[S390] Add per-cpu idle time / idle count sysfs attributes.

Add two new sysfs entries per cpu: idle_count and idle_time.
idle_count contains the number of times a cpu went into idle state.
idle_time contains the time a cpu spent in idle state in microseconds.
This can be used e.g. by powertop to tell how often idle state is
entered and left.

# cat /sys/devices/system/cpu/cpu0/idle_count
504
# cat /sys/devices/system/cpu/cpu0/idle_time
469734037 us

Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/include/asm-s390/cpu.h b/include/asm-s390/cpu.h
new file mode 100644
index 000000000000..352dde194f3c
--- /dev/null
+++ b/include/asm-s390/cpu.h
@@ -0,0 +1,25 @@
+/*
+ *  include/asm-s390/cpu.h
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#ifndef _ASM_S390_CPU_H_
+#define _ASM_S390_CPU_H_
+
+#include <linux/types.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+struct s390_idle_data {
+        spinlock_t lock;
+        unsigned int in_idle;
+        unsigned long long idle_count;
+        unsigned long long idle_enter;
+        unsigned long long idle_time;
+};
+
+DECLARE_PER_CPU(struct s390_idle_data, s390_idle);
+
+#endif /* _ASM_S390_CPU_H_ */