[S390] ap bus: add support for irq statistics

Add support for AP Bus I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/irq.h

@@ -25,6 +25,7 @@ enum interruption_class {
 	IOINT_LCS,
 	IOINT_CLW,
 	IOINT_CTC,
+	IOINT_APB,
 	NMI_NMI,
 	NR_IRQS,
 };

arch/s390/kernel/irq.c

@@ -42,6 +42,7 @@ static const struct irq_class intrclass_names[] = {
 	{.name = "LCS", .desc = "[I/O] LCS" },
 	{.name = "CLW", .desc = "[I/O] CLAW" },
 	{.name = "CTC", .desc = "[I/O] CTC" },
+	{.name = "APB", .desc = "[I/O] AP Bus" },
 	{.name = "NMI", .desc = "[NMI] Machine Check" },
 };
 

drivers/s390/crypto/ap_bus.c

@@ -27,6 +27,7 @@
 #define KMSG_COMPONENT "ap"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
+#include <linux/kernel_stat.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/delay.h>
@@ -1042,6 +1043,7 @@ static int ap_probe_device_type(struct ap_device *ap_dev)
 
 static void ap_interrupt_handler(void *unused1, void *unused2)
 {
+	kstat_cpu(smp_processor_id()).irqs[IOINT_APB]++;
 	tasklet_schedule(&ap_tasklet);
 }