[PATCH net-next 1/6] devlink: Clean registration of devlink port

[Leon Romanovsky <leon@kernel.org>]

From: Leon Romanovsky <leonro@nvidia.com>

devlink_port_register() is in-kernel API and as such can't really
fail as long as driver author didn't make a mistake by providing
already existing port index.

Instead of relying on various error prints from the driver, convert
the existence check to be WARN_ON(), so such a mistake will be caught
immediately.

Tested-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 net/core/devlink.c | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index db3b52110cf2..34d0f623b2a9 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -268,12 +268,6 @@ static struct devlink_port *devlink_port_get_by_index(struct devlink *devlink,
 	return NULL;
 }
 
-static bool devlink_port_index_exists(struct devlink *devlink,
-				      unsigned int port_index)
-{
-	return devlink_port_get_by_index(devlink, port_index);
-}
-
 static struct devlink_port *devlink_port_get_from_attrs(struct devlink *devlink,
 							struct nlattr **attrs)
 {
@@ -9255,25 +9249,24 @@ int devlink_port_register(struct devlink *devlink,
 			  struct devlink_port *devlink_port,
 			  unsigned int port_index)
 {
-	mutex_lock(&devlink->lock);
-	if (devlink_port_index_exists(devlink, port_index)) {
-		mutex_unlock(&devlink->lock);
-		return -EEXIST;
-	}
-
+	WARN_ON(devlink_port_get_by_index(devlink, port_index));
 	WARN_ON(devlink_port->devlink);
+
 	devlink_port->devlink = devlink;
 	devlink_port->index = port_index;
 	spin_lock_init(&devlink_port->type_lock);
 	INIT_LIST_HEAD(&devlink_port->reporter_list);
 	mutex_init(&devlink_port->reporters_lock);
-	list_add_tail(&devlink_port->list, &devlink->port_list);
 	INIT_LIST_HEAD(&devlink_port->param_list);
 	INIT_LIST_HEAD(&devlink_port->region_list);
-	mutex_unlock(&devlink->lock);
 	INIT_DELAYED_WORK(&devlink_port->type_warn_dw, &devlink_port_type_warn);
-	devlink_port_type_warn_schedule(devlink_port);
+
+	mutex_lock(&devlink->lock);
+	list_add_tail(&devlink_port->list, &devlink->port_list);
+	mutex_unlock(&devlink->lock);
+
 	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
+	devlink_port_type_warn_schedule(devlink_port);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(devlink_port_register);
-- 
2.33.1