[patch 33/38] Processor degradation notification.

Martin Schwidefsky
2007-04-27T14:09:12Z

[-- Attachment #1: 136-cpu-degradation.diff --]
[-- Type: text/plain, Size: 7044 bytes --]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

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>
---

arch/s390/kernel/smp.c | 48 ++++++++++++++++++++++---
drivers/s390/char/Makefile | 2 -
drivers/s390/char/sclp.h | 2 +
drivers/s390/char/sclp_config.c | 75 ++++++++++++++++++++++++++++++++++++++++
drivers/s390/sysinfo.c | 18 +++++++++
include/asm-s390/processor.h | 1
6 files changed, 140 insertions(+), 6 deletions(-)

Index: quilt-2.6/arch/s390/kernel/smp.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/smp.c 2007-04-27 16:04:59.000000000 +0200
+++ quilt-2.6/arch/s390/kernel/smp.c 2007-04-27 16:05:00.000000000 +0200
@@ -821,19 +821,57 @@

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;
}
Index: quilt-2.6/drivers/s390/char/Makefile
===================================================================
--- quilt-2.6.orig/drivers/s390/char/Makefile 2007-04-27 16:04:59.000000000 +0200
+++ quilt-2.6/drivers/s390/char/Makefile 2007-04-27 16:05:00.000000000 +0200
@@ -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
Index: quilt-2.6/drivers/s390/char/sclp_config.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ quilt-2.6/drivers/s390/char/sclp_config.c 2007-04-27 16:05:00.000000000 +0200
@@ -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);
Index: quilt-2.6/drivers/s390/char/sclp.h
===================================================================
--- quilt-2.6.orig/drivers/s390/char/sclp.h 2007-04-27 16:05:00.000000000 +0200
+++ quilt-2.6/drivers/s390/char/sclp.h 2007-04-27 16:05:00.000000000 +0200
@@ -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
Index: quilt-2.6/drivers/s390/sysinfo.c
===================================================================
--- quilt-2.6.orig/drivers/s390/sysinfo.c 2007-04-27 16:01:49.000000000 +0200
+++ quilt-2.6/drivers/s390/sysinfo.c 2007-04-27 16:05:00.000000000 +0200
@@ -357,6 +357,24 @@

__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.
*/
Index: quilt-2.6/include/asm-s390/processor.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/processor.h 2007-04-27 16:04:56.000000000 +0200
+++ quilt-2.6/include/asm-s390/processor.h 2007-04-27 16:05:00.000000000 +0200
@@ -57,6 +57,7 @@

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;