There are two types of duplicate OPPs that get different behavior from the core: A). An earlier OPP is marked 'available' and has same freq/voltages as the new one. B). An earlier OPP with same frequency, but is marked 'unavailable' OR doesn't have same voltages as the new one.

The OPP core returns 0 for the first one, but -EEXIST for the second.

While the OPP core returns 0 for the first case, its callers don't free the newly allocated OPP structure which isn't used anymore. Fix that by returning -EBUSY instead of 0, but make the callers return 0 eventually.

As this isn't a critical fix, its not getting marked for stable kernel.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/base/power/opp/core.c | 18 ++++++++++++++++-- drivers/base/power/opp/of.c | 6 +++++- 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index a0e6294baf1d..9ff816217c6e 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -1080,6 +1080,16 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp, return true; }

+/* + * Returns: + * 0: On success. And appropriate error message for duplicate OPPs. + * -EBUSY: For OPP with same freq/volt and is available. The callers of + * _opp_add() must return 0 if they receive -EBUSY from it. This is to make + * sure we don't print error messages unnecessarily if different parts of + * kernel try to initialize the OPP table. + * -EEXIST: For OPP with same freq but different volt or is unavailable. This + * should be considered an error by the callers of _opp_add(). + */ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table) { @@ -1112,7 +1122,7 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,

/* Should we compare voltages for all regulators here ? */ return opp->available && - new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST; + new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST; }

new_opp->opp_table = opp_table; @@ -1186,8 +1196,12 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, new_opp->dynamic = dynamic;

ret = _opp_add(dev, new_opp, opp_table); - if (ret) + if (ret) { + /* Don't return error for duplicate OPPs */ + if (ret == -EBUSY) + ret = 0; goto free_opp; + }

mutex_unlock(&opp_table_lock);

diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c index 3f7d2591b173..356c75edd656 100644 --- a/drivers/base/power/opp/of.c +++ b/drivers/base/power/opp/of.c @@ -327,8 +327,12 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) goto free_opp;

ret = _opp_add(dev, new_opp, opp_table); - if (ret) + if (ret) { + /* Don't return error for duplicate OPPs */ + if (ret == -EBUSY) + ret = 0; goto free_opp; + }

/* OPP to select on device suspend */ if (of_property_read_bool(np, "opp-suspend")) {

Make the naming consistent with how other routines are named.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Reviewed-by: Stephen Boyd sboyd@codeaurora.org --- drivers/base/power/opp/core.c | 4 ++-- drivers/base/power/opp/of.c | 2 +- drivers/base/power/opp/opp.h | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 9ff816217c6e..621a3dc94bfe 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -1027,7 +1027,7 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) } EXPORT_SYMBOL_GPL(dev_pm_opp_remove);

-struct dev_pm_opp *_allocate_opp(struct device *dev, +struct dev_pm_opp *_opp_allocate(struct device *dev, struct opp_table **opp_table) { struct dev_pm_opp *opp; @@ -1180,7 +1180,7 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, /* Hold our table modification lock here */ mutex_lock(&opp_table_lock);

- new_opp = _allocate_opp(dev, &opp_table); + new_opp = _opp_allocate(dev, &opp_table); if (!new_opp) { ret = -ENOMEM; goto unlock; diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c index 996ca3b42f47..f8512ca2bf41 100644 --- a/drivers/base/power/opp/of.c +++ b/drivers/base/power/opp/of.c @@ -287,7 +287,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) /* Hold our table modification lock here */ mutex_lock(&opp_table_lock);

- new_opp = _allocate_opp(dev, &opp_table); + new_opp = _opp_allocate(dev, &opp_table); if (!new_opp) { ret = -ENOMEM; goto unlock; diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h index af9f2b849a66..0f23a1059605 100644 --- a/drivers/base/power/opp/opp.h +++ b/drivers/base/power/opp/opp.h @@ -193,7 +193,7 @@ struct opp_table { struct opp_table *_find_opp_table(struct device *dev); struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table); void _dev_pm_opp_remove_table(struct device *dev, bool remove_all); -struct dev_pm_opp *_allocate_opp(struct device *dev, struct opp_table **opp_table); +struct dev_pm_opp *_opp_allocate(struct device *dev, struct opp_table **opp_table); int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table); void _opp_remove(struct opp_table *opp_table, struct dev_pm_opp *opp, bool notify); int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, bool dynamic);

The OPPs which are never successfully added using _opp_add() are not required to be freed with the _opp_remove() routine, as a simple kfree() is enough for them.

Introduce a new light weight routine _opp_free(), which will do that.

That also helps us removing the 'notify' parameter to _opp_remove(), which isn't required anymore.

Note that _opp_free() contains a call to _remove_opp_table() as the OPP table might have been added for this very OPP only. The _remove_opp_table() routine returns quickly if there are more OPPs in the table. This will be simplified in later patches though.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Reviewed-by: Stephen Boyd sboyd@codeaurora.org --- drivers/base/power/opp/core.c | 20 +++++++++++--------- drivers/base/power/opp/of.c | 2 +- drivers/base/power/opp/opp.h | 2 +- 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 621a3dc94bfe..2f3dbca282ba 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -942,6 +942,12 @@ static void _remove_opp_table(struct opp_table *opp_table) _kfree_device_rcu); }

+void _opp_free(struct dev_pm_opp *opp, struct opp_table *opp_table) +{ + kfree(opp); + _remove_opp_table(opp_table); +} + /** * _kfree_opp_rcu() - Free OPP RCU handler * @head: RCU head @@ -957,7 +963,6 @@ static void _kfree_opp_rcu(struct rcu_head *head) * _opp_remove() - Remove an OPP from a table definition * @opp_table: points back to the opp_table struct this opp belongs to * @opp: pointer to the OPP to remove - * @notify: OPP_EVENT_REMOVE notification should be sent or not * * This function removes an opp definition from the opp table. * @@ -965,16 +970,13 @@ static void _kfree_opp_rcu(struct rcu_head *head) * It is assumed that the caller holds required mutex for an RCU updater * strategy. */ -void _opp_remove(struct opp_table *opp_table, struct dev_pm_opp *opp, - bool notify) +static void _opp_remove(struct opp_table *opp_table, struct dev_pm_opp *opp) { /* * Notify the changes in the availability of the operable * frequency/voltage list. */ - if (notify) - srcu_notifier_call_chain(&opp_table->srcu_head, - OPP_EVENT_REMOVE, opp); + srcu_notifier_call_chain(&opp_table->srcu_head, OPP_EVENT_REMOVE, opp); opp_debug_remove_one(opp); list_del_rcu(&opp->node); call_srcu(&opp_table->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu); @@ -1021,7 +1023,7 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) goto unlock; }

- _opp_remove(opp_table, opp, true); + _opp_remove(opp_table, opp); unlock: mutex_unlock(&opp_table_lock); } @@ -1213,7 +1215,7 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, return 0;

free_opp: - _opp_remove(opp_table, new_opp, false); + _opp_free(new_opp, opp_table); unlock: mutex_unlock(&opp_table_lock); return ret; @@ -1925,7 +1927,7 @@ void _dev_pm_opp_remove_table(struct device *dev, bool remove_all) /* Free static OPPs */ list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) { if (remove_all || !opp->dynamic) - _opp_remove(opp_table, opp, true); + _opp_remove(opp_table, opp); } } else { _remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table); diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c index c8fe815774ff..67c9eeded4e1 100644 --- a/drivers/base/power/opp/of.c +++ b/drivers/base/power/opp/of.c @@ -362,7 +362,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) return 0;

free_opp: - _opp_remove(opp_table, new_opp, false); + _opp_free(new_opp, opp_table); unlock: mutex_unlock(&opp_table_lock); return ret; diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h index 0f23a1059605..334f7570df32 100644 --- a/drivers/base/power/opp/opp.h +++ b/drivers/base/power/opp/opp.h @@ -194,8 +194,8 @@ struct opp_table *_find_opp_table(struct device *dev); struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table); void _dev_pm_opp_remove_table(struct device *dev, bool remove_all); struct dev_pm_opp *_opp_allocate(struct device *dev, struct opp_table **opp_table); +void _opp_free(struct dev_pm_opp *opp, struct opp_table *opp_table); int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table); -void _opp_remove(struct opp_table *opp_table, struct dev_pm_opp *opp, bool notify); int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, bool dynamic); void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, bool of);

There is no point in trying to find/allocate the table for every OPP that is added for a device. It would be far more efficient to allocate the table only once and pass its pointer to the routines that add the OPP entry.

Locking is removed from _opp_add_static_v2() and _opp_add_v1() now as the callers call them with that lock already held.

Call to _remove_opp_table() routine is also removed from _opp_free() now, as opp_table isn't allocated from within _opp_allocate(). This is handled by the routines which created the OPP table in the first place.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/base/power/opp/core.c | 66 +++++++++++++++++++------------------ drivers/base/power/opp/of.c | 75 ++++++++++++++++++++++--------------------- drivers/base/power/opp/opp.h | 9 ++++-- 3 files changed, 78 insertions(+), 72 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 11496fbb2ee2..6f61809c5760 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -842,7 +842,7 @@ struct opp_device *_add_opp_dev(const struct device *dev, * * Return: valid opp_table pointer if success, else NULL. */ -static struct opp_table *_add_opp_table(struct device *dev) +struct opp_table *_add_opp_table(struct device *dev) { struct opp_table *opp_table; struct opp_device *opp_dev; @@ -942,10 +942,9 @@ static void _remove_opp_table(struct opp_table *opp_table) _kfree_device_rcu); }

-void _opp_free(struct dev_pm_opp *opp, struct opp_table *opp_table) +void _opp_free(struct dev_pm_opp *opp) { kfree(opp); - _remove_opp_table(opp_table); }

/** @@ -1030,15 +1029,10 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) EXPORT_SYMBOL_GPL(dev_pm_opp_remove);

struct dev_pm_opp *_opp_allocate(struct device *dev, - struct opp_table **opp_table) + struct opp_table *table) { struct dev_pm_opp *opp; int count, supply_size; - struct opp_table *table; - - table = _add_opp_table(dev); - if (!table) - return NULL;

/* Allocate space for at least one supply */ count = table->regulator_count ? table->regulator_count : 1; @@ -1046,17 +1040,13 @@ struct dev_pm_opp *_opp_allocate(struct device *dev,

/* allocate new OPP node and supplies structures */ opp = kzalloc(sizeof(*opp) + supply_size, GFP_KERNEL); - if (!opp) { - kfree(table); + if (!opp) return NULL; - }

/* Put the supplies at the end of the OPP structure as an empty array */ opp->supplies = (struct dev_pm_opp_supply *)(opp + 1); INIT_LIST_HEAD(&opp->node);

- *opp_table = table; - return opp; }

@@ -1146,6 +1136,7 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,

/** * _opp_add_v1() - Allocate a OPP based on v1 bindings. + * @opp_table: OPP table * @dev: device for which we do this operation * @freq: Frequency in Hz for this OPP * @u_volt: Voltage in uVolts for this OPP @@ -1171,22 +1162,18 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, * Duplicate OPPs (both freq and volt are same) and !opp->available * -ENOMEM Memory allocation failure */ -int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, - bool dynamic) +int _opp_add_v1(struct opp_table *opp_table, struct device *dev, + unsigned long freq, long u_volt, bool dynamic) { - struct opp_table *opp_table; struct dev_pm_opp *new_opp; unsigned long tol; int ret;

- /* Hold our table modification lock here */ - mutex_lock(&opp_table_lock); + opp_rcu_lockdep_assert();

- new_opp = _opp_allocate(dev, &opp_table); - if (!new_opp) { - ret = -ENOMEM; - goto unlock; - } + new_opp = _opp_allocate(dev, opp_table); + if (!new_opp) + return -ENOMEM;

/* populate the opp table */ new_opp->rate = freq; @@ -1205,8 +1192,6 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, goto free_opp; }

- mutex_unlock(&opp_table_lock); - /* * Notify the changes in the availability of the operable * frequency/voltage list. @@ -1215,9 +1200,8 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, return 0;

free_opp: - _opp_free(new_opp, opp_table); -unlock: - mutex_unlock(&opp_table_lock); + _opp_free(new_opp); + return ret; }

@@ -1735,7 +1719,25 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_register_put_opp_helper); */ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) { - return _opp_add_v1(dev, freq, u_volt, true); + struct opp_table *opp_table; + int ret; + + /* Hold our table modification lock here */ + mutex_lock(&opp_table_lock); + + opp_table = _add_opp_table(dev); + if (!opp_table) { + ret = -ENOMEM; + goto unlock; + } + + ret = _opp_add_v1(opp_table, dev, freq, u_volt, true); + if (ret) + _remove_opp_table(opp_table); + +unlock: + mutex_unlock(&opp_table_lock); + return ret; } EXPORT_SYMBOL_GPL(dev_pm_opp_add);

@@ -1901,8 +1903,8 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier); * Free OPPs either created using static entries present in DT or even the * dynamically added entries based on remove_all param. */ -static void _dev_pm_opp_remove_table(struct opp_table *opp_table, - struct device *dev, bool remove_all) +void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev, + bool remove_all) { struct dev_pm_opp *opp, *tmp;

diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c index 442fa46c4f5c..38efc14d829c 100644 --- a/drivers/base/power/opp/of.c +++ b/drivers/base/power/opp/of.c @@ -255,6 +255,7 @@ static struct device_node *_of_get_opp_desc_node(struct device *dev)

/** * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings) + * @opp_table: OPP table * @dev: device for which we do this operation * @np: device node * @@ -276,22 +277,17 @@ static struct device_node *_of_get_opp_desc_node(struct device *dev) * -ENOMEM Memory allocation failure * -EINVAL Failed parsing the OPP node */ -static int _opp_add_static_v2(struct device *dev, struct device_node *np) +static int _opp_add_static_v2(struct opp_table *opp_table, struct device *dev, + struct device_node *np) { - struct opp_table *opp_table; struct dev_pm_opp *new_opp; u64 rate; u32 val; int ret;

- /* Hold our table modification lock here */ - mutex_lock(&opp_table_lock); - - new_opp = _opp_allocate(dev, &opp_table); - if (!new_opp) { - ret = -ENOMEM; - goto unlock; - } + new_opp = _opp_allocate(dev, opp_table); + if (!new_opp) + return -ENOMEM;

ret = of_property_read_u64(np, "opp-hz", &rate); if (ret < 0) { @@ -347,8 +343,6 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max) opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;

- mutex_unlock(&opp_table_lock); - pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n", __func__, new_opp->turbo, new_opp->rate, new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min, @@ -362,9 +356,8 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) return 0;

free_opp: - _opp_free(new_opp, opp_table); -unlock: - mutex_unlock(&opp_table_lock); + _opp_free(new_opp); + return ret; }

@@ -382,16 +375,20 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) /* OPPs are already managed */ if (!_add_opp_dev(dev, opp_table)) ret = -ENOMEM; - mutex_unlock(&opp_table_lock); - return ret; + goto unlock; + } + + opp_table = _add_opp_table(dev); + if (!opp_table) { + ret = -ENOMEM; + goto unlock; } - mutex_unlock(&opp_table_lock);

/* We have opp-table node now, iterate over it and add OPPs */ for_each_available_child_of_node(opp_np, np) { count++;

- ret = _opp_add_static_v2(dev, np); + ret = _opp_add_static_v2(opp_table, dev, np); if (ret) { dev_err(dev, "%s: Failed to add OPP, %d\n", __func__, ret); @@ -400,15 +397,8 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) }

/* There should be one of more OPP defined */ - if (WARN_ON(!count)) - return -ENOENT; - - mutex_lock(&opp_table_lock); - - opp_table = _find_opp_table(dev); - if (WARN_ON(IS_ERR(opp_table))) { - ret = PTR_ERR(opp_table); - mutex_unlock(&opp_table_lock); + if (WARN_ON(!count)) { + ret = -ENOENT; goto free_table; }

@@ -418,12 +408,12 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) else opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;

- mutex_unlock(&opp_table_lock); - - return 0; + goto unlock;

free_table: - dev_pm_opp_of_remove_table(dev); + _dev_pm_opp_remove_table(opp_table, dev, false); +unlock: + mutex_unlock(&opp_table_lock);

return ret; } @@ -431,9 +421,10 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) /* Initializes OPP tables based on old-deprecated bindings */ static int _of_add_opp_table_v1(struct device *dev) { + struct opp_table *opp_table; const struct property *prop; const __be32 *val; - int nr, ret; + int nr, ret = 0;

prop = of_find_property(dev->of_node, "operating-points", NULL); if (!prop) @@ -451,22 +442,32 @@ static int _of_add_opp_table_v1(struct device *dev) return -EINVAL; }

+ mutex_lock(&opp_table_lock); + + opp_table = _add_opp_table(dev); + if (!opp_table) { + ret = -ENOMEM; + goto unlock; + } + val = prop->value; while (nr) { unsigned long freq = be32_to_cpup(val++) * 1000; unsigned long volt = be32_to_cpup(val++);

- ret = _opp_add_v1(dev, freq, volt, false); + ret = _opp_add_v1(opp_table, dev, freq, volt, false); if (ret) { dev_err(dev, "%s: Failed to add OPP %ld (%d)\n", __func__, freq, ret); - dev_pm_opp_of_remove_table(dev); - return ret; + _dev_pm_opp_remove_table(opp_table, dev, false); + break; } nr -= 2; }

- return 0; +unlock: + mutex_unlock(&opp_table_lock); + return ret; }

/** diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h index c4b539a8533a..e32dc80ddc12 100644 --- a/drivers/base/power/opp/opp.h +++ b/drivers/base/power/opp/opp.h @@ -191,13 +191,16 @@ struct opp_table {

/* Routines internal to opp core */ struct opp_table *_find_opp_table(struct device *dev); +struct opp_table *_add_opp_table(struct device *dev); struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table); +void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev, bool remove_all); void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all); -struct dev_pm_opp *_opp_allocate(struct device *dev, struct opp_table **opp_table); -void _opp_free(struct dev_pm_opp *opp, struct opp_table *opp_table); +struct dev_pm_opp *_opp_allocate(struct device *dev, struct opp_table *opp_table); +void _opp_free(struct dev_pm_opp *opp); int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table); -int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, bool dynamic); +int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic); void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, bool of); +struct opp_table *_add_opp_table(struct device *dev);

#ifdef CONFIG_OF void _of_init_opp_table(struct opp_table *opp_table, struct device *dev);

Let the OPP core provide helpers to register notifiers for any device, instead of exposing srcu_head outside of the core.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Acked-by: MyungJoo Ham myungjoo.ham@samsung.com Reviewed-by: Stephen Boyd sboyd@codeaurora.org --- drivers/base/power/opp/core.c | 66 ++++++++++++++++++++++++++++++++----------- drivers/devfreq/devfreq.c | 26 ++--------------- include/linux/pm_opp.h | 14 ++++++--- 3 files changed, 62 insertions(+), 44 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index dfbe0610b675..074a42185819 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -1874,29 +1874,63 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq) 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 OPP table. + * dev_pm_opp_register_notifier() - Register OPP notifier for the device + * @dev: Device for which notifier needs to be registered + * @nb: Notifier block to be registered * - * 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. + * Return: 0 on success or a negative error value. + */ +int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb) +{ + struct opp_table *opp_table; + int ret; + + rcu_read_lock(); + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) { + ret = PTR_ERR(opp_table); + goto unlock; + } + + ret = srcu_notifier_chain_register(&opp_table->srcu_head, nb); + +unlock: + rcu_read_unlock(); + + return ret; +} +EXPORT_SYMBOL(dev_pm_opp_register_notifier); + +/** + * dev_pm_opp_unregister_notifier() - Unregister OPP notifier for the device + * @dev: Device for which notifier needs to be unregistered + * @nb: Notifier block to be unregistered * - * Locking: This function must be called under rcu_read_lock(). opp_table 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. + * Return: 0 on success or a negative error value. */ -struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) +int dev_pm_opp_unregister_notifier(struct device *dev, + struct notifier_block *nb) { - struct opp_table *opp_table = _find_opp_table(dev); + struct opp_table *opp_table; + int ret;

- if (IS_ERR(opp_table)) - return ERR_CAST(opp_table); /* matching type */ + rcu_read_lock(); + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) { + ret = PTR_ERR(opp_table); + goto unlock; + } + + ret = srcu_notifier_chain_unregister(&opp_table->srcu_head, nb);

- return &opp_table->srcu_head; +unlock: + rcu_read_unlock(); + + return ret; } -EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier); +EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);

/* * Free OPPs either created using static entries present in DT or even the diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index a324801d6a66..b0de42972b74 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -1260,18 +1260,7 @@ EXPORT_SYMBOL(devfreq_recommended_opp); */ int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) { - struct srcu_notifier_head *nh; - int ret = 0; - - rcu_read_lock(); - nh = dev_pm_opp_get_notifier(dev); - if (IS_ERR(nh)) - ret = PTR_ERR(nh); - rcu_read_unlock(); - if (!ret) - ret = srcu_notifier_chain_register(nh, &devfreq->nb); - - return ret; + return dev_pm_opp_register_notifier(dev, &devfreq->nb); } EXPORT_SYMBOL(devfreq_register_opp_notifier);

@@ -1287,18 +1276,7 @@ EXPORT_SYMBOL(devfreq_register_opp_notifier); */ int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) { - struct srcu_notifier_head *nh; - int ret = 0; - - rcu_read_lock(); - nh = dev_pm_opp_get_notifier(dev); - if (IS_ERR(nh)) - ret = PTR_ERR(nh); - rcu_read_unlock(); - if (!ret) - ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); - - return ret; + return dev_pm_opp_unregister_notifier(dev, &devfreq->nb); } EXPORT_SYMBOL(devfreq_unregister_opp_notifier);

diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 7483ff291a8e..66a02deeb03f 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -108,7 +108,9 @@ 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); +int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb); +int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb); + int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions, unsigned int count); void dev_pm_opp_put_supported_hw(struct device *dev); @@ -202,10 +204,14 @@ static inline int dev_pm_opp_disable(struct device *dev, unsigned long freq) return 0; }

-static inline struct srcu_notifier_head *dev_pm_opp_get_notifier( - struct device *dev) +static inline int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb) { - return ERR_PTR(-ENOTSUPP); + return -ENOTSUPP; +} + +static inline int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb) +{ + return -ENOTSUPP; }

static inline int dev_pm_opp_set_supported_hw(struct device *dev,