MIPS: SGI-IP27: Fix crash, when CPUs are disabled via nr_cpus parameter

If number of CPUs are limited by the kernel commandline parameter nr_cpus
assignment of interrupts accourding to numa rules might not be possibe.
As a fallback use one of the online CPUs as interrupt destination.

Fixes: 69a07a4 ("MIPS: SGI-IP27: rework HUB interrupts")
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

arch/mips/sgi-ip27/ip27-irq.c

@@ -73,6 +73,9 @@ static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask)
 	int cpu;
 
 	cpu = cpumask_first_and(mask, cpu_online_mask);
+	if (cpu >= nr_cpu_ids)
+		cpu = cpumask_any(cpu_online_mask);
+
 	nasid = cpu_to_node(cpu);
 	hd->cpu = cpu;
 	if (!cputoslice(cpu)) {
@@ -139,6 +142,7 @@ static int hub_domain_alloc(struct irq_domain *domain, unsigned int virq,
 	/* use CPU connected to nearest hub */
 	hub = hub_data(info->nasid);
 	setup_hub_mask(hd, &hub->h_cpus);
+	info->nasid = cpu_to_node(hd->cpu);
 
 	/* Make sure it's not already pending when we connect it. */
 	REMOTE_HUB_CLR_INTR(info->nasid, swlevel);