1 files changed, 82 insertions, 0 deletions
diff --git a/include/linux/phy_link_topology.h b/include/linux/phy_link_topology.h
new file mode 100644
index 000000000000..68a59e25821c
--- /dev/null
+++ b/include/linux/phy_link_topology.h
@@ -0,0 +1,82 @@
+/* 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/netdevice.h>
+
+struct xarray;
+struct phy_device;
+struct sfp_bus;
+
+struct phy_link_topology {
+	struct xarray phys;
+	u32 next_phy_index;
+};
+
+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;
+};
+
+#if IS_ENABLED(CONFIG_PHYLIB)
+int phy_link_topo_add_phy(struct net_device *dev,
+			  struct phy_device *phy,
+			  enum phy_upstream upt, void *upstream);
+
+void phy_link_topo_del_phy(struct net_device *dev, struct phy_device *phy);
+
+static inline struct phy_device *
+phy_link_topo_get_phy(struct net_device *dev, u32 phyindex)
+{
+	struct phy_link_topology *topo = dev->link_topo;
+	struct phy_device_node *pdn;
+
+	if (!topo)
+		return NULL;
+
+	pdn = xa_load(&topo->phys, phyindex);
+	if (pdn)
+		return pdn->phy;
+
+	return NULL;
+}
+
+#else
+static inline int phy_link_topo_add_phy(struct net_device *dev,
+					struct phy_device *phy,
+					enum phy_upstream upt, void *upstream)
+{
+	return 0;
+}
+
+static inline void phy_link_topo_del_phy(struct net_device *dev,
+					 struct phy_device *phy)
+{
+}
+
+static inline struct phy_device *
+phy_link_topo_get_phy(struct net_device *dev, u32 phyindex)
+{
+	return NULL;
+}
+#endif
+
+#endif /* __PHY_LINK_TOPOLOGY_H */