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v6.2
  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
  8struct blk_mq_tag_set;
  9
 10struct 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 */
 18struct 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
 
 
 
 
 
 
 
 
 
 33void blk_mq_submit_bio(struct bio *bio);
 34int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
 35		unsigned int flags);
 36void blk_mq_exit_queue(struct request_queue *q);
 37int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
 38void blk_mq_wake_waiters(struct request_queue *q);
 39bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
 40			     unsigned int);
 41void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
 42				bool kick_requeue_list);
 43void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
 44struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
 45					struct blk_mq_ctx *start);
 46void blk_mq_put_rq_ref(struct request *rq);
 47
 48/*
 49 * Internal helpers for allocating/freeing the request map
 50 */
 51void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 52		     unsigned int hctx_idx);
 53void blk_mq_free_rq_map(struct blk_mq_tags *tags);
 54struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
 55				unsigned int hctx_idx, unsigned int depth);
 56void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
 57			     struct blk_mq_tags *tags,
 58			     unsigned int hctx_idx);
 59/*
 60 * Internal helpers for request insertion into sw queues
 61 */
 62void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 63				bool at_head);
 64void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
 65				  bool run_queue);
 66void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 67				struct list_head *list);
 68void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
 69				    struct list_head *list);
 70
 71/*
 72 * CPU -> queue mappings
 73 */
 74extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
 75
 76/*
 77 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
 78 * @q: request queue
 79 * @type: the hctx type index
 80 * @cpu: CPU
 81 */
 82static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
 83							  enum hctx_type type,
 84							  unsigned int cpu)
 85{
 86	return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]);
 87}
 88
 89static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)
 90{
 91	enum hctx_type type = HCTX_TYPE_DEFAULT;
 92
 93	/*
 94	 * The caller ensure that if REQ_POLLED, poll must be enabled.
 95	 */
 96	if (opf & REQ_POLLED)
 97		type = HCTX_TYPE_POLL;
 98	else if ((opf & REQ_OP_MASK) == REQ_OP_READ)
 99		type = HCTX_TYPE_READ;
100	return type;
101}
102
103/*
104 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
105 * @q: request queue
106 * @opf: operation type (REQ_OP_*) and flags (e.g. REQ_POLLED).
107 * @ctx: software queue cpu ctx
108 */
109static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
110						     blk_opf_t opf,
111						     struct blk_mq_ctx *ctx)
112{
113	return ctx->hctxs[blk_mq_get_hctx_type(opf)];
114}
115
116/*
117 * sysfs helpers
118 */
119extern void blk_mq_sysfs_init(struct request_queue *q);
120extern void blk_mq_sysfs_deinit(struct request_queue *q);
121int blk_mq_sysfs_register(struct gendisk *disk);
122void blk_mq_sysfs_unregister(struct gendisk *disk);
123int blk_mq_sysfs_register_hctxs(struct request_queue *q);
124void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
125extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
126void blk_mq_free_plug_rqs(struct blk_plug *plug);
127void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
128
129void blk_mq_cancel_work_sync(struct request_queue *q);
130
131void blk_mq_release(struct request_queue *q);
132
133static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
134					   unsigned int cpu)
135{
136	return per_cpu_ptr(q->queue_ctx, cpu);
137}
138
139/*
140 * This assumes per-cpu software queueing queues. They could be per-node
141 * as well, for instance. For now this is hardcoded as-is. Note that we don't
142 * care about preemption, since we know the ctx's are persistent. This does
143 * mean that we can't rely on ctx always matching the currently running CPU.
144 */
145static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
146{
147	return __blk_mq_get_ctx(q, raw_smp_processor_id());
148}
149
150struct blk_mq_alloc_data {
151	/* input parameter */
152	struct request_queue *q;
153	blk_mq_req_flags_t flags;
154	unsigned int shallow_depth;
155	blk_opf_t cmd_flags;
156	req_flags_t rq_flags;
157
158	/* allocate multiple requests/tags in one go */
159	unsigned int nr_tags;
160	struct request **cached_rq;
161
162	/* input & output parameter */
163	struct blk_mq_ctx *ctx;
164	struct blk_mq_hw_ctx *hctx;
165};
166
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
167static inline bool blk_mq_is_shared_tags(unsigned int flags)
168{
169	return flags & BLK_MQ_F_TAG_HCTX_SHARED;
170}
171
172static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
173{
174	if (!(data->rq_flags & RQF_ELV))
175		return data->hctx->tags;
176	return data->hctx->sched_tags;
177}
178
179static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
180{
181	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
182}
183
184static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
185{
186	return hctx->nr_ctx && hctx->tags;
187}
188
189unsigned int blk_mq_in_flight(struct request_queue *q,
190		struct block_device *part);
191void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
192		unsigned int inflight[2]);
193
194static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
195					      int budget_token)
196{
197	if (q->mq_ops->put_budget)
198		q->mq_ops->put_budget(q, budget_token);
199}
200
201static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
202{
203	if (q->mq_ops->get_budget)
204		return q->mq_ops->get_budget(q);
205	return 0;
206}
207
208static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
209{
210	if (token < 0)
211		return;
212
213	if (rq->q->mq_ops->set_rq_budget_token)
214		rq->q->mq_ops->set_rq_budget_token(rq, token);
215}
216
217static inline int blk_mq_get_rq_budget_token(struct request *rq)
218{
219	if (rq->q->mq_ops->get_rq_budget_token)
220		return rq->q->mq_ops->get_rq_budget_token(rq);
221	return -1;
222}
223
224static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
 
225{
226	if (blk_mq_is_shared_tags(hctx->flags))
227		atomic_inc(&hctx->queue->nr_active_requests_shared_tags);
228	else
229		atomic_inc(&hctx->nr_active);
 
 
 
 
 
230}
231
232static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
233		int val)
234{
235	if (blk_mq_is_shared_tags(hctx->flags))
236		atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
237	else
238		atomic_sub(val, &hctx->nr_active);
239}
240
241static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
242{
243	__blk_mq_sub_active_requests(hctx, 1);
244}
245
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
246static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
247{
248	if (blk_mq_is_shared_tags(hctx->flags))
249		return atomic_read(&hctx->queue->nr_active_requests_shared_tags);
250	return atomic_read(&hctx->nr_active);
251}
252static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
253					   struct request *rq)
254{
 
255	blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
256	rq->tag = BLK_MQ_NO_TAG;
257
258	if (rq->rq_flags & RQF_MQ_INFLIGHT) {
259		rq->rq_flags &= ~RQF_MQ_INFLIGHT;
260		__blk_mq_dec_active_requests(hctx);
261	}
262}
263
264static inline void blk_mq_put_driver_tag(struct request *rq)
265{
266	if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
267		return;
268
269	__blk_mq_put_driver_tag(rq->mq_hctx, rq);
270}
271
272bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq);
273
274static inline bool blk_mq_get_driver_tag(struct request *rq)
275{
276	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
 
277
278	if (rq->tag != BLK_MQ_NO_TAG &&
279	    !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
280		hctx->tags->rqs[rq->tag] = rq;
281		return true;
282	}
283
284	return __blk_mq_get_driver_tag(hctx, rq);
285}
286
287static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
288{
289	int cpu;
290
291	for_each_possible_cpu(cpu)
292		qmap->mq_map[cpu] = 0;
293}
294
295/*
296 * blk_mq_plug() - Get caller context plug
297 * @bio : the bio being submitted by the caller context
298 *
299 * Plugging, by design, may delay the insertion of BIOs into the elevator in
300 * order to increase BIO merging opportunities. This however can cause BIO
301 * insertion order to change from the order in which submit_bio() is being
302 * executed in the case of multiple contexts concurrently issuing BIOs to a
303 * device, even if these context are synchronized to tightly control BIO issuing
304 * order. While this is not a problem with regular block devices, this ordering
305 * change can cause write BIO failures with zoned block devices as these
306 * require sequential write patterns to zones. Prevent this from happening by
307 * ignoring the plug state of a BIO issuing context if it is for a zoned block
308 * device and the BIO to plug is a write operation.
309 *
310 * Return current->plug if the bio can be plugged and NULL otherwise
311 */
312static inline struct blk_plug *blk_mq_plug( struct bio *bio)
313{
314	/* Zoned block device write operation case: do not plug the BIO */
315	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
316	    bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
317		return NULL;
318
319	/*
320	 * For regular block devices or read operations, use the context plug
321	 * which may be NULL if blk_start_plug() was not executed.
322	 */
323	return current->plug;
324}
325
326/* Free all requests on the list */
327static inline void blk_mq_free_requests(struct list_head *list)
328{
329	while (!list_empty(list)) {
330		struct request *rq = list_entry_rq(list->next);
331
332		list_del_init(&rq->queuelist);
333		blk_mq_free_request(rq);
334	}
335}
336
337/*
338 * For shared tag users, we track the number of currently active users
339 * and attempt to provide a fair share of the tag depth for each of them.
340 */
341static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
342				  struct sbitmap_queue *bt)
343{
344	unsigned int depth, users;
345
346	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
347		return true;
348
349	/*
350	 * Don't try dividing an ant
351	 */
352	if (bt->sb.depth == 1)
353		return true;
354
355	if (blk_mq_is_shared_tags(hctx->flags)) {
356		struct request_queue *q = hctx->queue;
357
358		if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
359			return true;
360	} else {
361		if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
362			return true;
363	}
364
365	users = atomic_read(&hctx->tags->active_queues);
366
367	if (!users)
368		return true;
369
370	/*
371	 * Allow at least some tags
372	 */
373	depth = max((bt->sb.depth + users - 1) / users, 4U);
374	return __blk_mq_active_requests(hctx) < depth;
375}
376
377/* run the code block in @dispatch_ops with rcu/srcu read lock held */
378#define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops)	\
379do {								\
380	if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) {		\
 
381		int srcu_idx;					\
382								\
383		might_sleep_if(check_sleep);			\
384		srcu_idx = srcu_read_lock((q)->tag_set->srcu);	\
385		(dispatch_ops);					\
386		srcu_read_unlock((q)->tag_set->srcu, srcu_idx);	\
387	} else {						\
388		rcu_read_lock();				\
389		(dispatch_ops);					\
390		rcu_read_unlock();				\
391	}							\
392} while (0)
393
394#define blk_mq_run_dispatch_ops(q, dispatch_ops)		\
395	__blk_mq_run_dispatch_ops(q, true, dispatch_ops)	\
396
397#endif
v6.8
  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
  8struct blk_mq_tag_set;
  9
 10struct 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 */
 18struct 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
 33enum {
 34	BLK_MQ_NO_TAG		= -1U,
 35	BLK_MQ_TAG_MIN		= 1,
 36	BLK_MQ_TAG_MAX		= BLK_MQ_NO_TAG - 1,
 37};
 38
 39typedef unsigned int __bitwise blk_insert_t;
 40#define BLK_MQ_INSERT_AT_HEAD		((__force blk_insert_t)0x01)
 41
 42void blk_mq_submit_bio(struct bio *bio);
 43int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
 44		unsigned int flags);
 45void blk_mq_exit_queue(struct request_queue *q);
 46int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
 47void blk_mq_wake_waiters(struct request_queue *q);
 48bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
 49			     unsigned int);
 
 
 50void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
 51struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
 52					struct blk_mq_ctx *start);
 53void blk_mq_put_rq_ref(struct request *rq);
 54
 55/*
 56 * Internal helpers for allocating/freeing the request map
 57 */
 58void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 59		     unsigned int hctx_idx);
 60void blk_mq_free_rq_map(struct blk_mq_tags *tags);
 61struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
 62				unsigned int hctx_idx, unsigned int depth);
 63void 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 */
 70extern 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 */
 78static 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
 85static 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 */
105static 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 */
115extern void blk_mq_sysfs_init(struct request_queue *q);
116extern void blk_mq_sysfs_deinit(struct request_queue *q);
117int blk_mq_sysfs_register(struct gendisk *disk);
118void blk_mq_sysfs_unregister(struct gendisk *disk);
119int blk_mq_sysfs_register_hctxs(struct request_queue *q);
120void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
121extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
122void blk_mq_free_plug_rqs(struct blk_plug *plug);
123void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
124
125void blk_mq_cancel_work_sync(struct request_queue *q);
126
127void blk_mq_release(struct request_queue *q);
128
129static 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 */
141static 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
146struct 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
163struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
164		unsigned int reserved_tags, int node, int alloc_policy);
165void blk_mq_free_tags(struct blk_mq_tags *tags);
166int 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
170unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
171unsigned long blk_mq_get_tags(struct blk_mq_alloc_data *data, int nr_tags,
172		unsigned int *offset);
173void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
174		unsigned int tag);
175void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags);
176int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
177		struct blk_mq_tags **tags, unsigned int depth, bool can_grow);
178void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set,
179		unsigned int size);
180void blk_mq_tag_update_sched_shared_tags(struct request_queue *q);
181
182void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
183void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_tag_iter_fn *fn,
184		void *priv);
185void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
186		void *priv);
187
188static 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
196void __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
197void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
198
199static 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
205static 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
211static 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
217static inline bool blk_mq_is_shared_tags(unsigned int flags)
218{
219	return flags & BLK_MQ_F_TAG_HCTX_SHARED;
220}
221
222static 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
229static 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
234static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
235{
236	return hctx->nr_ctx && hctx->tags;
237}
238
239unsigned int blk_mq_in_flight(struct request_queue *q,
240		struct block_device *part);
241void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
242		unsigned int inflight[2]);
243
244static 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
251static 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
258static 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
267static 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
274static inline void __blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx,
275						int val)
276{
277	if (blk_mq_is_shared_tags(hctx->flags))
278		atomic_add(val, &hctx->queue->nr_active_requests_shared_tags);
279	else
280		atomic_add(val, &hctx->nr_active);
281}
282
283static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
284{
285	__blk_mq_add_active_requests(hctx, 1);
286}
287
288static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
289		int val)
290{
291	if (blk_mq_is_shared_tags(hctx->flags))
292		atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
293	else
294		atomic_sub(val, &hctx->nr_active);
295}
296
297static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
298{
299	__blk_mq_sub_active_requests(hctx, 1);
300}
301
302static inline void blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx,
303					      int val)
304{
305	if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
306		__blk_mq_add_active_requests(hctx, val);
307}
308
309static inline void blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
310{
311	if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
312		__blk_mq_inc_active_requests(hctx);
313}
314
315static inline void blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
316					      int val)
317{
318	if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
319		__blk_mq_sub_active_requests(hctx, val);
320}
321
322static inline void blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
323{
324	if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
325		__blk_mq_dec_active_requests(hctx);
326}
327
328static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
329{
330	if (blk_mq_is_shared_tags(hctx->flags))
331		return atomic_read(&hctx->queue->nr_active_requests_shared_tags);
332	return atomic_read(&hctx->nr_active);
333}
334static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
335					   struct request *rq)
336{
337	blk_mq_dec_active_requests(hctx);
338	blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
339	rq->tag = BLK_MQ_NO_TAG;
 
 
 
 
 
340}
341
342static inline void blk_mq_put_driver_tag(struct request *rq)
343{
344	if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
345		return;
346
347	__blk_mq_put_driver_tag(rq->mq_hctx, rq);
348}
349
350bool __blk_mq_alloc_driver_tag(struct request *rq);
351
352static inline bool blk_mq_get_driver_tag(struct request *rq)
353{
354	if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq))
355		return false;
356
357	return true;
 
 
 
 
 
 
358}
359
360static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
361{
362	int cpu;
363
364	for_each_possible_cpu(cpu)
365		qmap->mq_map[cpu] = 0;
366}
367
368/*
369 * blk_mq_plug() - Get caller context plug
370 * @bio : the bio being submitted by the caller context
371 *
372 * Plugging, by design, may delay the insertion of BIOs into the elevator in
373 * order to increase BIO merging opportunities. This however can cause BIO
374 * insertion order to change from the order in which submit_bio() is being
375 * executed in the case of multiple contexts concurrently issuing BIOs to a
376 * device, even if these context are synchronized to tightly control BIO issuing
377 * order. While this is not a problem with regular block devices, this ordering
378 * change can cause write BIO failures with zoned block devices as these
379 * require sequential write patterns to zones. Prevent this from happening by
380 * ignoring the plug state of a BIO issuing context if it is for a zoned block
381 * device and the BIO to plug is a write operation.
382 *
383 * Return current->plug if the bio can be plugged and NULL otherwise
384 */
385static inline struct blk_plug *blk_mq_plug( struct bio *bio)
386{
387	/* Zoned block device write operation case: do not plug the BIO */
388	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
389	    bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
390		return NULL;
391
392	/*
393	 * For regular block devices or read operations, use the context plug
394	 * which may be NULL if blk_start_plug() was not executed.
395	 */
396	return current->plug;
397}
398
399/* Free all requests on the list */
400static inline void blk_mq_free_requests(struct list_head *list)
401{
402	while (!list_empty(list)) {
403		struct request *rq = list_entry_rq(list->next);
404
405		list_del_init(&rq->queuelist);
406		blk_mq_free_request(rq);
407	}
408}
409
410/*
411 * For shared tag users, we track the number of currently active users
412 * and attempt to provide a fair share of the tag depth for each of them.
413 */
414static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
415				  struct sbitmap_queue *bt)
416{
417	unsigned int depth, users;
418
419	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
420		return true;
421
422	/*
423	 * Don't try dividing an ant
424	 */
425	if (bt->sb.depth == 1)
426		return true;
427
428	if (blk_mq_is_shared_tags(hctx->flags)) {
429		struct request_queue *q = hctx->queue;
430
431		if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
432			return true;
433	} else {
434		if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
435			return true;
436	}
437
438	users = READ_ONCE(hctx->tags->active_queues);
 
439	if (!users)
440		return true;
441
442	/*
443	 * Allow at least some tags
444	 */
445	depth = max((bt->sb.depth + users - 1) / users, 4U);
446	return __blk_mq_active_requests(hctx) < depth;
447}
448
449/* run the code block in @dispatch_ops with rcu/srcu read lock held */
450#define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops)	\
451do {								\
452	if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) {		\
453		struct blk_mq_tag_set *__tag_set = (q)->tag_set; \
454		int srcu_idx;					\
455								\
456		might_sleep_if(check_sleep);			\
457		srcu_idx = srcu_read_lock(__tag_set->srcu);	\
458		(dispatch_ops);					\
459		srcu_read_unlock(__tag_set->srcu, srcu_idx);	\
460	} else {						\
461		rcu_read_lock();				\
462		(dispatch_ops);					\
463		rcu_read_unlock();				\
464	}							\
465} while (0)
466
467#define blk_mq_run_dispatch_ops(q, dispatch_ops)		\
468	__blk_mq_run_dispatch_ops(q, true, dispatch_ops)	\
469
470#endif