From faaa5b62d3f7907e217b179556038f9f8e157ee0 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 6 Jul 2017 15:38:50 -0700 Subject: [PATCH] mm/follow_page_mask: add support for hugetlb pgd entries ppc64 supports pgd hugetlb entries. Add code to handle hugetlb pgd entries to follow_page_mask so that ppc64 can switch to it to handle hugetlbe entries. Link: http://lkml.kernel.org/r/1494926612-23928-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Anshuman Khandual Signed-off-by: Aneesh Kumar K.V Cc: Naoya Horiguchi Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Mike Kravetz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 4 ++++ mm/gup.c | 7 +++++++ mm/hugetlb.c | 9 +++++++++ 3 files changed, 20 insertions(+) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index aa1df49b9a14..3656ce605dc9 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -121,6 +121,9 @@ struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int flags); struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address, pud_t *pud, int flags); +struct page *follow_huge_pgd(struct mm_struct *mm, unsigned long address, + pgd_t *pgd, int flags); + int pmd_huge(pmd_t pmd); int pud_huge(pud_t pud); unsigned long hugetlb_change_protection(struct vm_area_struct *vma, @@ -150,6 +153,7 @@ static inline void hugetlb_show_meminfo(void) } #define follow_huge_pmd(mm, addr, pmd, flags) NULL #define follow_huge_pud(mm, addr, pud, flags) NULL +#define follow_huge_pgd(mm, addr, pgd, flags) NULL #define prepare_hugepage_range(file, addr, len) (-EINVAL) #define pmd_huge(x) 0 #define pud_huge(x) 0 diff --git a/mm/gup.c b/mm/gup.c index bf68e21d7a3a..fe95a37a4172 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -357,6 +357,13 @@ struct page *follow_page_mask(struct vm_area_struct *vma, if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) return no_page_table(vma, flags); + if (pgd_huge(*pgd)) { + page = follow_huge_pgd(mm, address, pgd, flags); + if (page) + return page; + return no_page_table(vma, flags); + } + return follow_p4d_mask(vma, address, pgd, flags, page_mask); } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 65c84414a6b7..a446869aa7f1 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4715,6 +4715,15 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address, return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); } +struct page * __weak +follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) +{ + if (flags & FOLL_GET) + return NULL; + + return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); +} + #ifdef CONFIG_MEMORY_FAILURE /* -- GitLab