drivers/mtd/mtdchar.c

   1 /*
   2  * Character-device access to raw MTD devices.
   3  *
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/fs.h>
   8 #include <linux/mm.h>
   9 #include <linux/err.h>
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/sched.h>
  15 #include <linux/smp_lock.h>
  16 #include <linux/backing-dev.h>
  17 #include <linux/compat.h>
  18 #include <linux/mount.h>
  19
  20 #include <linux/mtd/mtd.h>
  21 #include <linux/mtd/compatmac.h>
  22
  23 #include <asm/uaccess.h>
  24
  25 #define MTD_INODE_FS_MAGIC 0x11307854
  26 static struct vfsmount *mtd_inode_mnt __read_mostly;
  27
  28 /*
  29  * Data structure to hold the pointer to the mtd device as well
  30  * as mode information ofr various use cases.
  31  */
  32 struct mtd_file_info {
  33         struct mtd_info *mtd;
  34         struct inode *ino;
  35         enum mtd_file_modes mode;
  36 };
  37
  38 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  39 {
  40         struct mtd_file_info *mfi = file->private_data;
  41         struct mtd_info *mtd = mfi->mtd;
  42
  43         switch (orig) {
  44         case SEEK_SET:
  45                 break;
  46         case SEEK_CUR:
  47                 offset += file->f_pos;
  48                 break;
  49         case SEEK_END:
  50                 offset += mtd->size;
  51                 break;
  52         default:
  53                 return -EINVAL;
  54         }
  55
  56         if (offset >= 0 && offset <= mtd->size)
  57                 return file->f_pos = offset;
  58
  59         return -EINVAL;
  60 }
  61
  62
  63
  64 static int mtd_open(struct inode *inode, struct file *file)
  65 {
  66         int minor = iminor(inode);
  67         int devnum = minor >> 1;
  68         int ret = 0;
  69         struct mtd_info *mtd;
  70         struct mtd_file_info *mfi;
  71         struct inode *mtd_ino;
  72
  73         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  74
  75         /* You can't open the RO devices RW */
  76         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  77                 return -EACCES;
  78
  79         lock_kernel();
  80         mtd = get_mtd_device(NULL, devnum);
  81
  82         if (IS_ERR(mtd)) {
  83                 ret = PTR_ERR(mtd);
  84                 goto out;
  85         }
  86
  87         if (mtd->type == MTD_ABSENT) {
  88                 put_mtd_device(mtd);
  89                 ret = -ENODEV;
  90                 goto out;
  91         }
  92
  93         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
  94         if (!mtd_ino) {
  95                 put_mtd_device(mtd);
  96                 ret = -ENOMEM;
  97                 goto out;
  98         }
  99         if (mtd_ino->i_state & I_NEW) {
 100                 mtd_ino->i_private = mtd;
 101                 mtd_ino->i_mode = S_IFCHR;
 102                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 103                 unlock_new_inode(mtd_ino);
 104         }
 105         file->f_mapping = mtd_ino->i_mapping;
 106
 107         /* You can't open it RW if it's not a writeable device */
 108         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 109                 iput(mtd_ino);
 110                 put_mtd_device(mtd);
 111                 ret = -EACCES;
 112                 goto out;
 113         }
 114
 115         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 116         if (!mfi) {
 117                 iput(mtd_ino);
 118                 put_mtd_device(mtd);
 119                 ret = -ENOMEM;
 120                 goto out;
 121         }
 122         mfi->ino = mtd_ino;
 123         mfi->mtd = mtd;
 124         file->private_data = mfi;
 125
 126 out:
 127         unlock_kernel();
 128         return ret;
 129 } /* mtd_open */
 130
 131 /*====================================================================*/
 132
 133 static int mtd_close(struct inode *inode, struct file *file)
 134 {
 135         struct mtd_file_info *mfi = file->private_data;
 136         struct mtd_info *mtd = mfi->mtd;
 137
 138         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 139
 140         /* Only sync if opened RW */
 141         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 142                 mtd->sync(mtd);
 143
 144         iput(mfi->ino);
 145
 146         put_mtd_device(mtd);
 147         file->private_data = NULL;
 148         kfree(mfi);
 149
 150         return 0;
 151 } /* mtd_close */
 152
 153 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 154    userspace buffer down and use it directly with readv/writev.
 155 */
 156 #define MAX_KMALLOC_SIZE 0x20000
 157
 158 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 159 {
 160         struct mtd_file_info *mfi = file->private_data;
 161         struct mtd_info *mtd = mfi->mtd;
 162         size_t retlen=0;
 163         size_t total_retlen=0;
 164         int ret=0;
 165         int len;
 166         char *kbuf;
 167
 168         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 169
 170         if (*ppos + count > mtd->size)
 171                 count = mtd->size - *ppos;
 172
 173         if (!count)
 174                 return 0;
 175
 176         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 177            and pass them directly to the MTD functions */
 178
 179         if (count > MAX_KMALLOC_SIZE)
 180                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 181         else
 182                 kbuf=kmalloc(count, GFP_KERNEL);
 183
 184         if (!kbuf)
 185                 return -ENOMEM;
 186
 187         while (count) {
 188
 189                 if (count > MAX_KMALLOC_SIZE)
 190                         len = MAX_KMALLOC_SIZE;
 191                 else
 192                         len = count;
 193
 194                 switch (mfi->mode) {
 195                 case MTD_MODE_OTP_FACTORY:
 196                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 197                         break;
 198                 case MTD_MODE_OTP_USER:
 199                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 200                         break;
 201                 case MTD_MODE_RAW:
 202                 {
 203                         struct mtd_oob_ops ops;
 204
 205                         ops.mode = MTD_OOB_RAW;
 206                         ops.datbuf = kbuf;
 207                         ops.oobbuf = NULL;
 208                         ops.len = len;
 209
 210                         ret = mtd->read_oob(mtd, *ppos, &ops);
 211                         retlen = ops.retlen;
 212                         break;
 213                 }
 214                 default:
 215                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 216                 }
 217                 /* Nand returns -EBADMSG on ecc errors, but it returns
 218                  * the data. For our userspace tools it is important
 219                  * to dump areas with ecc errors !
 220                  * For kernel internal usage it also might return -EUCLEAN
 221                  * to signal the caller that a bitflip has occured and has
 222                  * been corrected by the ECC algorithm.
 223                  * Userspace software which accesses NAND this way
 224                  * must be aware of the fact that it deals with NAND
 225                  */
 226                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 227                         *ppos += retlen;
 228                         if (copy_to_user(buf, kbuf, retlen)) {
 229                                 kfree(kbuf);
 230                                 return -EFAULT;
 231                         }
 232                         else
 233                                 total_retlen += retlen;
 234
 235                         count -= retlen;
 236                         buf += retlen;
 237                         if (retlen == 0)
 238                                 count = 0;
 239                 }
 240                 else {
 241                         kfree(kbuf);
 242                         return ret;
 243                 }
 244
 245         }
 246
 247         kfree(kbuf);
 248         return total_retlen;
 249 } /* mtd_read */
 250
 251 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 252 {
 253         struct mtd_file_info *mfi = file->private_data;
 254         struct mtd_info *mtd = mfi->mtd;
 255         char *kbuf;
 256         size_t retlen;
 257         size_t total_retlen=0;
 258         int ret=0;
 259         int len;
 260
 261         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 262
 263         if (*ppos == mtd->size)
 264                 return -ENOSPC;
 265
 266         if (*ppos + count > mtd->size)
 267                 count = mtd->size - *ppos;
 268
 269         if (!count)
 270                 return 0;
 271
 272         if (count > MAX_KMALLOC_SIZE)
 273                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 274         else
 275                 kbuf=kmalloc(count, GFP_KERNEL);
 276
 277         if (!kbuf)
 278                 return -ENOMEM;
 279
 280         while (count) {
 281
 282                 if (count > MAX_KMALLOC_SIZE)
 283                         len = MAX_KMALLOC_SIZE;
 284                 else
 285                         len = count;
 286
 287                 if (copy_from_user(kbuf, buf, len)) {
 288                         kfree(kbuf);
 289                         return -EFAULT;
 290                 }
 291
 292                 switch (mfi->mode) {
 293                 case MTD_MODE_OTP_FACTORY:
 294                         ret = -EROFS;
 295                         break;
 296                 case MTD_MODE_OTP_USER:
 297                         if (!mtd->write_user_prot_reg) {
 298                                 ret = -EOPNOTSUPP;
 299                                 break;
 300                         }
 301                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 302                         break;
 303
 304                 case MTD_MODE_RAW:
 305                 {
 306                         struct mtd_oob_ops ops;
 307
 308                         ops.mode = MTD_OOB_RAW;
 309                         ops.datbuf = kbuf;
 310                         ops.oobbuf = NULL;
 311                         ops.len = len;
 312
 313                         ret = mtd->write_oob(mtd, *ppos, &ops);
 314                         retlen = ops.retlen;
 315                         break;
 316                 }
 317
 318                 default:
 319                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 320                 }
 321                 if (!ret) {
 322                         *ppos += retlen;
 323                         total_retlen += retlen;
 324                         count -= retlen;
 325                         buf += retlen;
 326                 }
 327                 else {
 328                         kfree(kbuf);
 329                         return ret;
 330                 }
 331         }
 332
 333         kfree(kbuf);
 334         return total_retlen;
 335 } /* mtd_write */
 336
 337 /*======================================================================
 338
 339     IOCTL calls for getting device parameters.
 340
 341 ======================================================================*/
 342 static void mtdchar_erase_callback (struct erase_info *instr)
 343 {
 344         wake_up((wait_queue_head_t *)instr->priv);
 345 }
 346
 347 #ifdef CONFIG_HAVE_MTD_OTP
 348 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 349 {
 350         struct mtd_info *mtd = mfi->mtd;
 351         int ret = 0;
 352
 353         switch (mode) {
 354         case MTD_OTP_FACTORY:
 355                 if (!mtd->read_fact_prot_reg)
 356                         ret = -EOPNOTSUPP;
 357                 else
 358                         mfi->mode = MTD_MODE_OTP_FACTORY;
 359                 break;
 360         case MTD_OTP_USER:
 361                 if (!mtd->read_fact_prot_reg)
 362                         ret = -EOPNOTSUPP;
 363                 else
 364                         mfi->mode = MTD_MODE_OTP_USER;
 365                 break;
 366         default:
 367                 ret = -EINVAL;
 368         case MTD_OTP_OFF:
 369                 break;
 370         }
 371         return ret;
 372 }
 373 #else
 374 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 375 #endif
 376
 377 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 378         uint64_t start, uint32_t length, void __user *ptr,
 379         uint32_t __user *retp)
 380 {
 381         struct mtd_oob_ops ops;
 382         uint32_t retlen;
 383         int ret = 0;
 384
 385         if (!(file->f_mode & FMODE_WRITE))
 386                 return -EPERM;
 387
 388         if (length > 4096)
 389                 return -EINVAL;
 390
 391         if (!mtd->write_oob)
 392                 ret = -EOPNOTSUPP;
 393         else
 394                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 395
 396         if (ret)
 397                 return ret;
 398
 399         ops.ooblen = length;
 400         ops.ooboffs = start & (mtd->oobsize - 1);
 401         ops.datbuf = NULL;
 402         ops.mode = MTD_OOB_PLACE;
 403
 404         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 405                 return -EINVAL;
 406
 407         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 408         if (!ops.oobbuf)
 409                 return -ENOMEM;
 410
 411         if (copy_from_user(ops.oobbuf, ptr, length)) {
 412                 kfree(ops.oobbuf);
 413                 return -EFAULT;
 414         }
 415
 416         start &= ~((uint64_t)mtd->oobsize - 1);
 417         ret = mtd->write_oob(mtd, start, &ops);
 418
 419         if (ops.oobretlen > 0xFFFFFFFFU)
 420                 ret = -EOVERFLOW;
 421         retlen = ops.oobretlen;
 422         if (copy_to_user(retp, &retlen, sizeof(length)))
 423                 ret = -EFAULT;
 424
 425         kfree(ops.oobbuf);
 426         return ret;
 427 }
 428
 429 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 430         uint32_t length, void __user *ptr, uint32_t __user *retp)
 431 {
 432         struct mtd_oob_ops ops;
 433         int ret = 0;
 434
 435         if (length > 4096)
 436                 return -EINVAL;
 437
 438         if (!mtd->read_oob)
 439                 ret = -EOPNOTSUPP;
 440         else
 441                 ret = access_ok(VERIFY_WRITE, ptr,
 442                                 length) ? 0 : -EFAULT;
 443         if (ret)
 444                 return ret;
 445
 446         ops.ooblen = length;
 447         ops.ooboffs = start & (mtd->oobsize - 1);
 448         ops.datbuf = NULL;
 449         ops.mode = MTD_OOB_PLACE;
 450
 451         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 452                 return -EINVAL;
 453
 454         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 455         if (!ops.oobbuf)
 456                 return -ENOMEM;
 457
 458         start &= ~((uint64_t)mtd->oobsize - 1);
 459         ret = mtd->read_oob(mtd, start, &ops);
 460
 461         if (put_user(ops.oobretlen, retp))
 462                 ret = -EFAULT;
 463         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 464                                             ops.oobretlen))
 465                 ret = -EFAULT;
 466
 467         kfree(ops.oobbuf);
 468         return ret;
 469 }
 470
 471 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 472 {
 473         struct mtd_file_info *mfi = file->private_data;
 474         struct mtd_info *mtd = mfi->mtd;
 475         void __user *argp = (void __user *)arg;
 476         int ret = 0;
 477         u_long size;
 478         struct mtd_info_user info;
 479
 480         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 481
 482         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 483         if (cmd & IOC_IN) {
 484                 if (!access_ok(VERIFY_READ, argp, size))
 485                         return -EFAULT;
 486         }
 487         if (cmd & IOC_OUT) {
 488                 if (!access_ok(VERIFY_WRITE, argp, size))
 489                         return -EFAULT;
 490         }
 491
 492         switch (cmd) {
 493         case MEMGETREGIONCOUNT:
 494                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 495                         return -EFAULT;
 496                 break;
 497
 498         case MEMGETREGIONINFO:
 499         {
 500                 uint32_t ur_idx;
 501                 struct mtd_erase_region_info *kr;
 502                 struct region_info_user __user *ur = argp;
 503
 504                 if (get_user(ur_idx, &(ur->regionindex)))
 505                         return -EFAULT;
 506
 507                 kr = &(mtd->eraseregions[ur_idx]);
 508
 509                 if (put_user(kr->offset, &(ur->offset))
 510                     || put_user(kr->erasesize, &(ur->erasesize))
 511                     || put_user(kr->numblocks, &(ur->numblocks)))
 512                         return -EFAULT;
 513
 514                 break;
 515         }
 516
 517         case MEMGETINFO:
 518                 info.type       = mtd->type;
 519                 info.flags      = mtd->flags;
 520                 info.size       = mtd->size;
 521                 info.erasesize  = mtd->erasesize;
 522                 info.writesize  = mtd->writesize;
 523                 info.oobsize    = mtd->oobsize;
 524                 /* The below fields are obsolete */
 525                 info.ecctype    = -1;
 526                 info.eccsize    = 0;
 527                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 528                         return -EFAULT;
 529                 break;
 530
 531         case MEMERASE:
 532         case MEMERASE64:
 533         {
 534                 struct erase_info *erase;
 535
 536                 if(!(file->f_mode & FMODE_WRITE))
 537                         return -EPERM;
 538
 539                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 540                 if (!erase)
 541                         ret = -ENOMEM;
 542                 else {
 543                         wait_queue_head_t waitq;
 544                         DECLARE_WAITQUEUE(wait, current);
 545
 546                         init_waitqueue_head(&waitq);
 547
 548                         if (cmd == MEMERASE64) {
 549                                 struct erase_info_user64 einfo64;
 550
 551                                 if (copy_from_user(&einfo64, argp,
 552                                             sizeof(struct erase_info_user64))) {
 553                                         kfree(erase);
 554                                         return -EFAULT;
 555                                 }
 556                                 erase->addr = einfo64.start;
 557                                 erase->len = einfo64.length;
 558                         } else {
 559                                 struct erase_info_user einfo32;
 560
 561                                 if (copy_from_user(&einfo32, argp,
 562                                             sizeof(struct erase_info_user))) {
 563                                         kfree(erase);
 564                                         return -EFAULT;
 565                                 }
 566                                 erase->addr = einfo32.start;
 567                                 erase->len = einfo32.length;
 568                         }
 569                         erase->mtd = mtd;
 570                         erase->callback = mtdchar_erase_callback;
 571                         erase->priv = (unsigned long)&waitq;
 572
 573                         /*
 574                           FIXME: Allow INTERRUPTIBLE. Which means
 575                           not having the wait_queue head on the stack.
 576
 577                           If the wq_head is on the stack, and we
 578                           leave because we got interrupted, then the
 579                           wq_head is no longer there when the
 580                           callback routine tries to wake us up.
 581                         */
 582                         ret = mtd->erase(mtd, erase);
 583                         if (!ret) {
 584                                 set_current_state(TASK_UNINTERRUPTIBLE);
 585                                 add_wait_queue(&waitq, &wait);
 586                                 if (erase->state != MTD_ERASE_DONE &&
 587                                     erase->state != MTD_ERASE_FAILED)
 588                                         schedule();
 589                                 remove_wait_queue(&waitq, &wait);
 590                                 set_current_state(TASK_RUNNING);
 591
 592                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 593                         }
 594                         kfree(erase);
 595                 }
 596                 break;
 597         }
 598
 599         case MEMWRITEOOB:
 600         {
 601                 struct mtd_oob_buf buf;
 602                 struct mtd_oob_buf __user *buf_user = argp;
 603
 604                 /* NOTE: writes return length to buf_user->length */
 605                 if (copy_from_user(&buf, argp, sizeof(buf)))
 606                         ret = -EFAULT;
 607                 else
 608                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 609                                 buf.ptr, &buf_user->length);
 610                 break;
 611         }
 612
 613         case MEMREADOOB:
 614         {
 615                 struct mtd_oob_buf buf;
 616                 struct mtd_oob_buf __user *buf_user = argp;
 617
 618                 /* NOTE: writes return length to buf_user->start */
 619                 if (copy_from_user(&buf, argp, sizeof(buf)))
 620                         ret = -EFAULT;
 621                 else
 622                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 623                                 buf.ptr, &buf_user->start);
 624                 break;
 625         }
 626
 627         case MEMWRITEOOB64:
 628         {
 629                 struct mtd_oob_buf64 buf;
 630                 struct mtd_oob_buf64 __user *buf_user = argp;
 631
 632                 if (copy_from_user(&buf, argp, sizeof(buf)))
 633                         ret = -EFAULT;
 634                 else
 635                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 636                                 (void __user *)(uintptr_t)buf.usr_ptr,
 637                                 &buf_user->length);
 638                 break;
 639         }
 640
 641         case MEMREADOOB64:
 642         {
 643                 struct mtd_oob_buf64 buf;
 644                 struct mtd_oob_buf64 __user *buf_user = argp;
 645
 646                 if (copy_from_user(&buf, argp, sizeof(buf)))
 647                         ret = -EFAULT;
 648                 else
 649                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 650                                 (void __user *)(uintptr_t)buf.usr_ptr,
 651                                 &buf_user->length);
 652                 break;
 653         }
 654
 655         case MEMLOCK:
 656         {
 657                 struct erase_info_user einfo;
 658
 659                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 660                         return -EFAULT;
 661
 662                 if (!mtd->lock)
 663                         ret = -EOPNOTSUPP;
 664                 else
 665                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 666                 break;
 667         }
 668
 669         case MEMUNLOCK:
 670         {
 671                 struct erase_info_user einfo;
 672
 673                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 674                         return -EFAULT;
 675
 676                 if (!mtd->unlock)
 677                         ret = -EOPNOTSUPP;
 678                 else
 679                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 680                 break;
 681         }
 682
 683         /* Legacy interface */
 684         case MEMGETOOBSEL:
 685         {
 686                 struct nand_oobinfo oi;
 687
 688                 if (!mtd->ecclayout)
 689                         return -EOPNOTSUPP;
 690                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 691                         return -EINVAL;
 692
 693                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 694                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 695                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 696                        sizeof(oi.oobfree));
 697                 oi.eccbytes = mtd->ecclayout->eccbytes;
 698
 699                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 700                         return -EFAULT;
 701                 break;
 702         }
 703
 704         case MEMGETBADBLOCK:
 705         {
 706                 loff_t offs;
 707
 708                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 709                         return -EFAULT;
 710                 if (!mtd->block_isbad)
 711                         ret = -EOPNOTSUPP;
 712                 else
 713                         return mtd->block_isbad(mtd, offs);
 714                 break;
 715         }
 716
 717         case MEMSETBADBLOCK:
 718         {
 719                 loff_t offs;
 720
 721                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 722                         return -EFAULT;
 723                 if (!mtd->block_markbad)
 724                         ret = -EOPNOTSUPP;
 725                 else
 726                         return mtd->block_markbad(mtd, offs);
 727                 break;
 728         }
 729
 730 #ifdef CONFIG_HAVE_MTD_OTP
 731         case OTPSELECT:
 732         {
 733                 int mode;
 734                 if (copy_from_user(&mode, argp, sizeof(int)))
 735                         return -EFAULT;
 736
 737                 mfi->mode = MTD_MODE_NORMAL;
 738
 739                 ret = otp_select_filemode(mfi, mode);
 740
 741                 file->f_pos = 0;
 742                 break;
 743         }
 744
 745         case OTPGETREGIONCOUNT:
 746         case OTPGETREGIONINFO:
 747         {
 748                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 749                 if (!buf)
 750                         return -ENOMEM;
 751                 ret = -EOPNOTSUPP;
 752                 switch (mfi->mode) {
 753                 case MTD_MODE_OTP_FACTORY:
 754                         if (mtd->get_fact_prot_info)
 755                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 756                         break;
 757                 case MTD_MODE_OTP_USER:
 758                         if (mtd->get_user_prot_info)
 759                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 760                         break;
 761                 default:
 762                         break;
 763                 }
 764                 if (ret >= 0) {
 765                         if (cmd == OTPGETREGIONCOUNT) {
 766                                 int nbr = ret / sizeof(struct otp_info);
 767                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 768                         } else
 769                                 ret = copy_to_user(argp, buf, ret);
 770                         if (ret)
 771                                 ret = -EFAULT;
 772                 }
 773                 kfree(buf);
 774                 break;
 775         }
 776
 777         case OTPLOCK:
 778         {
 779                 struct otp_info oinfo;
 780
 781                 if (mfi->mode != MTD_MODE_OTP_USER)
 782                         return -EINVAL;
 783                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 784                         return -EFAULT;
 785                 if (!mtd->lock_user_prot_reg)
 786                         return -EOPNOTSUPP;
 787                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 788                 break;
 789         }
 790 #endif
 791
 792         case ECCGETLAYOUT:
 793         {
 794                 if (!mtd->ecclayout)
 795                         return -EOPNOTSUPP;
 796
 797                 if (copy_to_user(argp, mtd->ecclayout,
 798                                  sizeof(struct nand_ecclayout)))
 799                         return -EFAULT;
 800                 break;
 801         }
 802
 803         case ECCGETSTATS:
 804         {
 805                 if (copy_to_user(argp, &mtd->ecc_stats,
 806                                  sizeof(struct mtd_ecc_stats)))
 807                         return -EFAULT;
 808                 break;
 809         }
 810
 811         case MTDFILEMODE:
 812         {
 813                 mfi->mode = 0;
 814
 815                 switch(arg) {
 816                 case MTD_MODE_OTP_FACTORY:
 817                 case MTD_MODE_OTP_USER:
 818                         ret = otp_select_filemode(mfi, arg);
 819                         break;
 820
 821                 case MTD_MODE_RAW:
 822                         if (!mtd->read_oob || !mtd->write_oob)
 823                                 return -EOPNOTSUPP;
 824                         mfi->mode = arg;
 825
 826                 case MTD_MODE_NORMAL:
 827                         break;
 828                 default:
 829                         ret = -EINVAL;
 830                 }
 831                 file->f_pos = 0;
 832                 break;
 833         }
 834
 835         default:
 836                 ret = -ENOTTY;
 837         }
 838
 839         return ret;
 840 } /* memory_ioctl */
 841
 842 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 843 {
 844         int ret;
 845
 846         lock_kernel();
 847         ret = mtd_ioctl(file, cmd, arg);
 848         unlock_kernel();
 849
 850         return ret;
 851 }
 852
 853 #ifdef CONFIG_COMPAT
 854
 855 struct mtd_oob_buf32 {
 856         u_int32_t start;
 857         u_int32_t length;
 858         compat_caddr_t ptr;     /* unsigned char* */
 859 };
 860
 861 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 862 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 863
 864 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 865         unsigned long arg)
 866 {
 867         struct mtd_file_info *mfi = file->private_data;
 868         struct mtd_info *mtd = mfi->mtd;
 869         void __user *argp = compat_ptr(arg);
 870         int ret = 0;
 871
 872         lock_kernel();
 873
 874         switch (cmd) {
 875         case MEMWRITEOOB32:
 876         {
 877                 struct mtd_oob_buf32 buf;
 878                 struct mtd_oob_buf32 __user *buf_user = argp;
 879
 880                 if (copy_from_user(&buf, argp, sizeof(buf)))
 881                         ret = -EFAULT;
 882                 else
 883                         ret = mtd_do_writeoob(file, mtd, buf.start,
 884                                 buf.length, compat_ptr(buf.ptr),
 885                                 &buf_user->length);
 886                 break;
 887         }
 888
 889         case MEMREADOOB32:
 890         {
 891                 struct mtd_oob_buf32 buf;
 892                 struct mtd_oob_buf32 __user *buf_user = argp;
 893
 894                 /* NOTE: writes return length to buf->start */
 895                 if (copy_from_user(&buf, argp, sizeof(buf)))
 896                         ret = -EFAULT;
 897                 else
 898                         ret = mtd_do_readoob(mtd, buf.start,
 899                                 buf.length, compat_ptr(buf.ptr),
 900                                 &buf_user->start);
 901                 break;
 902         }
 903         default:
 904                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
 905         }
 906
 907         unlock_kernel();
 908
 909         return ret;
 910 }
 911
 912 #endif /* CONFIG_COMPAT */
 913
 914 /*
 915  * try to determine where a shared mapping can be made
 916  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 917  *   mappings)
 918  */
 919 #ifndef CONFIG_MMU
 920 static unsigned long mtd_get_unmapped_area(struct file *file,
 921                                            unsigned long addr,
 922                                            unsigned long len,
 923                                            unsigned long pgoff,
 924                                            unsigned long flags)
 925 {
 926         struct mtd_file_info *mfi = file->private_data;
 927         struct mtd_info *mtd = mfi->mtd;
 928
 929         if (mtd->get_unmapped_area) {
 930                 unsigned long offset;
 931
 932                 if (addr != 0)
 933                         return (unsigned long) -EINVAL;
 934
 935                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
 936                         return (unsigned long) -EINVAL;
 937
 938                 offset = pgoff << PAGE_SHIFT;
 939                 if (offset > mtd->size - len)
 940                         return (unsigned long) -EINVAL;
 941
 942                 return mtd->get_unmapped_area(mtd, len, offset, flags);
 943         }
 944
 945         /* can't map directly */
 946         return (unsigned long) -ENOSYS;
 947 }
 948 #endif
 949
 950 /*
 951  * set up a mapping for shared memory segments
 952  */
 953 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 954 {
 955 #ifdef CONFIG_MMU
 956         struct mtd_file_info *mfi = file->private_data;
 957         struct mtd_info *mtd = mfi->mtd;
 958
 959         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
 960                 return 0;
 961         return -ENOSYS;
 962 #else
 963         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
 964 #endif
 965 }
 966
 967 static const struct file_operations mtd_fops = {
 968         .owner          = THIS_MODULE,
 969         .llseek         = mtd_lseek,
 970         .read           = mtd_read,
 971         .write          = mtd_write,
 972         .unlocked_ioctl = mtd_unlocked_ioctl,
 973 #ifdef CONFIG_COMPAT
 974         .compat_ioctl   = mtd_compat_ioctl,
 975 #endif
 976         .open           = mtd_open,
 977         .release        = mtd_close,
 978         .mmap           = mtd_mmap,
 979 #ifndef CONFIG_MMU
 980         .get_unmapped_area = mtd_get_unmapped_area,
 981 #endif
 982 };
 983
 984 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
 985                                const char *dev_name, void *data,
 986                                struct vfsmount *mnt)
 987 {
 988         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
 989                              mnt);
 990 }
 991
 992 static struct file_system_type mtd_inodefs_type = {
 993        .name = "mtd_inodefs",
 994        .get_sb = mtd_inodefs_get_sb,
 995        .kill_sb = kill_anon_super,
 996 };
 997
 998 static void mtdchar_notify_add(struct mtd_info *mtd)
 999 {
1000 }
1001
1002 static void mtdchar_notify_remove(struct mtd_info *mtd)
1003 {
1004         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1005
1006         if (mtd_ino) {
1007                 /* Destroy the inode if it exists */
1008                 mtd_ino->i_nlink = 0;
1009                 iput(mtd_ino);
1010         }
1011 }
1012
1013 static struct mtd_notifier mtdchar_notifier = {
1014         .add = mtdchar_notify_add,
1015         .remove = mtdchar_notify_remove,
1016 };
1017
1018 static int __init init_mtdchar(void)
1019 {
1020         int ret;
1021
1022         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1023                                    "mtd", &mtd_fops);
1024         if (ret < 0) {
1025                 pr_notice("Can't allocate major number %d for "
1026                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1027                 return ret;
1028         }
1029
1030         ret = register_filesystem(&mtd_inodefs_type);
1031         if (ret) {
1032                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1033                 goto err_unregister_chdev;
1034         }
1035
1036         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1037         if (IS_ERR(mtd_inode_mnt)) {
1038                 ret = PTR_ERR(mtd_inode_mnt);
1039                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1040                 goto err_unregister_filesystem;
1041         }
1042         register_mtd_user(&mtdchar_notifier);
1043
1044         return ret;
1045
1046 err_unregister_filesystem:
1047         unregister_filesystem(&mtd_inodefs_type);
1048 err_unregister_chdev:
1049         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1050         return ret;
1051 }
1052
1053 static void __exit cleanup_mtdchar(void)
1054 {
1055         unregister_mtd_user(&mtdchar_notifier);
1056         mntput(mtd_inode_mnt);
1057         unregister_filesystem(&mtd_inodefs_type);
1058         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1059 }
1060
1061 module_init(init_mtdchar);
1062 module_exit(cleanup_mtdchar);
1063
1064 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1065
1066 MODULE_LICENSE("GPL");
1067 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1068 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1069 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);