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, 3 insertions, 0 deletions

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index f985856a538b..77b3938d6bfa 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -30,6 +30,7 @@
 #include <linux/uaccess.h>
 #include <linux/hugetlb.h>
 #include <asm/asm-offsets.h>
+#include <asm/diag.h>
 #include <asm/pgtable.h>
 #include <asm/irq.h>
 #include <asm/mmu_context.h>
@@ -597,6 +598,7 @@ int pfault_init(void)
 
         if (pfault_disable)
                 return -1;
+        diag_stat_inc(DIAG_STAT_X258);
         asm volatile(
                 "       diag    %1,%0,0x258\n"
                 "0:     j       2f\n"
@@ -618,6 +620,7 @@ void pfault_fini(void)
 
         if (pfault_disable)
                 return;
+        diag_stat_inc(DIAG_STAT_X258);
         asm volatile(
                 "       diag    %0,0,0x258\n"
                 "0:\n"