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Commit 2fc2d1e9 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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[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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
parent db77aa5f

arch/s390/kernel/smp.c

+43 −5
Original line number Diff line number Diff line
@@ -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;

}

drivers/s390/char/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

drivers/s390/char/sclp.h

+2 −0
Original line number Diff line number Diff line
@@ -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

drivers/s390/char/sclp_config.c

0 → 100644
+75 −0
Original line number Diff line number Diff line 
/*

 *  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);

drivers/s390/sysinfo.c

+18 −0
Original line number Diff line number Diff line
@@ -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.

 */