[RFC PATCH 3/9] powerpc/mm/64: Use physical addresses in upper page table tree levels

[Paul Mackerras]

On Sat, Feb 20, 2016 at 10:05:58PM +0530, Aneesh Kumar K.V wrote:
> Paul Mackerras <paulus at samba.org> writes:
> 
> > This changes the Linux page tables to store physical addresses
> > rather than kernel virtual addresses in the upper levels of the
> > tree (pgd, pud and pmd) for all 64-bit machines.
> >
> > This frees up some high order bits, and will be needed with book3s
> > PowerISA v3.0 machines which read the page table tree in hardware
> > in radix mode.
> 
> 
> Should we not update pmd_pgtable ?

Not sure what you mean by this - the patch does update pmd_pgtable
for the 64k page case (the 4k case is already fine).

> I have the below patch in my series.
> 
> http://mid.gmane.org/1455814254-10226-13-git-send-email-aneesh.kumar@linux.vnet.ibm.com

That looks like a reasonable thing to do.

Paul.