int add_cache(int next, 
              unsigned flags, 
              unsigned line_size, 
              unsigned num_lines, 
              const struct callout_rtn *rtn);

Add an entry to the cacheattr section of the system page structure. Parameters map one-to-one with the structure's fields. The return value is the array index number of the added entry. Note that if there's already an entry that matches the one you're trying to add, that entry's index is returned — nothing new is added to the section.