x86: check command line when CONFIG_X86_MPPARSE is not set, v2

if acpi=off, acpi=noirq and pci=noacpi, we need to disable apic.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

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