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- /*
- * 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);
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