powerpc/mm: NUMA pte should be handled via slow path in get_user_pages_fast()

We need to handle numa pte via the slow path

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, 13 insertions, 0 deletions

diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c
index c5f734e20b0f..d8746684f606 100644
--- a/arch/powerpc/mm/gup.c
+++ b/arch/powerpc/mm/gup.c
@@ -36,6 +36,11 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
         do {
                 pte_t pte = ACCESS_ONCE(*ptep);
                 struct page *page;
+                /*
+                 * Similar to the PMD case, NUMA hinting must take slow path
+                 */
+                if (pte_numa(pte))
+                        return 0;
 
                 if ((pte_val(pte) & mask) != result)
                         return 0;
@@ -75,6 +80,14 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
                 if (pmd_none(pmd) || pmd_trans_splitting(pmd))
                         return 0;
                 if (pmd_huge(pmd) || pmd_large(pmd)) {
+                        /*
+                         * NUMA hinting faults need to be handled in the GUP
+                         * slowpath for accounting purposes and so that they
+                         * can be serialised against THP migration.
+                         */
+                        if (pmd_numa(pmd))
+                                return 0;
+
                         if (!gup_hugepte((pte_t *)pmdp, PMD_SIZE, addr, next,
                                          write, pages, nr))
                                 return 0;