drivers/mmc/mmc_block.c

   1 /*
   2  * Block driver for media (i.e., flash cards)
   3  *
   4  * Copyright 2002 Hewlett-Packard Company
   5  *
   6  * Use consistent with the GNU GPL is permitted,
   7  * provided that this copyright notice is
   8  * preserved in its entirety in all copies and derived works.
   9  *
  10  * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
  11  * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
  12  * FITNESS FOR ANY PARTICULAR PURPOSE.
  13  *
  14  * Many thanks to Alessandro Rubini and Jonathan Corbet!
  15  *
  16  * Author:  Andrew Christian
  17  *          28 May 2002
  18  */
  19 #include <linux/moduleparam.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22
  23 #include <linux/kernel.h>
  24 #include <linux/fs.h>
  25 #include <linux/errno.h>
  26 #include <linux/hdreg.h>
  27 #include <linux/kdev_t.h>
  28 #include <linux/blkdev.h>
  29 #include <linux/mutex.h>
  30 #include <linux/scatterlist.h>
  31
  32 #include <linux/mmc/card.h>
  33 #include <linux/mmc/host.h>
  34 #include <linux/mmc/protocol.h>
  35 #include <linux/mmc/host.h>
  36
  37 #include <asm/system.h>
  38 #include <asm/uaccess.h>
  39
  40 #include "mmc_queue.h"
  41
  42 /*
  43  * max 8 partitions per card
  44  */
  45 #define MMC_SHIFT       3
  46
  47 static int major;
  48
  49 /*
  50  * There is one mmc_blk_data per slot.
  51  */
  52 struct mmc_blk_data {
  53         spinlock_t      lock;
  54         struct gendisk  *disk;
  55         struct mmc_queue queue;
  56
  57         unsigned int    usage;
  58         unsigned int    block_bits;
  59         unsigned int    read_only;
  60 };
  61
  62 static DEFINE_MUTEX(open_lock);
  63
  64 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  65 {
  66         struct mmc_blk_data *md;
  67
  68         mutex_lock(&open_lock);
  69         md = disk->private_data;
  70         if (md && md->usage == 0)
  71                 md = NULL;
  72         if (md)
  73                 md->usage++;
  74         mutex_unlock(&open_lock);
  75
  76         return md;
  77 }
  78
  79 static void mmc_blk_put(struct mmc_blk_data *md)
  80 {
  81         mutex_lock(&open_lock);
  82         md->usage--;
  83         if (md->usage == 0) {
  84                 put_disk(md->disk);
  85                 kfree(md);
  86         }
  87         mutex_unlock(&open_lock);
  88 }
  89
  90 static int mmc_blk_open(struct inode *inode, struct file *filp)
  91 {
  92         struct mmc_blk_data *md;
  93         int ret = -ENXIO;
  94
  95         md = mmc_blk_get(inode->i_bdev->bd_disk);
  96         if (md) {
  97                 if (md->usage == 2)
  98                         check_disk_change(inode->i_bdev);
  99                 ret = 0;
 100
 101                 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
 102                         ret = -EROFS;
 103         }
 104
 105         return ret;
 106 }
 107
 108 static int mmc_blk_release(struct inode *inode, struct file *filp)
 109 {
 110         struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
 111
 112         mmc_blk_put(md);
 113         return 0;
 114 }
 115
 116 static int
 117 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 118 {
 119         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 120         geo->heads = 4;
 121         geo->sectors = 16;
 122         return 0;
 123 }
 124
 125 static struct block_device_operations mmc_bdops = {
 126         .open                   = mmc_blk_open,
 127         .release                = mmc_blk_release,
 128         .getgeo                 = mmc_blk_getgeo,
 129         .owner                  = THIS_MODULE,
 130 };
 131
 132 struct mmc_blk_request {
 133         struct mmc_request      mrq;
 134         struct mmc_command      cmd;
 135         struct mmc_command      stop;
 136         struct mmc_data         data;
 137 };
 138
 139 static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
 140 {
 141         struct mmc_blk_data *md = mq->data;
 142         int stat = BLKPREP_OK;
 143
 144         /*
 145          * If we have no device, we haven't finished initialising.
 146          */
 147         if (!md || !mq->card) {
 148                 printk(KERN_ERR "%s: killing request - no device/host\n",
 149                        req->rq_disk->disk_name);
 150                 stat = BLKPREP_KILL;
 151         }
 152
 153         return stat;
 154 }
 155
 156 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 157 {
 158         int err;
 159         u32 blocks;
 160
 161         struct mmc_request mrq;
 162         struct mmc_command cmd;
 163         struct mmc_data data;
 164         unsigned int timeout_us;
 165
 166         struct scatterlist sg;
 167
 168         memset(&cmd, 0, sizeof(struct mmc_command));
 169
 170         cmd.opcode = MMC_APP_CMD;
 171         cmd.arg = card->rca << 16;
 172         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 173
 174         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 175         if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD))
 176                 return (u32)-1;
 177
 178         memset(&cmd, 0, sizeof(struct mmc_command));
 179
 180         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 181         cmd.arg = 0;
 182         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 183
 184         memset(&data, 0, sizeof(struct mmc_data));
 185
 186         data.timeout_ns = card->csd.tacc_ns * 100;
 187         data.timeout_clks = card->csd.tacc_clks * 100;
 188
 189         timeout_us = data.timeout_ns / 1000;
 190         timeout_us += data.timeout_clks * 1000 /
 191                 (card->host->ios.clock / 1000);
 192
 193         if (timeout_us > 100000) {
 194                 data.timeout_ns = 100000000;
 195                 data.timeout_clks = 0;
 196         }
 197
 198         data.blksz = 4;
 199         data.blocks = 1;
 200         data.flags = MMC_DATA_READ;
 201         data.sg = &sg;
 202         data.sg_len = 1;
 203
 204         memset(&mrq, 0, sizeof(struct mmc_request));
 205
 206         mrq.cmd = &cmd;
 207         mrq.data = &data;
 208
 209         sg_init_one(&sg, &blocks, 4);
 210
 211         mmc_wait_for_req(card->host, &mrq);
 212
 213         if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE)
 214                 return (u32)-1;
 215
 216         blocks = ntohl(blocks);
 217
 218         return blocks;
 219 }
 220
 221 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 222 {
 223         struct mmc_blk_data *md = mq->data;
 224         struct mmc_card *card = md->queue.card;
 225         struct mmc_blk_request brq;
 226         int ret = 1;
 227
 228         if (mmc_card_claim_host(card))
 229                 goto flush_queue;
 230
 231         do {
 232                 struct mmc_command cmd;
 233                 u32 readcmd, writecmd;
 234
 235                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 236                 brq.mrq.cmd = &brq.cmd;
 237                 brq.mrq.data = &brq.data;
 238
 239                 brq.cmd.arg = req->sector;
 240                 if (!mmc_card_blockaddr(card))
 241                         brq.cmd.arg <<= 9;
 242                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 243                 brq.data.blksz = 1 << md->block_bits;
 244                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 245                 brq.stop.arg = 0;
 246                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 247                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 248                 if (brq.data.blocks > card->host->max_blk_count)
 249                         brq.data.blocks = card->host->max_blk_count;
 250
 251                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 252
 253                 /*
 254                  * If the host doesn't support multiple block writes, force
 255                  * block writes to single block. SD cards are excepted from
 256                  * this rule as they support querying the number of
 257                  * successfully written sectors.
 258                  */
 259                 if (rq_data_dir(req) != READ &&
 260                     !(card->host->caps & MMC_CAP_MULTIWRITE) &&
 261                     !mmc_card_sd(card))
 262                         brq.data.blocks = 1;
 263
 264                 if (brq.data.blocks > 1) {
 265                         brq.data.flags |= MMC_DATA_MULTI;
 266                         brq.mrq.stop = &brq.stop;
 267                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 268                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 269                 } else {
 270                         brq.mrq.stop = NULL;
 271                         readcmd = MMC_READ_SINGLE_BLOCK;
 272                         writecmd = MMC_WRITE_BLOCK;
 273                 }
 274
 275                 if (rq_data_dir(req) == READ) {
 276                         brq.cmd.opcode = readcmd;
 277                         brq.data.flags |= MMC_DATA_READ;
 278                 } else {
 279                         brq.cmd.opcode = writecmd;
 280                         brq.data.flags |= MMC_DATA_WRITE;
 281                 }
 282
 283                 brq.data.sg = mq->sg;
 284                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 285
 286                 mmc_wait_for_req(card->host, &brq.mrq);
 287                 if (brq.cmd.error) {
 288                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 289                                req->rq_disk->disk_name, brq.cmd.error);
 290                         goto cmd_err;
 291                 }
 292
 293                 if (brq.data.error) {
 294                         printk(KERN_ERR "%s: error %d transferring data\n",
 295                                req->rq_disk->disk_name, brq.data.error);
 296                         goto cmd_err;
 297                 }
 298
 299                 if (brq.stop.error) {
 300                         printk(KERN_ERR "%s: error %d sending stop command\n",
 301                                req->rq_disk->disk_name, brq.stop.error);
 302                         goto cmd_err;
 303                 }
 304
 305                 if (rq_data_dir(req) != READ) {
 306                         do {
 307                                 int err;
 308
 309                                 cmd.opcode = MMC_SEND_STATUS;
 310                                 cmd.arg = card->rca << 16;
 311                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 312                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 313                                 if (err) {
 314                                         printk(KERN_ERR "%s: error %d requesting status\n",
 315                                                req->rq_disk->disk_name, err);
 316                                         goto cmd_err;
 317                                 }
 318                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 319
 320 #if 0
 321                         if (cmd.resp[0] & ~0x00000900)
 322                                 printk(KERN_ERR "%s: status = %08x\n",
 323                                        req->rq_disk->disk_name, cmd.resp[0]);
 324                         if (mmc_decode_status(cmd.resp))
 325                                 goto cmd_err;
 326 #endif
 327                 }
 328
 329                 /*
 330                  * A block was successfully transferred.
 331                  */
 332                 spin_lock_irq(&md->lock);
 333                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 334                 if (!ret) {
 335                         /*
 336                          * The whole request completed successfully.
 337                          */
 338                         add_disk_randomness(req->rq_disk);
 339                         blkdev_dequeue_request(req);
 340                         end_that_request_last(req, 1);
 341                 }
 342                 spin_unlock_irq(&md->lock);
 343         } while (ret);
 344
 345         mmc_card_release_host(card);
 346
 347         return 1;
 348
 349  cmd_err:
 350         /*
 351          * If this is an SD card and we're writing, we can first
 352          * mark the known good sectors as ok.
 353          *
 354          * If the card is not SD, we can still ok written sectors
 355          * if the controller can do proper error reporting.
 356          *
 357          * For reads we just fail the entire chunk as that should
 358          * be safe in all cases.
 359          */
 360         if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
 361                 u32 blocks;
 362                 unsigned int bytes;
 363
 364                 blocks = mmc_sd_num_wr_blocks(card);
 365                 if (blocks != (u32)-1) {
 366                         if (card->csd.write_partial)
 367                                 bytes = blocks << md->block_bits;
 368                         else
 369                                 bytes = blocks << 9;
 370                         spin_lock_irq(&md->lock);
 371                         ret = end_that_request_chunk(req, 1, bytes);
 372                         spin_unlock_irq(&md->lock);
 373                 }
 374         } else if (rq_data_dir(req) != READ &&
 375                    (card->host->caps & MMC_CAP_MULTIWRITE)) {
 376                 spin_lock_irq(&md->lock);
 377                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 378                 spin_unlock_irq(&md->lock);
 379         }
 380
 381 flush_queue:
 382
 383         mmc_card_release_host(card);
 384
 385         spin_lock_irq(&md->lock);
 386         while (ret) {
 387                 ret = end_that_request_chunk(req, 0,
 388                                 req->current_nr_sectors << 9);
 389         }
 390
 391         add_disk_randomness(req->rq_disk);
 392         blkdev_dequeue_request(req);
 393         end_that_request_last(req, 0);
 394         spin_unlock_irq(&md->lock);
 395
 396         return 0;
 397 }
 398
 399 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 400
 401 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 402
 403 static inline int mmc_blk_readonly(struct mmc_card *card)
 404 {
 405         return mmc_card_readonly(card) ||
 406                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 407 }
 408
 409 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 410 {
 411         struct mmc_blk_data *md;
 412         int devidx, ret;
 413
 414         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 415         if (devidx >= MMC_NUM_MINORS)
 416                 return ERR_PTR(-ENOSPC);
 417         __set_bit(devidx, dev_use);
 418
 419         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 420         if (!md) {
 421                 ret = -ENOMEM;
 422                 goto out;
 423         }
 424
 425         memset(md, 0, sizeof(struct mmc_blk_data));
 426
 427         /*
 428          * Set the read-only status based on the supported commands
 429          * and the write protect switch.
 430          */
 431         md->read_only = mmc_blk_readonly(card);
 432
 433         /*
 434          * Both SD and MMC specifications state (although a bit
 435          * unclearly in the MMC case) that a block size of 512
 436          * bytes must always be supported by the card.
 437          */
 438         md->block_bits = 9;
 439
 440         md->disk = alloc_disk(1 << MMC_SHIFT);
 441         if (md->disk == NULL) {
 442                 ret = -ENOMEM;
 443                 goto err_kfree;
 444         }
 445
 446         spin_lock_init(&md->lock);
 447         md->usage = 1;
 448
 449         ret = mmc_init_queue(&md->queue, card, &md->lock);
 450         if (ret)
 451                 goto err_putdisk;
 452
 453         md->queue.prep_fn = mmc_blk_prep_rq;
 454         md->queue.issue_fn = mmc_blk_issue_rq;
 455         md->queue.data = md;
 456
 457         md->disk->major = 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         /*
 481          * The CSD capacity field is in units of read_blkbits.
 482          * set_capacity takes units of 512 bytes.
 483          */
 484         set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
 485         return md;
 486
 487  err_putdisk:
 488         put_disk(md->disk);
 489  err_kfree:
 490         kfree(md);
 491  out:
 492         return ERR_PTR(ret);
 493 }
 494
 495 static int
 496 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 497 {
 498         struct mmc_command cmd;
 499         int err;
 500
 501         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 502         if (mmc_card_blockaddr(card))
 503                 return 0;
 504
 505         mmc_card_claim_host(card);
 506         cmd.opcode = MMC_SET_BLOCKLEN;
 507         cmd.arg = 1 << md->block_bits;
 508         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 509         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 510         mmc_card_release_host(card);
 511
 512         if (err) {
 513                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 514                         md->disk->disk_name, cmd.arg, err);
 515                 return -EINVAL;
 516         }
 517
 518         return 0;
 519 }
 520
 521 static int mmc_blk_probe(struct mmc_card *card)
 522 {
 523         struct mmc_blk_data *md;
 524         int err;
 525
 526         /*
 527          * Check that the card supports the command class(es) we need.
 528          */
 529         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 530                 return -ENODEV;
 531
 532         md = mmc_blk_alloc(card);
 533         if (IS_ERR(md))
 534                 return PTR_ERR(md);
 535
 536         err = mmc_blk_set_blksize(md, card);
 537         if (err)
 538                 goto out;
 539
 540         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 541                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 542                 (unsigned long long)(get_capacity(md->disk) >> 1),
 543                 md->read_only ? "(ro)" : "");
 544
 545         mmc_set_drvdata(card, md);
 546         add_disk(md->disk);
 547         return 0;
 548
 549  out:
 550         mmc_blk_put(md);
 551
 552         return err;
 553 }
 554
 555 static void mmc_blk_remove(struct mmc_card *card)
 556 {
 557         struct mmc_blk_data *md = mmc_get_drvdata(card);
 558
 559         if (md) {
 560                 int devidx;
 561
 562                 /* Stop new requests from getting into the queue */
 563                 del_gendisk(md->disk);
 564
 565                 /* Then flush out any already in there */
 566                 mmc_cleanup_queue(&md->queue);
 567
 568                 devidx = md->disk->first_minor >> MMC_SHIFT;
 569                 __clear_bit(devidx, dev_use);
 570
 571                 mmc_blk_put(md);
 572         }
 573         mmc_set_drvdata(card, NULL);
 574 }
 575
 576 #ifdef CONFIG_PM
 577 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 578 {
 579         struct mmc_blk_data *md = mmc_get_drvdata(card);
 580
 581         if (md) {
 582                 mmc_queue_suspend(&md->queue);
 583         }
 584         return 0;
 585 }
 586
 587 static int mmc_blk_resume(struct mmc_card *card)
 588 {
 589         struct mmc_blk_data *md = mmc_get_drvdata(card);
 590
 591         if (md) {
 592                 mmc_blk_set_blksize(md, card);
 593                 mmc_queue_resume(&md->queue);
 594         }
 595         return 0;
 596 }
 597 #else
 598 #define mmc_blk_suspend NULL
 599 #define mmc_blk_resume  NULL
 600 #endif
 601
 602 static struct mmc_driver mmc_driver = {
 603         .drv            = {
 604                 .name   = "mmcblk",
 605         },
 606         .probe          = mmc_blk_probe,
 607         .remove         = mmc_blk_remove,
 608         .suspend        = mmc_blk_suspend,
 609         .resume         = mmc_blk_resume,
 610 };
 611
 612 static int __init mmc_blk_init(void)
 613 {
 614         int res = -ENOMEM;
 615
 616         res = register_blkdev(major, "mmc");
 617         if (res < 0) {
 618                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 619                        major, res);
 620                 goto out;
 621         }
 622         if (major == 0)
 623                 major = res;
 624
 625         return mmc_register_driver(&mmc_driver);
 626
 627  out:
 628         return res;
 629 }
 630
 631 static void __exit mmc_blk_exit(void)
 632 {
 633         mmc_unregister_driver(&mmc_driver);
 634         unregister_blkdev(major, "mmc");
 635 }
 636
 637 module_init(mmc_blk_init);
 638 module_exit(mmc_blk_exit);
 639
 640 MODULE_LICENSE("GPL");
 641 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 642
 643 module_param(major, int, 0444);
 644 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");