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/sched.h>
  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 "mmc_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;
 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 << 9;
 241                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 242                 brq.data.blksz = 1 << md->block_bits;
 243                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 244                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 245                 brq.stop.arg = 0;
 246                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 247
 248                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 249
 250                 /*
 251                  * If the host doesn't support multiple block writes, force
 252                  * block writes to single block. SD cards are excepted from
 253                  * this rule as they support querying the number of
 254                  * successfully written sectors.
 255                  */
 256                 if (rq_data_dir(req) != READ &&
 257                     !(card->host->caps & MMC_CAP_MULTIWRITE) &&
 258                     !mmc_card_sd(card))
 259                         brq.data.blocks = 1;
 260
 261                 if (brq.data.blocks > 1) {
 262                         brq.data.flags |= MMC_DATA_MULTI;
 263                         brq.mrq.stop = &brq.stop;
 264                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 265                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 266                 } else {
 267                         brq.mrq.stop = NULL;
 268                         readcmd = MMC_READ_SINGLE_BLOCK;
 269                         writecmd = MMC_WRITE_BLOCK;
 270                 }
 271
 272                 if (rq_data_dir(req) == READ) {
 273                         brq.cmd.opcode = readcmd;
 274                         brq.data.flags |= MMC_DATA_READ;
 275                 } else {
 276                         brq.cmd.opcode = writecmd;
 277                         brq.data.flags |= MMC_DATA_WRITE;
 278                 }
 279
 280                 brq.data.sg = mq->sg;
 281                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 282
 283                 mmc_wait_for_req(card->host, &brq.mrq);
 284                 if (brq.cmd.error) {
 285                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 286                                req->rq_disk->disk_name, brq.cmd.error);
 287                         goto cmd_err;
 288                 }
 289
 290                 if (brq.data.error) {
 291                         printk(KERN_ERR "%s: error %d transferring data\n",
 292                                req->rq_disk->disk_name, brq.data.error);
 293                         goto cmd_err;
 294                 }
 295
 296                 if (brq.stop.error) {
 297                         printk(KERN_ERR "%s: error %d sending stop command\n",
 298                                req->rq_disk->disk_name, brq.stop.error);
 299                         goto cmd_err;
 300                 }
 301
 302                 if (rq_data_dir(req) != READ) {
 303                         do {
 304                                 int err;
 305
 306                                 cmd.opcode = MMC_SEND_STATUS;
 307                                 cmd.arg = card->rca << 16;
 308                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 309                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 310                                 if (err) {
 311                                         printk(KERN_ERR "%s: error %d requesting status\n",
 312                                                req->rq_disk->disk_name, err);
 313                                         goto cmd_err;
 314                                 }
 315                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 316
 317 #if 0
 318                         if (cmd.resp[0] & ~0x00000900)
 319                                 printk(KERN_ERR "%s: status = %08x\n",
 320                                        req->rq_disk->disk_name, cmd.resp[0]);
 321                         if (mmc_decode_status(cmd.resp))
 322                                 goto cmd_err;
 323 #endif
 324                 }
 325
 326                 /*
 327                  * A block was successfully transferred.
 328                  */
 329                 spin_lock_irq(&md->lock);
 330                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 331                 if (!ret) {
 332                         /*
 333                          * The whole request completed successfully.
 334                          */
 335                         add_disk_randomness(req->rq_disk);
 336                         blkdev_dequeue_request(req);
 337                         end_that_request_last(req, 1);
 338                 }
 339                 spin_unlock_irq(&md->lock);
 340         } while (ret);
 341
 342         mmc_card_release_host(card);
 343
 344         return 1;
 345
 346  cmd_err:
 347         /*
 348          * If this is an SD card and we're writing, we can first
 349          * mark the known good sectors as ok.
 350          *
 351          * If the card is not SD, we can still ok written sectors
 352          * if the controller can do proper error reporting.
 353          *
 354          * For reads we just fail the entire chunk as that should
 355          * be safe in all cases.
 356          */
 357         if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
 358                 u32 blocks;
 359                 unsigned int bytes;
 360
 361                 blocks = mmc_sd_num_wr_blocks(card);
 362                 if (blocks != (u32)-1) {
 363                         if (card->csd.write_partial)
 364                                 bytes = blocks << md->block_bits;
 365                         else
 366                                 bytes = blocks << 9;
 367                         spin_lock_irq(&md->lock);
 368                         ret = end_that_request_chunk(req, 1, bytes);
 369                         spin_unlock_irq(&md->lock);
 370                 }
 371         } else if (rq_data_dir(req) != READ &&
 372                    (card->host->caps & MMC_CAP_MULTIWRITE)) {
 373                 spin_lock_irq(&md->lock);
 374                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 375                 spin_unlock_irq(&md->lock);
 376         }
 377
 378         mmc_card_release_host(card);
 379
 380 flush_queue:
 381         spin_lock_irq(&md->lock);
 382         while (ret) {
 383                 ret = end_that_request_chunk(req, 0,
 384                                 req->current_nr_sectors << 9);
 385         }
 386
 387         add_disk_randomness(req->rq_disk);
 388         blkdev_dequeue_request(req);
 389         end_that_request_last(req, 0);
 390         spin_unlock_irq(&md->lock);
 391
 392         return 0;
 393 }
 394
 395 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 396
 397 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 398
 399 static inline int mmc_blk_readonly(struct mmc_card *card)
 400 {
 401         return mmc_card_readonly(card) ||
 402                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 403 }
 404
 405 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 406 {
 407         struct mmc_blk_data *md;
 408         int devidx, ret;
 409
 410         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 411         if (devidx >= MMC_NUM_MINORS)
 412                 return ERR_PTR(-ENOSPC);
 413         __set_bit(devidx, dev_use);
 414
 415         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 416         if (!md) {
 417                 ret = -ENOMEM;
 418                 goto out;
 419         }
 420
 421         memset(md, 0, sizeof(struct mmc_blk_data));
 422
 423         /*
 424          * Set the read-only status based on the supported commands
 425          * and the write protect switch.
 426          */
 427         md->read_only = mmc_blk_readonly(card);
 428
 429         /*
 430          * Both SD and MMC specifications state (although a bit
 431          * unclearly in the MMC case) that a block size of 512
 432          * bytes must always be supported by the card.
 433          */
 434         md->block_bits = 9;
 435
 436         md->disk = alloc_disk(1 << MMC_SHIFT);
 437         if (md->disk == NULL) {
 438                 ret = -ENOMEM;
 439                 goto err_kfree;
 440         }
 441
 442         spin_lock_init(&md->lock);
 443         md->usage = 1;
 444
 445         ret = mmc_init_queue(&md->queue, card, &md->lock);
 446         if (ret)
 447                 goto err_putdisk;
 448
 449         md->queue.prep_fn = mmc_blk_prep_rq;
 450         md->queue.issue_fn = mmc_blk_issue_rq;
 451         md->queue.data = md;
 452
 453         md->disk->major = major;
 454         md->disk->first_minor = devidx << MMC_SHIFT;
 455         md->disk->fops = &mmc_bdops;
 456         md->disk->private_data = md;
 457         md->disk->queue = md->queue.queue;
 458         md->disk->driverfs_dev = &card->dev;
 459
 460         /*
 461          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 462          *
 463          * - be set for removable media with permanent block devices
 464          * - be unset for removable block devices with permanent media
 465          *
 466          * Since MMC block devices clearly fall under the second
 467          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 468          * should use the block device creation/destruction hotplug
 469          * messages to tell when the card is present.
 470          */
 471
 472         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 473
 474         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 475
 476         /*
 477          * The CSD capacity field is in units of read_blkbits.
 478          * set_capacity takes units of 512 bytes.
 479          */
 480         set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
 481         return md;
 482
 483  err_putdisk:
 484         put_disk(md->disk);
 485  err_kfree:
 486         kfree(md);
 487  out:
 488         return ERR_PTR(ret);
 489 }
 490
 491 static int
 492 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 493 {
 494         struct mmc_command cmd;
 495         int err;
 496
 497         mmc_card_claim_host(card);
 498         cmd.opcode = MMC_SET_BLOCKLEN;
 499         cmd.arg = 1 << md->block_bits;
 500         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 501         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 502         mmc_card_release_host(card);
 503
 504         if (err) {
 505                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 506                         md->disk->disk_name, cmd.arg, err);
 507                 return -EINVAL;
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int mmc_blk_probe(struct mmc_card *card)
 514 {
 515         struct mmc_blk_data *md;
 516         int err;
 517
 518         /*
 519          * Check that the card supports the command class(es) we need.
 520          */
 521         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 522                 return -ENODEV;
 523
 524         md = mmc_blk_alloc(card);
 525         if (IS_ERR(md))
 526                 return PTR_ERR(md);
 527
 528         err = mmc_blk_set_blksize(md, card);
 529         if (err)
 530                 goto out;
 531
 532         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 533                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 534                 (unsigned long long)(get_capacity(md->disk) >> 1),
 535                 md->read_only ? "(ro)" : "");
 536
 537         mmc_set_drvdata(card, md);
 538         add_disk(md->disk);
 539         return 0;
 540
 541  out:
 542         mmc_blk_put(md);
 543
 544         return err;
 545 }
 546
 547 static void mmc_blk_remove(struct mmc_card *card)
 548 {
 549         struct mmc_blk_data *md = mmc_get_drvdata(card);
 550
 551         if (md) {
 552                 int devidx;
 553
 554                 /* Stop new requests from getting into the queue */
 555                 del_gendisk(md->disk);
 556
 557                 /* Then flush out any already in there */
 558                 mmc_cleanup_queue(&md->queue);
 559
 560                 devidx = md->disk->first_minor >> MMC_SHIFT;
 561                 __clear_bit(devidx, dev_use);
 562
 563                 mmc_blk_put(md);
 564         }
 565         mmc_set_drvdata(card, NULL);
 566 }
 567
 568 #ifdef CONFIG_PM
 569 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 570 {
 571         struct mmc_blk_data *md = mmc_get_drvdata(card);
 572
 573         if (md) {
 574                 mmc_queue_suspend(&md->queue);
 575         }
 576         return 0;
 577 }
 578
 579 static int mmc_blk_resume(struct mmc_card *card)
 580 {
 581         struct mmc_blk_data *md = mmc_get_drvdata(card);
 582
 583         if (md) {
 584                 mmc_blk_set_blksize(md, card);
 585                 mmc_queue_resume(&md->queue);
 586         }
 587         return 0;
 588 }
 589 #else
 590 #define mmc_blk_suspend NULL
 591 #define mmc_blk_resume  NULL
 592 #endif
 593
 594 static struct mmc_driver mmc_driver = {
 595         .drv            = {
 596                 .name   = "mmcblk",
 597         },
 598         .probe          = mmc_blk_probe,
 599         .remove         = mmc_blk_remove,
 600         .suspend        = mmc_blk_suspend,
 601         .resume         = mmc_blk_resume,
 602 };
 603
 604 static int __init mmc_blk_init(void)
 605 {
 606         int res = -ENOMEM;
 607
 608         res = register_blkdev(major, "mmc");
 609         if (res < 0) {
 610                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 611                        major, res);
 612                 goto out;
 613         }
 614         if (major == 0)
 615                 major = res;
 616
 617         return mmc_register_driver(&mmc_driver);
 618
 619  out:
 620         return res;
 621 }
 622
 623 static void __exit mmc_blk_exit(void)
 624 {
 625         mmc_unregister_driver(&mmc_driver);
 626         unregister_blkdev(major, "mmc");
 627 }
 628
 629 module_init(mmc_blk_init);
 630 module_exit(mmc_blk_exit);
 631
 632 MODULE_LICENSE("GPL");
 633 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 634
 635 module_param(major, int, 0444);
 636 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");