powerpc: Convert irq_domain_add_legacy_isa use to irq_domain_add_legacy

irq_domain_add_legacy_isa is a pain. It only exists for the benefit of
two PPC-specific drivers, and creates an ugly dependency between asm/irq.h
and linux/irqdomain.h

Instead, let's convert these two drivers to irq_domain_add_legacy(),
stop using NUM_ISA_INTERRUPTS by directly setting NR_IRQS_LEGACY.

The dependency cannot be broken yet as there is a lot of PPC-related
code that depends on it, but that's the first step towards it.

A followup patch will remove irq_domain_add_legacy_isa.

Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/powerpc/include/asm/irq.h

@@ -23,8 +23,8 @@ extern atomic_t ppc_n_lost_interrupts;
 /* Total number of virq in the platform */
 #define NR_IRQS		CONFIG_NR_IRQS
 
-/* Same thing, used by the generic IRQ code */
-#define NR_IRQS_LEGACY		NUM_ISA_INTERRUPTS
+/* Number of irqs reserved for a legacy isa controller */
+#define NR_IRQS_LEGACY		16
 
 extern irq_hw_number_t virq_to_hw(unsigned int virq);
 

arch/powerpc/platforms/ps3/interrupt.c

@@ -46,7 +46,7 @@
  * implementation equates HV plug value to Linux virq value, constrains each
  * interrupt to have a system wide unique plug number, and limits the range
  * of the plug values to map into the first dword of the bitmaps.  This
- * gives a usable range of plug values of  {NUM_ISA_INTERRUPTS..63}.  Note
+ * gives a usable range of plug values of  {NR_IRQS_LEGACY..63}.  Note
  * that there is no constraint on how many in this set an individual thread
  * can acquire.
  *
@@ -722,7 +722,7 @@ static unsigned int ps3_get_irq(void)
 	}
 
 #if defined(DEBUG)
-	if (unlikely(plug < NUM_ISA_INTERRUPTS || plug > PS3_PLUG_MAX)) {
+	if (unlikely(plug < NR_IRQS_LEGACY || plug > PS3_PLUG_MAX)) {
 		dump_bmp(&per_cpu(ps3_private, 0));
 		dump_bmp(&per_cpu(ps3_private, 1));
 		BUG();

arch/powerpc/sysdev/i8259.c

@@ -260,7 +260,8 @@ void i8259_init(struct device_node *node, unsigned long intack_addr)
 	raw_spin_unlock_irqrestore(&i8259_lock, flags);
 
 	/* create a legacy host */
-	i8259_host = irq_domain_add_legacy_isa(node, &i8259_host_ops, NULL);
+	i8259_host = irq_domain_add_legacy(node, NR_IRQS_LEGACY, 0, 0,
+					   &i8259_host_ops, NULL);
 	if (i8259_host == NULL) {
 		printk(KERN_ERR "i8259: failed to allocate irq host !\n");
 		return;

arch/powerpc/sysdev/mpic.c

@@ -602,7 +602,7 @@ static void __init mpic_scan_ht_pics(struct mpic *mpic)
 /* Find an mpic associated with a given linux interrupt */
 static struct mpic *mpic_find(unsigned int irq)
 {
-	if (irq < NUM_ISA_INTERRUPTS)
+	if (irq < NR_IRQS_LEGACY)
 		return NULL;
 
 	return irq_get_chip_data(irq);

arch/powerpc/sysdev/tsi108_pci.c

@@ -404,7 +404,8 @@ void __init tsi108_pci_int_init(struct device_node *node)
 {
 	DBG("Tsi108_pci_int_init: initializing PCI interrupts\n");
 
-	pci_irq_host = irq_domain_add_legacy_isa(node, &pci_irq_domain_ops, NULL);
+	pci_irq_host = irq_domain_add_legacy(node, NR_IRQS_LEGACY, 0, 0,
+					     &pci_irq_domain_ops, NULL);
 	if (pci_irq_host == NULL) {
 		printk(KERN_ERR "pci_irq_host: failed to allocate irq domain!\n");
 		return;

arch/powerpc/sysdev/xics/xics-common.c

@@ -201,7 +201,7 @@ void xics_migrate_irqs_away(void)
 		struct ics *ics;
 
 		/* We can't set affinity on ISA interrupts */
-		if (virq < NUM_ISA_INTERRUPTS)
+		if (virq < NR_IRQS_LEGACY)
 			continue;
 		/* We only need to migrate enabled IRQS */
 		if (!desc->action)