@@ -86,16 +86,33 @@ struct dev_pm_opp {
};
/**
+ * struct device_list_opp - devices managed by 'struct device_opp'
+ * @node: list node
+ * @dev: device to which the struct object belongs
+ * @rcu_head: RCU callback head used for deferred freeing
+ *
+ * This is an internal data structure maintaining the list of devices that are
+ * managed by 'struct device_opp'.
+ */
+struct device_list_opp {
+ struct list_head node;
+ const struct device *dev;
+ struct rcu_head rcu_head;
+};
+
+/**
* struct device_opp - Device opp structure
* @node: list node - contains the devices with OPPs that
* have been registered. Nodes once added are not modified in this
* list.
* 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
* @srcu_head: notifier head to notify the OPP availability changes.
* @rcu_head: RCU callback head used for deferred freeing
+ * @dev_list: list of devices that share these OPPs
* @opp_list: list of opps
+ * @np: struct device_node pointer for opp's DT node.
+ * @shared_opp: OPP is shared between multiple devices.
*
* 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
@@ -108,12 +125,14 @@ struct dev_pm_opp {
struct device_opp {
struct list_head node;
- struct device *dev;
struct srcu_notifier_head srcu_head;
struct rcu_head rcu_head;
+ struct list_head dev_list;
struct list_head opp_list;
+ struct device_node *np;
unsigned long clock_latency_ns_max;
+ bool shared_opp;
};
/*
@@ -133,6 +152,38 @@ do { \
"dev_opp_list_lock protection"); \
} while (0)
+static struct device_list_opp *_find_list_dev(const struct device *dev,
+ struct device_opp *dev_opp)
+{
+ struct device_list_opp *list_dev;
+
+ list_for_each_entry(list_dev, &dev_opp->dev_list, node)
+ if (list_dev->dev == dev)
+ return list_dev;
+
+ return NULL;
+}
+
+static struct device_opp *_managed_opp(const struct device_node *np)
+{
+ struct device_opp *dev_opp;
+
+ list_for_each_entry_rcu(dev_opp, &dev_opp_list, node) {
+ if (dev_opp->np == np) {
+ /*
+ * Multiple devices can point to the same OPP table and
+ * so will have same node-pointer, np.
+ *
+ * But the OPPs will be considered as shared only if the
+ * OPP table contains a "opp-shared" property.
+ */
+ return dev_opp->shared_opp ? dev_opp : NULL;
+ }
+ }
+
+ return NULL;
+}
+
/**
* _find_device_opp() - find device_opp struct using device pointer
* @dev: device pointer used to lookup device OPPs
@@ -149,21 +200,18 @@ do { \
*/
static struct device_opp *_find_device_opp(struct device *dev)
{
- struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV);
+ struct device_opp *dev_opp;
if (unlikely(IS_ERR_OR_NULL(dev))) {
pr_err("%s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL);
}
- list_for_each_entry_rcu(tmp_dev_opp, &dev_opp_list, node) {
- if (tmp_dev_opp->dev == dev) {
- dev_opp = tmp_dev_opp;
- break;
- }
- }
+ list_for_each_entry_rcu(dev_opp, &dev_opp_list, node)
+ if (_find_list_dev(dev, dev_opp))
+ return dev_opp;
- return dev_opp;
+ return ERR_PTR(-ENODEV);
}
/**
@@ -450,6 +498,39 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
+/* List-dev Helpers */
+static void _kfree_list_dev_rcu(struct rcu_head *head)
+{
+ struct device_list_opp *list_dev;
+
+ list_dev = container_of(head, struct device_list_opp, rcu_head);
+ kfree_rcu(list_dev, rcu_head);
+}
+
+static void _remove_list_dev(struct device_list_opp *list_dev,
+ struct device_opp *dev_opp)
+{
+ list_del(&list_dev->node);
+ call_srcu(&dev_opp->srcu_head.srcu, &list_dev->rcu_head,
+ _kfree_list_dev_rcu);
+}
+
+static struct device_list_opp *_add_list_dev(const struct device *dev,
+ struct device_opp *dev_opp)
+{
+ struct device_list_opp *list_dev;
+
+ list_dev = kzalloc(sizeof(*list_dev), GFP_KERNEL);
+ if (!list_dev)
+ return NULL;
+
+ /* Initialize list-dev */
+ list_add_rcu(&list_dev->node, &dev_opp->dev_list);
+ list_dev->dev = dev;
+
+ return list_dev;
+}
+
/**
* _add_device_opp() - Find device OPP table or allocate a new one
* @dev: device for which we do this operation
@@ -462,6 +543,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
static struct device_opp *_add_device_opp(struct device *dev)
{
struct device_opp *dev_opp;
+ struct device_list_opp *list_dev;
/* Check for existing list for 'dev' first */
dev_opp = _find_device_opp(dev);
@@ -476,7 +558,14 @@ static struct device_opp *_add_device_opp(struct device *dev)
if (!dev_opp)
return NULL;
- dev_opp->dev = dev;
+ INIT_LIST_HEAD(&dev_opp->dev_list);
+
+ list_dev = _add_list_dev(dev, dev_opp);
+ if (!list_dev) {
+ kfree(dev_opp);
+ return NULL;
+ }
+
srcu_init_notifier_head(&dev_opp->srcu_head);
INIT_LIST_HEAD(&dev_opp->opp_list);
@@ -504,9 +593,19 @@ static void _kfree_device_rcu(struct rcu_head *head)
*/
static void _remove_device_opp(struct device_opp *dev_opp)
{
+ struct device_list_opp *list_dev;
+
if (!list_empty(&dev_opp->opp_list))
return;
+ list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
+ node);
+
+ _remove_list_dev(list_dev, dev_opp);
+
+ /* dev_list must be empty now */
+ WARN_ON(!list_empty(&dev_opp->dev_list));
+
list_del_rcu(&dev_opp->node);
call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
_kfree_device_rcu);
@@ -616,7 +715,8 @@ static struct dev_pm_opp *_allocate_opp(struct device *dev,
return opp;
}
-static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)
+static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
+ struct device_opp *dev_opp)
{
struct dev_pm_opp *opp;
struct list_head *head = &dev_opp->opp_list;
@@ -632,7 +732,7 @@ static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)
break;
/* Duplicate OPPs */
- dev_warn(dev_opp->dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
+ dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
__func__, opp->rate, opp->u_volt, opp->available,
new_opp->rate, new_opp->u_volt, new_opp->available);
@@ -695,7 +795,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
new_opp->available = true;
new_opp->dynamic = dynamic;
- ret = _opp_add(new_opp, dev_opp);
+ ret = _opp_add(dev, new_opp, dev_opp);
if (ret)
goto free_opp;
@@ -805,7 +905,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
of_property_read_u32(np, "opp-microamp", (u32 *)&new_opp->u_amp);
- ret = _opp_add(new_opp, dev_opp);
+ ret = _opp_add(dev, new_opp, dev_opp);
if (ret)
goto free_opp;
@@ -1038,6 +1138,9 @@ void of_free_opp_table(struct device *dev)
struct device_opp *dev_opp;
struct dev_pm_opp *opp, *tmp;
+ /* Hold our list modification lock here */
+ mutex_lock(&dev_opp_list_lock);
+
/* Check for existing list for 'dev' */
dev_opp = _find_device_opp(dev);
if (IS_ERR(dev_opp)) {
@@ -1048,18 +1151,21 @@ void of_free_opp_table(struct device *dev)
IS_ERR_OR_NULL(dev) ?
"Invalid device" : dev_name(dev),
error);
- return;
+ goto unlock;
}
- /* 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)
- _opp_remove(dev_opp, opp, true);
+ /* Find if dev_opp manages a single device */
+ if (list_is_singular(&dev_opp->dev_list)) {
+ /* Free static OPPs */
+ list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
+ if (!opp->dynamic)
+ _opp_remove(dev_opp, opp, true);
+ }
+ } else {
+ _remove_list_dev(_find_list_dev(dev, dev_opp), dev_opp);
}
+unlock:
mutex_unlock(&dev_opp_list_lock);
}
EXPORT_SYMBOL_GPL(of_free_opp_table);
@@ -1085,6 +1191,7 @@ static int _of_init_opp_table_v2(struct device *dev,
const struct property *prop)
{
struct device_node *opp_np, *np;
+ struct device_opp *dev_opp;
int ret = 0, count = 0;
if (!prop->value)
@@ -1095,6 +1202,14 @@ static int _of_init_opp_table_v2(struct device *dev,
if (IS_ERR(opp_np))
return PTR_ERR(opp_np);
+ dev_opp = _managed_opp(opp_np);
+ if (dev_opp) {
+ /* OPPs are already managed */
+ if (!_add_list_dev(dev, dev_opp))
+ ret = -ENOMEM;
+ goto put_opp_np;
+ }
+
/* We have opp-list node now, iterate over it and add OPPs */
for_each_available_child_of_node(opp_np, np) {
count++;
@@ -1111,8 +1226,19 @@ static int _of_init_opp_table_v2(struct device *dev,
if (WARN_ON(!count))
goto put_opp_np;
- if (ret)
+ if (!ret) {
+ if (!dev_opp) {
+ dev_opp = _find_device_opp(dev);
+ if (WARN_ON(!dev_opp))
+ goto put_opp_np;
+ }
+
+ dev_opp->np = opp_np;
+ dev_opp->shared_opp = of_property_read_bool(opp_np,
+ "opp-shared");
+ } else {
of_free_opp_table(dev);
+ }
put_opp_np:
of_node_put(opp_np);