When a thermal zone is created that has sub thermal zones via devicetree or via thermal_zone_add_subtz() expose that relationship in sysfs.
Cc: Zhang Rui <[email protected]> Cc: Eduardo Valentin <[email protected]> Signed-off-by: Javi Merino <[email protected]> --- Documentation/thermal/sysfs-api.txt | 33 ++++++++++ drivers/thermal/thermal_core.c | 125 ++++++++++++++++++++++++++++++++++++ include/linux/thermal.h | 3 + 3 files changed, 161 insertions(+) diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt index dda24a0bdeec..5636a531f0b1 100644 --- a/Documentation/thermal/sysfs-api.txt +++ b/Documentation/thermal/sysfs-api.txt @@ -219,11 +219,16 @@ Thermal zone device sys I/F, created once it's registered: |---temp: Current temperature |---mode: Working mode of the thermal zone |---policy: Thermal governor used for this zone + |---aggregation_function: Function to use when aggregating the + temperature of this zone's slave thermal zones |---available_policies: Available thermal governors for this zone |---trip_point_[0-*]_temp: Trip point temperature |---trip_point_[0-*]_type: Trip point type |---trip_point_[0-*]_hyst: Hysteresis value for this trip point |---emul_temp: Emulated temperature set node + |---subtz[0-*]: Slave thermal zones of this thermal zone + |---subtz[0-*]_weight: Weight of the slave thermal zone on + this thermal zone |---sustainable_power: Sustainable dissipatable power |---k_po: Proportional term during temperature overshoot |---k_pu: Proportional term during temperature undershoot @@ -296,6 +301,19 @@ policy One of the various thermal governors used for a particular zone. RW, Required +aggregation_function + The aggregation function used to calculate the temperature of + this thermal zone when it has sub thermal zones. It can + either be "max" or "weighted_average". If it's "max", the + temperature of this thermal zone is the maximum of the + temperatures of the sub thermal zones. If + aggregation_function is "weighted_average", the temperature of + this thermal zone is the weighted average of the temperatures + of the sub thermal zones. The weights are specified in + subtz[0-*]_weights. The aggregation_function sysfs entry + doesn't exist for thermal zones without sub thermal zones. + RW, Optional + available_policies Available thermal governors which can be used for a particular zone. RO, Required @@ -359,6 +377,21 @@ emul_temp because userland can easily disable the thermal policy by simply flooding this sysfs node with low temperature values. +subtz[0-*] + sysfs link to the slave thermal zone device. + RO, Optional + +subtz[0-*]_weight + The influence of subtz[0-*] in this thermal zone. This + parameter is only used when using "weighted_average" as the + aggregation_function. When calculating the temperature of + this thermal zone, the temperature of each of the thermal + zone's slaves is multiplied by its weight. The result is + divided by the sum of all weights. If all weights are 0, + the temperature of this thermal zone is the average of the + temperatures of the sub thermal zones. + RW, Optional + sustainable_power An estimate of the sustained power that can be dissipated by the thermal zone. Used by the power allocator governor. For diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 98bdb63b3b95..2bb1af0a9349 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -63,14 +63,23 @@ static struct thermal_governor *def_governor; /** * struct thermal_zone_link - a link between "master" and "slave" thermal zones + * @id: link number in the master thermal zone + * @name: filename in the master thermal zone's sysfs directory * @weight: weight of the @slave thermal zone in the master * calculation. Used when the master thermal zone's * aggregation function is THERMAL_AGG_WEIGHTED_AVG + * @weight_attr_name: filename of the weight attribute in the master's thermal + * zone sysfs directory + * @weight_attr: device attribute for the weight entry in sysfs * @slave: pointer to the slave thermal zone * @node: list node in the master thermal zone's slave_tzs list. */ struct thermal_zone_link { + int id; + char name[THERMAL_NAME_LENGTH]; int weight; + char weight_attr_name[THERMAL_NAME_LENGTH]; + struct device_attribute weight_attr; struct thermal_zone_device *slave; struct list_head node; }; @@ -990,6 +999,45 @@ emul_temp_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR(emul_temp, S_IWUSR, NULL, emul_temp_store); static ssize_t +agg_func_show(struct device *dev, struct device_attribute *devattr, char *buf) +{ + struct thermal_zone_device *tz = to_thermal_zone(dev); + + if (tz->slave_agg_function == THERMAL_AGG_MAX) + return sprintf(buf, "max\n"); + else if (tz->slave_agg_function == THERMAL_AGG_WEIGHTED_AVG) + return sprintf(buf, "weighted_average\n"); + else + return sprintf(buf, "(invalid)\n"); +} + +static ssize_t +agg_func_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret = 0; + struct thermal_zone_device *tz = to_thermal_zone(dev); + char func_name[THERMAL_NAME_LENGTH]; + + snprintf(func_name, sizeof(func_name), "%s", buf); + + mutex_lock(&tz->lock); + + if (sysfs_streq(func_name, "max")) + tz->slave_agg_function = THERMAL_AGG_MAX; + else if (sysfs_streq(func_name, "weighted_average")) + tz->slave_agg_function = THERMAL_AGG_WEIGHTED_AVG; + else + ret = -EINVAL; + + mutex_unlock(&tz->lock); + + return ret ? ret : count; +} +static DEVICE_ATTR(aggregation_function, S_IRUGO | S_IWUSR, agg_func_show, + agg_func_store); + +static ssize_t sustainable_power_show(struct device *dev, struct device_attribute *devattr, char *buf) { @@ -1305,6 +1353,35 @@ thermal_cooling_device_weight_store(struct device *dev, return count; } + +static ssize_t +thermal_subtz_weight_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct thermal_zone_link *link; + + link = container_of(attr, struct thermal_zone_link, weight_attr); + + return sprintf(buf, "%d\n", link->weight); +} + +static ssize_t +thermal_subtz_weight_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct thermal_zone_link *link; + int ret, weight; + + ret = kstrtoint(buf, 0, &weight); + if (ret) + return ret; + + link = container_of(attr, struct thermal_zone_link, weight_attr); + link->weight = weight; + + return count; +} + /* Device management */ /** @@ -2135,6 +2212,47 @@ int thermal_zone_add_subtz(struct thermal_zone_device *tz, link->weight = weight; list_add_tail(&link->node, &tz->slave_tzs); + if (list_is_singular(&tz->slave_tzs)) { + ret = device_create_file(&tz->device, + &dev_attr_aggregation_function); + if (ret) + pr_warn("Failed to create aggregation_function sysfs file: %d\n", + ret); + /* + * Fall through: we failed to create the sysfs file, but + * it's not fatal + */ + } + + ret = get_idr(&tz->link_idr, NULL, &link->id); + if (ret) { + /* + * Even if we can't create the symlink in sysfs, + * we've linked the thermal zones, so return success + */ + ret = 0; + goto unlock; + } + + snprintf(link->name, ARRAY_SIZE(link->name), "subtz%d", link->id); + ret = sysfs_create_link(&tz->device.kobj, &subtz->device.kobj, + link->name); + if (ret) + pr_warn("Failed to create symlink to sub thermal zone: %d\n", + ret); + + snprintf(link->weight_attr_name, THERMAL_NAME_LENGTH, "subtz%d_weight", + link->id); + sysfs_attr_init(&link->weight_attr.attr); + link->weight_attr.attr.name = link->weight_attr_name; + link->weight_attr.attr.mode = S_IWUSR | S_IRUGO; + link->weight_attr.show = thermal_subtz_weight_show; + link->weight_attr.store = thermal_subtz_weight_store; + ret = device_create_file(&tz->device, &link->weight_attr); + if (ret) + pr_warn("Failed to create sub thermal zone weight: %d\n", + ret); + ret = 0; unlock: @@ -2166,6 +2284,10 @@ int thermal_zone_del_subtz(struct thermal_zone_device *tz, list_for_each_entry(link, &tz->slave_tzs, node) { if (link->slave == subtz) { + device_remove_file(&tz->device, &link->weight_attr); + sysfs_remove_link(&tz->device.kobj, link->name); + release_idr(&tz->link_idr, NULL, link->id); + list_del(&link->node); kfree(link); @@ -2174,6 +2296,9 @@ int thermal_zone_del_subtz(struct thermal_zone_device *tz, } } + if (list_empty(&tz->slave_tzs)) + device_remove_file(&tz->device, &dev_attr_aggregation_function); + mutex_unlock(&tz->lock); return ret; diff --git a/include/linux/thermal.h b/include/linux/thermal.h index dc3d2ab77ab6..f14884353230 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -192,6 +192,8 @@ struct thermal_attr { * @thermal_instances: list of &struct thermal_instance of this thermal zone * @idr: &struct idr to generate unique id for this zone's cooling * devices + * @link_idr: &struct idr to generate unique ids for this zone's links to + * other thermal zones * @lock: lock to protect thermal_instances list * @node: node in thermal_tz_list (in thermal_core.c) * @poll_queue: delayed work for polling @@ -221,6 +223,7 @@ struct thermal_zone_device { void *governor_data; struct list_head thermal_instances; struct idr idr; + struct idr link_idr; struct mutex lock; struct list_head node; struct delayed_work poll_queue; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
