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 (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
116 q->rq_qos)
117 __rq_qos_cleanup(q->rq_qos, bio);
118 }
119
rq_qos_done(struct request_queue * q,struct request * rq)120 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
121 {
122 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
123 q->rq_qos && !blk_rq_is_passthrough(rq))
124 __rq_qos_done(q->rq_qos, rq);
125 }
126
rq_qos_issue(struct request_queue * q,struct request * rq)127 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
128 {
129 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
130 q->rq_qos)
131 __rq_qos_issue(q->rq_qos, rq);
132 }
133
rq_qos_requeue(struct request_queue * q,struct request * rq)134 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
135 {
136 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
137 q->rq_qos)
138 __rq_qos_requeue(q->rq_qos, rq);
139 }
140
rq_qos_done_bio(struct bio * bio)141 static inline void rq_qos_done_bio(struct bio *bio)
142 {
143 struct request_queue *q;
144
145 if (!bio->bi_bdev || (!bio_flagged(bio, BIO_QOS_THROTTLED) &&
146 !bio_flagged(bio, BIO_QOS_MERGED)))
147 return;
148
149 q = bdev_get_queue(bio->bi_bdev);
150
151 /*
152 * A BIO may carry BIO_QOS_* flags even if the associated request_queue
153 * does not have rq_qos enabled. This can happen with stacked block
154 * devices — for example, NVMe multipath, where it's possible that the
155 * bottom device has QoS enabled but the top device does not. Therefore,
156 * always verify that q->rq_qos is present and QoS is enabled before
157 * calling __rq_qos_done_bio().
158 */
159 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos)
160 __rq_qos_done_bio(q->rq_qos, bio);
161 }
162
rq_qos_throttle(struct request_queue * q,struct bio * bio)163 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
164 {
165 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
166 q->rq_qos) {
167 bio_set_flag(bio, BIO_QOS_THROTTLED);
168 __rq_qos_throttle(q->rq_qos, bio);
169 }
170 }
171
rq_qos_track(struct request_queue * q,struct request * rq,struct bio * bio)172 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
173 struct bio *bio)
174 {
175 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
176 q->rq_qos)
177 __rq_qos_track(q->rq_qos, rq, bio);
178 }
179
rq_qos_merge(struct request_queue * q,struct request * rq,struct bio * bio)180 static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
181 struct bio *bio)
182 {
183 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
184 q->rq_qos) {
185 bio_set_flag(bio, BIO_QOS_MERGED);
186 __rq_qos_merge(q->rq_qos, rq, bio);
187 }
188 }
189
rq_qos_queue_depth_changed(struct request_queue * q)190 static inline void rq_qos_queue_depth_changed(struct request_queue *q)
191 {
192 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) &&
193 q->rq_qos)
194 __rq_qos_queue_depth_changed(q->rq_qos);
195 }
196
197 void rq_qos_exit(struct request_queue *);
198
199 #endif
200