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>
14 struct sysdev_class cpu_sysdev_class
= {
17 EXPORT_SYMBOL(cpu_sysdev_class
);
19 #ifdef CONFIG_HOTPLUG_CPU
20 int __attribute__((weak
)) smp_prepare_cpu (int cpu
)
25 static ssize_t
show_online(struct sys_device
*dev
, char *buf
)
27 struct cpu
*cpu
= container_of(dev
, struct cpu
, sysdev
);
29 return sprintf(buf
, "%u\n", !!cpu_online(cpu
->sysdev
.id
));
32 static ssize_t
store_online(struct sys_device
*dev
, const char *buf
,
35 struct cpu
*cpu
= container_of(dev
, struct cpu
, sysdev
);
40 ret
= cpu_down(cpu
->sysdev
.id
);
42 kobject_hotplug(&dev
->kobj
, KOBJ_OFFLINE
);
45 ret
= smp_prepare_cpu(cpu
->sysdev
.id
);
47 ret
= cpu_up(cpu
->sysdev
.id
);
49 kobject_hotplug(&dev
->kobj
, KOBJ_ONLINE
);
59 static SYSDEV_ATTR(online
, 0600, show_online
, store_online
);
61 static void __devinit
register_cpu_control(struct cpu
*cpu
)
63 sysdev_create_file(&cpu
->sysdev
, &attr_online
);
65 void unregister_cpu(struct cpu
*cpu
, struct node
*root
)
69 sysfs_remove_link(&root
->sysdev
.kobj
,
70 kobject_name(&cpu
->sysdev
.kobj
));
71 sysdev_remove_file(&cpu
->sysdev
, &attr_online
);
73 sysdev_unregister(&cpu
->sysdev
);
77 #else /* ... !CONFIG_HOTPLUG_CPU */
78 static inline void register_cpu_control(struct cpu
*cpu
)
81 #endif /* CONFIG_HOTPLUG_CPU */
84 * register_cpu - Setup a driverfs device for a CPU.
85 * @cpu - Callers can set the cpu->no_control field to 1, to indicate not to
86 * generate a control file in sysfs for this CPU.
87 * @num - CPU number to use when creating the device.
89 * Initialize and register the CPU device.
91 int __devinit
register_cpu(struct cpu
*cpu
, int num
, struct node
*root
)
95 cpu
->node_id
= cpu_to_node(num
);
97 cpu
->sysdev
.cls
= &cpu_sysdev_class
;
99 error
= sysdev_register(&cpu
->sysdev
);
101 error
= sysfs_create_link(&root
->sysdev
.kobj
,
103 kobject_name(&cpu
->sysdev
.kobj
));
104 if (!error
&& !cpu
->no_control
)
105 register_cpu_control(cpu
);
111 int __init
cpu_dev_init(void)
113 return sysdev_class_register(&cpu_sysdev_class
);