powerpc/mm: use macro PGTABLE_EADDR_SIZE instead of digital

In case of extending the eaddr in future, use this macro
PGTABLE_EADDR_SIZE to ease the maintenance of the code.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 17aa6df..e0b3cf4 100644 (file)
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -35,7 +35,7 @@ _GLOBAL(slb_allocate_realmode)
         * check for bad kernel/user address
         * (ea & ~REGION_MASK) >= PGTABLE_RANGE
         */
-       rldicr. r9,r3,4,(63 - 46 - 4)
+       rldicr. r9,r3,4,(63 - PGTABLE_EADDR_SIZE - 4)
        bne-    8f
 
        srdi    r9,r3,60                /* get region */