On 05/16/2014 04:09 AM, Inderpal Singh wrote:
> At the driver unloading time the associated opp table may need
> to be deleted. Otherwise it amounts to memory leak. The existing
> OPP library does not have provison to do so.
>
> Hence this patch implements the function to free the opp table.
>
> Signed-off-by: Inderpal Singh <[email protected]>
> ---
> drivers/base/power/opp.c | 41 +++++++++++++++++++++++++++++++++++++++++
> include/linux/pm_opp.h | 6 ++++++
> 2 files changed, 47 insertions(+)
>
> diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
> index d9e376a..d45ffd5 100644
> --- a/drivers/base/power/opp.c
> +++ b/drivers/base/power/opp.c
> @@ -654,4 +654,45 @@ int of_init_opp_table(struct device *dev)
> return 0;
> }
> EXPORT_SYMBOL_GPL(of_init_opp_table);
> +
> +/**
> + * dev_pm_opp_free_opp_table() - free the opp table
> + * @dev: device for which we do this operation
> + *
> + * Free up the allocated opp table
> + *
> + * Locking: The internal device_opp and opp structures are RCU protected.
> + * Hence this function internally uses RCU updater strategy with mutex locks
> to
> + * keep the integrity of the internal data structures. Callers should ensure
> + * that this function is *NOT* called under RCU protection or in contexts
> where
> + * mutex locking or synchronize_rcu() blocking calls cannot be used.
> + */
> +void dev_pm_opp_free_opp_table(struct device *dev)
> +{
> + struct device_opp *dev_opp = NULL;
> + struct dev_pm_opp *opp;
> +
if (!dev)
return;
> + /* Hold our list modification lock here */
> + mutex_lock(&dev_opp_list_lock);
> +
> + /* Check for existing list for 'dev' */
> + dev_opp = find_device_opp(dev);
> + if (IS_ERR(dev_opp)) {
> + mutex_unlock(&dev_opp_list_lock);
> + return;
> + }
> +
> + while (!list_empty(&dev_opp->opp_list)) {
> + opp = list_entry_rcu(dev_opp->opp_list.next,
> + struct dev_pm_opp, node);
> + list_del_rcu(&opp->node);
> + kfree_rcu(opp, head);
> + }
How about the OPP notifiers? should'nt we add a new event
OPP_EVENT_REMOVE?
To maintain non-dt behavior coherency, should'nt we rather add a
opp_remove or an opp_del function?
> +
> + list_del_rcu(&dev_opp->node);
> + mutex_unlock(&dev_opp_list_lock);
> + synchronize_rcu();
> + kfree(dev_opp);
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_opp_free_opp_table);
> #endif
> diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
> index 0330217..3c29620 100644
> --- a/include/linux/pm_opp.h
> +++ b/include/linux/pm_opp.h
> @@ -50,6 +50,8 @@ 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);
> +
> +void dev_pm_opp_free_opp_table(struct device *dev);
> #else
> static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
> {
> @@ -105,6 +107,10 @@ static inline struct srcu_notifier_head
> *dev_pm_opp_get_notifier(
> {
> return ERR_PTR(-EINVAL);
> }
> +
> +void dev_pm_opp_free_opp_table(struct device *dev)
> +{
> +}
> #endif /* CONFIG_PM_OPP */
>
> #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
>
--
Regards,
Nishanth Menon
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