iommu/amd: Implement select() method on remapping irqdomain

Preparatory change to remove irq_remapping_get_irq_domain().
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-25-dwmw2@infradead.org

drivers/iommu/amd/iommu.c

@@ -3882,7 +3882,26 @@ static void irq_remapping_deactivate(struct irq_domain *domain,
 					    irte_info->index);
 }
 
+static int irq_remapping_select(struct irq_domain *d, struct irq_fwspec *fwspec,
+				enum irq_domain_bus_token bus_token)
+{
+	struct amd_iommu *iommu;
+	int devid = -1;
+
+	if (x86_fwspec_is_ioapic(fwspec))
+		devid = get_ioapic_devid(fwspec->param[0]);
+	else if (x86_fwspec_is_hpet(fwspec))
+		devid = get_hpet_devid(fwspec->param[0]);
+
+	if (devid < 0)
+		return 0;
+
+	iommu = amd_iommu_rlookup_table[devid];
+	return iommu && iommu->ir_domain == d;
+}
+
 static const struct irq_domain_ops amd_ir_domain_ops = {
+	.select = irq_remapping_select,
 	.alloc = irq_remapping_alloc,
 	.free = irq_remapping_free,
 	.activate = irq_remapping_activate,