drivers/mmc/core/queue.c

   1 /*
   2  *  Copyright (C) 2003 Russell King, All Rights Reserved.
   3  *  Copyright 2006-2007 Pierre Ossman
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  */
  10 #include <linux/slab.h>
  11 #include <linux/module.h>
  12 #include <linux/blkdev.h>
  13 #include <linux/freezer.h>
  14 #include <linux/kthread.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/dma-mapping.h>
  17
  18 #include <linux/mmc/card.h>
  19 #include <linux/mmc/host.h>
  20
  21 #include "queue.h"
  22 #include "block.h"
  23 #include "core.h"
  24 #include "card.h"
  25 #include "host.h"
  26
  27 static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq)
  28 {
  29         /* Allow only 1 DCMD at a time */
  30         return mq->in_flight[MMC_ISSUE_DCMD];
  31 }
  32
  33 void mmc_cqe_check_busy(struct mmc_queue *mq)
  34 {
  35         if ((mq->cqe_busy & MMC_CQE_DCMD_BUSY) && !mmc_cqe_dcmd_busy(mq))
  36                 mq->cqe_busy &= ~MMC_CQE_DCMD_BUSY;
  37
  38         mq->cqe_busy &= ~MMC_CQE_QUEUE_FULL;
  39 }
  40
  41 static inline bool mmc_cqe_can_dcmd(struct mmc_host *host)
  42 {
  43         return host->caps2 & MMC_CAP2_CQE_DCMD;
  44 }
  45
  46 static enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
  47                                               struct request *req)
  48 {
  49         switch (req_op(req)) {
  50         case REQ_OP_DRV_IN:
  51         case REQ_OP_DRV_OUT:
  52         case REQ_OP_DISCARD:
  53         case REQ_OP_SECURE_ERASE:
  54                 return MMC_ISSUE_SYNC;
  55         case REQ_OP_FLUSH:
  56                 return mmc_cqe_can_dcmd(host) ? MMC_ISSUE_DCMD : MMC_ISSUE_SYNC;
  57         default:
  58                 return MMC_ISSUE_ASYNC;
  59         }
  60 }
  61
  62 enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req)
  63 {
  64         struct mmc_host *host = mq->card->host;
  65
  66         if (mq->use_cqe)
  67                 return mmc_cqe_issue_type(host, req);
  68
  69         if (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_WRITE)
  70                 return MMC_ISSUE_ASYNC;
  71
  72         return MMC_ISSUE_SYNC;
  73 }
  74
  75 static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq)
  76 {
  77         if (!mq->recovery_needed) {
  78                 mq->recovery_needed = true;
  79                 schedule_work(&mq->recovery_work);
  80         }
  81 }
  82
  83 void mmc_cqe_recovery_notifier(struct mmc_request *mrq)
  84 {
  85         struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req,
  86                                                   brq.mrq);
  87         struct request *req = mmc_queue_req_to_req(mqrq);
  88         struct request_queue *q = req->q;
  89         struct mmc_queue *mq = q->queuedata;
  90         unsigned long flags;
  91
  92         spin_lock_irqsave(q->queue_lock, flags);
  93         __mmc_cqe_recovery_notifier(mq);
  94         spin_unlock_irqrestore(q->queue_lock, flags);
  95 }
  96
  97 static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
  98 {
  99         struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
 100         struct mmc_request *mrq = &mqrq->brq.mrq;
 101         struct mmc_queue *mq = req->q->queuedata;
 102         struct mmc_host *host = mq->card->host;
 103         enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
 104         bool recovery_needed = false;
 105
 106         switch (issue_type) {
 107         case MMC_ISSUE_ASYNC:
 108         case MMC_ISSUE_DCMD:
 109                 if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) {
 110                         if (recovery_needed)
 111                                 __mmc_cqe_recovery_notifier(mq);
 112                         return BLK_EH_RESET_TIMER;
 113                 }
 114                 /* No timeout (XXX: huh? comment doesn't make much sense) */
 115                 blk_mq_complete_request(req);
 116                 return BLK_EH_DONE;
 117         default:
 118                 /* Timeout is handled by mmc core */
 119                 return BLK_EH_RESET_TIMER;
 120         }
 121 }
 122
 123 static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req,
 124                                                  bool reserved)
 125 {
 126         struct request_queue *q = req->q;
 127         struct mmc_queue *mq = q->queuedata;
 128         unsigned long flags;
 129         int ret;
 130
 131         spin_lock_irqsave(q->queue_lock, flags);
 132
 133         if (mq->recovery_needed || !mq->use_cqe)
 134                 ret = BLK_EH_RESET_TIMER;
 135         else
 136                 ret = mmc_cqe_timed_out(req);
 137
 138         spin_unlock_irqrestore(q->queue_lock, flags);
 139
 140         return ret;
 141 }
 142
 143 static void mmc_mq_recovery_handler(struct work_struct *work)
 144 {
 145         struct mmc_queue *mq = container_of(work, struct mmc_queue,
 146                                             recovery_work);
 147         struct request_queue *q = mq->queue;
 148
 149         mmc_get_card(mq->card, &mq->ctx);
 150
 151         mq->in_recovery = true;
 152
 153         if (mq->use_cqe)
 154                 mmc_blk_cqe_recovery(mq);
 155         else
 156                 mmc_blk_mq_recovery(mq);
 157
 158         mq->in_recovery = false;
 159
 160         spin_lock_irq(q->queue_lock);
 161         mq->recovery_needed = false;
 162         spin_unlock_irq(q->queue_lock);
 163
 164         mmc_put_card(mq->card, &mq->ctx);
 165
 166         blk_mq_run_hw_queues(q, true);
 167 }
 168
 169 static struct scatterlist *mmc_alloc_sg(int sg_len, gfp_t gfp)
 170 {
 171         struct scatterlist *sg;
 172
 173         sg = kmalloc_array(sg_len, sizeof(*sg), gfp);
 174         if (sg)
 175                 sg_init_table(sg, sg_len);
 176
 177         return sg;
 178 }
 179
 180 static void mmc_queue_setup_discard(struct request_queue *q,
 181                                     struct mmc_card *card)
 182 {
 183         unsigned max_discard;
 184
 185         max_discard = mmc_calc_max_discard(card);
 186         if (!max_discard)
 187                 return;
 188
 189         blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
 190         blk_queue_max_discard_sectors(q, max_discard);
 191         q->limits.discard_granularity = card->pref_erase << 9;
 192         /* granularity must not be greater than max. discard */
 193         if (card->pref_erase > max_discard)
 194                 q->limits.discard_granularity = 0;
 195         if (mmc_can_secure_erase_trim(card))
 196                 blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
 197 }
 198
 199 /**
 200  * mmc_init_request() - initialize the MMC-specific per-request data
 201  * @q: the request queue
 202  * @req: the request
 203  * @gfp: memory allocation policy
 204  */
 205 static int __mmc_init_request(struct mmc_queue *mq, struct request *req,
 206                               gfp_t gfp)
 207 {
 208         struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
 209         struct mmc_card *card = mq->card;
 210         struct mmc_host *host = card->host;
 211
 212         mq_rq->sg = mmc_alloc_sg(host->max_segs, gfp);
 213         if (!mq_rq->sg)
 214                 return -ENOMEM;
 215
 216         return 0;
 217 }
 218
 219 static void mmc_exit_request(struct request_queue *q, struct request *req)
 220 {
 221         struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
 222
 223         kfree(mq_rq->sg);
 224         mq_rq->sg = NULL;
 225 }
 226
 227 static int mmc_mq_init_request(struct blk_mq_tag_set *set, struct request *req,
 228                                unsigned int hctx_idx, unsigned int numa_node)
 229 {
 230         return __mmc_init_request(set->driver_data, req, GFP_KERNEL);
 231 }
 232
 233 static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request *req,
 234                                 unsigned int hctx_idx)
 235 {
 236         struct mmc_queue *mq = set->driver_data;
 237
 238         mmc_exit_request(mq->queue, req);
 239 }
 240
 241 static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
 242                                     const struct blk_mq_queue_data *bd)
 243 {
 244         struct request *req = bd->rq;
 245         struct request_queue *q = req->q;
 246         struct mmc_queue *mq = q->queuedata;
 247         struct mmc_card *card = mq->card;
 248         struct mmc_host *host = card->host;
 249         enum mmc_issue_type issue_type;
 250         enum mmc_issued issued;
 251         bool get_card, cqe_retune_ok;
 252         int ret;
 253
 254         if (mmc_card_removed(mq->card)) {
 255                 req->rq_flags |= RQF_QUIET;
 256                 return BLK_STS_IOERR;
 257         }
 258
 259         issue_type = mmc_issue_type(mq, req);
 260
 261         spin_lock_irq(q->queue_lock);
 262
 263         if (mq->recovery_needed || mq->busy) {
 264                 spin_unlock_irq(q->queue_lock);
 265                 return BLK_STS_RESOURCE;
 266         }
 267
 268         switch (issue_type) {
 269         case MMC_ISSUE_DCMD:
 270                 if (mmc_cqe_dcmd_busy(mq)) {
 271                         mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
 272                         spin_unlock_irq(q->queue_lock);
 273                         return BLK_STS_RESOURCE;
 274                 }
 275                 break;
 276         case MMC_ISSUE_ASYNC:
 277                 break;
 278         default:
 279                 /*
 280                  * Timeouts are handled by mmc core, and we don't have a host
 281                  * API to abort requests, so we can't handle the timeout anyway.
 282                  * However, when the timeout happens, blk_mq_complete_request()
 283                  * no longer works (to stop the request disappearing under us).
 284                  * To avoid racing with that, set a large timeout.
 285                  */
 286                 req->timeout = 600 * HZ;
 287                 break;
 288         }
 289
 290         /* Parallel dispatch of requests is not supported at the moment */
 291         mq->busy = true;
 292
 293         mq->in_flight[issue_type] += 1;
 294         get_card = (mmc_tot_in_flight(mq) == 1);
 295         cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);
 296
 297         spin_unlock_irq(q->queue_lock);
 298
 299         if (!(req->rq_flags & RQF_DONTPREP)) {
 300                 req_to_mmc_queue_req(req)->retries = 0;
 301                 req->rq_flags |= RQF_DONTPREP;
 302         }
 303
 304         if (get_card)
 305                 mmc_get_card(card, &mq->ctx);
 306
 307         if (mq->use_cqe) {
 308                 host->retune_now = host->need_retune && cqe_retune_ok &&
 309                                    !host->hold_retune;
 310         }
 311
 312         blk_mq_start_request(req);
 313
 314         issued = mmc_blk_mq_issue_rq(mq, req);
 315
 316         switch (issued) {
 317         case MMC_REQ_BUSY:
 318                 ret = BLK_STS_RESOURCE;
 319                 break;
 320         case MMC_REQ_FAILED_TO_START:
 321                 ret = BLK_STS_IOERR;
 322                 break;
 323         default:
 324                 ret = BLK_STS_OK;
 325                 break;
 326         }
 327
 328         if (issued != MMC_REQ_STARTED) {
 329                 bool put_card = false;
 330
 331                 spin_lock_irq(q->queue_lock);
 332                 mq->in_flight[issue_type] -= 1;
 333                 if (mmc_tot_in_flight(mq) == 0)
 334                         put_card = true;
 335                 mq->busy = false;
 336                 spin_unlock_irq(q->queue_lock);
 337                 if (put_card)
 338                         mmc_put_card(card, &mq->ctx);
 339         } else {
 340                 WRITE_ONCE(mq->busy, false);
 341         }
 342
 343         return ret;
 344 }
 345
 346 static const struct blk_mq_ops mmc_mq_ops = {
 347         .queue_rq       = mmc_mq_queue_rq,
 348         .init_request   = mmc_mq_init_request,
 349         .exit_request   = mmc_mq_exit_request,
 350         .complete       = mmc_blk_mq_complete,
 351         .timeout        = mmc_mq_timed_out,
 352 };
 353
 354 static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 355 {
 356         struct mmc_host *host = card->host;
 357         u64 limit = BLK_BOUNCE_HIGH;
 358
 359         if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 360                 limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
 361
 362         blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
 363         blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 364         if (mmc_can_erase(card))
 365                 mmc_queue_setup_discard(mq->queue, card);
 366
 367         blk_queue_bounce_limit(mq->queue, limit);
 368         blk_queue_max_hw_sectors(mq->queue,
 369                 min(host->max_blk_count, host->max_req_size / 512));
 370         blk_queue_max_segments(mq->queue, host->max_segs);
 371         blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 372
 373         INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
 374         INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
 375
 376         mutex_init(&mq->complete_lock);
 377
 378         init_waitqueue_head(&mq->wait);
 379 }
 380
 381 static int mmc_mq_init_queue(struct mmc_queue *mq, int q_depth,
 382                              const struct blk_mq_ops *mq_ops, spinlock_t *lock)
 383 {
 384         int ret;
 385
 386         memset(&mq->tag_set, 0, sizeof(mq->tag_set));
 387         mq->tag_set.ops = mq_ops;
 388         mq->tag_set.queue_depth = q_depth;
 389         mq->tag_set.numa_node = NUMA_NO_NODE;
 390         mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE |
 391                             BLK_MQ_F_BLOCKING;
 392         mq->tag_set.nr_hw_queues = 1;
 393         mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
 394         mq->tag_set.driver_data = mq;
 395
 396         ret = blk_mq_alloc_tag_set(&mq->tag_set);
 397         if (ret)
 398                 return ret;
 399
 400         mq->queue = blk_mq_init_queue(&mq->tag_set);
 401         if (IS_ERR(mq->queue)) {
 402                 ret = PTR_ERR(mq->queue);
 403                 goto free_tag_set;
 404         }
 405
 406         mq->queue->queue_lock = lock;
 407         mq->queue->queuedata = mq;
 408
 409         return 0;
 410
 411 free_tag_set:
 412         blk_mq_free_tag_set(&mq->tag_set);
 413
 414         return ret;
 415 }
 416
 417 /* Set queue depth to get a reasonable value for q->nr_requests */
 418 #define MMC_QUEUE_DEPTH 64
 419
 420 static int mmc_mq_init(struct mmc_queue *mq, struct mmc_card *card,
 421                          spinlock_t *lock)
 422 {
 423         struct mmc_host *host = card->host;
 424         int q_depth;
 425         int ret;
 426
 427         /*
 428          * The queue depth for CQE must match the hardware because the request
 429          * tag is used to index the hardware queue.
 430          */
 431         if (mq->use_cqe)
 432                 q_depth = min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
 433         else
 434                 q_depth = MMC_QUEUE_DEPTH;
 435
 436         ret = mmc_mq_init_queue(mq, q_depth, &mmc_mq_ops, lock);
 437         if (ret)
 438                 return ret;
 439
 440         blk_queue_rq_timeout(mq->queue, 60 * HZ);
 441
 442         mmc_setup_queue(mq, card);
 443
 444         return 0;
 445 }
 446
 447 /**
 448  * mmc_init_queue - initialise a queue structure.
 449  * @mq: mmc queue
 450  * @card: mmc card to attach this queue
 451  * @lock: queue lock
 452  * @subname: partition subname
 453  *
 454  * Initialise a MMC card request queue.
 455  */
 456 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 457                    spinlock_t *lock, const char *subname)
 458 {
 459         struct mmc_host *host = card->host;
 460
 461         mq->card = card;
 462
 463         mq->use_cqe = host->cqe_enabled;
 464
 465         return mmc_mq_init(mq, card, lock);
 466 }
 467
 468 void mmc_queue_suspend(struct mmc_queue *mq)
 469 {
 470         blk_mq_quiesce_queue(mq->queue);
 471
 472         /*
 473          * The host remains claimed while there are outstanding requests, so
 474          * simply claiming and releasing here ensures there are none.
 475          */
 476         mmc_claim_host(mq->card->host);
 477         mmc_release_host(mq->card->host);
 478 }
 479
 480 void mmc_queue_resume(struct mmc_queue *mq)
 481 {
 482         blk_mq_unquiesce_queue(mq->queue);
 483 }
 484
 485 void mmc_cleanup_queue(struct mmc_queue *mq)
 486 {
 487         struct request_queue *q = mq->queue;
 488
 489         /*
 490          * The legacy code handled the possibility of being suspended,
 491          * so do that here too.
 492          */
 493         if (blk_queue_quiesced(q))
 494                 blk_mq_unquiesce_queue(q);
 495
 496         blk_cleanup_queue(q);
 497
 498         /*
 499          * A request can be completed before the next request, potentially
 500          * leaving a complete_work with nothing to do. Such a work item might
 501          * still be queued at this point. Flush it.
 502          */
 503         flush_work(&mq->complete_work);
 504
 505         mq->card = NULL;
 506 }
 507
 508 /*
 509  * Prepare the sg list(s) to be handed of to the host driver
 510  */
 511 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
 512 {
 513         struct request *req = mmc_queue_req_to_req(mqrq);
 514
 515         return blk_rq_map_sg(mq->queue, req, mqrq->sg);
 516 }