/* 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,
struct opp_table *opp_table)
return NULL;
}
+static struct opp_table *_find_opp_table_unlocked(struct device *dev)
+{
+ struct opp_table *opp_table;
+
+ list_for_each_entry(opp_table, &opp_tables, node) {
+ if (_find_opp_dev(dev, opp_table)) {
+ _get_opp_table_kref(opp_table);
+
+ return opp_table;
+ }
+ }
+
+ return ERR_PTR(-ENODEV);
+}
+
/**
* _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.
*
- * Locking: For readers, this function must be called under rcu_read_lock().
- * opp_table is a RCU protected pointer, which means that opp_table is valid
- * as long as we are under RCU lock.
- *
- * For Writers, this function must be called with opp_table_lock held.
+ * The callers must call dev_pm_opp_put_opp_table() after the table is used.
*/
struct opp_table *_find_opp_table(struct device *dev)
{
struct opp_table *opp_table;
- opp_rcu_lockdep_assert();
-
if (IS_ERR_OR_NULL(dev)) {
pr_err("%s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL);
}
- list_for_each_entry_rcu(opp_table, &opp_tables, node)
- if (_find_opp_dev(dev, opp_table))
- return opp_table;
+ mutex_lock(&opp_table_lock);
+ opp_table = _find_opp_table_unlocked(dev);
+ mutex_unlock(&opp_table_lock);
- return ERR_PTR(-ENODEV);
+ return opp_table;
}
/**
* return 0
*
* This is useful only for devices with single power supply.
- *
- * Locking: This function must be called under rcu_read_lock(). opp is a rcu
- * protected pointer. This means that opp which could have been fetched by
- * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
- * under RCU lock. The pointer returned by the opp_find_freq family must be
- * used in the same section as the usage of this function with the pointer
- * prior to unlocking with rcu_read_unlock() to maintain the integrity of the
- * pointer.
*/
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 (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;
+ }
- return v;
+ return opp->supplies[0].u_volt;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
*
* 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
- * protected pointer. This means that opp which could have been fetched by
- * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
- * under RCU lock. The pointer returned by the opp_find_freq family must be
- * used in the same section as the usage of this function with the pointer
- * prior to unlocking with rcu_read_unlock() to maintain the integrity of the
- * pointer.
*/
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 (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;
+ }
- return f;
+ return opp->rate;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
* quickly. Running on them for longer times may overheat the chip.
*
* Return: true if opp is turbo opp, else false.
- *
- * Locking: This function must be called under rcu_read_lock(). opp is a rcu
- * protected pointer. This means that opp which could have been fetched by
- * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
- * under RCU lock. The pointer returned by the opp_find_freq family must be
- * used in the same section as the usage of this function with the pointer
- * prior to unlocking with rcu_read_unlock() to maintain the integrity of the
- * pointer.
*/
bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp)
{
- struct dev_pm_opp *tmp_opp;
-
- opp_rcu_lockdep_assert();
-
- 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;
}
- return tmp_opp->turbo;
+ return opp->turbo;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_is_turbo);
* @dev: device for which we do this operation
*
* Return: This function returns the max clock latency in nanoseconds.
- *
- * Locking: This function takes rcu_read_lock().
*/
unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
{
struct opp_table *opp_table;
unsigned long clock_latency_ns;
- rcu_read_lock();
-
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
- clock_latency_ns = 0;
- else
- clock_latency_ns = opp_table->clock_latency_ns_max;
-
- rcu_read_unlock();
- return clock_latency_ns;
-}
-EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
-
-static int _get_regulator_count(struct device *dev)
-{
- struct opp_table *opp_table;
- int count;
-
- rcu_read_lock();
+ return 0;
- opp_table = _find_opp_table(dev);
- if (!IS_ERR(opp_table))
- count = opp_table->regulator_count;
- else
- count = 0;
+ clock_latency_ns = opp_table->clock_latency_ns_max;
- rcu_read_unlock();
+ dev_pm_opp_put_opp_table(opp_table);
- return count;
+ return clock_latency_ns;
}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
/**
* dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
* @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)
{
unsigned long max;
} *uV;
- count = _get_regulator_count(dev);
+ opp_table = _find_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return 0;
+
+ count = opp_table->regulator_count;
/* Regulator may not be required for the device */
if (!count)
- return 0;
+ goto put_opp_table;
regulators = kmalloc_array(count, sizeof(*regulators), GFP_KERNEL);
if (!regulators)
- return 0;
+ goto put_opp_table;
uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
if (!uV)
goto free_regulators;
- rcu_read_lock();
-
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- rcu_read_unlock();
- goto free_uV;
- }
-
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;
}
}
- rcu_read_unlock();
+ mutex_unlock(&opp_table->lock);
/*
* The caller needs to ensure that opp_table (and hence the regulator)
* isn't freed, while we are executing this routine.
*/
- for (i = 0; reg = regulators[i], i < count; i++) {
+ for (i = 0; i < count; i++) {
+ reg = regulators[i];
ret = regulator_set_voltage_time(reg, uV[i].min, uV[i].max);
if (ret > 0)
latency_ns += ret * 1000;
}
-free_uV:
kfree(uV);
free_regulators:
kfree(regulators);
+put_opp_table:
+ dev_pm_opp_put_opp_table(opp_table);
return latency_ns;
}
*
* 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)
{
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);
/**
- * dev_pm_opp_get_suspend_opp() - Get suspend opp
+ * dev_pm_opp_get_suspend_opp_freq() - Get frequency of suspend opp in Hz
* @dev: device for which we do this operation
*
- * Return: This function returns pointer to the suspend opp if it is
- * defined and available, otherwise it returns NULL.
- *
- * Locking: This function must be called under rcu_read_lock(). 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.
+ * Return: This function returns the frequency of the OPP marked as suspend_opp
+ * if one is available, else returns 0;
*/
-struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev)
+unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev)
{
struct opp_table *opp_table;
-
- opp_rcu_lockdep_assert();
+ unsigned long freq = 0;
opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table) || !opp_table->suspend_opp ||
- !opp_table->suspend_opp->available)
- return NULL;
+ if (IS_ERR(opp_table))
+ return 0;
+
+ if (opp_table->suspend_opp && opp_table->suspend_opp->available)
+ freq = dev_pm_opp_get_freq(opp_table->suspend_opp);
- return opp_table->suspend_opp;
+ dev_pm_opp_put_opp_table(opp_table);
+
+ return freq;
}
-EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp);
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp_freq);
/**
* dev_pm_opp_get_opp_count() - Get number of opps available in the opp table
*
* 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)
{
struct dev_pm_opp *temp_opp;
int count = 0;
- rcu_read_lock();
-
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
count = PTR_ERR(opp_table);
dev_err(dev, "%s: OPP table not found (%d)\n",
__func__, count);
- goto out_unlock;
+ return count;
}
- 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)
count++;
}
-out_unlock:
- rcu_read_unlock();
+ mutex_unlock(&opp_table->lock);
+ dev_pm_opp_put_opp_table(opp_table);
+
return count;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
* This provides a mechanism to enable an opp which is not available currently
* or the opposite as well.
*
- * Locking: This function must be called under rcu_read_lock(). 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.
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
*/
struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
unsigned long freq,
struct opp_table *opp_table;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
- opp_rcu_lockdep_assert();
-
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
int r = PTR_ERR(opp_table);
return ERR_PTR(r);
}
- 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 == available &&
temp_opp->rate == freq) {
opp = temp_opp;
+
+ /* Increment the reference count of OPP */
+ dev_pm_opp_get(opp);
break;
}
}
+ mutex_unlock(&opp_table->lock);
+ dev_pm_opp_put_opp_table(opp_table);
+
return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
{
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;
+
+ /* Increment the reference count of OPP */
+ dev_pm_opp_get(opp);
break;
}
}
+ mutex_unlock(&opp_table->lock);
+
return opp;
}
* ERANGE: no match found for search
* ENODEV: if device not found in list of registered devices
*
- * Locking: This function must be called under rcu_read_lock(). 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.
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
*/
struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
unsigned long *freq)
{
struct opp_table *opp_table;
-
- opp_rcu_lockdep_assert();
+ struct dev_pm_opp *opp;
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
if (IS_ERR(opp_table))
return ERR_CAST(opp_table);
- return _find_freq_ceil(opp_table, freq);
+ opp = _find_freq_ceil(opp_table, freq);
+
+ dev_pm_opp_put_opp_table(opp_table);
+
+ return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
* ERANGE: no match found for search
* ENODEV: if device not found in list of registered devices
*
- * Locking: This function must be called under rcu_read_lock(). 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.
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
*/
struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
unsigned long *freq)
struct opp_table *opp_table;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
- opp_rcu_lockdep_assert();
-
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
return ERR_PTR(-EINVAL);
if (IS_ERR(opp_table))
return ERR_CAST(opp_table);
- 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) {
/* go to the next node, before choosing prev */
if (temp_opp->rate > *freq)
opp = temp_opp;
}
}
+
+ /* Increment the reference count of OPP */
+ if (!IS_ERR(opp))
+ dev_pm_opp_get(opp);
+ mutex_unlock(&opp_table->lock);
+ dev_pm_opp_put_opp_table(opp_table);
+
if (!IS_ERR(opp))
*freq = opp->rate;
}
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;
-
- rcu_read_lock();
-
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- dev_err(dev, "%s: device opp doesn't exist\n", __func__);
- clk = ERR_CAST(opp_table);
- goto unlock;
- }
-
- clk = opp_table->clk;
- if (IS_ERR(clk))
- dev_err(dev, "%s: No clock available for the device\n",
- __func__);
-
-unlock:
- rcu_read_unlock();
- return clk;
-}
-
static int _set_opp_voltage(struct device *dev, struct regulator *reg,
struct dev_pm_opp_supply *supply)
{
*
* 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)
{
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)
if (old_freq == freq) {
dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
__func__, freq);
- return 0;
- }
-
- rcu_read_lock();
-
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- dev_err(dev, "%s: device opp doesn't exist\n", __func__);
- rcu_read_unlock();
- return PTR_ERR(opp_table);
+ ret = 0;
+ goto put_opp_table;
}
old_opp = _find_freq_ceil(opp_table, &old_freq);
ret = PTR_ERR(opp);
dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
__func__, freq, ret);
- rcu_read_unlock();
- return ret;
+ goto put_old_opp;
}
dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__,
/* Only frequency scaling */
if (!regulators) {
- rcu_read_unlock();
- 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)
data->new_opp.rate = freq;
memcpy(data->new_opp.supplies, opp->supplies, size);
- rcu_read_unlock();
+ ret = set_opp(data);
- return set_opp(data);
+put_opps:
+ dev_pm_opp_put(opp);
+put_old_opp:
+ if (!IS_ERR(old_opp))
+ dev_pm_opp_put(old_opp);
+put_opp_table:
+ dev_pm_opp_put_opp_table(opp_table);
+ 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,
/* 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);
return opp_dev;
}
-/**
- * _add_opp_table() - Find OPP table or allocate a new one
- * @dev: device for which we do this operation
- *
- * It tries to find an existing table first, if it couldn't find one, it
- * allocates a new OPP table and returns that.
- *
- * Return: valid opp_table pointer if success, else NULL.
- */
-static struct opp_table *_add_opp_table(struct device *dev)
+static struct opp_table *_allocate_opp_table(struct device *dev)
{
struct opp_table *opp_table;
struct opp_device *opp_dev;
int ret;
- /* Check for existing table for 'dev' first */
- opp_table = _find_opp_table(dev);
- if (!IS_ERR(opp_table))
- return opp_table;
-
/*
* Allocate a new OPP table. In the infrequent case where a new
* device is needed to be added, we pay this penalty.
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)
+void _get_opp_table_kref(struct opp_table *opp_table)
{
- struct opp_table *opp_table = container_of(head, struct opp_table,
- rcu_head);
-
- kfree_rcu(opp_table, rcu_head);
+ kref_get(&opp_table->kref);
}
-/**
- * _remove_opp_table() - Removes a OPP table
- * @opp_table: OPP table to be removed.
- *
- * Removes/frees OPP table if it doesn't contain any OPPs.
- */
-static void _remove_opp_table(struct opp_table *opp_table)
+struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
{
- struct opp_device *opp_dev;
+ struct opp_table *opp_table;
- if (!list_empty(&opp_table->opp_list))
- return;
+ /* Hold our table modification lock here */
+ mutex_lock(&opp_table_lock);
- if (opp_table->supported_hw)
- return;
+ opp_table = _find_opp_table_unlocked(dev);
+ if (!IS_ERR(opp_table))
+ goto unlock;
- if (opp_table->prop_name)
- return;
+ opp_table = _allocate_opp_table(dev);
- if (opp_table->regulators)
- return;
+unlock:
+ mutex_unlock(&opp_table_lock);
- if (opp_table->set_opp)
- return;
+ return opp_table;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);
+
+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;
/* Release clk */
if (!IS_ERR(opp_table->clk))
/* dev_list must be empty now */
WARN_ON(!list_empty(&opp_table->dev_list));
- list_del_rcu(&opp_table->node);
- call_srcu(&opp_table->srcu_head.srcu, &opp_table->rcu_head,
- _kfree_device_rcu);
+ mutex_destroy(&opp_table->lock);
+ list_del(&opp_table->node);
+ kfree(opp_table);
+
+ mutex_unlock(&opp_table_lock);
}
-/**
- * _kfree_opp_rcu() - Free OPP RCU handler
- * @head: RCU head
- */
-static void _kfree_opp_rcu(struct rcu_head *head)
+void dev_pm_opp_put_opp_table(struct opp_table *opp_table)
{
- struct dev_pm_opp *opp = container_of(head, struct dev_pm_opp, rcu_head);
+ kref_put_mutex(&opp_table->kref, _opp_table_kref_release,
+ &opp_table_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_opp_table);
- kfree_rcu(opp, rcu_head);
+void _opp_free(struct dev_pm_opp *opp)
+{
+ kfree(opp);
}
-/**
- * _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.
- *
- * Locking: The internal opp_table and opp structures are RCU protected.
- * 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_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;
+
/*
* 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);
+ 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);
- _remove_opp_table(opp_table);
+ mutex_unlock(&opp_table->lock);
+ dev_pm_opp_put_opp_table(opp_table);
+}
+
+static 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, &opp->opp_table->lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put);
+
/**
* dev_pm_opp_remove() - Remove an OPP from OPP table
* @dev: device for which we do this operation
* @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)
{
struct opp_table *opp_table;
bool found = false;
- /* Hold our table modification lock here */
- mutex_lock(&opp_table_lock);
-
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
- goto unlock;
+ return;
+
+ mutex_lock(&opp_table->lock);
list_for_each_entry(opp, &opp_table->opp_list, node) {
if (opp->rate == freq) {
}
}
- if (!found) {
+ mutex_unlock(&opp_table->lock);
+
+ if (found) {
+ dev_pm_opp_put(opp);
+ } else {
dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
__func__, freq);
- goto unlock;
}
- _opp_remove(opp_table, opp, true);
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
-struct dev_pm_opp *_allocate_opp(struct device *dev,
- struct opp_table **opp_table)
+struct dev_pm_opp *_opp_allocate(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;
/* 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;
}
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)
{
struct dev_pm_opp *opp;
- struct list_head *head = &opp_table->opp_list;
+ struct list_head *head;
int ret;
/*
* loop, don't replace it with head otherwise it will become an infinite
* loop.
*/
- list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {
+ mutex_lock(&opp_table->lock);
+ head = &opp_table->opp_list;
+
+ list_for_each_entry(opp, &opp_table->opp_list, node) {
if (new_opp->rate > opp->rate) {
head = &opp->node;
continue;
new_opp->supplies[0].u_volt, new_opp->available);
/* Should we compare voltages for all regulators here ? */
- return opp->available &&
- new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST;
+ ret = opp->available &&
+ new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST;
+
+ mutex_unlock(&opp_table->lock);
+ return ret;
}
+ list_add(&new_opp->node, head);
+ mutex_unlock(&opp_table->lock);
+
new_opp->opp_table = opp_table;
- list_add_rcu(&new_opp->node, head);
+ kref_init(&new_opp->kref);
+
+ /* Get a reference to the OPP table */
+ _get_opp_table_kref(opp_table);
ret = opp_debug_create_one(new_opp, opp_table);
if (ret)
/**
* _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
* 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
* 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);
-
- new_opp = _allocate_opp(dev, &opp_table);
- if (!new_opp) {
- ret = -ENOMEM;
- goto unlock;
- }
+ new_opp = _opp_allocate(opp_table);
+ if (!new_opp)
+ return -ENOMEM;
/* populate the opp table */
new_opp->rate = freq;
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);
+ }
/*
* 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:
- _opp_remove(opp_table, new_opp, false);
-unlock:
- mutex_unlock(&opp_table_lock);
+ _opp_free(new_opp);
+
return ret;
}
* specify the hierarchy of versions it supports. OPP layer will then enable
* OPPs, which are available for those versions, based on its 'opp-supported-hw'
* property.
- *
- * 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_supported_hw(struct device *dev, const u32 *versions,
- unsigned int count)
+struct opp_table *dev_pm_opp_set_supported_hw(struct device *dev,
+ const u32 *versions, unsigned int count)
{
struct opp_table *opp_table;
- int ret = 0;
-
- /* Hold our table modification lock here */
- mutex_lock(&opp_table_lock);
+ int ret;
- opp_table = _add_opp_table(dev);
- if (!opp_table) {
- ret = -ENOMEM;
- goto unlock;
- }
+ opp_table = dev_pm_opp_get_opp_table(dev);
+ if (!opp_table)
+ return ERR_PTR(-ENOMEM);
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
}
opp_table->supported_hw_count = count;
- mutex_unlock(&opp_table_lock);
- return 0;
+
+ return opp_table;
err:
- _remove_opp_table(opp_table);
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
- return ret;
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
/**
* dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
- * @dev: Device for which supported-hw has to be put.
+ * @opp_table: OPP table returned by dev_pm_opp_set_supported_hw().
*
* This is required only for the V2 bindings, and is called for a matching
* dev_pm_opp_set_supported_hw(). Until this is called, the opp_table structure
* will not be freed.
- *
- * 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_put_supported_hw(struct device *dev)
+void dev_pm_opp_put_supported_hw(struct opp_table *opp_table)
{
- struct opp_table *opp_table;
-
- /* Hold our table modification lock here */
- mutex_lock(&opp_table_lock);
-
- /* Check for existing table for 'dev' first */
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- dev_err(dev, "Failed to find opp_table: %ld\n",
- PTR_ERR(opp_table));
- goto unlock;
- }
-
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
if (!opp_table->supported_hw) {
- dev_err(dev, "%s: Doesn't have supported hardware list\n",
- __func__);
- goto unlock;
+ pr_err("%s: Doesn't have supported hardware list\n",
+ __func__);
+ return;
}
kfree(opp_table->supported_hw);
opp_table->supported_hw = NULL;
opp_table->supported_hw_count = 0;
- /* Try freeing opp_table if this was the last blocking resource */
- _remove_opp_table(opp_table);
-
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
* specify the extn to be used for certain property names. The properties to
* which the extension will apply are opp-microvolt and opp-microamp. OPP core
* should postfix the property name with -<name> while looking for them.
- *
- * 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_prop_name(struct device *dev, const char *name)
+struct opp_table *dev_pm_opp_set_prop_name(struct device *dev, const char *name)
{
struct opp_table *opp_table;
- int ret = 0;
-
- /* Hold our table modification lock here */
- mutex_lock(&opp_table_lock);
+ int ret;
- opp_table = _add_opp_table(dev);
- if (!opp_table) {
- ret = -ENOMEM;
- goto unlock;
- }
+ opp_table = dev_pm_opp_get_opp_table(dev);
+ if (!opp_table)
+ return ERR_PTR(-ENOMEM);
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
goto err;
}
- mutex_unlock(&opp_table_lock);
- return 0;
+ return opp_table;
err:
- _remove_opp_table(opp_table);
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
- return ret;
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
/**
* dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
- * @dev: Device for which the prop-name has to be put.
+ * @opp_table: OPP table returned by dev_pm_opp_set_prop_name().
*
* This is required only for the V2 bindings, and is called for a matching
* dev_pm_opp_set_prop_name(). Until this is called, the opp_table structure
* will not be freed.
- *
- * 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_put_prop_name(struct device *dev)
+void dev_pm_opp_put_prop_name(struct opp_table *opp_table)
{
- struct opp_table *opp_table;
-
- /* Hold our table modification lock here */
- mutex_lock(&opp_table_lock);
-
- /* Check for existing table for 'dev' first */
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- dev_err(dev, "Failed to find opp_table: %ld\n",
- PTR_ERR(opp_table));
- goto unlock;
- }
-
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
if (!opp_table->prop_name) {
- dev_err(dev, "%s: Doesn't have a prop-name\n", __func__);
- goto unlock;
+ pr_err("%s: Doesn't have a prop-name\n", __func__);
+ return;
}
kfree(opp_table->prop_name);
opp_table->prop_name = NULL;
- /* Try freeing opp_table if this was the last blocking resource */
- _remove_opp_table(opp_table);
-
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
* well.
*
* This must be called before any OPPs are initialized for the device.
- *
- * 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.
*/
struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
const char * const names[],
struct regulator *reg;
int ret, i;
- mutex_lock(&opp_table_lock);
-
- opp_table = _add_opp_table(dev);
- if (!opp_table) {
- ret = -ENOMEM;
- goto unlock;
- }
+ opp_table = dev_pm_opp_get_opp_table(dev);
+ if (!opp_table)
+ return ERR_PTR(-ENOMEM);
/* This should be called before OPPs are initialized */
if (WARN_ON(!list_empty(&opp_table->opp_list))) {
if (ret)
goto free_regulators;
- mutex_unlock(&opp_table_lock);
return opp_table;
free_regulators:
opp_table->regulators = NULL;
opp_table->regulator_count = 0;
err:
- _remove_opp_table(opp_table);
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
return ERR_PTR(ret);
}
/**
* dev_pm_opp_put_regulators() - Releases resources blocked for regulator
* @opp_table: OPP table returned from dev_pm_opp_set_regulators().
- *
- * 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_put_regulators(struct opp_table *opp_table)
{
int i;
- mutex_lock(&opp_table_lock);
-
if (!opp_table->regulators) {
pr_err("%s: Doesn't have regulators set\n", __func__);
- goto unlock;
+ return;
}
/* Make sure there are no concurrent readers while updating opp_table */
opp_table->regulators = NULL;
opp_table->regulator_count = 0;
- /* Try freeing opp_table if this was the last blocking resource */
- _remove_opp_table(opp_table);
-
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators);
* regulators per device), instead of the generic OPP set rate helper.
*
* This must be called before any OPPs are initialized for the device.
- *
- * 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_register_set_opp_helper(struct device *dev,
+struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev,
int (*set_opp)(struct dev_pm_set_opp_data *data))
{
struct opp_table *opp_table;
int ret;
if (!set_opp)
- return -EINVAL;
-
- mutex_lock(&opp_table_lock);
+ return ERR_PTR(-EINVAL);
- opp_table = _add_opp_table(dev);
- if (!opp_table) {
- ret = -ENOMEM;
- goto unlock;
- }
+ opp_table = dev_pm_opp_get_opp_table(dev);
+ if (!opp_table)
+ return ERR_PTR(-ENOMEM);
/* This should be called before OPPs are initialized */
if (WARN_ON(!list_empty(&opp_table->opp_list))) {
opp_table->set_opp = set_opp;
- mutex_unlock(&opp_table_lock);
- return 0;
+ return opp_table;
err:
- _remove_opp_table(opp_table);
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
- return ret;
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_register_set_opp_helper);
/**
* dev_pm_opp_register_put_opp_helper() - Releases resources blocked for
* set_opp helper
- * @dev: Device for which custom set_opp helper has to be cleared.
+ * @opp_table: OPP table returned from dev_pm_opp_register_set_opp_helper().
*
- * 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.
+ * Release resources blocked for platform specific set_opp helper.
*/
-void dev_pm_opp_register_put_opp_helper(struct device *dev)
+void dev_pm_opp_register_put_opp_helper(struct opp_table *opp_table)
{
- struct opp_table *opp_table;
-
- mutex_lock(&opp_table_lock);
-
- /* Check for existing table for 'dev' first */
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table)) {
- dev_err(dev, "Failed to find opp_table: %ld\n",
- PTR_ERR(opp_table));
- goto unlock;
- }
-
if (!opp_table->set_opp) {
- dev_err(dev, "%s: Doesn't have custom set_opp helper set\n",
- __func__);
- goto unlock;
+ pr_err("%s: Doesn't have custom set_opp helper set\n",
+ __func__);
+ return;
}
/* Make sure there are no concurrent readers while updating opp_table */
opp_table->set_opp = NULL;
- /* Try freeing opp_table if this was the last blocking resource */
- _remove_opp_table(opp_table);
-
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
}
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
*/
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;
+
+ opp_table = dev_pm_opp_get_opp_table(dev);
+ if (!opp_table)
+ return -ENOMEM;
+
+ ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
+
+ dev_pm_opp_put_opp_table(opp_table);
+ return ret;
}
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)
{
struct opp_table *opp_table;
- struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV);
+ struct dev_pm_opp *tmp_opp, *opp = ERR_PTR(-ENODEV);
int r = 0;
- /* keep the node allocated */
- new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL);
- if (!new_opp)
- return -ENOMEM;
-
- mutex_lock(&opp_table_lock);
-
/* Find the opp_table */
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
r = PTR_ERR(opp_table);
dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
- goto unlock;
+ return r;
}
+ mutex_lock(&opp_table->lock);
+
/* Do we have the frequency? */
list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
if (tmp_opp->rate == freq) {
break;
}
}
+
if (IS_ERR(opp)) {
r = PTR_ERR(opp);
goto unlock;
/* Is update really needed? */
if (opp->available == availability_req)
goto unlock;
- /* copy the old data over */
- *new_opp = *opp;
- /* plug in new node */
- new_opp->available = availability_req;
-
- list_replace_rcu(&opp->node, &new_opp->node);
- mutex_unlock(&opp_table_lock);
- call_srcu(&opp_table->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
+ opp->available = availability_req;
/* 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,
+ opp);
else
- srcu_notifier_call_chain(&opp_table->srcu_head,
- OPP_EVENT_DISABLE, new_opp);
-
- return 0;
+ blocking_notifier_call_chain(&opp_table->head,
+ OPP_EVENT_DISABLE, opp);
unlock:
- mutex_unlock(&opp_table_lock);
- kfree(new_opp);
+ mutex_unlock(&opp_table->lock);
+ dev_pm_opp_put_opp_table(opp_table);
return r;
}
* 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.
* 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.
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;
+
+ opp_table = _find_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return PTR_ERR(opp_table);
+
+ ret = blocking_notifier_chain_register(&opp_table->head, nb);
+
+ dev_pm_opp_put_opp_table(opp_table);
+
+ 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;
+ opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
- return ERR_CAST(opp_table); /* matching type */
+ return PTR_ERR(opp_table);
+
+ ret = blocking_notifier_chain_unregister(&opp_table->head, nb);
- return &opp_table->srcu_head;
+ dev_pm_opp_put_opp_table(opp_table);
+
+ 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
* dynamically added entries based on remove_all param.
*/
-void _dev_pm_opp_remove_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 opp_table *opp_table;
struct dev_pm_opp *opp, *tmp;
- /* Hold our table modification lock here */
- mutex_lock(&opp_table_lock);
+ /* Find if opp_table manages a single device */
+ if (list_is_singular(&opp_table->dev_list)) {
+ /* Free static OPPs */
+ list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
+ if (remove_all || !opp->dynamic)
+ dev_pm_opp_put(opp);
+ }
+ } else {
+ _remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table);
+ }
+}
+
+void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all)
+{
+ struct opp_table *opp_table;
/* Check for existing table for 'dev' */
opp_table = _find_opp_table(dev);
IS_ERR_OR_NULL(dev) ?
"Invalid device" : dev_name(dev),
error);
- goto unlock;
+ return;
}
- /* Find if opp_table manages a single device */
- if (list_is_singular(&opp_table->dev_list)) {
- /* 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);
- }
- } else {
- _remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table);
- }
+ _dev_pm_opp_remove_table(opp_table, dev, remove_all);
-unlock:
- mutex_unlock(&opp_table_lock);
+ dev_pm_opp_put_opp_table(opp_table);
}
/**
*
* 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)
{
- _dev_pm_opp_remove_table(dev, true);
+ _dev_pm_opp_find_and_remove_table(dev, true);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);
projects / karo-tx-linux.git / blobdiff