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PM / QoS: Add support for MIN/MAX frequency constraints
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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>
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Viresh Kumar authored and Rafael J. Wysocki committed Jul 4, 2019
1 parent 2a79ea5 commit 208637b
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Showing 2 changed files with 109 additions and 14 deletions.
111 changes: 97 additions & 14 deletions drivers/base/power/qos.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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:
Expand Down Expand Up @@ -492,20 +542,35 @@ 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))
ret = -ENODEV;
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;
}
Expand All @@ -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);

Expand Down Expand Up @@ -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);
Expand Down
12 changes: 12 additions & 0 deletions include/linux/pm_qos.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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,
};

Expand Down Expand Up @@ -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 */
Expand Down Expand Up @@ -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;
Expand Down

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