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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/kstrtox.h>
11#include <linux/slab.h>
12#include <linux/powercap.h>
13
14#define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
15#define to_powercap_control_type(n) \
16 container_of(n, struct powercap_control_type, dev)
17
18/* Power zone show function */
19#define define_power_zone_show(_attr) \
20static ssize_t _attr##_show(struct device *dev, \
21 struct device_attribute *dev_attr,\
22 char *buf) \
23{ \
24 u64 value; \
25 ssize_t len = -EINVAL; \
26 struct powercap_zone *power_zone = to_powercap_zone(dev); \
27 \
28 if (power_zone->ops->get_##_attr) { \
29 if (!power_zone->ops->get_##_attr(power_zone, &value)) \
30 len = sysfs_emit(buf, "%lld\n", value); \
31 } \
32 \
33 return len; \
34}
35
36/* The only meaningful input is 0 (reset), others are silently ignored */
37#define define_power_zone_store(_attr) \
38static ssize_t _attr##_store(struct device *dev,\
39 struct device_attribute *dev_attr, \
40 const char *buf, size_t count) \
41{ \
42 int err; \
43 struct powercap_zone *power_zone = to_powercap_zone(dev); \
44 u64 value; \
45 \
46 err = kstrtoull(buf, 10, &value); \
47 if (err) \
48 return -EINVAL; \
49 if (value) \
50 return count; \
51 if (power_zone->ops->reset_##_attr) { \
52 if (!power_zone->ops->reset_##_attr(power_zone)) \
53 return count; \
54 } \
55 \
56 return -EINVAL; \
57}
58
59/* Power zone constraint show function */
60#define define_power_zone_constraint_show(_attr) \
61static ssize_t show_constraint_##_attr(struct device *dev, \
62 struct device_attribute *dev_attr,\
63 char *buf) \
64{ \
65 u64 value; \
66 ssize_t len = -ENODATA; \
67 struct powercap_zone *power_zone = to_powercap_zone(dev); \
68 int id; \
69 struct powercap_zone_constraint *pconst;\
70 \
71 if (sscanf(dev_attr->attr.name, "constraint_%d_", &id) != 1) \
72 return -EINVAL; \
73 if (id >= power_zone->const_id_cnt) \
74 return -EINVAL; \
75 pconst = &power_zone->constraints[id]; \
76 if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
77 if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
78 len = sysfs_emit(buf, "%lld\n", value); \
79 } \
80 \
81 return len; \
82}
83
84/* Power zone constraint store function */
85#define define_power_zone_constraint_store(_attr) \
86static ssize_t store_constraint_##_attr(struct device *dev,\
87 struct device_attribute *dev_attr, \
88 const char *buf, size_t count) \
89{ \
90 int err; \
91 u64 value; \
92 struct powercap_zone *power_zone = to_powercap_zone(dev); \
93 int id; \
94 struct powercap_zone_constraint *pconst;\
95 \
96 if (sscanf(dev_attr->attr.name, "constraint_%d_", &id) != 1) \
97 return -EINVAL; \
98 if (id >= power_zone->const_id_cnt) \
99 return -EINVAL; \
100 pconst = &power_zone->constraints[id]; \
101 err = kstrtoull(buf, 10, &value); \
102 if (err) \
103 return -EINVAL; \
104 if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
105 if (!pconst->ops->set_##_attr(power_zone, id, value)) \
106 return count; \
107 } \
108 \
109 return -ENODATA; \
110}
111
112/* Power zone information callbacks */
113define_power_zone_show(power_uw);
114define_power_zone_show(max_power_range_uw);
115define_power_zone_show(energy_uj);
116define_power_zone_store(energy_uj);
117define_power_zone_show(max_energy_range_uj);
118
119/* Power zone attributes */
120static DEVICE_ATTR_RO(max_power_range_uw);
121static DEVICE_ATTR_RO(power_uw);
122static DEVICE_ATTR_RO(max_energy_range_uj);
123static DEVICE_ATTR_RW(energy_uj);
124
125/* Power zone constraint attributes callbacks */
126define_power_zone_constraint_show(power_limit_uw);
127define_power_zone_constraint_store(power_limit_uw);
128define_power_zone_constraint_show(time_window_us);
129define_power_zone_constraint_store(time_window_us);
130define_power_zone_constraint_show(max_power_uw);
131define_power_zone_constraint_show(min_power_uw);
132define_power_zone_constraint_show(max_time_window_us);
133define_power_zone_constraint_show(min_time_window_us);
134
135/* For one time seeding of constraint device attributes */
136struct powercap_constraint_attr {
137 struct device_attribute power_limit_attr;
138 struct device_attribute time_window_attr;
139 struct device_attribute max_power_attr;
140 struct device_attribute min_power_attr;
141 struct device_attribute max_time_window_attr;
142 struct device_attribute min_time_window_attr;
143 struct device_attribute name_attr;
144};
145
146static struct powercap_constraint_attr
147 constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
148
149/* A list of powercap control_types */
150static LIST_HEAD(powercap_cntrl_list);
151/* Mutex to protect list of powercap control_types */
152static DEFINE_MUTEX(powercap_cntrl_list_lock);
153
154#define POWERCAP_CONSTRAINT_NAME_LEN 30 /* Some limit to avoid overflow */
155static ssize_t show_constraint_name(struct device *dev,
156 struct device_attribute *dev_attr,
157 char *buf)
158{
159 const char *name;
160 struct powercap_zone *power_zone = to_powercap_zone(dev);
161 int id;
162 ssize_t len = -ENODATA;
163 struct powercap_zone_constraint *pconst;
164
165 if (sscanf(dev_attr->attr.name, "constraint_%d_", &id) != 1)
166 return -EINVAL;
167 if (id >= power_zone->const_id_cnt)
168 return -EINVAL;
169 pconst = &power_zone->constraints[id];
170
171 if (pconst && pconst->ops && pconst->ops->get_name) {
172 name = pconst->ops->get_name(power_zone, id);
173 if (name) {
174 len = sysfs_emit(buf, "%.*s\n",
175 POWERCAP_CONSTRAINT_NAME_LEN - 1, name);
176 }
177 }
178
179 return len;
180}
181
182static int create_constraint_attribute(int id, const char *name,
183 int mode,
184 struct device_attribute *dev_attr,
185 ssize_t (*show)(struct device *,
186 struct device_attribute *, char *),
187 ssize_t (*store)(struct device *,
188 struct device_attribute *,
189 const char *, size_t)
190 )
191{
192
193 dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s",
194 id, name);
195 if (!dev_attr->attr.name)
196 return -ENOMEM;
197 dev_attr->attr.mode = mode;
198 dev_attr->show = show;
199 dev_attr->store = store;
200
201 return 0;
202}
203
204static void free_constraint_attributes(void)
205{
206 int i;
207
208 for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
209 kfree(constraint_attrs[i].power_limit_attr.attr.name);
210 kfree(constraint_attrs[i].time_window_attr.attr.name);
211 kfree(constraint_attrs[i].name_attr.attr.name);
212 kfree(constraint_attrs[i].max_power_attr.attr.name);
213 kfree(constraint_attrs[i].min_power_attr.attr.name);
214 kfree(constraint_attrs[i].max_time_window_attr.attr.name);
215 kfree(constraint_attrs[i].min_time_window_attr.attr.name);
216 }
217}
218
219static int seed_constraint_attributes(void)
220{
221 int i;
222 int ret;
223
224 for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
225 ret = create_constraint_attribute(i, "power_limit_uw",
226 S_IWUSR | S_IRUGO,
227 &constraint_attrs[i].power_limit_attr,
228 show_constraint_power_limit_uw,
229 store_constraint_power_limit_uw);
230 if (ret)
231 goto err_alloc;
232 ret = create_constraint_attribute(i, "time_window_us",
233 S_IWUSR | S_IRUGO,
234 &constraint_attrs[i].time_window_attr,
235 show_constraint_time_window_us,
236 store_constraint_time_window_us);
237 if (ret)
238 goto err_alloc;
239 ret = create_constraint_attribute(i, "name", S_IRUGO,
240 &constraint_attrs[i].name_attr,
241 show_constraint_name,
242 NULL);
243 if (ret)
244 goto err_alloc;
245 ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO,
246 &constraint_attrs[i].max_power_attr,
247 show_constraint_max_power_uw,
248 NULL);
249 if (ret)
250 goto err_alloc;
251 ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO,
252 &constraint_attrs[i].min_power_attr,
253 show_constraint_min_power_uw,
254 NULL);
255 if (ret)
256 goto err_alloc;
257 ret = create_constraint_attribute(i, "max_time_window_us",
258 S_IRUGO,
259 &constraint_attrs[i].max_time_window_attr,
260 show_constraint_max_time_window_us,
261 NULL);
262 if (ret)
263 goto err_alloc;
264 ret = create_constraint_attribute(i, "min_time_window_us",
265 S_IRUGO,
266 &constraint_attrs[i].min_time_window_attr,
267 show_constraint_min_time_window_us,
268 NULL);
269 if (ret)
270 goto err_alloc;
271
272 }
273
274 return 0;
275
276err_alloc:
277 free_constraint_attributes();
278
279 return ret;
280}
281
282static int create_constraints(struct powercap_zone *power_zone,
283 int nr_constraints,
284 const struct powercap_zone_constraint_ops *const_ops)
285{
286 int i;
287 int ret = 0;
288 int count;
289 struct powercap_zone_constraint *pconst;
290
291 if (!power_zone || !const_ops || !const_ops->get_power_limit_uw ||
292 !const_ops->set_power_limit_uw ||
293 !const_ops->get_time_window_us ||
294 !const_ops->set_time_window_us)
295 return -EINVAL;
296
297 count = power_zone->zone_attr_count;
298 for (i = 0; i < nr_constraints; ++i) {
299 pconst = &power_zone->constraints[i];
300 pconst->ops = const_ops;
301 pconst->id = power_zone->const_id_cnt;
302 power_zone->const_id_cnt++;
303 power_zone->zone_dev_attrs[count++] =
304 &constraint_attrs[i].power_limit_attr.attr;
305 power_zone->zone_dev_attrs[count++] =
306 &constraint_attrs[i].time_window_attr.attr;
307 if (pconst->ops->get_name)
308 power_zone->zone_dev_attrs[count++] =
309 &constraint_attrs[i].name_attr.attr;
310 if (pconst->ops->get_max_power_uw)
311 power_zone->zone_dev_attrs[count++] =
312 &constraint_attrs[i].max_power_attr.attr;
313 if (pconst->ops->get_min_power_uw)
314 power_zone->zone_dev_attrs[count++] =
315 &constraint_attrs[i].min_power_attr.attr;
316 if (pconst->ops->get_max_time_window_us)
317 power_zone->zone_dev_attrs[count++] =
318 &constraint_attrs[i].max_time_window_attr.attr;
319 if (pconst->ops->get_min_time_window_us)
320 power_zone->zone_dev_attrs[count++] =
321 &constraint_attrs[i].min_time_window_attr.attr;
322 }
323 power_zone->zone_attr_count = count;
324
325 return ret;
326}
327
328static bool control_type_valid(void *control_type)
329{
330 struct powercap_control_type *pos = NULL;
331 bool found = false;
332
333 mutex_lock(&powercap_cntrl_list_lock);
334
335 list_for_each_entry(pos, &powercap_cntrl_list, node) {
336 if (pos == control_type) {
337 found = true;
338 break;
339 }
340 }
341 mutex_unlock(&powercap_cntrl_list_lock);
342
343 return found;
344}
345
346static ssize_t name_show(struct device *dev,
347 struct device_attribute *attr,
348 char *buf)
349{
350 struct powercap_zone *power_zone = to_powercap_zone(dev);
351
352 return sysfs_emit(buf, "%s\n", power_zone->name);
353}
354
355static DEVICE_ATTR_RO(name);
356
357/* Create zone and attributes in sysfs */
358static void create_power_zone_common_attributes(
359 struct powercap_zone *power_zone)
360{
361 int count = 0;
362
363 power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr;
364 if (power_zone->ops->get_max_energy_range_uj)
365 power_zone->zone_dev_attrs[count++] =
366 &dev_attr_max_energy_range_uj.attr;
367 if (power_zone->ops->get_energy_uj) {
368 if (power_zone->ops->reset_energy_uj)
369 dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUSR;
370 else
371 dev_attr_energy_uj.attr.mode = S_IRUSR;
372 power_zone->zone_dev_attrs[count++] =
373 &dev_attr_energy_uj.attr;
374 }
375 if (power_zone->ops->get_power_uw)
376 power_zone->zone_dev_attrs[count++] =
377 &dev_attr_power_uw.attr;
378 if (power_zone->ops->get_max_power_range_uw)
379 power_zone->zone_dev_attrs[count++] =
380 &dev_attr_max_power_range_uw.attr;
381 power_zone->zone_dev_attrs[count] = NULL;
382 power_zone->zone_attr_count = count;
383}
384
385static void powercap_release(struct device *dev)
386{
387 bool allocated;
388
389 if (dev->parent) {
390 struct powercap_zone *power_zone = to_powercap_zone(dev);
391
392 /* Store flag as the release() may free memory */
393 allocated = power_zone->allocated;
394 /* Remove id from parent idr struct */
395 idr_remove(power_zone->parent_idr, power_zone->id);
396 /* Destroy idrs allocated for this zone */
397 idr_destroy(&power_zone->idr);
398 kfree(power_zone->name);
399 kfree(power_zone->zone_dev_attrs);
400 kfree(power_zone->constraints);
401 if (power_zone->ops->release)
402 power_zone->ops->release(power_zone);
403 if (allocated)
404 kfree(power_zone);
405 } else {
406 struct powercap_control_type *control_type =
407 to_powercap_control_type(dev);
408
409 /* Store flag as the release() may free memory */
410 allocated = control_type->allocated;
411 idr_destroy(&control_type->idr);
412 mutex_destroy(&control_type->lock);
413 if (control_type->ops && control_type->ops->release)
414 control_type->ops->release(control_type);
415 if (allocated)
416 kfree(control_type);
417 }
418}
419
420static ssize_t enabled_show(struct device *dev,
421 struct device_attribute *attr,
422 char *buf)
423{
424 bool mode = true;
425
426 /* Default is enabled */
427 if (dev->parent) {
428 struct powercap_zone *power_zone = to_powercap_zone(dev);
429 if (power_zone->ops->get_enable)
430 if (power_zone->ops->get_enable(power_zone, &mode))
431 mode = false;
432 } else {
433 struct powercap_control_type *control_type =
434 to_powercap_control_type(dev);
435 if (control_type->ops && control_type->ops->get_enable)
436 if (control_type->ops->get_enable(control_type, &mode))
437 mode = false;
438 }
439
440 return sysfs_emit(buf, "%d\n", mode);
441}
442
443static ssize_t enabled_store(struct device *dev,
444 struct device_attribute *attr,
445 const char *buf, size_t len)
446{
447 bool mode;
448
449 if (kstrtobool(buf, &mode))
450 return -EINVAL;
451 if (dev->parent) {
452 struct powercap_zone *power_zone = to_powercap_zone(dev);
453 if (power_zone->ops->set_enable)
454 if (!power_zone->ops->set_enable(power_zone, mode))
455 return len;
456 } else {
457 struct powercap_control_type *control_type =
458 to_powercap_control_type(dev);
459 if (control_type->ops && control_type->ops->set_enable)
460 if (!control_type->ops->set_enable(control_type, mode))
461 return len;
462 }
463
464 return -ENOSYS;
465}
466
467static DEVICE_ATTR_RW(enabled);
468
469static struct attribute *powercap_attrs[] = {
470 &dev_attr_enabled.attr,
471 NULL,
472};
473ATTRIBUTE_GROUPS(powercap);
474
475static struct class powercap_class = {
476 .name = "powercap",
477 .dev_release = powercap_release,
478 .dev_groups = powercap_groups,
479};
480
481struct powercap_zone *powercap_register_zone(
482 struct powercap_zone *power_zone,
483 struct powercap_control_type *control_type,
484 const char *name,
485 struct powercap_zone *parent,
486 const struct powercap_zone_ops *ops,
487 int nr_constraints,
488 const struct powercap_zone_constraint_ops *const_ops)
489{
490 int result;
491 int nr_attrs;
492
493 if (!name || !control_type || !ops ||
494 nr_constraints > MAX_CONSTRAINTS_PER_ZONE ||
495 (!ops->get_energy_uj && !ops->get_power_uw) ||
496 !control_type_valid(control_type))
497 return ERR_PTR(-EINVAL);
498
499 if (power_zone) {
500 if (!ops->release)
501 return ERR_PTR(-EINVAL);
502 memset(power_zone, 0, sizeof(*power_zone));
503 } else {
504 power_zone = kzalloc_obj(*power_zone);
505 if (!power_zone)
506 return ERR_PTR(-ENOMEM);
507 power_zone->allocated = true;
508 }
509 power_zone->ops = ops;
510 power_zone->control_type_inst = control_type;
511 if (!parent) {
512 power_zone->dev.parent = &control_type->dev;
513 power_zone->parent_idr = &control_type->idr;
514 } else {
515 power_zone->dev.parent = &parent->dev;
516 power_zone->parent_idr = &parent->idr;
517 }
518 power_zone->dev.class = &powercap_class;
519
520 mutex_lock(&control_type->lock);
521 /* Using idr to get the unique id */
522 result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL);
523 if (result < 0)
524 goto err_idr_alloc;
525
526 power_zone->id = result;
527 idr_init(&power_zone->idr);
528 result = -ENOMEM;
529 power_zone->name = kstrdup(name, GFP_KERNEL);
530 if (!power_zone->name)
531 goto err_name_alloc;
532 power_zone->constraints = kzalloc_objs(*power_zone->constraints,
533 nr_constraints);
534 if (!power_zone->constraints)
535 goto err_const_alloc;
536
537 nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
538 POWERCAP_ZONE_MAX_ATTRS + 1;
539 power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *),
540 GFP_KERNEL);
541 if (!power_zone->zone_dev_attrs)
542 goto err_attr_alloc;
543 create_power_zone_common_attributes(power_zone);
544 result = create_constraints(power_zone, nr_constraints, const_ops);
545 if (result)
546 goto err_dev_ret;
547
548 power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
549 power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
550 power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
551 power_zone->dev_attr_groups[1] = NULL;
552 power_zone->dev.groups = power_zone->dev_attr_groups;
553 dev_set_name(&power_zone->dev, "%s:%x",
554 dev_name(power_zone->dev.parent),
555 power_zone->id);
556 result = device_register(&power_zone->dev);
557 if (result) {
558 put_device(&power_zone->dev);
559 mutex_unlock(&control_type->lock);
560
561 return ERR_PTR(result);
562 }
563
564 control_type->nr_zones++;
565 mutex_unlock(&control_type->lock);
566
567 return power_zone;
568
569err_dev_ret:
570 kfree(power_zone->zone_dev_attrs);
571err_attr_alloc:
572 kfree(power_zone->constraints);
573err_const_alloc:
574 kfree(power_zone->name);
575err_name_alloc:
576 idr_remove(power_zone->parent_idr, power_zone->id);
577err_idr_alloc:
578 if (power_zone->allocated)
579 kfree(power_zone);
580 mutex_unlock(&control_type->lock);
581
582 return ERR_PTR(result);
583}
584EXPORT_SYMBOL_GPL(powercap_register_zone);
585
586int powercap_unregister_zone(struct powercap_control_type *control_type,
587 struct powercap_zone *power_zone)
588{
589 if (!power_zone || !control_type)
590 return -EINVAL;
591
592 mutex_lock(&control_type->lock);
593 control_type->nr_zones--;
594 mutex_unlock(&control_type->lock);
595
596 device_unregister(&power_zone->dev);
597
598 return 0;
599}
600EXPORT_SYMBOL_GPL(powercap_unregister_zone);
601
602struct powercap_control_type *powercap_register_control_type(
603 struct powercap_control_type *control_type,
604 const char *name,
605 const struct powercap_control_type_ops *ops)
606{
607 int result;
608
609 if (!name)
610 return ERR_PTR(-EINVAL);
611 if (control_type) {
612 if (!ops || !ops->release)
613 return ERR_PTR(-EINVAL);
614 memset(control_type, 0, sizeof(*control_type));
615 } else {
616 control_type = kzalloc_obj(*control_type);
617 if (!control_type)
618 return ERR_PTR(-ENOMEM);
619 control_type->allocated = true;
620 }
621 mutex_init(&control_type->lock);
622 control_type->ops = ops;
623 INIT_LIST_HEAD(&control_type->node);
624 control_type->dev.class = &powercap_class;
625 dev_set_name(&control_type->dev, "%s", name);
626 idr_init(&control_type->idr);
627
628 mutex_lock(&powercap_cntrl_list_lock);
629 list_add_tail(&control_type->node, &powercap_cntrl_list);
630 mutex_unlock(&powercap_cntrl_list_lock);
631
632 result = device_register(&control_type->dev);
633 if (result) {
634 mutex_lock(&powercap_cntrl_list_lock);
635 list_del(&control_type->node);
636 mutex_unlock(&powercap_cntrl_list_lock);
637
638 idr_destroy(&control_type->idr);
639 put_device(&control_type->dev);
640 return ERR_PTR(result);
641 }
642
643 return control_type;
644}
645EXPORT_SYMBOL_GPL(powercap_register_control_type);
646
647int powercap_unregister_control_type(struct powercap_control_type *control_type)
648{
649 struct powercap_control_type *pos = NULL;
650
651 if (control_type->nr_zones) {
652 dev_err(&control_type->dev, "Zones of this type still not freed\n");
653 return -EINVAL;
654 }
655 mutex_lock(&powercap_cntrl_list_lock);
656 list_for_each_entry(pos, &powercap_cntrl_list, node) {
657 if (pos == control_type) {
658 list_del(&control_type->node);
659 mutex_unlock(&powercap_cntrl_list_lock);
660 device_unregister(&control_type->dev);
661 return 0;
662 }
663 }
664 mutex_unlock(&powercap_cntrl_list_lock);
665
666 return -ENODEV;
667}
668EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
669
670static int __init powercap_init(void)
671{
672 int result;
673
674 result = seed_constraint_attributes();
675 if (result)
676 return result;
677
678 return class_register(&powercap_class);
679}
680
681fs_initcall(powercap_init);
682
683MODULE_DESCRIPTION("PowerCap sysfs Driver");
684MODULE_AUTHOR("Srinivas Pandruvada <[email protected]>");