drivers/mmc/card/block.c

   1 /*
   2  * Block driver for media (i.e., flash cards)
   3  *
   4  * Copyright 2002 Hewlett-Packard Company
   5  * Copyright 2005-2007 Pierre Ossman
   6  *
   7  * Use consistent with the GNU GPL is permitted,
   8  * provided that this copyright notice is
   9  * preserved in its entirety in all copies and derived works.
  10  *
  11  * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
  12  * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
  13  * FITNESS FOR ANY PARTICULAR PURPOSE.
  14  *
  15  * Many thanks to Alessandro Rubini and Jonathan Corbet!
  16  *
  17  * Author:  Andrew Christian
  18  *          28 May 2002
  19  */
  20 #include <linux/moduleparam.h>
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23
  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/mmc.h>
  36 #include <linux/mmc/sd.h>
  37
  38 #include <asm/system.h>
  39 #include <asm/uaccess.h>
  40
  41 #include "queue.h"
  42
  43 /*
  44  * max 8 partitions per card
  45  */
  46 #define MMC_SHIFT       3
  47 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
  48
  49 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
  50
  51 /*
  52  * There is one mmc_blk_data per slot.
  53  */
  54 struct mmc_blk_data {
  55         spinlock_t      lock;
  56         struct gendisk  *disk;
  57         struct mmc_queue queue;
  58
  59         unsigned int    usage;
  60         unsigned int    block_bits;
  61         unsigned int    read_only;
  62 };
  63
  64 static DEFINE_MUTEX(open_lock);
  65
  66 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  67 {
  68         struct mmc_blk_data *md;
  69
  70         mutex_lock(&open_lock);
  71         md = disk->private_data;
  72         if (md && md->usage == 0)
  73                 md = NULL;
  74         if (md)
  75                 md->usage++;
  76         mutex_unlock(&open_lock);
  77
  78         return md;
  79 }
  80
  81 static void mmc_blk_put(struct mmc_blk_data *md)
  82 {
  83         mutex_lock(&open_lock);
  84         md->usage--;
  85         if (md->usage == 0) {
  86                 int devidx = md->disk->first_minor >> MMC_SHIFT;
  87                 __clear_bit(devidx, dev_use);
  88
  89                 put_disk(md->disk);
  90                 kfree(md);
  91         }
  92         mutex_unlock(&open_lock);
  93 }
  94
  95 static int mmc_blk_open(struct inode *inode, struct file *filp)
  96 {
  97         struct mmc_blk_data *md;
  98         int ret = -ENXIO;
  99
 100         md = mmc_blk_get(inode->i_bdev->bd_disk);
 101         if (md) {
 102                 if (md->usage == 2)
 103                         check_disk_change(inode->i_bdev);
 104                 ret = 0;
 105
 106                 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
 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_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 123 {
 124         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 125         geo->heads = 4;
 126         geo->sectors = 16;
 127         return 0;
 128 }
 129
 130 static struct block_device_operations mmc_bdops = {
 131         .open                   = mmc_blk_open,
 132         .release                = mmc_blk_release,
 133         .getgeo                 = mmc_blk_getgeo,
 134         .owner                  = THIS_MODULE,
 135 };
 136
 137 struct mmc_blk_request {
 138         struct mmc_request      mrq;
 139         struct mmc_command      cmd;
 140         struct mmc_command      stop;
 141         struct mmc_data         data;
 142 };
 143
 144 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 145 {
 146         int err;
 147         u32 blocks;
 148
 149         struct mmc_request mrq;
 150         struct mmc_command cmd;
 151         struct mmc_data data;
 152         unsigned int timeout_us;
 153
 154         struct scatterlist sg;
 155
 156         memset(&cmd, 0, sizeof(struct mmc_command));
 157
 158         cmd.opcode = MMC_APP_CMD;
 159         cmd.arg = card->rca << 16;
 160         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 161
 162         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 163         if (err)
 164                 return (u32)-1;
 165         if (!mmc_host_is_spi(card->host) && !(cmd.resp[0] & R1_APP_CMD))
 166                 return (u32)-1;
 167
 168         memset(&cmd, 0, sizeof(struct mmc_command));
 169
 170         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 171         cmd.arg = 0;
 172         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 173
 174         memset(&data, 0, sizeof(struct mmc_data));
 175
 176         data.timeout_ns = card->csd.tacc_ns * 100;
 177         data.timeout_clks = card->csd.tacc_clks * 100;
 178
 179         timeout_us = data.timeout_ns / 1000;
 180         timeout_us += data.timeout_clks * 1000 /
 181                 (card->host->ios.clock / 1000);
 182
 183         if (timeout_us > 100000) {
 184                 data.timeout_ns = 100000000;
 185                 data.timeout_clks = 0;
 186         }
 187
 188         data.blksz = 4;
 189         data.blocks = 1;
 190         data.flags = MMC_DATA_READ;
 191         data.sg = &sg;
 192         data.sg_len = 1;
 193
 194         memset(&mrq, 0, sizeof(struct mmc_request));
 195
 196         mrq.cmd = &cmd;
 197         mrq.data = &data;
 198
 199         sg_init_one(&sg, &blocks, 4);
 200
 201         mmc_wait_for_req(card->host, &mrq);
 202
 203         if (cmd.error || data.error)
 204                 return (u32)-1;
 205
 206         blocks = ntohl(blocks);
 207
 208         return blocks;
 209 }
 210
 211 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 212 {
 213         struct mmc_blk_data *md = mq->data;
 214         struct mmc_card *card = md->queue.card;
 215         struct mmc_blk_request brq;
 216         int ret = 1, sg_pos, data_size;
 217
 218         mmc_claim_host(card->host);
 219
 220         do {
 221                 struct mmc_command cmd;
 222                 u32 readcmd, writecmd;
 223
 224                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 225                 brq.mrq.cmd = &brq.cmd;
 226                 brq.mrq.data = &brq.data;
 227
 228                 brq.cmd.arg = req->sector;
 229                 if (!mmc_card_blockaddr(card))
 230                         brq.cmd.arg <<= 9;
 231                 brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 232                 brq.data.blksz = 1 << md->block_bits;
 233                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 234                 brq.stop.arg = 0;
 235                 brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
 236                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 237                 if (brq.data.blocks > card->host->max_blk_count)
 238                         brq.data.blocks = card->host->max_blk_count;
 239
 240                 /*
 241                  * If the host doesn't support multiple block writes, force
 242                  * block writes to single block. SD cards are excepted from
 243                  * this rule as they support querying the number of
 244                  * successfully written sectors.
 245                  */
 246                 if (rq_data_dir(req) != READ &&
 247                     !(card->host->caps & MMC_CAP_MULTIWRITE) &&
 248                     !mmc_card_sd(card))
 249                         brq.data.blocks = 1;
 250
 251                 if (brq.data.blocks > 1) {
 252                         /* SPI multiblock writes terminate using a special
 253                          * token, not a STOP_TRANSMISSION request.
 254                          */
 255                         if (!mmc_host_is_spi(card->host)
 256                                         || rq_data_dir(req) == READ)
 257                                 brq.mrq.stop = &brq.stop;
 258                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 259                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 260                 } else {
 261                         brq.mrq.stop = NULL;
 262                         readcmd = MMC_READ_SINGLE_BLOCK;
 263                         writecmd = MMC_WRITE_BLOCK;
 264                 }
 265
 266                 if (rq_data_dir(req) == READ) {
 267                         brq.cmd.opcode = readcmd;
 268                         brq.data.flags |= MMC_DATA_READ;
 269                 } else {
 270                         brq.cmd.opcode = writecmd;
 271                         brq.data.flags |= MMC_DATA_WRITE;
 272                 }
 273
 274                 mmc_set_data_timeout(&brq.data, card);
 275
 276                 brq.data.sg = mq->sg;
 277                 brq.data.sg_len = mmc_queue_map_sg(mq);
 278
 279                 mmc_queue_bounce_pre(mq);
 280
 281                 if (brq.data.blocks !=
 282                     (req->nr_sectors >> (md->block_bits - 9))) {
 283                         data_size = brq.data.blocks * brq.data.blksz;
 284                         for (sg_pos = 0; sg_pos < brq.data.sg_len; sg_pos++) {
 285                                 data_size -= mq->sg[sg_pos].length;
 286                                 if (data_size <= 0) {
 287                                         mq->sg[sg_pos].length += data_size;
 288                                         sg_pos++;
 289                                         break;
 290                                 }
 291                         }
 292                         brq.data.sg_len = sg_pos;
 293                 }
 294
 295                 mmc_wait_for_req(card->host, &brq.mrq);
 296
 297                 mmc_queue_bounce_post(mq);
 298
 299                 if (brq.cmd.error) {
 300                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 301                                req->rq_disk->disk_name, brq.cmd.error);
 302                         goto cmd_err;
 303                 }
 304
 305                 if (brq.data.error) {
 306                         printk(KERN_ERR "%s: error %d transferring data\n",
 307                                req->rq_disk->disk_name, brq.data.error);
 308                         goto cmd_err;
 309                 }
 310
 311                 if (brq.stop.error) {
 312                         printk(KERN_ERR "%s: error %d sending stop command\n",
 313                                req->rq_disk->disk_name, brq.stop.error);
 314                         goto cmd_err;
 315                 }
 316
 317                 if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
 318                         do {
 319                                 int err;
 320
 321                                 cmd.opcode = MMC_SEND_STATUS;
 322                                 cmd.arg = card->rca << 16;
 323                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 324                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 325                                 if (err) {
 326                                         printk(KERN_ERR "%s: error %d requesting status\n",
 327                                                req->rq_disk->disk_name, err);
 328                                         goto cmd_err;
 329                                 }
 330                                 /*
 331                                  * Some cards mishandle the status bits,
 332                                  * so make sure to check both the busy
 333                                  * indication and the card state.
 334                                  */
 335                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
 336                                 (R1_CURRENT_STATE(cmd.resp[0]) == 7));
 337
 338 #if 0
 339                         if (cmd.resp[0] & ~0x00000900)
 340                                 printk(KERN_ERR "%s: status = %08x\n",
 341                                        req->rq_disk->disk_name, cmd.resp[0]);
 342                         if (mmc_decode_status(cmd.resp))
 343                                 goto cmd_err;
 344 #endif
 345                 }
 346
 347                 /*
 348                  * A block was successfully transferred.
 349                  */
 350                 spin_lock_irq(&md->lock);
 351                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 352                 spin_unlock_irq(&md->lock);
 353         } while (ret);
 354
 355         mmc_release_host(card->host);
 356
 357         return 1;
 358
 359  cmd_err:
 360         /*
 361          * If this is an SD card and we're writing, we can first
 362          * mark the known good sectors as ok.
 363          *
 364          * If the card is not SD, we can still ok written sectors
 365          * if the controller can do proper error reporting.
 366          *
 367          * For reads we just fail the entire chunk as that should
 368          * be safe in all cases.
 369          */
 370         if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
 371                 u32 blocks;
 372                 unsigned int bytes;
 373
 374                 blocks = mmc_sd_num_wr_blocks(card);
 375                 if (blocks != (u32)-1) {
 376                         if (card->csd.write_partial)
 377                                 bytes = blocks << md->block_bits;
 378                         else
 379                                 bytes = blocks << 9;
 380                         spin_lock_irq(&md->lock);
 381                         ret = __blk_end_request(req, 0, bytes);
 382                         spin_unlock_irq(&md->lock);
 383                 }
 384         } else if (rq_data_dir(req) != READ &&
 385                    (card->host->caps & MMC_CAP_MULTIWRITE)) {
 386                 spin_lock_irq(&md->lock);
 387                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 388                 spin_unlock_irq(&md->lock);
 389         }
 390
 391         mmc_release_host(card->host);
 392
 393         spin_lock_irq(&md->lock);
 394         while (ret)
 395                 ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
 396         spin_unlock_irq(&md->lock);
 397
 398         return 0;
 399 }
 400
 401
 402 static inline int mmc_blk_readonly(struct mmc_card *card)
 403 {
 404         return mmc_card_readonly(card) ||
 405                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 406 }
 407
 408 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 409 {
 410         struct mmc_blk_data *md;
 411         int devidx, ret;
 412
 413         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 414         if (devidx >= MMC_NUM_MINORS)
 415                 return ERR_PTR(-ENOSPC);
 416         __set_bit(devidx, dev_use);
 417
 418         md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 419         if (!md) {
 420                 ret = -ENOMEM;
 421                 goto out;
 422         }
 423
 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.issue_fn = mmc_blk_issue_rq;
 452         md->queue.data = md;
 453
 454         md->disk->major = MMC_BLOCK_MAJOR;
 455         md->disk->first_minor = devidx << MMC_SHIFT;
 456         md->disk->fops = &mmc_bdops;
 457         md->disk->private_data = md;
 458         md->disk->queue = md->queue.queue;
 459         md->disk->driverfs_dev = &card->dev;
 460
 461         /*
 462          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 463          *
 464          * - be set for removable media with permanent block devices
 465          * - be unset for removable block devices with permanent media
 466          *
 467          * Since MMC block devices clearly fall under the second
 468          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 469          * should use the block device creation/destruction hotplug
 470          * messages to tell when the card is present.
 471          */
 472
 473         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 474
 475         blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 476
 477         if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 478                 /*
 479                  * The EXT_CSD sector count is in number or 512 byte
 480                  * sectors.
 481                  */
 482                 set_capacity(md->disk, card->ext_csd.sectors);
 483         } else {
 484                 /*
 485                  * The CSD capacity field is in units of read_blkbits.
 486                  * set_capacity takes units of 512 bytes.
 487                  */
 488                 set_capacity(md->disk,
 489                         card->csd.capacity << (card->csd.read_blkbits - 9));
 490         }
 491         return md;
 492
 493  err_putdisk:
 494         put_disk(md->disk);
 495  err_kfree:
 496         kfree(md);
 497  out:
 498         return ERR_PTR(ret);
 499 }
 500
 501 static int
 502 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 503 {
 504         struct mmc_command cmd;
 505         int err;
 506
 507         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 508         if (mmc_card_blockaddr(card))
 509                 return 0;
 510
 511         mmc_claim_host(card->host);
 512         cmd.opcode = MMC_SET_BLOCKLEN;
 513         cmd.arg = 1 << md->block_bits;
 514         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 515         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 516         mmc_release_host(card->host);
 517
 518         if (err) {
 519                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 520                         md->disk->disk_name, cmd.arg, err);
 521                 return -EINVAL;
 522         }
 523
 524         return 0;
 525 }
 526
 527 static int mmc_blk_probe(struct mmc_card *card)
 528 {
 529         struct mmc_blk_data *md;
 530         int err;
 531
 532         /*
 533          * Check that the card supports the command class(es) we need.
 534          */
 535         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 536                 return -ENODEV;
 537
 538         md = mmc_blk_alloc(card);
 539         if (IS_ERR(md))
 540                 return PTR_ERR(md);
 541
 542         err = mmc_blk_set_blksize(md, card);
 543         if (err)
 544                 goto out;
 545
 546         printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
 547                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 548                 (unsigned long long)(get_capacity(md->disk) >> 1),
 549                 md->read_only ? "(ro)" : "");
 550
 551         mmc_set_drvdata(card, md);
 552         add_disk(md->disk);
 553         return 0;
 554
 555  out:
 556         mmc_blk_put(md);
 557
 558         return err;
 559 }
 560
 561 static void mmc_blk_remove(struct mmc_card *card)
 562 {
 563         struct mmc_blk_data *md = mmc_get_drvdata(card);
 564
 565         if (md) {
 566                 /* Stop new requests from getting into the queue */
 567                 del_gendisk(md->disk);
 568
 569                 /* Then flush out any already in there */
 570                 mmc_cleanup_queue(&md->queue);
 571
 572                 mmc_blk_put(md);
 573         }
 574         mmc_set_drvdata(card, NULL);
 575 }
 576
 577 #ifdef CONFIG_PM
 578 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 579 {
 580         struct mmc_blk_data *md = mmc_get_drvdata(card);
 581
 582         if (md) {
 583                 mmc_queue_suspend(&md->queue);
 584         }
 585         return 0;
 586 }
 587
 588 static int mmc_blk_resume(struct mmc_card *card)
 589 {
 590         struct mmc_blk_data *md = mmc_get_drvdata(card);
 591
 592         if (md) {
 593                 mmc_blk_set_blksize(md, card);
 594                 mmc_queue_resume(&md->queue);
 595         }
 596         return 0;
 597 }
 598 #else
 599 #define mmc_blk_suspend NULL
 600 #define mmc_blk_resume  NULL
 601 #endif
 602
 603 static struct mmc_driver mmc_driver = {
 604         .drv            = {
 605                 .name   = "mmcblk",
 606         },
 607         .probe          = mmc_blk_probe,
 608         .remove         = mmc_blk_remove,
 609         .suspend        = mmc_blk_suspend,
 610         .resume         = mmc_blk_resume,
 611 };
 612
 613 static int __init mmc_blk_init(void)
 614 {
 615         int res = -ENOMEM;
 616
 617         res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 618         if (res)
 619                 goto out;
 620
 621         return mmc_register_driver(&mmc_driver);
 622
 623  out:
 624         return res;
 625 }
 626
 627 static void __exit mmc_blk_exit(void)
 628 {
 629         mmc_unregister_driver(&mmc_driver);
 630         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 631 }
 632
 633 module_init(mmc_blk_init);
 634 module_exit(mmc_blk_exit);
 635
 636 MODULE_LICENSE("GPL");
 637 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 638