net: ethtool: phy: Convert the PHY_GET command to generic phy dump

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 <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/ethtool/netlink.c

···
 	[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)
···
 	},
 	{
 		.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,
 	},

net/ethtool/netlink.h

···
 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);

net/ethtool/phy.c

···
 #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 (rep_data->upstream_sfp_name)
+		size += nla_total_size(strlen(rep_data->upstream_sfp_name) + 1);
 
-		/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
-		if (upstream_sfp_name)
-			size += nla_total_size(strlen(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;
-
-	ptype = pdn->upstream_type;
-
-	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;
-
-	if (phydev->drv &&
-	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, phydev->drv->name))
-		return -EMSGSIZE;
-
-	if (ptype == 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;
-	}
-
-	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_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;
 
-	phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_PHY_HEADER,
-				      extack);
-	if (!phydev)
-		return 0;
+	/* 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 (IS_ERR(phydev))
-		return PTR_ERR(phydev);
+	pdn = xa_load(&topo->phys, phydev->phyindex);
+	if (!pdn)
+		return -EOPNOTSUPP;
 
-	if (!topo)
-		return 0;
+	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;
 
-	req_info->pdn = xa_load(&topo->phys, phydev->phyindex);
+	if (pdn->upstream_type == PHY_UPSTREAM_PHY) {
+		struct phy_device *upstream = pdn->upstream.phydev;
+		rep_data->upstream_index = upstream->phyindex;
+	}
+
+	if (pdn->parent_sfp_bus)
+		rep_data->upstream_sfp_name = kstrdup(sfp_get_name(pdn->parent_sfp_bus),
+						      GFP_KERNEL);
+
+	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;
+	struct phy_reply_data *rep_data = PHY_REPDATA(reply_data);
 
-	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;
+	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;
 
-	rtnl_lock();
-	netdev_lock_ops(req_info.base.dev);
+	if (rep_data->drvname &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, rep_data->drvname))
+		return -EMSGSIZE;
 
-	ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
-	if (ret < 0)
-		goto err_unlock;
+	if (rep_data->upstream_index &&
+	    nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX,
+			rep_data->upstream_index))
+		return -EMSGSIZE;
 
-	/* No PHY, return early */
-	if (!req_info.pdn)
-		goto err_unlock;
+	if (rep_data->upstream_sfp_name &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
+			   rep_data->upstream_sfp_name))
+		return -EMSGSIZE;
 
-	ret = ethnl_phy_reply_size(&req_info.base, info->extack);
-	if (ret < 0)
-		goto err_unlock;
-	reply_len = ret + ethnl_reply_header_size();
+	if (rep_data->downstream_sfp_name &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
+			   rep_data->downstream_sfp_name))
+		return -EMSGSIZE;
 
-	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;
-
-	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;
+	return 0;
 }
 
-struct ethnl_phy_dump_ctx {
-	struct phy_req_info	*phy_req_info;
-	unsigned long ifindex;
-	unsigned long phy_index;
+static void phy_cleanup_data(struct ethnl_reply_data *reply_data)
+{
+	struct phy_reply_data *rep_data = PHY_REPDATA(reply_data);
+
+	kfree(rep_data->drvname);
+	kfree(rep_data->name);
+	kfree(rep_data->upstream_sfp_name);
+	kfree(rep_data->downstream_sfp_name);
+}
+
+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,
 };
-
-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);
-
-	return ret;
-}
-
-int ethnl_phy_done(struct netlink_callback *cb)
-{
-	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
-
-	if (ctx->phy_req_info->base.dev)
-		ethnl_parse_header_dev_put(&ctx->phy_req_info->base);
-
-	kfree(ctx->phy_req_info);
-
-	return 0;
-}
-
-static int ethnl_phy_dump_one_dev(struct sk_buff *skb, struct net_device *dev,
-				  struct netlink_callback *cb)
-{
-	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);
-	}
-
-	return ret;
-}
-
-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;
-}