mm: remove rest of ACCESS_ONCE() usages

We converted some of the usages of ACCESS_ONCE to READ_ONCE in the mm/
tree since it doesn't work reliably on non-scalar types.

This patch removes the rest of the usages of ACCESS_ONCE, and use the new
READ_ONCE API for the read accesses.  This makes things cleaner, instead
of using separate/multiple sets of APIs.

Signed-off-by: Jason Low <jason.low2@hp.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/mm/ksm.c b/mm/ksm.c
index 4162dce2eb44..7ee101eaacdf 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -542,7 +542,7 @@ static struct page *get_ksm_page(struct stable_node *stable_node, bool lock_it)
         expected_mapping = (void *)stable_node +
                                 (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
 again:
-        kpfn = ACCESS_ONCE(stable_node->kpfn);
+        kpfn = READ_ONCE(stable_node->kpfn);
         page = pfn_to_page(kpfn);
 
         /*
@@ -551,7 +551,7 @@ again:
          * but on Alpha we need to be more careful.
          */
         smp_read_barrier_depends();
-        if (ACCESS_ONCE(page->mapping) != expected_mapping)
+        if (READ_ONCE(page->mapping) != expected_mapping)
                 goto stale;
 
         /*
@@ -577,14 +577,14 @@ again:
                 cpu_relax();
         }
 
-        if (ACCESS_ONCE(page->mapping) != expected_mapping) {
+        if (READ_ONCE(page->mapping) != expected_mapping) {
                 put_page(page);
                 goto stale;
         }
 
         if (lock_it) {
                 lock_page(page);
-                if (ACCESS_ONCE(page->mapping) != expected_mapping) {
+                if (READ_ONCE(page->mapping) != expected_mapping) {
                         unlock_page(page);
                         put_page(page);
                         goto stale;
@@ -600,7 +600,7 @@ stale:
          * before checking whether node->kpfn has been changed.
          */
         smp_rmb();
-        if (ACCESS_ONCE(stable_node->kpfn) != kpfn)
+        if (READ_ONCE(stable_node->kpfn) != kpfn)
                 goto again;
         remove_node_from_stable_tree(stable_node);
         return NULL;