You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
156 lines
3.5 KiB
156 lines
3.5 KiB
/*
|
|
* 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>
|
|
|
|
#include "base.h"
|
|
|
|
struct sysdev_class cpu_sysdev_class = {
|
|
set_kset_name("cpu"),
|
|
};
|
|
EXPORT_SYMBOL(cpu_sysdev_class);
|
|
|
|
static struct sys_device *cpu_sys_devices[NR_CPUS];
|
|
|
|
#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_uevent(&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_uevent(&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)
|
|
{
|
|
int logical_cpu = cpu->sysdev.id;
|
|
|
|
if (root)
|
|
sysfs_remove_link(&root->sysdev.kobj,
|
|
kobject_name(&cpu->sysdev.kobj));
|
|
sysdev_remove_file(&cpu->sysdev, &attr_online);
|
|
|
|
sysdev_unregister(&cpu->sysdev);
|
|
cpu_sys_devices[logical_cpu] = NULL;
|
|
return;
|
|
}
|
|
#else /* ... !CONFIG_HOTPLUG_CPU */
|
|
static inline void register_cpu_control(struct cpu *cpu)
|
|
{
|
|
}
|
|
#endif /* CONFIG_HOTPLUG_CPU */
|
|
|
|
#ifdef CONFIG_KEXEC
|
|
#include <linux/kexec.h>
|
|
|
|
static ssize_t show_crash_notes(struct sys_device *dev, char *buf)
|
|
{
|
|
struct cpu *cpu = container_of(dev, struct cpu, sysdev);
|
|
ssize_t rc;
|
|
unsigned long long addr;
|
|
int cpunum;
|
|
|
|
cpunum = cpu->sysdev.id;
|
|
|
|
/*
|
|
* Might be reading other cpu's data based on which cpu read thread
|
|
* has been scheduled. But cpu data (memory) is allocated once during
|
|
* boot up and this data does not change there after. Hence this
|
|
* operation should be safe. No locking required.
|
|
*/
|
|
addr = __pa(per_cpu_ptr(crash_notes, cpunum));
|
|
rc = sprintf(buf, "%Lx\n", addr);
|
|
return rc;
|
|
}
|
|
static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
|
|
#endif
|
|
|
|
/*
|
|
* 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);
|
|
if (!error)
|
|
cpu_sys_devices[num] = &cpu->sysdev;
|
|
|
|
#ifdef CONFIG_KEXEC
|
|
if (!error)
|
|
error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
|
|
#endif
|
|
return error;
|
|
}
|
|
|
|
struct sys_device *get_cpu_sysdev(int cpu)
|
|
{
|
|
if (cpu < NR_CPUS)
|
|
return cpu_sys_devices[cpu];
|
|
else
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_cpu_sysdev);
|
|
|
|
int __init cpu_dev_init(void)
|
|
{
|
|
return sysdev_class_register(&cpu_sysdev_class);
|
|
}
|
|
|