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->cmd_flags & REQ_DISCARD)) {
  37                 blk_dump_rq_flags(req, "MMC bad request");
  38                 return BLKPREP_KILL;
  39         }
  40
  41         if (mq && mmc_card_removed(mq->card))
  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                 struct mmc_queue_req *tmp;
  60                 unsigned int cmd_flags = 0;
  61
  62                 spin_lock_irq(q->queue_lock);
  63                 set_current_state(TASK_INTERRUPTIBLE);
  64                 req = blk_fetch_request(q);
  65                 mq->mqrq_cur->req = req;
  66                 spin_unlock_irq(q->queue_lock);
  67
  68                 if (req || mq->mqrq_prev->req) {
  69                         set_current_state(TASK_RUNNING);
  70                         cmd_flags = req ? req->cmd_flags : 0;
  71                         mq->issue_fn(mq, req);
  72                         if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
  73                                 mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
  74                                 continue; /* fetch again */
  75                         }
  76
  77                         /*
  78                          * Current request becomes previous request
  79                          * and vice versa.
  80                          * In case of special requests, current request
  81                          * has been finished. Do not assign it to previous
  82                          * request.
  83                          */
  84                         if (cmd_flags & MMC_REQ_SPECIAL_MASK)
  85                                 mq->mqrq_cur->req = NULL;
  86
  87                         mq->mqrq_prev->brq.mrq.data = NULL;
  88                         mq->mqrq_prev->req = NULL;
  89                         tmp = mq->mqrq_prev;
  90                         mq->mqrq_prev = mq->mqrq_cur;
  91                         mq->mqrq_cur = tmp;
  92                 } else {
  93                         if (kthread_should_stop()) {
  94                                 set_current_state(TASK_RUNNING);
  95                                 break;
  96                         }
  97                         up(&mq->thread_sem);
  98                         schedule();
  99                         down(&mq->thread_sem);
 100                 }
 101         } while (1);
 102         up(&mq->thread_sem);
 103
 104         return 0;
 105 }
 106
 107 /*
 108  * Generic MMC request handler.  This is called for any queue on a
 109  * particular host.  When the host is not busy, we look for a request
 110  * on any queue on this host, and attempt to issue it.  This may
 111  * not be the queue we were asked to process.
 112  */
 113 static void mmc_request_fn(struct request_queue *q)
 114 {
 115         struct mmc_queue *mq = q->queuedata;
 116         struct request *req;
 117         unsigned long flags;
 118         struct mmc_context_info *cntx;
 119
 120         if (!mq) {
 121                 while ((req = blk_fetch_request(q)) != NULL) {
 122                         req->cmd_flags |= REQ_QUIET;
 123                         __blk_end_request_all(req, -EIO);
 124                 }
 125                 return;
 126         }
 127
 128         cntx = &mq->card->host->context_info;
 129         if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
 130                 /*
 131                  * New MMC request arrived when MMC thread may be
 132                  * blocked on the previous request to be complete
 133                  * with no current request fetched
 134                  */
 135                 spin_lock_irqsave(&cntx->lock, flags);
 136                 if (cntx->is_waiting_last_req) {
 137                         cntx->is_new_req = true;
 138                         wake_up_interruptible(&cntx->wait);
 139                 }
 140                 spin_unlock_irqrestore(&cntx->lock, flags);
 141         } else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
 142                 wake_up_process(mq->thread);
 143 }
 144
 145 static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
 146 {
 147         struct scatterlist *sg;
 148
 149         sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
 150         if (!sg)
 151                 *err = -ENOMEM;
 152         else {
 153                 *err = 0;
 154                 sg_init_table(sg, sg_len);
 155         }
 156
 157         return sg;
 158 }
 159
 160 static void mmc_queue_setup_discard(struct request_queue *q,
 161                                     struct mmc_card *card)
 162 {
 163         unsigned max_discard;
 164
 165         max_discard = mmc_calc_max_discard(card);
 166         if (!max_discard)
 167                 return;
 168
 169         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 170         q->limits.max_discard_sectors = max_discard;
 171         if (card->erased_byte == 0 && !mmc_can_discard(card))
 172                 q->limits.discard_zeroes_data = 1;
 173         q->limits.discard_granularity = card->pref_erase << 9;
 174         /* granularity must not be greater than max. discard */
 175         if (card->pref_erase > max_discard)
 176                 q->limits.discard_granularity = 0;
 177         if (mmc_can_secure_erase_trim(card))
 178                 queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
 179 }
 180
 181 /**
 182  * mmc_init_queue - initialise a queue structure.
 183  * @mq: mmc queue
 184  * @card: mmc card to attach this queue
 185  * @lock: queue lock
 186  * @subname: partition subname
 187  *
 188  * Initialise a MMC card request queue.
 189  */
 190 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 191                    spinlock_t *lock, const char *subname)
 192 {
 193         struct mmc_host *host = card->host;
 194         u64 limit = BLK_BOUNCE_HIGH;
 195         int ret;
 196         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 197         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 198
 199         if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 200                 limit = dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
 201
 202         mq->card = card;
 203         mq->queue = blk_init_queue(mmc_request_fn, lock);
 204         if (!mq->queue)
 205                 return -ENOMEM;
 206
 207         mq->mqrq_cur = mqrq_cur;
 208         mq->mqrq_prev = mqrq_prev;
 209         mq->queue->queuedata = mq;
 210
 211         blk_queue_prep_rq(mq->queue, mmc_prep_request);
 212         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
 213         if (mmc_can_erase(card))
 214                 mmc_queue_setup_discard(mq->queue, card);
 215
 216 #ifdef CONFIG_MMC_BLOCK_BOUNCE
 217         if (host->max_segs == 1) {
 218                 unsigned int bouncesz;
 219
 220                 bouncesz = MMC_QUEUE_BOUNCESZ;
 221
 222                 if (bouncesz > host->max_req_size)
 223                         bouncesz = host->max_req_size;
 224                 if (bouncesz > host->max_seg_size)
 225                         bouncesz = host->max_seg_size;
 226                 if (bouncesz > (host->max_blk_count * 512))
 227                         bouncesz = host->max_blk_count * 512;
 228
 229                 if (bouncesz > 512) {
 230                         mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
 231                         if (!mqrq_cur->bounce_buf) {
 232                                 pr_warning("%s: unable to "
 233                                         "allocate bounce cur buffer\n",
 234                                         mmc_card_name(card));
 235                         }
 236                         mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
 237                         if (!mqrq_prev->bounce_buf) {
 238                                 pr_warning("%s: unable to "
 239                                         "allocate bounce prev buffer\n",
 240                                         mmc_card_name(card));
 241                                 kfree(mqrq_cur->bounce_buf);
 242                                 mqrq_cur->bounce_buf = NULL;
 243                         }
 244                 }
 245
 246                 if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
 247                         blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
 248                         blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
 249                         blk_queue_max_segments(mq->queue, bouncesz / 512);
 250                         blk_queue_max_segment_size(mq->queue, bouncesz);
 251
 252                         mqrq_cur->sg = mmc_alloc_sg(1, &ret);
 253                         if (ret)
 254                                 goto cleanup_queue;
 255
 256                         mqrq_cur->bounce_sg =
 257                                 mmc_alloc_sg(bouncesz / 512, &ret);
 258                         if (ret)
 259                                 goto cleanup_queue;
 260
 261                         mqrq_prev->sg = mmc_alloc_sg(1, &ret);
 262                         if (ret)
 263                                 goto cleanup_queue;
 264
 265                         mqrq_prev->bounce_sg =
 266                                 mmc_alloc_sg(bouncesz / 512, &ret);
 267                         if (ret)
 268                                 goto cleanup_queue;
 269                 }
 270         }
 271 #endif
 272
 273         if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
 274                 blk_queue_bounce_limit(mq->queue, limit);
 275                 blk_queue_max_hw_sectors(mq->queue,
 276                         min(host->max_blk_count, host->max_req_size / 512));
 277                 blk_queue_max_segments(mq->queue, host->max_segs);
 278                 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 279
 280                 mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
 281                 if (ret)
 282                         goto cleanup_queue;
 283
 284
 285                 mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
 286                 if (ret)
 287                         goto cleanup_queue;
 288         }
 289
 290         sema_init(&mq->thread_sem, 1);
 291
 292         mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
 293                 host->index, subname ? subname : "");
 294
 295         if (IS_ERR(mq->thread)) {
 296                 ret = PTR_ERR(mq->thread);
 297                 goto free_bounce_sg;
 298         }
 299
 300         return 0;
 301  free_bounce_sg:
 302         kfree(mqrq_cur->bounce_sg);
 303         mqrq_cur->bounce_sg = NULL;
 304         kfree(mqrq_prev->bounce_sg);
 305         mqrq_prev->bounce_sg = NULL;
 306
 307  cleanup_queue:
 308         kfree(mqrq_cur->sg);
 309         mqrq_cur->sg = NULL;
 310         kfree(mqrq_cur->bounce_buf);
 311         mqrq_cur->bounce_buf = NULL;
 312
 313         kfree(mqrq_prev->sg);
 314         mqrq_prev->sg = NULL;
 315         kfree(mqrq_prev->bounce_buf);
 316         mqrq_prev->bounce_buf = NULL;
 317
 318         blk_cleanup_queue(mq->queue);
 319         return ret;
 320 }
 321
 322 void mmc_cleanup_queue(struct mmc_queue *mq)
 323 {
 324         struct request_queue *q = mq->queue;
 325         unsigned long flags;
 326         struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
 327         struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
 328
 329         /* Make sure the queue isn't suspended, as that will deadlock */
 330         mmc_queue_resume(mq);
 331
 332         /* Then terminate our worker thread */
 333         kthread_stop(mq->thread);
 334
 335         /* Empty the queue */
 336         spin_lock_irqsave(q->queue_lock, flags);
 337         q->queuedata = NULL;
 338         blk_start_queue(q);
 339         spin_unlock_irqrestore(q->queue_lock, flags);
 340
 341         kfree(mqrq_cur->bounce_sg);
 342         mqrq_cur->bounce_sg = NULL;
 343
 344         kfree(mqrq_cur->sg);
 345         mqrq_cur->sg = NULL;
 346
 347         kfree(mqrq_cur->bounce_buf);
 348         mqrq_cur->bounce_buf = NULL;
 349
 350         kfree(mqrq_prev->bounce_sg);
 351         mqrq_prev->bounce_sg = NULL;
 352
 353         kfree(mqrq_prev->sg);
 354         mqrq_prev->sg = NULL;
 355
 356         kfree(mqrq_prev->bounce_buf);
 357         mqrq_prev->bounce_buf = NULL;
 358
 359         mq->card = NULL;
 360 }
 361 EXPORT_SYMBOL(mmc_cleanup_queue);
 362
 363 int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
 364 {
 365         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 366         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 367         int ret = 0;
 368
 369
 370         mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
 371         if (!mqrq_cur->packed) {
 372                 pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
 373                         mmc_card_name(card));
 374                 ret = -ENOMEM;
 375                 goto out;
 376         }
 377
 378         mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
 379         if (!mqrq_prev->packed) {
 380                 pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
 381                         mmc_card_name(card));
 382                 kfree(mqrq_cur->packed);
 383                 mqrq_cur->packed = NULL;
 384                 ret = -ENOMEM;
 385                 goto out;
 386         }
 387
 388         INIT_LIST_HEAD(&mqrq_cur->packed->list);
 389         INIT_LIST_HEAD(&mqrq_prev->packed->list);
 390
 391 out:
 392         return ret;
 393 }
 394
 395 void mmc_packed_clean(struct mmc_queue *mq)
 396 {
 397         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 398         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 399
 400         kfree(mqrq_cur->packed);
 401         mqrq_cur->packed = NULL;
 402         kfree(mqrq_prev->packed);
 403         mqrq_prev->packed = NULL;
 404 }
 405
 406 /**
 407  * mmc_queue_suspend - suspend a MMC request queue
 408  * @mq: MMC queue to suspend
 409  *
 410  * Stop the block request queue, and wait for our thread to
 411  * complete any outstanding requests.  This ensures that we
 412  * won't suspend while a request is being processed.
 413  */
 414 void mmc_queue_suspend(struct mmc_queue *mq)
 415 {
 416         struct request_queue *q = mq->queue;
 417         unsigned long flags;
 418
 419         if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
 420                 mq->flags |= MMC_QUEUE_SUSPENDED;
 421
 422                 spin_lock_irqsave(q->queue_lock, flags);
 423                 blk_stop_queue(q);
 424                 spin_unlock_irqrestore(q->queue_lock, flags);
 425
 426                 down(&mq->thread_sem);
 427         }
 428 }
 429
 430 /**
 431  * mmc_queue_resume - resume a previously suspended MMC request queue
 432  * @mq: MMC queue to resume
 433  */
 434 void mmc_queue_resume(struct mmc_queue *mq)
 435 {
 436         struct request_queue *q = mq->queue;
 437         unsigned long flags;
 438
 439         if (mq->flags & MMC_QUEUE_SUSPENDED) {
 440                 mq->flags &= ~MMC_QUEUE_SUSPENDED;
 441
 442                 up(&mq->thread_sem);
 443
 444                 spin_lock_irqsave(q->queue_lock, flags);
 445                 blk_start_queue(q);
 446                 spin_unlock_irqrestore(q->queue_lock, flags);
 447         }
 448 }
 449
 450 static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
 451                                             struct mmc_packed *packed,
 452                                             struct scatterlist *sg,
 453                                             enum mmc_packed_type cmd_type)
 454 {
 455         struct scatterlist *__sg = sg;
 456         unsigned int sg_len = 0;
 457         struct request *req;
 458
 459         if (mmc_packed_wr(cmd_type)) {
 460                 unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
 461                 unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
 462                 unsigned int len, remain, offset = 0;
 463                 u8 *buf = (u8 *)packed->cmd_hdr;
 464
 465                 remain = hdr_sz;
 466                 do {
 467                         len = min(remain, max_seg_sz);
 468                         sg_set_buf(__sg, buf + offset, len);
 469                         offset += len;
 470                         remain -= len;
 471                         (__sg++)->page_link &= ~0x02;
 472                         sg_len++;
 473                 } while (remain);
 474         }
 475
 476         list_for_each_entry(req, &packed->list, queuelist) {
 477                 sg_len += blk_rq_map_sg(mq->queue, req, __sg);
 478                 __sg = sg + (sg_len - 1);
 479                 (__sg++)->page_link &= ~0x02;
 480         }
 481         sg_mark_end(sg + (sg_len - 1));
 482         return sg_len;
 483 }
 484
 485 /*
 486  * Prepare the sg list(s) to be handed of to the host driver
 487  */
 488 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
 489 {
 490         unsigned int sg_len;
 491         size_t buflen;
 492         struct scatterlist *sg;
 493         enum mmc_packed_type cmd_type;
 494         int i;
 495
 496         cmd_type = mqrq->cmd_type;
 497
 498         if (!mqrq->bounce_buf) {
 499                 if (mmc_packed_cmd(cmd_type))
 500                         return mmc_queue_packed_map_sg(mq, mqrq->packed,
 501                                                        mqrq->sg, cmd_type);
 502                 else
 503                         return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
 504         }
 505
 506         BUG_ON(!mqrq->bounce_sg);
 507
 508         if (mmc_packed_cmd(cmd_type))
 509                 sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
 510                                                  mqrq->bounce_sg, cmd_type);
 511         else
 512                 sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
 513
 514         mqrq->bounce_sg_len = sg_len;
 515
 516         buflen = 0;
 517         for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
 518                 buflen += sg->length;
 519
 520         sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
 521
 522         return 1;
 523 }
 524
 525 /*
 526  * If writing, bounce the data to the buffer before the request
 527  * is sent to the host driver
 528  */
 529 void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
 530 {
 531         if (!mqrq->bounce_buf)
 532                 return;
 533
 534         if (rq_data_dir(mqrq->req) != WRITE)
 535                 return;
 536
 537         sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
 538                 mqrq->bounce_buf, mqrq->sg[0].length);
 539 }
 540
 541 /*
 542  * If reading, bounce the data from the buffer after the request
 543  * has been handled by the host driver
 544  */
 545 void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
 546 {
 547         if (!mqrq->bounce_buf)
 548                 return;
 549
 550         if (rq_data_dir(mqrq->req) != READ)
 551                 return;
 552
 553         sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
 554                 mqrq->bounce_buf, mqrq->sg[0].length);
 555 }