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 int __attribute__((weak
)) smp_prepare_cpu (int cpu
)
24 static ssize_t
show_online(struct sys_device
*dev
, char *buf
)
26 struct cpu
*cpu
= container_of(dev
, struct cpu
, sysdev
);
28 return sprintf(buf
, "%u\n", !!cpu_online(cpu
->sysdev
.id
));
31 static ssize_t
store_online(struct sys_device
*dev
, const char *buf
,
34 struct cpu
*cpu
= container_of(dev
, struct cpu
, sysdev
);
39 ret
= cpu_down(cpu
->sysdev
.id
);
41 kobject_hotplug(&dev
->kobj
, KOBJ_OFFLINE
);
44 ret
= smp_prepare_cpu(cpu
->sysdev
.id
);
46 ret
= cpu_up(cpu
->sysdev
.id
);
48 kobject_hotplug(&dev
->kobj
, KOBJ_ONLINE
);
58 static SYSDEV_ATTR(online
, 0600, show_online
, store_online
);
60 static void __devinit
register_cpu_control(struct cpu
*cpu
)
62 sysdev_create_file(&cpu
->sysdev
, &attr_online
);
64 void unregister_cpu(struct cpu
*cpu
, struct node
*root
)
68 sysfs_remove_link(&root
->sysdev
.kobj
,
69 kobject_name(&cpu
->sysdev
.kobj
));
70 sysdev_remove_file(&cpu
->sysdev
, &attr_online
);
72 sysdev_unregister(&cpu
->sysdev
);
76 #else /* ... !CONFIG_HOTPLUG_CPU */
77 static inline void register_cpu_control(struct cpu
*cpu
)
80 #endif /* CONFIG_HOTPLUG_CPU */
83 * register_cpu - Setup a driverfs device for a CPU.
84 * @cpu - Callers can set the cpu->no_control field to 1, to indicate not to
85 * generate a control file in sysfs for this CPU.
86 * @num - CPU number to use when creating the device.
88 * Initialize and register the CPU device.
90 int __devinit
register_cpu(struct cpu
*cpu
, int num
, struct node
*root
)
94 cpu
->node_id
= cpu_to_node(num
);
96 cpu
->sysdev
.cls
= &cpu_sysdev_class
;
98 error
= sysdev_register(&cpu
->sysdev
);
100 error
= sysfs_create_link(&root
->sysdev
.kobj
,
102 kobject_name(&cpu
->sysdev
.kobj
));
103 if (!error
&& !cpu
->no_control
)
104 register_cpu_control(cpu
);
110 int __init
cpu_dev_init(void)
112 return sysdev_class_register(&cpu_sysdev_class
);