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)
  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         unsigned long flags;
 128         int ret;
 129
 130         spin_lock_irqsave(&mq->lock, flags);
 131
 132         if (mq->recovery_needed || !mq->use_cqe)
 133                 ret = BLK_EH_RESET_TIMER;
 134         else
 135                 ret = mmc_cqe_timed_out(req);
 136
 137         spin_unlock_irqrestore(&mq->lock, flags);
 138
 139         return ret;
 140 }
 141
 142 static void mmc_mq_recovery_handler(struct work_struct *work)
 143 {
 144         struct mmc_queue *mq = container_of(work, struct mmc_queue,
 145                                             recovery_work);
 146         struct request_queue *q = mq->queue;
 147
 148         mmc_get_card(mq->card, &mq->ctx);
 149
 150         mq->in_recovery = true;
 151
 152         if (mq->use_cqe)
 153                 mmc_blk_cqe_recovery(mq);
 154         else
 155                 mmc_blk_mq_recovery(mq);
 156
 157         mq->in_recovery = false;
 158
 159         spin_lock_irq(&mq->lock);
 160         mq->recovery_needed = false;
 161         spin_unlock_irq(&mq->lock);
 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 = 0;
 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  * @q: 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                 break;
 283         default:
 284                 /*
 285                  * Timeouts are handled by mmc core, and we don't have a host
 286                  * API to abort requests, so we can't handle the timeout anyway.
 287                  * However, when the timeout happens, blk_mq_complete_request()
 288                  * no longer works (to stop the request disappearing under us).
 289                  * To avoid racing with that, set a large timeout.
 290                  */
 291                 req->timeout = 600 * HZ;
 292                 break;
 293         }
 294
 295         /* Parallel dispatch of requests is not supported at the moment */
 296         mq->busy = true;
 297
 298         mq->in_flight[issue_type] += 1;
 299         get_card = (mmc_tot_in_flight(mq) == 1);
 300         cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);
 301
 302         spin_unlock_irq(&mq->lock);
 303
 304         if (!(req->rq_flags & RQF_DONTPREP)) {
 305                 req_to_mmc_queue_req(req)->retries = 0;
 306                 req->rq_flags |= RQF_DONTPREP;
 307         }
 308
 309         if (get_card)
 310                 mmc_get_card(card, &mq->ctx);
 311
 312         if (mq->use_cqe) {
 313                 host->retune_now = host->need_retune && cqe_retune_ok &&
 314                                    !host->hold_retune;
 315         }
 316
 317         blk_mq_start_request(req);
 318
 319         issued = mmc_blk_mq_issue_rq(mq, req);
 320
 321         switch (issued) {
 322         case MMC_REQ_BUSY:
 323                 ret = BLK_STS_RESOURCE;
 324                 break;
 325         case MMC_REQ_FAILED_TO_START:
 326                 ret = BLK_STS_IOERR;
 327                 break;
 328         default:
 329                 ret = BLK_STS_OK;
 330                 break;
 331         }
 332
 333         if (issued != MMC_REQ_STARTED) {
 334                 bool put_card = false;
 335
 336                 spin_lock_irq(&mq->lock);
 337                 mq->in_flight[issue_type] -= 1;
 338                 if (mmc_tot_in_flight(mq) == 0)
 339                         put_card = true;
 340                 mq->busy = false;
 341                 spin_unlock_irq(&mq->lock);
 342                 if (put_card)
 343                         mmc_put_card(card, &mq->ctx);
 344         } else {
 345                 WRITE_ONCE(mq->busy, false);
 346         }
 347
 348         return ret;
 349 }
 350
 351 static const struct blk_mq_ops mmc_mq_ops = {
 352         .queue_rq       = mmc_mq_queue_rq,
 353         .init_request   = mmc_mq_init_request,
 354         .exit_request   = mmc_mq_exit_request,
 355         .complete       = mmc_blk_mq_complete,
 356         .timeout        = mmc_mq_timed_out,
 357 };
 358
 359 static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 360 {
 361         struct mmc_host *host = card->host;
 362         unsigned block_size = 512;
 363
 364         blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
 365         blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 366         if (mmc_can_erase(card))
 367                 mmc_queue_setup_discard(mq->queue, card);
 368
 369         if (!mmc_dev(host)->dma_mask || !*mmc_dev(host)->dma_mask)
 370                 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
 371         blk_queue_max_hw_sectors(mq->queue,
 372                 min(host->max_blk_count, host->max_req_size / 512));
 373         if (host->can_dma_map_merge)
 374                 WARN(!blk_queue_can_use_dma_map_merging(mq->queue,
 375                                                         mmc_dev(host)),
 376                      "merging was advertised but not possible");
 377         blk_queue_max_segments(mq->queue, mmc_get_max_segments(host));
 378
 379         if (mmc_card_mmc(card))
 380                 block_size = card->ext_csd.data_sector_size;
 381
 382         blk_queue_logical_block_size(mq->queue, block_size);
 383         /*
 384          * After blk_queue_can_use_dma_map_merging() was called with succeed,
 385          * since it calls blk_queue_virt_boundary(), the mmc should not call
 386          * both blk_queue_max_segment_size().
 387          */
 388         if (!host->can_dma_map_merge)
 389                 blk_queue_max_segment_size(mq->queue,
 390                         round_down(host->max_seg_size, block_size));
 391
 392         dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));
 393
 394         INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
 395         INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
 396
 397         mutex_init(&mq->complete_lock);
 398
 399         init_waitqueue_head(&mq->wait);
 400 }
 401
 402 static inline bool mmc_merge_capable(struct mmc_host *host)
 403 {
 404         return host->caps2 & MMC_CAP2_MERGE_CAPABLE;
 405 }
 406
 407 /* Set queue depth to get a reasonable value for q->nr_requests */
 408 #define MMC_QUEUE_DEPTH 64
 409
 410 /**
 411  * mmc_init_queue - initialise a queue structure.
 412  * @mq: mmc queue
 413  * @card: mmc card to attach this queue
 414  *
 415  * Initialise a MMC card request queue.
 416  */
 417 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
 418 {
 419         struct mmc_host *host = card->host;
 420         int ret;
 421
 422         mq->card = card;
 423         mq->use_cqe = host->cqe_enabled;
 424
 425         spin_lock_init(&mq->lock);
 426
 427         memset(&mq->tag_set, 0, sizeof(mq->tag_set));
 428         mq->tag_set.ops = &mmc_mq_ops;
 429         /*
 430          * The queue depth for CQE must match the hardware because the request
 431          * tag is used to index the hardware queue.
 432          */
 433         if (mq->use_cqe)
 434                 mq->tag_set.queue_depth =
 435                         min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
 436         else
 437                 mq->tag_set.queue_depth = MMC_QUEUE_DEPTH;
 438         mq->tag_set.numa_node = NUMA_NO_NODE;
 439         mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING;
 440         mq->tag_set.nr_hw_queues = 1;
 441         mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
 442         mq->tag_set.driver_data = mq;
 443
 444         /*
 445          * Since blk_mq_alloc_tag_set() calls .init_request() of mmc_mq_ops,
 446          * the host->can_dma_map_merge should be set before to get max_segs
 447          * from mmc_get_max_segments().
 448          */
 449         if (mmc_merge_capable(host) &&
 450             host->max_segs < MMC_DMA_MAP_MERGE_SEGMENTS &&
 451             dma_get_merge_boundary(mmc_dev(host)))
 452                 host->can_dma_map_merge = 1;
 453         else
 454                 host->can_dma_map_merge = 0;
 455
 456         ret = blk_mq_alloc_tag_set(&mq->tag_set);
 457         if (ret)
 458                 return ret;
 459
 460         mq->queue = blk_mq_init_queue(&mq->tag_set);
 461         if (IS_ERR(mq->queue)) {
 462                 ret = PTR_ERR(mq->queue);
 463                 goto free_tag_set;
 464         }
 465
 466         if (mmc_host_is_spi(host) && host->use_spi_crc)
 467                 mq->queue->backing_dev_info->capabilities |=
 468                         BDI_CAP_STABLE_WRITES;
 469
 470         mq->queue->queuedata = mq;
 471         blk_queue_rq_timeout(mq->queue, 60 * HZ);
 472
 473         mmc_setup_queue(mq, card);
 474         return 0;
 475
 476 free_tag_set:
 477         blk_mq_free_tag_set(&mq->tag_set);
 478         return ret;
 479 }
 480
 481 void mmc_queue_suspend(struct mmc_queue *mq)
 482 {
 483         blk_mq_quiesce_queue(mq->queue);
 484
 485         /*
 486          * The host remains claimed while there are outstanding requests, so
 487          * simply claiming and releasing here ensures there are none.
 488          */
 489         mmc_claim_host(mq->card->host);
 490         mmc_release_host(mq->card->host);
 491 }
 492
 493 void mmc_queue_resume(struct mmc_queue *mq)
 494 {
 495         blk_mq_unquiesce_queue(mq->queue);
 496 }
 497
 498 void mmc_cleanup_queue(struct mmc_queue *mq)
 499 {
 500         struct request_queue *q = mq->queue;
 501
 502         /*
 503          * The legacy code handled the possibility of being suspended,
 504          * so do that here too.
 505          */
 506         if (blk_queue_quiesced(q))
 507                 blk_mq_unquiesce_queue(q);
 508
 509         blk_cleanup_queue(q);
 510         blk_mq_free_tag_set(&mq->tag_set);
 511
 512         /*
 513          * A request can be completed before the next request, potentially
 514          * leaving a complete_work with nothing to do. Such a work item might
 515          * still be queued at this point. Flush it.
 516          */
 517         flush_work(&mq->complete_work);
 518
 519         mq->card = NULL;
 520 }
 521
 522 /*
 523  * Prepare the sg list(s) to be handed of to the host driver
 524  */
 525 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
 526 {
 527         struct request *req = mmc_queue_req_to_req(mqrq);
 528
 529         return blk_rq_map_sg(mq->queue, req, mqrq->sg);
 530 }