Since the commit 2a4eb7358aba ("OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()"), dynamically created OPP aren't automatically removed anymore by dev_pm_opp_cpumask_remove_table(). This affects the scpi and scmi cpufreq drivers which no longer free OPPs on failures or on invocations of the policy->exit() callback.
Create a generic OPP helper dev_pm_opp_remove_all_dynamic() which can be called from these drivers instead of dev_pm_opp_cpumask_remove_table().
In dev_pm_opp_remove_all_dynamic(), we need to make sure that the opp_list isn't getting accessed simultaneously from other parts of the OPP core while the helper is freeing dynamic OPPs, i.e. we can't drop the opp_table->lock while traversing through the OPP list. And to accomplish that, this patch also creates _opp_kref_release_unlocked() which can be called from this new helper with the opp_table lock already held.
Cc: 4.20 stable@vger.kernel.org # v4.20 Reported-by: Valentin Schneider valentin.schneider@arm.com Fixes: 2a4eb7358aba ("OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()") Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/cpufreq/scmi-cpufreq.c | 4 +-- drivers/cpufreq/scpi-cpufreq.c | 4 +-- drivers/opp/core.c | 63 +++++++++++++++++++++++++++++++--- include/linux/pm_opp.h | 5 +++ 4 files changed, 67 insertions(+), 9 deletions(-)
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c index 50b1551ba894..c2e66528f5ee 100644 --- a/drivers/cpufreq/scmi-cpufreq.c +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -176,7 +176,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy) out_free_priv: kfree(priv); out_free_opp: - dev_pm_opp_cpumask_remove_table(policy->cpus); + dev_pm_opp_remove_all_dynamic(cpu_dev);
return ret; } @@ -188,7 +188,7 @@ static int scmi_cpufreq_exit(struct cpufreq_policy *policy) cpufreq_cooling_unregister(priv->cdev); dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); kfree(priv); - dev_pm_opp_cpumask_remove_table(policy->related_cpus); + dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
return 0; } diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c index 87a98ec77773..99449738faa4 100644 --- a/drivers/cpufreq/scpi-cpufreq.c +++ b/drivers/cpufreq/scpi-cpufreq.c @@ -177,7 +177,7 @@ static int scpi_cpufreq_init(struct cpufreq_policy *policy) out_free_priv: kfree(priv); out_free_opp: - dev_pm_opp_cpumask_remove_table(policy->cpus); + dev_pm_opp_remove_all_dynamic(cpu_dev);
return ret; } @@ -190,7 +190,7 @@ static int scpi_cpufreq_exit(struct cpufreq_policy *policy) clk_put(priv->clk); dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); kfree(priv); - dev_pm_opp_cpumask_remove_table(policy->related_cpus); + dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
return 0; } diff --git a/drivers/opp/core.c b/drivers/opp/core.c index e5507add8f04..18f1639dbc4a 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -988,11 +988,9 @@ void _opp_free(struct dev_pm_opp *opp) kfree(opp); }
-static void _opp_kref_release(struct kref *kref) +static void _opp_kref_release(struct dev_pm_opp *opp, + struct opp_table *opp_table) { - struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref); - struct opp_table *opp_table = opp->opp_table; - /* * Notify the changes in the availability of the operable * frequency/voltage list. @@ -1002,7 +1000,22 @@ static void _opp_kref_release(struct kref *kref) opp_debug_remove_one(opp); list_del(&opp->node); kfree(opp); +}
+static void _opp_kref_release_unlocked(struct kref *kref) +{ + struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref); + struct opp_table *opp_table = opp->opp_table; + + _opp_kref_release(opp, opp_table); +} + +static void _opp_kref_release_locked(struct kref *kref) +{ + struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref); + struct opp_table *opp_table = opp->opp_table; + + _opp_kref_release(opp, opp_table); mutex_unlock(&opp_table->lock); }
@@ -1013,10 +1026,16 @@ void dev_pm_opp_get(struct dev_pm_opp *opp)
void dev_pm_opp_put(struct dev_pm_opp *opp) { - kref_put_mutex(&opp->kref, _opp_kref_release, &opp->opp_table->lock); + kref_put_mutex(&opp->kref, _opp_kref_release_locked, + &opp->opp_table->lock); } EXPORT_SYMBOL_GPL(dev_pm_opp_put);
+static void dev_pm_opp_put_unlocked(struct dev_pm_opp *opp) +{ + kref_put(&opp->kref, _opp_kref_release_unlocked); +} + /** * dev_pm_opp_remove() - Remove an OPP from OPP table * @dev: device for which we do this operation @@ -1060,6 +1079,40 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) } EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
+/** + * dev_pm_opp_remove_all_dynamic() - Remove all dynamically created OPPs + * @dev: device for which we do this operation + * + * This function removes all dynamically created OPPs from the opp table. + */ +void dev_pm_opp_remove_all_dynamic(struct device *dev) +{ + struct opp_table *opp_table; + struct dev_pm_opp *opp, *temp; + int count = 0; + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) + return; + + mutex_lock(&opp_table->lock); + list_for_each_entry_safe(opp, temp, &opp_table->opp_list, node) { + if (opp->dynamic) { + dev_pm_opp_put_unlocked(opp); + count++; + } + } + mutex_unlock(&opp_table->lock); + + /* Drop the references taken by dev_pm_opp_add() */ + while (count--) + dev_pm_opp_put_opp_table(opp_table); + + /* Drop the reference taken by _find_opp_table() */ + dev_pm_opp_put_opp_table(opp_table); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_remove_all_dynamic); + struct dev_pm_opp *_opp_allocate(struct opp_table *table) { struct dev_pm_opp *opp; diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 0a2a88e5a383..b895f4e79868 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -108,6 +108,7 @@ void dev_pm_opp_put(struct dev_pm_opp *opp); int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt); void dev_pm_opp_remove(struct device *dev, unsigned long freq); +void dev_pm_opp_remove_all_dynamic(struct device *dev);
int dev_pm_opp_enable(struct device *dev, unsigned long freq);
@@ -217,6 +218,10 @@ static inline void dev_pm_opp_remove(struct device *dev, unsigned long freq) { }
+static inline void dev_pm_opp_remove_all_dynamic(struct device *dev) +{ +} + static inline int dev_pm_opp_enable(struct device *dev, unsigned long freq) { return 0;