devlink: Add API to register packet trap groups

Currently, packet trap groups are implicitly registered by drivers upon
packet trap registration. When the traps are registered, each is
associated with a group and the group is created by devlink, if it does
not exist already.

This makes it difficult for drivers to pass additional attributes for
the groups.

Therefore, as a preparation for future patches that require passing
additional group attributes, add an API to explicitly register /
unregister these groups.

Next patches will convert existing drivers to use this API.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/devlink.h

@@ -1057,6 +1057,12 @@ void devlink_trap_report(struct devlink *devlink, struct sk_buff *skb,
 			 void *trap_ctx, struct devlink_port *in_devlink_port,
 			 const struct flow_action_cookie *fa_cookie);
 void *devlink_trap_ctx_priv(void *trap_ctx);
+int devlink_trap_groups_register(struct devlink *devlink,
+				 const struct devlink_trap_group *groups,
+				 size_t groups_count);
+void devlink_trap_groups_unregister(struct devlink *devlink,
+				    const struct devlink_trap_group *groups,
+				    size_t groups_count);
 
 #if IS_ENABLED(CONFIG_NET_DEVLINK)
 

net/core/devlink.c

@@ -8278,6 +8278,123 @@ void *devlink_trap_ctx_priv(void *trap_ctx)
 }
 EXPORT_SYMBOL_GPL(devlink_trap_ctx_priv);
 
+static int
+devlink_trap_group_register(struct devlink *devlink,
+			    const struct devlink_trap_group *group)
+{
+	struct devlink_trap_group_item *group_item;
+	int err;
+
+	if (devlink_trap_group_item_lookup(devlink, group->name))
+		return -EEXIST;
+
+	group_item = kzalloc(sizeof(*group_item), GFP_KERNEL);
+	if (!group_item)
+		return -ENOMEM;
+
+	group_item->stats = netdev_alloc_pcpu_stats(struct devlink_stats);
+	if (!group_item->stats) {
+		err = -ENOMEM;
+		goto err_stats_alloc;
+	}
+
+	group_item->group = group;
+	refcount_set(&group_item->refcount, 1);
+
+	if (devlink->ops->trap_group_init) {
+		err = devlink->ops->trap_group_init(devlink, group);
+		if (err)
+			goto err_group_init;
+	}
+
+	list_add_tail(&group_item->list, &devlink->trap_group_list);
+	devlink_trap_group_notify(devlink, group_item,
+				  DEVLINK_CMD_TRAP_GROUP_NEW);
+
+	return 0;
+
+err_group_init:
+	free_percpu(group_item->stats);
+err_stats_alloc:
+	kfree(group_item);
+	return err;
+}
+
+static void
+devlink_trap_group_unregister(struct devlink *devlink,
+			      const struct devlink_trap_group *group)
+{
+	struct devlink_trap_group_item *group_item;
+
+	group_item = devlink_trap_group_item_lookup(devlink, group->name);
+	if (WARN_ON_ONCE(!group_item))
+		return;
+
+	devlink_trap_group_notify(devlink, group_item,
+				  DEVLINK_CMD_TRAP_GROUP_DEL);
+	list_del(&group_item->list);
+	free_percpu(group_item->stats);
+	kfree(group_item);
+}
+
+/**
+ * devlink_trap_groups_register - Register packet trap groups with devlink.
+ * @devlink: devlink.
+ * @groups: Packet trap groups.
+ * @groups_count: Count of provided packet trap groups.
+ *
+ * Return: Non-zero value on failure.
+ */
+int devlink_trap_groups_register(struct devlink *devlink,
+				 const struct devlink_trap_group *groups,
+				 size_t groups_count)
+{
+	int i, err;
+
+	mutex_lock(&devlink->lock);
+	for (i = 0; i < groups_count; i++) {
+		const struct devlink_trap_group *group = &groups[i];
+
+		err = devlink_trap_group_verify(group);
+		if (err)
+			goto err_trap_group_verify;
+
+		err = devlink_trap_group_register(devlink, group);
+		if (err)
+			goto err_trap_group_register;
+	}
+	mutex_unlock(&devlink->lock);
+
+	return 0;
+
+err_trap_group_register:
+err_trap_group_verify:
+	for (i--; i >= 0; i--)
+		devlink_trap_group_unregister(devlink, &groups[i]);
+	mutex_unlock(&devlink->lock);
+	return err;
+}
+EXPORT_SYMBOL_GPL(devlink_trap_groups_register);
+
+/**
+ * devlink_trap_groups_unregister - Unregister packet trap groups from devlink.
+ * @devlink: devlink.
+ * @groups: Packet trap groups.
+ * @groups_count: Count of provided packet trap groups.
+ */
+void devlink_trap_groups_unregister(struct devlink *devlink,
+				    const struct devlink_trap_group *groups,
+				    size_t groups_count)
+{
+	int i;
+
+	mutex_lock(&devlink->lock);
+	for (i = groups_count - 1; i >= 0; i--)
+		devlink_trap_group_unregister(devlink, &groups[i]);
+	mutex_unlock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devlink_trap_groups_unregister);
+
 static void __devlink_compat_running_version(struct devlink *devlink,
 					     char *buf, size_t len)
 {