1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef INT_BLK_MQ_H
3 #define INT_BLK_MQ_H
4 
5 #include <linux/blk-mq.h>
6 #include "blk-stat.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 	struct request_queue	*queue;
29 	struct blk_mq_ctxs      *ctxs;
30 	struct kobject		kobj;
31 } ____cacheline_aligned_in_smp;
32 
33 enum {
34 	BLK_MQ_NO_TAG		= -1U,
35 	BLK_MQ_TAG_MIN		= 1,
36 	BLK_MQ_TAG_MAX		= BLK_MQ_NO_TAG - 1,
37 };
38 
39 typedef unsigned int __bitwise blk_insert_t;
40 #define BLK_MQ_INSERT_AT_HEAD		((__force blk_insert_t)0x01)
41 
42 void blk_mq_submit_bio(struct bio *bio);
43 int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
44 		unsigned int flags);
45 void blk_mq_exit_queue(struct request_queue *q);
46 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
47 void blk_mq_wake_waiters(struct request_queue *q);
48 bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
49 			     unsigned int);
50 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
51 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
52 					struct blk_mq_ctx *start);
53 void blk_mq_put_rq_ref(struct request *rq);
54 
55 /*
56  * Internal helpers for allocating/freeing the request map
57  */
58 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
59 		     unsigned int hctx_idx);
60 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
61 struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
62 				unsigned int hctx_idx, unsigned int depth);
63 void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
64 			     struct blk_mq_tags *tags,
65 			     unsigned int hctx_idx);
66 
67 /*
68  * CPU -> queue mappings
69  */
70 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
71 
72 /*
73  * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
74  * @q: request queue
75  * @type: the hctx type index
76  * @cpu: CPU
77  */
blk_mq_map_queue_type(struct request_queue * q,enum hctx_type type,unsigned int cpu)78 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
79 							  enum hctx_type type,
80 							  unsigned int cpu)
81 {
82 	return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]);
83 }
84 
blk_mq_get_hctx_type(blk_opf_t opf)85 static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)
86 {
87 	enum hctx_type type = HCTX_TYPE_DEFAULT;
88 
89 	/*
90 	 * The caller ensure that if REQ_POLLED, poll must be enabled.
91 	 */
92 	if (opf & REQ_POLLED)
93 		type = HCTX_TYPE_POLL;
94 	else if ((opf & REQ_OP_MASK) == REQ_OP_READ)
95 		type = HCTX_TYPE_READ;
96 	return type;
97 }
98 
99 /*
100  * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
101  * @q: request queue
102  * @opf: operation type (REQ_OP_*) and flags (e.g. REQ_POLLED).
103  * @ctx: software queue cpu ctx
104  */
blk_mq_map_queue(struct request_queue * q,blk_opf_t opf,struct blk_mq_ctx * ctx)105 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
106 						     blk_opf_t opf,
107 						     struct blk_mq_ctx *ctx)
108 {
109 	return ctx->hctxs[blk_mq_get_hctx_type(opf)];
110 }
111 
112 /*
113  * sysfs helpers
114  */
115 extern void blk_mq_sysfs_init(struct request_queue *q);
116 extern void blk_mq_sysfs_deinit(struct request_queue *q);
117 int blk_mq_sysfs_register(struct gendisk *disk);
118 void blk_mq_sysfs_unregister(struct gendisk *disk);
119 int blk_mq_sysfs_register_hctxs(struct request_queue *q);
120 void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
121 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
122 void blk_mq_free_plug_rqs(struct blk_plug *plug);
123 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
124 
125 void blk_mq_cancel_work_sync(struct request_queue *q);
126 
127 void blk_mq_release(struct request_queue *q);
128 
__blk_mq_get_ctx(struct request_queue * q,unsigned int cpu)129 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
130 					   unsigned int cpu)
131 {
132 	return per_cpu_ptr(q->queue_ctx, cpu);
133 }
134 
135 /*
136  * This assumes per-cpu software queueing queues. They could be per-node
137  * as well, for instance. For now this is hardcoded as-is. Note that we don't
138  * care about preemption, since we know the ctx's are persistent. This does
139  * mean that we can't rely on ctx always matching the currently running CPU.
140  */
blk_mq_get_ctx(struct request_queue * q)141 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
142 {
143 	return __blk_mq_get_ctx(q, raw_smp_processor_id());
144 }
145 
146 struct blk_mq_alloc_data {
147 	/* input parameter */
148 	struct request_queue *q;
149 	blk_mq_req_flags_t flags;
150 	unsigned int shallow_depth;
151 	blk_opf_t cmd_flags;
152 	req_flags_t rq_flags;
153 
154 	/* allocate multiple requests/tags in one go */
155 	unsigned int nr_tags;
156 	struct request **cached_rq;
157 
158 	/* input & output parameter */
159 	struct blk_mq_ctx *ctx;
160 	struct blk_mq_hw_ctx *hctx;
161 };
162 
163 struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
164 		unsigned int reserved_tags, int node, int alloc_policy);
165 void blk_mq_free_tags(struct blk_mq_tags *tags);
166 int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
167 		struct sbitmap_queue *breserved_tags, unsigned int queue_depth,
168 		unsigned int reserved, int node, int alloc_policy);
169 
170 unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
171 unsigned long blk_mq_get_tags(struct blk_mq_alloc_data *data, int nr_tags,
172 		unsigned int *offset);
173 void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
174 		unsigned int tag);
175 void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags);
176 int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
177 		struct blk_mq_tags **tags, unsigned int depth, bool can_grow);
178 void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set,
179 		unsigned int size);
180 void blk_mq_tag_update_sched_shared_tags(struct request_queue *q);
181 
182 void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
183 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_tag_iter_fn *fn,
184 		void *priv);
185 void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
186 		void *priv);
187 
bt_wait_ptr(struct sbitmap_queue * bt,struct blk_mq_hw_ctx * hctx)188 static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
189 						 struct blk_mq_hw_ctx *hctx)
190 {
191 	if (!hctx)
192 		return &bt->ws[0];
193 	return sbq_wait_ptr(bt, &hctx->wait_index);
194 }
195 
196 void __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
197 void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
198 
blk_mq_tag_busy(struct blk_mq_hw_ctx * hctx)199 static inline void blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
200 {
201 	if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
202 		__blk_mq_tag_busy(hctx);
203 }
204 
blk_mq_tag_idle(struct blk_mq_hw_ctx * hctx)205 static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
206 {
207 	if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
208 		__blk_mq_tag_idle(hctx);
209 }
210 
blk_mq_tag_is_reserved(struct blk_mq_tags * tags,unsigned int tag)211 static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags,
212 					  unsigned int tag)
213 {
214 	return tag < tags->nr_reserved_tags;
215 }
216 
blk_mq_is_shared_tags(unsigned int flags)217 static inline bool blk_mq_is_shared_tags(unsigned int flags)
218 {
219 	return flags & BLK_MQ_F_TAG_HCTX_SHARED;
220 }
221 
blk_mq_tags_from_data(struct blk_mq_alloc_data * data)222 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
223 {
224 	if (data->rq_flags & RQF_SCHED_TAGS)
225 		return data->hctx->sched_tags;
226 	return data->hctx->tags;
227 }
228 
blk_mq_hctx_stopped(struct blk_mq_hw_ctx * hctx)229 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
230 {
231 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
232 }
233 
blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx * hctx)234 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
235 {
236 	return hctx->nr_ctx && hctx->tags;
237 }
238 
239 unsigned int blk_mq_in_flight(struct request_queue *q,
240 		struct block_device *part);
241 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
242 		unsigned int inflight[2]);
243 
blk_mq_put_dispatch_budget(struct request_queue * q,int budget_token)244 static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
245 					      int budget_token)
246 {
247 	if (q->mq_ops->put_budget)
248 		q->mq_ops->put_budget(q, budget_token);
249 }
250 
blk_mq_get_dispatch_budget(struct request_queue * q)251 static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
252 {
253 	if (q->mq_ops->get_budget)
254 		return q->mq_ops->get_budget(q);
255 	return 0;
256 }
257 
blk_mq_set_rq_budget_token(struct request * rq,int token)258 static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
259 {
260 	if (token < 0)
261 		return;
262 
263 	if (rq->q->mq_ops->set_rq_budget_token)
264 		rq->q->mq_ops->set_rq_budget_token(rq, token);
265 }
266 
blk_mq_get_rq_budget_token(struct request * rq)267 static inline int blk_mq_get_rq_budget_token(struct request *rq)
268 {
269 	if (rq->q->mq_ops->get_rq_budget_token)
270 		return rq->q->mq_ops->get_rq_budget_token(rq);
271 	return -1;
272 }
273 
__blk_mq_inc_active_requests(struct blk_mq_hw_ctx * hctx)274 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
275 {
276 	if (blk_mq_is_shared_tags(hctx->flags))
277 		atomic_inc(&hctx->queue->nr_active_requests_shared_tags);
278 	else
279 		atomic_inc(&hctx->nr_active);
280 }
281 
__blk_mq_sub_active_requests(struct blk_mq_hw_ctx * hctx,int val)282 static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
283 		int val)
284 {
285 	if (blk_mq_is_shared_tags(hctx->flags))
286 		atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
287 	else
288 		atomic_sub(val, &hctx->nr_active);
289 }
290 
__blk_mq_dec_active_requests(struct blk_mq_hw_ctx * hctx)291 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
292 {
293 	__blk_mq_sub_active_requests(hctx, 1);
294 }
295 
__blk_mq_active_requests(struct blk_mq_hw_ctx * hctx)296 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
297 {
298 	if (blk_mq_is_shared_tags(hctx->flags))
299 		return atomic_read(&hctx->queue->nr_active_requests_shared_tags);
300 	return atomic_read(&hctx->nr_active);
301 }
__blk_mq_put_driver_tag(struct blk_mq_hw_ctx * hctx,struct request * rq)302 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
303 					   struct request *rq)
304 {
305 	blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
306 	rq->tag = BLK_MQ_NO_TAG;
307 
308 	if (rq->rq_flags & RQF_MQ_INFLIGHT) {
309 		rq->rq_flags &= ~RQF_MQ_INFLIGHT;
310 		__blk_mq_dec_active_requests(hctx);
311 	}
312 }
313 
blk_mq_put_driver_tag(struct request * rq)314 static inline void blk_mq_put_driver_tag(struct request *rq)
315 {
316 	if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
317 		return;
318 
319 	__blk_mq_put_driver_tag(rq->mq_hctx, rq);
320 }
321 
322 bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq);
323 
blk_mq_get_driver_tag(struct request * rq)324 static inline bool blk_mq_get_driver_tag(struct request *rq)
325 {
326 	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
327 
328 	if (rq->tag != BLK_MQ_NO_TAG &&
329 	    !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
330 		hctx->tags->rqs[rq->tag] = rq;
331 		return true;
332 	}
333 
334 	return __blk_mq_get_driver_tag(hctx, rq);
335 }
336 
blk_mq_clear_mq_map(struct blk_mq_queue_map * qmap)337 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
338 {
339 	int cpu;
340 
341 	for_each_possible_cpu(cpu)
342 		qmap->mq_map[cpu] = 0;
343 }
344 
345 /*
346  * blk_mq_plug() - Get caller context plug
347  * @bio : the bio being submitted by the caller context
348  *
349  * Plugging, by design, may delay the insertion of BIOs into the elevator in
350  * order to increase BIO merging opportunities. This however can cause BIO
351  * insertion order to change from the order in which submit_bio() is being
352  * executed in the case of multiple contexts concurrently issuing BIOs to a
353  * device, even if these context are synchronized to tightly control BIO issuing
354  * order. While this is not a problem with regular block devices, this ordering
355  * change can cause write BIO failures with zoned block devices as these
356  * require sequential write patterns to zones. Prevent this from happening by
357  * ignoring the plug state of a BIO issuing context if it is for a zoned block
358  * device and the BIO to plug is a write operation.
359  *
360  * Return current->plug if the bio can be plugged and NULL otherwise
361  */
blk_mq_plug(struct bio * bio)362 static inline struct blk_plug *blk_mq_plug( struct bio *bio)
363 {
364 	/* Zoned block device write operation case: do not plug the BIO */
365 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
366 	    bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
367 		return NULL;
368 
369 	/*
370 	 * For regular block devices or read operations, use the context plug
371 	 * which may be NULL if blk_start_plug() was not executed.
372 	 */
373 	return current->plug;
374 }
375 
376 /* Free all requests on the list */
blk_mq_free_requests(struct list_head * list)377 static inline void blk_mq_free_requests(struct list_head *list)
378 {
379 	while (!list_empty(list)) {
380 		struct request *rq = list_entry_rq(list->next);
381 
382 		list_del_init(&rq->queuelist);
383 		blk_mq_free_request(rq);
384 	}
385 }
386 
387 /*
388  * For shared tag users, we track the number of currently active users
389  * and attempt to provide a fair share of the tag depth for each of them.
390  */
hctx_may_queue(struct blk_mq_hw_ctx * hctx,struct sbitmap_queue * bt)391 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
392 				  struct sbitmap_queue *bt)
393 {
394 	unsigned int depth, users;
395 
396 	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
397 		return true;
398 
399 	/*
400 	 * Don't try dividing an ant
401 	 */
402 	if (bt->sb.depth == 1)
403 		return true;
404 
405 	if (blk_mq_is_shared_tags(hctx->flags)) {
406 		struct request_queue *q = hctx->queue;
407 
408 		if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
409 			return true;
410 	} else {
411 		if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
412 			return true;
413 	}
414 
415 	users = READ_ONCE(hctx->tags->active_queues);
416 	if (!users)
417 		return true;
418 
419 	/*
420 	 * Allow at least some tags
421 	 */
422 	depth = max((bt->sb.depth + users - 1) / users, 4U);
423 	return __blk_mq_active_requests(hctx) < depth;
424 }
425 
426 /* run the code block in @dispatch_ops with rcu/srcu read lock held */
427 #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops)	\
428 do {								\
429 	if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) {		\
430 		struct blk_mq_tag_set *__tag_set = (q)->tag_set; \
431 		int srcu_idx;					\
432 								\
433 		might_sleep_if(check_sleep);			\
434 		srcu_idx = srcu_read_lock(__tag_set->srcu);	\
435 		(dispatch_ops);					\
436 		srcu_read_unlock(__tag_set->srcu, srcu_idx);	\
437 	} else {						\
438 		rcu_read_lock();				\
439 		(dispatch_ops);					\
440 		rcu_read_unlock();				\
441 	}							\
442 } while (0)
443 
444 #define blk_mq_run_dispatch_ops(q, dispatch_ops)		\
445 	__blk_mq_run_dispatch_ops(q, true, dispatch_ops)	\
446 
447 #endif
448