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

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>
Cc: stable@kernel.org [v2.6.32+]
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 3f838d537392..78218135b48e 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1389,6 +1389,14 @@ 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