Adding cache shape info to powerpc

[Steven Munroe]

On Thu, 2016-08-18 at 10:17 +1000, Benjamin Herrenschmidt wrote:
> On Wed, 2016-08-17 at 10:36 +0200, Florian Weimer wrote:
> > > I've chosen this format. Is that ok with the community ? Can I still use
> > > the same AT_* vector numbers or should I create new ones ?
> > 
> > If the old format was in mainline at any point (or in a vendor kernel, 
> > but let's hope vendors don't do this anymore), you need to pick new numbers.
> > 
> > Do you expect that IFUNC resolvers will need this information?
> 
> The old format was only used by other architectures, not powerpc, do I
> still need to pick different numbers in that case ?
> 
> As for IFUNC I don't think so but I'll let Steve reply as I believe he
> is the original requestor for the functionality.
> 
Ben were are we on this? 

This is needed to fix a customer reported bug for lack of
sysconf(_SC_*CACHE_SIZE) support on powerpc.

Adding this information to the cputable and then auxv fits into the
current sysconf infrastructure best.

When we know the AT_ info format and upstream Kernel version we can
update kernel-features.h and enable a sysconf.c fragment to return these
values for powerpc