x86, fixmap: define FIXADDR_BOOT_* and redefine FIX_ADDR_SIZE

Impact: new interface, not yet used

Now, with these macros, x86_64 code can know where start the
permanent and non-permanent fixed mapped address.
This patch make these macros equal fixmap_32.h for future
x86 integration.
Signed-off-by: NGustavo F. Padovan <gustavo@las.ic.unicamp.br>
Acked-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

arch/x86/include/asm/fixmap_64.h

@@ -69,8 +69,11 @@ enum fixed_addresses {
 };
 
 #define FIXADDR_TOP	(VSYSCALL_END-PAGE_SIZE)
-#define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
-#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
+
+#define FIXADDR_SIZE	(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_BOOT_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_BOOT_START	(FIXADDR_TOP - FIXADDR_BOOT_SIZE)
 
 /* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
 #define FIXADDR_USER_START	((unsigned long)VSYSCALL32_VSYSCALL)