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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Power capping class4 * 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_attr147 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 else372 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>");682