Commit 2af3411f authored by Rafael J. Wysocki's avatar Rafael J. Wysocki

Merge branch 'pm-opp' into pm-cpufreq

parents 8a497cfd b4037aaa
......@@ -49,11 +49,12 @@
* are protected by the dev_opp_list_lock for integrity.
* IMPORTANT: the opp nodes should be maintained in increasing
* order.
* @dynamic: not-created from static DT entries.
* @available: true/false - marks if this OPP as available or not
* @rate: Frequency in hertz
* @u_volt: Nominal voltage in microvolts corresponding to this OPP
* @dev_opp: points back to the device_opp struct this opp belongs to
* @head: RCU callback head used for deferred freeing
* @rcu_head: RCU callback head used for deferred freeing
*
* This structure stores the OPP information for a given device.
*/
......@@ -61,11 +62,12 @@ struct dev_pm_opp {
struct list_head node;
bool available;
bool dynamic;
unsigned long rate;
unsigned long u_volt;
struct device_opp *dev_opp;
struct rcu_head head;
struct rcu_head rcu_head;
};
/**
......@@ -76,7 +78,8 @@ struct dev_pm_opp {
* RCU usage: nodes are not modified in the list of device_opp,
* however addition is possible and is secured by dev_opp_list_lock
* @dev: device pointer
* @head: notifier head to notify the OPP availability changes.
* @srcu_head: notifier head to notify the OPP availability changes.
* @rcu_head: RCU callback head used for deferred freeing
* @opp_list: list of opps
*
* This is an internal data structure maintaining the link to opps attached to
......@@ -87,7 +90,8 @@ struct device_opp {
struct list_head node;
struct device *dev;
struct srcu_notifier_head head;
struct srcu_notifier_head srcu_head;
struct rcu_head rcu_head;
struct list_head opp_list;
};
......@@ -378,30 +382,8 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
/**
* dev_pm_opp_add() - Add an OPP table from a table definitions
* @dev: device for which we do this operation
* @freq: Frequency in Hz for this OPP
* @u_volt: Voltage in uVolts for this OPP
*
* This function adds an opp definition to the opp list and returns status.
* The opp is made available by default and it can be controlled using
* dev_pm_opp_enable/disable functions.
*
* Locking: The internal device_opp 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
* -EEXIST: Freq are same and volt are different OR
* Duplicate OPPs (both freq and volt are same) and !opp->available
* -ENOMEM: Memory allocation failure
*/
int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq,
unsigned long u_volt, bool dynamic)
{
struct device_opp *dev_opp = NULL;
struct dev_pm_opp *opp, *new_opp;
......@@ -417,6 +399,13 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
/* Hold our list modification lock here */
mutex_lock(&dev_opp_list_lock);
/* populate the opp table */
new_opp->dev_opp = dev_opp;
new_opp->rate = freq;
new_opp->u_volt = u_volt;
new_opp->available = true;
new_opp->dynamic = dynamic;
/* Check for existing list for 'dev' */
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp)) {
......@@ -436,19 +425,15 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
}
dev_opp->dev = dev;
srcu_init_notifier_head(&dev_opp->head);
srcu_init_notifier_head(&dev_opp->srcu_head);
INIT_LIST_HEAD(&dev_opp->opp_list);
/* Secure the device list modification */
list_add_rcu(&dev_opp->node, &dev_opp_list);
head = &dev_opp->opp_list;
goto list_add;
}
/* populate the opp table */
new_opp->dev_opp = dev_opp;
new_opp->rate = freq;
new_opp->u_volt = u_volt;
new_opp->available = true;
/*
* Insert new OPP in order of increasing frequency
* and discard if already present
......@@ -474,6 +459,7 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
return ret;
}
list_add:
list_add_rcu(&new_opp->node, head);
mutex_unlock(&dev_opp_list_lock);
......@@ -481,11 +467,109 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
* Notify the changes in the availability of the operable
* frequency/voltage list.
*/
srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ADD, new_opp);
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ADD, new_opp);
return 0;
}
/**
* dev_pm_opp_add() - Add an OPP table from a table definitions
* @dev: device for which we do this operation
* @freq: Frequency in Hz for this OPP
* @u_volt: Voltage in uVolts for this OPP
*
* This function adds an opp definition to the opp list and returns status.
* The opp is made available by default and it can be controlled using
* dev_pm_opp_enable/disable functions.
*
* Locking: The internal device_opp 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
* -EEXIST: Freq are same and volt are different OR
* Duplicate OPPs (both freq and volt are same) and !opp->available
* -ENOMEM: Memory allocation failure
*/
int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
{
return dev_pm_opp_add_dynamic(dev, freq, u_volt, true);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_add);
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 kfree_device_rcu(struct rcu_head *head)
{
struct device_opp *device_opp = container_of(head, struct device_opp, rcu_head);
kfree(device_opp);
}
void __dev_pm_opp_remove(struct device_opp *dev_opp, struct dev_pm_opp *opp)
{
/*
* Notify the changes in the availability of the operable
* frequency/voltage list.
*/
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
list_del_rcu(&opp->node);
call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, kfree_opp_rcu);
if (list_empty(&dev_opp->opp_list)) {
list_del_rcu(&dev_opp->node);
call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
kfree_device_rcu);
}
}
/**
* dev_pm_opp_remove() - Remove an OPP from OPP list
* @dev: device for which we do this operation
* @freq: OPP to remove with matching 'freq'
*
* This function removes an opp from the opp list.
*/
void dev_pm_opp_remove(struct device *dev, unsigned long freq)
{
struct dev_pm_opp *opp;
struct device_opp *dev_opp;
bool found = false;
/* Hold our list modification lock here */
mutex_lock(&dev_opp_list_lock);
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp))
goto unlock;
list_for_each_entry(opp, &dev_opp->opp_list, node) {
if (opp->rate == freq) {
found = true;
break;
}
}
if (!found) {
dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
__func__, freq);
goto unlock;
}
__dev_pm_opp_remove(dev_opp, opp);
unlock:
mutex_unlock(&dev_opp_list_lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
/**
* opp_set_availability() - helper to set the availability of an opp
* @dev: device for which we do this operation
......@@ -557,14 +641,14 @@ static int opp_set_availability(struct device *dev, unsigned long freq,
list_replace_rcu(&opp->node, &new_opp->node);
mutex_unlock(&dev_opp_list_lock);
kfree_rcu(opp, head);
call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, kfree_opp_rcu);
/* Notify the change of the OPP availability */
if (availability_req)
srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ENABLE,
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ENABLE,
new_opp);
else
srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_DISABLE,
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_DISABLE,
new_opp);
return 0;
......@@ -629,7 +713,7 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev)
if (IS_ERR(dev_opp))
return ERR_CAST(dev_opp); /* matching type */
return &dev_opp->head;
return &dev_opp->srcu_head;
}
#ifdef CONFIG_OF
......@@ -666,7 +750,7 @@ int of_init_opp_table(struct device *dev)
unsigned long freq = be32_to_cpup(val++) * 1000;
unsigned long volt = be32_to_cpup(val++);
if (dev_pm_opp_add(dev, freq, volt))
if (dev_pm_opp_add_dynamic(dev, freq, volt, false))
dev_warn(dev, "%s: Failed to add OPP %ld\n",
__func__, freq);
nr -= 2;
......@@ -675,4 +759,34 @@ int of_init_opp_table(struct device *dev)
return 0;
}
EXPORT_SYMBOL_GPL(of_init_opp_table);
/**
* of_free_opp_table() - Free OPP table entries created from static DT entries
* @dev: device pointer used to lookup device OPPs.
*
* Free OPPs created using static entries present in DT.
*/
void of_free_opp_table(struct device *dev)
{
struct device_opp *dev_opp = find_device_opp(dev);
struct dev_pm_opp *opp, *tmp;
/* Check for existing list for 'dev' */
dev_opp = find_device_opp(dev);
if (WARN(IS_ERR(dev_opp), "%s: dev_opp: %ld\n", dev_name(dev),
PTR_ERR(dev_opp)))
return;
/* Hold our list modification lock here */
mutex_lock(&dev_opp_list_lock);
/* Free static OPPs */
list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
if (!opp->dynamic)
__dev_pm_opp_remove(dev_opp, opp);
}
mutex_unlock(&dev_opp_list_lock);
}
EXPORT_SYMBOL_GPL(of_free_opp_table);
#endif
......@@ -21,7 +21,7 @@ struct dev_pm_opp;
struct device;
enum dev_pm_opp_event {
OPP_EVENT_ADD, OPP_EVENT_ENABLE, OPP_EVENT_DISABLE,
OPP_EVENT_ADD, OPP_EVENT_REMOVE, OPP_EVENT_ENABLE, OPP_EVENT_DISABLE,
};
#if defined(CONFIG_PM_OPP)
......@@ -44,6 +44,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
int dev_pm_opp_add(struct device *dev, unsigned long freq,
unsigned long u_volt);
void dev_pm_opp_remove(struct device *dev, unsigned long freq);
int dev_pm_opp_enable(struct device *dev, unsigned long freq);
......@@ -90,6 +91,10 @@ static inline int dev_pm_opp_add(struct device *dev, unsigned long freq,
return -EINVAL;
}
static inline void dev_pm_opp_remove(struct device *dev, unsigned long freq)
{
}
static inline int dev_pm_opp_enable(struct device *dev, unsigned long freq)
{
return 0;
......@@ -109,11 +114,16 @@ static inline struct srcu_notifier_head *dev_pm_opp_get_notifier(
#if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
int of_init_opp_table(struct device *dev);
void of_free_opp_table(struct device *dev);
#else
static inline int of_init_opp_table(struct device *dev)
{
return -EINVAL;
}
static inline void of_free_opp_table(struct device *dev)
{
}
#endif
#endif /* __LINUX_OPP_H__ */
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