1 // SPDX-License-Identifier: GPL-2.0-only
3  * Power Management Quality of Service (PM QoS) support base.
11  * Provided here is an interface for specifying PM QoS dependencies.  It allows
15  * or through a built-in notification mechanism.
50  * pm_qos_read_value - Return the current effective constraint value.
51  * @c: List of PM QoS constraint requests.
55 	return READ_ONCE(c->target_value);  in pm_qos_read_value()
60 	if (plist_head_empty(&c->list))  in pm_qos_get_value()
61 		return c->no_constraint_value;  in pm_qos_get_value()
63 	switch (c->type) {  in pm_qos_get_value()
65 		return plist_first(&c->list)->prio;  in pm_qos_get_value()
68 		return plist_last(&c->list)->prio;  in pm_qos_get_value()
71 		WARN(1, "Unknown PM QoS type in %s\n", __func__);  in pm_qos_get_value()
78 	WRITE_ONCE(c->target_value, value);  in pm_qos_set_value()
82  * pm_qos_update_target - Update a list of PM QoS constraint requests.
83  * @c: List of PM QoS requests.
88  * Update the given list of PM QoS constraint requests, @c, by carrying an
108 		new_value = c->default_value;  in pm_qos_update_target()
114 		plist_del(node, &c->list);  in pm_qos_update_target()
121 		plist_del(node, &c->list);  in pm_qos_update_target()
125 		plist_add(node, &c->list);  in pm_qos_update_target()
142 	if (c->notifiers)  in pm_qos_update_target()
143 		blocking_notifier_call_chain(c->notifiers, curr_value, NULL);  in pm_qos_update_target()
149  * pm_qos_flags_remove_req - Remove device PM QoS flags request.
150  * @pqf: Device PM QoS flags set to remove the request from.
158 	list_del(&req->node);  in pm_qos_flags_remove_req()
159 	list_for_each_entry(req, &pqf->list, node)  in pm_qos_flags_remove_req()
160 		val |= req->flags;  in pm_qos_flags_remove_req()
162 	pqf->effective_flags = val;  in pm_qos_flags_remove_req()
166  * pm_qos_update_flags - Update a set of PM QoS flags.
167  * @pqf: Set of PM QoS flags to update.
183 	prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;  in pm_qos_update_flags()
193 		req->flags = val;  in pm_qos_update_flags()
194 		INIT_LIST_HEAD(&req->node);  in pm_qos_update_flags()
195 		list_add_tail(&req->node, &pqf->list);  in pm_qos_update_flags()
196 		pqf->effective_flags |= val;  in pm_qos_update_flags()
203 	curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;  in pm_qos_update_flags()
213 /* Definitions related to the CPU latency QoS. */
229  * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit.
237  * cpu_latency_qos_request_active - Check the given PM QoS request.
238  * @req: PM QoS request to check.
245 	return req->qos == &cpu_latency_constraints;  in cpu_latency_qos_request_active()
252 	int ret = pm_qos_update_target(req->qos, &req->node, action, value);  in cpu_latency_qos_apply()
258  * cpu_latency_qos_add_request - Add new CPU latency QoS request.
281 	req->qos = &cpu_latency_constraints;  in cpu_latency_qos_add_request()
287  * cpu_latency_qos_update_request - Modify existing CPU latency QoS request.
307 	if (new_value == req->node.prio)  in cpu_latency_qos_update_request()
315  * cpu_latency_qos_remove_request - Remove existing CPU latency QoS request.
346 		return -ENOMEM;  in cpu_latency_qos_open()
349 	filp->private_data = req;  in cpu_latency_qos_open()
356 	struct pm_qos_request *req = filp->private_data;  in cpu_latency_qos_release()
358 	filp->private_data = NULL;  in cpu_latency_qos_release()
369 	struct pm_qos_request *req = filp->private_data;  in cpu_latency_qos_read()
374 		return -EINVAL;  in cpu_latency_qos_read()
390 			return -EFAULT;  in cpu_latency_qos_write()
399 	cpu_latency_qos_update_request(filp->private_data, value);  in cpu_latency_qos_write()
432 /* Definitions related to the frequency QoS below. */
440  * freq_constraints_init - Initialize frequency QoS constraints.
447 	c = &qos->min_freq;  in freq_constraints_init()
448 	plist_head_init(&c->list);  in freq_constraints_init()
449 	c->target_value = FREQ_QOS_MIN_DEFAULT_VALUE;  in freq_constraints_init()
450 	c->default_value = FREQ_QOS_MIN_DEFAULT_VALUE;  in freq_constraints_init()
451 	c->no_constraint_value = FREQ_QOS_MIN_DEFAULT_VALUE;  in freq_constraints_init()
452 	c->type = PM_QOS_MAX;  in freq_constraints_init()
453 	c->notifiers = &qos->min_freq_notifiers;  in freq_constraints_init()
454 	BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);  in freq_constraints_init()
456 	c = &qos->max_freq;  in freq_constraints_init()
457 	plist_head_init(&c->list);  in freq_constraints_init()
458 	c->target_value = FREQ_QOS_MAX_DEFAULT_VALUE;  in freq_constraints_init()
459 	c->default_value = FREQ_QOS_MAX_DEFAULT_VALUE;  in freq_constraints_init()
460 	c->no_constraint_value = FREQ_QOS_MAX_DEFAULT_VALUE;  in freq_constraints_init()
461 	c->type = PM_QOS_MIN;  in freq_constraints_init()
462 	c->notifiers = &qos->max_freq_notifiers;  in freq_constraints_init()
463 	BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);  in freq_constraints_init()
467  * freq_qos_read_value - Get frequency QoS constraint for a given list.
480 			pm_qos_read_value(&qos->min_freq);  in freq_qos_read_value()
485 			pm_qos_read_value(&qos->max_freq);  in freq_qos_read_value()
496  * freq_qos_apply - Add/modify/remove frequency QoS request.
508 	switch(req->type) {  in freq_qos_apply()
510 		ret = pm_qos_update_target(&req->qos->min_freq, &req->pnode,  in freq_qos_apply()
514 		ret = pm_qos_update_target(&req->qos->max_freq, &req->pnode,  in freq_qos_apply()
518 		ret = -EINVAL;  in freq_qos_apply()
525  * freq_qos_add_request - Insert new frequency QoS request into a given list.
545 		return -EINVAL;  in freq_qos_add_request()
549 		return -EINVAL;  in freq_qos_add_request()
551 	req->qos = qos;  in freq_qos_add_request()
552 	req->type = type;  in freq_qos_add_request()
555 		req->qos = NULL;  in freq_qos_add_request()
556 		req->type = 0;  in freq_qos_add_request()
564  * freq_qos_update_request - Modify existing frequency QoS request.
577 		return -EINVAL;  in freq_qos_update_request()
581 		return -EINVAL;  in freq_qos_update_request()
583 	if (req->pnode.prio == new_value)  in freq_qos_update_request()
591  * freq_qos_remove_request - Remove frequency QoS request from its list.
605 		return -EINVAL;  in freq_qos_remove_request()
609 		return -EINVAL;  in freq_qos_remove_request()
612 	req->qos = NULL;  in freq_qos_remove_request()
613 	req->type = 0;  in freq_qos_remove_request()
620  * freq_qos_add_notifier - Add frequency QoS change notifier.
632 		return -EINVAL;  in freq_qos_add_notifier()
636 		ret = blocking_notifier_chain_register(qos->min_freq.notifiers,  in freq_qos_add_notifier()
640 		ret = blocking_notifier_chain_register(qos->max_freq.notifiers,  in freq_qos_add_notifier()
645 		ret = -EINVAL;  in freq_qos_add_notifier()
653  * freq_qos_remove_notifier - Remove frequency QoS change notifier.
665 		return -EINVAL;  in freq_qos_remove_notifier()
669 		ret = blocking_notifier_chain_unregister(qos->min_freq.notifiers,  in freq_qos_remove_notifier()
673 		ret = blocking_notifier_chain_unregister(qos->max_freq.notifiers,  in freq_qos_remove_notifier()
678 		ret = -EINVAL;  in freq_qos_remove_notifier()