On Fri, Mar 25, 2022 at 3:25 AM Michael Ellerman <[email protected]> wrote:
>
> Livepatch support for 32-bit is probably the standout new feature, otherwise mostly just
> lots of bits and pieces all over the board.
Heh. I would have expected 32-bit ppc to be entirely legacy by now, so
it's a bit surprising to see that being a standout feature.
That said:
> There's a series of commits cleaning up function descriptor handling,
For some reason I also thought that powerpc had actually moved away
from function descriptors, so I'm clearly not keeping up with the
times.
Anyway, unification in that odd area is all good. Pulled,
Linus
Linus Torvalds <[email protected]> writes:
> On Fri, Mar 25, 2022 at 3:25 AM Michael Ellerman <[email protected]> wrote:
>>
>> Livepatch support for 32-bit is probably the standout new feature, otherwise mostly just
>> lots of bits and pieces all over the board.
>
> Heh. I would have expected 32-bit ppc to be entirely legacy by now, so
> it's a bit surprising to see that being a standout feature.
We still get the odd bug report from people running mainline, or recent
stable kernels, on 32-bit.
And obviously Christophe has been doing lots of work on the Linux side,
so in that sense 32-bit is alive and well.
Having said that I don't think we'll see any new 32-bit CPU designs, so
the clock is slowly ticking.
> That said:
>
>> There's a series of commits cleaning up function descriptor handling,
>
> For some reason I also thought that powerpc had actually moved away
> from function descriptors, so I'm clearly not keeping up with the
> times.
No you're right, we have moved away from them, but not entirely.
Functions descriptors are still used for 64-bit big endian, but they're
not used for 64-bit little endian, or 32-bit.
cheers
On Mon, Mar 28, 2022 at 08:07:13PM +1100, Michael Ellerman wrote:
> Linus Torvalds <[email protected]> writes:
> > On Fri, Mar 25, 2022 at 3:25 AM Michael Ellerman <[email protected]> wrote:
>
> > That said:
> >
> >> There's a series of commits cleaning up function descriptor handling,
> >
> > For some reason I also thought that powerpc had actually moved away
> > from function descriptors, so I'm clearly not keeping up with the
> > times.
>
> No you're right, we have moved away from them, but not entirely.
>
> Functions descriptors are still used for 64-bit big endian, but they're
> not used for 64-bit little endian, or 32-bit.
There was a patch to use ABIv2 for ppc64 big endian. I suppose that
would rid usof the gunction descriptors for good.
Somehow the discussion of that change tralied off without any results.
Maybe it's worth resurrecting?
Thanks
Michal