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 *, bool);
44 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
45 bool kick_requeue_list);
46 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
47 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
48 struct blk_mq_ctx *start);
51 * Internal helpers for allocating/freeing the request map
53 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
54 unsigned int hctx_idx);
55 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
56 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
57 unsigned int hctx_idx,
59 unsigned int reserved_tags);
60 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
61 unsigned int hctx_idx, unsigned int depth);
64 * Internal helpers for request insertion into sw queues
66 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
68 void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
70 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
71 struct list_head *list);
73 /* Used by blk_insert_cloned_request() to issue request directly */
74 blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
75 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
76 struct list_head *list);
79 * CPU -> queue mappings
81 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
84 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
86 * @type: the hctx type index
89 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
93 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
97 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
99 * @flags: request command flags
102 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
104 struct blk_mq_ctx *ctx)
106 enum hctx_type type = HCTX_TYPE_DEFAULT;
109 * The caller ensure that if REQ_HIPRI, poll must be enabled.
111 if (flags & REQ_HIPRI)
112 type = HCTX_TYPE_POLL;
113 else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
114 type = HCTX_TYPE_READ;
116 return ctx->hctxs[type];
122 extern void blk_mq_sysfs_init(struct request_queue *q);
123 extern void blk_mq_sysfs_deinit(struct request_queue *q);
124 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
125 extern int blk_mq_sysfs_register(struct request_queue *q);
126 extern void blk_mq_sysfs_unregister(struct request_queue *q);
127 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
129 void blk_mq_release(struct request_queue *q);
131 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
134 return per_cpu_ptr(q->queue_ctx, cpu);
138 * This assumes per-cpu software queueing queues. They could be per-node
139 * as well, for instance. For now this is hardcoded as-is. Note that we don't
140 * care about preemption, since we know the ctx's are persistent. This does
141 * mean that we can't rely on ctx always matching the currently running CPU.
143 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
145 return __blk_mq_get_ctx(q, raw_smp_processor_id());
148 struct blk_mq_alloc_data {
149 /* input parameter */
150 struct request_queue *q;
151 blk_mq_req_flags_t flags;
152 unsigned int shallow_depth;
153 unsigned int cmd_flags;
155 /* input & output parameter */
156 struct blk_mq_ctx *ctx;
157 struct blk_mq_hw_ctx *hctx;
160 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
162 if (data->q->elevator)
163 return data->hctx->sched_tags;
165 return data->hctx->tags;
168 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
170 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
173 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
175 return hctx->nr_ctx && hctx->tags;
178 unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
179 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
180 unsigned int inflight[2]);
182 static inline void blk_mq_put_dispatch_budget(struct request_queue *q)
184 if (q->mq_ops->put_budget)
185 q->mq_ops->put_budget(q);
188 static inline bool blk_mq_get_dispatch_budget(struct request_queue *q)
190 if (q->mq_ops->get_budget)
191 return q->mq_ops->get_budget(q);
195 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
198 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
199 rq->tag = BLK_MQ_NO_TAG;
201 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
202 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
203 atomic_dec(&hctx->nr_active);
207 static inline void blk_mq_put_driver_tag(struct request *rq)
209 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
212 __blk_mq_put_driver_tag(rq->mq_hctx, rq);
215 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
219 for_each_possible_cpu(cpu)
220 qmap->mq_map[cpu] = 0;
224 * blk_mq_plug() - Get caller context plug
226 * @bio : the bio being submitted by the caller context
228 * Plugging, by design, may delay the insertion of BIOs into the elevator in
229 * order to increase BIO merging opportunities. This however can cause BIO
230 * insertion order to change from the order in which submit_bio() is being
231 * executed in the case of multiple contexts concurrently issuing BIOs to a
232 * device, even if these context are synchronized to tightly control BIO issuing
233 * order. While this is not a problem with regular block devices, this ordering
234 * change can cause write BIO failures with zoned block devices as these
235 * require sequential write patterns to zones. Prevent this from happening by
236 * ignoring the plug state of a BIO issuing context if the target request queue
237 * is for a zoned block device and the BIO to plug is a write operation.
239 * Return current->plug if the bio can be plugged and NULL otherwise
241 static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
245 * For regular block devices or read operations, use the context plug
246 * which may be NULL if blk_start_plug() was not executed.
248 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
249 return current->plug;
251 /* Zoned block device write operation case: do not plug the BIO */