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
  48 /*
  49  * There is one mmc_blk_data per slot.
  50  */
  51 struct mmc_blk_data {
  52         spinlock_t      lock;
  53         struct gendisk  *disk;
  54         struct mmc_queue queue;
  55
  56         unsigned int    usage;
  57         unsigned int    block_bits;
  58         unsigned int    read_only;
  59 };
  60
  61 static DEFINE_MUTEX(open_lock);
  62
  63 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  64 {
  65         struct mmc_blk_data *md;
  66
  67         mutex_lock(&open_lock);
  68         md = disk->private_data;
  69         if (md && md->usage == 0)
  70                 md = NULL;
  71         if (md)
  72                 md->usage++;
  73         mutex_unlock(&open_lock);
  74
  75         return md;
  76 }
  77
  78 static void mmc_blk_put(struct mmc_blk_data *md)
  79 {
  80         mutex_lock(&open_lock);
  81         md->usage--;
  82         if (md->usage == 0) {
  83                 put_disk(md->disk);
  84                 kfree(md);
  85         }
  86         mutex_unlock(&open_lock);
  87 }
  88
  89 static int mmc_blk_open(struct inode *inode, struct file *filp)
  90 {
  91         struct mmc_blk_data *md;
  92         int ret = -ENXIO;
  93
  94         md = mmc_blk_get(inode->i_bdev->bd_disk);
  95         if (md) {
  96                 if (md->usage == 2)
  97                         check_disk_change(inode->i_bdev);
  98                 ret = 0;
  99
 100                 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
 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_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 117 {
 118         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 119         geo->heads = 4;
 120         geo->sectors = 16;
 121         return 0;
 122 }
 123
 124 static struct block_device_operations mmc_bdops = {
 125         .open                   = mmc_blk_open,
 126         .release                = mmc_blk_release,
 127         .getgeo                 = mmc_blk_getgeo,
 128         .owner                  = THIS_MODULE,
 129 };
 130
 131 struct mmc_blk_request {
 132         struct mmc_request      mrq;
 133         struct mmc_command      cmd;
 134         struct mmc_command      stop;
 135         struct mmc_data         data;
 136 };
 137
 138 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 139 {
 140         int err;
 141         u32 blocks;
 142
 143         struct mmc_request mrq;
 144         struct mmc_command cmd;
 145         struct mmc_data data;
 146         unsigned int timeout_us;
 147
 148         struct scatterlist sg;
 149
 150         memset(&cmd, 0, sizeof(struct mmc_command));
 151
 152         cmd.opcode = MMC_APP_CMD;
 153         cmd.arg = card->rca << 16;
 154         cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 155
 156         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 157         if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD))
 158                 return (u32)-1;
 159
 160         memset(&cmd, 0, sizeof(struct mmc_command));
 161
 162         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 163         cmd.arg = 0;
 164         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 165
 166         memset(&data, 0, sizeof(struct mmc_data));
 167
 168         data.timeout_ns = card->csd.tacc_ns * 100;
 169         data.timeout_clks = card->csd.tacc_clks * 100;
 170
 171         timeout_us = data.timeout_ns / 1000;
 172         timeout_us += data.timeout_clks * 1000 /
 173                 (card->host->ios.clock / 1000);
 174
 175         if (timeout_us > 100000) {
 176                 data.timeout_ns = 100000000;
 177                 data.timeout_clks = 0;
 178         }
 179
 180         data.blksz = 4;
 181         data.blocks = 1;
 182         data.flags = MMC_DATA_READ;
 183         data.sg = &sg;
 184         data.sg_len = 1;
 185
 186         memset(&mrq, 0, sizeof(struct mmc_request));
 187
 188         mrq.cmd = &cmd;
 189         mrq.data = &data;
 190
 191         sg_init_one(&sg, &blocks, 4);
 192
 193         mmc_wait_for_req(card->host, &mrq);
 194
 195         if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE)
 196                 return (u32)-1;
 197
 198         blocks = ntohl(blocks);
 199
 200         return blocks;
 201 }
 202
 203 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 204 {
 205         struct mmc_blk_data *md = mq->data;
 206         struct mmc_card *card = md->queue.card;
 207         struct mmc_blk_request brq;
 208         int ret = 1, sg_pos, data_size;
 209
 210         mmc_claim_host(card->host);
 211
 212         do {
 213                 struct mmc_command cmd;
 214                 u32 readcmd, writecmd;
 215
 216                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 217                 brq.mrq.cmd = &brq.cmd;
 218                 brq.mrq.data = &brq.data;
 219
 220                 brq.cmd.arg = req->sector;
 221                 if (!mmc_card_blockaddr(card))
 222                         brq.cmd.arg <<= 9;
 223                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 224                 brq.data.blksz = 1 << md->block_bits;
 225                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 226                 brq.stop.arg = 0;
 227                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 228                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 229                 if (brq.data.blocks > card->host->max_blk_count)
 230                         brq.data.blocks = card->host->max_blk_count;
 231
 232                 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
 233
 234                 /*
 235                  * If the host doesn't support multiple block writes, force
 236                  * block writes to single block. SD cards are excepted from
 237                  * this rule as they support querying the number of
 238                  * successfully written sectors.
 239                  */
 240                 if (rq_data_dir(req) != READ &&
 241                     !(card->host->caps & MMC_CAP_MULTIWRITE) &&
 242                     !mmc_card_sd(card))
 243                         brq.data.blocks = 1;
 244
 245                 if (brq.data.blocks > 1) {
 246                         brq.data.flags |= MMC_DATA_MULTI;
 247                         brq.mrq.stop = &brq.stop;
 248                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 249                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 250                 } else {
 251                         brq.mrq.stop = NULL;
 252                         readcmd = MMC_READ_SINGLE_BLOCK;
 253                         writecmd = MMC_WRITE_BLOCK;
 254                 }
 255
 256                 if (rq_data_dir(req) == READ) {
 257                         brq.cmd.opcode = readcmd;
 258                         brq.data.flags |= MMC_DATA_READ;
 259                 } else {
 260                         brq.cmd.opcode = writecmd;
 261                         brq.data.flags |= MMC_DATA_WRITE;
 262                 }
 263
 264                 brq.data.sg = mq->sg;
 265                 brq.data.sg_len = mmc_queue_map_sg(mq);
 266
 267                 mmc_queue_bounce_pre(mq);
 268
 269                 if (brq.data.blocks !=
 270                     (req->nr_sectors >> (md->block_bits - 9))) {
 271                         data_size = brq.data.blocks * brq.data.blksz;
 272                         for (sg_pos = 0; sg_pos < brq.data.sg_len; sg_pos++) {
 273                                 data_size -= mq->sg[sg_pos].length;
 274                                 if (data_size <= 0) {
 275                                         mq->sg[sg_pos].length += data_size;
 276                                         sg_pos++;
 277                                         break;
 278                                 }
 279                         }
 280                         brq.data.sg_len = sg_pos;
 281                 }
 282
 283                 mmc_wait_for_req(card->host, &brq.mrq);
 284
 285                 mmc_queue_bounce_post(mq);
 286
 287                 if (brq.cmd.error) {
 288                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 289                                req->rq_disk->disk_name, brq.cmd.error);
 290                         goto cmd_err;
 291                 }
 292
 293                 if (brq.data.error) {
 294                         printk(KERN_ERR "%s: error %d transferring data\n",
 295                                req->rq_disk->disk_name, brq.data.error);
 296                         goto cmd_err;
 297                 }
 298
 299                 if (brq.stop.error) {
 300                         printk(KERN_ERR "%s: error %d sending stop command\n",
 301                                req->rq_disk->disk_name, brq.stop.error);
 302                         goto cmd_err;
 303                 }
 304
 305                 if (rq_data_dir(req) != READ) {
 306                         do {
 307                                 int err;
 308
 309                                 cmd.opcode = MMC_SEND_STATUS;
 310                                 cmd.arg = card->rca << 16;
 311                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 312                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 313                                 if (err) {
 314                                         printk(KERN_ERR "%s: error %d requesting status\n",
 315                                                req->rq_disk->disk_name, err);
 316                                         goto cmd_err;
 317                                 }
 318                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 319
 320 #if 0
 321                         if (cmd.resp[0] & ~0x00000900)
 322                                 printk(KERN_ERR "%s: status = %08x\n",
 323                                        req->rq_disk->disk_name, cmd.resp[0]);
 324                         if (mmc_decode_status(cmd.resp))
 325                                 goto cmd_err;
 326 #endif
 327                 }
 328
 329                 /*
 330                  * A block was successfully transferred.
 331                  */
 332                 spin_lock_irq(&md->lock);
 333                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 334                 if (!ret) {
 335                         /*
 336                          * The whole request completed successfully.
 337                          */
 338                         add_disk_randomness(req->rq_disk);
 339                         blkdev_dequeue_request(req);
 340                         end_that_request_last(req, 1);
 341                 }
 342                 spin_unlock_irq(&md->lock);
 343         } while (ret);
 344
 345         mmc_release_host(card->host);
 346
 347         return 1;
 348
 349  cmd_err:
 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_release_host(card->host);
 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.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_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                 int devidx;
 567
 568                 /* Stop new requests from getting into the queue */
 569                 del_gendisk(md->disk);
 570
 571                 /* Then flush out any already in there */
 572                 mmc_cleanup_queue(&md->queue);
 573
 574                 devidx = md->disk->first_minor >> MMC_SHIFT;
 575                 __clear_bit(devidx, dev_use);
 576
 577                 mmc_blk_put(md);
 578         }
 579         mmc_set_drvdata(card, NULL);
 580 }
 581
 582 #ifdef CONFIG_PM
 583 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 584 {
 585         struct mmc_blk_data *md = mmc_get_drvdata(card);
 586
 587         if (md) {
 588                 mmc_queue_suspend(&md->queue);
 589         }
 590         return 0;
 591 }
 592
 593 static int mmc_blk_resume(struct mmc_card *card)
 594 {
 595         struct mmc_blk_data *md = mmc_get_drvdata(card);
 596
 597         if (md) {
 598                 mmc_blk_set_blksize(md, card);
 599                 mmc_queue_resume(&md->queue);
 600         }
 601         return 0;
 602 }
 603 #else
 604 #define mmc_blk_suspend NULL
 605 #define mmc_blk_resume  NULL
 606 #endif
 607
 608 static struct mmc_driver mmc_driver = {
 609         .drv            = {
 610                 .name   = "mmcblk",
 611         },
 612         .probe          = mmc_blk_probe,
 613         .remove         = mmc_blk_remove,
 614         .suspend        = mmc_blk_suspend,
 615         .resume         = mmc_blk_resume,
 616 };
 617
 618 static int __init mmc_blk_init(void)
 619 {
 620         int res = -ENOMEM;
 621
 622         res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 623         if (res)
 624                 goto out;
 625
 626         return mmc_register_driver(&mmc_driver);
 627
 628  out:
 629         return res;
 630 }
 631
 632 static void __exit mmc_blk_exit(void)
 633 {
 634         mmc_unregister_driver(&mmc_driver);
 635         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 636 }
 637
 638 module_init(mmc_blk_init);
 639 module_exit(mmc_blk_exit);
 640
 641 MODULE_LICENSE("GPL");
 642 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 643