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 };
21
22 struct rq_wait {
23 wait_queue_head_t wait;
24 atomic_t inflight;
25 };
26
27 struct rq_qos {
28 struct rq_qos_ops *ops;
29 struct request_queue *q;
30 enum rq_qos_id id;
31 struct rq_qos *next;
32 #ifdef CONFIG_BLK_DEBUG_FS
33 struct dentry *debugfs_dir;
34 #endif
35 };
36
37 struct rq_qos_ops {
38 void (*throttle)(struct rq_qos *, struct bio *);
39 void (*track)(struct rq_qos *, struct request *, struct bio *);
40 void (*merge)(struct rq_qos *, struct request *, struct bio *);
41 void (*issue)(struct rq_qos *, struct request *);
42 void (*requeue)(struct rq_qos *, struct request *);
43 void (*done)(struct rq_qos *, struct request *);
44 void (*done_bio)(struct rq_qos *, struct bio *);
45 void (*cleanup)(struct rq_qos *, struct bio *);
46 void (*queue_depth_changed)(struct rq_qos *);
47 void (*exit)(struct rq_qos *);
48 const struct blk_mq_debugfs_attr *debugfs_attrs;
49 };
50
51 struct rq_depth {
52 unsigned int max_depth;
53
54 int scale_step;
55 bool scaled_max;
56
57 unsigned int queue_depth;
58 unsigned int default_depth;
59 };
60
rq_qos_id(struct request_queue * q,enum rq_qos_id id)61 static inline struct rq_qos *rq_qos_id(struct request_queue *q,
62 enum rq_qos_id id)
63 {
64 struct rq_qos *rqos;
65 for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
66 if (rqos->id == id)
67 break;
68 }
69 return rqos;
70 }
71
wbt_rq_qos(struct request_queue * q)72 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
73 {
74 return rq_qos_id(q, RQ_QOS_WBT);
75 }
76
blkcg_rq_qos(struct request_queue * q)77 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
78 {
79 return rq_qos_id(q, RQ_QOS_LATENCY);
80 }
81
rq_wait_init(struct rq_wait * rq_wait)82 static inline void rq_wait_init(struct rq_wait *rq_wait)
83 {
84 atomic_set(&rq_wait->inflight, 0);
85 init_waitqueue_head(&rq_wait->wait);
86 }
87
rq_qos_add(struct request_queue * q,struct rq_qos * rqos)88 static inline int rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
89 {
90 /*
91 * No IO can be in-flight when adding rqos, so freeze queue, which
92 * is fine since we only support rq_qos for blk-mq queue.
93 *
94 * Reuse ->queue_lock for protecting against other concurrent
95 * rq_qos adding/deleting
96 */
97 blk_mq_freeze_queue(q);
98
99 spin_lock_irq(&q->queue_lock);
100 if (rq_qos_id(q, rqos->id))
101 goto ebusy;
102 rqos->next = q->rq_qos;
103 q->rq_qos = rqos;
104 spin_unlock_irq(&q->queue_lock);
105
106 blk_mq_unfreeze_queue(q);
107
108 if (rqos->ops->debugfs_attrs) {
109 mutex_lock(&q->debugfs_mutex);
110 blk_mq_debugfs_register_rqos(rqos);
111 mutex_unlock(&q->debugfs_mutex);
112 }
113
114 return 0;
115 ebusy:
116 spin_unlock_irq(&q->queue_lock);
117 blk_mq_unfreeze_queue(q);
118 return -EBUSY;
119
120 }
121
rq_qos_del(struct request_queue * q,struct rq_qos * rqos)122 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
123 {
124 struct rq_qos **cur;
125
126 /*
127 * See comment in rq_qos_add() about freezing queue & using
128 * ->queue_lock.
129 */
130 blk_mq_freeze_queue(q);
131
132 spin_lock_irq(&q->queue_lock);
133 for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
134 if (*cur == rqos) {
135 *cur = rqos->next;
136 break;
137 }
138 }
139 spin_unlock_irq(&q->queue_lock);
140
141 blk_mq_unfreeze_queue(q);
142
143 mutex_lock(&q->debugfs_mutex);
144 blk_mq_debugfs_unregister_rqos(rqos);
145 mutex_unlock(&q->debugfs_mutex);
146 }
147
148 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
149 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
150
151 void rq_qos_wait(struct rq_wait *rqw, void *private_data,
152 acquire_inflight_cb_t *acquire_inflight_cb,
153 cleanup_cb_t *cleanup_cb);
154 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
155 bool rq_depth_scale_up(struct rq_depth *rqd);
156 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
157 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
158
159 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
160 void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
161 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
162 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
163 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
164 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
165 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
166 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
167 void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
168
rq_qos_cleanup(struct request_queue * q,struct bio * bio)169 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
170 {
171 if (q->rq_qos)
172 __rq_qos_cleanup(q->rq_qos, bio);
173 }
174
rq_qos_done(struct request_queue * q,struct request * rq)175 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
176 {
177 if (q->rq_qos)
178 __rq_qos_done(q->rq_qos, rq);
179 }
180
rq_qos_issue(struct request_queue * q,struct request * rq)181 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
182 {
183 if (q->rq_qos)
184 __rq_qos_issue(q->rq_qos, rq);
185 }
186
rq_qos_requeue(struct request_queue * q,struct request * rq)187 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
188 {
189 if (q->rq_qos)
190 __rq_qos_requeue(q->rq_qos, rq);
191 }
192
rq_qos_done_bio(struct bio * bio)193 static inline void rq_qos_done_bio(struct bio *bio)
194 {
195 if (bio->bi_bdev && (bio_flagged(bio, BIO_QOS_THROTTLED) ||
196 bio_flagged(bio, BIO_QOS_MERGED))) {
197 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
198 if (q->rq_qos)
199 __rq_qos_done_bio(q->rq_qos, bio);
200 }
201 }
202
rq_qos_throttle(struct request_queue * q,struct bio * bio)203 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
204 {
205 if (q->rq_qos) {
206 bio_set_flag(bio, BIO_QOS_THROTTLED);
207 __rq_qos_throttle(q->rq_qos, bio);
208 }
209 }
210
rq_qos_track(struct request_queue * q,struct request * rq,struct bio * bio)211 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
212 struct bio *bio)
213 {
214 if (q->rq_qos)
215 __rq_qos_track(q->rq_qos, rq, bio);
216 }
217
rq_qos_merge(struct request_queue * q,struct request * rq,struct bio * bio)218 static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
219 struct bio *bio)
220 {
221 if (q->rq_qos) {
222 bio_set_flag(bio, BIO_QOS_MERGED);
223 __rq_qos_merge(q->rq_qos, rq, bio);
224 }
225 }
226
rq_qos_queue_depth_changed(struct request_queue * q)227 static inline void rq_qos_queue_depth_changed(struct request_queue *q)
228 {
229 if (q->rq_qos)
230 __rq_qos_queue_depth_changed(q->rq_qos);
231 }
232
233 void rq_qos_exit(struct request_queue *);
234
235 #endif
236