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Commit 1d78a62c authored by Catalin Marinas's avatar Catalin Marinas Committed by Linus Torvalds
Browse files

arm64: provide pmdp_establish() helper 

We need an atomic way to setup pmd page table entry, avoiding races with
CPU setting dirty/accessed bits.  This is required to implement
pmdp_invalidate() that doesn't lose these bits.

Link: http://lkml.kernel.org/r/20171213105756.69879-5-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ef298cc5

arch/arm64/include/asm/pgtable.h

+7 −0
Original line number Diff line number Diff line
@@ -706,6 +706,13 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, 
{

	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);

}



#define pmdp_establish pmdp_establish

static inline pmd_t pmdp_establish(struct vm_area_struct *vma,

		unsigned long address, pmd_t *pmdp, pmd_t pmd)

{

	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));

}

#endif



extern pgd_t swapper_pg_dir[PTRS_PER_PGD];