diff options
-rw-r--r-- | drivers/base/power/opp.c | 174 |
1 files changed, 150 insertions, 24 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 8638204..5d699e3 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -86,16 +86,33 @@ struct dev_pm_opp { }; /** + * struct device_list_opp - devices managed by 'struct device_opp' + * @node: list node + * @dev: device to which the struct object belongs + * @rcu_head: RCU callback head used for deferred freeing + * + * This is an internal data structure maintaining the list of devices that are + * managed by 'struct device_opp'. + */ +struct device_list_opp { + struct list_head node; + const struct device *dev; + struct rcu_head rcu_head; +}; + +/** * struct device_opp - Device opp structure * @node: list node - contains the devices with OPPs that * have been registered. Nodes once added are not modified in this * list. * 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 * @srcu_head: notifier head to notify the OPP availability changes. * @rcu_head: RCU callback head used for deferred freeing + * @dev_list: list of devices that share these OPPs * @opp_list: list of opps + * @np: struct device_node pointer for opp's DT node. + * @shared_opp: OPP is shared between multiple devices. * * This is an internal data structure maintaining the link to opps attached to * a device. This structure is not meant to be shared to users as it is @@ -108,12 +125,14 @@ struct dev_pm_opp { struct device_opp { struct list_head node; - struct device *dev; struct srcu_notifier_head srcu_head; struct rcu_head rcu_head; + struct list_head dev_list; struct list_head opp_list; + struct device_node *np; unsigned long clock_latency_ns_max; + bool shared_opp; }; /* @@ -133,6 +152,38 @@ do { \ "dev_opp_list_lock protection"); \ } while (0) +static struct device_list_opp *_find_list_dev(const struct device *dev, + struct device_opp *dev_opp) +{ + struct device_list_opp *list_dev; + + list_for_each_entry(list_dev, &dev_opp->dev_list, node) + if (list_dev->dev == dev) + return list_dev; + + return NULL; +} + +static struct device_opp *_managed_opp(const struct device_node *np) +{ + struct device_opp *dev_opp; + + list_for_each_entry_rcu(dev_opp, &dev_opp_list, node) { + if (dev_opp->np == np) { + /* + * Multiple devices can point to the same OPP table and + * so will have same node-pointer, np. + * + * But the OPPs will be considered as shared only if the + * OPP table contains a "opp-shared" property. + */ + return dev_opp->shared_opp ? dev_opp : NULL; + } + } + + return NULL; +} + /** * _find_device_opp() - find device_opp struct using device pointer * @dev: device pointer used to lookup device OPPs @@ -149,21 +200,18 @@ do { \ */ static struct device_opp *_find_device_opp(struct device *dev) { - struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV); + struct device_opp *dev_opp; if (unlikely(IS_ERR_OR_NULL(dev))) { pr_err("%s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } - list_for_each_entry_rcu(tmp_dev_opp, &dev_opp_list, node) { - if (tmp_dev_opp->dev == dev) { - dev_opp = tmp_dev_opp; - break; - } - } + list_for_each_entry_rcu(dev_opp, &dev_opp_list, node) + if (_find_list_dev(dev, dev_opp)) + return dev_opp; - return dev_opp; + return ERR_PTR(-ENODEV); } /** @@ -450,6 +498,39 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); +/* List-dev Helpers */ +static void _kfree_list_dev_rcu(struct rcu_head *head) +{ + struct device_list_opp *list_dev; + + list_dev = container_of(head, struct device_list_opp, rcu_head); + kfree_rcu(list_dev, rcu_head); +} + +static void _remove_list_dev(struct device_list_opp *list_dev, + struct device_opp *dev_opp) +{ + list_del(&list_dev->node); + call_srcu(&dev_opp->srcu_head.srcu, &list_dev->rcu_head, + _kfree_list_dev_rcu); +} + +static struct device_list_opp *_add_list_dev(const struct device *dev, + struct device_opp *dev_opp) +{ + struct device_list_opp *list_dev; + + list_dev = kzalloc(sizeof(*list_dev), GFP_KERNEL); + if (!list_dev) + return NULL; + + /* Initialize list-dev */ + list_dev->dev = dev; + list_add_rcu(&list_dev->node, &dev_opp->dev_list); + + return list_dev; +} + /** * _add_device_opp() - Find device OPP table or allocate a new one * @dev: device for which we do this operation @@ -462,6 +543,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); static struct device_opp *_add_device_opp(struct device *dev) { struct device_opp *dev_opp; + struct device_list_opp *list_dev; /* Check for existing list for 'dev' first */ dev_opp = _find_device_opp(dev); @@ -476,7 +558,14 @@ static struct device_opp *_add_device_opp(struct device *dev) if (!dev_opp) return NULL; - dev_opp->dev = dev; + INIT_LIST_HEAD(&dev_opp->dev_list); + + list_dev = _add_list_dev(dev, dev_opp); + if (!list_dev) { + kfree(dev_opp); + return NULL; + } + srcu_init_notifier_head(&dev_opp->srcu_head); INIT_LIST_HEAD(&dev_opp->opp_list); @@ -504,9 +593,19 @@ static void _kfree_device_rcu(struct rcu_head *head) */ static void _remove_device_opp(struct device_opp *dev_opp) { + struct device_list_opp *list_dev; + if (!list_empty(&dev_opp->opp_list)) return; + list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp, + node); + + _remove_list_dev(list_dev, dev_opp); + + /* dev_list must be empty now */ + WARN_ON(!list_empty(&dev_opp->dev_list)); + list_del_rcu(&dev_opp->node); call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head, _kfree_device_rcu); @@ -616,7 +715,8 @@ static struct dev_pm_opp *_allocate_opp(struct device *dev, return opp; } -static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp) +static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, + struct device_opp *dev_opp) { struct dev_pm_opp *opp; struct list_head *head = &dev_opp->opp_list; @@ -639,7 +739,7 @@ static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp) break; /* Duplicate OPPs */ - dev_warn(dev_opp->dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", + dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", __func__, opp->rate, opp->u_volt, opp->available, new_opp->rate, new_opp->u_volt, new_opp->available); @@ -702,7 +802,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, new_opp->available = true; new_opp->dynamic = dynamic; - ret = _opp_add(new_opp, dev_opp); + ret = _opp_add(dev, new_opp, dev_opp); if (ret) goto free_opp; @@ -819,7 +919,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) of_property_read_u32(np, "opp-microamp", (u32 *)&new_opp->u_amp); - ret = _opp_add(new_opp, dev_opp); + ret = _opp_add(dev, new_opp, dev_opp); if (ret) goto free_opp; @@ -1052,6 +1152,9 @@ void of_free_opp_table(struct device *dev) struct device_opp *dev_opp; struct dev_pm_opp *opp, *tmp; + /* 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)) { @@ -1062,18 +1165,21 @@ void of_free_opp_table(struct device *dev) IS_ERR_OR_NULL(dev) ? "Invalid device" : dev_name(dev), error); - return; + goto unlock; } - /* 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) - _opp_remove(dev_opp, opp, true); + /* Find if dev_opp manages a single device */ + if (list_is_singular(&dev_opp->dev_list)) { + /* Free static OPPs */ + list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) { + if (!opp->dynamic) + _opp_remove(dev_opp, opp, true); + } + } else { + _remove_list_dev(_find_list_dev(dev, dev_opp), dev_opp); } +unlock: mutex_unlock(&dev_opp_list_lock); } EXPORT_SYMBOL_GPL(of_free_opp_table); @@ -1099,6 +1205,7 @@ static int _of_init_opp_table_v2(struct device *dev, const struct property *prop) { struct device_node *opp_np, *np; + struct device_opp *dev_opp; int ret = 0, count = 0; if (!prop->value) @@ -1109,6 +1216,14 @@ static int _of_init_opp_table_v2(struct device *dev, if (IS_ERR(opp_np)) return PTR_ERR(opp_np); + dev_opp = _managed_opp(opp_np); + if (dev_opp) { + /* OPPs are already managed */ + if (!_add_list_dev(dev, dev_opp)) + ret = -ENOMEM; + goto put_opp_np; + } + /* We have opp-list node now, iterate over it and add OPPs */ for_each_available_child_of_node(opp_np, np) { count++; @@ -1125,8 +1240,19 @@ static int _of_init_opp_table_v2(struct device *dev, if (WARN_ON(!count)) goto put_opp_np; - if (ret) + if (!ret) { + if (!dev_opp) { + dev_opp = _find_device_opp(dev); + if (WARN_ON(!dev_opp)) + goto put_opp_np; + } + + dev_opp->np = opp_np; + dev_opp->shared_opp = of_property_read_bool(opp_np, + "opp-shared"); + } else { of_free_opp_table(dev); + } put_opp_np: of_node_put(opp_np); |