kernel-ark/drivers/s390/char/sclp_config.c
Gautham R Shenoy 86ef5c9a8e cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus()
Replace all lock_cpu_hotplug/unlock_cpu_hotplug from the kernel and use
get_online_cpus and put_online_cpus instead as it highlights the
refcount semantics in these operations.

The new API guarantees protection against the cpu-hotplug operation, but
it doesn't guarantee serialized access to any of the local data
structures. Hence the changes needs to be reviewed.

In case of pseries_add_processor/pseries_remove_processor, use
cpu_maps_update_begin()/cpu_maps_update_done() as we're modifying the
cpu_present_map there.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:02 +01:00

76 lines
1.6 KiB
C

/*
* 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");
get_online_cpus();
for_each_online_cpu(cpu) {
sysdev = get_cpu_sysdev(cpu);
kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
}
put_online_cpus();
}
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);