KVM: Remove memory alias support

[pandora-kernel.git] / arch / powerpc / mm / hugetlbpage-hash64.c

diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index 1995398..cc5c273 100644 (file)
--- 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;
 }