x86: check bigsmp in smp_sanity_check instead of cpu_up
clear bits for cpu nr > 8.
This allows us to boot the full range of possible CPUs that the
supported APIC model will allow. Previously we'd hang or boot up
with less than 8 CPUs.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index e25287e..a8fb8a9 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -994,17 +994,7 @@
flush_tlb_all();
low_mappings = 1;
-#ifdef CONFIG_X86_PC
- if (def_to_bigsmp && apicid > 8) {
- printk(KERN_WARNING
- "More than 8 CPUs detected - skipping them.\n"
- "Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.\n");
- err = -1;
- } else
- err = do_boot_cpu(apicid, cpu);
-#else
err = do_boot_cpu(apicid, cpu);
-#endif
zap_low_mappings();
low_mappings = 0;
@@ -1058,6 +1048,34 @@
static int __init smp_sanity_check(unsigned max_cpus)
{
preempt_disable();
+
+#if defined(CONFIG_X86_PC) && defined(CONFIG_X86_32)
+ if (def_to_bigsmp && nr_cpu_ids > 8) {
+ unsigned int cpu;
+ unsigned nr;
+
+ printk(KERN_WARNING
+ "More than 8 CPUs detected - skipping them.\n"
+ "Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.\n");
+
+ nr = 0;
+ for_each_present_cpu(cpu) {
+ if (nr >= 8)
+ cpu_clear(cpu, cpu_present_map);
+ nr++;
+ }
+
+ nr = 0;
+ for_each_possible_cpu(cpu) {
+ if (nr >= 8)
+ cpu_clear(cpu, cpu_possible_map);
+ nr++;
+ }
+
+ nr_cpu_ids = 8;
+ }
+#endif
+
if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
printk(KERN_WARNING "weird, boot CPU (#%d) not listed"
"by the BIOS.\n", hard_smp_processor_id());