devlink: Move input checks from driver to devlink

Currently, all the input checks are done in driver.

After adding the split capability to devlink port, move the checks to
devlink.

Signed-off-by: Danielle Ratson <danieller@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -2236,13 +2236,6 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u8 local_port,
 		return -EINVAL;
 	}
 
-	/* Split ports cannot be split. */
-	if (mlxsw_sp_port->split) {
-		netdev_err(mlxsw_sp_port->dev, "Port cannot be split further\n");
-		NL_SET_ERR_MSG_MOD(extack, "Port cannot be split further");
-		return -EINVAL;
-	}
-
 	max_width = mlxsw_core_module_max_width(mlxsw_core,
 						mlxsw_sp_port->mapping.module);
 	if (max_width < 0) {
@@ -2251,19 +2244,13 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u8 local_port,
 		return max_width;
 	}
 
-	/* Split port with non-max and 1 module width cannot be split. */
-	if (mlxsw_sp_port->mapping.width != max_width || max_width == 1) {
+	/* Split port with non-max cannot be split. */
+	if (mlxsw_sp_port->mapping.width != max_width) {
 		netdev_err(mlxsw_sp_port->dev, "Port cannot be split\n");
 		NL_SET_ERR_MSG_MOD(extack, "Port cannot be split");
 		return -EINVAL;
 	}
 
-	if (count == 1 || !is_power_of_2(count) || count > max_width) {
-		netdev_err(mlxsw_sp_port->dev, "Invalid split count\n");
-		NL_SET_ERR_MSG_MOD(extack, "Invalid split count");
-		return -EINVAL;
-	}
-
 	offset = mlxsw_sp_local_ports_offset(mlxsw_core, count, max_width);
 	if (offset < 0) {
 		netdev_err(mlxsw_sp_port->dev, "Cannot obtain local port offset\n");

drivers/net/ethernet/netronome/nfp/nfp_devlink.c

@@ -70,9 +70,6 @@ nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
 	unsigned int lanes;
 	int ret;
 
-	if (count < 2)
-		return -EINVAL;
-
 	mutex_lock(&pf->lock);
 
 	rtnl_lock();
@@ -81,7 +78,7 @@ nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
 	if (ret)
 		goto out;
 
-	if (eth_port.is_split || eth_port.port_lanes % count) {
+	if (eth_port.port_lanes % count) {
 		ret = -EINVAL;
 		goto out;
 	}

net/core/devlink.c

@@ -940,15 +940,35 @@ static int devlink_nl_cmd_port_split_doit(struct sk_buff *skb,
 					  struct genl_info *info)
 {
 	struct devlink *devlink = info->user_ptr[0];
+	struct devlink_port *devlink_port;
 	u32 port_index;
 	u32 count;
 
 	if (!info->attrs[DEVLINK_ATTR_PORT_INDEX] ||
 	    !info->attrs[DEVLINK_ATTR_PORT_SPLIT_COUNT])
 		return -EINVAL;
 
+	devlink_port = devlink_port_get_from_info(devlink, info);
 	port_index = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_INDEX]);
 	count = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_SPLIT_COUNT]);
+
+	if (IS_ERR(devlink_port))
+		return -EINVAL;
+
+	if (!devlink_port->attrs.splittable) {
+		/* Split ports cannot be split. */
+		if (devlink_port->attrs.split)
+			NL_SET_ERR_MSG_MOD(info->extack, "Port cannot be split further");
+		else
+			NL_SET_ERR_MSG_MOD(info->extack, "Port cannot be split");
+		return -EINVAL;
+	}
+
+	if (count < 2 || !is_power_of_2(count) || count > devlink_port->attrs.lanes) {
+		NL_SET_ERR_MSG_MOD(info->extack, "Invalid split count");
+		return -EINVAL;
+	}
+
 	return devlink_port_split(devlink, port_index, count, info->extack);
 }