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1#ifndef INT_BLK_MQ_H
2#define INT_BLK_MQ_H
3
4struct blk_mq_tag_set;
5
6struct blk_mq_ctx {
7 struct {
8 spinlock_t lock;
9 struct list_head rq_list;
10 } ____cacheline_aligned_in_smp;
11
12 unsigned int cpu;
13 unsigned int index_hw;
14
15 unsigned int last_tag ____cacheline_aligned_in_smp;
16
17 /* incremented at dispatch time */
18 unsigned long rq_dispatched[2];
19 unsigned long rq_merged;
20
21 /* incremented at completion time */
22 unsigned long ____cacheline_aligned_in_smp rq_completed[2];
23
24 struct request_queue *queue;
25 struct kobject kobj;
26} ____cacheline_aligned_in_smp;
27
28void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
29void blk_mq_freeze_queue(struct request_queue *q);
30void blk_mq_free_queue(struct request_queue *q);
31int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
32void blk_mq_wake_waiters(struct request_queue *q);
33
34/*
35 * CPU hotplug helpers
36 */
37struct blk_mq_cpu_notifier;
38void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
39 int (*fn)(void *, unsigned long, unsigned int),
40 void *data);
41void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
42void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
43void blk_mq_cpu_init(void);
44void blk_mq_enable_hotplug(void);
45void blk_mq_disable_hotplug(void);
46
47/*
48 * CPU -> queue mappings
49 */
50extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
51extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues,
52 const struct cpumask *online_mask);
53extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
54
55/*
56 * sysfs helpers
57 */
58extern int blk_mq_sysfs_register(struct request_queue *q);
59extern void blk_mq_sysfs_unregister(struct request_queue *q);
60extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
61
62extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
63
64void blk_mq_release(struct request_queue *q);
65
66/*
67 * Basic implementation of sparser bitmap, allowing the user to spread
68 * the bits over more cachelines.
69 */
70struct blk_align_bitmap {
71 unsigned long word;
72 unsigned long depth;
73} ____cacheline_aligned_in_smp;
74
75static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
76 unsigned int cpu)
77{
78 return per_cpu_ptr(q->queue_ctx, cpu);
79}
80
81/*
82 * This assumes per-cpu software queueing queues. They could be per-node
83 * as well, for instance. For now this is hardcoded as-is. Note that we don't
84 * care about preemption, since we know the ctx's are persistent. This does
85 * mean that we can't rely on ctx always matching the currently running CPU.
86 */
87static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
88{
89 return __blk_mq_get_ctx(q, get_cpu());
90}
91
92static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
93{
94 put_cpu();
95}
96
97struct blk_mq_alloc_data {
98 /* input parameter */
99 struct request_queue *q;
100 unsigned int flags;
101
102 /* input & output parameter */
103 struct blk_mq_ctx *ctx;
104 struct blk_mq_hw_ctx *hctx;
105};
106
107static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
108 struct request_queue *q, unsigned int flags,
109 struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
110{
111 data->q = q;
112 data->flags = flags;
113 data->ctx = ctx;
114 data->hctx = hctx;
115}
116
117static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
118{
119 return hctx->nr_ctx && hctx->tags;
120}
121
122#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 /* 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} ____cacheline_aligned_in_smp;
39
40void blk_mq_exit_queue(struct request_queue *q);
41int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
42void blk_mq_wake_waiters(struct request_queue *q);
43bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
44 unsigned int);
45void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
46 bool kick_requeue_list);
47void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
48struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
49 struct blk_mq_ctx *start);
50void blk_mq_put_rq_ref(struct request *rq);
51
52/*
53 * Internal helpers for allocating/freeing the request map
54 */
55void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
56 unsigned int hctx_idx);
57void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags);
58struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
59 unsigned int hctx_idx,
60 unsigned int nr_tags,
61 unsigned int reserved_tags,
62 unsigned int flags);
63int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
64 unsigned int hctx_idx, unsigned int depth);
65
66/*
67 * Internal helpers for request insertion into sw queues
68 */
69void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
70 bool at_head);
71void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
72 bool run_queue);
73void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
74 struct list_head *list);
75
76/* Used by blk_insert_cloned_request() to issue request directly */
77blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
78void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
79 struct list_head *list);
80
81/*
82 * CPU -> queue mappings
83 */
84extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
85
86/*
87 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
88 * @q: request queue
89 * @type: the hctx type index
90 * @cpu: CPU
91 */
92static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
93 enum hctx_type type,
94 unsigned int cpu)
95{
96 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
97}
98
99/*
100 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
101 * @q: request queue
102 * @flags: request command flags
103 * @ctx: software queue cpu ctx
104 */
105static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
106 unsigned int flags,
107 struct blk_mq_ctx *ctx)
108{
109 enum hctx_type type = HCTX_TYPE_DEFAULT;
110
111 /*
112 * The caller ensure that if REQ_HIPRI, poll must be enabled.
113 */
114 if (flags & REQ_HIPRI)
115 type = HCTX_TYPE_POLL;
116 else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
117 type = HCTX_TYPE_READ;
118
119 return ctx->hctxs[type];
120}
121
122/*
123 * sysfs helpers
124 */
125extern void blk_mq_sysfs_init(struct request_queue *q);
126extern void blk_mq_sysfs_deinit(struct request_queue *q);
127extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
128extern int blk_mq_sysfs_register(struct request_queue *q);
129extern void blk_mq_sysfs_unregister(struct request_queue *q);
130extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
131
132void blk_mq_release(struct request_queue *q);
133
134static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
135 unsigned int cpu)
136{
137 return per_cpu_ptr(q->queue_ctx, cpu);
138}
139
140/*
141 * This assumes per-cpu software queueing queues. They could be per-node
142 * as well, for instance. For now this is hardcoded as-is. Note that we don't
143 * care about preemption, since we know the ctx's are persistent. This does
144 * mean that we can't rely on ctx always matching the currently running CPU.
145 */
146static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
147{
148 return __blk_mq_get_ctx(q, raw_smp_processor_id());
149}
150
151struct blk_mq_alloc_data {
152 /* input parameter */
153 struct request_queue *q;
154 blk_mq_req_flags_t flags;
155 unsigned int shallow_depth;
156 unsigned int cmd_flags;
157
158 /* input & output parameter */
159 struct blk_mq_ctx *ctx;
160 struct blk_mq_hw_ctx *hctx;
161};
162
163static inline bool blk_mq_is_sbitmap_shared(unsigned int flags)
164{
165 return flags & BLK_MQ_F_TAG_HCTX_SHARED;
166}
167
168static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
169{
170 if (data->q->elevator)
171 return data->hctx->sched_tags;
172
173 return data->hctx->tags;
174}
175
176static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
177{
178 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
179}
180
181static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
182{
183 return hctx->nr_ctx && hctx->tags;
184}
185
186unsigned int blk_mq_in_flight(struct request_queue *q,
187 struct block_device *part);
188void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
189 unsigned int inflight[2]);
190
191static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
192 int budget_token)
193{
194 if (q->mq_ops->put_budget)
195 q->mq_ops->put_budget(q, budget_token);
196}
197
198static inline int 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 0;
203}
204
205static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
206{
207 if (token < 0)
208 return;
209
210 if (rq->q->mq_ops->set_rq_budget_token)
211 rq->q->mq_ops->set_rq_budget_token(rq, token);
212}
213
214static inline int blk_mq_get_rq_budget_token(struct request *rq)
215{
216 if (rq->q->mq_ops->get_rq_budget_token)
217 return rq->q->mq_ops->get_rq_budget_token(rq);
218 return -1;
219}
220
221static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
222{
223 if (blk_mq_is_sbitmap_shared(hctx->flags))
224 atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap);
225 else
226 atomic_inc(&hctx->nr_active);
227}
228
229static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
230{
231 if (blk_mq_is_sbitmap_shared(hctx->flags))
232 atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap);
233 else
234 atomic_dec(&hctx->nr_active);
235}
236
237static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
238{
239 if (blk_mq_is_sbitmap_shared(hctx->flags))
240 return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap);
241 return atomic_read(&hctx->nr_active);
242}
243static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
244 struct request *rq)
245{
246 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
247 rq->tag = BLK_MQ_NO_TAG;
248
249 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
250 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
251 __blk_mq_dec_active_requests(hctx);
252 }
253}
254
255static inline void blk_mq_put_driver_tag(struct request *rq)
256{
257 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
258 return;
259
260 __blk_mq_put_driver_tag(rq->mq_hctx, rq);
261}
262
263bool blk_mq_get_driver_tag(struct request *rq);
264
265static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
266{
267 int cpu;
268
269 for_each_possible_cpu(cpu)
270 qmap->mq_map[cpu] = 0;
271}
272
273/*
274 * blk_mq_plug() - Get caller context plug
275 * @q: request queue
276 * @bio : the bio being submitted by the caller context
277 *
278 * Plugging, by design, may delay the insertion of BIOs into the elevator in
279 * order to increase BIO merging opportunities. This however can cause BIO
280 * insertion order to change from the order in which submit_bio() is being
281 * executed in the case of multiple contexts concurrently issuing BIOs to a
282 * device, even if these context are synchronized to tightly control BIO issuing
283 * order. While this is not a problem with regular block devices, this ordering
284 * change can cause write BIO failures with zoned block devices as these
285 * require sequential write patterns to zones. Prevent this from happening by
286 * ignoring the plug state of a BIO issuing context if the target request queue
287 * is for a zoned block device and the BIO to plug is a write operation.
288 *
289 * Return current->plug if the bio can be plugged and NULL otherwise
290 */
291static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
292 struct bio *bio)
293{
294 /*
295 * For regular block devices or read operations, use the context plug
296 * which may be NULL if blk_start_plug() was not executed.
297 */
298 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
299 return current->plug;
300
301 /* Zoned block device write operation case: do not plug the BIO */
302 return NULL;
303}
304
305/* Free all requests on the list */
306static inline void blk_mq_free_requests(struct list_head *list)
307{
308 while (!list_empty(list)) {
309 struct request *rq = list_entry_rq(list->next);
310
311 list_del_init(&rq->queuelist);
312 blk_mq_free_request(rq);
313 }
314}
315
316/*
317 * For shared tag users, we track the number of currently active users
318 * and attempt to provide a fair share of the tag depth for each of them.
319 */
320static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
321 struct sbitmap_queue *bt)
322{
323 unsigned int depth, users;
324
325 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
326 return true;
327
328 /*
329 * Don't try dividing an ant
330 */
331 if (bt->sb.depth == 1)
332 return true;
333
334 if (blk_mq_is_sbitmap_shared(hctx->flags)) {
335 struct request_queue *q = hctx->queue;
336 struct blk_mq_tag_set *set = q->tag_set;
337
338 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
339 return true;
340 users = atomic_read(&set->active_queues_shared_sbitmap);
341 } else {
342 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
343 return true;
344 users = atomic_read(&hctx->tags->active_queues);
345 }
346
347 if (!users)
348 return true;
349
350 /*
351 * Allow at least some tags
352 */
353 depth = max((bt->sb.depth + users - 1) / users, 4U);
354 return __blk_mq_active_requests(hctx) < depth;
355}
356
357
358#endif