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 
show_available_governors(struct device * dev,struct device_attribute * attr,char * buf)21 static ssize_t show_available_governors(struct device *dev,
22 					struct device_attribute *attr,
23 					char *buf)
24 {
25 	ssize_t i = 0;
26 	struct cpuidle_governor *tmp;
27 
28 	mutex_lock(&cpuidle_lock);
29 	list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
30 		if (i >= (ssize_t) (PAGE_SIZE - (CPUIDLE_NAME_LEN + 2)))
31 			goto out;
32 
33 		i += scnprintf(&buf[i], CPUIDLE_NAME_LEN + 1, "%s ", tmp->name);
34 	}
35 
36 out:
37 	i+= sprintf(&buf[i], "\n");
38 	mutex_unlock(&cpuidle_lock);
39 	return i;
40 }
41 
show_current_driver(struct device * dev,struct device_attribute * attr,char * buf)42 static ssize_t show_current_driver(struct device *dev,
43 				   struct device_attribute *attr,
44 				   char *buf)
45 {
46 	ssize_t ret;
47 	struct cpuidle_driver *drv;
48 
49 	spin_lock(&cpuidle_driver_lock);
50 	drv = cpuidle_get_driver();
51 	if (drv)
52 		ret = sprintf(buf, "%s\n", drv->name);
53 	else
54 		ret = sprintf(buf, "none\n");
55 	spin_unlock(&cpuidle_driver_lock);
56 
57 	return ret;
58 }
59 
show_current_governor(struct device * dev,struct device_attribute * attr,char * buf)60 static ssize_t show_current_governor(struct device *dev,
61 				     struct device_attribute *attr,
62 				     char *buf)
63 {
64 	ssize_t ret;
65 
66 	mutex_lock(&cpuidle_lock);
67 	if (cpuidle_curr_governor)
68 		ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
69 	else
70 		ret = sprintf(buf, "none\n");
71 	mutex_unlock(&cpuidle_lock);
72 
73 	return ret;
74 }
75 
store_current_governor(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)76 static ssize_t store_current_governor(struct device *dev,
77 				      struct device_attribute *attr,
78 				      const char *buf, size_t count)
79 {
80 	char gov_name[CPUIDLE_NAME_LEN + 1];
81 	int ret;
82 	struct cpuidle_governor *gov;
83 
84 	ret = sscanf(buf, "%" __stringify(CPUIDLE_NAME_LEN) "s", gov_name);
85 	if (ret != 1)
86 		return -EINVAL;
87 
88 	mutex_lock(&cpuidle_lock);
89 	ret = -EINVAL;
90 	list_for_each_entry(gov, &cpuidle_governors, governor_list) {
91 		if (!strncmp(gov->name, gov_name, CPUIDLE_NAME_LEN)) {
92 			ret = cpuidle_switch_governor(gov);
93 			break;
94 		}
95 	}
96 	mutex_unlock(&cpuidle_lock);
97 
98 	return ret ? ret : count;
99 }
100 
101 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
102 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
103 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
104 				   store_current_governor);
105 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
106 
107 static struct attribute *cpuidle_attrs[] = {
108 	&dev_attr_available_governors.attr,
109 	&dev_attr_current_driver.attr,
110 	&dev_attr_current_governor.attr,
111 	&dev_attr_current_governor_ro.attr,
112 	NULL
113 };
114 
115 static struct attribute_group cpuidle_attr_group = {
116 	.attrs = cpuidle_attrs,
117 	.name = "cpuidle",
118 };
119 
120 /**
121  * cpuidle_add_interface - add CPU global sysfs attributes
122  */
cpuidle_add_interface(void)123 int cpuidle_add_interface(void)
124 {
125 	struct device *dev_root = bus_get_dev_root(&cpu_subsys);
126 	int retval;
127 
128 	if (!dev_root)
129 		return -EINVAL;
130 
131 	retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group);
132 	put_device(dev_root);
133 	return retval;
134 }
135 
136 /**
137  * cpuidle_remove_interface - remove CPU global sysfs attributes
138  * @dev: the target device
139  */
cpuidle_remove_interface(struct device * dev)140 void cpuidle_remove_interface(struct device *dev)
141 {
142 	sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
143 }
144 
145 struct cpuidle_attr {
146 	struct attribute attr;
147 	ssize_t (*show)(struct cpuidle_device *, char *);
148 	ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
149 };
150 
151 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
152 
153 struct cpuidle_device_kobj {
154 	struct cpuidle_device *dev;
155 	struct completion kobj_unregister;
156 	struct kobject kobj;
157 };
158 
to_cpuidle_device(struct kobject * kobj)159 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
160 {
161 	struct cpuidle_device_kobj *kdev =
162 		container_of(kobj, struct cpuidle_device_kobj, kobj);
163 
164 	return kdev->dev;
165 }
166 
cpuidle_show(struct kobject * kobj,struct attribute * attr,char * buf)167 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
168 			    char *buf)
169 {
170 	int ret = -EIO;
171 	struct cpuidle_device *dev = to_cpuidle_device(kobj);
172 	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
173 
174 	if (cattr->show) {
175 		mutex_lock(&cpuidle_lock);
176 		ret = cattr->show(dev, buf);
177 		mutex_unlock(&cpuidle_lock);
178 	}
179 	return ret;
180 }
181 
cpuidle_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t count)182 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
183 			     const char *buf, size_t count)
184 {
185 	int ret = -EIO;
186 	struct cpuidle_device *dev = to_cpuidle_device(kobj);
187 	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
188 
189 	if (cattr->store) {
190 		mutex_lock(&cpuidle_lock);
191 		ret = cattr->store(dev, buf, count);
192 		mutex_unlock(&cpuidle_lock);
193 	}
194 	return ret;
195 }
196 
197 static const struct sysfs_ops cpuidle_sysfs_ops = {
198 	.show = cpuidle_show,
199 	.store = cpuidle_store,
200 };
201 
cpuidle_sysfs_release(struct kobject * kobj)202 static void cpuidle_sysfs_release(struct kobject *kobj)
203 {
204 	struct cpuidle_device_kobj *kdev =
205 		container_of(kobj, struct cpuidle_device_kobj, kobj);
206 
207 	complete(&kdev->kobj_unregister);
208 }
209 
210 static const struct kobj_type ktype_cpuidle = {
211 	.sysfs_ops = &cpuidle_sysfs_ops,
212 	.release = cpuidle_sysfs_release,
213 };
214 
215 struct cpuidle_state_attr {
216 	struct attribute attr;
217 	ssize_t (*show)(struct cpuidle_state *, \
218 					struct cpuidle_state_usage *, char *);
219 	ssize_t (*store)(struct cpuidle_state *, \
220 			struct cpuidle_state_usage *, 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_show_state_ull_function(_name) \
237 static ssize_t show_state_##_name(struct cpuidle_state *state, \
238 				  struct cpuidle_state_usage *state_usage, \
239 				  char *buf)				\
240 { \
241 	return sprintf(buf, "%llu\n", state_usage->_name);\
242 }
243 
244 #define define_show_state_str_function(_name) \
245 static ssize_t show_state_##_name(struct cpuidle_state *state, \
246 				  struct cpuidle_state_usage *state_usage, \
247 				  char *buf)				\
248 { \
249 	if (state->_name[0] == '\0')\
250 		return sprintf(buf, "<null>\n");\
251 	return sprintf(buf, "%s\n", state->_name);\
252 }
253 
254 #define define_show_state_time_function(_name) \
255 static ssize_t show_state_##_name(struct cpuidle_state *state, \
256 				  struct cpuidle_state_usage *state_usage, \
257 				  char *buf) \
258 { \
259 	return sprintf(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
260 }
261 
262 define_show_state_time_function(exit_latency)
define_show_state_time_function(target_residency)263 define_show_state_time_function(target_residency)
264 define_show_state_function(power_usage)
265 define_show_state_ull_function(usage)
266 define_show_state_ull_function(rejected)
267 define_show_state_str_function(name)
268 define_show_state_str_function(desc)
269 define_show_state_ull_function(above)
270 define_show_state_ull_function(below)
271 
272 static ssize_t show_state_time(struct cpuidle_state *state,
273 			       struct cpuidle_state_usage *state_usage,
274 			       char *buf)
275 {
276 	return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
277 }
278 
show_state_disable(struct cpuidle_state * state,struct cpuidle_state_usage * state_usage,char * buf)279 static ssize_t show_state_disable(struct cpuidle_state *state,
280 				  struct cpuidle_state_usage *state_usage,
281 				  char *buf)
282 {
283 	return sprintf(buf, "%llu\n",
284 		       state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
285 }
286 
store_state_disable(struct cpuidle_state * state,struct cpuidle_state_usage * state_usage,const char * buf,size_t size)287 static ssize_t store_state_disable(struct cpuidle_state *state,
288 				   struct cpuidle_state_usage *state_usage,
289 				   const char *buf, size_t size)
290 {
291 	unsigned int value;
292 	int err;
293 
294 	if (!capable(CAP_SYS_ADMIN))
295 		return -EPERM;
296 
297 	err = kstrtouint(buf, 0, &value);
298 	if (err)
299 		return err;
300 
301 	if (value)
302 		state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
303 	else
304 		state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
305 
306 	return size;
307 }
308 
show_state_default_status(struct cpuidle_state * state,struct cpuidle_state_usage * state_usage,char * buf)309 static ssize_t show_state_default_status(struct cpuidle_state *state,
310 					  struct cpuidle_state_usage *state_usage,
311 					  char *buf)
312 {
313 	return sprintf(buf, "%s\n",
314 		       state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
315 }
316 
317 define_one_state_ro(name, show_state_name);
318 define_one_state_ro(desc, show_state_desc);
319 define_one_state_ro(latency, show_state_exit_latency);
320 define_one_state_ro(residency, show_state_target_residency);
321 define_one_state_ro(power, show_state_power_usage);
322 define_one_state_ro(usage, show_state_usage);
323 define_one_state_ro(rejected, show_state_rejected);
324 define_one_state_ro(time, show_state_time);
325 define_one_state_rw(disable, show_state_disable, store_state_disable);
326 define_one_state_ro(above, show_state_above);
327 define_one_state_ro(below, show_state_below);
328 define_one_state_ro(default_status, show_state_default_status);
329 
330 static struct attribute *cpuidle_state_default_attrs[] = {
331 	&attr_name.attr,
332 	&attr_desc.attr,
333 	&attr_latency.attr,
334 	&attr_residency.attr,
335 	&attr_power.attr,
336 	&attr_usage.attr,
337 	&attr_rejected.attr,
338 	&attr_time.attr,
339 	&attr_disable.attr,
340 	&attr_above.attr,
341 	&attr_below.attr,
342 	&attr_default_status.attr,
343 	NULL
344 };
345 ATTRIBUTE_GROUPS(cpuidle_state_default);
346 
347 struct cpuidle_state_kobj {
348 	struct cpuidle_state *state;
349 	struct cpuidle_state_usage *state_usage;
350 	struct completion kobj_unregister;
351 	struct kobject kobj;
352 	struct cpuidle_device *device;
353 };
354 
355 #ifdef CONFIG_SUSPEND
356 #define define_show_state_s2idle_ull_function(_name) \
357 static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
358 					 struct cpuidle_state_usage *state_usage, \
359 					 char *buf)				\
360 { \
361 	return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
362 }
363 
364 define_show_state_s2idle_ull_function(usage);
365 define_show_state_s2idle_ull_function(time);
366 
367 #define define_one_state_s2idle_ro(_name, show) \
368 static struct cpuidle_state_attr attr_s2idle_##_name = \
369 	__ATTR(_name, 0444, show, NULL)
370 
371 define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
372 define_one_state_s2idle_ro(time, show_state_s2idle_time);
373 
374 static struct attribute *cpuidle_state_s2idle_attrs[] = {
375 	&attr_s2idle_usage.attr,
376 	&attr_s2idle_time.attr,
377 	NULL
378 };
379 
380 static const struct attribute_group cpuidle_state_s2idle_group = {
381 	.name	= "s2idle",
382 	.attrs	= cpuidle_state_s2idle_attrs,
383 };
384 
cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj * kobj)385 static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
386 {
387 	int ret;
388 
389 	if (!kobj->state->enter_s2idle)
390 		return;
391 
392 	ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
393 	if (ret)
394 		pr_debug("%s: sysfs attribute group not created\n", __func__);
395 }
396 
cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj * kobj)397 static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
398 {
399 	if (kobj->state->enter_s2idle)
400 		sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
401 }
402 #else
cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj * kobj)403 static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj * kobj)404 static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
405 #endif /* CONFIG_SUSPEND */
406 
407 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
408 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
409 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
410 #define kobj_to_device(k) (kobj_to_state_obj(k)->device)
411 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
412 
cpuidle_state_show(struct kobject * kobj,struct attribute * attr,char * buf)413 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
414 				  char *buf)
415 {
416 	int ret = -EIO;
417 	struct cpuidle_state *state = kobj_to_state(kobj);
418 	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
419 	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
420 
421 	if (cattr->show)
422 		ret = cattr->show(state, state_usage, buf);
423 
424 	return ret;
425 }
426 
cpuidle_state_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t size)427 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
428 				   const char *buf, size_t size)
429 {
430 	int ret = -EIO;
431 	struct cpuidle_state *state = kobj_to_state(kobj);
432 	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
433 	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
434 	struct cpuidle_device *dev = kobj_to_device(kobj);
435 
436 	if (cattr->store)
437 		ret = cattr->store(state, state_usage, buf, size);
438 
439 	/* reset poll time cache */
440 	dev->poll_limit_ns = 0;
441 
442 	return ret;
443 }
444 
445 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
446 	.show = cpuidle_state_show,
447 	.store = cpuidle_state_store,
448 };
449 
cpuidle_state_sysfs_release(struct kobject * kobj)450 static void cpuidle_state_sysfs_release(struct kobject *kobj)
451 {
452 	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
453 
454 	complete(&state_obj->kobj_unregister);
455 }
456 
457 static const struct kobj_type ktype_state_cpuidle = {
458 	.sysfs_ops = &cpuidle_state_sysfs_ops,
459 	.default_groups = cpuidle_state_default_groups,
460 	.release = cpuidle_state_sysfs_release,
461 };
462 
cpuidle_free_state_kobj(struct cpuidle_device * device,int i)463 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
464 {
465 	cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
466 	kobject_put(&device->kobjs[i]->kobj);
467 	wait_for_completion(&device->kobjs[i]->kobj_unregister);
468 	kfree(device->kobjs[i]);
469 	device->kobjs[i] = NULL;
470 }
471 
472 /**
473  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
474  * @device: the target device
475  */
cpuidle_add_state_sysfs(struct cpuidle_device * device)476 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
477 {
478 	int i, ret = -ENOMEM;
479 	struct cpuidle_state_kobj *kobj;
480 	struct cpuidle_device_kobj *kdev = device->kobj_dev;
481 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
482 
483 	/* state statistics */
484 	for (i = 0; i < drv->state_count; i++) {
485 		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
486 		if (!kobj) {
487 			ret = -ENOMEM;
488 			goto error_state;
489 		}
490 		kobj->state = &drv->states[i];
491 		kobj->state_usage = &device->states_usage[i];
492 		kobj->device = device;
493 		init_completion(&kobj->kobj_unregister);
494 
495 		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
496 					   &kdev->kobj, "state%d", i);
497 		if (ret) {
498 			kobject_put(&kobj->kobj);
499 			kfree(kobj);
500 			goto error_state;
501 		}
502 		cpuidle_add_s2idle_attr_group(kobj);
503 		kobject_uevent(&kobj->kobj, KOBJ_ADD);
504 		device->kobjs[i] = kobj;
505 	}
506 
507 	return 0;
508 
509 error_state:
510 	for (i = i - 1; i >= 0; i--)
511 		cpuidle_free_state_kobj(device, i);
512 	return ret;
513 }
514 
515 /**
516  * cpuidle_remove_state_sysfs - removes the cpuidle states sysfs attributes
517  * @device: the target device
518  */
cpuidle_remove_state_sysfs(struct cpuidle_device * device)519 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
520 {
521 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
522 	int i;
523 
524 	for (i = 0; i < drv->state_count; i++)
525 		cpuidle_free_state_kobj(device, i);
526 }
527 
528 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
529 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
530 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
531 
532 #define define_one_driver_ro(_name, show)                       \
533 	static struct cpuidle_driver_attr attr_driver_##_name = \
534 		__ATTR(_name, 0444, show, NULL)
535 
536 struct cpuidle_driver_kobj {
537 	struct cpuidle_driver *drv;
538 	struct completion kobj_unregister;
539 	struct kobject kobj;
540 };
541 
542 struct cpuidle_driver_attr {
543 	struct attribute attr;
544 	ssize_t (*show)(struct cpuidle_driver *, char *);
545 	ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
546 };
547 
show_driver_name(struct cpuidle_driver * drv,char * buf)548 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
549 {
550 	ssize_t ret;
551 
552 	spin_lock(&cpuidle_driver_lock);
553 	ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
554 	spin_unlock(&cpuidle_driver_lock);
555 
556 	return ret;
557 }
558 
cpuidle_driver_sysfs_release(struct kobject * kobj)559 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
560 {
561 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
562 	complete(&driver_kobj->kobj_unregister);
563 }
564 
cpuidle_driver_show(struct kobject * kobj,struct attribute * attr,char * buf)565 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
566 				   char *buf)
567 {
568 	int ret = -EIO;
569 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
570 	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
571 
572 	if (dattr->show)
573 		ret = dattr->show(driver_kobj->drv, buf);
574 
575 	return ret;
576 }
577 
cpuidle_driver_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t size)578 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
579 				    const char *buf, size_t size)
580 {
581 	int ret = -EIO;
582 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
583 	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
584 
585 	if (dattr->store)
586 		ret = dattr->store(driver_kobj->drv, buf, size);
587 
588 	return ret;
589 }
590 
591 define_one_driver_ro(name, show_driver_name);
592 
593 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
594 	.show = cpuidle_driver_show,
595 	.store = cpuidle_driver_store,
596 };
597 
598 static struct attribute *cpuidle_driver_default_attrs[] = {
599 	&attr_driver_name.attr,
600 	NULL
601 };
602 ATTRIBUTE_GROUPS(cpuidle_driver_default);
603 
604 static const struct kobj_type ktype_driver_cpuidle = {
605 	.sysfs_ops = &cpuidle_driver_sysfs_ops,
606 	.default_groups = cpuidle_driver_default_groups,
607 	.release = cpuidle_driver_sysfs_release,
608 };
609 
610 /**
611  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
612  * @dev: the target device
613  */
cpuidle_add_driver_sysfs(struct cpuidle_device * dev)614 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
615 {
616 	struct cpuidle_driver_kobj *kdrv;
617 	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
618 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
619 	int ret;
620 
621 	kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
622 	if (!kdrv)
623 		return -ENOMEM;
624 
625 	kdrv->drv = drv;
626 	init_completion(&kdrv->kobj_unregister);
627 
628 	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
629 				   &kdev->kobj, "driver");
630 	if (ret) {
631 		kobject_put(&kdrv->kobj);
632 		kfree(kdrv);
633 		return ret;
634 	}
635 
636 	kobject_uevent(&kdrv->kobj, KOBJ_ADD);
637 	dev->kobj_driver = kdrv;
638 
639 	return ret;
640 }
641 
642 /**
643  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
644  * @dev: the target device
645  */
cpuidle_remove_driver_sysfs(struct cpuidle_device * dev)646 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
647 {
648 	struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
649 	kobject_put(&kdrv->kobj);
650 	wait_for_completion(&kdrv->kobj_unregister);
651 	kfree(kdrv);
652 }
653 #else
cpuidle_add_driver_sysfs(struct cpuidle_device * dev)654 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
655 {
656 	return 0;
657 }
658 
cpuidle_remove_driver_sysfs(struct cpuidle_device * dev)659 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
660 {
661 	;
662 }
663 #endif
664 
665 /**
666  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
667  * @device: the target device
668  */
cpuidle_add_device_sysfs(struct cpuidle_device * device)669 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
670 {
671 	int ret;
672 
673 	ret = cpuidle_add_state_sysfs(device);
674 	if (ret)
675 		return ret;
676 
677 	ret = cpuidle_add_driver_sysfs(device);
678 	if (ret)
679 		cpuidle_remove_state_sysfs(device);
680 	return ret;
681 }
682 
683 /**
684  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
685  * @device : the target device
686  */
cpuidle_remove_device_sysfs(struct cpuidle_device * device)687 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
688 {
689 	cpuidle_remove_driver_sysfs(device);
690 	cpuidle_remove_state_sysfs(device);
691 }
692 
693 /**
694  * cpuidle_add_sysfs - creates a sysfs instance for the target device
695  * @dev: the target device
696  */
cpuidle_add_sysfs(struct cpuidle_device * dev)697 int cpuidle_add_sysfs(struct cpuidle_device *dev)
698 {
699 	struct cpuidle_device_kobj *kdev;
700 	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
701 	int error;
702 
703 	/*
704 	 * Return if cpu_device is not setup for this CPU.
705 	 *
706 	 * This could happen if the arch did not set up cpu_device
707 	 * since this CPU is not in cpu_present mask and the
708 	 * driver did not send a correct CPU mask during registration.
709 	 * Without this check we would end up passing bogus
710 	 * value for &cpu_dev->kobj in kobject_init_and_add()
711 	 */
712 	if (!cpu_dev)
713 		return -ENODEV;
714 
715 	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
716 	if (!kdev)
717 		return -ENOMEM;
718 	kdev->dev = dev;
719 
720 	init_completion(&kdev->kobj_unregister);
721 
722 	error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
723 				   "cpuidle");
724 	if (error) {
725 		kobject_put(&kdev->kobj);
726 		kfree(kdev);
727 		return error;
728 	}
729 
730 	dev->kobj_dev = kdev;
731 	kobject_uevent(&kdev->kobj, KOBJ_ADD);
732 
733 	return 0;
734 }
735 
736 /**
737  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
738  * @dev: the target device
739  */
cpuidle_remove_sysfs(struct cpuidle_device * dev)740 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
741 {
742 	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
743 
744 	kobject_put(&kdev->kobj);
745 	wait_for_completion(&kdev->kobj_unregister);
746 	kfree(kdev);
747 }
748