[PATCH 0/4] PM: Make power.subsys_data be more useful

[PATCH 0/4] PM: Make power.subsys_data be more useful

[Rafael J. Wysocki]

Hi,

The following patchset reworks the power.subsys_data field of
struct device so that it can be used not only for clock PM
management.

[1/4] - Introduce struct pm_subsys_data to be point to by power.subsys_data.
[2/4] - Add reference counting for power.subsys_data.
[3/4] - Optimize generic PM domains code by making it use power.subsys_data.
[4/4] - Move PM clock management headers and definitions to a separate file.

The patchset is on top of the pm-domains branch of the linux-pm tree at:

git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git pm-domains

It has been tested on an ARM shmobile Mackerel board.

Thanks,
Rafael

[PATCH 1/4] PM: Introduce struct pm_subsys_data

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Introduce struct pm_subsys_data that may be subclassed by subsystems
to store subsystem-specific information related to the device.  Move
the clock management fields accessed through the power.subsys_data
pointer in struct device to the new strucutre.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 arch/arm/mach-shmobile/pm-sh7372.c |    2 
 drivers/base/power/clock_ops.c     |  122 +++++++++++++++++++------------------
 include/linux/device.h             |    5 +
 include/linux/pm.h                 |   10 ++-
 include/linux/pm_runtime.h         |    8 +-
 5 files changed, 85 insertions(+), 62 deletions(-)

Index: linux-2.6/drivers/base/power/clock_ops.c
===================================================================
--- linux-2.6.orig/drivers/base/power/clock_ops.c
+++ linux-2.6/drivers/base/power/clock_ops.c
@@ -17,11 +17,6 @@
 
 #ifdef CONFIG_PM
 
-struct pm_clk_data {
-	struct list_head clock_list;
-	struct mutex lock;
-};
-
 enum pce_status {
 	PCE_STATUS_NONE = 0,
 	PCE_STATUS_ACQUIRED,
@@ -36,11 +31,6 @@ struct pm_clock_entry {
 	enum pce_status status;
 };
 
-static struct pm_clk_data *__to_pcd(struct device *dev)
-{
-	return dev ? dev->power.subsys_data : NULL;
-}
-
 /**
  * pm_clk_add - Start using a device clock for power management.
  * @dev: Device whose clock is going to be used for power management.
@@ -51,10 +41,10 @@ static struct pm_clk_data *__to_pcd(stru
  */
 int pm_clk_add(struct device *dev, const char *con_id)
 {
-	struct pm_clk_data *pcd = __to_pcd(dev);
+	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce;
 
-	if (!pcd)
+	if (!psd)
 		return -EINVAL;
 
 	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
@@ -73,9 +63,9 @@ int pm_clk_add(struct device *dev, const
 		}
 	}
 
-	mutex_lock(&pcd->lock);
-	list_add_tail(&ce->node, &pcd->clock_list);
-	mutex_unlock(&pcd->lock);
+	mutex_lock(&psd->lock);
+	list_add_tail(&ce->node, &psd->clock_list);
+	mutex_unlock(&psd->lock);
 	return 0;
 }
 
@@ -117,15 +107,15 @@ static void __pm_clk_remove(struct pm_cl
  */
 void pm_clk_remove(struct device *dev, const char *con_id)
 {
-	struct pm_clk_data *pcd = __to_pcd(dev);
+	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce;
 
-	if (!pcd)
+	if (!psd)
 		return;
 
-	mutex_lock(&pcd->lock);
+	mutex_lock(&psd->lock);
 
-	list_for_each_entry(ce, &pcd->clock_list, node) {
+	list_for_each_entry(ce, &psd->clock_list, node) {
 		if (!con_id && !ce->con_id) {
 			__pm_clk_remove(ce);
 			break;
@@ -137,29 +127,45 @@ void pm_clk_remove(struct device *dev, c
 		}
 	}
 
-	mutex_unlock(&pcd->lock);
+	mutex_unlock(&psd->lock);
 }
 
 /**
  * pm_clk_init - Initialize a device's list of power management clocks.
  * @dev: Device to initialize the list of PM clocks for.
  *
- * Allocate a struct pm_clk_data object, initialize its lock member and
- * make the @dev's power.subsys_data field point to it.
+ * Initialize the lock and clock_list members of the device's pm_subsys_data
+ * object.
  */
-int pm_clk_init(struct device *dev)
+void pm_clk_init(struct device *dev)
 {
-	struct pm_clk_data *pcd;
+	struct pm_subsys_data *psd = dev_to_psd(dev);
+
+	if (!psd)
+		return;
 
-	pcd = kzalloc(sizeof(*pcd), GFP_KERNEL);
-	if (!pcd) {
+	INIT_LIST_HEAD(&psd->clock_list);
+	mutex_init(&psd->lock);
+}
+
+/**
+ * pm_clk_create - Create and initialize a device's list of PM clocks.
+ * @dev: Device to create and initialize the list of PM clocks for.
+ *
+ * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
+ * members and make the @dev's power.subsys_data field point to it.
+ */
+int pm_clk_create(struct device *dev)
+{
+	struct pm_subsys_data *psd;
+
+	psd = kzalloc(sizeof(*psd), GFP_KERNEL);
+	if (!psd) {
 		dev_err(dev, "Not enough memory for PM clock data.\n");
 		return -ENOMEM;
 	}
-
-	INIT_LIST_HEAD(&pcd->clock_list);
-	mutex_init(&pcd->lock);
-	dev->power.subsys_data = pcd;
+	dev->power.subsys_data = psd;
+	pm_clk_init(dev);
 	return 0;
 }
 
@@ -168,27 +174,27 @@ int pm_clk_init(struct device *dev)
  * @dev: Device to destroy the list of PM clocks for.
  *
  * Clear the @dev's power.subsys_data field, remove the list of clock entries
- * from the struct pm_clk_data object pointed to by it before and free
+ * from the struct pm_subsys_data object pointed to by it before and free
  * that object.
  */
 void pm_clk_destroy(struct device *dev)
 {
-	struct pm_clk_data *pcd = __to_pcd(dev);
+	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce, *c;
 
-	if (!pcd)
+	if (!psd)
 		return;
 
 	dev->power.subsys_data = NULL;
 
-	mutex_lock(&pcd->lock);
+	mutex_lock(&psd->lock);
 
-	list_for_each_entry_safe_reverse(ce, c, &pcd->clock_list, node)
+	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
 		__pm_clk_remove(ce);
 
-	mutex_unlock(&pcd->lock);
+	mutex_unlock(&psd->lock);
 
-	kfree(pcd);
+	kfree(psd);
 }
 
 #endif /* CONFIG_PM */
@@ -218,17 +224,17 @@ static void pm_clk_acquire(struct device
  */
 int pm_clk_suspend(struct device *dev)
 {
-	struct pm_clk_data *pcd = __to_pcd(dev);
+	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
-	if (!pcd)
+	if (!psd)
 		return 0;
 
-	mutex_lock(&pcd->lock);
+	mutex_lock(&psd->lock);
 
-	list_for_each_entry_reverse(ce, &pcd->clock_list, node) {
+	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
 		if (ce->status == PCE_STATUS_NONE)
 			pm_clk_acquire(dev, ce);
 
@@ -238,7 +244,7 @@ int pm_clk_suspend(struct device *dev)
 		}
 	}
 
-	mutex_unlock(&pcd->lock);
+	mutex_unlock(&psd->lock);
 
 	return 0;
 }
@@ -249,17 +255,17 @@ int pm_clk_suspend(struct device *dev)
  */
 int pm_clk_resume(struct device *dev)
 {
-	struct pm_clk_data *pcd = __to_pcd(dev);
+	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
-	if (!pcd)
+	if (!psd)
 		return 0;
 
-	mutex_lock(&pcd->lock);
+	mutex_lock(&psd->lock);
 
-	list_for_each_entry(ce, &pcd->clock_list, node) {
+	list_for_each_entry(ce, &psd->clock_list, node) {
 		if (ce->status == PCE_STATUS_NONE)
 			pm_clk_acquire(dev, ce);
 
@@ -269,7 +275,7 @@ int pm_clk_resume(struct device *dev)
 		}
 	}
 
-	mutex_unlock(&pcd->lock);
+	mutex_unlock(&psd->lock);
 
 	return 0;
 }
@@ -307,7 +313,7 @@ static int pm_clk_notify(struct notifier
 		if (dev->pm_domain)
 			break;
 
-		error = pm_clk_init(dev);
+		error = pm_clk_create(dev);
 		if (error)
 			break;
 
@@ -342,21 +348,21 @@ static int pm_clk_notify(struct notifier
  */
 int pm_clk_suspend(struct device *dev)
 {
-	struct pm_clk_data *pcd = __to_pcd(dev);
+	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
 	/* If there is no driver, the clocks are already disabled. */
-	if (!pcd || !dev->driver)
+	if (!psd || !dev->driver)
 		return 0;
 
-	mutex_lock(&pcd->lock);
+	mutex_lock(&psd->lock);
 
-	list_for_each_entry_reverse(ce, &pcd->clock_list, node)
+	list_for_each_entry_reverse(ce, &psd->clock_list, node)
 		clk_disable(ce->clk);
 
-	mutex_unlock(&pcd->lock);
+	mutex_unlock(&psd->lock);
 
 	return 0;
 }
@@ -367,21 +373,21 @@ int pm_clk_suspend(struct device *dev)
  */
 int pm_clk_resume(struct device *dev)
 {
-	struct pm_clk_data *pcd = __to_pcd(dev);
+	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
 	/* If there is no driver, the clocks should remain disabled. */
-	if (!pcd || !dev->driver)
+	if (!psd || !dev->driver)
 		return 0;
 
-	mutex_lock(&pcd->lock);
+	mutex_lock(&psd->lock);
 
-	list_for_each_entry(ce, &pcd->clock_list, node)
+	list_for_each_entry(ce, &psd->clock_list, node)
 		clk_enable(ce->clk);
 
-	mutex_unlock(&pcd->lock);
+	mutex_unlock(&psd->lock);
 
 	return 0;
 }
Index: linux-2.6/include/linux/device.h
===================================================================
--- linux-2.6.orig/include/linux/device.h
+++ linux-2.6/include/linux/device.h
@@ -636,6 +636,11 @@ static inline void set_dev_node(struct d
 }
 #endif
 
+static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
+{
+	return dev ? dev->power.subsys_data : NULL;
+}
+
 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
 {
 	return dev->kobj.uevent_suppress;
Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -24,6 +24,7 @@
 #include <linux/list.h>
 #include <linux/workqueue.h>
 #include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/wait.h>
 #include <linux/timer.h>
 #include <linux/completion.h>
@@ -421,6 +422,13 @@ enum rpm_request {
 
 struct wakeup_source;
 
+struct pm_subsys_data {
+	struct mutex lock;
+#ifdef CONFIG_PM_CLK
+	struct list_head clock_list;
+#endif
+};
+
 struct dev_pm_info {
 	pm_message_t		power_state;
 	unsigned int		can_wakeup:1;
@@ -462,7 +470,7 @@ struct dev_pm_info {
 	unsigned long		suspended_jiffies;
 	unsigned long		accounting_timestamp;
 #endif
-	void			*subsys_data;  /* Owned by the subsystem. */
+	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
 };
 
 extern void update_pm_runtime_accounting(struct device *dev);
Index: linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shmobile/pm-sh7372.c
+++ linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
@@ -115,7 +115,7 @@ void sh7372_add_device_to_domain(struct
 	struct device *dev = &pdev->dev;
 
 	if (!dev->power.subsys_data) {
-		pm_clk_init(dev);
+		pm_clk_create(dev);
 		pm_clk_add(dev, NULL);
 	}
 	pm_genpd_add_device(&sh7372_pd->genpd, dev);
Index: linux-2.6/include/linux/pm_runtime.h
===================================================================
--- linux-2.6.orig/include/linux/pm_runtime.h
+++ linux-2.6/include/linux/pm_runtime.h
@@ -258,14 +258,18 @@ struct pm_clk_notifier_block {
 };
 
 #ifdef CONFIG_PM_CLK
-extern int pm_clk_init(struct device *dev);
+extern void pm_clk_init(struct device *dev);
+extern int pm_clk_create(struct device *dev);
 extern void pm_clk_destroy(struct device *dev);
 extern int pm_clk_add(struct device *dev, const char *con_id);
 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 int pm_clk_init(struct device *dev)
+static inline void pm_clk_init(struct device *dev)
+{
+}
+static inline int pm_clk_create(struct device *dev)
 {
 	return -EINVAL;
 }

[PATCH 2/4] PM: Reference counting of power.subsys_data

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Since the power.subsys_data device field will be used by multiple
filesystems, introduce a reference counting mechanism for it to avoid
freeing it prematurely or changing its value at a wrong time.

Make the PM clocks management code that currently is the only user of
power.subsys_data use the new reference counting.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/base/power/Makefile    |    2 
 drivers/base/power/clock_ops.c |   24 ++---------
 drivers/base/power/common.c    |   86 +++++++++++++++++++++++++++++++++++++++++
 include/linux/pm.h             |    3 +
 4 files changed, 95 insertions(+), 20 deletions(-)

Index: linux-2.6/drivers/base/power/common.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/base/power/common.c
@@ -0,0 +1,86 @@
+/*
+ * drivers/base/power/common.c - Common device power management code.
+ *
+ * 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/slab.h>
+#include <linux/device.h>
+#include <linux/pm_runtime.h>
+
+/**
+ * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
+ * @dev: Device to handle.
+ *
+ * If power.subsys_data is NULL, point it to a new object, otherwise increment
+ * its reference counter.  Return 1 if a new object has been created, otherwise
+ * return 0 or error code.
+ */
+int dev_pm_get_subsys_data(struct device *dev)
+{
+	struct pm_subsys_data *psd;
+	int ret = 0;
+
+	psd = kzalloc(sizeof(*psd), GFP_KERNEL);
+	if (!psd)
+		return -ENOMEM;
+
+	spin_lock_irq(&dev->power.lock);
+
+	if (dev->power.subsys_data) {
+		dev->power.subsys_data->refcount++;
+	} else {
+		mutex_init(&psd->lock);
+		psd->refcount = 1;
+		dev->power.subsys_data = psd;
+		pm_clk_init(dev);
+		psd = NULL;
+		ret = 1;
+	}
+
+	spin_unlock_irq(&dev->power.lock);
+
+	/* kfree() verifies that its argument is nonzero. */
+	kfree(psd);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
+
+/**
+ * dev_pm_put_subsys_data - Drop reference to power.subsys_data.
+ * @dev: Device to handle.
+ *
+ * If the reference counter of power.subsys_data is zero after dropping the
+ * reference, power.subsys_data is removed.  Return 1 if that happens or 0
+ * otherwise.
+ */
+int dev_pm_put_subsys_data(struct device *dev)
+{
+	struct pm_subsys_data *psd;
+	int ret = 0;
+
+	spin_lock_irq(&dev->power.lock);
+
+	psd = dev_to_psd(dev);
+	if (!psd) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (--psd->refcount == 0) {
+		dev->power.subsys_data = NULL;
+		kfree(psd);
+		ret = 1;
+	}
+
+ out:
+	spin_unlock_irq(&dev->power.lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -424,6 +424,7 @@ struct wakeup_source;
 
 struct pm_subsys_data {
 	struct mutex lock;
+	unsigned int refcount;
 #ifdef CONFIG_PM_CLK
 	struct list_head clock_list;
 #endif
@@ -474,6 +475,8 @@ struct dev_pm_info {
 };
 
 extern void update_pm_runtime_accounting(struct device *dev);
+extern int dev_pm_get_subsys_data(struct device *dev);
+extern int dev_pm_put_subsys_data(struct device *dev);
 
 /*
  * Power domains provide callbacks that are executed during system suspend,
Index: linux-2.6/drivers/base/power/Makefile
===================================================================
--- linux-2.6.orig/drivers/base/power/Makefile
+++ linux-2.6/drivers/base/power/Makefile
@@ -1,4 +1,4 @@
-obj-$(CONFIG_PM)	+= sysfs.o generic_ops.o
+obj-$(CONFIG_PM)	+= sysfs.o generic_ops.o common.o
 obj-$(CONFIG_PM_SLEEP)	+= main.o wakeup.o
 obj-$(CONFIG_PM_RUNTIME)	+= runtime.o
 obj-$(CONFIG_PM_TRACE_RTC)	+= trace.o
Index: linux-2.6/drivers/base/power/clock_ops.c
===================================================================
--- linux-2.6.orig/drivers/base/power/clock_ops.c
+++ linux-2.6/drivers/base/power/clock_ops.c
@@ -140,12 +140,8 @@ void pm_clk_remove(struct device *dev, c
 void pm_clk_init(struct device *dev)
 {
 	struct pm_subsys_data *psd = dev_to_psd(dev);
-
-	if (!psd)
-		return;
-
-	INIT_LIST_HEAD(&psd->clock_list);
-	mutex_init(&psd->lock);
+	if (psd)
+		INIT_LIST_HEAD(&psd->clock_list);
 }
 
 /**
@@ -157,16 +153,8 @@ void pm_clk_init(struct device *dev)
  */
 int pm_clk_create(struct device *dev)
 {
-	struct pm_subsys_data *psd;
-
-	psd = kzalloc(sizeof(*psd), GFP_KERNEL);
-	if (!psd) {
-		dev_err(dev, "Not enough memory for PM clock data.\n");
-		return -ENOMEM;
-	}
-	dev->power.subsys_data = psd;
-	pm_clk_init(dev);
-	return 0;
+	int ret = dev_pm_get_subsys_data(dev);
+	return ret < 0 ? ret : 0;
 }
 
 /**
@@ -185,8 +173,6 @@ void pm_clk_destroy(struct device *dev)
 	if (!psd)
 		return;
 
-	dev->power.subsys_data = NULL;
-
 	mutex_lock(&psd->lock);
 
 	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
@@ -194,7 +180,7 @@ void pm_clk_destroy(struct device *dev)
 
 	mutex_unlock(&psd->lock);
 
-	kfree(psd);
+	dev_pm_put_subsys_data(dev);
 }
 
 #endif /* CONFIG_PM */

[PATCH 3/4] PM / Domains: Use power.sybsys_data to reduce overhead

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

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>
---
 arch/arm/mach-shmobile/pm-sh7372.c |    6 --
 drivers/base/power/domain.c        |   87 ++++++++++++-------------------------
 include/linux/pm.h                 |    9 +++
 include/linux/pm_domain.h          |    6 --
 include/linux/pm_runtime.h         |   10 ++++
 5 files changed, 51 insertions(+), 67 deletions(-)

Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -422,12 +422,21 @@ 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 {
 	struct mutex 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 {
Index: linux-2.6/include/linux/pm_domain.h
===================================================================
--- linux-2.6.orig/include/linux/pm_domain.h
+++ linux-2.6/include/linux/pm_domain.h
@@ -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);
Index: linux-2.6/drivers/base/power/domain.c
===================================================================
--- linux-2.6.orig/drivers/base/power/domain.c
+++ linux-2.6/drivers/base/power/domain.c
@@ -181,18 +181,18 @@ int pm_genpd_poweron(struct generic_pm_d
 
 /**
  * __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);
@@ -210,24 +210,24 @@ static int __pm_genpd_save_device(struct
 	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);
@@ -244,7 +244,7 @@ static void __pm_genpd_restore_device(st
 
 	mutex_lock(&genpd->lock);
 
-	dle->need_restore = false;
+	pdd->need_restore = false;
 }
 
 /**
@@ -286,7 +286,7 @@ void genpd_queue_power_off_work(struct g
 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;
@@ -308,8 +308,8 @@ static int pm_genpd_poweroff(struct gene
 		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)
@@ -332,9 +332,9 @@ static int pm_genpd_poweroff(struct gene
 	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;
@@ -433,24 +433,6 @@ static int pm_genpd_runtime_suspend(stru
 }
 
 /**
- * __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.
  *
@@ -495,7 +477,7 @@ static int pm_genpd_runtime_resume(struc
 		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);
@@ -510,8 +492,6 @@ static int pm_genpd_runtime_resume(struc
 #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
@@ -1068,7 +1048,7 @@ static void pm_genpd_complete(struct 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__);
@@ -1088,26 +1068,20 @@ int pm_genpd_add_device(struct generic_p
 		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);
@@ -1123,7 +1097,7 @@ int pm_genpd_add_device(struct generic_p
 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__);
@@ -1138,17 +1112,16 @@ int pm_genpd_remove_device(struct generi
 		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;
Index: linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shmobile/pm-sh7372.c
+++ linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
@@ -114,11 +114,9 @@ void sh7372_add_device_to_domain(struct
 {
 	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);
 }
 
 struct sh7372_pm_domain sh7372_a4lc = {
Index: linux-2.6/include/linux/pm_runtime.h
===================================================================
--- linux-2.6.orig/include/linux/pm_runtime.h
+++ linux-2.6/include/linux/pm_runtime.h
@@ -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);
@@ -266,6 +272,10 @@ extern void pm_clk_remove(struct device
 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)
 {
 }

[PATCH 4/4] PM: Move clock-related definitions and headers to separate file

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Since the PM clock management code in drivers/base/power/clock_ops.c
is used for both runtime PM and system suspend/hibernation, the
definitions of data structures and headers related to it should not
be located in include/linux/pm_rumtime.h.  Move them to a separate
header file.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 arch/arm/mach-omap1/pm_bus.c            |    1 
 arch/arm/mach-shmobile/board-ap4evb.c   |    1 
 arch/arm/mach-shmobile/board-mackerel.c |    2 
 arch/arm/mach-shmobile/pm-sh7372.c      |    2 
 arch/arm/mach-shmobile/pm_runtime.c     |    1 
 drivers/base/power/clock_ops.c          |    2 
 drivers/base/power/common.c             |    3 -
 include/linux/pm_clock.h                |   70 ++++++++++++++++++++++++++++++++
 include/linux/pm_runtime.h              |   56 -------------------------
 9 files changed, 77 insertions(+), 61 deletions(-)

Index: linux-2.6/drivers/base/power/common.c
===================================================================
--- linux-2.6.orig/drivers/base/power/common.c
+++ linux-2.6/drivers/base/power/common.c
@@ -9,8 +9,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
-#include <linux/device.h>
-#include <linux/pm_runtime.h>
+#include <linux/pm_clock.h>
 
 /**
  * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
Index: linux-2.6/include/linux/pm_clock.h
===================================================================
--- /dev/null
+++ linux-2.6/include/linux/pm_clock.h
@@ -0,0 +1,70 @@
+/*
+ * pm_clock.h - Definitions and headers related to device clocks.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#ifndef _LINUX_PM_CLOCK_H
+#define _LINUX_PM_CLOCK_H
+
+#include <linux/device.h>
+
+struct pm_clk_notifier_block {
+	struct notifier_block nb;
+	struct dev_pm_domain *pm_domain;
+	char *con_ids[];
+};
+
+#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);
+extern int pm_clk_add(struct device *dev, const char *con_id);
+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)
+{
+}
+static inline int pm_clk_create(struct device *dev)
+{
+	return -EINVAL;
+}
+static inline void pm_clk_destroy(struct device *dev)
+{
+}
+static inline int pm_clk_add(struct device *dev, const char *con_id)
+{
+	return -EINVAL;
+}
+static inline void pm_clk_remove(struct device *dev, const char *con_id)
+{
+}
+#define pm_clk_suspend	NULL
+#define pm_clk_resume	NULL
+#endif
+
+#ifdef CONFIG_HAVE_CLK
+extern void pm_clk_add_notifier(struct bus_type *bus,
+					struct pm_clk_notifier_block *clknb);
+#else
+static inline void pm_clk_add_notifier(struct bus_type *bus,
+					struct pm_clk_notifier_block *clknb)
+{
+}
+#endif
+
+#endif
Index: linux-2.6/include/linux/pm_runtime.h
===================================================================
--- linux-2.6.orig/include/linux/pm_runtime.h
+++ linux-2.6/include/linux/pm_runtime.h
@@ -251,60 +251,4 @@ static inline void pm_runtime_dont_use_a
 	__pm_runtime_use_autosuspend(dev, false);
 }
 
-struct pm_clk_notifier_block {
-	struct notifier_block nb;
-	struct dev_pm_domain *pm_domain;
-	char *con_ids[];
-};
-
-#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);
-extern int pm_clk_add(struct device *dev, const char *con_id);
-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)
-{
-}
-static inline int pm_clk_create(struct device *dev)
-{
-	return -EINVAL;
-}
-static inline void pm_clk_destroy(struct device *dev)
-{
-}
-static inline int pm_clk_add(struct device *dev, const char *con_id)
-{
-	return -EINVAL;
-}
-static inline void pm_clk_remove(struct device *dev, const char *con_id)
-{
-}
-#define pm_clk_suspend	NULL
-#define pm_clk_resume	NULL
-#endif
-
-#ifdef CONFIG_HAVE_CLK
-extern void pm_clk_add_notifier(struct bus_type *bus,
-					struct pm_clk_notifier_block *clknb);
-#else
-static inline void pm_clk_add_notifier(struct bus_type *bus,
-					struct pm_clk_notifier_block *clknb)
-{
-}
-#endif
-
 #endif
Index: linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shmobile/pm-sh7372.c
+++ linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
@@ -15,7 +15,7 @@
 #include <linux/list.h>
 #include <linux/err.h>
 #include <linux/slab.h>
-#include <linux/pm_runtime.h>
+#include <linux/pm_clock.h>
 #include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <asm/system.h>
Index: linux-2.6/drivers/base/power/clock_ops.c
===================================================================
--- linux-2.6.orig/drivers/base/power/clock_ops.c
+++ linux-2.6/drivers/base/power/clock_ops.c
@@ -10,7 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/pm.h>
-#include <linux/pm_runtime.h>
+#include <linux/pm_clock.h>
 #include <linux/clk.h>
 #include <linux/slab.h>
 #include <linux/err.h>
Index: linux-2.6/arch/arm/mach-shmobile/pm_runtime.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shmobile/pm_runtime.c
+++ linux-2.6/arch/arm/mach-shmobile/pm_runtime.c
@@ -15,6 +15,7 @@
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm_domain.h>
+#include <linux/pm_clock.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/sh_clk.h>
Index: linux-2.6/arch/arm/mach-shmobile/board-mackerel.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shmobile/board-mackerel.c
+++ linux-2.6/arch/arm/mach-shmobile/board-mackerel.c
@@ -39,7 +39,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 #include <linux/mtd/physmap.h>
-#include <linux/pm_runtime.h>
+#include <linux/pm_clock.h>
 #include <linux/smsc911x.h>
 #include <linux/sh_intc.h>
 #include <linux/tca6416_keypad.h>
Index: linux-2.6/arch/arm/mach-shmobile/board-ap4evb.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shmobile/board-ap4evb.c
+++ linux-2.6/arch/arm/mach-shmobile/board-ap4evb.c
@@ -42,6 +42,7 @@
 #include <linux/leds.h>
 #include <linux/input/sh_keysc.h>
 #include <linux/usb/r8a66597.h>
+#include <linux/pm_clock.h>
 
 #include <media/sh_mobile_ceu.h>
 #include <media/sh_mobile_csi2.h>
Index: linux-2.6/arch/arm/mach-omap1/pm_bus.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-omap1/pm_bus.c
+++ linux-2.6/arch/arm/mach-omap1/pm_bus.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_clock.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>
 #include <linux/clk.h>

Re: [PATCH 2/4] PM: Reference counting of power.subsys_data

[Pavel Machek]

Hi!
> Since the power.subsys_data device field will be used by multiple
> filesystems, introduce a reference counting mechanism for it to avoid
> freeing it prematurely or changing its value at a wrong time.
> 
> Make the PM clocks management code that currently is the only user of
> power.subsys_data use the new reference counting.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/base/power/Makefile    |    2 
>  drivers/base/power/clock_ops.c |   24 ++---------
>  drivers/base/power/common.c    |   86 +++++++++++++++++++++++++++++++++++++++++
>  include/linux/pm.h             |    3 +
>  4 files changed, 95 insertions(+), 20 deletions(-)
> 
> Index: linux-2.6/drivers/base/power/common.c
> ===================================================================
> --- /dev/null
> +++ linux-2.6/drivers/base/power/common.c
> @@ -0,0 +1,86 @@
> +/*
> + * drivers/base/power/common.c - Common device power management code.
> + *
> + * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.

This looks like you now work for Renesas....?

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html