Re: [PATCH 3/6] 8xx: invalidate non present TLBs

On Thu, 2009-10-08 at 13:11 -0700, Dan Malek wrote:

There are many comments written about 8xx as various
behavior was discovered.  Worse, some of these details
would be different among the different processor versions.
You need to be careful and test as many different part
versions as possible to ensure you have everything
covered.....  then someone will find a part that doesn't
quite work, "fix" it, and break others :-)

In this particular case, the PEM does state dcbst is treated
as a load, but from experience we know 8xx doesn't work
that way.  Of course, since dcbst is a store operation,
you could argue that 8xx got it correct :-) 

Hehe. Well, it's architecturally incorrect, as dcbst is not really a
store operation in the sense that it doesn't modify the target cache
line, and as such doesn't (mustn't) be covered by write access
protection, shouldn't set DIRTY, etc...

So I would argue that 8xx got it wrong either way :-)

Cheers,
Ben.