protection_map[] is an array based construct that translates given vm_flags combination. This array contains page protection map, which is populated by the platform via [__S000 .. __S111] and [__P000 .. __P111] exported macros. Primary usage for protection_map[] is for vm_get_page_prot(), which is used to determine page protection value for a given vm_flags. vm_get_page_prot() implementation, could again call platform overrides arch_vm_get_page_prot() and arch_filter_pgprot(). Some platforms override protection_map[] that was originally built with __SXXX/__PXXX with different runtime values. Currently there are multiple layers of abstraction i.e __SXXX/__PXXX macros , protection_map[], arch_vm_get_page_prot() and arch_filter_pgprot() built between the platform and generic MM, finally defining vm_get_page_prot(). Hence this series proposes to drop all these abstraction levels and instead just move the responsibility of defining vm_get_page_prot() to the platform itself making it clean and simple. This first introduces ARCH_HAS_VM_GET_PAGE_PROT which enables the platforms to define custom vm_get_page_prot(). This starts converting platforms that either change protection_map[] or define the overrides arch_filter_pgprot() or arch_vm_get_page_prot() which enables for those constructs to be dropped off completely. This series then converts remaining platforms which enables for __SXXX/__PXXX constructs to be dropped off completely. Finally it drops the generic vm_get_page_prot() and then ARCH_HAS_VM_GET_PAGE_PROT as every platform now defines their own vm_get_page_prot(). The series has been inspired from an earlier discuss with Christoph Hellwig https://lore.kernel.org/all/1632712920-8171-1-git-send-email-anshuman.khandual@xxxxxxx/ This series applies on 5.17-rc5 after the following patch. https://lore.kernel.org/all/1643004823-16441-1-git-send-email-anshuman.khandual@xxxxxxx/ This series has been cross built for multiple platforms. - Anshuman Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-mm@xxxxxxxxx Cc: linux-arch@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Changes in V2: - Dropped the entire comment block in [PATCH 30/30] per Geert - Replaced __P010 (although commented) with __PAGE_COPY on arm platform - Replaced __P101 with PAGE_READONLY on um platform Changes in V1: https://lore.kernel.org/all/1644805853-21338-1-git-send-email-anshuman.khandual@xxxxxxx/ - Add white spaces around the | operators - Moved powerpc_vm_get_page_prot() near vm_get_page_prot() on powerpc - Moved arm64_vm_get_page_prot() near vm_get_page_prot() on arm64 - Moved sparc_vm_get_page_prot() near vm_get_page_prot() on sparc - Compacted vm_get_page_prot() switch cases on all platforms - _PAGE_CACHE040 inclusion is dependent on CPU_IS_040_OR_060 - VM_SHARED case should return PAGE_NONE (not PAGE_COPY) on SH platform - Reorganized VM_SHARED, VM_EXEC, VM_WRITE, VM_READ - Dropped the last patch [RFC V1 31/31] which added macros for vm_flags combinations https://lore.kernel.org/all/1643029028-12710-32-git-send-email-anshuman.khandual@xxxxxxx/ Changes in RFC: https://lore.kernel.org/all/1643029028-12710-1-git-send-email-anshuman.khandual@xxxxxxx/ Anshuman Khandual (29): mm/debug_vm_pgtable: Drop protection_map[] usage mm/mmap: Clarify protection_map[] indices mm/mmap: Add new config ARCH_HAS_VM_GET_PAGE_PROT powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT arm64/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT sparc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT mips/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT m68k/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT arm/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT mm/mmap: Drop protection_map[] mm/mmap: Drop arch_filter_pgprot() mm/mmap: Drop arch_vm_get_page_pgprot() s390/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT riscv/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT alpha/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT sh/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT arc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT csky/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT extensa/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT parisc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT openrisc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT um/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT microblaze/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT nios2/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT hexagon/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT nds32/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT ia64/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT mm/mmap: Drop generic vm_get_page_prot() mm/mmap: Drop ARCH_HAS_VM_GET_PAGE_PROT Christoph Hellwig (1): x86/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT arch/alpha/include/asm/pgtable.h | 17 ---- arch/alpha/mm/init.c | 37 ++++++++ arch/arc/include/asm/pgtable-bits-arcv2.h | 17 ---- arch/arc/mm/mmap.c | 41 +++++++++ arch/arm/include/asm/pgtable.h | 18 ---- arch/arm/lib/uaccess_with_memcpy.c | 2 +- arch/arm/mm/mmu.c | 44 +++++++-- arch/arm64/Kconfig | 1 - arch/arm64/include/asm/mman.h | 24 ----- arch/arm64/include/asm/pgtable-prot.h | 18 ---- arch/arm64/include/asm/pgtable.h | 11 --- arch/arm64/mm/mmap.c | 78 ++++++++++++++++ arch/csky/include/asm/pgtable.h | 18 ---- arch/csky/mm/init.c | 32 +++++++ arch/hexagon/include/asm/pgtable.h | 24 ----- arch/hexagon/mm/init.c | 67 ++++++++++++++ arch/ia64/include/asm/pgtable.h | 17 ---- arch/ia64/mm/init.c | 41 ++++++++- arch/m68k/include/asm/mcf_pgtable.h | 59 ------------ arch/m68k/include/asm/motorola_pgtable.h | 22 ----- arch/m68k/include/asm/sun3_pgtable.h | 22 ----- arch/m68k/mm/init.c | 104 ++++++++++++++++++++++ arch/m68k/mm/motorola.c | 48 +++++++++- arch/microblaze/include/asm/pgtable.h | 17 ---- arch/microblaze/mm/init.c | 41 +++++++++ arch/mips/include/asm/pgtable.h | 22 ----- arch/mips/mm/cache.c | 60 +++++++------ arch/nds32/include/asm/pgtable.h | 17 ---- arch/nds32/mm/mmap.c | 37 ++++++++ arch/nios2/include/asm/pgtable.h | 16 ---- arch/nios2/mm/init.c | 45 ++++++++++ arch/openrisc/include/asm/pgtable.h | 18 ---- arch/openrisc/mm/init.c | 41 +++++++++ arch/parisc/include/asm/pgtable.h | 20 ----- arch/parisc/mm/init.c | 40 +++++++++ arch/powerpc/include/asm/mman.h | 12 --- arch/powerpc/include/asm/pgtable.h | 19 ---- arch/powerpc/mm/mmap.c | 59 ++++++++++++ arch/riscv/include/asm/pgtable.h | 16 ---- arch/riscv/mm/init.c | 42 +++++++++ arch/s390/include/asm/pgtable.h | 17 ---- arch/s390/mm/mmap.c | 33 +++++++ arch/sh/include/asm/pgtable.h | 17 ---- arch/sh/mm/mmap.c | 38 ++++++++ arch/sparc/include/asm/mman.h | 6 -- arch/sparc/include/asm/pgtable_32.h | 19 ---- arch/sparc/include/asm/pgtable_64.h | 19 ---- arch/sparc/mm/init_32.c | 35 ++++++++ arch/sparc/mm/init_64.c | 70 +++++++++++---- arch/um/include/asm/pgtable.h | 17 ---- arch/um/kernel/mem.c | 35 ++++++++ arch/x86/Kconfig | 1 - arch/x86/include/asm/pgtable.h | 5 -- arch/x86/include/asm/pgtable_types.h | 19 ---- arch/x86/include/uapi/asm/mman.h | 14 --- arch/x86/mm/Makefile | 2 +- arch/x86/mm/mem_encrypt_amd.c | 4 - arch/x86/mm/pgprot.c | 71 +++++++++++++++ arch/x86/um/mem_32.c | 2 +- arch/xtensa/include/asm/pgtable.h | 18 ---- arch/xtensa/mm/init.c | 35 ++++++++ include/linux/mm.h | 6 -- include/linux/mman.h | 4 - mm/Kconfig | 3 - mm/debug_vm_pgtable.c | 31 ++++--- mm/mmap.c | 42 --------- 66 files changed, 1142 insertions(+), 705 deletions(-) create mode 100644 arch/x86/mm/pgprot.c -- 2.25.1
