diff --git a/drivers/net/mdio/of_mdio.c b/drivers/net/mdio/of_mdio.c
index 051e449bbe7c..a8313b3721f6 100644
--- a/drivers/net/mdio/of_mdio.c
+++ b/drivers/net/mdio/of_mdio.c
@@ -13,6 +13,7 @@
 #include <linux/fwnode_mdio.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/netdevice.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
@@ -20,6 +21,8 @@
 #include <linux/of_net.h>
 #include <linux/phy.h>
 #include <linux/phy_fixed.h>
+#include <linux/sched.h>
+#include <linux/string.h>
 
 #define DEFAULT_GPIO_RESET_DELAY	10	/* in microseconds */
 
@@ -27,6 +30,52 @@ MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("OpenFirmware MDIO bus (Ethernet PHY) accessors");
 
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+/*
+ * OF changes can nest when probing one MDIO device enables another node on
+ * the same bus. Serialize independent changes while allowing that nesting.
+ */
+static DEFINE_MUTEX(of_mdio_reconfig_mutex);
+static struct task_struct *of_mdio_reconfig_owner;
+static unsigned int of_mdio_reconfig_depth;
+
+static void of_mdio_reconfig_lock(void)
+{
+	if (!mutex_trylock(&of_mdio_reconfig_mutex)) {
+		if (of_mdio_reconfig_owner == current) {
+			of_mdio_reconfig_depth++;
+			return;
+		}
+		mutex_lock(&of_mdio_reconfig_mutex);
+	}
+
+	WARN_ON_ONCE(of_mdio_reconfig_owner);
+	WARN_ON_ONCE(of_mdio_reconfig_depth);
+	of_mdio_reconfig_owner = current;
+	of_mdio_reconfig_depth = 1;
+}
+
+static void of_mdio_reconfig_unlock(void)
+{
+	WARN_ON_ONCE(of_mdio_reconfig_owner != current);
+	WARN_ON_ONCE(!of_mdio_reconfig_depth);
+
+	if (--of_mdio_reconfig_depth)
+		return;
+
+	of_mdio_reconfig_owner = NULL;
+	mutex_unlock(&of_mdio_reconfig_mutex);
+}
+#else
+static inline void of_mdio_reconfig_lock(void)
+{
+}
+
+static inline void of_mdio_reconfig_unlock(void)
+{
+}
+#endif
+
 /* Extract the clause 22 phy ID from the compatible string of the form
  * ethernet-phy-idAAAA.BBBB */
 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
@@ -44,7 +93,7 @@ int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
 EXPORT_SYMBOL(of_mdiobus_phy_device_register);
 
 static int of_mdiobus_register_phy(struct mii_bus *mdio,
-				    struct device_node *child, u32 addr)
+				   struct device_node *child, u32 addr)
 {
 	return fwnode_mdiobus_register_phy(mdio, of_fwnode_handle(child), addr);
 }
@@ -80,10 +129,20 @@ static int of_mdiobus_register_device(struct mii_bus *mdio,
 static int of_mdiobus_register_child(struct mii_bus *mdio,
 				     struct device_node *child, u32 addr)
 {
+	int rc;
+
+	if (of_node_test_and_set_flag(child, OF_POPULATED))
+		return 0;
+
 	if (of_mdiobus_child_is_phy(child))
-		return of_mdiobus_register_phy(mdio, child, addr);
+		rc = of_mdiobus_register_phy(mdio, child, addr);
+	else
+		rc = of_mdiobus_register_device(mdio, child, addr);
 
-	return of_mdiobus_register_device(mdio, child, addr);
+	if (rc)
+		of_node_clear_flag(child, OF_POPULATED);
+
+	return rc;
 }
 
 /* The following is a list of PHY compatible strings which appear in
@@ -255,13 +314,21 @@ int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
 	if (rc)
 		return rc;
 
+	of_mdio_reconfig_lock();
+	rc = mdiobus_device_change_begin(mdio, false);
+	if (rc) {
+		of_mdio_reconfig_unlock();
+		mdiobus_unregister(mdio);
+		return rc;
+	}
+
 	/* Loop over the child nodes and register a phy_device for each phy */
 	rc = __of_mdiobus_parse_phys(mdio, np, &scanphys);
 	if (rc)
-		goto unregister;
+		goto out_change;
 
 	if (!scanphys)
-		return 0;
+		goto out_change;
 
 	/* auto scan for PHYs with empty reg property */
 	for_each_available_child_of_node(np, child) {
@@ -272,19 +339,380 @@ int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
 
 		rc = of_mdiobus_scan_phy(mdio, child);
 		if (rc && rc != -ENODEV)
-			goto put_unregister;
+			goto put_child;
+		rc = 0;
 	}
 
-	return 0;
+out_change:
+	mdiobus_device_change_end(mdio, false);
+	of_mdio_reconfig_unlock();
+	if (!rc)
+		return 0;
 
-put_unregister:
-	of_node_put(child);
-unregister:
 	mdiobus_unregister(mdio);
 	return rc;
+
+put_child:
+	of_node_put(child);
+	goto out_change;
 }
 EXPORT_SYMBOL(__of_mdiobus_register);
 
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+static bool of_mdiobus_node_is_available(struct device_node *node)
+{
+	return !of_node_check_flag(node, OF_DETACHED) &&
+	       of_device_is_available(node);
+}
+
+static int of_mdiobus_add_node(struct mii_bus *mdio,
+			       struct device_node *node)
+{
+	struct device_node *child;
+	int addr, rc, ret = 0;
+
+	if (!of_mdiobus_node_is_available(node))
+		return 0;
+
+	if (of_node_name_eq(node, "ethernet-phy-package")) {
+		if (!of_property_present(node, "reg"))
+			return 0;
+
+		for_each_available_child_of_node(node, child) {
+			rc = of_mdiobus_add_node(mdio, child);
+			if (rc && rc != -ENODEV && !ret)
+				ret = rc;
+		}
+
+		return ret;
+	}
+
+	addr = of_mdio_parse_addr(&mdio->dev, node);
+	if (addr < 0)
+		rc = of_mdiobus_scan_phy(mdio, node);
+	else
+		rc = of_mdiobus_register_child(mdio, node, addr);
+
+	if (rc == -ENODEV && addr >= 0)
+		dev_err(&mdio->dev,
+			"MDIO device at address %d is missing.\n", addr);
+
+	return rc;
+}
+
+static bool of_mdiobus_node_is_busy(struct mii_bus *mdio,
+				    struct device_node *node)
+{
+	struct mdio_device *mdiodev;
+	bool busy = false;
+
+	if (of_node_name_eq(node, "ethernet-phy-package")) {
+		for_each_child_of_node_scoped(node, child) {
+			if (of_mdiobus_node_is_busy(mdio, child))
+				return true;
+		}
+
+		return false;
+	}
+
+	if (!of_node_check_flag(node, OF_POPULATED))
+		return false;
+
+	mdiodev = of_mdio_find_device(node);
+	if (!mdiodev)
+		return true;
+	if (mdiodev->bus != mdio) {
+		put_device(&mdiodev->dev);
+		return false;
+	}
+
+	mutex_lock(&mdio->mdio_map_lock);
+	busy = mdio->mdio_map[mdiodev->addr] != mdiodev ||
+	       (mdio->mdio_map_pending & BIT(mdiodev->addr));
+	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
+		struct phy_device *phydev = to_phy_device(&mdiodev->dev);
+
+		if (phydev->attached) {
+			busy = true;
+			dev_warn(&mdiodev->dev,
+				 "cannot remove an attached PHY; remove its consumer first\n");
+		}
+	}
+	mutex_unlock(&mdio->mdio_map_lock);
+	put_device(&mdiodev->dev);
+
+	return busy;
+}
+
+static struct device_node *
+of_mdiobus_get_removal_scope(struct device_node *node)
+{
+	struct device_node *parent;
+
+	if (of_node_name_eq(node, "ethernet-phy-package"))
+		return of_node_get(node);
+
+	parent = of_get_parent(node);
+	if (of_node_name_eq(parent, "ethernet-phy-package"))
+		return parent;
+
+	of_node_put(parent);
+	return of_node_get(node);
+}
+
+static int of_mdiobus_remove_node(struct mii_bus *mdio,
+				  struct device_node *node)
+{
+	struct mdio_device *mdiodev;
+	struct device_node *child;
+	int ret;
+
+	if (of_node_name_eq(node, "ethernet-phy-package")) {
+		for_each_child_of_node(node, child) {
+			ret = of_mdiobus_remove_node(mdio, child);
+			if (ret) {
+				of_node_put(child);
+				return ret;
+			}
+		}
+		return 0;
+	}
+
+	if (!of_node_check_flag(node, OF_POPULATED))
+		return 0;
+
+	/* The OF node lookup also covers PHYs found by address scanning. */
+	mdiodev = of_mdio_find_device(node);
+	if (!mdiodev)
+		return -EBUSY;
+	if (mdiodev->bus != mdio) {
+		put_device(&mdiodev->dev);
+		return -ENODEV;
+	}
+
+	ret = mdiodev->device_remove_dynamic(mdiodev);
+	if (!ret)
+		mdiodev->device_free(mdiodev);
+	put_device(&mdiodev->dev);
+
+	return ret == -ENODEV ? 0 : ret;
+}
+
+static struct mii_bus *of_mdiobus_find_parent(struct device_node *node)
+{
+	struct device_node *parent, *bus_node;
+	struct mii_bus *mdio;
+
+	parent = of_get_parent(node);
+	if (!parent)
+		return NULL;
+
+	if (of_node_name_eq(parent, "ethernet-phy-package")) {
+		if (!of_device_is_available(parent) ||
+		    !of_property_present(parent, "reg")) {
+			of_node_put(parent);
+			return NULL;
+		}
+
+		bus_node = of_get_parent(parent);
+		of_node_put(parent);
+	} else {
+		bus_node = parent;
+	}
+
+	mdio = of_mdio_find_bus(bus_node);
+	of_node_put(bus_node);
+
+	return mdio;
+}
+
+#if IS_ENABLED(CONFIG_OF_OVERLAY)
+/* Overlay entry notifier errors cannot stop removal after the tree changed. */
+static bool of_mdiobus_live_node_is_busy(struct device_node *node)
+{
+	struct device_node *scope;
+	struct mii_bus *mdio;
+	bool busy = true;
+
+	scope = of_mdiobus_get_removal_scope(node);
+	mdio = of_mdiobus_find_parent(scope);
+	if (!mdio)
+		goto out_put_scope;
+
+	if (!mdiobus_device_change_begin(mdio, true)) {
+		busy = of_mdiobus_node_is_busy(mdio, scope);
+		mdiobus_device_change_end(mdio, true);
+	}
+	put_device(&mdio->dev);
+
+out_put_scope:
+	of_node_put(scope);
+	return busy;
+}
+
+static struct device_node *
+of_mdiobus_overlay_target_child(struct device_node *target,
+				struct device_node *overlay_child)
+{
+	const char *name = kbasename(overlay_child->full_name);
+	struct device_node *child;
+
+	for_each_child_of_node(target, child) {
+		if (!of_node_cmp(kbasename(child->full_name), name))
+			return child;
+	}
+
+	return NULL;
+}
+
+static bool of_mdiobus_overlay_node_is_busy(struct device_node *overlay,
+					    struct device_node *target,
+					    bool added)
+{
+	struct device_node *overlay_child, *target_child;
+	bool busy, child_added;
+
+	if ((added || of_property_present(overlay, "status")) &&
+	    of_mdiobus_live_node_is_busy(target))
+		return true;
+
+	for_each_child_of_node(overlay, overlay_child) {
+		target_child = of_mdiobus_overlay_target_child(target,
+							       overlay_child);
+		if (!target_child)
+			continue;
+
+		child_added = of_node_check_flag(target_child, OF_OVERLAY);
+		busy = of_mdiobus_overlay_node_is_busy(overlay_child,
+						       target_child, child_added);
+		of_node_put(target_child);
+		if (busy) {
+			of_node_put(overlay_child);
+			return true;
+		}
+	}
+
+	return false;
+}
+
+static int of_mdiobus_overlay_notify(struct notifier_block *nb,
+				     unsigned long action, void *arg)
+{
+	struct of_overlay_notify_data *nd = arg;
+	bool busy;
+
+	if (action != OF_OVERLAY_PRE_REMOVE)
+		return NOTIFY_OK;
+
+	of_mdio_reconfig_lock();
+	busy = of_mdiobus_overlay_node_is_busy(nd->overlay, nd->target,
+					       false);
+	of_mdio_reconfig_unlock();
+
+	return busy ? notifier_from_errno(-EBUSY) : NOTIFY_OK;
+}
+
+static struct notifier_block of_mdio_overlay_notifier = {
+	.notifier_call = of_mdiobus_overlay_notify,
+};
+#endif
+
+static int of_mdiobus_notify(struct notifier_block *nb, unsigned long action,
+			     void *arg)
+{
+	struct of_reconfig_data *rd = arg;
+	struct device_node *scope;
+	struct mii_bus *mdio;
+	enum of_reconfig_change change;
+	bool removing;
+	int rc, ret = NOTIFY_OK;
+
+	of_mdio_reconfig_lock();
+	change = of_reconfig_get_state_change(action, rd);
+	switch (change) {
+	case OF_RECONFIG_CHANGE_ADD:
+		/* A newer change may have made this notification stale. */
+		if (!of_mdiobus_node_is_available(rd->dn))
+			goto out_unlock;
+		removing = false;
+		break;
+	case OF_RECONFIG_CHANGE_REMOVE:
+		/* A newer change may have made this notification stale. */
+		if (of_mdiobus_node_is_available(rd->dn))
+			goto out_unlock;
+		removing = true;
+		break;
+	default:
+		goto out_unlock;
+	}
+
+	mdio = of_mdiobus_find_parent(rd->dn);
+	if (!mdio)
+		goto out_unlock;
+
+	rc = mdiobus_device_change_begin(mdio, removing);
+	if (rc) {
+		if (!removing)
+			ret = notifier_from_errno(-EPROBE_DEFER);
+		goto out_put_mdio;
+	}
+
+	if (!removing) {
+		rc = of_mdiobus_add_node(mdio, rd->dn);
+	} else {
+		/* The node may already be detached from its parent hierarchy. */
+		scope = of_mdiobus_get_removal_scope(rd->dn);
+		if (of_mdiobus_node_is_busy(mdio, scope))
+			rc = -EBUSY;
+		else
+			rc = of_mdiobus_remove_node(mdio, rd->dn);
+		of_node_put(scope);
+	}
+
+	mdiobus_device_change_end(mdio, removing);
+	if (rc && (removing || rc != -ENODEV))
+		ret = notifier_from_errno(rc);
+
+out_put_mdio:
+	put_device(&mdio->dev);
+out_unlock:
+	of_mdio_reconfig_unlock();
+
+	return ret;
+}
+
+static struct notifier_block of_mdio_notifier = {
+	.notifier_call = of_mdiobus_notify,
+};
+
+static int __init of_mdio_init(void)
+{
+	int ret;
+
+	ret = of_reconfig_notifier_register(&of_mdio_notifier);
+	if (ret)
+		return ret;
+
+#if IS_ENABLED(CONFIG_OF_OVERLAY)
+	ret = of_overlay_notifier_register(&of_mdio_overlay_notifier);
+	if (ret)
+		of_reconfig_notifier_unregister(&of_mdio_notifier);
+#endif
+
+	return ret;
+}
+module_init(of_mdio_init);
+
+static void __exit of_mdio_exit(void)
+{
+#if IS_ENABLED(CONFIG_OF_OVERLAY)
+	of_overlay_notifier_unregister(&of_mdio_overlay_notifier);
+#endif
+	of_reconfig_notifier_unregister(&of_mdio_notifier);
+}
+module_exit(of_mdio_exit);
+#endif /* CONFIG_OF_DYNAMIC */
+
 /**
  * of_mdio_find_device - Given a device tree node, find the mdio_device
  * @np: pointer to the mdio_device's device tree node