fb69c3907e
We already do kobject_hotplug for cpu offline; this adds a kobject_hotplug call for the online case. This is being requested by developers of an application which wants to be notified about both kinds of events. Signed-off-by: Nathan Lynch <ntl@pobox.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
113 lines
2.4 KiB
C
113 lines
2.4 KiB
C
/*
|
|
* drivers/base/cpu.c - basic CPU class support
|
|
*/
|
|
|
|
#include <linux/sysdev.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/topology.h>
|
|
#include <linux/device.h>
|
|
|
|
|
|
struct sysdev_class cpu_sysdev_class = {
|
|
set_kset_name("cpu"),
|
|
};
|
|
EXPORT_SYMBOL(cpu_sysdev_class);
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
int __attribute__((weak)) smp_prepare_cpu (int cpu)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t show_online(struct sys_device *dev, char *buf)
|
|
{
|
|
struct cpu *cpu = container_of(dev, struct cpu, sysdev);
|
|
|
|
return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
|
|
}
|
|
|
|
static ssize_t store_online(struct sys_device *dev, const char *buf,
|
|
size_t count)
|
|
{
|
|
struct cpu *cpu = container_of(dev, struct cpu, sysdev);
|
|
ssize_t ret;
|
|
|
|
switch (buf[0]) {
|
|
case '0':
|
|
ret = cpu_down(cpu->sysdev.id);
|
|
if (!ret)
|
|
kobject_hotplug(&dev->kobj, KOBJ_OFFLINE);
|
|
break;
|
|
case '1':
|
|
ret = smp_prepare_cpu(cpu->sysdev.id);
|
|
if (!ret)
|
|
ret = cpu_up(cpu->sysdev.id);
|
|
if (!ret)
|
|
kobject_hotplug(&dev->kobj, KOBJ_ONLINE);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
if (ret >= 0)
|
|
ret = count;
|
|
return ret;
|
|
}
|
|
static SYSDEV_ATTR(online, 0600, show_online, store_online);
|
|
|
|
static void __devinit register_cpu_control(struct cpu *cpu)
|
|
{
|
|
sysdev_create_file(&cpu->sysdev, &attr_online);
|
|
}
|
|
void unregister_cpu(struct cpu *cpu, struct node *root)
|
|
{
|
|
|
|
if (root)
|
|
sysfs_remove_link(&root->sysdev.kobj,
|
|
kobject_name(&cpu->sysdev.kobj));
|
|
sysdev_remove_file(&cpu->sysdev, &attr_online);
|
|
|
|
sysdev_unregister(&cpu->sysdev);
|
|
|
|
return;
|
|
}
|
|
#else /* ... !CONFIG_HOTPLUG_CPU */
|
|
static inline void register_cpu_control(struct cpu *cpu)
|
|
{
|
|
}
|
|
#endif /* CONFIG_HOTPLUG_CPU */
|
|
|
|
/*
|
|
* register_cpu - Setup a driverfs device for a CPU.
|
|
* @cpu - Callers can set the cpu->no_control field to 1, to indicate not to
|
|
* generate a control file in sysfs for this CPU.
|
|
* @num - CPU number to use when creating the device.
|
|
*
|
|
* Initialize and register the CPU device.
|
|
*/
|
|
int __devinit register_cpu(struct cpu *cpu, int num, struct node *root)
|
|
{
|
|
int error;
|
|
|
|
cpu->node_id = cpu_to_node(num);
|
|
cpu->sysdev.id = num;
|
|
cpu->sysdev.cls = &cpu_sysdev_class;
|
|
|
|
error = sysdev_register(&cpu->sysdev);
|
|
if (!error && root)
|
|
error = sysfs_create_link(&root->sysdev.kobj,
|
|
&cpu->sysdev.kobj,
|
|
kobject_name(&cpu->sysdev.kobj));
|
|
if (!error && !cpu->no_control)
|
|
register_cpu_control(cpu);
|
|
return error;
|
|
}
|
|
|
|
|
|
|
|
int __init cpu_dev_init(void)
|
|
{
|
|
return sysdev_class_register(&cpu_sysdev_class);
|
|
}
|