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_ctx {
  11         struct {
  12                 spinlock_t              lock;
  13                 struct list_head        rq_list;
  14         }  ____cacheline_aligned_in_smp;
  15
  16         unsigned int            cpu;
  17         unsigned int            index_hw;
  18
  19         /* incremented at dispatch time */
  20         unsigned long           rq_dispatched[2];
  21         unsigned long           rq_merged;
  22
  23         /* incremented at completion time */
  24         unsigned long           ____cacheline_aligned_in_smp rq_completed[2];
  25
  26         struct request_queue    *queue;
  27         struct kobject          kobj;
  28 } ____cacheline_aligned_in_smp;
  29
  30 /*
  31  * Bits for request->gstate.  The lower two bits carry MQ_RQ_* state value
  32  * and the upper bits the generation number.
  33  */
  34 enum mq_rq_state {
  35         MQ_RQ_IDLE              = 0,
  36         MQ_RQ_IN_FLIGHT         = 1,
  37         MQ_RQ_COMPLETE          = 2,
  38
  39         MQ_RQ_STATE_BITS        = 2,
  40         MQ_RQ_STATE_MASK        = (1 << MQ_RQ_STATE_BITS) - 1,
  41         MQ_RQ_GEN_INC           = 1 << MQ_RQ_STATE_BITS,
  42 };
  43
  44 void blk_mq_freeze_queue(struct request_queue *q);
  45 void blk_mq_free_queue(struct request_queue *q);
  46 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  47 void blk_mq_wake_waiters(struct request_queue *q);
  48 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
  49 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  50 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
  51                                 bool wait);
  52 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  53                                         struct blk_mq_ctx *start);
  54
  55 /*
  56  * Internal helpers for allocating/freeing the request map
  57  */
  58 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  59                      unsigned int hctx_idx);
  60 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  61 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  62                                         unsigned int hctx_idx,
  63                                         unsigned int nr_tags,
  64                                         unsigned int reserved_tags);
  65 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  66                      unsigned int hctx_idx, unsigned int depth);
  67
  68 /*
  69  * Internal helpers for request insertion into sw queues
  70  */
  71 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  72                                 bool at_head);
  73 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
  74 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  75                                 struct list_head *list);
  76
  77 /* Used by blk_insert_cloned_request() to issue request directly */
  78 blk_status_t blk_mq_request_issue_directly(struct request *rq);
  79
  80 /*
  81  * CPU -> queue mappings
  82  */
  83 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  84
  85 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  86                 int cpu)
  87 {
  88         return q->queue_hw_ctx[q->mq_map[cpu]];
  89 }
  90
  91 /*
  92  * sysfs helpers
  93  */
  94 extern void blk_mq_sysfs_init(struct request_queue *q);
  95 extern void blk_mq_sysfs_deinit(struct request_queue *q);
  96 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
  97 extern int blk_mq_sysfs_register(struct request_queue *q);
  98 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  99 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
 100
 101 void blk_mq_release(struct request_queue *q);
 102
 103 /**
 104  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
 105  * @rq: target request.
 106  */
 107 static inline int blk_mq_rq_state(struct request *rq)
 108 {
 109         return READ_ONCE(rq->gstate) & MQ_RQ_STATE_MASK;
 110 }
 111
 112 /**
 113  * blk_mq_rq_update_state() - set the current MQ_RQ_* state of a request
 114  * @rq: target request.
 115  * @state: new state to set.
 116  *
 117  * Set @rq's state to @state.  The caller is responsible for ensuring that
 118  * there are no other updaters.  A request can transition into IN_FLIGHT
 119  * only from IDLE and doing so increments the generation number.
 120  */
 121 static inline void blk_mq_rq_update_state(struct request *rq,
 122                                           enum mq_rq_state state)
 123 {
 124         u64 old_val = READ_ONCE(rq->gstate);
 125         u64 new_val = (old_val & ~MQ_RQ_STATE_MASK) | state;
 126
 127         if (state == MQ_RQ_IN_FLIGHT) {
 128                 WARN_ON_ONCE((old_val & MQ_RQ_STATE_MASK) != MQ_RQ_IDLE);
 129                 new_val += MQ_RQ_GEN_INC;
 130         }
 131
 132         /* avoid exposing interim values */
 133         WRITE_ONCE(rq->gstate, new_val);
 134 }
 135
 136 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 137                                            unsigned int cpu)
 138 {
 139         return per_cpu_ptr(q->queue_ctx, cpu);
 140 }
 141
 142 /*
 143  * This assumes per-cpu software queueing queues. They could be per-node
 144  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 145  * care about preemption, since we know the ctx's are persistent. This does
 146  * mean that we can't rely on ctx always matching the currently running CPU.
 147  */
 148 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 149 {
 150         return __blk_mq_get_ctx(q, get_cpu());
 151 }
 152
 153 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 154 {
 155         put_cpu();
 156 }
 157
 158 struct blk_mq_alloc_data {
 159         /* input parameter */
 160         struct request_queue *q;
 161         blk_mq_req_flags_t flags;
 162         unsigned int shallow_depth;
 163
 164         /* input & output parameter */
 165         struct blk_mq_ctx *ctx;
 166         struct blk_mq_hw_ctx *hctx;
 167 };
 168
 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
 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
 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 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 188                         unsigned int inflight[2]);
 189
 190 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 191 {
 192         struct request_queue *q = hctx->queue;
 193
 194         if (q->mq_ops->put_budget)
 195                 q->mq_ops->put_budget(hctx);
 196 }
 197
 198 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 199 {
 200         struct request_queue *q = hctx->queue;
 201
 202         if (q->mq_ops->get_budget)
 203                 return q->mq_ops->get_budget(hctx);
 204         return true;
 205 }
 206
 207 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 208                                            struct request *rq)
 209 {
 210         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 211         rq->tag = -1;
 212
 213         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 214                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 215                 atomic_dec(&hctx->nr_active);
 216         }
 217 }
 218
 219 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 220                                        struct request *rq)
 221 {
 222         if (rq->tag == -1 || rq->internal_tag == -1)
 223                 return;
 224
 225         __blk_mq_put_driver_tag(hctx, rq);
 226 }
 227
 228 static inline void blk_mq_put_driver_tag(struct request *rq)
 229 {
 230         struct blk_mq_hw_ctx *hctx;
 231
 232         if (rq->tag == -1 || rq->internal_tag == -1)
 233                 return;
 234
 235         hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
 236         __blk_mq_put_driver_tag(hctx, rq);
 237 }
 238
 239 #endif