devlink: parse linecard attr in doit() callbacks

No need to give the linecards any special treatment in netlink attribute
parsing, as unlike for ports, there is only a couple of commands
benefiting from that.

Remove DEVLINK_NL_FLAG_NEED_LINECARD, make pre_doit() callback simpler
by moving the linecard attribute parsing to linecard_[gs]et_doit() ops.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230811155714.1736405-2-jiri@resnulli.usSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/devlink/devl_internal.h

@@ -94,7 +94,6 @@ static inline bool devl_is_registered(struct devlink *devlink)
 #define DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT	BIT(1)
 #define DEVLINK_NL_FLAG_NEED_RATE		BIT(2)
 #define DEVLINK_NL_FLAG_NEED_RATE_NODE		BIT(3)
-#define DEVLINK_NL_FLAG_NEED_LINECARD		BIT(4)
 
 enum devlink_multicast_groups {
 	DEVLINK_MCGRP_CONFIG,
@@ -203,12 +202,6 @@ int devlink_resources_validate(struct devlink *devlink,
 			       struct devlink_resource *resource,
 			       struct genl_info *info);
 
-/* Line cards */
-struct devlink_linecard;
-
-struct devlink_linecard *
-devlink_linecard_get_from_info(struct devlink *devlink, struct genl_info *info);
-
 /* Rates */
 int devlink_rate_nodes_check(struct devlink *devlink, u16 mode,
 			     struct netlink_ext_ack *extack);

net/devlink/leftover.c

@@ -285,7 +285,7 @@ devlink_linecard_get_from_attrs(struct devlink *devlink, struct nlattr **attrs)
 	return ERR_PTR(-EINVAL);
 }
 
-struct devlink_linecard *
+static struct devlink_linecard *
 devlink_linecard_get_from_info(struct devlink *devlink, struct genl_info *info)
 {
 	return devlink_linecard_get_from_attrs(devlink, info->attrs);
@@ -1814,11 +1814,15 @@ static void devlink_linecard_notify(struct devlink_linecard *linecard,
 static int devlink_nl_cmd_linecard_get_doit(struct sk_buff *skb,
 					    struct genl_info *info)
 {
-	struct devlink_linecard *linecard = info->user_ptr[1];
-	struct devlink *devlink = linecard->devlink;
+	struct devlink *devlink = info->user_ptr[0];
+	struct devlink_linecard *linecard;
 	struct sk_buff *msg;
 	int err;
 
+	linecard = devlink_linecard_get_from_info(devlink, info);
+	if (IS_ERR(linecard))
+		return PTR_ERR(linecard);
+
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;
@@ -2008,10 +2012,15 @@ static int devlink_linecard_type_unset(struct devlink_linecard *linecard,
 static int devlink_nl_cmd_linecard_set_doit(struct sk_buff *skb,
 					    struct genl_info *info)
 {
-	struct devlink_linecard *linecard = info->user_ptr[1];
 	struct netlink_ext_ack *extack = info->extack;
+	struct devlink *devlink = info->user_ptr[0];
+	struct devlink_linecard *linecard;
 	int err;
 
+	linecard = devlink_linecard_get_from_info(devlink, info);
+	if (IS_ERR(linecard))
+		return PTR_ERR(linecard);
+
 	if (info->attrs[DEVLINK_ATTR_LINECARD_TYPE]) {
 		const char *type;
 
@@ -6347,14 +6356,12 @@ const struct genl_small_ops devlink_nl_small_ops[54] = {
 		.cmd = DEVLINK_CMD_LINECARD_GET,
 		.doit = devlink_nl_cmd_linecard_get_doit,
 		.dumpit = devlink_nl_instance_iter_dumpit,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_LINECARD,
 		/* can be retrieved by unprivileged users */
 	},
 	{
 		.cmd = DEVLINK_CMD_LINECARD_SET,
 		.doit = devlink_nl_cmd_linecard_set_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_LINECARD,
 	},
 	{
 		.cmd = DEVLINK_CMD_SB_GET,

net/devlink/netlink.c

@@ -112,7 +112,6 @@ devlink_get_from_attrs_lock(struct net *net, struct nlattr **attrs)
 int devlink_nl_pre_doit(const struct genl_split_ops *ops,
 			struct sk_buff *skb, struct genl_info *info)
 {
-	struct devlink_linecard *linecard;
 	struct devlink_port *devlink_port;
 	struct devlink *devlink;
 	int err;
@@ -151,13 +150,6 @@ int devlink_nl_pre_doit(const struct genl_split_ops *ops,
 			goto unlock;
 		}
 		info->user_ptr[1] = rate_node;
-	} else if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_LINECARD) {
-		linecard = devlink_linecard_get_from_info(devlink, info);
-		if (IS_ERR(linecard)) {
-			err = PTR_ERR(linecard);
-			goto unlock;
-		}
-		info->user_ptr[1] = linecard;
 	}
 	return 0;