xref: /openbmc/linux/drivers/cpuidle/sysfs.c (revision cd5d5810) 
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 *cpuidle_driver = cpuidle_get_driver();
56 
57 	spin_lock(&cpuidle_driver_lock);
58 	if (cpuidle_driver)
59 		ret = sprintf(buf, "%s\n", cpuidle_driver->name);
60 	else
61 		ret = sprintf(buf, "none\n");
62 	spin_unlock(&cpuidle_driver_lock);
63 
64 	return ret;
65 }
66 
67 static ssize_t show_current_governor(struct device *dev,
68 				     struct device_attribute *attr,
69 				     char *buf)
70 {
71 	ssize_t ret;
72 
73 	mutex_lock(&cpuidle_lock);
74 	if (cpuidle_curr_governor)
75 		ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
76 	else
77 		ret = sprintf(buf, "none\n");
78 	mutex_unlock(&cpuidle_lock);
79 
80 	return ret;
81 }
82 
83 static ssize_t store_current_governor(struct device *dev,
84 				      struct device_attribute *attr,
85 				      const char *buf, size_t count)
86 {
87 	char gov_name[CPUIDLE_NAME_LEN];
88 	int ret = -EINVAL;
89 	size_t len = count;
90 	struct cpuidle_governor *gov;
91 
92 	if (!len || len >= sizeof(gov_name))
93 		return -EINVAL;
94 
95 	memcpy(gov_name, buf, len);
96 	gov_name[len] = '\0';
97 	if (gov_name[len - 1] == '\n')
98 		gov_name[--len] = '\0';
99 
100 	mutex_lock(&cpuidle_lock);
101 
102 	list_for_each_entry(gov, &cpuidle_governors, governor_list) {
103 		if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
104 			ret = cpuidle_switch_governor(gov);
105 			break;
106 		}
107 	}
108 
109 	mutex_unlock(&cpuidle_lock);
110 
111 	if (ret)
112 		return ret;
113 	else
114 		return count;
115 }
116 
117 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
118 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
119 
120 static struct attribute *cpuidle_default_attrs[] = {
121 	&dev_attr_current_driver.attr,
122 	&dev_attr_current_governor_ro.attr,
123 	NULL
124 };
125 
126 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
127 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
128 		   store_current_governor);
129 
130 static struct attribute *cpuidle_switch_attrs[] = {
131 	&dev_attr_available_governors.attr,
132 	&dev_attr_current_driver.attr,
133 	&dev_attr_current_governor.attr,
134 	NULL
135 };
136 
137 static struct attribute_group cpuidle_attr_group = {
138 	.attrs = cpuidle_default_attrs,
139 	.name = "cpuidle",
140 };
141 
142 /**
143  * cpuidle_add_interface - add CPU global sysfs attributes
144  */
145 int cpuidle_add_interface(struct device *dev)
146 {
147 	if (sysfs_switch)
148 		cpuidle_attr_group.attrs = cpuidle_switch_attrs;
149 
150 	return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
151 }
152 
153 /**
154  * cpuidle_remove_interface - remove CPU global sysfs attributes
155  */
156 void cpuidle_remove_interface(struct device *dev)
157 {
158 	sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
159 }
160 
161 struct cpuidle_attr {
162 	struct attribute attr;
163 	ssize_t (*show)(struct cpuidle_device *, char *);
164 	ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
165 };
166 
167 #define define_one_ro(_name, show) \
168 	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
169 #define define_one_rw(_name, show, store) \
170 	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
171 
172 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
173 
174 struct cpuidle_device_kobj {
175 	struct cpuidle_device *dev;
176 	struct completion kobj_unregister;
177 	struct kobject kobj;
178 };
179 
180 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
181 {
182 	struct cpuidle_device_kobj *kdev =
183 		container_of(kobj, struct cpuidle_device_kobj, kobj);
184 
185 	return kdev->dev;
186 }
187 
188 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
189 			    char *buf)
190 {
191 	int ret = -EIO;
192 	struct cpuidle_device *dev = to_cpuidle_device(kobj);
193 	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
194 
195 	if (cattr->show) {
196 		mutex_lock(&cpuidle_lock);
197 		ret = cattr->show(dev, buf);
198 		mutex_unlock(&cpuidle_lock);
199 	}
200 	return ret;
201 }
202 
203 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
204 			     const char *buf, size_t count)
205 {
206 	int ret = -EIO;
207 	struct cpuidle_device *dev = to_cpuidle_device(kobj);
208 	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
209 
210 	if (cattr->store) {
211 		mutex_lock(&cpuidle_lock);
212 		ret = cattr->store(dev, buf, count);
213 		mutex_unlock(&cpuidle_lock);
214 	}
215 	return ret;
216 }
217 
218 static const struct sysfs_ops cpuidle_sysfs_ops = {
219 	.show = cpuidle_show,
220 	.store = cpuidle_store,
221 };
222 
223 static void cpuidle_sysfs_release(struct kobject *kobj)
224 {
225 	struct cpuidle_device_kobj *kdev =
226 		container_of(kobj, struct cpuidle_device_kobj, kobj);
227 
228 	complete(&kdev->kobj_unregister);
229 }
230 
231 static struct kobj_type ktype_cpuidle = {
232 	.sysfs_ops = &cpuidle_sysfs_ops,
233 	.release = cpuidle_sysfs_release,
234 };
235 
236 struct cpuidle_state_attr {
237 	struct attribute attr;
238 	ssize_t (*show)(struct cpuidle_state *, \
239 					struct cpuidle_state_usage *, char *);
240 	ssize_t (*store)(struct cpuidle_state *, \
241 			struct cpuidle_state_usage *, const char *, size_t);
242 };
243 
244 #define define_one_state_ro(_name, show) \
245 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
246 
247 #define define_one_state_rw(_name, show, store) \
248 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
249 
250 #define define_show_state_function(_name) \
251 static ssize_t show_state_##_name(struct cpuidle_state *state, \
252 			 struct cpuidle_state_usage *state_usage, char *buf) \
253 { \
254 	return sprintf(buf, "%u\n", state->_name);\
255 }
256 
257 #define define_store_state_ull_function(_name) \
258 static ssize_t store_state_##_name(struct cpuidle_state *state, \
259 				   struct cpuidle_state_usage *state_usage, \
260 				   const char *buf, size_t size)	\
261 { \
262 	unsigned long long value; \
263 	int err; \
264 	if (!capable(CAP_SYS_ADMIN)) \
265 		return -EPERM; \
266 	err = kstrtoull(buf, 0, &value); \
267 	if (err) \
268 		return err; \
269 	if (value) \
270 		state_usage->_name = 1; \
271 	else \
272 		state_usage->_name = 0; \
273 	return size; \
274 }
275 
276 #define define_show_state_ull_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", state_usage->_name);\
282 }
283 
284 #define define_show_state_str_function(_name) \
285 static ssize_t show_state_##_name(struct cpuidle_state *state, \
286 				  struct cpuidle_state_usage *state_usage, \
287 				  char *buf)				\
288 { \
289 	if (state->_name[0] == '\0')\
290 		return sprintf(buf, "<null>\n");\
291 	return sprintf(buf, "%s\n", state->_name);\
292 }
293 
294 define_show_state_function(exit_latency)
295 define_show_state_function(power_usage)
296 define_show_state_ull_function(usage)
297 define_show_state_ull_function(time)
298 define_show_state_str_function(name)
299 define_show_state_str_function(desc)
300 define_show_state_ull_function(disable)
301 define_store_state_ull_function(disable)
302 
303 define_one_state_ro(name, show_state_name);
304 define_one_state_ro(desc, show_state_desc);
305 define_one_state_ro(latency, show_state_exit_latency);
306 define_one_state_ro(power, show_state_power_usage);
307 define_one_state_ro(usage, show_state_usage);
308 define_one_state_ro(time, show_state_time);
309 define_one_state_rw(disable, show_state_disable, store_state_disable);
310 
311 static struct attribute *cpuidle_state_default_attrs[] = {
312 	&attr_name.attr,
313 	&attr_desc.attr,
314 	&attr_latency.attr,
315 	&attr_power.attr,
316 	&attr_usage.attr,
317 	&attr_time.attr,
318 	&attr_disable.attr,
319 	NULL
320 };
321 
322 struct cpuidle_state_kobj {
323 	struct cpuidle_state *state;
324 	struct cpuidle_state_usage *state_usage;
325 	struct completion kobj_unregister;
326 	struct kobject kobj;
327 };
328 
329 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
330 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
331 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
332 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
333 
334 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
335 				  char * buf)
336 {
337 	int ret = -EIO;
338 	struct cpuidle_state *state = kobj_to_state(kobj);
339 	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
340 	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
341 
342 	if (cattr->show)
343 		ret = cattr->show(state, state_usage, buf);
344 
345 	return ret;
346 }
347 
348 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
349 				   const char *buf, size_t size)
350 {
351 	int ret = -EIO;
352 	struct cpuidle_state *state = kobj_to_state(kobj);
353 	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
354 	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
355 
356 	if (cattr->store)
357 		ret = cattr->store(state, state_usage, buf, size);
358 
359 	return ret;
360 }
361 
362 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
363 	.show = cpuidle_state_show,
364 	.store = cpuidle_state_store,
365 };
366 
367 static void cpuidle_state_sysfs_release(struct kobject *kobj)
368 {
369 	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
370 
371 	complete(&state_obj->kobj_unregister);
372 }
373 
374 static struct kobj_type ktype_state_cpuidle = {
375 	.sysfs_ops = &cpuidle_state_sysfs_ops,
376 	.default_attrs = cpuidle_state_default_attrs,
377 	.release = cpuidle_state_sysfs_release,
378 };
379 
380 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
381 {
382 	kobject_put(&device->kobjs[i]->kobj);
383 	wait_for_completion(&device->kobjs[i]->kobj_unregister);
384 	kfree(device->kobjs[i]);
385 	device->kobjs[i] = NULL;
386 }
387 
388 /**
389  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
390  * @device: the target device
391  */
392 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
393 {
394 	int i, ret = -ENOMEM;
395 	struct cpuidle_state_kobj *kobj;
396 	struct cpuidle_device_kobj *kdev = device->kobj_dev;
397 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
398 
399 	/* state statistics */
400 	for (i = 0; i < device->state_count; i++) {
401 		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
402 		if (!kobj)
403 			goto error_state;
404 		kobj->state = &drv->states[i];
405 		kobj->state_usage = &device->states_usage[i];
406 		init_completion(&kobj->kobj_unregister);
407 
408 		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
409 					   &kdev->kobj, "state%d", i);
410 		if (ret) {
411 			kfree(kobj);
412 			goto error_state;
413 		}
414 		kobject_uevent(&kobj->kobj, KOBJ_ADD);
415 		device->kobjs[i] = kobj;
416 	}
417 
418 	return 0;
419 
420 error_state:
421 	for (i = i - 1; i >= 0; i--)
422 		cpuidle_free_state_kobj(device, i);
423 	return ret;
424 }
425 
426 /**
427  * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
428  * @device: the target device
429  */
430 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
431 {
432 	int i;
433 
434 	for (i = 0; i < device->state_count; i++)
435 		cpuidle_free_state_kobj(device, i);
436 }
437 
438 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
439 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
440 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
441 
442 #define define_one_driver_ro(_name, show)                       \
443 	static struct cpuidle_driver_attr attr_driver_##_name = \
444 		__ATTR(_name, 0644, show, NULL)
445 
446 struct cpuidle_driver_kobj {
447 	struct cpuidle_driver *drv;
448 	struct completion kobj_unregister;
449 	struct kobject kobj;
450 };
451 
452 struct cpuidle_driver_attr {
453 	struct attribute attr;
454 	ssize_t (*show)(struct cpuidle_driver *, char *);
455 	ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
456 };
457 
458 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
459 {
460 	ssize_t ret;
461 
462 	spin_lock(&cpuidle_driver_lock);
463 	ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
464 	spin_unlock(&cpuidle_driver_lock);
465 
466 	return ret;
467 }
468 
469 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
470 {
471 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
472 	complete(&driver_kobj->kobj_unregister);
473 }
474 
475 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
476 				   char *buf)
477 {
478 	int ret = -EIO;
479 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
480 	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
481 
482 	if (dattr->show)
483 		ret = dattr->show(driver_kobj->drv, buf);
484 
485 	return ret;
486 }
487 
488 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
489 				    const char *buf, size_t size)
490 {
491 	int ret = -EIO;
492 	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
493 	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
494 
495 	if (dattr->store)
496 		ret = dattr->store(driver_kobj->drv, buf, size);
497 
498 	return ret;
499 }
500 
501 define_one_driver_ro(name, show_driver_name);
502 
503 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
504 	.show = cpuidle_driver_show,
505 	.store = cpuidle_driver_store,
506 };
507 
508 static struct attribute *cpuidle_driver_default_attrs[] = {
509 	&attr_driver_name.attr,
510 	NULL
511 };
512 
513 static struct kobj_type ktype_driver_cpuidle = {
514 	.sysfs_ops = &cpuidle_driver_sysfs_ops,
515 	.default_attrs = cpuidle_driver_default_attrs,
516 	.release = cpuidle_driver_sysfs_release,
517 };
518 
519 /**
520  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
521  * @device: the target device
522  */
523 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
524 {
525 	struct cpuidle_driver_kobj *kdrv;
526 	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
527 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
528 	int ret;
529 
530 	kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
531 	if (!kdrv)
532 		return -ENOMEM;
533 
534 	kdrv->drv = drv;
535 	init_completion(&kdrv->kobj_unregister);
536 
537 	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
538 				   &kdev->kobj, "driver");
539 	if (ret) {
540 		kfree(kdrv);
541 		return ret;
542 	}
543 
544 	kobject_uevent(&kdrv->kobj, KOBJ_ADD);
545 	dev->kobj_driver = kdrv;
546 
547 	return ret;
548 }
549 
550 /**
551  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
552  * @device: the target device
553  */
554 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
555 {
556 	struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
557 	kobject_put(&kdrv->kobj);
558 	wait_for_completion(&kdrv->kobj_unregister);
559 	kfree(kdrv);
560 }
561 #else
562 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
563 {
564 	return 0;
565 }
566 
567 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
568 {
569 	;
570 }
571 #endif
572 
573 /**
574  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
575  * @device: the target device
576  */
577 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
578 {
579 	int ret;
580 
581 	ret = cpuidle_add_state_sysfs(device);
582 	if (ret)
583 		return ret;
584 
585 	ret = cpuidle_add_driver_sysfs(device);
586 	if (ret)
587 		cpuidle_remove_state_sysfs(device);
588 	return ret;
589 }
590 
591 /**
592  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
593  * @device : the target device
594  */
595 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
596 {
597 	cpuidle_remove_driver_sysfs(device);
598 	cpuidle_remove_state_sysfs(device);
599 }
600 
601 /**
602  * cpuidle_add_sysfs - creates a sysfs instance for the target device
603  * @dev: the target device
604  */
605 int cpuidle_add_sysfs(struct cpuidle_device *dev)
606 {
607 	struct cpuidle_device_kobj *kdev;
608 	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
609 	int error;
610 
611 	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
612 	if (!kdev)
613 		return -ENOMEM;
614 	kdev->dev = dev;
615 	dev->kobj_dev = kdev;
616 
617 	init_completion(&kdev->kobj_unregister);
618 
619 	error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
620 				   "cpuidle");
621 	if (error) {
622 		kfree(kdev);
623 		return error;
624 	}
625 
626 	kobject_uevent(&kdev->kobj, KOBJ_ADD);
627 
628 	return 0;
629 }
630 
631 /**
632  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
633  * @dev: the target device
634  */
635 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
636 {
637 	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
638 
639 	kobject_put(&kdev->kobj);
640 	wait_for_completion(&kdev->kobj_unregister);
641 	kfree(kdev);
642 }
643