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
8 struct blk_mq_tag_set;
9
10 struct 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 */
18 struct 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
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 request_queue *, 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 bool blk_mq_get_driver_tag(struct request *rq);
48 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
49 struct blk_mq_ctx *start);
50
51 /*
52 * Internal helpers for allocating/freeing the request map
53 */
54 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
55 unsigned int hctx_idx);
56 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
57 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
58 unsigned int hctx_idx,
59 unsigned int nr_tags,
60 unsigned int reserved_tags);
61 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
62 unsigned int hctx_idx, unsigned int depth);
63
64 /*
65 * Internal helpers for request insertion into sw queues
66 */
67 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
68 bool at_head);
69 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
70 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
71 struct list_head *list);
72
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);
77
78 /*
79 * CPU -> queue mappings
80 */
81 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
82
83 /*
84 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
85 * @q: request queue
86 * @type: the hctx type index
87 * @cpu: CPU
88 */
blk_mq_map_queue_type(struct request_queue * q,enum hctx_type type,unsigned int cpu)89 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
90 enum hctx_type type,
91 unsigned int cpu)
92 {
93 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
94 }
95
96 /*
97 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
98 * @q: request queue
99 * @flags: request command flags
100 * @cpu: cpu ctx
101 */
blk_mq_map_queue(struct request_queue * q,unsigned int flags,struct blk_mq_ctx * ctx)102 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
103 unsigned int flags,
104 struct blk_mq_ctx *ctx)
105 {
106 enum hctx_type type = HCTX_TYPE_DEFAULT;
107
108 /*
109 * The caller ensure that if REQ_HIPRI, poll must be enabled.
110 */
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;
115
116 return ctx->hctxs[type];
117 }
118
119 /*
120 * sysfs helpers
121 */
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);
128
129 void blk_mq_release(struct request_queue *q);
130
131 /**
132 * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
133 * @rq: target request.
134 */
blk_mq_rq_state(struct request * rq)135 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
136 {
137 return READ_ONCE(rq->state);
138 }
139
__blk_mq_get_ctx(struct request_queue * q,unsigned int cpu)140 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
141 unsigned int cpu)
142 {
143 return per_cpu_ptr(q->queue_ctx, cpu);
144 }
145
146 /*
147 * This assumes per-cpu software queueing queues. They could be per-node
148 * as well, for instance. For now this is hardcoded as-is. Note that we don't
149 * care about preemption, since we know the ctx's are persistent. This does
150 * mean that we can't rely on ctx always matching the currently running CPU.
151 */
blk_mq_get_ctx(struct request_queue * q)152 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
153 {
154 return __blk_mq_get_ctx(q, raw_smp_processor_id());
155 }
156
157 struct blk_mq_alloc_data {
158 /* input parameter */
159 struct request_queue *q;
160 blk_mq_req_flags_t flags;
161 unsigned int shallow_depth;
162 unsigned int cmd_flags;
163
164 /* input & output parameter */
165 struct blk_mq_ctx *ctx;
166 struct blk_mq_hw_ctx *hctx;
167 };
168
blk_mq_tags_from_data(struct blk_mq_alloc_data * data)169 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
170 {
171 if (data->flags & BLK_MQ_REQ_INTERNAL)
172 return data->hctx->sched_tags;
173
174 return data->hctx->tags;
175 }
176
blk_mq_hctx_stopped(struct blk_mq_hw_ctx * hctx)177 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
178 {
179 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
180 }
181
blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx * hctx)182 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
183 {
184 return hctx->nr_ctx && hctx->tags;
185 }
186
187 unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
188 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
189 unsigned int inflight[2]);
190
blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx * hctx)191 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
192 {
193 struct request_queue *q = hctx->queue;
194
195 if (q->mq_ops->put_budget)
196 q->mq_ops->put_budget(hctx);
197 }
198
blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx * hctx)199 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
200 {
201 struct request_queue *q = hctx->queue;
202
203 if (q->mq_ops->get_budget)
204 return q->mq_ops->get_budget(hctx);
205 return true;
206 }
207
__blk_mq_put_driver_tag(struct blk_mq_hw_ctx * hctx,struct request * rq)208 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
209 struct request *rq)
210 {
211 blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
212 rq->tag = -1;
213
214 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
215 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
216 atomic_dec(&hctx->nr_active);
217 }
218 }
219
blk_mq_put_driver_tag(struct request * rq)220 static inline void blk_mq_put_driver_tag(struct request *rq)
221 {
222 if (rq->tag == -1 || rq->internal_tag == -1)
223 return;
224
225 __blk_mq_put_driver_tag(rq->mq_hctx, rq);
226 }
227
blk_mq_clear_mq_map(struct blk_mq_queue_map * qmap)228 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
229 {
230 int cpu;
231
232 for_each_possible_cpu(cpu)
233 qmap->mq_map[cpu] = 0;
234 }
235
236 /*
237 * blk_mq_plug() - Get caller context plug
238 * @q: request queue
239 * @bio : the bio being submitted by the caller context
240 *
241 * Plugging, by design, may delay the insertion of BIOs into the elevator in
242 * order to increase BIO merging opportunities. This however can cause BIO
243 * insertion order to change from the order in which submit_bio() is being
244 * executed in the case of multiple contexts concurrently issuing BIOs to a
245 * device, even if these context are synchronized to tightly control BIO issuing
246 * order. While this is not a problem with regular block devices, this ordering
247 * change can cause write BIO failures with zoned block devices as these
248 * require sequential write patterns to zones. Prevent this from happening by
249 * ignoring the plug state of a BIO issuing context if the target request queue
250 * is for a zoned block device and the BIO to plug is a write operation.
251 *
252 * Return current->plug if the bio can be plugged and NULL otherwise
253 */
blk_mq_plug(struct request_queue * q,struct bio * bio)254 static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
255 struct bio *bio)
256 {
257 /*
258 * For regular block devices or read operations, use the context plug
259 * which may be NULL if blk_start_plug() was not executed.
260 */
261 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
262 return current->plug;
263
264 /* Zoned block device write operation case: do not plug the BIO */
265 return NULL;
266 }
267
268 #endif
269
