PM / QoS: Prepare device structure for adding more constraint types

Currently struct dev_pm_info contains only one PM QoS constraints
pointer reserved for latency requirements.  Since one more device
constraints type (i.e. flags) will be necessary, introduce a new
structure, struct dev_pm_qos, that eventually will contain all of
the available device PM QoS constraints and replace the "constraints"
pointer in struct dev_pm_info with a pointer to the new structure
called "qos".

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>

3 files changed, 27 insertions, 21 deletions

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 74a67e0019a2..40ff1b02a7c5 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -55,9 +55,7 @@ static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
  */
 s32 __dev_pm_qos_read_value(struct device *dev)
 {
-        struct pm_qos_constraints *c = dev->power.constraints;
-
-        return c ? pm_qos_read_value(c) : 0;
+        return dev->power.qos ? pm_qos_read_value(&dev->power.qos->latency) : 0;
 }
 
 /**
@@ -91,12 +89,12 @@ static int apply_constraint(struct dev_pm_qos_request *req,
 {
         int ret, curr_value;
 
-        ret = pm_qos_update_target(req->dev->power.constraints,
+        ret = pm_qos_update_target(&req->dev->power.qos->latency,
                                    &req->node, action, value);
 
         if (ret) {
                 /* Call the global callbacks if needed */
-                curr_value = pm_qos_read_value(req->dev->power.constraints);
+                curr_value = pm_qos_read_value(&req->dev->power.qos->latency);
                 blocking_notifier_call_chain(&dev_pm_notifiers,
                                              (unsigned long)curr_value,
                                              req);
@@ -114,20 +112,22 @@ static int apply_constraint(struct dev_pm_qos_request *req,
  */
 static int dev_pm_qos_constraints_allocate(struct device *dev)
 {
+        struct dev_pm_qos *qos;
         struct pm_qos_constraints *c;
         struct blocking_notifier_head *n;
 
-        c = kzalloc(sizeof(*c), GFP_KERNEL);
-        if (!c)
+        qos = kzalloc(sizeof(*qos), GFP_KERNEL);
+        if (!qos)
                 return -ENOMEM;
 
         n = kzalloc(sizeof(*n), GFP_KERNEL);
         if (!n) {
-                kfree(c);
+                kfree(qos);
                 return -ENOMEM;
         }
         BLOCKING_INIT_NOTIFIER_HEAD(n);
 
+        c = &qos->latency;
         plist_head_init(&c->list);
         c->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
         c->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
@@ -135,7 +135,7 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
         c->notifiers = n;
 
         spin_lock_irq(&dev->power.lock);
-        dev->power.constraints = c;
+        dev->power.qos = qos;
         spin_unlock_irq(&dev->power.lock);
 
         return 0;
@@ -151,7 +151,7 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
 void dev_pm_qos_constraints_init(struct device *dev)
 {
         mutex_lock(&dev_pm_qos_mtx);
-        dev->power.constraints = NULL;
+        dev->power.qos = NULL;
         dev->power.power_state = PMSG_ON;
         mutex_unlock(&dev_pm_qos_mtx);
 }
@@ -164,6 +164,7 @@ void dev_pm_qos_constraints_init(struct device *dev)
  */
 void dev_pm_qos_constraints_destroy(struct device *dev)
 {
+        struct dev_pm_qos *qos;
         struct dev_pm_qos_request *req, *tmp;
         struct pm_qos_constraints *c;
 
@@ -176,10 +177,11 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
         mutex_lock(&dev_pm_qos_mtx);
 
         dev->power.power_state = PMSG_INVALID;
-        c = dev->power.constraints;
-        if (!c)
+        qos = dev->power.qos;
+        if (!qos)
                 goto out;
 
+        c = &qos->latency;
         /* Flush the constraints list for the device */
         plist_for_each_entry_safe(req, tmp, &c->list, node) {
                 /*
@@ -191,7 +193,7 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
         }
 
         spin_lock_irq(&dev->power.lock);
-        dev->power.constraints = NULL;
+        dev->power.qos = NULL;
         spin_unlock_irq(&dev->power.lock);
 
         kfree(c->notifiers);
@@ -235,7 +237,7 @@ int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
 
         mutex_lock(&dev_pm_qos_mtx);
 
-        if (!dev->power.constraints) {
+        if (!dev->power.qos) {
                 if (dev->power.power_state.event == PM_EVENT_INVALID) {
                         /* The device has been removed from the system. */
                         req->dev = NULL;
@@ -290,7 +292,7 @@ int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 
         mutex_lock(&dev_pm_qos_mtx);
 
-        if (req->dev->power.constraints) {
+        if (req->dev->power.qos) {
                 if (new_value != req->node.prio)
                         ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
                                                new_value);
@@ -329,7 +331,7 @@ int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
 
         mutex_lock(&dev_pm_qos_mtx);
 
-        if (req->dev->power.constraints) {
+        if (req->dev->power.qos) {
                 ret = apply_constraint(req, PM_QOS_REMOVE_REQ,
                                        PM_QOS_DEFAULT_VALUE);
                 memset(req, 0, sizeof(*req));
@@ -362,13 +364,13 @@ int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
 
         mutex_lock(&dev_pm_qos_mtx);
 
-        if (!dev->power.constraints)
+        if (!dev->power.qos)
                 ret = dev->power.power_state.event != PM_EVENT_INVALID ?
                         dev_pm_qos_constraints_allocate(dev) : -ENODEV;
 
         if (!ret)
                 ret = blocking_notifier_chain_register(
-                                dev->power.constraints->notifiers, notifier);
+                                dev->power.qos->latency.notifiers, notifier);
 
         mutex_unlock(&dev_pm_qos_mtx);
         return ret;
@@ -393,9 +395,9 @@ int dev_pm_qos_remove_notifier(struct device *dev,
         mutex_lock(&dev_pm_qos_mtx);
 
         /* Silently return if the constraints object is not present. */
-        if (dev->power.constraints)
+        if (dev->power.qos)
                 retval = blocking_notifier_chain_unregister(
-                                dev->power.constraints->notifiers,
+                                dev->power.qos->latency.notifiers,
                                 notifier);
 
         mutex_unlock(&dev_pm_qos_mtx);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 007e687c4f69..0ce6df94221a 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -549,7 +549,7 @@ struct dev_pm_info {
         struct dev_pm_qos_request *pq_req;
 #endif
         struct pm_subsys_data   *subsys_data;  /* Owned by the subsystem. */
-        struct pm_qos_constraints *constraints;
+        struct dev_pm_qos       *qos;
 };
 
 extern void update_pm_runtime_accounting(struct device *dev);
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 9924ea1f22e0..30e9ad72e797 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -57,6 +57,10 @@ struct pm_qos_constraints {
         struct blocking_notifier_head *notifiers;
 };
 
+struct dev_pm_qos {
+        struct pm_qos_constraints latency;
+};
+
 /* Action requested to pm_qos_update_target */
 enum pm_qos_req_action {
         PM_QOS_ADD_REQ,         /* Add a new request */