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_R1 | MMC_CMD_AC;
 155
 156         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 157         if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD))
 158                 return (u32)-1;
 159
 160         memset(&cmd, 0, sizeof(struct mmc_command));
 161
 162         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 163         cmd.arg = 0;
 164         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 165
 166         memset(&data, 0, sizeof(struct mmc_data));
 167
 168         data.timeout_ns = card->csd.tacc_ns * 100;
 169         data.timeout_clks = card->csd.tacc_clks * 100;
 170
 171         timeout_us = data.timeout_ns / 1000;
 172         timeout_us += data.timeout_clks * 1000 /
 173                 (card->host->ios.clock / 1000);
 174
 175         if (timeout_us > 100000) {
 176                 data.timeout_ns = 100000000;
 177                 data.timeout_clks = 0;
 178         }
 179
 180         data.blksz = 4;
 181         data.blocks = 1;
 182         data.flags = MMC_DATA_READ;
 183         data.sg = &sg;
 184         data.sg_len = 1;
 185
 186         memset(&mrq, 0, sizeof(struct mmc_request));
 187
 188         mrq.cmd = &cmd;
 189         mrq.data = &data;
 190
 191         sg_init_one(&sg, &blocks, 4);
 192
 193         mmc_wait_for_req(card->host, &mrq);
 194
 195         if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE)
 196                 return (u32)-1;
 197
 198         blocks = ntohl(blocks);
 199
 200         return blocks;
 201 }
 202
 203 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 204 {
 205         struct mmc_blk_data *md = mq->data;
 206         struct mmc_card *card = md->queue.card;
 207         struct mmc_blk_request brq;
 208         int ret = 1, sg_pos, data_size;
 209
 210         mmc_claim_host(card->host);
 211
 212         do {
 213                 struct mmc_command cmd;
 214                 u32 readcmd, writecmd;
 215
 216                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 217                 brq.mrq.cmd = &brq.cmd;
 218                 brq.mrq.data = &brq.data;
 219
 220                 brq.cmd.arg = req->sector;
 221                 if (!mmc_card_blockaddr(card))
 222                         brq.cmd.arg <<= 9;
 223                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 224                 brq.data.blksz = 1 << md->block_bits;
 225                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 226                 brq.stop.arg = 0;
 227                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 228                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 229                 if (brq.data.blocks > card->host->max_blk_count)
 230                         brq.data.blocks = card->host->max_blk_count;
 231
 232                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 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                         brq.data.flags |= MMC_DATA_MULTI;
 247                         brq.mrq.stop = &brq.stop;
 248                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 249                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 250                 } else {
 251                         brq.mrq.stop = NULL;
 252                         readcmd = MMC_READ_SINGLE_BLOCK;
 253                         writecmd = MMC_WRITE_BLOCK;
 254                 }
 255
 256                 if (rq_data_dir(req) == READ) {
 257                         brq.cmd.opcode = readcmd;
 258                         brq.data.flags |= MMC_DATA_READ;
 259                 } else {
 260                         brq.cmd.opcode = writecmd;
 261                         brq.data.flags |= MMC_DATA_WRITE;
 262                 }
 263
 264                 brq.data.sg = mq->sg;
 265                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 266
 267                 if (brq.data.blocks !=
 268                     (req->nr_sectors >> (md->block_bits - 9))) {
 269                         data_size = brq.data.blocks * brq.data.blksz;
 270                         for (sg_pos = 0; sg_pos < brq.data.sg_len; sg_pos++) {
 271                                 data_size -= mq->sg[sg_pos].length;
 272                                 if (data_size <= 0) {
 273                                         mq->sg[sg_pos].length += data_size;
 274                                         sg_pos++;
 275                                         break;
 276                                 }
 277                         }
 278                         brq.data.sg_len = sg_pos;
 279                 }
 280
 281                 mmc_wait_for_req(card->host, &brq.mrq);
 282                 if (brq.cmd.error) {
 283                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 284                                req->rq_disk->disk_name, brq.cmd.error);
 285                         goto cmd_err;
 286                 }
 287
 288                 if (brq.data.error) {
 289                         printk(KERN_ERR "%s: error %d transferring data\n",
 290                                req->rq_disk->disk_name, brq.data.error);
 291                         goto cmd_err;
 292                 }
 293
 294                 if (brq.stop.error) {
 295                         printk(KERN_ERR "%s: error %d sending stop command\n",
 296                                req->rq_disk->disk_name, brq.stop.error);
 297                         goto cmd_err;
 298                 }
 299
 300                 if (rq_data_dir(req) != READ) {
 301                         do {
 302                                 int err;
 303
 304                                 cmd.opcode = MMC_SEND_STATUS;
 305                                 cmd.arg = card->rca << 16;
 306                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 307                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 308                                 if (err) {
 309                                         printk(KERN_ERR "%s: error %d requesting status\n",
 310                                                req->rq_disk->disk_name, err);
 311                                         goto cmd_err;
 312                                 }
 313                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 314
 315 #if 0
 316                         if (cmd.resp[0] & ~0x00000900)
 317                                 printk(KERN_ERR "%s: status = %08x\n",
 318                                        req->rq_disk->disk_name, cmd.resp[0]);
 319                         if (mmc_decode_status(cmd.resp))
 320                                 goto cmd_err;
 321 #endif
 322                 }
 323
 324                 /*
 325                  * A block was successfully transferred.
 326                  */
 327                 spin_lock_irq(&md->lock);
 328                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 329                 if (!ret) {
 330                         /*
 331                          * The whole request completed successfully.
 332                          */
 333                         add_disk_randomness(req->rq_disk);
 334                         blkdev_dequeue_request(req);
 335                         end_that_request_last(req, 1);
 336                 }
 337                 spin_unlock_irq(&md->lock);
 338         } while (ret);
 339
 340         mmc_release_host(card->host);
 341
 342         return 1;
 343
 344  cmd_err:
 345         /*
 346          * If this is an SD card and we're writing, we can first
 347          * mark the known good sectors as ok.
 348          *
 349          * If the card is not SD, we can still ok written sectors
 350          * if the controller can do proper error reporting.
 351          *
 352          * For reads we just fail the entire chunk as that should
 353          * be safe in all cases.
 354          */
 355         if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
 356                 u32 blocks;
 357                 unsigned int bytes;
 358
 359                 blocks = mmc_sd_num_wr_blocks(card);
 360                 if (blocks != (u32)-1) {
 361                         if (card->csd.write_partial)
 362                                 bytes = blocks << md->block_bits;
 363                         else
 364                                 bytes = blocks << 9;
 365                         spin_lock_irq(&md->lock);
 366                         ret = end_that_request_chunk(req, 1, bytes);
 367                         spin_unlock_irq(&md->lock);
 368                 }
 369         } else if (rq_data_dir(req) != READ &&
 370                    (card->host->caps & MMC_CAP_MULTIWRITE)) {
 371                 spin_lock_irq(&md->lock);
 372                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 373                 spin_unlock_irq(&md->lock);
 374         }
 375
 376         mmc_release_host(card->host);
 377
 378         spin_lock_irq(&md->lock);
 379         while (ret) {
 380                 ret = end_that_request_chunk(req, 0,
 381                                 req->current_nr_sectors << 9);
 382         }
 383
 384         add_disk_randomness(req->rq_disk);
 385         blkdev_dequeue_request(req);
 386         end_that_request_last(req, 0);
 387         spin_unlock_irq(&md->lock);
 388
 389         return 0;
 390 }
 391
 392 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 393
 394 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 395
 396 static inline int mmc_blk_readonly(struct mmc_card *card)
 397 {
 398         return mmc_card_readonly(card) ||
 399                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 400 }
 401
 402 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 403 {
 404         struct mmc_blk_data *md;
 405         int devidx, ret;
 406
 407         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 408         if (devidx >= MMC_NUM_MINORS)
 409                 return ERR_PTR(-ENOSPC);
 410         __set_bit(devidx, dev_use);
 411
 412         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 413         if (!md) {
 414                 ret = -ENOMEM;
 415                 goto out;
 416         }
 417
 418         memset(md, 0, sizeof(struct mmc_blk_data));
 419
 420         /*
 421          * Set the read-only status based on the supported commands
 422          * and the write protect switch.
 423          */
 424         md->read_only = mmc_blk_readonly(card);
 425
 426         /*
 427          * Both SD and MMC specifications state (although a bit
 428          * unclearly in the MMC case) that a block size of 512
 429          * bytes must always be supported by the card.
 430          */
 431         md->block_bits = 9;
 432
 433         md->disk = alloc_disk(1 << MMC_SHIFT);
 434         if (md->disk == NULL) {
 435                 ret = -ENOMEM;
 436                 goto err_kfree;
 437         }
 438
 439         spin_lock_init(&md->lock);
 440         md->usage = 1;
 441
 442         ret = mmc_init_queue(&md->queue, card, &md->lock);
 443         if (ret)
 444                 goto err_putdisk;
 445
 446         md->queue.issue_fn = mmc_blk_issue_rq;
 447         md->queue.data = md;
 448
 449         md->disk->major = MMC_BLOCK_MAJOR;
 450         md->disk->first_minor = devidx << MMC_SHIFT;
 451         md->disk->fops = &mmc_bdops;
 452         md->disk->private_data = md;
 453         md->disk->queue = md->queue.queue;
 454         md->disk->driverfs_dev = &card->dev;
 455
 456         /*
 457          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 458          *
 459          * - be set for removable media with permanent block devices
 460          * - be unset for removable block devices with permanent media
 461          *
 462          * Since MMC block devices clearly fall under the second
 463          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 464          * should use the block device creation/destruction hotplug
 465          * messages to tell when the card is present.
 466          */
 467
 468         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 469
 470         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 471
 472         if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 473                 /*
 474                  * The EXT_CSD sector count is in number or 512 byte
 475                  * sectors.
 476                  */
 477                 set_capacity(md->disk, card->ext_csd.sectors);
 478         } else {
 479                 /*
 480                  * The CSD capacity field is in units of read_blkbits.
 481                  * set_capacity takes units of 512 bytes.
 482                  */
 483                 set_capacity(md->disk,
 484                         card->csd.capacity << (card->csd.read_blkbits - 9));
 485         }
 486         return md;
 487
 488  err_putdisk:
 489         put_disk(md->disk);
 490  err_kfree:
 491         kfree(md);
 492  out:
 493         return ERR_PTR(ret);
 494 }
 495
 496 static int
 497 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 498 {
 499         struct mmc_command cmd;
 500         int err;
 501
 502         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 503         if (mmc_card_blockaddr(card))
 504                 return 0;
 505
 506         mmc_claim_host(card->host);
 507         cmd.opcode = MMC_SET_BLOCKLEN;
 508         cmd.arg = 1 << md->block_bits;
 509         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 510         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 511         mmc_release_host(card->host);
 512
 513         if (err) {
 514                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 515                         md->disk->disk_name, cmd.arg, err);
 516                 return -EINVAL;
 517         }
 518
 519         return 0;
 520 }
 521
 522 static int mmc_blk_probe(struct mmc_card *card)
 523 {
 524         struct mmc_blk_data *md;
 525         int err;
 526
 527         /*
 528          * Check that the card supports the command class(es) we need.
 529          */
 530         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 531                 return -ENODEV;
 532
 533         md = mmc_blk_alloc(card);
 534         if (IS_ERR(md))
 535                 return PTR_ERR(md);
 536
 537         err = mmc_blk_set_blksize(md, card);
 538         if (err)
 539                 goto out;
 540
 541         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 542                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 543                 (unsigned long long)(get_capacity(md->disk) >> 1),
 544                 md->read_only ? "(ro)" : "");
 545
 546         mmc_set_drvdata(card, md);
 547         add_disk(md->disk);
 548         return 0;
 549
 550  out:
 551         mmc_blk_put(md);
 552
 553         return err;
 554 }
 555
 556 static void mmc_blk_remove(struct mmc_card *card)
 557 {
 558         struct mmc_blk_data *md = mmc_get_drvdata(card);
 559
 560         if (md) {
 561                 int devidx;
 562
 563                 /* Stop new requests from getting into the queue */
 564                 del_gendisk(md->disk);
 565
 566                 /* Then flush out any already in there */
 567                 mmc_cleanup_queue(&md->queue);
 568
 569                 devidx = md->disk->first_minor >> MMC_SHIFT;
 570                 __clear_bit(devidx, dev_use);
 571
 572                 mmc_blk_put(md);
 573         }
 574         mmc_set_drvdata(card, NULL);
 575 }
 576
 577 #ifdef CONFIG_PM
 578 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 579 {
 580         struct mmc_blk_data *md = mmc_get_drvdata(card);
 581
 582         if (md) {
 583                 mmc_queue_suspend(&md->queue);
 584         }
 585         return 0;
 586 }
 587
 588 static int mmc_blk_resume(struct mmc_card *card)
 589 {
 590         struct mmc_blk_data *md = mmc_get_drvdata(card);
 591
 592         if (md) {
 593                 mmc_blk_set_blksize(md, card);
 594                 mmc_queue_resume(&md->queue);
 595         }
 596         return 0;
 597 }
 598 #else
 599 #define mmc_blk_suspend NULL
 600 #define mmc_blk_resume  NULL
 601 #endif
 602
 603 static struct mmc_driver mmc_driver = {
 604         .drv            = {
 605                 .name   = "mmcblk",
 606         },
 607         .probe          = mmc_blk_probe,
 608         .remove         = mmc_blk_remove,
 609         .suspend        = mmc_blk_suspend,
 610         .resume         = mmc_blk_resume,
 611 };
 612
 613 static int __init mmc_blk_init(void)
 614 {
 615         int res = -ENOMEM;
 616
 617         res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 618         if (res)
 619                 goto out;
 620
 621         return mmc_register_driver(&mmc_driver);
 622
 623  out:
 624         return res;
 625 }
 626
 627 static void __exit mmc_blk_exit(void)
 628 {
 629         mmc_unregister_driver(&mmc_driver);
 630         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 631 }
 632
 633 module_init(mmc_blk_init);
 634 module_exit(mmc_blk_exit);
 635
 636 MODULE_LICENSE("GPL");
 637 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 638