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 */
 115                 return BLK_EH_HANDLED;
 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(q->queue_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(q->queue_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(q->queue_lock);
 160         mq->recovery_needed = false;
 161         spin_unlock_irq(q->queue_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         queue_flag_set_unlocked(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                 queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q);
 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(host->max_segs, 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 /*
 241  * We use BLK_MQ_F_BLOCKING and have only 1 hardware queue, which means requests
 242  * will not be dispatched in parallel.
 243  */
 244 static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
 245                                     const struct blk_mq_queue_data *bd)
 246 {
 247         struct request *req = bd->rq;
 248         struct request_queue *q = req->q;
 249         struct mmc_queue *mq = q->queuedata;
 250         struct mmc_card *card = mq->card;
 251         struct mmc_host *host = card->host;
 252         enum mmc_issue_type issue_type;
 253         enum mmc_issued issued;
 254         bool get_card, cqe_retune_ok;
 255         int ret;
 256
 257         if (mmc_card_removed(mq->card)) {
 258                 req->rq_flags |= RQF_QUIET;
 259                 return BLK_STS_IOERR;
 260         }
 261
 262         issue_type = mmc_issue_type(mq, req);
 263
 264         spin_lock_irq(q->queue_lock);
 265
 266         if (mq->recovery_needed) {
 267                 spin_unlock_irq(q->queue_lock);
 268                 return BLK_STS_RESOURCE;
 269         }
 270
 271         switch (issue_type) {
 272         case MMC_ISSUE_DCMD:
 273                 if (mmc_cqe_dcmd_busy(mq)) {
 274                         mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
 275                         spin_unlock_irq(q->queue_lock);
 276                         return BLK_STS_RESOURCE;
 277                 }
 278                 break;
 279         case MMC_ISSUE_ASYNC:
 280                 break;
 281         default:
 282                 /*
 283                  * Timeouts are handled by mmc core, and we don't have a host
 284                  * API to abort requests, so we can't handle the timeout anyway.
 285                  * However, when the timeout happens, blk_mq_complete_request()
 286                  * no longer works (to stop the request disappearing under us).
 287                  * To avoid racing with that, set a large timeout.
 288                  */
 289                 req->timeout = 600 * HZ;
 290                 break;
 291         }
 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                 spin_unlock_irq(q->queue_lock);
 336                 if (put_card)
 337                         mmc_put_card(card, &mq->ctx);
 338         }
 339
 340         return ret;
 341 }
 342
 343 static const struct blk_mq_ops mmc_mq_ops = {
 344         .queue_rq       = mmc_mq_queue_rq,
 345         .init_request   = mmc_mq_init_request,
 346         .exit_request   = mmc_mq_exit_request,
 347         .complete       = mmc_blk_mq_complete,
 348         .timeout        = mmc_mq_timed_out,
 349 };
 350
 351 static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 352 {
 353         struct mmc_host *host = card->host;
 354         u64 limit = BLK_BOUNCE_HIGH;
 355
 356         if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 357                 limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
 358
 359         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
 360         queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 361         if (mmc_can_erase(card))
 362                 mmc_queue_setup_discard(mq->queue, card);
 363
 364         blk_queue_bounce_limit(mq->queue, limit);
 365         blk_queue_max_hw_sectors(mq->queue,
 366                 min(host->max_blk_count, host->max_req_size / 512));
 367         blk_queue_max_segments(mq->queue, host->max_segs);
 368         blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 369
 370         INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
 371         INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
 372
 373         mutex_init(&mq->complete_lock);
 374
 375         init_waitqueue_head(&mq->wait);
 376 }
 377
 378 static int mmc_mq_init_queue(struct mmc_queue *mq, int q_depth,
 379                              const struct blk_mq_ops *mq_ops, spinlock_t *lock)
 380 {
 381         int ret;
 382
 383         memset(&mq->tag_set, 0, sizeof(mq->tag_set));
 384         mq->tag_set.ops = mq_ops;
 385         mq->tag_set.queue_depth = q_depth;
 386         mq->tag_set.numa_node = NUMA_NO_NODE;
 387         mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE |
 388                             BLK_MQ_F_BLOCKING;
 389         mq->tag_set.nr_hw_queues = 1;
 390         mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
 391         mq->tag_set.driver_data = mq;
 392
 393         ret = blk_mq_alloc_tag_set(&mq->tag_set);
 394         if (ret)
 395                 return ret;
 396
 397         mq->queue = blk_mq_init_queue(&mq->tag_set);
 398         if (IS_ERR(mq->queue)) {
 399                 ret = PTR_ERR(mq->queue);
 400                 goto free_tag_set;
 401         }
 402
 403         mq->queue->queue_lock = lock;
 404         mq->queue->queuedata = mq;
 405
 406         return 0;
 407
 408 free_tag_set:
 409         blk_mq_free_tag_set(&mq->tag_set);
 410
 411         return ret;
 412 }
 413
 414 /* Set queue depth to get a reasonable value for q->nr_requests */
 415 #define MMC_QUEUE_DEPTH 64
 416
 417 static int mmc_mq_init(struct mmc_queue *mq, struct mmc_card *card,
 418                          spinlock_t *lock)
 419 {
 420         struct mmc_host *host = card->host;
 421         int q_depth;
 422         int ret;
 423
 424         /*
 425          * The queue depth for CQE must match the hardware because the request
 426          * tag is used to index the hardware queue.
 427          */
 428         if (mq->use_cqe)
 429                 q_depth = min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
 430         else
 431                 q_depth = MMC_QUEUE_DEPTH;
 432
 433         ret = mmc_mq_init_queue(mq, q_depth, &mmc_mq_ops, lock);
 434         if (ret)
 435                 return ret;
 436
 437         blk_queue_rq_timeout(mq->queue, 60 * HZ);
 438
 439         mmc_setup_queue(mq, card);
 440
 441         return 0;
 442 }
 443
 444 /**
 445  * mmc_init_queue - initialise a queue structure.
 446  * @mq: mmc queue
 447  * @card: mmc card to attach this queue
 448  * @lock: queue lock
 449  * @subname: partition subname
 450  *
 451  * Initialise a MMC card request queue.
 452  */
 453 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 454                    spinlock_t *lock, const char *subname)
 455 {
 456         struct mmc_host *host = card->host;
 457
 458         mq->card = card;
 459
 460         mq->use_cqe = host->cqe_enabled;
 461
 462         return mmc_mq_init(mq, card, lock);
 463 }
 464
 465 void mmc_queue_suspend(struct mmc_queue *mq)
 466 {
 467         blk_mq_quiesce_queue(mq->queue);
 468
 469         /*
 470          * The host remains claimed while there are outstanding requests, so
 471          * simply claiming and releasing here ensures there are none.
 472          */
 473         mmc_claim_host(mq->card->host);
 474         mmc_release_host(mq->card->host);
 475 }
 476
 477 void mmc_queue_resume(struct mmc_queue *mq)
 478 {
 479         blk_mq_unquiesce_queue(mq->queue);
 480 }
 481
 482 void mmc_cleanup_queue(struct mmc_queue *mq)
 483 {
 484         struct request_queue *q = mq->queue;
 485
 486         /*
 487          * The legacy code handled the possibility of being suspended,
 488          * so do that here too.
 489          */
 490         if (blk_queue_quiesced(q))
 491                 blk_mq_unquiesce_queue(q);
 492
 493         blk_cleanup_queue(q);
 494
 495         /*
 496          * A request can be completed before the next request, potentially
 497          * leaving a complete_work with nothing to do. Such a work item might
 498          * still be queued at this point. Flush it.
 499          */
 500         flush_work(&mq->complete_work);
 501
 502         mq->card = NULL;
 503 }
 504
 505 /*
 506  * Prepare the sg list(s) to be handed of to the host driver
 507  */
 508 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
 509 {
 510         struct request *req = mmc_queue_req_to_req(mqrq);
 511
 512         return blk_rq_map_sg(mq->queue, req, mqrq->sg);
 513 }