PM / Domains: Add device stop governor function (v4)
Rafael J. Wysocki [Wed, 30 Nov 2011 23:02:05 +0000 (00:02 +0100)]
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>
Acked-by: Magnus Damm <damm@opensource.se>

arch/arm/mach-shmobile/pm-sh7372.c
drivers/base/power/Makefile
drivers/base/power/domain.c
drivers/base/power/domain_governor.c [new file with mode: 0644]
include/linux/pm_domain.h

index 6777bb1..adf1765 100644 (file)
@@ -169,6 +169,7 @@ static bool sh7372_power_down_forbidden(struct dev_pm_domain *domain)
 
 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 device *dev)
 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;
index 81676dd..2e58ebb 100644 (file)
@@ -3,7 +3,7 @@ obj-$(CONFIG_PM_SLEEP)  += main.o wakeup.o
 obj-$(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 9a77080..3af9f5a 100644 (file)
@@ -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(struct work_struct *work)
 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(struct device *dev)
 
        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.
@@ -1048,11 +1056,13 @@ static void pm_genpd_complete(struct device *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;
@@ -1095,6 +1105,8 @@ int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
        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);
@@ -1255,8 +1267,10 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
  * 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;
@@ -1272,6 +1286,8 @@ int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops)
                struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 
                gpd_data->ops = *ops;
+               if (td)
+                       gpd_data->td = *td;
        } else {
                ret = -EINVAL;
        }
@@ -1284,10 +1300,11 @@ int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops)
 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;
@@ -1303,6 +1320,8 @@ int pm_genpd_remove_callbacks(struct device *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;
        }
@@ -1312,7 +1331,7 @@ int pm_genpd_remove_callbacks(struct device *dev)
 
        return ret;
 }
-EXPORT_SYMBOL_GPL(pm_genpd_remove_callbacks);
+EXPORT_SYMBOL_GPL(__pm_genpd_remove_callbacks);
 
 /* Default device callbacks for generic PM domains. */
 
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c
new file mode 100644 (file)
index 0000000..97b21c1
--- /dev/null
@@ -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 10a197d..f6745c2 100644 (file)
@@ -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 {
@@ -76,9 +77,16 @@ 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;
 };
 
@@ -93,20 +101,48 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
        return to_gpd_data(dev->power.subsys_data->domain_data);
 }
 
-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)
 {
@@ -128,22 +164,33 @@ static inline int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
        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);