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>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c
index e6e077ae3990..7ce00e7a709a 100644
--- a/arch/s390/kernel/processor.c
+++ b/arch/s390/kernel/processor.c
@@ -11,6 +11,7 @@
 #include <linux/seq_file.h>
 #include <linux/delay.h>
 #include <linux/cpu.h>
+#include <asm/diag.h>
 #include <asm/elf.h>
 #include <asm/lowcore.h>
 #include <asm/param.h>
@@ -20,8 +21,10 @@ static DEFINE_PER_CPU(struct cpuid, cpu_id);
 
 void notrace cpu_relax(void)
 {
-        if (!smp_cpu_mtid && MACHINE_HAS_DIAG44)
+        if (!smp_cpu_mtid && MACHINE_HAS_DIAG44) {
+                diag_stat_inc(DIAG_STAT_X044);
                 asm volatile("diag 0,0,0x44");
+        }
         barrier();
 }
 EXPORT_SYMBOL(cpu_relax);