3 files changed, 8 insertions, 9 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 20a614275064..3dd53f997b11 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1721,10 +1721,8 @@ void __init xen_setup_machphys_mapping(void)
                 machine_to_phys_nr = MACH2PHYS_NR_ENTRIES;
         }
 #ifdef CONFIG_X86_32
-        if ((machine_to_phys_mapping + machine_to_phys_nr)
-            < machine_to_phys_mapping)
-                machine_to_phys_nr = (unsigned long *)NULL
-                                     - machine_to_phys_mapping;
+        WARN_ON((machine_to_phys_mapping + (machine_to_phys_nr - 1))
+                < machine_to_phys_mapping);
 #endif
 }
 
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index c3b8d440873c..46d6d21dbdbe 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -306,10 +306,12 @@ char * __init xen_memory_setup(void)
         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 
         extra_limit = xen_get_max_pages();
-        if (extra_limit >= max_pfn)
-                extra_pages = extra_limit - max_pfn;
-        else
-                extra_pages = 0;
+        if (max_pfn + extra_pages > extra_limit) {
+                if (extra_limit > max_pfn)
+                        extra_pages = extra_limit - max_pfn;
+                else
+                        extra_pages = 0;
+        }
 
         extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
 
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index d4fc6d454f8d..041d4fe9dfe4 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -532,7 +532,6 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
         WARN_ON(xen_smp_intr_init(0));
 
         xen_init_lock_cpu(0);
-        xen_init_spinlocks();
 }
 
 static int __cpuinit xen_hvm_cpu_up(unsigned int cpu)