[S390] merge page_test_dirty and page_clear_dirty

The page_clear_dirty primitive always sets the default storage key
which resets the access control bits and the fetch protection bit.
That will surprise a KVM guest that sets non-zero access control
bits or the fetch protection bit. Merge page_test_dirty and
page_clear_dirty back to a single function and only clear the
dirty bit from the storage key.

In addition move the function page_test_and_clear_dirty and
page_test_and_clear_young to page.h where they belong. This
requires to change the parameter from a struct page * to a page
frame number.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 8da044a1db0f..522e4a93cadd 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -719,7 +719,7 @@ int page_referenced(struct page *page,
                         unlock_page(page);
         }
 out:
-        if (page_test_and_clear_young(page))
+        if (page_test_and_clear_young(page_to_pfn(page)))
                 referenced++;
 
         return referenced;
@@ -785,10 +785,8 @@ int page_mkclean(struct page *page)
                 struct address_space *mapping = page_mapping(page);
                 if (mapping) {
                         ret = page_mkclean_file(mapping, page);
-                        if (page_test_dirty(page)) {
-                                page_clear_dirty(page, 1);
+                        if (page_test_and_clear_dirty(page_to_pfn(page), 1))
                                 ret = 1;
-                        }
                 }
         }
 
@@ -981,10 +979,9 @@ void page_remove_rmap(struct page *page)
          * not if it's in swapcache - there might be another pte slot
          * containing the swap entry, but page not yet written to swap.
          */
-        if ((!PageAnon(page) || PageSwapCache(page)) && page_test_dirty(page)) {
-                page_clear_dirty(page, 1);
+        if ((!PageAnon(page) || PageSwapCache(page)) &&
+            page_test_and_clear_dirty(page_to_pfn(page), 1))
                 set_page_dirty(page);
-        }
         /*
          * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED
          * and not charged by memcg for now.