LIST_HEAD(opp_tables);
/* Lock to allow exclusive modification to the device and opp lists */
DEFINE_MUTEX(opp_table_lock);
+/* Flag indicating that opp_tables list is being updated at the moment */
+static bool opp_tables_busy;
-static struct opp_device *_find_opp_dev(const struct device *dev,
- struct opp_table *opp_table)
+static bool _find_opp_dev(const struct device *dev, struct opp_table *opp_table)
{
struct opp_device *opp_dev;
+ bool found = false;
+ mutex_lock(&opp_table->lock);
list_for_each_entry(opp_dev, &opp_table->dev_list, node)
- if (opp_dev->dev == dev)
- return opp_dev;
+ if (opp_dev->dev == dev) {
+ found = true;
+ break;
+ }
- return NULL;
+ mutex_unlock(&opp_table->lock);
+ return found;
}
static struct opp_table *_find_opp_table_unlocked(struct device *dev)
{
struct opp_table *opp_table;
- bool found;
list_for_each_entry(opp_table, &opp_tables, node) {
- mutex_lock(&opp_table->lock);
- found = !!_find_opp_dev(dev, opp_table);
- mutex_unlock(&opp_table->lock);
-
- if (found) {
+ if (_find_opp_dev(dev, opp_table)) {
_get_opp_table_kref(opp_table);
-
return opp_table;
}
}
* Enable the regulator after setting its voltages, otherwise it breaks
* some boot-enabled regulators.
*/
- if (unlikely(!opp_table->regulator_enabled)) {
+ if (unlikely(!opp_table->enabled)) {
ret = regulator_enable(reg);
if (ret < 0)
dev_warn(dev, "Failed to enable regulator: %d", ret);
- else
- opp_table->regulator_enabled = true;
}
return 0;
return opp_table->set_opp(data);
}
+static int _set_required_opp(struct device *dev, struct device *pd_dev,
+ struct dev_pm_opp *opp, int i)
+{
+ unsigned int pstate = likely(opp) ? opp->required_opps[i]->pstate : 0;
+ int ret;
+
+ if (!pd_dev)
+ return 0;
+
+ ret = dev_pm_genpd_set_performance_state(pd_dev, pstate);
+ if (ret) {
+ dev_err(dev, "Failed to set performance rate of %s: %d (%d)\n",
+ dev_name(pd_dev), pstate, ret);
+ }
+
+ return ret;
+}
+
/* This is only called for PM domain for now */
static int _set_required_opps(struct device *dev,
struct opp_table *opp_table,
- struct dev_pm_opp *opp)
+ struct dev_pm_opp *opp, bool up)
{
struct opp_table **required_opp_tables = opp_table->required_opp_tables;
struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
- unsigned int pstate;
int i, ret = 0;
if (!required_opp_tables)
return 0;
/* Single genpd case */
- if (!genpd_virt_devs) {
- pstate = likely(opp) ? opp->required_opps[0]->pstate : 0;
- ret = dev_pm_genpd_set_performance_state(dev, pstate);
- if (ret) {
- dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
- dev_name(dev), pstate, ret);
- }
- return ret;
- }
+ if (!genpd_virt_devs)
+ return _set_required_opp(dev, dev, opp, 0);
/* Multiple genpd case */
*/
mutex_lock(&opp_table->genpd_virt_dev_lock);
- for (i = 0; i < opp_table->required_opp_count; i++) {
- pstate = likely(opp) ? opp->required_opps[i]->pstate : 0;
-
- if (!genpd_virt_devs[i])
- continue;
-
- ret = dev_pm_genpd_set_performance_state(genpd_virt_devs[i], pstate);
- if (ret) {
- dev_err(dev, "Failed to set performance rate of %s: %d (%d)\n",
- dev_name(genpd_virt_devs[i]), pstate, ret);
- break;
+ /* Scaling up? Set required OPPs in normal order, else reverse */
+ if (up) {
+ for (i = 0; i < opp_table->required_opp_count; i++) {
+ ret = _set_required_opp(dev, genpd_virt_devs[i], opp, i);
+ if (ret)
+ break;
+ }
+ } else {
+ for (i = opp_table->required_opp_count - 1; i >= 0; i--) {
+ ret = _set_required_opp(dev, genpd_virt_devs[i], opp, i);
+ if (ret)
+ break;
}
}
+
mutex_unlock(&opp_table->genpd_virt_dev_lock);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_bw);
+static int _opp_set_rate_zero(struct device *dev, struct opp_table *opp_table)
+{
+ int ret;
+
+ if (!opp_table->enabled)
+ return 0;
+
+ /*
+ * Some drivers need to support cases where some platforms may
+ * have OPP table for the device, while others don't and
+ * opp_set_rate() just needs to behave like clk_set_rate().
+ */
+ if (!_get_opp_count(opp_table))
+ return 0;
+
+ ret = _set_opp_bw(opp_table, NULL, dev, true);
+ if (ret)
+ return ret;
+
+ if (opp_table->regulators)
+ regulator_disable(opp_table->regulators[0]);
+
+ ret = _set_required_opps(dev, opp_table, NULL, false);
+
+ opp_table->enabled = false;
+ return ret;
+}
+
/**
* dev_pm_opp_set_rate() - Configure new OPP based on frequency
* @dev: device for which we do this operation
}
if (unlikely(!target_freq)) {
- /*
- * Some drivers need to support cases where some platforms may
- * have OPP table for the device, while others don't and
- * opp_set_rate() just needs to behave like clk_set_rate().
- */
- if (!_get_opp_count(opp_table)) {
- ret = 0;
- goto put_opp_table;
- }
-
- if (!opp_table->required_opp_tables && !opp_table->regulators &&
- !opp_table->paths) {
- dev_err(dev, "target frequency can't be 0\n");
- ret = -EINVAL;
- goto put_opp_table;
- }
-
- ret = _set_opp_bw(opp_table, NULL, dev, true);
- if (ret)
- goto put_opp_table;
-
- if (opp_table->regulator_enabled) {
- regulator_disable(opp_table->regulators[0]);
- opp_table->regulator_enabled = false;
- }
-
- ret = _set_required_opps(dev, opp_table, NULL);
+ ret = _opp_set_rate_zero(dev, opp_table);
goto put_opp_table;
}
old_freq = clk_get_rate(clk);
/* Return early if nothing to do */
- if (old_freq == freq) {
- if (!opp_table->required_opp_tables && !opp_table->regulators &&
- !opp_table->paths) {
- dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
- __func__, freq);
- ret = 0;
- goto put_opp_table;
- }
+ if (opp_table->enabled && old_freq == freq) {
+ dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
+ __func__, freq);
+ ret = 0;
+ goto put_opp_table;
}
/*
/* Scaling up? Configure required OPPs before frequency */
if (freq >= old_freq) {
- ret = _set_required_opps(dev, opp_table, opp);
+ ret = _set_required_opps(dev, opp_table, opp, true);
if (ret)
goto put_opp;
}
/* Scaling down? Configure required OPPs after frequency */
if (!ret && freq < old_freq) {
- ret = _set_required_opps(dev, opp_table, opp);
+ ret = _set_required_opps(dev, opp_table, opp, false);
if (ret)
dev_err(dev, "Failed to set required opps: %d\n", ret);
}
- if (!ret)
+ if (!ret) {
ret = _set_opp_bw(opp_table, opp, dev, false);
+ if (!ret)
+ opp_table->enabled = true;
+ }
put_opp:
dev_pm_opp_put(opp);
kfree(opp_dev);
}
-static struct opp_device *_add_opp_dev_unlocked(const struct device *dev,
- struct opp_table *opp_table)
+struct opp_device *_add_opp_dev(const struct device *dev,
+ struct opp_table *opp_table)
{
struct opp_device *opp_dev;
/* Initialize opp-dev */
opp_dev->dev = dev;
+ mutex_lock(&opp_table->lock);
list_add(&opp_dev->node, &opp_table->dev_list);
+ mutex_unlock(&opp_table->lock);
/* Create debugfs entries for the opp_table */
opp_debug_register(opp_dev, opp_table);
return opp_dev;
}
-struct opp_device *_add_opp_dev(const struct device *dev,
- struct opp_table *opp_table)
-{
- struct opp_device *opp_dev;
-
- mutex_lock(&opp_table->lock);
- opp_dev = _add_opp_dev_unlocked(dev, opp_table);
- mutex_unlock(&opp_table->lock);
-
- return opp_dev;
-}
-
static struct opp_table *_allocate_opp_table(struct device *dev, int index)
{
struct opp_table *opp_table;
*/
opp_table = kzalloc(sizeof(*opp_table), GFP_KERNEL);
if (!opp_table)
- return NULL;
+ return ERR_PTR(-ENOMEM);
mutex_init(&opp_table->lock);
mutex_init(&opp_table->genpd_virt_dev_lock);
opp_dev = _add_opp_dev(dev, opp_table);
if (!opp_dev) {
- kfree(opp_table);
- return NULL;
+ ret = -ENOMEM;
+ goto err;
}
_of_init_opp_table(opp_table, dev, index);
opp_table->clk = clk_get(dev, NULL);
if (IS_ERR(opp_table->clk)) {
ret = PTR_ERR(opp_table->clk);
- if (ret != -EPROBE_DEFER)
- dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__,
- ret);
+ if (ret == -EPROBE_DEFER)
+ goto err;
+
+ dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__, ret);
}
/* Find interconnect path(s) for the device */
ret = dev_pm_opp_of_find_icc_paths(dev, opp_table);
- if (ret)
+ if (ret) {
+ if (ret == -EPROBE_DEFER)
+ goto err;
+
dev_warn(dev, "%s: Error finding interconnect paths: %d\n",
__func__, ret);
+ }
BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
INIT_LIST_HEAD(&opp_table->opp_list);
kref_init(&opp_table->kref);
- /* Secure the device table modification */
- list_add(&opp_table->node, &opp_tables);
return opp_table;
+
+err:
+ kfree(opp_table);
+ return ERR_PTR(ret);
}
void _get_opp_table_kref(struct opp_table *opp_table)
kref_get(&opp_table->kref);
}
-static struct opp_table *_opp_get_opp_table(struct device *dev, int index)
+/*
+ * We need to make sure that the OPP table for a device doesn't get added twice,
+ * if this routine gets called in parallel with the same device pointer.
+ *
+ * The simplest way to enforce that is to perform everything (find existing
+ * table and if not found, create a new one) under the opp_table_lock, so only
+ * one creator gets access to the same. But that expands the critical section
+ * under the lock and may end up causing circular dependencies with frameworks
+ * like debugfs, interconnect or clock framework as they may be direct or
+ * indirect users of OPP core.
+ *
+ * And for that reason we have to go for a bit tricky implementation here, which
+ * uses the opp_tables_busy flag to indicate if another creator is in the middle
+ * of adding an OPP table and others should wait for it to finish.
+ */
+struct opp_table *_add_opp_table_indexed(struct device *dev, int index)
{
struct opp_table *opp_table;
- /* Hold our table modification lock here */
+again:
mutex_lock(&opp_table_lock);
opp_table = _find_opp_table_unlocked(dev);
if (!IS_ERR(opp_table))
goto unlock;
+ /*
+ * The opp_tables list or an OPP table's dev_list is getting updated by
+ * another user, wait for it to finish.
+ */
+ if (unlikely(opp_tables_busy)) {
+ mutex_unlock(&opp_table_lock);
+ cpu_relax();
+ goto again;
+ }
+
+ opp_tables_busy = true;
opp_table = _managed_opp(dev, index);
+
+ /* Drop the lock to reduce the size of critical section */
+ mutex_unlock(&opp_table_lock);
+
if (opp_table) {
- if (!_add_opp_dev_unlocked(dev, opp_table)) {
+ if (!_add_opp_dev(dev, opp_table)) {
dev_pm_opp_put_opp_table(opp_table);
- opp_table = NULL;
+ opp_table = ERR_PTR(-ENOMEM);
}
- goto unlock;
+
+ mutex_lock(&opp_table_lock);
+ } else {
+ opp_table = _allocate_opp_table(dev, index);
+
+ mutex_lock(&opp_table_lock);
+ if (!IS_ERR(opp_table))
+ list_add(&opp_table->node, &opp_tables);
}
- opp_table = _allocate_opp_table(dev, index);
+ opp_tables_busy = false;
unlock:
mutex_unlock(&opp_table_lock);
return opp_table;
}
-struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
+struct opp_table *_add_opp_table(struct device *dev)
{
- return _opp_get_opp_table(dev, 0);
+ return _add_opp_table_indexed(dev, 0);
}
-EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);
-struct opp_table *dev_pm_opp_get_opp_table_indexed(struct device *dev,
- int index)
+struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
{
- return _opp_get_opp_table(dev, index);
+ return _find_opp_table(dev);
}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);
static void _opp_table_kref_release(struct kref *kref)
{
struct opp_device *opp_dev, *temp;
int i;
+ /* Drop the lock as soon as we can */
+ list_del(&opp_table->node);
+ mutex_unlock(&opp_table_lock);
+
_of_clear_opp_table(opp_table);
/* Release clk */
mutex_destroy(&opp_table->genpd_virt_dev_lock);
mutex_destroy(&opp_table->lock);
- list_del(&opp_table->node);
kfree(opp_table);
-
- mutex_unlock(&opp_table_lock);
}
void dev_pm_opp_put_opp_table(struct opp_table *opp_table)
kfree(opp);
}
-static void _opp_kref_release(struct dev_pm_opp *opp,
- struct opp_table *opp_table)
+static void _opp_kref_release(struct kref *kref)
{
+ struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
+ struct opp_table *opp_table = opp->opp_table;
+
+ list_del(&opp->node);
+ mutex_unlock(&opp_table->lock);
+
/*
* Notify the changes in the availability of the operable
* frequency/voltage list.
blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_REMOVE, opp);
_of_opp_free_required_opps(opp_table, opp);
opp_debug_remove_one(opp);
- list_del(&opp->node);
kfree(opp);
}
-static void _opp_kref_release_unlocked(struct kref *kref)
-{
- struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
- struct opp_table *opp_table = opp->opp_table;
-
- _opp_kref_release(opp, opp_table);
-}
-
-static void _opp_kref_release_locked(struct kref *kref)
-{
- struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
- struct opp_table *opp_table = opp->opp_table;
-
- _opp_kref_release(opp, opp_table);
- mutex_unlock(&opp_table->lock);
-}
-
void dev_pm_opp_get(struct dev_pm_opp *opp)
{
kref_get(&opp->kref);
void dev_pm_opp_put(struct dev_pm_opp *opp)
{
- kref_put_mutex(&opp->kref, _opp_kref_release_locked,
- &opp->opp_table->lock);
+ kref_put_mutex(&opp->kref, _opp_kref_release, &opp->opp_table->lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put);
-static void dev_pm_opp_put_unlocked(struct dev_pm_opp *opp)
-{
- kref_put(&opp->kref, _opp_kref_release_unlocked);
-}
-
/**
* dev_pm_opp_remove() - Remove an OPP from OPP table
* @dev: device for which we do this operation
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
+static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
+ bool dynamic)
+{
+ struct dev_pm_opp *opp = NULL, *temp;
+
+ mutex_lock(&opp_table->lock);
+ list_for_each_entry(temp, &opp_table->opp_list, node) {
+ if (dynamic == temp->dynamic) {
+ opp = temp;
+ break;
+ }
+ }
+
+ mutex_unlock(&opp_table->lock);
+ return opp;
+}
+
bool _opp_remove_all_static(struct opp_table *opp_table)
{
- struct dev_pm_opp *opp, *tmp;
- bool ret = true;
+ struct dev_pm_opp *opp;
mutex_lock(&opp_table->lock);
if (!opp_table->parsed_static_opps) {
- ret = false;
- goto unlock;
+ mutex_unlock(&opp_table->lock);
+ return false;
}
- if (--opp_table->parsed_static_opps)
- goto unlock;
-
- list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
- if (!opp->dynamic)
- dev_pm_opp_put_unlocked(opp);
+ if (--opp_table->parsed_static_opps) {
+ mutex_unlock(&opp_table->lock);
+ return true;
}
-unlock:
mutex_unlock(&opp_table->lock);
- return ret;
+ /*
+ * Can't remove the OPP from under the lock, debugfs removal needs to
+ * happen lock less to avoid circular dependency issues.
+ */
+ while ((opp = _opp_get_next(opp_table, false)))
+ dev_pm_opp_put(opp);
+
+ return true;
}
/**
void dev_pm_opp_remove_all_dynamic(struct device *dev)
{
struct opp_table *opp_table;
- struct dev_pm_opp *opp, *temp;
+ struct dev_pm_opp *opp;
int count = 0;
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
return;
- mutex_lock(&opp_table->lock);
- list_for_each_entry_safe(opp, temp, &opp_table->opp_list, node) {
- if (opp->dynamic) {
- dev_pm_opp_put_unlocked(opp);
- count++;
- }
+ /*
+ * Can't remove the OPP from under the lock, debugfs removal needs to
+ * happen lock less to avoid circular dependency issues.
+ */
+ while ((opp = _opp_get_next(opp_table, true))) {
+ dev_pm_opp_put(opp);
+ count++;
}
- mutex_unlock(&opp_table->lock);
/* Drop the references taken by dev_pm_opp_add() */
while (count--)
{
struct opp_table *opp_table;
- opp_table = dev_pm_opp_get_opp_table(dev);
- if (!opp_table)
- return ERR_PTR(-ENOMEM);
+ opp_table = _add_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return opp_table;
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
{
struct opp_table *opp_table;
- opp_table = dev_pm_opp_get_opp_table(dev);
- if (!opp_table)
- return ERR_PTR(-ENOMEM);
+ opp_table = _add_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return opp_table;
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
struct regulator *reg;
int ret, i;
- opp_table = dev_pm_opp_get_opp_table(dev);
- if (!opp_table)
- return ERR_PTR(-ENOMEM);
+ opp_table = _add_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return opp_table;
/* This should be called before OPPs are initialized */
if (WARN_ON(!list_empty(&opp_table->opp_list))) {
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
- if (opp_table->regulator_enabled) {
+ if (opp_table->enabled) {
for (i = opp_table->regulator_count - 1; i >= 0; i--)
regulator_disable(opp_table->regulators[i]);
-
- opp_table->regulator_enabled = false;
}
for (i = opp_table->regulator_count - 1; i >= 0; i--)
struct opp_table *opp_table;
int ret;
- opp_table = dev_pm_opp_get_opp_table(dev);
- if (!opp_table)
- return ERR_PTR(-ENOMEM);
+ opp_table = _add_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return opp_table;
/* This should be called before OPPs are initialized */
if (WARN_ON(!list_empty(&opp_table->opp_list))) {
if (!set_opp)
return ERR_PTR(-EINVAL);
- opp_table = dev_pm_opp_get_opp_table(dev);
- if (!opp_table)
- return ERR_PTR(-ENOMEM);
+ opp_table = _add_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return opp_table;
/* This should be called before OPPs are initialized */
if (WARN_ON(!list_empty(&opp_table->opp_list))) {
{
int index;
+ if (!opp_table->genpd_virt_devs)
+ return;
+
for (index = 0; index < opp_table->required_opp_count; index++) {
if (!opp_table->genpd_virt_devs[index])
continue;
int index = 0, ret = -EINVAL;
const char **name = names;
- opp_table = dev_pm_opp_get_opp_table(dev);
- if (!opp_table)
- return ERR_PTR(-ENOMEM);
+ opp_table = _add_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return opp_table;
+
+ if (opp_table->genpd_virt_devs)
+ return opp_table;
/*
* If the genpd's OPP table isn't already initialized, parsing of the
goto err;
}
- if (opp_table->genpd_virt_devs[index]) {
- dev_err(dev, "Genpd virtual device already set %s\n",
- *name);
- goto err;
- }
-
virt_dev = dev_pm_domain_attach_by_name(dev, *name);
if (IS_ERR(virt_dev)) {
ret = PTR_ERR(virt_dev);
int dest_pstate = -EINVAL;
int i;
- if (!pstate)
- return 0;
-
/*
* Normally the src_table will have the "required_opps" property set to
* point to one of the OPPs in the dst_table, but in some cases the
struct opp_table *opp_table;
int ret;
- opp_table = dev_pm_opp_get_opp_table(dev);
- if (!opp_table)
- return -ENOMEM;
+ opp_table = _add_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return PTR_ERR(opp_table);
/* Fix regulator count for dynamic OPPs */
opp_table->regulator_count = 1;
}
EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);
-void _dev_pm_opp_find_and_remove_table(struct device *dev)
+/**
+ * dev_pm_opp_remove_table() - Free all OPPs associated with the device
+ * @dev: device pointer used to lookup OPP table.
+ *
+ * Free both OPPs created using static entries present in DT and the
+ * dynamically added entries.
+ */
+void dev_pm_opp_remove_table(struct device *dev)
{
struct opp_table *opp_table;
/* Drop reference taken by _find_opp_table() */
dev_pm_opp_put_opp_table(opp_table);
}
-
-/**
- * dev_pm_opp_remove_table() - Free all OPPs associated with the device
- * @dev: device pointer used to lookup OPP table.
- *
- * Free both OPPs created using static entries present in DT and the
- * dynamically added entries.
- */
-void dev_pm_opp_remove_table(struct device *dev)
-{
- _dev_pm_opp_find_and_remove_table(dev);
-}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);
projects / linux-2.6-microblaze.git / blobdiff