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> | |
76b67ed9 | 11 | #include <linux/node.h> |
1da177e4 | 12 | |
a1bdc7aa | 13 | #include "base.h" |
1da177e4 LT |
14 | |
15 | struct sysdev_class cpu_sysdev_class = { | |
16 | set_kset_name("cpu"), | |
17 | }; | |
18 | EXPORT_SYMBOL(cpu_sysdev_class); | |
19 | ||
ad74557a AR |
20 | static struct sys_device *cpu_sys_devices[NR_CPUS]; |
21 | ||
1da177e4 LT |
22 | #ifdef CONFIG_HOTPLUG_CPU |
23 | static ssize_t show_online(struct sys_device *dev, char *buf) | |
24 | { | |
25 | struct cpu *cpu = container_of(dev, struct cpu, sysdev); | |
26 | ||
27 | return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id)); | |
28 | } | |
29 | ||
30 | static ssize_t store_online(struct sys_device *dev, const char *buf, | |
31 | size_t count) | |
32 | { | |
33 | struct cpu *cpu = container_of(dev, struct cpu, sysdev); | |
34 | ssize_t ret; | |
35 | ||
36 | switch (buf[0]) { | |
37 | case '0': | |
38 | ret = cpu_down(cpu->sysdev.id); | |
39 | if (!ret) | |
312c004d | 40 | kobject_uevent(&dev->kobj, KOBJ_OFFLINE); |
1da177e4 LT |
41 | break; |
42 | case '1': | |
34f361ad | 43 | ret = cpu_up(cpu->sysdev.id); |
fb69c390 | 44 | if (!ret) |
312c004d | 45 | kobject_uevent(&dev->kobj, KOBJ_ONLINE); |
1da177e4 LT |
46 | break; |
47 | default: | |
48 | ret = -EINVAL; | |
49 | } | |
50 | ||
51 | if (ret >= 0) | |
52 | ret = count; | |
53 | return ret; | |
54 | } | |
55 | static SYSDEV_ATTR(online, 0600, show_online, store_online); | |
56 | ||
57 | static void __devinit register_cpu_control(struct cpu *cpu) | |
58 | { | |
59 | sysdev_create_file(&cpu->sysdev, &attr_online); | |
60 | } | |
76b67ed9 | 61 | void unregister_cpu(struct cpu *cpu) |
1da177e4 | 62 | { |
ad74557a | 63 | int logical_cpu = cpu->sysdev.id; |
1da177e4 | 64 | |
76b67ed9 KH |
65 | unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); |
66 | ||
1da177e4 LT |
67 | sysdev_remove_file(&cpu->sysdev, &attr_online); |
68 | ||
69 | sysdev_unregister(&cpu->sysdev); | |
ad74557a | 70 | cpu_sys_devices[logical_cpu] = NULL; |
1da177e4 LT |
71 | return; |
72 | } | |
73 | #else /* ... !CONFIG_HOTPLUG_CPU */ | |
74 | static inline void register_cpu_control(struct cpu *cpu) | |
75 | { | |
76 | } | |
77 | #endif /* CONFIG_HOTPLUG_CPU */ | |
78 | ||
51be5606 VG |
79 | #ifdef CONFIG_KEXEC |
80 | #include <linux/kexec.h> | |
81 | ||
82 | static ssize_t show_crash_notes(struct sys_device *dev, char *buf) | |
83 | { | |
84 | struct cpu *cpu = container_of(dev, struct cpu, sysdev); | |
85 | ssize_t rc; | |
86 | unsigned long long addr; | |
87 | int cpunum; | |
88 | ||
89 | cpunum = cpu->sysdev.id; | |
90 | ||
91 | /* | |
92 | * Might be reading other cpu's data based on which cpu read thread | |
93 | * has been scheduled. But cpu data (memory) is allocated once during | |
94 | * boot up and this data does not change there after. Hence this | |
95 | * operation should be safe. No locking required. | |
96 | */ | |
51be5606 VG |
97 | addr = __pa(per_cpu_ptr(crash_notes, cpunum)); |
98 | rc = sprintf(buf, "%Lx\n", addr); | |
51be5606 VG |
99 | return rc; |
100 | } | |
101 | static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL); | |
102 | #endif | |
103 | ||
1da177e4 LT |
104 | /* |
105 | * register_cpu - Setup a driverfs device for a CPU. | |
106 | * @cpu - Callers can set the cpu->no_control field to 1, to indicate not to | |
107 | * generate a control file in sysfs for this CPU. | |
108 | * @num - CPU number to use when creating the device. | |
109 | * | |
110 | * Initialize and register the CPU device. | |
111 | */ | |
76b67ed9 | 112 | int __devinit register_cpu(struct cpu *cpu, int num) |
1da177e4 LT |
113 | { |
114 | int error; | |
1da177e4 LT |
115 | cpu->node_id = cpu_to_node(num); |
116 | cpu->sysdev.id = num; | |
117 | cpu->sysdev.cls = &cpu_sysdev_class; | |
118 | ||
119 | error = sysdev_register(&cpu->sysdev); | |
76b67ed9 | 120 | |
1da177e4 LT |
121 | if (!error && !cpu->no_control) |
122 | register_cpu_control(cpu); | |
ad74557a AR |
123 | if (!error) |
124 | cpu_sys_devices[num] = &cpu->sysdev; | |
76b67ed9 KH |
125 | if (!error) |
126 | register_cpu_under_node(num, cpu_to_node(num)); | |
51be5606 VG |
127 | |
128 | #ifdef CONFIG_KEXEC | |
129 | if (!error) | |
130 | error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes); | |
131 | #endif | |
1da177e4 LT |
132 | return error; |
133 | } | |
134 | ||
a29d642a | 135 | struct sys_device *get_cpu_sysdev(unsigned cpu) |
ad74557a AR |
136 | { |
137 | if (cpu < NR_CPUS) | |
138 | return cpu_sys_devices[cpu]; | |
139 | else | |
140 | return NULL; | |
141 | } | |
142 | EXPORT_SYMBOL_GPL(get_cpu_sysdev); | |
1da177e4 LT |
143 | |
144 | int __init cpu_dev_init(void) | |
145 | { | |
146 | return sysdev_class_register(&cpu_sysdev_class); | |
147 | } |