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x86, irq: Update the vector domain for legacy irqs handled by io-apic 

In the recent change of not reserving IRQ0_VECTOR..IRQ15_VECTOR's on all
cpu's, we start with irq 0..15 getting directed to (and handled on) cpu-0.

In the logical flat mode, once the AP's are online (and before irqbalance
comes into picture), kernel intends to handle these IRQ's on any cpu (as the
logical flat mode allows to specify multiple cpu's for the irq destination and
the chipset based routing can deliver to the interrupt to any one of
the specified cpu's). This was broken with our recent change, which was ending
up using only cpu 0 as the destination, even when the kernel was specifying to
use all online cpu's for the logical flat mode case.

Fix this by updating vector allocation domain (cfg->domain) for legacy irqs,
when the IO-APIC handles them.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20100129194330.207790269@sbs-t61.sc.intel.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Suresh Siddha 2010-01-29 11:42:20 -08:00 committed by H. Peter Anvin
parent 97943390b0
commit 69c89efb51
1 changed files with 8 additions and 0 deletions
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8
arch/x86/kernel/apic/io_apic.c
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@ -1428,6 +1428,14 @@ static void setup_IO_APIC_irq(int apic_id, int pin, unsigned int irq, struct irq
cfg = desc->chip_data;
/*
* For legacy irqs, cfg->domain starts with cpu 0 for legacy
* controllers like 8259. Now that IO-APIC can handle this irq, update
* the cfg->domain.
*/
if (irq < nr_legacy_irqs && cpumask_test_cpu(0, cfg->domain))
apic->vector_allocation_domain(0, cfg->domain);
if (assign_irq_vector(irq, cfg, apic->target_cpus()))
return;