powerpc: define support for 16G hugepages

The huge page size is defined for 16G pages.  If a hugepagesz of 16G is
specified at boot-time then it becomes the huge page size instead of the
default 16M.

The change in pgtable-64K.h is to the macro pte_iterate_hashed_subpages to
make the increment to va (the 1 being shifted) be a long so that it is not
shifted to 0.  Otherwise it would create an infinite loop when the shift
value is for a 16G page (when base page size is 64K).

Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-powerpc/pgtable-64k.h b/include/asm-powerpc/pgtable-64k.h
index c500771..7e54adb 100644
--- a/include/asm-powerpc/pgtable-64k.h
+++ b/include/asm-powerpc/pgtable-64k.h
@@ -138,7 +138,7 @@
                 unsigned __split = (psize == MMU_PAGE_4K ||                 \
 				    psize == MMU_PAGE_64K_AP);              \
                 shift = mmu_psize_defs[psize].shift;                        \
-	        for (index = 0; va < __end; index++, va += (1 << shift)) {  \
+		for (index = 0; va < __end; index++, va += (1L << shift)) { \
 		        if (!__split || __rpte_sub_valid(rpte, index)) do { \
 
 #define pte_iterate_hashed_end() } while(0); } } while(0)