iopt_area_index_to_iova
unsigned long start_iova = iopt_area_index_to_iova(area, start_index);
iova = iopt_area_index_to_iova(area, start_index);
iova = iopt_area_index_to_iova(area, start_index);
iopt_area_index_to_iova(area, start_index);