2 files changed, 10 insertions, 5 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index a991b57f91fe..aef7af92b28b 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1473,16 +1473,20 @@ static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
 #endif
 }
 
+#ifdef CONFIG_X86_32
 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
 {
-        unsigned long pfn = pte_pfn(pte);
-
-#ifdef CONFIG_X86_32
         /* If there's an existing pte, then don't allow _PAGE_RW to be set */
         if (pte_val_ma(*ptep) & _PAGE_PRESENT)
                 pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
                                pte_val_ma(pte));
-#endif
+
+        return pte;
+}
+#else /* CONFIG_X86_64 */
+static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
+{
+        unsigned long pfn = pte_pfn(pte);
 
         /*
          * If the new pfn is within the range of the newly allocated
@@ -1497,6 +1501,7 @@ static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
 
         return pte;
 }
+#endif /* CONFIG_X86_64 */
 
 /* Init-time set_pte while constructing initial pagetables, which
    doesn't allow RO pagetable pages to be remapped RW */
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index fa0269a99377..90bac0aac3a5 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -227,7 +227,7 @@ char * __init xen_memory_setup(void)
 
         memcpy(map_raw, map, sizeof(map));
         e820.nr_map = 0;
-        xen_extra_mem_start = mem_end;
+        xen_extra_mem_start = max((1ULL << 32), mem_end);
         for (i = 0; i < memmap.nr_entries; i++) {
                 unsigned long long end;