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 #include <linux/blk-mq.h>
11
12 #include "blk-mq-debugfs.h"
13
14 struct blk_mq_debugfs_attr;
15
16 enum rq_qos_id {
17 RQ_QOS_WBT,
18 RQ_QOS_LATENCY,
19 RQ_QOS_COST,
20 RQ_QOS_IOPRIO,
21 };
22
23 struct rq_wait {
24 wait_queue_head_t wait;
25 atomic_t inflight;
26 };
27
28 struct rq_qos {
29 struct rq_qos_ops *ops;
30 struct request_queue *q;
31 enum rq_qos_id id;
32 struct rq_qos *next;
33 #ifdef CONFIG_BLK_DEBUG_FS
34 struct dentry *debugfs_dir;
35 #endif
36 };
37
38 struct rq_qos_ops {
39 void (*throttle)(struct rq_qos *, struct bio *);
40 void (*track)(struct rq_qos *, struct request *, struct bio *);
41 void (*merge)(struct rq_qos *, struct request *, struct bio *);
42 void (*issue)(struct rq_qos *, struct request *);
43 void (*requeue)(struct rq_qos *, struct request *);
44 void (*done)(struct rq_qos *, struct request *);
45 void (*done_bio)(struct rq_qos *, struct bio *);
46 void (*cleanup)(struct rq_qos *, struct bio *);
47 void (*queue_depth_changed)(struct rq_qos *);
48 void (*exit)(struct rq_qos *);
49 const struct blk_mq_debugfs_attr *debugfs_attrs;
50 };
51
52 struct rq_depth {
53 unsigned int max_depth;
54
55 int scale_step;
56 bool scaled_max;
57
58 unsigned int queue_depth;
59 unsigned int default_depth;
60 };
61
rq_qos_id(struct request_queue * q,enum rq_qos_id id)62 static inline struct rq_qos *rq_qos_id(struct request_queue *q,
63 enum rq_qos_id id)
64 {
65 struct rq_qos *rqos;
66 for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
67 if (rqos->id == id)
68 break;
69 }
70 return rqos;
71 }
72
wbt_rq_qos(struct request_queue * q)73 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
74 {
75 return rq_qos_id(q, RQ_QOS_WBT);
76 }
77
blkcg_rq_qos(struct request_queue * q)78 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
79 {
80 return rq_qos_id(q, RQ_QOS_LATENCY);
81 }
82
rq_wait_init(struct rq_wait * rq_wait)83 static inline void rq_wait_init(struct rq_wait *rq_wait)
84 {
85 atomic_set(&rq_wait->inflight, 0);
86 init_waitqueue_head(&rq_wait->wait);
87 }
88
rq_qos_add(struct request_queue * q,struct rq_qos * rqos)89 static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
90 {
91 /*
92 * No IO can be in-flight when adding rqos, so freeze queue, which
93 * is fine since we only support rq_qos for blk-mq queue.
94 *
95 * Reuse ->queue_lock for protecting against other concurrent
96 * rq_qos adding/deleting
97 */
98 blk_mq_freeze_queue(q);
99
100 spin_lock_irq(&q->queue_lock);
101 rqos->next = q->rq_qos;
102 q->rq_qos = rqos;
103 spin_unlock_irq(&q->queue_lock);
104
105 blk_mq_unfreeze_queue(q);
106
107 if (rqos->ops->debugfs_attrs)
108 blk_mq_debugfs_register_rqos(rqos);
109 }
110
rq_qos_del(struct request_queue * q,struct rq_qos * rqos)111 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
112 {
113 struct rq_qos **cur;
114
115 /*
116 * See comment in rq_qos_add() about freezing queue & using
117 * ->queue_lock.
118 */
119 blk_mq_freeze_queue(q);
120
121 spin_lock_irq(&q->queue_lock);
122 for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
123 if (*cur == rqos) {
124 *cur = rqos->next;
125 break;
126 }
127 }
128 spin_unlock_irq(&q->queue_lock);
129
130 blk_mq_unfreeze_queue(q);
131
132 blk_mq_debugfs_unregister_rqos(rqos);
133 }
134
135 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
136 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
137
138 void rq_qos_wait(struct rq_wait *rqw, void *private_data,
139 acquire_inflight_cb_t *acquire_inflight_cb,
140 cleanup_cb_t *cleanup_cb);
141 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
142 bool rq_depth_scale_up(struct rq_depth *rqd);
143 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
144 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
145
146 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
147 void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
148 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
149 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
150 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
151 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
152 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
153 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
154 void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
155
rq_qos_cleanup(struct request_queue * q,struct bio * bio)156 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
157 {
158 if (q->rq_qos)
159 __rq_qos_cleanup(q->rq_qos, bio);
160 }
161
rq_qos_done(struct request_queue * q,struct request * rq)162 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
163 {
164 if (q->rq_qos)
165 __rq_qos_done(q->rq_qos, rq);
166 }
167
rq_qos_issue(struct request_queue * q,struct request * rq)168 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
169 {
170 if (q->rq_qos)
171 __rq_qos_issue(q->rq_qos, rq);
172 }
173
rq_qos_requeue(struct request_queue * q,struct request * rq)174 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
175 {
176 if (q->rq_qos)
177 __rq_qos_requeue(q->rq_qos, rq);
178 }
179
rq_qos_done_bio(struct request_queue * q,struct bio * bio)180 static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio)
181 {
182 if (q->rq_qos)
183 __rq_qos_done_bio(q->rq_qos, bio);
184 }
185
rq_qos_throttle(struct request_queue * q,struct bio * bio)186 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
187 {
188 /*
189 * BIO_TRACKED lets controllers know that a bio went through the
190 * normal rq_qos path.
191 */
192 bio_set_flag(bio, BIO_TRACKED);
193 if (q->rq_qos)
194 __rq_qos_throttle(q->rq_qos, bio);
195 }
196
rq_qos_track(struct request_queue * q,struct request * rq,struct bio * bio)197 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
198 struct bio *bio)
199 {
200 if (q->rq_qos)
201 __rq_qos_track(q->rq_qos, rq, bio);
202 }
203
rq_qos_merge(struct request_queue * q,struct request * rq,struct bio * bio)204 static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
205 struct bio *bio)
206 {
207 if (q->rq_qos)
208 __rq_qos_merge(q->rq_qos, rq, bio);
209 }
210
rq_qos_queue_depth_changed(struct request_queue * q)211 static inline void rq_qos_queue_depth_changed(struct request_queue *q)
212 {
213 if (q->rq_qos)
214 __rq_qos_queue_depth_changed(q->rq_qos);
215 }
216
217 void rq_qos_exit(struct request_queue *);
218
219 #endif
220
