
+			  enum phy_upstream upt, void *upstream)
+{
+	struct phy_device_node *pdn;
+	int ret;
+
+	pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
+	if (!pdn)
+		return -ENOMEM;
+
+	pdn->phy = phy;
+	switch (upt) {
+	case PHY_UPSTREAM_MAC:
+		pdn->upstream.netdev = (struct net_device *)upstream;
+		if (phy_on_sfp(phy))
+			pdn->parent_sfp_bus = pdn->upstream.netdev->sfp_bus;
+		break;
+	case PHY_UPSTREAM_PHY:
+		pdn->upstream.phydev = (struct phy_device *)upstream;
+		if (phy_on_sfp(phy))
+			pdn->parent_sfp_bus = pdn->upstream.phydev->sfp_bus;
+		break;
+	default:
+		ret = -EINVAL;
+		goto err;
+	}
+	pdn->upstream_type = upt;
+
+	/* Attempt to re-use a previously allocated phy_index */
+	if (phy->phyindex) {
+		ret = xa_insert(&topo->phys, phy->phyindex, pdn, GFP_KERNEL);
+
+		/* Errors could be either -ENOMEM or -EBUSY. If the phy has an
+		 * index, and there's another entry at the same index, this is
+		 * unexpected and we still error-out
+		 */
+		if (ret)
+			goto err;
+		return 0;
+	}
+
+	ret = xa_alloc_cyclic(&topo->phys, &phy->phyindex, pdn, xa_limit_32b,
+			      &topo->next_phy_index, GFP_KERNEL);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	kfree(pdn);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_link_topo_add_phy);
+
+void phy_link_topo_del_phy(struct phy_link_topology *topo,
+			   struct phy_device *phy)
+{
+	struct phy_device_node *pdn = xa_erase(&topo->phys, phy->phyindex);
+
+	/* We delete the PHY from the topology, however we don't re-set the
+	 * phy->phyindex field. If the PHY isn't gone, we can re-assign it the
+	 * same index next time it's added back to the topology
+	 */
+
+	kfree(pdn);
+}
+EXPORT_SYMBOL_GPL(phy_link_topo_del_phy);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 09023e44db4e..9f1a137d07c1 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -40,7 +40,6 @@
 #include <net/dcbnl.h>
 #endif
 #include <net/netprio_cgroup.h>
-
 #include <linux/netdev_features.h>
 #include <linux/neighbour.h>
 #include <uapi/linux/netdevice.h>
@@ -52,6 +51,7 @@
 #include <net/net_trackers.h>
 #include <net/net_debug.h>
 #include <net/dropreason-core.h>
+#include <linux/phy_link_topology_core.h>
 
 struct netpoll_info;
 struct device;
@@ -2056,6 +2056,7 @@ enum netdev_reg_state {
  *	@fcoe_ddp_xid:	Max exchange id for FCoE LRO by ddp
  *
  *	@priomap:	XXX: need comments on this one
+ *	@link_topo:	Physical link topology tracking attached PHYs
  *	@phydev:	Physical device may attach itself
  *			for hardware timestamping
  *	@sfp_bus:	attached &struct sfp_bus structure.
@@ -2444,6 +2445,7 @@ struct net_device {
 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
 	struct netprio_map __rcu *priomap;
 #endif
+	struct phy_link_topology	*link_topo;
 	struct phy_device	*phydev;
 	struct sfp_bus		*sfp_bus;
 	struct lock_class_key	*qdisc_tx_busylock;
diff --git a/include/linux/phy.h b/include/linux/phy.h
index e3ab2c347a59..236b95472865 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -549,6 +549,9 @@ struct macsec_ops;
  * @drv: Pointer to the driver for this PHY instance
  * @devlink: Create a link between phy dev and mac dev, if the external phy
  *           used by current mac interface is managed by another mac interface.
+ * @phyindex: Unique id across the phy's parent tree of phys to address the PHY
+ *	      from userspace, similar to ifindex. A zero index means the PHY
+ *	      wasn't assigned an id yet.
  * @phy_id: UID for this device found during discovery
  * @c45_ids: 802.3-c45 Device Identifiers if is_c45.
  * @is_c45:  Set to true if this PHY uses clause 45 addressing.
@@ -647,6 +650,7 @@ struct phy_device {
 
 	struct device_link *devlink;
 
+	u32 phyindex;
 	u32 phy_id;
 
 	struct phy_c45_device_ids c45_ids;
diff --git a/include/linux/phy_link_topology.h b/include/linux/phy_link_topology.h
new file mode 100644
index 000000000000..6b79feb607e7
--- /dev/null
+++ b/include/linux/phy_link_topology.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * PHY device list allow maintaining a list of PHY devices that are
+ * part of a netdevice's link topology. PHYs can for example be chained,
+ * as is the case when using a PHY that exposes an SFP module, on which an
+ * SFP transceiver that embeds a PHY is connected.
+ *
+ * This list can then be used by userspace to leverage individual PHY
+ * capabilities.
+ */
+#ifndef __PHY_LINK_TOPOLOGY_H
+#define __PHY_LINK_TOPOLOGY_H
+
+#include <linux/ethtool.h>
+#include <linux/phy_link_topology_core.h>
+
+struct xarray;
+struct phy_device;
+struct net_device;
+struct sfp_bus;
+
+struct phy_device_node {
+	enum phy_upstream upstream_type;
+
+	union {
+		struct net_device	*netdev;
+		struct phy_device	*phydev;
+	} upstream;
+
+	struct sfp_bus *parent_sfp_bus;
+
+	struct phy_device *phy;
+};
+
+struct phy_link_topology {
+	struct xarray phys;
+	u32 next_phy_index;
+};
+
+static inline struct phy_device *
+phy_link_topo_get_phy(struct phy_link_topology *topo, u32 phyindex)
+{
+	struct phy_device_node *pdn = xa_load(&topo->phys, phyindex);
+
+	if (pdn)
+		return pdn->phy;
+
+	return NULL;
+}
+
+#if IS_REACHABLE(CONFIG_PHYLIB)
+int phy_link_topo_add_phy(struct phy_link_topology *topo,
+			  struct phy_device *phy,
+			  enum phy_upstream upt, void *upstream);
+
+void phy_link_topo_del_phy(struct phy_link_topology *lt, struct phy_device *phy);
+
+#else
+static inline int phy_link_topo_add_phy(struct phy_link_topology *topo,
+					struct phy_device *phy,
+					enum phy_upstream upt, void *upstream)
+{
+	return 0;
+}
+
+static inline void phy_link_topo_del_phy(struct phy_link_topology *topo,
+					 struct phy_device *phy)
+{
+}
+#endif
+
+#endif /* __PHY_LINK_TOPOLOGY_H */
diff --git a/include/linux/phy_link_topology_core.h b/include/linux/phy_link_topology_core.h
new file mode 100644
index 000000000000..0a6479055745
--- /dev/null
+++ b/include/linux/phy_link_topology_core.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PHY_LINK_TOPOLOGY_CORE_H
+#define __PHY_LINK_TOPOLOGY_CORE_H
+
+struct phy_link_topology;
+
+#if IS_REACHABLE(CONFIG_PHYLIB)
+
+struct phy_link_topology *phy_link_topo_create(struct net_device *dev);
+void phy_link_topo_destroy(struct phy_link_topology *topo);
+
+#else
+
+static inline struct phy_link_topology *phy_link_topo_create(struct net_device *dev)
+{
+	return NULL;
+}
+
+static inline void phy_link_topo_destroy(struct phy_link_topology *topo)
+{
+}
+
+#endif
+
+#endif /* __PHY_LINK_TOPOLOGY_CORE_H */
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 06ef6b78b7de..01ba529dbb6d 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -2220,4 +2220,20 @@ struct ethtool_link_settings {
 	 * __u32 map_lp_advertising[link_mode_masks_nwords];
 	 */
 };
+
+/**
+ * enum phy_upstream - Represents the upstream component a given PHY device
+ * is connected to, as in what is on the other end of the MII bus. Most PHYs
+ * will be attached to an Ethernet MAC controller, but in some cases, there's
+ * an intermediate PHY used as a media-converter, which will driver another
+ * MII interface as its output.
+ * @PHY_UPSTREAM_MAC: Upstream component is a MAC (a switch port,
+ *		      or ethernet controller)
+ * @PHY_UPSTREAM_PHY: Upstream component is a PHY (likely a media converter)
+ */
+enum phy_upstream {
+	PHY_UPSTREAM_MAC,
+	PHY_UPSTREAM_PHY,
+};
+
 #endif /* _UAPI_LINUX_ETHTOOL_H */
diff --git a/net/core/dev.c b/net/core/dev.c
index 275fd5259a4a..a1124a72f77c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -155,6 +155,7 @@
 #include <net/netdev_rx_queue.h>
 #include <net/page_pool/types.h>
 #include <net/page_pool/helpers.h>
+#include <linux/phy_link_topology_core.h>
 
 #include "dev.h"
 #include "net-sysfs.h"
@@ -10920,6 +10921,12 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
 #ifdef CONFIG_NET_SCHED
 	hash_init(dev->qdisc_hash);
 #endif
+	dev->link_topo = phy_link_topo_create(dev);
+	if (IS_ERR(dev->link_topo)) {
+		dev->link_topo = NULL;
+		goto free_all;
+	}
+
 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
 	setup(dev);
 
@@ -11008,6 +11015,8 @@ void free_netdev(struct net_device *dev)
 	free_percpu(dev->xdp_bulkq);
 	dev->xdp_bulkq = NULL;
 
+	phy_link_topo_destroy(dev->link_topo);
+
 	/*  Compatibility with error handling in drivers */
 	if (dev->reg_state == NETREG_UNINITIALIZED) {
 		netdev_freemem(dev);
