[update][PATCH 5/7] PM / Domains: Add device stop governor function (v4)

Rafael J. Wysocki
2011-11-14T00:26:23Z

Add a function deciding whether or not devices should be stopped in
pm_genpd_runtime_suspend() depending on their PM QoS constraints
and stop/start timing values. Make it possible to add information
used by this function to device objects.

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 | 33 ++++++++++++++----
drivers/base/power/domain_governor.c | 33 ++++++++++++++++++
include/linux/pm_domain.h | 63 ++++++++++++++++++++++++++++++-----
5 files changed, 118 insertions(+), 17 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 gpd_dev_ops {
@@ -72,9 +73,16 @@ struct gpd_link {
struct list_head slave_node;
};

+struct gpd_timing_data {
+ s64 stop_latency_ns;
+ s64 start_latency_ns;
+ s64 break_even_ns;
+};
+
struct generic_pm_domain_data {
struct pm_domain_data base;
struct gpd_dev_ops ops;
+ struct gpd_timing_data td;
bool need_restore;
};

@@ -89,20 +97,48 @@ 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_timing_data *td);
+
+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,
struct generic_pm_domain *new_subdomain);
extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *target);
-extern int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops);
-extern int pm_genpd_remove_callbacks(struct device *dev);
+extern int pm_genpd_add_callbacks(struct device *dev,
+ struct gpd_dev_ops *ops,
+ struct gpd_timing_data *td);
+extern int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td);
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_timing_data *td)
+{
+ return -ENOSYS;
+}
static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev)
{
@@ -124,22 +160,33 @@ static inline int pm_genpd_remove_subdom
return -ENOSYS;
}
static inline int pm_genpd_add_callbacks(struct device *dev,
- struct gpd_dev_ops *ops)
+ struct gpd_dev_ops *ops,
+ struct gpd_timing_data *td)
{
return -ENOSYS;
}
-static inline int pm_genpd_remove_callbacks(struct device *dev)
+static inline int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td)
{
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

+static inline int pm_genpd_remove_callbacks(struct device *dev)
+{
+ return __pm_genpd_remove_callbacks(dev, true);
+}
+
#ifdef CONFIG_PM_GENERIC_DOMAINS_RUNTIME
extern void genpd_queue_power_off_work(struct generic_pm_domain *genpd);
extern void pm_genpd_poweroff_unused(void);
Index: linux/drivers/base/power/domain.c
===================================================================
--- linux.orig/drivers/base/power/domain.c
+++ linux/drivers/base/power/domain.c
@@ -38,7 +38,7 @@ 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);
@@ -436,6 +436,7 @@ static void genpd_power_off_work_fn(stru
static int pm_genpd_runtime_suspend(struct device *dev)
{
struct generic_pm_domain *genpd;
+ bool (*stop_ok)(struct device *__dev);
int ret;

dev_dbg(dev, "%s()\n", __func__);
@@ -446,10 +447,17 @@ static int pm_genpd_runtime_suspend(stru

might_sleep_if(!genpd->dev_irq_safe);

+ stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
+ if (stop_ok && !stop_ok(dev))
+ return -EBUSY;
+
ret = genpd_stop_dev(genpd, dev);
if (ret)
return ret;

+ pm_runtime_update_max_time_suspended(dev,
+ dev_gpd_data(dev)->td.start_latency_ns);
+
/*
* If power.irq_safe is set, this routine will be run with interrupts
* off, so it can't use mutexes.
@@ -1022,11 +1030,13 @@ 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.
+ * @td: Set of PM QoS timing 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_timing_data *td)
{
struct generic_pm_domain_data *gpd_data;
struct pm_domain_data *pdd;
@@ -1069,6 +1079,8 @@ 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);
+ if (td)
+ gpd_data->td = *td;

out:
genpd_release_lock(genpd);
@@ -1229,8 +1241,10 @@ int pm_genpd_remove_subdomain(struct gen
* pm_genpd_add_callbacks - Add PM domain callbacks to a given device.
* @dev: Device to add the callbacks to.
* @ops: Set of callbacks to add.
+ * @td: Timing data to add to the device along with the callbacks (optional).
*/
-int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops)
+int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops,
+ struct gpd_timing_data *td)
{
struct pm_domain_data *pdd;
int ret = 0;
@@ -1246,6 +1260,8 @@ int pm_genpd_add_callbacks(struct device
struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);

gpd_data->ops = *ops;
+ if (td)
+ gpd_data->td = *td;
} else {
ret = -EINVAL;
}
@@ -1258,10 +1274,11 @@ int pm_genpd_add_callbacks(struct device
EXPORT_SYMBOL_GPL(pm_genpd_add_callbacks);

/**
- * pm_genpd_remove_callbacks - Remove PM domain callbacks from a given device.
+ * __pm_genpd_remove_callbacks - Remove PM domain callbacks from a given device.
* @dev: Device to remove the callbacks from.
+ * @clear_td: If set, clear the device's timing data too.
*/
-int pm_genpd_remove_callbacks(struct device *dev)
+int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td)
{
struct pm_domain_data *pdd;
int ret = 0;
@@ -1277,6 +1294,8 @@ int pm_genpd_remove_callbacks(struct dev
struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);

gpd_data->ops = (struct gpd_dev_ops){ 0 };
+ if (clear_td)
+ gpd_data->td = (struct gpd_timing_data){ 0 };
} else {
ret = -EINVAL;
}
@@ -1286,7 +1305,7 @@ int pm_genpd_remove_callbacks(struct dev

return ret;
}
-EXPORT_SYMBOL_GPL(pm_genpd_remove_callbacks);
+EXPORT_SYMBOL_GPL(__pm_genpd_remove_callbacks);

/* Default device callbacks for generic PM domains. */

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 +1,33 @@
+/*
+ * 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>
+
+/**
+ * default_stop_ok - Default PM domain governor routine for stopping devices.
+ * @dev: Device to check.
+ */
+bool default_stop_ok(struct device *dev)
+{
+ struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
+
+ dev_dbg(dev, "%s()\n", __func__);
+
+ if (dev->power.max_time_suspended_ns < 0 || td->break_even_ns == 0)
+ return true;
+
+ return td->stop_latency_ns + td->start_latency_ns < td->break_even_ns
+ && td->break_even_ns < dev->power.max_time_suspended_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
@@ -169,6 +169,7 @@ 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,
};

static int sh7372_stop_dev(struct device *dev)
@@ -203,8 +204,9 @@ static int sh7372_start_dev(struct devic
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->dev_ops.stop = sh7372_stop_dev;
genpd->dev_ops.start = sh7372_start_dev;
genpd->dev_ops.active_wakeup = pd_active_wakeup;