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| author | Anshuman Khandual <anshuman.khandual@arm.com> | 2022-04-28 23:16:12 -0700 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-04-28 23:16:12 -0700 |
| commit | 67436193c2874c2e0e2d654820fadb9e79785335 (patch) | |
| tree | 64dff03160060d25bc2983099c2cafc83b0d5aaa /mm/mmap.c | |
| parent | c5d8a3643d91be748d7ff12eedc5876f32cc8283 (diff) | |
| download | linux-67436193c2874c2e0e2d654820fadb9e79785335.tar.gz linux-67436193c2874c2e0e2d654820fadb9e79785335.tar.bz2 linux-67436193c2874c2e0e2d654820fadb9e79785335.zip | |
mm/mmap: add new config ARCH_HAS_VM_GET_PAGE_PROT
Patch series "mm/mmap: Drop arch_vm_get_page_prot() and arch_filter_pgprot()", v7.
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 later two abstraction levels and
instead just move the responsibility of defining vm_get_page_prot() to the
platform (still utilizing generic protection_map[] array) 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 define the overrides arch_filter_pgprot() or
arch_vm_get_page_prot() which enables for those constructs to be dropped
off completely.
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@arm.com/
This patch (of 7):
Add a new config ARCH_HAS_VM_GET_PAGE_PROT, which when subscribed enables
a given platform to define its own vm_get_page_prot() but still utilizing
the generic protection_map[] array.
Link: https://lkml.kernel.org/r/20220414062125.609297-1-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/20220414062125.609297-2-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index e32640456c92..c1376ce34316 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -120,6 +120,7 @@ pgprot_t protection_map[16] __ro_after_init = { [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __S111 }; +#ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT #ifndef CONFIG_ARCH_HAS_FILTER_PGPROT static inline pgprot_t arch_filter_pgprot(pgprot_t prot) { @@ -136,6 +137,7 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags) return arch_filter_pgprot(ret); } EXPORT_SYMBOL(vm_get_page_prot); +#endif /* CONFIG_ARCH_HAS_VM_GET_PAGE_PROT */ static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags) { |