powerpc/mm: Fix little-endian 4K hugetlb

When we switched to big endian page table, we never updated the hugepd
format such that it can work for both big endian and little endian
config. This patch series update hugepd format such that it is looked at
as __be64 value in big endian page table config.

This patch also switch hugepd_t.pd from signed long to unsigned long.
I did update the FSL hugepd_ok check to check for the top bit instead
of checking > 0.

Fixes: 5dc1ef858c12 ("powerpc/mm: Use big endian Linux page tables for book3s 64")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 15 insertions, 12 deletions

diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index d5026f3800b6..37b5f91e381b 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -125,11 +125,14 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 int hugepd_ok(hugepd_t hpd)
 {
 	bool is_hugepd;
+	unsigned long hpdval;
+
+	hpdval = hpd_val(hpd);
 
 	/*
 	 * We should not find this format in page directory, warn otherwise.
 	 */
-	is_hugepd = (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
+	is_hugepd = (((hpdval & 0x3) == 0x0) && ((hpdval & HUGEPD_SHIFT_MASK) != 0));
 	WARN(is_hugepd, "Found wrong page directory format\n");
 	return 0;
 }
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 8797df11c51f..8c3389cbcd12 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -53,7 +53,7 @@ static u64 gpage_freearray[MAX_NUMBER_GPAGES];
 static unsigned nr_gpages;
 #endif
 
-#define hugepd_none(hpd)	((hpd).pd == 0)
+#define hugepd_none(hpd)	(hpd_val(hpd) == 0)
 
 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 {
@@ -103,24 +103,24 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
 	for (i = 0; i < num_hugepd; i++, hpdp++) {
 		if (unlikely(!hugepd_none(*hpdp)))
 			break;
-		else
+		else {
 #ifdef CONFIG_PPC_BOOK3S_64
-			hpdp->pd = __pa(new) |
-				   (shift_to_mmu_psize(pshift) << 2);
+			*hpdp = __hugepd(__pa(new) |
+					 (shift_to_mmu_psize(pshift) << 2));
 #elif defined(CONFIG_PPC_8xx)
-			hpdp->pd = __pa(new) |
-				   (pshift == PAGE_SHIFT_8M ? _PMD_PAGE_8M :
-							      _PMD_PAGE_512K) |
-				   _PMD_PRESENT;
+			*hpdp = __hugepd(__pa(new) |
+					 (pshift == PAGE_SHIFT_8M ? _PMD_PAGE_8M :
+					  _PMD_PAGE_512K) | _PMD_PRESENT);
 #else
 			/* We use the old format for PPC_FSL_BOOK3E */
-			hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
+			*hpdp = __hugepd(((unsigned long)new & ~PD_HUGE) | pshift);
 #endif
+		}
 	}
 	/* If we bailed from the for loop early, an error occurred, clean up */
 	if (i < num_hugepd) {
 		for (i = i - 1 ; i >= 0; i--, hpdp--)
-			hpdp->pd = 0;
+			*hpdp = __hugepd(0);
 		kmem_cache_free(cachep, new);
 	}
 	spin_unlock(&mm->page_table_lock);
@@ -454,7 +454,7 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif
 		return;
 
 	for (i = 0; i < num_hugepd; i++, hpdp++)
-		hpdp->pd = 0;
+		*hpdp = __hugepd(0);
 
 	if (shift >= pdshift)
 		hugepd_free(tlb, hugepte);