s390/airq: simplify adapter interrupt code

There are three users of adapter interrupts: AP, QDIO and PCI. Each
registers a single adapter interrupt with independent ISCs. Define
a "struct airq" with the interrupt handler, a pointer and a mask for
the local summary indicator and the ISC for the adapter interrupt
source. Convert the indicator array with its fixed number of adapter
interrupt sources per ISE to an array of hlists. This removes the
limitation to 32 adapter interrupts per ISC and allows for arbitrary
memory locations for the local summary indicator.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 51c3ca8..e2956ad 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -82,8 +82,13 @@
 
 static struct intr_bucket *bucket;
 
-/* Adapter local summary indicator */
-static u8 *zpci_irq_si;
+/* Adapter interrupt definitions */
+static void zpci_irq_handler(struct airq_struct *airq);
+
+static struct airq_struct zpci_airq = {
+	.handler = zpci_irq_handler,
+	.isc = PCI_ISC,
+};
 
 /* I/O Map */
 static DEFINE_SPINLOCK(zpci_iomap_lock);
@@ -402,7 +407,7 @@
 /* store the last handled bit to implement fair scheduling of devices */
 static DEFINE_PER_CPU(unsigned long, next_sbit);
 
-static void zpci_irq_handler(void *dont, void *need)
+static void zpci_irq_handler(struct airq_struct *airq)
 {
 	unsigned long sbit, mbit, last = 0, start = __get_cpu_var(next_sbit);
 	int rescan = 0, max = aisb_max;
@@ -712,25 +717,20 @@
 		goto out_alloc;
 	}
 
-	isc_register(PCI_ISC);
-	zpci_irq_si = s390_register_adapter_interrupt(&zpci_irq_handler, NULL, PCI_ISC);
-	if (IS_ERR(zpci_irq_si)) {
-		rc = PTR_ERR(zpci_irq_si);
-		zpci_irq_si = NULL;
+	rc = register_adapter_interrupt(&zpci_airq);
+	if (rc)
 		goto out_ai;
-	}
+	/* Set summary to 1 to be called every time for the ISC. */
+	*zpci_airq.lsi_ptr = 1;
 
 	for_each_online_cpu(cpu)
 		per_cpu(next_sbit, cpu) = 0;
 
 	spin_lock_init(&bucket->lock);
-	/* set summary to 1 to be called every time for the ISC */
-	*zpci_irq_si = 1;
 	set_irq_ctrl(SIC_IRQ_MODE_SINGLE, NULL, PCI_ISC);
 	return 0;
 
 out_ai:
-	isc_unregister(PCI_ISC);
 	free_page((unsigned long) bucket->alloc);
 out_alloc:
 	free_page((unsigned long) bucket->aisb);
@@ -743,8 +743,7 @@
 {
 	free_page((unsigned long) bucket->alloc);
 	free_page((unsigned long) bucket->aisb);
-	s390_unregister_adapter_interrupt(zpci_irq_si, PCI_ISC);
-	isc_unregister(PCI_ISC);
+	unregister_adapter_interrupt(&zpci_airq);
 	kfree(bucket);
 }