@@ -307,6 +307,10 @@ static inline void flush_anon_page(struct vm_area_struct *vma,
 #define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
 static inline void flush_kernel_dcache_page(struct page *page)
 {
+	extern void __flush_kernel_dcache_page(struct page *);
+	/* highmem pages are always flushed upon kunmap already */
+	if (!PageHighMem(page))
+		__flush_kernel_dcache_page(page);
 }
 
 #define flush_dcache_mmap_lock(mapping) \

@@ -192,6 +192,48 @@ void __flush_dcache_page(struct address_space *mapping, struct page *page)
 				page->index << PAGE_CACHE_SHIFT);
 }
 
+/*
+ * Ensure cache coherency for the kernel mapping of this page.
+ *
+ * If the page only exists in the page cache and there are no user
+ * space mappings, we can be lazy and remember that we may have dirty
+ * kernel cache lines for later.  Otherwise, we need to flush the
+ * dirty kernel cache lines directly.
+ *
+ * Note that we disable the lazy flush for SMP configurations where
+ * the cache maintenance operations are not automatically broadcasted.
+ *
+ * We can assume that the page is no high mem page, see
+ * flush_kernel_dcache_page.
+ */
+void __flush_kernel_dcache_page(struct page *page)
+{
+	struct address_space *mapping;
+
+	/*
+	 * The zero page is never written to, so never has any dirty
+	 * cache lines, and therefore never needs to be flushed.
+	 */
+	if (page == ZERO_PAGE(0))
+		return;
+
+	mapping = page_mapping(page);
+
+	if (!cache_ops_need_broadcast()) {
+		if ((mapping && !mapping_mapped(mapping)) ||
+		    (!mapping && cache_is_vipt_nonaliasing())) {
+			clear_bit(PG_dcache_clean, &page->flags);
+			return;
+		}
+	}
+
+	__cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
+	if (mapping && !cache_is_vivt())
+		__flush_icache_all();
+	set_bit(PG_dcache_clean, &page->flags);
+}
+EXPORT_SYMBOL(__flush_kernel_dcache_page);
+
 static void __flush_dcache_aliases(struct address_space *mapping, struct page *page)
 {
 	struct mm_struct *mm = current->active_mm;