x86, apic: Fix missed handling of discrete apics

In case of discrete (pretty old) apics we may have cpu_has_apic bit
not set but have to check if smp_found_config (MP spec) is there
and apic was not disabled.

Also don't forget to print apic/io-apic for such case as well.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090915071230.GA10604@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/apic.h

@@ -65,6 +65,19 @@ static inline void default_inquire_remote_apic(int apicid)
 		__inquire_remote_apic(apicid);
 }
 
+/*
+ * With 82489DX we can't rely on apic feature bit
+ * retrieved via cpuid but still have to deal with
+ * such an apic chip so we assume that SMP configuration
+ * is found from MP table (64bit case uses ACPI mostly
+ * which set smp presence flag as well so we are safe
+ * to use this helper too).
+ */
+static inline bool apic_from_smp_config(void)
+{
+	return smp_found_config && !disable_apic;
+}
+
 /*
  * Basic functions accessing APICs.
  */

arch/x86/kernel/apic/apic.c

@@ -978,7 +978,7 @@ void lapic_shutdown(void)
 {
 	unsigned long flags;
 
-	if (!cpu_has_apic)
+	if (!cpu_has_apic && !apic_from_smp_config())
 		return;
 
 	local_irq_save(flags);

arch/x86/kernel/apic/io_apic.c

@@ -1863,7 +1863,7 @@ __apicdebuginit(int) print_all_ICs(void)
 	print_PIC();
 
 	/* don't print out if apic is not there */
-	if (!cpu_has_apic || disable_apic)
+	if (!cpu_has_apic && !apic_from_smp_config())
 		return 0;
 
 	print_all_local_APICs();
@@ -1981,7 +1981,7 @@ void disable_IO_APIC(void)
 	/*
 	 * Use virtual wire A mode when interrupt remapping is enabled.
 	 */
-	if (cpu_has_apic)
+	if (cpu_has_apic || apic_from_smp_config())
 		disconnect_bsp_APIC(!intr_remapping_enabled &&
 				ioapic_i8259.pin != -1);
 }