xref: /linux/block/blk-rq-qos.h (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e) 
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 enum rq_qos_id {
11 	RQ_QOS_WBT,
12 	RQ_QOS_CGROUP,
13 };
14 
15 struct rq_wait {
16 	wait_queue_head_t wait;
17 	atomic_t inflight;
18 };
19 
20 struct rq_qos {
21 	struct rq_qos_ops *ops;
22 	struct request_queue *q;
23 	enum rq_qos_id id;
24 	struct rq_qos *next;
25 };
26 
27 struct rq_qos_ops {
28 	void (*throttle)(struct rq_qos *, struct bio *, spinlock_t *);
29 	void (*track)(struct rq_qos *, struct request *, struct bio *);
30 	void (*issue)(struct rq_qos *, struct request *);
31 	void (*requeue)(struct rq_qos *, struct request *);
32 	void (*done)(struct rq_qos *, struct request *);
33 	void (*done_bio)(struct rq_qos *, struct bio *);
34 	void (*cleanup)(struct rq_qos *, struct bio *);
35 	void (*exit)(struct rq_qos *);
36 };
37 
38 struct rq_depth {
39 	unsigned int max_depth;
40 
41 	int scale_step;
42 	bool scaled_max;
43 
44 	unsigned int queue_depth;
45 	unsigned int default_depth;
46 };
47 
48 static inline struct rq_qos *rq_qos_id(struct request_queue *q,
49 				       enum rq_qos_id id)
50 {
51 	struct rq_qos *rqos;
52 	for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
53 		if (rqos->id == id)
54 			break;
55 	}
56 	return rqos;
57 }
58 
59 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
60 {
61 	return rq_qos_id(q, RQ_QOS_WBT);
62 }
63 
64 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
65 {
66 	return rq_qos_id(q, RQ_QOS_CGROUP);
67 }
68 
69 static inline void rq_wait_init(struct rq_wait *rq_wait)
70 {
71 	atomic_set(&rq_wait->inflight, 0);
72 	init_waitqueue_head(&rq_wait->wait);
73 }
74 
75 static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
76 {
77 	rqos->next = q->rq_qos;
78 	q->rq_qos = rqos;
79 }
80 
81 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
82 {
83 	struct rq_qos *cur, *prev = NULL;
84 	for (cur = q->rq_qos; cur; cur = cur->next) {
85 		if (cur == rqos) {
86 			if (prev)
87 				prev->next = rqos->next;
88 			else
89 				q->rq_qos = cur;
90 			break;
91 		}
92 		prev = cur;
93 	}
94 }
95 
96 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
97 void rq_depth_scale_up(struct rq_depth *rqd);
98 void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
99 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
100 
101 void rq_qos_cleanup(struct request_queue *, struct bio *);
102 void rq_qos_done(struct request_queue *, struct request *);
103 void rq_qos_issue(struct request_queue *, struct request *);
104 void rq_qos_requeue(struct request_queue *, struct request *);
105 void rq_qos_done_bio(struct request_queue *q, struct bio *bio);
106 void rq_qos_throttle(struct request_queue *, struct bio *, spinlock_t *);
107 void rq_qos_track(struct request_queue *q, struct request *, struct bio *);
108 void rq_qos_exit(struct request_queue *);
109 #endif
110