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