forked from Minki/linux
8e1023016c
When the seqfile /proc/cpuinfo gets accesses for each possible cpu loops_per_jiffy gets recalculated. However its value is only needed on first access. In addition loops_per_jiffy should be recalculated when the machine reports a capability change. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
92 lines
1.9 KiB
C
92 lines
1.9 KiB
C
/*
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* drivers/s390/char/sclp_config.c
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*
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* Copyright IBM Corp. 2007
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* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#define KMSG_COMPONENT "sclp_config"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/cpu.h>
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#include <linux/sysdev.h>
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#include <linux/workqueue.h>
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#include <asm/smp.h>
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#include "sclp.h"
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struct conf_mgm_data {
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u8 reserved;
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u8 ev_qualifier;
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} __attribute__((packed));
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#define EV_QUAL_CPU_CHANGE 1
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#define EV_QUAL_CAP_CHANGE 3
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static struct work_struct sclp_cpu_capability_work;
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static struct work_struct sclp_cpu_change_work;
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static void sclp_cpu_capability_notify(struct work_struct *work)
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{
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int cpu;
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struct sys_device *sysdev;
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s390_adjust_jiffies();
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pr_warning("cpu capability changed.\n");
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get_online_cpus();
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for_each_online_cpu(cpu) {
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sysdev = get_cpu_sysdev(cpu);
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kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
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}
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put_online_cpus();
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}
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static void __ref sclp_cpu_change_notify(struct work_struct *work)
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{
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smp_rescan_cpus();
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}
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static void sclp_conf_receiver_fn(struct evbuf_header *evbuf)
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{
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struct conf_mgm_data *cdata;
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cdata = (struct conf_mgm_data *)(evbuf + 1);
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switch (cdata->ev_qualifier) {
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case EV_QUAL_CPU_CHANGE:
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schedule_work(&sclp_cpu_change_work);
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break;
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case EV_QUAL_CAP_CHANGE:
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schedule_work(&sclp_cpu_capability_work);
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break;
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}
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}
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static struct sclp_register sclp_conf_register =
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{
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.receive_mask = EVTYP_CONFMGMDATA_MASK,
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.receiver_fn = sclp_conf_receiver_fn,
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};
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static int __init sclp_conf_init(void)
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{
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int rc;
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INIT_WORK(&sclp_cpu_capability_work, sclp_cpu_capability_notify);
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INIT_WORK(&sclp_cpu_change_work, sclp_cpu_change_notify);
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rc = sclp_register(&sclp_conf_register);
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if (rc)
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return rc;
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if (!(sclp_conf_register.sclp_send_mask & EVTYP_CONFMGMDATA_MASK)) {
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pr_warning("no configuration management.\n");
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sclp_unregister(&sclp_conf_register);
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rc = -ENOSYS;
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}
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return rc;
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}
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__initcall(sclp_conf_init);
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