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