QoS: Modify data structures and function arguments for scalability.

QoS add requests uses a handle to the priority list that is used
internally to save the request, but this does not extend well. Also,
dev_pm_qos structure definition seems to use a list object directly.
The 'derivative' relationship seems to be broken.

Use pm_qos_request objects instead of passing around the protected
priority list object.

Change-Id: Ie4c9c22dd4ea13265fe01f080ba68cf77d9d484d
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
[mattw@codeaurora.org: resolve context conflicts and extend
struct modifications to additional affected users]
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>

Conflicts:
	include/linux/pm_qos.h

drivers/base/power/qos.c

@@ -147,7 +147,7 @@ static int apply_constraint(struct dev_pm_qos_request *req,
 	switch(req->type) {
 	case DEV_PM_QOS_RESUME_LATENCY:
 		ret = pm_qos_update_target(&qos->resume_latency,
-					   &req->data.pnode, action, value);
+					   &req->data.lat, action, value);
 		if (ret) {
 			value = pm_qos_read_value(&qos->resume_latency);
 			blocking_notifier_call_chain(&dev_pm_notifiers,
@@ -157,7 +157,7 @@ static int apply_constraint(struct dev_pm_qos_request *req,
 		break;
 	case DEV_PM_QOS_LATENCY_TOLERANCE:
 		ret = pm_qos_update_target(&qos->latency_tolerance,
-					   &req->data.pnode, action, value);
+					   &req->data.lat, action, value);
 		if (ret) {
 			value = pm_qos_read_value(&qos->latency_tolerance);
 			req->dev->power.set_latency_tolerance(req->dev, value);
@@ -258,7 +258,7 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
 
 	/* Flush the constraints lists for the device. */
 	c = &qos->resume_latency;
-	plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
+	plist_for_each_entry_safe(req, tmp, &c->list, data.lat.node) {
 		/*
 		 * Update constraints list and call the notification
 		 * callbacks if needed
@@ -267,7 +267,7 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
 		memset(req, 0, sizeof(*req));
 	}
 	c = &qos->latency_tolerance;
-	plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
+	plist_for_each_entry_safe(req, tmp, &c->list, data.lat.node) {
 		apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
 		memset(req, 0, sizeof(*req));
 	}
@@ -382,7 +382,7 @@ static int __dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 	switch(req->type) {
 	case DEV_PM_QOS_RESUME_LATENCY:
 	case DEV_PM_QOS_LATENCY_TOLERANCE:
-		curr_value = req->data.pnode.prio;
+		curr_value = req->data.lat.node.prio;
 		break;
 	case DEV_PM_QOS_FLAGS:
 		curr_value = req->data.flr.flags;
@@ -835,7 +835,7 @@ s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev)
 	ret = IS_ERR_OR_NULL(dev->power.qos)
 		|| !dev->power.qos->latency_tolerance_req ?
 			PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT :
-			dev->power.qos->latency_tolerance_req->data.pnode.prio;
+			dev->power.qos->latency_tolerance_req->data.lat.node.prio;
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }

include/linux/pm_qos.h

@@ -62,7 +62,7 @@ enum dev_pm_qos_req_type {
 struct dev_pm_qos_request {
 	enum dev_pm_qos_req_type type;
 	union {
-		struct plist_node pnode;
+		struct pm_qos_request lat;
 		struct pm_qos_flags_request flr;
 	} data;
 	struct device *dev;
@@ -115,8 +115,9 @@ static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
 	return req->dev != NULL;
 }
 
-int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
+int pm_qos_update_target(struct pm_qos_constraints *c,
-			 enum pm_qos_req_action action, int value);
+				struct pm_qos_request *req,
+				enum pm_qos_req_action action, int value);
 bool pm_qos_update_flags(struct pm_qos_flags *pqf,
 			 struct pm_qos_flags_request *req,
 			 enum pm_qos_req_action action, s32 val);
@@ -166,7 +167,7 @@ void dev_pm_qos_hide_latency_tolerance(struct device *dev);
 
 static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
 {
-	return dev->power.qos->resume_latency_req->data.pnode.prio;
+	return dev->power.qos->resume_latency_req->data.lat.node.prio;
 }
 
 static inline s32 dev_pm_qos_requested_flags(struct device *dev)

kernel/power/qos.c

@@ -263,18 +263,20 @@ static const struct file_operations pm_qos_debug_fops = {
  * pm_qos_update_target - manages the constraints list and calls the notifiers
  *  if needed
  * @c: constraints data struct
- * @node: request to add to the list, to update or to remove
+ * @req: request to add to the list, to update or to remove
  * @action: action to take on the constraints list
  * @value: value of the request to add or update
  *
  * This function returns 1 if the aggregated constraint value has changed, 0
  *  otherwise.
  */
-int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
+int pm_qos_update_target(struct pm_qos_constraints *c,
-			 enum pm_qos_req_action action, int value)
+				struct pm_qos_request *req,
+				enum pm_qos_req_action action, int value)
 {
 	unsigned long flags;
 	int prev_value, curr_value, new_value;
+	struct plist_node *node = &req->node;
 	int ret;
 
 	spin_lock_irqsave(&pm_qos_lock, flags);
@@ -412,7 +414,7 @@ static void __pm_qos_update_request(struct pm_qos_request *req,
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
 			pm_qos_array[req->pm_qos_class]->constraints,
-			&req->node, PM_QOS_UPDATE_REQ, new_value);
+			req, PM_QOS_UPDATE_REQ, new_value);
 }
 
 /**
@@ -457,7 +459,7 @@ void pm_qos_add_request(struct pm_qos_request *req,
 	INIT_DELAYED_WORK(&req->work, pm_qos_work_fn);
 	trace_pm_qos_add_request(pm_qos_class, value);
 	pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints,
-			     &req->node, PM_QOS_ADD_REQ, value);
+			     req, PM_QOS_ADD_REQ, value);
 }
 EXPORT_SYMBOL_GPL(pm_qos_add_request);
 
@@ -511,7 +513,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
 			pm_qos_array[req->pm_qos_class]->constraints,
-			&req->node, PM_QOS_UPDATE_REQ, new_value);
+			req, PM_QOS_UPDATE_REQ, new_value);
 
 	schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us));
 }
@@ -539,7 +541,7 @@ void pm_qos_remove_request(struct pm_qos_request *req)
 
 	trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE);
 	pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
-			     &req->node, PM_QOS_REMOVE_REQ,
+			     req, PM_QOS_REMOVE_REQ,
 			     PM_QOS_DEFAULT_VALUE);
 	memset(req, 0, sizeof(*req));
 }