Linux Audio

Check our new training course

Real-Time Linux with PREEMPT_RT training

Feb 18-20, 2025
Register
Loading...
v3.15
 
 1#ifndef INT_BLK_MQ_H
 2#define INT_BLK_MQ_H
 3
 
 
 
 
 
 
 
 
 
 
 
 
 
 4struct blk_mq_ctx {
 5	struct {
 6		spinlock_t		lock;
 7		struct list_head	rq_list;
 8	}  ____cacheline_aligned_in_smp;
 9
10	unsigned int		cpu;
11	unsigned int		index_hw;
12	unsigned int		ipi_redirect;
13
14	/* incremented at dispatch time */
15	unsigned long		rq_dispatched[2];
16	unsigned long		rq_merged;
17
18	/* incremented at completion time */
19	unsigned long		____cacheline_aligned_in_smp rq_completed[2];
20
21	struct request_queue	*queue;
 
22	struct kobject		kobj;
23};
 
 
 
 
 
 
 
 
 
 
 
24
25void __blk_mq_complete_request(struct request *rq);
26void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
27void blk_mq_init_flush(struct request_queue *q);
28void blk_mq_drain_queue(struct request_queue *q);
29void blk_mq_free_queue(struct request_queue *q);
30void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq);
31
32/*
33 * CPU hotplug helpers
34 */
35struct blk_mq_cpu_notifier;
36void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
37			      void (*fn)(void *, unsigned long, unsigned int),
38			      void *data);
39void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
40void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
41void blk_mq_cpu_init(void);
42void blk_mq_enable_hotplug(void);
43void blk_mq_disable_hotplug(void);
 
 
 
 
 
 
 
 
44
45/*
46 * CPU -> queue mappings
47 */
48struct blk_mq_reg;
49extern unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg);
50extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
51
52void blk_mq_add_timer(struct request *rq);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
53
54#endif
v5.9
  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