1/*
2 * Power capping class
3 * Copyright (c) 2013, Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.
16 *
17 */
18
19#include <linux/module.h>
20#include <linux/device.h>
21#include <linux/err.h>
22#include <linux/slab.h>
23#include <linux/powercap.h>
24
25#define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
26#define to_powercap_control_type(n) \
27			container_of(n, struct powercap_control_type, dev)
28
29/* Power zone show function */
30#define define_power_zone_show(_attr)		\
31static ssize_t _attr##_show(struct device *dev, \
32					struct device_attribute *dev_attr,\
33					char *buf) \
34{ \
35	u64 value; \
36	ssize_t len = -EINVAL; \
37	struct powercap_zone *power_zone = to_powercap_zone(dev); \
38	\
39	if (power_zone->ops->get_##_attr) { \
40		if (!power_zone->ops->get_##_attr(power_zone, &value)) \
41			len = sprintf(buf, "%lld\n", value); \
42	} \
43	\
44	return len; \
45}
46
47/* The only meaningful input is 0 (reset), others are silently ignored */
48#define define_power_zone_store(_attr)		\
49static ssize_t _attr##_store(struct device *dev,\
50				struct device_attribute *dev_attr, \
51				const char *buf, size_t count) \
52{ \
53	int err; \
54	struct powercap_zone *power_zone = to_powercap_zone(dev); \
55	u64 value; \
56	\
57	err = kstrtoull(buf, 10, &value); \
58	if (err) \
59		return -EINVAL; \
60	if (value) \
61		return count; \
62	if (power_zone->ops->reset_##_attr) { \
63		if (!power_zone->ops->reset_##_attr(power_zone)) \
64			return count; \
65	} \
66	\
67	return -EINVAL; \
68}
69
70/* Power zone constraint show function */
71#define define_power_zone_constraint_show(_attr) \
72static ssize_t show_constraint_##_attr(struct device *dev, \
73				struct device_attribute *dev_attr,\
74				char *buf) \
75{ \
76	u64 value; \
77	ssize_t len = -ENODATA; \
78	struct powercap_zone *power_zone = to_powercap_zone(dev); \
79	int id; \
80	struct powercap_zone_constraint *pconst;\
81	\
82	if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
83		return -EINVAL; \
84	if (id >= power_zone->const_id_cnt)	\
85		return -EINVAL; \
86	pconst = &power_zone->constraints[id]; \
87	if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
88		if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
89			len = sprintf(buf, "%lld\n", value); \
90	} \
91	\
92	return len; \
93}
94
95/* Power zone constraint store function */
96#define define_power_zone_constraint_store(_attr) \
97static ssize_t store_constraint_##_attr(struct device *dev,\
98				struct device_attribute *dev_attr, \
99				const char *buf, size_t count) \
100{ \
101	int err; \
102	u64 value; \
103	struct powercap_zone *power_zone = to_powercap_zone(dev); \
104	int id; \
105	struct powercap_zone_constraint *pconst;\
106	\
107	if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
108		return -EINVAL; \
109	if (id >= power_zone->const_id_cnt)	\
110		return -EINVAL; \
111	pconst = &power_zone->constraints[id]; \
112	err = kstrtoull(buf, 10, &value); \
113	if (err) \
114		return -EINVAL; \
115	if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
116		if (!pconst->ops->set_##_attr(power_zone, id, value)) \
117			return count; \
118	} \
119	\
120	return -ENODATA; \
121}
122
123/* Power zone information callbacks */
124define_power_zone_show(power_uw);
125define_power_zone_show(max_power_range_uw);
126define_power_zone_show(energy_uj);
127define_power_zone_store(energy_uj);
128define_power_zone_show(max_energy_range_uj);
129
130/* Power zone attributes */
131static DEVICE_ATTR_RO(max_power_range_uw);
132static DEVICE_ATTR_RO(power_uw);
133static DEVICE_ATTR_RO(max_energy_range_uj);
134static DEVICE_ATTR_RW(energy_uj);
135
136/* Power zone constraint attributes callbacks */
137define_power_zone_constraint_show(power_limit_uw);
138define_power_zone_constraint_store(power_limit_uw);
139define_power_zone_constraint_show(time_window_us);
140define_power_zone_constraint_store(time_window_us);
141define_power_zone_constraint_show(max_power_uw);
142define_power_zone_constraint_show(min_power_uw);
143define_power_zone_constraint_show(max_time_window_us);
144define_power_zone_constraint_show(min_time_window_us);
145
146/* For one time seeding of constraint device attributes */
147struct powercap_constraint_attr {
148	struct device_attribute power_limit_attr;
149	struct device_attribute time_window_attr;
150	struct device_attribute max_power_attr;
151	struct device_attribute min_power_attr;
152	struct device_attribute max_time_window_attr;
153	struct device_attribute min_time_window_attr;
154	struct device_attribute name_attr;
155};
156
157static struct powercap_constraint_attr
158				constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
159
160/* A list of powercap control_types */
161static LIST_HEAD(powercap_cntrl_list);
162/* Mutex to protect list of powercap control_types */
163static DEFINE_MUTEX(powercap_cntrl_list_lock);
164
165#define POWERCAP_CONSTRAINT_NAME_LEN	30 /* Some limit to avoid overflow */
166static ssize_t show_constraint_name(struct device *dev,
167				struct device_attribute *dev_attr,
168				char *buf)
169{
170	const char *name;
171	struct powercap_zone *power_zone = to_powercap_zone(dev);
172	int id;
173	ssize_t len = -ENODATA;
174	struct powercap_zone_constraint *pconst;
175
176	if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id))
177		return -EINVAL;
178	if (id >= power_zone->const_id_cnt)
179		return -EINVAL;
180	pconst = &power_zone->constraints[id];
181
182	if (pconst && pconst->ops && pconst->ops->get_name) {
183		name = pconst->ops->get_name(power_zone, id);
184		if (name) {
185			snprintf(buf, POWERCAP_CONSTRAINT_NAME_LEN,
186								"%s\n", name);
187			buf[POWERCAP_CONSTRAINT_NAME_LEN] = '\0';
188			len = strlen(buf);
189		}
190	}
191
192	return len;
193}
194
195static int create_constraint_attribute(int id, const char *name,
196				int mode,
197				struct device_attribute *dev_attr,
198				ssize_t (*show)(struct device *,
199					struct device_attribute *, char *),
200				ssize_t (*store)(struct device *,
201					struct device_attribute *,
202				const char *, size_t)
203				)
204{
205
206	dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s",
207								id, name);
208	if (!dev_attr->attr.name)
209		return -ENOMEM;
210	dev_attr->attr.mode = mode;
211	dev_attr->show = show;
212	dev_attr->store = store;
213
214	return 0;
215}
216
217static void free_constraint_attributes(void)
218{
219	int i;
220
221	for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
222		kfree(constraint_attrs[i].power_limit_attr.attr.name);
223		kfree(constraint_attrs[i].time_window_attr.attr.name);
224		kfree(constraint_attrs[i].name_attr.attr.name);
225		kfree(constraint_attrs[i].max_power_attr.attr.name);
226		kfree(constraint_attrs[i].min_power_attr.attr.name);
227		kfree(constraint_attrs[i].max_time_window_attr.attr.name);
228		kfree(constraint_attrs[i].min_time_window_attr.attr.name);
229	}
230}
231
232static int seed_constraint_attributes(void)
233{
234	int i;
235	int ret;
236
237	for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
238		ret = create_constraint_attribute(i, "power_limit_uw",
239					S_IWUSR | S_IRUGO,
240					&constraint_attrs[i].power_limit_attr,
241					show_constraint_power_limit_uw,
242					store_constraint_power_limit_uw);
243		if (ret)
244			goto err_alloc;
245		ret = create_constraint_attribute(i, "time_window_us",
246					S_IWUSR | S_IRUGO,
247					&constraint_attrs[i].time_window_attr,
248					show_constraint_time_window_us,
249					store_constraint_time_window_us);
250		if (ret)
251			goto err_alloc;
252		ret = create_constraint_attribute(i, "name", S_IRUGO,
253				&constraint_attrs[i].name_attr,
254				show_constraint_name,
255				NULL);
256		if (ret)
257			goto err_alloc;
258		ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO,
259				&constraint_attrs[i].max_power_attr,
260				show_constraint_max_power_uw,
261				NULL);
262		if (ret)
263			goto err_alloc;
264		ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO,
265				&constraint_attrs[i].min_power_attr,
266				show_constraint_min_power_uw,
267				NULL);
268		if (ret)
269			goto err_alloc;
270		ret = create_constraint_attribute(i, "max_time_window_us",
271				S_IRUGO,
272				&constraint_attrs[i].max_time_window_attr,
273				show_constraint_max_time_window_us,
274				NULL);
275		if (ret)
276			goto err_alloc;
277		ret = create_constraint_attribute(i, "min_time_window_us",
278				S_IRUGO,
279				&constraint_attrs[i].min_time_window_attr,
280				show_constraint_min_time_window_us,
281				NULL);
282		if (ret)
283			goto err_alloc;
284
285	}
286
287	return 0;
288
289err_alloc:
290	free_constraint_attributes();
291
292	return ret;
293}
294
295static int create_constraints(struct powercap_zone *power_zone,
296				int nr_constraints,
297				struct powercap_zone_constraint_ops *const_ops)
298{
299	int i;
300	int ret = 0;
301	int count;
302	struct powercap_zone_constraint *pconst;
303
304	if (!power_zone || !const_ops || !const_ops->get_power_limit_uw ||
305					!const_ops->set_power_limit_uw ||
306					!const_ops->get_time_window_us ||
307					!const_ops->set_time_window_us)
308		return -EINVAL;
309
310	count = power_zone->zone_attr_count;
311	for (i = 0; i < nr_constraints; ++i) {
312		pconst = &power_zone->constraints[i];
313		pconst->ops = const_ops;
314		pconst->id = power_zone->const_id_cnt;
315		power_zone->const_id_cnt++;
316		power_zone->zone_dev_attrs[count++] =
317				&constraint_attrs[i].power_limit_attr.attr;
318		power_zone->zone_dev_attrs[count++] =
319				&constraint_attrs[i].time_window_attr.attr;
320		if (pconst->ops->get_name)
321			power_zone->zone_dev_attrs[count++] =
322				&constraint_attrs[i].name_attr.attr;
323		if (pconst->ops->get_max_power_uw)
324			power_zone->zone_dev_attrs[count++] =
325				&constraint_attrs[i].max_power_attr.attr;
326		if (pconst->ops->get_min_power_uw)
327			power_zone->zone_dev_attrs[count++] =
328				&constraint_attrs[i].min_power_attr.attr;
329		if (pconst->ops->get_max_time_window_us)
330			power_zone->zone_dev_attrs[count++] =
331				&constraint_attrs[i].max_time_window_attr.attr;
332		if (pconst->ops->get_min_time_window_us)
333			power_zone->zone_dev_attrs[count++] =
334				&constraint_attrs[i].min_time_window_attr.attr;
335	}
336	power_zone->zone_attr_count = count;
337
338	return ret;
339}
340
341static bool control_type_valid(void *control_type)
342{
343	struct powercap_control_type *pos = NULL;
344	bool found = false;
345
346	mutex_lock(&powercap_cntrl_list_lock);
347
348	list_for_each_entry(pos, &powercap_cntrl_list, node) {
349		if (pos == control_type) {
350			found = true;
351			break;
352		}
353	}
354	mutex_unlock(&powercap_cntrl_list_lock);
355
356	return found;
357}
358
359static ssize_t name_show(struct device *dev,
360				struct device_attribute *attr,
361				char *buf)
362{
363	struct powercap_zone *power_zone = to_powercap_zone(dev);
364
365	return sprintf(buf, "%s\n", power_zone->name);
366}
367
368static DEVICE_ATTR_RO(name);
369
370/* Create zone and attributes in sysfs */
371static void create_power_zone_common_attributes(
372					struct powercap_zone *power_zone)
373{
374	int count = 0;
375
376	power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr;
377	if (power_zone->ops->get_max_energy_range_uj)
378		power_zone->zone_dev_attrs[count++] =
379					&dev_attr_max_energy_range_uj.attr;
380	if (power_zone->ops->get_energy_uj) {
381		if (power_zone->ops->reset_energy_uj)
382			dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUGO;
383		else
384			dev_attr_energy_uj.attr.mode = S_IRUGO;
385		power_zone->zone_dev_attrs[count++] =
386					&dev_attr_energy_uj.attr;
387	}
388	if (power_zone->ops->get_power_uw)
389		power_zone->zone_dev_attrs[count++] =
390					&dev_attr_power_uw.attr;
391	if (power_zone->ops->get_max_power_range_uw)
392		power_zone->zone_dev_attrs[count++] =
393					&dev_attr_max_power_range_uw.attr;
394	power_zone->zone_dev_attrs[count] = NULL;
395	power_zone->zone_attr_count = count;
396}
397
398static void powercap_release(struct device *dev)
399{
400	bool allocated;
401
402	if (dev->parent) {
403		struct powercap_zone *power_zone = to_powercap_zone(dev);
404
405		/* Store flag as the release() may free memory */
406		allocated = power_zone->allocated;
407		/* Remove id from parent idr struct */
408		idr_remove(power_zone->parent_idr, power_zone->id);
409		/* Destroy idrs allocated for this zone */
410		idr_destroy(&power_zone->idr);
411		kfree(power_zone->name);
412		kfree(power_zone->zone_dev_attrs);
413		kfree(power_zone->constraints);
414		if (power_zone->ops->release)
415			power_zone->ops->release(power_zone);
416		if (allocated)
417			kfree(power_zone);
418	} else {
419		struct powercap_control_type *control_type =
420						to_powercap_control_type(dev);
421
422		/* Store flag as the release() may free memory */
423		allocated = control_type->allocated;
424		idr_destroy(&control_type->idr);
425		mutex_destroy(&control_type->lock);
426		if (control_type->ops && control_type->ops->release)
427			control_type->ops->release(control_type);
428		if (allocated)
429			kfree(control_type);
430	}
431}
432
433static ssize_t enabled_show(struct device *dev,
434				struct device_attribute *attr,
435				char *buf)
436{
437	bool mode = true;
438
439	/* Default is enabled */
440	if (dev->parent) {
441		struct powercap_zone *power_zone = to_powercap_zone(dev);
442		if (power_zone->ops->get_enable)
443			if (power_zone->ops->get_enable(power_zone, &mode))
444				mode = false;
445	} else {
446		struct powercap_control_type *control_type =
447						to_powercap_control_type(dev);
448		if (control_type->ops && control_type->ops->get_enable)
449			if (control_type->ops->get_enable(control_type, &mode))
450				mode = false;
451	}
452
453	return sprintf(buf, "%d\n", mode);
454}
455
456static ssize_t enabled_store(struct device *dev,
457				struct device_attribute *attr,
458				const char *buf,  size_t len)
459{
460	bool mode;
461
462	if (strtobool(buf, &mode))
463		return -EINVAL;
464	if (dev->parent) {
465		struct powercap_zone *power_zone = to_powercap_zone(dev);
466		if (power_zone->ops->set_enable)
467			if (!power_zone->ops->set_enable(power_zone, mode))
468				return len;
469	} else {
470		struct powercap_control_type *control_type =
471						to_powercap_control_type(dev);
472		if (control_type->ops && control_type->ops->set_enable)
473			if (!control_type->ops->set_enable(control_type, mode))
474				return len;
475	}
476
477	return -ENOSYS;
478}
479
480static DEVICE_ATTR_RW(enabled);
481
482static struct attribute *powercap_attrs[] = {
483	&dev_attr_enabled.attr,
484	NULL,
485};
486ATTRIBUTE_GROUPS(powercap);
487
488static struct class powercap_class = {
489	.name = "powercap",
490	.dev_release = powercap_release,
491	.dev_groups = powercap_groups,
492};
493
494struct powercap_zone *powercap_register_zone(
495				struct powercap_zone *power_zone,
496				struct powercap_control_type *control_type,
497				const char *name,
498				struct powercap_zone *parent,
499				const struct powercap_zone_ops *ops,
500				int nr_constraints,
501				struct powercap_zone_constraint_ops *const_ops)
502{
503	int result;
504	int nr_attrs;
505
506	if (!name || !control_type || !ops ||
507			nr_constraints > MAX_CONSTRAINTS_PER_ZONE ||
508			(!ops->get_energy_uj && !ops->get_power_uw) ||
509			!control_type_valid(control_type))
510		return ERR_PTR(-EINVAL);
511
512	if (power_zone) {
513		if (!ops->release)
514			return ERR_PTR(-EINVAL);
515		memset(power_zone, 0, sizeof(*power_zone));
516	} else {
517		power_zone = kzalloc(sizeof(*power_zone), GFP_KERNEL);
518		if (!power_zone)
519			return ERR_PTR(-ENOMEM);
520		power_zone->allocated = true;
521	}
522	power_zone->ops = ops;
523	power_zone->control_type_inst = control_type;
524	if (!parent) {
525		power_zone->dev.parent = &control_type->dev;
526		power_zone->parent_idr = &control_type->idr;
527	} else {
528		power_zone->dev.parent = &parent->dev;
529		power_zone->parent_idr = &parent->idr;
530	}
531	power_zone->dev.class = &powercap_class;
532
533	mutex_lock(&control_type->lock);
534	/* Using idr to get the unique id */
535	result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL);
536	if (result < 0)
537		goto err_idr_alloc;
538
539	power_zone->id = result;
540	idr_init(&power_zone->idr);
541	power_zone->name = kstrdup(name, GFP_KERNEL);
542	if (!power_zone->name)
543		goto err_name_alloc;
544	dev_set_name(&power_zone->dev, "%s:%x",
545					dev_name(power_zone->dev.parent),
546					power_zone->id);
547	power_zone->constraints = kzalloc(sizeof(*power_zone->constraints) *
548					 nr_constraints, GFP_KERNEL);
549	if (!power_zone->constraints)
550		goto err_const_alloc;
551
552	nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
553						POWERCAP_ZONE_MAX_ATTRS + 1;
554	power_zone->zone_dev_attrs = kzalloc(sizeof(void *) *
555						nr_attrs, GFP_KERNEL);
556	if (!power_zone->zone_dev_attrs)
557		goto err_attr_alloc;
558	create_power_zone_common_attributes(power_zone);
559	result = create_constraints(power_zone, nr_constraints, const_ops);
560	if (result)
561		goto err_dev_ret;
562
563	power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
564	power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
565	power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
566	power_zone->dev_attr_groups[1] = NULL;
567	power_zone->dev.groups = power_zone->dev_attr_groups;
568	result = device_register(&power_zone->dev);
569	if (result)
570		goto err_dev_ret;
571
572	control_type->nr_zones++;
573	mutex_unlock(&control_type->lock);
574
575	return power_zone;
576
577err_dev_ret:
578	kfree(power_zone->zone_dev_attrs);
579err_attr_alloc:
580	kfree(power_zone->constraints);
581err_const_alloc:
582	kfree(power_zone->name);
583err_name_alloc:
584	idr_remove(power_zone->parent_idr, power_zone->id);
585err_idr_alloc:
586	if (power_zone->allocated)
587		kfree(power_zone);
588	mutex_unlock(&control_type->lock);
589
590	return ERR_PTR(result);
591}
592EXPORT_SYMBOL_GPL(powercap_register_zone);
593
594int powercap_unregister_zone(struct powercap_control_type *control_type,
595				struct powercap_zone *power_zone)
596{
597	if (!power_zone || !control_type)
598		return -EINVAL;
599
600	mutex_lock(&control_type->lock);
601	control_type->nr_zones--;
602	mutex_unlock(&control_type->lock);
603
604	device_unregister(&power_zone->dev);
605
606	return 0;
607}
608EXPORT_SYMBOL_GPL(powercap_unregister_zone);
609
610struct powercap_control_type *powercap_register_control_type(
611				struct powercap_control_type *control_type,
612				const char *name,
613				const struct powercap_control_type_ops *ops)
614{
615	int result;
616
617	if (!name)
618		return ERR_PTR(-EINVAL);
619	if (control_type) {
620		if (!ops || !ops->release)
621			return ERR_PTR(-EINVAL);
622		memset(control_type, 0, sizeof(*control_type));
623	} else {
624		control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
625		if (!control_type)
626			return ERR_PTR(-ENOMEM);
627		control_type->allocated = true;
628	}
629	mutex_init(&control_type->lock);
630	control_type->ops = ops;
631	INIT_LIST_HEAD(&control_type->node);
632	control_type->dev.class = &powercap_class;
633	dev_set_name(&control_type->dev, "%s", name);
634	result = device_register(&control_type->dev);
635	if (result) {
636		if (control_type->allocated)
637			kfree(control_type);
638		return ERR_PTR(result);
639	}
640	idr_init(&control_type->idr);
641
642	mutex_lock(&powercap_cntrl_list_lock);
643	list_add_tail(&control_type->node, &powercap_cntrl_list);
644	mutex_unlock(&powercap_cntrl_list_lock);
645
646	return control_type;
647}
648EXPORT_SYMBOL_GPL(powercap_register_control_type);
649
650int powercap_unregister_control_type(struct powercap_control_type *control_type)
651{
652	struct powercap_control_type *pos = NULL;
653
654	if (control_type->nr_zones) {
655		dev_err(&control_type->dev, "Zones of this type still not freed\n");
656		return -EINVAL;
657	}
658	mutex_lock(&powercap_cntrl_list_lock);
659	list_for_each_entry(pos, &powercap_cntrl_list, node) {
660		if (pos == control_type) {
661			list_del(&control_type->node);
662			mutex_unlock(&powercap_cntrl_list_lock);
663			device_unregister(&control_type->dev);
664			return 0;
665		}
666	}
667	mutex_unlock(&powercap_cntrl_list_lock);
668
669	return -ENODEV;
670}
671EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
672
673static int __init powercap_init(void)
674{
675	int result = 0;
676
677	result = seed_constraint_attributes();
678	if (result)
679		return result;
680
681	result = class_register(&powercap_class);
682
683	return result;
684}
685
686device_initcall(powercap_init);
687
688MODULE_DESCRIPTION("PowerCap sysfs Driver");
689MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
690MODULE_LICENSE("GPL v2");
691