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

On Sat, Feb 20, 2016 at 10:05:58PM +0530, Aneesh Kumar K.V wrote:

Paul Mackerras [off-list ref] writes:

quoted

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.