@@ -32,14 +32,6 @@ LIST_HEAD(opp_tables);
/* Lock to allow exclusive modification to the device and opp lists */
DEFINE_MUTEX(opp_table_lock);
-#define opp_rcu_lockdep_assert() \
-do { \
- RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
- !lockdep_is_held(&opp_table_lock), \
- "Missing rcu_read_lock() or " \
- "opp_table_lock protection"); \
-} while (0)
-
static void dev_pm_opp_get(struct dev_pm_opp *opp);
static struct opp_device *_find_opp_dev(const struct device *dev,
@@ -73,8 +65,7 @@ struct opp_table *_find_opp_table_unlocked(struct device *dev)
* _find_opp_table() - find opp_table struct using device pointer
* @dev: device pointer used to lookup OPP table
*
- * Search OPP table for one containing matching device. Does a RCU reader
- * operation to grab the pointer needed.
+ * Search OPP table for one containing matching device.
*
* Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or
* -EINVAL based on type of error.
@@ -108,19 +99,12 @@ struct opp_table *_find_opp_table(struct device *dev)
*/
unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
{
- struct dev_pm_opp *tmp_opp;
- unsigned long v = 0;
-
- rcu_read_lock();
-
- tmp_opp = rcu_dereference(opp);
- if (IS_ERR_OR_NULL(tmp_opp))
+ if (IS_ERR_OR_NULL(opp)) {
pr_err("%s: Invalid parameters\n", __func__);
- else
- v = tmp_opp->supplies[0].u_volt;
+ return 0;
+ }
- rcu_read_unlock();
- return v;
+ return opp->supplies[0].u_volt;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
@@ -133,19 +117,12 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
*/
unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
{
- struct dev_pm_opp *tmp_opp;
- unsigned long f = 0;
-
- rcu_read_lock();
-
- tmp_opp = rcu_dereference(opp);
- if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available)
+ if (IS_ERR_OR_NULL(opp) || !opp->available) {
pr_err("%s: Invalid parameters\n", __func__);
- else
- f = tmp_opp->rate;
+ return 0;
+ }
- rcu_read_unlock();
- return f;
+ return opp->rate;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
@@ -161,21 +138,12 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
*/
bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp)
{
- struct dev_pm_opp *tmp_opp;
- bool turbo;
-
- rcu_read_lock();
-
- tmp_opp = rcu_dereference(opp);
- if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) {
+ if (IS_ERR_OR_NULL(opp) || !opp->available) {
pr_err("%s: Invalid parameters\n", __func__);
return false;
}
- turbo = tmp_opp->turbo;
-
- rcu_read_unlock();
- return turbo;
+ return opp->turbo;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_is_turbo);
@@ -223,8 +191,6 @@ static int _get_regulator_count(struct device *dev)
* @dev: device for which we do this operation
*
* Return: This function returns the max voltage latency in nanoseconds.
- *
- * Locking: This function takes rcu_read_lock().
*/
unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
{
@@ -256,15 +222,15 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
if (IS_ERR(opp_table))
goto free_uV;
- rcu_read_lock();
-
memcpy(regulators, opp_table->regulators, count * sizeof(*regulators));
+ mutex_lock(&opp_table->lock);
+
for (i = 0; i < count; i++) {
uV[i].min = ~0;
uV[i].max = 0;
- list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {
+ list_for_each_entry(opp, &opp_table->opp_list, node) {
if (!opp->available)
continue;
@@ -275,7 +241,7 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
}
}
- rcu_read_unlock();
+ mutex_unlock(&opp_table->lock);
dev_pm_opp_put_opp_table(opp_table);
/*
@@ -304,8 +270,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
*
* Return: This function returns the max transition latency, in nanoseconds, to
* switch from one OPP to other.
- *
- * Locking: This function takes rcu_read_lock().
*/
unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
{
@@ -345,8 +309,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp_freq);
*
* 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().
*/
int dev_pm_opp_get_opp_count(struct device *dev)
{
@@ -362,14 +324,14 @@ int dev_pm_opp_get_opp_count(struct device *dev)
return count;
}
- rcu_read_lock();
+ mutex_lock(&opp_table->lock);
- list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
+ list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available)
count++;
}
- rcu_read_unlock();
+ mutex_unlock(&opp_table->lock);
dev_pm_opp_put_opp_table(opp_table);
return count;
@@ -414,9 +376,9 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
return ERR_PTR(r);
}
- rcu_read_lock();
+ mutex_lock(&opp_table->lock);
- list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
+ list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available == available &&
temp_opp->rate == freq) {
opp = temp_opp;
@@ -427,7 +389,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
}
}
- rcu_read_unlock();
+ mutex_unlock(&opp_table->lock);
dev_pm_opp_put_opp_table(opp_table);
return opp;
@@ -439,7 +401,9 @@ static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
{
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
- list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
+ mutex_lock(&opp_table->lock);
+
+ list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available && temp_opp->rate >= *freq) {
opp = temp_opp;
*freq = opp->rate;
@@ -450,6 +414,8 @@ static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
}
}
+ mutex_unlock(&opp_table->lock);
+
return opp;
}
@@ -486,11 +452,8 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
if (IS_ERR(opp_table))
return ERR_CAST(opp_table);
- rcu_read_lock();
-
opp = _find_freq_ceil(opp_table, freq);
- rcu_read_unlock();
dev_pm_opp_put_opp_table(opp_table);
return opp;
@@ -530,9 +493,9 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
if (IS_ERR(opp_table))
return ERR_CAST(opp_table);
- rcu_read_lock();
+ mutex_lock(&opp_table->lock);
- list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
+ list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available) {
/* go to the next node, before choosing prev */
if (temp_opp->rate > *freq)
@@ -545,7 +508,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
/* Increment the reference count of OPP */
if (!IS_ERR(opp))
dev_pm_opp_get(opp);
- rcu_read_unlock();
+ mutex_unlock(&opp_table->lock);
dev_pm_opp_put_opp_table(opp_table);
if (!IS_ERR(opp))
@@ -555,30 +518,6 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
-/*
- * The caller needs to ensure that opp_table (and hence the clk) isn't freed,
- * while clk returned here is used.
- */
-static struct clk *_get_opp_clk(struct device *dev)
-{
- struct opp_table *opp_table;
- struct clk *clk;
-
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- dev_err(dev, "%s: device opp doesn't exist\n", __func__);
- return ERR_CAST(opp_table);
- }
-
- clk = opp_table->clk;
- if (IS_ERR(clk))
- dev_err(dev, "%s: No clock available for the device\n",
- __func__);
- dev_pm_opp_put_opp_table(opp_table);
-
- return clk;
-}
-
static int _set_opp_voltage(struct device *dev, struct regulator *reg,
struct dev_pm_opp_supply *supply)
{
@@ -674,8 +613,6 @@ static int _generic_set_opp(struct dev_pm_set_opp_data *data)
*
* This configures the power-supplies and clock source to the levels specified
* by the OPP corresponding to the target_freq.
- *
- * Locking: This function takes rcu_read_lock().
*/
int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
{
@@ -694,9 +631,19 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
return -EINVAL;
}
- clk = _get_opp_clk(dev);
- if (IS_ERR(clk))
- return PTR_ERR(clk);
+ opp_table = _find_opp_table(dev);
+ if (IS_ERR(opp_table)) {
+ dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+ return PTR_ERR(opp_table);
+ }
+
+ clk = opp_table->clk;
+ if (IS_ERR(clk)) {
+ dev_err(dev, "%s: No clock available for the device\n",
+ __func__);
+ ret = PTR_ERR(clk);
+ goto put_opp_table;
+ }
freq = clk_round_rate(clk, target_freq);
if ((long)freq <= 0)
@@ -708,17 +655,10 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
if (old_freq == freq) {
dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
__func__, freq);
- return 0;
- }
-
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- dev_err(dev, "%s: device opp doesn't exist\n", __func__);
- return PTR_ERR(opp_table);
+ ret = 0;
+ goto put_opp_table;
}
- rcu_read_lock();
-
old_opp = _find_freq_ceil(opp_table, &old_freq);
if (IS_ERR(old_opp)) {
dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n",
@@ -730,11 +670,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
ret = PTR_ERR(opp);
dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
__func__, freq, ret);
- if (!IS_ERR(old_opp))
- dev_pm_opp_put(old_opp);
- rcu_read_unlock();
- dev_pm_opp_put_opp_table(opp_table);
- return ret;
+ goto put_old_opp;
}
dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__,
@@ -744,12 +680,8 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
/* Only frequency scaling */
if (!regulators) {
- dev_pm_opp_put(opp);
- if (!IS_ERR(old_opp))
- dev_pm_opp_put(old_opp);
- rcu_read_unlock();
- dev_pm_opp_put_opp_table(opp_table);
- return _generic_set_opp_clk_only(dev, clk, old_freq, freq);
+ ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
+ goto put_opps;
}
if (opp_table->set_opp)
@@ -773,32 +705,26 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
data->new_opp.rate = freq;
memcpy(data->new_opp.supplies, opp->supplies, size);
+ ret = set_opp(data);
+
+put_opps:
dev_pm_opp_put(opp);
+put_old_opp:
if (!IS_ERR(old_opp))
dev_pm_opp_put(old_opp);
- rcu_read_unlock();
+put_opp_table:
dev_pm_opp_put_opp_table(opp_table);
-
- return set_opp(data);
+ return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
/* OPP-dev Helpers */
-static void _kfree_opp_dev_rcu(struct rcu_head *head)
-{
- struct opp_device *opp_dev;
-
- opp_dev = container_of(head, struct opp_device, rcu_head);
- kfree_rcu(opp_dev, rcu_head);
-}
-
static void _remove_opp_dev(struct opp_device *opp_dev,
struct opp_table *opp_table)
{
opp_debug_unregister(opp_dev, opp_table);
list_del(&opp_dev->node);
- call_srcu(&opp_table->srcu_head.srcu, &opp_dev->rcu_head,
- _kfree_opp_dev_rcu);
+ kfree(opp_dev);
}
struct opp_device *_add_opp_dev(const struct device *dev,
@@ -813,7 +739,7 @@ struct opp_device *_add_opp_dev(const struct device *dev,
/* Initialize opp-dev */
opp_dev->dev = dev;
- list_add_rcu(&opp_dev->node, &opp_table->dev_list);
+ list_add(&opp_dev->node, &opp_table->dev_list);
/* Create debugfs entries for the opp_table */
ret = opp_debug_register(opp_dev, opp_table);
@@ -857,28 +783,16 @@ static struct opp_table *_allocate_opp_table(struct device *dev)
ret);
}
- srcu_init_notifier_head(&opp_table->srcu_head);
+ BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
INIT_LIST_HEAD(&opp_table->opp_list);
mutex_init(&opp_table->lock);
kref_init(&opp_table->kref);
/* Secure the device table modification */
- list_add_rcu(&opp_table->node, &opp_tables);
+ list_add(&opp_table->node, &opp_tables);
return opp_table;
}
-/**
- * _kfree_device_rcu() - Free opp_table RCU handler
- * @head: RCU head
- */
-static void _kfree_device_rcu(struct rcu_head *head)
-{
- struct opp_table *opp_table = container_of(head, struct opp_table,
- rcu_head);
-
- kfree_rcu(opp_table, rcu_head);
-}
-
void _get_opp_table_kref(struct opp_table *opp_table)
{
kref_get(&opp_table->kref);
@@ -922,9 +836,8 @@ static void _opp_table_kref_release(struct kref *kref)
WARN_ON(!list_empty(&opp_table->dev_list));
mutex_destroy(&opp_table->lock);
- list_del_rcu(&opp_table->node);
- call_srcu(&opp_table->srcu_head.srcu, &opp_table->rcu_head,
- _kfree_device_rcu);
+ list_del(&opp_table->node);
+ kfree(opp_table);
mutex_unlock(&opp_table_lock);
}
@@ -941,17 +854,6 @@ void _opp_free(struct dev_pm_opp *opp)
kfree(opp);
}
-/**
- * _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 _opp_kref_release(struct kref *kref)
{
struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
@@ -961,10 +863,10 @@ static void _opp_kref_release(struct kref *kref)
* Notify the changes in the availability of the operable
* frequency/voltage list.
*/
- srcu_notifier_call_chain(&opp_table->srcu_head, OPP_EVENT_REMOVE, opp);
+ blocking_notifier_call_chain(&opp_table->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);
+ list_del(&opp->node);
+ kfree(opp);
mutex_unlock(&opp_table->lock);
dev_pm_opp_put_opp_table(opp_table);
@@ -987,12 +889,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_put);
* @freq: OPP to remove with matching 'freq'
*
* This function removes an opp from the opp table.
- *
- * Locking: The internal opp_table 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)
{
@@ -1097,7 +993,7 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
mutex_lock(&opp_table->lock);
head = &opp_table->opp_list;
- list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {
+ list_for_each_entry(opp, &opp_table->opp_list, node) {
if (new_opp->rate > opp->rate) {
head = &opp->node;
continue;
@@ -1120,7 +1016,7 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
return ret;
}
- list_add_rcu(&new_opp->node, head);
+ list_add(&new_opp->node, head);
mutex_unlock(&opp_table->lock);
new_opp->opp_table = opp_table;
@@ -1158,12 +1054,6 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
* NOTE: "dynamic" parameter impacts OPPs added by the dev_pm_opp_of_add_table
* and freed by dev_pm_opp_of_remove_table.
*
- * Locking: The internal opp_table 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
@@ -1203,7 +1093,7 @@ int _opp_add_v1(struct opp_table *opp_table, struct device *dev,
* Notify the changes in the availability of the operable
* frequency/voltage list.
*/
- srcu_notifier_call_chain(&opp_table->srcu_head, OPP_EVENT_ADD, new_opp);
+ blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
return 0;
free_opp:
@@ -1580,12 +1470,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_register_put_opp_helper);
* The opp is made available by default and it can be controlled using
* dev_pm_opp_enable/disable functions.
*
- * Locking: The internal opp_table 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
@@ -1615,18 +1499,12 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_add);
* @freq: OPP frequency to modify availability
* @availability_req: availability status requested for this opp
*
- * Set the availability of an OPP with an RCU operation, opp_{enable,disable}
- * share a common logic which is isolated here.
+ * Set the availability of an OPP, opp_{enable,disable} share a common logic
+ * which is isolated here.
*
* Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
* copy operation, returns 0 if no modification was done OR modification was
* successful.
- *
- * Locking: The internal opp_table 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 locking or synchronize_rcu() blocking calls cannot be used.
*/
static int _opp_set_availability(struct device *dev, unsigned long freq,
bool availability_req)
@@ -1672,16 +1550,16 @@ static int _opp_set_availability(struct device *dev, unsigned long freq,
/* plug in new node */
new_opp->available = availability_req;
- list_replace_rcu(&opp->node, &new_opp->node);
- call_srcu(&opp_table->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
+ list_replace(&opp->node, &new_opp->node);
+ kfree(opp);
/* Notify the change of the OPP availability */
if (availability_req)
- srcu_notifier_call_chain(&opp_table->srcu_head,
- OPP_EVENT_ENABLE, new_opp);
+ blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ENABLE,
+ new_opp);
else
- srcu_notifier_call_chain(&opp_table->srcu_head,
- OPP_EVENT_DISABLE, new_opp);
+ blocking_notifier_call_chain(&opp_table->head,
+ OPP_EVENT_DISABLE, new_opp);
mutex_unlock(&opp_table->lock);
dev_pm_opp_put_opp_table(opp_table);
@@ -1704,12 +1582,6 @@ static int _opp_set_availability(struct device *dev, unsigned long freq,
* corresponding error value. It is meant to be used for users an OPP available
* after being temporarily made unavailable with dev_pm_opp_disable.
*
- * Locking: The internal opp_table and opp structures are RCU protected.
- * Hence this function indirectly uses RCU and 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 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 modification was done OR modification was
* successful.
@@ -1730,12 +1602,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_enable);
* control by users to make this OPP not available until the circumstances are
* right to make it available again (with a call to dev_pm_opp_enable).
*
- * Locking: The internal opp_table and opp structures are RCU protected.
- * Hence this function indirectly uses RCU and 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 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 modification was done OR modification was
* successful.
@@ -1762,11 +1628,8 @@ int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb)
if (IS_ERR(opp_table))
return PTR_ERR(opp_table);
- rcu_read_lock();
-
- ret = srcu_notifier_chain_register(&opp_table->srcu_head, nb);
+ ret = blocking_notifier_chain_register(&opp_table->head, nb);
- rcu_read_unlock();
dev_pm_opp_put_opp_table(opp_table);
return ret;
@@ -1790,9 +1653,8 @@ int dev_pm_opp_unregister_notifier(struct device *dev,
if (IS_ERR(opp_table))
return PTR_ERR(opp_table);
- ret = srcu_notifier_chain_unregister(&opp_table->srcu_head, nb);
+ ret = blocking_notifier_chain_unregister(&opp_table->head, nb);
- rcu_read_unlock();
dev_pm_opp_put_opp_table(opp_table);
return ret;
@@ -1848,12 +1710,6 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all)
*
* Free both OPPs created using static entries present in DT and the
* dynamically added entries.
- *
- * Locking: The internal opp_table 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 dev_pm_opp_remove_table(struct device *dev)
{
@@ -137,12 +137,6 @@ void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, bool of)
* This removes the OPP tables for CPUs present in the @cpumask.
* This should be used to remove all the OPPs entries associated with
* the cpus in @cpumask.
- *
- * Locking: The internal opp_table 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_cpumask_remove_table(const struct cpumask *cpumask)
{
@@ -159,12 +153,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_cpumask_remove_table);
* @cpumask.
*
* Returns -ENODEV if OPP table isn't already present.
- *
- * Locking: The internal opp_table 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.
*/
int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev,
const struct cpumask *cpumask)
@@ -215,12 +203,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
*
* Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP
* table's status is access-unknown.
- *
- * Locking: The internal opp_table 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.
*/
int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
{
@@ -28,7 +28,7 @@ static struct opp_table *_managed_opp(const struct device_node *np)
mutex_lock(&opp_table_lock);
- list_for_each_entry_rcu(opp_table, &opp_tables, node) {
+ list_for_each_entry(opp_table, &opp_tables, node) {
if (opp_table->np == np) {
/*
* Multiple devices can point to the same OPP table and
@@ -235,12 +235,6 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
* @dev: device pointer used to lookup OPP table.
*
* Free OPPs created using static entries present in DT.
- *
- * Locking: The internal opp_table 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 dev_pm_opp_of_remove_table(struct device *dev)
{
@@ -269,12 +263,6 @@ static struct device_node *_of_get_opp_desc_node(struct device *dev)
* opp can be controlled using dev_pm_opp_enable/disable functions and may be
* removed by dev_pm_opp_remove.
*
- * Locking: The internal opp_table 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
@@ -358,7 +346,7 @@ static int _opp_add_static_v2(struct opp_table *opp_table, struct device *dev,
* Notify the changes in the availability of the operable
* frequency/voltage list.
*/
- srcu_notifier_call_chain(&opp_table->srcu_head, OPP_EVENT_ADD, new_opp);
+ blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
return 0;
free_opp:
@@ -470,12 +458,6 @@ static int _of_add_opp_table_v1(struct device *dev)
*
* Register the initial OPP table with the OPP library for given device.
*
- * Locking: The internal opp_table 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
@@ -520,12 +502,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
*
* This removes the OPP tables for CPUs present in the @cpumask.
* This should be used only to remove static entries created from DT.
- *
- * Locking: The internal opp_table 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_of_cpumask_remove_table(const struct cpumask *cpumask)
{
@@ -538,12 +514,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
* @cpumask: cpumask for which OPP table needs to be added.
*
* This adds the OPP tables for CPUs present in the @cpumask.
- *
- * Locking: The internal opp_table 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.
*/
int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
{
@@ -591,12 +561,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
* This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
*
* Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
- *
- * Locking: The internal opp_table 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.
*/
int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
struct cpumask *cpumask)
@@ -20,8 +20,7 @@
#include <linux/list.h>
#include <linux/limits.h>
#include <linux/pm_opp.h>
-#include <linux/rculist.h>
-#include <linux/rcupdate.h>
+#include <linux/notifier.h>
struct clk;
struct regulator;
@@ -52,9 +51,6 @@ extern struct list_head opp_tables;
* @node: opp table node. The nodes are maintained throughout the lifetime
* of boot. It is expected only an optimal set of OPPs are
* added to the library by the SoC framework.
- * RCU usage: opp table is traversed with RCU locks. node
- * modification is possible realtime, hence the modifications
- * are protected by the opp_table_lock for integrity.
* IMPORTANT: the opp nodes should be maintained in increasing
* order.
* @kref: for reference count of the OPP.
@@ -67,7 +63,6 @@ extern struct list_head opp_tables;
* @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
* frequency from any other OPP's frequency.
* @opp_table: points back to the opp_table struct this opp belongs to
- * @rcu_head: RCU callback head used for deferred freeing
* @np: OPP's device node.
* @dentry: debugfs dentry pointer (per opp)
*
@@ -88,7 +83,6 @@ struct dev_pm_opp {
unsigned long clock_latency_ns;
struct opp_table *opp_table;
- struct rcu_head rcu_head;
struct device_node *np;
@@ -101,7 +95,6 @@ struct dev_pm_opp {
* struct opp_device - devices managed by 'struct opp_table'
* @node: list node
* @dev: device to which the struct object belongs
- * @rcu_head: RCU callback head used for deferred freeing
* @dentry: debugfs dentry pointer (per device)
*
* This is an internal data structure maintaining the devices that are managed
@@ -110,7 +103,6 @@ struct dev_pm_opp {
struct opp_device {
struct list_head node;
const struct device *dev;
- struct rcu_head rcu_head;
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
@@ -128,10 +120,7 @@ enum opp_table_access {
* @node: table node - contains the devices with OPPs that
* have been registered. Nodes once added are not modified in this
* table.
- * RCU usage: nodes are not modified in the table of opp_table,
- * however addition is possible and is secured by opp_table_lock
- * @srcu_head: notifier head to notify the OPP availability changes.
- * @rcu_head: RCU callback head used for deferred freeing
+ * @head: notifier head to notify the OPP availability changes.
* @dev_list: list of devices that share these OPPs
* @opp_list: table of opps
* @kref: for reference count of the table.
@@ -156,16 +145,11 @@ enum opp_table_access {
* This is an internal data structure maintaining the link to opps attached to
* a device. This structure is not meant to be shared to users as it is
* meant for book keeping and private to OPP library.
- *
- * Because the opp structures can be used from both rcu and srcu readers, we
- * need to wait for the grace period of both of them before freeing any
- * resources. And so we have used kfree_rcu() from within call_srcu() handlers.
*/
struct opp_table {
struct list_head node;
- struct srcu_notifier_head srcu_head;
- struct rcu_head rcu_head;
+ struct blocking_notifier_head head;
struct list_head dev_list;
struct list_head opp_list;
struct kref kref;