xref: /openbmc/linux/block/blk-mq.h (revision fb960bd2) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef INT_BLK_MQ_H
3 #define INT_BLK_MQ_H
4 
5 #include "blk-stat.h"
6 #include "blk-mq-tag.h"
7 
8 struct blk_mq_tag_set;
9 
10 struct blk_mq_ctx {
11 	struct {
12 		spinlock_t		lock;
13 		struct list_head	rq_list;
14 	}  ____cacheline_aligned_in_smp;
15 
16 	unsigned int		cpu;
17 	unsigned int		index_hw;
18 
19 	/* incremented at dispatch time */
20 	unsigned long		rq_dispatched[2];
21 	unsigned long		rq_merged;
22 
23 	/* incremented at completion time */
24 	unsigned long		____cacheline_aligned_in_smp rq_completed[2];
25 
26 	struct request_queue	*queue;
27 	struct kobject		kobj;
28 } ____cacheline_aligned_in_smp;
29 
30 void blk_mq_freeze_queue(struct request_queue *q);
31 void blk_mq_free_queue(struct request_queue *q);
32 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
33 void blk_mq_wake_waiters(struct request_queue *q);
34 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
35 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
36 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
37 				bool wait);
38 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
39 					struct blk_mq_ctx *start);
40 
41 /*
42  * Internal helpers for allocating/freeing the request map
43  */
44 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
45 		     unsigned int hctx_idx);
46 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
47 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
48 					unsigned int hctx_idx,
49 					unsigned int nr_tags,
50 					unsigned int reserved_tags);
51 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
52 		     unsigned int hctx_idx, unsigned int depth);
53 
54 /*
55  * Internal helpers for request insertion into sw queues
56  */
57 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
58 				bool at_head);
59 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
60 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
61 				struct list_head *list);
62 
63 /*
64  * CPU -> queue mappings
65  */
66 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
67 
68 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
69 		int cpu)
70 {
71 	return q->queue_hw_ctx[q->mq_map[cpu]];
72 }
73 
74 /*
75  * sysfs helpers
76  */
77 extern void blk_mq_sysfs_init(struct request_queue *q);
78 extern void blk_mq_sysfs_deinit(struct request_queue *q);
79 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
80 extern int blk_mq_sysfs_register(struct request_queue *q);
81 extern void blk_mq_sysfs_unregister(struct request_queue *q);
82 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
83 
84 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
85 
86 void blk_mq_release(struct request_queue *q);
87 
88 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
89 					   unsigned int cpu)
90 {
91 	return per_cpu_ptr(q->queue_ctx, cpu);
92 }
93 
94 /*
95  * This assumes per-cpu software queueing queues. They could be per-node
96  * as well, for instance. For now this is hardcoded as-is. Note that we don't
97  * care about preemption, since we know the ctx's are persistent. This does
98  * mean that we can't rely on ctx always matching the currently running CPU.
99  */
100 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
101 {
102 	return __blk_mq_get_ctx(q, get_cpu());
103 }
104 
105 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
106 {
107 	put_cpu();
108 }
109 
110 struct blk_mq_alloc_data {
111 	/* input parameter */
112 	struct request_queue *q;
113 	blk_mq_req_flags_t flags;
114 	unsigned int shallow_depth;
115 
116 	/* input & output parameter */
117 	struct blk_mq_ctx *ctx;
118 	struct blk_mq_hw_ctx *hctx;
119 };
120 
121 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
122 {
123 	if (data->flags & BLK_MQ_REQ_INTERNAL)
124 		return data->hctx->sched_tags;
125 
126 	return data->hctx->tags;
127 }
128 
129 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
130 {
131 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
132 }
133 
134 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
135 {
136 	return hctx->nr_ctx && hctx->tags;
137 }
138 
139 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
140 			unsigned int inflight[2]);
141 
142 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
143 {
144 	struct request_queue *q = hctx->queue;
145 
146 	if (q->mq_ops->put_budget)
147 		q->mq_ops->put_budget(hctx);
148 }
149 
150 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
151 {
152 	struct request_queue *q = hctx->queue;
153 
154 	if (q->mq_ops->get_budget)
155 		return q->mq_ops->get_budget(hctx);
156 	return true;
157 }
158 
159 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
160 					   struct request *rq)
161 {
162 	blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
163 	rq->tag = -1;
164 
165 	if (rq->rq_flags & RQF_MQ_INFLIGHT) {
166 		rq->rq_flags &= ~RQF_MQ_INFLIGHT;
167 		atomic_dec(&hctx->nr_active);
168 	}
169 }
170 
171 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
172 				       struct request *rq)
173 {
174 	if (rq->tag == -1 || rq->internal_tag == -1)
175 		return;
176 
177 	__blk_mq_put_driver_tag(hctx, rq);
178 }
179 
180 static inline void blk_mq_put_driver_tag(struct request *rq)
181 {
182 	struct blk_mq_hw_ctx *hctx;
183 
184 	if (rq->tag == -1 || rq->internal_tag == -1)
185 		return;
186 
187 	hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
188 	__blk_mq_put_driver_tag(hctx, rq);
189 }
190 
191 #endif
192