drivers/mmc/card/block.c

   1 /*
   2  * Block driver for media (i.e., flash cards)
   3  *
   4  * Copyright 2002 Hewlett-Packard Company
   5  * Copyright 2005-2008 Pierre Ossman
   6  *
   7  * Use consistent with the GNU GPL is permitted,
   8  * provided that this copyright notice is
   9  * preserved in its entirety in all copies and derived works.
  10  *
  11  * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
  12  * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
  13  * FITNESS FOR ANY PARTICULAR PURPOSE.
  14  *
  15  * Many thanks to Alessandro Rubini and Jonathan Corbet!
  16  *
  17  * Author:  Andrew Christian
  18  *          28 May 2002
  19  */
  20 #include <linux/moduleparam.h>
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23
  24 #include <linux/kernel.h>
  25 #include <linux/fs.h>
  26 #include <linux/slab.h>
  27 #include <linux/errno.h>
  28 #include <linux/hdreg.h>
  29 #include <linux/kdev_t.h>
  30 #include <linux/blkdev.h>
  31 #include <linux/mutex.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/scatterlist.h>
  34 #include <linux/string_helpers.h>
  35
  36 #include <linux/mmc/card.h>
  37 #include <linux/mmc/host.h>
  38 #include <linux/mmc/mmc.h>
  39 #include <linux/mmc/sd.h>
  40
  41 #include <asm/system.h>
  42 #include <asm/uaccess.h>
  43
  44 #include "queue.h"
  45
  46 MODULE_ALIAS("mmc:block");
  47
  48 /*
  49  * max 8 partitions per card
  50  */
  51 #define MMC_SHIFT       3
  52 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
  53
  54 static DECLARE_BITMAP(dev_use, MMC_NUM_MINORS);
  55
  56 /*
  57  * There is one mmc_blk_data per slot.
  58  */
  59 struct mmc_blk_data {
  60         spinlock_t      lock;
  61         struct gendisk  *disk;
  62         struct mmc_queue queue;
  63
  64         unsigned int    usage;
  65         unsigned int    read_only;
  66 };
  67
  68 static DEFINE_MUTEX(open_lock);
  69
  70 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  71 {
  72         struct mmc_blk_data *md;
  73
  74         mutex_lock(&open_lock);
  75         md = disk->private_data;
  76         if (md && md->usage == 0)
  77                 md = NULL;
  78         if (md)
  79                 md->usage++;
  80         mutex_unlock(&open_lock);
  81
  82         return md;
  83 }
  84
  85 static void mmc_blk_put(struct mmc_blk_data *md)
  86 {
  87         mutex_lock(&open_lock);
  88         md->usage--;
  89         if (md->usage == 0) {
  90                 int devmaj = MAJOR(disk_devt(md->disk));
  91                 int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT;
  92
  93                 if (!devmaj)
  94                         devidx = md->disk->first_minor >> MMC_SHIFT;
  95
  96                 blk_cleanup_queue(md->queue.queue);
  97
  98                 __clear_bit(devidx, dev_use);
  99
 100                 put_disk(md->disk);
 101                 kfree(md);
 102         }
 103         mutex_unlock(&open_lock);
 104 }
 105
 106 static int mmc_blk_open(struct block_device *bdev, fmode_t mode)
 107 {
 108         struct mmc_blk_data *md = mmc_blk_get(bdev->bd_disk);
 109         int ret = -ENXIO;
 110
 111         lock_kernel();
 112         if (md) {
 113                 if (md->usage == 2)
 114                         check_disk_change(bdev);
 115                 ret = 0;
 116
 117                 if ((mode & FMODE_WRITE) && md->read_only) {
 118                         mmc_blk_put(md);
 119                         ret = -EROFS;
 120                 }
 121         }
 122         unlock_kernel();
 123
 124         return ret;
 125 }
 126
 127 static int mmc_blk_release(struct gendisk *disk, fmode_t mode)
 128 {
 129         struct mmc_blk_data *md = disk->private_data;
 130
 131         lock_kernel();
 132         mmc_blk_put(md);
 133         unlock_kernel();
 134         return 0;
 135 }
 136
 137 static int
 138 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 139 {
 140         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 141         geo->heads = 4;
 142         geo->sectors = 16;
 143         return 0;
 144 }
 145
 146 static const struct block_device_operations mmc_bdops = {
 147         .open                   = mmc_blk_open,
 148         .release                = mmc_blk_release,
 149         .getgeo                 = mmc_blk_getgeo,
 150         .owner                  = THIS_MODULE,
 151 };
 152
 153 struct mmc_blk_request {
 154         struct mmc_request      mrq;
 155         struct mmc_command      cmd;
 156         struct mmc_command      stop;
 157         struct mmc_data         data;
 158 };
 159
 160 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 161 {
 162         int err;
 163         u32 result;
 164         __be32 *blocks;
 165
 166         struct mmc_request mrq;
 167         struct mmc_command cmd;
 168         struct mmc_data data;
 169         unsigned int timeout_us;
 170
 171         struct scatterlist sg;
 172
 173         memset(&cmd, 0, sizeof(struct mmc_command));
 174
 175         cmd.opcode = MMC_APP_CMD;
 176         cmd.arg = card->rca << 16;
 177         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 178
 179         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 180         if (err)
 181                 return (u32)-1;
 182         if (!mmc_host_is_spi(card->host) && !(cmd.resp[0] & R1_APP_CMD))
 183                 return (u32)-1;
 184
 185         memset(&cmd, 0, sizeof(struct mmc_command));
 186
 187         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 188         cmd.arg = 0;
 189         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 190
 191         memset(&data, 0, sizeof(struct mmc_data));
 192
 193         data.timeout_ns = card->csd.tacc_ns * 100;
 194         data.timeout_clks = card->csd.tacc_clks * 100;
 195
 196         timeout_us = data.timeout_ns / 1000;
 197         timeout_us += data.timeout_clks * 1000 /
 198                 (card->host->ios.clock / 1000);
 199
 200         if (timeout_us > 100000) {
 201                 data.timeout_ns = 100000000;
 202                 data.timeout_clks = 0;
 203         }
 204
 205         data.blksz = 4;
 206         data.blocks = 1;
 207         data.flags = MMC_DATA_READ;
 208         data.sg = &sg;
 209         data.sg_len = 1;
 210
 211         memset(&mrq, 0, sizeof(struct mmc_request));
 212
 213         mrq.cmd = &cmd;
 214         mrq.data = &data;
 215
 216         blocks = kmalloc(4, GFP_KERNEL);
 217         if (!blocks)
 218                 return (u32)-1;
 219
 220         sg_init_one(&sg, blocks, 4);
 221
 222         mmc_wait_for_req(card->host, &mrq);
 223
 224         result = ntohl(*blocks);
 225         kfree(blocks);
 226
 227         if (cmd.error || data.error)
 228                 result = (u32)-1;
 229
 230         return result;
 231 }
 232
 233 static u32 get_card_status(struct mmc_card *card, struct request *req)
 234 {
 235         struct mmc_command cmd;
 236         int err;
 237
 238         memset(&cmd, 0, sizeof(struct mmc_command));
 239         cmd.opcode = MMC_SEND_STATUS;
 240         if (!mmc_host_is_spi(card->host))
 241                 cmd.arg = card->rca << 16;
 242         cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
 243         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 244         if (err)
 245                 printk(KERN_ERR "%s: error %d sending status comand",
 246                        req->rq_disk->disk_name, err);
 247         return cmd.resp[0];
 248 }
 249
 250 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 251 {
 252         struct mmc_blk_data *md = mq->data;
 253         struct mmc_card *card = md->queue.card;
 254         struct mmc_blk_request brq;
 255         int ret = 1, disable_multi = 0;
 256
 257         mmc_claim_host(card->host);
 258
 259         do {
 260                 struct mmc_command cmd;
 261                 u32 readcmd, writecmd, status = 0;
 262
 263                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 264                 brq.mrq.cmd = &brq.cmd;
 265                 brq.mrq.data = &brq.data;
 266
 267                 brq.cmd.arg = blk_rq_pos(req);
 268                 if (!mmc_card_blockaddr(card))
 269                         brq.cmd.arg <<= 9;
 270                 brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 271                 brq.data.blksz = 512;
 272                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 273                 brq.stop.arg = 0;
 274                 brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
 275                 brq.data.blocks = blk_rq_sectors(req);
 276
 277                 /*
 278                  * The block layer doesn't support all sector count
 279                  * restrictions, so we need to be prepared for too big
 280                  * requests.
 281                  */
 282                 if (brq.data.blocks > card->host->max_blk_count)
 283                         brq.data.blocks = card->host->max_blk_count;
 284
 285                 /*
 286                  * After a read error, we redo the request one sector at a time
 287                  * in order to accurately determine which sectors can be read
 288                  * successfully.
 289                  */
 290                 if (disable_multi && brq.data.blocks > 1)
 291                         brq.data.blocks = 1;
 292
 293                 if (brq.data.blocks > 1) {
 294                         /* SPI multiblock writes terminate using a special
 295                          * token, not a STOP_TRANSMISSION request.
 296                          */
 297                         if (!mmc_host_is_spi(card->host)
 298                                         || rq_data_dir(req) == READ)
 299                                 brq.mrq.stop = &brq.stop;
 300                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 301                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 302                 } else {
 303                         brq.mrq.stop = NULL;
 304                         readcmd = MMC_READ_SINGLE_BLOCK;
 305                         writecmd = MMC_WRITE_BLOCK;
 306                 }
 307
 308                 if (rq_data_dir(req) == READ) {
 309                         brq.cmd.opcode = readcmd;
 310                         brq.data.flags |= MMC_DATA_READ;
 311                 } else {
 312                         brq.cmd.opcode = writecmd;
 313                         brq.data.flags |= MMC_DATA_WRITE;
 314                 }
 315
 316                 mmc_set_data_timeout(&brq.data, card);
 317
 318                 brq.data.sg = mq->sg;
 319                 brq.data.sg_len = mmc_queue_map_sg(mq);
 320
 321                 /*
 322                  * Adjust the sg list so it is the same size as the
 323                  * request.
 324                  */
 325                 if (brq.data.blocks != blk_rq_sectors(req)) {
 326                         int i, data_size = brq.data.blocks << 9;
 327                         struct scatterlist *sg;
 328
 329                         for_each_sg(brq.data.sg, sg, brq.data.sg_len, i) {
 330                                 data_size -= sg->length;
 331                                 if (data_size <= 0) {
 332                                         sg->length += data_size;
 333                                         i++;
 334                                         break;
 335                                 }
 336                         }
 337                         brq.data.sg_len = i;
 338                 }
 339
 340                 mmc_queue_bounce_pre(mq);
 341
 342                 mmc_wait_for_req(card->host, &brq.mrq);
 343
 344                 mmc_queue_bounce_post(mq);
 345
 346                 /*
 347                  * Check for errors here, but don't jump to cmd_err
 348                  * until later as we need to wait for the card to leave
 349                  * programming mode even when things go wrong.
 350                  */
 351                 if (brq.cmd.error || brq.data.error || brq.stop.error) {
 352                         if (brq.data.blocks > 1 && rq_data_dir(req) == READ) {
 353                                 /* Redo read one sector at a time */
 354                                 printk(KERN_WARNING "%s: retrying using single "
 355                                        "block read\n", req->rq_disk->disk_name);
 356                                 disable_multi = 1;
 357                                 continue;
 358                         }
 359                         status = get_card_status(card, req);
 360                 }
 361
 362                 if (brq.cmd.error) {
 363                         printk(KERN_ERR "%s: error %d sending read/write "
 364                                "command, response %#x, card status %#x\n",
 365                                req->rq_disk->disk_name, brq.cmd.error,
 366                                brq.cmd.resp[0], status);
 367                 }
 368
 369                 if (brq.data.error) {
 370                         if (brq.data.error == -ETIMEDOUT && brq.mrq.stop)
 371                                 /* 'Stop' response contains card status */
 372                                 status = brq.mrq.stop->resp[0];
 373                         printk(KERN_ERR "%s: error %d transferring data,"
 374                                " sector %u, nr %u, card status %#x\n",
 375                                req->rq_disk->disk_name, brq.data.error,
 376                                (unsigned)blk_rq_pos(req),
 377                                (unsigned)blk_rq_sectors(req), status);
 378                 }
 379
 380                 if (brq.stop.error) {
 381                         printk(KERN_ERR "%s: error %d sending stop command, "
 382                                "response %#x, card status %#x\n",
 383                                req->rq_disk->disk_name, brq.stop.error,
 384                                brq.stop.resp[0], status);
 385                 }
 386
 387                 if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
 388                         do {
 389                                 int err;
 390
 391                                 cmd.opcode = MMC_SEND_STATUS;
 392                                 cmd.arg = card->rca << 16;
 393                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 394                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 395                                 if (err) {
 396                                         printk(KERN_ERR "%s: error %d requesting status\n",
 397                                                req->rq_disk->disk_name, err);
 398                                         goto cmd_err;
 399                                 }
 400                                 /*
 401                                  * Some cards mishandle the status bits,
 402                                  * so make sure to check both the busy
 403                                  * indication and the card state.
 404                                  */
 405                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
 406                                 (R1_CURRENT_STATE(cmd.resp[0]) == 7));
 407
 408 #if 0
 409                         if (cmd.resp[0] & ~0x00000900)
 410                                 printk(KERN_ERR "%s: status = %08x\n",
 411                                        req->rq_disk->disk_name, cmd.resp[0]);
 412                         if (mmc_decode_status(cmd.resp))
 413                                 goto cmd_err;
 414 #endif
 415                 }
 416
 417                 if (brq.cmd.error || brq.stop.error || brq.data.error) {
 418                         if (rq_data_dir(req) == READ) {
 419                                 /*
 420                                  * After an error, we redo I/O one sector at a
 421                                  * time, so we only reach here after trying to
 422                                  * read a single sector.
 423                                  */
 424                                 spin_lock_irq(&md->lock);
 425                                 ret = __blk_end_request(req, -EIO, brq.data.blksz);
 426                                 spin_unlock_irq(&md->lock);
 427                                 continue;
 428                         }
 429                         goto cmd_err;
 430                 }
 431
 432                 /*
 433                  * A block was successfully transferred.
 434                  */
 435                 spin_lock_irq(&md->lock);
 436                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 437                 spin_unlock_irq(&md->lock);
 438         } while (ret);
 439
 440         mmc_release_host(card->host);
 441
 442         return 1;
 443
 444  cmd_err:
 445         /*
 446          * If this is an SD card and we're writing, we can first
 447          * mark the known good sectors as ok.
 448          *
 449          * If the card is not SD, we can still ok written sectors
 450          * as reported by the controller (which might be less than
 451          * the real number of written sectors, but never more).
 452          */
 453         if (mmc_card_sd(card)) {
 454                 u32 blocks;
 455
 456                 blocks = mmc_sd_num_wr_blocks(card);
 457                 if (blocks != (u32)-1) {
 458                         spin_lock_irq(&md->lock);
 459                         ret = __blk_end_request(req, 0, blocks << 9);
 460                         spin_unlock_irq(&md->lock);
 461                 }
 462         } else {
 463                 spin_lock_irq(&md->lock);
 464                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 465                 spin_unlock_irq(&md->lock);
 466         }
 467
 468         mmc_release_host(card->host);
 469
 470         spin_lock_irq(&md->lock);
 471         while (ret)
 472                 ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
 473         spin_unlock_irq(&md->lock);
 474
 475         return 0;
 476 }
 477
 478
 479 static inline int mmc_blk_readonly(struct mmc_card *card)
 480 {
 481         return mmc_card_readonly(card) ||
 482                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 483 }
 484
 485 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 486 {
 487         struct mmc_blk_data *md;
 488         int devidx, ret;
 489
 490         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 491         if (devidx >= MMC_NUM_MINORS)
 492                 return ERR_PTR(-ENOSPC);
 493         __set_bit(devidx, dev_use);
 494
 495         md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 496         if (!md) {
 497                 ret = -ENOMEM;
 498                 goto out;
 499         }
 500
 501
 502         /*
 503          * Set the read-only status based on the supported commands
 504          * and the write protect switch.
 505          */
 506         md->read_only = mmc_blk_readonly(card);
 507
 508         md->disk = alloc_disk(1 << MMC_SHIFT);
 509         if (md->disk == NULL) {
 510                 ret = -ENOMEM;
 511                 goto err_kfree;
 512         }
 513
 514         spin_lock_init(&md->lock);
 515         md->usage = 1;
 516
 517         ret = mmc_init_queue(&md->queue, card, &md->lock);
 518         if (ret)
 519                 goto err_putdisk;
 520
 521         md->queue.issue_fn = mmc_blk_issue_rq;
 522         md->queue.data = md;
 523
 524         md->disk->major = MMC_BLOCK_MAJOR;
 525         md->disk->first_minor = devidx << MMC_SHIFT;
 526         md->disk->fops = &mmc_bdops;
 527         md->disk->private_data = md;
 528         md->disk->queue = md->queue.queue;
 529         md->disk->driverfs_dev = &card->dev;
 530
 531         /*
 532          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 533          *
 534          * - be set for removable media with permanent block devices
 535          * - be unset for removable block devices with permanent media
 536          *
 537          * Since MMC block devices clearly fall under the second
 538          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 539          * should use the block device creation/destruction hotplug
 540          * messages to tell when the card is present.
 541          */
 542
 543         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 544
 545         blk_queue_logical_block_size(md->queue.queue, 512);
 546
 547         if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 548                 /*
 549                  * The EXT_CSD sector count is in number or 512 byte
 550                  * sectors.
 551                  */
 552                 set_capacity(md->disk, card->ext_csd.sectors);
 553         } else {
 554                 /*
 555                  * The CSD capacity field is in units of read_blkbits.
 556                  * set_capacity takes units of 512 bytes.
 557                  */
 558                 set_capacity(md->disk,
 559                         card->csd.capacity << (card->csd.read_blkbits - 9));
 560         }
 561         return md;
 562
 563  err_putdisk:
 564         put_disk(md->disk);
 565  err_kfree:
 566         kfree(md);
 567  out:
 568         return ERR_PTR(ret);
 569 }
 570
 571 static int
 572 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 573 {
 574         struct mmc_command cmd;
 575         int err;
 576
 577         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 578         if (mmc_card_blockaddr(card))
 579                 return 0;
 580
 581         mmc_claim_host(card->host);
 582         cmd.opcode = MMC_SET_BLOCKLEN;
 583         cmd.arg = 512;
 584         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 585         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 586         mmc_release_host(card->host);
 587
 588         if (err) {
 589                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 590                         md->disk->disk_name, cmd.arg, err);
 591                 return -EINVAL;
 592         }
 593
 594         return 0;
 595 }
 596
 597 static int mmc_blk_probe(struct mmc_card *card)
 598 {
 599         struct mmc_blk_data *md;
 600         int err;
 601
 602         char cap_str[10];
 603
 604         /*
 605          * Check that the card supports the command class(es) we need.
 606          */
 607         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 608                 return -ENODEV;
 609
 610         md = mmc_blk_alloc(card);
 611         if (IS_ERR(md))
 612                 return PTR_ERR(md);
 613
 614         err = mmc_blk_set_blksize(md, card);
 615         if (err)
 616                 goto out;
 617
 618         string_get_size((u64)get_capacity(md->disk) << 9, STRING_UNITS_2,
 619                         cap_str, sizeof(cap_str));
 620         printk(KERN_INFO "%s: %s %s %s %s\n",
 621                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 622                 cap_str, md->read_only ? "(ro)" : "");
 623
 624         mmc_set_drvdata(card, md);
 625         add_disk(md->disk);
 626         return 0;
 627
 628  out:
 629         mmc_cleanup_queue(&md->queue);
 630         mmc_blk_put(md);
 631
 632         return err;
 633 }
 634
 635 static void mmc_blk_remove(struct mmc_card *card)
 636 {
 637         struct mmc_blk_data *md = mmc_get_drvdata(card);
 638
 639         if (md) {
 640                 /* Stop new requests from getting into the queue */
 641                 del_gendisk(md->disk);
 642
 643                 /* Then flush out any already in there */
 644                 mmc_cleanup_queue(&md->queue);
 645
 646                 mmc_blk_put(md);
 647         }
 648         mmc_set_drvdata(card, NULL);
 649 }
 650
 651 #ifdef CONFIG_PM
 652 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 653 {
 654         struct mmc_blk_data *md = mmc_get_drvdata(card);
 655
 656         if (md) {
 657                 mmc_queue_suspend(&md->queue);
 658         }
 659         return 0;
 660 }
 661
 662 static int mmc_blk_resume(struct mmc_card *card)
 663 {
 664         struct mmc_blk_data *md = mmc_get_drvdata(card);
 665
 666         if (md) {
 667                 mmc_blk_set_blksize(md, card);
 668                 mmc_queue_resume(&md->queue);
 669         }
 670         return 0;
 671 }
 672 #else
 673 #define mmc_blk_suspend NULL
 674 #define mmc_blk_resume  NULL
 675 #endif
 676
 677 static struct mmc_driver mmc_driver = {
 678         .drv            = {
 679                 .name   = "mmcblk",
 680         },
 681         .probe          = mmc_blk_probe,
 682         .remove         = mmc_blk_remove,
 683         .suspend        = mmc_blk_suspend,
 684         .resume         = mmc_blk_resume,
 685 };
 686
 687 static int __init mmc_blk_init(void)
 688 {
 689         int res;
 690
 691         res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 692         if (res)
 693                 goto out;
 694
 695         res = mmc_register_driver(&mmc_driver);
 696         if (res)
 697                 goto out2;
 698
 699         return 0;
 700  out2:
 701         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 702  out:
 703         return res;
 704 }
 705
 706 static void __exit mmc_blk_exit(void)
 707 {
 708         mmc_unregister_driver(&mmc_driver);
 709         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 710 }
 711
 712 module_init(mmc_blk_init);
 713 module_exit(mmc_blk_exit);
 714
 715 MODULE_LICENSE("GPL");
 716 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 717