x86: Enable the intr-remap fault handling after local APIC setup

commit 7f7fbf45c6 upstream.

Interrupt-remapping gets enabled very early in the boot, as it determines the
apic mode that the processor can use. And the current code enables the vt-d
fault handling before the setup_local_APIC(). And hence the APIC LDR registers
and data structure in the memory may not be initialized. So the vt-d fault
handling in logical xapic/x2apic modes were broken.

Fix this by enabling the vt-d fault handling in the end_local_APIC_setup()

A cleaner fix of enabling fault handling while enabling intr-remapping
will be addressed for v2.6.38. [ Enabling intr-remapping determines the
usage of x2apic mode and the apic mode determines the fault-handling
configuration. ]

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
LKML-Reference: <20101201062244.541996375@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/kernel/apic/apic.c

@@ -1340,6 +1340,14 @@ void __cpuinit end_local_APIC_setup(void)
 
 	setup_apic_nmi_watchdog(NULL);
 	apic_pm_activate();
+
+	/*
+	 * Now that local APIC setup is completed for BP, configure the fault
+	 * handling for interrupt remapping.
+	 */
+	if (!smp_processor_id() && intr_remapping_enabled)
+		enable_drhd_fault_handling();
+
 }
 
 #ifdef CONFIG_X86_X2APIC

arch/x86/kernel/apic/probe_64.c

@@ -76,13 +76,6 @@ void __init default_setup_apic_routing(void)
 		/* need to update phys_pkg_id */
 		apic->phys_pkg_id = apicid_phys_pkg_id;
 	}
-
-	/*
-	 * Now that apic routing model is selected, configure the
-	 * fault handling for intr remapping.
-	 */
-	if (intr_remapping_enabled)
-		enable_drhd_fault_handling();
 }
 
 /* Same for both flat and physical. */