1 files changed, 22 insertions, 18 deletions

diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index 199539882f92..cc5c273086cf 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -21,21 +21,13 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
         unsigned long old_pte, new_pte;
         unsigned long va, rflags, pa, sz;
         long slot;
-        int err = 1;
 
         BUG_ON(shift != mmu_psize_defs[mmu_psize].shift);
 
         /* Search the Linux page table for a match with va */
         va = hpt_va(ea, vsid, ssize);
 
-        /*
-         * Check the user's access rights to the page.  If access should be
-         * prevented then send the problem up to do_page_fault.
-         */
-        if (unlikely(access & ~pte_val(*ptep)))
-                goto out;
-        /*
-         * At this point, we have a pte (old_pte) which can be used to build
+        /* At this point, we have a pte (old_pte) which can be used to build
          * or update an HPTE. There are 2 cases:
          *
          * 1. There is a valid (present) pte with no associated HPTE (this is
@@ -49,9 +41,17 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 
         do {
                 old_pte = pte_val(*ptep);
-                if (old_pte & _PAGE_BUSY)
-                        goto out;
+                /* If PTE busy, retry the access */
+                if (unlikely(old_pte & _PAGE_BUSY))
+                        return 0;
+                /* If PTE permissions don't match, take page fault */
+                if (unlikely(access & ~old_pte))
+                        return 1;
+                /* Try to lock the PTE, add ACCESSED and DIRTY if it was
+                 * a write access */
                 new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
+                if (access & _PAGE_RW)
+                        new_pte |= _PAGE_DIRTY;
         } while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
                                          old_pte, new_pte));
 
@@ -121,8 +121,16 @@ repeat:
                         }
                 }
 
-                if (unlikely(slot == -2))
-                        panic("hash_huge_page: pte_insert failed\n");
+                /*
+                 * Hypervisor failure. Restore old pte and return -1
+                 * similar to __hash_page_*
+                 */
+                if (unlikely(slot == -2)) {
+                        *ptep = __pte(old_pte);
+                        hash_failure_debug(ea, access, vsid, trap, ssize,
+                                           mmu_psize, old_pte);
+                        return -1;
+                }
 
                 new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX);
         }
@@ -131,9 +139,5 @@ repeat:
          * No need to use ldarx/stdcx here
          */
         *ptep = __pte(new_pte & ~_PAGE_BUSY);
-
-        err = 0;
-
- out:
-        return err;
+        return 0;
 }