Re: [RFC] Improved add_timer_randomness for __CRIS__ (instead of rdtsc())

[johan.adolfsson@axis.com]

> > Put an inline function or macro in asm/timex.h (?) together with an
> > ARCH_HAS_RANDOM_TIMESTAMP define?
> 
> I don't think we want to make it specific to random. I think we just
> want to call it hires. 
> 
> > E.g. like this for i386:
> > #define ARCH_HAS_RANDOM_TIMESTAMP
> > #define RANDOM_TIMESTAMP(time, num) do{\
..  
> > And then in random.c:
> > ifdef ARCH_HAS_RANDOM_TIMESTAMP
> >   RANDOM_TIMESTAMP(time, num);
> > #else
> >   time = jiffies;
> > #endif
> 
> Again, too random-specific. And we need a way to get the timescale.
> Perhaps something like:
> 
> speed=get_timestamp_khz;
> lowbits=get_hires_timestamp();

But isn't the "num ^= high;" a way to improve the randomness
and the high value doesn't really need to be linear to the time?
Thus it would be random-specific and not just a timestamp.

/Johan