Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * drivers/base/cpu.c - basic CPU class support | |
3 | */ | |
4 | ||
5 | #include <linux/sysdev.h> | |
6 | #include <linux/module.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/cpu.h> | |
9 | #include <linux/topology.h> | |
10 | #include <linux/device.h> | |
11 | ||
a1bdc7aa | 12 | #include "base.h" |
1da177e4 LT |
13 | |
14 | struct sysdev_class cpu_sysdev_class = { | |
15 | set_kset_name("cpu"), | |
16 | }; | |
17 | EXPORT_SYMBOL(cpu_sysdev_class); | |
18 | ||
ad74557a AR |
19 | static struct sys_device *cpu_sys_devices[NR_CPUS]; |
20 | ||
1da177e4 | 21 | #ifdef CONFIG_HOTPLUG_CPU |
52a119fe AR |
22 | int __attribute__((weak)) smp_prepare_cpu (int cpu) |
23 | { | |
24 | return 0; | |
25 | } | |
e1367daf | 26 | |
1da177e4 LT |
27 | static ssize_t show_online(struct sys_device *dev, char *buf) |
28 | { | |
29 | struct cpu *cpu = container_of(dev, struct cpu, sysdev); | |
30 | ||
31 | return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id)); | |
32 | } | |
33 | ||
34 | static ssize_t store_online(struct sys_device *dev, const char *buf, | |
35 | size_t count) | |
36 | { | |
37 | struct cpu *cpu = container_of(dev, struct cpu, sysdev); | |
38 | ssize_t ret; | |
39 | ||
40 | switch (buf[0]) { | |
41 | case '0': | |
42 | ret = cpu_down(cpu->sysdev.id); | |
43 | if (!ret) | |
312c004d | 44 | kobject_uevent(&dev->kobj, KOBJ_OFFLINE); |
1da177e4 LT |
45 | break; |
46 | case '1': | |
e1367daf | 47 | ret = smp_prepare_cpu(cpu->sysdev.id); |
52a119fe | 48 | if (!ret) |
e1367daf | 49 | ret = cpu_up(cpu->sysdev.id); |
fb69c390 | 50 | if (!ret) |
312c004d | 51 | kobject_uevent(&dev->kobj, KOBJ_ONLINE); |
1da177e4 LT |
52 | break; |
53 | default: | |
54 | ret = -EINVAL; | |
55 | } | |
56 | ||
57 | if (ret >= 0) | |
58 | ret = count; | |
59 | return ret; | |
60 | } | |
61 | static SYSDEV_ATTR(online, 0600, show_online, store_online); | |
62 | ||
63 | static void __devinit register_cpu_control(struct cpu *cpu) | |
64 | { | |
65 | sysdev_create_file(&cpu->sysdev, &attr_online); | |
66 | } | |
67 | void unregister_cpu(struct cpu *cpu, struct node *root) | |
68 | { | |
ad74557a | 69 | int logical_cpu = cpu->sysdev.id; |
1da177e4 LT |
70 | |
71 | if (root) | |
72 | sysfs_remove_link(&root->sysdev.kobj, | |
73 | kobject_name(&cpu->sysdev.kobj)); | |
74 | sysdev_remove_file(&cpu->sysdev, &attr_online); | |
75 | ||
76 | sysdev_unregister(&cpu->sysdev); | |
ad74557a | 77 | cpu_sys_devices[logical_cpu] = NULL; |
1da177e4 LT |
78 | return; |
79 | } | |
80 | #else /* ... !CONFIG_HOTPLUG_CPU */ | |
81 | static inline void register_cpu_control(struct cpu *cpu) | |
82 | { | |
83 | } | |
84 | #endif /* CONFIG_HOTPLUG_CPU */ | |
85 | ||
86 | /* | |
87 | * register_cpu - Setup a driverfs device for a CPU. | |
88 | * @cpu - Callers can set the cpu->no_control field to 1, to indicate not to | |
89 | * generate a control file in sysfs for this CPU. | |
90 | * @num - CPU number to use when creating the device. | |
91 | * | |
92 | * Initialize and register the CPU device. | |
93 | */ | |
94 | int __devinit register_cpu(struct cpu *cpu, int num, struct node *root) | |
95 | { | |
96 | int error; | |
97 | ||
98 | cpu->node_id = cpu_to_node(num); | |
99 | cpu->sysdev.id = num; | |
100 | cpu->sysdev.cls = &cpu_sysdev_class; | |
101 | ||
102 | error = sysdev_register(&cpu->sysdev); | |
103 | if (!error && root) | |
104 | error = sysfs_create_link(&root->sysdev.kobj, | |
105 | &cpu->sysdev.kobj, | |
106 | kobject_name(&cpu->sysdev.kobj)); | |
107 | if (!error && !cpu->no_control) | |
108 | register_cpu_control(cpu); | |
ad74557a AR |
109 | if (!error) |
110 | cpu_sys_devices[num] = &cpu->sysdev; | |
1da177e4 LT |
111 | return error; |
112 | } | |
113 | ||
ad74557a AR |
114 | struct sys_device *get_cpu_sysdev(int cpu) |
115 | { | |
116 | if (cpu < NR_CPUS) | |
117 | return cpu_sys_devices[cpu]; | |
118 | else | |
119 | return NULL; | |
120 | } | |
121 | EXPORT_SYMBOL_GPL(get_cpu_sysdev); | |
1da177e4 LT |
122 | |
123 | int __init cpu_dev_init(void) | |
124 | { | |
125 | return sysdev_class_register(&cpu_sysdev_class); | |
126 | } |