[PATCH] Fix up page_mkclean_one(): virtual caches, s390

 - add flush_cache_page() for all those virtual indexed cache
   architectures.

 - handle s390.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[chrisw: fold in d6e88e67]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

mm/rmap.c

@@ -432,7 +432,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	unsigned long address;
-	pte_t *pte, entry;
+	pte_t *pte;
 	spinlock_t *ptl;
 	int ret = 0;
 
@@ -444,17 +444,18 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
 	if (!pte)
 		goto out;
 
-	if (!pte_dirty(*pte) && !pte_write(*pte))
-		goto unlock;
+	if (pte_dirty(*pte) || pte_write(*pte)) {
+		pte_t entry;
 
-	entry = ptep_get_and_clear(mm, address, pte);
-	entry = pte_mkclean(entry);
-	entry = pte_wrprotect(entry);
-	ptep_establish(vma, address, pte, entry);
-	lazy_mmu_prot_update(entry);
-	ret = 1;
+		flush_cache_page(vma, address, pte_pfn(*pte));
+		entry = ptep_clear_flush(vma, address, pte);
+		entry = pte_wrprotect(entry);
+		entry = pte_mkclean(entry);
+		set_pte_at(mm, address, pte, entry);
+		lazy_mmu_prot_update(entry);
+		ret = 1;
+	}
 
-unlock:
 	pte_unmap_unlock(pte, ptl);
 out:
 	return ret;
@@ -489,6 +490,8 @@ int page_mkclean(struct page *page)
 		if (mapping)
 			ret = page_mkclean_file(mapping, page);
 	}
+	if (page_test_and_clear_dirty(page))
+		ret = 1;
 
 	return ret;
 }