Subject: [PATCH v4 01/13] mm/memblock: add MEMBLOCK_NOMAP attribute to memblock memory table

From: [email-masked] (Will Deacon)
Date: Tue, 8 Dec 2015 12:07:44 +0000

Hi Ard,

On Thu, Dec 03, 2015 at 11:55:53AM +0100, Ard Biesheuvel wrote:
> On 30 November 2015 at 13:28, Ard Biesheuvel <[email-masked]> wrote:
> > This introduces the MEMBLOCK_NOMAP attribute and the required plumbing
> > to make it usable as an indicator that some parts of normal memory
> > should not be covered by the kernel direct mapping. It is up to the
> > arch to actually honor the attribute when laying out this mapping,
> > but the memblock code itself is modified to disregard these regions
> > for allocations and other general use.
> >
> > Cc: linux-mm at kvack.org
> > Cc: Alexander Kuleshov <[email-masked]>
> > Cc: Andrew Morton <[email-masked]>
> > Reviewed-by: Matt Fleming <[email-masked]>
> > Signed-off-by: Ard Biesheuvel <[email-masked]>
> > ---
> >  include/linux/memblock.h |  8 ++++++
> >  mm/memblock.c            | 28 ++++++++++++++++++++
> >  2 files changed, 36 insertions(+)

[...]

> May I kindly ask team-mm/Andrew/Alexander to chime in here, and
> indicate whether you are ok with this patch going in for 4.5? If so,
> could you please provide your ack so the patch can be kept together
> with the rest of the series, which depends on it?

I'm keen to queue this in the arm64 tree, since it's a prerequisite for
cleaning up a bunch of our EFI code and sharing it with 32-bit ARM.

> I should note that this change should not affect any memblock users
> that never set the MEMBLOCK_NOMAP flag, but please, if you see any
> issues beyond 'this may conflict with other stuff we have queued for
> 4.5', please do let me know.

Indeed, I can't see that this would cause any issues, but I would really
like an Ack from one of the MM maintainers before taking this.

Please could somebody take a look?

Will