xref: /linux/block/blk-mq-sched.h (revision d30c1683aaecb93d2ab95685dc4300a33d3cea7a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef BLK_MQ_SCHED_H
3 #define BLK_MQ_SCHED_H
4 
5 #include "elevator.h"
6 #include "blk-mq.h"
7 
8 #define MAX_SCHED_RQ (16 * BLKDEV_DEFAULT_RQ)
9 
10 bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
11 		unsigned int nr_segs, struct request **merged_request);
12 bool blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio,
13 		unsigned int nr_segs);
14 bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq,
15 				   struct list_head *free);
16 void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx);
17 void __blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx);
18 
19 void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx);
20 
21 int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e,
22 		struct elevator_resources *res);
23 void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e);
24 void blk_mq_sched_free_rqs(struct request_queue *q);
25 
26 struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set,
27 		unsigned int nr_hw_queues, unsigned int nr_requests);
28 int blk_mq_alloc_sched_res(struct request_queue *q,
29 		struct elevator_type *type,
30 		struct elevator_resources *res,
31 		unsigned int nr_hw_queues);
32 int blk_mq_alloc_sched_res_batch(struct xarray *elv_tbl,
33 		struct blk_mq_tag_set *set, unsigned int nr_hw_queues);
34 int blk_mq_alloc_sched_ctx_batch(struct xarray *elv_tbl,
35 		struct blk_mq_tag_set *set);
36 void blk_mq_free_sched_ctx_batch(struct xarray *elv_tbl);
37 void blk_mq_free_sched_tags(struct elevator_tags *et,
38 		struct blk_mq_tag_set *set);
39 void blk_mq_free_sched_res(struct elevator_resources *res,
40 		struct elevator_type *type,
41 		struct blk_mq_tag_set *set);
42 void blk_mq_free_sched_res_batch(struct xarray *et_table,
43 		struct blk_mq_tag_set *set);
44 /*
45  * blk_mq_alloc_sched_data() - Allocates scheduler specific data
46  * Returns:
47  *         - Pointer to allocated data on success
48  *         - NULL if no allocation needed
49  *         - ERR_PTR(-ENOMEM) in case of failure
50  */
51 static inline void *blk_mq_alloc_sched_data(struct request_queue *q,
52 		struct elevator_type *e)
53 {
54 	void *sched_data;
55 
56 	if (!e || !e->ops.alloc_sched_data)
57 		return NULL;
58 
59 	sched_data = e->ops.alloc_sched_data(q);
60 	return (sched_data) ?: ERR_PTR(-ENOMEM);
61 }
62 
63 static inline void blk_mq_free_sched_data(struct elevator_type *e, void *data)
64 {
65 	if (e && e->ops.free_sched_data)
66 		e->ops.free_sched_data(data);
67 }
68 
69 static inline void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx)
70 {
71 	if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
72 		__blk_mq_sched_restart(hctx);
73 }
74 
75 static inline bool bio_mergeable(struct bio *bio)
76 {
77 	return !(bio->bi_opf & REQ_NOMERGE_FLAGS);
78 }
79 
80 static inline bool
81 blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq,
82 			 struct bio *bio)
83 {
84 	if (rq->rq_flags & RQF_USE_SCHED) {
85 		struct elevator_queue *e = q->elevator;
86 
87 		if (e->type->ops.allow_merge)
88 			return e->type->ops.allow_merge(q, rq, bio);
89 	}
90 	return true;
91 }
92 
93 static inline void blk_mq_sched_completed_request(struct request *rq, u64 now)
94 {
95 	if (rq->rq_flags & RQF_USE_SCHED) {
96 		struct elevator_queue *e = rq->q->elevator;
97 
98 		if (e->type->ops.completed_request)
99 			e->type->ops.completed_request(rq, now);
100 	}
101 }
102 
103 static inline void blk_mq_sched_requeue_request(struct request *rq)
104 {
105 	if (rq->rq_flags & RQF_USE_SCHED) {
106 		struct request_queue *q = rq->q;
107 		struct elevator_queue *e = q->elevator;
108 
109 		if (e->type->ops.requeue_request)
110 			e->type->ops.requeue_request(rq);
111 	}
112 }
113 
114 static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx)
115 {
116 	struct elevator_queue *e = hctx->queue->elevator;
117 
118 	if (e && e->type->ops.has_work)
119 		return e->type->ops.has_work(hctx);
120 
121 	return false;
122 }
123 
124 static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx)
125 {
126 	return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
127 }
128 
129 static inline void blk_mq_set_min_shallow_depth(struct request_queue *q,
130 						unsigned int depth)
131 {
132 	struct blk_mq_hw_ctx *hctx;
133 	unsigned long i;
134 
135 	queue_for_each_hw_ctx(q, hctx, i)
136 		sbitmap_queue_min_shallow_depth(&hctx->sched_tags->bitmap_tags,
137 						depth);
138 }
139 
140 #endif
141