From cdd6ed90cdb6c2fd982909501f0a109274147fb4 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Wed, 12 Sep 2018 12:35:19 +0530 Subject: OPP: Use a single mechanism to free the OPP table Currently there are two separate ways to free the OPP table based on how it is created in the first place. We call _dev_pm_opp_remove_table() to free the static and/or dynamic OPP, OPP list devices, etc. This is done for the case where the OPP table is added while initializing the OPPs, like via the path dev_pm_opp_of_add_table(). We also call dev_pm_opp_put_opp_table() in some cases which eventually frees the OPP table structure once the reference count reaches 0. This is used by the first case as well as other cases like dev_pm_opp_set_regulators() where the OPPs aren't necessarily initialized at this point. This whole thing is a bit unclear and messy and obstruct any further cleanup/fixup of OPP core. This patch tries to streamline this by keeping a single path for OPP table destruction, i.e. dev_pm_opp_put_opp_table(). All the cleanup happens in _opp_table_kref_release() now after the reference count reaches 0. _dev_pm_opp_remove_table() is removed as it isn't required anymore. We don't drop the reference to the OPP table after creating it from _of_add_opp_table_v{1|2}() anymore and the same is dropped only when we try to remove them. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar --- drivers/opp/core.c | 54 ++++++++++++++++-------------------------------------- drivers/opp/of.c | 32 ++++++++++++++++++-------------- drivers/opp/opp.h | 2 +- 3 files changed, 35 insertions(+), 53 deletions(-) diff --git a/drivers/opp/core.c b/drivers/opp/core.c index 2319ad4a0177..d3e33fd32694 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -867,23 +867,24 @@ struct opp_table *dev_pm_opp_get_opp_table_indexed(struct device *dev, static void _opp_table_kref_release(struct kref *kref) { struct opp_table *opp_table = container_of(kref, struct opp_table, kref); - struct opp_device *opp_dev; + struct opp_device *opp_dev, *temp; /* Release clk */ if (!IS_ERR(opp_table->clk)) clk_put(opp_table->clk); - /* - * No need to take opp_table->lock here as we are guaranteed that no - * references to the OPP table are taken at this point. - */ - opp_dev = list_first_entry(&opp_table->dev_list, struct opp_device, - node); + WARN_ON(!list_empty(&opp_table->opp_list)); - _remove_opp_dev(opp_dev, opp_table); + list_for_each_entry_safe(opp_dev, temp, &opp_table->dev_list, node) { + /* + * The OPP table is getting removed, drop the performance state + * constraints. + */ + if (opp_table->genpd_performance_state) + dev_pm_genpd_set_performance_state((struct device *)(opp_dev->dev), 0); - /* dev_list must be empty now */ - WARN_ON(!list_empty(&opp_table->dev_list)); + _remove_opp_dev(opp_dev, opp_table); + } mutex_destroy(&opp_table->lock); list_del(&opp_table->node); @@ -1758,33 +1759,6 @@ int dev_pm_opp_unregister_notifier(struct device *dev, } EXPORT_SYMBOL(dev_pm_opp_unregister_notifier); -/* - * Free OPPs either created using static entries present in DT. - */ -void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev) -{ - /* Protect dev_list */ - mutex_lock(&opp_table->lock); - - /* Find if opp_table manages a single device */ - if (list_is_singular(&opp_table->dev_list)) { - /* Free static OPPs */ - _put_opp_list_kref(opp_table); - - /* - * The OPP table is getting removed, drop the performance state - * constraints. - */ - if (opp_table->genpd_performance_state) - dev_pm_genpd_set_performance_state(dev, 0); - } else { - _put_opp_list_kref(opp_table); - _remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table); - } - - mutex_unlock(&opp_table->lock); -} - void _dev_pm_opp_find_and_remove_table(struct device *dev) { struct opp_table *opp_table; @@ -1802,8 +1776,12 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev) return; } - _dev_pm_opp_remove_table(opp_table, dev); + _put_opp_list_kref(opp_table); + + /* Drop reference taken by _find_opp_table() */ + dev_pm_opp_put_opp_table(opp_table); + /* Drop reference taken while the OPP table was added */ dev_pm_opp_put_opp_table(opp_table); } diff --git a/drivers/opp/of.c b/drivers/opp/of.c index 861cc75de329..ae0436eaa911 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -407,14 +407,17 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np, opp_table = _managed_opp(opp_np); if (opp_table) { /* OPPs are already managed */ - if (!_add_opp_dev(dev, opp_table)) + if (!_add_opp_dev(dev, opp_table)) { ret = -ENOMEM; - else if (!opp_table->parsed_static_opps) - goto initialize_static_opps; - else + goto put_opp_table; + } + + if (opp_table->parsed_static_opps) { kref_get(&opp_table->list_kref); + return 0; + } - goto put_opp_table; + goto initialize_static_opps; } opp_table = dev_pm_opp_get_opp_table_indexed(dev, index); @@ -432,17 +435,15 @@ initialize_static_opps: if (ret) { dev_err(dev, "%s: Failed to add OPP, %d\n", __func__, ret); - _dev_pm_opp_remove_table(opp_table, dev); of_node_put(np); - goto put_opp_table; + goto put_list_kref; } } /* There should be one of more OPP defined */ if (WARN_ON(!count)) { ret = -ENOENT; - _put_opp_list_kref(opp_table); - goto put_opp_table; + goto put_list_kref; } list_for_each_entry(opp, &opp_table->opp_list, node) @@ -453,8 +454,7 @@ initialize_static_opps: dev_err(dev, "Not all nodes have performance state set (%d: %d)\n", count, pstate_count); ret = -ENOENT; - _dev_pm_opp_remove_table(opp_table, dev); - goto put_opp_table; + goto put_list_kref; } if (pstate_count) @@ -462,6 +462,10 @@ initialize_static_opps: opp_table->parsed_static_opps = true; + return 0; + +put_list_kref: + _put_opp_list_kref(opp_table); put_opp_table: dev_pm_opp_put_opp_table(opp_table); @@ -507,13 +511,13 @@ static int _of_add_opp_table_v1(struct device *dev) if (ret) { dev_err(dev, "%s: Failed to add OPP %ld (%d)\n", __func__, freq, ret); - _dev_pm_opp_remove_table(opp_table, dev); - break; + _put_opp_list_kref(opp_table); + dev_pm_opp_put_opp_table(opp_table); + return ret; } nr -= 2; } - dev_pm_opp_put_opp_table(opp_table); return ret; } diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h index 98dd7d39e1ad..f9fbb7553fc4 100644 --- a/drivers/opp/opp.h +++ b/drivers/opp/opp.h @@ -190,11 +190,11 @@ struct opp_table { /* Routines internal to opp core */ void dev_pm_opp_get(struct dev_pm_opp *opp); +void _opp_remove_all_static(struct opp_table *opp_table); void _get_opp_table_kref(struct opp_table *opp_table); int _get_opp_count(struct opp_table *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 opp_table *opp_table, struct device *dev); void _dev_pm_opp_find_and_remove_table(struct device *dev); struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table); void _opp_free(struct dev_pm_opp *opp); -- cgit v1.2.3