drivers/mmc/core/queue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Copyright (C) 2003 Russell King, All Rights Reserved.
   4  *  Copyright 2006-2007 Pierre Ossman
   5  */
   6 #include <linux/slab.h>
   7 #include <linux/module.h>
   8 #include <linux/blkdev.h>
   9 #include <linux/freezer.h>
  10 #include <linux/kthread.h>
  11 #include <linux/scatterlist.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/backing-dev.h>
  14
  15 #include <linux/mmc/card.h>
  16 #include <linux/mmc/host.h>
  17
  18 #include "queue.h"
  19 #include "block.h"
  20 #include "core.h"
  21 #include "card.h"
  22 #include "host.h"
  23
  24 #define MMC_DMA_MAP_MERGE_SEGMENTS      512
  25
  26 static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq)
  27 {
  28         /* Allow only 1 DCMD at a time */
  29         return mq->in_flight[MMC_ISSUE_DCMD];
  30 }
  31
  32 void mmc_cqe_check_busy(struct mmc_queue *mq)
  33 {
  34         if ((mq->cqe_busy & MMC_CQE_DCMD_BUSY) && !mmc_cqe_dcmd_busy(mq))
  35                 mq->cqe_busy &= ~MMC_CQE_DCMD_BUSY;
  36
  37         mq->cqe_busy &= ~MMC_CQE_QUEUE_FULL;
  38 }
  39
  40 static inline bool mmc_cqe_can_dcmd(struct mmc_host *host)
  41 {
  42         return host->caps2 & MMC_CAP2_CQE_DCMD;
  43 }
  44
  45 static enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
  46                                               struct request *req)
  47 {
  48         switch (req_op(req)) {
  49         case REQ_OP_DRV_IN:
  50         case REQ_OP_DRV_OUT:
  51         case REQ_OP_DISCARD:
  52         case REQ_OP_SECURE_ERASE:
  53                 return MMC_ISSUE_SYNC;
  54         case REQ_OP_FLUSH:
  55                 return mmc_cqe_can_dcmd(host) ? MMC_ISSUE_DCMD : MMC_ISSUE_SYNC;
  56         default:
  57                 return MMC_ISSUE_ASYNC;
  58         }
  59 }
  60
  61 enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req)
  62 {
  63         struct mmc_host *host = mq->card->host;
  64
  65         if (mq->use_cqe && !host->hsq_enabled)
  66                 return mmc_cqe_issue_type(host, req);
  67
  68         if (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_WRITE)
  69                 return MMC_ISSUE_ASYNC;
  70
  71         return MMC_ISSUE_SYNC;
  72 }
  73
  74 static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq)
  75 {
  76         if (!mq->recovery_needed) {
  77                 mq->recovery_needed = true;
  78                 schedule_work(&mq->recovery_work);
  79         }
  80 }
  81
  82 void mmc_cqe_recovery_notifier(struct mmc_request *mrq)
  83 {
  84         struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req,
  85                                                   brq.mrq);
  86         struct request *req = mmc_queue_req_to_req(mqrq);
  87         struct request_queue *q = req->q;
  88         struct mmc_queue *mq = q->queuedata;
  89         unsigned long flags;
  90
  91         spin_lock_irqsave(&mq->lock, flags);
  92         __mmc_cqe_recovery_notifier(mq);
  93         spin_unlock_irqrestore(&mq->lock, flags);
  94 }
  95
  96 static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
  97 {
  98         struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
  99         struct mmc_request *mrq = &mqrq->brq.mrq;
 100         struct mmc_queue *mq = req->q->queuedata;
 101         struct mmc_host *host = mq->card->host;
 102         enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
 103         bool recovery_needed = false;
 104
 105         switch (issue_type) {
 106         case MMC_ISSUE_ASYNC:
 107         case MMC_ISSUE_DCMD:
 108                 if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) {
 109                         if (recovery_needed)
 110                                 __mmc_cqe_recovery_notifier(mq);
 111                         return BLK_EH_RESET_TIMER;
 112                 }
 113                 /* No timeout (XXX: huh? comment doesn't make much sense) */
 114                 blk_mq_complete_request(req);
 115                 return BLK_EH_DONE;
 116         default:
 117                 /* Timeout is handled by mmc core */
 118                 return BLK_EH_RESET_TIMER;
 119         }
 120 }
 121
 122 static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req,
 123                                                  bool reserved)
 124 {
 125         struct request_queue *q = req->q;
 126         struct mmc_queue *mq = q->queuedata;
 127         struct mmc_card *card = mq->card;
 128         struct mmc_host *host = card->host;
 129         unsigned long flags;
 130         int ret;
 131
 132         spin_lock_irqsave(&mq->lock, flags);
 133
 134         if (mq->recovery_needed || !mq->use_cqe || host->hsq_enabled)
 135                 ret = BLK_EH_RESET_TIMER;
 136         else
 137                 ret = mmc_cqe_timed_out(req);
 138
 139         spin_unlock_irqrestore(&mq->lock, flags);
 140
 141         return ret;
 142 }
 143
 144 static void mmc_mq_recovery_handler(struct work_struct *work)
 145 {
 146         struct mmc_queue *mq = container_of(work, struct mmc_queue,
 147                                             recovery_work);
 148         struct request_queue *q = mq->queue;
 149         struct mmc_host *host = mq->card->host;
 150
 151         mmc_get_card(mq->card, &mq->ctx);
 152
 153         mq->in_recovery = true;
 154
 155         if (mq->use_cqe && !host->hsq_enabled)
 156                 mmc_blk_cqe_recovery(mq);
 157         else
 158                 mmc_blk_mq_recovery(mq);
 159
 160         mq->in_recovery = false;
 161
 162         spin_lock_irq(&mq->lock);
 163         mq->recovery_needed = false;
 164         spin_unlock_irq(&mq->lock);
 165
 166         if (host->hsq_enabled)
 167                 host->cqe_ops->cqe_recovery_finish(host);
 168
 169         mmc_put_card(mq->card, &mq->ctx);
 170
 171         blk_mq_run_hw_queues(q, true);
 172 }
 173
 174 static struct scatterlist *mmc_alloc_sg(int sg_len, gfp_t gfp)
 175 {
 176         struct scatterlist *sg;
 177
 178         sg = kmalloc_array(sg_len, sizeof(*sg), gfp);
 179         if (sg)
 180                 sg_init_table(sg, sg_len);
 181
 182         return sg;
 183 }
 184
 185 static void mmc_queue_setup_discard(struct request_queue *q,
 186                                     struct mmc_card *card)
 187 {
 188         unsigned max_discard;
 189
 190         max_discard = mmc_calc_max_discard(card);
 191         if (!max_discard)
 192                 return;
 193
 194         blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
 195         blk_queue_max_discard_sectors(q, max_discard);
 196         q->limits.discard_granularity = card->pref_erase << 9;
 197         /* granularity must not be greater than max. discard */
 198         if (card->pref_erase > max_discard)
 199                 q->limits.discard_granularity = 0;
 200         if (mmc_can_secure_erase_trim(card))
 201                 blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
 202 }
 203
 204 static unsigned int mmc_get_max_segments(struct mmc_host *host)
 205 {
 206         return host->can_dma_map_merge ? MMC_DMA_MAP_MERGE_SEGMENTS :
 207                                          host->max_segs;
 208 }
 209
 210 /**
 211  * mmc_init_request() - initialize the MMC-specific per-request data
 212  * @q: the request queue
 213  * @req: the request
 214  * @gfp: memory allocation policy
 215  */
 216 static int __mmc_init_request(struct mmc_queue *mq, struct request *req,
 217                               gfp_t gfp)
 218 {
 219         struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
 220         struct mmc_card *card = mq->card;
 221         struct mmc_host *host = card->host;
 222
 223         mq_rq->sg = mmc_alloc_sg(mmc_get_max_segments(host), gfp);
 224         if (!mq_rq->sg)
 225                 return -ENOMEM;
 226
 227         return 0;
 228 }
 229
 230 static void mmc_exit_request(struct request_queue *q, struct request *req)
 231 {
 232         struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
 233
 234         kfree(mq_rq->sg);
 235         mq_rq->sg = NULL;
 236 }
 237
 238 static int mmc_mq_init_request(struct blk_mq_tag_set *set, struct request *req,
 239                                unsigned int hctx_idx, unsigned int numa_node)
 240 {
 241         return __mmc_init_request(set->driver_data, req, GFP_KERNEL);
 242 }
 243
 244 static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request *req,
 245                                 unsigned int hctx_idx)
 246 {
 247         struct mmc_queue *mq = set->driver_data;
 248
 249         mmc_exit_request(mq->queue, req);
 250 }
 251
 252 static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
 253                                     const struct blk_mq_queue_data *bd)
 254 {
 255         struct request *req = bd->rq;
 256         struct request_queue *q = req->q;
 257         struct mmc_queue *mq = q->queuedata;
 258         struct mmc_card *card = mq->card;
 259         struct mmc_host *host = card->host;
 260         enum mmc_issue_type issue_type;
 261         enum mmc_issued issued;
 262         bool get_card, cqe_retune_ok;
 263         int ret;
 264
 265         if (mmc_card_removed(mq->card)) {
 266                 req->rq_flags |= RQF_QUIET;
 267                 return BLK_STS_IOERR;
 268         }
 269
 270         issue_type = mmc_issue_type(mq, req);
 271
 272         spin_lock_irq(&mq->lock);
 273
 274         if (mq->recovery_needed || mq->busy) {
 275                 spin_unlock_irq(&mq->lock);
 276                 return BLK_STS_RESOURCE;
 277         }
 278
 279         switch (issue_type) {
 280         case MMC_ISSUE_DCMD:
 281                 if (mmc_cqe_dcmd_busy(mq)) {
 282                         mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
 283                         spin_unlock_irq(&mq->lock);
 284                         return BLK_STS_RESOURCE;
 285                 }
 286                 break;
 287         case MMC_ISSUE_ASYNC:
 288                 /*
 289                  * For MMC host software queue, we only allow 2 requests in
 290                  * flight to avoid a long latency.
 291                  */
 292                 if (host->hsq_enabled && mq->in_flight[issue_type] > 2) {
 293                         spin_unlock_irq(&mq->lock);
 294                         return BLK_STS_RESOURCE;
 295                 }
 296                 break;
 297         default:
 298                 /*
 299                  * Timeouts are handled by mmc core, and we don't have a host
 300                  * API to abort requests, so we can't handle the timeout anyway.
 301                  * However, when the timeout happens, blk_mq_complete_request()
 302                  * no longer works (to stop the request disappearing under us).
 303                  * To avoid racing with that, set a large timeout.
 304                  */
 305                 req->timeout = 600 * HZ;
 306                 break;
 307         }
 308
 309         /* Parallel dispatch of requests is not supported at the moment */
 310         mq->busy = true;
 311
 312         mq->in_flight[issue_type] += 1;
 313         get_card = (mmc_tot_in_flight(mq) == 1);
 314         cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);
 315
 316         spin_unlock_irq(&mq->lock);
 317
 318         if (!(req->rq_flags & RQF_DONTPREP)) {
 319                 req_to_mmc_queue_req(req)->retries = 0;
 320                 req->rq_flags |= RQF_DONTPREP;
 321         }
 322
 323         if (get_card)
 324                 mmc_get_card(card, &mq->ctx);
 325
 326         if (mq->use_cqe) {
 327                 host->retune_now = host->need_retune && cqe_retune_ok &&
 328                                    !host->hold_retune;
 329         }
 330
 331         blk_mq_start_request(req);
 332
 333         issued = mmc_blk_mq_issue_rq(mq, req);
 334
 335         switch (issued) {
 336         case MMC_REQ_BUSY:
 337                 ret = BLK_STS_RESOURCE;
 338                 break;
 339         case MMC_REQ_FAILED_TO_START:
 340                 ret = BLK_STS_IOERR;
 341                 break;
 342         default:
 343                 ret = BLK_STS_OK;
 344                 break;
 345         }
 346
 347         if (issued != MMC_REQ_STARTED) {
 348                 bool put_card = false;
 349
 350                 spin_lock_irq(&mq->lock);
 351                 mq->in_flight[issue_type] -= 1;
 352                 if (mmc_tot_in_flight(mq) == 0)
 353                         put_card = true;
 354                 mq->busy = false;
 355                 spin_unlock_irq(&mq->lock);
 356                 if (put_card)
 357                         mmc_put_card(card, &mq->ctx);
 358         } else {
 359                 WRITE_ONCE(mq->busy, false);
 360         }
 361
 362         return ret;
 363 }
 364
 365 static const struct blk_mq_ops mmc_mq_ops = {
 366         .queue_rq       = mmc_mq_queue_rq,
 367         .init_request   = mmc_mq_init_request,
 368         .exit_request   = mmc_mq_exit_request,
 369         .complete       = mmc_blk_mq_complete,
 370         .timeout        = mmc_mq_timed_out,
 371 };
 372
 373 static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 374 {
 375         struct mmc_host *host = card->host;
 376         unsigned block_size = 512;
 377
 378         blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
 379         blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 380         if (mmc_can_erase(card))
 381                 mmc_queue_setup_discard(mq->queue, card);
 382
 383         if (!mmc_dev(host)->dma_mask || !*mmc_dev(host)->dma_mask)
 384                 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
 385         blk_queue_max_hw_sectors(mq->queue,
 386                 min(host->max_blk_count, host->max_req_size / 512));
 387         if (host->can_dma_map_merge)
 388                 WARN(!blk_queue_can_use_dma_map_merging(mq->queue,
 389                                                         mmc_dev(host)),
 390                      "merging was advertised but not possible");
 391         blk_queue_max_segments(mq->queue, mmc_get_max_segments(host));
 392
 393         if (mmc_card_mmc(card))
 394                 block_size = card->ext_csd.data_sector_size;
 395
 396         blk_queue_logical_block_size(mq->queue, block_size);
 397         /*
 398          * After blk_queue_can_use_dma_map_merging() was called with succeed,
 399          * since it calls blk_queue_virt_boundary(), the mmc should not call
 400          * both blk_queue_max_segment_size().
 401          */
 402         if (!host->can_dma_map_merge)
 403                 blk_queue_max_segment_size(mq->queue,
 404                         round_down(host->max_seg_size, block_size));
 405
 406         dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));
 407
 408         INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
 409         INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
 410
 411         mutex_init(&mq->complete_lock);
 412
 413         init_waitqueue_head(&mq->wait);
 414 }
 415
 416 static inline bool mmc_merge_capable(struct mmc_host *host)
 417 {
 418         return host->caps2 & MMC_CAP2_MERGE_CAPABLE;
 419 }
 420
 421 /* Set queue depth to get a reasonable value for q->nr_requests */
 422 #define MMC_QUEUE_DEPTH 64
 423
 424 /**
 425  * mmc_init_queue - initialise a queue structure.
 426  * @mq: mmc queue
 427  * @card: mmc card to attach this queue
 428  *
 429  * Initialise a MMC card request queue.
 430  */
 431 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
 432 {
 433         struct mmc_host *host = card->host;
 434         int ret;
 435
 436         mq->card = card;
 437         mq->use_cqe = host->cqe_enabled;
 438
 439         spin_lock_init(&mq->lock);
 440
 441         memset(&mq->tag_set, 0, sizeof(mq->tag_set));
 442         mq->tag_set.ops = &mmc_mq_ops;
 443         /*
 444          * The queue depth for CQE must match the hardware because the request
 445          * tag is used to index the hardware queue.
 446          */
 447         if (mq->use_cqe && !host->hsq_enabled)
 448                 mq->tag_set.queue_depth =
 449                         min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
 450         else
 451                 mq->tag_set.queue_depth = MMC_QUEUE_DEPTH;
 452         mq->tag_set.numa_node = NUMA_NO_NODE;
 453         mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING;
 454         mq->tag_set.nr_hw_queues = 1;
 455         mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
 456         mq->tag_set.driver_data = mq;
 457
 458         /*
 459          * Since blk_mq_alloc_tag_set() calls .init_request() of mmc_mq_ops,
 460          * the host->can_dma_map_merge should be set before to get max_segs
 461          * from mmc_get_max_segments().
 462          */
 463         if (mmc_merge_capable(host) &&
 464             host->max_segs < MMC_DMA_MAP_MERGE_SEGMENTS &&
 465             dma_get_merge_boundary(mmc_dev(host)))
 466                 host->can_dma_map_merge = 1;
 467         else
 468                 host->can_dma_map_merge = 0;
 469
 470         ret = blk_mq_alloc_tag_set(&mq->tag_set);
 471         if (ret)
 472                 return ret;
 473
 474         mq->queue = blk_mq_init_queue(&mq->tag_set);
 475         if (IS_ERR(mq->queue)) {
 476                 ret = PTR_ERR(mq->queue);
 477                 goto free_tag_set;
 478         }
 479
 480         if (mmc_host_is_spi(host) && host->use_spi_crc)
 481                 mq->queue->backing_dev_info->capabilities |=
 482                         BDI_CAP_STABLE_WRITES;
 483
 484         mq->queue->queuedata = mq;
 485         blk_queue_rq_timeout(mq->queue, 60 * HZ);
 486
 487         mmc_setup_queue(mq, card);
 488         return 0;
 489
 490 free_tag_set:
 491         blk_mq_free_tag_set(&mq->tag_set);
 492         return ret;
 493 }
 494
 495 void mmc_queue_suspend(struct mmc_queue *mq)
 496 {
 497         blk_mq_quiesce_queue(mq->queue);
 498
 499         /*
 500          * The host remains claimed while there are outstanding requests, so
 501          * simply claiming and releasing here ensures there are none.
 502          */
 503         mmc_claim_host(mq->card->host);
 504         mmc_release_host(mq->card->host);
 505 }
 506
 507 void mmc_queue_resume(struct mmc_queue *mq)
 508 {
 509         blk_mq_unquiesce_queue(mq->queue);
 510 }
 511
 512 void mmc_cleanup_queue(struct mmc_queue *mq)
 513 {
 514         struct request_queue *q = mq->queue;
 515
 516         /*
 517          * The legacy code handled the possibility of being suspended,
 518          * so do that here too.
 519          */
 520         if (blk_queue_quiesced(q))
 521                 blk_mq_unquiesce_queue(q);
 522
 523         blk_cleanup_queue(q);
 524         blk_mq_free_tag_set(&mq->tag_set);
 525
 526         /*
 527          * A request can be completed before the next request, potentially
 528          * leaving a complete_work with nothing to do. Such a work item might
 529          * still be queued at this point. Flush it.
 530          */
 531         flush_work(&mq->complete_work);
 532
 533         mq->card = NULL;
 534 }
 535
 536 /*
 537  * Prepare the sg list(s) to be handed of to the host driver
 538  */
 539 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
 540 {
 541         struct request *req = mmc_queue_req_to_req(mqrq);
 542
 543         return blk_rq_map_sg(mq->queue, req, mqrq->sg);
 544 }