PM / QoS: Add support for MIN/MAX frequency constraints

This patch introduces the min-frequency and max-frequency device
constraints, which will be used by the cpufreq core to begin with.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

2 files changed, 109 insertions, 14 deletions

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 2461fed0efa0..6c90fd7e2ff8 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -120,6 +120,14 @@ s32 dev_pm_qos_read_value(struct device *dev, enum dev_pm_qos_req_type type)
                 ret = IS_ERR_OR_NULL(qos) ? PM_QOS_RESUME_LATENCY_NO_CONSTRAINT
                         : pm_qos_read_value(&qos->resume_latency);
                 break;
+        case DEV_PM_QOS_MIN_FREQUENCY:
+                ret = IS_ERR_OR_NULL(qos) ? PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE
+                        : pm_qos_read_value(&qos->min_frequency);
+                break;
+        case DEV_PM_QOS_MAX_FREQUENCY:
+                ret = IS_ERR_OR_NULL(qos) ? PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE
+                        : pm_qos_read_value(&qos->max_frequency);
+                break;
         default:
                 WARN_ON(1);
                 ret = 0;
@@ -161,6 +169,14 @@ static int apply_constraint(struct dev_pm_qos_request *req,
                         req->dev->power.set_latency_tolerance(req->dev, value);
                 }
                 break;
+        case DEV_PM_QOS_MIN_FREQUENCY:
+                ret = pm_qos_update_target(&qos->min_frequency,
+                                           &req->data.pnode, action, value);
+                break;
+        case DEV_PM_QOS_MAX_FREQUENCY:
+                ret = pm_qos_update_target(&qos->max_frequency,
+                                           &req->data.pnode, action, value);
+                break;
         case DEV_PM_QOS_FLAGS:
                 ret = pm_qos_update_flags(&qos->flags, &req->data.flr,
                                           action, value);
@@ -189,12 +205,11 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
         if (!qos)
                 return -ENOMEM;
 
-        n = kzalloc(sizeof(*n), GFP_KERNEL);
+        n = kzalloc(3 * sizeof(*n), GFP_KERNEL);
         if (!n) {
                 kfree(qos);
                 return -ENOMEM;
         }
-        BLOCKING_INIT_NOTIFIER_HEAD(n);
 
         c = &qos->resume_latency;
         plist_head_init(&c->list);
@@ -203,6 +218,7 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
         c->no_constraint_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
         c->type = PM_QOS_MIN;
         c->notifiers = n;
+        BLOCKING_INIT_NOTIFIER_HEAD(n);
 
         c = &qos->latency_tolerance;
         plist_head_init(&c->list);
@@ -211,6 +227,24 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
         c->no_constraint_value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
         c->type = PM_QOS_MIN;
 
+        c = &qos->min_frequency;
+        plist_head_init(&c->list);
+        c->target_value = PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE;
+        c->default_value = PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE;
+        c->no_constraint_value = PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE;
+        c->type = PM_QOS_MAX;
+        c->notifiers = ++n;
+        BLOCKING_INIT_NOTIFIER_HEAD(n);
+
+        c = &qos->max_frequency;
+        plist_head_init(&c->list);
+        c->target_value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
+        c->default_value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
+        c->no_constraint_value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
+        c->type = PM_QOS_MIN;
+        c->notifiers = ++n;
+        BLOCKING_INIT_NOTIFIER_HEAD(n);
+
         INIT_LIST_HEAD(&qos->flags.list);
 
         spin_lock_irq(&dev->power.lock);
@@ -264,11 +298,25 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
                 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
                 memset(req, 0, sizeof(*req));
         }
+
         c = &qos->latency_tolerance;
         plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
                 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
                 memset(req, 0, sizeof(*req));
         }
+
+        c = &qos->min_frequency;
+        plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
+                apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE);
+                memset(req, 0, sizeof(*req));
+        }
+
+        c = &qos->max_frequency;
+        plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
+                apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
+                memset(req, 0, sizeof(*req));
+        }
+
         f = &qos->flags;
         list_for_each_entry_safe(req, tmp, &f->list, data.flr.node) {
                 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
@@ -380,6 +428,8 @@ 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:
+        case DEV_PM_QOS_MIN_FREQUENCY:
+        case DEV_PM_QOS_MAX_FREQUENCY:
                 curr_value = req->data.pnode.prio;
                 break;
         case DEV_PM_QOS_FLAGS:
@@ -492,9 +542,6 @@ int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier,
 {
         int ret = 0;
 
-        if (WARN_ON(type != DEV_PM_QOS_RESUME_LATENCY))
-                return -EINVAL;
-
         mutex_lock(&dev_pm_qos_mtx);
 
         if (IS_ERR(dev->power.qos))
@@ -502,10 +549,28 @@ int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier,
         else if (!dev->power.qos)
                 ret = dev_pm_qos_constraints_allocate(dev);
 
-        if (!ret)
+        if (ret)
+                goto unlock;
+
+        switch (type) {
+        case DEV_PM_QOS_RESUME_LATENCY:
                 ret = blocking_notifier_chain_register(dev->power.qos->resume_latency.notifiers,
                                                        notifier);
+                break;
+        case DEV_PM_QOS_MIN_FREQUENCY:
+                ret = blocking_notifier_chain_register(dev->power.qos->min_frequency.notifiers,
+                                                       notifier);
+                break;
+        case DEV_PM_QOS_MAX_FREQUENCY:
+                ret = blocking_notifier_chain_register(dev->power.qos->max_frequency.notifiers,
+                                                       notifier);
+                break;
+        default:
+                WARN_ON(1);
+                ret = -EINVAL;
+        }
 
+unlock:
         mutex_unlock(&dev_pm_qos_mtx);
         return ret;
 }
@@ -526,20 +591,35 @@ int dev_pm_qos_remove_notifier(struct device *dev,
                                struct notifier_block *notifier,
                                enum dev_pm_qos_req_type type)
 {
-        int retval = 0;
-
-        if (WARN_ON(type != DEV_PM_QOS_RESUME_LATENCY))
-                return -EINVAL;
+        int ret = 0;
 
         mutex_lock(&dev_pm_qos_mtx);
 
         /* Silently return if the constraints object is not present. */
-        if (!IS_ERR_OR_NULL(dev->power.qos))
-                retval = blocking_notifier_chain_unregister(dev->power.qos->resume_latency.notifiers,
-                                                            notifier);
+        if (IS_ERR_OR_NULL(dev->power.qos))
+                goto unlock;
+
+        switch (type) {
+        case DEV_PM_QOS_RESUME_LATENCY:
+                ret = blocking_notifier_chain_unregister(dev->power.qos->resume_latency.notifiers,
+                                                         notifier);
+                break;
+        case DEV_PM_QOS_MIN_FREQUENCY:
+                ret = blocking_notifier_chain_unregister(dev->power.qos->min_frequency.notifiers,
+                                                         notifier);
+                break;
+        case DEV_PM_QOS_MAX_FREQUENCY:
+                ret = blocking_notifier_chain_unregister(dev->power.qos->max_frequency.notifiers,
+                                                         notifier);
+                break;
+        default:
+                WARN_ON(1);
+                ret = -EINVAL;
+        }
 
+unlock:
         mutex_unlock(&dev_pm_qos_mtx);
-        return retval;
+        return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier);
 
@@ -599,6 +679,9 @@ static void __dev_pm_qos_drop_user_request(struct device *dev,
                 req = dev->power.qos->flags_req;
                 dev->power.qos->flags_req = NULL;
                 break;
+        default:
+                WARN_ON(1);
+                return;
         }
         __dev_pm_qos_remove_request(req);
         kfree(req);
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 9a21b7ba72ae..2aebbc5b9950 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -40,6 +40,8 @@ enum pm_qos_flags_status {
 #define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT     PM_QOS_LATENCY_ANY
 #define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS  PM_QOS_LATENCY_ANY_NS
 #define PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE  0
+#define PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE      0
+#define PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE      (-1)
 #define PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT  (-1)
 
 #define PM_QOS_FLAG_NO_POWER_OFF        (1 << 0)
@@ -58,6 +60,8 @@ struct pm_qos_flags_request {
 enum dev_pm_qos_req_type {
         DEV_PM_QOS_RESUME_LATENCY = 1,
         DEV_PM_QOS_LATENCY_TOLERANCE,
+        DEV_PM_QOS_MIN_FREQUENCY,
+        DEV_PM_QOS_MAX_FREQUENCY,
         DEV_PM_QOS_FLAGS,
 };
 
@@ -99,10 +103,14 @@ struct pm_qos_flags {
 struct dev_pm_qos {
         struct pm_qos_constraints resume_latency;
         struct pm_qos_constraints latency_tolerance;
+        struct pm_qos_constraints min_frequency;
+        struct pm_qos_constraints max_frequency;
         struct pm_qos_flags flags;
         struct dev_pm_qos_request *resume_latency_req;
         struct dev_pm_qos_request *latency_tolerance_req;
         struct dev_pm_qos_request *flags_req;
+        struct dev_pm_qos_request *min_frequency_req;
+        struct dev_pm_qos_request *max_frequency_req;
 };
 
 /* Action requested to pm_qos_update_target */
@@ -197,6 +205,10 @@ static inline s32 dev_pm_qos_read_value(struct device *dev,
         switch (type) {
         case DEV_PM_QOS_RESUME_LATENCY:
                 return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
+        case DEV_PM_QOS_MIN_FREQUENCY:
+                return PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE;
+        case DEV_PM_QOS_MAX_FREQUENCY:
+                return PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
         default:
                 WARN_ON(1);
                 return 0;