roundup_u64
upper = roundup_u64(fst->speed + min_trip_distance, fan->fan_trip_granularity);
start_tsf += roundup_u64(min_time - start_tsf, bcn_intvl_ref_us);
tsf_lmt += roundup_u64(tsf - tsf_lmt, interval);
alarm = roundup_u64(alarm, NSEC_PER_SEC);
alarm = roundup_u64(alarm, integral_period);
stime += roundup_u64(delta, period);
alarm = roundup_u64(stime - period, integral_period);