root/drivers/mmc/core/queue.c

DEFINITIONS

1. mmc_cqe_dcmd_busy
2. mmc_cqe_check_busy
3. mmc_cqe_can_dcmd
4. mmc_cqe_issue_type
5. __mmc_cqe_recovery_notifier
6. mmc_cqe_recovery_notifier
7. mmc_cqe_timed_out
8. mmc_mq_timed_out
9. mmc_mq_recovery_handler
10. mmc_alloc_sg
11. mmc_queue_setup_discard
12. mmc_get_max_segments
13. __mmc_init_request
14. mmc_exit_request
15. mmc_mq_init_request
16. mmc_mq_exit_request
17. mmc_mq_queue_rq
18. mmc_setup_queue
19. mmc_merge_capable
20. mmc_init_queue
21. mmc_queue_suspend
22. mmc_queue_resume
23. mmc_cleanup_queue
24. mmc_queue_map_sg

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