1bd166ef1SJens Axboe /* 2bd166ef1SJens Axboe * blk-mq scheduling framework 3bd166ef1SJens Axboe * 4bd166ef1SJens Axboe * Copyright (C) 2016 Jens Axboe 5bd166ef1SJens Axboe */ 6bd166ef1SJens Axboe #include <linux/kernel.h> 7bd166ef1SJens Axboe #include <linux/module.h> 8bd166ef1SJens Axboe #include <linux/blk-mq.h> 9bd166ef1SJens Axboe 10bd166ef1SJens Axboe #include <trace/events/block.h> 11bd166ef1SJens Axboe 12bd166ef1SJens Axboe #include "blk.h" 13bd166ef1SJens Axboe #include "blk-mq.h" 14bd166ef1SJens Axboe #include "blk-mq-sched.h" 15bd166ef1SJens Axboe #include "blk-mq-tag.h" 16bd166ef1SJens Axboe #include "blk-wbt.h" 17bd166ef1SJens Axboe 18bd166ef1SJens Axboe void blk_mq_sched_free_hctx_data(struct request_queue *q, 19bd166ef1SJens Axboe void (*exit)(struct blk_mq_hw_ctx *)) 20bd166ef1SJens Axboe { 21bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx; 22bd166ef1SJens Axboe int i; 23bd166ef1SJens Axboe 24bd166ef1SJens Axboe queue_for_each_hw_ctx(q, hctx, i) { 25bd166ef1SJens Axboe if (exit && hctx->sched_data) 26bd166ef1SJens Axboe exit(hctx); 27bd166ef1SJens Axboe kfree(hctx->sched_data); 28bd166ef1SJens Axboe hctx->sched_data = NULL; 29bd166ef1SJens Axboe } 30bd166ef1SJens Axboe } 31bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data); 32bd166ef1SJens Axboe 33bd166ef1SJens Axboe static void __blk_mq_sched_assign_ioc(struct request_queue *q, 34f1ba8261SPaolo Valente struct request *rq, 35f1ba8261SPaolo Valente struct bio *bio, 36f1ba8261SPaolo Valente struct io_context *ioc) 37bd166ef1SJens Axboe { 38bd166ef1SJens Axboe struct io_cq *icq; 39bd166ef1SJens Axboe 40bd166ef1SJens Axboe spin_lock_irq(q->queue_lock); 41bd166ef1SJens Axboe icq = ioc_lookup_icq(ioc, q); 42bd166ef1SJens Axboe spin_unlock_irq(q->queue_lock); 43bd166ef1SJens Axboe 44bd166ef1SJens Axboe if (!icq) { 45bd166ef1SJens Axboe icq = ioc_create_icq(ioc, q, GFP_ATOMIC); 46bd166ef1SJens Axboe if (!icq) 47bd166ef1SJens Axboe return; 48bd166ef1SJens Axboe } 49bd166ef1SJens Axboe 50bd166ef1SJens Axboe rq->elv.icq = icq; 51f1ba8261SPaolo Valente if (!blk_mq_sched_get_rq_priv(q, rq, bio)) { 52bd166ef1SJens Axboe rq->rq_flags |= RQF_ELVPRIV; 53bd166ef1SJens Axboe get_io_context(icq->ioc); 54bd166ef1SJens Axboe return; 55bd166ef1SJens Axboe } 56bd166ef1SJens Axboe 57bd166ef1SJens Axboe rq->elv.icq = NULL; 58bd166ef1SJens Axboe } 59bd166ef1SJens Axboe 60bd166ef1SJens Axboe static void blk_mq_sched_assign_ioc(struct request_queue *q, 61bd166ef1SJens Axboe struct request *rq, struct bio *bio) 62bd166ef1SJens Axboe { 63bd166ef1SJens Axboe struct io_context *ioc; 64bd166ef1SJens Axboe 65bd166ef1SJens Axboe ioc = rq_ioc(bio); 66bd166ef1SJens Axboe if (ioc) 67f1ba8261SPaolo Valente __blk_mq_sched_assign_ioc(q, rq, bio, ioc); 68bd166ef1SJens Axboe } 69bd166ef1SJens Axboe 70bd166ef1SJens Axboe struct request *blk_mq_sched_get_request(struct request_queue *q, 71bd166ef1SJens Axboe struct bio *bio, 72bd166ef1SJens Axboe unsigned int op, 73bd166ef1SJens Axboe struct blk_mq_alloc_data *data) 74bd166ef1SJens Axboe { 75bd166ef1SJens Axboe struct elevator_queue *e = q->elevator; 76bd166ef1SJens Axboe struct request *rq; 77bd166ef1SJens Axboe 78bd166ef1SJens Axboe blk_queue_enter_live(q); 796d2809d5SOmar Sandoval data->q = q; 806d2809d5SOmar Sandoval if (likely(!data->ctx)) 816d2809d5SOmar Sandoval data->ctx = blk_mq_get_ctx(q); 826d2809d5SOmar Sandoval if (likely(!data->hctx)) 836d2809d5SOmar Sandoval data->hctx = blk_mq_map_queue(q, data->ctx->cpu); 84bd166ef1SJens Axboe 85bd166ef1SJens Axboe if (e) { 86bd166ef1SJens Axboe data->flags |= BLK_MQ_REQ_INTERNAL; 87bd166ef1SJens Axboe 88bd166ef1SJens Axboe /* 89bd166ef1SJens Axboe * Flush requests are special and go directly to the 90bd166ef1SJens Axboe * dispatch list. 91bd166ef1SJens Axboe */ 92f73f44ebSChristoph Hellwig if (!op_is_flush(op) && e->type->ops.mq.get_request) { 93bd166ef1SJens Axboe rq = e->type->ops.mq.get_request(q, op, data); 94bd166ef1SJens Axboe if (rq) 95bd166ef1SJens Axboe rq->rq_flags |= RQF_QUEUED; 96bd166ef1SJens Axboe } else 97bd166ef1SJens Axboe rq = __blk_mq_alloc_request(data, op); 98bd166ef1SJens Axboe } else { 99bd166ef1SJens Axboe rq = __blk_mq_alloc_request(data, op); 100bd166ef1SJens Axboe } 101bd166ef1SJens Axboe 102bd166ef1SJens Axboe if (rq) { 103f73f44ebSChristoph Hellwig if (!op_is_flush(op)) { 104bd166ef1SJens Axboe rq->elv.icq = NULL; 105bd166ef1SJens Axboe if (e && e->type->icq_cache) 106bd166ef1SJens Axboe blk_mq_sched_assign_ioc(q, rq, bio); 107bd166ef1SJens Axboe } 108bd166ef1SJens Axboe data->hctx->queued++; 109bd166ef1SJens Axboe return rq; 110bd166ef1SJens Axboe } 111bd166ef1SJens Axboe 112bd166ef1SJens Axboe blk_queue_exit(q); 113bd166ef1SJens Axboe return NULL; 114bd166ef1SJens Axboe } 115bd166ef1SJens Axboe 116bd166ef1SJens Axboe void blk_mq_sched_put_request(struct request *rq) 117bd166ef1SJens Axboe { 118bd166ef1SJens Axboe struct request_queue *q = rq->q; 119bd166ef1SJens Axboe struct elevator_queue *e = q->elevator; 120bd166ef1SJens Axboe 121bd166ef1SJens Axboe if (rq->rq_flags & RQF_ELVPRIV) { 122bd166ef1SJens Axboe blk_mq_sched_put_rq_priv(rq->q, rq); 123bd166ef1SJens Axboe if (rq->elv.icq) { 124bd166ef1SJens Axboe put_io_context(rq->elv.icq->ioc); 125bd166ef1SJens Axboe rq->elv.icq = NULL; 126bd166ef1SJens Axboe } 127bd166ef1SJens Axboe } 128bd166ef1SJens Axboe 129bd166ef1SJens Axboe if ((rq->rq_flags & RQF_QUEUED) && e && e->type->ops.mq.put_request) 130bd166ef1SJens Axboe e->type->ops.mq.put_request(rq); 131bd166ef1SJens Axboe else 132bd166ef1SJens Axboe blk_mq_finish_request(rq); 133bd166ef1SJens Axboe } 134bd166ef1SJens Axboe 135bd166ef1SJens Axboe void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) 136bd166ef1SJens Axboe { 13781380ca1SOmar Sandoval struct request_queue *q = hctx->queue; 13881380ca1SOmar Sandoval struct elevator_queue *e = q->elevator; 13964765a75SJens Axboe const bool has_sched_dispatch = e && e->type->ops.mq.dispatch_request; 14064765a75SJens Axboe bool did_work = false; 141bd166ef1SJens Axboe LIST_HEAD(rq_list); 142bd166ef1SJens Axboe 143bd166ef1SJens Axboe if (unlikely(blk_mq_hctx_stopped(hctx))) 144bd166ef1SJens Axboe return; 145bd166ef1SJens Axboe 146bd166ef1SJens Axboe hctx->run++; 147bd166ef1SJens Axboe 148bd166ef1SJens Axboe /* 149bd166ef1SJens Axboe * If we have previous entries on our dispatch list, grab them first for 150bd166ef1SJens Axboe * more fair dispatch. 151bd166ef1SJens Axboe */ 152bd166ef1SJens Axboe if (!list_empty_careful(&hctx->dispatch)) { 153bd166ef1SJens Axboe spin_lock(&hctx->lock); 154bd166ef1SJens Axboe if (!list_empty(&hctx->dispatch)) 155bd166ef1SJens Axboe list_splice_init(&hctx->dispatch, &rq_list); 156bd166ef1SJens Axboe spin_unlock(&hctx->lock); 157bd166ef1SJens Axboe } 158bd166ef1SJens Axboe 159bd166ef1SJens Axboe /* 160bd166ef1SJens Axboe * Only ask the scheduler for requests, if we didn't have residual 161bd166ef1SJens Axboe * requests from the dispatch list. This is to avoid the case where 162bd166ef1SJens Axboe * we only ever dispatch a fraction of the requests available because 163bd166ef1SJens Axboe * of low device queue depth. Once we pull requests out of the IO 164bd166ef1SJens Axboe * scheduler, we can no longer merge or sort them. So it's best to 165bd166ef1SJens Axboe * leave them there for as long as we can. Mark the hw queue as 166bd166ef1SJens Axboe * needing a restart in that case. 167bd166ef1SJens Axboe */ 168c13660a0SJens Axboe if (!list_empty(&rq_list)) { 169d38d3515SOmar Sandoval blk_mq_sched_mark_restart_hctx(hctx); 17081380ca1SOmar Sandoval did_work = blk_mq_dispatch_rq_list(q, &rq_list); 17164765a75SJens Axboe } else if (!has_sched_dispatch) { 172c13660a0SJens Axboe blk_mq_flush_busy_ctxs(hctx, &rq_list); 17381380ca1SOmar Sandoval blk_mq_dispatch_rq_list(q, &rq_list); 17464765a75SJens Axboe } 17564765a75SJens Axboe 17664765a75SJens Axboe /* 17764765a75SJens Axboe * We want to dispatch from the scheduler if we had no work left 17864765a75SJens Axboe * on the dispatch list, OR if we did have work but weren't able 17964765a75SJens Axboe * to make progress. 18064765a75SJens Axboe */ 18164765a75SJens Axboe if (!did_work && has_sched_dispatch) { 182c13660a0SJens Axboe do { 183c13660a0SJens Axboe struct request *rq; 184c13660a0SJens Axboe 185c13660a0SJens Axboe rq = e->type->ops.mq.dispatch_request(hctx); 186c13660a0SJens Axboe if (!rq) 187c13660a0SJens Axboe break; 188c13660a0SJens Axboe list_add(&rq->queuelist, &rq_list); 18981380ca1SOmar Sandoval } while (blk_mq_dispatch_rq_list(q, &rq_list)); 190c13660a0SJens Axboe } 191bd166ef1SJens Axboe } 192bd166ef1SJens Axboe 193bd166ef1SJens Axboe void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, 194bd166ef1SJens Axboe struct list_head *rq_list, 195bd166ef1SJens Axboe struct request *(*get_rq)(struct blk_mq_hw_ctx *)) 196bd166ef1SJens Axboe { 197bd166ef1SJens Axboe do { 198bd166ef1SJens Axboe struct request *rq; 199bd166ef1SJens Axboe 200bd166ef1SJens Axboe rq = get_rq(hctx); 201bd166ef1SJens Axboe if (!rq) 202bd166ef1SJens Axboe break; 203bd166ef1SJens Axboe 204bd166ef1SJens Axboe list_add_tail(&rq->queuelist, rq_list); 205bd166ef1SJens Axboe } while (1); 206bd166ef1SJens Axboe } 207bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_move_to_dispatch); 208bd166ef1SJens Axboe 209e4d750c9SJens Axboe bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, 210e4d750c9SJens Axboe struct request **merged_request) 211bd166ef1SJens Axboe { 212bd166ef1SJens Axboe struct request *rq; 213bd166ef1SJens Axboe 21434fe7c05SChristoph Hellwig switch (elv_merge(q, &rq, bio)) { 21534fe7c05SChristoph Hellwig case ELEVATOR_BACK_MERGE: 216bd166ef1SJens Axboe if (!blk_mq_sched_allow_merge(q, rq, bio)) 217bd166ef1SJens Axboe return false; 21834fe7c05SChristoph Hellwig if (!bio_attempt_back_merge(q, rq, bio)) 21934fe7c05SChristoph Hellwig return false; 220e4d750c9SJens Axboe *merged_request = attempt_back_merge(q, rq); 221e4d750c9SJens Axboe if (!*merged_request) 22234fe7c05SChristoph Hellwig elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); 223bd166ef1SJens Axboe return true; 22434fe7c05SChristoph Hellwig case ELEVATOR_FRONT_MERGE: 225bd166ef1SJens Axboe if (!blk_mq_sched_allow_merge(q, rq, bio)) 226bd166ef1SJens Axboe return false; 22734fe7c05SChristoph Hellwig if (!bio_attempt_front_merge(q, rq, bio)) 22834fe7c05SChristoph Hellwig return false; 229e4d750c9SJens Axboe *merged_request = attempt_front_merge(q, rq); 230e4d750c9SJens Axboe if (!*merged_request) 23134fe7c05SChristoph Hellwig elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); 232bd166ef1SJens Axboe return true; 23334fe7c05SChristoph Hellwig default: 234bd166ef1SJens Axboe return false; 235bd166ef1SJens Axboe } 23634fe7c05SChristoph Hellwig } 237bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); 238bd166ef1SJens Axboe 239bd166ef1SJens Axboe bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) 240bd166ef1SJens Axboe { 241bd166ef1SJens Axboe struct elevator_queue *e = q->elevator; 242bd166ef1SJens Axboe 243bd166ef1SJens Axboe if (e->type->ops.mq.bio_merge) { 244bd166ef1SJens Axboe struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); 245bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); 246bd166ef1SJens Axboe 247bd166ef1SJens Axboe blk_mq_put_ctx(ctx); 248bd166ef1SJens Axboe return e->type->ops.mq.bio_merge(hctx, bio); 249bd166ef1SJens Axboe } 250bd166ef1SJens Axboe 251bd166ef1SJens Axboe return false; 252bd166ef1SJens Axboe } 253bd166ef1SJens Axboe 254bd166ef1SJens Axboe bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq) 255bd166ef1SJens Axboe { 256bd166ef1SJens Axboe return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq); 257bd166ef1SJens Axboe } 258bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge); 259bd166ef1SJens Axboe 260bd166ef1SJens Axboe void blk_mq_sched_request_inserted(struct request *rq) 261bd166ef1SJens Axboe { 262bd166ef1SJens Axboe trace_block_rq_insert(rq->q, rq); 263bd166ef1SJens Axboe } 264bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); 265bd166ef1SJens Axboe 2660cacba6cSOmar Sandoval static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, 2670cacba6cSOmar Sandoval struct request *rq) 268bd166ef1SJens Axboe { 269bd166ef1SJens Axboe if (rq->tag == -1) { 270bd166ef1SJens Axboe rq->rq_flags |= RQF_SORTED; 271bd166ef1SJens Axboe return false; 272bd166ef1SJens Axboe } 273bd166ef1SJens Axboe 274bd166ef1SJens Axboe /* 275bd166ef1SJens Axboe * If we already have a real request tag, send directly to 276bd166ef1SJens Axboe * the dispatch list. 277bd166ef1SJens Axboe */ 278bd166ef1SJens Axboe spin_lock(&hctx->lock); 279bd166ef1SJens Axboe list_add(&rq->queuelist, &hctx->dispatch); 280bd166ef1SJens Axboe spin_unlock(&hctx->lock); 281bd166ef1SJens Axboe return true; 282bd166ef1SJens Axboe } 283bd166ef1SJens Axboe 2846d8c6c0fSBart Van Assche static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx) 28550e1dab8SJens Axboe { 28650e1dab8SJens Axboe if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { 28750e1dab8SJens Axboe clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); 2886d8c6c0fSBart Van Assche if (blk_mq_hctx_has_pending(hctx)) { 28950e1dab8SJens Axboe blk_mq_run_hw_queue(hctx, true); 2906d8c6c0fSBart Van Assche return true; 29150e1dab8SJens Axboe } 29250e1dab8SJens Axboe } 2936d8c6c0fSBart Van Assche return false; 2946d8c6c0fSBart Van Assche } 29550e1dab8SJens Axboe 2966d8c6c0fSBart Van Assche /** 2976d8c6c0fSBart Van Assche * list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list 2986d8c6c0fSBart Van Assche * @pos: loop cursor. 2996d8c6c0fSBart Van Assche * @skip: the list element that will not be examined. Iteration starts at 3006d8c6c0fSBart Van Assche * @skip->next. 3016d8c6c0fSBart Van Assche * @head: head of the list to examine. This list must have at least one 3026d8c6c0fSBart Van Assche * element, namely @skip. 3036d8c6c0fSBart Van Assche * @member: name of the list_head structure within typeof(*pos). 3046d8c6c0fSBart Van Assche */ 3056d8c6c0fSBart Van Assche #define list_for_each_entry_rcu_rr(pos, skip, head, member) \ 3066d8c6c0fSBart Van Assche for ((pos) = (skip); \ 3076d8c6c0fSBart Van Assche (pos = (pos)->member.next != (head) ? list_entry_rcu( \ 3086d8c6c0fSBart Van Assche (pos)->member.next, typeof(*pos), member) : \ 3096d8c6c0fSBart Van Assche list_entry_rcu((pos)->member.next->next, typeof(*pos), member)), \ 3106d8c6c0fSBart Van Assche (pos) != (skip); ) 3116d8c6c0fSBart Van Assche 3126d8c6c0fSBart Van Assche /* 3136d8c6c0fSBart Van Assche * Called after a driver tag has been freed to check whether a hctx needs to 3146d8c6c0fSBart Van Assche * be restarted. Restarts @hctx if its tag set is not shared. Restarts hardware 3156d8c6c0fSBart Van Assche * queues in a round-robin fashion if the tag set of @hctx is shared with other 3166d8c6c0fSBart Van Assche * hardware queues. 3176d8c6c0fSBart Van Assche */ 3186d8c6c0fSBart Van Assche void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx) 31950e1dab8SJens Axboe { 3206d8c6c0fSBart Van Assche struct blk_mq_tags *const tags = hctx->tags; 3216d8c6c0fSBart Van Assche struct blk_mq_tag_set *const set = hctx->queue->tag_set; 3226d8c6c0fSBart Van Assche struct request_queue *const queue = hctx->queue, *q; 3236d8c6c0fSBart Van Assche struct blk_mq_hw_ctx *hctx2; 3246d8c6c0fSBart Van Assche unsigned int i, j; 32550e1dab8SJens Axboe 3266d8c6c0fSBart Van Assche if (set->flags & BLK_MQ_F_TAG_SHARED) { 3276d8c6c0fSBart Van Assche rcu_read_lock(); 3286d8c6c0fSBart Van Assche list_for_each_entry_rcu_rr(q, queue, &set->tag_list, 3296d8c6c0fSBart Van Assche tag_set_list) { 3306d8c6c0fSBart Van Assche queue_for_each_hw_ctx(q, hctx2, i) 3316d8c6c0fSBart Van Assche if (hctx2->tags == tags && 3326d8c6c0fSBart Van Assche blk_mq_sched_restart_hctx(hctx2)) 3336d8c6c0fSBart Van Assche goto done; 33450e1dab8SJens Axboe } 3356d8c6c0fSBart Van Assche j = hctx->queue_num + 1; 3366d8c6c0fSBart Van Assche for (i = 0; i < queue->nr_hw_queues; i++, j++) { 3376d8c6c0fSBart Van Assche if (j == queue->nr_hw_queues) 3386d8c6c0fSBart Van Assche j = 0; 3396d8c6c0fSBart Van Assche hctx2 = queue->queue_hw_ctx[j]; 3406d8c6c0fSBart Van Assche if (hctx2->tags == tags && 3416d8c6c0fSBart Van Assche blk_mq_sched_restart_hctx(hctx2)) 3426d8c6c0fSBart Van Assche break; 3436d8c6c0fSBart Van Assche } 3446d8c6c0fSBart Van Assche done: 3456d8c6c0fSBart Van Assche rcu_read_unlock(); 346d38d3515SOmar Sandoval } else { 347d38d3515SOmar Sandoval blk_mq_sched_restart_hctx(hctx); 348d38d3515SOmar Sandoval } 34950e1dab8SJens Axboe } 35050e1dab8SJens Axboe 351bd6737f1SJens Axboe /* 352bd6737f1SJens Axboe * Add flush/fua to the queue. If we fail getting a driver tag, then 353bd6737f1SJens Axboe * punt to the requeue list. Requeue will re-invoke us from a context 354bd6737f1SJens Axboe * that's safe to block from. 355bd6737f1SJens Axboe */ 356bd6737f1SJens Axboe static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx, 357bd6737f1SJens Axboe struct request *rq, bool can_block) 358bd6737f1SJens Axboe { 359bd6737f1SJens Axboe if (blk_mq_get_driver_tag(rq, &hctx, can_block)) { 360bd6737f1SJens Axboe blk_insert_flush(rq); 361bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, true); 362bd6737f1SJens Axboe } else 363c7a571b4SJens Axboe blk_mq_add_to_requeue_list(rq, false, true); 364bd6737f1SJens Axboe } 365bd6737f1SJens Axboe 366bd6737f1SJens Axboe void blk_mq_sched_insert_request(struct request *rq, bool at_head, 367bd6737f1SJens Axboe bool run_queue, bool async, bool can_block) 368bd6737f1SJens Axboe { 369bd6737f1SJens Axboe struct request_queue *q = rq->q; 370bd6737f1SJens Axboe struct elevator_queue *e = q->elevator; 371bd6737f1SJens Axboe struct blk_mq_ctx *ctx = rq->mq_ctx; 372bd6737f1SJens Axboe struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); 373bd6737f1SJens Axboe 374f3a8ab7dSJens Axboe if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) { 375bd6737f1SJens Axboe blk_mq_sched_insert_flush(hctx, rq, can_block); 376bd6737f1SJens Axboe return; 377bd6737f1SJens Axboe } 378bd6737f1SJens Axboe 3790cacba6cSOmar Sandoval if (e && blk_mq_sched_bypass_insert(hctx, rq)) 3800cacba6cSOmar Sandoval goto run; 3810cacba6cSOmar Sandoval 382bd6737f1SJens Axboe if (e && e->type->ops.mq.insert_requests) { 383bd6737f1SJens Axboe LIST_HEAD(list); 384bd6737f1SJens Axboe 385bd6737f1SJens Axboe list_add(&rq->queuelist, &list); 386bd6737f1SJens Axboe e->type->ops.mq.insert_requests(hctx, &list, at_head); 387bd6737f1SJens Axboe } else { 388bd6737f1SJens Axboe spin_lock(&ctx->lock); 389bd6737f1SJens Axboe __blk_mq_insert_request(hctx, rq, at_head); 390bd6737f1SJens Axboe spin_unlock(&ctx->lock); 391bd6737f1SJens Axboe } 392bd6737f1SJens Axboe 3930cacba6cSOmar Sandoval run: 394bd6737f1SJens Axboe if (run_queue) 395bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, async); 396bd6737f1SJens Axboe } 397bd6737f1SJens Axboe 398bd6737f1SJens Axboe void blk_mq_sched_insert_requests(struct request_queue *q, 399bd6737f1SJens Axboe struct blk_mq_ctx *ctx, 400bd6737f1SJens Axboe struct list_head *list, bool run_queue_async) 401bd6737f1SJens Axboe { 402bd6737f1SJens Axboe struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); 403bd6737f1SJens Axboe struct elevator_queue *e = hctx->queue->elevator; 404bd6737f1SJens Axboe 4050cacba6cSOmar Sandoval if (e) { 4060cacba6cSOmar Sandoval struct request *rq, *next; 4070cacba6cSOmar Sandoval 4080cacba6cSOmar Sandoval /* 4090cacba6cSOmar Sandoval * We bypass requests that already have a driver tag assigned, 4100cacba6cSOmar Sandoval * which should only be flushes. Flushes are only ever inserted 4110cacba6cSOmar Sandoval * as single requests, so we shouldn't ever hit the 4120cacba6cSOmar Sandoval * WARN_ON_ONCE() below (but let's handle it just in case). 4130cacba6cSOmar Sandoval */ 4140cacba6cSOmar Sandoval list_for_each_entry_safe(rq, next, list, queuelist) { 4150cacba6cSOmar Sandoval if (WARN_ON_ONCE(rq->tag != -1)) { 4160cacba6cSOmar Sandoval list_del_init(&rq->queuelist); 4170cacba6cSOmar Sandoval blk_mq_sched_bypass_insert(hctx, rq); 4180cacba6cSOmar Sandoval } 4190cacba6cSOmar Sandoval } 4200cacba6cSOmar Sandoval } 4210cacba6cSOmar Sandoval 422bd6737f1SJens Axboe if (e && e->type->ops.mq.insert_requests) 423bd6737f1SJens Axboe e->type->ops.mq.insert_requests(hctx, list, false); 424bd6737f1SJens Axboe else 425bd6737f1SJens Axboe blk_mq_insert_requests(hctx, ctx, list); 426bd6737f1SJens Axboe 427bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, run_queue_async); 428bd6737f1SJens Axboe } 429bd6737f1SJens Axboe 430bd166ef1SJens Axboe static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, 431bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx, 432bd166ef1SJens Axboe unsigned int hctx_idx) 433bd166ef1SJens Axboe { 434bd166ef1SJens Axboe if (hctx->sched_tags) { 435bd166ef1SJens Axboe blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); 436bd166ef1SJens Axboe blk_mq_free_rq_map(hctx->sched_tags); 437bd166ef1SJens Axboe hctx->sched_tags = NULL; 438bd166ef1SJens Axboe } 439bd166ef1SJens Axboe } 440bd166ef1SJens Axboe 4416917ff0bSOmar Sandoval static int blk_mq_sched_alloc_tags(struct request_queue *q, 4426917ff0bSOmar Sandoval struct blk_mq_hw_ctx *hctx, 4436917ff0bSOmar Sandoval unsigned int hctx_idx) 444bd166ef1SJens Axboe { 445bd166ef1SJens Axboe struct blk_mq_tag_set *set = q->tag_set; 4466917ff0bSOmar Sandoval int ret; 447bd166ef1SJens Axboe 4486917ff0bSOmar Sandoval hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, 4496917ff0bSOmar Sandoval set->reserved_tags); 450bd166ef1SJens Axboe if (!hctx->sched_tags) 4516917ff0bSOmar Sandoval return -ENOMEM; 4526917ff0bSOmar Sandoval 4536917ff0bSOmar Sandoval ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); 4546917ff0bSOmar Sandoval if (ret) 4556917ff0bSOmar Sandoval blk_mq_sched_free_tags(set, hctx, hctx_idx); 456bd166ef1SJens Axboe 457bd166ef1SJens Axboe return ret; 458bd166ef1SJens Axboe } 459bd166ef1SJens Axboe 46054d5329dSOmar Sandoval static void blk_mq_sched_tags_teardown(struct request_queue *q) 461bd166ef1SJens Axboe { 462bd166ef1SJens Axboe struct blk_mq_tag_set *set = q->tag_set; 463bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx; 464bd166ef1SJens Axboe int i; 465bd166ef1SJens Axboe 466bd166ef1SJens Axboe queue_for_each_hw_ctx(q, hctx, i) 467bd166ef1SJens Axboe blk_mq_sched_free_tags(set, hctx, i); 468bd166ef1SJens Axboe } 469d3484991SJens Axboe 47093252632SOmar Sandoval int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, 47193252632SOmar Sandoval unsigned int hctx_idx) 47293252632SOmar Sandoval { 47393252632SOmar Sandoval struct elevator_queue *e = q->elevator; 474ee056f98SOmar Sandoval int ret; 47593252632SOmar Sandoval 47693252632SOmar Sandoval if (!e) 47793252632SOmar Sandoval return 0; 47893252632SOmar Sandoval 479ee056f98SOmar Sandoval ret = blk_mq_sched_alloc_tags(q, hctx, hctx_idx); 480ee056f98SOmar Sandoval if (ret) 481ee056f98SOmar Sandoval return ret; 482ee056f98SOmar Sandoval 483ee056f98SOmar Sandoval if (e->type->ops.mq.init_hctx) { 484ee056f98SOmar Sandoval ret = e->type->ops.mq.init_hctx(hctx, hctx_idx); 485ee056f98SOmar Sandoval if (ret) { 486ee056f98SOmar Sandoval blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); 487ee056f98SOmar Sandoval return ret; 488ee056f98SOmar Sandoval } 489ee056f98SOmar Sandoval } 490ee056f98SOmar Sandoval 491ee056f98SOmar Sandoval return 0; 49293252632SOmar Sandoval } 49393252632SOmar Sandoval 49493252632SOmar Sandoval void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, 49593252632SOmar Sandoval unsigned int hctx_idx) 49693252632SOmar Sandoval { 49793252632SOmar Sandoval struct elevator_queue *e = q->elevator; 49893252632SOmar Sandoval 49993252632SOmar Sandoval if (!e) 50093252632SOmar Sandoval return; 50193252632SOmar Sandoval 502ee056f98SOmar Sandoval if (e->type->ops.mq.exit_hctx && hctx->sched_data) { 503ee056f98SOmar Sandoval e->type->ops.mq.exit_hctx(hctx, hctx_idx); 504ee056f98SOmar Sandoval hctx->sched_data = NULL; 505ee056f98SOmar Sandoval } 506ee056f98SOmar Sandoval 50793252632SOmar Sandoval blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); 50893252632SOmar Sandoval } 50993252632SOmar Sandoval 5106917ff0bSOmar Sandoval int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) 5116917ff0bSOmar Sandoval { 5126917ff0bSOmar Sandoval struct blk_mq_hw_ctx *hctx; 513ee056f98SOmar Sandoval struct elevator_queue *eq; 5146917ff0bSOmar Sandoval unsigned int i; 5156917ff0bSOmar Sandoval int ret; 5166917ff0bSOmar Sandoval 5176917ff0bSOmar Sandoval if (!e) { 5186917ff0bSOmar Sandoval q->elevator = NULL; 5196917ff0bSOmar Sandoval return 0; 5206917ff0bSOmar Sandoval } 5216917ff0bSOmar Sandoval 5226917ff0bSOmar Sandoval /* 5236917ff0bSOmar Sandoval * Default to 256, since we don't split into sync/async like the 5246917ff0bSOmar Sandoval * old code did. Additionally, this is a per-hw queue depth. 5256917ff0bSOmar Sandoval */ 5266917ff0bSOmar Sandoval q->nr_requests = 2 * BLKDEV_MAX_RQ; 5276917ff0bSOmar Sandoval 5286917ff0bSOmar Sandoval queue_for_each_hw_ctx(q, hctx, i) { 5296917ff0bSOmar Sandoval ret = blk_mq_sched_alloc_tags(q, hctx, i); 5306917ff0bSOmar Sandoval if (ret) 5316917ff0bSOmar Sandoval goto err; 5326917ff0bSOmar Sandoval } 5336917ff0bSOmar Sandoval 5346917ff0bSOmar Sandoval ret = e->ops.mq.init_sched(q, e); 5356917ff0bSOmar Sandoval if (ret) 5366917ff0bSOmar Sandoval goto err; 5376917ff0bSOmar Sandoval 538ee056f98SOmar Sandoval if (e->ops.mq.init_hctx) { 539ee056f98SOmar Sandoval queue_for_each_hw_ctx(q, hctx, i) { 540ee056f98SOmar Sandoval ret = e->ops.mq.init_hctx(hctx, i); 541ee056f98SOmar Sandoval if (ret) { 542ee056f98SOmar Sandoval eq = q->elevator; 543ee056f98SOmar Sandoval blk_mq_exit_sched(q, eq); 544ee056f98SOmar Sandoval kobject_put(&eq->kobj); 545ee056f98SOmar Sandoval return ret; 546ee056f98SOmar Sandoval } 547ee056f98SOmar Sandoval } 548ee056f98SOmar Sandoval } 549ee056f98SOmar Sandoval 5506917ff0bSOmar Sandoval return 0; 5516917ff0bSOmar Sandoval 5526917ff0bSOmar Sandoval err: 55354d5329dSOmar Sandoval blk_mq_sched_tags_teardown(q); 55454d5329dSOmar Sandoval q->elevator = NULL; 5556917ff0bSOmar Sandoval return ret; 5566917ff0bSOmar Sandoval } 5576917ff0bSOmar Sandoval 55854d5329dSOmar Sandoval void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) 55954d5329dSOmar Sandoval { 560ee056f98SOmar Sandoval struct blk_mq_hw_ctx *hctx; 561ee056f98SOmar Sandoval unsigned int i; 562ee056f98SOmar Sandoval 563ee056f98SOmar Sandoval if (e->type->ops.mq.exit_hctx) { 564ee056f98SOmar Sandoval queue_for_each_hw_ctx(q, hctx, i) { 565ee056f98SOmar Sandoval if (hctx->sched_data) { 566ee056f98SOmar Sandoval e->type->ops.mq.exit_hctx(hctx, i); 567ee056f98SOmar Sandoval hctx->sched_data = NULL; 568ee056f98SOmar Sandoval } 569ee056f98SOmar Sandoval } 570ee056f98SOmar Sandoval } 57154d5329dSOmar Sandoval if (e->type->ops.mq.exit_sched) 57254d5329dSOmar Sandoval e->type->ops.mq.exit_sched(e); 57354d5329dSOmar Sandoval blk_mq_sched_tags_teardown(q); 57454d5329dSOmar Sandoval q->elevator = NULL; 57554d5329dSOmar Sandoval } 57654d5329dSOmar Sandoval 577d3484991SJens Axboe int blk_mq_sched_init(struct request_queue *q) 578d3484991SJens Axboe { 579d3484991SJens Axboe int ret; 580d3484991SJens Axboe 581d3484991SJens Axboe mutex_lock(&q->sysfs_lock); 582d3484991SJens Axboe ret = elevator_init(q, NULL); 583d3484991SJens Axboe mutex_unlock(&q->sysfs_lock); 584d3484991SJens Axboe 585d3484991SJens Axboe return ret; 586d3484991SJens Axboe } 587