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