[S390] Processor degradation notification.

Generate uevents for all cpus if cpu capability changes. This can
happen e.g. because the cpus are overheating. The cpu capability can
be read via /sys/devices/system/cpu/cpuN/capability.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/s390/sysinfo.c b/drivers/s390/sysinfo.c
index 090743d2f914..19343f9675c3 100644
--- a/drivers/s390/sysinfo.c
+++ b/drivers/s390/sysinfo.c
@@ -357,6 +357,24 @@ static __init int create_proc_sysinfo(void)
 
 __initcall(create_proc_sysinfo);
 
+int get_cpu_capability(unsigned int *capability)
+{
+        struct sysinfo_1_2_2 *info;
+        int rc;
+
+        info = (void *) get_zeroed_page(GFP_KERNEL);
+        if (!info)
+                return -ENOMEM;
+        rc = stsi(info, 1, 2, 2);
+        if (rc == -ENOSYS)
+                goto out;
+        rc = 0;
+        *capability = info->capability;
+out:
+        free_page((unsigned long) info);
+        return rc;
+}
+
 /*
  * CPU capability might have changed. Therefore recalculate loops_per_jiffy.
  */