[PATCH 1/7] PM / QoS: Prepare device structure for adding more constraint types

Rafael J. Wysocki
2012-10-08T08:10:38Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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>
---
drivers/base/power/qos.c | 42 ++++++++++++++++++++++--------------------
include/linux/pm.h | 2 +-
include/linux/pm_qos.h | 4 ++++
3 files changed, 27 insertions(+), 21 deletions(-)

Index: linux/include/linux/pm.h
===================================================================
--- linux.orig/include/linux/pm.h
+++ linux/include/linux/pm.h
@@ -551,7 +551,7 @@ 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);
Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/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 */
Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -55,9 +55,7 @@ static BLOCKING_NOTIFIER_HEAD(dev_pm_not
*/
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_p
{
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_p
*/
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_alloca
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_alloca
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
*/
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(stru
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(stru
}

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

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

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

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 devic

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 de
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);