1 files changed, 21 insertions, 8 deletions

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 6b087ab6cd8f..56078d61c793 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -86,6 +86,7 @@ void *x86_bios_cpu_apicid_early_ptr;
 
 #ifdef CONFIG_X86_32
 u8 apicid_2_node[MAX_APICID];
+static int low_mappings;
 #endif
 
 /* State of each CPU */
@@ -326,6 +327,12 @@ static void __cpuinit start_secondary(void *unused)
                 enable_8259A_irq(0);
         }
 
+#ifdef CONFIG_X86_32
+        while (low_mappings)
+                cpu_relax();
+        __flush_tlb_all();
+#endif
+
         /* This must be done before setting cpu_online_map */
         set_cpu_sibling_map(raw_smp_processor_id());
         wmb();
@@ -1040,14 +1047,20 @@ int __cpuinit native_cpu_up(unsigned int cpu)
 #ifdef CONFIG_X86_32
         /* init low mem mapping */
         clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
-                        min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
+                min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
         flush_tlb_all();
-#endif
+        low_mappings = 1;
+
+        err = do_boot_cpu(apicid, cpu);
 
+        zap_low_mappings();
+        low_mappings = 0;
+#else
         err = do_boot_cpu(apicid, cpu);
-        if (err < 0) {
+#endif
+        if (err) {
                 Dprintk("do_boot_cpu failed %d\n", err);
-                return err;
+                return -EIO;
         }
 
         /*
@@ -1177,6 +1190,7 @@ static void __init smp_cpu_index_default(void)
  */
 void __init native_smp_prepare_cpus(unsigned int max_cpus)
 {
+        preempt_disable();
         nmi_watchdog_default();
         smp_cpu_index_default();
         current_cpu_data = boot_cpu_data;
@@ -1193,7 +1207,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
         if (smp_sanity_check(max_cpus) < 0) {
                 printk(KERN_INFO "SMP disabled\n");
                 disable_smp();
-                return;
+                goto out;
         }
 
         preempt_disable();
@@ -1233,6 +1247,8 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
         printk(KERN_INFO "CPU%d: ", 0);
         print_cpu_info(&cpu_data(0));
         setup_boot_clock();
+out:
+        preempt_enable();
 }
 /*
  * Early setup to make printk work.
@@ -1259,9 +1275,6 @@ void __init native_smp_cpus_done(unsigned int max_cpus)
         setup_ioapic_dest();
 #endif
         check_nmi_watchdog();
-#ifdef CONFIG_X86_32
-        zap_low_mappings();
-#endif
 }
 
 #ifdef CONFIG_HOTPLUG_CPU