* [RFC][PATCH 1/2] PM / Domains: Add device stop governor function (v2)
2011-10-21 23:09 [RFC][PATCH 0/2] PM: Generic PM domains and device PM QoS (v2) Rafael J. Wysocki
@ 2011-10-21 23:10 ` Rafael J. Wysocki
2011-10-21 23:11 ` [RFC][PATCH 2/2] PM / Domains: Add default power off " Rafael J. Wysocki
1 sibling, 0 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2011-10-21 23:10 UTC (permalink / raw)
To: Linux PM list; +Cc: LKML, Linux-sh list, Jean Pihet, Magnus Damm
From: Rafael J. Wysocki <rjw@sisk.pl>
Add a function deciding whether or not devices should be
stopped in pm_genpd_runtime_suspend() depending on their
PM QoS values.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
arch/arm/mach-shmobile/pm-sh7372.c | 4 ++-
drivers/base/power/Makefile | 2 -
drivers/base/power/domain.c | 29 ++++++++++++++++++----
drivers/base/power/domain_governor.c | 40 +++++++++++++++++++++++++++++++
include/linux/pm_domain.h | 45 +++++++++++++++++++++++++++++++----
5 files changed, 109 insertions(+), 11 deletions(-)
Index: linux/include/linux/pm_domain.h
=================================--- linux.orig/include/linux/pm_domain.h
+++ linux/include/linux/pm_domain.h
@@ -21,6 +21,7 @@ enum gpd_status {
struct dev_power_governor {
bool (*power_down_ok)(struct dev_pm_domain *domain);
+ bool (*stop_ok)(struct device *dev);
};
struct generic_pm_domain {
@@ -62,8 +63,13 @@ struct gpd_link {
struct list_head slave_node;
};
+struct gpd_gov_dev_data {
+ s64 break_even_ns;
+};
+
struct generic_pm_domain_data {
struct pm_domain_data base;
+ struct gpd_gov_dev_data *gov_data;
bool need_restore;
};
@@ -73,8 +79,19 @@ static inline struct generic_pm_domain_d
}
#ifdef CONFIG_PM_GENERIC_DOMAINS
-extern int pm_genpd_add_device(struct generic_pm_domain *genpd,
- struct device *dev);
+extern struct dev_power_governor simple_qos_governor;
+
+extern struct generic_pm_domain *dev_to_genpd(struct device *dev);
+extern int __pm_genpd_add_device(struct generic_pm_domain *genpd,
+ struct device *dev,
+ struct gpd_gov_dev_data *gov_data);
+
+static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
+ struct device *dev)
+{
+ return __pm_genpd_add_device(genpd, dev, NULL);
+}
+
extern int pm_genpd_remove_device(struct generic_pm_domain *genpd,
struct device *dev);
extern int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
@@ -83,8 +100,23 @@ extern int pm_genpd_remove_subdomain(str
struct generic_pm_domain *target);
extern void pm_genpd_init(struct generic_pm_domain *genpd,
struct dev_power_governor *gov, bool is_off);
+
extern int pm_genpd_poweron(struct generic_pm_domain *genpd);
+
+extern bool default_stop_ok(struct device *dev);
+
#else
+
+static inline struct generic_pm_domain *dev_to_genpd(struct device *dev)
+{
+ return ERR_PTR(-ENOSYS);
+}
+static inline int __pm_genpd_add_device(struct generic_pm_domain *genpd,
+ struct device *dev,
+ struct gpd_gov_dev_data *gov_data)
+{
+ return -ENOSYS;
+}
static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev)
{
@@ -105,12 +137,17 @@ static inline int pm_genpd_remove_subdom
{
return -ENOSYS;
}
-static inline void pm_genpd_init(struct generic_pm_domain *genpd,
- struct dev_power_governor *gov, bool is_off) {}
+static inline void pm_genpd_init(struct generic_pm_domain *genpd, bool is_off)
+{
+}
static inline int pm_genpd_poweron(struct generic_pm_domain *genpd)
{
return -ENOSYS;
}
+static inline bool default_stop_ok(struct device *dev)
+{
+ return false;
+}
#endif
#ifdef CONFIG_PM_GENERIC_DOMAINS_RUNTIME
Index: linux/drivers/base/power/domain.c
=================================--- linux.orig/drivers/base/power/domain.c
+++ linux/drivers/base/power/domain.c
@@ -21,7 +21,7 @@ static DEFINE_MUTEX(gpd_list_lock);
#ifdef CONFIG_PM
-static struct generic_pm_domain *dev_to_genpd(struct device *dev)
+struct generic_pm_domain *dev_to_genpd(struct device *dev)
{
if (IS_ERR_OR_NULL(dev->pm_domain))
return ERR_PTR(-EINVAL);
@@ -403,6 +403,22 @@ static void genpd_power_off_work_fn(stru
}
/**
+ * genpd_stop_dev - Stop a given device if that's beneficial.
+ * @genpd: PM domain the device belongs to.
+ * @dev: Device to stop.
+ */
+static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
+{
+ bool (*stop_ok)(struct device *dev);
+
+ stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
+ if (stop_ok && !stop_ok(dev))
+ return -EBUSY;
+
+ return genpd->stop_device(dev);
+}
+
+/**
* pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
* @dev: Device to suspend.
*
@@ -423,7 +439,7 @@ static int pm_genpd_runtime_suspend(stru
might_sleep_if(!genpd->dev_irq_safe);
if (genpd->stop_device) {
- int ret = genpd->stop_device(dev);
+ int ret = genpd_stop_dev(genpd, dev);
if (ret)
return ret;
}
@@ -495,7 +511,7 @@ static int pm_genpd_runtime_resume(struc
mutex_lock(&genpd->lock);
}
finish_wait(&genpd->status_wait_queue, &wait);
- __pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
+ __pm_genpd_restore_device(dev_to_psd(dev)->domain_data, genpd);
genpd->resume_count--;
genpd_set_active(genpd);
wake_up_all(&genpd->status_wait_queue);
@@ -1076,11 +1092,13 @@ static void pm_genpd_complete(struct dev
#endif /* CONFIG_PM_SLEEP */
/**
- * pm_genpd_add_device - Add a device to an I/O PM domain.
+ * __pm_genpd_add_device - Add a device to an I/O PM domain.
* @genpd: PM domain to add the device to.
* @dev: Device to be added.
+ * @gov_data: Set of PM QoS parameters to attach to the device.
*/
-int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
+int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
+ struct gpd_gov_dev_data *gov_data)
{
struct generic_pm_domain_data *gpd_data;
struct pm_domain_data *pdd;
@@ -1123,6 +1141,7 @@ int pm_genpd_add_device(struct generic_p
gpd_data->base.dev = dev;
gpd_data->need_restore = false;
list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
+ gpd_data->gov_data = gov_data;
out:
genpd_release_lock(genpd);
Index: linux/drivers/base/power/Makefile
=================================--- linux.orig/drivers/base/power/Makefile
+++ linux/drivers/base/power/Makefile
@@ -3,7 +3,7 @@ obj-$(CONFIG_PM_SLEEP) += main.o wakeup.
obj-$(CONFIG_PM_RUNTIME) += runtime.o
obj-$(CONFIG_PM_TRACE_RTC) += trace.o
obj-$(CONFIG_PM_OPP) += opp.o
-obj-$(CONFIG_PM_GENERIC_DOMAINS) += domain.o
+obj-$(CONFIG_PM_GENERIC_DOMAINS) += domain.o domain_governor.o
obj-$(CONFIG_HAVE_CLK) += clock_ops.o
ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
Index: linux/drivers/base/power/domain_governor.c
=================================--- /dev/null
+++ linux/drivers/base/power/domain_governor.c
@@ -0,0 +1,40 @@
+/*
+ * drivers/base/power/domain_governor.c - Governors for device PM domains.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_qos.h>
+
+bool default_stop_ok(struct device *dev)
+{
+ struct gpd_gov_dev_data *gov_data;
+ s64 constraint_ns;
+ s32 constraint;
+
+ dev_dbg(dev, "%s()\n", __func__);
+
+ gov_data = to_gpd_data(dev_to_psd(dev)->domain_data)->gov_data;
+ if (!gov_data)
+ return true;
+
+ constraint = dev_pm_qos_read_value(dev);
+ if (constraint < 0)
+ return false;
+ else if (constraint = 0) /* 0 means "don't care" */
+ return true;
+
+ constraint_ns = constraint;
+ constraint_ns *= NSEC_PER_USEC;
+
+ return constraint_ns > gov_data->break_even_ns;
+}
+
+struct dev_power_governor simple_qos_governor = {
+ .stop_ok = default_stop_ok,
+};
Index: linux/arch/arm/mach-shmobile/pm-sh7372.c
=================================--- linux.orig/arch/arm/mach-shmobile/pm-sh7372.c
+++ linux/arch/arm/mach-shmobile/pm-sh7372.c
@@ -161,13 +161,15 @@ static bool sh7372_power_down_forbidden(
struct dev_power_governor sh7372_always_on_gov = {
.power_down_ok = sh7372_power_down_forbidden,
+ .stop_ok = default_stop_ok,
};
void sh7372_init_pm_domain(struct sh7372_pm_domain *sh7372_pd)
{
struct generic_pm_domain *genpd = &sh7372_pd->genpd;
+ struct dev_power_governor *gov = sh7372_pd->gov;
- pm_genpd_init(genpd, sh7372_pd->gov, false);
+ pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
genpd->stop_device = pm_clk_suspend;
genpd->start_device = pm_clk_resume;
genpd->dev_irq_safe = true;
^ permalink raw reply [flat|nested] 3+ messages in thread* [RFC][PATCH 2/2] PM / Domains: Add default power off governor function (v2)
2011-10-21 23:09 [RFC][PATCH 0/2] PM: Generic PM domains and device PM QoS (v2) Rafael J. Wysocki
2011-10-21 23:10 ` [RFC][PATCH 1/2] PM / Domains: Add device stop governor function (v2) Rafael J. Wysocki
@ 2011-10-21 23:11 ` Rafael J. Wysocki
1 sibling, 0 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2011-10-21 23:11 UTC (permalink / raw)
To: Linux PM list; +Cc: LKML, Linux-sh list, Jean Pihet, Magnus Damm
From: Rafael J. Wysocki <rjw@sisk.pl>
Add a function deciding whether or not a given PM domain should
be powered off on the basis of that domain's devices' PM QoS
constraints.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/base/power/domain_governor.c | 96 +++++++++++++++++++++++++++++++++++
include/linux/pm_domain.h | 7 ++
2 files changed, 103 insertions(+)
Index: linux/include/linux/pm_domain.h
=================================--- linux.orig/include/linux/pm_domain.h
+++ linux/include/linux/pm_domain.h
@@ -49,6 +49,10 @@ struct generic_pm_domain {
int (*start_device)(struct device *dev);
int (*stop_device)(struct device *dev);
bool (*active_wakeup)(struct device *dev);
+ ktime_t power_off_latency;
+ ktime_t power_on_latency;
+ s64 break_even_ns;
+ s64 min_delta_ns;
};
static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)
@@ -64,6 +68,9 @@ struct gpd_link {
};
struct gpd_gov_dev_data {
+ ktime_t start_latency;
+ ktime_t suspend_latency;
+ ktime_t resume_latency;
s64 break_even_ns;
};
Index: linux/drivers/base/power/domain_governor.c
=================================--- linux.orig/drivers/base/power/domain_governor.c
+++ linux/drivers/base/power/domain_governor.c
@@ -35,6 +35,102 @@ bool default_stop_ok(struct device *dev)
return constraint_ns > gov_data->break_even_ns;
}
+/* This routine must be executed under the PM domain's lock. */
+static bool default_power_down_ok(struct dev_pm_domain *pd)
+{
+ struct generic_pm_domain *genpd = pd_to_genpd(pd);
+ struct gpd_link *link;
+ struct pm_domain_data *pdd;
+ ktime_t off_time, on_time;
+ s64 delta_ns, min_delta_ns;
+
+ on_time = genpd->power_on_latency;
+ /* Check if slave domains can be off for enough time. */
+ delta_ns = ktime_to_ns(ktime_add(genpd->power_off_latency, on_time));
+ min_delta_ns = 0;
+ /* All slave domains have been powered off at this point. */
+ list_for_each_entry(link, &genpd->master_links, master_node) {
+ if (delta_ns > link->slave->min_delta_ns)
+ return false;
+
+ delta_ns = link->slave->min_delta_ns - delta_ns;
+ if (delta_ns < min_delta_ns)
+ min_delta_ns = delta_ns;
+ }
+
+ genpd->min_delta_ns = min_delta_ns;
+
+ /* Compute the total time needed to power off the domain. */
+ off_time = ktime_set(0, 0);
+ /* All devices have been stopped at this point. */
+ list_for_each_entry(pdd, &genpd->dev_list, list_node) {
+ struct gpd_gov_dev_data *gov_data;
+
+ if (!pdd->dev->driver)
+ continue;
+
+ gov_data = to_gpd_data(pdd)->gov_data;
+ if (!gov_data)
+ continue;
+
+ off_time = ktime_add(off_time, gov_data->suspend_latency);
+ }
+ off_time = ktime_add(off_time, genpd->power_off_latency);
+
+ /*
+ * For each device in the domain compute the difference between the
+ * QoS value and the total time required to bring the device back
+ * assuming that the domain will be powered off and compute the minimum
+ * of those.
+ */
+ min_delta_ns = 0;
+ on_time = ktime_add(on_time, off_time);
+ list_for_each_entry(pdd, &genpd->dev_list, list_node) {
+ struct gpd_gov_dev_data *gov_data;
+ struct device *dev = pdd->dev;
+ ktime_t dev_up_time;
+ s32 constraint;
+ s64 constraint_ns;
+
+ if (!dev->driver)
+ continue;
+
+ gov_data = to_gpd_data(pdd)->gov_data;
+ if (gov_data) {
+ dev_up_time = ktime_add(on_time,
+ gov_data->resume_latency);
+ dev_up_time = ktime_add(dev_up_time,
+ gov_data->start_latency);
+ } else {
+ dev_up_time = on_time;
+ }
+
+ constraint = dev_pm_qos_read_value(dev);
+ if (constraint < 0)
+ return false;
+ else if (constraint = 0) /* 0 means "don't care" */
+ continue;
+
+ constraint_ns = constraint;
+ constraint_ns *= NSEC_PER_USEC;
+ delta_ns = constraint_ns - ktime_to_ns(dev_up_time);
+ if (min_delta_ns > delta_ns)
+ min_delta_ns = delta_ns;
+ }
+
+ /* Compare the computed delta with the break even value. */
+ if (min_delta_ns < genpd->break_even_ns)
+ return false;
+
+ /* Store the computed value for the masters to use. */
+ if (genpd->min_delta_ns > min_delta_ns)
+ genpd->min_delta_ns = min_delta_ns;
+
+ /* The domain can be powered off. */
+ return true;
+}
+
struct dev_power_governor simple_qos_governor = {
.stop_ok = default_stop_ok,
+ .power_down_ok = default_power_down_ok,
};
^ permalink raw reply [flat|nested] 3+ messages in thread