summaryrefslogtreecommitdiff
path: root/arch/s390/mm/gup.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/mm/gup.c')
-rw-r--r--arch/s390/mm/gup.c45
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);