[PATCH V2 3/5] PM / QoS: Add support for MIN/MAX frequency constraints

From: Viresh Kumar
Date: Thu Feb 21 2019 - 06:30:05 EST


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

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/base/power/qos.c | 103 +++++++++++++++++++++++++++++++++------
include/linux/pm_qos.h | 18 +++++++
2 files changed, 107 insertions(+), 14 deletions(-)

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index fda7266970e9..30fe1e98b343 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -155,6 +155,14 @@ 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);
@@ -183,12 +191,11 @@ 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);
@@ -197,6 +204,7 @@ 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);
@@ -205,6 +213,24 @@ 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);
@@ -258,11 +284,25 @@ 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);
@@ -374,6 +414,8 @@ 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:
@@ -486,9 +528,6 @@ 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))
@@ -496,10 +535,28 @@ 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;
}
@@ -520,20 +577,35 @@ 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);

@@ -593,6 +665,9 @@ 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 55814d48c39c..3f994283a5ae 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 */
@@ -185,6 +193,12 @@ static inline s32 dev_pm_qos_raw_read_value(struct device *dev,
case DEV_PM_QOS_RESUME_LATENCY:
return IS_ERR_OR_NULL(qos) ? PM_QOS_RESUME_LATENCY_NO_CONSTRAINT
: pm_qos_read_value(&qos->resume_latency);
+ case DEV_PM_QOS_MIN_FREQUENCY:
+ return IS_ERR_OR_NULL(qos) ? PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE
+ : pm_qos_read_value(&qos->min_frequency);
+ case DEV_PM_QOS_MAX_FREQUENCY:
+ return IS_ERR_OR_NULL(qos) ? PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE
+ : pm_qos_read_value(&qos->max_frequency);
default:
WARN_ON(1);
return 0;
@@ -256,6 +270,10 @@ static inline s32 dev_pm_qos_raw_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