diff options
Diffstat (limited to 'arch/s390/mm/gup.c')
| -rw-r--r-- | arch/s390/mm/gup.c | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c index a8a6765f1a51..adb0c34bf431 100644 --- a/arch/s390/mm/gup.c +++ b/arch/s390/mm/gup.c @@ -128,6 +128,44 @@ static inline int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, return 1; } +static int gup_huge_pud(pud_t *pudp, pud_t pud, unsigned long addr, + unsigned long end, int write, struct page **pages, int *nr) +{ + struct page *head, *page; + unsigned long mask; + int refs; + + mask = (write ? _REGION_ENTRY_PROTECT : 0) | _REGION_ENTRY_INVALID; + if ((pud_val(pud) & mask) != 0) + return 0; + VM_BUG_ON(!pfn_valid(pud_pfn(pud))); + + refs = 0; + head = pud_page(pud); + page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT); + do { + VM_BUG_ON_PAGE(compound_head(page) != head, page); + pages[*nr] = page; + (*nr)++; + page++; + refs++; + } while (addr += PAGE_SIZE, addr != end); + + if (!page_cache_add_speculative(head, refs)) { + *nr -= refs; + return 0; + } + + if (unlikely(pud_val(pud) != pud_val(*pudp))) { + *nr -= refs; + while (refs--) + put_page(head); + return 0; + } + + return 1; +} + static inline int gup_pud_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { @@ -144,7 +182,12 @@ static inline int gup_pud_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, next = pud_addr_end(addr, end); if (pud_none(pud)) return 0; - if (!gup_pmd_range(pudp, pud, addr, next, write, pages, nr)) + if (unlikely(pud_large(pud))) { + if (!gup_huge_pud(pudp, pud, addr, next, write, pages, + nr)) + return 0; + } else if (!gup_pmd_range(pudp, pud, addr, next, write, pages, + nr)) return 0; } while (pudp++, addr = next, addr != end); |