[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>

2 files changed, 5 insertions, 9 deletions

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index b4bfe338ea0e..e9b8e5926bef 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -184,22 +184,18 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
 
-#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
-#define page_test_dirty(page)           (0)
+#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
+#define page_test_and_clear_dirty(pfn, mapped)  (0)
 #endif
 
-#ifndef __HAVE_ARCH_PAGE_CLEAR_DIRTY
-#define page_clear_dirty(page, mapped)  do { } while (0)
-#endif
-
-#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
+#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
 #define pte_maybe_dirty(pte)            pte_dirty(pte)
 #else
 #define pte_maybe_dirty(pte)            (1)
 #endif
 
 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
-#define page_test_and_clear_young(page) (0)
+#define page_test_and_clear_young(pfn) (0)
 #endif
 
 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 811183de1ef5..79a6700b7162 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -308,7 +308,7 @@ static inline void SetPageUptodate(struct page *page)
 {
 #ifdef CONFIG_S390
         if (!test_and_set_bit(PG_uptodate, &page->flags))
-                page_clear_dirty(page, 0);
+                page_set_storage_key(page_to_pfn(page), PAGE_DEFAULT_KEY, 0);
 #else
         /*
          * Memory barrier must be issued before setting the PG_uptodate bit,