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v6.8
  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 = sprintf(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)) \
 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 = sprintf(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)) \
 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))
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			sprintf(buf, "%.*s\n", POWERCAP_CONSTRAINT_NAME_LEN - 1,
175				name);
 
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_IRUSR;
371		else
372			dev_attr_energy_uj.attr.mode = S_IRUSR;
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 (kstrtobool(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	power_zone->constraints = kcalloc(nr_constraints,
534					  sizeof(*power_zone->constraints),
535					  GFP_KERNEL);
 
 
536	if (!power_zone->constraints)
537		goto err_const_alloc;
538
539	nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
540						POWERCAP_ZONE_MAX_ATTRS + 1;
541	power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *),
542					     GFP_KERNEL);
543	if (!power_zone->zone_dev_attrs)
544		goto err_attr_alloc;
545	create_power_zone_common_attributes(power_zone);
546	result = create_constraints(power_zone, nr_constraints, const_ops);
547	if (result)
548		goto err_dev_ret;
549
550	power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
551	power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
552	power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
553	power_zone->dev_attr_groups[1] = NULL;
554	power_zone->dev.groups = power_zone->dev_attr_groups;
555	dev_set_name(&power_zone->dev, "%s:%x",
556					dev_name(power_zone->dev.parent),
557					power_zone->id);
558	result = device_register(&power_zone->dev);
559	if (result) {
560		put_device(&power_zone->dev);
561		mutex_unlock(&control_type->lock);
562
563		return ERR_PTR(result);
564	}
565
566	control_type->nr_zones++;
567	mutex_unlock(&control_type->lock);
568
569	return power_zone;
570
571err_dev_ret:
572	kfree(power_zone->zone_dev_attrs);
573err_attr_alloc:
574	kfree(power_zone->constraints);
575err_const_alloc:
576	kfree(power_zone->name);
577err_name_alloc:
578	idr_remove(power_zone->parent_idr, power_zone->id);
579err_idr_alloc:
580	if (power_zone->allocated)
581		kfree(power_zone);
582	mutex_unlock(&control_type->lock);
583
584	return ERR_PTR(result);
585}
586EXPORT_SYMBOL_GPL(powercap_register_zone);
587
588int powercap_unregister_zone(struct powercap_control_type *control_type,
589				struct powercap_zone *power_zone)
590{
591	if (!power_zone || !control_type)
592		return -EINVAL;
593
594	mutex_lock(&control_type->lock);
595	control_type->nr_zones--;
596	mutex_unlock(&control_type->lock);
597
598	device_unregister(&power_zone->dev);
599
600	return 0;
601}
602EXPORT_SYMBOL_GPL(powercap_unregister_zone);
603
604struct powercap_control_type *powercap_register_control_type(
605				struct powercap_control_type *control_type,
606				const char *name,
607				const struct powercap_control_type_ops *ops)
608{
609	int result;
610
611	if (!name)
612		return ERR_PTR(-EINVAL);
613	if (control_type) {
614		if (!ops || !ops->release)
615			return ERR_PTR(-EINVAL);
616		memset(control_type, 0, sizeof(*control_type));
617	} else {
618		control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
619		if (!control_type)
620			return ERR_PTR(-ENOMEM);
621		control_type->allocated = true;
622	}
623	mutex_init(&control_type->lock);
624	control_type->ops = ops;
625	INIT_LIST_HEAD(&control_type->node);
626	control_type->dev.class = &powercap_class;
627	dev_set_name(&control_type->dev, "%s", name);
628	result = device_register(&control_type->dev);
629	if (result) {
630		if (control_type->allocated)
631			kfree(control_type);
632		return ERR_PTR(result);
633	}
634	idr_init(&control_type->idr);
635
636	mutex_lock(&powercap_cntrl_list_lock);
637	list_add_tail(&control_type->node, &powercap_cntrl_list);
638	mutex_unlock(&powercap_cntrl_list_lock);
639
640	return control_type;
641}
642EXPORT_SYMBOL_GPL(powercap_register_control_type);
643
644int powercap_unregister_control_type(struct powercap_control_type *control_type)
645{
646	struct powercap_control_type *pos = NULL;
647
648	if (control_type->nr_zones) {
649		dev_err(&control_type->dev, "Zones of this type still not freed\n");
650		return -EINVAL;
651	}
652	mutex_lock(&powercap_cntrl_list_lock);
653	list_for_each_entry(pos, &powercap_cntrl_list, node) {
654		if (pos == control_type) {
655			list_del(&control_type->node);
656			mutex_unlock(&powercap_cntrl_list_lock);
657			device_unregister(&control_type->dev);
658			return 0;
659		}
660	}
661	mutex_unlock(&powercap_cntrl_list_lock);
662
663	return -ENODEV;
664}
665EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
666
667static int __init powercap_init(void)
668{
669	int result;
670
671	result = seed_constraint_attributes();
672	if (result)
673		return result;
674
675	return class_register(&powercap_class);
 
 
676}
677
678fs_initcall(powercap_init);
679
680MODULE_DESCRIPTION("PowerCap sysfs Driver");
681MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
v3.15
 
  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");