[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 0000000..5322e5e
--- /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);