[RFC PATCH 1/2]powerpc: foundation code to handle CR5 for local_t

[Benjamin Herrenschmidt]

On Fri, 2014-11-28 at 08:45 +0530, Madhavan Srinivasan wrote:
> > Can't we just unconditionally clear at as long as we do that after we've
> > saved it ? In that case, it's just a matter for the fixup code to check
> > the saved version rather than the actual CR..
> > 
> I use CR bit setting in the interrupt return path to enter the fixup
> section search. If we unconditionally clear it, we will have to enter
> the fixup section for every kernel return nip right?

As I said above. Can't we look at the saved version ?

IE.

 - On interrupt entry:

	* Save CR to CCR(r1)
	* clear CR5

 - On exit

	* Check CCR(r1)'s CR5 field
	* restore CR

Cheers,
Ben.