1 /* SPDX-License-Identifier: GPL-2.0 */
6 #include "blk-mq-tag.h"
12 struct blk_mq_ctx __percpu *queue_ctx;
16 * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
21 struct list_head rq_lists[HCTX_MAX_TYPES];
22 } ____cacheline_aligned_in_smp;
25 unsigned short index_hw[HCTX_MAX_TYPES];
26 struct blk_mq_hw_ctx *hctxs[HCTX_MAX_TYPES];
28 /* incremented at dispatch time */
29 unsigned long rq_dispatched[2];
30 unsigned long rq_merged;
32 /* incremented at completion time */
33 unsigned long ____cacheline_aligned_in_smp rq_completed[2];
35 struct request_queue *queue;
36 struct blk_mq_ctxs *ctxs;
38 } ____cacheline_aligned_in_smp;
40 void blk_mq_exit_queue(struct request_queue *q);
41 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
42 void blk_mq_wake_waiters(struct request_queue *q);
43 bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
45 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
46 bool kick_requeue_list);
47 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
48 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
49 struct blk_mq_ctx *start);
50 void blk_mq_put_rq_ref(struct request *rq);
53 * Internal helpers for allocating/freeing the request map
55 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
56 unsigned int hctx_idx);
57 void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags);
58 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
59 unsigned int hctx_idx,
61 unsigned int reserved_tags,
63 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
64 unsigned int hctx_idx, unsigned int depth);
67 * Internal helpers for request insertion into sw queues
69 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
71 void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
73 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
74 struct list_head *list);
76 /* Used by blk_insert_cloned_request() to issue request directly */
77 blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
78 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
79 struct list_head *list);
82 * CPU -> queue mappings
84 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
87 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
89 * @type: the hctx type index
92 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
96 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
100 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
102 * @flags: request command flags
103 * @ctx: software queue cpu ctx
105 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
107 struct blk_mq_ctx *ctx)
109 enum hctx_type type = HCTX_TYPE_DEFAULT;
112 * The caller ensure that if REQ_HIPRI, poll must be enabled.
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;
119 return ctx->hctxs[type];
125 extern void blk_mq_sysfs_init(struct request_queue *q);
126 extern void blk_mq_sysfs_deinit(struct request_queue *q);
127 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
128 extern int blk_mq_sysfs_register(struct request_queue *q);
129 extern void blk_mq_sysfs_unregister(struct request_queue *q);
130 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
132 void blk_mq_cancel_work_sync(struct request_queue *q);
134 void blk_mq_release(struct request_queue *q);
136 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
139 return per_cpu_ptr(q->queue_ctx, cpu);
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.
148 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
150 return __blk_mq_get_ctx(q, raw_smp_processor_id());
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;
160 /* input & output parameter */
161 struct blk_mq_ctx *ctx;
162 struct blk_mq_hw_ctx *hctx;
165 static inline bool blk_mq_is_sbitmap_shared(unsigned int flags)
167 return flags & BLK_MQ_F_TAG_HCTX_SHARED;
170 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
172 if (data->q->elevator)
173 return data->hctx->sched_tags;
175 return data->hctx->tags;
178 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
180 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
183 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
185 return hctx->nr_ctx && hctx->tags;
188 unsigned int blk_mq_in_flight(struct request_queue *q,
189 struct block_device *part);
190 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
191 unsigned int inflight[2]);
193 static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
196 if (q->mq_ops->put_budget)
197 q->mq_ops->put_budget(q, budget_token);
200 static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
202 if (q->mq_ops->get_budget)
203 return q->mq_ops->get_budget(q);
207 static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
212 if (rq->q->mq_ops->set_rq_budget_token)
213 rq->q->mq_ops->set_rq_budget_token(rq, token);
216 static inline int blk_mq_get_rq_budget_token(struct request *rq)
218 if (rq->q->mq_ops->get_rq_budget_token)
219 return rq->q->mq_ops->get_rq_budget_token(rq);
223 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
225 if (blk_mq_is_sbitmap_shared(hctx->flags))
226 atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap);
228 atomic_inc(&hctx->nr_active);
231 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
233 if (blk_mq_is_sbitmap_shared(hctx->flags))
234 atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap);
236 atomic_dec(&hctx->nr_active);
239 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
241 if (blk_mq_is_sbitmap_shared(hctx->flags))
242 return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap);
243 return atomic_read(&hctx->nr_active);
245 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
248 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
249 rq->tag = BLK_MQ_NO_TAG;
251 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
252 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
253 __blk_mq_dec_active_requests(hctx);
257 static inline void blk_mq_put_driver_tag(struct request *rq)
259 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
262 __blk_mq_put_driver_tag(rq->mq_hctx, rq);
265 bool blk_mq_get_driver_tag(struct request *rq);
267 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
271 for_each_possible_cpu(cpu)
272 qmap->mq_map[cpu] = 0;
276 * blk_mq_plug() - Get caller context plug
278 * @bio : the bio being submitted by the caller context
280 * Plugging, by design, may delay the insertion of BIOs into the elevator in
281 * order to increase BIO merging opportunities. This however can cause BIO
282 * insertion order to change from the order in which submit_bio() is being
283 * executed in the case of multiple contexts concurrently issuing BIOs to a
284 * device, even if these context are synchronized to tightly control BIO issuing
285 * order. While this is not a problem with regular block devices, this ordering
286 * change can cause write BIO failures with zoned block devices as these
287 * require sequential write patterns to zones. Prevent this from happening by
288 * ignoring the plug state of a BIO issuing context if the target request queue
289 * is for a zoned block device and the BIO to plug is a write operation.
291 * Return current->plug if the bio can be plugged and NULL otherwise
293 static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
297 * For regular block devices or read operations, use the context plug
298 * which may be NULL if blk_start_plug() was not executed.
300 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
301 return current->plug;
303 /* Zoned block device write operation case: do not plug the BIO */
307 /* Free all requests on the list */
308 static inline void blk_mq_free_requests(struct list_head *list)
310 while (!list_empty(list)) {
311 struct request *rq = list_entry_rq(list->next);
313 list_del_init(&rq->queuelist);
314 blk_mq_free_request(rq);
319 * For shared tag users, we track the number of currently active users
320 * and attempt to provide a fair share of the tag depth for each of them.
322 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
323 struct sbitmap_queue *bt)
325 unsigned int depth, users;
327 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
331 * Don't try dividing an ant
333 if (bt->sb.depth == 1)
336 if (blk_mq_is_sbitmap_shared(hctx->flags)) {
337 struct request_queue *q = hctx->queue;
338 struct blk_mq_tag_set *set = q->tag_set;
340 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
342 users = atomic_read(&set->active_queues_shared_sbitmap);
344 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
346 users = atomic_read(&hctx->tags->active_queues);
353 * Allow at least some tags
355 depth = max((bt->sb.depth + users - 1) / users, 4U);
356 return __blk_mq_active_requests(hctx) < depth;