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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
8struct blk_mq_tag_set;
9
10/**
11 * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
12 */
13struct 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/*
34 * Bits for request->gstate. The lower two bits carry MQ_RQ_* state value
35 * and the upper bits the generation number.
36 */
37enum mq_rq_state {
38 MQ_RQ_IDLE = 0,
39 MQ_RQ_IN_FLIGHT = 1,
40 MQ_RQ_COMPLETE = 2,
41
42 MQ_RQ_STATE_BITS = 2,
43 MQ_RQ_STATE_MASK = (1 << MQ_RQ_STATE_BITS) - 1,
44 MQ_RQ_GEN_INC = 1 << MQ_RQ_STATE_BITS,
45};
46
47void blk_mq_freeze_queue(struct request_queue *q);
48void blk_mq_free_queue(struct request_queue *q);
49int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
50void blk_mq_wake_waiters(struct request_queue *q);
51bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
52void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
53bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
54 bool wait);
55struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
56 struct blk_mq_ctx *start);
57
58/*
59 * Internal helpers for allocating/freeing the request map
60 */
61void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
62 unsigned int hctx_idx);
63void blk_mq_free_rq_map(struct blk_mq_tags *tags);
64struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
65 unsigned int hctx_idx,
66 unsigned int nr_tags,
67 unsigned int reserved_tags);
68int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
69 unsigned int hctx_idx, unsigned int depth);
70
71/*
72 * Internal helpers for request insertion into sw queues
73 */
74void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
75 bool at_head);
76void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
77void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
78 struct list_head *list);
79
80/* Used by blk_insert_cloned_request() to issue request directly */
81blk_status_t blk_mq_request_issue_directly(struct request *rq);
82
83/*
84 * CPU -> queue mappings
85 */
86extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
87
88static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
89 int cpu)
90{
91 return q->queue_hw_ctx[q->mq_map[cpu]];
92}
93
94/*
95 * sysfs helpers
96 */
97extern void blk_mq_sysfs_init(struct request_queue *q);
98extern void blk_mq_sysfs_deinit(struct request_queue *q);
99extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
100extern int blk_mq_sysfs_register(struct request_queue *q);
101extern void blk_mq_sysfs_unregister(struct request_queue *q);
102extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
103
104void blk_mq_release(struct request_queue *q);
105
106/**
107 * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
108 * @rq: target request.
109 */
110static inline int blk_mq_rq_state(struct request *rq)
111{
112 return READ_ONCE(rq->gstate) & MQ_RQ_STATE_MASK;
113}
114
115/**
116 * blk_mq_rq_update_state() - set the current MQ_RQ_* state of a request
117 * @rq: target request.
118 * @state: new state to set.
119 *
120 * Set @rq's state to @state. The caller is responsible for ensuring that
121 * there are no other updaters. A request can transition into IN_FLIGHT
122 * only from IDLE and doing so increments the generation number.
123 */
124static inline void blk_mq_rq_update_state(struct request *rq,
125 enum mq_rq_state state)
126{
127 u64 old_val = READ_ONCE(rq->gstate);
128 u64 new_val = (old_val & ~MQ_RQ_STATE_MASK) | state;
129
130 if (state == MQ_RQ_IN_FLIGHT) {
131 WARN_ON_ONCE((old_val & MQ_RQ_STATE_MASK) != MQ_RQ_IDLE);
132 new_val += MQ_RQ_GEN_INC;
133 }
134
135 /* avoid exposing interim values */
136 WRITE_ONCE(rq->gstate, new_val);
137}
138
139static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
140 unsigned int cpu)
141{
142 return per_cpu_ptr(q->queue_ctx, cpu);
143}
144
145/*
146 * This assumes per-cpu software queueing queues. They could be per-node
147 * as well, for instance. For now this is hardcoded as-is. Note that we don't
148 * care about preemption, since we know the ctx's are persistent. This does
149 * mean that we can't rely on ctx always matching the currently running CPU.
150 */
151static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
152{
153 return __blk_mq_get_ctx(q, get_cpu());
154}
155
156static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
157{
158 put_cpu();
159}
160
161struct blk_mq_alloc_data {
162 /* input parameter */
163 struct request_queue *q;
164 blk_mq_req_flags_t flags;
165 unsigned int shallow_depth;
166
167 /* input & output parameter */
168 struct blk_mq_ctx *ctx;
169 struct blk_mq_hw_ctx *hctx;
170};
171
172static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
173{
174 if (data->flags & BLK_MQ_REQ_INTERNAL)
175 return data->hctx->sched_tags;
176
177 return data->hctx->tags;
178}
179
180static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
181{
182 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
183}
184
185static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
186{
187 return hctx->nr_ctx && hctx->tags;
188}
189
190void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
191 unsigned int inflight[2]);
192void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
193 unsigned int inflight[2]);
194
195static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
196{
197 struct request_queue *q = hctx->queue;
198
199 if (q->mq_ops->put_budget)
200 q->mq_ops->put_budget(hctx);
201}
202
203static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
204{
205 struct request_queue *q = hctx->queue;
206
207 if (q->mq_ops->get_budget)
208 return q->mq_ops->get_budget(hctx);
209 return true;
210}
211
212static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
213 struct request *rq)
214{
215 blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
216 rq->tag = -1;
217
218 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
219 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
220 atomic_dec(&hctx->nr_active);
221 }
222}
223
224static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
225 struct request *rq)
226{
227 if (rq->tag == -1 || rq->internal_tag == -1)
228 return;
229
230 __blk_mq_put_driver_tag(hctx, rq);
231}
232
233static inline void blk_mq_put_driver_tag(struct request *rq)
234{
235 struct blk_mq_hw_ctx *hctx;
236
237 if (rq->tag == -1 || rq->internal_tag == -1)
238 return;
239
240 hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
241 __blk_mq_put_driver_tag(hctx, rq);
242}
243
244#endif
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