A couple of size checks: On Wed, Nov 25, 2015 at 03:09:46PM +0000, Javi Merino wrote: > 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");
Do we need to check for buf size (snprintf)?
> +}
> +
> +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);
please use sizeof(link->weight_att_name) instead of THERMAL_NAME_LENGTH.
> + 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
>
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