[PATCH net-next v5 0/4] net: ethtool: Introduce ethnl dump helpers

[PATCH net-next v5 0/4] net: ethtool: Introduce ethnl dump helpers

[Maxime Chevallier]

Hi everyone,

Here's another approach to get a better handling for ethnl dump when we
have phy-targetting commands.

Previous versions of that series introduced new ethnl ops for DUMP, but
only useful for PHY dump.

This series takes a step back and implements new perphy ops at the genl
level :
 ->start()
 ->dumpit()
 ->done()

This avoids having to flag commands that use filtered DUMPs, as this is
handled directly in the custom ->start(), and we can use our own dump
context without using dynamic allocs.

The drawback though is that this duplicates some logic from the
ethnl_default_xxx dump ops.

Patch 2 reworks the whole net/ethtool/phy.c to fallback to ethnl ops,
while patches 3 and 4 convert pse-pd and plca to this new dump method.

Let me know what you think,

Maxime

Changes in V5:
 - Move to a less generic approach, focusing only on the PHY case.

Changes in V4:
 - Don't grab rcu_read_lock when we already have a refcounter netdev on
   the filtered dump path (Paolo)
 - Move the dump_all stuff in a dedicated helper (Paolo)
 - Added patch 1 to set the dev in ctx->req_info

Changes in V3:
 - Fixed some typos and xmas tree issues
 - Added a missing check for EOPNOTSUPP in patch 1
 - Added missing kdoc
 - Added missing comments in phy_reply_size

Changes in V2:
 - Rebased on the netdev_lock work by Stanislav and the fixes from Eric
 - Fixed a bissectability issue
 - Fixed kdoc for the new ethnl ops and fields

V1: https://lore.kernel.org/netdev/20250305141938.319282-1-maxime.chevallier@bootlin.com/
V2: https://lore.kernel.org/netdev/20250308155440.267782-1-maxime.chevallier@bootlin.com/
V3: https://lore.kernel.org/netdev/20250313182647.250007-1-maxime.chevallier@bootlin.com/
V4: https://lore.kernel.org/netdev/20250324104012.367366-1-maxime.chevallier@bootlin.com/

Maxime Chevallier (4):
  net: ethtool: Introduce per-PHY DUMP operations
  net: ethtool: phy: Convert the PHY_GET command to generic phy dump
  net: ethtool: plca: Use per-PHY DUMP operations
  net: ethtool: pse-pd: Use per-PHY DUMP operations

 net/ethtool/netlink.c | 189 +++++++++++++++++++++--
 net/ethtool/netlink.h |   4 -
 net/ethtool/phy.c     | 342 ++++++++++++------------------------------
 3 files changed, 272 insertions(+), 263 deletions(-)

-- 
2.49.0

[PATCH net-next v5 1/4] net: ethtool: Introduce per-PHY DUMP operations

[Maxime Chevallier]

ethnl commands that target a phy_device need a DUMP implementation that
will fill the reply for every PHY behind a netdev. We therefore need to
iterate over the dev->topo to list them.

When multiple PHYs are behind the same netdev, it's also useful to
perform DUMP with a filter on a given netdev, to get the capability of
every PHY.

Implement dedicated genl ->start(), ->dumpit() and ->done() operations
for PHY-targetting command, allowing filtered dumps and using a dump
context that keep track of the PHY iteration for multi-message dump.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 net/ethtool/netlink.c | 162 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 162 insertions(+)

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index a163d40c6431..343faa6886a3 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -357,6 +357,16 @@ struct ethnl_dump_ctx {
 	unsigned long			pos_ifindex;
 };
 
+/**
+ * struct ethnl_perphy_dump_ctx - context for dumpit() PHY-aware callbacks
+ * @ethnl_ctx: generic ethnl context
+ * @pos_phyindex: iterator position for multi-msg DUMP
+ */
+struct ethnl_perphy_dump_ctx {
+	struct ethnl_dump_ctx	ethnl_ctx;
+	unsigned long		pos_phyindex;
+};
+
 static const struct ethnl_request_ops *
 ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_STRSET_GET]	= &ethnl_strset_request_ops,
@@ -407,6 +417,12 @@ static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
 	return (struct ethnl_dump_ctx *)cb->ctx;
 }
 
+static struct ethnl_perphy_dump_ctx *
+ethnl_perphy_dump_context(struct netlink_callback *cb)
+{
+	return (struct ethnl_perphy_dump_ctx *)cb->ctx;
+}
+
 /**
  * ethnl_default_parse() - Parse request message
  * @req_info:    pointer to structure to put data into
@@ -661,6 +677,152 @@ static int ethnl_default_start(struct netlink_callback *cb)
 	return ret;
 }
 
+/* perphy ->start() handler for GET requests */
+static int ethnl_perphy_start(struct netlink_callback *cb)
+{
+	struct ethnl_perphy_dump_ctx *phy_ctx = ethnl_perphy_dump_context(cb);
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
+	struct ethnl_dump_ctx *ctx = &phy_ctx->ethnl_ctx;
+	struct ethnl_reply_data *reply_data;
+	const struct ethnl_request_ops *ops;
+	struct ethnl_req_info *req_info;
+	struct genlmsghdr *ghdr;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+
+	ghdr = nlmsg_data(cb->nlh);
+	ops = ethnl_default_requests[ghdr->cmd];
+	if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", ghdr->cmd))
+		return -EOPNOTSUPP;
+	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
+	if (!req_info)
+		return -ENOMEM;
+	reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
+	if (!reply_data) {
+		ret = -ENOMEM;
+		goto free_req_info;
+	}
+
+	/* Don't ignore the dev even for DUMP requests */
+	ret = ethnl_default_parse(req_info, &info->info, ops, false);
+	if (ret < 0)
+		goto free_reply_data;
+
+	ctx->ops = ops;
+	ctx->req_info = req_info;
+	ctx->reply_data = reply_data;
+	ctx->pos_ifindex = 0;
+
+	return 0;
+
+free_reply_data:
+	kfree(reply_data);
+free_req_info:
+	kfree(req_info);
+
+	return ret;
+}
+
+static int ethnl_perphy_dump_one_dev(struct sk_buff *skb,
+				     struct net_device *dev,
+				     struct ethnl_perphy_dump_ctx *ctx,
+				     const struct genl_info *info)
+{
+	struct ethnl_dump_ctx *ethnl_ctx = &ctx->ethnl_ctx;
+	struct phy_device_node *pdn;
+	int ret = 0;
+
+	if (!dev->link_topo)
+		return 0;
+
+	xa_for_each_start(&dev->link_topo->phys, ctx->pos_phyindex, pdn,
+			  ctx->pos_phyindex) {
+		ethnl_ctx->req_info->phy_index = ctx->pos_phyindex;
+
+		/* We can re-use the original dump_one as ->prepare_data in
+		 * commands use ethnl_req_get_phydev(), which gets the PHY from
+		 * the req_info->phy_index
+		 */
+		ret = ethnl_default_dump_one(skb, dev, ethnl_ctx, info);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static int ethnl_perphy_dump_all_dev(struct sk_buff *skb,
+				     struct ethnl_perphy_dump_ctx *ctx,
+				     const struct genl_info *info)
+{
+	struct ethnl_dump_ctx *ethnl_ctx = &ctx->ethnl_ctx;
+	struct net *net = sock_net(skb->sk);
+	struct net_device *dev;
+	int ret = 0;
+
+	rcu_read_lock();
+	for_each_netdev_dump(net, dev, ethnl_ctx->pos_ifindex) {
+		dev_hold(dev);
+		rcu_read_unlock();
+
+		/* per-PHY commands use ethnl_req_get_phydev(), which needs the
+		 * net_device in the req_info
+		 */
+		ethnl_ctx->req_info->dev = dev;
+		ret = ethnl_perphy_dump_one_dev(skb, dev, ctx, info);
+
+		rcu_read_lock();
+		dev_put(dev);
+
+		if (ret < 0 && ret != -EOPNOTSUPP) {
+			if (likely(skb->len))
+				ret = skb->len;
+			break;
+		}
+		ret = 0;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+/* perphy ->dumpit() handler for GET requests. */
+static int ethnl_perphy_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct ethnl_perphy_dump_ctx *ctx = ethnl_perphy_dump_context(cb);
+	struct ethnl_dump_ctx *ethnl_ctx = &ctx->ethnl_ctx;
+	int ret = 0;
+
+	if (ethnl_ctx->req_info->dev) {
+		ret = ethnl_perphy_dump_one_dev(skb, ethnl_ctx->req_info->dev,
+						ctx, genl_info_dump(cb));
+
+		if (ret < 0 && ret != -EOPNOTSUPP && likely(skb->len))
+			ret = skb->len;
+
+		netdev_put(ethnl_ctx->req_info->dev,
+			   &ethnl_ctx->req_info->dev_tracker);
+	} else {
+		ret = ethnl_perphy_dump_all_dev(skb, ctx, genl_info_dump(cb));
+	}
+
+	return ret;
+}
+
+/* perphy ->done() handler for GET requests */
+static int ethnl_perphy_done(struct netlink_callback *cb)
+{
+	struct ethnl_perphy_dump_ctx *ctx = ethnl_perphy_dump_context(cb);
+	struct ethnl_dump_ctx *ethnl_ctx = &ctx->ethnl_ctx;
+
+	kfree(ethnl_ctx->reply_data);
+	kfree(ethnl_ctx->req_info);
+
+	return 0;
+}
+
 /* default ->done() handler for GET requests */
 static int ethnl_default_done(struct netlink_callback *cb)
 {
-- 
2.49.0

[PATCH net-next v5 2/4] net: ethtool: phy: Convert the PHY_GET command to generic phy dump

[Maxime Chevallier]

Now that we have an infrastructure in ethnl for perphy DUMPs, we can get
rid of the custom ->doit and ->dumpit to deal with PHY listing commands.

As most of the code was custom, this basically means re-writing how we
deal with PHY listing.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 net/ethtool/netlink.c |   9 +-
 net/ethtool/netlink.h |   4 -
 net/ethtool/phy.c     | 342 ++++++++++++------------------------------
 3 files changed, 101 insertions(+), 254 deletions(-)

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 343faa6886a3..69c3f62ac82c 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -410,6 +410,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_MM_SET]		= &ethnl_mm_request_ops,
 	[ETHTOOL_MSG_TSCONFIG_GET]	= &ethnl_tsconfig_request_ops,
 	[ETHTOOL_MSG_TSCONFIG_SET]	= &ethnl_tsconfig_request_ops,
+	[ETHTOOL_MSG_PHY_GET]		= &ethnl_phy_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -1431,10 +1432,10 @@ static const struct genl_ops ethtool_genl_ops[] = {
 	},
 	{
 		.cmd	= ETHTOOL_MSG_PHY_GET,
-		.doit	= ethnl_phy_doit,
-		.start	= ethnl_phy_start,
-		.dumpit	= ethnl_phy_dumpit,
-		.done	= ethnl_phy_done,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_perphy_start,
+		.dumpit	= ethnl_perphy_dumpit,
+		.done	= ethnl_perphy_done,
 		.policy = ethnl_phy_get_policy,
 		.maxattr = ARRAY_SIZE(ethnl_phy_get_policy) - 1,
 	},
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index ec6ab5443a6f..91b953924af3 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -499,10 +499,6 @@ int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_act_module_fw_flash(struct sk_buff *skb, struct genl_info *info);
 int ethnl_rss_dump_start(struct netlink_callback *cb);
 int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
-int ethnl_phy_start(struct netlink_callback *cb);
-int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info);
-int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
-int ethnl_phy_done(struct netlink_callback *cb);
 int ethnl_tsinfo_start(struct netlink_callback *cb);
 int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_tsinfo_done(struct netlink_callback *cb);
diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
index 1f590e8d75ed..68372bef4b2f 100644
--- a/net/ethtool/phy.c
+++ b/net/ethtool/phy.c
@@ -12,304 +12,154 @@
 #include <net/netdev_lock.h>
 
 struct phy_req_info {
-	struct ethnl_req_info		base;
-	struct phy_device_node		*pdn;
+	struct ethnl_req_info base;
 };
 
-#define PHY_REQINFO(__req_base) \
-	container_of(__req_base, struct phy_req_info, base)
+struct phy_reply_data {
+	struct ethnl_reply_data	base;
+	u32 phyindex;
+	char *drvname;
+	char *name;
+	unsigned int upstream_type;
+	char *upstream_sfp_name;
+	unsigned int upstream_index;
+	char *downstream_sfp_name;
+};
+
+#define PHY_REPDATA(__reply_base) \
+	container_of(__reply_base, struct phy_reply_data, base)
 
 const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1] = {
 	[ETHTOOL_A_PHY_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
 };
 
-/* Caller holds rtnl */
-static ssize_t
-ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
-		     struct netlink_ext_ack *extack)
+static int phy_reply_size(const struct ethnl_req_info *req_info,
+			  const struct ethnl_reply_data *reply_data)
 {
-	struct phy_req_info *req_info = PHY_REQINFO(req_base);
-	struct phy_device_node *pdn = req_info->pdn;
-	struct phy_device *phydev = pdn->phy;
+	struct phy_reply_data *rep_data = PHY_REPDATA(reply_data);
 	size_t size = 0;
 
-	ASSERT_RTNL();
-
 	/* ETHTOOL_A_PHY_INDEX */
 	size += nla_total_size(sizeof(u32));
 
 	/* ETHTOOL_A_DRVNAME */
-	if (phydev->drv)
-		size += nla_total_size(strlen(phydev->drv->name) + 1);
+	if (rep_data->drvname)
+		size += nla_total_size(strlen(rep_data->drvname) + 1);
 
 	/* ETHTOOL_A_NAME */
-	size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)) + 1);
+	size += nla_total_size(strlen(rep_data->name) + 1);
 
 	/* ETHTOOL_A_PHY_UPSTREAM_TYPE */
 	size += nla_total_size(sizeof(u32));
 
-	if (phy_on_sfp(phydev)) {
-		const char *upstream_sfp_name = sfp_get_name(pdn->parent_sfp_bus);
-
-		/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
-		if (upstream_sfp_name)
-			size += nla_total_size(strlen(upstream_sfp_name) + 1);
+	/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
+	if (rep_data->upstream_sfp_name)
+		size += nla_total_size(strlen(rep_data->upstream_sfp_name) + 1);
 
-		/* ETHTOOL_A_PHY_UPSTREAM_INDEX */
+	/* ETHTOOL_A_PHY_UPSTREAM_INDEX */
+	if (rep_data->upstream_index)
 		size += nla_total_size(sizeof(u32));
-	}
 
 	/* ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME */
-	if (phydev->sfp_bus) {
-		const char *sfp_name = sfp_get_name(phydev->sfp_bus);
-
-		if (sfp_name)
-			size += nla_total_size(strlen(sfp_name) + 1);
-	}
+	if (rep_data->downstream_sfp_name)
+		size += nla_total_size(strlen(rep_data->downstream_sfp_name) + 1);
 
 	return size;
 }
 
-static int
-ethnl_phy_fill_reply(const struct ethnl_req_info *req_base, struct sk_buff *skb)
+static int phy_prepare_data(const struct ethnl_req_info *req_info,
+			    struct ethnl_reply_data *reply_data,
+			    const struct genl_info *info)
 {
-	struct phy_req_info *req_info = PHY_REQINFO(req_base);
-	struct phy_device_node *pdn = req_info->pdn;
-	struct phy_device *phydev = pdn->phy;
-	enum phy_upstream ptype;
+	struct phy_link_topology *topo = reply_data->dev->link_topo;
+	struct phy_reply_data *rep_data = PHY_REPDATA(reply_data);
+	struct nlattr **tb = info->attrs;
+	struct phy_device_node *pdn;
+	struct phy_device *phydev;
 
-	ptype = pdn->upstream_type;
+	/* RTNL is held by the caller */
+	phydev = ethnl_req_get_phydev(req_info, tb, ETHTOOL_A_PHY_HEADER,
+				      info->extack);
+	if (IS_ERR_OR_NULL(phydev))
+		return -EOPNOTSUPP;
 
-	if (nla_put_u32(skb, ETHTOOL_A_PHY_INDEX, phydev->phyindex) ||
-	    nla_put_string(skb, ETHTOOL_A_PHY_NAME, dev_name(&phydev->mdio.dev)) ||
-	    nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_TYPE, ptype))
-		return -EMSGSIZE;
+	pdn = xa_load(&topo->phys, phydev->phyindex);
+	if (!pdn)
+		return -EOPNOTSUPP;
 
-	if (phydev->drv &&
-	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, phydev->drv->name))
-		return -EMSGSIZE;
+	rep_data->phyindex = phydev->phyindex;
+	rep_data->name = kstrdup(dev_name(&phydev->mdio.dev), GFP_KERNEL);
+	rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL);
+	rep_data->upstream_type = pdn->upstream_type;
 
-	if (ptype == PHY_UPSTREAM_PHY) {
+	if (pdn->upstream_type == PHY_UPSTREAM_PHY) {
 		struct phy_device *upstream = pdn->upstream.phydev;
-		const char *sfp_upstream_name;
-
-		/* Parent index */
-		if (nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX, upstream->phyindex))
-			return -EMSGSIZE;
-
-		if (pdn->parent_sfp_bus) {
-			sfp_upstream_name = sfp_get_name(pdn->parent_sfp_bus);
-			if (sfp_upstream_name &&
-			    nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
-					   sfp_upstream_name))
-				return -EMSGSIZE;
-		}
-	}
-
-	if (phydev->sfp_bus) {
-		const char *sfp_name = sfp_get_name(phydev->sfp_bus);
-
-		if (sfp_name &&
-		    nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
-				   sfp_name))
-			return -EMSGSIZE;
+		rep_data->upstream_index = upstream->phyindex;
 	}
 
-	return 0;
-}
-
-static int ethnl_phy_parse_request(struct ethnl_req_info *req_base,
-				   struct nlattr **tb,
-				   struct netlink_ext_ack *extack)
-{
-	struct phy_link_topology *topo = req_base->dev->link_topo;
-	struct phy_req_info *req_info = PHY_REQINFO(req_base);
-	struct phy_device *phydev;
+	if (pdn->parent_sfp_bus)
+		rep_data->upstream_sfp_name = kstrdup(sfp_get_name(pdn->parent_sfp_bus),
+						      GFP_KERNEL);
 
-	phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_PHY_HEADER,
-				      extack);
-	if (!phydev)
-		return 0;
-
-	if (IS_ERR(phydev))
-		return PTR_ERR(phydev);
-
-	if (!topo)
-		return 0;
-
-	req_info->pdn = xa_load(&topo->phys, phydev->phyindex);
+	if (phydev->sfp_bus)
+		rep_data->downstream_sfp_name = kstrdup(sfp_get_name(phydev->sfp_bus),
+							GFP_KERNEL);
 
 	return 0;
 }
 
-int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
+static int phy_fill_reply(struct sk_buff *skb,
+			  const struct ethnl_req_info *req_info,
+			  const struct ethnl_reply_data *reply_data)
 {
-	struct phy_req_info req_info = {};
-	struct nlattr **tb = info->attrs;
-	struct sk_buff *rskb;
-	void *reply_payload;
-	int reply_len;
-	int ret;
-
-	ret = ethnl_parse_header_dev_get(&req_info.base,
-					 tb[ETHTOOL_A_PHY_HEADER],
-					 genl_info_net(info), info->extack,
-					 true);
-	if (ret < 0)
-		return ret;
-
-	rtnl_lock();
-	netdev_lock_ops(req_info.base.dev);
-
-	ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
-	if (ret < 0)
-		goto err_unlock;
-
-	/* No PHY, return early */
-	if (!req_info.pdn)
-		goto err_unlock;
-
-	ret = ethnl_phy_reply_size(&req_info.base, info->extack);
-	if (ret < 0)
-		goto err_unlock;
-	reply_len = ret + ethnl_reply_header_size();
-
-	rskb = ethnl_reply_init(reply_len, req_info.base.dev,
-				ETHTOOL_MSG_PHY_GET_REPLY,
-				ETHTOOL_A_PHY_HEADER,
-				info, &reply_payload);
-	if (!rskb) {
-		ret = -ENOMEM;
-		goto err_unlock;
-	}
-
-	ret = ethnl_phy_fill_reply(&req_info.base, rskb);
-	if (ret)
-		goto err_free_msg;
+	struct phy_reply_data *rep_data = PHY_REPDATA(reply_data);
 
-	netdev_unlock_ops(req_info.base.dev);
-	rtnl_unlock();
-	ethnl_parse_header_dev_put(&req_info.base);
-	genlmsg_end(rskb, reply_payload);
-
-	return genlmsg_reply(rskb, info);
-
-err_free_msg:
-	nlmsg_free(rskb);
-err_unlock:
-	netdev_unlock_ops(req_info.base.dev);
-	rtnl_unlock();
-	ethnl_parse_header_dev_put(&req_info.base);
-	return ret;
-}
-
-struct ethnl_phy_dump_ctx {
-	struct phy_req_info	*phy_req_info;
-	unsigned long ifindex;
-	unsigned long phy_index;
-};
-
-int ethnl_phy_start(struct netlink_callback *cb)
-{
-	const struct genl_info *info = genl_info_dump(cb);
-	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
-	int ret;
-
-	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
-
-	ctx->phy_req_info = kzalloc(sizeof(*ctx->phy_req_info), GFP_KERNEL);
-	if (!ctx->phy_req_info)
-		return -ENOMEM;
-
-	ret = ethnl_parse_header_dev_get(&ctx->phy_req_info->base,
-					 info->attrs[ETHTOOL_A_PHY_HEADER],
-					 sock_net(cb->skb->sk), cb->extack,
-					 false);
-	ctx->ifindex = 0;
-	ctx->phy_index = 0;
-
-	if (ret)
-		kfree(ctx->phy_req_info);
+	if (nla_put_u32(skb, ETHTOOL_A_PHY_INDEX, rep_data->phyindex) ||
+	    nla_put_string(skb, ETHTOOL_A_PHY_NAME, rep_data->name) ||
+	    nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_TYPE, rep_data->upstream_type))
+		return -EMSGSIZE;
 
-	return ret;
-}
+	if (rep_data->drvname &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, rep_data->drvname))
+		return -EMSGSIZE;
 
-int ethnl_phy_done(struct netlink_callback *cb)
-{
-	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	if (rep_data->upstream_index &&
+	    nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX,
+			rep_data->upstream_index))
+		return -EMSGSIZE;
 
-	if (ctx->phy_req_info->base.dev)
-		ethnl_parse_header_dev_put(&ctx->phy_req_info->base);
+	if (rep_data->upstream_sfp_name &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
+			   rep_data->upstream_sfp_name))
+		return -EMSGSIZE;
 
-	kfree(ctx->phy_req_info);
+	if (rep_data->downstream_sfp_name &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
+			   rep_data->downstream_sfp_name))
+		return -EMSGSIZE;
 
 	return 0;
 }
 
-static int ethnl_phy_dump_one_dev(struct sk_buff *skb, struct net_device *dev,
-				  struct netlink_callback *cb)
+static void phy_cleanup_data(struct ethnl_reply_data *reply_data)
 {
-	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
-	struct phy_req_info *pri = ctx->phy_req_info;
-	struct phy_device_node *pdn;
-	int ret = 0;
-	void *ehdr;
-
-	if (!dev->link_topo)
-		return 0;
-
-	xa_for_each_start(&dev->link_topo->phys, ctx->phy_index, pdn, ctx->phy_index) {
-		ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_PHY_GET_REPLY);
-		if (!ehdr) {
-			ret = -EMSGSIZE;
-			break;
-		}
-
-		ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_PHY_HEADER);
-		if (ret < 0) {
-			genlmsg_cancel(skb, ehdr);
-			break;
-		}
-
-		pri->pdn = pdn;
-		ret = ethnl_phy_fill_reply(&pri->base, skb);
-		if (ret < 0) {
-			genlmsg_cancel(skb, ehdr);
-			break;
-		}
-
-		genlmsg_end(skb, ehdr);
-	}
+	struct phy_reply_data *rep_data = PHY_REPDATA(reply_data);
 
-	return ret;
+	kfree(rep_data->drvname);
+	kfree(rep_data->name);
+	kfree(rep_data->upstream_sfp_name);
+	kfree(rep_data->downstream_sfp_name);
 }
 
-int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
-{
-	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
-	struct net *net = sock_net(skb->sk);
-	struct net_device *dev;
-	int ret = 0;
-
-	rtnl_lock();
-
-	if (ctx->phy_req_info->base.dev) {
-		dev = ctx->phy_req_info->base.dev;
-		netdev_lock_ops(dev);
-		ret = ethnl_phy_dump_one_dev(skb, dev, cb);
-		netdev_unlock_ops(dev);
-	} else {
-		for_each_netdev_dump(net, dev, ctx->ifindex) {
-			netdev_lock_ops(dev);
-			ret = ethnl_phy_dump_one_dev(skb, dev, cb);
-			netdev_unlock_ops(dev);
-			if (ret)
-				break;
-
-			ctx->phy_index = 0;
-		}
-	}
-	rtnl_unlock();
-
-	return ret;
-}
+const struct ethnl_request_ops ethnl_phy_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_PHY_GET,
+	.reply_cmd		= ETHTOOL_MSG_PHY_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_PHY_HEADER,
+	.req_info_size		= sizeof(struct phy_req_info),
+	.reply_data_size	= sizeof(struct phy_reply_data),
+
+	.prepare_data		= phy_prepare_data,
+	.reply_size		= phy_reply_size,
+	.fill_reply		= phy_fill_reply,
+	.cleanup_data		= phy_cleanup_data,
+};
-- 
2.49.0

[PATCH net-next v5 3/4] net: ethtool: plca: Use per-PHY DUMP operations

[Maxime Chevallier]

Leverage the per-phy ethnl DUMP helpers in case we have more that one
PLCA-able PHY on the link.

This is done for both PLCA status and PLCA config.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 net/ethtool/netlink.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 69c3f62ac82c..dd4eaa77dd8c 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -1385,9 +1385,9 @@ static const struct genl_ops ethtool_genl_ops[] = {
 	{
 		.cmd	= ETHTOOL_MSG_PLCA_GET_CFG,
 		.doit	= ethnl_default_doit,
-		.start	= ethnl_default_start,
-		.dumpit	= ethnl_default_dumpit,
-		.done	= ethnl_default_done,
+		.start	= ethnl_perphy_start,
+		.dumpit	= ethnl_perphy_dumpit,
+		.done	= ethnl_perphy_done,
 		.policy = ethnl_plca_get_cfg_policy,
 		.maxattr = ARRAY_SIZE(ethnl_plca_get_cfg_policy) - 1,
 	},
@@ -1401,9 +1401,9 @@ static const struct genl_ops ethtool_genl_ops[] = {
 	{
 		.cmd	= ETHTOOL_MSG_PLCA_GET_STATUS,
 		.doit	= ethnl_default_doit,
-		.start	= ethnl_default_start,
-		.dumpit	= ethnl_default_dumpit,
-		.done	= ethnl_default_done,
+		.start	= ethnl_perphy_start,
+		.dumpit	= ethnl_perphy_dumpit,
+		.done	= ethnl_perphy_done,
 		.policy = ethnl_plca_get_status_policy,
 		.maxattr = ARRAY_SIZE(ethnl_plca_get_status_policy) - 1,
 	},
-- 
2.49.0

[PATCH net-next v5 4/4] net: ethtool: pse-pd: Use per-PHY DUMP operations

[Maxime Chevallier]

Leverage the per-phy ethnl DUMP helpers in case we have more that one
PSE PHY on the link.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 net/ethtool/netlink.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index dd4eaa77dd8c..7186c465f429 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -1361,9 +1361,9 @@ static const struct genl_ops ethtool_genl_ops[] = {
 	{
 		.cmd	= ETHTOOL_MSG_PSE_GET,
 		.doit	= ethnl_default_doit,
-		.start	= ethnl_default_start,
-		.dumpit	= ethnl_default_dumpit,
-		.done	= ethnl_default_done,
+		.start	= ethnl_perphy_start,
+		.dumpit	= ethnl_perphy_dumpit,
+		.done	= ethnl_perphy_done,
 		.policy = ethnl_pse_get_policy,
 		.maxattr = ARRAY_SIZE(ethnl_pse_get_policy) - 1,
 	},
-- 
2.49.0

Re: [PATCH net-next v5 1/4] net: ethtool: Introduce per-PHY DUMP operations

[Jakub Kicinski]

On Thu, 10 Apr 2025 14:33:46 +0200 Maxime Chevallier wrote:
> ethnl commands that target a phy_device need a DUMP implementation that
> will fill the reply for every PHY behind a netdev. We therefore need to
> iterate over the dev->topo to list them.
> 
> When multiple PHYs are behind the same netdev, it's also useful to
> perform DUMP with a filter on a given netdev, to get the capability of
> every PHY.
> 
> Implement dedicated genl ->start(), ->dumpit() and ->done() operations
> for PHY-targetting command, allowing filtered dumps and using a dump
> context that keep track of the PHY iteration for multi-message dump.

Transient warnings here that the new functions are not used :(
Would it work to squash the 3rd and 4th patches in?
Not ideal but better than having a warning.
-- 
pw-bot: cr

Re: [PATCH net-next v5 1/4] net: ethtool: Introduce per-PHY DUMP operations

[Maxime Chevallier]

Hi Jakub,

On Thu, 10 Apr 2025 17:21:55 -0700
Jakub Kicinski <kuba@kernel.org> wrote:

> On Thu, 10 Apr 2025 14:33:46 +0200 Maxime Chevallier wrote:
> > ethnl commands that target a phy_device need a DUMP implementation that
> > will fill the reply for every PHY behind a netdev. We therefore need to
> > iterate over the dev->topo to list them.
> > 
> > When multiple PHYs are behind the same netdev, it's also useful to
> > perform DUMP with a filter on a given netdev, to get the capability of
> > every PHY.
> > 
> > Implement dedicated genl ->start(), ->dumpit() and ->done() operations
> > for PHY-targetting command, allowing filtered dumps and using a dump
> > context that keep track of the PHY iteration for multi-message dump.  
> 
> Transient warnings here that the new functions are not used :(
> Would it work to squash the 3rd and 4th patches in?
> Not ideal but better than having a warning.

ah damn yes indeed... meh sorry about that, I'll squash the other
patches in (except for the net/ethtool/phy.c patch). That said are you
more comfortable with this approach ? I was unsure this was what you
were expecting from the previous iteration.

Thanks,

Maxime

Re: [PATCH net-next v5 1/4] net: ethtool: Introduce per-PHY DUMP operations

[Jakub Kicinski]

On Fri, 11 Apr 2025 09:26:19 +0200 Maxime Chevallier wrote:
> > Transient warnings here that the new functions are not used :(
> > Would it work to squash the 3rd and 4th patches in?
> > Not ideal but better than having a warning.  
> 
> ah damn yes indeed... meh sorry about that, I'll squash the other
> patches in (except for the net/ethtool/phy.c patch). That said are you
> more comfortable with this approach ? I was unsure this was what you
> were expecting from the previous iteration.

I'm not sure if I did expect anything in particular after the idea I had
proved to not be feasible :) This looks good at a quick look.