irq: change io_apic_set_pci_routing() to use device parameter

Make actual use of the device parameter passed down to
io_apic_set_pci_routing() - to have the IRQ descriptor
on the home node of the device.

If no device has been passed down, we assume it's a platform
device and use the boot node ID for the IRQ descriptor.

[ Impact: optimization, make IO-APIC code more NUMA aware ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49F6557E.3080101@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic/io_apic.c

@@ -3963,7 +3963,7 @@ int io_apic_set_pci_routing(struct device *dev, int ioapic, int pin, int irq,
 {
 	struct irq_desc *desc;
 	struct irq_cfg *cfg;
-	int node = cpu_to_node(boot_cpu_id);
+	int node;
 
 	if (!IO_APIC_IRQ(irq)) {
 		apic_printk(APIC_QUIET,KERN_ERR "IOAPIC[%d]: Invalid reference to IRQ 0\n",
@@ -3971,6 +3971,11 @@ int io_apic_set_pci_routing(struct device *dev, int ioapic, int pin, int irq,
 		return -EINVAL;
 	}
 
+	if (dev)
+		node = dev_to_node(dev);
+	else
+		node = cpu_to_node(boot_cpu_id);
+
 	desc = irq_to_desc_alloc_node(irq, node);
 	if (!desc) {
 		printk(KERN_INFO "can not get irq_desc %d\n", irq);