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 const struct rq_qos_ops *ops;
29 struct gendisk *disk;
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
iolat_rq_qos(struct request_queue * q)77 static inline struct rq_qos *iolat_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
88 int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
89 const struct rq_qos_ops *ops);
90 void rq_qos_del(struct rq_qos *rqos);
91
92 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
93 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
94
95 void rq_qos_wait(struct rq_wait *rqw, void *private_data,
96 acquire_inflight_cb_t *acquire_inflight_cb,
97 cleanup_cb_t *cleanup_cb);
98 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
99 bool rq_depth_scale_up(struct rq_depth *rqd);
100 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
101 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
102
103 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
104 void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
105 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
106 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
107 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
108 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
109 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
110 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
111 void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
112
rq_qos_cleanup(struct request_queue * q,struct bio * bio)113 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
114 {
115 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
116 __rq_qos_cleanup(q->rq_qos, bio);
117 }
118
rq_qos_done(struct request_queue * q,struct request * rq)119 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
120 {
121 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) &&
122 q->rq_qos && !blk_rq_is_passthrough(rq))
123 __rq_qos_done(q->rq_qos, rq);
124 }
125
rq_qos_issue(struct request_queue * q,struct request * rq)126 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
127 {
128 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
129 __rq_qos_issue(q->rq_qos, rq);
130 }
131
rq_qos_requeue(struct request_queue * q,struct request * rq)132 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
133 {
134 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
135 __rq_qos_requeue(q->rq_qos, rq);
136 }
137
rq_qos_done_bio(struct bio * bio)138 static inline void rq_qos_done_bio(struct bio *bio)
139 {
140 struct request_queue *q;
141
142 if (!bio->bi_bdev || (!bio_flagged(bio, BIO_QOS_THROTTLED) &&
143 !bio_flagged(bio, BIO_QOS_MERGED)))
144 return;
145
146 q = bdev_get_queue(bio->bi_bdev);
147
148 /*
149 * A BIO may carry BIO_QOS_* flags even if the associated request_queue
150 * does not have rq_qos enabled. This can happen with stacked block
151 * devices — for example, NVMe multipath, where it's possible that the
152 * bottom device has QoS enabled but the top device does not. Therefore,
153 * always verify that q->rq_qos is present and QoS is enabled before
154 * calling __rq_qos_done_bio().
155 */
156 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
157 __rq_qos_done_bio(q->rq_qos, bio);
158 }
159
rq_qos_throttle(struct request_queue * q,struct bio * bio)160 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
161 {
162 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos) {
163 bio_set_flag(bio, BIO_QOS_THROTTLED);
164 __rq_qos_throttle(q->rq_qos, bio);
165 }
166 }
167
rq_qos_track(struct request_queue * q,struct request * rq,struct bio * bio)168 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
169 struct bio *bio)
170 {
171 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
172 __rq_qos_track(q->rq_qos, rq, bio);
173 }
174
rq_qos_merge(struct request_queue * q,struct request * rq,struct bio * bio)175 static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
176 struct bio *bio)
177 {
178 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos) {
179 bio_set_flag(bio, BIO_QOS_MERGED);
180 __rq_qos_merge(q->rq_qos, rq, bio);
181 }
182 }
183
rq_qos_queue_depth_changed(struct request_queue * q)184 static inline void rq_qos_queue_depth_changed(struct request_queue *q)
185 {
186 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
187 __rq_qos_queue_depth_changed(q->rq_qos);
188 }
189
190 void rq_qos_exit(struct request_queue *);
191
192 #endif
193