x86: Handle legacy PIC interrupts on all the cpu's

Ingo Molnar reported that with the recent changes of not
statically blocking IRQ0_VECTOR..IRQ15_VECTOR's on all the
cpu's, broke an AMD platform (with Nvidia chipset) boot when
"noapic" boot option is used.

On this platform, legacy PIC interrupts are getting delivered to
all the cpu's instead of just the boot cpu. Thus not
initializing the vector to irq mapping for the legacy irq's
resulted in not handling certain interrupts causing boot hang.

Fix this by initializing the vector to irq mapping on all the
logical cpu's, if the legacy IRQ is handled by the legacy PIC.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
[ -v2: io-apic-enabled improvement ]
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
LKML-Reference: <1268692386.3296.43.camel@sbs-t61.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e4e0ddcb1546..463de9a858ad 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1268,6 +1268,14 @@ void __setup_vector_irq(int cpu)
         /* Mark the inuse vectors */
         for_each_irq_desc(irq, desc) {
                 cfg = desc->chip_data;
+
+                /*
+                 * If it is a legacy IRQ handled by the legacy PIC, this cpu
+                 * will be part of the irq_cfg's domain.
+                 */
+                if (irq < legacy_pic->nr_legacy_irqs && !IO_APIC_IRQ(irq))
+                        cpumask_set_cpu(cpu, cfg->domain);
+
                 if (!cpumask_test_cpu(cpu, cfg->domain))
                         continue;
                 vector = cfg->vector;