]>
Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
8a25a2fd | 2 | * CPU subsystem support |
1da177e4 LT |
3 | */ |
4 | ||
024f7846 | 5 | #include <linux/kernel.h> |
1da177e4 LT |
6 | #include <linux/module.h> |
7 | #include <linux/init.h> | |
f6a57033 | 8 | #include <linux/sched.h> |
1da177e4 LT |
9 | #include <linux/cpu.h> |
10 | #include <linux/topology.h> | |
11 | #include <linux/device.h> | |
76b67ed9 | 12 | #include <linux/node.h> |
5a0e3ad6 | 13 | #include <linux/gfp.h> |
fad12ac8 | 14 | #include <linux/slab.h> |
9f13a1fd | 15 | #include <linux/percpu.h> |
1da177e4 | 16 | |
a1bdc7aa | 17 | #include "base.h" |
1da177e4 | 18 | |
8a25a2fd | 19 | struct bus_type cpu_subsys = { |
af5ca3f4 | 20 | .name = "cpu", |
8a25a2fd | 21 | .dev_name = "cpu", |
1da177e4 | 22 | }; |
8a25a2fd | 23 | EXPORT_SYMBOL_GPL(cpu_subsys); |
1da177e4 | 24 | |
8a25a2fd | 25 | static DEFINE_PER_CPU(struct device *, cpu_sys_devices); |
ad74557a | 26 | |
1da177e4 | 27 | #ifdef CONFIG_HOTPLUG_CPU |
8a25a2fd KS |
28 | static ssize_t show_online(struct device *dev, |
29 | struct device_attribute *attr, | |
4a0b2b4d | 30 | char *buf) |
1da177e4 | 31 | { |
8a25a2fd | 32 | struct cpu *cpu = container_of(dev, struct cpu, dev); |
1da177e4 | 33 | |
8a25a2fd | 34 | return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id)); |
1da177e4 LT |
35 | } |
36 | ||
8a25a2fd KS |
37 | static ssize_t __ref store_online(struct device *dev, |
38 | struct device_attribute *attr, | |
39 | const char *buf, size_t count) | |
1da177e4 | 40 | { |
8a25a2fd | 41 | struct cpu *cpu = container_of(dev, struct cpu, dev); |
1da177e4 LT |
42 | ssize_t ret; |
43 | ||
51badebd | 44 | cpu_hotplug_driver_lock(); |
1da177e4 LT |
45 | switch (buf[0]) { |
46 | case '0': | |
8a25a2fd | 47 | ret = cpu_down(cpu->dev.id); |
1da177e4 | 48 | if (!ret) |
312c004d | 49 | kobject_uevent(&dev->kobj, KOBJ_OFFLINE); |
1da177e4 LT |
50 | break; |
51 | case '1': | |
8a25a2fd | 52 | ret = cpu_up(cpu->dev.id); |
fb69c390 | 53 | if (!ret) |
312c004d | 54 | kobject_uevent(&dev->kobj, KOBJ_ONLINE); |
1da177e4 LT |
55 | break; |
56 | default: | |
57 | ret = -EINVAL; | |
58 | } | |
51badebd | 59 | cpu_hotplug_driver_unlock(); |
1da177e4 LT |
60 | |
61 | if (ret >= 0) | |
62 | ret = count; | |
63 | return ret; | |
64 | } | |
8a25a2fd | 65 | static DEVICE_ATTR(online, 0644, show_online, store_online); |
1da177e4 | 66 | |
6c847402 | 67 | static void __cpuinit register_cpu_control(struct cpu *cpu) |
1da177e4 | 68 | { |
8a25a2fd | 69 | device_create_file(&cpu->dev, &dev_attr_online); |
1da177e4 | 70 | } |
76b67ed9 | 71 | void unregister_cpu(struct cpu *cpu) |
1da177e4 | 72 | { |
8a25a2fd | 73 | int logical_cpu = cpu->dev.id; |
1da177e4 | 74 | |
76b67ed9 KH |
75 | unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); |
76 | ||
8a25a2fd | 77 | device_remove_file(&cpu->dev, &dev_attr_online); |
1da177e4 | 78 | |
8a25a2fd | 79 | device_unregister(&cpu->dev); |
e37d05da | 80 | per_cpu(cpu_sys_devices, logical_cpu) = NULL; |
1da177e4 LT |
81 | return; |
82 | } | |
12633e80 NF |
83 | |
84 | #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE | |
8a25a2fd KS |
85 | static ssize_t cpu_probe_store(struct device *dev, |
86 | struct device_attribute *attr, | |
67fc233f | 87 | const char *buf, |
12633e80 NF |
88 | size_t count) |
89 | { | |
90 | return arch_cpu_probe(buf, count); | |
91 | } | |
92 | ||
8a25a2fd KS |
93 | static ssize_t cpu_release_store(struct device *dev, |
94 | struct device_attribute *attr, | |
67fc233f | 95 | const char *buf, |
12633e80 NF |
96 | size_t count) |
97 | { | |
98 | return arch_cpu_release(buf, count); | |
99 | } | |
100 | ||
8a25a2fd KS |
101 | static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store); |
102 | static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store); | |
12633e80 NF |
103 | #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ |
104 | ||
1da177e4 LT |
105 | #else /* ... !CONFIG_HOTPLUG_CPU */ |
106 | static inline void register_cpu_control(struct cpu *cpu) | |
107 | { | |
108 | } | |
109 | #endif /* CONFIG_HOTPLUG_CPU */ | |
110 | ||
51be5606 VG |
111 | #ifdef CONFIG_KEXEC |
112 | #include <linux/kexec.h> | |
113 | ||
8a25a2fd | 114 | static ssize_t show_crash_notes(struct device *dev, struct device_attribute *attr, |
4a0b2b4d | 115 | char *buf) |
51be5606 | 116 | { |
8a25a2fd | 117 | struct cpu *cpu = container_of(dev, struct cpu, dev); |
51be5606 VG |
118 | ssize_t rc; |
119 | unsigned long long addr; | |
120 | int cpunum; | |
121 | ||
8a25a2fd | 122 | cpunum = cpu->dev.id; |
51be5606 VG |
123 | |
124 | /* | |
125 | * Might be reading other cpu's data based on which cpu read thread | |
126 | * has been scheduled. But cpu data (memory) is allocated once during | |
127 | * boot up and this data does not change there after. Hence this | |
128 | * operation should be safe. No locking required. | |
129 | */ | |
3b034b0d | 130 | addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum)); |
51be5606 | 131 | rc = sprintf(buf, "%Lx\n", addr); |
51be5606 VG |
132 | return rc; |
133 | } | |
8a25a2fd | 134 | static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL); |
eca4549f ZY |
135 | |
136 | static ssize_t show_crash_notes_size(struct device *dev, | |
137 | struct device_attribute *attr, | |
138 | char *buf) | |
139 | { | |
140 | ssize_t rc; | |
141 | ||
142 | rc = sprintf(buf, "%lu\n", sizeof(note_buf_t)); | |
143 | return rc; | |
144 | } | |
145 | static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL); | |
51be5606 VG |
146 | #endif |
147 | ||
9d1fe323 MT |
148 | /* |
149 | * Print cpu online, possible, present, and system maps | |
150 | */ | |
265d2e2e AK |
151 | |
152 | struct cpu_attr { | |
8a25a2fd | 153 | struct device_attribute attr; |
265d2e2e AK |
154 | const struct cpumask *const * const map; |
155 | }; | |
156 | ||
8a25a2fd KS |
157 | static ssize_t show_cpus_attr(struct device *dev, |
158 | struct device_attribute *attr, | |
265d2e2e | 159 | char *buf) |
9d1fe323 | 160 | { |
265d2e2e AK |
161 | struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr); |
162 | int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map)); | |
9d1fe323 MT |
163 | |
164 | buf[n++] = '\n'; | |
165 | buf[n] = '\0'; | |
166 | return n; | |
167 | } | |
168 | ||
8a25a2fd KS |
169 | #define _CPU_ATTR(name, map) \ |
170 | { __ATTR(name, 0444, show_cpus_attr, NULL), map } | |
9d1fe323 | 171 | |
8a25a2fd | 172 | /* Keep in sync with cpu_subsys_attrs */ |
265d2e2e AK |
173 | static struct cpu_attr cpu_attrs[] = { |
174 | _CPU_ATTR(online, &cpu_online_mask), | |
175 | _CPU_ATTR(possible, &cpu_possible_mask), | |
176 | _CPU_ATTR(present, &cpu_present_mask), | |
177 | }; | |
9d1fe323 | 178 | |
e057d7ae MT |
179 | /* |
180 | * Print values for NR_CPUS and offlined cpus | |
181 | */ | |
8a25a2fd KS |
182 | static ssize_t print_cpus_kernel_max(struct device *dev, |
183 | struct device_attribute *attr, char *buf) | |
e057d7ae | 184 | { |
8fd2d2d5 | 185 | int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1); |
e057d7ae MT |
186 | return n; |
187 | } | |
8a25a2fd | 188 | static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL); |
e057d7ae MT |
189 | |
190 | /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */ | |
191 | unsigned int total_cpus; | |
192 | ||
8a25a2fd KS |
193 | static ssize_t print_cpus_offline(struct device *dev, |
194 | struct device_attribute *attr, char *buf) | |
e057d7ae MT |
195 | { |
196 | int n = 0, len = PAGE_SIZE-2; | |
197 | cpumask_var_t offline; | |
198 | ||
199 | /* display offline cpus < nr_cpu_ids */ | |
200 | if (!alloc_cpumask_var(&offline, GFP_KERNEL)) | |
201 | return -ENOMEM; | |
cdc6e3d3 | 202 | cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask); |
e057d7ae MT |
203 | n = cpulist_scnprintf(buf, len, offline); |
204 | free_cpumask_var(offline); | |
205 | ||
206 | /* display offline cpus >= nr_cpu_ids */ | |
207 | if (total_cpus && nr_cpu_ids < total_cpus) { | |
208 | if (n && n < len) | |
209 | buf[n++] = ','; | |
210 | ||
211 | if (nr_cpu_ids == total_cpus-1) | |
212 | n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids); | |
213 | else | |
214 | n += snprintf(&buf[n], len - n, "%d-%d", | |
215 | nr_cpu_ids, total_cpus-1); | |
216 | } | |
217 | ||
218 | n += snprintf(&buf[n], len - n, "\n"); | |
219 | return n; | |
220 | } | |
8a25a2fd | 221 | static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); |
e057d7ae | 222 | |
2885e25c GKH |
223 | static void cpu_device_release(struct device *dev) |
224 | { | |
225 | /* | |
226 | * This is an empty function to prevent the driver core from spitting a | |
227 | * warning at us. Yes, I know this is directly opposite of what the | |
228 | * documentation for the driver core and kobjects say, and the author | |
229 | * of this code has already been publically ridiculed for doing | |
230 | * something as foolish as this. However, at this point in time, it is | |
231 | * the only way to handle the issue of statically allocated cpu | |
232 | * devices. The different architectures will have their cpu device | |
233 | * code reworked to properly handle this in the near future, so this | |
234 | * function will then be changed to correctly free up the memory held | |
235 | * by the cpu device. | |
236 | * | |
237 | * Never copy this way of doing things, or you too will be made fun of | |
30a4840a | 238 | * on the linux-kernel list, you have been warned. |
2885e25c GKH |
239 | */ |
240 | } | |
241 | ||
1da177e4 | 242 | /* |
405ae7d3 | 243 | * register_cpu - Setup a sysfs device for a CPU. |
72486f1f SS |
244 | * @cpu - cpu->hotpluggable field set to 1 will generate a control file in |
245 | * sysfs for this CPU. | |
1da177e4 LT |
246 | * @num - CPU number to use when creating the device. |
247 | * | |
248 | * Initialize and register the CPU device. | |
249 | */ | |
33b5f31b | 250 | int __cpuinit register_cpu(struct cpu *cpu, int num) |
1da177e4 LT |
251 | { |
252 | int error; | |
76b67ed9 | 253 | |
8a25a2fd | 254 | cpu->node_id = cpu_to_node(num); |
29bb5d4f | 255 | memset(&cpu->dev, 0x00, sizeof(struct device)); |
8a25a2fd KS |
256 | cpu->dev.id = num; |
257 | cpu->dev.bus = &cpu_subsys; | |
2885e25c | 258 | cpu->dev.release = cpu_device_release; |
fad12ac8 TR |
259 | #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE |
260 | cpu->dev.bus->uevent = arch_cpu_uevent; | |
261 | #endif | |
8a25a2fd | 262 | error = device_register(&cpu->dev); |
72486f1f | 263 | if (!error && cpu->hotpluggable) |
1da177e4 | 264 | register_cpu_control(cpu); |
ad74557a | 265 | if (!error) |
8a25a2fd | 266 | per_cpu(cpu_sys_devices, num) = &cpu->dev; |
76b67ed9 KH |
267 | if (!error) |
268 | register_cpu_under_node(num, cpu_to_node(num)); | |
51be5606 VG |
269 | |
270 | #ifdef CONFIG_KEXEC | |
271 | if (!error) | |
8a25a2fd | 272 | error = device_create_file(&cpu->dev, &dev_attr_crash_notes); |
eca4549f ZY |
273 | if (!error) |
274 | error = device_create_file(&cpu->dev, | |
275 | &dev_attr_crash_notes_size); | |
51be5606 | 276 | #endif |
1da177e4 LT |
277 | return error; |
278 | } | |
279 | ||
8a25a2fd | 280 | struct device *get_cpu_device(unsigned cpu) |
ad74557a | 281 | { |
e37d05da MT |
282 | if (cpu < nr_cpu_ids && cpu_possible(cpu)) |
283 | return per_cpu(cpu_sys_devices, cpu); | |
ad74557a AR |
284 | else |
285 | return NULL; | |
286 | } | |
8a25a2fd KS |
287 | EXPORT_SYMBOL_GPL(get_cpu_device); |
288 | ||
fad12ac8 TR |
289 | #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE |
290 | static DEVICE_ATTR(modalias, 0444, arch_print_cpu_modalias, NULL); | |
291 | #endif | |
292 | ||
8a25a2fd KS |
293 | static struct attribute *cpu_root_attrs[] = { |
294 | #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE | |
295 | &dev_attr_probe.attr, | |
296 | &dev_attr_release.attr, | |
297 | #endif | |
298 | &cpu_attrs[0].attr.attr, | |
299 | &cpu_attrs[1].attr.attr, | |
300 | &cpu_attrs[2].attr.attr, | |
301 | &dev_attr_kernel_max.attr, | |
302 | &dev_attr_offline.attr, | |
fad12ac8 TR |
303 | #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE |
304 | &dev_attr_modalias.attr, | |
305 | #endif | |
8a25a2fd KS |
306 | NULL |
307 | }; | |
308 | ||
309 | static struct attribute_group cpu_root_attr_group = { | |
310 | .attrs = cpu_root_attrs, | |
311 | }; | |
312 | ||
313 | static const struct attribute_group *cpu_root_attr_groups[] = { | |
314 | &cpu_root_attr_group, | |
315 | NULL, | |
316 | }; | |
1da177e4 | 317 | |
2987557f JT |
318 | bool cpu_is_hotpluggable(unsigned cpu) |
319 | { | |
7affca35 LT |
320 | struct device *dev = get_cpu_device(cpu); |
321 | return dev && container_of(dev, struct cpu, dev)->hotpluggable; | |
2987557f JT |
322 | } |
323 | EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); | |
324 | ||
9f13a1fd BH |
325 | #ifdef CONFIG_GENERIC_CPU_DEVICES |
326 | static DEFINE_PER_CPU(struct cpu, cpu_devices); | |
327 | #endif | |
328 | ||
329 | static void __init cpu_dev_register_generic(void) | |
330 | { | |
331 | #ifdef CONFIG_GENERIC_CPU_DEVICES | |
332 | int i; | |
333 | ||
334 | for_each_possible_cpu(i) { | |
335 | if (register_cpu(&per_cpu(cpu_devices, i), i)) | |
336 | panic("Failed to register CPU device"); | |
337 | } | |
338 | #endif | |
339 | } | |
340 | ||
024f7846 | 341 | void __init cpu_dev_init(void) |
1da177e4 | 342 | { |
024f7846 BH |
343 | if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups)) |
344 | panic("Failed to register CPU subsystem"); | |
8a25a2fd | 345 | |
9f13a1fd | 346 | cpu_dev_register_generic(); |
1da177e4 | 347 | } |