Merge branch 'phy-listing-link_topology-tracking'

Maxime Chevallier says:

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

This is V11 for the link topology addition, allowing to track all PHYs
that are linked to netdevices.

This V11 addresses the various netlink-related issues that were raised
by Jakub, and fixes some typos in the documentation.

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
PHY id: 0
Upstream type: MAC

PHY for eth0:
PHY index: 2
Driver name: Marvell 88E1111
PHY device name: i2c:sfp-eth0:16
PHY id: 21040322
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
PHY id: 21040593
Upstream type: MAC

Ethtool patches : https://github.com/minimaxwell/ethtool/tree/link-topo-v6
====================

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

3 files changed, 60 insertions, 2 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 92f5bddbc2de..854a3a28a8d8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -158,6 +158,7 @@
 #include <net/page_pool/types.h>
 #include <net/page_pool/helpers.h>
 #include <net/rps.h>
+#include <linux/phy_link_topology_core.h>
 
 #include "dev.h"
 #include "net-sysfs.h"
@@ -10962,6 +10963,12 @@ 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);
 
@@ -11050,6 +11057,8 @@ 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);
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index bd04f28d5cf4..563e94e0cbd8 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -4,6 +4,7 @@
 #include <linux/ethtool_netlink.h>
 #include <linux/pm_runtime.h>
 #include "netlink.h"
+#include <linux/phy_link_topology.h>
 
 static struct genl_family ethtool_genl_family;
 
@@ -30,6 +31,24 @@ const struct nla_policy ethnl_header_policy_stats[] = {
 							  ETHTOOL_FLAGS_STATS),
 };
 
+const struct nla_policy ethnl_header_policy_phy[] = {
+	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
+	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
+					    .len = ALTIFNAMSIZ - 1 },
+	[ETHTOOL_A_HEADER_FLAGS]	= NLA_POLICY_MASK(NLA_U32,
+							  ETHTOOL_FLAGS_BASIC),
+	[ETHTOOL_A_HEADER_PHY_INDEX]		= NLA_POLICY_MIN(NLA_U32, 1),
+};
+
+const struct nla_policy ethnl_header_policy_phy_stats[] = {
+	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
+	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
+					    .len = ALTIFNAMSIZ - 1 },
+	[ETHTOOL_A_HEADER_FLAGS]	= NLA_POLICY_MASK(NLA_U32,
+							  ETHTOOL_FLAGS_STATS),
+	[ETHTOOL_A_HEADER_PHY_INDEX]		= NLA_POLICY_MIN(NLA_U32, 1),
+};
+
 int ethnl_ops_begin(struct net_device *dev)
 {
 	int ret;
@@ -89,8 +108,9 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
 			       const struct nlattr *header, struct net *net,
 			       struct netlink_ext_ack *extack, bool require_dev)
 {
-	struct nlattr *tb[ARRAY_SIZE(ethnl_header_policy)];
+	struct nlattr *tb[ARRAY_SIZE(ethnl_header_policy_phy)];
 	const struct nlattr *devname_attr;
+	struct phy_device *phydev = NULL;
 	struct net_device *dev = NULL;
 	u32 flags = 0;
 	int ret;
@@ -104,7 +124,7 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
 	/* No validation here, command policy should have a nested policy set
 	 * for the header, therefore validation should have already been done.
 	 */
-	ret = nla_parse_nested(tb, ARRAY_SIZE(ethnl_header_policy) - 1, header,
+	ret = nla_parse_nested(tb, ARRAY_SIZE(ethnl_header_policy_phy) - 1, header,
 			       NULL, extack);
 	if (ret < 0)
 		return ret;
@@ -145,6 +165,30 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
 		return -EINVAL;
 	}
 
+	if (dev) {
+		if (tb[ETHTOOL_A_HEADER_PHY_INDEX]) {
+			struct nlattr *phy_id;
+
+			phy_id = tb[ETHTOOL_A_HEADER_PHY_INDEX];
+			phydev = phy_link_topo_get_phy(dev->link_topo,
+						       nla_get_u32(phy_id));
+			if (!phydev) {
+				NL_SET_BAD_ATTR(extack, phy_id);
+				return -ENODEV;
+			}
+		} else {
+			/* If we need a PHY but no phy index is specified, fallback
+			 * to dev->phydev
+			 */
+			phydev = dev->phydev;
+		}
+	} else if (tb[ETHTOOL_A_HEADER_PHY_INDEX]) {
+		NL_SET_ERR_MSG_ATTR(extack, header,
+				    "can't target a PHY without a netdev");
+		return -EINVAL;
+	}
+
+	req_info->phydev = phydev;
 	req_info->dev = dev;
 	req_info->flags = flags;
 	return 0;
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 9a333a8d04c1..d57a890b5d9e 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -250,6 +250,7 @@ static inline unsigned int ethnl_reply_header_size(void)
  * @dev:   network device the request is for (may be null)
  * @dev_tracker: refcount tracker for @dev reference
  * @flags: request flags common for all request types
+ * @phydev: phy_device connected to @dev this request is for (may be null)
  *
  * This is a common base for request specific structures holding data from
  * parsed userspace request. These always embed struct ethnl_req_info at
@@ -259,6 +260,7 @@ struct ethnl_req_info {
 	struct net_device	*dev;
 	netdevice_tracker	dev_tracker;
 	u32			flags;
+	struct phy_device	*phydev;
 };
 
 static inline void ethnl_parse_header_dev_put(struct ethnl_req_info *req_info)
@@ -395,9 +397,12 @@ extern const struct ethnl_request_ops ethnl_rss_request_ops;
 extern const struct ethnl_request_ops ethnl_plca_cfg_request_ops;
 extern const struct ethnl_request_ops ethnl_plca_status_request_ops;
 extern const struct ethnl_request_ops ethnl_mm_request_ops;
+extern const struct ethnl_request_ops ethnl_phy_request_ops;
 
 extern const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_FLAGS + 1];
 extern const struct nla_policy ethnl_header_policy_stats[ETHTOOL_A_HEADER_FLAGS + 1];
+extern const struct nla_policy ethnl_header_policy_phy[ETHTOOL_A_HEADER_PHY_INDEX + 1];
+extern const struct nla_policy ethnl_header_policy_phy_stats[ETHTOOL_A_HEADER_PHY_INDEX + 1];
 extern const struct nla_policy ethnl_strset_get_policy[ETHTOOL_A_STRSET_COUNTS_ONLY + 1];
 extern const struct nla_policy ethnl_linkinfo_get_policy[ETHTOOL_A_LINKINFO_HEADER + 1];
 extern const struct nla_policy ethnl_linkinfo_set_policy[ETHTOOL_A_LINKINFO_TP_MDIX_CTRL + 1];