2 * drivers/base/cpu.c - basic CPU class support
5 #include <linux/sysdev.h>
6 #include <linux/module.h>
7 #include <linux/init.h>
9 #include <linux/topology.h>
10 #include <linux/device.h>
13 struct sysdev_class cpu_sysdev_class = {
16 EXPORT_SYMBOL(cpu_sysdev_class);
18 #ifdef CONFIG_HOTPLUG_CPU
19 static ssize_t show_online(struct sys_device *dev, char *buf)
21 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
23 return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
26 static ssize_t store_online(struct sys_device *dev, const char *buf,
29 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
34 ret = cpu_down(cpu->sysdev.id);
36 kobject_hotplug(&dev->kobj, KOBJ_OFFLINE);
39 ret = cpu_up(cpu->sysdev.id);
49 static SYSDEV_ATTR(online, 0600, show_online, store_online);
51 static void __init register_cpu_control(struct cpu *cpu)
53 sysdev_create_file(&cpu->sysdev, &attr_online);
55 #else /* ... !CONFIG_HOTPLUG_CPU */
56 static inline void register_cpu_control(struct cpu *cpu)
59 #endif /* CONFIG_HOTPLUG_CPU */
62 * register_cpu - Setup a driverfs device for a CPU.
63 * @cpu - Callers can set the cpu->no_control field to 1, to indicate not to
64 * generate a control file in sysfs for this CPU.
65 * @num - CPU number to use when creating the device.
67 * Initialize and register the CPU device.
69 int __init register_cpu(struct cpu *cpu, int num, struct node *root)
73 cpu->node_id = cpu_to_node(num);
75 cpu->sysdev.cls = &cpu_sysdev_class;
77 error = sysdev_register(&cpu->sysdev);
79 error = sysfs_create_link(&root->sysdev.kobj,
81 kobject_name(&cpu->sysdev.kobj));
82 if (!error && !cpu->no_control)
83 register_cpu_control(cpu);
89 int __init cpu_dev_init(void)
91 return sysdev_class_register(&cpu_sysdev_class);