1 /*
2 * sysfs.c - sysfs support
3 *
4 * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
5 *
6 * This code is licenced under the GPL.
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/cpuidle.h>
11 #include <linux/sysfs.h>
12 #include <linux/slab.h>
13 #include <linux/cpu.h>
14 #include <linux/capability.h>
15
16 #include "cpuidle.h"
17
18 static unsigned int sysfs_switch;
cpuidle_sysfs_setup(char * unused)19 static int __init cpuidle_sysfs_setup(char *unused)
20 {
21 sysfs_switch = 1;
22 return 1;
23 }
24 __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
25
show_available_governors(struct device * dev,struct device_attribute * attr,char * buf)26 static ssize_t show_available_governors(struct device *dev,
27 struct device_attribute *attr,
28 char *buf)
29 {
30 ssize_t i = 0;
31 struct cpuidle_governor *tmp;
32
33 mutex_lock(&cpuidle_lock);
34 list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
35 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
36 goto out;
37 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
38 }
39
40 out:
41 i+= sprintf(&buf[i], "\n");
42 mutex_unlock(&cpuidle_lock);
43 return i;
44 }
45
show_current_driver(struct device * dev,struct device_attribute * attr,char * buf)46 static ssize_t show_current_driver(struct device *dev,
47 struct device_attribute *attr,
48 char *buf)
49 {
50 ssize_t ret;
51 struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
52
53 spin_lock(&cpuidle_driver_lock);
54 if (cpuidle_driver)
55 ret = sprintf(buf, "%s\n", cpuidle_driver->name);
56 else
57 ret = sprintf(buf, "none\n");
58 spin_unlock(&cpuidle_driver_lock);
59
60 return ret;
61 }
62
show_current_governor(struct device * dev,struct device_attribute * attr,char * buf)63 static ssize_t show_current_governor(struct device *dev,
64 struct device_attribute *attr,
65 char *buf)
66 {
67 ssize_t ret;
68
69 mutex_lock(&cpuidle_lock);
70 if (cpuidle_curr_governor)
71 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
72 else
73 ret = sprintf(buf, "none\n");
74 mutex_unlock(&cpuidle_lock);
75
76 return ret;
77 }
78
store_current_governor(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)79 static ssize_t store_current_governor(struct device *dev,
80 struct device_attribute *attr,
81 const char *buf, size_t count)
82 {
83 char gov_name[CPUIDLE_NAME_LEN];
84 int ret = -EINVAL;
85 size_t len = count;
86 struct cpuidle_governor *gov;
87
88 if (!len || len >= sizeof(gov_name))
89 return -EINVAL;
90
91 memcpy(gov_name, buf, len);
92 gov_name[len] = '\0';
93 if (gov_name[len - 1] == '\n')
94 gov_name[--len] = '\0';
95
96 mutex_lock(&cpuidle_lock);
97
98 list_for_each_entry(gov, &cpuidle_governors, governor_list) {
99 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
100 ret = cpuidle_switch_governor(gov);
101 break;
102 }
103 }
104
105 mutex_unlock(&cpuidle_lock);
106
107 if (ret)
108 return ret;
109 else
110 return count;
111 }
112
113 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
114 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
115
116 static struct attribute *cpuidle_default_attrs[] = {
117 &dev_attr_current_driver.attr,
118 &dev_attr_current_governor_ro.attr,
119 NULL
120 };
121
122 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
123 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
124 store_current_governor);
125
126 static struct attribute *cpuidle_switch_attrs[] = {
127 &dev_attr_available_governors.attr,
128 &dev_attr_current_driver.attr,
129 &dev_attr_current_governor.attr,
130 NULL
131 };
132
133 static struct attribute_group cpuidle_attr_group = {
134 .attrs = cpuidle_default_attrs,
135 .name = "cpuidle",
136 };
137
138 /**
139 * cpuidle_add_interface - add CPU global sysfs attributes
140 */
cpuidle_add_interface(struct device * dev)141 int cpuidle_add_interface(struct device *dev)
142 {
143 if (sysfs_switch)
144 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
145
146 return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
147 }
148
149 /**
150 * cpuidle_remove_interface - remove CPU global sysfs attributes
151 */
cpuidle_remove_interface(struct device * dev)152 void cpuidle_remove_interface(struct device *dev)
153 {
154 sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
155 }
156
157 struct cpuidle_attr {
158 struct attribute attr;
159 ssize_t (*show)(struct cpuidle_device *, char *);
160 ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
161 };
162
163 #define define_one_ro(_name, show) \
164 static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
165 #define define_one_rw(_name, show, store) \
166 static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
167
168 #define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
169 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
cpuidle_show(struct kobject * kobj,struct attribute * attr,char * buf)170 static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
171 {
172 int ret = -EIO;
173 struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
174 struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
175
176 if (cattr->show) {
177 mutex_lock(&cpuidle_lock);
178 ret = cattr->show(dev, buf);
179 mutex_unlock(&cpuidle_lock);
180 }
181 return ret;
182 }
183
cpuidle_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t count)184 static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
185 const char * buf, size_t count)
186 {
187 int ret = -EIO;
188 struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
189 struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
190
191 if (cattr->store) {
192 mutex_lock(&cpuidle_lock);
193 ret = cattr->store(dev, buf, count);
194 mutex_unlock(&cpuidle_lock);
195 }
196 return ret;
197 }
198
199 static const struct sysfs_ops cpuidle_sysfs_ops = {
200 .show = cpuidle_show,
201 .store = cpuidle_store,
202 };
203
cpuidle_sysfs_release(struct kobject * kobj)204 static void cpuidle_sysfs_release(struct kobject *kobj)
205 {
206 struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
207
208 complete(&dev->kobj_unregister);
209 }
210
211 static struct kobj_type ktype_cpuidle = {
212 .sysfs_ops = &cpuidle_sysfs_ops,
213 .release = cpuidle_sysfs_release,
214 };
215
216 struct cpuidle_state_attr {
217 struct attribute attr;
218 ssize_t (*show)(struct cpuidle_state *, \
219 struct cpuidle_state_usage *, char *);
220 ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
221 };
222
223 #define define_one_state_ro(_name, show) \
224 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
225
226 #define define_one_state_rw(_name, show, store) \
227 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
228
229 #define define_show_state_function(_name) \
230 static ssize_t show_state_##_name(struct cpuidle_state *state, \
231 struct cpuidle_state_usage *state_usage, char *buf) \
232 { \
233 return sprintf(buf, "%u\n", state->_name);\
234 }
235
236 #define define_store_state_function(_name) \
237 static ssize_t store_state_##_name(struct cpuidle_state *state, \
238 const char *buf, size_t size) \
239 { \
240 long value; \
241 int err; \
242 if (!capable(CAP_SYS_ADMIN)) \
243 return -EPERM; \
244 err = kstrtol(buf, 0, &value); \
245 if (err) \
246 return err; \
247 if (value) \
248 state->disable = 1; \
249 else \
250 state->disable = 0; \
251 return size; \
252 }
253
254 #define define_show_state_ull_function(_name) \
255 static ssize_t show_state_##_name(struct cpuidle_state *state, \
256 struct cpuidle_state_usage *state_usage, char *buf) \
257 { \
258 return sprintf(buf, "%llu\n", state_usage->_name);\
259 }
260
261 #define define_show_state_str_function(_name) \
262 static ssize_t show_state_##_name(struct cpuidle_state *state, \
263 struct cpuidle_state_usage *state_usage, char *buf) \
264 { \
265 if (state->_name[0] == '\0')\
266 return sprintf(buf, "<null>\n");\
267 return sprintf(buf, "%s\n", state->_name);\
268 }
269
270 define_show_state_function(exit_latency)
271 define_show_state_function(power_usage)
272 define_show_state_ull_function(usage)
273 define_show_state_ull_function(time)
274 define_show_state_str_function(name)
275 define_show_state_str_function(desc)
276 define_show_state_function(disable)
277 define_store_state_function(disable)
278
279 define_one_state_ro(name, show_state_name);
280 define_one_state_ro(desc, show_state_desc);
281 define_one_state_ro(latency, show_state_exit_latency);
282 define_one_state_ro(power, show_state_power_usage);
283 define_one_state_ro(usage, show_state_usage);
284 define_one_state_ro(time, show_state_time);
285 define_one_state_rw(disable, show_state_disable, store_state_disable);
286
287 static struct attribute *cpuidle_state_default_attrs[] = {
288 &attr_name.attr,
289 &attr_desc.attr,
290 &attr_latency.attr,
291 &attr_power.attr,
292 &attr_usage.attr,
293 &attr_time.attr,
294 &attr_disable.attr,
295 NULL
296 };
297
298 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
299 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
300 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
301 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
cpuidle_state_show(struct kobject * kobj,struct attribute * attr,char * buf)302 static ssize_t cpuidle_state_show(struct kobject * kobj,
303 struct attribute * attr ,char * buf)
304 {
305 int ret = -EIO;
306 struct cpuidle_state *state = kobj_to_state(kobj);
307 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
308 struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
309
310 if (cattr->show)
311 ret = cattr->show(state, state_usage, buf);
312
313 return ret;
314 }
315
cpuidle_state_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t size)316 static ssize_t cpuidle_state_store(struct kobject *kobj,
317 struct attribute *attr, const char *buf, size_t size)
318 {
319 int ret = -EIO;
320 struct cpuidle_state *state = kobj_to_state(kobj);
321 struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
322
323 if (cattr->store)
324 ret = cattr->store(state, buf, size);
325
326 return ret;
327 }
328
329 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
330 .show = cpuidle_state_show,
331 .store = cpuidle_state_store,
332 };
333
cpuidle_state_sysfs_release(struct kobject * kobj)334 static void cpuidle_state_sysfs_release(struct kobject *kobj)
335 {
336 struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
337
338 complete(&state_obj->kobj_unregister);
339 }
340
341 static struct kobj_type ktype_state_cpuidle = {
342 .sysfs_ops = &cpuidle_state_sysfs_ops,
343 .default_attrs = cpuidle_state_default_attrs,
344 .release = cpuidle_state_sysfs_release,
345 };
346
cpuidle_free_state_kobj(struct cpuidle_device * device,int i)347 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
348 {
349 kobject_put(&device->kobjs[i]->kobj);
350 wait_for_completion(&device->kobjs[i]->kobj_unregister);
351 kfree(device->kobjs[i]);
352 device->kobjs[i] = NULL;
353 }
354
355 /**
356 * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
357 * @device: the target device
358 */
cpuidle_add_state_sysfs(struct cpuidle_device * device)359 int cpuidle_add_state_sysfs(struct cpuidle_device *device)
360 {
361 int i, ret = -ENOMEM;
362 struct cpuidle_state_kobj *kobj;
363 struct cpuidle_driver *drv = cpuidle_get_driver();
364
365 /* state statistics */
366 for (i = 0; i < device->state_count; i++) {
367 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
368 if (!kobj)
369 goto error_state;
370 kobj->state = &drv->states[i];
371 kobj->state_usage = &device->states_usage[i];
372 init_completion(&kobj->kobj_unregister);
373
374 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
375 "state%d", i);
376 if (ret) {
377 kfree(kobj);
378 goto error_state;
379 }
380 kobject_uevent(&kobj->kobj, KOBJ_ADD);
381 device->kobjs[i] = kobj;
382 }
383
384 return 0;
385
386 error_state:
387 for (i = i - 1; i >= 0; i--)
388 cpuidle_free_state_kobj(device, i);
389 return ret;
390 }
391
392 /**
393 * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
394 * @device: the target device
395 */
cpuidle_remove_state_sysfs(struct cpuidle_device * device)396 void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
397 {
398 int i;
399
400 for (i = 0; i < device->state_count; i++)
401 cpuidle_free_state_kobj(device, i);
402 }
403
404 /**
405 * cpuidle_add_sysfs - creates a sysfs instance for the target device
406 * @dev: the target device
407 */
cpuidle_add_sysfs(struct device * cpu_dev)408 int cpuidle_add_sysfs(struct device *cpu_dev)
409 {
410 int cpu = cpu_dev->id;
411 struct cpuidle_device *dev;
412 int error;
413
414 dev = per_cpu(cpuidle_devices, cpu);
415 error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
416 "cpuidle");
417 if (!error)
418 kobject_uevent(&dev->kobj, KOBJ_ADD);
419 return error;
420 }
421
422 /**
423 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
424 * @dev: the target device
425 */
cpuidle_remove_sysfs(struct device * cpu_dev)426 void cpuidle_remove_sysfs(struct device *cpu_dev)
427 {
428 int cpu = cpu_dev->id;
429 struct cpuidle_device *dev;
430
431 dev = per_cpu(cpuidle_devices, cpu);
432 kobject_put(&dev->kobj);
433 }
434