From 4679ec3727a0eb4d57e23dffa8e19ce911362c9f Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Wed, 24 Dec 2014 11:22:55 -0600 Subject: PM / OPP: export dev_pm_opp_get_notifier Allows user drivers such as devfreq to be modules. Signed-off-by: Nishanth Menon Signed-off-by: Rafael J. Wysocki --- drivers/base/power/opp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/base') diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 106c69359306..435c94e93263 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -742,6 +742,7 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) return &dev_opp->srcu_head; } +EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier); #ifdef CONFIG_OF /** -- cgit From 327854c871178af58461b34f116a0300fbb3a74f Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Wed, 24 Dec 2014 11:22:56 -0600 Subject: PM / OPP: Ensure consistent naming of static functions All exported functions use dev_pm_* prefix and all static functions are now standardized with _ prefix. This is better than having to deal with multiple function naming styles within the same file. Signed-off-by: Nishanth Menon Signed-off-by: Rafael J. Wysocki --- drivers/base/power/opp.c | 62 ++++++++++++++++++++++++------------------------ 1 file changed, 31 insertions(+), 31 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 435c94e93263..f4aa85a72d36 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -117,7 +117,7 @@ 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 @@ -130,7 +130,7 @@ do { \ * 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); @@ -226,7 +226,7 @@ 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", @@ -280,7 +280,7 @@ 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); @@ -333,7 +333,7 @@ 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); @@ -383,7 +383,7 @@ 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 +403,7 @@ 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) +static struct device_opp *_add_device_opp(struct device *dev) { struct device_opp *dev_opp; @@ -424,8 +424,8 @@ 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) +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; @@ -449,9 +449,9 @@ 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; @@ -527,26 +527,26 @@ free_opp: */ 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) +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) +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) +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 +554,12 @@ 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); } } @@ -579,7 +579,7 @@ 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 +596,14 @@ 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 @@ -621,8 +621,8 @@ 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); @@ -638,7 +638,7 @@ static int opp_set_availability(struct device *dev, unsigned long freq, 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 +668,7 @@ 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) @@ -703,7 +703,7 @@ unlock: */ 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); @@ -725,7 +725,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_enable); */ 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); @@ -735,7 +735,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_disable); */ 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 */ @@ -778,7 +778,7 @@ 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; @@ -800,7 +800,7 @@ 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) @@ -817,7 +817,7 @@ 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); -- cgit From 984f16c8490cba715444124a453ed4a2ac7a5a54 Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Wed, 24 Dec 2014 11:22:57 -0600 Subject: PM / OPP: Update kernel documentation kernel doc has gotten bit-rotted over time. Re-sync with Locking and Return information. document all functions properly and ensure that ./scripts/kernel-doc -v ./drivers/base/power/opp.c >/dev/null returns no errors Signed-off-by: Nishanth Menon Signed-off-by: Rafael J. Wysocki --- drivers/base/power/opp.c | 127 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 114 insertions(+), 13 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index f4aa85a72d36..1d20e095569c 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -123,7 +123,7 @@ do { \ * 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 @@ -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 @@ -183,7 +183,7 @@ 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 @@ -213,7 +213,7 @@ 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(). @@ -251,9 +251,9 @@ 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 @@ -307,7 +307,7 @@ 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 @@ -357,7 +357,7 @@ 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 @@ -403,6 +403,15 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); +/** + * _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; @@ -424,6 +433,33 @@ static struct device_opp *_add_device_opp(struct device *dev) return dev_opp; } +/** + * _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) { @@ -519,11 +555,11 @@ 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) { @@ -531,6 +567,10 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) } EXPORT_SYMBOL_GPL(dev_pm_opp_add); +/** + * _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); @@ -538,6 +578,10 @@ static void _kfree_opp_rcu(struct rcu_head *head) kfree_rcu(opp, rcu_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); @@ -545,6 +589,17 @@ static void _kfree_device_rcu(struct rcu_head *head) kfree_rcu(device_opp, rcu_head); } +/** + * _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) { @@ -569,6 +624,12 @@ static void _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) { @@ -611,7 +672,7 @@ 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. * @@ -700,6 +761,10 @@ 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) { @@ -722,6 +787,10 @@ 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) { @@ -732,6 +801,16 @@ 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) { @@ -750,6 +829,22 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier); * @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) { @@ -793,6 +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) { -- cgit From f90b8ad83a6ae984edb6b489ed02e45dadfd263e Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 9 Jan 2015 09:27:58 +0100 Subject: PM / QoS: Use lockdep asserts to find missing hold of power.lock Add lockdep asserts for holding the dev->power.lock to non-static functions which require this. They could be used outside of the file so asserts may help in detecting locking misuse. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Rafael J. Wysocki --- drivers/base/power/qos.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/base') 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); } -- cgit From 04bf1c7f76b05be8134a833ec023f1c96f81b8a1 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 9 Jan 2015 09:27:57 +0100 Subject: PM / OPP: Assert RCU lock in exported functions Add lockdep asserts for holding the RCU lock when calling dev_pm_opp_get_freq() and dev_pm_opp_get_voltage() to aid in detecting RCU misuses. These are called often after dev_pm_opp_find_freq_ceil/exact() which already asserts for RCU lock. However one could make an error by releasing lock too early - just after dev_pm_opp_find_freq_ceil(). Signed-off-by: Krzysztof Kozlowski Signed-off-by: Rafael J. Wysocki --- drivers/base/power/opp.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 1d20e095569c..15bf29974c31 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -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__); @@ -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__); -- cgit