[RFD][PATCH 0/7] PM / QoS: Support for PM QoS device flags

[RFD][PATCH 0/7] PM / QoS: Support for PM QoS device flags

[Rafael J. Wysocki]

Hi All,

The following patch series extends the existing device PM QoS core code to
support PM QoS flags representing binary (on/off) requirements, such as
whether or not power may be removed entirely from the device or whether
or not remote wakeup (i.e. signalling of external events while suspended)
should work for it.

[1/7] Prepare PM QoS device structure for adding more constraint types.
[2/7] Introduce request and constraint data types for PM QoS flags.
[3/7] Prepare struct dev_pm_qos_request for representing more request types. 
[4/7] Introduce device PM QoS flags support.
[5/7] Make it possible to expose PM QoS device flags to user space.
[6/7] PM / Domains: Check device PM QoS flags in pm_genpd_poweroff().
[7/7] PM / ACPI: Take device PM QoS flags into account.

The last two patches make the generic PM domains framework and ACPI / PCI,
respectively, take the PM QoS device flags introduced by patch [5/7] into
accont when making their decisions.

The changelogs describe the details, but if anything isn't clear, please let
me know.

Thanks,
Rafael

[RFD][PATCH 1/7] PM / QoS: Prepare device structure for adding more constraint types

[Rafael J. Wysocki]

Currently struct dev_pm_info contains only one PM QoS constraints
pointer reserved for latency requirements.  Since one more device
constraints type (i.e. flags) will be necessary, introduce a new
structure, struct dev_pm_qos, that eventually will contain all of
the available device PM QoS constraints and replace the "constraints"
pointer in struct dev_pm_info with a pointer to the new structure
called "qos".

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/base/power/qos.c |   42 ++++++++++++++++++++++--------------------
 include/linux/pm.h       |    2 +-
 include/linux/pm_qos.h   |    4 ++++
 3 files changed, 27 insertions(+), 21 deletions(-)

Index: linux/include/linux/pm.h
===================================================================
--- linux.orig/include/linux/pm.h
+++ linux/include/linux/pm.h
@@ -551,7 +551,7 @@ struct dev_pm_info {
 	struct dev_pm_qos_request *pq_req;
 #endif
 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
-	struct pm_qos_constraints *constraints;
+	struct dev_pm_qos	*qos;
 };
 
 extern void update_pm_runtime_accounting(struct device *dev);
Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -57,6 +57,10 @@ struct pm_qos_constraints {
 	struct blocking_notifier_head *notifiers;
 };
 
+struct dev_pm_qos {
+	struct pm_qos_constraints latency;
+};
+
 /* Action requested to pm_qos_update_target */
 enum pm_qos_req_action {
 	PM_QOS_ADD_REQ,		/* Add a new request */
Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -55,9 +55,7 @@ static BLOCKING_NOTIFIER_HEAD(dev_pm_not
  */
 s32 __dev_pm_qos_read_value(struct device *dev)
 {
-	struct pm_qos_constraints *c = dev->power.constraints;
-
-	return c ? pm_qos_read_value(c) : 0;
+	return dev->power.qos ? pm_qos_read_value(&dev->power.qos->latency) : 0;
 }
 
 /**
@@ -91,12 +89,12 @@ static int apply_constraint(struct dev_p
 {
 	int ret, curr_value;
 
-	ret = pm_qos_update_target(req->dev->power.constraints,
+	ret = pm_qos_update_target(&req->dev->power.qos->latency,
 				   &req->node, action, value);
 
 	if (ret) {
 		/* Call the global callbacks if needed */
-		curr_value = pm_qos_read_value(req->dev->power.constraints);
+		curr_value = pm_qos_read_value(&req->dev->power.qos->latency);
 		blocking_notifier_call_chain(&dev_pm_notifiers,
 					     (unsigned long)curr_value,
 					     req);
@@ -114,20 +112,22 @@ static int apply_constraint(struct dev_p
  */
 static int dev_pm_qos_constraints_allocate(struct device *dev)
 {
+	struct dev_pm_qos *qos;
 	struct pm_qos_constraints *c;
 	struct blocking_notifier_head *n;
 
-	c = kzalloc(sizeof(*c), GFP_KERNEL);
-	if (!c)
+	qos = kzalloc(sizeof(*qos), GFP_KERNEL);
+	if (!qos)
 		return -ENOMEM;
 
 	n = kzalloc(sizeof(*n), GFP_KERNEL);
 	if (!n) {
-		kfree(c);
+		kfree(qos);
 		return -ENOMEM;
 	}
 	BLOCKING_INIT_NOTIFIER_HEAD(n);
 
+	c = &qos->latency;
 	plist_head_init(&c->list);
 	c->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
 	c->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
@@ -135,7 +135,7 @@ static int dev_pm_qos_constraints_alloca
 	c->notifiers = n;
 
 	spin_lock_irq(&dev->power.lock);
-	dev->power.constraints = c;
+	dev->power.qos = qos;
 	spin_unlock_irq(&dev->power.lock);
 
 	return 0;
@@ -151,7 +151,7 @@ static int dev_pm_qos_constraints_alloca
 void dev_pm_qos_constraints_init(struct device *dev)
 {
 	mutex_lock(&dev_pm_qos_mtx);
-	dev->power.constraints = NULL;
+	dev->power.qos = NULL;
 	dev->power.power_state = PMSG_ON;
 	mutex_unlock(&dev_pm_qos_mtx);
 }
@@ -164,6 +164,7 @@ void dev_pm_qos_constraints_init(struct
  */
 void dev_pm_qos_constraints_destroy(struct device *dev)
 {
+	struct dev_pm_qos *qos;
 	struct dev_pm_qos_request *req, *tmp;
 	struct pm_qos_constraints *c;
 
@@ -176,10 +177,11 @@ void dev_pm_qos_constraints_destroy(stru
 	mutex_lock(&dev_pm_qos_mtx);
 
 	dev->power.power_state = PMSG_INVALID;
-	c = dev->power.constraints;
-	if (!c)
+	qos = dev->power.qos;
+	if (!qos)
 		goto out;
 
+	c = &qos->latency;
 	/* Flush the constraints list for the device */
 	plist_for_each_entry_safe(req, tmp, &c->list, node) {
 		/*
@@ -191,7 +193,7 @@ void dev_pm_qos_constraints_destroy(stru
 	}
 
 	spin_lock_irq(&dev->power.lock);
-	dev->power.constraints = NULL;
+	dev->power.qos = NULL;
 	spin_unlock_irq(&dev->power.lock);
 
 	kfree(c->notifiers);
@@ -235,7 +237,7 @@ int dev_pm_qos_add_request(struct device
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (!dev->power.constraints) {
+	if (!dev->power.qos) {
 		if (dev->power.power_state.event == PM_EVENT_INVALID) {
 			/* The device has been removed from the system. */
 			req->dev = NULL;
@@ -290,7 +292,7 @@ int dev_pm_qos_update_request(struct dev
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (req->dev->power.constraints) {
+	if (req->dev->power.qos) {
 		if (new_value != req->node.prio)
 			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
 					       new_value);
@@ -329,7 +331,7 @@ int dev_pm_qos_remove_request(struct dev
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (req->dev->power.constraints) {
+	if (req->dev->power.qos) {
 		ret = apply_constraint(req, PM_QOS_REMOVE_REQ,
 				       PM_QOS_DEFAULT_VALUE);
 		memset(req, 0, sizeof(*req));
@@ -362,13 +364,13 @@ int dev_pm_qos_add_notifier(struct devic
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (!dev->power.constraints)
+	if (!dev->power.qos)
 		ret = dev->power.power_state.event != PM_EVENT_INVALID ?
 			dev_pm_qos_constraints_allocate(dev) : -ENODEV;
 
 	if (!ret)
 		ret = blocking_notifier_chain_register(
-				dev->power.constraints->notifiers, notifier);
+				dev->power.qos->latency.notifiers, notifier);
 
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
@@ -393,9 +395,9 @@ int dev_pm_qos_remove_notifier(struct de
 	mutex_lock(&dev_pm_qos_mtx);
 
 	/* Silently return if the constraints object is not present. */
-	if (dev->power.constraints)
+	if (dev->power.qos)
 		retval = blocking_notifier_chain_unregister(
-				dev->power.constraints->notifiers,
+				dev->power.qos->latency.notifiers,
 				notifier);
 
 	mutex_unlock(&dev_pm_qos_mtx);

[RFD][PATCH 2/7] PM / QoS: Introduce request and constraint data types for PM QoS flags

[Rafael J. Wysocki]

Introduce struct pm_qos_flags_request and struct pm_qos_flags
representing PM QoS flags request type and PM QoS flags constraint
type, respectively.  With these definitions the data structures
will be arranged so that the list member of a struct pm_qos_flags
object will contain the head of a list of struct pm_qos_flags_request
objects representing all of the "flags" requests present for the
given device.  Then, the effective_flags member of a struct
pm_qos_flags object will contain the bitwise OR of the flags members
of all the struct pm_qos_flags_request objects in the list.

Additionally, introduce helper function pm_qos_update_flags()
allowing the caller to manage the list of struct pm_qos_flags_request
pointed to by the list member of struct pm_qos_flags.

The flags are of type s32 so that the request's "value" field
is always of the same type regardless of what kind of request it
is (latency requests already have value fields of type s32).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 include/linux/pm_qos.h |   17 +++++++++++--
 kernel/power/qos.c     |   63 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 2 deletions(-)

Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -33,6 +33,11 @@ struct pm_qos_request {
 	struct delayed_work work; /* for pm_qos_update_request_timeout */
 };
 
+struct pm_qos_flags_request {
+	struct list_head node;
+	s32 flags;	/* Do not change to 64 bit */
+};
+
 struct dev_pm_qos_request {
 	struct plist_node node;
 	struct device *dev;
@@ -45,8 +50,8 @@ enum pm_qos_type {
 };
 
 /*
- * Note: The lockless read path depends on the CPU accessing
- * target_value atomically.  Atomic access is only guaranteed on all CPU
+ * Note: The lockless read path depends on the CPU accessing target_value
+ * or effective_flags atomically.  Atomic access is only guaranteed on all CPU
  * types linux supports for 32 bit quantites
  */
 struct pm_qos_constraints {
@@ -57,6 +62,11 @@ struct pm_qos_constraints {
 	struct blocking_notifier_head *notifiers;
 };
 
+struct pm_qos_flags {
+	struct list_head list;
+	s32 effective_flags;	/* Do not change to 64 bit */
+};
+
 struct dev_pm_qos {
 	struct pm_qos_constraints latency;
 };
@@ -75,6 +85,9 @@ static inline int dev_pm_qos_request_act
 
 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 			 enum pm_qos_req_action action, int value);
+bool pm_qos_update_flags(struct pm_qos_flags *pqf,
+			 struct pm_qos_flags_request *req,
+			 enum pm_qos_req_action action, s32 val);
 void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
 			s32 value);
 void pm_qos_update_request(struct pm_qos_request *req,
Index: linux/kernel/power/qos.c
===================================================================
--- linux.orig/kernel/power/qos.c
+++ linux/kernel/power/qos.c
@@ -213,6 +213,69 @@ int pm_qos_update_target(struct pm_qos_c
 }
 
 /**
+ * pm_qos_flags_remove_req - Remove device PM QoS flags request.
+ * @f: Device PM QoS flags set to remove the request from.
+ * @req: Request to remove from the set.
+ */
+static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
+				    struct pm_qos_flags_request *req)
+{
+	s32 val = 0;
+
+	list_del(&req->node);
+	list_for_each_entry(req, &pqf->list, node)
+		val |= req->flags;
+
+	pqf->effective_flags = val;
+}
+
+/**
+ * pm_qos_update_flags - Update a set of PM QoS flags.
+ * @pqf: Set of flags to update.
+ * @req: Request to add to the set, to modify, or to remove from the set.
+ * @action: Action to take on the set.
+ * @val: Value of the request to add or modify.
+ *
+ * Update the given set of PM QoS flags and call notifiers if the aggregate
+ * value has changed.  Returns 1 if the aggregate constraint value has changed,
+ * 0 otherwise.
+ */
+bool pm_qos_update_flags(struct pm_qos_flags *pqf,
+			 struct pm_qos_flags_request *req,
+			 enum pm_qos_req_action action, s32 val)
+{
+	unsigned long irqflags;
+	s32 prev_value, curr_value;
+
+	spin_lock_irqsave(&pm_qos_lock, irqflags);
+
+	prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+	switch (action) {
+	case PM_QOS_REMOVE_REQ:
+		pm_qos_flags_remove_req(pqf, req);
+		break;
+	case PM_QOS_UPDATE_REQ:
+		pm_qos_flags_remove_req(pqf, req);
+	case PM_QOS_ADD_REQ:
+		req->flags = val;
+		INIT_LIST_HEAD(&req->node);
+		list_add_tail(&req->node, &pqf->list);
+		pqf->effective_flags |= val;
+		break;
+	default:
+		/* no action */
+		;
+	}
+
+	curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+	spin_unlock_irqrestore(&pm_qos_lock, irqflags);
+
+	return prev_value != curr_value;
+}
+
+/**
  * pm_qos_request - returns current system wide qos expectation
  * @pm_qos_class: identification of which qos value is requested
  *

Re: [RFD][PATCH 2/7] PM / QoS: Introduce request and constraint data types for PM QoS flags

[Lan Tianyu]

On 2012/9/29 5:52, Rafael J. Wysocki wrote:
> Index: linux/kernel/power/qos.c
> ===================================================================
> --- linux.orig/kernel/power/qos.c
> +++ linux/kernel/power/qos.c
> @@ -213,6 +213,69 @@ int pm_qos_update_target(struct pm_qos_c
>   }
>
>   /**
> + * pm_qos_flags_remove_req - Remove device PM QoS flags request.
> + * @f: Device PM QoS flags set to remove the request from.
-------^
A typo     	
> + * @req: Request to remove from the set.
> + */


-- 
Best Regards
Tianyu Lan
linux kernel enabling team

Re: [RFD][PATCH 2/7] PM / QoS: Introduce request and constraint data types for PM QoS flags

[Rafael J. Wysocki]

On Saturday, September 29, 2012, Lan Tianyu wrote:
> On 2012/9/29 5:52, Rafael J. Wysocki wrote:
> > Index: linux/kernel/power/qos.c
> > ===================================================================
> > --- linux.orig/kernel/power/qos.c
> > +++ linux/kernel/power/qos.c
> > @@ -213,6 +213,69 @@ int pm_qos_update_target(struct pm_qos_c
> >   }
> >
> >   /**
> > + * pm_qos_flags_remove_req - Remove device PM QoS flags request.
> > + * @f: Device PM QoS flags set to remove the request from.
> -------^
> A typo     	
> > + * @req: Request to remove from the set.
> > + */

Yes, thanks!

Rafael

[RFD][PATCH 3/7] PM / QoS: Prepare struct dev_pm_qos_request for more request types

[Rafael J. Wysocki]

The subsequent patches will use struct dev_pm_qos_request for
representing both latency requests and flags requests.  To make that
easier, put the node member of struct dev_pm_qos_request (under the
name "pnode") into a union called "data" that will represent the
request's  value and list node depending on its type.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/base/power/qos.c   |    6 +++---
 drivers/base/power/sysfs.c |    2 +-
 include/linux/pm_qos.h     |    4 +++-
 3 files changed, 7 insertions(+), 5 deletions(-)

Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -39,7 +39,9 @@ struct pm_qos_flags_request {
 };
 
 struct dev_pm_qos_request {
-	struct plist_node node;
+	union {
+		struct plist_node pnode;
+	} data;
 	struct device *dev;
 };
 
Index: linux/drivers/base/power/sysfs.c
===================================================================
--- linux.orig/drivers/base/power/sysfs.c
+++ linux/drivers/base/power/sysfs.c
@@ -221,7 +221,7 @@ static DEVICE_ATTR(autosuspend_delay_ms,
 static ssize_t pm_qos_latency_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", dev->power.pq_req->node.prio);
+	return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
 }
 
 static ssize_t pm_qos_latency_store(struct device *dev,
Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -90,7 +90,7 @@ static int apply_constraint(struct dev_p
 	int ret, curr_value;
 
 	ret = pm_qos_update_target(&req->dev->power.qos->latency,
-				   &req->node, action, value);
+				   &req->data.pnode, action, value);
 
 	if (ret) {
 		/* Call the global callbacks if needed */
@@ -183,7 +183,7 @@ void dev_pm_qos_constraints_destroy(stru
 
 	c = &qos->latency;
 	/* Flush the constraints list for the device */
-	plist_for_each_entry_safe(req, tmp, &c->list, node) {
+	plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
 		/*
 		 * Update constraints list and call the notification
 		 * callbacks if needed
@@ -293,7 +293,7 @@ int dev_pm_qos_update_request(struct dev
 	mutex_lock(&dev_pm_qos_mtx);
 
 	if (req->dev->power.qos) {
-		if (new_value != req->node.prio)
+		if (new_value != req->data.pnode.prio)
 			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
 					       new_value);
 	} else {

[RFD][PATCH 4/7] PM / QoS: Introduce device PM QoS flags support

[Rafael J. Wysocki]

Modify the device PM QoS core code to support PM QoS flags requests.

First, add a new field of type struct pm_qos_flags called "flags"
to struct dev_pm_qos for representing the list of PM QoS flags
requests for the given device.  Accordingly, add a new "type" field
to struct dev_pm_qos_request (along with an enum for representing
request types) and a new member called "flr" to its data union for
representig flags requests.

Second, modify dev_pm_qos_add_request(), dev_pm_qos_update_request(),
the internal routine apply_constraint() used by them and their
existing callers to cover flags requests as well as latency
requests.  In particular, dev_pm_qos_add_request() gets a new
argument called "type" for specifying the type of a request to be
added.

Finally, introduce two routines, __dev_pm_qos_flags() and
dev_pm_qos_flags(), allowing their callers to check which PM QoS
flags have been requested for the given device (the caller is
supposed to pass the mask of flags to check as the routine's
second argument and examine its return value for the result).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 Documentation/power/pm_qos_interface.txt |    2 
 drivers/base/power/qos.c                 |  124 ++++++++++++++++++++++++-------
 drivers/mtd/nand/sh_flctl.c              |    4 -
 include/linux/pm_qos.h                   |   26 ++++++
 4 files changed, 127 insertions(+), 29 deletions(-)

Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -48,6 +48,50 @@ static DEFINE_MUTEX(dev_pm_qos_mtx);
 static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
 
 /**
+ * __dev_pm_qos_flags - Check PM QoS flags for a given device.
+ * @dev: Device to check the PM QoS flags for.
+ * @mask: Flags to check against.
+ *
+ * This routine must be called with dev->power.lock held.
+ */
+enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask)
+{
+	struct dev_pm_qos *qos = dev->power.qos;
+	struct pm_qos_flags *pqf;
+	s32 val;
+
+	if (!qos)
+		return PM_QOS_FLAGS_UNDEFINED;
+
+	pqf = &qos->flags;
+	if (list_empty(&pqf->list))
+		return PM_QOS_FLAGS_UNDEFINED;
+
+	val = pqf->effective_flags & mask;
+	if (val)
+		return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME;
+
+	return PM_QOS_FLAGS_NONE;
+}
+
+/**
+ * dev_pm_qos_flags - Check PM QoS flags for a given device (locked).
+ * @dev: Device to check the PM QoS flags for.
+ * @mask: Flags to check against.
+ */
+enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask)
+{
+	unsigned long irqflags;
+	enum pm_qos_flags_status ret;
+
+	spin_lock_irqsave(&dev->power.lock, irqflags);
+	ret = __dev_pm_qos_flags(dev, mask);
+	spin_unlock_irqrestore(&dev->power.lock, irqflags);
+
+	return ret;
+}
+
+/**
  * __dev_pm_qos_read_value - Get PM QoS constraint for a given device.
  * @dev: Device to get the PM QoS constraint value for.
  *
@@ -74,30 +118,39 @@ s32 dev_pm_qos_read_value(struct device
 	return ret;
 }
 
-/*
- * apply_constraint
- * @req: constraint request to apply
- * @action: action to perform add/update/remove, of type enum pm_qos_req_action
- * @value: defines the qos request
+/**
+ * apply_constraint - Add/modify/remove device PM QoS request.
+ * @req: Constraint request to apply
+ * @action: Action to perform (add/update/remove).
+ * @value: Value to assign to the QoS request.
  *
  * Internal function to update the constraints list using the PM QoS core
  * code and if needed call the per-device and the global notification
  * callbacks
  */
 static int apply_constraint(struct dev_pm_qos_request *req,
-			    enum pm_qos_req_action action, int value)
+			    enum pm_qos_req_action action, s32 value)
 {
-	int ret, curr_value;
-
-	ret = pm_qos_update_target(&req->dev->power.qos->latency,
-				   &req->data.pnode, action, value);
+	struct dev_pm_qos *qos = req->dev->power.qos;
+	int ret;
 
-	if (ret) {
-		/* Call the global callbacks if needed */
-		curr_value = pm_qos_read_value(&req->dev->power.qos->latency);
-		blocking_notifier_call_chain(&dev_pm_notifiers,
-					     (unsigned long)curr_value,
-					     req);
+	switch(req->type) {
+	case DEV_PM_QOS_LATENCY:
+		ret = pm_qos_update_target(&qos->latency, &req->data.pnode,
+					   action, value);
+		if (ret) {
+			value = pm_qos_read_value(&qos->latency);
+			blocking_notifier_call_chain(&dev_pm_notifiers,
+						     (unsigned long)value,
+						     req);
+		}
+		break;
+	case DEV_PM_QOS_FLAGS:
+		ret = pm_qos_update_flags(&qos->flags, &req->data.flr,
+					  action, value);
+		break;
+	default:
+		ret = -EINVAL;
 	}
 
 	return ret;
@@ -134,6 +187,8 @@ static int dev_pm_qos_constraints_alloca
 	c->type = PM_QOS_MIN;
 	c->notifiers = n;
 
+	INIT_LIST_HEAD(&qos->flags.list);
+
 	spin_lock_irq(&dev->power.lock);
 	dev->power.qos = qos;
 	spin_unlock_irq(&dev->power.lock);
@@ -207,6 +262,7 @@ void dev_pm_qos_constraints_destroy(stru
  * dev_pm_qos_add_request - inserts new qos request into the list
  * @dev: target device for the constraint
  * @req: pointer to a preallocated handle
+ * @type: type of the request
  * @value: defines the qos request
  *
  * This function inserts a new entry in the device constraints list of
@@ -222,7 +278,7 @@ void dev_pm_qos_constraints_destroy(stru
  * from the system.
  */
 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
-			   s32 value)
+			   enum dev_pm_qos_req_type type, s32 value)
 {
 	int ret = 0;
 
@@ -253,8 +309,10 @@ int dev_pm_qos_add_request(struct device
 		}
 	}
 
-	if (!ret)
+	if (!ret) {
+		req->type = type;
 		ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
+	}
 
  out:
 	mutex_unlock(&dev_pm_qos_mtx);
@@ -281,6 +339,7 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
 int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 			      s32 new_value)
 {
+	s32 curr_value;
 	int ret = 0;
 
 	if (!req) /*guard against callers passing in null */
@@ -292,15 +351,27 @@ int dev_pm_qos_update_request(struct dev
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (req->dev->power.qos) {
-		if (new_value != req->data.pnode.prio)
-			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
-					       new_value);
-	} else {
-		/* Return if the device has been removed */
+	if (!req->dev->power.qos) {
 		ret = -ENODEV;
+		goto out;
 	}
 
+	switch(req->type) {
+	case DEV_PM_QOS_LATENCY:
+		curr_value = req->data.pnode.prio;
+		break;
+	case DEV_PM_QOS_FLAGS:
+		curr_value = req->data.flr.flags;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (curr_value != new_value)
+		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
+
+ out:
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }
@@ -451,7 +522,8 @@ int dev_pm_qos_add_ancestor_request(stru
 		ancestor = ancestor->parent;
 
 	if (ancestor)
-		error = dev_pm_qos_add_request(ancestor, req, value);
+		error = dev_pm_qos_add_request(ancestor, req,
+					       DEV_PM_QOS_LATENCY, value);
 
 	if (error)
 		req->dev = NULL;
@@ -487,7 +559,7 @@ int dev_pm_qos_expose_latency_limit(stru
 	if (!req)
 		return -ENOMEM;
 
-	ret = dev_pm_qos_add_request(dev, req, value);
+	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY, value);
 	if (ret < 0)
 		return ret;
 
Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -20,6 +20,13 @@ enum {
 	PM_QOS_NUM_CLASSES,
 };
 
+enum pm_qos_flags_status {
+	PM_QOS_FLAGS_UNDEFINED = -1,
+	PM_QOS_FLAGS_NONE,
+	PM_QOS_FLAGS_SOME,
+	PM_QOS_FLAGS_ALL,
+};
+
 #define PM_QOS_DEFAULT_VALUE -1
 
 #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE	(2000 * USEC_PER_SEC)
@@ -38,9 +45,16 @@ struct pm_qos_flags_request {
 	s32 flags;	/* Do not change to 64 bit */
 };
 
+enum dev_pm_qos_req_type {
+	DEV_PM_QOS_LATENCY = 1,
+	DEV_PM_QOS_FLAGS,
+};
+
 struct dev_pm_qos_request {
+	enum dev_pm_qos_req_type type;
 	union {
 		struct plist_node pnode;
+		struct pm_qos_flags_request flr;
 	} data;
 	struct device *dev;
 };
@@ -71,6 +85,7 @@ struct pm_qos_flags {
 
 struct dev_pm_qos {
 	struct pm_qos_constraints latency;
+	struct pm_qos_flags flags;
 };
 
 /* Action requested to pm_qos_update_target */
@@ -105,10 +120,12 @@ int pm_qos_request_active(struct pm_qos_
 s32 pm_qos_read_value(struct pm_qos_constraints *c);
 
 #ifdef CONFIG_PM
+enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
+enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask);
 s32 __dev_pm_qos_read_value(struct device *dev);
 s32 dev_pm_qos_read_value(struct device *dev);
 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
-			   s32 value);
+			   enum dev_pm_qos_req_type type, s32 value);
 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
 int dev_pm_qos_add_notifier(struct device *dev,
@@ -122,12 +139,19 @@ void dev_pm_qos_constraints_destroy(stru
 int dev_pm_qos_add_ancestor_request(struct device *dev,
 				    struct dev_pm_qos_request *req, s32 value);
 #else
+static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
+							  s32 mask)
+			{ return PM_QOS_FLAGS_UNDEFINED; }
+static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
+							s32 mask)
+			{ return PM_QOS_FLAGS_UNDEFINED; }
 static inline s32 __dev_pm_qos_read_value(struct device *dev)
 			{ return 0; }
 static inline s32 dev_pm_qos_read_value(struct device *dev)
 			{ return 0; }
 static inline int dev_pm_qos_add_request(struct device *dev,
 					 struct dev_pm_qos_request *req,
+					 enum dev_pm_qos_req_type type,
 					 s32 value)
 			{ return 0; }
 static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
Index: linux/drivers/mtd/nand/sh_flctl.c
===================================================================
--- linux.orig/drivers/mtd/nand/sh_flctl.c
+++ linux/drivers/mtd/nand/sh_flctl.c
@@ -710,7 +710,9 @@ static void flctl_select_chip(struct mtd
 
 		if (!flctl->qos_request) {
 			ret = dev_pm_qos_add_request(&flctl->pdev->dev,
-							&flctl->pm_qos, 100);
+							&flctl->pm_qos,
+							DEV_PM_QOS_LATENCY,
+							100);
 			if (ret < 0)
 				dev_err(&flctl->pdev->dev,
 					"PM QoS request failed: %d\n", ret);
Index: linux/Documentation/power/pm_qos_interface.txt
===================================================================
--- linux.orig/Documentation/power/pm_qos_interface.txt
+++ linux/Documentation/power/pm_qos_interface.txt
@@ -99,7 +99,7 @@ reading the aggregated value does not re
 
 From kernel mode the use of this interface is the following:
 
-int dev_pm_qos_add_request(device, handle, value):
+int dev_pm_qos_add_request(device, handle, type, value):
 Will insert an element into the list for that identified device with the
 target value.  Upon change to this list the new target is recomputed and any
 registered notifiers are called only if the target value is now different.

[RFD][PATCH 5/7] PM / QoS: Make it possible to expose PM QoS device flags to user space

[Rafael J. Wysocki]

Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF
and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines
dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the
caller to expose those two flags to user space or to hide them
from it, respectively.

After the flags have been exposed, user space will see two
additional sysfs attributes, pm_qos_no_power_off and
pm_qos_remote_wakeup, under the device's /sys/devices/.../power/
directory.  Then, writing 1 to one of them will update the
PM QoS flags request owned by user space so that the corresponding
flag is requested to be set.  In turn, writing 0 to one of them
will cause the corresponding flag in the user space's request to
be cleared (however, the owners of the other PM QoS flags requests
for the same device may still request the flag to be set and it
may be effectively set even if user space doesn't request that).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 Documentation/ABI/testing/sysfs-devices-power |   31 ++++
 drivers/base/power/power.h                    |    6 
 drivers/base/power/qos.c                      |  169 ++++++++++++++++++++------
 drivers/base/power/sysfs.c                    |   95 +++++++++++++-
 include/linux/pm.h                            |    1 
 include/linux/pm_qos.h                        |   26 ++++
 6 files changed, 280 insertions(+), 48 deletions(-)

Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -34,6 +34,9 @@ enum pm_qos_flags_status {
 #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE	0
 #define PM_QOS_DEV_LAT_DEFAULT_VALUE		0
 
+#define PM_QOS_FLAG_NO_POWER_OFF	(1 << 0)
+#define PM_QOS_FLAG_REMOTE_WAKEUP	(1 << 1)
+
 struct pm_qos_request {
 	struct plist_node node;
 	int pm_qos_class;
@@ -86,6 +89,8 @@ struct pm_qos_flags {
 struct dev_pm_qos {
 	struct pm_qos_constraints latency;
 	struct pm_qos_flags flags;
+	struct dev_pm_qos_request *latency_req;
+	struct dev_pm_qos_request *flags_req;
 };
 
 /* Action requested to pm_qos_update_target */
@@ -187,10 +192,31 @@ static inline int dev_pm_qos_add_ancesto
 #ifdef CONFIG_PM_RUNTIME
 int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value);
 void dev_pm_qos_hide_latency_limit(struct device *dev);
+int dev_pm_qos_expose_flags(struct device *dev, s32 value);
+void dev_pm_qos_hide_flags(struct device *dev);
+int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set);
+
+static inline s32 dev_pm_qos_requested_latency(struct device *dev)
+{
+	return dev->power.qos->latency_req->data.pnode.prio;
+}
+
+static inline s32 dev_pm_qos_requested_flags(struct device *dev)
+{
+	return dev->power.qos->flags_req->data.flr.flags;
+}
 #else
 static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
 			{ return 0; }
 static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {}
+static inline int dev_pm_qos_expose_flags(struct device *dev, s32 value)
+			{ return 0; }
+static inline void dev_pm_qos_hide_flags(struct device *dev) {}
+static inline int dev_pm_qos_update_flags(struct device *dev, s32 m, bool set)
+			{ return 0; }
+
+static inline s32 dev_pm_qos_requested_latency(struct device *dev) { return 0; }
+static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
 #endif
 
 #endif
Index: linux/include/linux/pm.h
===================================================================
--- linux.orig/include/linux/pm.h
+++ linux/include/linux/pm.h
@@ -548,7 +548,6 @@ struct dev_pm_info {
 	unsigned long		active_jiffies;
 	unsigned long		suspended_jiffies;
 	unsigned long		accounting_timestamp;
-	struct dev_pm_qos_request *pq_req;
 #endif
 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
 	struct dev_pm_qos	*qos;
Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -40,6 +40,7 @@
 #include <linux/device.h>
 #include <linux/mutex.h>
 #include <linux/export.h>
+#include <linux/pm_runtime.h>
 
 #include "power.h"
 
@@ -322,6 +323,38 @@ int dev_pm_qos_add_request(struct device
 EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
 
 /**
+ * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
+ * @req : PM QoS request to modify.
+ * @new_value: New value to request.
+ */
+int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
+{
+	s32 curr_value;
+	int ret = 0;
+
+	if (!req->dev->power.qos) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	switch(req->type) {
+	case DEV_PM_QOS_LATENCY:
+		curr_value = req->data.pnode.prio;
+		break;
+	case DEV_PM_QOS_FLAGS:
+		curr_value = req->data.flr.flags;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (curr_value != new_value)
+		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
+
+	return ret;
+}
+
+/**
  * dev_pm_qos_update_request - modifies an existing qos request
  * @req : handle to list element holding a dev_pm_qos request to use
  * @new_value: defines the qos request
@@ -336,11 +369,9 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
  * -EINVAL in case of wrong parameters, -ENODEV if the device has been
  * removed from the system
  */
-int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
-			      s32 new_value)
+int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
 {
-	s32 curr_value;
-	int ret = 0;
+	int ret;
 
 	if (!req) /*guard against callers passing in null */
 		return -EINVAL;
@@ -350,29 +381,9 @@ int dev_pm_qos_update_request(struct dev
 		return -EINVAL;
 
 	mutex_lock(&dev_pm_qos_mtx);
-
-	if (!req->dev->power.qos) {
-		ret = -ENODEV;
-		goto out;
-	}
-
-	switch(req->type) {
-	case DEV_PM_QOS_LATENCY:
-		curr_value = req->data.pnode.prio;
-		break;
-	case DEV_PM_QOS_FLAGS:
-		curr_value = req->data.flr.flags;
-		break;
-	default:
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (curr_value != new_value)
-		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
-
- out:
+	__dev_pm_qos_update_request(req, new_value);
 	mutex_unlock(&dev_pm_qos_mtx);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
@@ -533,10 +544,19 @@ int dev_pm_qos_add_ancestor_request(stru
 EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
 
 #ifdef CONFIG_PM_RUNTIME
-static void __dev_pm_qos_drop_user_request(struct device *dev)
+static void __dev_pm_qos_drop_user_request(struct device *dev,
+					   enum dev_pm_qos_req_type type)
 {
-	dev_pm_qos_remove_request(dev->power.pq_req);
-	dev->power.pq_req = NULL;
+	switch(type) {
+	case DEV_PM_QOS_LATENCY:
+		dev_pm_qos_remove_request(dev->power.qos->latency_req);
+		dev->power.qos->latency_req = NULL;
+		break;
+	case DEV_PM_QOS_FLAGS:
+		dev_pm_qos_remove_request(dev->power.qos->flags_req);
+		dev->power.qos->flags_req = NULL;
+		break;
+	}
 }
 
 /**
@@ -552,7 +572,7 @@ int dev_pm_qos_expose_latency_limit(stru
 	if (!device_is_registered(dev) || value < 0)
 		return -EINVAL;
 
-	if (dev->power.pq_req)
+	if (dev->power.qos && dev->power.qos->latency_req)
 		return -EEXIST;
 
 	req = kzalloc(sizeof(*req), GFP_KERNEL);
@@ -563,10 +583,10 @@ int dev_pm_qos_expose_latency_limit(stru
 	if (ret < 0)
 		return ret;
 
-	dev->power.pq_req = req;
-	ret = pm_qos_sysfs_add(dev);
+	dev->power.qos->latency_req = req;
+	ret = pm_qos_sysfs_add_latency(dev);
 	if (ret)
-		__dev_pm_qos_drop_user_request(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
 
 	return ret;
 }
@@ -578,10 +598,87 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_expose_late
  */
 void dev_pm_qos_hide_latency_limit(struct device *dev)
 {
-	if (dev->power.pq_req) {
-		pm_qos_sysfs_remove(dev);
-		__dev_pm_qos_drop_user_request(dev);
+	if (dev->power.qos && dev->power.qos->latency_req) {
+		pm_qos_sysfs_remove_latency(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
 	}
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit);
+
+/**
+ * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space.
+ * @dev: Device whose PM QoS flags are to be exposed to user space.
+ * @val: Initial values of the flags.
+ */
+int dev_pm_qos_expose_flags(struct device *dev, s32 val)
+{
+	struct dev_pm_qos_request *req;
+	int ret;
+
+	if (!device_is_registered(dev))
+		return -EINVAL;
+
+	if (dev->power.qos && dev->power.qos->flags_req)
+		return -EEXIST;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val);
+	if (ret < 0)
+		return ret;
+
+	dev->power.qos->flags_req = req;
+	ret = pm_qos_sysfs_add_flags(dev);
+	if (ret)
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags);
+
+/**
+ * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space.
+ * @dev: Device whose PM QoS flags are to be hidden from user space.
+ */
+void dev_pm_qos_hide_flags(struct device *dev)
+{
+	if (dev->power.qos && dev->power.qos->flags_req) {
+		pm_qos_sysfs_remove_flags(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
+	}
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags);
+
+/**
+ * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space.
+ * @dev: Device to update the PM QoS flags request for.
+ * @mask: Flags to set/clear.
+ * @set: Whether to set or clear the flags (true means set).
+ */
+int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set)
+{
+	s32 value;
+	int ret;
+
+	if (!dev->power.qos || !dev->power.qos->flags_req)
+		return -EINVAL;
+
+	pm_runtime_get_sync(dev);
+	mutex_lock(&dev_pm_qos_mtx);
+
+	value = dev_pm_qos_requested_flags(dev);
+	if (set)
+		value |= mask;
+	else
+		value &= ~mask;
+
+	ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value);
+
+	mutex_unlock(&dev_pm_qos_mtx);
+	pm_runtime_put(dev);
+
+	return ret;
+}
 #endif /* CONFIG_PM_RUNTIME */
Index: linux/drivers/base/power/power.h
===================================================================
--- linux.orig/drivers/base/power/power.h
+++ linux/drivers/base/power/power.h
@@ -93,8 +93,10 @@ extern void dpm_sysfs_remove(struct devi
 extern void rpm_sysfs_remove(struct device *dev);
 extern int wakeup_sysfs_add(struct device *dev);
 extern void wakeup_sysfs_remove(struct device *dev);
-extern int pm_qos_sysfs_add(struct device *dev);
-extern void pm_qos_sysfs_remove(struct device *dev);
+extern int pm_qos_sysfs_add_latency(struct device *dev);
+extern void pm_qos_sysfs_remove_latency(struct device *dev);
+extern int pm_qos_sysfs_add_flags(struct device *dev);
+extern void pm_qos_sysfs_remove_flags(struct device *dev);
 
 #else /* CONFIG_PM */
 
Index: linux/drivers/base/power/sysfs.c
===================================================================
--- linux.orig/drivers/base/power/sysfs.c
+++ linux/drivers/base/power/sysfs.c
@@ -221,7 +221,7 @@ static DEVICE_ATTR(autosuspend_delay_ms,
 static ssize_t pm_qos_latency_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
+	return sprintf(buf, "%d\n", dev_pm_qos_requested_latency(dev));
 }
 
 static ssize_t pm_qos_latency_store(struct device *dev,
@@ -237,12 +237,67 @@ static ssize_t pm_qos_latency_store(stru
 	if (value < 0)
 		return -EINVAL;
 
-	ret = dev_pm_qos_update_request(dev->power.pq_req, value);
+	ret = dev_pm_qos_update_request(dev->power.qos->latency_req, value);
 	return ret < 0 ? ret : n;
 }
 
 static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
 		   pm_qos_latency_show, pm_qos_latency_store);
+
+static ssize_t pm_qos_no_power_off_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
+					& PM_QOS_FLAG_NO_POWER_OFF));
+}
+
+static ssize_t pm_qos_no_power_off_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t n)
+{
+	int ret;
+
+	if (kstrtoint(buf, 0, &ret))
+		return -EINVAL;
+
+	if (ret != 0 && ret != 1)
+		return -EINVAL;
+
+	ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
+	return ret < 0 ? ret : n;
+}
+
+static DEVICE_ATTR(pm_qos_no_power_off, 0644,
+		   pm_qos_no_power_off_show, pm_qos_no_power_off_store);
+
+static ssize_t pm_qos_remote_wakeup_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
+					& PM_QOS_FLAG_REMOTE_WAKEUP));
+}
+
+static ssize_t pm_qos_remote_wakeup_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t n)
+{
+	s32 value;
+	int ret;
+
+	if (kstrtoint(buf, 0, &ret))
+		return -EINVAL;
+
+	if (ret != 0 && ret != 1)
+		return -EINVAL;
+
+	ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP, ret);
+	return ret < 0 ? ret : n;
+}
+
+static DEVICE_ATTR(pm_qos_remote_wakeup, 0644,
+		   pm_qos_remote_wakeup_show, pm_qos_remote_wakeup_store);
 #endif /* CONFIG_PM_RUNTIME */
 
 #ifdef CONFIG_PM_SLEEP
@@ -564,15 +619,27 @@ static struct attribute_group pm_runtime
 	.attrs	= runtime_attrs,
 };
 
-static struct attribute *pm_qos_attrs[] = {
+static struct attribute *pm_qos_latency_attrs[] = {
 #ifdef CONFIG_PM_RUNTIME
 	&dev_attr_pm_qos_resume_latency_us.attr,
 #endif /* CONFIG_PM_RUNTIME */
 	NULL,
 };
-static struct attribute_group pm_qos_attr_group = {
+static struct attribute_group pm_qos_latency_attr_group = {
+	.name	= power_group_name,
+	.attrs	= pm_qos_latency_attrs,
+};
+
+static struct attribute *pm_qos_flags_attrs[] = {
+#ifdef CONFIG_PM_RUNTIME
+	&dev_attr_pm_qos_no_power_off.attr,
+	&dev_attr_pm_qos_remote_wakeup.attr,
+#endif /* CONFIG_PM_RUNTIME */
+	NULL,
+};
+static struct attribute_group pm_qos_flags_attr_group = {
 	.name	= power_group_name,
-	.attrs	= pm_qos_attrs,
+	.attrs	= pm_qos_flags_attrs,
 };
 
 int dpm_sysfs_add(struct device *dev)
@@ -615,14 +682,24 @@ void wakeup_sysfs_remove(struct device *
 	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 }
 
-int pm_qos_sysfs_add(struct device *dev)
+int pm_qos_sysfs_add_latency(struct device *dev)
+{
+	return sysfs_merge_group(&dev->kobj, &pm_qos_latency_attr_group);
+}
+
+void pm_qos_sysfs_remove_latency(struct device *dev)
+{
+	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_attr_group);
+}
+
+int pm_qos_sysfs_add_flags(struct device *dev)
 {
-	return sysfs_merge_group(&dev->kobj, &pm_qos_attr_group);
+	return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
-void pm_qos_sysfs_remove(struct device *dev)
+void pm_qos_sysfs_remove_flags(struct device *dev)
 {
-	sysfs_unmerge_group(&dev->kobj, &pm_qos_attr_group);
+	sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
 void rpm_sysfs_remove(struct device *dev)
Index: linux/Documentation/ABI/testing/sysfs-devices-power
===================================================================
--- linux.orig/Documentation/ABI/testing/sysfs-devices-power
+++ linux/Documentation/ABI/testing/sysfs-devices-power
@@ -204,3 +204,34 @@ Description:
 
 		This attribute has no effect on system-wide suspend/resume and
 		hibernation.
+
+What:		/sys/devices/.../power/pm_qos_no_power_off
+Date:		September 2012
+Contact:	Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+		The /sys/devices/.../power/pm_qos_no_power_off attribute
+		is used for manipulating the PM QoS "no power off" flag.  If
+		set, this flag indicates to the kernel that power should not
+		be removed entirely from the device.
+
+		Not all drivers support this attribute.  If it isn't supported,
+		it is not present.
+
+		This attribute has no effect on system-wide suspend/resume and
+		hibernation.
+
+What:		/sys/devices/.../power/pm_qos_remote_wakeup
+Date:		September 2012
+Contact:	Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+		The /sys/devices/.../power/pm_qos_remote_wakeup attribute
+		is used for manipulating the PM QoS "remote wakeup required"
+		flag.  If set, this flag indicates to the kernel that the
+		device is a source of user events that have to be signaled from
+		its low-power states.
+
+		Not all drivers support this attribute.  If it isn't supported,
+		it is not present.
+
+		This attribute has no effect on system-wide suspend/resume and
+		hibernation.

Re: [RFD][PATCH 5/7] PM / QoS: Make it possible to expose PM QoS device flags to user space

[Aaron Lu]

On 09/29/2012 05:55 AM, Rafael J. Wysocki wrote:
> Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF
> and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines
> dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the
> caller to expose those two flags to user space or to hide them
> from it, respectively.
> 
> After the flags have been exposed, user space will see two
> additional sysfs attributes, pm_qos_no_power_off and
> pm_qos_remote_wakeup, under the device's /sys/devices/.../power/
> directory.  Then, writing 1 to one of them will update the
> PM QoS flags request owned by user space so that the corresponding
> flag is requested to be set.  In turn, writing 0 to one of them
> will cause the corresponding flag in the user space's request to
> be cleared (however, the owners of the other PM QoS flags requests
> for the same device may still request the flag to be set and it
> may be effectively set even if user space doesn't request that).
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  Documentation/ABI/testing/sysfs-devices-power |   31 ++++
>  drivers/base/power/power.h                    |    6 
>  drivers/base/power/qos.c                      |  169 ++++++++++++++++++++------
>  drivers/base/power/sysfs.c                    |   95 +++++++++++++-
>  include/linux/pm.h                            |    1 
>  include/linux/pm_qos.h                        |   26 ++++
>  6 files changed, 280 insertions(+), 48 deletions(-)
> 
> Index: linux/drivers/base/power/qos.c
> ===================================================================
> --- linux.orig/drivers/base/power/qos.c
> +++ linux/drivers/base/power/qos.c
> @@ -40,6 +40,7 @@
>  #include <linux/device.h>
>  #include <linux/mutex.h>
>  #include <linux/export.h>
> +#include <linux/pm_runtime.h>
>  
>  #include "power.h"
>  
> @@ -322,6 +323,38 @@ int dev_pm_qos_add_request(struct device
>  EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
>  
>  /**
> + * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
> + * @req : PM QoS request to modify.
> + * @new_value: New value to request.
> + */
> +int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
> +{
> +	s32 curr_value;
> +	int ret = 0;
> +
> +	if (!req->dev->power.qos) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	switch(req->type) {
> +	case DEV_PM_QOS_LATENCY:
> +		curr_value = req->data.pnode.prio;
> +		break;
> +	case DEV_PM_QOS_FLAGS:
> +		curr_value = req->data.flr.flags;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (curr_value != new_value)
> +		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> +
> +	return ret;
> +}
> +
> +/**
>   * dev_pm_qos_update_request - modifies an existing qos request
>   * @req : handle to list element holding a dev_pm_qos request to use
>   * @new_value: defines the qos request
> @@ -336,11 +369,9 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
>   * -EINVAL in case of wrong parameters, -ENODEV if the device has been
>   * removed from the system
>   */
> -int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
> -			      s32 new_value)
> +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
>  {
> -	s32 curr_value;
> -	int ret = 0;
> +	int ret;
>  
>  	if (!req) /*guard against callers passing in null */
>  		return -EINVAL;
> @@ -350,29 +381,9 @@ int dev_pm_qos_update_request(struct dev
>  		return -EINVAL;
>  
>  	mutex_lock(&dev_pm_qos_mtx);
> -
> -	if (!req->dev->power.qos) {
> -		ret = -ENODEV;
> -		goto out;
> -	}
> -
> -	switch(req->type) {
> -	case DEV_PM_QOS_LATENCY:
> -		curr_value = req->data.pnode.prio;
> -		break;
> -	case DEV_PM_QOS_FLAGS:
> -		curr_value = req->data.flr.flags;
> -		break;
> -	default:
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
> -	if (curr_value != new_value)
> -		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> -
> - out:
> +	__dev_pm_qos_update_request(req, new_value);

You forgot to assign the return value here.

Thanks,
Aaron

>  	mutex_unlock(&dev_pm_qos_mtx);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
> @@ -533,10 +544,19 @@ int dev_pm_qos_add_ancestor_request(stru
>  EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);

Re: [RFD][PATCH 5/7] PM / QoS: Make it possible to expose PM QoS device flags to user space

[Rafael J. Wysocki]

On Tuesday, October 30, 2012 04:53:28 PM Aaron Lu wrote:
> On 09/29/2012 05:55 AM, Rafael J. Wysocki wrote:
> > Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF
> > and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines
> > dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the
> > caller to expose those two flags to user space or to hide them
> > from it, respectively.
> > 
> > After the flags have been exposed, user space will see two
> > additional sysfs attributes, pm_qos_no_power_off and
> > pm_qos_remote_wakeup, under the device's /sys/devices/.../power/
> > directory.  Then, writing 1 to one of them will update the
> > PM QoS flags request owned by user space so that the corresponding
> > flag is requested to be set.  In turn, writing 0 to one of them
> > will cause the corresponding flag in the user space's request to
> > be cleared (however, the owners of the other PM QoS flags requests
> > for the same device may still request the flag to be set and it
> > may be effectively set even if user space doesn't request that).
> > 
> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > ---
> >  Documentation/ABI/testing/sysfs-devices-power |   31 ++++
> >  drivers/base/power/power.h                    |    6 
> >  drivers/base/power/qos.c                      |  169 ++++++++++++++++++++------
> >  drivers/base/power/sysfs.c                    |   95 +++++++++++++-
> >  include/linux/pm.h                            |    1 
> >  include/linux/pm_qos.h                        |   26 ++++
> >  6 files changed, 280 insertions(+), 48 deletions(-)
> > 
> > Index: linux/drivers/base/power/qos.c
> > ===================================================================
> > --- linux.orig/drivers/base/power/qos.c
> > +++ linux/drivers/base/power/qos.c
> > @@ -40,6 +40,7 @@
> >  #include <linux/device.h>
> >  #include <linux/mutex.h>
> >  #include <linux/export.h>
> > +#include <linux/pm_runtime.h>
> >  
> >  #include "power.h"
> >  
> > @@ -322,6 +323,38 @@ int dev_pm_qos_add_request(struct device
> >  EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
> >  
> >  /**
> > + * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
> > + * @req : PM QoS request to modify.
> > + * @new_value: New value to request.
> > + */
> > +int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
> > +{
> > +	s32 curr_value;
> > +	int ret = 0;
> > +
> > +	if (!req->dev->power.qos) {
> > +		ret = -ENODEV;
> > +		goto out;
> > +	}
> > +
> > +	switch(req->type) {
> > +	case DEV_PM_QOS_LATENCY:
> > +		curr_value = req->data.pnode.prio;
> > +		break;
> > +	case DEV_PM_QOS_FLAGS:
> > +		curr_value = req->data.flr.flags;
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (curr_value != new_value)
> > +		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> > +
> > +	return ret;
> > +}
> > +
> > +/**
> >   * dev_pm_qos_update_request - modifies an existing qos request
> >   * @req : handle to list element holding a dev_pm_qos request to use
> >   * @new_value: defines the qos request
> > @@ -336,11 +369,9 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
> >   * -EINVAL in case of wrong parameters, -ENODEV if the device has been
> >   * removed from the system
> >   */
> > -int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
> > -			      s32 new_value)
> > +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
> >  {
> > -	s32 curr_value;
> > -	int ret = 0;
> > +	int ret;
> >  
> >  	if (!req) /*guard against callers passing in null */
> >  		return -EINVAL;
> > @@ -350,29 +381,9 @@ int dev_pm_qos_update_request(struct dev
> >  		return -EINVAL;
> >  
> >  	mutex_lock(&dev_pm_qos_mtx);
> > -
> > -	if (!req->dev->power.qos) {
> > -		ret = -ENODEV;
> > -		goto out;
> > -	}
> > -
> > -	switch(req->type) {
> > -	case DEV_PM_QOS_LATENCY:
> > -		curr_value = req->data.pnode.prio;
> > -		break;
> > -	case DEV_PM_QOS_FLAGS:
> > -		curr_value = req->data.flr.flags;
> > -		break;
> > -	default:
> > -		ret = -EINVAL;
> > -		goto out;
> > -	}
> > -
> > -	if (curr_value != new_value)
> > -		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> > -
> > - out:
> > +	__dev_pm_qos_update_request(req, new_value);
> 
> You forgot to assign the return value here.

Quite obviously.  I'm going to apply the appended patch for that.

Thanks for spotting it!

Rafael


---
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subject: PM / QoS: Fix the return value of dev_pm_qos_update_request()

Commit e39473d (PM / QoS: Make it possible to expose PM QoS device)
flags to user space introduced __dev_pm_qos_update_request() to be
called internally by dev_pm_qos_update_request(), but forgot to make
the latter actually use the return value of the former.  Fix this
mistake.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/base/power/qos.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -380,7 +380,7 @@ int dev_pm_qos_update_request(struct dev
 		return -EINVAL;
 
 	mutex_lock(&dev_pm_qos_mtx);
-	__dev_pm_qos_update_request(req, new_value);
+	ret = __dev_pm_qos_update_request(req, new_value);
 	mutex_unlock(&dev_pm_qos_mtx);
 
 	return ret;

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

[RFD][PATCH 6/7] PM / Domains: Check device PM QoS flags in pm_genpd_poweroff()

[Rafael J. Wysocki]

Make the generic PM domains pm_genpd_poweroff() function take
device PM QoS flags into account when deciding whether or not to
remove power from the domain.

After this change the routine will return -EBUSY without executing
the domain's .power_off() callback if there is at least one PM QoS
flags request for at least one device in the domain and at least of
those request has at least one of the NO_POWER_OFF and REMOTE_WAKEUP
flags set.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/base/power/domain.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Index: linux/drivers/base/power/domain.c
===================================================================
--- linux.orig/drivers/base/power/domain.c
+++ linux/drivers/base/power/domain.c
@@ -474,10 +474,19 @@ static int pm_genpd_poweroff(struct gene
 		return -EBUSY;
 
 	not_suspended = 0;
-	list_for_each_entry(pdd, &genpd->dev_list, list_node)
+	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
+		enum pm_qos_flags_status stat;
+
+		stat = dev_pm_qos_flags(pdd->dev,
+					PM_QOS_FLAG_NO_POWER_OFF
+						| PM_QOS_FLAG_REMOTE_WAKEUP);
+		if (stat > PM_QOS_FLAGS_NONE)
+			return -EBUSY;
+
 		if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
 		    || pdd->dev->power.irq_safe))
 			not_suspended++;
+	}
 
 	if (not_suspended > genpd->in_progress)
 		return -EBUSY;

[RFD][PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[Rafael J. Wysocki]

Make ACPI power management routines and PCI power management
routines depending on ACPI take device PM QoS flags into account
when deciding what power state to put the device into.

In particular, after this change acpi_pm_device_sleep_state() will
not return ACPI_STATE_D3_COLD as the deepest available low-power
state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
will not require remote wakeup to work for the device in the returned
low-power state if there is at least one PM QoS flags request for the
device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.

Accordingly, acpi_pci_set_power_state() will refuse to put the
device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/acpi/sleep.c   |   16 ++++++++++++----
 drivers/pci/pci-acpi.c |    8 +++++++-
 2 files changed, 19 insertions(+), 5 deletions(-)

Index: linux/drivers/pci/pci-acpi.c
===================================================================
--- linux.orig/drivers/pci/pci-acpi.c
+++ linux/drivers/pci/pci-acpi.c
@@ -17,6 +17,7 @@
 
 #include <linux/pci-acpi.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_qos.h>
 #include "pci.h"
 
 static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
@@ -257,11 +258,16 @@ static int acpi_pci_set_power_state(stru
 		return -ENODEV;
 
 	switch (state) {
+	case PCI_D3cold:
+		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
+				PM_QOS_FLAGS_ALL) {
+			error = -EBUSY;
+			break;
+		}
 	case PCI_D0:
 	case PCI_D1:
 	case PCI_D2:
 	case PCI_D3hot:
-	case PCI_D3cold:
 		error = acpi_bus_set_power(handle, state_conv[state]);
 	}
 
Index: linux/drivers/acpi/sleep.c
===================================================================
--- linux.orig/drivers/acpi/sleep.c
+++ linux/drivers/acpi/sleep.c
@@ -19,6 +19,7 @@
 #include <linux/acpi.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_qos.h>
 
 #include <asm/io.h>
 
@@ -711,6 +712,7 @@ int acpi_pm_device_sleep_state(struct de
 	struct acpi_device *adev;
 	char acpi_method[] = "_SxD";
 	unsigned long long d_min, d_max;
+	bool wakeup = false;
 
 	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
 		return -EINVAL;
@@ -718,6 +720,8 @@ int acpi_pm_device_sleep_state(struct de
 		printk(KERN_DEBUG "ACPI handle has no context!\n");
 		return -ENODEV;
 	}
+	if (dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF) == PM_QOS_FLAGS_ALL)
+		d_max_in = ACPI_STATE_D3_HOT;
 
 	acpi_method[2] = '0' + acpi_target_sleep_state;
 	/*
@@ -737,8 +741,14 @@ int acpi_pm_device_sleep_state(struct de
 	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
 	 * provided -- that's our fault recovery, we ignore retval.
 	 */
-	if (acpi_target_sleep_state > ACPI_STATE_S0)
+	if (acpi_target_sleep_state > ACPI_STATE_S0) {
 		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
+		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
+			&& adev->wakeup.sleep_state >= acpi_target_sleep_state;
+	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
+			PM_QOS_FLAGS_NONE) {
+		wakeup = adev->wakeup.flags.valid;
+	}
 
 	/*
 	 * If _PRW says we can wake up the system from the target sleep state,
@@ -747,9 +757,7 @@ int acpi_pm_device_sleep_state(struct de
 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 	 * can wake the system.  _S0W may be valid, too.
 	 */
-	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
-	    (device_may_wakeup(dev) && adev->wakeup.flags.valid &&
-	     adev->wakeup.sleep_state >= acpi_target_sleep_state)) {
+	if (wakeup) {
 		acpi_status status;
 
 		acpi_method[3] = 'W';

Re: [RFD][PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[Huang Ying]

On Fri, 2012-09-28 at 23:56 +0200, Rafael J. Wysocki wrote:
> Make ACPI power management routines and PCI power management
> routines depending on ACPI take device PM QoS flags into account
> when deciding what power state to put the device into.
> 
> In particular, after this change acpi_pm_device_sleep_state() will
> not return ACPI_STATE_D3_COLD as the deepest available low-power
> state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
> will not require remote wakeup to work for the device in the returned
> low-power state if there is at least one PM QoS flags request for the
> device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.
> 
> Accordingly, acpi_pci_set_power_state() will refuse to put the
> device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/acpi/sleep.c   |   16 ++++++++++++----
>  drivers/pci/pci-acpi.c |    8 +++++++-
>  2 files changed, 19 insertions(+), 5 deletions(-)
> 
> Index: linux/drivers/pci/pci-acpi.c
> ===================================================================
> --- linux.orig/drivers/pci/pci-acpi.c
> +++ linux/drivers/pci/pci-acpi.c
> @@ -17,6 +17,7 @@
>  
>  #include <linux/pci-acpi.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/pm_qos.h>
>  #include "pci.h"
>  
>  static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
> @@ -257,11 +258,16 @@ static int acpi_pci_set_power_state(stru
>  		return -ENODEV;
>  
>  	switch (state) {
> +	case PCI_D3cold:
> +		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
> +				PM_QOS_FLAGS_ALL) {
> +			error = -EBUSY;
> +			break;
> +		}
>  	case PCI_D0:
>  	case PCI_D1:
>  	case PCI_D2:
>  	case PCI_D3hot:
> -	case PCI_D3cold:
>  		error = acpi_bus_set_power(handle, state_conv[state]);
>  	}
>  
> Index: linux/drivers/acpi/sleep.c
> ===================================================================
> --- linux.orig/drivers/acpi/sleep.c
> +++ linux/drivers/acpi/sleep.c
> @@ -19,6 +19,7 @@
>  #include <linux/acpi.h>
>  #include <linux/module.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/pm_qos.h>
>  
>  #include <asm/io.h>
>  
> @@ -711,6 +712,7 @@ int acpi_pm_device_sleep_state(struct de
>  	struct acpi_device *adev;
>  	char acpi_method[] = "_SxD";
>  	unsigned long long d_min, d_max;
> +	bool wakeup = false;
>  
>  	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
>  		return -EINVAL;
> @@ -718,6 +720,8 @@ int acpi_pm_device_sleep_state(struct de
>  		printk(KERN_DEBUG "ACPI handle has no context!\n");
>  		return -ENODEV;
>  	}
> +	if (dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF) == PM_QOS_FLAGS_ALL)
> +		d_max_in = ACPI_STATE_D3_HOT;

In theory, d_max_in may < ACPI_STATE_D3_HOT.  So better to be

d_max_in = min_t(int, d_max_in, ACPI_STATE_D3_HOT);

But in fact, d_max_in is introduced to support something similar to
PM_QOS_FLAG_NO_POWER_OFF, so I think we can remove d_max_in in the
future.

Best Regards,
Huang Ying

>  
>  	acpi_method[2] = '0' + acpi_target_sleep_state;
>  	/*
> @@ -737,8 +741,14 @@ int acpi_pm_device_sleep_state(struct de
>  	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
>  	 * provided -- that's our fault recovery, we ignore retval.
>  	 */
> -	if (acpi_target_sleep_state > ACPI_STATE_S0)
> +	if (acpi_target_sleep_state > ACPI_STATE_S0) {
>  		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
> +		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
> +			&& adev->wakeup.sleep_state >= acpi_target_sleep_state;
> +	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
> +			PM_QOS_FLAGS_NONE) {
> +		wakeup = adev->wakeup.flags.valid;
> +	}
>  
>  	/*
>  	 * If _PRW says we can wake up the system from the target sleep state,
> @@ -747,9 +757,7 @@ int acpi_pm_device_sleep_state(struct de
>  	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
>  	 * can wake the system.  _S0W may be valid, too.
>  	 */
> -	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
> -	    (device_may_wakeup(dev) && adev->wakeup.flags.valid &&
> -	     adev->wakeup.sleep_state >= acpi_target_sleep_state)) {
> +	if (wakeup) {
>  		acpi_status status;
>  
>  		acpi_method[3] = 'W';
> 

Re: [RFD][PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[Rafael J. Wysocki]

On Saturday, September 29, 2012, Huang Ying wrote:
> On Fri, 2012-09-28 at 23:56 +0200, Rafael J. Wysocki wrote:
> > Make ACPI power management routines and PCI power management
> > routines depending on ACPI take device PM QoS flags into account
> > when deciding what power state to put the device into.
> > 
> > In particular, after this change acpi_pm_device_sleep_state() will
> > not return ACPI_STATE_D3_COLD as the deepest available low-power
> > state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
> > will not require remote wakeup to work for the device in the returned
> > low-power state if there is at least one PM QoS flags request for the
> > device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.
> > 
> > Accordingly, acpi_pci_set_power_state() will refuse to put the
> > device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.
> > 
> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > ---
> >  drivers/acpi/sleep.c   |   16 ++++++++++++----
> >  drivers/pci/pci-acpi.c |    8 +++++++-
> >  2 files changed, 19 insertions(+), 5 deletions(-)
> > 
> > Index: linux/drivers/pci/pci-acpi.c
> > ===================================================================
> > --- linux.orig/drivers/pci/pci-acpi.c
> > +++ linux/drivers/pci/pci-acpi.c
> > @@ -17,6 +17,7 @@
> >  
> >  #include <linux/pci-acpi.h>
> >  #include <linux/pm_runtime.h>
> > +#include <linux/pm_qos.h>
> >  #include "pci.h"
> >  
> >  static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
> > @@ -257,11 +258,16 @@ static int acpi_pci_set_power_state(stru
> >  		return -ENODEV;
> >  
> >  	switch (state) {
> > +	case PCI_D3cold:
> > +		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
> > +				PM_QOS_FLAGS_ALL) {
> > +			error = -EBUSY;
> > +			break;
> > +		}
> >  	case PCI_D0:
> >  	case PCI_D1:
> >  	case PCI_D2:
> >  	case PCI_D3hot:
> > -	case PCI_D3cold:
> >  		error = acpi_bus_set_power(handle, state_conv[state]);
> >  	}
> >  
> > Index: linux/drivers/acpi/sleep.c
> > ===================================================================
> > --- linux.orig/drivers/acpi/sleep.c
> > +++ linux/drivers/acpi/sleep.c
> > @@ -19,6 +19,7 @@
> >  #include <linux/acpi.h>
> >  #include <linux/module.h>
> >  #include <linux/pm_runtime.h>
> > +#include <linux/pm_qos.h>
> >  
> >  #include <asm/io.h>
> >  
> > @@ -711,6 +712,7 @@ int acpi_pm_device_sleep_state(struct de
> >  	struct acpi_device *adev;
> >  	char acpi_method[] = "_SxD";
> >  	unsigned long long d_min, d_max;
> > +	bool wakeup = false;
> >  
> >  	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
> >  		return -EINVAL;
> > @@ -718,6 +720,8 @@ int acpi_pm_device_sleep_state(struct de
> >  		printk(KERN_DEBUG "ACPI handle has no context!\n");
> >  		return -ENODEV;
> >  	}
> > +	if (dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF) == PM_QOS_FLAGS_ALL)
> > +		d_max_in = ACPI_STATE_D3_HOT;
> 
> In theory, d_max_in may < ACPI_STATE_D3_HOT.

Good catch!

> So better to be
> 
> d_max_in = min_t(int, d_max_in, ACPI_STATE_D3_HOT);

In fact, we don't even need to check the PM  QoS flags if d_max_in is not D3_COLD.

> But in fact, d_max_in is introduced to support something similar to
> PM_QOS_FLAG_NO_POWER_OFF, so I think we can remove d_max_in in the
> future.

We probably can, but for now I'll fix the patch.

Thanks,
Rafael

Re: [RFD][PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[Bjorn Helgaas]

On Fri, Sep 28, 2012 at 3:56 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> Make ACPI power management routines and PCI power management
> routines depending on ACPI take device PM QoS flags into account
> when deciding what power state to put the device into.
>
> In particular, after this change acpi_pm_device_sleep_state() will
> not return ACPI_STATE_D3_COLD as the deepest available low-power
> state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
> will not require remote wakeup to work for the device in the returned
> low-power state if there is at least one PM QoS flags request for the
> device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.
>
> Accordingly, acpi_pci_set_power_state() will refuse to put the
> device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.
>
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/acpi/sleep.c   |   16 ++++++++++++----
>  drivers/pci/pci-acpi.c |    8 +++++++-

This touches a file in drivers/pci, but I expect it depends on all the
previous patches in the series, so if you haven't merged it already,
Rafael, it seems like it makes sense for you to merge this instead of
me.

Bjorn

Re: [RFD][PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[Rafael J. Wysocki]

On Monday, November 12, 2012 02:07:03 PM Bjorn Helgaas wrote:
> On Fri, Sep 28, 2012 at 3:56 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > Make ACPI power management routines and PCI power management
> > routines depending on ACPI take device PM QoS flags into account
> > when deciding what power state to put the device into.
> >
> > In particular, after this change acpi_pm_device_sleep_state() will
> > not return ACPI_STATE_D3_COLD as the deepest available low-power
> > state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
> > will not require remote wakeup to work for the device in the returned
> > low-power state if there is at least one PM QoS flags request for the
> > device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.
> >
> > Accordingly, acpi_pci_set_power_state() will refuse to put the
> > device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.
> >
> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > ---
> >  drivers/acpi/sleep.c   |   16 ++++++++++++----
> >  drivers/pci/pci-acpi.c |    8 +++++++-
> 
> This touches a file in drivers/pci, but I expect it depends on all the
> previous patches in the series, so if you haven't merged it already,
> Rafael, it seems like it makes sense for you to merge this instead of
> me.

I will, thanks a lot!

Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [RFD][PATCH 0/7] PM / QoS: Support for PM QoS device flags

[Pihet-XID, Jean]

Hi Rafael,

On Fri, Sep 28, 2012 at 11:51 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> Hi All,
>
> The following patch series extends the existing device PM QoS core code to
> support PM QoS flags representing binary (on/off) requirements, such as
> whether or not power may be removed entirely from the device or whether
> or not remote wakeup (i.e. signalling of external events while suspended)
> should work for it.
>
> [1/7] Prepare PM QoS device structure for adding more constraint types.
> [2/7] Introduce request and constraint data types for PM QoS flags.
> [3/7] Prepare struct dev_pm_qos_request for representing more request types.
> [4/7] Introduce device PM QoS flags support.
> [5/7] Make it possible to expose PM QoS device flags to user space.
> [6/7] PM / Domains: Check device PM QoS flags in pm_genpd_poweroff().
> [7/7] PM / ACPI: Take device PM QoS flags into account.
>
> The last two patches make the generic PM domains framework and ACPI / PCI,
> respectively, take the PM QoS device flags introduced by patch [5/7] into
> accont when making their decisions.
>
> The changelogs describe the details, but if anything isn't clear, please let
> me know.
That looks OK after review. FWIW:
Reviewed-by: Jean Pihet <j-pihet@ti.com>

Thanks!
Jean

>
> Thanks,
> Rafael
>

Re: [RFD][PATCH 0/7] PM / QoS: Support for PM QoS device flags

[Rafael J. Wysocki]

On Monday 01 of October 2012 18:17:10 Pihet-XID, Jean wrote:
> Hi Rafael,
> 
> On Fri, Sep 28, 2012 at 11:51 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > Hi All,
> >
> > The following patch series extends the existing device PM QoS core code to
> > support PM QoS flags representing binary (on/off) requirements, such as
> > whether or not power may be removed entirely from the device or whether
> > or not remote wakeup (i.e. signalling of external events while suspended)
> > should work for it.
> >
> > [1/7] Prepare PM QoS device structure for adding more constraint types.
> > [2/7] Introduce request and constraint data types for PM QoS flags.
> > [3/7] Prepare struct dev_pm_qos_request for representing more request types.
> > [4/7] Introduce device PM QoS flags support.
> > [5/7] Make it possible to expose PM QoS device flags to user space.
> > [6/7] PM / Domains: Check device PM QoS flags in pm_genpd_poweroff().
> > [7/7] PM / ACPI: Take device PM QoS flags into account.
> >
> > The last two patches make the generic PM domains framework and ACPI / PCI,
> > respectively, take the PM QoS device flags introduced by patch [5/7] into
> > accont when making their decisions.
> >
> > The changelogs describe the details, but if anything isn't clear, please let
> > me know.
> That looks OK after review. FWIW:
> Reviewed-by: Jean Pihet <j-pihet@ti.com>

Thanks!

Rafael

[PATCH 0/7] PM / QoS: Support for PM QoS device flags

[Rafael J. Wysocki]

Hi All,

On Friday 28 of September 2012 23:51:10 Rafael J. Wysocki wrote:
> 
> The following patch series extends the existing device PM QoS core code to
> support PM QoS flags representing binary (on/off) requirements, such as
> whether or not power may be removed entirely from the device or whether
> or not remote wakeup (i.e. signalling of external events while suspended)
> should work for it.
> 
> [1/7] Prepare PM QoS device structure for adding more constraint types.
> [2/7] Introduce request and constraint data types for PM QoS flags.
> [3/7] Prepare struct dev_pm_qos_request for representing more request types. 
> [4/7] Introduce device PM QoS flags support.
> [5/7] Make it possible to expose PM QoS device flags to user space.
> [6/7] PM / Domains: Check device PM QoS flags in pm_genpd_poweroff().
> [7/7] PM / ACPI: Take device PM QoS flags into account.
> 
> The last two patches make the generic PM domains framework and ACPI / PCI,
> respectively, take the PM QoS device flags introduced by patch [5/7] into
> accont when making their decisions.
> 
> The changelogs describe the details, but if anything isn't clear, please let
> me know.

Time for a real submission, it seems. :-)

The changes since the previous iteration are addressed comments and a small
optimization in patch [5/7] (it won't resume the device if the setting is not
going to change in dev_pm_qos_update_flags()).

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

[PATCH 1/7] PM / QoS: Prepare device structure for adding more constraint types

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently struct dev_pm_info contains only one PM QoS constraints
pointer reserved for latency requirements.  Since one more device
constraints type (i.e. flags) will be necessary, introduce a new
structure, struct dev_pm_qos, that eventually will contain all of
the available device PM QoS constraints and replace the "constraints"
pointer in struct dev_pm_info with a pointer to the new structure
called "qos".

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
---
 drivers/base/power/qos.c |   42 ++++++++++++++++++++++--------------------
 include/linux/pm.h       |    2 +-
 include/linux/pm_qos.h   |    4 ++++
 3 files changed, 27 insertions(+), 21 deletions(-)

Index: linux/include/linux/pm.h
===================================================================
--- linux.orig/include/linux/pm.h
+++ linux/include/linux/pm.h
@@ -551,7 +551,7 @@ struct dev_pm_info {
 	struct dev_pm_qos_request *pq_req;
 #endif
 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
-	struct pm_qos_constraints *constraints;
+	struct dev_pm_qos	*qos;
 };
 
 extern void update_pm_runtime_accounting(struct device *dev);
Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -57,6 +57,10 @@ struct pm_qos_constraints {
 	struct blocking_notifier_head *notifiers;
 };
 
+struct dev_pm_qos {
+	struct pm_qos_constraints latency;
+};
+
 /* Action requested to pm_qos_update_target */
 enum pm_qos_req_action {
 	PM_QOS_ADD_REQ,		/* Add a new request */
Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -55,9 +55,7 @@ static BLOCKING_NOTIFIER_HEAD(dev_pm_not
  */
 s32 __dev_pm_qos_read_value(struct device *dev)
 {
-	struct pm_qos_constraints *c = dev->power.constraints;
-
-	return c ? pm_qos_read_value(c) : 0;
+	return dev->power.qos ? pm_qos_read_value(&dev->power.qos->latency) : 0;
 }
 
 /**
@@ -91,12 +89,12 @@ static int apply_constraint(struct dev_p
 {
 	int ret, curr_value;
 
-	ret = pm_qos_update_target(req->dev->power.constraints,
+	ret = pm_qos_update_target(&req->dev->power.qos->latency,
 				   &req->node, action, value);
 
 	if (ret) {
 		/* Call the global callbacks if needed */
-		curr_value = pm_qos_read_value(req->dev->power.constraints);
+		curr_value = pm_qos_read_value(&req->dev->power.qos->latency);
 		blocking_notifier_call_chain(&dev_pm_notifiers,
 					     (unsigned long)curr_value,
 					     req);
@@ -114,20 +112,22 @@ static int apply_constraint(struct dev_p
  */
 static int dev_pm_qos_constraints_allocate(struct device *dev)
 {
+	struct dev_pm_qos *qos;
 	struct pm_qos_constraints *c;
 	struct blocking_notifier_head *n;
 
-	c = kzalloc(sizeof(*c), GFP_KERNEL);
-	if (!c)
+	qos = kzalloc(sizeof(*qos), GFP_KERNEL);
+	if (!qos)
 		return -ENOMEM;
 
 	n = kzalloc(sizeof(*n), GFP_KERNEL);
 	if (!n) {
-		kfree(c);
+		kfree(qos);
 		return -ENOMEM;
 	}
 	BLOCKING_INIT_NOTIFIER_HEAD(n);
 
+	c = &qos->latency;
 	plist_head_init(&c->list);
 	c->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
 	c->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
@@ -135,7 +135,7 @@ static int dev_pm_qos_constraints_alloca
 	c->notifiers = n;
 
 	spin_lock_irq(&dev->power.lock);
-	dev->power.constraints = c;
+	dev->power.qos = qos;
 	spin_unlock_irq(&dev->power.lock);
 
 	return 0;
@@ -151,7 +151,7 @@ static int dev_pm_qos_constraints_alloca
 void dev_pm_qos_constraints_init(struct device *dev)
 {
 	mutex_lock(&dev_pm_qos_mtx);
-	dev->power.constraints = NULL;
+	dev->power.qos = NULL;
 	dev->power.power_state = PMSG_ON;
 	mutex_unlock(&dev_pm_qos_mtx);
 }
@@ -164,6 +164,7 @@ void dev_pm_qos_constraints_init(struct
  */
 void dev_pm_qos_constraints_destroy(struct device *dev)
 {
+	struct dev_pm_qos *qos;
 	struct dev_pm_qos_request *req, *tmp;
 	struct pm_qos_constraints *c;
 
@@ -176,10 +177,11 @@ void dev_pm_qos_constraints_destroy(stru
 	mutex_lock(&dev_pm_qos_mtx);
 
 	dev->power.power_state = PMSG_INVALID;
-	c = dev->power.constraints;
-	if (!c)
+	qos = dev->power.qos;
+	if (!qos)
 		goto out;
 
+	c = &qos->latency;
 	/* Flush the constraints list for the device */
 	plist_for_each_entry_safe(req, tmp, &c->list, node) {
 		/*
@@ -191,7 +193,7 @@ void dev_pm_qos_constraints_destroy(stru
 	}
 
 	spin_lock_irq(&dev->power.lock);
-	dev->power.constraints = NULL;
+	dev->power.qos = NULL;
 	spin_unlock_irq(&dev->power.lock);
 
 	kfree(c->notifiers);
@@ -235,7 +237,7 @@ int dev_pm_qos_add_request(struct device
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (!dev->power.constraints) {
+	if (!dev->power.qos) {
 		if (dev->power.power_state.event == PM_EVENT_INVALID) {
 			/* The device has been removed from the system. */
 			req->dev = NULL;
@@ -290,7 +292,7 @@ int dev_pm_qos_update_request(struct dev
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (req->dev->power.constraints) {
+	if (req->dev->power.qos) {
 		if (new_value != req->node.prio)
 			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
 					       new_value);
@@ -329,7 +331,7 @@ int dev_pm_qos_remove_request(struct dev
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (req->dev->power.constraints) {
+	if (req->dev->power.qos) {
 		ret = apply_constraint(req, PM_QOS_REMOVE_REQ,
 				       PM_QOS_DEFAULT_VALUE);
 		memset(req, 0, sizeof(*req));
@@ -362,13 +364,13 @@ int dev_pm_qos_add_notifier(struct devic
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (!dev->power.constraints)
+	if (!dev->power.qos)
 		ret = dev->power.power_state.event != PM_EVENT_INVALID ?
 			dev_pm_qos_constraints_allocate(dev) : -ENODEV;
 
 	if (!ret)
 		ret = blocking_notifier_chain_register(
-				dev->power.constraints->notifiers, notifier);
+				dev->power.qos->latency.notifiers, notifier);
 
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
@@ -393,9 +395,9 @@ int dev_pm_qos_remove_notifier(struct de
 	mutex_lock(&dev_pm_qos_mtx);
 
 	/* Silently return if the constraints object is not present. */
-	if (dev->power.constraints)
+	if (dev->power.qos)
 		retval = blocking_notifier_chain_unregister(
-				dev->power.constraints->notifiers,
+				dev->power.qos->latency.notifiers,
 				notifier);
 
 	mutex_unlock(&dev_pm_qos_mtx);

Re: [PATCH 1/7] PM / QoS: Prepare device structure for adding more constraint types

[mark gross]

On Mon, Oct 08, 2012 at 10:04:03AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Currently struct dev_pm_info contains only one PM QoS constraints
> pointer reserved for latency requirements.  Since one more device
> constraints type (i.e. flags) will be necessary, introduce a new
> structure, struct dev_pm_qos, that eventually will contain all of
> the available device PM QoS constraints and replace the "constraints"
> pointer in struct dev_pm_info with a pointer to the new structure
> called "qos".
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
>  drivers/base/power/qos.c |   42 ++++++++++++++++++++++--------------------
>  include/linux/pm.h       |    2 +-
>  include/linux/pm_qos.h   |    4 ++++
>  3 files changed, 27 insertions(+), 21 deletions(-)
> 
> Index: linux/include/linux/pm.h
> ===================================================================
> --- linux.orig/include/linux/pm.h
> +++ linux/include/linux/pm.h
> @@ -551,7 +551,7 @@ struct dev_pm_info {
>  	struct dev_pm_qos_request *pq_req;
>  #endif
>  	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
> -	struct pm_qos_constraints *constraints;
> +	struct dev_pm_qos	*qos;
>  };
>  
>  extern void update_pm_runtime_accounting(struct device *dev);
> Index: linux/include/linux/pm_qos.h
> ===================================================================
> --- linux.orig/include/linux/pm_qos.h
> +++ linux/include/linux/pm_qos.h
> @@ -57,6 +57,10 @@ struct pm_qos_constraints {
>  	struct blocking_notifier_head *notifiers;
>  };
>  
> +struct dev_pm_qos {
> +	struct pm_qos_constraints latency;
What about non-latency constraints?  This pretty much makes it explicit
that dev_pm_qos is all about latency.  from the commit comment I thought
you where trying to make it more genaric.  Why not call "latency"
"constraint" or something less specific?

--mark

> +};
> +
>  /* Action requested to pm_qos_update_target */
>  enum pm_qos_req_action {
>  	PM_QOS_ADD_REQ,		/* Add a new request */
> Index: linux/drivers/base/power/qos.c
> ===================================================================
> --- linux.orig/drivers/base/power/qos.c
> +++ linux/drivers/base/power/qos.c
> @@ -55,9 +55,7 @@ static BLOCKING_NOTIFIER_HEAD(dev_pm_not
>   */
>  s32 __dev_pm_qos_read_value(struct device *dev)
>  {
> -	struct pm_qos_constraints *c = dev->power.constraints;
> -
> -	return c ? pm_qos_read_value(c) : 0;
> +	return dev->power.qos ? pm_qos_read_value(&dev->power.qos->latency) : 0;
>  }
>  
>  /**
> @@ -91,12 +89,12 @@ static int apply_constraint(struct dev_p
>  {
>  	int ret, curr_value;
>  
> -	ret = pm_qos_update_target(req->dev->power.constraints,
> +	ret = pm_qos_update_target(&req->dev->power.qos->latency,
>  				   &req->node, action, value);
>  
>  	if (ret) {
>  		/* Call the global callbacks if needed */
> -		curr_value = pm_qos_read_value(req->dev->power.constraints);
> +		curr_value = pm_qos_read_value(&req->dev->power.qos->latency);
>  		blocking_notifier_call_chain(&dev_pm_notifiers,
>  					     (unsigned long)curr_value,
>  					     req);
> @@ -114,20 +112,22 @@ static int apply_constraint(struct dev_p
>   */
>  static int dev_pm_qos_constraints_allocate(struct device *dev)
>  {
> +	struct dev_pm_qos *qos;
>  	struct pm_qos_constraints *c;
>  	struct blocking_notifier_head *n;
>  
> -	c = kzalloc(sizeof(*c), GFP_KERNEL);
> -	if (!c)
> +	qos = kzalloc(sizeof(*qos), GFP_KERNEL);
> +	if (!qos)
>  		return -ENOMEM;
>  
>  	n = kzalloc(sizeof(*n), GFP_KERNEL);
>  	if (!n) {
> -		kfree(c);
> +		kfree(qos);
>  		return -ENOMEM;
>  	}
>  	BLOCKING_INIT_NOTIFIER_HEAD(n);
>  
> +	c = &qos->latency;
>  	plist_head_init(&c->list);
>  	c->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
>  	c->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE;
> @@ -135,7 +135,7 @@ static int dev_pm_qos_constraints_alloca
>  	c->notifiers = n;
>  
>  	spin_lock_irq(&dev->power.lock);
> -	dev->power.constraints = c;
> +	dev->power.qos = qos;
>  	spin_unlock_irq(&dev->power.lock);
>  
>  	return 0;
> @@ -151,7 +151,7 @@ static int dev_pm_qos_constraints_alloca
>  void dev_pm_qos_constraints_init(struct device *dev)
>  {
>  	mutex_lock(&dev_pm_qos_mtx);
> -	dev->power.constraints = NULL;
> +	dev->power.qos = NULL;
>  	dev->power.power_state = PMSG_ON;
>  	mutex_unlock(&dev_pm_qos_mtx);
>  }
> @@ -164,6 +164,7 @@ void dev_pm_qos_constraints_init(struct
>   */
>  void dev_pm_qos_constraints_destroy(struct device *dev)
>  {
> +	struct dev_pm_qos *qos;
>  	struct dev_pm_qos_request *req, *tmp;
>  	struct pm_qos_constraints *c;
>  
> @@ -176,10 +177,11 @@ void dev_pm_qos_constraints_destroy(stru
>  	mutex_lock(&dev_pm_qos_mtx);
>  
>  	dev->power.power_state = PMSG_INVALID;
> -	c = dev->power.constraints;
> -	if (!c)
> +	qos = dev->power.qos;
> +	if (!qos)
>  		goto out;
>  
> +	c = &qos->latency;
>  	/* Flush the constraints list for the device */
>  	plist_for_each_entry_safe(req, tmp, &c->list, node) {
>  		/*
> @@ -191,7 +193,7 @@ void dev_pm_qos_constraints_destroy(stru
>  	}
>  
>  	spin_lock_irq(&dev->power.lock);
> -	dev->power.constraints = NULL;
> +	dev->power.qos = NULL;
>  	spin_unlock_irq(&dev->power.lock);
>  
>  	kfree(c->notifiers);
> @@ -235,7 +237,7 @@ int dev_pm_qos_add_request(struct device
>  
>  	mutex_lock(&dev_pm_qos_mtx);
>  
> -	if (!dev->power.constraints) {
> +	if (!dev->power.qos) {
>  		if (dev->power.power_state.event == PM_EVENT_INVALID) {
>  			/* The device has been removed from the system. */
>  			req->dev = NULL;
> @@ -290,7 +292,7 @@ int dev_pm_qos_update_request(struct dev
>  
>  	mutex_lock(&dev_pm_qos_mtx);
>  
> -	if (req->dev->power.constraints) {
> +	if (req->dev->power.qos) {
>  		if (new_value != req->node.prio)
>  			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
>  					       new_value);
> @@ -329,7 +331,7 @@ int dev_pm_qos_remove_request(struct dev
>  
>  	mutex_lock(&dev_pm_qos_mtx);
>  
> -	if (req->dev->power.constraints) {
> +	if (req->dev->power.qos) {
>  		ret = apply_constraint(req, PM_QOS_REMOVE_REQ,
>  				       PM_QOS_DEFAULT_VALUE);
>  		memset(req, 0, sizeof(*req));
> @@ -362,13 +364,13 @@ int dev_pm_qos_add_notifier(struct devic
>  
>  	mutex_lock(&dev_pm_qos_mtx);
>  
> -	if (!dev->power.constraints)
> +	if (!dev->power.qos)
>  		ret = dev->power.power_state.event != PM_EVENT_INVALID ?
>  			dev_pm_qos_constraints_allocate(dev) : -ENODEV;
>  
>  	if (!ret)
>  		ret = blocking_notifier_chain_register(
> -				dev->power.constraints->notifiers, notifier);
> +				dev->power.qos->latency.notifiers, notifier);
>  
>  	mutex_unlock(&dev_pm_qos_mtx);
>  	return ret;
> @@ -393,9 +395,9 @@ int dev_pm_qos_remove_notifier(struct de
>  	mutex_lock(&dev_pm_qos_mtx);
>  
>  	/* Silently return if the constraints object is not present. */
> -	if (dev->power.constraints)
> +	if (dev->power.qos)
>  		retval = blocking_notifier_chain_unregister(
> -				dev->power.constraints->notifiers,
> +				dev->power.qos->latency.notifiers,
>  				notifier);
>  
>  	mutex_unlock(&dev_pm_qos_mtx);
> 

Re: [PATCH 1/7] PM / QoS: Prepare device structure for adding more constraint types

[Rafael J. Wysocki]

On Tuesday 09 of October 2012 20:15:47 mark gross wrote:
> On Mon, Oct 08, 2012 at 10:04:03AM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > 
> > Currently struct dev_pm_info contains only one PM QoS constraints
> > pointer reserved for latency requirements.  Since one more device
> > constraints type (i.e. flags) will be necessary, introduce a new
> > structure, struct dev_pm_qos, that eventually will contain all of
> > the available device PM QoS constraints and replace the "constraints"
> > pointer in struct dev_pm_info with a pointer to the new structure
> > called "qos".
> > 
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > Reviewed-by: Jean Pihet <j-pihet@ti.com>
> > ---
> >  drivers/base/power/qos.c |   42 ++++++++++++++++++++++--------------------
> >  include/linux/pm.h       |    2 +-
> >  include/linux/pm_qos.h   |    4 ++++
> >  3 files changed, 27 insertions(+), 21 deletions(-)
> > 
> > Index: linux/include/linux/pm.h
> > ===================================================================
> > --- linux.orig/include/linux/pm.h
> > +++ linux/include/linux/pm.h
> > @@ -551,7 +551,7 @@ struct dev_pm_info {
> >  	struct dev_pm_qos_request *pq_req;
> >  #endif
> >  	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
> > -	struct pm_qos_constraints *constraints;
> > +	struct dev_pm_qos	*qos;
> >  };
> >  
> >  extern void update_pm_runtime_accounting(struct device *dev);
> > Index: linux/include/linux/pm_qos.h
> > ===================================================================
> > --- linux.orig/include/linux/pm_qos.h
> > +++ linux/include/linux/pm_qos.h
> > @@ -57,6 +57,10 @@ struct pm_qos_constraints {
> >  	struct blocking_notifier_head *notifiers;
> >  };
> >  
> > +struct dev_pm_qos {
> > +	struct pm_qos_constraints latency;
> What about non-latency constraints?  This pretty much makes it explicit
> that dev_pm_qos is all about latency.  from the commit comment I thought
> you where trying to make it more genaric.  Why not call "latency"
> "constraint" or something less specific?

Please see the next patches in the series that add one more constraint type.

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

[PATCH 2/7] PM / QoS: Introduce request and constraint data types for PM QoS flags

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Introduce struct pm_qos_flags_request and struct pm_qos_flags
representing PM QoS flags request type and PM QoS flags constraint
type, respectively.  With these definitions the data structures
will be arranged so that the list member of a struct pm_qos_flags
object will contain the head of a list of struct pm_qos_flags_request
objects representing all of the "flags" requests present for the
given device.  Then, the effective_flags member of a struct
pm_qos_flags object will contain the bitwise OR of the flags members
of all the struct pm_qos_flags_request objects in the list.

Additionally, introduce helper function pm_qos_update_flags()
allowing the caller to manage the list of struct pm_qos_flags_request
pointed to by the list member of struct pm_qos_flags.

The flags are of type s32 so that the request's "value" field
is always of the same type regardless of what kind of request it
is (latency requests already have value fields of type s32).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
---
 include/linux/pm_qos.h |   17 +++++++++++--
 kernel/power/qos.c     |   63 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 2 deletions(-)

Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -33,6 +33,11 @@ struct pm_qos_request {
 	struct delayed_work work; /* for pm_qos_update_request_timeout */
 };
 
+struct pm_qos_flags_request {
+	struct list_head node;
+	s32 flags;	/* Do not change to 64 bit */
+};
+
 struct dev_pm_qos_request {
 	struct plist_node node;
 	struct device *dev;
@@ -45,8 +50,8 @@ enum pm_qos_type {
 };
 
 /*
- * Note: The lockless read path depends on the CPU accessing
- * target_value atomically.  Atomic access is only guaranteed on all CPU
+ * Note: The lockless read path depends on the CPU accessing target_value
+ * or effective_flags atomically.  Atomic access is only guaranteed on all CPU
  * types linux supports for 32 bit quantites
  */
 struct pm_qos_constraints {
@@ -57,6 +62,11 @@ struct pm_qos_constraints {
 	struct blocking_notifier_head *notifiers;
 };
 
+struct pm_qos_flags {
+	struct list_head list;
+	s32 effective_flags;	/* Do not change to 64 bit */
+};
+
 struct dev_pm_qos {
 	struct pm_qos_constraints latency;
 };
@@ -75,6 +85,9 @@ static inline int dev_pm_qos_request_act
 
 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 			 enum pm_qos_req_action action, int value);
+bool pm_qos_update_flags(struct pm_qos_flags *pqf,
+			 struct pm_qos_flags_request *req,
+			 enum pm_qos_req_action action, s32 val);
 void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
 			s32 value);
 void pm_qos_update_request(struct pm_qos_request *req,
Index: linux/kernel/power/qos.c
===================================================================
--- linux.orig/kernel/power/qos.c
+++ linux/kernel/power/qos.c
@@ -213,6 +213,69 @@ int pm_qos_update_target(struct pm_qos_c
 }
 
 /**
+ * pm_qos_flags_remove_req - Remove device PM QoS flags request.
+ * @pqf: Device PM QoS flags set to remove the request from.
+ * @req: Request to remove from the set.
+ */
+static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
+				    struct pm_qos_flags_request *req)
+{
+	s32 val = 0;
+
+	list_del(&req->node);
+	list_for_each_entry(req, &pqf->list, node)
+		val |= req->flags;
+
+	pqf->effective_flags = val;
+}
+
+/**
+ * pm_qos_update_flags - Update a set of PM QoS flags.
+ * @pqf: Set of flags to update.
+ * @req: Request to add to the set, to modify, or to remove from the set.
+ * @action: Action to take on the set.
+ * @val: Value of the request to add or modify.
+ *
+ * Update the given set of PM QoS flags and call notifiers if the aggregate
+ * value has changed.  Returns 1 if the aggregate constraint value has changed,
+ * 0 otherwise.
+ */
+bool pm_qos_update_flags(struct pm_qos_flags *pqf,
+			 struct pm_qos_flags_request *req,
+			 enum pm_qos_req_action action, s32 val)
+{
+	unsigned long irqflags;
+	s32 prev_value, curr_value;
+
+	spin_lock_irqsave(&pm_qos_lock, irqflags);
+
+	prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+	switch (action) {
+	case PM_QOS_REMOVE_REQ:
+		pm_qos_flags_remove_req(pqf, req);
+		break;
+	case PM_QOS_UPDATE_REQ:
+		pm_qos_flags_remove_req(pqf, req);
+	case PM_QOS_ADD_REQ:
+		req->flags = val;
+		INIT_LIST_HEAD(&req->node);
+		list_add_tail(&req->node, &pqf->list);
+		pqf->effective_flags |= val;
+		break;
+	default:
+		/* no action */
+		;
+	}
+
+	curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+	spin_unlock_irqrestore(&pm_qos_lock, irqflags);
+
+	return prev_value != curr_value;
+}
+
+/**
  * pm_qos_request - returns current system wide qos expectation
  * @pm_qos_class: identification of which qos value is requested
  *

Re: [PATCH 2/7] PM / QoS: Introduce request and constraint data types for PM QoS flags

[mark gross]

On Mon, Oct 08, 2012 at 10:05:07AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Introduce struct pm_qos_flags_request and struct pm_qos_flags
> representing PM QoS flags request type and PM QoS flags constraint
> type, respectively.  With these definitions the data structures
> will be arranged so that the list member of a struct pm_qos_flags
> object will contain the head of a list of struct pm_qos_flags_request
> objects representing all of the "flags" requests present for the
> given device.  Then, the effective_flags member of a struct
> pm_qos_flags object will contain the bitwise OR of the flags members
> of all the struct pm_qos_flags_request objects in the list.
> 
> Additionally, introduce helper function pm_qos_update_flags()
> allowing the caller to manage the list of struct pm_qos_flags_request
> pointed to by the list member of struct pm_qos_flags.
> 
> The flags are of type s32 so that the request's "value" field
> is always of the same type regardless of what kind of request it
> is (latency requests already have value fields of type s32).
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
>  include/linux/pm_qos.h |   17 +++++++++++--
>  kernel/power/qos.c     |   63 +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 78 insertions(+), 2 deletions(-)
> 
> Index: linux/include/linux/pm_qos.h
> ===================================================================
> --- linux.orig/include/linux/pm_qos.h
> +++ linux/include/linux/pm_qos.h
> @@ -33,6 +33,11 @@ struct pm_qos_request {
>  	struct delayed_work work; /* for pm_qos_update_request_timeout */
>  };
>  
> +struct pm_qos_flags_request {
> +	struct list_head node;
> +	s32 flags;	/* Do not change to 64 bit */
> +};
> +
>  struct dev_pm_qos_request {
>  	struct plist_node node;
>  	struct device *dev;
> @@ -45,8 +50,8 @@ enum pm_qos_type {
>  };
>  
>  /*
> - * Note: The lockless read path depends on the CPU accessing
> - * target_value atomically.  Atomic access is only guaranteed on all CPU
> + * Note: The lockless read path depends on the CPU accessing target_value
> + * or effective_flags atomically.  Atomic access is only guaranteed on all CPU
>   * types linux supports for 32 bit quantites
>   */
>  struct pm_qos_constraints {
> @@ -57,6 +62,11 @@ struct pm_qos_constraints {
>  	struct blocking_notifier_head *notifiers;
>  };
>  
> +struct pm_qos_flags {
> +	struct list_head list;
> +	s32 effective_flags;	/* Do not change to 64 bit */
> +};
> +
>  struct dev_pm_qos {
>  	struct pm_qos_constraints latency;
>  };
> @@ -75,6 +85,9 @@ static inline int dev_pm_qos_request_act
>  
>  int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
>  			 enum pm_qos_req_action action, int value);
> +bool pm_qos_update_flags(struct pm_qos_flags *pqf,
> +			 struct pm_qos_flags_request *req,
> +			 enum pm_qos_req_action action, s32 val);
>  void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
>  			s32 value);
>  void pm_qos_update_request(struct pm_qos_request *req,
> Index: linux/kernel/power/qos.c
> ===================================================================
> --- linux.orig/kernel/power/qos.c
> +++ linux/kernel/power/qos.c
> @@ -213,6 +213,69 @@ int pm_qos_update_target(struct pm_qos_c
>  }
>  
>  /**
> + * pm_qos_flags_remove_req - Remove device PM QoS flags request.
> + * @pqf: Device PM QoS flags set to remove the request from.
> + * @req: Request to remove from the set.
> + */
> +static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
> +				    struct pm_qos_flags_request *req)
> +{
> +	s32 val = 0;
> +
> +	list_del(&req->node);
> +	list_for_each_entry(req, &pqf->list, node)
> +		val |= req->flags;
> +
> +	pqf->effective_flags = val;
> +}
> +
> +/**
> + * pm_qos_update_flags - Update a set of PM QoS flags.
> + * @pqf: Set of flags to update.
> + * @req: Request to add to the set, to modify, or to remove from the set.
> + * @action: Action to take on the set.
> + * @val: Value of the request to add or modify.
> + *
> + * Update the given set of PM QoS flags and call notifiers if the aggregate
> + * value has changed.  Returns 1 if the aggregate constraint value has changed,
> + * 0 otherwise.
> + */
> +bool pm_qos_update_flags(struct pm_qos_flags *pqf,
> +			 struct pm_qos_flags_request *req,
> +			 enum pm_qos_req_action action, s32 val)
> +{
> +	unsigned long irqflags;
> +	s32 prev_value, curr_value;
> +
> +	spin_lock_irqsave(&pm_qos_lock, irqflags);
> +
> +	prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
> +
> +	switch (action) {
> +	case PM_QOS_REMOVE_REQ:
> +		pm_qos_flags_remove_req(pqf, req);
> +		break;
> +	case PM_QOS_UPDATE_REQ:
> +		pm_qos_flags_remove_req(pqf, req);
> +	case PM_QOS_ADD_REQ:
> +		req->flags = val;
> +		INIT_LIST_HEAD(&req->node);
> +		list_add_tail(&req->node, &pqf->list);
> +		pqf->effective_flags |= val;
> +		break;
> +	default:
> +		/* no action */
> +		;
> +	}
> +
> +	curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
> +
> +	spin_unlock_irqrestore(&pm_qos_lock, irqflags);
> +
> +	return prev_value != curr_value;
> +}
> +
> +/**
>   * pm_qos_request - returns current system wide qos expectation
>   * @pm_qos_class: identification of which qos value is requested
>   *
> 

acked-by: mark gross <markgross@thegnar.org>
--mark

[PATCH 3/7] PM / QoS: Prepare struct dev_pm_qos_request for more request types

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The subsequent patches will use struct dev_pm_qos_request for
representing both latency requests and flags requests.  To make that
easier, put the node member of struct dev_pm_qos_request (under the
name "pnode") into a union called "data" that will represent the
request's  value and list node depending on its type.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
---
 drivers/base/power/qos.c   |    6 +++---
 drivers/base/power/sysfs.c |    2 +-
 include/linux/pm_qos.h     |    4 +++-
 3 files changed, 7 insertions(+), 5 deletions(-)

Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -39,7 +39,9 @@ struct pm_qos_flags_request {
 };
 
 struct dev_pm_qos_request {
-	struct plist_node node;
+	union {
+		struct plist_node pnode;
+	} data;
 	struct device *dev;
 };
 
Index: linux/drivers/base/power/sysfs.c
===================================================================
--- linux.orig/drivers/base/power/sysfs.c
+++ linux/drivers/base/power/sysfs.c
@@ -221,7 +221,7 @@ static DEVICE_ATTR(autosuspend_delay_ms,
 static ssize_t pm_qos_latency_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", dev->power.pq_req->node.prio);
+	return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
 }
 
 static ssize_t pm_qos_latency_store(struct device *dev,
Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -90,7 +90,7 @@ static int apply_constraint(struct dev_p
 	int ret, curr_value;
 
 	ret = pm_qos_update_target(&req->dev->power.qos->latency,
-				   &req->node, action, value);
+				   &req->data.pnode, action, value);
 
 	if (ret) {
 		/* Call the global callbacks if needed */
@@ -183,7 +183,7 @@ void dev_pm_qos_constraints_destroy(stru
 
 	c = &qos->latency;
 	/* Flush the constraints list for the device */
-	plist_for_each_entry_safe(req, tmp, &c->list, node) {
+	plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
 		/*
 		 * Update constraints list and call the notification
 		 * callbacks if needed
@@ -293,7 +293,7 @@ int dev_pm_qos_update_request(struct dev
 	mutex_lock(&dev_pm_qos_mtx);
 
 	if (req->dev->power.qos) {
-		if (new_value != req->node.prio)
+		if (new_value != req->data.pnode.prio)
 			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
 					       new_value);
 	} else {

Re: [PATCH 3/7] PM / QoS: Prepare struct dev_pm_qos_request for more request types

[mark gross]

On Mon, Oct 08, 2012 at 10:06:08AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> The subsequent patches will use struct dev_pm_qos_request for
> representing both latency requests and flags requests.  To make that
> easier, put the node member of struct dev_pm_qos_request (under the
> name "pnode") into a union called "data" that will represent the
> request's  value and list node depending on its type.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
>  drivers/base/power/qos.c   |    6 +++---
>  drivers/base/power/sysfs.c |    2 +-
>  include/linux/pm_qos.h     |    4 +++-
>  3 files changed, 7 insertions(+), 5 deletions(-)
> 
> Index: linux/include/linux/pm_qos.h
> ===================================================================
> --- linux.orig/include/linux/pm_qos.h
> +++ linux/include/linux/pm_qos.h
> @@ -39,7 +39,9 @@ struct pm_qos_flags_request {
>  };
>  
>  struct dev_pm_qos_request {
> -	struct plist_node node;
> +	union {
> +		struct plist_node pnode;
> +	} data;
>  	struct device *dev;
>  };
>  
> Index: linux/drivers/base/power/sysfs.c
> ===================================================================
> --- linux.orig/drivers/base/power/sysfs.c
> +++ linux/drivers/base/power/sysfs.c
> @@ -221,7 +221,7 @@ static DEVICE_ATTR(autosuspend_delay_ms,
>  static ssize_t pm_qos_latency_show(struct device *dev,
>  				   struct device_attribute *attr, char *buf)
>  {
> -	return sprintf(buf, "%d\n", dev->power.pq_req->node.prio);
> +	return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
>  }
>  
>  static ssize_t pm_qos_latency_store(struct device *dev,
> Index: linux/drivers/base/power/qos.c
> ===================================================================
> --- linux.orig/drivers/base/power/qos.c
> +++ linux/drivers/base/power/qos.c
> @@ -90,7 +90,7 @@ static int apply_constraint(struct dev_p
>  	int ret, curr_value;
>  
>  	ret = pm_qos_update_target(&req->dev->power.qos->latency,
> -				   &req->node, action, value);
> +				   &req->data.pnode, action, value);
>  
>  	if (ret) {
>  		/* Call the global callbacks if needed */
> @@ -183,7 +183,7 @@ void dev_pm_qos_constraints_destroy(stru
>  
>  	c = &qos->latency;
>  	/* Flush the constraints list for the device */
> -	plist_for_each_entry_safe(req, tmp, &c->list, node) {
> +	plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
>  		/*
>  		 * Update constraints list and call the notification
>  		 * callbacks if needed
> @@ -293,7 +293,7 @@ int dev_pm_qos_update_request(struct dev
>  	mutex_lock(&dev_pm_qos_mtx);
>  
>  	if (req->dev->power.qos) {
> -		if (new_value != req->node.prio)
> +		if (new_value != req->data.pnode.prio)
>  			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
>  					       new_value);
>  	} else {
> 
Reviewed-by: mark gross <markgross@thegnar.org>

[PATCH 4/7] PM / QoS: Introduce PM QoS device flags support

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify the device PM QoS core code to support PM QoS flags requests.

First, add a new field of type struct pm_qos_flags called "flags"
to struct dev_pm_qos for representing the list of PM QoS flags
requests for the given device.  Accordingly, add a new "type" field
to struct dev_pm_qos_request (along with an enum for representing
request types) and a new member called "flr" to its data union for
representig flags requests.

Second, modify dev_pm_qos_add_request(), dev_pm_qos_update_request(),
the internal routine apply_constraint() used by them and their
existing callers to cover flags requests as well as latency
requests.  In particular, dev_pm_qos_add_request() gets a new
argument called "type" for specifying the type of a request to be
added.

Finally, introduce two routines, __dev_pm_qos_flags() and
dev_pm_qos_flags(), allowing their callers to check which PM QoS
flags have been requested for the given device (the caller is
supposed to pass the mask of flags to check as the routine's
second argument and examine its return value for the result).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
---
 Documentation/power/pm_qos_interface.txt |    2 
 drivers/base/power/qos.c                 |  124 ++++++++++++++++++++++++-------
 drivers/mtd/nand/sh_flctl.c              |    4 -
 include/linux/pm_qos.h                   |   26 ++++++
 4 files changed, 127 insertions(+), 29 deletions(-)

Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -48,6 +48,50 @@ static DEFINE_MUTEX(dev_pm_qos_mtx);
 static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
 
 /**
+ * __dev_pm_qos_flags - Check PM QoS flags for a given device.
+ * @dev: Device to check the PM QoS flags for.
+ * @mask: Flags to check against.
+ *
+ * This routine must be called with dev->power.lock held.
+ */
+enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask)
+{
+	struct dev_pm_qos *qos = dev->power.qos;
+	struct pm_qos_flags *pqf;
+	s32 val;
+
+	if (!qos)
+		return PM_QOS_FLAGS_UNDEFINED;
+
+	pqf = &qos->flags;
+	if (list_empty(&pqf->list))
+		return PM_QOS_FLAGS_UNDEFINED;
+
+	val = pqf->effective_flags & mask;
+	if (val)
+		return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME;
+
+	return PM_QOS_FLAGS_NONE;
+}
+
+/**
+ * dev_pm_qos_flags - Check PM QoS flags for a given device (locked).
+ * @dev: Device to check the PM QoS flags for.
+ * @mask: Flags to check against.
+ */
+enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask)
+{
+	unsigned long irqflags;
+	enum pm_qos_flags_status ret;
+
+	spin_lock_irqsave(&dev->power.lock, irqflags);
+	ret = __dev_pm_qos_flags(dev, mask);
+	spin_unlock_irqrestore(&dev->power.lock, irqflags);
+
+	return ret;
+}
+
+/**
  * __dev_pm_qos_read_value - Get PM QoS constraint for a given device.
  * @dev: Device to get the PM QoS constraint value for.
  *
@@ -74,30 +118,39 @@ s32 dev_pm_qos_read_value(struct device
 	return ret;
 }
 
-/*
- * apply_constraint
- * @req: constraint request to apply
- * @action: action to perform add/update/remove, of type enum pm_qos_req_action
- * @value: defines the qos request
+/**
+ * apply_constraint - Add/modify/remove device PM QoS request.
+ * @req: Constraint request to apply
+ * @action: Action to perform (add/update/remove).
+ * @value: Value to assign to the QoS request.
  *
  * Internal function to update the constraints list using the PM QoS core
  * code and if needed call the per-device and the global notification
  * callbacks
  */
 static int apply_constraint(struct dev_pm_qos_request *req,
-			    enum pm_qos_req_action action, int value)
+			    enum pm_qos_req_action action, s32 value)
 {
-	int ret, curr_value;
-
-	ret = pm_qos_update_target(&req->dev->power.qos->latency,
-				   &req->data.pnode, action, value);
+	struct dev_pm_qos *qos = req->dev->power.qos;
+	int ret;
 
-	if (ret) {
-		/* Call the global callbacks if needed */
-		curr_value = pm_qos_read_value(&req->dev->power.qos->latency);
-		blocking_notifier_call_chain(&dev_pm_notifiers,
-					     (unsigned long)curr_value,
-					     req);
+	switch(req->type) {
+	case DEV_PM_QOS_LATENCY:
+		ret = pm_qos_update_target(&qos->latency, &req->data.pnode,
+					   action, value);
+		if (ret) {
+			value = pm_qos_read_value(&qos->latency);
+			blocking_notifier_call_chain(&dev_pm_notifiers,
+						     (unsigned long)value,
+						     req);
+		}
+		break;
+	case DEV_PM_QOS_FLAGS:
+		ret = pm_qos_update_flags(&qos->flags, &req->data.flr,
+					  action, value);
+		break;
+	default:
+		ret = -EINVAL;
 	}
 
 	return ret;
@@ -134,6 +187,8 @@ static int dev_pm_qos_constraints_alloca
 	c->type = PM_QOS_MIN;
 	c->notifiers = n;
 
+	INIT_LIST_HEAD(&qos->flags.list);
+
 	spin_lock_irq(&dev->power.lock);
 	dev->power.qos = qos;
 	spin_unlock_irq(&dev->power.lock);
@@ -207,6 +262,7 @@ void dev_pm_qos_constraints_destroy(stru
  * dev_pm_qos_add_request - inserts new qos request into the list
  * @dev: target device for the constraint
  * @req: pointer to a preallocated handle
+ * @type: type of the request
  * @value: defines the qos request
  *
  * This function inserts a new entry in the device constraints list of
@@ -222,7 +278,7 @@ void dev_pm_qos_constraints_destroy(stru
  * from the system.
  */
 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
-			   s32 value)
+			   enum dev_pm_qos_req_type type, s32 value)
 {
 	int ret = 0;
 
@@ -253,8 +309,10 @@ int dev_pm_qos_add_request(struct device
 		}
 	}
 
-	if (!ret)
+	if (!ret) {
+		req->type = type;
 		ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
+	}
 
  out:
 	mutex_unlock(&dev_pm_qos_mtx);
@@ -281,6 +339,7 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
 int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 			      s32 new_value)
 {
+	s32 curr_value;
 	int ret = 0;
 
 	if (!req) /*guard against callers passing in null */
@@ -292,15 +351,27 @@ int dev_pm_qos_update_request(struct dev
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (req->dev->power.qos) {
-		if (new_value != req->data.pnode.prio)
-			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
-					       new_value);
-	} else {
-		/* Return if the device has been removed */
+	if (!req->dev->power.qos) {
 		ret = -ENODEV;
+		goto out;
 	}
 
+	switch(req->type) {
+	case DEV_PM_QOS_LATENCY:
+		curr_value = req->data.pnode.prio;
+		break;
+	case DEV_PM_QOS_FLAGS:
+		curr_value = req->data.flr.flags;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (curr_value != new_value)
+		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
+
+ out:
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }
@@ -451,7 +522,8 @@ int dev_pm_qos_add_ancestor_request(stru
 		ancestor = ancestor->parent;
 
 	if (ancestor)
-		error = dev_pm_qos_add_request(ancestor, req, value);
+		error = dev_pm_qos_add_request(ancestor, req,
+					       DEV_PM_QOS_LATENCY, value);
 
 	if (error)
 		req->dev = NULL;
@@ -487,7 +559,7 @@ int dev_pm_qos_expose_latency_limit(stru
 	if (!req)
 		return -ENOMEM;
 
-	ret = dev_pm_qos_add_request(dev, req, value);
+	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY, value);
 	if (ret < 0)
 		return ret;
 
Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -20,6 +20,13 @@ enum {
 	PM_QOS_NUM_CLASSES,
 };
 
+enum pm_qos_flags_status {
+	PM_QOS_FLAGS_UNDEFINED = -1,
+	PM_QOS_FLAGS_NONE,
+	PM_QOS_FLAGS_SOME,
+	PM_QOS_FLAGS_ALL,
+};
+
 #define PM_QOS_DEFAULT_VALUE -1
 
 #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE	(2000 * USEC_PER_SEC)
@@ -38,9 +45,16 @@ struct pm_qos_flags_request {
 	s32 flags;	/* Do not change to 64 bit */
 };
 
+enum dev_pm_qos_req_type {
+	DEV_PM_QOS_LATENCY = 1,
+	DEV_PM_QOS_FLAGS,
+};
+
 struct dev_pm_qos_request {
+	enum dev_pm_qos_req_type type;
 	union {
 		struct plist_node pnode;
+		struct pm_qos_flags_request flr;
 	} data;
 	struct device *dev;
 };
@@ -71,6 +85,7 @@ struct pm_qos_flags {
 
 struct dev_pm_qos {
 	struct pm_qos_constraints latency;
+	struct pm_qos_flags flags;
 };
 
 /* Action requested to pm_qos_update_target */
@@ -105,10 +120,12 @@ int pm_qos_request_active(struct pm_qos_
 s32 pm_qos_read_value(struct pm_qos_constraints *c);
 
 #ifdef CONFIG_PM
+enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
+enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask);
 s32 __dev_pm_qos_read_value(struct device *dev);
 s32 dev_pm_qos_read_value(struct device *dev);
 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
-			   s32 value);
+			   enum dev_pm_qos_req_type type, s32 value);
 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
 int dev_pm_qos_add_notifier(struct device *dev,
@@ -122,12 +139,19 @@ void dev_pm_qos_constraints_destroy(stru
 int dev_pm_qos_add_ancestor_request(struct device *dev,
 				    struct dev_pm_qos_request *req, s32 value);
 #else
+static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
+							  s32 mask)
+			{ return PM_QOS_FLAGS_UNDEFINED; }
+static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
+							s32 mask)
+			{ return PM_QOS_FLAGS_UNDEFINED; }
 static inline s32 __dev_pm_qos_read_value(struct device *dev)
 			{ return 0; }
 static inline s32 dev_pm_qos_read_value(struct device *dev)
 			{ return 0; }
 static inline int dev_pm_qos_add_request(struct device *dev,
 					 struct dev_pm_qos_request *req,
+					 enum dev_pm_qos_req_type type,
 					 s32 value)
 			{ return 0; }
 static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
Index: linux/drivers/mtd/nand/sh_flctl.c
===================================================================
--- linux.orig/drivers/mtd/nand/sh_flctl.c
+++ linux/drivers/mtd/nand/sh_flctl.c
@@ -710,7 +710,9 @@ static void flctl_select_chip(struct mtd
 
 		if (!flctl->qos_request) {
 			ret = dev_pm_qos_add_request(&flctl->pdev->dev,
-							&flctl->pm_qos, 100);
+							&flctl->pm_qos,
+							DEV_PM_QOS_LATENCY,
+							100);
 			if (ret < 0)
 				dev_err(&flctl->pdev->dev,
 					"PM QoS request failed: %d\n", ret);
Index: linux/Documentation/power/pm_qos_interface.txt
===================================================================
--- linux.orig/Documentation/power/pm_qos_interface.txt
+++ linux/Documentation/power/pm_qos_interface.txt
@@ -99,7 +99,7 @@ reading the aggregated value does not re
 
 From kernel mode the use of this interface is the following:
 
-int dev_pm_qos_add_request(device, handle, value):
+int dev_pm_qos_add_request(device, handle, type, value):
 Will insert an element into the list for that identified device with the
 target value.  Upon change to this list the new target is recomputed and any
 registered notifiers are called only if the target value is now different.

Re: [PATCH 4/7] PM / QoS: Introduce PM QoS device flags support

[mark gross]

On Mon, Oct 08, 2012 at 10:07:10AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Modify the device PM QoS core code to support PM QoS flags requests.
> 
> First, add a new field of type struct pm_qos_flags called "flags"
> to struct dev_pm_qos for representing the list of PM QoS flags
> requests for the given device.  Accordingly, add a new "type" field
> to struct dev_pm_qos_request (along with an enum for representing
> request types) and a new member called "flr" to its data union for
> representig flags requests.
> 
> Second, modify dev_pm_qos_add_request(), dev_pm_qos_update_request(),
> the internal routine apply_constraint() used by them and their
> existing callers to cover flags requests as well as latency
> requests.  In particular, dev_pm_qos_add_request() gets a new
> argument called "type" for specifying the type of a request to be
> added.
> 
> Finally, introduce two routines, __dev_pm_qos_flags() and
> dev_pm_qos_flags(), allowing their callers to check which PM QoS
> flags have been requested for the given device (the caller is
> supposed to pass the mask of flags to check as the routine's
> second argument and examine its return value for the result).
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
>  Documentation/power/pm_qos_interface.txt |    2 
>  drivers/base/power/qos.c                 |  124 ++++++++++++++++++++++++-------
>  drivers/mtd/nand/sh_flctl.c              |    4 -
>  include/linux/pm_qos.h                   |   26 ++++++
>  4 files changed, 127 insertions(+), 29 deletions(-)
> 
> Index: linux/drivers/base/power/qos.c
> ===================================================================
> --- linux.orig/drivers/base/power/qos.c
> +++ linux/drivers/base/power/qos.c
> @@ -48,6 +48,50 @@ static DEFINE_MUTEX(dev_pm_qos_mtx);
>  static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
>  
>  /**
> + * __dev_pm_qos_flags - Check PM QoS flags for a given device.
> + * @dev: Device to check the PM QoS flags for.
> + * @mask: Flags to check against.
> + *
> + * This routine must be called with dev->power.lock held.
> + */
> +enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask)
> +{
> +	struct dev_pm_qos *qos = dev->power.qos;
> +	struct pm_qos_flags *pqf;
> +	s32 val;
> +
> +	if (!qos)
> +		return PM_QOS_FLAGS_UNDEFINED;
> +
> +	pqf = &qos->flags;
> +	if (list_empty(&pqf->list))
> +		return PM_QOS_FLAGS_UNDEFINED;
> +
> +	val = pqf->effective_flags & mask;
> +	if (val)
> +		return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME;
> +
> +	return PM_QOS_FLAGS_NONE;
> +}
> +
> +/**
> + * dev_pm_qos_flags - Check PM QoS flags for a given device (locked).
> + * @dev: Device to check the PM QoS flags for.
> + * @mask: Flags to check against.
> + */
> +enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask)
> +{
> +	unsigned long irqflags;
> +	enum pm_qos_flags_status ret;
> +
> +	spin_lock_irqsave(&dev->power.lock, irqflags);
> +	ret = __dev_pm_qos_flags(dev, mask);
> +	spin_unlock_irqrestore(&dev->power.lock, irqflags);
> +
> +	return ret;
> +}
> +
> +/**
>   * __dev_pm_qos_read_value - Get PM QoS constraint for a given device.
>   * @dev: Device to get the PM QoS constraint value for.
>   *
> @@ -74,30 +118,39 @@ s32 dev_pm_qos_read_value(struct device
>  	return ret;
>  }
>  
> -/*
> - * apply_constraint
> - * @req: constraint request to apply
> - * @action: action to perform add/update/remove, of type enum pm_qos_req_action
> - * @value: defines the qos request
> +/**
> + * apply_constraint - Add/modify/remove device PM QoS request.
> + * @req: Constraint request to apply
> + * @action: Action to perform (add/update/remove).
> + * @value: Value to assign to the QoS request.
>   *
>   * Internal function to update the constraints list using the PM QoS core
>   * code and if needed call the per-device and the global notification
>   * callbacks
>   */
>  static int apply_constraint(struct dev_pm_qos_request *req,
> -			    enum pm_qos_req_action action, int value)
> +			    enum pm_qos_req_action action, s32 value)
>  {
> -	int ret, curr_value;
> -
> -	ret = pm_qos_update_target(&req->dev->power.qos->latency,
> -				   &req->data.pnode, action, value);
> +	struct dev_pm_qos *qos = req->dev->power.qos;
> +	int ret;
>  
> -	if (ret) {
> -		/* Call the global callbacks if needed */
> -		curr_value = pm_qos_read_value(&req->dev->power.qos->latency);
> -		blocking_notifier_call_chain(&dev_pm_notifiers,
> -					     (unsigned long)curr_value,
> -					     req);
> +	switch(req->type) {
> +	case DEV_PM_QOS_LATENCY:
> +		ret = pm_qos_update_target(&qos->latency, &req->data.pnode,
> +					   action, value);
> +		if (ret) {
> +			value = pm_qos_read_value(&qos->latency);
> +			blocking_notifier_call_chain(&dev_pm_notifiers,
> +						     (unsigned long)value,
> +						     req);
> +		}
> +		break;
> +	case DEV_PM_QOS_FLAGS:
> +		ret = pm_qos_update_flags(&qos->flags, &req->data.flr,
> +					  action, value);
> +		break;
> +	default:
> +		ret = -EINVAL;
>  	}
>  
>  	return ret;
> @@ -134,6 +187,8 @@ static int dev_pm_qos_constraints_alloca
>  	c->type = PM_QOS_MIN;
>  	c->notifiers = n;
>  
> +	INIT_LIST_HEAD(&qos->flags.list);
> +
>  	spin_lock_irq(&dev->power.lock);
>  	dev->power.qos = qos;
>  	spin_unlock_irq(&dev->power.lock);
> @@ -207,6 +262,7 @@ void dev_pm_qos_constraints_destroy(stru
>   * dev_pm_qos_add_request - inserts new qos request into the list
>   * @dev: target device for the constraint
>   * @req: pointer to a preallocated handle
> + * @type: type of the request
>   * @value: defines the qos request
>   *
>   * This function inserts a new entry in the device constraints list of
> @@ -222,7 +278,7 @@ void dev_pm_qos_constraints_destroy(stru
>   * from the system.
>   */
>  int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
> -			   s32 value)
> +			   enum dev_pm_qos_req_type type, s32 value)
>  {
>  	int ret = 0;
>  
> @@ -253,8 +309,10 @@ int dev_pm_qos_add_request(struct device
>  		}
>  	}
>  
> -	if (!ret)
> +	if (!ret) {
> +		req->type = type;
>  		ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
> +	}
>  
>   out:
>  	mutex_unlock(&dev_pm_qos_mtx);
> @@ -281,6 +339,7 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
>  int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
>  			      s32 new_value)
>  {
> +	s32 curr_value;
>  	int ret = 0;
>  
>  	if (!req) /*guard against callers passing in null */
> @@ -292,15 +351,27 @@ int dev_pm_qos_update_request(struct dev
>  
>  	mutex_lock(&dev_pm_qos_mtx);
>  
> -	if (req->dev->power.qos) {
> -		if (new_value != req->data.pnode.prio)
> -			ret = apply_constraint(req, PM_QOS_UPDATE_REQ,
> -					       new_value);
> -	} else {
> -		/* Return if the device has been removed */
> +	if (!req->dev->power.qos) {
>  		ret = -ENODEV;
> +		goto out;
>  	}
>  
> +	switch(req->type) {
> +	case DEV_PM_QOS_LATENCY:
> +		curr_value = req->data.pnode.prio;
> +		break;
> +	case DEV_PM_QOS_FLAGS:
> +		curr_value = req->data.flr.flags;
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (curr_value != new_value)
> +		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> +
> + out:
>  	mutex_unlock(&dev_pm_qos_mtx);
>  	return ret;
>  }
> @@ -451,7 +522,8 @@ int dev_pm_qos_add_ancestor_request(stru
>  		ancestor = ancestor->parent;
>  
>  	if (ancestor)
> -		error = dev_pm_qos_add_request(ancestor, req, value);
> +		error = dev_pm_qos_add_request(ancestor, req,
> +					       DEV_PM_QOS_LATENCY, value);
>  
>  	if (error)
>  		req->dev = NULL;
> @@ -487,7 +559,7 @@ int dev_pm_qos_expose_latency_limit(stru
>  	if (!req)
>  		return -ENOMEM;
>  
> -	ret = dev_pm_qos_add_request(dev, req, value);
> +	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY, value);
>  	if (ret < 0)
>  		return ret;
>  
> Index: linux/include/linux/pm_qos.h
> ===================================================================
> --- linux.orig/include/linux/pm_qos.h
> +++ linux/include/linux/pm_qos.h
> @@ -20,6 +20,13 @@ enum {
>  	PM_QOS_NUM_CLASSES,
>  };
>  
> +enum pm_qos_flags_status {
> +	PM_QOS_FLAGS_UNDEFINED = -1,
> +	PM_QOS_FLAGS_NONE,
> +	PM_QOS_FLAGS_SOME,
> +	PM_QOS_FLAGS_ALL,
> +};
> +
>  #define PM_QOS_DEFAULT_VALUE -1
>  
>  #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE	(2000 * USEC_PER_SEC)
> @@ -38,9 +45,16 @@ struct pm_qos_flags_request {
>  	s32 flags;	/* Do not change to 64 bit */
>  };
>  
> +enum dev_pm_qos_req_type {
> +	DEV_PM_QOS_LATENCY = 1,
> +	DEV_PM_QOS_FLAGS,
> +};
> +
>  struct dev_pm_qos_request {
> +	enum dev_pm_qos_req_type type;
>  	union {
>  		struct plist_node pnode;
> +		struct pm_qos_flags_request flr;
>  	} data;
>  	struct device *dev;
>  };
> @@ -71,6 +85,7 @@ struct pm_qos_flags {
>  
>  struct dev_pm_qos {
>  	struct pm_qos_constraints latency;
> +	struct pm_qos_flags flags;
>  };
>  
>  /* Action requested to pm_qos_update_target */
> @@ -105,10 +120,12 @@ int pm_qos_request_active(struct pm_qos_
>  s32 pm_qos_read_value(struct pm_qos_constraints *c);
>  
>  #ifdef CONFIG_PM
> +enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
> +enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask);
>  s32 __dev_pm_qos_read_value(struct device *dev);
>  s32 dev_pm_qos_read_value(struct device *dev);
>  int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
> -			   s32 value);
> +			   enum dev_pm_qos_req_type type, s32 value);
>  int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
>  int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
>  int dev_pm_qos_add_notifier(struct device *dev,
> @@ -122,12 +139,19 @@ void dev_pm_qos_constraints_destroy(stru
>  int dev_pm_qos_add_ancestor_request(struct device *dev,
>  				    struct dev_pm_qos_request *req, s32 value);
>  #else
> +static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
> +							  s32 mask)
> +			{ return PM_QOS_FLAGS_UNDEFINED; }
> +static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
> +							s32 mask)
> +			{ return PM_QOS_FLAGS_UNDEFINED; }
>  static inline s32 __dev_pm_qos_read_value(struct device *dev)
>  			{ return 0; }
>  static inline s32 dev_pm_qos_read_value(struct device *dev)
>  			{ return 0; }
>  static inline int dev_pm_qos_add_request(struct device *dev,
>  					 struct dev_pm_qos_request *req,
> +					 enum dev_pm_qos_req_type type,
>  					 s32 value)
>  			{ return 0; }
>  static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
> Index: linux/drivers/mtd/nand/sh_flctl.c
> ===================================================================
> --- linux.orig/drivers/mtd/nand/sh_flctl.c
> +++ linux/drivers/mtd/nand/sh_flctl.c
> @@ -710,7 +710,9 @@ static void flctl_select_chip(struct mtd
>  
>  		if (!flctl->qos_request) {
>  			ret = dev_pm_qos_add_request(&flctl->pdev->dev,
> -							&flctl->pm_qos, 100);
> +							&flctl->pm_qos,
> +							DEV_PM_QOS_LATENCY,
> +							100);
>  			if (ret < 0)
>  				dev_err(&flctl->pdev->dev,
>  					"PM QoS request failed: %d\n", ret);
> Index: linux/Documentation/power/pm_qos_interface.txt
> ===================================================================
> --- linux.orig/Documentation/power/pm_qos_interface.txt
> +++ linux/Documentation/power/pm_qos_interface.txt
> @@ -99,7 +99,7 @@ reading the aggregated value does not re
>  
>  From kernel mode the use of this interface is the following:
>  
> -int dev_pm_qos_add_request(device, handle, value):
> +int dev_pm_qos_add_request(device, handle, type, value):
>  Will insert an element into the list for that identified device with the
>  target value.  Upon change to this list the new target is recomputed and any
>  registered notifiers are called only if the target value is now different.
> 
Reviewed-by: mark gross <markgross@thegnar.org>

[PATCH 5/7] PM / QoS: Make it possible to expose PM QoS device flags to user space

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF
and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines
dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the
caller to expose those two flags to user space or to hide them
from it, respectively.

After the flags have been exposed, user space will see two
additional sysfs attributes, pm_qos_no_power_off and
pm_qos_remote_wakeup, under the device's /sys/devices/.../power/
directory.  Then, writing 1 to one of them will update the
PM QoS flags request owned by user space so that the corresponding
flag is requested to be set.  In turn, writing 0 to one of them
will cause the corresponding flag in the user space's request to
be cleared (however, the owners of the other PM QoS flags requests
for the same device may still request the flag to be set and it
may be effectively set even if user space doesn't request that).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
---
 Documentation/ABI/testing/sysfs-devices-power |   31 ++++
 drivers/base/power/power.h                    |    6 
 drivers/base/power/qos.c                      |  167 ++++++++++++++++++++------
 drivers/base/power/sysfs.c                    |   95 +++++++++++++-
 include/linux/pm.h                            |    1 
 include/linux/pm_qos.h                        |   26 ++++
 6 files changed, 278 insertions(+), 48 deletions(-)

Index: linux/include/linux/pm_qos.h
===================================================================
--- linux.orig/include/linux/pm_qos.h
+++ linux/include/linux/pm_qos.h
@@ -34,6 +34,9 @@ enum pm_qos_flags_status {
 #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE	0
 #define PM_QOS_DEV_LAT_DEFAULT_VALUE		0
 
+#define PM_QOS_FLAG_NO_POWER_OFF	(1 << 0)
+#define PM_QOS_FLAG_REMOTE_WAKEUP	(1 << 1)
+
 struct pm_qos_request {
 	struct plist_node node;
 	int pm_qos_class;
@@ -86,6 +89,8 @@ struct pm_qos_flags {
 struct dev_pm_qos {
 	struct pm_qos_constraints latency;
 	struct pm_qos_flags flags;
+	struct dev_pm_qos_request *latency_req;
+	struct dev_pm_qos_request *flags_req;
 };
 
 /* Action requested to pm_qos_update_target */
@@ -187,10 +192,31 @@ static inline int dev_pm_qos_add_ancesto
 #ifdef CONFIG_PM_RUNTIME
 int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value);
 void dev_pm_qos_hide_latency_limit(struct device *dev);
+int dev_pm_qos_expose_flags(struct device *dev, s32 value);
+void dev_pm_qos_hide_flags(struct device *dev);
+int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set);
+
+static inline s32 dev_pm_qos_requested_latency(struct device *dev)
+{
+	return dev->power.qos->latency_req->data.pnode.prio;
+}
+
+static inline s32 dev_pm_qos_requested_flags(struct device *dev)
+{
+	return dev->power.qos->flags_req->data.flr.flags;
+}
 #else
 static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
 			{ return 0; }
 static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {}
+static inline int dev_pm_qos_expose_flags(struct device *dev, s32 value)
+			{ return 0; }
+static inline void dev_pm_qos_hide_flags(struct device *dev) {}
+static inline int dev_pm_qos_update_flags(struct device *dev, s32 m, bool set)
+			{ return 0; }
+
+static inline s32 dev_pm_qos_requested_latency(struct device *dev) { return 0; }
+static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
 #endif
 
 #endif
Index: linux/include/linux/pm.h
===================================================================
--- linux.orig/include/linux/pm.h
+++ linux/include/linux/pm.h
@@ -548,7 +548,6 @@ struct dev_pm_info {
 	unsigned long		active_jiffies;
 	unsigned long		suspended_jiffies;
 	unsigned long		accounting_timestamp;
-	struct dev_pm_qos_request *pq_req;
 #endif
 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
 	struct dev_pm_qos	*qos;
Index: linux/drivers/base/power/qos.c
===================================================================
--- linux.orig/drivers/base/power/qos.c
+++ linux/drivers/base/power/qos.c
@@ -40,6 +40,7 @@
 #include <linux/device.h>
 #include <linux/mutex.h>
 #include <linux/export.h>
+#include <linux/pm_runtime.h>
 
 #include "power.h"
 
@@ -322,6 +323,36 @@ int dev_pm_qos_add_request(struct device
 EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
 
 /**
+ * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
+ * @req : PM QoS request to modify.
+ * @new_value: New value to request.
+ */
+int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
+{
+	s32 curr_value;
+	int ret = 0;
+
+	if (!req->dev->power.qos)
+		return -ENODEV;
+
+	switch(req->type) {
+	case DEV_PM_QOS_LATENCY:
+		curr_value = req->data.pnode.prio;
+		break;
+	case DEV_PM_QOS_FLAGS:
+		curr_value = req->data.flr.flags;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (curr_value != new_value)
+		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
+
+	return ret;
+}
+
+/**
  * dev_pm_qos_update_request - modifies an existing qos request
  * @req : handle to list element holding a dev_pm_qos request to use
  * @new_value: defines the qos request
@@ -336,11 +367,9 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
  * -EINVAL in case of wrong parameters, -ENODEV if the device has been
  * removed from the system
  */
-int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
-			      s32 new_value)
+int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
 {
-	s32 curr_value;
-	int ret = 0;
+	int ret;
 
 	if (!req) /*guard against callers passing in null */
 		return -EINVAL;
@@ -350,29 +379,9 @@ int dev_pm_qos_update_request(struct dev
 		return -EINVAL;
 
 	mutex_lock(&dev_pm_qos_mtx);
-
-	if (!req->dev->power.qos) {
-		ret = -ENODEV;
-		goto out;
-	}
-
-	switch(req->type) {
-	case DEV_PM_QOS_LATENCY:
-		curr_value = req->data.pnode.prio;
-		break;
-	case DEV_PM_QOS_FLAGS:
-		curr_value = req->data.flr.flags;
-		break;
-	default:
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (curr_value != new_value)
-		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
-
- out:
+	__dev_pm_qos_update_request(req, new_value);
 	mutex_unlock(&dev_pm_qos_mtx);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
@@ -533,10 +542,19 @@ int dev_pm_qos_add_ancestor_request(stru
 EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
 
 #ifdef CONFIG_PM_RUNTIME
-static void __dev_pm_qos_drop_user_request(struct device *dev)
+static void __dev_pm_qos_drop_user_request(struct device *dev,
+					   enum dev_pm_qos_req_type type)
 {
-	dev_pm_qos_remove_request(dev->power.pq_req);
-	dev->power.pq_req = NULL;
+	switch(type) {
+	case DEV_PM_QOS_LATENCY:
+		dev_pm_qos_remove_request(dev->power.qos->latency_req);
+		dev->power.qos->latency_req = NULL;
+		break;
+	case DEV_PM_QOS_FLAGS:
+		dev_pm_qos_remove_request(dev->power.qos->flags_req);
+		dev->power.qos->flags_req = NULL;
+		break;
+	}
 }
 
 /**
@@ -552,7 +570,7 @@ int dev_pm_qos_expose_latency_limit(stru
 	if (!device_is_registered(dev) || value < 0)
 		return -EINVAL;
 
-	if (dev->power.pq_req)
+	if (dev->power.qos && dev->power.qos->latency_req)
 		return -EEXIST;
 
 	req = kzalloc(sizeof(*req), GFP_KERNEL);
@@ -563,10 +581,10 @@ int dev_pm_qos_expose_latency_limit(stru
 	if (ret < 0)
 		return ret;
 
-	dev->power.pq_req = req;
-	ret = pm_qos_sysfs_add(dev);
+	dev->power.qos->latency_req = req;
+	ret = pm_qos_sysfs_add_latency(dev);
 	if (ret)
-		__dev_pm_qos_drop_user_request(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
 
 	return ret;
 }
@@ -578,10 +596,87 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_expose_late
  */
 void dev_pm_qos_hide_latency_limit(struct device *dev)
 {
-	if (dev->power.pq_req) {
-		pm_qos_sysfs_remove(dev);
-		__dev_pm_qos_drop_user_request(dev);
+	if (dev->power.qos && dev->power.qos->latency_req) {
+		pm_qos_sysfs_remove_latency(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
 	}
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit);
+
+/**
+ * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space.
+ * @dev: Device whose PM QoS flags are to be exposed to user space.
+ * @val: Initial values of the flags.
+ */
+int dev_pm_qos_expose_flags(struct device *dev, s32 val)
+{
+	struct dev_pm_qos_request *req;
+	int ret;
+
+	if (!device_is_registered(dev))
+		return -EINVAL;
+
+	if (dev->power.qos && dev->power.qos->flags_req)
+		return -EEXIST;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val);
+	if (ret < 0)
+		return ret;
+
+	dev->power.qos->flags_req = req;
+	ret = pm_qos_sysfs_add_flags(dev);
+	if (ret)
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags);
+
+/**
+ * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space.
+ * @dev: Device whose PM QoS flags are to be hidden from user space.
+ */
+void dev_pm_qos_hide_flags(struct device *dev)
+{
+	if (dev->power.qos && dev->power.qos->flags_req) {
+		pm_qos_sysfs_remove_flags(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
+	}
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags);
+
+/**
+ * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space.
+ * @dev: Device to update the PM QoS flags request for.
+ * @mask: Flags to set/clear.
+ * @set: Whether to set or clear the flags (true means set).
+ */
+int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set)
+{
+	s32 value;
+	int ret;
+
+	if (!dev->power.qos || !dev->power.qos->flags_req)
+		return -EINVAL;
+
+	pm_runtime_get_sync(dev);
+	mutex_lock(&dev_pm_qos_mtx);
+
+	value = dev_pm_qos_requested_flags(dev);
+	if (set)
+		value |= mask;
+	else
+		value &= ~mask;
+
+	ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value);
+
+	mutex_unlock(&dev_pm_qos_mtx);
+	pm_runtime_put(dev);
+
+	return ret;
+}
 #endif /* CONFIG_PM_RUNTIME */
Index: linux/drivers/base/power/power.h
===================================================================
--- linux.orig/drivers/base/power/power.h
+++ linux/drivers/base/power/power.h
@@ -93,8 +93,10 @@ extern void dpm_sysfs_remove(struct devi
 extern void rpm_sysfs_remove(struct device *dev);
 extern int wakeup_sysfs_add(struct device *dev);
 extern void wakeup_sysfs_remove(struct device *dev);
-extern int pm_qos_sysfs_add(struct device *dev);
-extern void pm_qos_sysfs_remove(struct device *dev);
+extern int pm_qos_sysfs_add_latency(struct device *dev);
+extern void pm_qos_sysfs_remove_latency(struct device *dev);
+extern int pm_qos_sysfs_add_flags(struct device *dev);
+extern void pm_qos_sysfs_remove_flags(struct device *dev);
 
 #else /* CONFIG_PM */
 
Index: linux/drivers/base/power/sysfs.c
===================================================================
--- linux.orig/drivers/base/power/sysfs.c
+++ linux/drivers/base/power/sysfs.c
@@ -221,7 +221,7 @@ static DEVICE_ATTR(autosuspend_delay_ms,
 static ssize_t pm_qos_latency_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
+	return sprintf(buf, "%d\n", dev_pm_qos_requested_latency(dev));
 }
 
 static ssize_t pm_qos_latency_store(struct device *dev,
@@ -237,12 +237,67 @@ static ssize_t pm_qos_latency_store(stru
 	if (value < 0)
 		return -EINVAL;
 
-	ret = dev_pm_qos_update_request(dev->power.pq_req, value);
+	ret = dev_pm_qos_update_request(dev->power.qos->latency_req, value);
 	return ret < 0 ? ret : n;
 }
 
 static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
 		   pm_qos_latency_show, pm_qos_latency_store);
+
+static ssize_t pm_qos_no_power_off_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
+					& PM_QOS_FLAG_NO_POWER_OFF));
+}
+
+static ssize_t pm_qos_no_power_off_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t n)
+{
+	int ret;
+
+	if (kstrtoint(buf, 0, &ret))
+		return -EINVAL;
+
+	if (ret != 0 && ret != 1)
+		return -EINVAL;
+
+	ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
+	return ret < 0 ? ret : n;
+}
+
+static DEVICE_ATTR(pm_qos_no_power_off, 0644,
+		   pm_qos_no_power_off_show, pm_qos_no_power_off_store);
+
+static ssize_t pm_qos_remote_wakeup_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
+					& PM_QOS_FLAG_REMOTE_WAKEUP));
+}
+
+static ssize_t pm_qos_remote_wakeup_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t n)
+{
+	s32 value;
+	int ret;
+
+	if (kstrtoint(buf, 0, &ret))
+		return -EINVAL;
+
+	if (ret != 0 && ret != 1)
+		return -EINVAL;
+
+	ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP, ret);
+	return ret < 0 ? ret : n;
+}
+
+static DEVICE_ATTR(pm_qos_remote_wakeup, 0644,
+		   pm_qos_remote_wakeup_show, pm_qos_remote_wakeup_store);
 #endif /* CONFIG_PM_RUNTIME */
 
 #ifdef CONFIG_PM_SLEEP
@@ -564,15 +619,27 @@ static struct attribute_group pm_runtime
 	.attrs	= runtime_attrs,
 };
 
-static struct attribute *pm_qos_attrs[] = {
+static struct attribute *pm_qos_latency_attrs[] = {
 #ifdef CONFIG_PM_RUNTIME
 	&dev_attr_pm_qos_resume_latency_us.attr,
 #endif /* CONFIG_PM_RUNTIME */
 	NULL,
 };
-static struct attribute_group pm_qos_attr_group = {
+static struct attribute_group pm_qos_latency_attr_group = {
+	.name	= power_group_name,
+	.attrs	= pm_qos_latency_attrs,
+};
+
+static struct attribute *pm_qos_flags_attrs[] = {
+#ifdef CONFIG_PM_RUNTIME
+	&dev_attr_pm_qos_no_power_off.attr,
+	&dev_attr_pm_qos_remote_wakeup.attr,
+#endif /* CONFIG_PM_RUNTIME */
+	NULL,
+};
+static struct attribute_group pm_qos_flags_attr_group = {
 	.name	= power_group_name,
-	.attrs	= pm_qos_attrs,
+	.attrs	= pm_qos_flags_attrs,
 };
 
 int dpm_sysfs_add(struct device *dev)
@@ -615,14 +682,24 @@ void wakeup_sysfs_remove(struct device *
 	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 }
 
-int pm_qos_sysfs_add(struct device *dev)
+int pm_qos_sysfs_add_latency(struct device *dev)
+{
+	return sysfs_merge_group(&dev->kobj, &pm_qos_latency_attr_group);
+}
+
+void pm_qos_sysfs_remove_latency(struct device *dev)
+{
+	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_attr_group);
+}
+
+int pm_qos_sysfs_add_flags(struct device *dev)
 {
-	return sysfs_merge_group(&dev->kobj, &pm_qos_attr_group);
+	return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
-void pm_qos_sysfs_remove(struct device *dev)
+void pm_qos_sysfs_remove_flags(struct device *dev)
 {
-	sysfs_unmerge_group(&dev->kobj, &pm_qos_attr_group);
+	sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
 void rpm_sysfs_remove(struct device *dev)
Index: linux/Documentation/ABI/testing/sysfs-devices-power
===================================================================
--- linux.orig/Documentation/ABI/testing/sysfs-devices-power
+++ linux/Documentation/ABI/testing/sysfs-devices-power
@@ -204,3 +204,34 @@ Description:
 
 		This attribute has no effect on system-wide suspend/resume and
 		hibernation.
+
+What:		/sys/devices/.../power/pm_qos_no_power_off
+Date:		September 2012
+Contact:	Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+		The /sys/devices/.../power/pm_qos_no_power_off attribute
+		is used for manipulating the PM QoS "no power off" flag.  If
+		set, this flag indicates to the kernel that power should not
+		be removed entirely from the device.
+
+		Not all drivers support this attribute.  If it isn't supported,
+		it is not present.
+
+		This attribute has no effect on system-wide suspend/resume and
+		hibernation.
+
+What:		/sys/devices/.../power/pm_qos_remote_wakeup
+Date:		September 2012
+Contact:	Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+		The /sys/devices/.../power/pm_qos_remote_wakeup attribute
+		is used for manipulating the PM QoS "remote wakeup required"
+		flag.  If set, this flag indicates to the kernel that the
+		device is a source of user events that have to be signaled from
+		its low-power states.
+
+		Not all drivers support this attribute.  If it isn't supported,
+		it is not present.
+
+		This attribute has no effect on system-wide suspend/resume and
+		hibernation.

Re: [PATCH 5/7] PM / QoS: Make it possible to expose PM QoS device flags to user space

[mark gross]

On Mon, Oct 08, 2012 at 10:07:58AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF
> and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines
> dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the
> caller to expose those two flags to user space or to hide them
> from it, respectively.
> 
> After the flags have been exposed, user space will see two
> additional sysfs attributes, pm_qos_no_power_off and
> pm_qos_remote_wakeup, under the device's /sys/devices/.../power/
> directory.  Then, writing 1 to one of them will update the
> PM QoS flags request owned by user space so that the corresponding
> flag is requested to be set.  In turn, writing 0 to one of them
> will cause the corresponding flag in the user space's request to
> be cleared (however, the owners of the other PM QoS flags requests
> for the same device may still request the flag to be set and it
> may be effectively set even if user space doesn't request that).
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
>  Documentation/ABI/testing/sysfs-devices-power |   31 ++++
>  drivers/base/power/power.h                    |    6 
>  drivers/base/power/qos.c                      |  167 ++++++++++++++++++++------
>  drivers/base/power/sysfs.c                    |   95 +++++++++++++-
>  include/linux/pm.h                            |    1 
>  include/linux/pm_qos.h                        |   26 ++++
>  6 files changed, 278 insertions(+), 48 deletions(-)
> 
> Index: linux/include/linux/pm_qos.h
> ===================================================================
> --- linux.orig/include/linux/pm_qos.h
> +++ linux/include/linux/pm_qos.h
> @@ -34,6 +34,9 @@ enum pm_qos_flags_status {
>  #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE	0
>  #define PM_QOS_DEV_LAT_DEFAULT_VALUE		0
>  
> +#define PM_QOS_FLAG_NO_POWER_OFF	(1 << 0)
> +#define PM_QOS_FLAG_REMOTE_WAKEUP	(1 << 1)
> +
>  struct pm_qos_request {
>  	struct plist_node node;
>  	int pm_qos_class;
> @@ -86,6 +89,8 @@ struct pm_qos_flags {
>  struct dev_pm_qos {
>  	struct pm_qos_constraints latency;
>  	struct pm_qos_flags flags;
> +	struct dev_pm_qos_request *latency_req;
> +	struct dev_pm_qos_request *flags_req;

I think I'm getting it now.  if someday we have per device throughput
you would have us add a pm_qos_constraints throughput; and a
dev_pm_qos_request *throughput_req;


>  };
>  
>  /* Action requested to pm_qos_update_target */
> @@ -187,10 +192,31 @@ static inline int dev_pm_qos_add_ancesto
>  #ifdef CONFIG_PM_RUNTIME
>  int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value);
>  void dev_pm_qos_hide_latency_limit(struct device *dev);
> +int dev_pm_qos_expose_flags(struct device *dev, s32 value);
> +void dev_pm_qos_hide_flags(struct device *dev);
> +int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set);
> +
> +static inline s32 dev_pm_qos_requested_latency(struct device *dev)
> +{
> +	return dev->power.qos->latency_req->data.pnode.prio;
> +}
> +
> +static inline s32 dev_pm_qos_requested_flags(struct device *dev)
> +{
> +	return dev->power.qos->flags_req->data.flr.flags;
> +}
>  #else
>  static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
>  			{ return 0; }
>  static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {}
> +static inline int dev_pm_qos_expose_flags(struct device *dev, s32 value)
> +			{ return 0; }
> +static inline void dev_pm_qos_hide_flags(struct device *dev) {}
> +static inline int dev_pm_qos_update_flags(struct device *dev, s32 m, bool set)
> +			{ return 0; }
> +
> +static inline s32 dev_pm_qos_requested_latency(struct device *dev) { return 0; }
> +static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
>  #endif
>  
>  #endif
> Index: linux/include/linux/pm.h
> ===================================================================
> --- linux.orig/include/linux/pm.h
> +++ linux/include/linux/pm.h
> @@ -548,7 +548,6 @@ struct dev_pm_info {
>  	unsigned long		active_jiffies;
>  	unsigned long		suspended_jiffies;
>  	unsigned long		accounting_timestamp;
> -	struct dev_pm_qos_request *pq_req;
>  #endif
>  	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
>  	struct dev_pm_qos	*qos;
> Index: linux/drivers/base/power/qos.c
> ===================================================================
> --- linux.orig/drivers/base/power/qos.c
> +++ linux/drivers/base/power/qos.c
> @@ -40,6 +40,7 @@
>  #include <linux/device.h>
>  #include <linux/mutex.h>
>  #include <linux/export.h>
> +#include <linux/pm_runtime.h>
>  
>  #include "power.h"
>  
> @@ -322,6 +323,36 @@ int dev_pm_qos_add_request(struct device
>  EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
>  
>  /**
> + * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
> + * @req : PM QoS request to modify.
> + * @new_value: New value to request.
> + */
> +int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
> +{
> +	s32 curr_value;
> +	int ret = 0;
> +
> +	if (!req->dev->power.qos)
> +		return -ENODEV;
> +
> +	switch(req->type) {
> +	case DEV_PM_QOS_LATENCY:
> +		curr_value = req->data.pnode.prio;
> +		break;
> +	case DEV_PM_QOS_FLAGS:
> +		curr_value = req->data.flr.flags;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (curr_value != new_value)
> +		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> +
> +	return ret;
> +}
> +
> +/**
>   * dev_pm_qos_update_request - modifies an existing qos request
>   * @req : handle to list element holding a dev_pm_qos request to use
>   * @new_value: defines the qos request
> @@ -336,11 +367,9 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
>   * -EINVAL in case of wrong parameters, -ENODEV if the device has been
>   * removed from the system
>   */
> -int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
> -			      s32 new_value)
> +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
>  {
> -	s32 curr_value;
> -	int ret = 0;
> +	int ret;
>  
>  	if (!req) /*guard against callers passing in null */
>  		return -EINVAL;
> @@ -350,29 +379,9 @@ int dev_pm_qos_update_request(struct dev
>  		return -EINVAL;
>  
>  	mutex_lock(&dev_pm_qos_mtx);
> -
> -	if (!req->dev->power.qos) {
> -		ret = -ENODEV;
> -		goto out;
> -	}
> -
> -	switch(req->type) {
> -	case DEV_PM_QOS_LATENCY:
> -		curr_value = req->data.pnode.prio;
> -		break;
> -	case DEV_PM_QOS_FLAGS:
> -		curr_value = req->data.flr.flags;
> -		break;
> -	default:
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
> -	if (curr_value != new_value)
> -		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> -
> - out:
> +	__dev_pm_qos_update_request(req, new_value);
>  	mutex_unlock(&dev_pm_qos_mtx);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
> @@ -533,10 +542,19 @@ int dev_pm_qos_add_ancestor_request(stru
>  EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
>  
>  #ifdef CONFIG_PM_RUNTIME
> -static void __dev_pm_qos_drop_user_request(struct device *dev)
> +static void __dev_pm_qos_drop_user_request(struct device *dev,
> +					   enum dev_pm_qos_req_type type)
>  {
> -	dev_pm_qos_remove_request(dev->power.pq_req);
> -	dev->power.pq_req = NULL;
> +	switch(type) {
> +	case DEV_PM_QOS_LATENCY:
> +		dev_pm_qos_remove_request(dev->power.qos->latency_req);
> +		dev->power.qos->latency_req = NULL;
> +		break;
> +	case DEV_PM_QOS_FLAGS:
> +		dev_pm_qos_remove_request(dev->power.qos->flags_req);
> +		dev->power.qos->flags_req = NULL;
> +		break;
> +	}
>  }
>  
>  /**
> @@ -552,7 +570,7 @@ int dev_pm_qos_expose_latency_limit(stru
>  	if (!device_is_registered(dev) || value < 0)
>  		return -EINVAL;
>  
> -	if (dev->power.pq_req)
> +	if (dev->power.qos && dev->power.qos->latency_req)
>  		return -EEXIST;
>  
>  	req = kzalloc(sizeof(*req), GFP_KERNEL);
> @@ -563,10 +581,10 @@ int dev_pm_qos_expose_latency_limit(stru
>  	if (ret < 0)
>  		return ret;
>  
> -	dev->power.pq_req = req;
> -	ret = pm_qos_sysfs_add(dev);
> +	dev->power.qos->latency_req = req;
> +	ret = pm_qos_sysfs_add_latency(dev);
>  	if (ret)
> -		__dev_pm_qos_drop_user_request(dev);
> +		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
>  
>  	return ret;
>  }
> @@ -578,10 +596,87 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_expose_late
>   */
>  void dev_pm_qos_hide_latency_limit(struct device *dev)
>  {
> -	if (dev->power.pq_req) {
> -		pm_qos_sysfs_remove(dev);
> -		__dev_pm_qos_drop_user_request(dev);
> +	if (dev->power.qos && dev->power.qos->latency_req) {
> +		pm_qos_sysfs_remove_latency(dev);
> +		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
>  	}
>  }
>  EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit);
> +
> +/**
> + * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space.
> + * @dev: Device whose PM QoS flags are to be exposed to user space.
> + * @val: Initial values of the flags.
> + */
> +int dev_pm_qos_expose_flags(struct device *dev, s32 val)
> +{
> +	struct dev_pm_qos_request *req;
> +	int ret;
> +
> +	if (!device_is_registered(dev))
> +		return -EINVAL;
> +
> +	if (dev->power.qos && dev->power.qos->flags_req)
> +		return -EEXIST;
> +
> +	req = kzalloc(sizeof(*req), GFP_KERNEL);
> +	if (!req)
> +		return -ENOMEM;
> +
> +	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev->power.qos->flags_req = req;
> +	ret = pm_qos_sysfs_add_flags(dev);
> +	if (ret)
> +		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags);
> +
> +/**
> + * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space.
> + * @dev: Device whose PM QoS flags are to be hidden from user space.
> + */
> +void dev_pm_qos_hide_flags(struct device *dev)
> +{
> +	if (dev->power.qos && dev->power.qos->flags_req) {
> +		pm_qos_sysfs_remove_flags(dev);
> +		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
> +	}
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags);
> +
> +/**
> + * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space.
> + * @dev: Device to update the PM QoS flags request for.
> + * @mask: Flags to set/clear.
> + * @set: Whether to set or clear the flags (true means set).
> + */
> +int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set)
> +{
> +	s32 value;
> +	int ret;
> +
> +	if (!dev->power.qos || !dev->power.qos->flags_req)
> +		return -EINVAL;
> +
> +	pm_runtime_get_sync(dev);
> +	mutex_lock(&dev_pm_qos_mtx);
> +
> +	value = dev_pm_qos_requested_flags(dev);
> +	if (set)
> +		value |= mask;
> +	else
> +		value &= ~mask;
> +
> +	ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value);
> +
> +	mutex_unlock(&dev_pm_qos_mtx);
> +	pm_runtime_put(dev);
> +
> +	return ret;
> +}
>  #endif /* CONFIG_PM_RUNTIME */
> Index: linux/drivers/base/power/power.h
> ===================================================================
> --- linux.orig/drivers/base/power/power.h
> +++ linux/drivers/base/power/power.h
> @@ -93,8 +93,10 @@ extern void dpm_sysfs_remove(struct devi
>  extern void rpm_sysfs_remove(struct device *dev);
>  extern int wakeup_sysfs_add(struct device *dev);
>  extern void wakeup_sysfs_remove(struct device *dev);
> -extern int pm_qos_sysfs_add(struct device *dev);
> -extern void pm_qos_sysfs_remove(struct device *dev);
> +extern int pm_qos_sysfs_add_latency(struct device *dev);
> +extern void pm_qos_sysfs_remove_latency(struct device *dev);
> +extern int pm_qos_sysfs_add_flags(struct device *dev);
> +extern void pm_qos_sysfs_remove_flags(struct device *dev);
>  
>  #else /* CONFIG_PM */
>  
> Index: linux/drivers/base/power/sysfs.c
> ===================================================================
> --- linux.orig/drivers/base/power/sysfs.c
> +++ linux/drivers/base/power/sysfs.c
> @@ -221,7 +221,7 @@ static DEVICE_ATTR(autosuspend_delay_ms,
>  static ssize_t pm_qos_latency_show(struct device *dev,
>  				   struct device_attribute *attr, char *buf)
>  {
> -	return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
> +	return sprintf(buf, "%d\n", dev_pm_qos_requested_latency(dev));
>  }
>  
>  static ssize_t pm_qos_latency_store(struct device *dev,
> @@ -237,12 +237,67 @@ static ssize_t pm_qos_latency_store(stru
>  	if (value < 0)
>  		return -EINVAL;
>  
> -	ret = dev_pm_qos_update_request(dev->power.pq_req, value);
> +	ret = dev_pm_qos_update_request(dev->power.qos->latency_req, value);
>  	return ret < 0 ? ret : n;
>  }
>  
>  static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
>  		   pm_qos_latency_show, pm_qos_latency_store);
> +
> +static ssize_t pm_qos_no_power_off_show(struct device *dev,
> +					struct device_attribute *attr,
> +					char *buf)
> +{
> +	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
> +					& PM_QOS_FLAG_NO_POWER_OFF));
> +}
> +
> +static ssize_t pm_qos_no_power_off_store(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t n)
> +{
> +	int ret;
> +
> +	if (kstrtoint(buf, 0, &ret))
> +		return -EINVAL;
> +
> +	if (ret != 0 && ret != 1)
> +		return -EINVAL;
> +
> +	ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
> +	return ret < 0 ? ret : n;
> +}
> +
> +static DEVICE_ATTR(pm_qos_no_power_off, 0644,
> +		   pm_qos_no_power_off_show, pm_qos_no_power_off_store);
> +
> +static ssize_t pm_qos_remote_wakeup_show(struct device *dev,
> +					 struct device_attribute *attr,
> +					 char *buf)
> +{
> +	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
> +					& PM_QOS_FLAG_REMOTE_WAKEUP));
> +}
> +
> +static ssize_t pm_qos_remote_wakeup_store(struct device *dev,
> +					  struct device_attribute *attr,
> +					  const char *buf, size_t n)
> +{
> +	s32 value;
> +	int ret;
> +
> +	if (kstrtoint(buf, 0, &ret))
> +		return -EINVAL;
> +
> +	if (ret != 0 && ret != 1)
> +		return -EINVAL;
> +
> +	ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP, ret);
> +	return ret < 0 ? ret : n;
> +}
> +
> +static DEVICE_ATTR(pm_qos_remote_wakeup, 0644,
> +		   pm_qos_remote_wakeup_show, pm_qos_remote_wakeup_store);
>  #endif /* CONFIG_PM_RUNTIME */
>  
>  #ifdef CONFIG_PM_SLEEP
> @@ -564,15 +619,27 @@ static struct attribute_group pm_runtime
>  	.attrs	= runtime_attrs,
>  };
>  
> -static struct attribute *pm_qos_attrs[] = {
> +static struct attribute *pm_qos_latency_attrs[] = {
>  #ifdef CONFIG_PM_RUNTIME
>  	&dev_attr_pm_qos_resume_latency_us.attr,
>  #endif /* CONFIG_PM_RUNTIME */
>  	NULL,
>  };
> -static struct attribute_group pm_qos_attr_group = {
> +static struct attribute_group pm_qos_latency_attr_group = {
> +	.name	= power_group_name,
> +	.attrs	= pm_qos_latency_attrs,
> +};
> +
> +static struct attribute *pm_qos_flags_attrs[] = {
> +#ifdef CONFIG_PM_RUNTIME
> +	&dev_attr_pm_qos_no_power_off.attr,
> +	&dev_attr_pm_qos_remote_wakeup.attr,
> +#endif /* CONFIG_PM_RUNTIME */
> +	NULL,
> +};
> +static struct attribute_group pm_qos_flags_attr_group = {
>  	.name	= power_group_name,
> -	.attrs	= pm_qos_attrs,
> +	.attrs	= pm_qos_flags_attrs,
>  };
>  
>  int dpm_sysfs_add(struct device *dev)
> @@ -615,14 +682,24 @@ void wakeup_sysfs_remove(struct device *
>  	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
>  }
>  
> -int pm_qos_sysfs_add(struct device *dev)
> +int pm_qos_sysfs_add_latency(struct device *dev)
> +{
> +	return sysfs_merge_group(&dev->kobj, &pm_qos_latency_attr_group);
> +}
> +
> +void pm_qos_sysfs_remove_latency(struct device *dev)
> +{
> +	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_attr_group);
> +}
> +
> +int pm_qos_sysfs_add_flags(struct device *dev)
>  {
> -	return sysfs_merge_group(&dev->kobj, &pm_qos_attr_group);
> +	return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
>  }
>  
> -void pm_qos_sysfs_remove(struct device *dev)
> +void pm_qos_sysfs_remove_flags(struct device *dev)
>  {
> -	sysfs_unmerge_group(&dev->kobj, &pm_qos_attr_group);
> +	sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
>  }
>  
>  void rpm_sysfs_remove(struct device *dev)
> Index: linux/Documentation/ABI/testing/sysfs-devices-power
> ===================================================================
> --- linux.orig/Documentation/ABI/testing/sysfs-devices-power
> +++ linux/Documentation/ABI/testing/sysfs-devices-power
> @@ -204,3 +204,34 @@ Description:
>  
>  		This attribute has no effect on system-wide suspend/resume and
>  		hibernation.
> +
> +What:		/sys/devices/.../power/pm_qos_no_power_off
> +Date:		September 2012
> +Contact:	Rafael J. Wysocki <rjw@sisk.pl>
> +Description:
> +		The /sys/devices/.../power/pm_qos_no_power_off attribute
> +		is used for manipulating the PM QoS "no power off" flag.  If
> +		set, this flag indicates to the kernel that power should not
> +		be removed entirely from the device.
> +
> +		Not all drivers support this attribute.  If it isn't supported,
> +		it is not present.
> +
> +		This attribute has no effect on system-wide suspend/resume and
> +		hibernation.
> +
> +What:		/sys/devices/.../power/pm_qos_remote_wakeup
> +Date:		September 2012
> +Contact:	Rafael J. Wysocki <rjw@sisk.pl>
> +Description:
> +		The /sys/devices/.../power/pm_qos_remote_wakeup attribute
> +		is used for manipulating the PM QoS "remote wakeup required"
> +		flag.  If set, this flag indicates to the kernel that the
> +		device is a source of user events that have to be signaled from
> +		its low-power states.
> +
> +		Not all drivers support this attribute.  If it isn't supported,
> +		it is not present.
> +
> +		This attribute has no effect on system-wide suspend/resume and
> +		hibernation.
>
acked-by: mark gross <markgross@thegnar.org>

[PATCH 6/7] PM / Domains: Check device PM QoS flags in pm_genpd_poweroff()

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the generic PM domains pm_genpd_poweroff() function take
device PM QoS flags into account when deciding whether or not to
remove power from the domain.

After this change the routine will return -EBUSY without executing
the domain's .power_off() callback if there is at least one PM QoS
flags request for at least one device in the domain and at least of
those request has at least one of the NO_POWER_OFF and REMOTE_WAKEUP
flags set.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
---
 drivers/base/power/domain.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Index: linux/drivers/base/power/domain.c
===================================================================
--- linux.orig/drivers/base/power/domain.c
+++ linux/drivers/base/power/domain.c
@@ -470,10 +470,19 @@ static int pm_genpd_poweroff(struct gene
 		return -EBUSY;
 
 	not_suspended = 0;
-	list_for_each_entry(pdd, &genpd->dev_list, list_node)
+	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
+		enum pm_qos_flags_status stat;
+
+		stat = dev_pm_qos_flags(pdd->dev,
+					PM_QOS_FLAG_NO_POWER_OFF
+						| PM_QOS_FLAG_REMOTE_WAKEUP);
+		if (stat > PM_QOS_FLAGS_NONE)
+			return -EBUSY;
+
 		if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
 		    || pdd->dev->power.irq_safe))
 			not_suspended++;
+	}
 
 	if (not_suspended > genpd->in_progress)
 		return -EBUSY;

Re: [PATCH 6/7] PM / Domains: Check device PM QoS flags in pm_genpd_poweroff()

[mark gross]

On Mon, Oct 08, 2012 at 10:08:39AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Make the generic PM domains pm_genpd_poweroff() function take
> device PM QoS flags into account when deciding whether or not to
> remove power from the domain.
> 
> After this change the routine will return -EBUSY without executing
> the domain's .power_off() callback if there is at least one PM QoS
> flags request for at least one device in the domain and at least of
> those request has at least one of the NO_POWER_OFF and REMOTE_WAKEUP
> flags set.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
>  drivers/base/power/domain.c |   11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> Index: linux/drivers/base/power/domain.c
> ===================================================================
> --- linux.orig/drivers/base/power/domain.c
> +++ linux/drivers/base/power/domain.c
> @@ -470,10 +470,19 @@ static int pm_genpd_poweroff(struct gene
>  		return -EBUSY;
>  
>  	not_suspended = 0;
> -	list_for_each_entry(pdd, &genpd->dev_list, list_node)
> +	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
> +		enum pm_qos_flags_status stat;
> +
> +		stat = dev_pm_qos_flags(pdd->dev,
> +					PM_QOS_FLAG_NO_POWER_OFF
> +						| PM_QOS_FLAG_REMOTE_WAKEUP);
> +		if (stat > PM_QOS_FLAGS_NONE)
> +			return -EBUSY;
> +
>  		if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
>  		    || pdd->dev->power.irq_safe))
>  			not_suspended++;
> +	}
>  
>  	if (not_suspended > genpd->in_progress)
>  		return -EBUSY;
>
looks ok to me.
Reviewed-by: mark gross <markgross@thegnar.org>

--mrak

[PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Make ACPI power management routines and PCI power management
routines depending on ACPI take device PM QoS flags into account
when deciding what power state to put the device into.

In particular, after this change acpi_pm_device_sleep_state() will
not return ACPI_STATE_D3_COLD as the deepest available low-power
state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
will not require remote wakeup to work for the device in the returned
low-power state if there is at least one PM QoS flags request for the
device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.

Accordingly, acpi_pci_set_power_state() will refuse to put the
device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
---
 drivers/acpi/sleep.c   |   21 +++++++++++++++++----
 drivers/pci/pci-acpi.c |    8 +++++++-
 2 files changed, 24 insertions(+), 5 deletions(-)

Index: linux/drivers/pci/pci-acpi.c
===================================================================
--- linux.orig/drivers/pci/pci-acpi.c
+++ linux/drivers/pci/pci-acpi.c
@@ -17,6 +17,7 @@
 
 #include <linux/pci-acpi.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_qos.h>
 #include "pci.h"
 
 static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
@@ -257,11 +258,16 @@ static int acpi_pci_set_power_state(stru
 		return -ENODEV;
 
 	switch (state) {
+	case PCI_D3cold:
+		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
+				PM_QOS_FLAGS_ALL) {
+			error = -EBUSY;
+			break;
+		}
 	case PCI_D0:
 	case PCI_D1:
 	case PCI_D2:
 	case PCI_D3hot:
-	case PCI_D3cold:
 		error = acpi_bus_set_power(handle, state_conv[state]);
 	}
 
Index: linux/drivers/acpi/sleep.c
===================================================================
--- linux.orig/drivers/acpi/sleep.c
+++ linux/drivers/acpi/sleep.c
@@ -19,6 +19,7 @@
 #include <linux/acpi.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_qos.h>
 
 #include <asm/io.h>
 
@@ -711,6 +712,7 @@ int acpi_pm_device_sleep_state(struct de
 	struct acpi_device *adev;
 	char acpi_method[] = "_SxD";
 	unsigned long long d_min, d_max;
+	bool wakeup = false;
 
 	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
 		return -EINVAL;
@@ -718,6 +720,13 @@ int acpi_pm_device_sleep_state(struct de
 		printk(KERN_DEBUG "ACPI handle has no context!\n");
 		return -ENODEV;
 	}
+	if (d_max_in > ACPI_STATE_D3_HOT) {
+		enum pm_qos_flags_status stat;
+
+		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
+		if (stat == PM_QOS_FLAGS_ALL)
+			d_max_in = ACPI_STATE_D3_HOT;
+	}
 
 	acpi_method[2] = '0' + acpi_target_sleep_state;
 	/*
@@ -737,8 +746,14 @@ int acpi_pm_device_sleep_state(struct de
 	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
 	 * provided -- that's our fault recovery, we ignore retval.
 	 */
-	if (acpi_target_sleep_state > ACPI_STATE_S0)
+	if (acpi_target_sleep_state > ACPI_STATE_S0) {
 		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
+		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
+			&& adev->wakeup.sleep_state >= acpi_target_sleep_state;
+	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
+			PM_QOS_FLAGS_NONE) {
+		wakeup = adev->wakeup.flags.valid;
+	}
 
 	/*
 	 * If _PRW says we can wake up the system from the target sleep state,
@@ -747,9 +762,7 @@ int acpi_pm_device_sleep_state(struct de
 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 	 * can wake the system.  _S0W may be valid, too.
 	 */
-	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
-	    (device_may_wakeup(dev) && adev->wakeup.flags.valid &&
-	     adev->wakeup.sleep_state >= acpi_target_sleep_state)) {
+	if (wakeup) {
 		acpi_status status;
 
 		acpi_method[3] = 'W';

Re: [PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[Huang Ying]

On Mon, 2012-10-08 at 10:09 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Make ACPI power management routines and PCI power management
> routines depending on ACPI take device PM QoS flags into account
> when deciding what power state to put the device into.
> 
> In particular, after this change acpi_pm_device_sleep_state() will
> not return ACPI_STATE_D3_COLD as the deepest available low-power
> state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
> will not require remote wakeup to work for the device in the returned
> low-power state if there is at least one PM QoS flags request for the
> device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.
> 
> Accordingly, acpi_pci_set_power_state() will refuse to put the
> device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>

Reviewed-by: Huang Ying <ying.huang@intel.com>

Best Regards,
Huang Ying

Re: [PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

[mark gross]

On Mon, Oct 08, 2012 at 10:09:26AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Make ACPI power management routines and PCI power management
> routines depending on ACPI take device PM QoS flags into account
> when deciding what power state to put the device into.
> 
> In particular, after this change acpi_pm_device_sleep_state() will
> not return ACPI_STATE_D3_COLD as the deepest available low-power
> state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
> will not require remote wakeup to work for the device in the returned
> low-power state if there is at least one PM QoS flags request for the
> device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.
> 
> Accordingly, acpi_pci_set_power_state() will refuse to put the
> device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
>  drivers/acpi/sleep.c   |   21 +++++++++++++++++----
>  drivers/pci/pci-acpi.c |    8 +++++++-
>  2 files changed, 24 insertions(+), 5 deletions(-)
> 
> Index: linux/drivers/pci/pci-acpi.c
> ===================================================================
> --- linux.orig/drivers/pci/pci-acpi.c
> +++ linux/drivers/pci/pci-acpi.c
> @@ -17,6 +17,7 @@
>  
>  #include <linux/pci-acpi.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/pm_qos.h>
>  #include "pci.h"
>  
>  static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
> @@ -257,11 +258,16 @@ static int acpi_pci_set_power_state(stru
>  		return -ENODEV;
>  
>  	switch (state) {
> +	case PCI_D3cold:
> +		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
> +				PM_QOS_FLAGS_ALL) {
> +			error = -EBUSY;
> +			break;
> +		}
>  	case PCI_D0:
>  	case PCI_D1:
>  	case PCI_D2:
>  	case PCI_D3hot:
> -	case PCI_D3cold:
>  		error = acpi_bus_set_power(handle, state_conv[state]);
>  	}
>  
> Index: linux/drivers/acpi/sleep.c
> ===================================================================
> --- linux.orig/drivers/acpi/sleep.c
> +++ linux/drivers/acpi/sleep.c
> @@ -19,6 +19,7 @@
>  #include <linux/acpi.h>
>  #include <linux/module.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/pm_qos.h>
>  
>  #include <asm/io.h>
>  
> @@ -711,6 +712,7 @@ int acpi_pm_device_sleep_state(struct de
>  	struct acpi_device *adev;
>  	char acpi_method[] = "_SxD";
>  	unsigned long long d_min, d_max;
> +	bool wakeup = false;
>  
>  	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
>  		return -EINVAL;
> @@ -718,6 +720,13 @@ int acpi_pm_device_sleep_state(struct de
>  		printk(KERN_DEBUG "ACPI handle has no context!\n");
>  		return -ENODEV;
>  	}
> +	if (d_max_in > ACPI_STATE_D3_HOT) {
> +		enum pm_qos_flags_status stat;
> +
> +		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
> +		if (stat == PM_QOS_FLAGS_ALL)
> +			d_max_in = ACPI_STATE_D3_HOT;
> +	}
>  
>  	acpi_method[2] = '0' + acpi_target_sleep_state;
>  	/*
> @@ -737,8 +746,14 @@ int acpi_pm_device_sleep_state(struct de
>  	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
>  	 * provided -- that's our fault recovery, we ignore retval.
>  	 */
> -	if (acpi_target_sleep_state > ACPI_STATE_S0)
> +	if (acpi_target_sleep_state > ACPI_STATE_S0) {
>  		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
> +		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
> +			&& adev->wakeup.sleep_state >= acpi_target_sleep_state;
> +	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
> +			PM_QOS_FLAGS_NONE) {
> +		wakeup = adev->wakeup.flags.valid;
> +	}
>  
>  	/*
>  	 * If _PRW says we can wake up the system from the target sleep state,
> @@ -747,9 +762,7 @@ int acpi_pm_device_sleep_state(struct de
>  	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
>  	 * can wake the system.  _S0W may be valid, too.
>  	 */
> -	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
> -	    (device_may_wakeup(dev) && adev->wakeup.flags.valid &&
> -	     adev->wakeup.sleep_state >= acpi_target_sleep_state)) {
> +	if (wakeup) {
>  		acpi_status status;
>  
>  		acpi_method[3] = 'W';
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Reviewed-by: mark gross <markgross@thegnar.org>