Re: [PATCH v3.1 4/4] arm64: mm: Implement pte_devmap support

From: Will Deacon
Date: Wed May 29 2019 - 06:07:09 EST


On Tue, May 28, 2019 at 02:46:59PM +0100, Robin Murphy wrote:
> In order for things like get_user_pages() to work on ZONE_DEVICE memory,
> we need a software PTE bit to identify device-backed PFNs. Hook this up
> along with the relevant helpers to join in with ARCH_HAS_PTE_DEVMAP.
>
> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> ---
>
> Fix to build correctly under all combinations of
> CONFIG_PGTABLE_LEVELS and CONFIG_TRANSPARENT_HUGEPAGE.
>
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/pgtable-prot.h | 1 +
> arch/arm64/include/asm/pgtable.h | 21 +++++++++++++++++++++
> 3 files changed, 23 insertions(+)

Acked-by: Will Deacon <will.deacon@xxxxxxx>

Andrew -- please can you update the previous version of this patch, which
I think you picked up?

Thanks,

Will