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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Power capping class
4 * Copyright (c) 2013, Intel Corporation.
5 */
6
7#include <linux/module.h>
8#include <linux/device.h>
9#include <linux/err.h>
10#include <linux/slab.h>
11#include <linux/powercap.h>
12
13#define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
14#define to_powercap_control_type(n) \
15 container_of(n, struct powercap_control_type, dev)
16
17/* Power zone show function */
18#define define_power_zone_show(_attr) \
19static ssize_t _attr##_show(struct device *dev, \
20 struct device_attribute *dev_attr,\
21 char *buf) \
22{ \
23 u64 value; \
24 ssize_t len = -EINVAL; \
25 struct powercap_zone *power_zone = to_powercap_zone(dev); \
26 \
27 if (power_zone->ops->get_##_attr) { \
28 if (!power_zone->ops->get_##_attr(power_zone, &value)) \
29 len = sprintf(buf, "%lld\n", value); \
30 } \
31 \
32 return len; \
33}
34
35/* The only meaningful input is 0 (reset), others are silently ignored */
36#define define_power_zone_store(_attr) \
37static ssize_t _attr##_store(struct device *dev,\
38 struct device_attribute *dev_attr, \
39 const char *buf, size_t count) \
40{ \
41 int err; \
42 struct powercap_zone *power_zone = to_powercap_zone(dev); \
43 u64 value; \
44 \
45 err = kstrtoull(buf, 10, &value); \
46 if (err) \
47 return -EINVAL; \
48 if (value) \
49 return count; \
50 if (power_zone->ops->reset_##_attr) { \
51 if (!power_zone->ops->reset_##_attr(power_zone)) \
52 return count; \
53 } \
54 \
55 return -EINVAL; \
56}
57
58/* Power zone constraint show function */
59#define define_power_zone_constraint_show(_attr) \
60static ssize_t show_constraint_##_attr(struct device *dev, \
61 struct device_attribute *dev_attr,\
62 char *buf) \
63{ \
64 u64 value; \
65 ssize_t len = -ENODATA; \
66 struct powercap_zone *power_zone = to_powercap_zone(dev); \
67 int id; \
68 struct powercap_zone_constraint *pconst;\
69 \
70 if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
71 return -EINVAL; \
72 if (id >= power_zone->const_id_cnt) \
73 return -EINVAL; \
74 pconst = &power_zone->constraints[id]; \
75 if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
76 if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
77 len = sprintf(buf, "%lld\n", value); \
78 } \
79 \
80 return len; \
81}
82
83/* Power zone constraint store function */
84#define define_power_zone_constraint_store(_attr) \
85static ssize_t store_constraint_##_attr(struct device *dev,\
86 struct device_attribute *dev_attr, \
87 const char *buf, size_t count) \
88{ \
89 int err; \
90 u64 value; \
91 struct powercap_zone *power_zone = to_powercap_zone(dev); \
92 int id; \
93 struct powercap_zone_constraint *pconst;\
94 \
95 if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
96 return -EINVAL; \
97 if (id >= power_zone->const_id_cnt) \
98 return -EINVAL; \
99 pconst = &power_zone->constraints[id]; \
100 err = kstrtoull(buf, 10, &value); \
101 if (err) \
102 return -EINVAL; \
103 if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
104 if (!pconst->ops->set_##_attr(power_zone, id, value)) \
105 return count; \
106 } \
107 \
108 return -ENODATA; \
109}
110
111/* Power zone information callbacks */
112define_power_zone_show(power_uw);
113define_power_zone_show(max_power_range_uw);
114define_power_zone_show(energy_uj);
115define_power_zone_store(energy_uj);
116define_power_zone_show(max_energy_range_uj);
117
118/* Power zone attributes */
119static DEVICE_ATTR_RO(max_power_range_uw);
120static DEVICE_ATTR_RO(power_uw);
121static DEVICE_ATTR_RO(max_energy_range_uj);
122static DEVICE_ATTR_RW(energy_uj);
123
124/* Power zone constraint attributes callbacks */
125define_power_zone_constraint_show(power_limit_uw);
126define_power_zone_constraint_store(power_limit_uw);
127define_power_zone_constraint_show(time_window_us);
128define_power_zone_constraint_store(time_window_us);
129define_power_zone_constraint_show(max_power_uw);
130define_power_zone_constraint_show(min_power_uw);
131define_power_zone_constraint_show(max_time_window_us);
132define_power_zone_constraint_show(min_time_window_us);
133
134/* For one time seeding of constraint device attributes */
135struct powercap_constraint_attr {
136 struct device_attribute power_limit_attr;
137 struct device_attribute time_window_attr;
138 struct device_attribute max_power_attr;
139 struct device_attribute min_power_attr;
140 struct device_attribute max_time_window_attr;
141 struct device_attribute min_time_window_attr;
142 struct device_attribute name_attr;
143};
144
145static struct powercap_constraint_attr
146 constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
147
148/* A list of powercap control_types */
149static LIST_HEAD(powercap_cntrl_list);
150/* Mutex to protect list of powercap control_types */
151static DEFINE_MUTEX(powercap_cntrl_list_lock);
152
153#define POWERCAP_CONSTRAINT_NAME_LEN 30 /* Some limit to avoid overflow */
154static ssize_t show_constraint_name(struct device *dev,
155 struct device_attribute *dev_attr,
156 char *buf)
157{
158 const char *name;
159 struct powercap_zone *power_zone = to_powercap_zone(dev);
160 int id;
161 ssize_t len = -ENODATA;
162 struct powercap_zone_constraint *pconst;
163
164 if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id))
165 return -EINVAL;
166 if (id >= power_zone->const_id_cnt)
167 return -EINVAL;
168 pconst = &power_zone->constraints[id];
169
170 if (pconst && pconst->ops && pconst->ops->get_name) {
171 name = pconst->ops->get_name(power_zone, id);
172 if (name) {
173 snprintf(buf, POWERCAP_CONSTRAINT_NAME_LEN,
174 "%s\n", name);
175 buf[POWERCAP_CONSTRAINT_NAME_LEN] = '\0';
176 len = strlen(buf);
177 }
178 }
179
180 return len;
181}
182
183static int create_constraint_attribute(int id, const char *name,
184 int mode,
185 struct device_attribute *dev_attr,
186 ssize_t (*show)(struct device *,
187 struct device_attribute *, char *),
188 ssize_t (*store)(struct device *,
189 struct device_attribute *,
190 const char *, size_t)
191 )
192{
193
194 dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s",
195 id, name);
196 if (!dev_attr->attr.name)
197 return -ENOMEM;
198 dev_attr->attr.mode = mode;
199 dev_attr->show = show;
200 dev_attr->store = store;
201
202 return 0;
203}
204
205static void free_constraint_attributes(void)
206{
207 int i;
208
209 for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
210 kfree(constraint_attrs[i].power_limit_attr.attr.name);
211 kfree(constraint_attrs[i].time_window_attr.attr.name);
212 kfree(constraint_attrs[i].name_attr.attr.name);
213 kfree(constraint_attrs[i].max_power_attr.attr.name);
214 kfree(constraint_attrs[i].min_power_attr.attr.name);
215 kfree(constraint_attrs[i].max_time_window_attr.attr.name);
216 kfree(constraint_attrs[i].min_time_window_attr.attr.name);
217 }
218}
219
220static int seed_constraint_attributes(void)
221{
222 int i;
223 int ret;
224
225 for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
226 ret = create_constraint_attribute(i, "power_limit_uw",
227 S_IWUSR | S_IRUGO,
228 &constraint_attrs[i].power_limit_attr,
229 show_constraint_power_limit_uw,
230 store_constraint_power_limit_uw);
231 if (ret)
232 goto err_alloc;
233 ret = create_constraint_attribute(i, "time_window_us",
234 S_IWUSR | S_IRUGO,
235 &constraint_attrs[i].time_window_attr,
236 show_constraint_time_window_us,
237 store_constraint_time_window_us);
238 if (ret)
239 goto err_alloc;
240 ret = create_constraint_attribute(i, "name", S_IRUGO,
241 &constraint_attrs[i].name_attr,
242 show_constraint_name,
243 NULL);
244 if (ret)
245 goto err_alloc;
246 ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO,
247 &constraint_attrs[i].max_power_attr,
248 show_constraint_max_power_uw,
249 NULL);
250 if (ret)
251 goto err_alloc;
252 ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO,
253 &constraint_attrs[i].min_power_attr,
254 show_constraint_min_power_uw,
255 NULL);
256 if (ret)
257 goto err_alloc;
258 ret = create_constraint_attribute(i, "max_time_window_us",
259 S_IRUGO,
260 &constraint_attrs[i].max_time_window_attr,
261 show_constraint_max_time_window_us,
262 NULL);
263 if (ret)
264 goto err_alloc;
265 ret = create_constraint_attribute(i, "min_time_window_us",
266 S_IRUGO,
267 &constraint_attrs[i].min_time_window_attr,
268 show_constraint_min_time_window_us,
269 NULL);
270 if (ret)
271 goto err_alloc;
272
273 }
274
275 return 0;
276
277err_alloc:
278 free_constraint_attributes();
279
280 return ret;
281}
282
283static int create_constraints(struct powercap_zone *power_zone,
284 int nr_constraints,
285 const struct powercap_zone_constraint_ops *const_ops)
286{
287 int i;
288 int ret = 0;
289 int count;
290 struct powercap_zone_constraint *pconst;
291
292 if (!power_zone || !const_ops || !const_ops->get_power_limit_uw ||
293 !const_ops->set_power_limit_uw ||
294 !const_ops->get_time_window_us ||
295 !const_ops->set_time_window_us)
296 return -EINVAL;
297
298 count = power_zone->zone_attr_count;
299 for (i = 0; i < nr_constraints; ++i) {
300 pconst = &power_zone->constraints[i];
301 pconst->ops = const_ops;
302 pconst->id = power_zone->const_id_cnt;
303 power_zone->const_id_cnt++;
304 power_zone->zone_dev_attrs[count++] =
305 &constraint_attrs[i].power_limit_attr.attr;
306 power_zone->zone_dev_attrs[count++] =
307 &constraint_attrs[i].time_window_attr.attr;
308 if (pconst->ops->get_name)
309 power_zone->zone_dev_attrs[count++] =
310 &constraint_attrs[i].name_attr.attr;
311 if (pconst->ops->get_max_power_uw)
312 power_zone->zone_dev_attrs[count++] =
313 &constraint_attrs[i].max_power_attr.attr;
314 if (pconst->ops->get_min_power_uw)
315 power_zone->zone_dev_attrs[count++] =
316 &constraint_attrs[i].min_power_attr.attr;
317 if (pconst->ops->get_max_time_window_us)
318 power_zone->zone_dev_attrs[count++] =
319 &constraint_attrs[i].max_time_window_attr.attr;
320 if (pconst->ops->get_min_time_window_us)
321 power_zone->zone_dev_attrs[count++] =
322 &constraint_attrs[i].min_time_window_attr.attr;
323 }
324 power_zone->zone_attr_count = count;
325
326 return ret;
327}
328
329static bool control_type_valid(void *control_type)
330{
331 struct powercap_control_type *pos = NULL;
332 bool found = false;
333
334 mutex_lock(&powercap_cntrl_list_lock);
335
336 list_for_each_entry(pos, &powercap_cntrl_list, node) {
337 if (pos == control_type) {
338 found = true;
339 break;
340 }
341 }
342 mutex_unlock(&powercap_cntrl_list_lock);
343
344 return found;
345}
346
347static ssize_t name_show(struct device *dev,
348 struct device_attribute *attr,
349 char *buf)
350{
351 struct powercap_zone *power_zone = to_powercap_zone(dev);
352
353 return sprintf(buf, "%s\n", power_zone->name);
354}
355
356static DEVICE_ATTR_RO(name);
357
358/* Create zone and attributes in sysfs */
359static void create_power_zone_common_attributes(
360 struct powercap_zone *power_zone)
361{
362 int count = 0;
363
364 power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr;
365 if (power_zone->ops->get_max_energy_range_uj)
366 power_zone->zone_dev_attrs[count++] =
367 &dev_attr_max_energy_range_uj.attr;
368 if (power_zone->ops->get_energy_uj) {
369 if (power_zone->ops->reset_energy_uj)
370 dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUGO;
371 else
372 dev_attr_energy_uj.attr.mode = S_IRUGO;
373 power_zone->zone_dev_attrs[count++] =
374 &dev_attr_energy_uj.attr;
375 }
376 if (power_zone->ops->get_power_uw)
377 power_zone->zone_dev_attrs[count++] =
378 &dev_attr_power_uw.attr;
379 if (power_zone->ops->get_max_power_range_uw)
380 power_zone->zone_dev_attrs[count++] =
381 &dev_attr_max_power_range_uw.attr;
382 power_zone->zone_dev_attrs[count] = NULL;
383 power_zone->zone_attr_count = count;
384}
385
386static void powercap_release(struct device *dev)
387{
388 bool allocated;
389
390 if (dev->parent) {
391 struct powercap_zone *power_zone = to_powercap_zone(dev);
392
393 /* Store flag as the release() may free memory */
394 allocated = power_zone->allocated;
395 /* Remove id from parent idr struct */
396 idr_remove(power_zone->parent_idr, power_zone->id);
397 /* Destroy idrs allocated for this zone */
398 idr_destroy(&power_zone->idr);
399 kfree(power_zone->name);
400 kfree(power_zone->zone_dev_attrs);
401 kfree(power_zone->constraints);
402 if (power_zone->ops->release)
403 power_zone->ops->release(power_zone);
404 if (allocated)
405 kfree(power_zone);
406 } else {
407 struct powercap_control_type *control_type =
408 to_powercap_control_type(dev);
409
410 /* Store flag as the release() may free memory */
411 allocated = control_type->allocated;
412 idr_destroy(&control_type->idr);
413 mutex_destroy(&control_type->lock);
414 if (control_type->ops && control_type->ops->release)
415 control_type->ops->release(control_type);
416 if (allocated)
417 kfree(control_type);
418 }
419}
420
421static ssize_t enabled_show(struct device *dev,
422 struct device_attribute *attr,
423 char *buf)
424{
425 bool mode = true;
426
427 /* Default is enabled */
428 if (dev->parent) {
429 struct powercap_zone *power_zone = to_powercap_zone(dev);
430 if (power_zone->ops->get_enable)
431 if (power_zone->ops->get_enable(power_zone, &mode))
432 mode = false;
433 } else {
434 struct powercap_control_type *control_type =
435 to_powercap_control_type(dev);
436 if (control_type->ops && control_type->ops->get_enable)
437 if (control_type->ops->get_enable(control_type, &mode))
438 mode = false;
439 }
440
441 return sprintf(buf, "%d\n", mode);
442}
443
444static ssize_t enabled_store(struct device *dev,
445 struct device_attribute *attr,
446 const char *buf, size_t len)
447{
448 bool mode;
449
450 if (strtobool(buf, &mode))
451 return -EINVAL;
452 if (dev->parent) {
453 struct powercap_zone *power_zone = to_powercap_zone(dev);
454 if (power_zone->ops->set_enable)
455 if (!power_zone->ops->set_enable(power_zone, mode))
456 return len;
457 } else {
458 struct powercap_control_type *control_type =
459 to_powercap_control_type(dev);
460 if (control_type->ops && control_type->ops->set_enable)
461 if (!control_type->ops->set_enable(control_type, mode))
462 return len;
463 }
464
465 return -ENOSYS;
466}
467
468static DEVICE_ATTR_RW(enabled);
469
470static struct attribute *powercap_attrs[] = {
471 &dev_attr_enabled.attr,
472 NULL,
473};
474ATTRIBUTE_GROUPS(powercap);
475
476static struct class powercap_class = {
477 .name = "powercap",
478 .dev_release = powercap_release,
479 .dev_groups = powercap_groups,
480};
481
482struct powercap_zone *powercap_register_zone(
483 struct powercap_zone *power_zone,
484 struct powercap_control_type *control_type,
485 const char *name,
486 struct powercap_zone *parent,
487 const struct powercap_zone_ops *ops,
488 int nr_constraints,
489 const struct powercap_zone_constraint_ops *const_ops)
490{
491 int result;
492 int nr_attrs;
493
494 if (!name || !control_type || !ops ||
495 nr_constraints > MAX_CONSTRAINTS_PER_ZONE ||
496 (!ops->get_energy_uj && !ops->get_power_uw) ||
497 !control_type_valid(control_type))
498 return ERR_PTR(-EINVAL);
499
500 if (power_zone) {
501 if (!ops->release)
502 return ERR_PTR(-EINVAL);
503 memset(power_zone, 0, sizeof(*power_zone));
504 } else {
505 power_zone = kzalloc(sizeof(*power_zone), GFP_KERNEL);
506 if (!power_zone)
507 return ERR_PTR(-ENOMEM);
508 power_zone->allocated = true;
509 }
510 power_zone->ops = ops;
511 power_zone->control_type_inst = control_type;
512 if (!parent) {
513 power_zone->dev.parent = &control_type->dev;
514 power_zone->parent_idr = &control_type->idr;
515 } else {
516 power_zone->dev.parent = &parent->dev;
517 power_zone->parent_idr = &parent->idr;
518 }
519 power_zone->dev.class = &powercap_class;
520
521 mutex_lock(&control_type->lock);
522 /* Using idr to get the unique id */
523 result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL);
524 if (result < 0)
525 goto err_idr_alloc;
526
527 power_zone->id = result;
528 idr_init(&power_zone->idr);
529 result = -ENOMEM;
530 power_zone->name = kstrdup(name, GFP_KERNEL);
531 if (!power_zone->name)
532 goto err_name_alloc;
533 dev_set_name(&power_zone->dev, "%s:%x",
534 dev_name(power_zone->dev.parent),
535 power_zone->id);
536 power_zone->constraints = kcalloc(nr_constraints,
537 sizeof(*power_zone->constraints),
538 GFP_KERNEL);
539 if (!power_zone->constraints)
540 goto err_const_alloc;
541
542 nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
543 POWERCAP_ZONE_MAX_ATTRS + 1;
544 power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *),
545 GFP_KERNEL);
546 if (!power_zone->zone_dev_attrs)
547 goto err_attr_alloc;
548 create_power_zone_common_attributes(power_zone);
549 result = create_constraints(power_zone, nr_constraints, const_ops);
550 if (result)
551 goto err_dev_ret;
552
553 power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
554 power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
555 power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
556 power_zone->dev_attr_groups[1] = NULL;
557 power_zone->dev.groups = power_zone->dev_attr_groups;
558 result = device_register(&power_zone->dev);
559 if (result)
560 goto err_dev_ret;
561
562 control_type->nr_zones++;
563 mutex_unlock(&control_type->lock);
564
565 return power_zone;
566
567err_dev_ret:
568 kfree(power_zone->zone_dev_attrs);
569err_attr_alloc:
570 kfree(power_zone->constraints);
571err_const_alloc:
572 kfree(power_zone->name);
573err_name_alloc:
574 idr_remove(power_zone->parent_idr, power_zone->id);
575err_idr_alloc:
576 if (power_zone->allocated)
577 kfree(power_zone);
578 mutex_unlock(&control_type->lock);
579
580 return ERR_PTR(result);
581}
582EXPORT_SYMBOL_GPL(powercap_register_zone);
583
584int powercap_unregister_zone(struct powercap_control_type *control_type,
585 struct powercap_zone *power_zone)
586{
587 if (!power_zone || !control_type)
588 return -EINVAL;
589
590 mutex_lock(&control_type->lock);
591 control_type->nr_zones--;
592 mutex_unlock(&control_type->lock);
593
594 device_unregister(&power_zone->dev);
595
596 return 0;
597}
598EXPORT_SYMBOL_GPL(powercap_unregister_zone);
599
600struct powercap_control_type *powercap_register_control_type(
601 struct powercap_control_type *control_type,
602 const char *name,
603 const struct powercap_control_type_ops *ops)
604{
605 int result;
606
607 if (!name)
608 return ERR_PTR(-EINVAL);
609 if (control_type) {
610 if (!ops || !ops->release)
611 return ERR_PTR(-EINVAL);
612 memset(control_type, 0, sizeof(*control_type));
613 } else {
614 control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
615 if (!control_type)
616 return ERR_PTR(-ENOMEM);
617 control_type->allocated = true;
618 }
619 mutex_init(&control_type->lock);
620 control_type->ops = ops;
621 INIT_LIST_HEAD(&control_type->node);
622 control_type->dev.class = &powercap_class;
623 dev_set_name(&control_type->dev, "%s", name);
624 result = device_register(&control_type->dev);
625 if (result) {
626 if (control_type->allocated)
627 kfree(control_type);
628 return ERR_PTR(result);
629 }
630 idr_init(&control_type->idr);
631
632 mutex_lock(&powercap_cntrl_list_lock);
633 list_add_tail(&control_type->node, &powercap_cntrl_list);
634 mutex_unlock(&powercap_cntrl_list_lock);
635
636 return control_type;
637}
638EXPORT_SYMBOL_GPL(powercap_register_control_type);
639
640int powercap_unregister_control_type(struct powercap_control_type *control_type)
641{
642 struct powercap_control_type *pos = NULL;
643
644 if (control_type->nr_zones) {
645 dev_err(&control_type->dev, "Zones of this type still not freed\n");
646 return -EINVAL;
647 }
648 mutex_lock(&powercap_cntrl_list_lock);
649 list_for_each_entry(pos, &powercap_cntrl_list, node) {
650 if (pos == control_type) {
651 list_del(&control_type->node);
652 mutex_unlock(&powercap_cntrl_list_lock);
653 device_unregister(&control_type->dev);
654 return 0;
655 }
656 }
657 mutex_unlock(&powercap_cntrl_list_lock);
658
659 return -ENODEV;
660}
661EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
662
663static int __init powercap_init(void)
664{
665 int result;
666
667 result = seed_constraint_attributes();
668 if (result)
669 return result;
670
671 return class_register(&powercap_class);
672}
673
674fs_initcall(powercap_init);
675
676MODULE_DESCRIPTION("PowerCap sysfs Driver");
677MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
678MODULE_LICENSE("GPL v2");