[PATCH V4 0/6] cpufreq: Use QoS layer to manage freq-constraints

[PATCH V4 0/6] cpufreq: Use QoS layer to manage freq-constraints

[Viresh Kumar]

Hello,

This patchset attempts to manage CPU frequency constraints using the PM
QoS framework. It only does the basic stuff right now and moves the
userspace constraints to use the QoS infrastructure.

This is rebased over pm/linux-next and another cleanup series [1].

Todo:
- Migrate all users to the QoS framework and get rid of cpufreq specific
  notifiers.
- Make PM QoS learn about the relation of CPUs in a policy, so a single
  list of constraints is managed for all of them instead of per-cpu
  constraints.

V3->V4:
- Few commit logs updated as suggested during reviews.
- Separate commit (2/6) to create resume-latency specific routines
- Reused earlier work ("update") for notifiers as well.
- Kept Reviewed-by tags as is as the patches normally got better only.
  Please take them back if you find any issues.

V2->V3:
- Add a comment in cpufreq.c as suggested by Qais.
- Rebased on latest pm/linux-next.

V1->V2:
- The previous version introduced a completely new framework, this one
  moves to PM QoS instead.
- Lots of changes because of this.

--
viresh

[1] http://lore.kernel.org/lkml/cover.1560999838.git.viresh.kumar@linaro.org

Viresh Kumar (6):
  PM / QOS: Pass request type to dev_pm_qos_{add|remove}_notifier()
  PM / QOS: Rename __dev_pm_qos_read_value() and
    dev_pm_qos_raw_read_value()
  PM / QOS: Pass request type to dev_pm_qos_read_value()
  PM / QoS: Add support for MIN/MAX frequency constraints
  cpufreq: Register notifiers with the PM QoS framework
  cpufreq: Add QoS requests for userspace constraints

 Documentation/power/pm_qos_interface.txt |  12 +-
 drivers/base/power/domain.c              |   8 +-
 drivers/base/power/domain_governor.c     |   4 +-
 drivers/base/power/qos.c                 | 135 ++++++++++++++--
 drivers/base/power/runtime.c             |   2 +-
 drivers/cpufreq/cpufreq.c                | 198 ++++++++++++++++-------
 drivers/cpuidle/governor.c               |   2 +-
 include/linux/cpufreq.h                  |  11 +-
 include/linux/pm_qos.h                   |  48 ++++--
 9 files changed, 316 insertions(+), 104 deletions(-)

-- 
2.21.0.rc0.269.g1a574e7a288b

[PATCH V4 1/6] PM / QOS: Pass request type to dev_pm_qos_{add|remove}_notifier()

[Viresh Kumar]

In order to use the same set of routines to register notifiers for
different request types, update the existing
dev_pm_qos_{add|remove}_notifier() routines with an additional
parameter: request-type.

For now, it only supports resume-latency request type but will be
extended to frequency limit (min/max) constraints later on.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 Documentation/power/pm_qos_interface.txt | 10 ++++++----
 drivers/base/power/domain.c              |  8 +++++---
 drivers/base/power/qos.c                 | 14 ++++++++++++--
 include/linux/pm_qos.h                   | 12 ++++++++----
 4 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt
index 19c5f7b1a7ba..ec7d662d1707 100644
--- a/Documentation/power/pm_qos_interface.txt
+++ b/Documentation/power/pm_qos_interface.txt
@@ -164,12 +164,14 @@ directory.
 Notification mechanisms:
 The per-device PM QoS framework has a per-device notification tree.
 
-int dev_pm_qos_add_notifier(device, notifier):
-Adds a notification callback function for the device.
+int dev_pm_qos_add_notifier(device, notifier, type):
+Adds a notification callback function for the device for a particular request
+type.
+
 The callback is called when the aggregated value of the device constraints list
-is changed (for resume latency device PM QoS only).
+is changed.
 
-int dev_pm_qos_remove_notifier(device, notifier):
+int dev_pm_qos_remove_notifier(device, notifier, type):
 Removes the notification callback function for the device.
 
 
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 33c30c1e6a30..b063bc41b0a9 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1536,7 +1536,8 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	if (ret)
 		genpd_free_dev_data(dev, gpd_data);
 	else
-		dev_pm_qos_add_notifier(dev, &gpd_data->nb);
+		dev_pm_qos_add_notifier(dev, &gpd_data->nb,
+					DEV_PM_QOS_RESUME_LATENCY);
 
 	return ret;
 }
@@ -1569,7 +1570,8 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
 
 	pdd = dev->power.subsys_data->domain_data;
 	gpd_data = to_gpd_data(pdd);
-	dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
+	dev_pm_qos_remove_notifier(dev, &gpd_data->nb,
+				   DEV_PM_QOS_RESUME_LATENCY);
 
 	genpd_lock(genpd);
 
@@ -1597,7 +1599,7 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
 
  out:
 	genpd_unlock(genpd);
-	dev_pm_qos_add_notifier(dev, &gpd_data->nb);
+	dev_pm_qos_add_notifier(dev, &gpd_data->nb, DEV_PM_QOS_RESUME_LATENCY);
 
 	return ret;
 }
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 6c91f8df1d59..cfd463212513 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -467,6 +467,7 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
  *
  * @dev: target device for the constraint
  * @notifier: notifier block managed by caller.
+ * @type: request type.
  *
  * Will register the notifier into a notification chain that gets called
  * upon changes to the target value for the device.
@@ -474,10 +475,14 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
  * If the device's constraints object doesn't exist when this routine is called,
  * it will be created (or error code will be returned if that fails).
  */
-int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
+int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier,
+			    enum dev_pm_qos_req_type type)
 {
 	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))
@@ -500,15 +505,20 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);
  *
  * @dev: target device for the constraint
  * @notifier: notifier block to be removed.
+ * @type: request type.
  *
  * Will remove the notifier from the notification chain that gets called
  * upon changes to the target value.
  */
 int dev_pm_qos_remove_notifier(struct device *dev,
-			       struct notifier_block *notifier)
+			       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;
+
 	mutex_lock(&dev_pm_qos_mtx);
 
 	/* Silently return if the constraints object is not present. */
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 6ea1ae373d77..1f4d456e8fff 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -146,9 +146,11 @@ int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
 int dev_pm_qos_add_notifier(struct device *dev,
-			    struct notifier_block *notifier);
+			    struct notifier_block *notifier,
+			    enum dev_pm_qos_req_type type);
 int dev_pm_qos_remove_notifier(struct device *dev,
-			       struct notifier_block *notifier);
+			       struct notifier_block *notifier,
+			       enum dev_pm_qos_req_type type);
 void dev_pm_qos_constraints_init(struct device *dev);
 void dev_pm_qos_constraints_destroy(struct device *dev);
 int dev_pm_qos_add_ancestor_request(struct device *dev,
@@ -202,10 +204,12 @@ static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
 			{ return 0; }
 static inline int dev_pm_qos_add_notifier(struct device *dev,
-					  struct notifier_block *notifier)
+					  struct notifier_block *notifier,
+					  enum dev_pm_qos_req_type type);
 			{ return 0; }
 static inline int dev_pm_qos_remove_notifier(struct device *dev,
-					     struct notifier_block *notifier)
+					     struct notifier_block *notifier,
+					     enum dev_pm_qos_req_type type)
 			{ return 0; }
 static inline void dev_pm_qos_constraints_init(struct device *dev)
 {
-- 
2.21.0.rc0.269.g1a574e7a288b

[PATCH V4 2/6] PM / QOS: Rename __dev_pm_qos_read_value() and dev_pm_qos_raw_read_value()

[Viresh Kumar]

dev_pm_qos_read_value() will soon need to support more constraint types
(min/max frequency) and will have another argument to it, i.e. type of
the constraint. While that is fine for the existing users of
dev_pm_qos_read_value(), but not that optimal for the callers of
__dev_pm_qos_read_value() and dev_pm_qos_raw_read_value() as all the
callers of these two routines are only looking for resume latency
constraint.

Lets make these two routines care only about the resume latency
constraint and rename them to __dev_pm_qos_resume_latency() and
dev_pm_qos_raw_resume_latency().

Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/domain_governor.c |  2 +-
 drivers/base/power/qos.c             | 13 +++++++++----
 drivers/base/power/runtime.c         |  2 +-
 drivers/cpuidle/governor.c           |  2 +-
 include/linux/pm_qos.h               |  8 ++++----
 5 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c
index 3838045c9277..20e56a5be01f 100644
--- a/drivers/base/power/domain_governor.c
+++ b/drivers/base/power/domain_governor.c
@@ -66,7 +66,7 @@ static bool default_suspend_ok(struct device *dev)
 	td->constraint_changed = false;
 	td->cached_suspend_ok = false;
 	td->effective_constraint_ns = 0;
-	constraint_ns = __dev_pm_qos_read_value(dev);
+	constraint_ns = __dev_pm_qos_resume_latency(dev);
 
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index cfd463212513..7a0d197f0809 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -90,16 +90,16 @@ enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask)
 EXPORT_SYMBOL_GPL(dev_pm_qos_flags);
 
 /**
- * __dev_pm_qos_read_value - Get PM QoS constraint for a given device.
+ * __dev_pm_qos_resume_latency - Get resume latency constraint for a given device.
  * @dev: Device to get the PM QoS constraint value for.
  *
  * This routine must be called with dev->power.lock held.
  */
-s32 __dev_pm_qos_read_value(struct device *dev)
+s32 __dev_pm_qos_resume_latency(struct device *dev)
 {
 	lockdep_assert_held(&dev->power.lock);
 
-	return dev_pm_qos_raw_read_value(dev);
+	return dev_pm_qos_raw_resume_latency(dev);
 }
 
 /**
@@ -112,7 +112,12 @@ s32 dev_pm_qos_read_value(struct device *dev)
 	s32 ret;
 
 	spin_lock_irqsave(&dev->power.lock, flags);
-	ret = __dev_pm_qos_read_value(dev);
+
+	if (IS_ERR_OR_NULL(dev->power.qos))
+		ret = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
+	else
+		ret = pm_qos_read_value(&dev->power.qos->resume_latency);
+
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 
 	return ret;
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 952a1e7057c7..b75335508d2c 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -275,7 +275,7 @@ static int rpm_check_suspend_allowed(struct device *dev)
 	    || (dev->power.request_pending
 			&& dev->power.request == RPM_REQ_RESUME))
 		retval = -EAGAIN;
-	else if (__dev_pm_qos_read_value(dev) == 0)
+	else if (__dev_pm_qos_resume_latency(dev) == 0)
 		retval = -EPERM;
 	else if (dev->power.runtime_status == RPM_SUSPENDED)
 		retval = 1;
diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
index 9fddf828a76f..2e3e14192bee 100644
--- a/drivers/cpuidle/governor.c
+++ b/drivers/cpuidle/governor.c
@@ -110,7 +110,7 @@ int cpuidle_governor_latency_req(unsigned int cpu)
 {
 	int global_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
 	struct device *device = get_cpu_device(cpu);
-	int device_req = dev_pm_qos_raw_read_value(device);
+	int device_req = dev_pm_qos_raw_resume_latency(device);
 
 	return device_req < global_req ? device_req : global_req;
 }
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 1f4d456e8fff..06aa88496761 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -139,7 +139,7 @@ s32 pm_qos_read_value(struct pm_qos_constraints *c);
 #ifdef CONFIG_PM
 enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
 enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask);
-s32 __dev_pm_qos_read_value(struct device *dev);
+s32 __dev_pm_qos_resume_latency(struct device *dev);
 s32 dev_pm_qos_read_value(struct device *dev);
 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
 			   enum dev_pm_qos_req_type type, s32 value);
@@ -176,7 +176,7 @@ static inline s32 dev_pm_qos_requested_flags(struct device *dev)
 	return dev->power.qos->flags_req->data.flr.flags;
 }
 
-static inline s32 dev_pm_qos_raw_read_value(struct device *dev)
+static inline s32 dev_pm_qos_raw_resume_latency(struct device *dev)
 {
 	return IS_ERR_OR_NULL(dev->power.qos) ?
 		PM_QOS_RESUME_LATENCY_NO_CONSTRAINT :
@@ -189,7 +189,7 @@ static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
 static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
 							s32 mask)
 			{ return PM_QOS_FLAGS_UNDEFINED; }
-static inline s32 __dev_pm_qos_read_value(struct device *dev)
+static inline s32 __dev_pm_qos_resume_latency(struct device *dev)
 			{ return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
 static inline s32 dev_pm_qos_read_value(struct device *dev)
 			{ return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
@@ -245,7 +245,7 @@ static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
 	return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
 }
 static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
-static inline s32 dev_pm_qos_raw_read_value(struct device *dev)
+static inline s32 dev_pm_qos_raw_resume_latency(struct device *dev)
 {
 	return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
 }
-- 
2.21.0.rc0.269.g1a574e7a288b

[PATCH V4 3/6] PM / QOS: Pass request type to dev_pm_qos_read_value()

[Viresh Kumar]

In order to allow dev_pm_qos_read_value() to read values for different
QoS requests, pass request type as a parameter to these routines.

For now, it only supports resume-latency request type but will be
extended to frequency limit (min/max) constraints later on.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 Documentation/power/pm_qos_interface.txt |  2 +-
 drivers/base/power/domain_governor.c     |  2 +-
 drivers/base/power/qos.c                 | 17 ++++++++++++-----
 include/linux/pm_qos.h                   | 16 +++++++++++++---
 4 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt
index ec7d662d1707..cfcb1df39799 100644
--- a/Documentation/power/pm_qos_interface.txt
+++ b/Documentation/power/pm_qos_interface.txt
@@ -123,7 +123,7 @@ Will remove the element.  After removal it will update the aggregate target and
 call the notification trees if the target was changed as a result of removing
 the request.
 
-s32 dev_pm_qos_read_value(device):
+s32 dev_pm_qos_read_value(device, type):
 Returns the aggregated value for a given device's constraints list.
 
 enum pm_qos_flags_status dev_pm_qos_flags(device, mask)
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c
index 20e56a5be01f..daa8c7689f7e 100644
--- a/drivers/base/power/domain_governor.c
+++ b/drivers/base/power/domain_governor.c
@@ -33,7 +33,7 @@ static int dev_update_qos_constraint(struct device *dev, void *data)
 		 * take its current PM QoS constraint (that's the only thing
 		 * known at this point anyway).
 		 */
-		constraint_ns = dev_pm_qos_read_value(dev);
+		constraint_ns = dev_pm_qos_read_value(dev, DEV_PM_QOS_RESUME_LATENCY);
 		constraint_ns *= NSEC_PER_USEC;
 	}
 
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 7a0d197f0809..2461fed0efa0 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -105,18 +105,25 @@ s32 __dev_pm_qos_resume_latency(struct device *dev)
 /**
  * dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked).
  * @dev: Device to get the PM QoS constraint value for.
+ * @type: QoS request type.
  */
-s32 dev_pm_qos_read_value(struct device *dev)
+s32 dev_pm_qos_read_value(struct device *dev, enum dev_pm_qos_req_type type)
 {
+	struct dev_pm_qos *qos = dev->power.qos;
 	unsigned long flags;
 	s32 ret;
 
 	spin_lock_irqsave(&dev->power.lock, flags);
 
-	if (IS_ERR_OR_NULL(dev->power.qos))
-		ret = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
-	else
-		ret = pm_qos_read_value(&dev->power.qos->resume_latency);
+	switch (type) {
+	case DEV_PM_QOS_RESUME_LATENCY:
+		ret = IS_ERR_OR_NULL(qos) ? PM_QOS_RESUME_LATENCY_NO_CONSTRAINT
+			: pm_qos_read_value(&qos->resume_latency);
+		break;
+	default:
+		WARN_ON(1);
+		ret = 0;
+	}
 
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 06aa88496761..5ce1c310373e 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -140,7 +140,7 @@ s32 pm_qos_read_value(struct pm_qos_constraints *c);
 enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
 enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask);
 s32 __dev_pm_qos_resume_latency(struct device *dev);
-s32 dev_pm_qos_read_value(struct device *dev);
+s32 dev_pm_qos_read_value(struct device *dev, enum dev_pm_qos_req_type type);
 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
 			   enum dev_pm_qos_req_type type, s32 value);
 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
@@ -191,8 +191,18 @@ static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
 			{ return PM_QOS_FLAGS_UNDEFINED; }
 static inline s32 __dev_pm_qos_resume_latency(struct device *dev)
 			{ return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
-static inline s32 dev_pm_qos_read_value(struct device *dev)
-			{ return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
+static inline s32 dev_pm_qos_read_value(struct device *dev,
+					enum dev_pm_qos_req_type type)
+{
+	switch type {
+	case DEV_PM_QOS_RESUME_LATENCY:
+		return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
+	default:
+		WARN_ON(1);
+		return 0;
+	}
+}
+
 static inline int dev_pm_qos_add_request(struct device *dev,
 					 struct dev_pm_qos_request *req,
 					 enum dev_pm_qos_req_type type,
-- 
2.21.0.rc0.269.g1a574e7a288b

[PATCH V4 4/6] PM / QoS: Add support for MIN/MAX frequency constraints

[Viresh Kumar]

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>
---
 drivers/base/power/qos.c | 111 ++++++++++++++++++++++++++++++++++-----
 include/linux/pm_qos.h   |  12 +++++
 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 5ce1c310373e..17132b10b233 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;
-- 
2.21.0.rc0.269.g1a574e7a288b

[PATCH V4 5/6] cpufreq: Register notifiers with the PM QoS framework

[Viresh Kumar]

This registers the notifiers for min/max frequency constraints with the
PM QoS framework. The constraints are also taken into consideration in
cpufreq_set_policy().

This also relocates cpufreq_policy_put_kobj() as it is required to be
called from cpufreq_policy_alloc() now.

reeval_frequency_limits() is updated to have proper locking in place and
avoid calling cpufreq_set_policy() for inactive policies.

No constraints are added until now though.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq.c | 135 ++++++++++++++++++++++++++++++--------
 include/linux/cpufreq.h   |   3 +
 2 files changed, 109 insertions(+), 29 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 0a73de7aae54..b47a6c094171 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -26,6 +26,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/pm_qos.h>
 #include <linux/slab.h>
 #include <linux/suspend.h>
 #include <linux/syscore_ops.h>
@@ -999,7 +1000,7 @@ static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
 {
 	struct device *dev = get_cpu_device(cpu);
 
-	if (!dev)
+	if (unlikely(!dev))
 		return;
 
 	if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
@@ -1117,14 +1118,20 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp
 
 static void reeval_frequency_limits(struct cpufreq_policy *policy)
 {
-	struct cpufreq_policy new_policy = *policy;
+	struct cpufreq_policy new_policy;
 
-	pr_debug("updating policy for CPU %u\n", policy->cpu);
+	down_write(&policy->rwsem);
+
+	if (!policy_is_inactive(policy)) {
+		new_policy = *policy;
+		pr_debug("updating policy for CPU %u\n", policy->cpu);
 
-	new_policy.min = policy->user_policy.min;
-	new_policy.max = policy->user_policy.max;
+		new_policy.min = policy->user_policy.min;
+		new_policy.max = policy->user_policy.max;
+		cpufreq_set_policy(policy, &new_policy);
+	}
 
-	cpufreq_set_policy(policy, &new_policy);
+	up_write(&policy->rwsem);
 }
 
 static void handle_update(struct work_struct *work)
@@ -1136,11 +1143,55 @@ static void handle_update(struct work_struct *work)
 	reeval_frequency_limits(policy);
 }
 
+static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
+				void *data)
+{
+	struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
+
+	schedule_work(&policy->update);
+	return 0;
+}
+
+static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
+				void *data)
+{
+	struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
+
+	schedule_work(&policy->update);
+	return 0;
+}
+
+static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
+{
+	struct kobject *kobj;
+	struct completion *cmp;
+
+	down_write(&policy->rwsem);
+	cpufreq_stats_free_table(policy);
+	kobj = &policy->kobj;
+	cmp = &policy->kobj_unregister;
+	up_write(&policy->rwsem);
+	kobject_put(kobj);
+
+	/*
+	 * We need to make sure that the underlying kobj is
+	 * actually not referenced anymore by anybody before we
+	 * proceed with unloading.
+	 */
+	pr_debug("waiting for dropping of refcount\n");
+	wait_for_completion(cmp);
+	pr_debug("wait complete\n");
+}
+
 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 {
 	struct cpufreq_policy *policy;
+	struct device *dev = get_cpu_device(cpu);
 	int ret;
 
+	if (!dev)
+		return NULL;
+
 	policy = kzalloc(sizeof(*policy), GFP_KERNEL);
 	if (!policy)
 		return NULL;
@@ -1157,7 +1208,7 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 	ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
 				   cpufreq_global_kobject, "policy%u", cpu);
 	if (ret) {
-		pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
+		dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
 		/*
 		 * The entire policy object will be freed below, but the extra
 		 * memory allocated for the kobject name needs to be freed by
@@ -1167,6 +1218,25 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 		goto err_free_real_cpus;
 	}
 
+	policy->nb_min.notifier_call = cpufreq_notifier_min;
+	policy->nb_max.notifier_call = cpufreq_notifier_max;
+
+	ret = dev_pm_qos_add_notifier(dev, &policy->nb_min,
+				      DEV_PM_QOS_MIN_FREQUENCY);
+	if (ret) {
+		dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
+			ret, cpumask_pr_args(policy->cpus));
+		goto err_kobj_remove;
+	}
+
+	ret = dev_pm_qos_add_notifier(dev, &policy->nb_max,
+				      DEV_PM_QOS_MAX_FREQUENCY);
+	if (ret) {
+		dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
+			ret, cpumask_pr_args(policy->cpus));
+		goto err_min_qos_notifier;
+	}
+
 	INIT_LIST_HEAD(&policy->policy_list);
 	init_rwsem(&policy->rwsem);
 	spin_lock_init(&policy->transition_lock);
@@ -1177,6 +1247,11 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 	policy->cpu = cpu;
 	return policy;
 
+err_min_qos_notifier:
+	dev_pm_qos_remove_notifier(dev, &policy->nb_min,
+				   DEV_PM_QOS_MIN_FREQUENCY);
+err_kobj_remove:
+	cpufreq_policy_put_kobj(policy);
 err_free_real_cpus:
 	free_cpumask_var(policy->real_cpus);
 err_free_rcpumask:
@@ -1189,30 +1264,9 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 	return NULL;
 }
 
-static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
-{
-	struct kobject *kobj;
-	struct completion *cmp;
-
-	down_write(&policy->rwsem);
-	cpufreq_stats_free_table(policy);
-	kobj = &policy->kobj;
-	cmp = &policy->kobj_unregister;
-	up_write(&policy->rwsem);
-	kobject_put(kobj);
-
-	/*
-	 * We need to make sure that the underlying kobj is
-	 * actually not referenced anymore by anybody before we
-	 * proceed with unloading.
-	 */
-	pr_debug("waiting for dropping of refcount\n");
-	wait_for_completion(cmp);
-	pr_debug("wait complete\n");
-}
-
 static void cpufreq_policy_free(struct cpufreq_policy *policy)
 {
+	struct device *dev = get_cpu_device(policy->cpu);
 	unsigned long flags;
 	int cpu;
 
@@ -1224,6 +1278,11 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
 		per_cpu(cpufreq_cpu_data, cpu) = NULL;
 	write_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
+	dev_pm_qos_remove_notifier(dev, &policy->nb_max,
+				   DEV_PM_QOS_MAX_FREQUENCY);
+	dev_pm_qos_remove_notifier(dev, &policy->nb_min,
+				   DEV_PM_QOS_MIN_FREQUENCY);
+
 	cpufreq_policy_put_kobj(policy);
 	free_cpumask_var(policy->real_cpus);
 	free_cpumask_var(policy->related_cpus);
@@ -2285,6 +2344,8 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
 		       struct cpufreq_policy *new_policy)
 {
 	struct cpufreq_governor *old_gov;
+	struct device *cpu_dev = get_cpu_device(policy->cpu);
+	unsigned long min, max;
 	int ret;
 
 	pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
@@ -2299,11 +2360,27 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
 	if (new_policy->min > new_policy->max)
 		return -EINVAL;
 
+	/*
+	 * PM QoS framework collects all the requests from users and provide us
+	 * the final aggregated value here.
+	 */
+	min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY);
+	max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY);
+
+	if (min > new_policy->min)
+		new_policy->min = min;
+	if (max < new_policy->max)
+		new_policy->max = max;
+
 	/* verify the cpu speed can be set within this limit */
 	ret = cpufreq_driver->verify(new_policy);
 	if (ret)
 		return ret;
 
+	/*
+	 * The notifier-chain shall be removed once all the users of
+	 * CPUFREQ_ADJUST are moved to use the QoS framework.
+	 */
 	/* adjust if necessary - all reasons */
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 			CPUFREQ_ADJUST, new_policy);
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index d01a74fbc4db..d8622cf3f46c 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -147,6 +147,9 @@ struct cpufreq_policy {
 
 	/* Pointer to the cooling device if used for thermal mitigation */
 	struct thermal_cooling_device *cdev;
+
+	struct notifier_block nb_min;
+	struct notifier_block nb_max;
 };
 
 struct cpufreq_freqs {
-- 
2.21.0.rc0.269.g1a574e7a288b

[PATCH V4 6/6] cpufreq: Add QoS requests for userspace constraints

[Viresh Kumar]

This implements QoS requests to manage userspace configuration of min
and max frequency.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq.c | 87 ++++++++++++++++++++-------------------
 include/linux/cpufreq.h   |  8 +---
 2 files changed, 46 insertions(+), 49 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b47a6c094171..5d050b4a3806 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -718,23 +718,15 @@ static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
 static ssize_t store_##file_name					\
 (struct cpufreq_policy *policy, const char *buf, size_t count)		\
 {									\
-	int ret, temp;							\
-	struct cpufreq_policy new_policy;				\
+	unsigned long val;						\
+	int ret;							\
 									\
-	memcpy(&new_policy, policy, sizeof(*policy));			\
-	new_policy.min = policy->user_policy.min;			\
-	new_policy.max = policy->user_policy.max;			\
-									\
-	ret = sscanf(buf, "%u", &new_policy.object);			\
+	ret = sscanf(buf, "%lu", &val);					\
 	if (ret != 1)							\
 		return -EINVAL;						\
 									\
-	temp = new_policy.object;					\
-	ret = cpufreq_set_policy(policy, &new_policy);		\
-	if (!ret)							\
-		policy->user_policy.object = temp;			\
-									\
-	return ret ? ret : count;					\
+	ret = dev_pm_qos_update_request(policy->object##_freq_req, val);\
+	return ret >= 0 ? count : ret;					\
 }
 
 store_one(scaling_min_freq, min);
@@ -1126,8 +1118,6 @@ static void reeval_frequency_limits(struct cpufreq_policy *policy)
 		new_policy = *policy;
 		pr_debug("updating policy for CPU %u\n", policy->cpu);
 
-		new_policy.min = policy->user_policy.min;
-		new_policy.max = policy->user_policy.max;
 		cpufreq_set_policy(policy, &new_policy);
 	}
 
@@ -1237,6 +1227,12 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 		goto err_min_qos_notifier;
 	}
 
+	policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
+				       GFP_KERNEL);
+	if (!policy->min_freq_req)
+		goto err_max_qos_notifier;
+
+	policy->max_freq_req = policy->min_freq_req + 1;
 	INIT_LIST_HEAD(&policy->policy_list);
 	init_rwsem(&policy->rwsem);
 	spin_lock_init(&policy->transition_lock);
@@ -1247,6 +1243,9 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 	policy->cpu = cpu;
 	return policy;
 
+err_max_qos_notifier:
+	dev_pm_qos_remove_notifier(dev, &policy->nb_max,
+				   DEV_PM_QOS_MAX_FREQUENCY);
 err_min_qos_notifier:
 	dev_pm_qos_remove_notifier(dev, &policy->nb_min,
 				   DEV_PM_QOS_MIN_FREQUENCY);
@@ -1282,6 +1281,9 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
 				   DEV_PM_QOS_MAX_FREQUENCY);
 	dev_pm_qos_remove_notifier(dev, &policy->nb_min,
 				   DEV_PM_QOS_MIN_FREQUENCY);
+	dev_pm_qos_remove_request(policy->max_freq_req);
+	dev_pm_qos_remove_request(policy->min_freq_req);
+	kfree(policy->min_freq_req);
 
 	cpufreq_policy_put_kobj(policy);
 	free_cpumask_var(policy->real_cpus);
@@ -1360,16 +1362,30 @@ static int cpufreq_online(unsigned int cpu)
 	cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
 
 	if (new_policy) {
-		policy->user_policy.min = policy->min;
-		policy->user_policy.max = policy->max;
+		struct device *dev = get_cpu_device(cpu);
 
 		for_each_cpu(j, policy->related_cpus) {
 			per_cpu(cpufreq_cpu_data, j) = policy;
 			add_cpu_dev_symlink(policy, j);
 		}
-	} else {
-		policy->min = policy->user_policy.min;
-		policy->max = policy->user_policy.max;
+
+		ret = dev_pm_qos_add_request(dev, policy->min_freq_req,
+					     DEV_PM_QOS_MIN_FREQUENCY,
+					     policy->min);
+		if (ret < 0) {
+			dev_err(dev, "Failed to add min-freq constraint (%d)\n",
+				ret);
+			goto out_destroy_policy;
+		}
+
+		ret = dev_pm_qos_add_request(dev, policy->max_freq_req,
+					     DEV_PM_QOS_MAX_FREQUENCY,
+					     policy->max);
+		if (ret < 0) {
+			dev_err(dev, "Failed to add max-freq constraint (%d)\n",
+				ret);
+			goto out_destroy_policy;
+		}
 	}
 
 	if (cpufreq_driver->get && has_target()) {
@@ -2345,7 +2361,6 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
 {
 	struct cpufreq_governor *old_gov;
 	struct device *cpu_dev = get_cpu_device(policy->cpu);
-	unsigned long min, max;
 	int ret;
 
 	pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
@@ -2353,24 +2368,12 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
 
 	memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
 
-	/*
-	* This check works well when we store new min/max freq attributes,
-	* because new_policy is a copy of policy with one field updated.
-	*/
-	if (new_policy->min > new_policy->max)
-		return -EINVAL;
-
 	/*
 	 * PM QoS framework collects all the requests from users and provide us
 	 * the final aggregated value here.
 	 */
-	min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY);
-	max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY);
-
-	if (min > new_policy->min)
-		new_policy->min = min;
-	if (max < new_policy->max)
-		new_policy->max = max;
+	new_policy->min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY);
+	new_policy->max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY);
 
 	/* verify the cpu speed can be set within this limit */
 	ret = cpufreq_driver->verify(new_policy);
@@ -2459,10 +2462,9 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
  * @cpu: CPU to re-evaluate the policy for.
  *
  * Update the current frequency for the cpufreq policy of @cpu and use
- * cpufreq_set_policy() to re-apply the min and max limits saved in the
- * user_policy sub-structure of that policy, which triggers the evaluation
- * of policy notifiers and the cpufreq driver's ->verify() callback for the
- * policy in question, among other things.
+ * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
+ * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
+ * for the policy in question, among other things.
  */
 void cpufreq_update_policy(unsigned int cpu)
 {
@@ -2522,10 +2524,9 @@ static int cpufreq_boost_set_sw(int state)
 			break;
 		}
 
-		down_write(&policy->rwsem);
-		policy->user_policy.max = policy->max;
-		cpufreq_governor_limits(policy);
-		up_write(&policy->rwsem);
+		ret = dev_pm_qos_update_request(policy->max_freq_req, policy->max);
+		if (ret)
+			break;
 	}
 
 	return ret;
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index d8622cf3f46c..b6245f512a26 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -50,11 +50,6 @@ struct cpufreq_cpuinfo {
 	unsigned int		transition_latency;
 };
 
-struct cpufreq_user_policy {
-	unsigned int		min;    /* in kHz */
-	unsigned int		max;    /* in kHz */
-};
-
 struct cpufreq_policy {
 	/* CPUs sharing clock, require sw coordination */
 	cpumask_var_t		cpus;	/* Online CPUs only */
@@ -84,7 +79,8 @@ struct cpufreq_policy {
 	struct work_struct	update; /* if update_policy() needs to be
 					 * called, but you're in IRQ context */
 
-	struct cpufreq_user_policy user_policy;
+	struct dev_pm_qos_request *min_freq_req;
+	struct dev_pm_qos_request *max_freq_req;
 	struct cpufreq_frequency_table	*freq_table;
 	enum cpufreq_table_sorting freq_table_sorted;
 
-- 
2.21.0.rc0.269.g1a574e7a288b