[PATCH V3 2/6] powerpc/mm/hugetlb/book3s: add _PAGE_PRESENT to hugepd pointer.

[Aneesh Kumar K.V]

This make hugetlb directory pointer similar to other page able entries. A hugepd
entry is identified by lack of _PAGE_PTE bit set and directory size stored in
HUGEPD_SHIFT_MASK. We update that to also look at _PAGE_PRESENT

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/hash-4k.h | 2 +-
 arch/powerpc/include/asm/book3s/64/hugetlb.h | 3 +++
 arch/powerpc/mm/hugetlbpage.c                | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index 9a3798660cef..15bc16b1dc9c 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -66,7 +66,7 @@ static inline int hash__hugepd_ok(hugepd_t hpd)
 	 * if it is not a pte and have hugepd shift mask
 	 * set, then it is a hugepd directory pointer
 	 */
-	if (!(hpdval & _PAGE_PTE) &&
+	if (!(hpdval & _PAGE_PTE) && (hpdval & _PAGE_PRESENT) &&
 	    ((hpdval & HUGEPD_SHIFT_MASK) != 0))
 		return true;
 	return false;
diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index 50888388a359..5b0177733994 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -39,4 +39,7 @@ static inline bool gigantic_page_supported(void)
 }
 #endif
 
+/* hugepd entry valid bit */
+#define HUGEPD_VAL_BITS		(0x8000000000000000UL)
+
 #endif
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index e87f9ef9115b..c6df73c66c40 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -95,7 +95,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
 			break;
 		else {
 #ifdef CONFIG_PPC_BOOK3S_64
-			*hpdp = __hugepd(__pa(new) |
+			*hpdp = __hugepd(__pa(new) | HUGEPD_VAL_BITS |
 					 (shift_to_mmu_psize(pshift) << 2));
 #elif defined(CONFIG_PPC_8xx)
 			*hpdp = __hugepd(__pa(new) | _PMD_USER |
-- 
2.17.1