1 files changed, 59 insertions, 0 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 39120619951..3ea66556e5e 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -276,3 +276,62 @@ void smp_generic_interrupt(struct pt_regs *regs)
 }
 
 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
+
+#ifdef CONFIG_HOTPLUG_CPU
+/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
+void fixup_irqs(void)
+{
+	unsigned int irq;
+	static int warned;
+	struct irq_desc *desc;
+
+	for_each_irq_desc(irq, desc) {
+		int break_affinity = 0;
+		int set_affinity = 1;
+		const struct cpumask *affinity;
+
+		if (!desc)
+			continue;
+		if (irq == 2)
+			continue;
+
+		/* interrupt's are disabled at this point */
+		spin_lock(&desc->lock);
+
+		affinity = desc->affinity;
+		if (!irq_has_action(irq) ||
+		    cpumask_equal(affinity, cpu_online_mask)) {
+			spin_unlock(&desc->lock);
+			continue;
+		}
+
+		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+			break_affinity = 1;
+			affinity = cpu_all_mask;
+		}
+
+		if (desc->chip->mask)
+			desc->chip->mask(irq);
+
+		if (desc->chip->set_affinity)
+			desc->chip->set_affinity(irq, affinity);
+		else if (!(warned++))
+			set_affinity = 0;
+
+		if (desc->chip->unmask)
+			desc->chip->unmask(irq);
+
+		spin_unlock(&desc->lock);
+
+		if (break_affinity && set_affinity)
+			printk("Broke affinity for irq %i\n", irq);
+		else if (!set_affinity)
+			printk("Cannot set affinity for irq %i\n", irq);
+	}
+
+	/* That doesn't seem sufficient.  Give it 1ms. */
+	local_irq_enable();
+	mdelay(1);
+	local_irq_disable();
+}
+#endif