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
  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                 mmc_cleanup_queue(&md->queue);
  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 int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 158 {
 159         struct mmc_blk_data *md = mq->data;
 160         struct mmc_card *card = md->queue.card;
 161         int ret;
 162
 163         if (mmc_card_claim_host(card))
 164                 goto cmd_err;
 165
 166         do {
 167                 struct mmc_blk_request brq;
 168                 struct mmc_command cmd;
 169                 u32 readcmd, writecmd;
 170
 171                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 172                 brq.mrq.cmd = &brq.cmd;
 173                 brq.mrq.data = &brq.data;
 174
 175                 brq.cmd.arg = req->sector << 9;
 176                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 177                 brq.data.blksz = 1 << md->block_bits;
 178                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 179                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 180                 brq.stop.arg = 0;
 181                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 182
 183                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 184
 185                 /*
 186                  * If the host doesn't support multiple block writes, force
 187                  * block writes to single block.
 188                  */
 189                 if (rq_data_dir(req) != READ &&
 190                     !(card->host->caps & MMC_CAP_MULTIWRITE))
 191                         brq.data.blocks = 1;
 192
 193                 if (brq.data.blocks > 1) {
 194                         brq.data.flags |= MMC_DATA_MULTI;
 195                         brq.mrq.stop = &brq.stop;
 196                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 197                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 198                 } else {
 199                         brq.mrq.stop = NULL;
 200                         readcmd = MMC_READ_SINGLE_BLOCK;
 201                         writecmd = MMC_WRITE_BLOCK;
 202                 }
 203
 204                 if (rq_data_dir(req) == READ) {
 205                         brq.cmd.opcode = readcmd;
 206                         brq.data.flags |= MMC_DATA_READ;
 207                 } else {
 208                         brq.cmd.opcode = writecmd;
 209                         brq.data.flags |= MMC_DATA_WRITE;
 210                 }
 211
 212                 brq.data.sg = mq->sg;
 213                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 214
 215                 mmc_wait_for_req(card->host, &brq.mrq);
 216                 if (brq.cmd.error) {
 217                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 218                                req->rq_disk->disk_name, brq.cmd.error);
 219                         goto cmd_err;
 220                 }
 221
 222                 if (brq.data.error) {
 223                         printk(KERN_ERR "%s: error %d transferring data\n",
 224                                req->rq_disk->disk_name, brq.data.error);
 225                         goto cmd_err;
 226                 }
 227
 228                 if (brq.stop.error) {
 229                         printk(KERN_ERR "%s: error %d sending stop command\n",
 230                                req->rq_disk->disk_name, brq.stop.error);
 231                         goto cmd_err;
 232                 }
 233
 234                 if (rq_data_dir(req) != READ) {
 235                         do {
 236                                 int err;
 237
 238                                 cmd.opcode = MMC_SEND_STATUS;
 239                                 cmd.arg = card->rca << 16;
 240                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 241                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 242                                 if (err) {
 243                                         printk(KERN_ERR "%s: error %d requesting status\n",
 244                                                req->rq_disk->disk_name, err);
 245                                         goto cmd_err;
 246                                 }
 247                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 248
 249 #if 0
 250                         if (cmd.resp[0] & ~0x00000900)
 251                                 printk(KERN_ERR "%s: status = %08x\n",
 252                                        req->rq_disk->disk_name, cmd.resp[0]);
 253                         if (mmc_decode_status(cmd.resp))
 254                                 goto cmd_err;
 255 #endif
 256                 }
 257
 258                 /*
 259                  * A block was successfully transferred.
 260                  */
 261                 spin_lock_irq(&md->lock);
 262                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 263                 if (!ret) {
 264                         /*
 265                          * The whole request completed successfully.
 266                          */
 267                         add_disk_randomness(req->rq_disk);
 268                         blkdev_dequeue_request(req);
 269                         end_that_request_last(req, 1);
 270                 }
 271                 spin_unlock_irq(&md->lock);
 272         } while (ret);
 273
 274         mmc_card_release_host(card);
 275
 276         return 1;
 277
 278  cmd_err:
 279         mmc_card_release_host(card);
 280
 281         /*
 282          * This is a little draconian, but until we get proper
 283          * error handling sorted out here, its the best we can
 284          * do - especially as some hosts have no idea how much
 285          * data was transferred before the error occurred.
 286          */
 287         spin_lock_irq(&md->lock);
 288         do {
 289                 ret = end_that_request_chunk(req, 0,
 290                                 req->current_nr_sectors << 9);
 291         } while (ret);
 292
 293         add_disk_randomness(req->rq_disk);
 294         blkdev_dequeue_request(req);
 295         end_that_request_last(req, 0);
 296         spin_unlock_irq(&md->lock);
 297
 298         return 0;
 299 }
 300
 301 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 302
 303 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 304
 305 static inline int mmc_blk_readonly(struct mmc_card *card)
 306 {
 307         return mmc_card_readonly(card) ||
 308                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 309 }
 310
 311 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 312 {
 313         struct mmc_blk_data *md;
 314         int devidx, ret;
 315
 316         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 317         if (devidx >= MMC_NUM_MINORS)
 318                 return ERR_PTR(-ENOSPC);
 319         __set_bit(devidx, dev_use);
 320
 321         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 322         if (!md) {
 323                 ret = -ENOMEM;
 324                 goto out;
 325         }
 326
 327         memset(md, 0, sizeof(struct mmc_blk_data));
 328
 329         /*
 330          * Set the read-only status based on the supported commands
 331          * and the write protect switch.
 332          */
 333         md->read_only = mmc_blk_readonly(card);
 334
 335         /*
 336          * Both SD and MMC specifications state (although a bit
 337          * unclearly in the MMC case) that a block size of 512
 338          * bytes must always be supported by the card.
 339          */
 340         md->block_bits = 9;
 341
 342         md->disk = alloc_disk(1 << MMC_SHIFT);
 343         if (md->disk == NULL) {
 344                 ret = -ENOMEM;
 345                 goto err_kfree;
 346         }
 347
 348         spin_lock_init(&md->lock);
 349         md->usage = 1;
 350
 351         ret = mmc_init_queue(&md->queue, card, &md->lock);
 352         if (ret)
 353                 goto err_putdisk;
 354
 355         md->queue.prep_fn = mmc_blk_prep_rq;
 356         md->queue.issue_fn = mmc_blk_issue_rq;
 357         md->queue.data = md;
 358
 359         md->disk->major = major;
 360         md->disk->first_minor = devidx << MMC_SHIFT;
 361         md->disk->fops = &mmc_bdops;
 362         md->disk->private_data = md;
 363         md->disk->queue = md->queue.queue;
 364         md->disk->driverfs_dev = &card->dev;
 365
 366         /*
 367          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 368          *
 369          * - be set for removable media with permanent block devices
 370          * - be unset for removable block devices with permanent media
 371          *
 372          * Since MMC block devices clearly fall under the second
 373          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 374          * should use the block device creation/destruction hotplug
 375          * messages to tell when the card is present.
 376          */
 377
 378         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 379
 380         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 381
 382         /*
 383          * The CSD capacity field is in units of read_blkbits.
 384          * set_capacity takes units of 512 bytes.
 385          */
 386         set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
 387         return md;
 388
 389  err_putdisk:
 390         put_disk(md->disk);
 391  err_kfree:
 392         kfree(md);
 393  out:
 394         return ERR_PTR(ret);
 395 }
 396
 397 static int
 398 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 399 {
 400         struct mmc_command cmd;
 401         int err;
 402
 403         mmc_card_claim_host(card);
 404         cmd.opcode = MMC_SET_BLOCKLEN;
 405         cmd.arg = 1 << md->block_bits;
 406         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 407         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 408         mmc_card_release_host(card);
 409
 410         if (err) {
 411                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 412                         md->disk->disk_name, cmd.arg, err);
 413                 return -EINVAL;
 414         }
 415
 416         return 0;
 417 }
 418
 419 static int mmc_blk_probe(struct mmc_card *card)
 420 {
 421         struct mmc_blk_data *md;
 422         int err;
 423
 424         /*
 425          * Check that the card supports the command class(es) we need.
 426          */
 427         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 428                 return -ENODEV;
 429
 430         md = mmc_blk_alloc(card);
 431         if (IS_ERR(md))
 432                 return PTR_ERR(md);
 433
 434         err = mmc_blk_set_blksize(md, card);
 435         if (err)
 436                 goto out;
 437
 438         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 439                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 440                 (unsigned long long)(get_capacity(md->disk) >> 1),
 441                 md->read_only ? "(ro)" : "");
 442
 443         mmc_set_drvdata(card, md);
 444         add_disk(md->disk);
 445         return 0;
 446
 447  out:
 448         mmc_blk_put(md);
 449
 450         return err;
 451 }
 452
 453 static void mmc_blk_remove(struct mmc_card *card)
 454 {
 455         struct mmc_blk_data *md = mmc_get_drvdata(card);
 456
 457         if (md) {
 458                 int devidx;
 459
 460                 del_gendisk(md->disk);
 461
 462                 /*
 463                  * I think this is needed.
 464                  */
 465                 md->disk->queue = NULL;
 466
 467                 devidx = md->disk->first_minor >> MMC_SHIFT;
 468                 __clear_bit(devidx, dev_use);
 469
 470                 mmc_blk_put(md);
 471         }
 472         mmc_set_drvdata(card, NULL);
 473 }
 474
 475 #ifdef CONFIG_PM
 476 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 477 {
 478         struct mmc_blk_data *md = mmc_get_drvdata(card);
 479
 480         if (md) {
 481                 mmc_queue_suspend(&md->queue);
 482         }
 483         return 0;
 484 }
 485
 486 static int mmc_blk_resume(struct mmc_card *card)
 487 {
 488         struct mmc_blk_data *md = mmc_get_drvdata(card);
 489
 490         if (md) {
 491                 mmc_blk_set_blksize(md, card);
 492                 mmc_queue_resume(&md->queue);
 493         }
 494         return 0;
 495 }
 496 #else
 497 #define mmc_blk_suspend NULL
 498 #define mmc_blk_resume  NULL
 499 #endif
 500
 501 static struct mmc_driver mmc_driver = {
 502         .drv            = {
 503                 .name   = "mmcblk",
 504         },
 505         .probe          = mmc_blk_probe,
 506         .remove         = mmc_blk_remove,
 507         .suspend        = mmc_blk_suspend,
 508         .resume         = mmc_blk_resume,
 509 };
 510
 511 static int __init mmc_blk_init(void)
 512 {
 513         int res = -ENOMEM;
 514
 515         res = register_blkdev(major, "mmc");
 516         if (res < 0) {
 517                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 518                        major, res);
 519                 goto out;
 520         }
 521         if (major == 0)
 522                 major = res;
 523
 524         return mmc_register_driver(&mmc_driver);
 525
 526  out:
 527         return res;
 528 }
 529
 530 static void __exit mmc_blk_exit(void)
 531 {
 532         mmc_unregister_driver(&mmc_driver);
 533         unregister_blkdev(major, "mmc");
 534 }
 535
 536 module_init(mmc_blk_init);
 537 module_exit(mmc_blk_exit);
 538
 539 MODULE_LICENSE("GPL");
 540 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 541
 542 module_param(major, int, 0444);
 543 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");