mod_64
counter = c->count - (mod_64((2 * d), c->count));
counter = c->count - mod_64(d, c->count);
out = ((mod_64(d, c->count) == 0) && (d != 0));
out = (mod_64(d, c->count) < ((c->count + 1) >> 1));
ns = mod_64(ktime_to_ns(remaining), apic->lapic_timer.period);