Re: [patch 1/6] mm: Allow architectures to define additional protection bits

On Tue, 2008-07-08 at 08:24 +1000, Benjamin Herrenschmidt wrote:

quoted

There is a little inconsistency, that arch_calc_vm_prot_bits
and arch_vm_get_page_prot just handle the exceptional flag (SAO),
whereas arch_validate_prot handles all of them; but I don't feel
so strongly about that to suggest resubmission.

And regarding VM_SAO added to include/linux/mm.h in 3/6: although
it's odd to be weaving back and forth between arch-specific and
common, it's already the case that mman definitions and pgtable
definitions are arch-specific but mm.h common: I'm much happier
to have VM_SAO defined once there as Dave has it, than get into
arch-specific vm_flags.

Is someone going to be asking for PROT_WC shortly?

I'll definitely come with PROT_ENDIAN soon :-) (ie, some powerpc
processors can have a per-page endian flag that when set causes all
load/store instructions on this are to be byte-flipped, support for
this
feature has been requested for some time, and now I have the
infrastructure to do it).

BTW. Do we have your ack ?

Andrew, what tree should this go via ? I have further powerpc patches
depending on this one... so on one hand I'd be happy to take it, but
on the other hand, it's more likely to clash with other things...

Maybe I should check how it applies on top of linux-next.

Ben.