-#define PPC_PGBYTES 4096 /* bytes per ppc page */
-#define PPC_PGSHIFT 12 /* number of bits to shift for pages */
+#define BYTE_SIZE 8 /* byte size in bits */
+
+#define PPC_PGBYTES 4096 /* bytes per ppc page */
+#define PPC_PGSHIFT 12 /* number of bits to shift for pages */
+
+#define PAGE_SIZE PPC_PGBYTES
+#define PAGE_SHIFT PPC_PGSHIFT
+#define PAGE_MASK (PAGE_SIZE - 1)
+
+#if 0
+#define VM_MAX_PAGE_ADDRESS 0xFFFFFFFFFFFFF000ULL
+#else
+/*
+ * LP64todo - For now, we are limited to 51-bits of user addressing
+ */
+#define VM_MAX_PAGE_ADDRESS 0x0007FFFFFFFFF000ULL
+#endif