drivers/mmc/card/queue.c

   1 /*
   2  *  linux/drivers/mmc/card/queue.c
   3  *
   4  *  Copyright (C) 2003 Russell King, All Rights Reserved.
   5  *  Copyright 2006-2007 Pierre Ossman
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  */
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include <linux/blkdev.h>
  15 #include <linux/freezer.h>
  16 #include <linux/kthread.h>
  17 #include <linux/scatterlist.h>
  18 #include <linux/dma-mapping.h>
  19
  20 #include <linux/mmc/card.h>
  21 #include <linux/mmc/host.h>
  22 #include "queue.h"
  23
  24 #define MMC_QUEUE_BOUNCESZ      65536
  25
  26 /*
  27  * Prepare a MMC request. This just filters out odd stuff.
  28  */
  29 static int mmc_prep_request(struct request_queue *q, struct request *req)
  30 {
  31         struct mmc_queue *mq = q->queuedata;
  32
  33         /*
  34          * We only like normal block requests and discards.
  35          */
  36         if (req->cmd_type != REQ_TYPE_FS && req_op(req) != REQ_OP_DISCARD) {
  37                 blk_dump_rq_flags(req, "MMC bad request");
  38                 return BLKPREP_KILL;
  39         }
  40
  41         if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
  42                 return BLKPREP_KILL;
  43
  44         req->cmd_flags |= REQ_DONTPREP;
  45
  46         return BLKPREP_OK;
  47 }
  48
  49 static int mmc_queue_thread(void *d)
  50 {
  51         struct mmc_queue *mq = d;
  52         struct request_queue *q = mq->queue;
  53
  54         current->flags |= PF_MEMALLOC;
  55
  56         down(&mq->thread_sem);
  57         do {
  58                 struct request *req = NULL;
  59
  60                 spin_lock_irq(q->queue_lock);
  61                 set_current_state(TASK_INTERRUPTIBLE);
  62                 req = blk_fetch_request(q);
  63                 mq->mqrq_cur->req = req;
  64                 spin_unlock_irq(q->queue_lock);
  65
  66                 if (req || mq->mqrq_prev->req) {
  67                         set_current_state(TASK_RUNNING);
  68                         mq->issue_fn(mq, req);
  69                         cond_resched();
  70                         if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
  71                                 mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
  72                                 continue; /* fetch again */
  73                         }
  74
  75                         /*
  76                          * Current request becomes previous request
  77                          * and vice versa.
  78                          * In case of special requests, current request
  79                          * has been finished. Do not assign it to previous
  80                          * request.
  81                          */
  82                         if (mmc_req_is_special(req))
  83                                 mq->mqrq_cur->req = NULL;
  84
  85                         mq->mqrq_prev->brq.mrq.data = NULL;
  86                         mq->mqrq_prev->req = NULL;
  87                         swap(mq->mqrq_prev, mq->mqrq_cur);
  88                 } else {
  89                         if (kthread_should_stop()) {
  90                                 set_current_state(TASK_RUNNING);
  91                                 break;
  92                         }
  93                         up(&mq->thread_sem);
  94                         schedule();
  95                         down(&mq->thread_sem);
  96                 }
  97         } while (1);
  98         up(&mq->thread_sem);
  99
 100         return 0;
 101 }
 102
 103 /*
 104  * Generic MMC request handler.  This is called for any queue on a
 105  * particular host.  When the host is not busy, we look for a request
 106  * on any queue on this host, and attempt to issue it.  This may
 107  * not be the queue we were asked to process.
 108  */
 109 static void mmc_request_fn(struct request_queue *q)
 110 {
 111         struct mmc_queue *mq = q->queuedata;
 112         struct request *req;
 113         unsigned long flags;
 114         struct mmc_context_info *cntx;
 115
 116         if (!mq) {
 117                 while ((req = blk_fetch_request(q)) != NULL) {
 118                         req->cmd_flags |= REQ_QUIET;
 119                         __blk_end_request_all(req, -EIO);
 120                 }
 121                 return;
 122         }
 123
 124         cntx = &mq->card->host->context_info;
 125         if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
 126                 /*
 127                  * New MMC request arrived when MMC thread may be
 128                  * blocked on the previous request to be complete
 129                  * with no current request fetched
 130                  */
 131                 spin_lock_irqsave(&cntx->lock, flags);
 132                 if (cntx->is_waiting_last_req) {
 133                         cntx->is_new_req = true;
 134                         wake_up_interruptible(&cntx->wait);
 135                 }
 136                 spin_unlock_irqrestore(&cntx->lock, flags);
 137         } else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
 138                 wake_up_process(mq->thread);
 139 }
 140
 141 static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
 142 {
 143         struct scatterlist *sg;
 144
 145         sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
 146         if (!sg)
 147                 *err = -ENOMEM;
 148         else {
 149                 *err = 0;
 150                 sg_init_table(sg, sg_len);
 151         }
 152
 153         return sg;
 154 }
 155
 156 static void mmc_queue_setup_discard(struct request_queue *q,
 157                                     struct mmc_card *card)
 158 {
 159         unsigned max_discard;
 160
 161         max_discard = mmc_calc_max_discard(card);
 162         if (!max_discard)
 163                 return;
 164
 165         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 166         blk_queue_max_discard_sectors(q, max_discard);
 167         if (card->erased_byte == 0 && !mmc_can_discard(card))
 168                 q->limits.discard_zeroes_data = 1;
 169         q->limits.discard_granularity = card->pref_erase << 9;
 170         /* granularity must not be greater than max. discard */
 171         if (card->pref_erase > max_discard)
 172                 q->limits.discard_granularity = 0;
 173         if (mmc_can_secure_erase_trim(card))
 174                 queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q);
 175 }
 176
 177 /**
 178  * mmc_init_queue - initialise a queue structure.
 179  * @mq: mmc queue
 180  * @card: mmc card to attach this queue
 181  * @lock: queue lock
 182  * @subname: partition subname
 183  *
 184  * Initialise a MMC card request queue.
 185  */
 186 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 187                    spinlock_t *lock, const char *subname)
 188 {
 189         struct mmc_host *host = card->host;
 190         u64 limit = BLK_BOUNCE_HIGH;
 191         int ret;
 192         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 193         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 194
 195         if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 196                 limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
 197
 198         mq->card = card;
 199         mq->queue = blk_init_queue(mmc_request_fn, lock);
 200         if (!mq->queue)
 201                 return -ENOMEM;
 202
 203         mq->mqrq_cur = mqrq_cur;
 204         mq->mqrq_prev = mqrq_prev;
 205         mq->queue->queuedata = mq;
 206
 207         blk_queue_prep_rq(mq->queue, mmc_prep_request);
 208         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
 209         queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 210         if (mmc_can_erase(card))
 211                 mmc_queue_setup_discard(mq->queue, card);
 212
 213 #ifdef CONFIG_MMC_BLOCK_BOUNCE
 214         if (host->max_segs == 1) {
 215                 unsigned int bouncesz;
 216
 217                 bouncesz = MMC_QUEUE_BOUNCESZ;
 218
 219                 if (bouncesz > host->max_req_size)
 220                         bouncesz = host->max_req_size;
 221                 if (bouncesz > host->max_seg_size)
 222                         bouncesz = host->max_seg_size;
 223                 if (bouncesz > (host->max_blk_count * 512))
 224                         bouncesz = host->max_blk_count * 512;
 225
 226                 if (bouncesz > 512) {
 227                         mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
 228                         if (!mqrq_cur->bounce_buf) {
 229                                 pr_warn("%s: unable to allocate bounce cur buffer\n",
 230                                         mmc_card_name(card));
 231                         } else {
 232                                 mqrq_prev->bounce_buf =
 233                                                 kmalloc(bouncesz, GFP_KERNEL);
 234                                 if (!mqrq_prev->bounce_buf) {
 235                                         pr_warn("%s: unable to allocate bounce prev buffer\n",
 236                                                 mmc_card_name(card));
 237                                         kfree(mqrq_cur->bounce_buf);
 238                                         mqrq_cur->bounce_buf = NULL;
 239                                 }
 240                         }
 241                 }
 242
 243                 if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
 244                         blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
 245                         blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
 246                         blk_queue_max_segments(mq->queue, bouncesz / 512);
 247                         blk_queue_max_segment_size(mq->queue, bouncesz);
 248
 249                         mqrq_cur->sg = mmc_alloc_sg(1, &ret);
 250                         if (ret)
 251                                 goto cleanup_queue;
 252
 253                         mqrq_cur->bounce_sg =
 254                                 mmc_alloc_sg(bouncesz / 512, &ret);
 255                         if (ret)
 256                                 goto cleanup_queue;
 257
 258                         mqrq_prev->sg = mmc_alloc_sg(1, &ret);
 259                         if (ret)
 260                                 goto cleanup_queue;
 261
 262                         mqrq_prev->bounce_sg =
 263                                 mmc_alloc_sg(bouncesz / 512, &ret);
 264                         if (ret)
 265                                 goto cleanup_queue;
 266                 }
 267         }
 268 #endif
 269
 270         if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
 271                 blk_queue_bounce_limit(mq->queue, limit);
 272                 blk_queue_max_hw_sectors(mq->queue,
 273                         min(host->max_blk_count, host->max_req_size / 512));
 274                 blk_queue_max_segments(mq->queue, host->max_segs);
 275                 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 276
 277                 mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
 278                 if (ret)
 279                         goto cleanup_queue;
 280
 281
 282                 mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
 283                 if (ret)
 284                         goto cleanup_queue;
 285         }
 286
 287         sema_init(&mq->thread_sem, 1);
 288
 289         mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
 290                 host->index, subname ? subname : "");
 291
 292         if (IS_ERR(mq->thread)) {
 293                 ret = PTR_ERR(mq->thread);
 294                 goto free_bounce_sg;
 295         }
 296
 297         return 0;
 298  free_bounce_sg:
 299         kfree(mqrq_cur->bounce_sg);
 300         mqrq_cur->bounce_sg = NULL;
 301         kfree(mqrq_prev->bounce_sg);
 302         mqrq_prev->bounce_sg = NULL;
 303
 304  cleanup_queue:
 305         kfree(mqrq_cur->sg);
 306         mqrq_cur->sg = NULL;
 307         kfree(mqrq_cur->bounce_buf);
 308         mqrq_cur->bounce_buf = NULL;
 309
 310         kfree(mqrq_prev->sg);
 311         mqrq_prev->sg = NULL;
 312         kfree(mqrq_prev->bounce_buf);
 313         mqrq_prev->bounce_buf = NULL;
 314
 315         blk_cleanup_queue(mq->queue);
 316         return ret;
 317 }
 318
 319 void mmc_cleanup_queue(struct mmc_queue *mq)
 320 {
 321         struct request_queue *q = mq->queue;
 322         unsigned long flags;
 323         struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
 324         struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
 325
 326         /* Make sure the queue isn't suspended, as that will deadlock */
 327         mmc_queue_resume(mq);
 328
 329         /* Then terminate our worker thread */
 330         kthread_stop(mq->thread);
 331
 332         /* Empty the queue */
 333         spin_lock_irqsave(q->queue_lock, flags);
 334         q->queuedata = NULL;
 335         blk_start_queue(q);
 336         spin_unlock_irqrestore(q->queue_lock, flags);
 337
 338         kfree(mqrq_cur->bounce_sg);
 339         mqrq_cur->bounce_sg = NULL;
 340
 341         kfree(mqrq_cur->sg);
 342         mqrq_cur->sg = NULL;
 343
 344         kfree(mqrq_cur->bounce_buf);
 345         mqrq_cur->bounce_buf = NULL;
 346
 347         kfree(mqrq_prev->bounce_sg);
 348         mqrq_prev->bounce_sg = NULL;
 349
 350         kfree(mqrq_prev->sg);
 351         mqrq_prev->sg = NULL;
 352
 353         kfree(mqrq_prev->bounce_buf);
 354         mqrq_prev->bounce_buf = NULL;
 355
 356         mq->card = NULL;
 357 }
 358 EXPORT_SYMBOL(mmc_cleanup_queue);
 359
 360 int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
 361 {
 362         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 363         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 364         int ret = 0;
 365
 366
 367         mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
 368         if (!mqrq_cur->packed) {
 369                 pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
 370                         mmc_card_name(card));
 371                 ret = -ENOMEM;
 372                 goto out;
 373         }
 374
 375         mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
 376         if (!mqrq_prev->packed) {
 377                 pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
 378                         mmc_card_name(card));
 379                 kfree(mqrq_cur->packed);
 380                 mqrq_cur->packed = NULL;
 381                 ret = -ENOMEM;
 382                 goto out;
 383         }
 384
 385         INIT_LIST_HEAD(&mqrq_cur->packed->list);
 386         INIT_LIST_HEAD(&mqrq_prev->packed->list);
 387
 388 out:
 389         return ret;
 390 }
 391
 392 void mmc_packed_clean(struct mmc_queue *mq)
 393 {
 394         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 395         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 396
 397         kfree(mqrq_cur->packed);
 398         mqrq_cur->packed = NULL;
 399         kfree(mqrq_prev->packed);
 400         mqrq_prev->packed = NULL;
 401 }
 402
 403 /**
 404  * mmc_queue_suspend - suspend a MMC request queue
 405  * @mq: MMC queue to suspend
 406  *
 407  * Stop the block request queue, and wait for our thread to
 408  * complete any outstanding requests.  This ensures that we
 409  * won't suspend while a request is being processed.
 410  */
 411 void mmc_queue_suspend(struct mmc_queue *mq)
 412 {
 413         struct request_queue *q = mq->queue;
 414         unsigned long flags;
 415
 416         if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
 417                 mq->flags |= MMC_QUEUE_SUSPENDED;
 418
 419                 spin_lock_irqsave(q->queue_lock, flags);
 420                 blk_stop_queue(q);
 421                 spin_unlock_irqrestore(q->queue_lock, flags);
 422
 423                 down(&mq->thread_sem);
 424         }
 425 }
 426
 427 /**
 428  * mmc_queue_resume - resume a previously suspended MMC request queue
 429  * @mq: MMC queue to resume
 430  */
 431 void mmc_queue_resume(struct mmc_queue *mq)
 432 {
 433         struct request_queue *q = mq->queue;
 434         unsigned long flags;
 435
 436         if (mq->flags & MMC_QUEUE_SUSPENDED) {
 437                 mq->flags &= ~MMC_QUEUE_SUSPENDED;
 438
 439                 up(&mq->thread_sem);
 440
 441                 spin_lock_irqsave(q->queue_lock, flags);
 442                 blk_start_queue(q);
 443                 spin_unlock_irqrestore(q->queue_lock, flags);
 444         }
 445 }
 446
 447 static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
 448                                             struct mmc_packed *packed,
 449                                             struct scatterlist *sg,
 450                                             enum mmc_packed_type cmd_type)
 451 {
 452         struct scatterlist *__sg = sg;
 453         unsigned int sg_len = 0;
 454         struct request *req;
 455
 456         if (mmc_packed_wr(cmd_type)) {
 457                 unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
 458                 unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
 459                 unsigned int len, remain, offset = 0;
 460                 u8 *buf = (u8 *)packed->cmd_hdr;
 461
 462                 remain = hdr_sz;
 463                 do {
 464                         len = min(remain, max_seg_sz);
 465                         sg_set_buf(__sg, buf + offset, len);
 466                         offset += len;
 467                         remain -= len;
 468                         sg_unmark_end(__sg++);
 469                         sg_len++;
 470                 } while (remain);
 471         }
 472
 473         list_for_each_entry(req, &packed->list, queuelist) {
 474                 sg_len += blk_rq_map_sg(mq->queue, req, __sg);
 475                 __sg = sg + (sg_len - 1);
 476                 sg_unmark_end(__sg++);
 477         }
 478         sg_mark_end(sg + (sg_len - 1));
 479         return sg_len;
 480 }
 481
 482 /*
 483  * Prepare the sg list(s) to be handed of to the host driver
 484  */
 485 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
 486 {
 487         unsigned int sg_len;
 488         size_t buflen;
 489         struct scatterlist *sg;
 490         enum mmc_packed_type cmd_type;
 491         int i;
 492
 493         cmd_type = mqrq->cmd_type;
 494
 495         if (!mqrq->bounce_buf) {
 496                 if (mmc_packed_cmd(cmd_type))
 497                         return mmc_queue_packed_map_sg(mq, mqrq->packed,
 498                                                        mqrq->sg, cmd_type);
 499                 else
 500                         return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
 501         }
 502
 503         BUG_ON(!mqrq->bounce_sg);
 504
 505         if (mmc_packed_cmd(cmd_type))
 506                 sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
 507                                                  mqrq->bounce_sg, cmd_type);
 508         else
 509                 sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
 510
 511         mqrq->bounce_sg_len = sg_len;
 512
 513         buflen = 0;
 514         for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
 515                 buflen += sg->length;
 516
 517         sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
 518
 519         return 1;
 520 }
 521
 522 /*
 523  * If writing, bounce the data to the buffer before the request
 524  * is sent to the host driver
 525  */
 526 void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
 527 {
 528         if (!mqrq->bounce_buf)
 529                 return;
 530
 531         if (rq_data_dir(mqrq->req) != WRITE)
 532                 return;
 533
 534         sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
 535                 mqrq->bounce_buf, mqrq->sg[0].length);
 536 }
 537
 538 /*
 539  * If reading, bounce the data from the buffer after the request
 540  * has been handled by the host driver
 541  */
 542 void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
 543 {
 544         if (!mqrq->bounce_buf)
 545                 return;
 546
 547         if (rq_data_dir(mqrq->req) != READ)
 548                 return;
 549
 550         sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
 551                 mqrq->bounce_buf, mqrq->sg[0].length);
 552 }