clocksource_cyc2ns
nsecs = clocksource_cyc2ns(cycles - last_cycles,
work_delay_ns = clocksource_cyc2ns(max_cycles, cc->mult, cc->shift);
return clocksource_cyc2ns(delta, cs->mult, cs->shift);
max_nsecs = clocksource_cyc2ns(max_cycles, mult - maxadj, shift);