xref: /openbmc/linux/block/blk-mq.h (revision 7e6f7d24) 
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 /**
11  * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
12  */
13 struct blk_mq_ctx {
14 	struct {
15 		spinlock_t		lock;
16 		struct list_head	rq_list;
17 	}  ____cacheline_aligned_in_smp;
18 
19 	unsigned int		cpu;
20 	unsigned int		index_hw;
21 
22 	/* incremented at dispatch time */
23 	unsigned long		rq_dispatched[2];
24 	unsigned long		rq_merged;
25 
26 	/* incremented at completion time */
27 	unsigned long		____cacheline_aligned_in_smp rq_completed[2];
28 
29 	struct request_queue	*queue;
30 	struct kobject		kobj;
31 } ____cacheline_aligned_in_smp;
32 
33 void blk_mq_freeze_queue(struct request_queue *q);
34 void blk_mq_free_queue(struct request_queue *q);
35 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
36 void blk_mq_wake_waiters(struct request_queue *q);
37 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
38 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
39 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
40 				bool wait);
41 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
42 					struct blk_mq_ctx *start);
43 
44 /*
45  * Internal helpers for allocating/freeing the request map
46  */
47 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
48 		     unsigned int hctx_idx);
49 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
50 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
51 					unsigned int hctx_idx,
52 					unsigned int nr_tags,
53 					unsigned int reserved_tags);
54 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
55 		     unsigned int hctx_idx, unsigned int depth);
56 
57 /*
58  * Internal helpers for request insertion into sw queues
59  */
60 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
61 				bool at_head);
62 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
63 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
64 				struct list_head *list);
65 
66 /* Used by blk_insert_cloned_request() to issue request directly */
67 blk_status_t blk_mq_request_issue_directly(struct request *rq);
68 
69 /*
70  * CPU -> queue mappings
71  */
72 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
73 
74 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
75 		int cpu)
76 {
77 	return q->queue_hw_ctx[q->mq_map[cpu]];
78 }
79 
80 /*
81  * sysfs helpers
82  */
83 extern void blk_mq_sysfs_init(struct request_queue *q);
84 extern void blk_mq_sysfs_deinit(struct request_queue *q);
85 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
86 extern int blk_mq_sysfs_register(struct request_queue *q);
87 extern void blk_mq_sysfs_unregister(struct request_queue *q);
88 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
89 
90 void blk_mq_release(struct request_queue *q);
91 
92 /**
93  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
94  * @rq: target request.
95  */
96 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
97 {
98 	return READ_ONCE(rq->state);
99 }
100 
101 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
102 					   unsigned int cpu)
103 {
104 	return per_cpu_ptr(q->queue_ctx, cpu);
105 }
106 
107 /*
108  * This assumes per-cpu software queueing queues. They could be per-node
109  * as well, for instance. For now this is hardcoded as-is. Note that we don't
110  * care about preemption, since we know the ctx's are persistent. This does
111  * mean that we can't rely on ctx always matching the currently running CPU.
112  */
113 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
114 {
115 	return __blk_mq_get_ctx(q, get_cpu());
116 }
117 
118 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
119 {
120 	put_cpu();
121 }
122 
123 struct blk_mq_alloc_data {
124 	/* input parameter */
125 	struct request_queue *q;
126 	blk_mq_req_flags_t flags;
127 	unsigned int shallow_depth;
128 
129 	/* input & output parameter */
130 	struct blk_mq_ctx *ctx;
131 	struct blk_mq_hw_ctx *hctx;
132 };
133 
134 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
135 {
136 	if (data->flags & BLK_MQ_REQ_INTERNAL)
137 		return data->hctx->sched_tags;
138 
139 	return data->hctx->tags;
140 }
141 
142 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
143 {
144 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
145 }
146 
147 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
148 {
149 	return hctx->nr_ctx && hctx->tags;
150 }
151 
152 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
153 		      unsigned int inflight[2]);
154 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
155 			 unsigned int inflight[2]);
156 
157 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
158 {
159 	struct request_queue *q = hctx->queue;
160 
161 	if (q->mq_ops->put_budget)
162 		q->mq_ops->put_budget(hctx);
163 }
164 
165 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
166 {
167 	struct request_queue *q = hctx->queue;
168 
169 	if (q->mq_ops->get_budget)
170 		return q->mq_ops->get_budget(hctx);
171 	return true;
172 }
173 
174 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
175 					   struct request *rq)
176 {
177 	blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
178 	rq->tag = -1;
179 
180 	if (rq->rq_flags & RQF_MQ_INFLIGHT) {
181 		rq->rq_flags &= ~RQF_MQ_INFLIGHT;
182 		atomic_dec(&hctx->nr_active);
183 	}
184 }
185 
186 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
187 				       struct request *rq)
188 {
189 	if (rq->tag == -1 || rq->internal_tag == -1)
190 		return;
191 
192 	__blk_mq_put_driver_tag(hctx, rq);
193 }
194 
195 static inline void blk_mq_put_driver_tag(struct request *rq)
196 {
197 	struct blk_mq_hw_ctx *hctx;
198 
199 	if (rq->tag == -1 || rq->internal_tag == -1)
200 		return;
201 
202 	hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
203 	__blk_mq_put_driver_tag(hctx, rq);
204 }
205 
206 #endif
207