[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>

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 7c0143f..2c5de92 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -821,19 +821,57 @@ int setup_profiling_timer(unsigned int multiplier)
 
 static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
+static ssize_t show_capability(struct sys_device *dev, char *buf)
+{
+       unsigned int capability;
+       int rc;
+
+       rc = get_cpu_capability(&capability);
+       if (rc)
+               return rc;
+       return sprintf(buf, "%u\n", capability);
+}
+static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
+
+static int __cpuinit smp_cpu_notify(struct notifier_block *self,
+                                   unsigned long action, void *hcpu)
+{
+       unsigned int cpu = (unsigned int)(long)hcpu;
+       struct cpu *c = &per_cpu(cpu_devices, cpu);
+       struct sys_device *s = &c->sysdev;
+
+       switch (action) {
+       case CPU_ONLINE:
+               if (sysdev_create_file(s, &attr_capability))
+                       return NOTIFY_BAD;
+               break;
+       case CPU_DEAD:
+               sysdev_remove_file(s, &attr_capability);
+               break;
+       }
+       return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata smp_cpu_nb = {
+       .notifier_call  = smp_cpu_notify,
+};
+
 static int __init topology_init(void)
 {
        int cpu;
-       int ret;
+
+       register_cpu_notifier(&smp_cpu_nb);
 
        for_each_possible_cpu(cpu) {
                struct cpu *c = &per_cpu(cpu_devices, cpu);
+               struct sys_device *s = &c->sysdev;
 
                c->hotpluggable = 1;
-               ret = register_cpu(c, cpu);
-               if (ret)
-                       printk(KERN_WARNING "topology_init: register_cpu %d "
-                              "failed (%d)\n", cpu, ret);
+               register_cpu(c, cpu);
+               if (!cpu_online(cpu))
+                       continue;
+               s = &c->sysdev;
+               sysdev_create_file(s, &attr_capability);
        }
        return 0;
 }

diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile
index a0f6db2..c210784 100644 (file)
--- a/drivers/s390/char/Makefile
+++ b/drivers/s390/char/Makefile
@@ -3,7 +3,7 @@
 #
 
 obj-y += ctrlchar.o keyboard.o defkeymap.o sclp.o sclp_rw.o sclp_quiesce.o \
-        sclp_info.o sclp_chp.o
+        sclp_info.o sclp_config.o sclp_chp.o
 
 obj-$(CONFIG_TN3270) += raw3270.o
 obj-$(CONFIG_TN3270_CONSOLE) += con3270.o

diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index e03dcf4..87ac4a3 100644 (file)
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -27,6 +27,7 @@
 #define EVTYP_CNTLPROGIDENT    0x0B
 #define EVTYP_SIGQUIESCE       0x1D
 #define EVTYP_VT220MSG         0x1A
+#define EVTYP_CONFMGMDATA      0x04
 #define EVTYP_SDIAS            0x1C
 
 #define EVTYP_OPCMD_MASK       0x80000000
@@ -37,6 +38,7 @@
 #define EVTYP_CTLPROGIDENT_MASK        0x00200000
 #define EVTYP_SIGQUIESCE_MASK  0x00000008
 #define EVTYP_VT220MSG_MASK    0x00000040
+#define EVTYP_CONFMGMDATA_MASK 0x10000000
 #define EVTYP_SDIAS_MASK       0x00000010
 
 #define GNRLMSGFLGS_DOM                0x8000

diff --git a/drivers/s390/char/sclp_config.c b/drivers/s390/char/sclp_config.c
new file mode 100644 (file)
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);

diff --git a/drivers/s390/sysinfo.c b/drivers/s390/sysinfo.c
index 090743d..19343f9 100644 (file)
--- 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.
  */

diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index 96a6f80..e0fcea8 100644 (file)
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -57,6 +57,7 @@ struct cpuinfo_S390
 
 extern void s390_adjust_jiffies(void);
 extern void print_cpu_info(struct cpuinfo_S390 *);
+extern int get_cpu_capability(unsigned int *);
 
 /* Lazy FPU handling on uni-processor */
 extern struct task_struct *last_task_used_math;