// SPDX-License-Identifier: GPL-2.0-only /* * Power capping class * Copyright (c) 2013, Intel Corporation. */ #include <linux/module.h> #include <linux/device.h> #include <linux/err.h> #include <linux/slab.h> #include <linux/powercap.h> #define to_powercap_zone(n) container_of(n, struct powercap_zone, dev) #define to_powercap_control_type(n) \ container_of(n, struct powercap_control_type, dev) /* Power zone show function */ #define define_power_zone_show(_attr) \ static ssize_t _attr##_show(struct device *dev, \ struct device_attribute *dev_attr,\ char *buf) \ { \ u64 value; \ ssize_t len = -EINVAL; \ struct powercap_zone *power_zone = to_powercap_zone(dev); \ \ if (power_zone->ops->get_##_attr) { \ if (!power_zone->ops->get_##_attr(power_zone, &value)) \ len = sprintf(buf, "%lld\n", value); \ } \ \ return len; \ } /* The only meaningful input is 0 (reset), others are silently ignored */ #define define_power_zone_store(_attr) \ static ssize_t _attr##_store(struct device *dev,\ struct device_attribute *dev_attr, \ const char *buf, size_t count) \ { \ int err; \ struct powercap_zone *power_zone = to_powercap_zone(dev); \ u64 value; \ \ err = kstrtoull(buf, 10, &value); \ if (err) \ return -EINVAL; \ if (value) \ return count; \ if (power_zone->ops->reset_##_attr) { \ if (!power_zone->ops->reset_##_attr(power_zone)) \ return count; \ } \ \ return -EINVAL; \ } /* Power zone constraint show function */ #define define_power_zone_constraint_show(_attr) \ static ssize_t show_constraint_##_attr(struct device *dev, \ struct device_attribute *dev_attr,\ char *buf) \ { \ u64 value; \ ssize_t len = -ENODATA; \ struct powercap_zone *power_zone = to_powercap_zone(dev); \ int id; \ struct powercap_zone_constraint *pconst;\ \ if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \ return -EINVAL; \ if (id >= power_zone->const_id_cnt) \ return -EINVAL; \ pconst = &power_zone->constraints[id]; \ if (pconst && pconst->ops && pconst->ops->get_##_attr) { \ if (!pconst->ops->get_##_attr(power_zone, id, &value)) \ len = sprintf(buf, "%lld\n", value); \ } \ \ return len; \ } /* Power zone constraint store function */ #define define_power_zone_constraint_store(_attr) \ static ssize_t store_constraint_##_attr(struct device *dev,\ struct device_attribute *dev_attr, \ const char *buf, size_t count) \ { \ int err; \ u64 value; \ struct powercap_zone *power_zone = to_powercap_zone(dev); \ int id; \ struct powercap_zone_constraint *pconst;\ \ if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \ return -EINVAL; \ if (id >= power_zone->const_id_cnt) \ return -EINVAL; \ pconst = &power_zone->constraints[id]; \ err = kstrtoull(buf, 10, &value); \ if (err) \ return -EINVAL; \ if (pconst && pconst->ops && pconst->ops->set_##_attr) { \ if (!pconst->ops->set_##_attr(power_zone, id, value)) \ return count; \ } \ \ return -ENODATA; \ } /* Power zone information callbacks */ define_power_zone_show(power_uw); define_power_zone_show(max_power_range_uw); define_power_zone_show(energy_uj); define_power_zone_store(energy_uj); define_power_zone_show(max_energy_range_uj); /* Power zone attributes */ static DEVICE_ATTR_RO(max_power_range_uw); static DEVICE_ATTR_RO(power_uw); static DEVICE_ATTR_RO(max_energy_range_uj); static DEVICE_ATTR_RW(energy_uj); /* Power zone constraint attributes callbacks */ define_power_zone_constraint_show(power_limit_uw); define_power_zone_constraint_store(power_limit_uw); define_power_zone_constraint_show(time_window_us); define_power_zone_constraint_store(time_window_us); define_power_zone_constraint_show(max_power_uw); define_power_zone_constraint_show(min_power_uw); define_power_zone_constraint_show(max_time_window_us); define_power_zone_constraint_show(min_time_window_us); /* For one time seeding of constraint device attributes */ struct powercap_constraint_attr { struct device_attribute power_limit_attr; struct device_attribute time_window_attr; struct device_attribute max_power_attr; struct device_attribute min_power_attr; struct device_attribute max_time_window_attr; struct device_attribute min_time_window_attr; struct device_attribute name_attr; }; static struct powercap_constraint_attr constraint_attrs[MAX_CONSTRAINTS_PER_ZONE]; /* A list of powercap control_types */ static LIST_HEAD(powercap_cntrl_list); /* Mutex to protect list of powercap control_types */ static DEFINE_MUTEX(powercap_cntrl_list_lock); #define POWERCAP_CONSTRAINT_NAME_LEN 30 /* Some limit to avoid overflow */ static ssize_t show_constraint_name(struct device *dev, struct device_attribute *dev_attr, char *buf) { const char *name; struct powercap_zone *power_zone = to_powercap_zone(dev); int id; ssize_t len = -ENODATA; struct powercap_zone_constraint *pconst; if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) return -EINVAL; if (id >= power_zone->const_id_cnt) return -EINVAL; pconst = &power_zone->constraints[id]; if (pconst && pconst->ops && pconst->ops->get_name) { name = pconst->ops->get_name(power_zone, id); if (name) { snprintf(buf, POWERCAP_CONSTRAINT_NAME_LEN, "%s\n", name); buf[POWERCAP_CONSTRAINT_NAME_LEN] = '\0'; len = strlen(buf); } } return len; } static int create_constraint_attribute(int id, const char *name, int mode, struct device_attribute *dev_attr, ssize_t (*show)(struct device *, struct device_attribute *, char *), ssize_t (*store)(struct device *, struct device_attribute *, const char *, size_t) ) { dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s", id, name); if (!dev_attr->attr.name) return -ENOMEM; dev_attr->attr.mode = mode; dev_attr->show = show; dev_attr->store = store; return 0; } static void free_constraint_attributes(void) { int i; for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) { kfree(constraint_attrs[i].power_limit_attr.attr.name); kfree(constraint_attrs[i].time_window_attr.attr.name); kfree(constraint_attrs[i].name_attr.attr.name); kfree(constraint_attrs[i].max_power_attr.attr.name); kfree(constraint_attrs[i].min_power_attr.attr.name); kfree(constraint_attrs[i].max_time_window_attr.attr.name); kfree(constraint_attrs[i].min_time_window_attr.attr.name); } } static int seed_constraint_attributes(void) { int i; int ret; for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) { ret = create_constraint_attribute(i, "power_limit_uw", S_IWUSR | S_IRUGO, &constraint_attrs[i].power_limit_attr, show_constraint_power_limit_uw, store_constraint_power_limit_uw); if (ret) goto err_alloc; ret = create_constraint_attribute(i, "time_window_us", S_IWUSR | S_IRUGO, &constraint_attrs[i].time_window_attr, show_constraint_time_window_us, store_constraint_time_window_us); if (ret) goto err_alloc; ret = create_constraint_attribute(i, "name", S_IRUGO, &constraint_attrs[i].name_attr, show_constraint_name, NULL); if (ret) goto err_alloc; ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO, &constraint_attrs[i].max_power_attr, show_constraint_max_power_uw, NULL); if (ret) goto err_alloc; ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO, &constraint_attrs[i].min_power_attr, show_constraint_min_power_uw, NULL); if (ret) goto err_alloc; ret = create_constraint_attribute(i, "max_time_window_us", S_IRUGO, &constraint_attrs[i].max_time_window_attr, show_constraint_max_time_window_us, NULL); if (ret) goto err_alloc; ret = create_constraint_attribute(i, "min_time_window_us", S_IRUGO, &constraint_attrs[i].min_time_window_attr, show_constraint_min_time_window_us, NULL); if (ret) goto err_alloc; } return 0; err_alloc: free_constraint_attributes(); return ret; } static int create_constraints(struct powercap_zone *power_zone, int nr_constraints, const struct powercap_zone_constraint_ops *const_ops) { int i; int ret = 0; int count; struct powercap_zone_constraint *pconst; if (!power_zone || !const_ops || !const_ops->get_power_limit_uw || !const_ops->set_power_limit_uw || !const_ops->get_time_window_us || !const_ops->set_time_window_us) return -EINVAL; count = power_zone->zone_attr_count; for (i = 0; i < nr_constraints; ++i) { pconst = &power_zone->constraints[i]; pconst->ops = const_ops; pconst->id = power_zone->const_id_cnt; power_zone->const_id_cnt++; power_zone->zone_dev_attrs[count++] = &constraint_attrs[i].power_limit_attr.attr; power_zone->zone_dev_attrs[count++] = &constraint_attrs[i].time_window_attr.attr; if (pconst->ops->get_name) power_zone->zone_dev_attrs[count++] = &constraint_attrs[i].name_attr.attr; if (pconst->ops->get_max_power_uw) power_zone->zone_dev_attrs[count++] = &constraint_attrs[i].max_power_attr.attr; if (pconst->ops->get_min_power_uw) power_zone->zone_dev_attrs[count++] = &constraint_attrs[i].min_power_attr.attr; if (pconst->ops->get_max_time_window_us) power_zone->zone_dev_attrs[count++] = &constraint_attrs[i].max_time_window_attr.attr; if (pconst->ops->get_min_time_window_us) power_zone->zone_dev_attrs[count++] = &constraint_attrs[i].min_time_window_attr.attr; } power_zone->zone_attr_count = count; return ret; } static bool control_type_valid(void *control_type) { struct powercap_control_type *pos = NULL; bool found = false; mutex_lock(&powercap_cntrl_list_lock); list_for_each_entry(pos, &powercap_cntrl_list, node) { if (pos == control_type) { found = true; break; } } mutex_unlock(&powercap_cntrl_list_lock); return found; } static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct powercap_zone *power_zone = to_powercap_zone(dev); return sprintf(buf, "%s\n", power_zone->name); } static DEVICE_ATTR_RO(name); /* Create zone and attributes in sysfs */ static void create_power_zone_common_attributes( struct powercap_zone *power_zone) { int count = 0; power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr; if (power_zone->ops->get_max_energy_range_uj) power_zone->zone_dev_attrs[count++] = &dev_attr_max_energy_range_uj.attr; if (power_zone->ops->get_energy_uj) { if (power_zone->ops->reset_energy_uj) dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUGO; else dev_attr_energy_uj.attr.mode = S_IRUGO; power_zone->zone_dev_attrs[count++] = &dev_attr_energy_uj.attr; } if (power_zone->ops->get_power_uw) power_zone->zone_dev_attrs[count++] = &dev_attr_power_uw.attr; if (power_zone->ops->get_max_power_range_uw) power_zone->zone_dev_attrs[count++] = &dev_attr_max_power_range_uw.attr; power_zone->zone_dev_attrs[count] = NULL; power_zone->zone_attr_count = count; } static void powercap_release(struct device *dev) { bool allocated; if (dev->parent) { struct powercap_zone *power_zone = to_powercap_zone(dev); /* Store flag as the release() may free memory */ allocated = power_zone->allocated; /* Remove id from parent idr struct */ idr_remove(power_zone->parent_idr, power_zone->id); /* Destroy idrs allocated for this zone */ idr_destroy(&power_zone->idr); kfree(power_zone->name); kfree(power_zone->zone_dev_attrs); kfree(power_zone->constraints); if (power_zone->ops->release) power_zone->ops->release(power_zone); if (allocated) kfree(power_zone); } else { struct powercap_control_type *control_type = to_powercap_control_type(dev); /* Store flag as the release() may free memory */ allocated = control_type->allocated; idr_destroy(&control_type->idr); mutex_destroy(&control_type->lock); if (control_type->ops && control_type->ops->release) control_type->ops->release(control_type); if (allocated) kfree(control_type); } } static ssize_t enabled_show(struct device *dev, struct device_attribute *attr, char *buf) { bool mode = true; /* Default is enabled */ if (dev->parent) { struct powercap_zone *power_zone = to_powercap_zone(dev); if (power_zone->ops->get_enable) if (power_zone->ops->get_enable(power_zone, &mode)) mode = false; } else { struct powercap_control_type *control_type = to_powercap_control_type(dev); if (control_type->ops && control_type->ops->get_enable) if (control_type->ops->get_enable(control_type, &mode)) mode = false; } return sprintf(buf, "%d\n", mode); } static ssize_t enabled_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { bool mode; if (strtobool(buf, &mode)) return -EINVAL; if (dev->parent) { struct powercap_zone *power_zone = to_powercap_zone(dev); if (power_zone->ops->set_enable) if (!power_zone->ops->set_enable(power_zone, mode)) return len; } else { struct powercap_control_type *control_type = to_powercap_control_type(dev); if (control_type->ops && control_type->ops->set_enable) if (!control_type->ops->set_enable(control_type, mode)) return len; } return -ENOSYS; } static DEVICE_ATTR_RW(enabled); static struct attribute *powercap_attrs[] = { &dev_attr_enabled.attr, NULL, }; ATTRIBUTE_GROUPS(powercap); static struct class powercap_class = { .name = "powercap", .dev_release = powercap_release, .dev_groups = powercap_groups, }; struct powercap_zone *powercap_register_zone( struct powercap_zone *power_zone, struct powercap_control_type *control_type, const char *name, struct powercap_zone *parent, const struct powercap_zone_ops *ops, int nr_constraints, const struct powercap_zone_constraint_ops *const_ops) { int result; int nr_attrs; if (!name || !control_type || !ops || nr_constraints > MAX_CONSTRAINTS_PER_ZONE || (!ops->get_energy_uj && !ops->get_power_uw) || !control_type_valid(control_type)) return ERR_PTR(-EINVAL); if (power_zone) { if (!ops->release) return ERR_PTR(-EINVAL); memset(power_zone, 0, sizeof(*power_zone)); } else { power_zone = kzalloc(sizeof(*power_zone), GFP_KERNEL); if (!power_zone) return ERR_PTR(-ENOMEM); power_zone->allocated = true; } power_zone->ops = ops; power_zone->control_type_inst = control_type; if (!parent) { power_zone->dev.parent = &control_type->dev; power_zone->parent_idr = &control_type->idr; } else { power_zone->dev.parent = &parent->dev; power_zone->parent_idr = &parent->idr; } power_zone->dev.class = &powercap_class; mutex_lock(&control_type->lock); /* Using idr to get the unique id */ result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL); if (result < 0) goto err_idr_alloc; power_zone->id = result; idr_init(&power_zone->idr); result = -ENOMEM; power_zone->name = kstrdup(name, GFP_KERNEL); if (!power_zone->name) goto err_name_alloc; dev_set_name(&power_zone->dev, "%s:%x", dev_name(power_zone->dev.parent), power_zone->id); power_zone->constraints = kcalloc(nr_constraints, sizeof(*power_zone->constraints), GFP_KERNEL); if (!power_zone->constraints) goto err_const_alloc; nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS + POWERCAP_ZONE_MAX_ATTRS + 1; power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *), GFP_KERNEL); if (!power_zone->zone_dev_attrs) goto err_attr_alloc; create_power_zone_common_attributes(power_zone); result = create_constraints(power_zone, nr_constraints, const_ops); if (result) goto err_dev_ret; power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL; power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs; power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group; power_zone->dev_attr_groups[1] = NULL; power_zone->dev.groups = power_zone->dev_attr_groups; result = device_register(&power_zone->dev); if (result) goto err_dev_ret; control_type->nr_zones++; mutex_unlock(&control_type->lock); return power_zone; err_dev_ret: kfree(power_zone->zone_dev_attrs); err_attr_alloc: kfree(power_zone->constraints); err_const_alloc: kfree(power_zone->name); err_name_alloc: idr_remove(power_zone->parent_idr, power_zone->id); err_idr_alloc: if (power_zone->allocated) kfree(power_zone); mutex_unlock(&control_type->lock); return ERR_PTR(result); } EXPORT_SYMBOL_GPL(powercap_register_zone); int powercap_unregister_zone(struct powercap_control_type *control_type, struct powercap_zone *power_zone) { if (!power_zone || !control_type) return -EINVAL; mutex_lock(&control_type->lock); control_type->nr_zones--; mutex_unlock(&control_type->lock); device_unregister(&power_zone->dev); return 0; } EXPORT_SYMBOL_GPL(powercap_unregister_zone); struct powercap_control_type *powercap_register_control_type( struct powercap_control_type *control_type, const char *name, const struct powercap_control_type_ops *ops) { int result; if (!name) return ERR_PTR(-EINVAL); if (control_type) { if (!ops || !ops->release) return ERR_PTR(-EINVAL); memset(control_type, 0, sizeof(*control_type)); } else { control_type = kzalloc(sizeof(*control_type), GFP_KERNEL); if (!control_type) return ERR_PTR(-ENOMEM); control_type->allocated = true; } mutex_init(&control_type->lock); control_type->ops = ops; INIT_LIST_HEAD(&control_type->node); control_type->dev.class = &powercap_class; dev_set_name(&control_type->dev, "%s", name); result = device_register(&control_type->dev); if (result) { if (control_type->allocated) kfree(control_type); return ERR_PTR(result); } idr_init(&control_type->idr); mutex_lock(&powercap_cntrl_list_lock); list_add_tail(&control_type->node, &powercap_cntrl_list); mutex_unlock(&powercap_cntrl_list_lock); return control_type; } EXPORT_SYMBOL_GPL(powercap_register_control_type); int powercap_unregister_control_type(struct powercap_control_type *control_type) { struct powercap_control_type *pos = NULL; if (control_type->nr_zones) { dev_err(&control_type->dev, "Zones of this type still not freed\n"); return -EINVAL; } mutex_lock(&powercap_cntrl_list_lock); list_for_each_entry(pos, &powercap_cntrl_list, node) { if (pos == control_type) { list_del(&control_type->node); mutex_unlock(&powercap_cntrl_list_lock); device_unregister(&control_type->dev); return 0; } } mutex_unlock(&powercap_cntrl_list_lock); return -ENODEV; } EXPORT_SYMBOL_GPL(powercap_unregister_control_type); static int __init powercap_init(void) { int result; result = seed_constraint_attributes(); if (result) return result; return class_register(&powercap_class); } fs_initcall(powercap_init); MODULE_DESCRIPTION("PowerCap sysfs Driver"); MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>"); MODULE_LICENSE("GPL v2");