Let the OPP core provide helpers to register notifiers for any device, instead of exposing srcu_head outside of the core.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Acked-by: MyungJoo Ham myungjoo.ham@samsung.com Reviewed-by: Stephen Boyd sboyd@codeaurora.org --- drivers/base/power/opp/core.c | 66 ++++++++++++++++++++++++++++++++----------- drivers/devfreq/devfreq.c | 26 ++--------------- include/linux/pm_opp.h | 14 ++++++--- 3 files changed, 62 insertions(+), 44 deletions(-)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index dfbe0610b675..074a42185819 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -1874,29 +1874,63 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq) EXPORT_SYMBOL_GPL(dev_pm_opp_disable);
/** - * dev_pm_opp_get_notifier() - find notifier_head of the device with opp - * @dev: device pointer used to lookup OPP table. + * dev_pm_opp_register_notifier() - Register OPP notifier for the device + * @dev: Device for which notifier needs to be registered + * @nb: Notifier block to be registered * - * Return: pointer to notifier head if found, otherwise -ENODEV or - * -EINVAL based on type of error casted as pointer. value must be checked - * with IS_ERR to determine valid pointer or error result. + * Return: 0 on success or a negative error value. + */ +int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb) +{ + struct opp_table *opp_table; + int ret; + + rcu_read_lock(); + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) { + ret = PTR_ERR(opp_table); + goto unlock; + } + + ret = srcu_notifier_chain_register(&opp_table->srcu_head, nb); + +unlock: + rcu_read_unlock(); + + return ret; +} +EXPORT_SYMBOL(dev_pm_opp_register_notifier); + +/** + * dev_pm_opp_unregister_notifier() - Unregister OPP notifier for the device + * @dev: Device for which notifier needs to be unregistered + * @nb: Notifier block to be unregistered * - * Locking: This function must be called under rcu_read_lock(). opp_table is a - * RCU protected pointer. The reason for the same is that the opp pointer which - * is returned will remain valid for use with opp_get_{voltage, freq} only while - * under the locked area. The pointer returned must be used prior to unlocking - * with rcu_read_unlock() to maintain the integrity of the pointer. + * Return: 0 on success or a negative error value. */ -struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) +int dev_pm_opp_unregister_notifier(struct device *dev, + struct notifier_block *nb) { - struct opp_table *opp_table = _find_opp_table(dev); + struct opp_table *opp_table; + int ret;
- if (IS_ERR(opp_table)) - return ERR_CAST(opp_table); /* matching type */ + rcu_read_lock(); + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) { + ret = PTR_ERR(opp_table); + goto unlock; + } + + ret = srcu_notifier_chain_unregister(&opp_table->srcu_head, nb);
- return &opp_table->srcu_head; +unlock: + rcu_read_unlock(); + + return ret; } -EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier); +EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);
/* * Free OPPs either created using static entries present in DT or even the diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index a324801d6a66..b0de42972b74 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -1260,18 +1260,7 @@ EXPORT_SYMBOL(devfreq_recommended_opp); */ int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) { - struct srcu_notifier_head *nh; - int ret = 0; - - rcu_read_lock(); - nh = dev_pm_opp_get_notifier(dev); - if (IS_ERR(nh)) - ret = PTR_ERR(nh); - rcu_read_unlock(); - if (!ret) - ret = srcu_notifier_chain_register(nh, &devfreq->nb); - - return ret; + return dev_pm_opp_register_notifier(dev, &devfreq->nb); } EXPORT_SYMBOL(devfreq_register_opp_notifier);
@@ -1287,18 +1276,7 @@ EXPORT_SYMBOL(devfreq_register_opp_notifier); */ int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) { - struct srcu_notifier_head *nh; - int ret = 0; - - rcu_read_lock(); - nh = dev_pm_opp_get_notifier(dev); - if (IS_ERR(nh)) - ret = PTR_ERR(nh); - rcu_read_unlock(); - if (!ret) - ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); - - return ret; + return dev_pm_opp_unregister_notifier(dev, &devfreq->nb); } EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 7483ff291a8e..66a02deeb03f 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -108,7 +108,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq);
int dev_pm_opp_disable(struct device *dev, unsigned long freq);
-struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev); +int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb); +int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb); + int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions, unsigned int count); void dev_pm_opp_put_supported_hw(struct device *dev); @@ -202,10 +204,14 @@ static inline int dev_pm_opp_disable(struct device *dev, unsigned long freq) return 0; }
-static inline struct srcu_notifier_head *dev_pm_opp_get_notifier( - struct device *dev) +static inline int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb) { - return ERR_PTR(-ENOTSUPP); + return -ENOTSUPP; +} + +static inline int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb) +{ + return -ENOTSUPP; }
static inline int dev_pm_opp_set_supported_hw(struct device *dev,