On Tue, Mar 21, 2023 at 4:08 PM Zhang, Rui <rui.zhang@xxxxxxxxx> wrote: > > On Fri, 2023-03-17 at 18:01 +0100, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > Introduce a core thermal API function, > > thermal_cooling_device_update(), > > for updating the max_state value for a cooling device and rearranging > > its statistics in sysfs after a possible change of its > > ->get_max_state() > > callback return value. > > > > That callback is now invoked only once, during cooling device > > registration, to populate the max_state field in the cooling device > > object, so if its return value changes, it needs to be invoked again > > and the new return value needs to be stored as max_state. Moreover, > > the statistics presented in sysfs need to be rearranged in general, > > because there may not be enough room in them to store data for all > > of the possible states (in the case when max_state grows). > > > > The new function takes care of that (and some other minor things > > related to it), but some extra locking and lockdep annotations are > > added in several places too to protect against crashes in the cases > > when the statistics are not present or when a stale max_state value > > might be used by sysfs attributes. > > > > Note that the actual user of the new function will be added > > separately. > > > > Link: > > https://lore.kernel.org/linux-pm/53ec1f06f61c984100868926f282647e57ecfb2d.camel@xxxxxxxxx/ > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > --- > > > > Rui, please have a look at this again and give it a go if > > possible. It is the > > only patch in the series changing in v3. > > Hi, Rafael, > > Thanks for the patch, I can confirm that it works, with ACPI passive > cooling activated on my side. > > Tested-by: Zhang Rui <rui.zhang@xxxxxxxxx> > Reviewed-by: Zhang Rui <rui.zhang@xxxxxxxxx> Thank you! I'll queue up this series for 6.3-rc4. > > v2 -> v3: > > Make thermal_cooling_device_update() check thermal instances > > involving the > > given thermal device and update the "upper" value for them if > > necessary (the > > "lower" and "target" values may need to be adjusted too in some > > cases) to avoid > > leaving thermal instances with "upper" above the new max_state of > > the > > corresponding cooling device. > > > > v1 -> v2: > > * Make thermal_cooling_device_update() do the full > > IS_ERR_OR_NULL() check > > on cdev, so that its callers don't need to do it. > > * Remove ->set_cur_state() callback invocation from > > thermal_cooling_device_update(), because it is redundant (and > > it doesn't > > make sense to pass a state value exceeding max_state to it > > anyway). > > > > --- > > drivers/thermal/thermal_core.c | 83 > > +++++++++++++++++++++++++++++++++++++++- > > drivers/thermal/thermal_core.h | 2 > > drivers/thermal/thermal_sysfs.c | 72 > > ++++++++++++++++++++++++++++++---- > > include/linux/thermal.h | 1 > > 4 files changed, 149 insertions(+), 9 deletions(-) > > > > Index: linux-pm/drivers/thermal/thermal_core.c > > =================================================================== > > --- linux-pm.orig/drivers/thermal/thermal_core.c > > +++ linux-pm/drivers/thermal/thermal_core.c > > @@ -613,6 +613,7 @@ int thermal_zone_bind_cooling_device(str > > struct thermal_instance *pos; > > struct thermal_zone_device *pos1; > > struct thermal_cooling_device *pos2; > > + bool upper_no_limit; > > int result; > > > > if (trip >= tz->num_trips || trip < 0) > > @@ -632,7 +633,13 @@ int thermal_zone_bind_cooling_device(str > > > > /* lower default 0, upper default max_state */ > > lower = lower == THERMAL_NO_LIMIT ? 0 : lower; > > - upper = upper == THERMAL_NO_LIMIT ? cdev->max_state : upper; > > + > > + if (upper == THERMAL_NO_LIMIT) { > > + upper = cdev->max_state; > > + upper_no_limit = true; > > + } else { > > + upper_no_limit = false; > > + } > > > > if (lower > upper || upper > cdev->max_state) > > return -EINVAL; > > @@ -644,6 +651,7 @@ int thermal_zone_bind_cooling_device(str > > dev->cdev = cdev; > > dev->trip = trip; > > dev->upper = upper; > > + dev->upper_no_limit = upper_no_limit; > > dev->lower = lower; > > dev->target = THERMAL_NO_TARGET; > > dev->weight = weight; > > @@ -1057,6 +1065,79 @@ static bool thermal_cooling_device_prese > > return false; > > } > > > > +/** > > + * thermal_cooling_device_update - Update a cooling device object > > + * @cdev: Target cooling device. > > + * > > + * Update @cdev to reflect a change of the underlying hardware or > > platform. > > + * > > + * Must be called when the maximum cooling state of @cdev becomes > > invalid and so > > + * its .get_max_state() callback needs to be run to produce the new > > maximum > > + * cooling state value. > > + */ > > +void thermal_cooling_device_update(struct thermal_cooling_device > > *cdev) > > +{ > > + struct thermal_instance *ti; > > + unsigned long state; > > + > > + if (IS_ERR_OR_NULL(cdev)) > > + return; > > + > > + /* > > + * Hold thermal_list_lock throughout the update to prevent the > > device > > + * from going away while being updated. > > + */ > > + mutex_lock(&thermal_list_lock); > > + > > + if (!thermal_cooling_device_present(cdev)) > > + goto unlock_list; > > + > > + /* > > + * Update under the cdev lock to prevent the state from being > > set beyond > > + * the new limit concurrently. > > + */ > > + mutex_lock(&cdev->lock); > > + > > + if (cdev->ops->get_max_state(cdev, &cdev->max_state)) > > + goto unlock; > > + > > + thermal_cooling_device_stats_reinit(cdev); > > + > > + list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) { > > + if (ti->upper == cdev->max_state) > > + continue; > > + > > + if (ti->upper < cdev->max_state) { > > + if (ti->upper_no_limit) > > + ti->upper = cdev->max_state; > > + > > + continue; > > + } > > + > > + ti->upper = cdev->max_state; > > + if (ti->lower > ti->upper) > > + ti->lower = ti->upper; > > + > > + if (ti->target == THERMAL_NO_TARGET) > > + continue; > > + > > + if (ti->target > ti->upper) > > + ti->target = ti->upper; > > + } > > + > > + if (cdev->ops->get_cur_state(cdev, &state) || state > cdev- > > >max_state) > > + goto unlock; > > + > > + thermal_cooling_device_stats_update(cdev, state); > > + > > +unlock: > > + mutex_unlock(&cdev->lock); > > + > > +unlock_list: > > + mutex_unlock(&thermal_list_lock); > > +} > > +EXPORT_SYMBOL_GPL(thermal_cooling_device_update); > > + > > static void __unbind(struct thermal_zone_device *tz, int mask, > > struct thermal_cooling_device *cdev) > > { > > Index: linux-pm/drivers/thermal/thermal_sysfs.c > > =================================================================== > > --- linux-pm.orig/drivers/thermal/thermal_sysfs.c > > +++ linux-pm/drivers/thermal/thermal_sysfs.c > > @@ -685,6 +685,8 @@ void thermal_cooling_device_stats_update > > { > > struct cooling_dev_stats *stats = cdev->stats; > > > > + lockdep_assert_held(&cdev->lock); > > + > > if (!stats) > > return; > > > > @@ -706,13 +708,22 @@ static ssize_t total_trans_show(struct d > > struct device_attribute *attr, char > > *buf) > > { > > struct thermal_cooling_device *cdev = to_cooling_device(dev); > > - struct cooling_dev_stats *stats = cdev->stats; > > + struct cooling_dev_stats *stats; > > int ret; > > > > + mutex_lock(&cdev->lock); > > + > > + stats = cdev->stats; > > + if (!stats) > > + goto unlock; > > + > > spin_lock(&stats->lock); > > ret = sprintf(buf, "%u\n", stats->total_trans); > > spin_unlock(&stats->lock); > > > > +unlock: > > + mutex_unlock(&cdev->lock); > > + > > return ret; > > } > > > > @@ -721,11 +732,18 @@ time_in_state_ms_show(struct device *dev > > char *buf) > > { > > struct thermal_cooling_device *cdev = to_cooling_device(dev); > > - struct cooling_dev_stats *stats = cdev->stats; > > + struct cooling_dev_stats *stats; > > ssize_t len = 0; > > int i; > > > > + mutex_lock(&cdev->lock); > > + > > + stats = cdev->stats; > > + if (!stats) > > + goto unlock; > > + > > spin_lock(&stats->lock); > > + > > update_time_in_state(stats); > > > > for (i = 0; i <= cdev->max_state; i++) { > > @@ -734,6 +752,9 @@ time_in_state_ms_show(struct device *dev > > } > > spin_unlock(&stats->lock); > > > > +unlock: > > + mutex_unlock(&cdev->lock); > > + > > return len; > > } > > > > @@ -742,8 +763,16 @@ reset_store(struct device *dev, struct d > > size_t count) > > { > > struct thermal_cooling_device *cdev = to_cooling_device(dev); > > - struct cooling_dev_stats *stats = cdev->stats; > > - int i, states = cdev->max_state + 1; > > + struct cooling_dev_stats *stats; > > + int i, states; > > + > > + mutex_lock(&cdev->lock); > > + > > + stats = cdev->stats; > > + if (!stats) > > + goto unlock; > > + > > + states = cdev->max_state + 1; > > > > spin_lock(&stats->lock); > > > > @@ -757,6 +786,9 @@ reset_store(struct device *dev, struct d > > > > spin_unlock(&stats->lock); > > > > +unlock: > > + mutex_unlock(&cdev->lock); > > + > > return count; > > } > > > > @@ -764,10 +796,18 @@ static ssize_t trans_table_show(struct d > > struct device_attribute *attr, char > > *buf) > > { > > struct thermal_cooling_device *cdev = to_cooling_device(dev); > > - struct cooling_dev_stats *stats = cdev->stats; > > + struct cooling_dev_stats *stats; > > ssize_t len = 0; > > int i, j; > > > > + mutex_lock(&cdev->lock); > > + > > + stats = cdev->stats; > > + if (!stats) { > > + len = -ENODATA; > > + goto unlock; > > + } > > + > > len += snprintf(buf + len, PAGE_SIZE - len, " > > From : To\n"); > > len += snprintf(buf + len, PAGE_SIZE - len, " : "); > > for (i = 0; i <= cdev->max_state; i++) { > > @@ -775,8 +815,10 @@ static ssize_t trans_table_show(struct d > > break; > > len += snprintf(buf + len, PAGE_SIZE - len, > > "state%2u ", i); > > } > > - if (len >= PAGE_SIZE) > > - return PAGE_SIZE; > > + if (len >= PAGE_SIZE) { > > + len = PAGE_SIZE; > > + goto unlock; > > + } > > > > len += snprintf(buf + len, PAGE_SIZE - len, "\n"); > > > > @@ -799,8 +841,12 @@ static ssize_t trans_table_show(struct d > > > > if (len >= PAGE_SIZE) { > > pr_warn_once("Thermal transition table exceeds > > PAGE_SIZE. Disabling\n"); > > - return -EFBIG; > > + len = -EFBIG; > > } > > + > > +unlock: > > + mutex_unlock(&cdev->lock); > > + > > return len; > > } > > > > @@ -830,6 +876,8 @@ static void cooling_device_stats_setup(s > > unsigned long states = cdev->max_state + 1; > > int var; > > > > + lockdep_assert_held(&cdev->lock); > > + > > var = sizeof(*stats); > > var += sizeof(*stats->time_in_state) * states; > > var += sizeof(*stats->trans_table) * states * states; > > @@ -855,6 +903,8 @@ out: > > > > static void cooling_device_stats_destroy(struct > > thermal_cooling_device *cdev) > > { > > + lockdep_assert_held(&cdev->lock); > > + > > kfree(cdev->stats); > > cdev->stats = NULL; > > } > > @@ -879,6 +929,12 @@ void thermal_cooling_device_destroy_sysf > > cooling_device_stats_destroy(cdev); > > } > > > > +void thermal_cooling_device_stats_reinit(struct > > thermal_cooling_device *cdev) > > +{ > > + cooling_device_stats_destroy(cdev); > > + cooling_device_stats_setup(cdev); > > +} > > + > > /* these helper will be used only at the time of bindig */ > > ssize_t > > trip_point_show(struct device *dev, struct device_attribute *attr, > > char *buf) > > Index: linux-pm/drivers/thermal/thermal_core.h > > =================================================================== > > --- linux-pm.orig/drivers/thermal/thermal_core.h > > +++ linux-pm/drivers/thermal/thermal_core.h > > @@ -101,6 +101,7 @@ struct thermal_instance { > > struct list_head tz_node; /* node in tz->thermal_instances */ > > struct list_head cdev_node; /* node in cdev->thermal_instances > > */ > > unsigned int weight; /* The weight of the cooling device */ > > + bool upper_no_limit; > > }; > > > > #define to_thermal_zone(_dev) \ > > @@ -127,6 +128,7 @@ int thermal_zone_create_device_groups(st > > void thermal_zone_destroy_device_groups(struct thermal_zone_device > > *); > > void thermal_cooling_device_setup_sysfs(struct > > thermal_cooling_device *); > > void thermal_cooling_device_destroy_sysfs(struct > > thermal_cooling_device *cdev); > > +void thermal_cooling_device_stats_reinit(struct > > thermal_cooling_device *cdev); > > /* used only at binding time */ > > ssize_t trip_point_show(struct device *, struct device_attribute *, > > char *); > > ssize_t weight_show(struct device *, struct device_attribute *, char > > *); > > Index: linux-pm/include/linux/thermal.h > > =================================================================== > > --- linux-pm.orig/include/linux/thermal.h > > +++ linux-pm/include/linux/thermal.h > > @@ -388,6 +388,7 @@ devm_thermal_of_cooling_device_register( > > struct device_node *np, > > char *type, void *devdata, > > const struct thermal_cooling_device_ops > > *ops); > > +void thermal_cooling_device_update(struct thermal_cooling_device *); > > void thermal_cooling_device_unregister(struct thermal_cooling_device > > *); > > struct thermal_zone_device *thermal_zone_get_zone_by_name(const char > > *name); > > int thermal_zone_get_temp(struct thermal_zone_device *tz, int > > *temp); > > > > > > > >
