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
  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    read_only;
  59 };
  60
  61 static DEFINE_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         mutex_lock(&open_lock);
  68         md = disk->private_data;
  69         if (md && md->usage == 0)
  70                 md = NULL;
  71         if (md)
  72                 md->usage++;
  73         mutex_unlock(&open_lock);
  74
  75         return md;
  76 }
  77
  78 static void mmc_blk_put(struct mmc_blk_data *md)
  79 {
  80         mutex_lock(&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         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 int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 157 {
 158         struct mmc_blk_data *md = mq->data;
 159         struct mmc_card *card = md->queue.card;
 160         int ret;
 161
 162         if (mmc_card_claim_host(card))
 163                 goto cmd_err;
 164
 165         do {
 166                 struct mmc_blk_request brq;
 167                 struct mmc_command cmd;
 168
 169                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 170                 brq.mrq.cmd = &brq.cmd;
 171                 brq.mrq.data = &brq.data;
 172
 173                 brq.cmd.arg = req->sector << 9;
 174                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 175                 brq.data.blksz_bits = md->block_bits;
 176                 brq.data.blksz = 1 << md->block_bits;
 177                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 178                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 179                 brq.stop.arg = 0;
 180                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 181
 182                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 183
 184                 if (rq_data_dir(req) == READ) {
 185                         brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
 186                         brq.data.flags |= MMC_DATA_READ;
 187                 } else {
 188                         brq.cmd.opcode = MMC_WRITE_BLOCK;
 189                         brq.data.flags |= MMC_DATA_WRITE;
 190                         brq.data.blocks = 1;
 191                 }
 192
 193                 if (brq.data.blocks > 1) {
 194                         brq.data.flags |= MMC_DATA_MULTI;
 195                         brq.mrq.stop = &brq.stop;
 196                 } else {
 197                         brq.mrq.stop = NULL;
 198                 }
 199
 200                 brq.data.sg = mq->sg;
 201                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 202
 203                 mmc_wait_for_req(card->host, &brq.mrq);
 204                 if (brq.cmd.error) {
 205                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 206                                req->rq_disk->disk_name, brq.cmd.error);
 207                         goto cmd_err;
 208                 }
 209
 210                 if (brq.data.error) {
 211                         printk(KERN_ERR "%s: error %d transferring data\n",
 212                                req->rq_disk->disk_name, brq.data.error);
 213                         goto cmd_err;
 214                 }
 215
 216                 if (brq.stop.error) {
 217                         printk(KERN_ERR "%s: error %d sending stop command\n",
 218                                req->rq_disk->disk_name, brq.stop.error);
 219                         goto cmd_err;
 220                 }
 221
 222                 do {
 223                         int err;
 224
 225                         cmd.opcode = MMC_SEND_STATUS;
 226                         cmd.arg = card->rca << 16;
 227                         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 228                         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 229                         if (err) {
 230                                 printk(KERN_ERR "%s: error %d requesting status\n",
 231                                        req->rq_disk->disk_name, err);
 232                                 goto cmd_err;
 233                         }
 234                 } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 235
 236 #if 0
 237                 if (cmd.resp[0] & ~0x00000900)
 238                         printk(KERN_ERR "%s: status = %08x\n",
 239                                req->rq_disk->disk_name, cmd.resp[0]);
 240                 if (mmc_decode_status(cmd.resp))
 241                         goto cmd_err;
 242 #endif
 243
 244                 /*
 245                  * A block was successfully transferred.
 246                  */
 247                 spin_lock_irq(&md->lock);
 248                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 249                 if (!ret) {
 250                         /*
 251                          * The whole request completed successfully.
 252                          */
 253                         add_disk_randomness(req->rq_disk);
 254                         blkdev_dequeue_request(req);
 255                         end_that_request_last(req, 1);
 256                 }
 257                 spin_unlock_irq(&md->lock);
 258         } while (ret);
 259
 260         mmc_card_release_host(card);
 261
 262         return 1;
 263
 264  cmd_err:
 265         mmc_card_release_host(card);
 266
 267         /*
 268          * This is a little draconian, but until we get proper
 269          * error handling sorted out here, its the best we can
 270          * do - especially as some hosts have no idea how much
 271          * data was transferred before the error occurred.
 272          */
 273         spin_lock_irq(&md->lock);
 274         do {
 275                 ret = end_that_request_chunk(req, 0,
 276                                 req->current_nr_sectors << 9);
 277         } while (ret);
 278
 279         add_disk_randomness(req->rq_disk);
 280         blkdev_dequeue_request(req);
 281         end_that_request_last(req, 0);
 282         spin_unlock_irq(&md->lock);
 283
 284         return 0;
 285 }
 286
 287 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 288
 289 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 290
 291 static inline int mmc_blk_readonly(struct mmc_card *card)
 292 {
 293         return mmc_card_readonly(card) ||
 294                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 295 }
 296
 297 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 298 {
 299         struct mmc_blk_data *md;
 300         int devidx, ret;
 301
 302         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 303         if (devidx >= MMC_NUM_MINORS)
 304                 return ERR_PTR(-ENOSPC);
 305         __set_bit(devidx, dev_use);
 306
 307         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 308         if (!md) {
 309                 ret = -ENOMEM;
 310                 goto out;
 311         }
 312
 313         memset(md, 0, sizeof(struct mmc_blk_data));
 314
 315         /*
 316          * Set the read-only status based on the supported commands
 317          * and the write protect switch.
 318          */
 319         md->read_only = mmc_blk_readonly(card);
 320
 321         /*
 322          * Both SD and MMC specifications state (although a bit
 323          * unclearly in the MMC case) that a block size of 512
 324          * bytes must always be supported by the card.
 325          */
 326         md->block_bits = 9;
 327
 328         md->disk = alloc_disk(1 << MMC_SHIFT);
 329         if (md->disk == NULL) {
 330                 ret = -ENOMEM;
 331                 goto err_kfree;
 332         }
 333
 334         spin_lock_init(&md->lock);
 335         md->usage = 1;
 336
 337         ret = mmc_init_queue(&md->queue, card, &md->lock);
 338         if (ret)
 339                 goto err_putdisk;
 340
 341         md->queue.prep_fn = mmc_blk_prep_rq;
 342         md->queue.issue_fn = mmc_blk_issue_rq;
 343         md->queue.data = md;
 344
 345         md->disk->major = major;
 346         md->disk->first_minor = devidx << MMC_SHIFT;
 347         md->disk->fops = &mmc_bdops;
 348         md->disk->private_data = md;
 349         md->disk->queue = md->queue.queue;
 350         md->disk->driverfs_dev = &card->dev;
 351
 352         /*
 353          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 354          *
 355          * - be set for removable media with permanent block devices
 356          * - be unset for removable block devices with permanent media
 357          *
 358          * Since MMC block devices clearly fall under the second
 359          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 360          * should use the block device creation/destruction hotplug
 361          * messages to tell when the card is present.
 362          */
 363
 364         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 365
 366         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 367
 368         /*
 369          * The CSD capacity field is in units of read_blkbits.
 370          * set_capacity takes units of 512 bytes.
 371          */
 372         set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
 373         return md;
 374
 375  err_putdisk:
 376         put_disk(md->disk);
 377  err_kfree:
 378         kfree(md);
 379  out:
 380         return ERR_PTR(ret);
 381 }
 382
 383 static int
 384 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 385 {
 386         struct mmc_command cmd;
 387         int err;
 388
 389         mmc_card_claim_host(card);
 390         cmd.opcode = MMC_SET_BLOCKLEN;
 391         cmd.arg = 1 << md->block_bits;
 392         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 393         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 394         mmc_card_release_host(card);
 395
 396         if (err) {
 397                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 398                         md->disk->disk_name, cmd.arg, err);
 399                 return -EINVAL;
 400         }
 401
 402         return 0;
 403 }
 404
 405 static int mmc_blk_probe(struct mmc_card *card)
 406 {
 407         struct mmc_blk_data *md;
 408         int err;
 409
 410         /*
 411          * Check that the card supports the command class(es) we need.
 412          */
 413         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 414                 return -ENODEV;
 415
 416         md = mmc_blk_alloc(card);
 417         if (IS_ERR(md))
 418                 return PTR_ERR(md);
 419
 420         err = mmc_blk_set_blksize(md, card);
 421         if (err)
 422                 goto out;
 423
 424         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 425                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 426                 (unsigned long long)(get_capacity(md->disk) >> 1),
 427                 md->read_only ? "(ro)" : "");
 428
 429         mmc_set_drvdata(card, md);
 430         add_disk(md->disk);
 431         return 0;
 432
 433  out:
 434         mmc_blk_put(md);
 435
 436         return err;
 437 }
 438
 439 static void mmc_blk_remove(struct mmc_card *card)
 440 {
 441         struct mmc_blk_data *md = mmc_get_drvdata(card);
 442
 443         if (md) {
 444                 int devidx;
 445
 446                 del_gendisk(md->disk);
 447
 448                 /*
 449                  * I think this is needed.
 450                  */
 451                 md->disk->queue = NULL;
 452
 453                 devidx = md->disk->first_minor >> MMC_SHIFT;
 454                 __clear_bit(devidx, dev_use);
 455
 456                 mmc_blk_put(md);
 457         }
 458         mmc_set_drvdata(card, NULL);
 459 }
 460
 461 #ifdef CONFIG_PM
 462 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 463 {
 464         struct mmc_blk_data *md = mmc_get_drvdata(card);
 465
 466         if (md) {
 467                 mmc_queue_suspend(&md->queue);
 468         }
 469         return 0;
 470 }
 471
 472 static int mmc_blk_resume(struct mmc_card *card)
 473 {
 474         struct mmc_blk_data *md = mmc_get_drvdata(card);
 475
 476         if (md) {
 477                 mmc_blk_set_blksize(md, card);
 478                 mmc_queue_resume(&md->queue);
 479         }
 480         return 0;
 481 }
 482 #else
 483 #define mmc_blk_suspend NULL
 484 #define mmc_blk_resume  NULL
 485 #endif
 486
 487 static struct mmc_driver mmc_driver = {
 488         .drv            = {
 489                 .name   = "mmcblk",
 490         },
 491         .probe          = mmc_blk_probe,
 492         .remove         = mmc_blk_remove,
 493         .suspend        = mmc_blk_suspend,
 494         .resume         = mmc_blk_resume,
 495 };
 496
 497 static int __init mmc_blk_init(void)
 498 {
 499         int res = -ENOMEM;
 500
 501         res = register_blkdev(major, "mmc");
 502         if (res < 0) {
 503                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 504                        major, res);
 505                 goto out;
 506         }
 507         if (major == 0)
 508                 major = res;
 509
 510         return mmc_register_driver(&mmc_driver);
 511
 512  out:
 513         return res;
 514 }
 515
 516 static void __exit mmc_blk_exit(void)
 517 {
 518         mmc_unregister_driver(&mmc_driver);
 519         unregister_blkdev(major, "mmc");
 520 }
 521
 522 module_init(mmc_blk_init);
 523 module_exit(mmc_blk_exit);
 524
 525 MODULE_LICENSE("GPL");
 526 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 527
 528 module_param(major, int, 0444);
 529 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");