- 根目录:
- drivers
- base
- power
- qos.c
/*
* Devices PM QoS constraints management
*
* Copyright (C) 2011 Texas Instruments, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*
* This module exposes the interface to kernel space for specifying
* per-device PM QoS dependencies. It provides infrastructure for registration
* of:
*
* Dependents on a QoS value : register requests
* Watchers of QoS value : get notified when target QoS value changes
*
* This QoS design is best effort based. Dependents register their QoS needs.
* Watchers register to keep track of the current QoS needs of the system.
* Watchers can register different types of notification callbacks:
* . a per-device notification callback using the dev_pm_qos_*_notifier API.
* The notification chain data is stored in the per-device constraint
* data struct.
* . a system-wide notification callback using the dev_pm_qos_*_global_notifier
* API. The notification chain data is stored in a static variable.
*
* Note about the per-device constraint data struct allocation:
* . The per-device constraints data struct ptr is tored into the device
* dev_pm_info.
* . To minimize the data usage by the per-device constraints, the data struct
* is only allocated at the first call to dev_pm_qos_add_request.
* . The data is later free'd when the device is removed from the system.
* . A global mutex protects the constraints users from the data being
* allocated and free'd.
*/
#include <linux/pm_qos.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/export.h>
#include <linux/pm_runtime.h>
#include <linux/err.h>
#include <trace/events/power.h>
#include "power.h"
static DEFINE_MUTEX(dev_pm_qos_mtx);
static DEFINE_MUTEX(dev_pm_qos_sysfs_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;
lockdep_assert_held(&dev->power.lock);
if (IS_ERR_OR_NULL(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;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_flags);
/**
* __dev_pm_qos_read_value - Get PM QoS constraint for a given device.
* @dev: Device to get the PM QoS constraint value for.
*
* This routine must be called with dev->power.lock held.
*/
s32 __dev_pm_qos_read_value(struct device *dev)
{
lockdep_assert_held(&dev->power.lock);
return IS_ERR_OR_NULL(dev->power.qos) ?
0 : pm_qos_read_value(&dev->power.qos->resume_latency);
}
/**
* dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked).
* @dev: Device to get the PM QoS constraint value for.
*/
s32 dev_pm_qos_read_value(struct device *dev)
{
unsigned long flags;
s32 ret;
spin_lock_irqsave(&dev->power.lock, flags);
ret = __dev_pm_qos_read_value(dev);
spin_unlock_irqrestore(&dev->power.lock, flags);
return ret;
}
/**
* 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, s32 value)
{
struct dev_pm_qos *qos = req->dev->power.qos;
int ret;
switch(req->type) {
case DEV_PM_QOS_RESUME_LATENCY:
ret = pm_qos_update_target(&qos->resume_latency,
&req->data.pnode, action, value);
if (ret) {
value = pm_qos_read_value(&qos->resume_latency);
blocking_notifier_call_chain(&dev_pm_notifiers,
(unsigned long)value,
req);
}
break;
case DEV_PM_QOS_LATENCY_TOLERANCE:
ret = pm_qos_update_target(&qos->latency_tolerance,
&req->data.pnode, action, value);
if (ret) {
value = pm_qos_read_value(&qos->latency_tolerance);
req->dev->power.set_latency_tolerance(req->dev, value);
}
break;
case DEV_PM_QOS_FLAGS:
ret = pm_qos_update_flags(&qos->flags, &req->data.flr,
action, value);
break;
default:
ret = -EINVAL;
}
return ret;
}
/*
* dev_pm_qos_constraints_allocate
* @dev: device to allocate data for
*
* Called at the first call to add_request, for constraint data allocation
* Must be called with the dev_pm_qos_mtx mutex held
*/
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;
qos = kzalloc(sizeof(*qos), GFP_KERNEL);
if (!qos)
return -ENOMEM;
n = kzalloc(sizeof(*n), GFP_KERNEL);
if (!n) {
kfree(qos);
return -ENOMEM;
}
BLOCKING_INIT_NOTIFIER_HEAD(n);
c = &qos->resume_latency;
plist_head_init(&c->list);
c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
c->no_constraint_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
c->type = PM_QOS_MIN;
c->notifiers = n;
c = &qos->latency_tolerance;
plist_head_init(&c->list);
c->target_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE;
c->default_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE;
c->no_constraint_value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
c->type = PM_QOS_MIN;
INIT_LIST_HEAD(&qos->flags.list);
spin_lock_irq(&dev->power.lock);
dev->power.qos = qos;
spin_unlock_irq(&dev->power.lock);
return 0;
}
static void __dev_pm_qos_hide_latency_limit(struct device *dev);
static void __dev_pm_qos_hide_flags(struct device *dev);
/**
* dev_pm_qos_constraints_destroy
* @dev: target device
*
* Called from the device PM subsystem on device removal under device_pm_lock().
*/
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;
struct pm_qos_flags *f;
mutex_lock(&dev_pm_qos_sysfs_mtx);
/*
* If the device's PM QoS resume latency limit or PM QoS flags have been
* exposed to user space, they have to be hidden at this point.
*/
pm_qos_sysfs_remove_resume_latency(dev);
pm_qos_sysfs_remove_flags(dev);
mutex_lock(&dev_pm_qos_mtx);
__dev_pm_qos_hide_latency_limit(dev);
__dev_pm_qos_hide_flags(dev);
qos = dev->power.qos;
if (!qos)
goto out;
/* Flush the constraints lists for the device. */
c = &qos->resume_latency;
plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
/*
* Update constraints list and call the notification
* callbacks if needed
*/
apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
memset(req, 0, sizeof(*req));
}
c = &qos->latency_tolerance;
plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
memset(req, 0, sizeof(*req));
}
f = &qos->flags;
list_for_each_entry_safe(req, tmp, &f->list, data.flr.node) {
apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
memset(req, 0, sizeof(*req));
}
spin_lock_irq(&dev->power.lock);
dev->power.qos = ERR_PTR(-ENODEV);
spin_unlock_irq(&dev->power.lock);
kfree(c->notifiers);
kfree(qos);
out:
mutex_unlock(&dev_pm_qos_mtx);
mutex_unlock(&dev_pm_qos_sysfs_mtx);
}
static bool dev_pm_qos_invalid_request(struct device *dev,
struct dev_pm_qos_request *req)
{
return !req || (req->type == DEV_PM_QOS_LATENCY_TOLERANCE
&& !dev->power.set_latency_tolerance);
}
static int __dev_pm_qos_add_request(struct device *dev,
struct dev_pm_qos_request *req,
enum dev_pm_qos_req_type type, s32 value)
{
int ret = 0;
if (!dev || dev_pm_qos_invalid_request(dev, req))
return -EINVAL;
if (WARN(dev_pm_qos_request_active(req),
"%s() called for already added request\n", __func__))
return -EINVAL;
if (IS_ERR(dev->power.qos))
ret = -ENODEV;
else if (!dev->power.qos)
ret = dev_pm_qos_constraints_allocate(dev);
trace_dev_pm_qos_add_request(dev_name(dev), type, value);
if (!ret) {
req->dev = dev;
req->type = type;
ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
}
return ret;
}
/**
* 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
* requested qos performance characteristics. It recomputes the aggregate
* QoS expectations of parameters and initializes the dev_pm_qos_request
* handle. Caller needs to save this handle for later use in updates and
* removal.
*
* Returns 1 if the aggregated constraint value has changed,
* 0 if the aggregated constraint value has not changed,
* -EINVAL in case of wrong parameters, -ENOMEM if there's not enough memory
* to allocate for data structures, -ENODEV if the device has just been removed
* from the system.
*
* Callers should ensure that the target device is not RPM_SUSPENDED before
* using this function for requests of type DEV_PM_QOS_FLAGS.
*/
int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
enum dev_pm_qos_req_type type, s32 value)
{
int ret;
mutex_lock(&dev_pm_qos_mtx);
ret = __dev_pm_qos_add_request(dev, req, type, value);
mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
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.
*/
static 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 */
return -EINVAL;
if (WARN(!dev_pm_qos_request_active(req),
"%s() called for unknown object\n", __func__))
return -EINVAL;
if (IS_ERR_OR_NULL(req->dev->power.qos))
return -ENODEV;
switch(req->type) {
case DEV_PM_QOS_RESUME_LATENCY:
case DEV_PM_QOS_LATENCY_TOLERANCE:
curr_value = req->data.pnode.prio;
break;
case DEV_PM_QOS_FLAGS:
curr_value = req->data.flr.flags;
break;
default:
return -EINVAL;
}
trace_dev_pm_qos_update_request(dev_name(req->dev), req->type,
new_value);
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
*
* Updates an existing dev PM qos request along with updating the
* target value.
*
* Attempts are made to make this code callable on hot code paths.
*
* Returns 1 if the aggregated constraint value has changed,
* 0 if the aggregated constraint value has not changed,
* -EINVAL in case of wrong parameters, -ENODEV if the device has been
* removed from the system
*
* Callers should ensure that the target device is not RPM_SUSPENDED before
* using this function for requests of type DEV_PM_QOS_FLAGS.
*/
int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
{
int ret;
mutex_lock(&dev_pm_qos_mtx);
ret = __dev_pm_qos_update_request(req, new_value);
mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
static int __dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
{
int ret;
if (!req) /*guard against callers passing in null */
return -EINVAL;
if (WARN(!dev_pm_qos_request_active(req),
"%s() called for unknown object\n", __func__))
return -EINVAL;
if (IS_ERR_OR_NULL(req->dev->power.qos))
return -ENODEV;
trace_dev_pm_qos_remove_request(dev_name(req->dev), req->type,
PM_QOS_DEFAULT_VALUE);
ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
memset(req, 0, sizeof(*req));
return ret;
}
/**
* dev_pm_qos_remove_request - modifies an existing qos request
* @req: handle to request list element
*
* Will remove pm qos request from the list of constraints and
* recompute the current target value. Call this on slow code paths.
*
* Returns 1 if the aggregated constraint value has changed,
* 0 if the aggregated constraint value has not changed,
* -EINVAL in case of wrong parameters, -ENODEV if the device has been
* removed from the system
*
* Callers should ensure that the target device is not RPM_SUSPENDED before
* using this function for requests of type DEV_PM_QOS_FLAGS.
*/
int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
{
int ret;
mutex_lock(&dev_pm_qos_mtx);
ret = __dev_pm_qos_remove_request(req);
mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
/**
* dev_pm_qos_add_notifier - sets notification entry for changes to target value
* of per-device PM QoS constraints
*
* @dev: target device for the constraint
* @notifier: notifier block managed by caller.
*
* Will register the notifier into a notification chain that gets called
* upon changes to the target value for the device.
*
* If the device's constraints object doesn't exist when this routine is called,
* it will be created (or error code will be returned if that fails).
*/
int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
{
int ret = 0;
mutex_lock(&dev_pm_qos_mtx);
if (IS_ERR(dev->power.qos))
ret = -ENODEV;
else if (!dev->power.qos)
ret = dev_pm_qos_constraints_allocate(dev);
if (!ret)
ret = blocking_notifier_chain_register(dev->power.qos->resume_latency.notifiers,
notifier);
mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);
/**
* dev_pm_qos_remove_notifier - deletes notification for changes to target value
* of per-device PM QoS constraints
*
* @dev: target device for the constraint
* @notifier: notifier block to be removed.
*
* Will remove the notifier from the notification chain that gets called
* upon changes to the target value.
*/
int dev_pm_qos_remove_notifier(struct device *dev,
struct notifier_block *notifier)
{
int retval = 0;
mutex_lock(&dev_pm_qos_mtx);
/* Silently return if the constraints object is not present. */
if (!IS_ERR_OR_NULL(dev->power.qos))
retval = blocking_notifier_chain_unregister(dev->power.qos->resume_latency.notifiers,
notifier);
mutex_unlock(&dev_pm_qos_mtx);
return retval;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier);
/**
* dev_pm_qos_add_global_notifier - sets notification entry for changes to
* target value of the PM QoS constraints for any device
*
* @notifier: notifier block managed by caller.
*
* Will register the notifier into a notification chain that gets called
* upon changes to the target value for any device.
*/
int dev_pm_qos_add_global_notifier(struct notifier_block *notifier)
{
return blocking_notifier_chain_register(&dev_pm_notifiers, notifier);
}
EXPORT_SYMBOL_GPL(dev_pm_qos_add_global_notifier);
/**
* dev_pm_qos_remove_global_notifier - deletes notification for changes to
* target value of PM QoS constraints for any device
*
* @notifier: notifier block to be removed.
*
* Will remove the notifier from the notification chain that gets called
* upon changes to the target value for any device.
*/
int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier)
{
return blocking_notifier_chain_unregister(&dev_pm_notifiers, notifier);
}
EXPORT_SYMBOL_GPL(dev_pm_qos_remove_global_notifier);
/**
* dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor.
* @dev: Device whose ancestor to add the request for.
* @req: Pointer to the preallocated handle.
* @type: Type of the request.
* @value: Constraint latency value.
*/
int dev_pm_qos_add_ancestor_request(struct device *dev,
struct dev_pm_qos_request *req,
enum dev_pm_qos_req_type type, s32 value)
{
struct device *ancestor = dev->parent;
int ret = -ENODEV;
switch (type) {
case DEV_PM_QOS_RESUME_LATENCY:
while (ancestor && !ancestor->power.ignore_children)
ancestor = ancestor->parent;
break;
case DEV_PM_QOS_LATENCY_TOLERANCE:
while (ancestor && !ancestor->power.set_latency_tolerance)
ancestor = ancestor->parent;
break;
default:
ancestor = NULL;
}
if (ancestor)
ret = dev_pm_qos_add_request(ancestor, req, type, value);
if (ret < 0)
req->dev = NULL;
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
static void __dev_pm_qos_drop_user_request(struct device *dev,
enum dev_pm_qos_req_type type)
{
struct dev_pm_qos_request *req = NULL;
switch(type) {
case DEV_PM_QOS_RESUME_LATENCY:
req = dev->power.qos->resume_latency_req;
dev->power.qos->resume_latency_req = NULL;
break;
case DEV_PM_QOS_LATENCY_TOLERANCE:
req = dev->power.qos->latency_tolerance_req;
dev->power.qos->latency_tolerance_req = NULL;
break;
case DEV_PM_QOS_FLAGS:
req = dev->power.qos->flags_req;
dev->power.qos->flags_req = NULL;
break;
}
__dev_pm_qos_remove_request(req);
kfree(req);
}
static void dev_pm_qos_drop_user_request(struct device *dev,
enum dev_pm_qos_req_type type)
{
mutex_lock(&dev_pm_qos_mtx);
__dev_pm_qos_drop_user_request(dev, type);
mutex_unlock(&dev_pm_qos_mtx);
}
/**
* dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space.
* @dev: Device whose PM QoS latency limit is to be exposed to user space.
* @value: Initial value of the latency limit.
*/
int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
{
struct dev_pm_qos_request *req;
int ret;
if (!device_is_registered(dev) || value < 0)
return -EINVAL;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_RESUME_LATENCY, value);
if (ret < 0) {
kfree(req);
return ret;
}
mutex_lock(&dev_pm_qos_sysfs_mtx);
mutex_lock(&dev_pm_qos_mtx);
if (IS_ERR_OR_NULL(dev->power.qos))
ret = -ENODEV;
else if (dev->power.qos->resume_latency_req)
ret = -EEXIST;
if (ret < 0) {
__dev_pm_qos_remove_request(req);
kfree(req);
mutex_unlock(&dev_pm_qos_mtx);
goto out;
}
dev->power.qos->resume_latency_req = req;
mutex_unlock(&dev_pm_qos_mtx);
ret = pm_qos_sysfs_add_resume_latency(dev);
if (ret)
dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY);
out:
mutex_unlock(&dev_pm_qos_sysfs_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit);
static void __dev_pm_qos_hide_latency_limit(struct device *dev)
{
if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->resume_latency_req)
__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY);
}
/**
* dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space.
* @dev: Device whose PM QoS latency limit is to be hidden from user space.
*/
void dev_pm_qos_hide_latency_limit(struct device *dev)
{
mutex_lock(&dev_pm_qos_sysfs_mtx);
pm_qos_sysfs_remove_resume_latency(dev);
mutex_lock(&dev_pm_qos_mtx);
__dev_pm_qos_hide_latency_limit(dev);
mutex_unlock(&dev_pm_qos_mtx);
mutex_unlock(&dev_pm_qos_sysfs_mtx);
}
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;
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) {
kfree(req);
return ret;
}
pm_runtime_get_sync(dev);
mutex_lock(&dev_pm_qos_sysfs_mtx);
mutex_lock(&dev_pm_qos_mtx);
if (IS_ERR_OR_NULL(dev->power.qos))
ret = -ENODEV;
else if (dev->power.qos->flags_req)
ret = -EEXIST;
if (ret < 0) {
__dev_pm_qos_remove_request(req);
kfree(req);
mutex_unlock(&dev_pm_qos_mtx);
goto out;
}
dev->power.qos->flags_req = req;
mutex_unlock(&dev_pm_qos_mtx);
ret = pm_qos_sysfs_add_flags(dev);
if (ret)
dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
out:
mutex_unlock(&dev_pm_qos_sysfs_mtx);
pm_runtime_put(dev);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags);
static void __dev_pm_qos_hide_flags(struct device *dev)
{
if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req)
__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_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)
{
pm_runtime_get_sync(dev);
mutex_lock(&dev_pm_qos_sysfs_mtx);
pm_qos_sysfs_remove_flags(dev);
mutex_lock(&dev_pm_qos_mtx);
__dev_pm_qos_hide_flags(dev);
mutex_unlock(&dev_pm_qos_mtx);
mutex_unlock(&dev_pm_qos_sysfs_mtx);
pm_runtime_put(dev);
}
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;
pm_runtime_get_sync(dev);
mutex_lock(&dev_pm_qos_mtx);
if (IS_ERR_OR_NULL(dev->power.qos) || !dev->power.qos->flags_req) {
ret = -EINVAL;
goto out;
}
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);
out:
mutex_unlock(&dev_pm_qos_mtx);
pm_runtime_put(dev);
return ret;
}
/**
* dev_pm_qos_get_user_latency_tolerance - Get user space latency tolerance.
* @dev: Device to obtain the user space latency tolerance for.
*/
s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev)
{
s32 ret;
mutex_lock(&dev_pm_qos_mtx);
ret = IS_ERR_OR_NULL(dev->power.qos)
|| !dev->power.qos->latency_tolerance_req ?
PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT :
dev->power.qos->latency_tolerance_req->data.pnode.prio;
mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
/**
* dev_pm_qos_update_user_latency_tolerance - Update user space latency tolerance.
* @dev: Device to update the user space latency tolerance for.
* @val: New user space latency tolerance for @dev (negative values disable).
*/
int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
{
int ret;
mutex_lock(&dev_pm_qos_mtx);
if (IS_ERR_OR_NULL(dev->power.qos)
|| !dev->power.qos->latency_tolerance_req) {
struct dev_pm_qos_request *req;
if (val < 0) {
ret = -EINVAL;
goto out;
}
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req) {
ret = -ENOMEM;
goto out;
}
ret = __dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY_TOLERANCE, val);
if (ret < 0) {
kfree(req);
goto out;
}
dev->power.qos->latency_tolerance_req = req;
} else {
if (val < 0) {
__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY_TOLERANCE);
ret = 0;
} else {
ret = __dev_pm_qos_update_request(dev->power.qos->latency_tolerance_req, val);
}
}
out:
mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
/**
* dev_pm_qos_expose_latency_tolerance - Expose latency tolerance to userspace
* @dev: Device whose latency tolerance to expose
*/
int dev_pm_qos_expose_latency_tolerance(struct device *dev)
{
int ret;
if (!dev->power.set_latency_tolerance)
return -EINVAL;
mutex_lock(&dev_pm_qos_sysfs_mtx);
ret = pm_qos_sysfs_add_latency_tolerance(dev);
mutex_unlock(&dev_pm_qos_sysfs_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_tolerance);
/**
* dev_pm_qos_hide_latency_tolerance - Hide latency tolerance from userspace
* @dev: Device whose latency tolerance to hide
*/
void dev_pm_qos_hide_latency_tolerance(struct device *dev)
{
mutex_lock(&dev_pm_qos_sysfs_mtx);
pm_qos_sysfs_remove_latency_tolerance(dev);
mutex_unlock(&dev_pm_qos_sysfs_mtx);
/* Remove the request from user space now */
pm_runtime_get_sync(dev);
dev_pm_qos_update_user_latency_tolerance(dev,
PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT);
pm_runtime_put(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance);