On Thu, Jun 27, 2024 at 10:54:28AM +1000, Alistair Popple wrote:

Now that DAX and all other reference counts to ZONE_DEVICE pages are
managed normally there is no need for the special devmap PTE/PMD/PUD
page table bits. So drop all references to these, freeing up a
software defined page table bit on architectures supporting it.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
---
 Documentation/mm/arch_pgtable_helpers.rst     |  6 +--
 arch/arm64/Kconfig                            |  1 +-
 arch/arm64/include/asm/pgtable-prot.h         |  1 +-
 arch/arm64/include/asm/pgtable.h              | 24 +--------

Not only do you exclusively remove code, but you also give us back a
pte bit! What's not to like?

Acked-by: Will Deacon <will@kernel.org> # arm64

Will