[PATCH] powerpc/mm: Recompute hash value after a failed update

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

If we had secondary hash flag set, we ended up modifying hash value in
the updatepp code path. Hence with a failed updatepp we will be using
a wrong hash value for the following hash insert. Fix this by
recomputing hash before insert.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/hugepage-hash64.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c
index 43dafb9d6a46..4d87122cf6a7 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -85,7 +85,6 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 	BUG_ON(index >= 4096);
 
 	vpn = hpt_vpn(ea, vsid, ssize);
-	hash = hpt_hash(vpn, shift, ssize);
 	hpte_slot_array = get_hpte_slot_array(pmdp);
 	if (psize == MMU_PAGE_4K) {
 		/*
@@ -101,6 +100,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 	valid = hpte_valid(hpte_slot_array, index);
 	if (valid) {
 		/* update the hpte bits */
+		hash = hpt_hash(vpn, shift, ssize);
 		hidx =  hpte_hash_index(hpte_slot_array, index);
 		if (hidx & _PTEIDX_SECONDARY)
 			hash = ~hash;
@@ -126,6 +126,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 	if (!valid) {
 		unsigned long hpte_group;
 
+		hash = hpt_hash(vpn, shift, ssize);
 		/* insert new entry */
 		pa = pmd_pfn(__pmd(old_pmd)) << PAGE_SHIFT;
 		new_pmd |= _PAGE_HASHPTE;
-- 
2.5.0