[PATCH 02/25] powerpc: define an additional vma bit for protection keys.

[Ram Pai]

On Thu, Sep 14, 2017 at 06:11:32PM +1000, Benjamin Herrenschmidt wrote:
> On Thu, 2017-09-14 at 14:38 +1000, Balbir Singh wrote:
> > On Fri,  8 Sep 2017 15:44:50 -0700
> > Ram Pai <linuxram at us.ibm.com> wrote:
> > 
> > > powerpc needs an additional vma bit to support 32 keys.
> > > Till the additional vma bit lands in include/linux/mm.h
> > > we have to define  it  in powerpc specific header file.
> > > This is  needed to get pkeys working on power.
> > > 
> > > Signed-off-by: Ram Pai <linuxram at us.ibm.com>
> > > ---
> > 
> > "This" being an arch specific hack for the additional bit?
> 
> Arch VMA bits ? really ? I'd rather we limit ourselves to 16 keys first
> then push for adding the extra bit to the generic code.

(hmm.. this mail did not land in my mailbox :( Sorry for the delay. Just
saw it in the mailing list.)

I think this is good idea. I can code it such a way that we
support 16 or 32 keys depending on the availability of the vma bit.

No more hunks in the code.


RP