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Anshuman Khandual
67436193c2
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/[email protected]/ 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/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Anshuman Khandual <[email protected]> Reviewed-by: Christophe Leroy <[email protected]> Reviewed-by: Catalin Marinas <[email protected]> Suggested-by: Christoph Hellwig <[email protected]> Cc: David S. Miller <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Khalid Aziz <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
Linux kernel
============
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