[S390] chsc_sch: add support for irq statistics

Add support for CHSC I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/irq.h

@@ -28,6 +28,7 @@ enum interruption_class {
 	IOINT_CLW,
 	IOINT_CTC,
 	IOINT_APB,
+	IOINT_CSC,
 	NMI_NMI,
 	NR_IRQS,
 };

arch/s390/kernel/irq.c

@@ -53,6 +53,7 @@ static const struct irq_class intrclass_names[] = {
 	{.name = "CLW", .desc = "[I/O] CLAW" },
 	{.name = "CTC", .desc = "[I/O] CTC" },
 	{.name = "APB", .desc = "[I/O] AP Bus" },
+	{.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
 	{.name = "NMI", .desc = "[NMI] Machine Check" },
 };
 

drivers/s390/cio/chsc_sch.c

 /*
  * Driver for s390 chsc subchannels
  *
- * Copyright IBM Corp. 2008, 2009
+ * Copyright IBM Corp. 2008, 2011
  *
  * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
  *
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/uaccess.h>
 #include <linux/miscdevice.h>
+#include <linux/kernel_stat.h>
 
 #include <asm/compat.h>
 #include <asm/cio.h>
@@ -56,6 +57,8 @@ static void chsc_subchannel_irq(struct subchannel *sch)
 
 	CHSC_LOG(4, "irb");
 	CHSC_LOG_HEX(4, irb, sizeof(*irb));
+	kstat_cpu(smp_processor_id()).irqs[IOINT_CSC]++;
+
 	/* Copy irb to provided request and set done. */
 	if (!request) {
 		CHSC_MSG(0, "Interrupt on sch 0.%x.%04x with no request\n",