drivers/mmc/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/protocol.h>
  36 #include <linux/mmc/host.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 static int major;
  49
  50 /*
  51  * There is one mmc_blk_data per slot.
  52  */
  53 struct mmc_blk_data {
  54         spinlock_t      lock;
  55         struct gendisk  *disk;
  56         struct mmc_queue queue;
  57
  58         unsigned int    usage;
  59         unsigned int    block_bits;
  60         unsigned int    read_only;
  61 };
  62
  63 static DEFINE_MUTEX(open_lock);
  64
  65 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  66 {
  67         struct mmc_blk_data *md;
  68
  69         mutex_lock(&open_lock);
  70         md = disk->private_data;
  71         if (md && md->usage == 0)
  72                 md = NULL;
  73         if (md)
  74                 md->usage++;
  75         mutex_unlock(&open_lock);
  76
  77         return md;
  78 }
  79
  80 static void mmc_blk_put(struct mmc_blk_data *md)
  81 {
  82         mutex_lock(&open_lock);
  83         md->usage--;
  84         if (md->usage == 0) {
  85                 put_disk(md->disk);
  86                 kfree(md);
  87         }
  88         mutex_unlock(&open_lock);
  89 }
  90
  91 static int mmc_blk_open(struct inode *inode, struct file *filp)
  92 {
  93         struct mmc_blk_data *md;
  94         int ret = -ENXIO;
  95
  96         md = mmc_blk_get(inode->i_bdev->bd_disk);
  97         if (md) {
  98                 if (md->usage == 2)
  99                         check_disk_change(inode->i_bdev);
 100                 ret = 0;
 101
 102                 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
 103                         ret = -EROFS;
 104         }
 105
 106         return ret;
 107 }
 108
 109 static int mmc_blk_release(struct inode *inode, struct file *filp)
 110 {
 111         struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
 112
 113         mmc_blk_put(md);
 114         return 0;
 115 }
 116
 117 static int
 118 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 119 {
 120         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 121         geo->heads = 4;
 122         geo->sectors = 16;
 123         return 0;
 124 }
 125
 126 static struct block_device_operations mmc_bdops = {
 127         .open                   = mmc_blk_open,
 128         .release                = mmc_blk_release,
 129         .getgeo                 = mmc_blk_getgeo,
 130         .owner                  = THIS_MODULE,
 131 };
 132
 133 struct mmc_blk_request {
 134         struct mmc_request      mrq;
 135         struct mmc_command      cmd;
 136         struct mmc_command      stop;
 137         struct mmc_data         data;
 138 };
 139
 140 static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
 141 {
 142         struct mmc_blk_data *md = mq->data;
 143         int stat = BLKPREP_OK;
 144
 145         /*
 146          * If we have no device, we haven't finished initialising.
 147          */
 148         if (!md || !mq->card) {
 149                 printk(KERN_ERR "%s: killing request - no device/host\n",
 150                        req->rq_disk->disk_name);
 151                 stat = BLKPREP_KILL;
 152         }
 153
 154         return stat;
 155 }
 156
 157 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 158 {
 159         int err;
 160         u32 blocks;
 161
 162         struct mmc_request mrq;
 163         struct mmc_command cmd;
 164         struct mmc_data data;
 165         unsigned int timeout_us;
 166
 167         struct scatterlist sg;
 168
 169         memset(&cmd, 0, sizeof(struct mmc_command));
 170
 171         cmd.opcode = MMC_APP_CMD;
 172         cmd.arg = card->rca << 16;
 173         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 174
 175         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 176         if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD))
 177                 return (u32)-1;
 178
 179         memset(&cmd, 0, sizeof(struct mmc_command));
 180
 181         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 182         cmd.arg = 0;
 183         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 184
 185         memset(&data, 0, sizeof(struct mmc_data));
 186
 187         data.timeout_ns = card->csd.tacc_ns * 100;
 188         data.timeout_clks = card->csd.tacc_clks * 100;
 189
 190         timeout_us = data.timeout_ns / 1000;
 191         timeout_us += data.timeout_clks * 1000 /
 192                 (card->host->ios.clock / 1000);
 193
 194         if (timeout_us > 100000) {
 195                 data.timeout_ns = 100000000;
 196                 data.timeout_clks = 0;
 197         }
 198
 199         data.blksz = 4;
 200         data.blocks = 1;
 201         data.flags = MMC_DATA_READ;
 202         data.sg = &sg;
 203         data.sg_len = 1;
 204
 205         memset(&mrq, 0, sizeof(struct mmc_request));
 206
 207         mrq.cmd = &cmd;
 208         mrq.data = &data;
 209
 210         sg_init_one(&sg, &blocks, 4);
 211
 212         mmc_wait_for_req(card->host, &mrq);
 213
 214         if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE)
 215                 return (u32)-1;
 216
 217         blocks = ntohl(blocks);
 218
 219         return blocks;
 220 }
 221
 222 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 223 {
 224         struct mmc_blk_data *md = mq->data;
 225         struct mmc_card *card = md->queue.card;
 226         struct mmc_blk_request brq;
 227         int ret = 1, sg_pos, data_size;
 228
 229         if (mmc_card_claim_host(card))
 230                 goto flush_queue;
 231
 232         do {
 233                 struct mmc_command cmd;
 234                 u32 readcmd, writecmd;
 235
 236                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 237                 brq.mrq.cmd = &brq.cmd;
 238                 brq.mrq.data = &brq.data;
 239
 240                 brq.cmd.arg = req->sector;
 241                 if (!mmc_card_blockaddr(card))
 242                         brq.cmd.arg <<= 9;
 243                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 244                 brq.data.blksz = 1 << md->block_bits;
 245                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 246                 brq.stop.arg = 0;
 247                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 248                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 249                 if (brq.data.blocks > card->host->max_blk_count)
 250                         brq.data.blocks = card->host->max_blk_count;
 251
 252                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 253
 254                 /*
 255                  * If the host doesn't support multiple block writes, force
 256                  * block writes to single block. SD cards are excepted from
 257                  * this rule as they support querying the number of
 258                  * successfully written sectors.
 259                  */
 260                 if (rq_data_dir(req) != READ &&
 261                     !(card->host->caps & MMC_CAP_MULTIWRITE) &&
 262                     !mmc_card_sd(card))
 263                         brq.data.blocks = 1;
 264
 265                 if (brq.data.blocks > 1) {
 266                         brq.data.flags |= MMC_DATA_MULTI;
 267                         brq.mrq.stop = &brq.stop;
 268                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 269                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 270                 } else {
 271                         brq.mrq.stop = NULL;
 272                         readcmd = MMC_READ_SINGLE_BLOCK;
 273                         writecmd = MMC_WRITE_BLOCK;
 274                 }
 275
 276                 if (rq_data_dir(req) == READ) {
 277                         brq.cmd.opcode = readcmd;
 278                         brq.data.flags |= MMC_DATA_READ;
 279                 } else {
 280                         brq.cmd.opcode = writecmd;
 281                         brq.data.flags |= MMC_DATA_WRITE;
 282                 }
 283
 284                 brq.data.sg = mq->sg;
 285                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 286
 287                 if (brq.data.blocks !=
 288                     (req->nr_sectors >> (md->block_bits - 9))) {
 289                         data_size = brq.data.blocks * brq.data.blksz;
 290                         for (sg_pos = 0; sg_pos < brq.data.sg_len; sg_pos++) {
 291                                 data_size -= mq->sg[sg_pos].length;
 292                                 if (data_size <= 0) {
 293                                         mq->sg[sg_pos].length += data_size;
 294                                         sg_pos++;
 295                                         break;
 296                                 }
 297                         }
 298                         brq.data.sg_len = sg_pos;
 299                 }
 300
 301                 mmc_wait_for_req(card->host, &brq.mrq);
 302                 if (brq.cmd.error) {
 303                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 304                                req->rq_disk->disk_name, brq.cmd.error);
 305                         goto cmd_err;
 306                 }
 307
 308                 if (brq.data.error) {
 309                         printk(KERN_ERR "%s: error %d transferring data\n",
 310                                req->rq_disk->disk_name, brq.data.error);
 311                         goto cmd_err;
 312                 }
 313
 314                 if (brq.stop.error) {
 315                         printk(KERN_ERR "%s: error %d sending stop command\n",
 316                                req->rq_disk->disk_name, brq.stop.error);
 317                         goto cmd_err;
 318                 }
 319
 320                 if (rq_data_dir(req) != READ) {
 321                         do {
 322                                 int err;
 323
 324                                 cmd.opcode = MMC_SEND_STATUS;
 325                                 cmd.arg = card->rca << 16;
 326                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 327                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 328                                 if (err) {
 329                                         printk(KERN_ERR "%s: error %d requesting status\n",
 330                                                req->rq_disk->disk_name, err);
 331                                         goto cmd_err;
 332                                 }
 333                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 334
 335 #if 0
 336                         if (cmd.resp[0] & ~0x00000900)
 337                                 printk(KERN_ERR "%s: status = %08x\n",
 338                                        req->rq_disk->disk_name, cmd.resp[0]);
 339                         if (mmc_decode_status(cmd.resp))
 340                                 goto cmd_err;
 341 #endif
 342                 }
 343
 344                 /*
 345                  * A block was successfully transferred.
 346                  */
 347                 spin_lock_irq(&md->lock);
 348                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 349                 if (!ret) {
 350                         /*
 351                          * The whole request completed successfully.
 352                          */
 353                         add_disk_randomness(req->rq_disk);
 354                         blkdev_dequeue_request(req);
 355                         end_that_request_last(req, 1);
 356                 }
 357                 spin_unlock_irq(&md->lock);
 358         } while (ret);
 359
 360         mmc_card_release_host(card);
 361
 362         return 1;
 363
 364  cmd_err:
 365         /*
 366          * If this is an SD card and we're writing, we can first
 367          * mark the known good sectors as ok.
 368          *
 369          * If the card is not SD, we can still ok written sectors
 370          * if the controller can do proper error reporting.
 371          *
 372          * For reads we just fail the entire chunk as that should
 373          * be safe in all cases.
 374          */
 375         if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
 376                 u32 blocks;
 377                 unsigned int bytes;
 378
 379                 blocks = mmc_sd_num_wr_blocks(card);
 380                 if (blocks != (u32)-1) {
 381                         if (card->csd.write_partial)
 382                                 bytes = blocks << md->block_bits;
 383                         else
 384                                 bytes = blocks << 9;
 385                         spin_lock_irq(&md->lock);
 386                         ret = end_that_request_chunk(req, 1, bytes);
 387                         spin_unlock_irq(&md->lock);
 388                 }
 389         } else if (rq_data_dir(req) != READ &&
 390                    (card->host->caps & MMC_CAP_MULTIWRITE)) {
 391                 spin_lock_irq(&md->lock);
 392                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 393                 spin_unlock_irq(&md->lock);
 394         }
 395
 396 flush_queue:
 397
 398         mmc_card_release_host(card);
 399
 400         spin_lock_irq(&md->lock);
 401         while (ret) {
 402                 ret = end_that_request_chunk(req, 0,
 403                                 req->current_nr_sectors << 9);
 404         }
 405
 406         add_disk_randomness(req->rq_disk);
 407         blkdev_dequeue_request(req);
 408         end_that_request_last(req, 0);
 409         spin_unlock_irq(&md->lock);
 410
 411         return 0;
 412 }
 413
 414 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 415
 416 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 417
 418 static inline int mmc_blk_readonly(struct mmc_card *card)
 419 {
 420         return mmc_card_readonly(card) ||
 421                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 422 }
 423
 424 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 425 {
 426         struct mmc_blk_data *md;
 427         int devidx, ret;
 428
 429         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 430         if (devidx >= MMC_NUM_MINORS)
 431                 return ERR_PTR(-ENOSPC);
 432         __set_bit(devidx, dev_use);
 433
 434         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 435         if (!md) {
 436                 ret = -ENOMEM;
 437                 goto out;
 438         }
 439
 440         memset(md, 0, sizeof(struct mmc_blk_data));
 441
 442         /*
 443          * Set the read-only status based on the supported commands
 444          * and the write protect switch.
 445          */
 446         md->read_only = mmc_blk_readonly(card);
 447
 448         /*
 449          * Both SD and MMC specifications state (although a bit
 450          * unclearly in the MMC case) that a block size of 512
 451          * bytes must always be supported by the card.
 452          */
 453         md->block_bits = 9;
 454
 455         md->disk = alloc_disk(1 << MMC_SHIFT);
 456         if (md->disk == NULL) {
 457                 ret = -ENOMEM;
 458                 goto err_kfree;
 459         }
 460
 461         spin_lock_init(&md->lock);
 462         md->usage = 1;
 463
 464         ret = mmc_init_queue(&md->queue, card, &md->lock);
 465         if (ret)
 466                 goto err_putdisk;
 467
 468         md->queue.prep_fn = mmc_blk_prep_rq;
 469         md->queue.issue_fn = mmc_blk_issue_rq;
 470         md->queue.data = md;
 471
 472         md->disk->major = major;
 473         md->disk->first_minor = devidx << MMC_SHIFT;
 474         md->disk->fops = &mmc_bdops;
 475         md->disk->private_data = md;
 476         md->disk->queue = md->queue.queue;
 477         md->disk->driverfs_dev = &card->dev;
 478
 479         /*
 480          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 481          *
 482          * - be set for removable media with permanent block devices
 483          * - be unset for removable block devices with permanent media
 484          *
 485          * Since MMC block devices clearly fall under the second
 486          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 487          * should use the block device creation/destruction hotplug
 488          * messages to tell when the card is present.
 489          */
 490
 491         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 492
 493         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 494
 495         if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 496                 /*
 497                  * The EXT_CSD sector count is in number or 512 byte
 498                  * sectors.
 499                  */
 500                 set_capacity(md->disk, card->ext_csd.sectors);
 501         } else {
 502                 /*
 503                  * The CSD capacity field is in units of read_blkbits.
 504                  * set_capacity takes units of 512 bytes.
 505                  */
 506                 set_capacity(md->disk,
 507                         card->csd.capacity << (card->csd.read_blkbits - 9));
 508         }
 509         return md;
 510
 511  err_putdisk:
 512         put_disk(md->disk);
 513  err_kfree:
 514         kfree(md);
 515  out:
 516         return ERR_PTR(ret);
 517 }
 518
 519 static int
 520 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 521 {
 522         struct mmc_command cmd;
 523         int err;
 524
 525         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 526         if (mmc_card_blockaddr(card))
 527                 return 0;
 528
 529         mmc_card_claim_host(card);
 530         cmd.opcode = MMC_SET_BLOCKLEN;
 531         cmd.arg = 1 << md->block_bits;
 532         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 533         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 534         mmc_card_release_host(card);
 535
 536         if (err) {
 537                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 538                         md->disk->disk_name, cmd.arg, err);
 539                 return -EINVAL;
 540         }
 541
 542         return 0;
 543 }
 544
 545 static int mmc_blk_probe(struct mmc_card *card)
 546 {
 547         struct mmc_blk_data *md;
 548         int err;
 549
 550         /*
 551          * Check that the card supports the command class(es) we need.
 552          */
 553         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 554                 return -ENODEV;
 555
 556         md = mmc_blk_alloc(card);
 557         if (IS_ERR(md))
 558                 return PTR_ERR(md);
 559
 560         err = mmc_blk_set_blksize(md, card);
 561         if (err)
 562                 goto out;
 563
 564         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 565                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 566                 (unsigned long long)(get_capacity(md->disk) >> 1),
 567                 md->read_only ? "(ro)" : "");
 568
 569         mmc_set_drvdata(card, md);
 570         add_disk(md->disk);
 571         return 0;
 572
 573  out:
 574         mmc_blk_put(md);
 575
 576         return err;
 577 }
 578
 579 static void mmc_blk_remove(struct mmc_card *card)
 580 {
 581         struct mmc_blk_data *md = mmc_get_drvdata(card);
 582
 583         if (md) {
 584                 int devidx;
 585
 586                 /* Stop new requests from getting into the queue */
 587                 del_gendisk(md->disk);
 588
 589                 /* Then flush out any already in there */
 590                 mmc_cleanup_queue(&md->queue);
 591
 592                 devidx = md->disk->first_minor >> MMC_SHIFT;
 593                 __clear_bit(devidx, dev_use);
 594
 595                 mmc_blk_put(md);
 596         }
 597         mmc_set_drvdata(card, NULL);
 598 }
 599
 600 #ifdef CONFIG_PM
 601 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 602 {
 603         struct mmc_blk_data *md = mmc_get_drvdata(card);
 604
 605         if (md) {
 606                 mmc_queue_suspend(&md->queue);
 607         }
 608         return 0;
 609 }
 610
 611 static int mmc_blk_resume(struct mmc_card *card)
 612 {
 613         struct mmc_blk_data *md = mmc_get_drvdata(card);
 614
 615         if (md) {
 616                 mmc_blk_set_blksize(md, card);
 617                 mmc_queue_resume(&md->queue);
 618         }
 619         return 0;
 620 }
 621 #else
 622 #define mmc_blk_suspend NULL
 623 #define mmc_blk_resume  NULL
 624 #endif
 625
 626 static struct mmc_driver mmc_driver = {
 627         .drv            = {
 628                 .name   = "mmcblk",
 629         },
 630         .probe          = mmc_blk_probe,
 631         .remove         = mmc_blk_remove,
 632         .suspend        = mmc_blk_suspend,
 633         .resume         = mmc_blk_resume,
 634 };
 635
 636 static int __init mmc_blk_init(void)
 637 {
 638         int res = -ENOMEM;
 639
 640         res = register_blkdev(major, "mmc");
 641         if (res < 0) {
 642                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 643                        major, res);
 644                 goto out;
 645         }
 646         if (major == 0)
 647                 major = res;
 648
 649         return mmc_register_driver(&mmc_driver);
 650
 651  out:
 652         return res;
 653 }
 654
 655 static void __exit mmc_blk_exit(void)
 656 {
 657         mmc_unregister_driver(&mmc_driver);
 658         unregister_blkdev(major, "mmc");
 659 }
 660
 661 module_init(mmc_blk_init);
 662 module_exit(mmc_blk_exit);
 663
 664 MODULE_LICENSE("GPL");
 665 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 666
 667 module_param(major, int, 0444);
 668 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");