5 files changed, 33 insertions, 1 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6516359922b..5c0107602b6 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1787,6 +1787,20 @@ static int __init parse_pci(char *arg)
 }
 early_param("pci", parse_pci);
 
+int __init acpi_mps_check(void)
+{
+#if defined(CONFIG_X86_LOCAL_APIC) && !defined(CONFIG_X86_MPPARSE)
+/* mptable code is not built-in*/
+	if (acpi_disabled || acpi_noirq) {
+		printk(KERN_WARNING "MPS support code is not built-in.\n"
+		       "Using acpi=off or acpi=noirq or pci=noacpi "
+		       "may have problem\n");
+		return 1;
+	}
+#endif
+	return 0;
+}
+
 #ifdef CONFIG_X86_IO_APIC
 static int __init parse_acpi_skip_timer_override(char *arg)
 {
diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
index dd8de26b278..4932d7813bc 100644
--- a/arch/x86/kernel/apic_32.c
+++ b/arch/x86/kernel/apic_32.c
@@ -57,7 +57,7 @@ unsigned long mp_lapic_addr;
  *
  * -1=force-disable, +1=force-enable
  */
-static int enable_local_apic __initdata;
+int enable_local_apic;
 
 /* Local APIC timer verification ok */
 static int local_apic_timer_verify_ok;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c5330f601b6..56aee55cf8d 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -161,6 +161,10 @@ void __init setup_per_cpu_areas(void)
 	char *ptr;
 	int cpu;
 
+	/* no processor from mptable or madt */
+	if (!num_processors)
+		num_processors = 1;
+
 #ifdef CONFIG_HOTPLUG_CPU
 	prefill_possible_map();
 #else
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index 369d0fe1ff9..cad4e893df0 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -677,6 +677,11 @@ void __init setup_arch(char **cmdline_p)
 
 	parse_early_param();
 
+	if (acpi_mps_check()){
+		enable_local_apic = -1;
+		clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
+	}
+
 	finish_e820_parsing();
 
 	probe_roms();
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index a93300de4da..175c696ec53 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -302,6 +302,11 @@ void __init setup_arch(char **cmdline_p)
 
 	parse_early_param();
 
+	if (acpi_mps_check()) {
+		disable_apic = 1;
+		clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
+	}
+
 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
 	if (init_ohci1394_dma_early)
 		init_ohci1394_dma_on_all_controllers();
@@ -723,6 +728,10 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
 		cpu_devs[c->x86_vendor]->c_early_init(c);
 
 	validate_pat_support(c);
+
+	/* early_param could clear that, but recall get it set again */
+	if (disable_apic)
+		clear_cpu_cap(c, X86_FEATURE_APIC);
 }
 
 /*