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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 /* 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);
50
51/*
52 * Internal helpers for allocating/freeing the request map
53 */
54void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
55 unsigned int hctx_idx);
56void blk_mq_free_rq_map(struct blk_mq_tags *tags);
57struct 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);
61int 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 */
67void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
68 bool at_head);
69void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
70 bool run_queue);
71void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
72 struct list_head *list);
73
74/* Used by blk_insert_cloned_request() to issue request directly */
75blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
76void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
77 struct list_head *list);
78
79/*
80 * CPU -> queue mappings
81 */
82extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
83
84/*
85 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
86 * @q: request queue
87 * @type: the hctx type index
88 * @cpu: CPU
89 */
90static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
91 enum hctx_type type,
92 unsigned int cpu)
93{
94 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
95}
96
97/*
98 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
99 * @q: request queue
100 * @flags: request command flags
101 * @cpu: cpu ctx
102 */
103static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
104 unsigned int flags,
105 struct blk_mq_ctx *ctx)
106{
107 enum hctx_type type = HCTX_TYPE_DEFAULT;
108
109 /*
110 * The caller ensure that if REQ_HIPRI, poll must be enabled.
111 */
112 if (flags & REQ_HIPRI)
113 type = HCTX_TYPE_POLL;
114 else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
115 type = HCTX_TYPE_READ;
116
117 return ctx->hctxs[type];
118}
119
120/*
121 * sysfs helpers
122 */
123extern void blk_mq_sysfs_init(struct request_queue *q);
124extern void blk_mq_sysfs_deinit(struct request_queue *q);
125extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
126extern int blk_mq_sysfs_register(struct request_queue *q);
127extern void blk_mq_sysfs_unregister(struct request_queue *q);
128extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
129
130void blk_mq_release(struct request_queue *q);
131
132static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
133 unsigned int cpu)
134{
135 return per_cpu_ptr(q->queue_ctx, cpu);
136}
137
138/*
139 * This assumes per-cpu software queueing queues. They could be per-node
140 * as well, for instance. For now this is hardcoded as-is. Note that we don't
141 * care about preemption, since we know the ctx's are persistent. This does
142 * mean that we can't rely on ctx always matching the currently running CPU.
143 */
144static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
145{
146 return __blk_mq_get_ctx(q, raw_smp_processor_id());
147}
148
149struct blk_mq_alloc_data {
150 /* input parameter */
151 struct request_queue *q;
152 blk_mq_req_flags_t flags;
153 unsigned int shallow_depth;
154 unsigned int cmd_flags;
155
156 /* input & output parameter */
157 struct blk_mq_ctx *ctx;
158 struct blk_mq_hw_ctx *hctx;
159};
160
161static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
162{
163 if (data->q->elevator)
164 return data->hctx->sched_tags;
165
166 return data->hctx->tags;
167}
168
169static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
170{
171 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
172}
173
174static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
175{
176 return hctx->nr_ctx && hctx->tags;
177}
178
179unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
180void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
181 unsigned int inflight[2]);
182
183static inline void blk_mq_put_dispatch_budget(struct request_queue *q)
184{
185 if (q->mq_ops->put_budget)
186 q->mq_ops->put_budget(q);
187}
188
189static inline bool blk_mq_get_dispatch_budget(struct request_queue *q)
190{
191 if (q->mq_ops->get_budget)
192 return q->mq_ops->get_budget(q);
193 return true;
194}
195
196static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
197 struct request *rq)
198{
199 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
200 rq->tag = BLK_MQ_NO_TAG;
201
202 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
203 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
204 atomic_dec(&hctx->nr_active);
205 }
206}
207
208static inline void blk_mq_put_driver_tag(struct request *rq)
209{
210 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
211 return;
212
213 __blk_mq_put_driver_tag(rq->mq_hctx, rq);
214}
215
216static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
217{
218 int cpu;
219
220 for_each_possible_cpu(cpu)
221 qmap->mq_map[cpu] = 0;
222}
223
224/*
225 * blk_mq_plug() - Get caller context plug
226 * @q: request queue
227 * @bio : the bio being submitted by the caller context
228 *
229 * Plugging, by design, may delay the insertion of BIOs into the elevator in
230 * order to increase BIO merging opportunities. This however can cause BIO
231 * insertion order to change from the order in which submit_bio() is being
232 * executed in the case of multiple contexts concurrently issuing BIOs to a
233 * device, even if these context are synchronized to tightly control BIO issuing
234 * order. While this is not a problem with regular block devices, this ordering
235 * change can cause write BIO failures with zoned block devices as these
236 * require sequential write patterns to zones. Prevent this from happening by
237 * ignoring the plug state of a BIO issuing context if the target request queue
238 * is for a zoned block device and the BIO to plug is a write operation.
239 *
240 * Return current->plug if the bio can be plugged and NULL otherwise
241 */
242static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
243 struct bio *bio)
244{
245 /*
246 * For regular block devices or read operations, use the context plug
247 * which may be NULL if blk_start_plug() was not executed.
248 */
249 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
250 return current->plug;
251
252 /* Zoned block device write operation case: do not plug the BIO */
253 return NULL;
254}
255
256#endif