1 // SPDX-License-Identifier: GPL-2.0
3 #include "blk-rq-qos.h"
23 	return atomic_inc_below(&rq_wait->inflight, limit);  in rq_wait_inc_below()
29 		if (rqos->ops->cleanup)  in __rq_qos_cleanup()
30 			rqos->ops->cleanup(rqos, bio);  in __rq_qos_cleanup()
31 		rqos = rqos->next;  in __rq_qos_cleanup()
38 		if (rqos->ops->done)  in __rq_qos_done()
39 			rqos->ops->done(rqos, rq);  in __rq_qos_done()
40 		rqos = rqos->next;  in __rq_qos_done()
47 		if (rqos->ops->issue)  in __rq_qos_issue()
48 			rqos->ops->issue(rqos, rq);  in __rq_qos_issue()
49 		rqos = rqos->next;  in __rq_qos_issue()
56 		if (rqos->ops->requeue)  in __rq_qos_requeue()
57 			rqos->ops->requeue(rqos, rq);  in __rq_qos_requeue()
58 		rqos = rqos->next;  in __rq_qos_requeue()
65 		if (rqos->ops->throttle)  in __rq_qos_throttle()
66 			rqos->ops->throttle(rqos, bio);  in __rq_qos_throttle()
67 		rqos = rqos->next;  in __rq_qos_throttle()
74 		if (rqos->ops->track)  in __rq_qos_track()
75 			rqos->ops->track(rqos, rq, bio);  in __rq_qos_track()
76 		rqos = rqos->next;  in __rq_qos_track()
83 		if (rqos->ops->merge)  in __rq_qos_merge()
84 			rqos->ops->merge(rqos, rq, bio);  in __rq_qos_merge()
85 		rqos = rqos->next;  in __rq_qos_merge()
92 		if (rqos->ops->done_bio)  in __rq_qos_done_bio()
93 			rqos->ops->done_bio(rqos, bio);  in __rq_qos_done_bio()
94 		rqos = rqos->next;  in __rq_qos_done_bio()
101 		if (rqos->ops->queue_depth_changed)  in __rq_qos_queue_depth_changed()
102 			rqos->ops->queue_depth_changed(rqos);  in __rq_qos_queue_depth_changed()
103 		rqos = rqos->next;  in __rq_qos_queue_depth_changed()
108  * Return true, if we can't increase the depth further by scaling
120 	 * scaling down, then keep a setting of 1/1/1.  in rq_depth_calc_max_depth()
122 	if (rqd->queue_depth == 1) {  in rq_depth_calc_max_depth()
123 		if (rqd->scale_step > 0)  in rq_depth_calc_max_depth()
124 			rqd->max_depth = 1;  in rq_depth_calc_max_depth()
126 			rqd->max_depth = 2;  in rq_depth_calc_max_depth()
137 		depth = min_t(unsigned int, rqd->default_depth,  in rq_depth_calc_max_depth()
138 			      rqd->queue_depth);  in rq_depth_calc_max_depth()
139 		if (rqd->scale_step > 0)  in rq_depth_calc_max_depth()
140 			depth = 1 + ((depth - 1) >> min(31, rqd->scale_step));  in rq_depth_calc_max_depth()
141 		else if (rqd->scale_step < 0) {  in rq_depth_calc_max_depth()
142 			unsigned int maxd = 3 * rqd->queue_depth / 4;  in rq_depth_calc_max_depth()
144 			depth = 1 + ((depth - 1) << -rqd->scale_step);  in rq_depth_calc_max_depth()
151 		rqd->max_depth = depth;  in rq_depth_calc_max_depth()
157 /* Returns true on success and false if scaling up wasn't possible */
163 	if (rqd->scaled_max)  in rq_depth_scale_up()
166 	rqd->scale_step--;  in rq_depth_scale_up()
168 	rqd->scaled_max = rq_depth_calc_max_depth(rqd);  in rq_depth_scale_up()
173  * Scale rwb down. If 'hard_throttle' is set, do it quicker, since we
175  * scaling down wasn't possible.
180 	 * Stop scaling down when we've hit the limit. This also prevents  in rq_depth_scale_down()
181 	 * ->scale_step from going to crazy values, if the device can't  in rq_depth_scale_down()
184 	if (rqd->max_depth == 1)  in rq_depth_scale_down()
187 	if (rqd->scale_step < 0 && hard_throttle)  in rq_depth_scale_down()
188 		rqd->scale_step = 0;  in rq_depth_scale_down()
190 		rqd->scale_step++;  in rq_depth_scale_down()
192 	rqd->scaled_max = false;  in rq_depth_scale_down()
213 	 * If we fail to get a budget, return -1 to interrupt the wake up loop  in rq_qos_wake_function()
216 	if (!data->cb(data->rqw, data->private_data))  in rq_qos_wake_function()
217 		return -1;  in rq_qos_wake_function()
219 	data->got_token = true;  in rq_qos_wake_function()
231 	 * also make sure the waiter will see the latest @data->got_token  in rq_qos_wake_function()
234 	list_del_init_careful(&curr->entry);  in rq_qos_wake_function()
239  * rq_qos_wait - throttle on a rqw if we need to
242  * @acquire_inflight_cb: inc the rqw->inflight counter if we can
248  * inc the rqw->inflight if we have the ability to do so, or return false if not
271 	if (!waitqueue_active(&rqw->wait) && acquire_inflight_cb(rqw, private_data))  in rq_qos_wait()
275 	first_waiter = prepare_to_wait_exclusive(&rqw->wait, &data.wq,  in rq_qos_wait()
283 	 * will re-check the waiting condition before going to sleep, thus  in rq_qos_wait()
287 		finish_wait(&rqw->wait, &data.wq);  in rq_qos_wait()
296 		 * the latest @data->got_token.  in rq_qos_wait()
310 	finish_wait(&rqw->wait, &data.wq);  in rq_qos_wait()
315 	mutex_lock(&q->rq_qos_mutex);  in rq_qos_exit()
316 	while (q->rq_qos) {  in rq_qos_exit()
317 		struct rq_qos *rqos = q->rq_qos;  in rq_qos_exit()
318 		q->rq_qos = rqos->next;  in rq_qos_exit()
319 		rqos->ops->exit(rqos);  in rq_qos_exit()
322 	mutex_unlock(&q->rq_qos_mutex);  in rq_qos_exit()
328 	struct request_queue *q = disk->queue;  in rq_qos_add()
331 	lockdep_assert_held(&q->rq_qos_mutex);  in rq_qos_add()
333 	rqos->disk = disk;  in rq_qos_add()
334 	rqos->id = id;  in rq_qos_add()
335 	rqos->ops = ops;  in rq_qos_add()
338 	 * No IO can be in-flight when adding rqos, so freeze queue, which  in rq_qos_add()
339 	 * is fine since we only support rq_qos for blk-mq queue.  in rq_qos_add()
343 	if (rq_qos_id(q, rqos->id))  in rq_qos_add()
345 	rqos->next = q->rq_qos;  in rq_qos_add()
346 	q->rq_qos = rqos;  in rq_qos_add()
351 	if (rqos->ops->debugfs_attrs) {  in rq_qos_add()
352 		mutex_lock(&q->debugfs_mutex);  in rq_qos_add()
354 		mutex_unlock(&q->debugfs_mutex);  in rq_qos_add()
360 	return -EBUSY;  in rq_qos_add()
365 	struct request_queue *q = rqos->disk->queue;  in rq_qos_del()
369 	lockdep_assert_held(&q->rq_qos_mutex);  in rq_qos_del()
372 	for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {  in rq_qos_del()
374 			*cur = rqos->next;  in rq_qos_del()
378 	if (!q->rq_qos)  in rq_qos_del()
382 	mutex_lock(&q->debugfs_mutex);  in rq_qos_del()
384 	mutex_unlock(&q->debugfs_mutex);  in rq_qos_del()