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PM / Domains: Use power.sybsys_data to reduce overhead
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Currently pm_genpd_runtime_resume() has to walk the list of devices
from the device's PM domain to find the corresponding device list
object containing the need_restore field to check if the driver's
.runtime_resume() callback should be executed for the device.
This is suboptimal and can be simplified by using power.sybsys_data
to store device information used by the generic PM domains code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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@rjwysocki
rjwysocki committed Aug 25, 2011
1 parent ef27bed commit 4605ab6
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Showing 5 changed files with 51 additions and 67 deletions.
6 changes: 2 additions & 4 deletions arch/arm/mach-shmobile/pm-sh7372.c
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Original file line number Diff line number Diff line change
Expand Up @@ -114,11 +114,9 @@ void sh7372_add_device_to_domain(struct sh7372_pm_domain *sh7372_pd,
{
struct device *dev = &pdev->dev;

if (!dev->power.subsys_data) {
pm_clk_create(dev);
pm_clk_add(dev, NULL);
}
pm_genpd_add_device(&sh7372_pd->genpd, dev);
if (pm_clk_no_clocks(dev))
pm_clk_add(dev, NULL);
}

void sh7372_pm_add_subdomain(struct sh7372_pm_domain *sh7372_pd,
Expand Down
87 changes: 30 additions & 57 deletions drivers/base/power/domain.c
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Original file line number Diff line number Diff line change
Expand Up @@ -181,18 +181,18 @@ int pm_genpd_poweron(struct generic_pm_domain *genpd)

/**
* __pm_genpd_save_device - Save the pre-suspend state of a device.
* @dle: Device list entry of the device to save the state of.
* @pdd: Domain data of the device to save the state of.
* @genpd: PM domain the device belongs to.
*/
static int __pm_genpd_save_device(struct dev_list_entry *dle,
static int __pm_genpd_save_device(struct pm_domain_data *pdd,
struct generic_pm_domain *genpd)
__releases(&genpd->lock) __acquires(&genpd->lock)
{
struct device *dev = dle->dev;
struct device *dev = pdd->dev;
struct device_driver *drv = dev->driver;
int ret = 0;

if (dle->need_restore)
if (pdd->need_restore)
return 0;

mutex_unlock(&genpd->lock);
Expand All @@ -210,24 +210,24 @@ static int __pm_genpd_save_device(struct dev_list_entry *dle,
mutex_lock(&genpd->lock);

if (!ret)
dle->need_restore = true;
pdd->need_restore = true;

return ret;
}

/**
* __pm_genpd_restore_device - Restore the pre-suspend state of a device.
* @dle: Device list entry of the device to restore the state of.
* @pdd: Domain data of the device to restore the state of.
* @genpd: PM domain the device belongs to.
*/
static void __pm_genpd_restore_device(struct dev_list_entry *dle,
static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
struct generic_pm_domain *genpd)
__releases(&genpd->lock) __acquires(&genpd->lock)
{
struct device *dev = dle->dev;
struct device *dev = pdd->dev;
struct device_driver *drv = dev->driver;

if (!dle->need_restore)
if (!pdd->need_restore)
return;

mutex_unlock(&genpd->lock);
Expand All @@ -244,7 +244,7 @@ static void __pm_genpd_restore_device(struct dev_list_entry *dle,

mutex_lock(&genpd->lock);

dle->need_restore = false;
pdd->need_restore = false;
}

/**
Expand Down Expand Up @@ -286,7 +286,7 @@ void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
__releases(&genpd->lock) __acquires(&genpd->lock)
{
struct dev_list_entry *dle;
struct pm_domain_data *pdd;
struct gpd_link *link;
unsigned int not_suspended;
int ret = 0;
Expand All @@ -308,8 +308,8 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
return -EBUSY;

not_suspended = 0;
list_for_each_entry(dle, &genpd->dev_list, node)
if (dle->dev->driver && !pm_runtime_suspended(dle->dev))
list_for_each_entry(pdd, &genpd->dev_list, list_node)
if (pdd->dev->driver && !pm_runtime_suspended(pdd->dev))
not_suspended++;

if (not_suspended > genpd->in_progress)
Expand All @@ -332,9 +332,9 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
genpd->status = GPD_STATE_BUSY;
genpd->poweroff_task = current;

list_for_each_entry_reverse(dle, &genpd->dev_list, node) {
list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
ret = atomic_read(&genpd->sd_count) == 0 ?
__pm_genpd_save_device(dle, genpd) : -EBUSY;
__pm_genpd_save_device(pdd, genpd) : -EBUSY;

if (genpd_abort_poweroff(genpd))
goto out;
Expand Down Expand Up @@ -432,24 +432,6 @@ static int pm_genpd_runtime_suspend(struct device *dev)
return 0;
}

/**
* __pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
* @dev: Device to resume.
* @genpd: PM domain the device belongs to.
*/
static void __pm_genpd_runtime_resume(struct device *dev,
struct generic_pm_domain *genpd)
{
struct dev_list_entry *dle;

list_for_each_entry(dle, &genpd->dev_list, node) {
if (dle->dev == dev) {
__pm_genpd_restore_device(dle, genpd);
break;
}
}
}

/**
* pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
* @dev: Device to resume.
Expand Down Expand Up @@ -495,7 +477,7 @@ static int pm_genpd_runtime_resume(struct device *dev)
mutex_lock(&genpd->lock);
}
finish_wait(&genpd->status_wait_queue, &wait);
__pm_genpd_runtime_resume(dev, genpd);
__pm_genpd_restore_device(&dev->power.subsys_data->domain_data, genpd);
genpd->resume_count--;
genpd_set_active(genpd);
wake_up_all(&genpd->status_wait_queue);
Expand Down Expand Up @@ -525,8 +507,6 @@ void pm_genpd_poweroff_unused(void)
#else

static inline void genpd_power_off_work_fn(struct work_struct *work) {}
static inline void __pm_genpd_runtime_resume(struct device *dev,
struct generic_pm_domain *genpd) {}

#define pm_genpd_runtime_suspend NULL
#define pm_genpd_runtime_resume NULL
Expand Down Expand Up @@ -1083,7 +1063,7 @@ static void pm_genpd_complete(struct device *dev)
*/
int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
{
struct dev_list_entry *dle;
struct pm_domain_data *pdd;
int ret = 0;

dev_dbg(dev, "%s()\n", __func__);
Expand All @@ -1103,26 +1083,20 @@ int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
goto out;
}

list_for_each_entry(dle, &genpd->dev_list, node)
if (dle->dev == dev) {
list_for_each_entry(pdd, &genpd->dev_list, list_node)
if (pdd->dev == dev) {
ret = -EINVAL;
goto out;
}

dle = kzalloc(sizeof(*dle), GFP_KERNEL);
if (!dle) {
ret = -ENOMEM;
goto out;
}

dle->dev = dev;
dle->need_restore = false;
list_add_tail(&dle->node, &genpd->dev_list);
genpd->device_count++;

spin_lock_irq(&dev->power.lock);
dev->pm_domain = &genpd->domain;
spin_unlock_irq(&dev->power.lock);
dev_pm_get_subsys_data(dev);
pdd = &dev->power.subsys_data->domain_data;
pdd->dev = dev;
pdd->need_restore = false;
list_add_tail(&pdd->list_node, &genpd->dev_list);

out:
genpd_release_lock(genpd);
Expand All @@ -1138,7 +1112,7 @@ int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
int pm_genpd_remove_device(struct generic_pm_domain *genpd,
struct device *dev)
{
struct dev_list_entry *dle;
struct pm_domain_data *pdd;
int ret = -EINVAL;

dev_dbg(dev, "%s()\n", __func__);
Expand All @@ -1153,17 +1127,16 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
goto out;
}

list_for_each_entry(dle, &genpd->dev_list, node) {
if (dle->dev != dev)
list_for_each_entry(pdd, &genpd->dev_list, list_node) {
if (pdd->dev != dev)
continue;

spin_lock_irq(&dev->power.lock);
list_del_init(&pdd->list_node);
pdd->dev = NULL;
dev_pm_put_subsys_data(dev);
dev->pm_domain = NULL;
spin_unlock_irq(&dev->power.lock);

genpd->device_count--;
list_del(&dle->node);
kfree(dle);

ret = 0;
break;
Expand Down
9 changes: 9 additions & 0 deletions include/linux/pm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -421,12 +421,21 @@ enum rpm_request {

struct wakeup_source;

struct pm_domain_data {
struct list_head list_node;
struct device *dev;
bool need_restore;
};

struct pm_subsys_data {
spinlock_t lock;
unsigned int refcount;
#ifdef CONFIG_PM_CLK
struct list_head clock_list;
#endif
#ifdef CONFIG_PM_GENERIC_DOMAINS
struct pm_domain_data domain_data;
#endif
};

struct dev_pm_info {
Expand Down
6 changes: 0 additions & 6 deletions include/linux/pm_domain.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,12 +61,6 @@ struct gpd_link {
struct list_head slave_node;
};

struct dev_list_entry {
struct list_head node;
struct device *dev;
bool need_restore;
};

#ifdef CONFIG_PM_GENERIC_DOMAINS
extern int pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev);
Expand Down
10 changes: 10 additions & 0 deletions include/linux/pm_runtime.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -258,6 +258,12 @@ struct pm_clk_notifier_block {
};

#ifdef CONFIG_PM_CLK
static inline bool pm_clk_no_clocks(struct device *dev)
{
return dev && dev->power.subsys_data
&& list_empty(&dev->power.subsys_data->clock_list);
}

extern void pm_clk_init(struct device *dev);
extern int pm_clk_create(struct device *dev);
extern void pm_clk_destroy(struct device *dev);
Expand All @@ -266,6 +272,10 @@ extern void pm_clk_remove(struct device *dev, const char *con_id);
extern int pm_clk_suspend(struct device *dev);
extern int pm_clk_resume(struct device *dev);
#else
static inline bool pm_clk_no_clocks(struct device *dev)
{
return true;
}
static inline void pm_clk_init(struct device *dev)
{
}
Expand Down

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