x86/apic: Mark the apic_intr_mode extern for sanity check cleanup

Calling native_smp_prepare_cpus() to prepare for SMP bootup, does some
sanity checking, enables APIC mode and disables SMP feature.

Now, APIC mode setup has been unified to apic_intr_mode_init(), some sanity
checks are redundant and need to be cleanup.

Mark the apic_intr_mode extern to refine the switch and remove the
redundant sanity check.

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-7-git-send-email-douly.fnst@cn.fujitsu.com

1 files changed, 9 insertions, 48 deletions

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index d0a1d28c23e8..161935c49166 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1190,17 +1190,10 @@ static __init void disable_smp(void)
 	cpumask_set_cpu(0, topology_core_cpumask(0));
 }
 
-enum {
-	SMP_OK,
-	SMP_NO_CONFIG,
-	SMP_NO_APIC,
-	SMP_FORCE_UP,
-};
-
 /*
  * Various sanity checks.
  */
-static int __init smp_sanity_check(unsigned max_cpus)
+static void __init smp_sanity_check(void)
 {
 	preempt_disable();
 
@@ -1238,16 +1231,6 @@ static int __init smp_sanity_check(unsigned max_cpus)
 	}
 
 	/*
-	 * If we couldn't find an SMP configuration at boot time,
-	 * get out of here now!
-	 */
-	if (!smp_found_config && !acpi_lapic) {
-		preempt_enable();
-		pr_notice("SMP motherboard not detected\n");
-		return SMP_NO_CONFIG;
-	}
-
-	/*
 	 * Should not be necessary because the MP table should list the boot
 	 * CPU too, but we do it for the sake of robustness anyway.
 	 */
@@ -1257,29 +1240,6 @@ static int __init smp_sanity_check(unsigned max_cpus)
 		physid_set(hard_smp_processor_id(), phys_cpu_present_map);
 	}
 	preempt_enable();
-
-	/*
-	 * If we couldn't find a local APIC, then get out of here now!
-	 */
-	if (APIC_INTEGRATED(boot_cpu_apic_version) &&
-	    !boot_cpu_has(X86_FEATURE_APIC)) {
-		if (!disable_apic) {
-			pr_err("BIOS bug, local APIC #%d not detected!...\n",
-				boot_cpu_physical_apicid);
-			pr_err("... forcing use of dummy APIC emulation (tell your hw vendor)\n");
-		}
-		return SMP_NO_APIC;
-	}
-
-	/*
-	 * If SMP should be disabled, then really disable it!
-	 */
-	if (!max_cpus) {
-		pr_info("SMP mode deactivated\n");
-		return SMP_FORCE_UP;
-	}
-
-	return SMP_OK;
 }
 
 static void __init smp_cpu_index_default(void)
@@ -1338,19 +1298,20 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 
 	apic_intr_mode_init();
 
-	switch (smp_sanity_check(max_cpus)) {
-	case SMP_NO_CONFIG:
-		disable_smp();
-		return;
-	case SMP_NO_APIC:
+	smp_sanity_check();
+
+	switch (apic_intr_mode) {
+	case APIC_PIC:
+	case APIC_VIRTUAL_WIRE_NO_CONFIG:
 		disable_smp();
 		return;
-	case SMP_FORCE_UP:
+	case APIC_SYMMETRIC_IO_NO_ROUTING:
 		disable_smp();
 		/* Setup local timer */
 		x86_init.timers.setup_percpu_clockev();
 		return;
-	case SMP_OK:
+	case APIC_VIRTUAL_WIRE:
+	case APIC_SYMMETRIC_IO:
 		break;
 	}