[PATCH 2/5] Implement generic time of day clocksource for powerpc machines.

[Paul Mackerras]

Daniel Walker writes:

> If you switch to the rtc do the shift and mult need to change?

You can't switch; any given CPU chip will have either the RTC or the
timebase but not both.

> > +       /* XXX this assumes clock->shift == 22 */
> > +       /* 4611686018 ~= 2^(20+64-22) / 1e9 */
> > +       t2x = (u64) clock->mult * 4611686018ULL;
> 
> It might make the code more readable if you put that constant into a
> macro that gives it a name.

The comment already gives more information than some arbitrary name
would.

Paul.