ppc/hugetlbfs: Replace ACCESS_ONCE with READ_ONCE

ACCESS_ONCE does not work reliably on non-scalar types. For
example gcc 4.6 and 4.7 might remove the volatile tag for such
accesses during the SRA (scalar replacement of aggregates) step
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145)

Change the ppc/hugetlbfs code to replace ACCESS_ONCE with READ_ONCE.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 5ff4e07d920a..620d0ec93e6f 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -978,7 +978,7 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift
                  */
                 pdshift = PUD_SHIFT;
                 pudp = pud_offset(&pgd, ea);
-                pud  = ACCESS_ONCE(*pudp);
+                pud  = READ_ONCE(*pudp);
 
                 if (pud_none(pud))
                         return NULL;
@@ -990,7 +990,7 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift
                 else {
                         pdshift = PMD_SHIFT;
                         pmdp = pmd_offset(&pud, ea);
-                        pmd  = ACCESS_ONCE(*pmdp);
+                        pmd  = READ_ONCE(*pmdp);
                         /*
                          * A hugepage collapse is captured by pmd_none, because
                          * it mark the pmd none and do a hpte invalidate.