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