1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef RQ_QOS_H
  3#define RQ_QOS_H
  4
  5#include <linux/kernel.h>
  6#include <linux/blkdev.h>
  7#include <linux/blk_types.h>
  8#include <linux/atomic.h>
  9#include <linux/wait.h>
 10
 11#include "blk-mq-debugfs.h"
 12
 13struct blk_mq_debugfs_attr;
 14
 15enum rq_qos_id {
 16	RQ_QOS_WBT,
 17	RQ_QOS_LATENCY,
 18	RQ_QOS_COST,
 19};
 20
 21struct rq_wait {
 22	wait_queue_head_t wait;
 23	atomic_t inflight;
 24};
 25
 26struct rq_qos {
 27	struct rq_qos_ops *ops;
 28	struct request_queue *q;
 29	enum rq_qos_id id;
 30	struct rq_qos *next;
 31#ifdef CONFIG_BLK_DEBUG_FS
 32	struct dentry *debugfs_dir;
 33#endif
 34};
 35
 36struct rq_qos_ops {
 37	void (*throttle)(struct rq_qos *, struct bio *);
 38	void (*track)(struct rq_qos *, struct request *, struct bio *);
 39	void (*merge)(struct rq_qos *, struct request *, struct bio *);
 40	void (*issue)(struct rq_qos *, struct request *);
 41	void (*requeue)(struct rq_qos *, struct request *);
 42	void (*done)(struct rq_qos *, struct request *);
 43	void (*done_bio)(struct rq_qos *, struct bio *);
 44	void (*cleanup)(struct rq_qos *, struct bio *);
 45	void (*queue_depth_changed)(struct rq_qos *);
 46	void (*exit)(struct rq_qos *);
 47	const struct blk_mq_debugfs_attr *debugfs_attrs;
 48};
 49
 50struct rq_depth {
 51	unsigned int max_depth;
 52
 53	int scale_step;
 54	bool scaled_max;
 55
 56	unsigned int queue_depth;
 57	unsigned int default_depth;
 58};
 59
 60static inline struct rq_qos *rq_qos_id(struct request_queue *q,
 61				       enum rq_qos_id id)
 62{
 63	struct rq_qos *rqos;
 64	for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
 65		if (rqos->id == id)
 66			break;
 67	}
 68	return rqos;
 69}
 70
 71static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
 72{
 73	return rq_qos_id(q, RQ_QOS_WBT);
 74}
 75
 76static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
 77{
 78	return rq_qos_id(q, RQ_QOS_LATENCY);
 79}
 80
 81static inline const char *rq_qos_id_to_name(enum rq_qos_id id)
 82{
 83	switch (id) {
 84	case RQ_QOS_WBT:
 85		return "wbt";
 86	case RQ_QOS_LATENCY:
 87		return "latency";
 88	case RQ_QOS_COST:
 89		return "cost";
 90	}
 91	return "unknown";
 92}
 93
 94static inline void rq_wait_init(struct rq_wait *rq_wait)
 95{
 96	atomic_set(&rq_wait->inflight, 0);
 97	init_waitqueue_head(&rq_wait->wait);
 98}
 99
100static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
101{
102	rqos->next = q->rq_qos;
103	q->rq_qos = rqos;
104
105	if (rqos->ops->debugfs_attrs)
106		blk_mq_debugfs_register_rqos(rqos);
107}
108
109static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
110{
111	struct rq_qos **cur;
112
113	for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
114		if (*cur == rqos) {
115			*cur = rqos->next;
116			break;
117		}
118	}
119
120	blk_mq_debugfs_unregister_rqos(rqos);
121}
122
123typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
124typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
125
126void rq_qos_wait(struct rq_wait *rqw, void *private_data,
127		 acquire_inflight_cb_t *acquire_inflight_cb,
128		 cleanup_cb_t *cleanup_cb);
129bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
130bool rq_depth_scale_up(struct rq_depth *rqd);
131bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
132bool rq_depth_calc_max_depth(struct rq_depth *rqd);
133
134void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
135void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
136void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
137void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
138void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
139void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
140void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
141void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
142void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
143
144static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
145{
146	if (q->rq_qos)
147		__rq_qos_cleanup(q->rq_qos, bio);
148}
149
150static inline void rq_qos_done(struct request_queue *q, struct request *rq)
151{
152	if (q->rq_qos)
153		__rq_qos_done(q->rq_qos, rq);
154}
155
156static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
157{
158	if (q->rq_qos)
159		__rq_qos_issue(q->rq_qos, rq);
160}
161
162static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
163{
164	if (q->rq_qos)
165		__rq_qos_requeue(q->rq_qos, rq);
166}
167
168static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio)
169{
170	if (q->rq_qos)
171		__rq_qos_done_bio(q->rq_qos, bio);
172}
173
174static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
175{
176	/*
177	 * BIO_TRACKED lets controllers know that a bio went through the
178	 * normal rq_qos path.
179	 */
180	bio_set_flag(bio, BIO_TRACKED);
181	if (q->rq_qos)
182		__rq_qos_throttle(q->rq_qos, bio);
183}
184
185static inline void rq_qos_track(struct request_queue *q, struct request *rq,
186				struct bio *bio)
187{
188	if (q->rq_qos)
189		__rq_qos_track(q->rq_qos, rq, bio);
190}
191
192static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
193				struct bio *bio)
194{
195	if (q->rq_qos)
196		__rq_qos_merge(q->rq_qos, rq, bio);
197}
198
199static inline void rq_qos_queue_depth_changed(struct request_queue *q)
200{
201	if (q->rq_qos)
202		__rq_qos_queue_depth_changed(q->rq_qos);
203}
204
205void rq_qos_exit(struct request_queue *);
206
207#endif