[PATCH] hp-timing for ppc32/64

[Kumar Gala]

>> Note that some CPUs like the 970 can have an externally clocked
>> timebase. Apple uses this feature to make the CPU immune to bus/cpu
>> frequency slewing, they use a 33Mhz clock for that.
>>
>>
> The 970 does not implement a alternate timebase. So for 970 the  
> timebase
>
> is the highest frequency counter available.
> It seems that Apple choose 33MHz to meet the minimum (slowest)CPU- 
> clock
> /
> 32 timebase. But that was their choice. The IBM hardware seems to be
> holding to the CPU_clock / 8 timebase (including 970 based JS20).

One could argue that the performance monitors could be used as a  
cycle counter on 970 :)

- kumar