[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>
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index a1ba52a..4f37c45 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/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 void ap_interrupt_handler(void *unused1, void *unused2)
 {
+	kstat_cpu(smp_processor_id()).irqs[IOINT_APB]++;
 	tasklet_schedule(&ap_tasklet);
 }