Index: uspace/lib/c/include/as.h
===================================================================
--- uspace/lib/c/include/as.h	(revision 664857412ee8f831442f0cce913b5ba1a15f2b33)
+++ uspace/lib/c/include/as.h	(revision ae6f303748db0f9a242fb1a15affe2c3ee62e621)
@@ -41,4 +41,17 @@
 #include <libarch/config.h>
 
+static inline size_t SIZE2PAGES(size_t size)
+{
+	if (size == 0)
+		return 0;
+	
+	return (size_t) ((size - 1) >> PAGE_WIDTH) + 1;
+}
+
+static inline size_t PAGES2SIZE(size_t pages)
+{
+	return (size_t) (pages << PAGE_WIDTH);
+}
+
 extern void *as_area_create(void *address, size_t size, int flags);
 extern int as_area_resize(void *address, size_t size, int flags);