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 #include <linux/scatterlist.h>
  32
  33 #include <linux/mmc/card.h>
  34 #include <linux/mmc/host.h>
  35 #include <linux/mmc/protocol.h>
  36 #include <linux/mmc/host.h>
  37
  38 #include <asm/system.h>
  39 #include <asm/uaccess.h>
  40
  41 #include "mmc_queue.h"
  42
  43 /*
  44  * max 8 partitions per card
  45  */
  46 #define MMC_SHIFT       3
  47
  48 static int major;
  49
  50 /*
  51  * There is one mmc_blk_data per slot.
  52  */
  53 struct mmc_blk_data {
  54         spinlock_t      lock;
  55         struct gendisk  *disk;
  56         struct mmc_queue queue;
  57
  58         unsigned int    usage;
  59         unsigned int    block_bits;
  60         unsigned int    read_only;
  61 };
  62
  63 static DEFINE_MUTEX(open_lock);
  64
  65 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  66 {
  67         struct mmc_blk_data *md;
  68
  69         mutex_lock(&open_lock);
  70         md = disk->private_data;
  71         if (md && md->usage == 0)
  72                 md = NULL;
  73         if (md)
  74                 md->usage++;
  75         mutex_unlock(&open_lock);
  76
  77         return md;
  78 }
  79
  80 static void mmc_blk_put(struct mmc_blk_data *md)
  81 {
  82         mutex_lock(&open_lock);
  83         md->usage--;
  84         if (md->usage == 0) {
  85                 put_disk(md->disk);
  86                 mmc_cleanup_queue(&md->queue);
  87                 kfree(md);
  88         }
  89         mutex_unlock(&open_lock);
  90 }
  91
  92 static int mmc_blk_open(struct inode *inode, struct file *filp)
  93 {
  94         struct mmc_blk_data *md;
  95         int ret = -ENXIO;
  96
  97         md = mmc_blk_get(inode->i_bdev->bd_disk);
  98         if (md) {
  99                 if (md->usage == 2)
 100                         check_disk_change(inode->i_bdev);
 101                 ret = 0;
 102
 103                 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
 104                         ret = -EROFS;
 105         }
 106
 107         return ret;
 108 }
 109
 110 static int mmc_blk_release(struct inode *inode, struct file *filp)
 111 {
 112         struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
 113
 114         mmc_blk_put(md);
 115         return 0;
 116 }
 117
 118 static int
 119 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 120 {
 121         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 122         geo->heads = 4;
 123         geo->sectors = 16;
 124         return 0;
 125 }
 126
 127 static struct block_device_operations mmc_bdops = {
 128         .open                   = mmc_blk_open,
 129         .release                = mmc_blk_release,
 130         .getgeo                 = mmc_blk_getgeo,
 131         .owner                  = THIS_MODULE,
 132 };
 133
 134 struct mmc_blk_request {
 135         struct mmc_request      mrq;
 136         struct mmc_command      cmd;
 137         struct mmc_command      stop;
 138         struct mmc_data         data;
 139 };
 140
 141 static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
 142 {
 143         struct mmc_blk_data *md = mq->data;
 144         int stat = BLKPREP_OK;
 145
 146         /*
 147          * If we have no device, we haven't finished initialising.
 148          */
 149         if (!md || !mq->card) {
 150                 printk(KERN_ERR "%s: killing request - no device/host\n",
 151                        req->rq_disk->disk_name);
 152                 stat = BLKPREP_KILL;
 153         }
 154
 155         return stat;
 156 }
 157
 158 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 159 {
 160         int err;
 161         u32 blocks;
 162
 163         struct mmc_request mrq;
 164         struct mmc_command cmd;
 165         struct mmc_data data;
 166         unsigned int timeout_us;
 167
 168         struct scatterlist sg;
 169
 170         memset(&cmd, 0, sizeof(struct mmc_command));
 171
 172         cmd.opcode = MMC_APP_CMD;
 173         cmd.arg = card->rca << 16;
 174         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 175
 176         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 177         if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD))
 178                 return (u32)-1;
 179
 180         memset(&cmd, 0, sizeof(struct mmc_command));
 181
 182         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 183         cmd.arg = 0;
 184         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 185
 186         memset(&data, 0, sizeof(struct mmc_data));
 187
 188         data.timeout_ns = card->csd.tacc_ns * 100;
 189         data.timeout_clks = card->csd.tacc_clks * 100;
 190
 191         timeout_us = data.timeout_ns / 1000;
 192         timeout_us += data.timeout_clks * 1000 /
 193                 (card->host->ios.clock / 1000);
 194
 195         if (timeout_us > 100000) {
 196                 data.timeout_ns = 100000000;
 197                 data.timeout_clks = 0;
 198         }
 199
 200         data.blksz = 4;
 201         data.blocks = 1;
 202         data.flags = MMC_DATA_READ;
 203         data.sg = &sg;
 204         data.sg_len = 1;
 205
 206         memset(&mrq, 0, sizeof(struct mmc_request));
 207
 208         mrq.cmd = &cmd;
 209         mrq.data = &data;
 210
 211         sg_init_one(&sg, &blocks, 4);
 212
 213         mmc_wait_for_req(card->host, &mrq);
 214
 215         if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE)
 216                 return (u32)-1;
 217
 218         blocks = ntohl(blocks);
 219
 220         return blocks;
 221 }
 222
 223 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 224 {
 225         struct mmc_blk_data *md = mq->data;
 226         struct mmc_card *card = md->queue.card;
 227         struct mmc_blk_request brq;
 228         int ret;
 229
 230         if (mmc_card_claim_host(card))
 231                 goto cmd_err;
 232
 233         do {
 234                 struct mmc_command cmd;
 235                 u32 readcmd, writecmd;
 236
 237                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 238                 brq.mrq.cmd = &brq.cmd;
 239                 brq.mrq.data = &brq.data;
 240
 241                 brq.cmd.arg = req->sector << 9;
 242                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 243                 brq.data.blksz = 1 << md->block_bits;
 244                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 245                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 246                 brq.stop.arg = 0;
 247                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 248
 249                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 250
 251                 /*
 252                  * If the host doesn't support multiple block writes, force
 253                  * block writes to single block. SD cards are excepted from
 254                  * this rule as they support querying the number of
 255                  * successfully written sectors.
 256                  */
 257                 if (rq_data_dir(req) != READ &&
 258                     !(card->host->caps & MMC_CAP_MULTIWRITE) &&
 259                     !mmc_card_sd(card))
 260                         brq.data.blocks = 1;
 261
 262                 if (brq.data.blocks > 1) {
 263                         brq.data.flags |= MMC_DATA_MULTI;
 264                         brq.mrq.stop = &brq.stop;
 265                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 266                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 267                 } else {
 268                         brq.mrq.stop = NULL;
 269                         readcmd = MMC_READ_SINGLE_BLOCK;
 270                         writecmd = MMC_WRITE_BLOCK;
 271                 }
 272
 273                 if (rq_data_dir(req) == READ) {
 274                         brq.cmd.opcode = readcmd;
 275                         brq.data.flags |= MMC_DATA_READ;
 276                 } else {
 277                         brq.cmd.opcode = writecmd;
 278                         brq.data.flags |= MMC_DATA_WRITE;
 279                 }
 280
 281                 brq.data.sg = mq->sg;
 282                 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
 283
 284                 mmc_wait_for_req(card->host, &brq.mrq);
 285                 if (brq.cmd.error) {
 286                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 287                                req->rq_disk->disk_name, brq.cmd.error);
 288                         goto cmd_err;
 289                 }
 290
 291                 if (brq.data.error) {
 292                         printk(KERN_ERR "%s: error %d transferring data\n",
 293                                req->rq_disk->disk_name, brq.data.error);
 294                         goto cmd_err;
 295                 }
 296
 297                 if (brq.stop.error) {
 298                         printk(KERN_ERR "%s: error %d sending stop command\n",
 299                                req->rq_disk->disk_name, brq.stop.error);
 300                         goto cmd_err;
 301                 }
 302
 303                 if (rq_data_dir(req) != READ) {
 304                         do {
 305                                 int err;
 306
 307                                 cmd.opcode = MMC_SEND_STATUS;
 308                                 cmd.arg = card->rca << 16;
 309                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 310                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 311                                 if (err) {
 312                                         printk(KERN_ERR "%s: error %d requesting status\n",
 313                                                req->rq_disk->disk_name, err);
 314                                         goto cmd_err;
 315                                 }
 316                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 317
 318 #if 0
 319                         if (cmd.resp[0] & ~0x00000900)
 320                                 printk(KERN_ERR "%s: status = %08x\n",
 321                                        req->rq_disk->disk_name, cmd.resp[0]);
 322                         if (mmc_decode_status(cmd.resp))
 323                                 goto cmd_err;
 324 #endif
 325                 }
 326
 327                 /*
 328                  * A block was successfully transferred.
 329                  */
 330                 spin_lock_irq(&md->lock);
 331                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 332                 if (!ret) {
 333                         /*
 334                          * The whole request completed successfully.
 335                          */
 336                         add_disk_randomness(req->rq_disk);
 337                         blkdev_dequeue_request(req);
 338                         end_that_request_last(req, 1);
 339                 }
 340                 spin_unlock_irq(&md->lock);
 341         } while (ret);
 342
 343         mmc_card_release_host(card);
 344
 345         return 1;
 346
 347  cmd_err:
 348         ret = 1;
 349
 350         /*
 351          * If this is an SD card and we're writing, we can first
 352          * mark the known good sectors as ok.
 353          *
 354          * If the card is not SD, we can still ok written sectors
 355          * if the controller can do proper error reporting.
 356          *
 357          * For reads we just fail the entire chunk as that should
 358          * be safe in all cases.
 359          */
 360         if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
 361                 u32 blocks;
 362                 unsigned int bytes;
 363
 364                 blocks = mmc_sd_num_wr_blocks(card);
 365                 if (blocks != (u32)-1) {
 366                         if (card->csd.write_partial)
 367                                 bytes = blocks << md->block_bits;
 368                         else
 369                                 bytes = blocks << 9;
 370                         spin_lock_irq(&md->lock);
 371                         ret = end_that_request_chunk(req, 1, bytes);
 372                         spin_unlock_irq(&md->lock);
 373                 }
 374         } else if (rq_data_dir(req) != READ &&
 375                    (card->host->caps & MMC_CAP_MULTIWRITE)) {
 376                 spin_lock_irq(&md->lock);
 377                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 378                 spin_unlock_irq(&md->lock);
 379         }
 380
 381         mmc_card_release_host(card);
 382
 383         spin_lock_irq(&md->lock);
 384         while (ret) {
 385                 ret = end_that_request_chunk(req, 0,
 386                                 req->current_nr_sectors << 9);
 387         }
 388
 389         add_disk_randomness(req->rq_disk);
 390         blkdev_dequeue_request(req);
 391         end_that_request_last(req, 0);
 392         spin_unlock_irq(&md->lock);
 393
 394         return 0;
 395 }
 396
 397 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 398
 399 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 400
 401 static inline int mmc_blk_readonly(struct mmc_card *card)
 402 {
 403         return mmc_card_readonly(card) ||
 404                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 405 }
 406
 407 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 408 {
 409         struct mmc_blk_data *md;
 410         int devidx, ret;
 411
 412         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 413         if (devidx >= MMC_NUM_MINORS)
 414                 return ERR_PTR(-ENOSPC);
 415         __set_bit(devidx, dev_use);
 416
 417         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 418         if (!md) {
 419                 ret = -ENOMEM;
 420                 goto out;
 421         }
 422
 423         memset(md, 0, sizeof(struct mmc_blk_data));
 424
 425         /*
 426          * Set the read-only status based on the supported commands
 427          * and the write protect switch.
 428          */
 429         md->read_only = mmc_blk_readonly(card);
 430
 431         /*
 432          * Both SD and MMC specifications state (although a bit
 433          * unclearly in the MMC case) that a block size of 512
 434          * bytes must always be supported by the card.
 435          */
 436         md->block_bits = 9;
 437
 438         md->disk = alloc_disk(1 << MMC_SHIFT);
 439         if (md->disk == NULL) {
 440                 ret = -ENOMEM;
 441                 goto err_kfree;
 442         }
 443
 444         spin_lock_init(&md->lock);
 445         md->usage = 1;
 446
 447         ret = mmc_init_queue(&md->queue, card, &md->lock);
 448         if (ret)
 449                 goto err_putdisk;
 450
 451         md->queue.prep_fn = mmc_blk_prep_rq;
 452         md->queue.issue_fn = mmc_blk_issue_rq;
 453         md->queue.data = md;
 454
 455         md->disk->major = major;
 456         md->disk->first_minor = devidx << MMC_SHIFT;
 457         md->disk->fops = &mmc_bdops;
 458         md->disk->private_data = md;
 459         md->disk->queue = md->queue.queue;
 460         md->disk->driverfs_dev = &card->dev;
 461
 462         /*
 463          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 464          *
 465          * - be set for removable media with permanent block devices
 466          * - be unset for removable block devices with permanent media
 467          *
 468          * Since MMC block devices clearly fall under the second
 469          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 470          * should use the block device creation/destruction hotplug
 471          * messages to tell when the card is present.
 472          */
 473
 474         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 475
 476         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 477
 478         /*
 479          * The CSD capacity field is in units of read_blkbits.
 480          * set_capacity takes units of 512 bytes.
 481          */
 482         set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
 483         return md;
 484
 485  err_putdisk:
 486         put_disk(md->disk);
 487  err_kfree:
 488         kfree(md);
 489  out:
 490         return ERR_PTR(ret);
 491 }
 492
 493 static int
 494 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 495 {
 496         struct mmc_command cmd;
 497         int err;
 498
 499         mmc_card_claim_host(card);
 500         cmd.opcode = MMC_SET_BLOCKLEN;
 501         cmd.arg = 1 << md->block_bits;
 502         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 503         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 504         mmc_card_release_host(card);
 505
 506         if (err) {
 507                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 508                         md->disk->disk_name, cmd.arg, err);
 509                 return -EINVAL;
 510         }
 511
 512         return 0;
 513 }
 514
 515 static int mmc_blk_probe(struct mmc_card *card)
 516 {
 517         struct mmc_blk_data *md;
 518         int err;
 519
 520         /*
 521          * Check that the card supports the command class(es) we need.
 522          */
 523         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 524                 return -ENODEV;
 525
 526         md = mmc_blk_alloc(card);
 527         if (IS_ERR(md))
 528                 return PTR_ERR(md);
 529
 530         err = mmc_blk_set_blksize(md, card);
 531         if (err)
 532                 goto out;
 533
 534         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 535                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 536                 (unsigned long long)(get_capacity(md->disk) >> 1),
 537                 md->read_only ? "(ro)" : "");
 538
 539         mmc_set_drvdata(card, md);
 540         add_disk(md->disk);
 541         return 0;
 542
 543  out:
 544         mmc_blk_put(md);
 545
 546         return err;
 547 }
 548
 549 static void mmc_blk_remove(struct mmc_card *card)
 550 {
 551         struct mmc_blk_data *md = mmc_get_drvdata(card);
 552
 553         if (md) {
 554                 int devidx;
 555
 556                 del_gendisk(md->disk);
 557
 558                 /*
 559                  * I think this is needed.
 560                  */
 561                 md->disk->queue = NULL;
 562
 563                 devidx = md->disk->first_minor >> MMC_SHIFT;
 564                 __clear_bit(devidx, dev_use);
 565
 566                 mmc_blk_put(md);
 567         }
 568         mmc_set_drvdata(card, NULL);
 569 }
 570
 571 #ifdef CONFIG_PM
 572 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 573 {
 574         struct mmc_blk_data *md = mmc_get_drvdata(card);
 575
 576         if (md) {
 577                 mmc_queue_suspend(&md->queue);
 578         }
 579         return 0;
 580 }
 581
 582 static int mmc_blk_resume(struct mmc_card *card)
 583 {
 584         struct mmc_blk_data *md = mmc_get_drvdata(card);
 585
 586         if (md) {
 587                 mmc_blk_set_blksize(md, card);
 588                 mmc_queue_resume(&md->queue);
 589         }
 590         return 0;
 591 }
 592 #else
 593 #define mmc_blk_suspend NULL
 594 #define mmc_blk_resume  NULL
 595 #endif
 596
 597 static struct mmc_driver mmc_driver = {
 598         .drv            = {
 599                 .name   = "mmcblk",
 600         },
 601         .probe          = mmc_blk_probe,
 602         .remove         = mmc_blk_remove,
 603         .suspend        = mmc_blk_suspend,
 604         .resume         = mmc_blk_resume,
 605 };
 606
 607 static int __init mmc_blk_init(void)
 608 {
 609         int res = -ENOMEM;
 610
 611         res = register_blkdev(major, "mmc");
 612         if (res < 0) {
 613                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 614                        major, res);
 615                 goto out;
 616         }
 617         if (major == 0)
 618                 major = res;
 619
 620         return mmc_register_driver(&mmc_driver);
 621
 622  out:
 623         return res;
 624 }
 625
 626 static void __exit mmc_blk_exit(void)
 627 {
 628         mmc_unregister_driver(&mmc_driver);
 629         unregister_blkdev(major, "mmc");
 630 }
 631
 632 module_init(mmc_blk_init);
 633 module_exit(mmc_blk_exit);
 634
 635 MODULE_LICENSE("GPL");
 636 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 637
 638 module_param(major, int, 0444);
 639 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");