[V2,0/2] mm/mmap: Drop __SXXX/__PXXX macros from across platforms

Message

Anshuman Khandual June 13, 2022, 5:33 a.m. UTC

__SXXX/__PXXX macros is an unnecessary abstraction layer in creating the
generic protection_map[] array which is used for vm_get_page_prot(). This
abstraction layer can be avoided, if the platforms just define the array
protection_map[] for all possible vm_flags access permission combinations.

This series drops __SXXX/__PXXX macros from across platforms in the tree.
First it makes protection_map[] array private (static) on platforms which
enable ARCH_HAS_VM_GET_PAGE_PROT, later moves protection_map[] array into
arch for all remaining platforms (!ARCH_HAS_VM_GET_PAGE_PROT), dropping
the generic one. In the process __SXXX/__PXXX macros become redundant and
thus get dropped off completely. I understand that the diff stat is large
here, but please do suggest if there is a better way. This series applies
on v5.19-rc1 and has been build tested for multiple platforms.

The CC list for this series has been reduced to just minimum, until there
is some initial agreement.

- Anshuman

Changes in V2:

- Add 'const' identifier to protection_map[] on powerpc
- Dropped #ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT check from sparc 32
- Dropped protection_map[] init from sparc 64
- Dropped all new platform changes subscribing ARCH_HAS_VM_GET_PAGE_PROT
- Added a second patch which moves generic protection_map[] array into
  all remaining platforms (!ARCH_HAS_VM_GET_PAGE_PROT)

Changes in V1:

https://lore.kernel.org/linux-mm/[e-mail]/

Cc: Andrew Morton <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]

Anshuman Khandual (2):
  mm/mmap: Restrict generic protection_map[] array visibility
  mm/mmap: Drop generic protection_map[] array

 arch/alpha/include/asm/pgtable.h          | 17 -------
 arch/alpha/mm/init.c                      | 21 +++++++++
 arch/arc/include/asm/pgtable-bits-arcv2.h | 18 --------
 arch/arc/mm/mmap.c                        | 19 ++++++++
 arch/arm/include/asm/pgtable.h            | 17 -------
 arch/arm/lib/uaccess_with_memcpy.c        |  2 +-
 arch/arm/mm/mmu.c                         | 19 ++++++++
 arch/arm64/include/asm/pgtable-prot.h     | 18 --------
 arch/arm64/mm/mmap.c                      | 21 +++++++++
 arch/csky/include/asm/pgtable.h           | 18 --------
 arch/csky/mm/init.c                       | 19 ++++++++
 arch/hexagon/include/asm/pgtable.h        | 27 ------------
 arch/hexagon/mm/init.c                    | 41 +++++++++++++++++
 arch/ia64/include/asm/pgtable.h           | 18 --------
 arch/ia64/mm/init.c                       | 27 +++++++++++-
 arch/loongarch/include/asm/pgtable-bits.h | 19 --------
 arch/loongarch/mm/cache.c                 | 45 +++++++++++++++++++
 arch/m68k/include/asm/mcf_pgtable.h       | 54 -----------------------
 arch/m68k/include/asm/motorola_pgtable.h  | 22 ---------
 arch/m68k/include/asm/sun3_pgtable.h      | 17 -------
 arch/m68k/mm/mcfmmu.c                     | 54 +++++++++++++++++++++++
 arch/m68k/mm/motorola.c                   | 19 ++++++++
 arch/m68k/mm/sun3mmu.c                    | 19 ++++++++
 arch/microblaze/include/asm/pgtable.h     | 17 -------
 arch/microblaze/mm/init.c                 | 19 ++++++++
 arch/mips/include/asm/pgtable.h           | 22 ---------
 arch/mips/mm/cache.c                      |  2 +
 arch/nios2/include/asm/pgtable.h          | 16 -------
 arch/nios2/mm/init.c                      | 19 ++++++++
 arch/openrisc/include/asm/pgtable.h       | 18 --------
 arch/openrisc/mm/init.c                   | 19 ++++++++
 arch/parisc/include/asm/pgtable.h         | 18 --------
 arch/parisc/mm/init.c                     | 19 ++++++++
 arch/powerpc/include/asm/pgtable.h        | 18 --------
 arch/powerpc/mm/book3s64/pgtable.c        |  1 +
 arch/powerpc/mm/pgtable.c                 | 19 ++++++++
 arch/riscv/include/asm/pgtable.h          | 20 ---------
 arch/riscv/mm/init.c                      | 19 ++++++++
 arch/s390/include/asm/pgtable.h           | 17 -------
 arch/s390/mm/mmap.c                       | 19 ++++++++
 arch/sh/include/asm/pgtable.h             | 17 -------
 arch/sh/mm/mmap.c                         | 19 ++++++++
 arch/sparc/include/asm/pgtable_32.h       | 19 --------
 arch/sparc/include/asm/pgtable_64.h       | 19 --------
 arch/sparc/mm/init_32.c                   | 19 ++++++++
 arch/sparc/mm/init_64.c                   |  3 ++
 arch/um/include/asm/pgtable.h             | 17 -------
 arch/um/kernel/mem.c                      | 19 ++++++++
 arch/x86/include/asm/pgtable_types.h      | 19 --------
 arch/x86/mm/pgprot.c                      | 19 ++++++++
 arch/x86/um/mem_32.c                      |  2 +-
 arch/xtensa/include/asm/pgtable.h         | 18 --------
 arch/xtensa/mm/init.c                     | 19 ++++++++
 include/linux/mm.h                        |  2 +
 mm/mmap.c                                 | 19 --------
 55 files changed, 541 insertions(+), 522 deletions(-)

Comments

Christoph Hellwig June 15, 2022, 1:15 p.m. UTC | #1

I relaly like this.  The __SXXX/__PXXX are a complete mess, and this
cleans it up nicely.  So with any remaining issues sorted out I'm
all for it:

Acked-by: Christoph Hellwig <[e-mail]>