x86/apic: Add select() method on vector irqdomain

This will be used to select the irqdomain for I/O-APIC and HPET.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-24-dwmw2@infradead.org

1 files changed, 43 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index bb2e2a2488a5..b9b05caa28a4 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -636,7 +636,50 @@ static void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d,
 }
 #endif
 
+int x86_fwspec_is_ioapic(struct irq_fwspec *fwspec)
+{
+	if (fwspec->param_count != 1)
+		return 0;
+
+	if (is_fwnode_irqchip(fwspec->fwnode)) {
+		const char *fwname = fwnode_get_name(fwspec->fwnode);
+		return fwname && !strncmp(fwname, "IO-APIC-", 8) &&
+			simple_strtol(fwname+8, NULL, 10) == fwspec->param[0];
+	}
+	return to_of_node(fwspec->fwnode) &&
+		of_device_is_compatible(to_of_node(fwspec->fwnode),
+					"intel,ce4100-ioapic");
+}
+
+int x86_fwspec_is_hpet(struct irq_fwspec *fwspec)
+{
+	if (fwspec->param_count != 1)
+		return 0;
+
+	if (is_fwnode_irqchip(fwspec->fwnode)) {
+		const char *fwname = fwnode_get_name(fwspec->fwnode);
+		return fwname && !strncmp(fwname, "HPET-MSI-", 9) &&
+			simple_strtol(fwname+9, NULL, 10) == fwspec->param[0];
+	}
+	return 0;
+}
+
+static int x86_vector_select(struct irq_domain *d, struct irq_fwspec *fwspec,
+			     enum irq_domain_bus_token bus_token)
+{
+	/*
+	 * HPET and I/OAPIC cannot be parented in the vector domain
+	 * if IRQ remapping is enabled. APIC IDs above 15 bits are
+	 * only permitted if IRQ remapping is enabled, so check that.
+	 */
+	if (apic->apic_id_valid(32768))
+		return 0;
+
+	return x86_fwspec_is_ioapic(fwspec) || x86_fwspec_is_hpet(fwspec);
+}
+
 static const struct irq_domain_ops x86_vector_domain_ops = {
+	.select		= x86_vector_select,
 	.alloc		= x86_vector_alloc_irqs,
 	.free		= x86_vector_free_irqs,
 	.activate	= x86_vector_activate,