[PATCH 12/12] mm: Remove devmap related functions and page table bits

[Chunyan Zhang]

Hi Alistair,

On Tue, 10 Sept 2024 at 12:21, Alistair Popple <apopple at nvidia.com> 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 at nvidia.com>
> Acked-by: Will Deacon <will at kernel.org> # arm64
> ---
>  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 +--------
>  arch/powerpc/Kconfig                          |  1 +-
>  arch/powerpc/include/asm/book3s/64/hash-4k.h  |  6 +--
>  arch/powerpc/include/asm/book3s/64/hash-64k.h |  7 +--
>  arch/powerpc/include/asm/book3s/64/pgtable.h  | 52 +------------------
>  arch/powerpc/include/asm/book3s/64/radix.h    | 14 +-----
>  arch/x86/Kconfig                              |  1 +-
>  arch/x86/include/asm/pgtable.h                | 50 +-----------------
>  arch/x86/include/asm/pgtable_types.h          |  5 +--

RISC-V's references also need to be cleanup, it simply can be done by
reverting the commit

216e04bf1e4d (riscv: mm: Add support for ZONE_DEVICE)

Thanks,
Chunyan

>  include/linux/mm.h                            |  7 +--
>  include/linux/pfn_t.h                         | 20 +-------
>  include/linux/pgtable.h                       | 19 +------
>  mm/Kconfig                                    |  4 +-
>  mm/debug_vm_pgtable.c                         | 59 +--------------------
>  mm/hmm.c                                      |  3 +-
>  18 files changed, 11 insertions(+), 269 deletions(-)
>