Platform specific huge_ptep_get() is required only when fetching the huge PTE involves more than just dereferencing the page table pointer. This is not the case on arm64 platform. Hence huge_ptep_pte() can be dropped along with it's __HAVE_ARCH_HUGE_PTEP_GET subscription. Before that, it updates the generic huge_ptep_get() with READ_ONCE() which will prevent known page table issues with THP on arm64. https://lore.kernel.org/r/1506527369-19535-1-git-send-email-will.deacon@xxxxxxx/ Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> --- arch/arm64/include/asm/hugetlb.h | 6 ------ include/asm-generic/hugetlb.h | 2 +- 2 files changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h index 2eb6c234d594..b88878ddc88b 100644 --- a/arch/arm64/include/asm/hugetlb.h +++ b/arch/arm64/include/asm/hugetlb.h @@ -17,12 +17,6 @@ extern bool arch_hugetlb_migration_supported(struct hstate *h); #endif -#define __HAVE_ARCH_HUGE_PTEP_GET -static inline pte_t huge_ptep_get(pte_t *ptep) -{ - return READ_ONCE(*ptep); -} - static inline int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr, unsigned long len) { diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h index 822f433ac95c..40f85decc2ee 100644 --- a/include/asm-generic/hugetlb.h +++ b/include/asm-generic/hugetlb.h @@ -122,7 +122,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma, #ifndef __HAVE_ARCH_HUGE_PTEP_GET static inline pte_t huge_ptep_get(pte_t *ptep) { - return *ptep; + return READ_ONCE(*ptep); } #endif -- 2.20.1
