s390/diag: add a statistic for diagnose calls

Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose
calls have been done by each CPU in the system.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/appldata.h b/arch/s390/include/asm/appldata.h
index 16887c5..a6263d4 100644
--- a/arch/s390/include/asm/appldata.h
+++ b/arch/s390/include/asm/appldata.h
@@ -7,6 +7,7 @@
 #ifndef _ASM_S390_APPLDATA_H
 #define _ASM_S390_APPLDATA_H
 
+#include <asm/diag.h>
 #include <asm/io.h>
 
 #define APPLDATA_START_INTERVAL_REC	0x80
@@ -53,6 +54,7 @@
 	parm_list.buffer_length = length;
 	parm_list.product_id_addr = (unsigned long) id;
 	parm_list.buffer_addr = virt_to_phys(buffer);
+	diag_stat_inc(DIAG_STAT_X0DC);
 	asm volatile(
 		"	diag	%1,%0,0xdc"
 		: "=d" (ry)