block/blk-mq.h

   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_free_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 blk_status_t blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
  74                                                 struct request *rq,
  75                                                 blk_qc_t *cookie,
  76                                                 bool bypass, bool last);
  77 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
  78                                     struct list_head *list);
  79
  80 /*
  81  * CPU -> queue mappings
  82  */
  83 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
  84
  85 /*
  86  * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
  87  * @q: request queue
  88  * @type: the hctx type index
  89  * @cpu: CPU
  90  */
  91 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
  92                                                           enum hctx_type type,
  93                                                           unsigned int cpu)
  94 {
  95         return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
  96 }
  97
  98 /*
  99  * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
 100  * @q: request queue
 101  * @flags: request command flags
 102  * @cpu: cpu ctx
 103  */
 104 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
 105                                                      unsigned int flags,
 106                                                      struct blk_mq_ctx *ctx)
 107 {
 108         enum hctx_type type = HCTX_TYPE_DEFAULT;
 109
 110         /*
 111          * The caller ensure that if REQ_HIPRI, poll must be enabled.
 112          */
 113         if (flags & REQ_HIPRI)
 114                 type = HCTX_TYPE_POLL;
 115         else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
 116                 type = HCTX_TYPE_READ;
 117
 118         return ctx->hctxs[type];
 119 }
 120
 121 /*
 122  * sysfs helpers
 123  */
 124 extern void blk_mq_sysfs_init(struct request_queue *q);
 125 extern void blk_mq_sysfs_deinit(struct request_queue *q);
 126 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
 127 extern int blk_mq_sysfs_register(struct request_queue *q);
 128 extern void blk_mq_sysfs_unregister(struct request_queue *q);
 129 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
 130
 131 void blk_mq_release(struct request_queue *q);
 132
 133 /**
 134  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
 135  * @rq: target request.
 136  */
 137 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
 138 {
 139         return READ_ONCE(rq->state);
 140 }
 141
 142 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 143                                            unsigned int cpu)
 144 {
 145         return per_cpu_ptr(q->queue_ctx, cpu);
 146 }
 147
 148 /*
 149  * This assumes per-cpu software queueing queues. They could be per-node
 150  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 151  * care about preemption, since we know the ctx's are persistent. This does
 152  * mean that we can't rely on ctx always matching the currently running CPU.
 153  */
 154 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 155 {
 156         return __blk_mq_get_ctx(q, get_cpu());
 157 }
 158
 159 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 160 {
 161         put_cpu();
 162 }
 163
 164 struct blk_mq_alloc_data {
 165         /* input parameter */
 166         struct request_queue *q;
 167         blk_mq_req_flags_t flags;
 168         unsigned int shallow_depth;
 169         unsigned int cmd_flags;
 170
 171         /* input & output parameter */
 172         struct blk_mq_ctx *ctx;
 173         struct blk_mq_hw_ctx *hctx;
 174 };
 175
 176 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 177 {
 178         if (data->flags & BLK_MQ_REQ_INTERNAL)
 179                 return data->hctx->sched_tags;
 180
 181         return data->hctx->tags;
 182 }
 183
 184 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 185 {
 186         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 187 }
 188
 189 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 190 {
 191         return hctx->nr_ctx && hctx->tags;
 192 }
 193
 194 unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
 195 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 196                          unsigned int inflight[2]);
 197
 198 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 199 {
 200         struct request_queue *q = hctx->queue;
 201
 202         if (q->mq_ops->put_budget)
 203                 q->mq_ops->put_budget(hctx);
 204 }
 205
 206 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 207 {
 208         struct request_queue *q = hctx->queue;
 209
 210         if (q->mq_ops->get_budget)
 211                 return q->mq_ops->get_budget(hctx);
 212         return true;
 213 }
 214
 215 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 216                                            struct request *rq)
 217 {
 218         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 219         rq->tag = -1;
 220
 221         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 222                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 223                 atomic_dec(&hctx->nr_active);
 224         }
 225 }
 226
 227 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 228                                        struct request *rq)
 229 {
 230         if (rq->tag == -1 || rq->internal_tag == -1)
 231                 return;
 232
 233         __blk_mq_put_driver_tag(hctx, rq);
 234 }
 235
 236 static inline void blk_mq_put_driver_tag(struct request *rq)
 237 {
 238         if (rq->tag == -1 || rq->internal_tag == -1)
 239                 return;
 240
 241         __blk_mq_put_driver_tag(rq->mq_hctx, rq);
 242 }
 243
 244 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
 245 {
 246         int cpu;
 247
 248         for_each_possible_cpu(cpu)
 249                 qmap->mq_map[cpu] = 0;
 250 }
 251
 252 #endif