drivers/mmc/card/block.c

   1 /*
   2  * Block driver for media (i.e., flash cards)
   3  *
   4  * Copyright 2002 Hewlett-Packard Company
   5  * Copyright 2005-2007 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
  48 /*
  49  * There is one mmc_blk_data per slot.
  50  */
  51 struct mmc_blk_data {
  52         spinlock_t      lock;
  53         struct gendisk  *disk;
  54         struct mmc_queue queue;
  55
  56         unsigned int    usage;
  57         unsigned int    block_bits;
  58         unsigned int    read_only;
  59 };
  60
  61 static DEFINE_MUTEX(open_lock);
  62
  63 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  64 {
  65         struct mmc_blk_data *md;
  66
  67         mutex_lock(&open_lock);
  68         md = disk->private_data;
  69         if (md && md->usage == 0)
  70                 md = NULL;
  71         if (md)
  72                 md->usage++;
  73         mutex_unlock(&open_lock);
  74
  75         return md;
  76 }
  77
  78 static void mmc_blk_put(struct mmc_blk_data *md)
  79 {
  80         mutex_lock(&open_lock);
  81         md->usage--;
  82         if (md->usage == 0) {
  83                 put_disk(md->disk);
  84                 kfree(md);
  85         }
  86         mutex_unlock(&open_lock);
  87 }
  88
  89 static int mmc_blk_open(struct inode *inode, struct file *filp)
  90 {
  91         struct mmc_blk_data *md;
  92         int ret = -ENXIO;
  93
  94         md = mmc_blk_get(inode->i_bdev->bd_disk);
  95         if (md) {
  96                 if (md->usage == 2)
  97                         check_disk_change(inode->i_bdev);
  98                 ret = 0;
  99
 100                 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
 101                         ret = -EROFS;
 102         }
 103
 104         return ret;
 105 }
 106
 107 static int mmc_blk_release(struct inode *inode, struct file *filp)
 108 {
 109         struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
 110
 111         mmc_blk_put(md);
 112         return 0;
 113 }
 114
 115 static int
 116 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 117 {
 118         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 119         geo->heads = 4;
 120         geo->sectors = 16;
 121         return 0;
 122 }
 123
 124 static struct block_device_operations mmc_bdops = {
 125         .open                   = mmc_blk_open,
 126         .release                = mmc_blk_release,
 127         .getgeo                 = mmc_blk_getgeo,
 128         .owner                  = THIS_MODULE,
 129 };
 130
 131 struct mmc_blk_request {
 132         struct mmc_request      mrq;
 133         struct mmc_command      cmd;
 134         struct mmc_command      stop;
 135         struct mmc_data         data;
 136 };
 137
 138 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 139 {
 140         int err;
 141         u32 blocks;
 142
 143         struct mmc_request mrq;
 144         struct mmc_command cmd;
 145         struct mmc_data data;
 146         unsigned int timeout_us;
 147
 148         struct scatterlist sg;
 149
 150         memset(&cmd, 0, sizeof(struct mmc_command));
 151
 152         cmd.opcode = MMC_APP_CMD;
 153         cmd.arg = card->rca << 16;
 154         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 155
 156         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 157         if (err)
 158                 return (u32)-1;
 159         if (!mmc_host_is_spi(card->host) && !(cmd.resp[0] & R1_APP_CMD))
 160                 return (u32)-1;
 161
 162         memset(&cmd, 0, sizeof(struct mmc_command));
 163
 164         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 165         cmd.arg = 0;
 166         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 167
 168         memset(&data, 0, sizeof(struct mmc_data));
 169
 170         data.timeout_ns = card->csd.tacc_ns * 100;
 171         data.timeout_clks = card->csd.tacc_clks * 100;
 172
 173         timeout_us = data.timeout_ns / 1000;
 174         timeout_us += data.timeout_clks * 1000 /
 175                 (card->host->ios.clock / 1000);
 176
 177         if (timeout_us > 100000) {
 178                 data.timeout_ns = 100000000;
 179                 data.timeout_clks = 0;
 180         }
 181
 182         data.blksz = 4;
 183         data.blocks = 1;
 184         data.flags = MMC_DATA_READ;
 185         data.sg = &sg;
 186         data.sg_len = 1;
 187
 188         memset(&mrq, 0, sizeof(struct mmc_request));
 189
 190         mrq.cmd = &cmd;
 191         mrq.data = &data;
 192
 193         sg_init_one(&sg, &blocks, 4);
 194
 195         mmc_wait_for_req(card->host, &mrq);
 196
 197         if (cmd.error || data.error)
 198                 return (u32)-1;
 199
 200         blocks = ntohl(blocks);
 201
 202         return blocks;
 203 }
 204
 205 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 206 {
 207         struct mmc_blk_data *md = mq->data;
 208         struct mmc_card *card = md->queue.card;
 209         struct mmc_blk_request brq;
 210         int ret = 1, sg_pos, data_size;
 211
 212         mmc_claim_host(card->host);
 213
 214         do {
 215                 struct mmc_command cmd;
 216                 u32 readcmd, writecmd;
 217
 218                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 219                 brq.mrq.cmd = &brq.cmd;
 220                 brq.mrq.data = &brq.data;
 221
 222                 brq.cmd.arg = req->sector;
 223                 if (!mmc_card_blockaddr(card))
 224                         brq.cmd.arg <<= 9;
 225                 brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 226                 brq.data.blksz = 1 << md->block_bits;
 227                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 228                 brq.stop.arg = 0;
 229                 brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
 230                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 231                 if (brq.data.blocks > card->host->max_blk_count)
 232                         brq.data.blocks = card->host->max_blk_count;
 233
 234                 /*
 235                  * If the host doesn't support multiple block writes, force
 236                  * block writes to single block. SD cards are excepted from
 237                  * this rule as they support querying the number of
 238                  * successfully written sectors.
 239                  */
 240                 if (rq_data_dir(req) != READ &&
 241                     !(card->host->caps & MMC_CAP_MULTIWRITE) &&
 242                     !mmc_card_sd(card))
 243                         brq.data.blocks = 1;
 244
 245                 if (brq.data.blocks > 1) {
 246                         /* SPI multiblock writes terminate using a special
 247                          * token, not a STOP_TRANSMISSION request.
 248                          */
 249                         if (!mmc_host_is_spi(card->host)
 250                                         || rq_data_dir(req) == READ)
 251                                 brq.mrq.stop = &brq.stop;
 252                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 253                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 254                 } else {
 255                         brq.mrq.stop = NULL;
 256                         readcmd = MMC_READ_SINGLE_BLOCK;
 257                         writecmd = MMC_WRITE_BLOCK;
 258                 }
 259
 260                 if (rq_data_dir(req) == READ) {
 261                         brq.cmd.opcode = readcmd;
 262                         brq.data.flags |= MMC_DATA_READ;
 263                 } else {
 264                         brq.cmd.opcode = writecmd;
 265                         brq.data.flags |= MMC_DATA_WRITE;
 266                 }
 267
 268                 mmc_set_data_timeout(&brq.data, card);
 269
 270                 brq.data.sg = mq->sg;
 271                 brq.data.sg_len = mmc_queue_map_sg(mq);
 272
 273                 mmc_queue_bounce_pre(mq);
 274
 275                 if (brq.data.blocks !=
 276                     (req->nr_sectors >> (md->block_bits - 9))) {
 277                         data_size = brq.data.blocks * brq.data.blksz;
 278                         for (sg_pos = 0; sg_pos < brq.data.sg_len; sg_pos++) {
 279                                 data_size -= mq->sg[sg_pos].length;
 280                                 if (data_size <= 0) {
 281                                         mq->sg[sg_pos].length += data_size;
 282                                         sg_pos++;
 283                                         break;
 284                                 }
 285                         }
 286                         brq.data.sg_len = sg_pos;
 287                 }
 288
 289                 mmc_wait_for_req(card->host, &brq.mrq);
 290
 291                 mmc_queue_bounce_post(mq);
 292
 293                 if (brq.cmd.error) {
 294                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 295                                req->rq_disk->disk_name, brq.cmd.error);
 296                         goto cmd_err;
 297                 }
 298
 299                 if (brq.data.error) {
 300                         printk(KERN_ERR "%s: error %d transferring data\n",
 301                                req->rq_disk->disk_name, brq.data.error);
 302                         goto cmd_err;
 303                 }
 304
 305                 if (brq.stop.error) {
 306                         printk(KERN_ERR "%s: error %d sending stop command\n",
 307                                req->rq_disk->disk_name, brq.stop.error);
 308                         goto cmd_err;
 309                 }
 310
 311                 if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
 312                         do {
 313                                 int err;
 314
 315                                 cmd.opcode = MMC_SEND_STATUS;
 316                                 cmd.arg = card->rca << 16;
 317                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 318                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 319                                 if (err) {
 320                                         printk(KERN_ERR "%s: error %d requesting status\n",
 321                                                req->rq_disk->disk_name, err);
 322                                         goto cmd_err;
 323                                 }
 324                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 325
 326 #if 0
 327                         if (cmd.resp[0] & ~0x00000900)
 328                                 printk(KERN_ERR "%s: status = %08x\n",
 329                                        req->rq_disk->disk_name, cmd.resp[0]);
 330                         if (mmc_decode_status(cmd.resp))
 331                                 goto cmd_err;
 332 #endif
 333                 }
 334
 335                 /*
 336                  * A block was successfully transferred.
 337                  */
 338                 spin_lock_irq(&md->lock);
 339                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 340                 if (!ret) {
 341                         /*
 342                          * The whole request completed successfully.
 343                          */
 344                         add_disk_randomness(req->rq_disk);
 345                         blkdev_dequeue_request(req);
 346                         end_that_request_last(req, 1);
 347                 }
 348                 spin_unlock_irq(&md->lock);
 349         } while (ret);
 350
 351         mmc_release_host(card->host);
 352
 353         return 1;
 354
 355  cmd_err:
 356         /*
 357          * If this is an SD card and we're writing, we can first
 358          * mark the known good sectors as ok.
 359          *
 360          * If the card is not SD, we can still ok written sectors
 361          * if the controller can do proper error reporting.
 362          *
 363          * For reads we just fail the entire chunk as that should
 364          * be safe in all cases.
 365          */
 366         if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
 367                 u32 blocks;
 368                 unsigned int bytes;
 369
 370                 blocks = mmc_sd_num_wr_blocks(card);
 371                 if (blocks != (u32)-1) {
 372                         if (card->csd.write_partial)
 373                                 bytes = blocks << md->block_bits;
 374                         else
 375                                 bytes = blocks << 9;
 376                         spin_lock_irq(&md->lock);
 377                         ret = end_that_request_chunk(req, 1, bytes);
 378                         spin_unlock_irq(&md->lock);
 379                 }
 380         } else if (rq_data_dir(req) != READ &&
 381                    (card->host->caps & MMC_CAP_MULTIWRITE)) {
 382                 spin_lock_irq(&md->lock);
 383                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 384                 spin_unlock_irq(&md->lock);
 385         }
 386
 387         mmc_release_host(card->host);
 388
 389         spin_lock_irq(&md->lock);
 390         while (ret) {
 391                 ret = end_that_request_chunk(req, 0,
 392                                 req->current_nr_sectors << 9);
 393         }
 394
 395         add_disk_randomness(req->rq_disk);
 396         blkdev_dequeue_request(req);
 397         end_that_request_last(req, 0);
 398         spin_unlock_irq(&md->lock);
 399
 400         return 0;
 401 }
 402
 403 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 404
 405 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 406
 407 static inline int mmc_blk_readonly(struct mmc_card *card)
 408 {
 409         return mmc_card_readonly(card) ||
 410                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 411 }
 412
 413 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 414 {
 415         struct mmc_blk_data *md;
 416         int devidx, ret;
 417
 418         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 419         if (devidx >= MMC_NUM_MINORS)
 420                 return ERR_PTR(-ENOSPC);
 421         __set_bit(devidx, dev_use);
 422
 423         md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 424         if (!md) {
 425                 ret = -ENOMEM;
 426                 goto out;
 427         }
 428
 429
 430         /*
 431          * Set the read-only status based on the supported commands
 432          * and the write protect switch.
 433          */
 434         md->read_only = mmc_blk_readonly(card);
 435
 436         /*
 437          * Both SD and MMC specifications state (although a bit
 438          * unclearly in the MMC case) that a block size of 512
 439          * bytes must always be supported by the card.
 440          */
 441         md->block_bits = 9;
 442
 443         md->disk = alloc_disk(1 << MMC_SHIFT);
 444         if (md->disk == NULL) {
 445                 ret = -ENOMEM;
 446                 goto err_kfree;
 447         }
 448
 449         spin_lock_init(&md->lock);
 450         md->usage = 1;
 451
 452         ret = mmc_init_queue(&md->queue, card, &md->lock);
 453         if (ret)
 454                 goto err_putdisk;
 455
 456         md->queue.issue_fn = mmc_blk_issue_rq;
 457         md->queue.data = md;
 458
 459         md->disk->major = MMC_BLOCK_MAJOR;
 460         md->disk->first_minor = devidx << MMC_SHIFT;
 461         md->disk->fops = &mmc_bdops;
 462         md->disk->private_data = md;
 463         md->disk->queue = md->queue.queue;
 464         md->disk->driverfs_dev = &card->dev;
 465
 466         /*
 467          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 468          *
 469          * - be set for removable media with permanent block devices
 470          * - be unset for removable block devices with permanent media
 471          *
 472          * Since MMC block devices clearly fall under the second
 473          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 474          * should use the block device creation/destruction hotplug
 475          * messages to tell when the card is present.
 476          */
 477
 478         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 479
 480         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 481
 482         if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 483                 /*
 484                  * The EXT_CSD sector count is in number or 512 byte
 485                  * sectors.
 486                  */
 487                 set_capacity(md->disk, card->ext_csd.sectors);
 488         } else {
 489                 /*
 490                  * The CSD capacity field is in units of read_blkbits.
 491                  * set_capacity takes units of 512 bytes.
 492                  */
 493                 set_capacity(md->disk,
 494                         card->csd.capacity << (card->csd.read_blkbits - 9));
 495         }
 496         return md;
 497
 498  err_putdisk:
 499         put_disk(md->disk);
 500  err_kfree:
 501         kfree(md);
 502  out:
 503         return ERR_PTR(ret);
 504 }
 505
 506 static int
 507 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 508 {
 509         struct mmc_command cmd;
 510         int err;
 511
 512         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 513         if (mmc_card_blockaddr(card))
 514                 return 0;
 515
 516         mmc_claim_host(card->host);
 517         cmd.opcode = MMC_SET_BLOCKLEN;
 518         cmd.arg = 1 << md->block_bits;
 519         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 520         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 521         mmc_release_host(card->host);
 522
 523         if (err) {
 524                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 525                         md->disk->disk_name, cmd.arg, err);
 526                 return -EINVAL;
 527         }
 528
 529         return 0;
 530 }
 531
 532 static int mmc_blk_probe(struct mmc_card *card)
 533 {
 534         struct mmc_blk_data *md;
 535         int err;
 536
 537         /*
 538          * Check that the card supports the command class(es) we need.
 539          */
 540         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 541                 return -ENODEV;
 542
 543         md = mmc_blk_alloc(card);
 544         if (IS_ERR(md))
 545                 return PTR_ERR(md);
 546
 547         err = mmc_blk_set_blksize(md, card);
 548         if (err)
 549                 goto out;
 550
 551         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 552                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 553                 (unsigned long long)(get_capacity(md->disk) >> 1),
 554                 md->read_only ? "(ro)" : "");
 555
 556         mmc_set_drvdata(card, md);
 557         add_disk(md->disk);
 558         return 0;
 559
 560  out:
 561         mmc_blk_put(md);
 562
 563         return err;
 564 }
 565
 566 static void mmc_blk_remove(struct mmc_card *card)
 567 {
 568         struct mmc_blk_data *md = mmc_get_drvdata(card);
 569
 570         if (md) {
 571                 int devidx;
 572
 573                 /* Stop new requests from getting into the queue */
 574                 del_gendisk(md->disk);
 575
 576                 /* Then flush out any already in there */
 577                 mmc_cleanup_queue(&md->queue);
 578
 579                 devidx = md->disk->first_minor >> MMC_SHIFT;
 580                 __clear_bit(devidx, dev_use);
 581
 582                 mmc_blk_put(md);
 583         }
 584         mmc_set_drvdata(card, NULL);
 585 }
 586
 587 #ifdef CONFIG_PM
 588 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 589 {
 590         struct mmc_blk_data *md = mmc_get_drvdata(card);
 591
 592         if (md) {
 593                 mmc_queue_suspend(&md->queue);
 594         }
 595         return 0;
 596 }
 597
 598 static int mmc_blk_resume(struct mmc_card *card)
 599 {
 600         struct mmc_blk_data *md = mmc_get_drvdata(card);
 601
 602         if (md) {
 603                 mmc_blk_set_blksize(md, card);
 604                 mmc_queue_resume(&md->queue);
 605         }
 606         return 0;
 607 }
 608 #else
 609 #define mmc_blk_suspend NULL
 610 #define mmc_blk_resume  NULL
 611 #endif
 612
 613 static struct mmc_driver mmc_driver = {
 614         .drv            = {
 615                 .name   = "mmcblk",
 616         },
 617         .probe          = mmc_blk_probe,
 618         .remove         = mmc_blk_remove,
 619         .suspend        = mmc_blk_suspend,
 620         .resume         = mmc_blk_resume,
 621 };
 622
 623 static int __init mmc_blk_init(void)
 624 {
 625         int res = -ENOMEM;
 626
 627         res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 628         if (res)
 629                 goto out;
 630
 631         return mmc_register_driver(&mmc_driver);
 632
 633  out:
 634         return res;
 635 }
 636
 637 static void __exit mmc_blk_exit(void)
 638 {
 639         mmc_unregister_driver(&mmc_driver);
 640         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 641 }
 642
 643 module_init(mmc_blk_init);
 644 module_exit(mmc_blk_exit);
 645
 646 MODULE_LICENSE("GPL");
 647 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 648