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         struct mmc_blk_request brq;
 162         int ret;
 163
 164         if (mmc_card_claim_host(card))
 165                 goto cmd_err;
 166
 167         do {
 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         ret = 1;
 282
 283         /*
 284          * For writes and where the host claims to support proper
 285          * error reporting, we first ok the successful blocks.
 286          *
 287          * For reads we just fail the entire chunk as that should
 288          * be safe in all cases.
 289          */
 290         if (rq_data_dir(req) != READ &&
 291             (card->host->caps & MMC_CAP_MULTIWRITE)) {
 292                 spin_lock_irq(&md->lock);
 293                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 294                 spin_unlock_irq(&md->lock);
 295         }
 296
 297         spin_lock_irq(&md->lock);
 298         while (ret) {
 299                 ret = end_that_request_chunk(req, 0,
 300                                 req->current_nr_sectors << 9);
 301         }
 302
 303         add_disk_randomness(req->rq_disk);
 304         blkdev_dequeue_request(req);
 305         end_that_request_last(req, 0);
 306         spin_unlock_irq(&md->lock);
 307
 308         return 0;
 309 }
 310
 311 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 312
 313 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 314
 315 static inline int mmc_blk_readonly(struct mmc_card *card)
 316 {
 317         return mmc_card_readonly(card) ||
 318                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 319 }
 320
 321 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 322 {
 323         struct mmc_blk_data *md;
 324         int devidx, ret;
 325
 326         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 327         if (devidx >= MMC_NUM_MINORS)
 328                 return ERR_PTR(-ENOSPC);
 329         __set_bit(devidx, dev_use);
 330
 331         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 332         if (!md) {
 333                 ret = -ENOMEM;
 334                 goto out;
 335         }
 336
 337         memset(md, 0, sizeof(struct mmc_blk_data));
 338
 339         /*
 340          * Set the read-only status based on the supported commands
 341          * and the write protect switch.
 342          */
 343         md->read_only = mmc_blk_readonly(card);
 344
 345         /*
 346          * Both SD and MMC specifications state (although a bit
 347          * unclearly in the MMC case) that a block size of 512
 348          * bytes must always be supported by the card.
 349          */
 350         md->block_bits = 9;
 351
 352         md->disk = alloc_disk(1 << MMC_SHIFT);
 353         if (md->disk == NULL) {
 354                 ret = -ENOMEM;
 355                 goto err_kfree;
 356         }
 357
 358         spin_lock_init(&md->lock);
 359         md->usage = 1;
 360
 361         ret = mmc_init_queue(&md->queue, card, &md->lock);
 362         if (ret)
 363                 goto err_putdisk;
 364
 365         md->queue.prep_fn = mmc_blk_prep_rq;
 366         md->queue.issue_fn = mmc_blk_issue_rq;
 367         md->queue.data = md;
 368
 369         md->disk->major = major;
 370         md->disk->first_minor = devidx << MMC_SHIFT;
 371         md->disk->fops = &mmc_bdops;
 372         md->disk->private_data = md;
 373         md->disk->queue = md->queue.queue;
 374         md->disk->driverfs_dev = &card->dev;
 375
 376         /*
 377          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 378          *
 379          * - be set for removable media with permanent block devices
 380          * - be unset for removable block devices with permanent media
 381          *
 382          * Since MMC block devices clearly fall under the second
 383          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 384          * should use the block device creation/destruction hotplug
 385          * messages to tell when the card is present.
 386          */
 387
 388         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 389
 390         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 391
 392         /*
 393          * The CSD capacity field is in units of read_blkbits.
 394          * set_capacity takes units of 512 bytes.
 395          */
 396         set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
 397         return md;
 398
 399  err_putdisk:
 400         put_disk(md->disk);
 401  err_kfree:
 402         kfree(md);
 403  out:
 404         return ERR_PTR(ret);
 405 }
 406
 407 static int
 408 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 409 {
 410         struct mmc_command cmd;
 411         int err;
 412
 413         mmc_card_claim_host(card);
 414         cmd.opcode = MMC_SET_BLOCKLEN;
 415         cmd.arg = 1 << md->block_bits;
 416         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 417         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 418         mmc_card_release_host(card);
 419
 420         if (err) {
 421                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 422                         md->disk->disk_name, cmd.arg, err);
 423                 return -EINVAL;
 424         }
 425
 426         return 0;
 427 }
 428
 429 static int mmc_blk_probe(struct mmc_card *card)
 430 {
 431         struct mmc_blk_data *md;
 432         int err;
 433
 434         /*
 435          * Check that the card supports the command class(es) we need.
 436          */
 437         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 438                 return -ENODEV;
 439
 440         md = mmc_blk_alloc(card);
 441         if (IS_ERR(md))
 442                 return PTR_ERR(md);
 443
 444         err = mmc_blk_set_blksize(md, card);
 445         if (err)
 446                 goto out;
 447
 448         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 449                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 450                 (unsigned long long)(get_capacity(md->disk) >> 1),
 451                 md->read_only ? "(ro)" : "");
 452
 453         mmc_set_drvdata(card, md);
 454         add_disk(md->disk);
 455         return 0;
 456
 457  out:
 458         mmc_blk_put(md);
 459
 460         return err;
 461 }
 462
 463 static void mmc_blk_remove(struct mmc_card *card)
 464 {
 465         struct mmc_blk_data *md = mmc_get_drvdata(card);
 466
 467         if (md) {
 468                 int devidx;
 469
 470                 del_gendisk(md->disk);
 471
 472                 /*
 473                  * I think this is needed.
 474                  */
 475                 md->disk->queue = NULL;
 476
 477                 devidx = md->disk->first_minor >> MMC_SHIFT;
 478                 __clear_bit(devidx, dev_use);
 479
 480                 mmc_blk_put(md);
 481         }
 482         mmc_set_drvdata(card, NULL);
 483 }
 484
 485 #ifdef CONFIG_PM
 486 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 487 {
 488         struct mmc_blk_data *md = mmc_get_drvdata(card);
 489
 490         if (md) {
 491                 mmc_queue_suspend(&md->queue);
 492         }
 493         return 0;
 494 }
 495
 496 static int mmc_blk_resume(struct mmc_card *card)
 497 {
 498         struct mmc_blk_data *md = mmc_get_drvdata(card);
 499
 500         if (md) {
 501                 mmc_blk_set_blksize(md, card);
 502                 mmc_queue_resume(&md->queue);
 503         }
 504         return 0;
 505 }
 506 #else
 507 #define mmc_blk_suspend NULL
 508 #define mmc_blk_resume  NULL
 509 #endif
 510
 511 static struct mmc_driver mmc_driver = {
 512         .drv            = {
 513                 .name   = "mmcblk",
 514         },
 515         .probe          = mmc_blk_probe,
 516         .remove         = mmc_blk_remove,
 517         .suspend        = mmc_blk_suspend,
 518         .resume         = mmc_blk_resume,
 519 };
 520
 521 static int __init mmc_blk_init(void)
 522 {
 523         int res = -ENOMEM;
 524
 525         res = register_blkdev(major, "mmc");
 526         if (res < 0) {
 527                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 528                        major, res);
 529                 goto out;
 530         }
 531         if (major == 0)
 532                 major = res;
 533
 534         return mmc_register_driver(&mmc_driver);
 535
 536  out:
 537         return res;
 538 }
 539
 540 static void __exit mmc_blk_exit(void)
 541 {
 542         mmc_unregister_driver(&mmc_driver);
 543         unregister_blkdev(major, "mmc");
 544 }
 545
 546 module_init(mmc_blk_init);
 547 module_exit(mmc_blk_exit);
 548
 549 MODULE_LICENSE("GPL");
 550 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 551
 552 module_param(major, int, 0444);
 553 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");