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_release(struct request_queue
*q
);
134 static inline struct blk_mq_ctx
*__blk_mq_get_ctx(struct request_queue
*q
,
137 return per_cpu_ptr(q
->queue_ctx
, cpu
);
141 * This assumes per-cpu software queueing queues. They could be per-node
142 * as well, for instance. For now this is hardcoded as-is. Note that we don't
143 * care about preemption, since we know the ctx's are persistent. This does
144 * mean that we can't rely on ctx always matching the currently running CPU.
146 static inline struct blk_mq_ctx
*blk_mq_get_ctx(struct request_queue
*q
)
148 return __blk_mq_get_ctx(q
, raw_smp_processor_id());
151 struct blk_mq_alloc_data
{
152 /* input parameter */
153 struct request_queue
*q
;
154 blk_mq_req_flags_t flags
;
155 unsigned int shallow_depth
;
156 unsigned int cmd_flags
;
158 /* input & output parameter */
159 struct blk_mq_ctx
*ctx
;
160 struct blk_mq_hw_ctx
*hctx
;
163 static inline bool blk_mq_is_sbitmap_shared(unsigned int flags
)
165 return flags
& BLK_MQ_F_TAG_HCTX_SHARED
;
168 static inline struct blk_mq_tags
*blk_mq_tags_from_data(struct blk_mq_alloc_data
*data
)
170 if (data
->q
->elevator
)
171 return data
->hctx
->sched_tags
;
173 return data
->hctx
->tags
;
176 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx
*hctx
)
178 return test_bit(BLK_MQ_S_STOPPED
, &hctx
->state
);
181 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx
*hctx
)
183 return hctx
->nr_ctx
&& hctx
->tags
;
186 unsigned int blk_mq_in_flight(struct request_queue
*q
,
187 struct block_device
*part
);
188 void blk_mq_in_flight_rw(struct request_queue
*q
, struct block_device
*part
,
189 unsigned int inflight
[2]);
191 static inline void blk_mq_put_dispatch_budget(struct request_queue
*q
,
194 if (q
->mq_ops
->put_budget
)
195 q
->mq_ops
->put_budget(q
, budget_token
);
198 static inline int blk_mq_get_dispatch_budget(struct request_queue
*q
)
200 if (q
->mq_ops
->get_budget
)
201 return q
->mq_ops
->get_budget(q
);
205 static inline void blk_mq_set_rq_budget_token(struct request
*rq
, int token
)
210 if (rq
->q
->mq_ops
->set_rq_budget_token
)
211 rq
->q
->mq_ops
->set_rq_budget_token(rq
, token
);
214 static inline int blk_mq_get_rq_budget_token(struct request
*rq
)
216 if (rq
->q
->mq_ops
->get_rq_budget_token
)
217 return rq
->q
->mq_ops
->get_rq_budget_token(rq
);
221 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx
*hctx
)
223 if (blk_mq_is_sbitmap_shared(hctx
->flags
))
224 atomic_inc(&hctx
->queue
->nr_active_requests_shared_sbitmap
);
226 atomic_inc(&hctx
->nr_active
);
229 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx
*hctx
)
231 if (blk_mq_is_sbitmap_shared(hctx
->flags
))
232 atomic_dec(&hctx
->queue
->nr_active_requests_shared_sbitmap
);
234 atomic_dec(&hctx
->nr_active
);
237 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx
*hctx
)
239 if (blk_mq_is_sbitmap_shared(hctx
->flags
))
240 return atomic_read(&hctx
->queue
->nr_active_requests_shared_sbitmap
);
241 return atomic_read(&hctx
->nr_active
);
243 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx
*hctx
,
246 blk_mq_put_tag(hctx
->tags
, rq
->mq_ctx
, rq
->tag
);
247 rq
->tag
= BLK_MQ_NO_TAG
;
249 if (rq
->rq_flags
& RQF_MQ_INFLIGHT
) {
250 rq
->rq_flags
&= ~RQF_MQ_INFLIGHT
;
251 __blk_mq_dec_active_requests(hctx
);
255 static inline void blk_mq_put_driver_tag(struct request
*rq
)
257 if (rq
->tag
== BLK_MQ_NO_TAG
|| rq
->internal_tag
== BLK_MQ_NO_TAG
)
260 __blk_mq_put_driver_tag(rq
->mq_hctx
, rq
);
263 bool blk_mq_get_driver_tag(struct request
*rq
);
265 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map
*qmap
)
269 for_each_possible_cpu(cpu
)
270 qmap
->mq_map
[cpu
] = 0;
274 * blk_mq_plug() - Get caller context plug
276 * @bio : the bio being submitted by the caller context
278 * Plugging, by design, may delay the insertion of BIOs into the elevator in
279 * order to increase BIO merging opportunities. This however can cause BIO
280 * insertion order to change from the order in which submit_bio() is being
281 * executed in the case of multiple contexts concurrently issuing BIOs to a
282 * device, even if these context are synchronized to tightly control BIO issuing
283 * order. While this is not a problem with regular block devices, this ordering
284 * change can cause write BIO failures with zoned block devices as these
285 * require sequential write patterns to zones. Prevent this from happening by
286 * ignoring the plug state of a BIO issuing context if the target request queue
287 * is for a zoned block device and the BIO to plug is a write operation.
289 * Return current->plug if the bio can be plugged and NULL otherwise
291 static inline struct blk_plug
*blk_mq_plug(struct request_queue
*q
,
295 * For regular block devices or read operations, use the context plug
296 * which may be NULL if blk_start_plug() was not executed.
298 if (!blk_queue_is_zoned(q
) || !op_is_write(bio_op(bio
)))
299 return current
->plug
;
301 /* Zoned block device write operation case: do not plug the BIO */
305 /* Free all requests on the list */
306 static inline void blk_mq_free_requests(struct list_head
*list
)
308 while (!list_empty(list
)) {
309 struct request
*rq
= list_entry_rq(list
->next
);
311 list_del_init(&rq
->queuelist
);
312 blk_mq_free_request(rq
);
317 * For shared tag users, we track the number of currently active users
318 * and attempt to provide a fair share of the tag depth for each of them.
320 static inline bool hctx_may_queue(struct blk_mq_hw_ctx
*hctx
,
321 struct sbitmap_queue
*bt
)
323 unsigned int depth
, users
;
325 if (!hctx
|| !(hctx
->flags
& BLK_MQ_F_TAG_QUEUE_SHARED
))
329 * Don't try dividing an ant
331 if (bt
->sb
.depth
== 1)
334 if (blk_mq_is_sbitmap_shared(hctx
->flags
)) {
335 struct request_queue
*q
= hctx
->queue
;
336 struct blk_mq_tag_set
*set
= q
->tag_set
;
338 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE
, &q
->queue_flags
))
340 users
= atomic_read(&set
->active_queues_shared_sbitmap
);
342 if (!test_bit(BLK_MQ_S_TAG_ACTIVE
, &hctx
->state
))
344 users
= atomic_read(&hctx
->tags
->active_queues
);
351 * Allow at least some tags
353 depth
= max((bt
->sb
.depth
+ users
- 1) / users
, 4U);
354 return __blk_mq_active_requests(hctx
) < depth
;