-ffff800000000000 - ffff80ffffffffff (=40bits) guard hole
-ffff810000000000 - ffffc0ffffffffff (=46bits) direct mapping of all phys. memory
-ffffc10000000000 - ffffc1ffffffffff (=40bits) hole
-ffffc20000000000 - ffffe1ffffffffff (=45bits) vmalloc/ioremap space
+ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole
+ffff810000000000 - ffffc0ffffffffff (=46 bits) direct mapping of all phys. memory
+ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole
+ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space