/* * This module exposes the interface to kernel space for specifying * 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. * * 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) * * 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> */ /*#define DEBUG*/ #include <linux/pm_qos.h>#include <linux/sched.h>#include <linux/spinlock.h>#include <linux/slab.h>#include <linux/time.h>#include <linux/fs.h>#include <linux/device.h>#include <linux/miscdevice.h>#include <linux/string.h>#include <linux/platform_device.h>#include <linux/init.h>#include <linux/kernel.h> #include <linux/uaccess.h>#include <linux/export.h> /* * locking rule: all changes to constraints or notifiers lists * 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,}; /* unlocked internal variant */static inline int pm_qos_get_value(struct pm_qos_constraints *c){ if (plist_head_empty(&c->list)) return c->default_value; switch (c->type) { case PM_QOS_MIN: return plist_first(&c->list)->prio; case PM_QOS_MAX: return plist_last(&c->list)->prio; default: /* runtime check for not using enum */ BUG(); }} s32 pm_qos_read_value(struct pm_qos_constraints *c){ return c->target_value;} static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value){ 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 * * This function returns 1 if the aggregated 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; 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; else new_value = value; switch (action) { case PM_QOS_REMOVE_REQ: plist_del(node, &c->list); 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 */ plist_del(node, &c->list); case PM_QOS_ADD_REQ: plist_node_init(node, new_value); plist_add(node, &c->list); break; default: /* no action */ ; } curr_value = pm_qos_get_value(c); pm_qos_set_value(c, curr_value); spin_unlock_irqrestore(&pm_qos_lock, flags); if (prev_value != curr_value) { blocking_notifier_call_chain(c->notifiers, (unsigned long)curr_value, NULL); return 1; } else { return 0; }} /** * 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); int pm_qos_request_active(struct pm_qos_request *req){ return req->pm_qos_class != 0;}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. */static void pm_qos_work_fn(struct work_struct *work){ 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);} /** * 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 * * 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. */ void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value){ if (!req) /*guard against callers passing in null */ return; 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); pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, &req->node, PM_QOS_ADD_REQ, value);}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 * * Updates an existing qos request for the pm_qos_class of parameters along * with updating the target pm_qos_class value. * * Attempts are made to make this code callable on hot code paths. */void pm_qos_update_request(struct pm_qos_request *req, s32 new_value){ if (!req) /*guard against callers passing in null */ return; if (!pm_qos_request_active(req)) { WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); return; } if (delayed_work_pending(&req->work)) cancel_delayed_work_sync(&req->work); 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);}EXPORT_SYMBOL_GPL(pm_qos_update_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. * * After timeout_us, this qos request is cancelled automatically. */void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, unsigned long timeout_us){ if (!req) return; if (WARN(!pm_qos_request_active(req), "%s called for unknown object.", __func__)) return; if (delayed_work_pending(&req->work)) cancel_delayed_work_sync(&req->work); 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); schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us));} /** * 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 for the pm_qos_class. Call this * on slow code paths. */void pm_qos_remove_request(struct pm_qos_request *req){ if (!req) /*guard against callers passing in null */ 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"); return; } if (delayed_work_pending(&req->work)) cancel_delayed_work_sync(&req->work); pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, &req->node, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req));}EXPORT_SYMBOL_GPL(pm_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){ int retval; retval = blocking_notifier_chain_register( pm_qos_array[pm_qos_class]->constraints->notifiers, notifier); return retval;}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){ int retval; retval = blocking_notifier_chain_unregister( pm_qos_array[pm_qos_class]->constraints->notifiers, notifier); return retval;}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){ 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; return misc_register(&qos->pm_qos_power_miscdev);} static int find_pm_qos_object_by_minor(int minor){ int pm_qos_class; for (pm_qos_class = 0; 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; } return -1;} static int pm_qos_power_open(struct inode *inode, struct file *filp){ long pm_qos_class; pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); if (!req) return -ENOMEM; pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); filp->private_data = req; return 0; } return -EPERM;} static int pm_qos_power_release(struct inode *inode, struct file *filp){ struct pm_qos_request *req; req = filp->private_data; pm_qos_remove_request(req); kfree(req); return 0;} static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos){ 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; 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 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){ 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; int ret; if (copy_from_user(ascii_value, buf, count)) return -EFAULT; if (count > 10) { if (ascii_value[10] == '\n') ascii_value[10] = '\0'; else return -EINVAL; } else { ascii_value[count] = '\0';Lines 1–500 of 538. 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/* * This module exposes the interface to kernel space for specifying * 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. * * 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) * * 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> */ /*#define DEBUG*/ #include <linux/pm_qos.h> #include <linux/sched.h> #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/time.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/miscdevice.h> #include <linux/string.h> #include <linux/platform_device.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/uaccess.h> #include <linux/export.h> /* * locking rule: all changes to constraints or notifiers lists * 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, }; /* unlocked internal variant */ static inline int pm_qos_get_value(struct pm_qos_constraints *c) { if (plist_head_empty(&c->list)) return c->default_value; switch (c->type) { case PM_QOS_MIN: return plist_first(&c->list)->prio; case PM_QOS_MAX: return plist_last(&c->list)->prio; default: /* runtime check for not using enum */ BUG(); } } s32 pm_qos_read_value(struct pm_qos_constraints *c) { return c->target_value; } static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) { 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 * * This function returns 1 if the aggregated 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; 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; else new_value = value; switch (action) { case PM_QOS_REMOVE_REQ: plist_del(node, &c->list); 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 */ plist_del(node, &c->list); case PM_QOS_ADD_REQ: plist_node_init(node, new_value); plist_add(node, &c->list); break; default: /* no action */ ; } curr_value = pm_qos_get_value(c); pm_qos_set_value(c, curr_value); spin_unlock_irqrestore(&pm_qos_lock, flags); if (prev_value != curr_value) { blocking_notifier_call_chain(c->notifiers, (unsigned long)curr_value, NULL); return 1; } else { return 0; } } /** * 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); int pm_qos_request_active(struct pm_qos_request *req) { return req->pm_qos_class != 0; } 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. */ static void pm_qos_work_fn(struct work_struct *work) { 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); } /** * 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 * * 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. */ void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value) { if (!req) /*guard against callers passing in null */ return; 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); pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, &req->node, PM_QOS_ADD_REQ, value); } 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 * * Updates an existing qos request for the pm_qos_class of parameters along * with updating the target pm_qos_class value. * * Attempts are made to make this code callable on hot code paths. */ void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) { if (!req) /*guard against callers passing in null */ return; if (!pm_qos_request_active(req)) { WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); return; } if (delayed_work_pending(&req->work)) cancel_delayed_work_sync(&req->work); 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); } EXPORT_SYMBOL_GPL(pm_qos_update_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. * * After timeout_us, this qos request is cancelled automatically. */ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, unsigned long timeout_us) { if (!req) return; if (WARN(!pm_qos_request_active(req), "%s called for unknown object.", __func__)) return; if (delayed_work_pending(&req->work)) cancel_delayed_work_sync(&req->work); 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); schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); } /** * 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 for the pm_qos_class. Call this * on slow code paths. */ void pm_qos_remove_request(struct pm_qos_request *req) { if (!req) /*guard against callers passing in null */ 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"); return; } if (delayed_work_pending(&req->work)) cancel_delayed_work_sync(&req->work); pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, &req->node, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } EXPORT_SYMBOL_GPL(pm_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) { int retval; retval = blocking_notifier_chain_register( pm_qos_array[pm_qos_class]->constraints->notifiers, notifier); return retval; } 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) { int retval; retval = blocking_notifier_chain_unregister( pm_qos_array[pm_qos_class]->constraints->notifiers, notifier); return retval; } 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) { 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; return misc_register(&qos->pm_qos_power_miscdev); } static int find_pm_qos_object_by_minor(int minor) { int pm_qos_class; for (pm_qos_class = 0; 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; } return -1; } static int pm_qos_power_open(struct inode *inode, struct file *filp) { long pm_qos_class; pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); if (!req) return -ENOMEM; pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); filp->private_data = req; return 0; } return -EPERM; } static int pm_qos_power_release(struct inode *inode, struct file *filp) { struct pm_qos_request *req; req = filp->private_data; pm_qos_remove_request(req); kfree(req); return 0; } static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) { 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; 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 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) { 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; int ret; if (copy_from_user(ascii_value, buf, count)) return -EFAULT; if (count > 10) { if (ascii_value[10] == '\n') ascii_value[10] = '\0'; else return -EINVAL; } else { ascii_value[count] = '\0';