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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 	struct blk_mq_hw_ctx 	*hctxs[HCTX_MAX_TYPES];
27 
28 	/* incremented at dispatch time */
29 	unsigned long		rq_dispatched[2];
30 	unsigned long		rq_merged;
31 
32 	/* incremented at completion time */
33 	unsigned long		____cacheline_aligned_in_smp rq_completed[2];
34 
35 	struct request_queue	*queue;
36 	struct blk_mq_ctxs      *ctxs;
37 	struct kobject		kobj;
38 
39 	ANDROID_OEM_DATA_ARRAY(1, 2);
40 } ____cacheline_aligned_in_smp;
41 
42 void blk_mq_exit_queue(struct request_queue *q);
43 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
44 void blk_mq_wake_waiters(struct request_queue *q);
45 bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
46 			     unsigned int);
47 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
48 				bool kick_requeue_list);
49 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
50 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
51 					struct blk_mq_ctx *start);
52 void blk_mq_put_rq_ref(struct request *rq);
53 
54 /*
55  * Internal helpers for allocating/freeing the request map
56  */
57 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
58 		     unsigned int hctx_idx);
59 void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags);
60 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
61 					unsigned int hctx_idx,
62 					unsigned int nr_tags,
63 					unsigned int reserved_tags,
64 					unsigned int flags);
65 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
66 		     unsigned int hctx_idx, unsigned int depth);
67 
68 /*
69  * Internal helpers for request insertion into sw queues
70  */
71 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
72 				bool at_head);
73 void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
74 				  bool run_queue);
75 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
76 				struct list_head *list);
77 
78 /* Used by blk_insert_cloned_request() to issue request directly */
79 blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
80 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
81 				    struct list_head *list);
82 
83 /*
84  * CPU -> queue mappings
85  */
86 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
87 
88 /*
89  * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
90  * @q: request queue
91  * @type: the hctx type index
92  * @cpu: CPU
93  */
blk_mq_map_queue_type(struct request_queue * q,enum hctx_type type,unsigned int cpu)94 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
95 							  enum hctx_type type,
96 							  unsigned int cpu)
97 {
98 	return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
99 }
100 
101 /*
102  * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
103  * @q: request queue
104  * @flags: request command flags
105  * @cpu: cpu ctx
106  */
blk_mq_map_queue(struct request_queue * q,unsigned int flags,struct blk_mq_ctx * ctx)107 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
108 						     unsigned int flags,
109 						     struct blk_mq_ctx *ctx)
110 {
111 	enum hctx_type type = HCTX_TYPE_DEFAULT;
112 
113 	/*
114 	 * The caller ensure that if REQ_HIPRI, poll must be enabled.
115 	 */
116 	if (flags & REQ_HIPRI)
117 		type = HCTX_TYPE_POLL;
118 	else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
119 		type = HCTX_TYPE_READ;
120 
121 	return ctx->hctxs[type];
122 }
123 
124 /*
125  * sysfs helpers
126  */
127 extern void blk_mq_sysfs_init(struct request_queue *q);
128 extern void blk_mq_sysfs_deinit(struct request_queue *q);
129 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
130 extern int blk_mq_sysfs_register(struct request_queue *q);
131 extern void blk_mq_sysfs_unregister(struct request_queue *q);
132 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
133 
134 void blk_mq_release(struct request_queue *q);
135 
__blk_mq_get_ctx(struct request_queue * q,unsigned int cpu)136 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
137 					   unsigned int cpu)
138 {
139 	return per_cpu_ptr(q->queue_ctx, cpu);
140 }
141 
142 /*
143  * This assumes per-cpu software queueing queues. They could be per-node
144  * as well, for instance. For now this is hardcoded as-is. Note that we don't
145  * care about preemption, since we know the ctx's are persistent. This does
146  * mean that we can't rely on ctx always matching the currently running CPU.
147  */
blk_mq_get_ctx(struct request_queue * q)148 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
149 {
150 	return __blk_mq_get_ctx(q, raw_smp_processor_id());
151 }
152 
153 struct blk_mq_alloc_data {
154 	/* input parameter */
155 	struct request_queue *q;
156 	blk_mq_req_flags_t flags;
157 	unsigned int shallow_depth;
158 	unsigned int cmd_flags;
159 
160 	/* input & output parameter */
161 	struct blk_mq_ctx *ctx;
162 	struct blk_mq_hw_ctx *hctx;
163 };
164 
blk_mq_is_sbitmap_shared(unsigned int flags)165 static inline bool blk_mq_is_sbitmap_shared(unsigned int flags)
166 {
167 	return flags & BLK_MQ_F_TAG_HCTX_SHARED;
168 }
169 
blk_mq_tags_from_data(struct blk_mq_alloc_data * data)170 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
171 {
172 	if (data->q->elevator)
173 		return data->hctx->sched_tags;
174 
175 	return data->hctx->tags;
176 }
177 
blk_mq_hctx_stopped(struct blk_mq_hw_ctx * hctx)178 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
179 {
180 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
181 }
182 
blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx * hctx)183 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
184 {
185 	return hctx->nr_ctx && hctx->tags;
186 }
187 
188 unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
189 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
190 			 unsigned int inflight[2]);
191 
blk_mq_put_dispatch_budget(struct request_queue * q)192 static inline void blk_mq_put_dispatch_budget(struct request_queue *q)
193 {
194 	if (q->mq_ops->put_budget)
195 		q->mq_ops->put_budget(q);
196 }
197 
blk_mq_get_dispatch_budget(struct request_queue * q)198 static inline bool blk_mq_get_dispatch_budget(struct request_queue *q)
199 {
200 	if (q->mq_ops->get_budget)
201 		return q->mq_ops->get_budget(q);
202 	return true;
203 }
204 
__blk_mq_inc_active_requests(struct blk_mq_hw_ctx * hctx)205 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
206 {
207 	if (blk_mq_is_sbitmap_shared(hctx->flags))
208 		atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap);
209 	else
210 		atomic_inc(&hctx->nr_active);
211 }
212 
__blk_mq_dec_active_requests(struct blk_mq_hw_ctx * hctx)213 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
214 {
215 	if (blk_mq_is_sbitmap_shared(hctx->flags))
216 		atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap);
217 	else
218 		atomic_dec(&hctx->nr_active);
219 }
220 
__blk_mq_active_requests(struct blk_mq_hw_ctx * hctx)221 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
222 {
223 	if (blk_mq_is_sbitmap_shared(hctx->flags))
224 		return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap);
225 	return atomic_read(&hctx->nr_active);
226 }
__blk_mq_put_driver_tag(struct blk_mq_hw_ctx * hctx,struct request * rq)227 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
228 					   struct request *rq)
229 {
230 	blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
231 	rq->tag = BLK_MQ_NO_TAG;
232 
233 	if (rq->rq_flags & RQF_MQ_INFLIGHT) {
234 		rq->rq_flags &= ~RQF_MQ_INFLIGHT;
235 		__blk_mq_dec_active_requests(hctx);
236 	}
237 }
238 
blk_mq_put_driver_tag(struct request * rq)239 static inline void blk_mq_put_driver_tag(struct request *rq)
240 {
241 	if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
242 		return;
243 
244 	__blk_mq_put_driver_tag(rq->mq_hctx, rq);
245 }
246 
blk_mq_clear_mq_map(struct blk_mq_queue_map * qmap)247 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
248 {
249 	int cpu;
250 
251 	for_each_possible_cpu(cpu)
252 		qmap->mq_map[cpu] = 0;
253 }
254 
255 /*
256  * blk_mq_plug() - Get caller context plug
257  * @q: request queue
258  * @bio : the bio being submitted by the caller context
259  *
260  * Plugging, by design, may delay the insertion of BIOs into the elevator in
261  * order to increase BIO merging opportunities. This however can cause BIO
262  * insertion order to change from the order in which submit_bio() is being
263  * executed in the case of multiple contexts concurrently issuing BIOs to a
264  * device, even if these context are synchronized to tightly control BIO issuing
265  * order. While this is not a problem with regular block devices, this ordering
266  * change can cause write BIO failures with zoned block devices as these
267  * require sequential write patterns to zones. Prevent this from happening by
268  * ignoring the plug state of a BIO issuing context if the target request queue
269  * is for a zoned block device and the BIO to plug is a write operation.
270  *
271  * Return current->plug if the bio can be plugged and NULL otherwise
272  */
blk_mq_plug(struct request_queue * q,struct bio * bio)273 static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
274 					   struct bio *bio)
275 {
276 	/*
277 	 * For regular block devices or read operations, use the context plug
278 	 * which may be NULL if blk_start_plug() was not executed.
279 	 */
280 	if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
281 		return current->plug;
282 
283 	/* Zoned block device write operation case: do not plug the BIO */
284 	return NULL;
285 }
286 
287 /*
288  * For shared tag users, we track the number of currently active users
289  * and attempt to provide a fair share of the tag depth for each of them.
290  */
hctx_may_queue(struct blk_mq_hw_ctx * hctx,struct sbitmap_queue * bt)291 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
292 				  struct sbitmap_queue *bt)
293 {
294 	unsigned int depth, users;
295 
296 	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
297 		return true;
298 
299 	/*
300 	 * Don't try dividing an ant
301 	 */
302 	if (bt->sb.depth == 1)
303 		return true;
304 
305 	if (blk_mq_is_sbitmap_shared(hctx->flags)) {
306 		struct request_queue *q = hctx->queue;
307 		struct blk_mq_tag_set *set = q->tag_set;
308 
309 		if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
310 			return true;
311 		users = atomic_read(&set->active_queues_shared_sbitmap);
312 	} else {
313 		if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
314 			return true;
315 		users = atomic_read(&hctx->tags->active_queues);
316 	}
317 
318 	if (!users)
319 		return true;
320 
321 	/*
322 	 * Allow at least some tags
323 	 */
324 	depth = max((bt->sb.depth + users - 1) / users, 4U);
325 	return __blk_mq_active_requests(hctx) < depth;
326 }
327 
328 
329 #endif
330