diff --git a/arch/powerpc/include/asm/pgalloc-64.h b/arch/powerpc/include/asm/pgalloc-64.h
index 91acb12..b66ae72 100644
--- a/arch/powerpc/include/asm/pgalloc-64.h
+++ b/arch/powerpc/include/asm/pgalloc-64.h
@@ -186,7 +186,7 @@
 
 static inline pgtable_t pmd_pgtable(pmd_t pmd)
 {
-	return (pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE);
+	return (pgtable_t)(pmd_val(pmd) & ~PMD_MASKED_BITS);
 }
 
 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,