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()
214 	 * If we fail to get a budget, return -1 to interrupt the wake up loop  in rq_qos_wake_function()
217 	if (!data->cb(data->rqw, data->private_data))  in rq_qos_wake_function()
218 		return -1;  in rq_qos_wake_function()
220 	data->got_token = true;  in rq_qos_wake_function()
222 	list_del_init(&curr->entry);  in rq_qos_wake_function()
223 	wake_up_process(data->task);  in rq_qos_wake_function()
228  * rq_qos_wait - throttle on a rqw if we need to
231  * @acquire_inflight_cb: inc the rqw->inflight counter if we can
237  * inc the rqw->inflight if we have the ability to do so, or return false if not
259 	has_sleeper = wq_has_sleeper(&rqw->wait);  in rq_qos_wait()
263 	has_sleeper = !prepare_to_wait_exclusive(&rqw->wait, &data.wq,  in rq_qos_wait()
270 			finish_wait(&rqw->wait, &data.wq);  in rq_qos_wait()
286 	finish_wait(&rqw->wait, &data.wq);  in rq_qos_wait()
291 	while (q->rq_qos) {  in rq_qos_exit()
292 		struct rq_qos *rqos = q->rq_qos;  in rq_qos_exit()
293 		q->rq_qos = rqos->next;  in rq_qos_exit()
294 		rqos->ops->exit(rqos);  in rq_qos_exit()