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>

arch/s390/kernel/early.c

@@ -17,6 +17,7 @@
 #include <linux/pfn.h>
 #include <linux/uaccess.h>
 #include <linux/kernel.h>
+#include <asm/diag.h>
 #include <asm/ebcdic.h>
 #include <asm/ipl.h>
 #include <asm/lowcore.h>
@@ -286,6 +287,7 @@ static __init void detect_diag9c(void)
 	int rc;
 
 	cpu_address = stap();
+	diag_stat_inc(DIAG_STAT_X09C);
 	asm volatile(
 		"	diag	%2,0,0x9c\n"
 		"0:	la	%0,0\n"
@@ -300,6 +302,7 @@ static __init void detect_diag44(void)
 {
 	int rc;
 
+	diag_stat_inc(DIAG_STAT_X044);
 	asm volatile(
 		"	diag	0,0,0x44\n"
 		"0:	la	%0,0\n"