diff options
Diffstat (limited to 'mali_kbase/ipa/mali_kbase_ipa_simple.c')
| -rw-r--r-- | mali_kbase/ipa/mali_kbase_ipa_simple.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/mali_kbase/ipa/mali_kbase_ipa_simple.c b/mali_kbase/ipa/mali_kbase_ipa_simple.c index 70e08b3..639ade2 100644 --- a/mali_kbase/ipa/mali_kbase_ipa_simple.c +++ b/mali_kbase/ipa/mali_kbase_ipa_simple.c @@ -7,14 +7,20 @@ * Foundation, and any use by you of this program is subject to the terms * of such GNU licence. * - * A copy of the licence is included with the program, and can also be obtained - * from Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, - * Boston, MA 02110-1301, USA. + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, you can access it online at + * http://www.gnu.org/licenses/gpl-2.0.html. + * + * SPDX-License-Identifier: GPL-2.0 * */ - - +#include <uapi/linux/thermal.h> #include <linux/thermal.h> #ifdef CONFIG_DEVFREQ_THERMAL #include <linux/devfreq_cooling.h> @@ -91,7 +97,7 @@ struct kbase_ipa_model_simple_data { u32 dynamic_coefficient; u32 static_coefficient; s32 ts[4]; - char tz_name[16]; + char tz_name[THERMAL_NAME_LENGTH]; struct thermal_zone_device *gpu_tz; struct task_struct *poll_temperature_thread; int current_temperature; @@ -283,20 +289,43 @@ static int kbase_simple_power_model_recalculate(struct kbase_ipa_model *model) (struct kbase_ipa_model_simple_data *)model->model_data; struct thermal_zone_device *tz; + lockdep_assert_held(&model->kbdev->ipa.lock); + if (!strnlen(model_data->tz_name, sizeof(model_data->tz_name))) { - tz = NULL; + model_data->gpu_tz = NULL; } else { - tz = thermal_zone_get_zone_by_name(model_data->tz_name); + char tz_name[THERMAL_NAME_LENGTH]; + + strlcpy(tz_name, model_data->tz_name, sizeof(tz_name)); + + /* Release ipa.lock so that thermal_list_lock is not acquired + * with ipa.lock held, thereby avoid lock ordering violation + * lockdep warning. The warning comes as a chain of locks + * ipa.lock --> thermal_list_lock --> tz->lock gets formed + * on registering devfreq cooling device when probe method + * of mali platform driver is invoked. + */ + mutex_unlock(&model->kbdev->ipa.lock); + tz = thermal_zone_get_zone_by_name(tz_name); + mutex_lock(&model->kbdev->ipa.lock); if (IS_ERR_OR_NULL(tz)) { pr_warn_ratelimited("Error %ld getting thermal zone \'%s\', not yet ready?\n", - PTR_ERR(tz), model_data->tz_name); - tz = NULL; + PTR_ERR(tz), tz_name); return -EPROBE_DEFER; } - } - ACCESS_ONCE(model_data->gpu_tz) = tz; + /* Check if another thread raced against us & updated the + * thermal zone name string. Update the gpu_tz pointer only if + * the name string did not change whilst we retrieved the new + * thermal_zone_device pointer, otherwise model_data->tz_name & + * model_data->gpu_tz would become inconsistent with each other. + * The below check will succeed only for the thread which last + * updated the name string. + */ + if (strncmp(tz_name, model_data->tz_name, sizeof(tz_name)) == 0) + model_data->gpu_tz = tz; + } return 0; } |