[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, 75 insertions, 0 deletions

diff --git a/drivers/s390/char/sclp_config.c b/drivers/s390/char/sclp_config.c
new file mode 100644
index 00000000000..5322e5e54a9
--- /dev/null
+++ b/drivers/s390/char/sclp_config.c
@@ -0,0 +1,75 @@
+/*
+ *  drivers/s390/char/sclp_config.c
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/cpu.h>
+#include <linux/sysdev.h>
+#include <linux/workqueue.h>
+#include "sclp.h"
+
+#define TAG     "sclp_config: "
+
+struct conf_mgm_data {
+        u8 reserved;
+        u8 ev_qualifier;
+} __attribute__((packed));
+
+#define EV_QUAL_CAP_CHANGE      3
+
+static struct work_struct sclp_cpu_capability_work;
+
+static void sclp_cpu_capability_notify(struct work_struct *work)
+{
+        int cpu;
+        struct sys_device *sysdev;
+
+        printk(KERN_WARNING TAG "cpu capability changed.\n");
+        lock_cpu_hotplug();
+        for_each_online_cpu(cpu) {
+                sysdev = get_cpu_sysdev(cpu);
+                kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
+        }
+        unlock_cpu_hotplug();
+}
+
+static void sclp_conf_receiver_fn(struct evbuf_header *evbuf)
+{
+        struct conf_mgm_data *cdata;
+
+        cdata = (struct conf_mgm_data *)(evbuf + 1);
+        if (cdata->ev_qualifier == EV_QUAL_CAP_CHANGE)
+                schedule_work(&sclp_cpu_capability_work);
+}
+
+static struct sclp_register sclp_conf_register =
+{
+        .receive_mask = EVTYP_CONFMGMDATA_MASK,
+        .receiver_fn  = sclp_conf_receiver_fn,
+};
+
+static int __init sclp_conf_init(void)
+{
+        int rc;
+
+        INIT_WORK(&sclp_cpu_capability_work, sclp_cpu_capability_notify);
+
+        rc = sclp_register(&sclp_conf_register);
+        if (rc) {
+                printk(KERN_ERR TAG "failed to register (%d).\n", rc);
+                return rc;
+        }
+
+        if (!(sclp_conf_register.sclp_receive_mask & EVTYP_CONFMGMDATA_MASK)) {
+                printk(KERN_WARNING TAG "no configuration management.\n");
+                sclp_unregister(&sclp_conf_register);
+                rc = -ENOSYS;
+        }
+        return rc;
+}
+
+__initcall(sclp_conf_init);