powerpc: Free a PTE bit on ppc64 with 64K pages

This frees a PTE bit when using 64K pages on ppc64.  This is done
by getting rid of the separate _PAGE_HASHPTE bit.  Instead, we just test
if any of the 16 sub-page bits is set.  For non-combo pages (ie. real
64K pages), we set SUB0 and the location encoding in that field.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index a02266dad215..8fa07f3f6c2b 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -458,8 +458,7 @@ int hash_huge_page(struct mm_struct *mm, unsigned long access,
                 old_pte = pte_val(*ptep);
                 if (old_pte & _PAGE_BUSY)
                         goto out;
-                new_pte = old_pte | _PAGE_BUSY |
-                        _PAGE_ACCESSED | _PAGE_HASHPTE;
+                new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
         } while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
                                          old_pte, new_pte));
 
@@ -499,8 +498,11 @@ repeat:
                               HPTES_PER_GROUP) & ~0x7UL;
 
                 /* clear HPTE slot informations in new PTE */
+#ifdef CONFIG_PPC_64K_PAGES
+                new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HPTE_SUB0;
+#else
                 new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE;
-
+#endif
                 /* Add in WIMG bits */
                 /* XXX We should store these in the pte */
                 /* --BenH: I think they are ... */