From: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx> Subject: 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@xxxxxxxxxxxxxxxxxx Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Mike Kravetz <kravetz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/hugetlb.h | 4 ++++ mm/gup.c | 7 +++++++ mm/hugetlb.c | 9 +++++++++ 3 files changed, 20 insertions(+) diff -puN include/linux/hugetlb.h~mm-follow_page_mask-add-support-for-hugetlb-pgd-entries include/linux/hugetlb.h --- a/include/linux/hugetlb.h~mm-follow_page_mask-add-support-for-hugetlb-pgd-entries +++ a/include/linux/hugetlb.h @@ -121,6 +121,9 @@ struct page *follow_huge_pmd(struct mm_s 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( } #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 -puN mm/gup.c~mm-follow_page_mask-add-support-for-hugetlb-pgd-entries mm/gup.c --- a/mm/gup.c~mm-follow_page_mask-add-support-for-hugetlb-pgd-entries +++ a/mm/gup.c @@ -357,6 +357,13 @@ struct page *follow_page_mask(struct vm_ 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 -puN mm/hugetlb.c~mm-follow_page_mask-add-support-for-hugetlb-pgd-entries mm/hugetlb.c --- a/mm/hugetlb.c~mm-follow_page_mask-add-support-for-hugetlb-pgd-entries +++ a/mm/hugetlb.c @@ -4715,6 +4715,15 @@ follow_huge_pud(struct mm_struct *mm, un 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 /* _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
