xref: /openbmc/linux/block/blk-rq-qos.h (revision 176f011b) 
1 #ifndef RQ_QOS_H
2 #define RQ_QOS_H
3 
4 #include <linux/kernel.h>
5 #include <linux/blkdev.h>
6 #include <linux/blk_types.h>
7 #include <linux/atomic.h>
8 #include <linux/wait.h>
9 
10 #include "blk-mq-debugfs.h"
11 
12 struct blk_mq_debugfs_attr;
13 
14 enum rq_qos_id {
15 	RQ_QOS_WBT,
16 	RQ_QOS_CGROUP,
17 };
18 
19 struct rq_wait {
20 	wait_queue_head_t wait;
21 	atomic_t inflight;
22 };
23 
24 struct rq_qos {
25 	struct rq_qos_ops *ops;
26 	struct request_queue *q;
27 	enum rq_qos_id id;
28 	struct rq_qos *next;
29 #ifdef CONFIG_BLK_DEBUG_FS
30 	struct dentry *debugfs_dir;
31 #endif
32 };
33 
34 struct rq_qos_ops {
35 	void (*throttle)(struct rq_qos *, struct bio *);
36 	void (*track)(struct rq_qos *, struct request *, struct bio *);
37 	void (*issue)(struct rq_qos *, struct request *);
38 	void (*requeue)(struct rq_qos *, struct request *);
39 	void (*done)(struct rq_qos *, struct request *);
40 	void (*done_bio)(struct rq_qos *, struct bio *);
41 	void (*cleanup)(struct rq_qos *, struct bio *);
42 	void (*exit)(struct rq_qos *);
43 	const struct blk_mq_debugfs_attr *debugfs_attrs;
44 };
45 
46 struct rq_depth {
47 	unsigned int max_depth;
48 
49 	int scale_step;
50 	bool scaled_max;
51 
52 	unsigned int queue_depth;
53 	unsigned int default_depth;
54 };
55 
56 static inline struct rq_qos *rq_qos_id(struct request_queue *q,
57 				       enum rq_qos_id id)
58 {
59 	struct rq_qos *rqos;
60 	for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
61 		if (rqos->id == id)
62 			break;
63 	}
64 	return rqos;
65 }
66 
67 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
68 {
69 	return rq_qos_id(q, RQ_QOS_WBT);
70 }
71 
72 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
73 {
74 	return rq_qos_id(q, RQ_QOS_CGROUP);
75 }
76 
77 static inline const char *rq_qos_id_to_name(enum rq_qos_id id)
78 {
79 	switch (id) {
80 	case RQ_QOS_WBT:
81 		return "wbt";
82 	case RQ_QOS_CGROUP:
83 		return "cgroup";
84 	}
85 	return "unknown";
86 }
87 
88 static inline void rq_wait_init(struct rq_wait *rq_wait)
89 {
90 	atomic_set(&rq_wait->inflight, 0);
91 	init_waitqueue_head(&rq_wait->wait);
92 }
93 
94 static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
95 {
96 	rqos->next = q->rq_qos;
97 	q->rq_qos = rqos;
98 
99 	if (rqos->ops->debugfs_attrs)
100 		blk_mq_debugfs_register_rqos(rqos);
101 }
102 
103 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
104 {
105 	struct rq_qos *cur, *prev = NULL;
106 	for (cur = q->rq_qos; cur; cur = cur->next) {
107 		if (cur == rqos) {
108 			if (prev)
109 				prev->next = rqos->next;
110 			else
111 				q->rq_qos = cur;
112 			break;
113 		}
114 		prev = cur;
115 	}
116 
117 	blk_mq_debugfs_unregister_rqos(rqos);
118 }
119 
120 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
121 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
122 
123 void rq_qos_wait(struct rq_wait *rqw, void *private_data,
124 		 acquire_inflight_cb_t *acquire_inflight_cb,
125 		 cleanup_cb_t *cleanup_cb);
126 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
127 void rq_depth_scale_up(struct rq_depth *rqd);
128 void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
129 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
130 
131 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
132 void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
133 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
134 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
135 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
136 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
137 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
138 
139 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
140 {
141 	if (q->rq_qos)
142 		__rq_qos_cleanup(q->rq_qos, bio);
143 }
144 
145 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
146 {
147 	if (q->rq_qos)
148 		__rq_qos_done(q->rq_qos, rq);
149 }
150 
151 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
152 {
153 	if (q->rq_qos)
154 		__rq_qos_issue(q->rq_qos, rq);
155 }
156 
157 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
158 {
159 	if (q->rq_qos)
160 		__rq_qos_requeue(q->rq_qos, rq);
161 }
162 
163 static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio)
164 {
165 	if (q->rq_qos)
166 		__rq_qos_done_bio(q->rq_qos, bio);
167 }
168 
169 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
170 {
171 	/*
172 	 * BIO_TRACKED lets controllers know that a bio went through the
173 	 * normal rq_qos path.
174 	 */
175 	bio_set_flag(bio, BIO_TRACKED);
176 	if (q->rq_qos)
177 		__rq_qos_throttle(q->rq_qos, bio);
178 }
179 
180 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
181 				struct bio *bio)
182 {
183 	if (q->rq_qos)
184 		__rq_qos_track(q->rq_qos, rq, bio);
185 }
186 
187 void rq_qos_exit(struct request_queue *);
188 
189 #endif
190