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/completion.h>
15 #include <linux/capability.h>
16 #include <linux/device.h>
17 #include <linux/kobject.h>
18
19 #include "cpuidle.h"
20
21 static unsigned int sysfs_switch;
cpuidle_sysfs_setup(char * unused)22 static int __init cpuidle_sysfs_setup(char *unused)
23 {
24 sysfs_switch = 1;
25 return 1;
26 }
27 __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
28
show_available_governors(struct device * dev,struct device_attribute * attr,char * buf)29 static ssize_t show_available_governors(struct device *dev,
30 struct device_attribute *attr,
31 char *buf)
32 {
33 ssize_t i = 0;
34 struct cpuidle_governor *tmp;
35
36 mutex_lock(&cpuidle_lock);
37 list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
38 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) -
39 CPUIDLE_NAME_LEN - 2))
40 goto out;
41 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
42 }
43
44 out:
45 i+= sprintf(&buf[i], "\n");
46 mutex_unlock(&cpuidle_lock);
47 return i;
48 }
49
show_current_driver(struct device * dev,struct device_attribute * attr,char * buf)50 static ssize_t show_current_driver(struct device *dev,
51 struct device_attribute *attr,
52 char *buf)
53 {
54 ssize_t ret;
55 struct cpuidle_driver *drv;
56
57 spin_lock(&cpuidle_driver_lock);
58 drv = cpuidle_get_driver();
59 if (drv)
60 ret = sprintf(buf, "%s\n", drv->name);
61 else
62 ret = sprintf(buf, "none\n");
63 spin_unlock(&cpuidle_driver_lock);
64
65 return ret;
66 }
67
show_current_governor(struct device * dev,struct device_attribute * attr,char * buf)68 static ssize_t show_current_governor(struct device *dev,
69 struct device_attribute *attr,
70 char *buf)
71 {
72 ssize_t ret;
73
74 mutex_lock(&cpuidle_lock);
75 if (cpuidle_curr_governor)
76 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
77 else
78 ret = sprintf(buf, "none\n");
79 mutex_unlock(&cpuidle_lock);
80
81 return ret;
82 }
83
store_current_governor(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)84 static ssize_t store_current_governor(struct device *dev,
85 struct device_attribute *attr,
86 const char *buf, size_t count)
87 {
88 char gov_name[CPUIDLE_NAME_LEN];
89 int ret = -EINVAL;
90 size_t len = count;
91 struct cpuidle_governor *gov;
92
93 if (!len || len >= sizeof(gov_name))
94 return -EINVAL;
95
96 memcpy(gov_name, buf, len);
97 gov_name[len] = '\0';
98 if (gov_name[len - 1] == '\n')
99 gov_name[--len] = '\0';
100
101 mutex_lock(&cpuidle_lock);
102
103 list_for_each_entry(gov, &cpuidle_governors, governor_list) {
104 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
105 ret = cpuidle_switch_governor(gov);
106 break;
107 }
108 }
109
110 mutex_unlock(&cpuidle_lock);
111
112 if (ret)
113 return ret;
114 else
115 return count;
116 }
117
118 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
119 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
120
121 static struct attribute *cpuidle_default_attrs[] = {
122 &dev_attr_current_driver.attr,
123 &dev_attr_current_governor_ro.attr,
124 NULL
125 };
126
127 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
128 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
129 store_current_governor);
130
131 static struct attribute *cpuidle_switch_attrs[] = {
132 &dev_attr_available_governors.attr,
133 &dev_attr_current_driver.attr,
134 &dev_attr_current_governor.attr,
135 NULL
136 };
137
138 static struct attribute_group cpuidle_attr_group = {
139 .attrs = cpuidle_default_attrs,
140 .name = "cpuidle",
141 };
142
143 /**
144 * cpuidle_add_interface - add CPU global sysfs attributes
145 */
cpuidle_add_interface(struct device * dev)146 int cpuidle_add_interface(struct device *dev)
147 {
148 if (sysfs_switch)
149 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
150
151 return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
152 }
153
154 /**
155 * cpuidle_remove_interface - remove CPU global sysfs attributes
156 */
cpuidle_remove_interface(struct device * dev)157 void cpuidle_remove_interface(struct device *dev)
158 {
159 sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
160 }
161
162 struct cpuidle_attr {
163 struct attribute attr;
164 ssize_t (*show)(struct cpuidle_device *, char *);
165 ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
166 };
167
168 #define define_one_ro(_name, show) \
169 static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
170 #define define_one_rw(_name, show, store) \
171 static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
172
173 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
174
175 struct cpuidle_device_kobj {
176 struct cpuidle_device *dev;
177 struct completion kobj_unregister;
178 struct kobject kobj;
179 };
180
to_cpuidle_device(struct kobject * kobj)181 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
182 {
183 struct cpuidle_device_kobj *kdev =
184 container_of(kobj, struct cpuidle_device_kobj, kobj);
185
186 return kdev->dev;
187 }
188
cpuidle_show(struct kobject * kobj,struct attribute * attr,char * buf)189 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
190 char *buf)
191 {
192 int ret = -EIO;
193 struct cpuidle_device *dev = to_cpuidle_device(kobj);
194 struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
195
196 if (cattr->show) {
197 mutex_lock(&cpuidle_lock);
198 ret = cattr->show(dev, buf);
199 mutex_unlock(&cpuidle_lock);
200 }
201 return ret;
202 }
203
cpuidle_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t count)204 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
205 const char *buf, size_t count)
206 {
207 int ret = -EIO;
208 struct cpuidle_device *dev = to_cpuidle_device(kobj);
209 struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
210
211 if (cattr->store) {
212 mutex_lock(&cpuidle_lock);
213 ret = cattr->store(dev, buf, count);
214 mutex_unlock(&cpuidle_lock);
215 }
216 return ret;
217 }
218
219 static const struct sysfs_ops cpuidle_sysfs_ops = {
220 .show = cpuidle_show,
221 .store = cpuidle_store,
222 };
223
cpuidle_sysfs_release(struct kobject * kobj)224 static void cpuidle_sysfs_release(struct kobject *kobj)
225 {
226 struct cpuidle_device_kobj *kdev =
227 container_of(kobj, struct cpuidle_device_kobj, kobj);
228
229 complete(&kdev->kobj_unregister);
230 }
231
232 static struct kobj_type ktype_cpuidle = {
233 .sysfs_ops = &cpuidle_sysfs_ops,
234 .release = cpuidle_sysfs_release,
235 };
236
237 struct cpuidle_state_attr {
238 struct attribute attr;
239 ssize_t (*show)(struct cpuidle_state *, \
240 struct cpuidle_state_usage *, char *);
241 ssize_t (*store)(struct cpuidle_state *, \
242 struct cpuidle_state_usage *, const char *, size_t);
243 };
244
245 #define define_one_state_ro(_name, show) \
246 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
247
248 #define define_one_state_rw(_name, show, store) \
249 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
250
251 #define define_show_state_function(_name) \
252 static ssize_t show_state_##_name(struct cpuidle_state *state, \
253 struct cpuidle_state_usage *state_usage, char *buf) \
254 { \
255 return sprintf(buf, "%u\n", state->_name);\
256 }
257
258 #define define_store_state_ull_function(_name) \
259 static ssize_t store_state_##_name(struct cpuidle_state *state, \
260 struct cpuidle_state_usage *state_usage, \
261 const char *buf, size_t size) \
262 { \
263 unsigned long long value; \
264 int err; \
265 if (!capable(CAP_SYS_ADMIN)) \
266 return -EPERM; \
267 err = kstrtoull(buf, 0, &value); \
268 if (err) \
269 return err; \
270 if (value) \
271 state_usage->_name = 1; \
272 else \
273 state_usage->_name = 0; \
274 return size; \
275 }
276
277 #define define_show_state_ull_function(_name) \
278 static ssize_t show_state_##_name(struct cpuidle_state *state, \
279 struct cpuidle_state_usage *state_usage, \
280 char *buf) \
281 { \
282 return sprintf(buf, "%llu\n", state_usage->_name);\
283 }
284
285 #define define_show_state_str_function(_name) \
286 static ssize_t show_state_##_name(struct cpuidle_state *state, \
287 struct cpuidle_state_usage *state_usage, \
288 char *buf) \
289 { \
290 if (state->_name[0] == '\0')\
291 return sprintf(buf, "<null>\n");\
292 return sprintf(buf, "%s\n", state->_name);\
293 }
294
295 define_show_state_function(exit_latency)
296 define_show_state_function(target_residency)
297 define_show_state_function(power_usage)
298 define_show_state_ull_function(usage)
299 define_show_state_ull_function(time)
300 define_show_state_str_function(name)
301 define_show_state_str_function(desc)
302 define_show_state_ull_function(disable)
303 define_store_state_ull_function(disable)
304
305 define_one_state_ro(name, show_state_name);
306 define_one_state_ro(desc, show_state_desc);
307 define_one_state_ro(latency, show_state_exit_latency);
308 define_one_state_ro(residency, show_state_target_residency);
309 define_one_state_ro(power, show_state_power_usage);
310 define_one_state_ro(usage, show_state_usage);
311 define_one_state_ro(time, show_state_time);
312 define_one_state_rw(disable, show_state_disable, store_state_disable);
313
314 static struct attribute *cpuidle_state_default_attrs[] = {
315 &attr_name.attr,
316 &attr_desc.attr,
317 &attr_latency.attr,
318 &attr_residency.attr,
319 &attr_power.attr,
320 &attr_usage.attr,
321 &attr_time.attr,
322 &attr_disable.attr,
323 NULL
324 };
325
326 struct cpuidle_state_kobj {
327 struct cpuidle_state *state;
328 struct cpuidle_state_usage *state_usage;
329 struct completion kobj_unregister;
330 struct kobject kobj;
331 };
332
333 #ifdef CONFIG_SUSPEND
334 #define define_show_state_s2idle_ull_function(_name) \
335 static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
336 struct cpuidle_state_usage *state_usage, \
337 char *buf) \
338 { \
339 return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
340 }
341
342 define_show_state_s2idle_ull_function(usage);
343 define_show_state_s2idle_ull_function(time);
344
345 #define define_one_state_s2idle_ro(_name, show) \
346 static struct cpuidle_state_attr attr_s2idle_##_name = \
347 __ATTR(_name, 0444, show, NULL)
348
349 define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
350 define_one_state_s2idle_ro(time, show_state_s2idle_time);
351
352 static struct attribute *cpuidle_state_s2idle_attrs[] = {
353 &attr_s2idle_usage.attr,
354 &attr_s2idle_time.attr,
355 NULL
356 };
357
358 static const struct attribute_group cpuidle_state_s2idle_group = {
359 .name = "s2idle",
360 .attrs = cpuidle_state_s2idle_attrs,
361 };
362
cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj * kobj)363 static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
364 {
365 int ret;
366
367 if (!kobj->state->enter_s2idle)
368 return;
369
370 ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
371 if (ret)
372 pr_debug("%s: sysfs attribute group not created\n", __func__);
373 }
374
cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj * kobj)375 static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
376 {
377 if (kobj->state->enter_s2idle)
378 sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
379 }
380 #else
cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj * kobj)381 static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj * kobj)382 static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
383 #endif /* CONFIG_SUSPEND */
384
385 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
386 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
387 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
388 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
389
cpuidle_state_show(struct kobject * kobj,struct attribute * attr,char * buf)390 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
391 char * buf)
392 {
393 int ret = -EIO;
394 struct cpuidle_state *state = kobj_to_state(kobj);
395 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
396 struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
397
398 if (cattr->show)
399 ret = cattr->show(state, state_usage, buf);
400
401 return ret;
402 }
403
cpuidle_state_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t size)404 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
405 const char *buf, size_t size)
406 {
407 int ret = -EIO;
408 struct cpuidle_state *state = kobj_to_state(kobj);
409 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
410 struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
411
412 if (cattr->store)
413 ret = cattr->store(state, state_usage, buf, size);
414
415 return ret;
416 }
417
418 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
419 .show = cpuidle_state_show,
420 .store = cpuidle_state_store,
421 };
422
cpuidle_state_sysfs_release(struct kobject * kobj)423 static void cpuidle_state_sysfs_release(struct kobject *kobj)
424 {
425 struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
426
427 complete(&state_obj->kobj_unregister);
428 }
429
430 static struct kobj_type ktype_state_cpuidle = {
431 .sysfs_ops = &cpuidle_state_sysfs_ops,
432 .default_attrs = cpuidle_state_default_attrs,
433 .release = cpuidle_state_sysfs_release,
434 };
435
cpuidle_free_state_kobj(struct cpuidle_device * device,int i)436 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
437 {
438 cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
439 kobject_put(&device->kobjs[i]->kobj);
440 wait_for_completion(&device->kobjs[i]->kobj_unregister);
441 kfree(device->kobjs[i]);
442 device->kobjs[i] = NULL;
443 }
444
445 /**
446 * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
447 * @device: the target device
448 */
cpuidle_add_state_sysfs(struct cpuidle_device * device)449 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
450 {
451 int i, ret = -ENOMEM;
452 struct cpuidle_state_kobj *kobj;
453 struct cpuidle_device_kobj *kdev = device->kobj_dev;
454 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
455
456 /* state statistics */
457 for (i = 0; i < drv->state_count; i++) {
458 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
459 if (!kobj) {
460 ret = -ENOMEM;
461 goto error_state;
462 }
463 kobj->state = &drv->states[i];
464 kobj->state_usage = &device->states_usage[i];
465 init_completion(&kobj->kobj_unregister);
466
467 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
468 &kdev->kobj, "state%d", i);
469 if (ret) {
470 kobject_put(&kobj->kobj);
471 kfree(kobj);
472 goto error_state;
473 }
474 cpuidle_add_s2idle_attr_group(kobj);
475 kobject_uevent(&kobj->kobj, KOBJ_ADD);
476 device->kobjs[i] = kobj;
477 }
478
479 return 0;
480
481 error_state:
482 for (i = i - 1; i >= 0; i--)
483 cpuidle_free_state_kobj(device, i);
484 return ret;
485 }
486
487 /**
488 * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
489 * @device: the target device
490 */
cpuidle_remove_state_sysfs(struct cpuidle_device * device)491 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
492 {
493 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
494 int i;
495
496 for (i = 0; i < drv->state_count; i++)
497 cpuidle_free_state_kobj(device, i);
498 }
499
500 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
501 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
502 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
503
504 #define define_one_driver_ro(_name, show) \
505 static struct cpuidle_driver_attr attr_driver_##_name = \
506 __ATTR(_name, 0444, show, NULL)
507
508 struct cpuidle_driver_kobj {
509 struct cpuidle_driver *drv;
510 struct completion kobj_unregister;
511 struct kobject kobj;
512 };
513
514 struct cpuidle_driver_attr {
515 struct attribute attr;
516 ssize_t (*show)(struct cpuidle_driver *, char *);
517 ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
518 };
519
show_driver_name(struct cpuidle_driver * drv,char * buf)520 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
521 {
522 ssize_t ret;
523
524 spin_lock(&cpuidle_driver_lock);
525 ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
526 spin_unlock(&cpuidle_driver_lock);
527
528 return ret;
529 }
530
cpuidle_driver_sysfs_release(struct kobject * kobj)531 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
532 {
533 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
534 complete(&driver_kobj->kobj_unregister);
535 }
536
cpuidle_driver_show(struct kobject * kobj,struct attribute * attr,char * buf)537 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
538 char *buf)
539 {
540 int ret = -EIO;
541 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
542 struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
543
544 if (dattr->show)
545 ret = dattr->show(driver_kobj->drv, buf);
546
547 return ret;
548 }
549
cpuidle_driver_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t size)550 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
551 const char *buf, size_t size)
552 {
553 int ret = -EIO;
554 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
555 struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
556
557 if (dattr->store)
558 ret = dattr->store(driver_kobj->drv, buf, size);
559
560 return ret;
561 }
562
563 define_one_driver_ro(name, show_driver_name);
564
565 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
566 .show = cpuidle_driver_show,
567 .store = cpuidle_driver_store,
568 };
569
570 static struct attribute *cpuidle_driver_default_attrs[] = {
571 &attr_driver_name.attr,
572 NULL
573 };
574
575 static struct kobj_type ktype_driver_cpuidle = {
576 .sysfs_ops = &cpuidle_driver_sysfs_ops,
577 .default_attrs = cpuidle_driver_default_attrs,
578 .release = cpuidle_driver_sysfs_release,
579 };
580
581 /**
582 * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
583 * @device: the target device
584 */
cpuidle_add_driver_sysfs(struct cpuidle_device * dev)585 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
586 {
587 struct cpuidle_driver_kobj *kdrv;
588 struct cpuidle_device_kobj *kdev = dev->kobj_dev;
589 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
590 int ret;
591
592 kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
593 if (!kdrv)
594 return -ENOMEM;
595
596 kdrv->drv = drv;
597 init_completion(&kdrv->kobj_unregister);
598
599 ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
600 &kdev->kobj, "driver");
601 if (ret) {
602 kobject_put(&kdrv->kobj);
603 kfree(kdrv);
604 return ret;
605 }
606
607 kobject_uevent(&kdrv->kobj, KOBJ_ADD);
608 dev->kobj_driver = kdrv;
609
610 return ret;
611 }
612
613 /**
614 * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
615 * @device: the target device
616 */
cpuidle_remove_driver_sysfs(struct cpuidle_device * dev)617 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
618 {
619 struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
620 kobject_put(&kdrv->kobj);
621 wait_for_completion(&kdrv->kobj_unregister);
622 kfree(kdrv);
623 }
624 #else
cpuidle_add_driver_sysfs(struct cpuidle_device * dev)625 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
626 {
627 return 0;
628 }
629
cpuidle_remove_driver_sysfs(struct cpuidle_device * dev)630 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
631 {
632 ;
633 }
634 #endif
635
636 /**
637 * cpuidle_add_device_sysfs - adds device specific sysfs attributes
638 * @device: the target device
639 */
cpuidle_add_device_sysfs(struct cpuidle_device * device)640 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
641 {
642 int ret;
643
644 ret = cpuidle_add_state_sysfs(device);
645 if (ret)
646 return ret;
647
648 ret = cpuidle_add_driver_sysfs(device);
649 if (ret)
650 cpuidle_remove_state_sysfs(device);
651 return ret;
652 }
653
654 /**
655 * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
656 * @device : the target device
657 */
cpuidle_remove_device_sysfs(struct cpuidle_device * device)658 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
659 {
660 cpuidle_remove_driver_sysfs(device);
661 cpuidle_remove_state_sysfs(device);
662 }
663
664 /**
665 * cpuidle_add_sysfs - creates a sysfs instance for the target device
666 * @dev: the target device
667 */
cpuidle_add_sysfs(struct cpuidle_device * dev)668 int cpuidle_add_sysfs(struct cpuidle_device *dev)
669 {
670 struct cpuidle_device_kobj *kdev;
671 struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
672 int error;
673
674 /*
675 * Return if cpu_device is not setup for this CPU.
676 *
677 * This could happen if the arch did not set up cpu_device
678 * since this CPU is not in cpu_present mask and the
679 * driver did not send a correct CPU mask during registration.
680 * Without this check we would end up passing bogus
681 * value for &cpu_dev->kobj in kobject_init_and_add()
682 */
683 if (!cpu_dev)
684 return -ENODEV;
685
686 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
687 if (!kdev)
688 return -ENOMEM;
689 kdev->dev = dev;
690
691 init_completion(&kdev->kobj_unregister);
692
693 error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
694 "cpuidle");
695 if (error) {
696 kobject_put(&kdev->kobj);
697 kfree(kdev);
698 return error;
699 }
700
701 dev->kobj_dev = kdev;
702 kobject_uevent(&kdev->kobj, KOBJ_ADD);
703
704 return 0;
705 }
706
707 /**
708 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
709 * @dev: the target device
710 */
cpuidle_remove_sysfs(struct cpuidle_device * dev)711 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
712 {
713 struct cpuidle_device_kobj *kdev = dev->kobj_dev;
714
715 kobject_put(&kdev->kobj);
716 wait_for_completion(&kdev->kobj_unregister);
717 kfree(kdev);
718 }
719