diff options
Diffstat (limited to 'kernel/power/qos.c')
| -rw-r--r-- | kernel/power/qos.c | 858 |
1 files changed, 520 insertions, 338 deletions
diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 06fe28589e9c..f7d8064e9adc 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -1,30 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0-only /* - * This module exposes the interface to kernel space for specifying - * QoS dependencies. It provides infrastructure for registration of: + * Power Management Quality of Service (PM QoS) support base. * - * Dependents on a QoS value : register requests - * Watchers of QoS value : get notified when target QoS value changes + * Copyright (C) 2020 Intel Corporation * - * 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. + * Authors: + * Mark Gross <mgross@linux.intel.com> + * Rafael J. Wysocki <rafael.j.wysocki@intel.com> * - * There are 3 basic classes of QoS parameter: latency, timeout, throughput - * each have defined units: - * latency: usec - * timeout: usec <-- currently not used. - * throughput: kbs (kilo byte / sec) + * Provided here is an interface for specifying PM QoS dependencies. It allows + * entities depending on QoS constraints to register their requests which are + * aggregated as appropriate to produce effective constraints (target values) + * that can be monitored by entities needing to respect them, either by polling + * or through a built-in notification mechanism. * - * There are lists of pm_qos_objects each one wrapping requests, notifiers - * - * User mode requests on a QOS parameter register themselves to the - * subsystem by opening the device node /dev/... and writing there request to - * the node. As long as the process holds a file handle open to the node the - * client continues to be accounted for. Upon file release the usermode - * request is removed and a new qos target is computed. This way when the - * request that the application has is cleaned up when closes the file - * pointer or exits the pm_qos_object will get an opportunity to clean up. - * - * Mark Gross <mgross@linux.intel.com> + * In addition to the basic functionality, more specific interfaces for managing + * global CPU latency QoS requests and frequency QoS requests are provided. */ /*#define DEBUG*/ @@ -41,6 +32,8 @@ #include <linux/platform_device.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> #include <linux/uaccess.h> #include <linux/export.h> @@ -51,84 +44,21 @@ * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock * held, taken with _irqsave. One lock to rule them all */ -struct pm_qos_object { - struct pm_qos_constraints *constraints; - struct miscdevice pm_qos_power_miscdev; - char *name; -}; - static DEFINE_SPINLOCK(pm_qos_lock); -static struct pm_qos_object null_pm_qos; - -static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); -static struct pm_qos_constraints cpu_dma_constraints = { - .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), - .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, - .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, - .type = PM_QOS_MIN, - .notifiers = &cpu_dma_lat_notifier, -}; -static struct pm_qos_object cpu_dma_pm_qos = { - .constraints = &cpu_dma_constraints, - .name = "cpu_dma_latency", -}; - -static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); -static struct pm_qos_constraints network_lat_constraints = { - .list = PLIST_HEAD_INIT(network_lat_constraints.list), - .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, - .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, - .type = PM_QOS_MIN, - .notifiers = &network_lat_notifier, -}; -static struct pm_qos_object network_lat_pm_qos = { - .constraints = &network_lat_constraints, - .name = "network_latency", -}; - - -static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); -static struct pm_qos_constraints network_tput_constraints = { - .list = PLIST_HEAD_INIT(network_tput_constraints.list), - .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, - .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, - .type = PM_QOS_MAX, - .notifiers = &network_throughput_notifier, -}; -static struct pm_qos_object network_throughput_pm_qos = { - .constraints = &network_tput_constraints, - .name = "network_throughput", -}; - - -static struct pm_qos_object *pm_qos_array[] = { - &null_pm_qos, - &cpu_dma_pm_qos, - &network_lat_pm_qos, - &network_throughput_pm_qos -}; - -static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, - size_t count, loff_t *f_pos); -static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, - size_t count, loff_t *f_pos); -static int pm_qos_power_open(struct inode *inode, struct file *filp); -static int pm_qos_power_release(struct inode *inode, struct file *filp); - -static const struct file_operations pm_qos_power_fops = { - .write = pm_qos_power_write, - .read = pm_qos_power_read, - .open = pm_qos_power_open, - .release = pm_qos_power_release, - .llseek = noop_llseek, -}; +/** + * pm_qos_read_value - Return the current effective constraint value. + * @c: List of PM QoS constraint requests. + */ +s32 pm_qos_read_value(struct pm_qos_constraints *c) +{ + return READ_ONCE(c->target_value); +} -/* unlocked internal variant */ -static inline int pm_qos_get_value(struct pm_qos_constraints *c) +static int pm_qos_get_value(struct pm_qos_constraints *c) { if (plist_head_empty(&c->list)) - return c->default_value; + return c->no_constraint_value; switch (c->type) { case PM_QOS_MIN: @@ -138,40 +68,41 @@ static inline int pm_qos_get_value(struct pm_qos_constraints *c) return plist_last(&c->list)->prio; default: - /* runtime check for not using enum */ - BUG(); + WARN(1, "Unknown PM QoS type in %s\n", __func__); return PM_QOS_DEFAULT_VALUE; } } -s32 pm_qos_read_value(struct pm_qos_constraints *c) +static void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) { - return c->target_value; -} - -static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) -{ - c->target_value = value; + WRITE_ONCE(c->target_value, value); } /** - * pm_qos_update_target - manages the constraints list and calls the notifiers - * if needed - * @c: constraints data struct - * @node: request to add to the list, to update or to remove - * @action: action to take on the constraints list - * @value: value of the request to add or update + * pm_qos_update_target - Update a list of PM QoS constraint requests. + * @c: List of PM QoS requests. + * @node: Target list entry. + * @action: Action to carry out (add, update or remove). + * @value: New request value for the target list entry. + * + * Update the given list of PM QoS constraint requests, @c, by carrying an + * @action involving the @node list entry and @value on it. * - * This function returns 1 if the aggregated constraint value has changed, 0 - * otherwise. + * The recognized values of @action are PM_QOS_ADD_REQ (store @value in @node + * and add it to the list), PM_QOS_UPDATE_REQ (remove @node from the list, store + * @value in it and add it to the list again), and PM_QOS_REMOVE_REQ (remove + * @node from the list, ignore @value). + * + * Return: 1 if the aggregate constraint value has changed, 0 otherwise. */ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, enum pm_qos_req_action action, int value) { - unsigned long flags; int prev_value, curr_value, new_value; + unsigned long flags; spin_lock_irqsave(&pm_qos_lock, flags); + prev_value = pm_qos_get_value(c); if (value == PM_QOS_DEFAULT_VALUE) new_value = c->default_value; @@ -184,11 +115,11 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, break; case PM_QOS_UPDATE_REQ: /* - * to change the list, we atomically remove, reinit - * with new value and add, then see if the extremal - * changed + * To change the list, atomically remove, reinit with new value + * and add, then see if the aggregate has changed. */ plist_del(node, &c->list); + fallthrough; case PM_QOS_ADD_REQ: plist_node_init(node, new_value); plist_add(node, &c->list); @@ -204,14 +135,14 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, spin_unlock_irqrestore(&pm_qos_lock, flags); trace_pm_qos_update_target(action, prev_value, curr_value); - if (prev_value != curr_value) { - blocking_notifier_call_chain(c->notifiers, - (unsigned long)curr_value, - NULL); - return 1; - } else { + + if (prev_value == curr_value) return 0; - } + + if (c->notifiers) + blocking_notifier_call_chain(c->notifiers, curr_value, NULL); + + return 1; } /** @@ -233,14 +164,12 @@ static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, /** * pm_qos_update_flags - Update a set of PM QoS flags. - * @pqf: Set of flags to update. + * @pqf: Set of PM QoS 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. + * Return: 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, @@ -259,6 +188,7 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, break; case PM_QOS_UPDATE_REQ: pm_qos_flags_remove_req(pqf, req); + fallthrough; case PM_QOS_ADD_REQ: req->flags = val; INIT_LIST_HEAD(&req->node); @@ -275,333 +205,585 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, spin_unlock_irqrestore(&pm_qos_lock, irqflags); trace_pm_qos_update_flags(action, prev_value, curr_value); + return prev_value != curr_value; } -/** - * pm_qos_request - returns current system wide qos expectation - * @pm_qos_class: identification of which qos value is requested - * - * This function returns the current target value. - */ -int pm_qos_request(int pm_qos_class) -{ - return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); -} -EXPORT_SYMBOL_GPL(pm_qos_request); +#ifdef CONFIG_CPU_IDLE +/* Definitions related to the CPU latency QoS. */ + +static struct pm_qos_constraints cpu_latency_constraints = { + .list = PLIST_HEAD_INIT(cpu_latency_constraints.list), + .target_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE, + .default_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE, + .no_constraint_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE, + .type = PM_QOS_MIN, +}; -int pm_qos_request_active(struct pm_qos_request *req) +static inline bool cpu_latency_qos_value_invalid(s32 value) { - return req->pm_qos_class != 0; + return value < 0 && value != PM_QOS_DEFAULT_VALUE; } -EXPORT_SYMBOL_GPL(pm_qos_request_active); /** - * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout - * @work: work struct for the delayed work (timeout) - * - * This cancels the timeout request by falling back to the default at timeout. + * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit. */ -static void pm_qos_work_fn(struct work_struct *work) +s32 cpu_latency_qos_limit(void) { - struct pm_qos_request *req = container_of(to_delayed_work(work), - struct pm_qos_request, - work); - - pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); + return pm_qos_read_value(&cpu_latency_constraints); } /** - * pm_qos_add_request - inserts new qos request into the list - * @req: pointer to a preallocated handle - * @pm_qos_class: identifies which list of qos request to use - * @value: defines the qos request + * cpu_latency_qos_request_active - Check the given PM QoS request. + * @req: PM QoS request to check. * - * This function inserts a new entry in the pm_qos_class list of requested qos - * performance characteristics. It recomputes the aggregate QoS expectations - * for the pm_qos_class of parameters and initializes the pm_qos_request - * handle. Caller needs to save this handle for later use in updates and - * removal. + * Return: 'true' if @req has been added to the CPU latency QoS list, 'false' + * otherwise. */ - -void pm_qos_add_request(struct pm_qos_request *req, - int pm_qos_class, s32 value) +bool cpu_latency_qos_request_active(struct pm_qos_request *req) { - if (!req) /*guard against callers passing in null */ - return; + return req->qos == &cpu_latency_constraints; +} +EXPORT_SYMBOL_GPL(cpu_latency_qos_request_active); - if (pm_qos_request_active(req)) { - WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); - return; - } - req->pm_qos_class = pm_qos_class; - INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); - trace_pm_qos_add_request(pm_qos_class, value); - pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, - &req->node, PM_QOS_ADD_REQ, value); +static void cpu_latency_qos_apply(struct pm_qos_request *req, + enum pm_qos_req_action action, s32 value) +{ + int ret = pm_qos_update_target(req->qos, &req->node, action, value); + if (ret > 0) + wake_up_all_idle_cpus(); } -EXPORT_SYMBOL_GPL(pm_qos_add_request); /** - * pm_qos_update_request - modifies an existing qos request - * @req : handle to list element holding a pm_qos request to use - * @value: defines the qos request + * cpu_latency_qos_add_request - Add new CPU latency QoS request. + * @req: Pointer to a preallocated handle. + * @value: Requested constraint value. * - * Updates an existing qos request for the pm_qos_class of parameters along - * with updating the target pm_qos_class value. + * Use @value to initialize the request handle pointed to by @req, insert it as + * a new entry to the CPU latency QoS list and recompute the effective QoS + * constraint for that list. * - * Attempts are made to make this code callable on hot code paths. + * Callers need to save the handle for later use in updates and removal of the + * QoS request represented by it. */ -void pm_qos_update_request(struct pm_qos_request *req, - s32 new_value) +void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value) { - if (!req) /*guard against callers passing in null */ + if (!req || cpu_latency_qos_value_invalid(value)) return; - if (!pm_qos_request_active(req)) { - WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); + if (cpu_latency_qos_request_active(req)) { + WARN(1, KERN_ERR "%s called for already added request\n", __func__); return; } - cancel_delayed_work_sync(&req->work); + trace_pm_qos_add_request(value); - trace_pm_qos_update_request(req->pm_qos_class, new_value); - if (new_value != req->node.prio) - pm_qos_update_target( - pm_qos_array[req->pm_qos_class]->constraints, - &req->node, PM_QOS_UPDATE_REQ, new_value); + req->qos = &cpu_latency_constraints; + cpu_latency_qos_apply(req, PM_QOS_ADD_REQ, value); } -EXPORT_SYMBOL_GPL(pm_qos_update_request); +EXPORT_SYMBOL_GPL(cpu_latency_qos_add_request); /** - * pm_qos_update_request_timeout - modifies an existing qos request temporarily. - * @req : handle to list element holding a pm_qos request to use - * @new_value: defines the temporal qos request - * @timeout_us: the effective duration of this qos request in usecs. + * cpu_latency_qos_update_request - Modify existing CPU latency QoS request. + * @req : QoS request to update. + * @new_value: New requested constraint value. * - * After timeout_us, this qos request is cancelled automatically. + * Use @new_value to update the QoS request represented by @req in the CPU + * latency QoS list along with updating the effective constraint value for that + * list. */ -void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, - unsigned long timeout_us) +void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value) { - if (!req) + if (!req || cpu_latency_qos_value_invalid(new_value)) return; - if (WARN(!pm_qos_request_active(req), - "%s called for unknown object.", __func__)) + + if (!cpu_latency_qos_request_active(req)) { + WARN(1, KERN_ERR "%s called for unknown object\n", __func__); return; + } - cancel_delayed_work_sync(&req->work); + trace_pm_qos_update_request(new_value); - trace_pm_qos_update_request_timeout(req->pm_qos_class, - new_value, timeout_us); - if (new_value != req->node.prio) - pm_qos_update_target( - pm_qos_array[req->pm_qos_class]->constraints, - &req->node, PM_QOS_UPDATE_REQ, new_value); + if (new_value == req->node.prio) + return; - schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); + cpu_latency_qos_apply(req, PM_QOS_UPDATE_REQ, new_value); } +EXPORT_SYMBOL_GPL(cpu_latency_qos_update_request); /** - * pm_qos_remove_request - modifies an existing qos request - * @req: handle to request list element + * cpu_latency_qos_remove_request - Remove existing CPU latency QoS request. + * @req: QoS request to remove. * - * Will remove pm qos request from the list of constraints and - * recompute the current target value for the pm_qos_class. Call this - * on slow code paths. + * Remove the CPU latency QoS request represented by @req from the CPU latency + * QoS list along with updating the effective constraint value for that list. */ -void pm_qos_remove_request(struct pm_qos_request *req) +void cpu_latency_qos_remove_request(struct pm_qos_request *req) { - if (!req) /*guard against callers passing in null */ + if (!req) return; - /* silent return to keep pcm code cleaner */ - if (!pm_qos_request_active(req)) { - WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); + if (!cpu_latency_qos_request_active(req)) { + WARN(1, KERN_ERR "%s called for unknown object\n", __func__); return; } - cancel_delayed_work_sync(&req->work); + trace_pm_qos_remove_request(PM_QOS_DEFAULT_VALUE); - trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE); - pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, - &req->node, PM_QOS_REMOVE_REQ, - PM_QOS_DEFAULT_VALUE); + cpu_latency_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } -EXPORT_SYMBOL_GPL(pm_qos_remove_request); +EXPORT_SYMBOL_GPL(cpu_latency_qos_remove_request); -/** - * pm_qos_add_notifier - sets notification entry for changes to target value - * @pm_qos_class: identifies which qos target changes should be notified. - * @notifier: notifier block managed by caller. - * - * will register the notifier into a notification chain that gets called - * upon changes to the pm_qos_class target value. - */ -int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) +/* User space interface to the CPU latency QoS via misc device. */ + +static int cpu_latency_qos_open(struct inode *inode, struct file *filp) { - int retval; + struct pm_qos_request *req; - retval = blocking_notifier_chain_register( - pm_qos_array[pm_qos_class]->constraints->notifiers, - notifier); + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return -ENOMEM; + + cpu_latency_qos_add_request(req, PM_QOS_DEFAULT_VALUE); + filp->private_data = req; - return retval; + return 0; } -EXPORT_SYMBOL_GPL(pm_qos_add_notifier); -/** - * pm_qos_remove_notifier - deletes notification entry from chain. - * @pm_qos_class: identifies which qos target changes are notified. - * @notifier: notifier block to be removed. - * - * will remove the notifier from the notification chain that gets called - * upon changes to the pm_qos_class target value. - */ -int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) +static int cpu_latency_qos_release(struct inode *inode, struct file *filp) { - int retval; + struct pm_qos_request *req = filp->private_data; - retval = blocking_notifier_chain_unregister( - pm_qos_array[pm_qos_class]->constraints->notifiers, - notifier); + filp->private_data = NULL; - return retval; + cpu_latency_qos_remove_request(req); + kfree(req); + + return 0; } -EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); -/* User space interface to PM QoS classes via misc devices */ -static int register_pm_qos_misc(struct pm_qos_object *qos) +static ssize_t cpu_latency_qos_read(struct file *filp, char __user *buf, + size_t count, loff_t *f_pos) { - qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; - qos->pm_qos_power_miscdev.name = qos->name; - qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; + struct pm_qos_request *req = filp->private_data; + unsigned long flags; + s32 value; + + if (!req || !cpu_latency_qos_request_active(req)) + return -EINVAL; - return misc_register(&qos->pm_qos_power_miscdev); + spin_lock_irqsave(&pm_qos_lock, flags); + value = pm_qos_get_value(&cpu_latency_constraints); + spin_unlock_irqrestore(&pm_qos_lock, flags); + + return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); } -static int find_pm_qos_object_by_minor(int minor) +static ssize_t cpu_latency_qos_write(struct file *filp, const char __user *buf, + size_t count, loff_t *f_pos) { - int pm_qos_class; + s32 value; - for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY; - pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { - if (minor == - pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) - return pm_qos_class; + if (count == sizeof(s32)) { + if (copy_from_user(&value, buf, sizeof(s32))) + return -EFAULT; + } else { + int ret; + + ret = kstrtos32_from_user(buf, count, 16, &value); + if (ret) + return ret; } - return -1; + + cpu_latency_qos_update_request(filp->private_data, value); + + return count; } -static int pm_qos_power_open(struct inode *inode, struct file *filp) -{ - long pm_qos_class; +static const struct file_operations cpu_latency_qos_fops = { + .write = cpu_latency_qos_write, + .read = cpu_latency_qos_read, + .open = cpu_latency_qos_open, + .release = cpu_latency_qos_release, + .llseek = noop_llseek, +}; - pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); - if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) { - struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); - if (!req) - return -ENOMEM; +static struct miscdevice cpu_latency_qos_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "cpu_dma_latency", + .fops = &cpu_latency_qos_fops, +}; - pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); - filp->private_data = req; +#ifdef CONFIG_PM_QOS_CPU_SYSTEM_WAKEUP +/* The CPU system wakeup latency QoS. */ +static struct pm_qos_constraints cpu_wakeup_latency_constraints = { + .list = PLIST_HEAD_INIT(cpu_wakeup_latency_constraints.list), + .target_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT, + .default_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT, + .no_constraint_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT, + .type = PM_QOS_MIN, +}; - return 0; - } - return -EPERM; +/** + * cpu_wakeup_latency_qos_limit - Current CPU system wakeup latency QoS limit. + * + * Returns the current CPU system wakeup latency QoS limit that may have been + * requested by user space. + */ +s32 cpu_wakeup_latency_qos_limit(void) +{ + return pm_qos_read_value(&cpu_wakeup_latency_constraints); } -static int pm_qos_power_release(struct inode *inode, struct file *filp) +static int cpu_wakeup_latency_qos_open(struct inode *inode, struct file *filp) { struct pm_qos_request *req; - req = filp->private_data; - pm_qos_remove_request(req); - kfree(req); + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return -ENOMEM; + + req->qos = &cpu_wakeup_latency_constraints; + pm_qos_update_target(req->qos, &req->node, PM_QOS_ADD_REQ, + PM_QOS_RESUME_LATENCY_NO_CONSTRAINT); + filp->private_data = req; return 0; } - -static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, - size_t count, loff_t *f_pos) +static int cpu_wakeup_latency_qos_release(struct inode *inode, + struct file *filp) { - s32 value; - unsigned long flags; struct pm_qos_request *req = filp->private_data; - if (!req) - return -EINVAL; - if (!pm_qos_request_active(req)) - return -EINVAL; + filp->private_data = NULL; + pm_qos_update_target(req->qos, &req->node, PM_QOS_REMOVE_REQ, + PM_QOS_RESUME_LATENCY_NO_CONSTRAINT); + kfree(req); - spin_lock_irqsave(&pm_qos_lock, flags); - value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); - spin_unlock_irqrestore(&pm_qos_lock, flags); + return 0; +} + +static ssize_t cpu_wakeup_latency_qos_read(struct file *filp, char __user *buf, + size_t count, loff_t *f_pos) +{ + s32 value = pm_qos_read_value(&cpu_wakeup_latency_constraints); return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); } -static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, - size_t count, loff_t *f_pos) +static ssize_t cpu_wakeup_latency_qos_write(struct file *filp, + const char __user *buf, + size_t count, loff_t *f_pos) { + struct pm_qos_request *req = filp->private_data; s32 value; - struct pm_qos_request *req; if (count == sizeof(s32)) { if (copy_from_user(&value, buf, sizeof(s32))) return -EFAULT; - } else if (count <= 11) { /* ASCII perhaps? */ - char ascii_value[11]; - unsigned long int ulval; + } else { int ret; - if (copy_from_user(ascii_value, buf, count)) - return -EFAULT; + ret = kstrtos32_from_user(buf, count, 16, &value); + if (ret) + return ret; + } - if (count > 10) { - if (ascii_value[10] == '\n') - ascii_value[10] = '\0'; - else - return -EINVAL; - } else { - ascii_value[count] = '\0'; - } - ret = kstrtoul(ascii_value, 16, &ulval); - if (ret) { - pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); - return -EINVAL; - } - value = (s32)lower_32_bits(ulval); - } else { + if (value < 0) return -EINVAL; - } - req = filp->private_data; - pm_qos_update_request(req, value); + pm_qos_update_target(req->qos, &req->node, PM_QOS_UPDATE_REQ, value); return count; } +static const struct file_operations cpu_wakeup_latency_qos_fops = { + .open = cpu_wakeup_latency_qos_open, + .release = cpu_wakeup_latency_qos_release, + .read = cpu_wakeup_latency_qos_read, + .write = cpu_wakeup_latency_qos_write, + .llseek = noop_llseek, +}; -static int __init pm_qos_power_init(void) +static struct miscdevice cpu_wakeup_latency_qos_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "cpu_wakeup_latency", + .fops = &cpu_wakeup_latency_qos_fops, +}; +#endif /* CONFIG_PM_QOS_CPU_SYSTEM_WAKEUP */ + +static int __init cpu_latency_qos_init(void) { - int ret = 0; - int i; + int ret; - BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); + ret = misc_register(&cpu_latency_qos_miscdev); + if (ret < 0) + pr_err("%s: %s setup failed\n", __func__, + cpu_latency_qos_miscdev.name); - for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { - ret = register_pm_qos_misc(pm_qos_array[i]); - if (ret < 0) { - printk(KERN_ERR "pm_qos_param: %s setup failed\n", - pm_qos_array[i]->name); - return ret; - } +#ifdef CONFIG_PM_QOS_CPU_SYSTEM_WAKEUP + ret = misc_register(&cpu_wakeup_latency_qos_miscdev); + if (ret < 0) + pr_err("%s: %s setup failed\n", __func__, + cpu_wakeup_latency_qos_miscdev.name); +#endif + + return ret; +} +late_initcall(cpu_latency_qos_init); +#endif /* CONFIG_CPU_IDLE */ + +/* Definitions related to the frequency QoS below. */ + +static inline bool freq_qos_value_invalid(s32 value) +{ + return value < 0 && value != PM_QOS_DEFAULT_VALUE; +} + +/** + * freq_constraints_init - Initialize frequency QoS constraints. + * @qos: Frequency QoS constraints to initialize. + */ +void freq_constraints_init(struct freq_constraints *qos) +{ + struct pm_qos_constraints *c; + + c = &qos->min_freq; + plist_head_init(&c->list); + c->target_value = FREQ_QOS_MIN_DEFAULT_VALUE; + c->default_value = FREQ_QOS_MIN_DEFAULT_VALUE; + c->no_constraint_value = FREQ_QOS_MIN_DEFAULT_VALUE; + c->type = PM_QOS_MAX; + c->notifiers = &qos->min_freq_notifiers; + BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers); + + c = &qos->max_freq; + plist_head_init(&c->list); + c->target_value = FREQ_QOS_MAX_DEFAULT_VALUE; + c->default_value = FREQ_QOS_MAX_DEFAULT_VALUE; + c->no_constraint_value = FREQ_QOS_MAX_DEFAULT_VALUE; + c->type = PM_QOS_MIN; + c->notifiers = &qos->max_freq_notifiers; + BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers); +} + +/** + * freq_qos_read_value - Get frequency QoS constraint for a given list. + * @qos: Constraints to evaluate. + * @type: QoS request type. + */ +s32 freq_qos_read_value(struct freq_constraints *qos, + enum freq_qos_req_type type) +{ + s32 ret; + + switch (type) { + case FREQ_QOS_MIN: + ret = IS_ERR_OR_NULL(qos) ? + FREQ_QOS_MIN_DEFAULT_VALUE : + pm_qos_read_value(&qos->min_freq); + break; + case FREQ_QOS_MAX: + ret = IS_ERR_OR_NULL(qos) ? + FREQ_QOS_MAX_DEFAULT_VALUE : + pm_qos_read_value(&qos->max_freq); + break; + default: + WARN_ON(1); + ret = 0; + } + + return ret; +} + +/** + * freq_qos_apply - Add/modify/remove frequency QoS request. + * @req: Constraint request to apply. + * @action: Action to perform (add/update/remove). + * @value: Value to assign to the QoS request. + * + * This is only meant to be called from inside pm_qos, not drivers. + */ +int freq_qos_apply(struct freq_qos_request *req, + enum pm_qos_req_action action, s32 value) +{ + int ret; + + switch(req->type) { + case FREQ_QOS_MIN: + ret = pm_qos_update_target(&req->qos->min_freq, &req->pnode, + action, value); + break; + case FREQ_QOS_MAX: + ret = pm_qos_update_target(&req->qos->max_freq, &req->pnode, + action, value); + break; + default: + ret = -EINVAL; + } + + return ret; +} + +/** + * freq_qos_add_request - Insert new frequency QoS request into a given list. + * @qos: Constraints to update. + * @req: Preallocated request object. + * @type: Request type. + * @value: Request value. + * + * Insert a new entry into the @qos list of requests, recompute the effective + * QoS constraint value for that list and initialize the @req object. The + * caller needs to save that object for later use in updates and removal. + * + * Return 1 if the effective constraint value has changed, 0 if the effective + * constraint value has not changed, or a negative error code on failures. + */ +int freq_qos_add_request(struct freq_constraints *qos, + struct freq_qos_request *req, + enum freq_qos_req_type type, s32 value) +{ + int ret; + + if (IS_ERR_OR_NULL(qos) || !req || freq_qos_value_invalid(value)) + return -EINVAL; + + if (WARN(freq_qos_request_active(req), + "%s() called for active request\n", __func__)) + return -EINVAL; + + req->qos = qos; + req->type = type; + ret = freq_qos_apply(req, PM_QOS_ADD_REQ, value); + if (ret < 0) { + req->qos = NULL; + req->type = 0; } return ret; } +EXPORT_SYMBOL_GPL(freq_qos_add_request); + +/** + * freq_qos_update_request - Modify existing frequency QoS request. + * @req: Request to modify. + * @new_value: New request value. + * + * Update an existing frequency QoS request along with the effective constraint + * value for the list of requests it belongs to. + * + * Return 1 if the effective constraint value has changed, 0 if the effective + * constraint value has not changed, or a negative error code on failures. + */ +int freq_qos_update_request(struct freq_qos_request *req, s32 new_value) +{ + if (!req || freq_qos_value_invalid(new_value)) + return -EINVAL; + + if (WARN(!freq_qos_request_active(req), + "%s() called for unknown object\n", __func__)) + return -EINVAL; + + if (req->pnode.prio == new_value) + return 0; + + return freq_qos_apply(req, PM_QOS_UPDATE_REQ, new_value); +} +EXPORT_SYMBOL_GPL(freq_qos_update_request); + +/** + * freq_qos_remove_request - Remove frequency QoS request from its list. + * @req: Request to remove. + * + * Remove the given frequency QoS request from the list of constraints it + * belongs to and recompute the effective constraint value for that list. + * + * Return 1 if the effective constraint value has changed, 0 if the effective + * constraint value has not changed, or a negative error code on failures. + */ +int freq_qos_remove_request(struct freq_qos_request *req) +{ + int ret; + + if (!req) + return -EINVAL; + + if (WARN(!freq_qos_request_active(req), + "%s() called for unknown object\n", __func__)) + return -EINVAL; + + ret = freq_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); + req->qos = NULL; + req->type = 0; -late_initcall(pm_qos_power_init); + return ret; +} +EXPORT_SYMBOL_GPL(freq_qos_remove_request); + +/** + * freq_qos_add_notifier - Add frequency QoS change notifier. + * @qos: List of requests to add the notifier to. + * @type: Request type. + * @notifier: Notifier block to add. + */ +int freq_qos_add_notifier(struct freq_constraints *qos, + enum freq_qos_req_type type, + struct notifier_block *notifier) +{ + int ret; + + if (IS_ERR_OR_NULL(qos) || !notifier) + return -EINVAL; + + switch (type) { + case FREQ_QOS_MIN: + ret = blocking_notifier_chain_register(qos->min_freq.notifiers, + notifier); + break; + case FREQ_QOS_MAX: + ret = blocking_notifier_chain_register(qos->max_freq.notifiers, + notifier); + break; + default: + WARN_ON(1); + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(freq_qos_add_notifier); + +/** + * freq_qos_remove_notifier - Remove frequency QoS change notifier. + * @qos: List of requests to remove the notifier from. + * @type: Request type. + * @notifier: Notifier block to remove. + */ +int freq_qos_remove_notifier(struct freq_constraints *qos, + enum freq_qos_req_type type, + struct notifier_block *notifier) +{ + int ret; + + if (IS_ERR_OR_NULL(qos) || !notifier) + return -EINVAL; + + switch (type) { + case FREQ_QOS_MIN: + ret = blocking_notifier_chain_unregister(qos->min_freq.notifiers, + notifier); + break; + case FREQ_QOS_MAX: + ret = blocking_notifier_chain_unregister(qos->max_freq.notifiers, + notifier); + break; + default: + WARN_ON(1); + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(freq_qos_remove_notifier); |