Check for roles inside model?

Hi,
i'm using Community Auth for Authentication. I want to restrict the database result based on the role
Right now in the model the funcions are like this:

get_finantial_report( some parameters, user_level, user_id)
and i get the user_level and user_id in the controller:
$this->auth_role
$this->auth_user_id

Would be better to remove those parameters (user_level, user_id) form the function and get them inside the funcion instead off passing them from controller to model?