x86: move prefill_possible_map calling early

call it right after we are done with MADT/mptable handling, instead of
doing that in setup_per_cpu_areas() later on...

this way for_possible_cpu() can be used early.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/setup.c

@@ -818,6 +818,7 @@ void __init setup_arch(char **cmdline_p)
 		get_smp_config();
 #endif
 
+	prefill_possible_map();
 #ifdef CONFIG_X86_64
 	init_cpu_to_node();
 #endif

arch/x86/kernel/setup_percpu.c

@@ -162,16 +162,6 @@ 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
-	nr_cpu_ids = num_processors;
-#endif
-
 	/* Setup cpu_pda map */
 	setup_cpu_pda_map();
 

arch/x86/kernel/smpboot.c

@@ -1278,12 +1278,20 @@ __init void prefill_possible_map(void)
 	int i;
 	int possible;
 
+	/* no processor from mptable or madt */
+	if (!num_processors)
+		num_processors = 1;
+
+#ifdef CONFIG_HOTPLUG_CPU
 	if (additional_cpus == -1) {
 		if (disabled_cpus > 0)
 			additional_cpus = disabled_cpus;
 		else
 			additional_cpus = 0;
 	}
+#else
+	additional_cpus = 0;
+#endif
 	possible = num_processors + additional_cpus;
 	if (possible > NR_CPUS)
 		possible = NR_CPUS;

include/asm-x86/smp.h

@@ -119,6 +119,10 @@ static inline int num_booting_cpus(void)
 {
 	return cpus_weight(cpu_callout_map);
 }
+#else
+static inline void prefill_possible_map(void)
+{
+}
 #endif /* CONFIG_SMP */
 
 extern unsigned disabled_cpus __cpuinitdata;