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/devfs_fs_kernel.h>
  31
  32 #include <linux/mmc/card.h>
  33 #include <linux/mmc/protocol.h>
  34 #include <linux/mmc/host.h>
  35
  36 #include <asm/system.h>
  37 #include <asm/uaccess.h>
  38
  39 #include "mmc_queue.h"
  40
  41 /*
  42  * max 8 partitions per card
  43  */
  44 #define MMC_SHIFT       3
  45
  46 static int major;
  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    suspended;
  59 };
  60
  61 static DECLARE_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         down(&open_lock);
  68         md = disk->private_data;
  69         if (md && md->usage == 0)
  70                 md = NULL;
  71         if (md)
  72                 md->usage++;
  73         up(&open_lock);
  74
  75         return md;
  76 }
  77
  78 static void mmc_blk_put(struct mmc_blk_data *md)
  79 {
  80         down(&open_lock);
  81         md->usage--;
  82         if (md->usage == 0) {
  83                 put_disk(md->disk);
  84                 mmc_cleanup_queue(&md->queue);
  85                 kfree(md);
  86         }
  87         up(&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) &&
 102                         mmc_card_readonly(md->queue.card))
 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_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
 119 {
 120         struct block_device *bdev = inode->i_bdev;
 121
 122         if (cmd == HDIO_GETGEO) {
 123                 struct hd_geometry geo;
 124
 125                 memset(&geo, 0, sizeof(struct hd_geometry));
 126
 127                 geo.cylinders   = get_capacity(bdev->bd_disk) / (4 * 16);
 128                 geo.heads       = 4;
 129                 geo.sectors     = 16;
 130                 geo.start       = get_start_sect(bdev);
 131
 132                 return copy_to_user((void __user *)arg, &geo, sizeof(geo))
 133                         ? -EFAULT : 0;
 134         }
 135
 136         return -ENOTTY;
 137 }
 138
 139 static struct block_device_operations mmc_bdops = {
 140         .open                   = mmc_blk_open,
 141         .release                = mmc_blk_release,
 142         .ioctl                  = mmc_blk_ioctl,
 143         .owner                  = THIS_MODULE,
 144 };
 145
 146 struct mmc_blk_request {
 147         struct mmc_request      mrq;
 148         struct mmc_command      cmd;
 149         struct mmc_command      stop;
 150         struct mmc_data         data;
 151 };
 152
 153 static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
 154 {
 155         struct mmc_blk_data *md = mq->data;
 156         int stat = BLKPREP_OK;
 157
 158         /*
 159          * If we have no device, we haven't finished initialising.
 160          */
 161         if (!md || !mq->card) {
 162                 printk(KERN_ERR "%s: killing request - no device/host\n",
 163                        req->rq_disk->disk_name);
 164                 stat = BLKPREP_KILL;
 165         }
 166
 167         if (md->suspended) {
 168                 blk_plug_device(md->queue.queue);
 169                 stat = BLKPREP_DEFER;
 170         }
 171
 172         /*
 173          * Check for excessive requests.
 174          */
 175         if (req->sector + req->nr_sectors > get_capacity(req->rq_disk)) {
 176                 printk("bad request size\n");
 177                 stat = BLKPREP_KILL;
 178         }
 179
 180         return stat;
 181 }
 182
 183 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 184 {
 185         struct mmc_blk_data *md = mq->data;
 186         struct mmc_card *card = md->queue.card;
 187         int ret;
 188
 189 #ifdef CONFIG_MMC_BULKTRANSFER
 190         int failsafe;
 191 #endif
 192
 193         if (mmc_card_claim_host(card))
 194                 goto cmd_err;
 195
 196 #ifdef CONFIG_MMC_BULKTRANSFER
 197         /*
 198          * We first try transfering multiple blocks. If this fails
 199          * we fall back to single block transfers.
 200          *
 201          * This gives us good performance when all is well and the
 202          * possibility to determine which sector fails when all
 203          * is not well.
 204          */
 205         failsafe = 0;
 206 #endif
 207
 208         do {
 209                 struct mmc_blk_request brq;
 210                 struct mmc_command cmd;
 211
 212                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 213                 brq.mrq.cmd = &brq.cmd;
 214                 brq.mrq.data = &brq.data;
 215
 216                 brq.cmd.arg = req->sector << 9;
 217                 brq.cmd.flags = MMC_RSP_R1;
 218                 brq.data.timeout_ns = card->csd.tacc_ns * 10;
 219                 brq.data.timeout_clks = card->csd.tacc_clks * 10;
 220                 brq.data.blksz_bits = md->block_bits;
 221                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 222                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 223                 brq.stop.arg = 0;
 224                 brq.stop.flags = MMC_RSP_R1B;
 225
 226 #ifdef CONFIG_MMC_BULKTRANSFER
 227                 /*
 228                  * A multi-block transfer failed. Falling back to single
 229                  * blocks.
 230                  */
 231                 if (failsafe)
 232                         brq.data.blocks = 1;
 233
 234 #else
 235                 /*
 236                  * Writes are done one sector at a time.
 237                  */
 238                 if (rq_data_dir(req) != READ)
 239                         brq.data.blocks = 1;
 240 #endif
 241
 242                 ret = 1;
 243
 244                 if (rq_data_dir(req) == READ) {
 245                         brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
 246                         brq.data.flags |= MMC_DATA_READ;
 247                 } else {
 248                         brq.cmd.opcode = brq.data.blocks > 1 ? MMC_WRITE_MULTIPLE_BLOCK :
 249                                 MMC_WRITE_BLOCK;
 250                         brq.cmd.flags = MMC_RSP_R1B;
 251                         brq.data.flags |= MMC_DATA_WRITE;
 252                 }
 253                 brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL;
 254
 255                 brq.data.sg = mq->sg;
 256                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 257
 258                 mmc_wait_for_req(card->host, &brq.mrq);
 259                 if (brq.cmd.error) {
 260                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 261                                req->rq_disk->disk_name, brq.cmd.error);
 262                         goto cmd_fail;
 263                 }
 264
 265                 if (brq.data.error) {
 266                         printk(KERN_ERR "%s: error %d transferring data\n",
 267                                req->rq_disk->disk_name, brq.data.error);
 268                         goto cmd_fail;
 269                 }
 270
 271                 if (brq.stop.error) {
 272                         printk(KERN_ERR "%s: error %d sending stop command\n",
 273                                req->rq_disk->disk_name, brq.stop.error);
 274                         goto cmd_fail;
 275                 }
 276
 277                 /* No need to check card status after a read */
 278                 if (rq_data_dir(req) == READ)
 279                         goto card_ready;
 280
 281                 do {
 282                         int err;
 283
 284                         cmd.opcode = MMC_SEND_STATUS;
 285                         cmd.arg = card->rca << 16;
 286                         cmd.flags = MMC_RSP_R1;
 287                         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 288                         if (err) {
 289                                 printk(KERN_ERR "%s: error %d requesting status\n",
 290                                        req->rq_disk->disk_name, err);
 291                                 goto cmd_fail;
 292                         }
 293 #ifdef CONFIG_MMC_BLOCK_BROKEN_RFD
 294                         /* Work-around for broken cards setting READY_FOR_DATA
 295                          * when not actually ready.
 296                          */
 297                         if (R1_CURRENT_STATE(cmd.resp[0]) == 7)
 298                                 cmd.resp[0] &= ~R1_READY_FOR_DATA;
 299 #endif
 300                 } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 301
 302 #if 0
 303                 if (cmd.resp[0] & ~0x00000900)
 304                         printk(KERN_ERR "%s: status = %08x\n",
 305                                req->rq_disk->disk_name, cmd.resp[0]);
 306                 if (mmc_decode_status(cmd.resp))
 307                         goto cmd_err;
 308 #endif
 309
 310         card_ready:
 311
 312                 /*
 313                  * A block was successfully transferred.
 314                  */
 315                 spin_lock_irq(&md->lock);
 316                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 317                 if (!ret) {
 318                         /*
 319                          * The whole request completed successfully.
 320                          */
 321                         add_disk_randomness(req->rq_disk);
 322                         blkdev_dequeue_request(req);
 323                         end_that_request_last(req);
 324                 }
 325                 spin_unlock_irq(&md->lock);
 326
 327 #ifdef CONFIG_MMC_BULKTRANSFER
 328                 /*
 329                  * Go back to bulk mode if in failsafe mode.
 330                  */
 331                 failsafe = 0;
 332 #endif
 333
 334                 continue;
 335
 336  cmd_fail:
 337
 338 #ifdef CONFIG_MMC_BULKTRANSFER
 339                 if (failsafe)
 340                         goto cmd_err;
 341                 else
 342                         failsafe = 1;
 343 #else
 344                 goto cmd_err;
 345 #endif
 346
 347         } while (ret);
 348
 349         mmc_card_release_host(card);
 350
 351         return 1;
 352
 353  cmd_err:
 354         mmc_card_release_host(card);
 355
 356         /*
 357          * This is a little draconian, but until we get proper
 358          * error handling sorted out here, its the best we can
 359          * do - especially as some hosts have no idea how much
 360          * data was transferred before the error occurred.
 361          */
 362         spin_lock_irq(&md->lock);
 363         do {
 364                 ret = end_that_request_chunk(req, 0,
 365                                 req->current_nr_sectors << 9);
 366         } while (ret);
 367
 368         add_disk_randomness(req->rq_disk);
 369         blkdev_dequeue_request(req);
 370         end_that_request_last(req);
 371         spin_unlock_irq(&md->lock);
 372
 373         /* If a command fails, the card might be removed. */
 374         mmc_detect_change(card->host);
 375
 376         return 0;
 377 }
 378
 379 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 380
 381 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 382
 383 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 384 {
 385         struct mmc_blk_data *md;
 386         int devidx, ret;
 387
 388         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 389         if (devidx >= MMC_NUM_MINORS)
 390                 return ERR_PTR(-ENOSPC);
 391         __set_bit(devidx, dev_use);
 392
 393         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 394         if (md) {
 395                 memset(md, 0, sizeof(struct mmc_blk_data));
 396
 397                 md->disk = alloc_disk(1 << MMC_SHIFT);
 398                 if (md->disk == NULL) {
 399                         kfree(md);
 400                         md = ERR_PTR(-ENOMEM);
 401                         goto out;
 402                 }
 403
 404                 spin_lock_init(&md->lock);
 405                 md->usage = 1;
 406
 407                 ret = mmc_init_queue(&md->queue, card, &md->lock);
 408                 if (ret) {
 409                         put_disk(md->disk);
 410                         kfree(md);
 411                         md = ERR_PTR(ret);
 412                         goto out;
 413                 }
 414                 md->queue.prep_fn = mmc_blk_prep_rq;
 415                 md->queue.issue_fn = mmc_blk_issue_rq;
 416                 md->queue.data = md;
 417
 418                 md->disk->major = major;
 419                 md->disk->first_minor = devidx << MMC_SHIFT;
 420                 md->disk->fops = &mmc_bdops;
 421                 md->disk->private_data = md;
 422                 md->disk->queue = md->queue.queue;
 423                 md->disk->driverfs_dev = &card->dev;
 424
 425                 /*
 426                  * As discussed on lkml, GENHD_FL_REMOVABLE should:
 427                  *
 428                  * - be set for removable media with permanent block devices
 429                  * - be unset for removable block devices with permanent media
 430                  *
 431                  * Since MMC block devices clearly fall under the second
 432                  * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 433                  * should use the block device creation/destruction hotplug
 434                  * messages to tell when the card is present.
 435                  */
 436
 437                 sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 438                 sprintf(md->disk->devfs_name, "mmc/blk%d", devidx);
 439
 440                 md->block_bits = card->csd.read_blkbits;
 441
 442                 blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 443                 set_capacity(md->disk, card->csd.capacity);
 444         }
 445  out:
 446         return md;
 447 }
 448
 449 static int
 450 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 451 {
 452         struct mmc_command cmd;
 453         int err;
 454
 455         mmc_card_claim_host(card);
 456         cmd.opcode = MMC_SET_BLOCKLEN;
 457         cmd.arg = 1 << card->csd.read_blkbits;
 458         cmd.flags = MMC_RSP_R1;
 459         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 460         mmc_card_release_host(card);
 461
 462         if (err) {
 463                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 464                         md->disk->disk_name, cmd.arg, err);
 465                 return -EINVAL;
 466         }
 467
 468         return 0;
 469 }
 470
 471 static int mmc_blk_probe(struct mmc_card *card)
 472 {
 473         struct mmc_blk_data *md;
 474         int err;
 475
 476         /*
 477          * Check that the card supports the command class(es) we need.
 478          */
 479         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 480                 return -ENODEV;
 481
 482         if (card->csd.read_blkbits < 9) {
 483                 printk(KERN_WARNING "%s: read blocksize too small (%u)\n",
 484                         mmc_card_id(card), 1 << card->csd.read_blkbits);
 485                 return -ENODEV;
 486         }
 487
 488         md = mmc_blk_alloc(card);
 489         if (IS_ERR(md))
 490                 return PTR_ERR(md);
 491
 492         err = mmc_blk_set_blksize(md, card);
 493         if (err)
 494                 goto out;
 495
 496         printk(KERN_INFO "%s: %s %s %dKiB %s\n",
 497                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 498                 (card->csd.capacity << card->csd.read_blkbits) / 1024,
 499                 mmc_card_readonly(card)?"(ro)":"");
 500
 501         mmc_set_drvdata(card, md);
 502         add_disk(md->disk);
 503         return 0;
 504
 505  out:
 506         mmc_blk_put(md);
 507
 508         return err;
 509 }
 510
 511 static void mmc_blk_remove(struct mmc_card *card)
 512 {
 513         struct mmc_blk_data *md = mmc_get_drvdata(card);
 514
 515         if (md) {
 516                 int devidx;
 517
 518                 del_gendisk(md->disk);
 519
 520                 /*
 521                  * I think this is needed.
 522                  */
 523                 md->disk->queue = NULL;
 524
 525                 devidx = md->disk->first_minor >> MMC_SHIFT;
 526                 __clear_bit(devidx, dev_use);
 527
 528                 mmc_blk_put(md);
 529         }
 530         mmc_set_drvdata(card, NULL);
 531 }
 532
 533 #ifdef CONFIG_PM
 534 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 535 {
 536         struct mmc_blk_data *md = mmc_get_drvdata(card);
 537
 538         if (md) {
 539                 mmc_queue_suspend(&md->queue);
 540         }
 541         return 0;
 542 }
 543
 544 static int mmc_blk_resume(struct mmc_card *card)
 545 {
 546         struct mmc_blk_data *md = mmc_get_drvdata(card);
 547
 548         if (md) {
 549                 mmc_blk_set_blksize(md, card);
 550                 mmc_queue_resume(&md->queue);
 551         }
 552         return 0;
 553 }
 554 #else
 555 #define mmc_blk_suspend NULL
 556 #define mmc_blk_resume  NULL
 557 #endif
 558
 559 static struct mmc_driver mmc_driver = {
 560         .drv            = {
 561                 .name   = "mmcblk",
 562         },
 563         .probe          = mmc_blk_probe,
 564         .remove         = mmc_blk_remove,
 565         .suspend        = mmc_blk_suspend,
 566         .resume         = mmc_blk_resume,
 567 };
 568
 569 static int __init mmc_blk_init(void)
 570 {
 571         int res = -ENOMEM;
 572
 573         res = register_blkdev(major, "mmc");
 574         if (res < 0) {
 575                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 576                        major, res);
 577                 goto out;
 578         }
 579         if (major == 0)
 580                 major = res;
 581
 582         devfs_mk_dir("mmc");
 583         return mmc_register_driver(&mmc_driver);
 584
 585  out:
 586         return res;
 587 }
 588
 589 static void __exit mmc_blk_exit(void)
 590 {
 591         mmc_unregister_driver(&mmc_driver);
 592         devfs_remove("mmc");
 593         unregister_blkdev(major, "mmc");
 594 }
 595
 596 module_init(mmc_blk_init);
 597 module_exit(mmc_blk_exit);
 598
 599 MODULE_LICENSE("GPL");
 600 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 601
 602 module_param(major, int, 0444);
 603 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");