xref: /openbmc/linux/block/blk-mq.h (revision 5a170e9e)
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_ctxs {
11 	struct kobject kobj;
12 	struct blk_mq_ctx __percpu	*queue_ctx;
13 };
14 
15 /**
16  * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
17  */
18 struct blk_mq_ctx {
19 	struct {
20 		spinlock_t		lock;
21 		struct list_head	rq_lists[HCTX_MAX_TYPES];
22 	} ____cacheline_aligned_in_smp;
23 
24 	unsigned int		cpu;
25 	unsigned short		index_hw[HCTX_MAX_TYPES];
26 
27 	/* incremented at dispatch time */
28 	unsigned long		rq_dispatched[2];
29 	unsigned long		rq_merged;
30 
31 	/* incremented at completion time */
32 	unsigned long		____cacheline_aligned_in_smp rq_completed[2];
33 
34 	struct request_queue	*queue;
35 	struct blk_mq_ctxs      *ctxs;
36 	struct kobject		kobj;
37 } ____cacheline_aligned_in_smp;
38 
39 void blk_mq_freeze_queue(struct request_queue *q);
40 void blk_mq_free_queue(struct request_queue *q);
41 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
42 void blk_mq_wake_waiters(struct request_queue *q);
43 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
44 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
45 bool blk_mq_get_driver_tag(struct request *rq);
46 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
47 					struct blk_mq_ctx *start);
48 
49 /*
50  * Internal helpers for allocating/freeing the request map
51  */
52 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
53 		     unsigned int hctx_idx);
54 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
55 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
56 					unsigned int hctx_idx,
57 					unsigned int nr_tags,
58 					unsigned int reserved_tags);
59 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
60 		     unsigned int hctx_idx, unsigned int depth);
61 
62 /*
63  * Internal helpers for request insertion into sw queues
64  */
65 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
66 				bool at_head);
67 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
68 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
69 				struct list_head *list);
70 
71 blk_status_t blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
72 						struct request *rq,
73 						blk_qc_t *cookie,
74 						bool bypass, bool last);
75 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
76 				    struct list_head *list);
77 
78 /*
79  * CPU -> queue mappings
80  */
81 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
82 
83 /*
84  * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
85  * @q: request queue
86  * @type: the hctx type index
87  * @cpu: CPU
88  */
89 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
90 							  enum hctx_type type,
91 							  unsigned int cpu)
92 {
93 	return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
94 }
95 
96 /*
97  * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
98  * @q: request queue
99  * @flags: request command flags
100  * @cpu: CPU
101  */
102 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
103 						     unsigned int flags,
104 						     unsigned int cpu)
105 {
106 	enum hctx_type type = HCTX_TYPE_DEFAULT;
107 
108 	if ((flags & REQ_HIPRI) &&
109 	    q->tag_set->nr_maps > HCTX_TYPE_POLL &&
110 	    q->tag_set->map[HCTX_TYPE_POLL].nr_queues &&
111 	    test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
112 		type = HCTX_TYPE_POLL;
113 
114 	else if (((flags & REQ_OP_MASK) == REQ_OP_READ) &&
115 	         q->tag_set->nr_maps > HCTX_TYPE_READ &&
116 		 q->tag_set->map[HCTX_TYPE_READ].nr_queues)
117 		type = HCTX_TYPE_READ;
118 
119 	return blk_mq_map_queue_type(q, type, cpu);
120 }
121 
122 /*
123  * sysfs helpers
124  */
125 extern void blk_mq_sysfs_init(struct request_queue *q);
126 extern void blk_mq_sysfs_deinit(struct request_queue *q);
127 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
128 extern int blk_mq_sysfs_register(struct request_queue *q);
129 extern void blk_mq_sysfs_unregister(struct request_queue *q);
130 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
131 
132 void blk_mq_release(struct request_queue *q);
133 
134 /**
135  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
136  * @rq: target request.
137  */
138 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
139 {
140 	return READ_ONCE(rq->state);
141 }
142 
143 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
144 					   unsigned int cpu)
145 {
146 	return per_cpu_ptr(q->queue_ctx, cpu);
147 }
148 
149 /*
150  * This assumes per-cpu software queueing queues. They could be per-node
151  * as well, for instance. For now this is hardcoded as-is. Note that we don't
152  * care about preemption, since we know the ctx's are persistent. This does
153  * mean that we can't rely on ctx always matching the currently running CPU.
154  */
155 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
156 {
157 	return __blk_mq_get_ctx(q, get_cpu());
158 }
159 
160 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
161 {
162 	put_cpu();
163 }
164 
165 struct blk_mq_alloc_data {
166 	/* input parameter */
167 	struct request_queue *q;
168 	blk_mq_req_flags_t flags;
169 	unsigned int shallow_depth;
170 	unsigned int cmd_flags;
171 
172 	/* input & output parameter */
173 	struct blk_mq_ctx *ctx;
174 	struct blk_mq_hw_ctx *hctx;
175 };
176 
177 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
178 {
179 	if (data->flags & BLK_MQ_REQ_INTERNAL)
180 		return data->hctx->sched_tags;
181 
182 	return data->hctx->tags;
183 }
184 
185 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
186 {
187 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
188 }
189 
190 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
191 {
192 	return hctx->nr_ctx && hctx->tags;
193 }
194 
195 unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
196 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
197 			 unsigned int inflight[2]);
198 
199 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
200 {
201 	struct request_queue *q = hctx->queue;
202 
203 	if (q->mq_ops->put_budget)
204 		q->mq_ops->put_budget(hctx);
205 }
206 
207 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
208 {
209 	struct request_queue *q = hctx->queue;
210 
211 	if (q->mq_ops->get_budget)
212 		return q->mq_ops->get_budget(hctx);
213 	return true;
214 }
215 
216 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
217 					   struct request *rq)
218 {
219 	blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
220 	rq->tag = -1;
221 
222 	if (rq->rq_flags & RQF_MQ_INFLIGHT) {
223 		rq->rq_flags &= ~RQF_MQ_INFLIGHT;
224 		atomic_dec(&hctx->nr_active);
225 	}
226 }
227 
228 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
229 				       struct request *rq)
230 {
231 	if (rq->tag == -1 || rq->internal_tag == -1)
232 		return;
233 
234 	__blk_mq_put_driver_tag(hctx, rq);
235 }
236 
237 static inline void blk_mq_put_driver_tag(struct request *rq)
238 {
239 	if (rq->tag == -1 || rq->internal_tag == -1)
240 		return;
241 
242 	__blk_mq_put_driver_tag(rq->mq_hctx, rq);
243 }
244 
245 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
246 {
247 	int cpu;
248 
249 	for_each_possible_cpu(cpu)
250 		qmap->mq_map[cpu] = 0;
251 }
252 
253 #endif
254