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
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37
  38 #include "mmc_queue.h"
  39
  40 /*
  41  * max 8 partitions per card
  42  */
  43 #define MMC_SHIFT       3
  44
  45 static int major;
  46
  47 /*
  48  * There is one mmc_blk_data per slot.
  49  */
  50 struct mmc_blk_data {
  51         spinlock_t      lock;
  52         struct gendisk  *disk;
  53         struct mmc_queue queue;
  54
  55         unsigned int    usage;
  56         unsigned int    block_bits;
  57 };
  58
  59 static DECLARE_MUTEX(open_lock);
  60
  61 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  62 {
  63         struct mmc_blk_data *md;
  64
  65         down(&open_lock);
  66         md = disk->private_data;
  67         if (md && md->usage == 0)
  68                 md = NULL;
  69         if (md)
  70                 md->usage++;
  71         up(&open_lock);
  72
  73         return md;
  74 }
  75
  76 static void mmc_blk_put(struct mmc_blk_data *md)
  77 {
  78         down(&open_lock);
  79         md->usage--;
  80         if (md->usage == 0) {
  81                 put_disk(md->disk);
  82                 mmc_cleanup_queue(&md->queue);
  83                 kfree(md);
  84         }
  85         up(&open_lock);
  86 }
  87
  88 static inline int mmc_blk_readonly(struct mmc_card *card)
  89 {
  90         return mmc_card_readonly(card) ||
  91                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
  92 }
  93
  94 static int mmc_blk_open(struct inode *inode, struct file *filp)
  95 {
  96         struct mmc_blk_data *md;
  97         int ret = -ENXIO;
  98
  99         md = mmc_blk_get(inode->i_bdev->bd_disk);
 100         if (md) {
 101                 if (md->usage == 2)
 102                         check_disk_change(inode->i_bdev);
 103                 ret = 0;
 104
 105                 if ((filp->f_mode & FMODE_WRITE) &&
 106                         mmc_blk_readonly(md->queue.card))
 107                         ret = -EROFS;
 108         }
 109
 110         return ret;
 111 }
 112
 113 static int mmc_blk_release(struct inode *inode, struct file *filp)
 114 {
 115         struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
 116
 117         mmc_blk_put(md);
 118         return 0;
 119 }
 120
 121 static int
 122 mmc_blk_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
 123 {
 124         struct block_device *bdev = inode->i_bdev;
 125
 126         if (cmd == HDIO_GETGEO) {
 127                 struct hd_geometry geo;
 128
 129                 memset(&geo, 0, sizeof(struct hd_geometry));
 130
 131                 geo.cylinders   = get_capacity(bdev->bd_disk) / (4 * 16);
 132                 geo.heads       = 4;
 133                 geo.sectors     = 16;
 134                 geo.start       = get_start_sect(bdev);
 135
 136                 return copy_to_user((void __user *)arg, &geo, sizeof(geo))
 137                         ? -EFAULT : 0;
 138         }
 139
 140         return -ENOTTY;
 141 }
 142
 143 static struct block_device_operations mmc_bdops = {
 144         .open                   = mmc_blk_open,
 145         .release                = mmc_blk_release,
 146         .ioctl                  = mmc_blk_ioctl,
 147         .owner                  = THIS_MODULE,
 148 };
 149
 150 struct mmc_blk_request {
 151         struct mmc_request      mrq;
 152         struct mmc_command      cmd;
 153         struct mmc_command      stop;
 154         struct mmc_data         data;
 155 };
 156
 157 static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
 158 {
 159         struct mmc_blk_data *md = mq->data;
 160         int stat = BLKPREP_OK;
 161
 162         /*
 163          * If we have no device, we haven't finished initialising.
 164          */
 165         if (!md || !mq->card) {
 166                 printk(KERN_ERR "%s: killing request - no device/host\n",
 167                        req->rq_disk->disk_name);
 168                 stat = BLKPREP_KILL;
 169         }
 170
 171         return stat;
 172 }
 173
 174 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 175 {
 176         struct mmc_blk_data *md = mq->data;
 177         struct mmc_card *card = md->queue.card;
 178         int ret;
 179
 180         if (mmc_card_claim_host(card))
 181                 goto cmd_err;
 182
 183         do {
 184                 struct mmc_blk_request brq;
 185                 struct mmc_command cmd;
 186
 187                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 188                 brq.mrq.cmd = &brq.cmd;
 189                 brq.mrq.data = &brq.data;
 190
 191                 brq.cmd.arg = req->sector << 9;
 192                 brq.cmd.flags = MMC_RSP_R1;
 193                 brq.data.timeout_ns = card->csd.tacc_ns * 10;
 194                 brq.data.timeout_clks = card->csd.tacc_clks * 10;
 195                 brq.data.blksz_bits = md->block_bits;
 196                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 197                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 198                 brq.stop.arg = 0;
 199                 brq.stop.flags = MMC_RSP_R1B;
 200
 201                 if (rq_data_dir(req) == READ) {
 202                         brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
 203                         brq.data.flags |= MMC_DATA_READ;
 204                 } else {
 205                         brq.cmd.opcode = MMC_WRITE_BLOCK;
 206                         brq.data.flags |= MMC_DATA_WRITE;
 207                         brq.data.blocks = 1;
 208                 }
 209                 brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL;
 210
 211                 brq.data.sg = mq->sg;
 212                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 213
 214                 mmc_wait_for_req(card->host, &brq.mrq);
 215                 if (brq.cmd.error) {
 216                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 217                                req->rq_disk->disk_name, brq.cmd.error);
 218                         goto cmd_err;
 219                 }
 220
 221                 if (brq.data.error) {
 222                         printk(KERN_ERR "%s: error %d transferring data\n",
 223                                req->rq_disk->disk_name, brq.data.error);
 224                         goto cmd_err;
 225                 }
 226
 227                 if (brq.stop.error) {
 228                         printk(KERN_ERR "%s: error %d sending stop command\n",
 229                                req->rq_disk->disk_name, brq.stop.error);
 230                         goto cmd_err;
 231                 }
 232
 233                 do {
 234                         int err;
 235
 236                         cmd.opcode = MMC_SEND_STATUS;
 237                         cmd.arg = card->rca << 16;
 238                         cmd.flags = MMC_RSP_R1;
 239                         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 240                         if (err) {
 241                                 printk(KERN_ERR "%s: error %d requesting status\n",
 242                                        req->rq_disk->disk_name, err);
 243                                 goto cmd_err;
 244                         }
 245                 } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 246
 247 #if 0
 248                 if (cmd.resp[0] & ~0x00000900)
 249                         printk(KERN_ERR "%s: status = %08x\n",
 250                                req->rq_disk->disk_name, cmd.resp[0]);
 251                 if (mmc_decode_status(cmd.resp))
 252                         goto cmd_err;
 253 #endif
 254
 255                 /*
 256                  * A block was successfully transferred.
 257                  */
 258                 spin_lock_irq(&md->lock);
 259                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 260                 if (!ret) {
 261                         /*
 262                          * The whole request completed successfully.
 263                          */
 264                         add_disk_randomness(req->rq_disk);
 265                         blkdev_dequeue_request(req);
 266                         end_that_request_last(req);
 267                 }
 268                 spin_unlock_irq(&md->lock);
 269         } while (ret);
 270
 271         mmc_card_release_host(card);
 272
 273         return 1;
 274
 275  cmd_err:
 276         mmc_card_release_host(card);
 277
 278         /*
 279          * This is a little draconian, but until we get proper
 280          * error handling sorted out here, its the best we can
 281          * do - especially as some hosts have no idea how much
 282          * data was transferred before the error occurred.
 283          */
 284         spin_lock_irq(&md->lock);
 285         do {
 286                 ret = end_that_request_chunk(req, 0,
 287                                 req->current_nr_sectors << 9);
 288         } while (ret);
 289
 290         add_disk_randomness(req->rq_disk);
 291         blkdev_dequeue_request(req);
 292         end_that_request_last(req);
 293         spin_unlock_irq(&md->lock);
 294
 295         return 0;
 296 }
 297
 298 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 299
 300 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 301
 302 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 303 {
 304         struct mmc_blk_data *md;
 305         int devidx, ret;
 306
 307         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 308         if (devidx >= MMC_NUM_MINORS)
 309                 return ERR_PTR(-ENOSPC);
 310         __set_bit(devidx, dev_use);
 311
 312         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 313         if (md) {
 314                 memset(md, 0, sizeof(struct mmc_blk_data));
 315
 316                 md->disk = alloc_disk(1 << MMC_SHIFT);
 317                 if (md->disk == NULL) {
 318                         kfree(md);
 319                         md = ERR_PTR(-ENOMEM);
 320                         goto out;
 321                 }
 322
 323                 spin_lock_init(&md->lock);
 324                 md->usage = 1;
 325
 326                 ret = mmc_init_queue(&md->queue, card, &md->lock);
 327                 if (ret) {
 328                         put_disk(md->disk);
 329                         kfree(md);
 330                         md = ERR_PTR(ret);
 331                         goto out;
 332                 }
 333                 md->queue.prep_fn = mmc_blk_prep_rq;
 334                 md->queue.issue_fn = mmc_blk_issue_rq;
 335                 md->queue.data = md;
 336
 337                 md->disk->major = major;
 338                 md->disk->first_minor = devidx << MMC_SHIFT;
 339                 md->disk->fops = &mmc_bdops;
 340                 md->disk->private_data = md;
 341                 md->disk->queue = md->queue.queue;
 342                 md->disk->driverfs_dev = &card->dev;
 343
 344                 /*
 345                  * As discussed on lkml, GENHD_FL_REMOVABLE should:
 346                  *
 347                  * - be set for removable media with permanent block devices
 348                  * - be unset for removable block devices with permanent media
 349                  *
 350                  * Since MMC block devices clearly fall under the second
 351                  * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 352                  * should use the block device creation/destruction hotplug
 353                  * messages to tell when the card is present.
 354                  */
 355
 356                 sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 357                 sprintf(md->disk->devfs_name, "mmc/blk%d", devidx);
 358
 359                 md->block_bits = card->csd.read_blkbits;
 360
 361                 blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 362                 set_capacity(md->disk, card->csd.capacity);
 363         }
 364  out:
 365         return md;
 366 }
 367
 368 static int
 369 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 370 {
 371         struct mmc_command cmd;
 372         int err;
 373
 374         mmc_card_claim_host(card);
 375         cmd.opcode = MMC_SET_BLOCKLEN;
 376         cmd.arg = 1 << card->csd.read_blkbits;
 377         cmd.flags = MMC_RSP_R1;
 378         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 379         mmc_card_release_host(card);
 380
 381         if (err) {
 382                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 383                         md->disk->disk_name, cmd.arg, err);
 384                 return -EINVAL;
 385         }
 386
 387         return 0;
 388 }
 389
 390 static int mmc_blk_probe(struct mmc_card *card)
 391 {
 392         struct mmc_blk_data *md;
 393         int err;
 394
 395         /*
 396          * Check that the card supports the command class(es) we need.
 397          */
 398         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 399                 return -ENODEV;
 400
 401         if (card->csd.read_blkbits < 9) {
 402                 printk(KERN_WARNING "%s: read blocksize too small (%u)\n",
 403                         mmc_card_id(card), 1 << card->csd.read_blkbits);
 404                 return -ENODEV;
 405         }
 406
 407         md = mmc_blk_alloc(card);
 408         if (IS_ERR(md))
 409                 return PTR_ERR(md);
 410
 411         err = mmc_blk_set_blksize(md, card);
 412         if (err)
 413                 goto out;
 414
 415         printk(KERN_INFO "%s: %s %s %dKiB %s\n",
 416                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 417                 (card->csd.capacity << card->csd.read_blkbits) / 1024,
 418                 mmc_blk_readonly(card)?"(ro)":"");
 419
 420         mmc_set_drvdata(card, md);
 421         add_disk(md->disk);
 422         return 0;
 423
 424  out:
 425         mmc_blk_put(md);
 426
 427         return err;
 428 }
 429
 430 static void mmc_blk_remove(struct mmc_card *card)
 431 {
 432         struct mmc_blk_data *md = mmc_get_drvdata(card);
 433
 434         if (md) {
 435                 int devidx;
 436
 437                 del_gendisk(md->disk);
 438
 439                 /*
 440                  * I think this is needed.
 441                  */
 442                 md->disk->queue = NULL;
 443
 444                 devidx = md->disk->first_minor >> MMC_SHIFT;
 445                 __clear_bit(devidx, dev_use);
 446
 447                 mmc_blk_put(md);
 448         }
 449         mmc_set_drvdata(card, NULL);
 450 }
 451
 452 #ifdef CONFIG_PM
 453 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 454 {
 455         struct mmc_blk_data *md = mmc_get_drvdata(card);
 456
 457         if (md) {
 458                 mmc_queue_suspend(&md->queue);
 459         }
 460         return 0;
 461 }
 462
 463 static int mmc_blk_resume(struct mmc_card *card)
 464 {
 465         struct mmc_blk_data *md = mmc_get_drvdata(card);
 466
 467         if (md) {
 468                 mmc_blk_set_blksize(md, card);
 469                 mmc_queue_resume(&md->queue);
 470         }
 471         return 0;
 472 }
 473 #else
 474 #define mmc_blk_suspend NULL
 475 #define mmc_blk_resume  NULL
 476 #endif
 477
 478 static struct mmc_driver mmc_driver = {
 479         .drv            = {
 480                 .name   = "mmcblk",
 481         },
 482         .probe          = mmc_blk_probe,
 483         .remove         = mmc_blk_remove,
 484         .suspend        = mmc_blk_suspend,
 485         .resume         = mmc_blk_resume,
 486 };
 487
 488 static int __init mmc_blk_init(void)
 489 {
 490         int res = -ENOMEM;
 491
 492         res = register_blkdev(major, "mmc");
 493         if (res < 0) {
 494                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 495                        major, res);
 496                 goto out;
 497         }
 498         if (major == 0)
 499                 major = res;
 500
 501         devfs_mk_dir("mmc");
 502         return mmc_register_driver(&mmc_driver);
 503
 504  out:
 505         return res;
 506 }
 507
 508 static void __exit mmc_blk_exit(void)
 509 {
 510         mmc_unregister_driver(&mmc_driver);
 511         devfs_remove("mmc");
 512         unregister_blkdev(major, "mmc");
 513 }
 514
 515 module_init(mmc_blk_init);
 516 module_exit(mmc_blk_exit);
 517
 518 MODULE_LICENSE("GPL");
 519 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 520
 521 module_param(major, int, 0444);
 522 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");