diff options
Diffstat (limited to 'drivers/base/power')
| -rw-r--r-- | drivers/base/power/clock_ops.c | 4 | ||||
| -rw-r--r-- | drivers/base/power/common.c | 18 | ||||
| -rw-r--r-- | drivers/base/power/domain.c | 157 | ||||
| -rw-r--r-- | drivers/base/power/opp.c | 202 | ||||
| -rw-r--r-- | drivers/base/power/qos.c | 4 |
5 files changed, 228 insertions, 157 deletions
diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c index d626576a4f75..7fdd0172605a 100644 --- a/drivers/base/power/clock_ops.c +++ b/drivers/base/power/clock_ops.c @@ -81,10 +81,8 @@ static int __pm_clk_add(struct device *dev, const char *con_id, return -EINVAL; ce = kzalloc(sizeof(*ce), GFP_KERNEL); - if (!ce) { - dev_err(dev, "Not enough memory for clock entry.\n"); + if (!ce) return -ENOMEM; - } if (con_id) { ce->con_id = kstrdup(con_id, GFP_KERNEL); diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c index b0f138806bbc..f32b802b98f4 100644 --- a/drivers/base/power/common.c +++ b/drivers/base/power/common.c @@ -19,8 +19,8 @@ * @dev: Device to handle. * * If power.subsys_data is NULL, point it to a new object, otherwise increment - * its reference counter. Return 1 if a new object has been created, otherwise - * return 0 or error code. + * its reference counter. Return 0 if new object has been created or refcount + * increased, otherwise negative error code. */ int dev_pm_get_subsys_data(struct device *dev) { @@ -56,13 +56,11 @@ EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data); * @dev: Device to handle. * * If the reference counter of power.subsys_data is zero after dropping the - * reference, power.subsys_data is removed. Return 1 if that happens or 0 - * otherwise. + * reference, power.subsys_data is removed. */ -int dev_pm_put_subsys_data(struct device *dev) +void dev_pm_put_subsys_data(struct device *dev) { struct pm_subsys_data *psd; - int ret = 1; spin_lock_irq(&dev->power.lock); @@ -70,18 +68,14 @@ int dev_pm_put_subsys_data(struct device *dev) if (!psd) goto out; - if (--psd->refcount == 0) { + if (--psd->refcount == 0) dev->power.subsys_data = NULL; - } else { + else psd = NULL; - ret = 0; - } out: spin_unlock_irq(&dev->power.lock); kfree(psd); - - return ret; } EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data); diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 0d8780c04a5e..ba4abbe4693c 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -344,14 +344,7 @@ static int genpd_dev_pm_qos_notifier(struct notifier_block *nb, struct device *dev; gpd_data = container_of(nb, struct generic_pm_domain_data, nb); - - mutex_lock(&gpd_data->lock); dev = gpd_data->base.dev; - if (!dev) { - mutex_unlock(&gpd_data->lock); - return NOTIFY_DONE; - } - mutex_unlock(&gpd_data->lock); for (;;) { struct generic_pm_domain *genpd; @@ -1384,25 +1377,66 @@ EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron); #endif /* CONFIG_PM_SLEEP */ -static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev) +static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev, + struct generic_pm_domain *genpd, + struct gpd_timing_data *td) { struct generic_pm_domain_data *gpd_data; + int ret; + + ret = dev_pm_get_subsys_data(dev); + if (ret) + return ERR_PTR(ret); gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL); - if (!gpd_data) - return NULL; + if (!gpd_data) { + ret = -ENOMEM; + goto err_put; + } + + if (td) + gpd_data->td = *td; - mutex_init(&gpd_data->lock); + gpd_data->base.dev = dev; + gpd_data->need_restore = -1; + gpd_data->td.constraint_changed = true; + gpd_data->td.effective_constraint_ns = -1; gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; - dev_pm_qos_add_notifier(dev, &gpd_data->nb); + + spin_lock_irq(&dev->power.lock); + + if (dev->power.subsys_data->domain_data) { + ret = -EINVAL; + goto err_free; + } + + dev->power.subsys_data->domain_data = &gpd_data->base; + dev->pm_domain = &genpd->domain; + + spin_unlock_irq(&dev->power.lock); + return gpd_data; + + err_free: + spin_unlock_irq(&dev->power.lock); + kfree(gpd_data); + err_put: + dev_pm_put_subsys_data(dev); + return ERR_PTR(ret); } -static void __pm_genpd_free_dev_data(struct device *dev, - struct generic_pm_domain_data *gpd_data) +static void genpd_free_dev_data(struct device *dev, + struct generic_pm_domain_data *gpd_data) { - dev_pm_qos_remove_notifier(dev, &gpd_data->nb); + spin_lock_irq(&dev->power.lock); + + dev->pm_domain = NULL; + dev->power.subsys_data->domain_data = NULL; + + spin_unlock_irq(&dev->power.lock); + kfree(gpd_data); + dev_pm_put_subsys_data(dev); } /** @@ -1414,8 +1448,7 @@ static void __pm_genpd_free_dev_data(struct device *dev, int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, struct gpd_timing_data *td) { - struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL; - struct pm_domain_data *pdd; + struct generic_pm_domain_data *gpd_data; int ret = 0; dev_dbg(dev, "%s()\n", __func__); @@ -1423,9 +1456,9 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) return -EINVAL; - gpd_data_new = __pm_genpd_alloc_dev_data(dev); - if (!gpd_data_new) - return -ENOMEM; + gpd_data = genpd_alloc_dev_data(dev, genpd, td); + if (IS_ERR(gpd_data)) + return PTR_ERR(gpd_data); genpd_acquire_lock(genpd); @@ -1434,50 +1467,22 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, goto out; } - list_for_each_entry(pdd, &genpd->dev_list, list_node) - if (pdd->dev == dev) { - ret = -EINVAL; - goto out; - } - - ret = dev_pm_get_subsys_data(dev); + ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0; if (ret) goto out; genpd->device_count++; genpd->max_off_time_changed = true; - spin_lock_irq(&dev->power.lock); - - dev->pm_domain = &genpd->domain; - if (dev->power.subsys_data->domain_data) { - gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); - } else { - gpd_data = gpd_data_new; - dev->power.subsys_data->domain_data = &gpd_data->base; - } - gpd_data->refcount++; - if (td) - gpd_data->td = *td; - - spin_unlock_irq(&dev->power.lock); - - if (genpd->attach_dev) - genpd->attach_dev(genpd, dev); - - mutex_lock(&gpd_data->lock); - gpd_data->base.dev = dev; list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); - gpd_data->need_restore = -1; - gpd_data->td.constraint_changed = true; - gpd_data->td.effective_constraint_ns = -1; - mutex_unlock(&gpd_data->lock); out: genpd_release_lock(genpd); - if (gpd_data != gpd_data_new) - __pm_genpd_free_dev_data(dev, gpd_data_new); + if (ret) + genpd_free_dev_data(dev, gpd_data); + else + dev_pm_qos_add_notifier(dev, &gpd_data->nb); return ret; } @@ -1504,7 +1509,6 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, { struct generic_pm_domain_data *gpd_data; struct pm_domain_data *pdd; - bool remove = false; int ret = 0; dev_dbg(dev, "%s()\n", __func__); @@ -1514,6 +1518,11 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, || pd_to_genpd(dev->pm_domain) != genpd) return -EINVAL; + /* The above validation also means we have existing domain_data. */ + pdd = dev->power.subsys_data->domain_data; + gpd_data = to_gpd_data(pdd); + dev_pm_qos_remove_notifier(dev, &gpd_data->nb); + genpd_acquire_lock(genpd); if (genpd->prepared_count > 0) { @@ -1527,58 +1536,22 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, if (genpd->detach_dev) genpd->detach_dev(genpd, dev); - spin_lock_irq(&dev->power.lock); - - dev->pm_domain = NULL; - pdd = dev->power.subsys_data->domain_data; list_del_init(&pdd->list_node); - gpd_data = to_gpd_data(pdd); - if (--gpd_data->refcount == 0) { - dev->power.subsys_data->domain_data = NULL; - remove = true; - } - - spin_unlock_irq(&dev->power.lock); - - mutex_lock(&gpd_data->lock); - pdd->dev = NULL; - mutex_unlock(&gpd_data->lock); genpd_release_lock(genpd); - dev_pm_put_subsys_data(dev); - if (remove) - __pm_genpd_free_dev_data(dev, gpd_data); + genpd_free_dev_data(dev, gpd_data); return 0; out: genpd_release_lock(genpd); + dev_pm_qos_add_notifier(dev, &gpd_data->nb); return ret; } /** - * pm_genpd_dev_need_restore - Set/unset the device's "need restore" flag. - * @dev: Device to set/unset the flag for. - * @val: The new value of the device's "need restore" flag. - */ -void pm_genpd_dev_need_restore(struct device *dev, bool val) -{ - struct pm_subsys_data *psd; - unsigned long flags; - - spin_lock_irqsave(&dev->power.lock, flags); - - psd = dev_to_psd(dev); - if (psd && psd->domain_data) - to_gpd_data(psd->domain_data)->need_restore = val ? 1 : 0; - - spin_unlock_irqrestore(&dev->power.lock, flags); -} -EXPORT_SYMBOL_GPL(pm_genpd_dev_need_restore); - -/** * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain. * @genpd: Master PM domain to add the subdomain to. * @subdomain: Subdomain to be added. diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 106c69359306..677fb2843553 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -117,20 +117,20 @@ do { \ } while (0) /** - * find_device_opp() - find device_opp struct using device pointer + * _find_device_opp() - find device_opp struct using device pointer * @dev: device pointer used to lookup device OPPs * * Search list of device OPPs for one containing matching device. Does a RCU * reader operation to grab the pointer needed. * - * Returns pointer to 'struct device_opp' if found, otherwise -ENODEV or + * Return: pointer to 'struct device_opp' if found, otherwise -ENODEV or * -EINVAL based on type of error. * * Locking: This function must be called under rcu_read_lock(). device_opp * is a RCU protected pointer. This means that device_opp is valid as long * as we are under RCU lock. */ -static struct device_opp *find_device_opp(struct device *dev) +static struct device_opp *_find_device_opp(struct device *dev) { struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV); @@ -153,7 +153,7 @@ static struct device_opp *find_device_opp(struct device *dev) * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an available opp * @opp: opp for which voltage has to be returned for * - * Return voltage in micro volt corresponding to the opp, else + * Return: voltage in micro volt corresponding to the opp, else * return 0 * * Locking: This function must be called under rcu_read_lock(). opp is a rcu @@ -169,6 +169,8 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) struct dev_pm_opp *tmp_opp; unsigned long v = 0; + opp_rcu_lockdep_assert(); + tmp_opp = rcu_dereference(opp); if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available) pr_err("%s: Invalid parameters\n", __func__); @@ -183,7 +185,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage); * dev_pm_opp_get_freq() - Gets the frequency corresponding to an available opp * @opp: opp for which frequency has to be returned for * - * Return frequency in hertz corresponding to the opp, else + * Return: frequency in hertz corresponding to the opp, else * return 0 * * Locking: This function must be called under rcu_read_lock(). opp is a rcu @@ -199,6 +201,8 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp) struct dev_pm_opp *tmp_opp; unsigned long f = 0; + opp_rcu_lockdep_assert(); + tmp_opp = rcu_dereference(opp); if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available) pr_err("%s: Invalid parameters\n", __func__); @@ -213,7 +217,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq); * dev_pm_opp_get_opp_count() - Get number of opps available in the opp list * @dev: device for which we do this operation * - * This function returns the number of available opps if there are any, + * Return: This function returns the number of available opps if there are any, * else returns 0 if none or the corresponding error value. * * Locking: This function takes rcu_read_lock(). @@ -226,7 +230,7 @@ int dev_pm_opp_get_opp_count(struct device *dev) rcu_read_lock(); - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) { count = PTR_ERR(dev_opp); dev_err(dev, "%s: device OPP not found (%d)\n", @@ -251,9 +255,9 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count); * @freq: frequency to search for * @available: true/false - match for available opp * - * Searches for exact match in the opp list and returns pointer to the matching - * opp if found, else returns ERR_PTR in case of error and should be handled - * using IS_ERR. Error return values can be: + * Return: Searches for exact match in the opp list and returns pointer to the + * matching opp if found, else returns ERR_PTR in case of error and should + * be handled using IS_ERR. Error return values can be: * EINVAL: for bad pointer * ERANGE: no match found for search * ENODEV: if device not found in list of registered devices @@ -280,7 +284,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, opp_rcu_lockdep_assert(); - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) { int r = PTR_ERR(dev_opp); dev_err(dev, "%s: device OPP not found (%d)\n", __func__, r); @@ -307,7 +311,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact); * Search for the matching ceil *available* OPP from a starting freq * for a device. * - * Returns matching *opp and refreshes *freq accordingly, else returns + * Return: matching *opp and refreshes *freq accordingly, else returns * ERR_PTR in case of error and should be handled using IS_ERR. Error return * values can be: * EINVAL: for bad pointer @@ -333,7 +337,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, return ERR_PTR(-EINVAL); } - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) return ERR_CAST(dev_opp); @@ -357,7 +361,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil); * Search for the matching floor *available* OPP from a starting freq * for a device. * - * Returns matching *opp and refreshes *freq accordingly, else returns + * Return: matching *opp and refreshes *freq accordingly, else returns * ERR_PTR in case of error and should be handled using IS_ERR. Error return * values can be: * EINVAL: for bad pointer @@ -383,7 +387,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, return ERR_PTR(-EINVAL); } - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) return ERR_CAST(dev_opp); @@ -403,7 +407,16 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); -static struct device_opp *add_device_opp(struct device *dev) +/** + * _add_device_opp() - Allocate a new device OPP table + * @dev: device for which we do this operation + * + * New device node which uses OPPs - used when multiple devices with OPP tables + * are maintained. + * + * Return: valid device_opp pointer if success, else NULL. + */ +static struct device_opp *_add_device_opp(struct device *dev) { struct device_opp *dev_opp; @@ -424,8 +437,35 @@ static struct device_opp *add_device_opp(struct device *dev) return dev_opp; } -static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq, - unsigned long u_volt, bool dynamic) +/** + * _opp_add_dynamic() - Allocate a dynamic OPP. + * @dev: device for which we do this operation + * @freq: Frequency in Hz for this OPP + * @u_volt: Voltage in uVolts for this OPP + * @dynamic: Dynamically added OPPs. + * + * 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 and may be removed by dev_pm_opp_remove. + * + * NOTE: "dynamic" parameter impacts OPPs added by the of_init_opp_table and + * freed by of_free_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 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 + */ +static int _opp_add_dynamic(struct device *dev, unsigned long freq, + long u_volt, bool dynamic) { struct device_opp *dev_opp = NULL; struct dev_pm_opp *opp, *new_opp; @@ -434,10 +474,8 @@ static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq, /* allocate new OPP node */ new_opp = kzalloc(sizeof(*new_opp), GFP_KERNEL); - if (!new_opp) { - dev_warn(dev, "%s: Unable to create new OPP node\n", __func__); + if (!new_opp) return -ENOMEM; - } /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); @@ -449,9 +487,9 @@ static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq, new_opp->dynamic = dynamic; /* Check for existing list for 'dev' */ - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) { - dev_opp = add_device_opp(dev); + dev_opp = _add_device_opp(dev); if (!dev_opp) { ret = -ENOMEM; goto free_opp; @@ -519,34 +557,53 @@ free_opp: * mutex cannot be locked. * * Return: - * 0: On success OR + * 0 On success OR * Duplicate OPPs (both freq and volt are same) and opp->available - * -EEXIST: Freq are same and volt are different OR + * -EEXIST Freq are same and volt are different OR * Duplicate OPPs (both freq and volt are same) and !opp->available - * -ENOMEM: Memory allocation failure + * -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); + return _opp_add_dynamic(dev, freq, u_volt, true); } EXPORT_SYMBOL_GPL(dev_pm_opp_add); -static void kfree_opp_rcu(struct rcu_head *head) +/** + * _kfree_opp_rcu() - Free OPP RCU handler + * @head: RCU head + */ +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) +/** + * _kfree_device_rcu() - Free device_opp RCU handler + * @head: 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_rcu(device_opp, rcu_head); } -static void __dev_pm_opp_remove(struct device_opp *dev_opp, - struct dev_pm_opp *opp) +/** + * _opp_remove() - Remove an OPP from a table definition + * @dev_opp: points back to the device_opp struct this opp belongs to + * @opp: pointer to the OPP to remove + * + * This function removes an opp definition from the opp list. + * + * Locking: The internal device_opp and opp structures are RCU protected. + * It is assumed that the caller holds required mutex for an RCU updater + * strategy. + */ +static void _opp_remove(struct device_opp *dev_opp, + struct dev_pm_opp *opp) { /* * Notify the changes in the availability of the operable @@ -554,12 +611,12 @@ static void __dev_pm_opp_remove(struct device_opp *dev_opp, */ 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); + 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); + _kfree_device_rcu); } } @@ -569,6 +626,12 @@ static void __dev_pm_opp_remove(struct device_opp *dev_opp, * @freq: OPP to remove with matching 'freq' * * This function removes an opp from the opp list. + * + * 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. */ void dev_pm_opp_remove(struct device *dev, unsigned long freq) { @@ -579,7 +642,7 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) goto unlock; @@ -596,14 +659,14 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) goto unlock; } - __dev_pm_opp_remove(dev_opp, opp); + _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 + * _opp_set_availability() - helper to set the availability of an opp * @dev: device for which we do this operation * @freq: OPP frequency to modify availability * @availability_req: availability status requested for this opp @@ -611,7 +674,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove); * Set the availability of an OPP with an RCU operation, opp_{enable,disable} * share a common logic which is isolated here. * - * Returns -EINVAL for bad pointers, -ENOMEM if no memory available for the + * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the * copy operation, returns 0 if no modifcation was done OR modification was * successful. * @@ -621,8 +684,8 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove); * that this function is *NOT* called under RCU protection or in contexts where * mutex locking or synchronize_rcu() blocking calls cannot be used. */ -static int opp_set_availability(struct device *dev, unsigned long freq, - bool availability_req) +static int _opp_set_availability(struct device *dev, unsigned long freq, + bool availability_req) { struct device_opp *dev_opp; struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV); @@ -630,15 +693,13 @@ static int opp_set_availability(struct device *dev, unsigned long freq, /* keep the node allocated */ new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL); - if (!new_opp) { - dev_warn(dev, "%s: Unable to create OPP\n", __func__); + if (!new_opp) return -ENOMEM; - } mutex_lock(&dev_opp_list_lock); /* Find the device_opp */ - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) { r = PTR_ERR(dev_opp); dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r); @@ -668,7 +729,7 @@ 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); - call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, kfree_opp_rcu); + call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu); /* Notify the change of the OPP availability */ if (availability_req) @@ -700,10 +761,14 @@ unlock: * 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. + * + * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the + * copy operation, returns 0 if no modifcation was done OR modification was + * successful. */ int dev_pm_opp_enable(struct device *dev, unsigned long freq) { - return opp_set_availability(dev, freq, true); + return _opp_set_availability(dev, freq, true); } EXPORT_SYMBOL_GPL(dev_pm_opp_enable); @@ -722,26 +787,41 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_enable); * 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. + * + * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the + * copy operation, returns 0 if no modifcation was done OR modification was + * successful. */ int dev_pm_opp_disable(struct device *dev, unsigned long freq) { - return opp_set_availability(dev, freq, false); + return _opp_set_availability(dev, freq, false); } 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 device OPPs. + * + * 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. + * + * Locking: This function must be called under rcu_read_lock(). dev_opp 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. */ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) { - struct device_opp *dev_opp = find_device_opp(dev); + struct device_opp *dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) return ERR_CAST(dev_opp); /* matching type */ return &dev_opp->srcu_head; } +EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier); #ifdef CONFIG_OF /** @@ -749,6 +829,22 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) * @dev: device pointer used to lookup device OPPs. * * Register the initial OPP table with the OPP library for given device. + * + * Locking: The internal device_opp and opp structures are RCU protected. + * Hence this function indirectly 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 + * -ENODEV when 'operating-points' property is not found or is invalid data + * in device node. + * -ENODATA when empty 'operating-points' property is found */ int of_init_opp_table(struct device *dev) { @@ -777,7 +873,7 @@ 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_dynamic(dev, freq, volt, false)) + if (_opp_add_dynamic(dev, freq, volt, false)) dev_warn(dev, "%s: Failed to add OPP %ld\n", __func__, freq); nr -= 2; @@ -792,6 +888,12 @@ EXPORT_SYMBOL_GPL(of_init_opp_table); * @dev: device pointer used to lookup device OPPs. * * Free OPPs created using static entries present in DT. + * + * Locking: The internal device_opp and opp structures are RCU protected. + * Hence this function indirectly 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. */ void of_free_opp_table(struct device *dev) { @@ -799,7 +901,7 @@ void of_free_opp_table(struct device *dev) struct dev_pm_opp *opp, *tmp; /* Check for existing list for 'dev' */ - dev_opp = find_device_opp(dev); + dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) { int error = PTR_ERR(dev_opp); if (error != -ENODEV) @@ -816,7 +918,7 @@ void of_free_opp_table(struct device *dev) /* 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); + _opp_remove(dev_opp, opp); } mutex_unlock(&dev_opp_list_lock); diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index a8fe4c1a8d07..e56d538d039e 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -64,6 +64,8 @@ enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask) struct pm_qos_flags *pqf; s32 val; + lockdep_assert_held(&dev->power.lock); + if (IS_ERR_OR_NULL(qos)) return PM_QOS_FLAGS_UNDEFINED; @@ -104,6 +106,8 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_flags); */ s32 __dev_pm_qos_read_value(struct device *dev) { + lockdep_assert_held(&dev->power.lock); + return IS_ERR_OR_NULL(dev->power.qos) ? 0 : pm_qos_read_value(&dev->power.qos->resume_latency); } |