mm/mremap: allow arch runtime override
Patch series "Speedup mremap on ppc64", v8. This patchset enables MOVE_PMD/MOVE_PUD support on power. This requires the platform to support updating higher-level page tables without updating page table entries. This also needs to invalidate the Page Walk Cache on architecture supporting the same. This patch (of 3): Architectures like ppc64 support faster mremap only with radix translation. Hence allow a runtime check w.r.t support for fast mremap. Link: https://lkml.kernel.org/r/20210616045735.374532-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20210616045735.374532-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -83,5 +83,11 @@ static inline int mm_is_thread_local(struct mm_struct *mm)
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}
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#endif
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#define arch_supports_page_table_move arch_supports_page_table_move
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static inline bool arch_supports_page_table_move(void)
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{
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return radix_enabled();
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}
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#endif /* __KERNEL__ */
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#endif /* __ASM_POWERPC_TLB_H */
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15
mm/mremap.c
15
mm/mremap.c
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@ -25,7 +25,7 @@
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#include <linux/userfaultfd_k.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/tlb.h>
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#include <asm/pgalloc.h>
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#include "internal.h"
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@ -210,6 +210,15 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
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drop_rmap_locks(vma);
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}
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#ifndef arch_supports_page_table_move
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#define arch_supports_page_table_move arch_supports_page_table_move
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static inline bool arch_supports_page_table_move(void)
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{
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return IS_ENABLED(CONFIG_HAVE_MOVE_PMD) ||
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IS_ENABLED(CONFIG_HAVE_MOVE_PUD);
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}
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#endif
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#ifdef CONFIG_HAVE_MOVE_PMD
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static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
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unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd)
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@ -218,6 +227,8 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
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struct mm_struct *mm = vma->vm_mm;
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pmd_t pmd;
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if (!arch_supports_page_table_move())
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return false;
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/*
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* The destination pmd shouldn't be established, free_pgtables()
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* should have released it.
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@ -284,6 +295,8 @@ static bool move_normal_pud(struct vm_area_struct *vma, unsigned long old_addr,
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struct mm_struct *mm = vma->vm_mm;
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pud_t pud;
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if (!arch_supports_page_table_move())
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return false;
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/*
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* The destination pud shouldn't be established, free_pgtables()
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* should have released it.
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