[Cbe-oss-dev] [PATCH] 64K support for Kexec

[Segher Boessenkool]

>> But AS isn't relevant for Linux.  The PowerPC arch 2.03
>> shows bits 0..15 as part of the VPN field.
>
> Ugh ? The PPC Architecture Specification Book III is irrelevant to
> Linux ? since when ? :-)

Yeah try talk your self out of it :-)  But I see your
smiley so let's drop it.

> Now, as I said, there has been some changes in that area since 2.01
> indeed, and while I don't have 2.03 (or later) at hand right now, I 
> have
> some of the RFCs leading to those changes and they do indeed seem to
> imply that we shouldn't zero out those bits.

On older implementations those bits (when considered part
of the VPN, like in 2.03) would be zeroes too.  At least
as far as I can see.  Check all Book IV's to be sure ;-)

> That makes it a bit annoying as that means we would need to add more
> cpu-version specific code in __tlbie() and __tlbiel() ... so far,
> however, every Book IV I've seen seems to show that those bits are
> unused by tlbie(l), only lower order bits matter (which makes sense).

That too.

I say just delete that masking off of bits, unless you
want to spend all of easter reading old Book IV's...


Segher