x86, hotplug: Handle retrigger irq by the first available CPU

The first cpu in irq cfg->domain is likely to be CPU 0 and may not be available
when CPU 0 is offline. Instead of using CPU 0 to handle retriggered irq, we use
first available CPU which is online and in this irq's domain.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-13-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 1817fa911024f07151d3edf91bd350722c9f79f8..f78fc2b4deb047381e32367958c4e2f967f08a95 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2199,9 +2199,11 @@ static int ioapic_retrigger_irq(struct irq_data *data)
 {
        struct irq_cfg *cfg = data->chip_data;
        unsigned long flags;
+       int cpu;
 
        raw_spin_lock_irqsave(&vector_lock, flags);
-       apic->send_IPI_mask(cpumask_of(cpumask_first(cfg->domain)), cfg->vector);
+       cpu = cpumask_first_and(cfg->domain, cpu_online_mask);
+       apic->send_IPI_mask(cpumask_of(cpu), cfg->vector);
        raw_spin_unlock_irqrestore(&vector_lock, flags);
 
        return 1;