diff options
Diffstat (limited to 'drivers/base/power/opp.c')
| -rw-r--r-- | drivers/base/power/opp.c | 196 |
1 files changed, 155 insertions, 41 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 89ced955fafa..2d195f3a1998 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -49,11 +49,12 @@ * are protected by the dev_opp_list_lock for integrity. * IMPORTANT: the opp nodes should be maintained in increasing * order. + * @dynamic: not-created from static DT entries. * @available: true/false - marks if this OPP as available or not * @rate: Frequency in hertz * @u_volt: Nominal voltage in microvolts corresponding to this OPP * @dev_opp: points back to the device_opp struct this opp belongs to - * @head: RCU callback head used for deferred freeing + * @rcu_head: RCU callback head used for deferred freeing * * This structure stores the OPP information for a given device. */ @@ -61,11 +62,12 @@ struct dev_pm_opp { struct list_head node; bool available; + bool dynamic; unsigned long rate; unsigned long u_volt; struct device_opp *dev_opp; - struct rcu_head head; + struct rcu_head rcu_head; }; /** @@ -76,7 +78,8 @@ struct dev_pm_opp { * RCU usage: nodes are not modified in the list of device_opp, * however addition is possible and is secured by dev_opp_list_lock * @dev: device pointer - * @head: notifier head to notify the OPP availability changes. + * @srcu_head: notifier head to notify the OPP availability changes. + * @rcu_head: RCU callback head used for deferred freeing * @opp_list: list of opps * * This is an internal data structure maintaining the link to opps attached to @@ -87,7 +90,8 @@ struct device_opp { struct list_head node; struct device *dev; - struct srcu_notifier_head head; + struct srcu_notifier_head srcu_head; + struct rcu_head rcu_head; struct list_head opp_list; }; @@ -378,30 +382,8 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); -/** - * dev_pm_opp_add() - Add an OPP table from a table definitions - * @dev: device for which we do this operation - * @freq: Frequency in Hz for this OPP - * @u_volt: Voltage in uVolts for this OPP - * - * This function adds an opp definition to the opp list and returns status. - * The opp is made available by default and it can be controlled using - * dev_pm_opp_enable/disable functions. - * - * 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 cannot be locked. - * - * Return: - * 0: On success OR - * Duplicate OPPs (both freq and volt are same) and opp->available - * -EEXIST: Freq are same and volt are different OR - * Duplicate OPPs (both freq and volt are same) and !opp->available - * -ENOMEM: Memory allocation failure - */ -int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) +static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq, + unsigned long u_volt, bool dynamic) { struct device_opp *dev_opp = NULL; struct dev_pm_opp *opp, *new_opp; @@ -417,6 +399,13 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); + /* populate the opp table */ + new_opp->dev_opp = dev_opp; + new_opp->rate = freq; + new_opp->u_volt = u_volt; + new_opp->available = true; + new_opp->dynamic = dynamic; + /* Check for existing list for 'dev' */ dev_opp = find_device_opp(dev); if (IS_ERR(dev_opp)) { @@ -436,19 +425,15 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) } dev_opp->dev = dev; - srcu_init_notifier_head(&dev_opp->head); + srcu_init_notifier_head(&dev_opp->srcu_head); INIT_LIST_HEAD(&dev_opp->opp_list); /* Secure the device list modification */ list_add_rcu(&dev_opp->node, &dev_opp_list); + head = &dev_opp->opp_list; + goto list_add; } - /* populate the opp table */ - new_opp->dev_opp = dev_opp; - new_opp->rate = freq; - new_opp->u_volt = u_volt; - new_opp->available = true; - /* * Insert new OPP in order of increasing frequency * and discard if already present @@ -474,6 +459,7 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) return ret; } +list_add: list_add_rcu(&new_opp->node, head); mutex_unlock(&dev_opp_list_lock); @@ -481,11 +467,109 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) * Notify the changes in the availability of the operable * frequency/voltage list. */ - srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ADD, new_opp); + srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ADD, new_opp); return 0; } + +/** + * dev_pm_opp_add() - Add an OPP table from a table definitions + * @dev: device for which we do this operation + * @freq: Frequency in Hz for this OPP + * @u_volt: Voltage in uVolts for this OPP + * + * This function adds an opp definition to the opp list and returns status. + * The opp is made available by default and it can be controlled using + * dev_pm_opp_enable/disable functions. + * + * 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 cannot be locked. + * + * Return: + * 0: On success OR + * Duplicate OPPs (both freq and volt are same) and opp->available + * -EEXIST: Freq are same and volt are different OR + * Duplicate OPPs (both freq and volt are same) and !opp->available + * -ENOMEM: Memory allocation failure + */ +int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) +{ + return dev_pm_opp_add_dynamic(dev, freq, u_volt, true); +} EXPORT_SYMBOL_GPL(dev_pm_opp_add); +static void kfree_opp_rcu(struct rcu_head *head) +{ + struct dev_pm_opp *opp = container_of(head, struct dev_pm_opp, rcu_head); + + kfree_rcu(opp, rcu_head); +} + +static void kfree_device_rcu(struct rcu_head *head) +{ + struct device_opp *device_opp = container_of(head, struct device_opp, rcu_head); + + kfree(device_opp); +} + +void __dev_pm_opp_remove(struct device_opp *dev_opp, struct dev_pm_opp *opp) +{ + /* + * Notify the changes in the availability of the operable + * frequency/voltage list. + */ + srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp); + list_del_rcu(&opp->node); + call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, kfree_opp_rcu); + + if (list_empty(&dev_opp->opp_list)) { + list_del_rcu(&dev_opp->node); + call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head, + kfree_device_rcu); + } +} + +/** + * dev_pm_opp_remove() - Remove an OPP from OPP list + * @dev: device for which we do this operation + * @freq: OPP to remove with matching 'freq' + * + * This function removes an opp from the opp list. + */ +void dev_pm_opp_remove(struct device *dev, unsigned long freq) +{ + struct dev_pm_opp *opp; + struct device_opp *dev_opp; + bool found = false; + + /* Hold our list modification lock here */ + mutex_lock(&dev_opp_list_lock); + + dev_opp = find_device_opp(dev); + if (IS_ERR(dev_opp)) + goto unlock; + + list_for_each_entry(opp, &dev_opp->opp_list, node) { + if (opp->rate == freq) { + found = true; + break; + } + } + + if (!found) { + dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n", + __func__, freq); + goto unlock; + } + + __dev_pm_opp_remove(dev_opp, opp); +unlock: + mutex_unlock(&dev_opp_list_lock); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_remove); + /** * opp_set_availability() - helper to set the availability of an opp * @dev: device for which we do this operation @@ -557,14 +641,14 @@ static int opp_set_availability(struct device *dev, unsigned long freq, list_replace_rcu(&opp->node, &new_opp->node); mutex_unlock(&dev_opp_list_lock); - kfree_rcu(opp, head); + call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, kfree_opp_rcu); /* Notify the change of the OPP availability */ if (availability_req) - srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ENABLE, + srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ENABLE, new_opp); else - srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_DISABLE, + srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_DISABLE, new_opp); return 0; @@ -629,7 +713,7 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) if (IS_ERR(dev_opp)) return ERR_CAST(dev_opp); /* matching type */ - return &dev_opp->head; + return &dev_opp->srcu_head; } #ifdef CONFIG_OF @@ -666,7 +750,7 @@ int of_init_opp_table(struct device *dev) unsigned long freq = be32_to_cpup(val++) * 1000; unsigned long volt = be32_to_cpup(val++); - if (dev_pm_opp_add(dev, freq, volt)) + if (dev_pm_opp_add_dynamic(dev, freq, volt, false)) dev_warn(dev, "%s: Failed to add OPP %ld\n", __func__, freq); nr -= 2; @@ -675,4 +759,34 @@ int of_init_opp_table(struct device *dev) return 0; } EXPORT_SYMBOL_GPL(of_init_opp_table); + +/** + * of_free_opp_table() - Free OPP table entries created from static DT entries + * @dev: device pointer used to lookup device OPPs. + * + * Free OPPs created using static entries present in DT. + */ +void of_free_opp_table(struct device *dev) +{ + struct device_opp *dev_opp = find_device_opp(dev); + struct dev_pm_opp *opp, *tmp; + + /* Check for existing list for 'dev' */ + dev_opp = find_device_opp(dev); + if (WARN(IS_ERR(dev_opp), "%s: dev_opp: %ld\n", dev_name(dev), + PTR_ERR(dev_opp))) + return; + + /* Hold our list modification lock here */ + mutex_lock(&dev_opp_list_lock); + + /* Free static OPPs */ + list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) { + if (!opp->dynamic) + __dev_pm_opp_remove(dev_opp, opp); + } + + mutex_unlock(&dev_opp_list_lock); +} +EXPORT_SYMBOL_GPL(of_free_opp_table); #endif |