powerpc: Update gup_pmd_range to handle transparent hugepages

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c
index 4b921affa495..223a255545fc 100644
--- a/arch/powerpc/mm/gup.c
+++ b/arch/powerpc/mm/gup.c
@@ -66,9 +66,15 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
                 pmd_t pmd = *pmdp;
 
                 next = pmd_addr_end(addr, end);
-                if (pmd_none(pmd))
+                /*
+                 * If we find a splitting transparent hugepage we
+                 * return zero. That will result in taking the slow
+                 * path which will call wait_split_huge_page()
+                 * if the pmd is still in splitting state
+                 */
+                if (pmd_none(pmd) || pmd_trans_splitting(pmd))
                         return 0;
-                if (pmd_huge(pmd)) {
+                if (pmd_huge(pmd) || pmd_large(pmd)) {
                         if (!gup_hugepte((pte_t *)pmdp, PMD_SIZE, addr, next,
                                          write, pages, nr))
                                 return 0;