xref: /openbmc/linux/drivers/cpuidle/sysfs.c (revision 9a6b55ac) 
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;
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 
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 
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 
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 
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  */
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  */
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 
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 
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 
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 
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_show_state_ull_function(_name) \
259 static ssize_t show_state_##_name(struct cpuidle_state *state, \
260 				  struct cpuidle_state_usage *state_usage, \
261 				  char *buf)				\
262 { \
263 	return sprintf(buf, "%llu\n", state_usage->_name);\
264 }
265 
266 #define define_show_state_str_function(_name) \
267 static ssize_t show_state_##_name(struct cpuidle_state *state, \
268 				  struct cpuidle_state_usage *state_usage, \
269 				  char *buf)				\
270 { \
271 	if (state->_name[0] == '\0')\
272 		return sprintf(buf, "<null>\n");\
273 	return sprintf(buf, "%s\n", state->_name);\
274 }
275 
276 #define define_show_state_time_function(_name) \
277 static ssize_t show_state_##_name(struct cpuidle_state *state, \
278 				  struct cpuidle_state_usage *state_usage, \
279 				  char *buf) \
280 { \
281 	return sprintf(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
282 }
283 
284 define_show_state_time_function(exit_latency)
285 define_show_state_time_function(target_residency)
286 define_show_state_function(power_usage)
287 define_show_state_ull_function(usage)
288 define_show_state_str_function(name)
289 define_show_state_str_function(desc)
290 define_show_state_ull_function(above)
291 define_show_state_ull_function(below)
292 
293 static ssize_t show_state_time(struct cpuidle_state *state,
294 			       struct cpuidle_state_usage *state_usage,
295 			       char *buf)
296 {
297 	return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
298 }
299 
300 static ssize_t show_state_disable(struct cpuidle_state *state,
301 				  struct cpuidle_state_usage *state_usage,
302 				  char *buf)
303 {
304 	return sprintf(buf, "%llu\n",
305 		       state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
306 }
307 
308 static ssize_t store_state_disable(struct cpuidle_state *state,
309 				   struct cpuidle_state_usage *state_usage,
310 				   const char *buf, size_t size)
311 {
312 	unsigned int value;
313 	int err;
314 
315 	if (!capable(CAP_SYS_ADMIN))
316 		return -EPERM;
317 
318 	err = kstrtouint(buf, 0, &value);
319 	if (err)
320 		return err;
321 
322 	if (value)
323 		state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
324 	else
325 		state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
326 
327 	return size;
328 }
329 
330 define_one_state_ro(name, show_state_name);
331 define_one_state_ro(desc, show_state_desc);
332 define_one_state_ro(latency, show_state_exit_latency);
333 define_one_state_ro(residency, show_state_target_residency);
334 define_one_state_ro(power, show_state_power_usage);
335 define_one_state_ro(usage, show_state_usage);
336 define_one_state_ro(time, show_state_time);
337 define_one_state_rw(disable, show_state_disable, store_state_disable);
338 define_one_state_ro(above, show_state_above);
339 define_one_state_ro(below, show_state_below);
340 
341 static struct attribute *cpuidle_state_default_attrs[] = {
342 	&attr_name.attr,
343 	&attr_desc.attr,
344 	&attr_latency.attr,
345 	&attr_residency.attr,
346 	&attr_power.attr,
347 	&attr_usage.attr,
348 	&attr_time.attr,
349 	&attr_disable.attr,
350 	&attr_above.attr,
351 	&attr_below.attr,
352 	NULL
353 };
354 
355 struct cpuidle_state_kobj {
356 	struct cpuidle_state *state;
357 	struct cpuidle_state_usage *state_usage;
358 	struct completion kobj_unregister;
359 	struct kobject kobj;
360 	struct cpuidle_device *device;
361 };
362 
363 #ifdef CONFIG_SUSPEND
364 #define define_show_state_s2idle_ull_function(_name) \
365 static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
366 					 struct cpuidle_state_usage *state_usage, \
367 					 char *buf)				\
368 { \
369 	return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
370 }
371 
372 define_show_state_s2idle_ull_function(usage);
373 define_show_state_s2idle_ull_function(time);
374 
375 #define define_one_state_s2idle_ro(_name, show) \
376 static struct cpuidle_state_attr attr_s2idle_##_name = \
377 	__ATTR(_name, 0444, show, NULL)
378 
379 define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
380 define_one_state_s2idle_ro(time, show_state_s2idle_time);
381 
382 static struct attribute *cpuidle_state_s2idle_attrs[] = {
383 	&attr_s2idle_usage.attr,
384 	&attr_s2idle_time.attr,
385 	NULL
386 };
387 
388 static const struct attribute_group cpuidle_state_s2idle_group = {
389 	.name	= "s2idle",
390 	.attrs	= cpuidle_state_s2idle_attrs,
391 };
392 
393 static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
394 {
395 	int ret;
396 
397 	if (!kobj->state->enter_s2idle)
398 		return;
399 
400 	ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
401 	if (ret)
402 		pr_debug("%s: sysfs attribute group not created\n", __func__);
403 }
404 
405 static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
406 {
407 	if (kobj->state->enter_s2idle)
408 		sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
409 }
410 #else
411 static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
412 static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
413 #endif /* CONFIG_SUSPEND */
414 
415 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
416 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
417 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
418 #define kobj_to_device(k) (kobj_to_state_obj(k)->device)
419 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
420 
421 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
422 				  char * buf)
423 {
424 	int ret = -EIO;
425 	struct cpuidle_state *state = kobj_to_state(kobj);
426 	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
427 	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
428 
429 	if (cattr->show)
430 		ret = cattr->show(state, state_usage, buf);
431 
432 	return ret;
433 }
434 
435 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
436 				   const char *buf, size_t size)
437 {
438 	int ret = -EIO;
439 	struct cpuidle_state *state = kobj_to_state(kobj);
440 	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
441 	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
442 	struct cpuidle_device *dev = kobj_to_device(kobj);
443 
444 	if (cattr->store)
445 		ret = cattr->store(state, state_usage, buf, size);
446 
447 	/* reset poll time cache */
448 	dev->poll_limit_ns = 0;
449 
450 	return ret;
451 }
452 
453 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
454 	.show = cpuidle_state_show,
455 	.store = cpuidle_state_store,
456 };
457 
458 static void cpuidle_state_sysfs_release(struct kobject *kobj)
459 {
460 	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
461 
462 	complete(&state_obj->kobj_unregister);
463 }
464 
465 static struct kobj_type ktype_state_cpuidle = {
466 	.sysfs_ops = &cpuidle_state_sysfs_ops,
467 	.default_attrs = cpuidle_state_default_attrs,
468 	.release = cpuidle_state_sysfs_release,
469 };
470 
471 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
472 {
473 	cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
474 	kobject_put(&device->kobjs[i]->kobj);
475 	wait_for_completion(&device->kobjs[i]->kobj_unregister);
476 	kfree(device->kobjs[i]);
477 	device->kobjs[i] = NULL;
478 }
479 
480 /**
481  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
482  * @device: the target device
483  */
484 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
485 {
486 	int i, ret = -ENOMEM;
487 	struct cpuidle_state_kobj *kobj;
488 	struct cpuidle_device_kobj *kdev = device->kobj_dev;
489 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
490 
491 	/* state statistics */
492 	for (i = 0; i < drv->state_count; i++) {
493 		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
494 		if (!kobj) {
495 			ret = -ENOMEM;
496 			goto error_state;
497 		}
498 		kobj->state = &drv->states[i];
499 		kobj->state_usage = &device->states_usage[i];
500 		kobj->device = device;
501 		init_completion(&kobj->kobj_unregister);
502 
503 		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
504 					   &kdev->kobj, "state%d", i);
505 		if (ret) {
506 			kfree(kobj);
507 			goto error_state;
508 		}
509 		cpuidle_add_s2idle_attr_group(kobj);
510 		kobject_uevent(&kobj->kobj, KOBJ_ADD);
511 		device->kobjs[i] = kobj;
512 	}
513 
514 	return 0;
515 
516 error_state:
517 	for (i = i - 1; i >= 0; i--)
518 		cpuidle_free_state_kobj(device, i);
519 	return ret;
520 }
521 
522 /**
523  * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
524  * @device: the target device
525  */
526 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
527 {
528 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
529 	int i;
530 
531 	for (i = 0; i < drv->state_count; i++)
532 		cpuidle_free_state_kobj(device, i);
533 }
534 
535 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
536 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
537 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
538 
539 #define define_one_driver_ro(_name, show)                       \
540 	static struct cpuidle_driver_attr attr_driver_##_name = \
541 		__ATTR(_name, 0444, show, NULL)
542 
543 struct cpuidle_driver_kobj {
544 	struct cpuidle_driver *drv;
545 	struct completion kobj_unregister;
546 	struct kobject kobj;
547 };
548 
549 struct cpuidle_driver_attr {
550 	struct attribute attr;
551 	ssize_t (*show)(struct cpuidle_driver *, char *);
552 	ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
553 };
554 
555 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
556 {
557 	ssize_t ret;
558 
559 	spin_lock(&cpuidle_driver_lock);
560 	ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
561 	spin_unlock(&cpuidle_driver_lock);
562 
563 	return ret;
564 }
565 
566 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
567 {
568 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
569 	complete(&driver_kobj->kobj_unregister);
570 }
571 
572 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
573 				   char *buf)
574 {
575 	int ret = -EIO;
576 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
577 	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
578 
579 	if (dattr->show)
580 		ret = dattr->show(driver_kobj->drv, buf);
581 
582 	return ret;
583 }
584 
585 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
586 				    const char *buf, size_t size)
587 {
588 	int ret = -EIO;
589 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
590 	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
591 
592 	if (dattr->store)
593 		ret = dattr->store(driver_kobj->drv, buf, size);
594 
595 	return ret;
596 }
597 
598 define_one_driver_ro(name, show_driver_name);
599 
600 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
601 	.show = cpuidle_driver_show,
602 	.store = cpuidle_driver_store,
603 };
604 
605 static struct attribute *cpuidle_driver_default_attrs[] = {
606 	&attr_driver_name.attr,
607 	NULL
608 };
609 
610 static struct kobj_type ktype_driver_cpuidle = {
611 	.sysfs_ops = &cpuidle_driver_sysfs_ops,
612 	.default_attrs = cpuidle_driver_default_attrs,
613 	.release = cpuidle_driver_sysfs_release,
614 };
615 
616 /**
617  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
618  * @device: the target device
619  */
620 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
621 {
622 	struct cpuidle_driver_kobj *kdrv;
623 	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
624 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
625 	int ret;
626 
627 	kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
628 	if (!kdrv)
629 		return -ENOMEM;
630 
631 	kdrv->drv = drv;
632 	init_completion(&kdrv->kobj_unregister);
633 
634 	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
635 				   &kdev->kobj, "driver");
636 	if (ret) {
637 		kfree(kdrv);
638 		return ret;
639 	}
640 
641 	kobject_uevent(&kdrv->kobj, KOBJ_ADD);
642 	dev->kobj_driver = kdrv;
643 
644 	return ret;
645 }
646 
647 /**
648  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
649  * @device: the target device
650  */
651 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
652 {
653 	struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
654 	kobject_put(&kdrv->kobj);
655 	wait_for_completion(&kdrv->kobj_unregister);
656 	kfree(kdrv);
657 }
658 #else
659 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
660 {
661 	return 0;
662 }
663 
664 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
665 {
666 	;
667 }
668 #endif
669 
670 /**
671  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
672  * @device: the target device
673  */
674 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
675 {
676 	int ret;
677 
678 	ret = cpuidle_add_state_sysfs(device);
679 	if (ret)
680 		return ret;
681 
682 	ret = cpuidle_add_driver_sysfs(device);
683 	if (ret)
684 		cpuidle_remove_state_sysfs(device);
685 	return ret;
686 }
687 
688 /**
689  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
690  * @device : the target device
691  */
692 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
693 {
694 	cpuidle_remove_driver_sysfs(device);
695 	cpuidle_remove_state_sysfs(device);
696 }
697 
698 /**
699  * cpuidle_add_sysfs - creates a sysfs instance for the target device
700  * @dev: the target device
701  */
702 int cpuidle_add_sysfs(struct cpuidle_device *dev)
703 {
704 	struct cpuidle_device_kobj *kdev;
705 	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
706 	int error;
707 
708 	/*
709 	 * Return if cpu_device is not setup for this CPU.
710 	 *
711 	 * This could happen if the arch did not set up cpu_device
712 	 * since this CPU is not in cpu_present mask and the
713 	 * driver did not send a correct CPU mask during registration.
714 	 * Without this check we would end up passing bogus
715 	 * value for &cpu_dev->kobj in kobject_init_and_add()
716 	 */
717 	if (!cpu_dev)
718 		return -ENODEV;
719 
720 	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
721 	if (!kdev)
722 		return -ENOMEM;
723 	kdev->dev = dev;
724 	dev->kobj_dev = kdev;
725 
726 	init_completion(&kdev->kobj_unregister);
727 
728 	error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
729 				   "cpuidle");
730 	if (error) {
731 		kfree(kdev);
732 		return error;
733 	}
734 
735 	kobject_uevent(&kdev->kobj, KOBJ_ADD);
736 
737 	return 0;
738 }
739 
740 /**
741  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
742  * @dev: the target device
743  */
744 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
745 {
746 	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
747 
748 	kobject_put(&kdev->kobj);
749 	wait_for_completion(&kdev->kobj_unregister);
750 	kfree(kdev);
751 }
752