Merge branch 'phy-listing-and-topology-tracking'

Maxime Chevallier says:

====================
Introduce PHY listing and link_topology tracking

This is V18 of the phy_link_topology series, aiming at improving support
for multiple PHYs being attached to the same MAC.

V18 is a simple rebase of the V17 on top of net-next, gathering the
tested-by and reviewed-by tags from Christophe (thanks !).

This iteration is also one patch shorter than V17 (patch 12/14 in V17 is gone),
as one of the patches used to fix an issue that has now been resolved by
Simon Horman in

743ff02152bc ethtool: Don't check for NULL info in prepare_data callbacks

As a remainder, here's what the PHY listings would look like :
 - eth0 has a 88x3310 acting as media converter, and an SFP module with
   an embedded 88e1111 PHY
 - eth2 has a 88e1510 PHY

PHY for eth0:
PHY index: 1
Driver name: mv88x3310
PHY device name: f212a600.mdio-mii:00
Downstream SFP bus name: sfp-eth0
Upstream type: MAC

PHY for eth0:
PHY index: 2
Driver name: Marvell 88E1111
PHY device name: i2c:sfp-eth0:16
Upstream type: PHY
Upstream PHY index: 1
Upstream SFP name: sfp-eth0

PHY for eth2:
PHY index: 1
Driver name: Marvell 88E1510
PHY device name: f212a200.mdio-mii:00
Upstream type: MAC

Ethtool patches : https://github.com/minimaxwell/ethtool/tree/mc/topo-v16
(this branch is compatible with this V18 series)

Link to V17: https://lore.kernel.org/netdev/20240709063039.2909536-1-maxime.chevallier@bootlin.com/
Link to V16: https://lore.kernel.org/netdev/20240705132706.13588-1-maxime.chevallier@bootlin.com/
Link to V15: https://lore.kernel.org/netdev/20240703140806.271938-1-maxime.chevallier@bootlin.com/
Link to V14: https://lore.kernel.org/netdev/20240701131801.1227740-1-maxime.chevallier@bootlin.com/
Link to V13: https://lore.kernel.org/netdev/20240607071836.911403-1-maxime.chevallier@bootlin.com/
Link to v12: https://lore.kernel.org/netdev/20240605124920.720690-1-maxime.chevallier@bootlin.com/
Link to v11: https://lore.kernel.org/netdev/20240404093004.2552221-1-maxime.chevallier@bootlin.com/
Link to V10: https://lore.kernel.org/netdev/20240304151011.1610175-1-maxime.chevallier@bootlin.com/
Link to V9: https://lore.kernel.org/netdev/20240228114728.51861-1-maxime.chevallier@bootlin.com/
Link to V8: https://lore.kernel.org/netdev/20240220184217.3689988-1-maxime.chevallier@bootlin.com/
Link to V7: https://lore.kernel.org/netdev/20240213150431.1796171-1-maxime.chevallier@bootlin.com/
Link to V6: https://lore.kernel.org/netdev/20240126183851.2081418-1-maxime.chevallier@bootlin.com/
Link to V5: https://lore.kernel.org/netdev/20231221180047.1924733-1-maxime.chevallier@bootlin.com/
Link to V4: https://lore.kernel.org/netdev/20231215171237.1152563-1-maxime.chevallier@bootlin.com/
Link to V3: https://lore.kernel.org/netdev/20231201163704.1306431-1-maxime.chevallier@bootlin.com/
Link to V2: https://lore.kernel.org/netdev/20231117162323.626979-1-maxime.chevallier@bootlin.com/
Link to V1: https://lore.kernel.org/netdev/20230907092407.647139-1-maxime.chevallier@bootlin.com/

More discussions on specific issues that happened in 6.9-rc:

https://lore.kernel.org/netdev/20240412104615.3779632-1-maxime.chevallier@bootlin.com/
https://lore.kernel.org/netdev/20240429131008.439231-1-maxime.chevallier@bootlin.com/
https://lore.kernel.org/netdev/20240507102822.2023826-1-maxime.chevallier@bootlin.com/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 98 insertions, 2 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 614ec5d3d75b..289a6133769c 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 <linux/netdevice_xmit.h>
@@ -81,6 +80,7 @@ struct xdp_frame;
 struct xdp_metadata_ops;
 struct xdp_md;
 struct ethtool_netdev_state;
+struct phy_link_topology;
 
 typedef u32 xdp_features_t;
 
@@ -1951,6 +1951,7 @@ 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.
@@ -2342,6 +2343,7 @@ 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 6b7d40d49129..a98bc91a0cde 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -554,6 +554,9 @@ 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.
@@ -656,6 +659,7 @@ struct phy_device {
 
 	struct device_link *devlink;
 
+	u32 phyindex;
 	u32 phy_id;
 
 	struct phy_c45_device_ids c45_ids;
@@ -1777,6 +1781,8 @@ int phy_suspend(struct phy_device *phydev);
 int phy_resume(struct phy_device *phydev);
 int __phy_resume(struct phy_device *phydev);
 int phy_loopback(struct phy_device *phydev, bool enable);
+int phy_sfp_connect_phy(void *upstream, struct phy_device *phy);
+void phy_sfp_disconnect_phy(void *upstream, struct phy_device *phy);
 void phy_sfp_attach(void *upstream, struct sfp_bus *bus);
 void phy_sfp_detach(void *upstream, struct sfp_bus *bus);
 int phy_sfp_probe(struct phy_device *phydev,
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 */
diff --git a/include/linux/sfp.h b/include/linux/sfp.h
index b14be59550e3..60c65cea74f6 100644
--- a/include/linux/sfp.h
+++ b/include/linux/sfp.h
@@ -550,7 +550,7 @@ struct sfp_upstream_ops {
 	void (*link_down)(void *priv);
 	void (*link_up)(void *priv);
 	int (*connect_phy)(void *priv, struct phy_device *);
-	void (*disconnect_phy)(void *priv);
+	void (*disconnect_phy)(void *priv, struct phy_device *);
 };
 
 #if IS_ENABLED(CONFIG_SFP)
@@ -576,6 +576,7 @@ struct sfp_bus *sfp_bus_find_fwnode(const struct fwnode_handle *fwnode);
 int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
 			 const struct sfp_upstream_ops *ops);
 void sfp_bus_del_upstream(struct sfp_bus *bus);
+const char *sfp_get_name(struct sfp_bus *bus);
 #else
 static inline int sfp_parse_port(struct sfp_bus *bus,
 				 const struct sfp_eeprom_id *id,
@@ -654,6 +655,11 @@ static inline int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
 static inline void sfp_bus_del_upstream(struct sfp_bus *bus)
 {
 }
+
+static inline const char *sfp_get_name(struct sfp_bus *bus)
+{
+	return NULL;
+}
 #endif
 
 #endif