[097/152] x86: Enable the intr-remap fault handling after local APIC setup

From: Greg KH
Date: Wed Jan 05 2011 - 19:43:26 EST

2.6.36-stable review patch. If anyone has any objections, please let us know.


From: Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>

commit 7f7fbf45c6b748074546f7f16b9488ca71de99c1 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@xxxxxxxxxxxxxx>
LKML-Reference: <20101201062244.541996375@xxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Acked-by: Chris Wright <chrisw@xxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

arch/x86/kernel/apic/apic.c | 8 ++++++++
arch/x86/kernel/apic/probe_64.c | 7 -------
2 files changed, 8 insertions(+), 7 deletions(-)

--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1340,6 +1340,14 @@ void __cpuinit end_local_APIC_setup(void

+ /*
+ * 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
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -76,13 +76,6 @@ void __init default_setup_apic_routing(v
/* 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. */

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