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
  38         MQ_RQ_STATE_BITS        = 2,
  39         MQ_RQ_STATE_MASK        = (1 << MQ_RQ_STATE_BITS) - 1,
  40         MQ_RQ_GEN_INC           = 1 << MQ_RQ_STATE_BITS,
  41 };
  42
  43 void blk_mq_freeze_queue(struct request_queue *q);
  44 void blk_mq_free_queue(struct request_queue *q);
  45 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  46 void blk_mq_wake_waiters(struct request_queue *q);
  47 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
  48 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  49 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
  50                                 bool wait);
  51 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  52                                         struct blk_mq_ctx *start);
  53
  54 /*
  55  * Internal helpers for allocating/freeing the request map
  56  */
  57 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  58                      unsigned int hctx_idx);
  59 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  60 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  61                                         unsigned int hctx_idx,
  62                                         unsigned int nr_tags,
  63                                         unsigned int reserved_tags);
  64 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  65                      unsigned int hctx_idx, unsigned int depth);
  66
  67 /*
  68  * Internal helpers for request insertion into sw queues
  69  */
  70 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  71                                 bool at_head);
  72 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
  73 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  74                                 struct list_head *list);
  75
  76 /*
  77  * CPU -> queue mappings
  78  */
  79 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  80
  81 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  82                 int cpu)
  83 {
  84         return q->queue_hw_ctx[q->mq_map[cpu]];
  85 }
  86
  87 /*
  88  * sysfs helpers
  89  */
  90 extern void blk_mq_sysfs_init(struct request_queue *q);
  91 extern void blk_mq_sysfs_deinit(struct request_queue *q);
  92 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
  93 extern int blk_mq_sysfs_register(struct request_queue *q);
  94 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  95 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  96
  97 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  98
  99 void blk_mq_release(struct request_queue *q);
 100
 101 /**
 102  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
 103  * @rq: target request.
 104  */
 105 static inline int blk_mq_rq_state(struct request *rq)
 106 {
 107         return READ_ONCE(rq->gstate) & MQ_RQ_STATE_MASK;
 108 }
 109
 110 /**
 111  * blk_mq_rq_update_state() - set the current MQ_RQ_* state of a request
 112  * @rq: target request.
 113  * @state: new state to set.
 114  *
 115  * Set @rq's state to @state.  The caller is responsible for ensuring that
 116  * there are no other updaters.  A request can transition into IN_FLIGHT
 117  * only from IDLE and doing so increments the generation number.
 118  */
 119 static inline void blk_mq_rq_update_state(struct request *rq,
 120                                           enum mq_rq_state state)
 121 {
 122         u64 old_val = READ_ONCE(rq->gstate);
 123         u64 new_val = (old_val & ~MQ_RQ_STATE_MASK) | state;
 124
 125         if (state == MQ_RQ_IN_FLIGHT) {
 126                 WARN_ON_ONCE((old_val & MQ_RQ_STATE_MASK) != MQ_RQ_IDLE);
 127                 new_val += MQ_RQ_GEN_INC;
 128         }
 129
 130         /* avoid exposing interim values */
 131         WRITE_ONCE(rq->gstate, new_val);
 132 }
 133
 134 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 135                                            unsigned int cpu)
 136 {
 137         return per_cpu_ptr(q->queue_ctx, cpu);
 138 }
 139
 140 /*
 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.
 145  */
 146 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 147 {
 148         return __blk_mq_get_ctx(q, get_cpu());
 149 }
 150
 151 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 152 {
 153         put_cpu();
 154 }
 155
 156 struct blk_mq_alloc_data {
 157         /* input parameter */
 158         struct request_queue *q;
 159         blk_mq_req_flags_t flags;
 160         unsigned int shallow_depth;
 161
 162         /* input & output parameter */
 163         struct blk_mq_ctx *ctx;
 164         struct blk_mq_hw_ctx *hctx;
 165 };
 166
 167 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 168 {
 169         if (data->flags & BLK_MQ_REQ_INTERNAL)
 170                 return data->hctx->sched_tags;
 171
 172         return data->hctx->tags;
 173 }
 174
 175 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 176 {
 177         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 178 }
 179
 180 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 181 {
 182         return hctx->nr_ctx && hctx->tags;
 183 }
 184
 185 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 186                         unsigned int inflight[2]);
 187
 188 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 189 {
 190         struct request_queue *q = hctx->queue;
 191
 192         if (q->mq_ops->put_budget)
 193                 q->mq_ops->put_budget(hctx);
 194 }
 195
 196 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 197 {
 198         struct request_queue *q = hctx->queue;
 199
 200         if (q->mq_ops->get_budget)
 201                 return q->mq_ops->get_budget(hctx);
 202         return true;
 203 }
 204
 205 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 206                                            struct request *rq)
 207 {
 208         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 209         rq->tag = -1;
 210
 211         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 212                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 213                 atomic_dec(&hctx->nr_active);
 214         }
 215 }
 216
 217 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 218                                        struct request *rq)
 219 {
 220         if (rq->tag == -1 || rq->internal_tag == -1)
 221                 return;
 222
 223         __blk_mq_put_driver_tag(hctx, rq);
 224 }
 225
 226 static inline void blk_mq_put_driver_tag(struct request *rq)
 227 {
 228         struct blk_mq_hw_ctx *hctx;
 229
 230         if (rq->tag == -1 || rq->internal_tag == -1)
 231                 return;
 232
 233         hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
 234         __blk_mq_put_driver_tag(hctx, rq);
 235 }
 236
 237 #endif