+/* Cast to unsigned long before casting to void * to avoid a warning from
+ * mmap_kmem about cutting a long long down to a void *. Not sure that
+ * casting is the right thing, but 32-bit UML can't have 64-bit virtual
+ * addresses
+ */
+#define __pa(virt) to_phys((void *) (unsigned long) (virt))
+#define __va(phys) to_virt((unsigned long) (phys))