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 = memdup_user(ptr, length);
 408         if (IS_ERR(ops.oobbuf))
 409                 return PTR_ERR(ops.oobbuf);
 410
 411         start &= ~((uint64_t)mtd->oobsize - 1);
 412         ret = mtd->write_oob(mtd, start, &ops);
 413
 414         if (ops.oobretlen > 0xFFFFFFFFU)
 415                 ret = -EOVERFLOW;
 416         retlen = ops.oobretlen;
 417         if (copy_to_user(retp, &retlen, sizeof(length)))
 418                 ret = -EFAULT;
 419
 420         kfree(ops.oobbuf);
 421         return ret;
 422 }
 423
 424 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 425         uint32_t length, void __user *ptr, uint32_t __user *retp)
 426 {
 427         struct mtd_oob_ops ops;
 428         int ret = 0;
 429
 430         if (length > 4096)
 431                 return -EINVAL;
 432
 433         if (!mtd->read_oob)
 434                 ret = -EOPNOTSUPP;
 435         else
 436                 ret = access_ok(VERIFY_WRITE, ptr,
 437                                 length) ? 0 : -EFAULT;
 438         if (ret)
 439                 return ret;
 440
 441         ops.ooblen = length;
 442         ops.ooboffs = start & (mtd->oobsize - 1);
 443         ops.datbuf = NULL;
 444         ops.mode = MTD_OOB_PLACE;
 445
 446         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 447                 return -EINVAL;
 448
 449         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 450         if (!ops.oobbuf)
 451                 return -ENOMEM;
 452
 453         start &= ~((uint64_t)mtd->oobsize - 1);
 454         ret = mtd->read_oob(mtd, start, &ops);
 455
 456         if (put_user(ops.oobretlen, retp))
 457                 ret = -EFAULT;
 458         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 459                                             ops.oobretlen))
 460                 ret = -EFAULT;
 461
 462         kfree(ops.oobbuf);
 463         return ret;
 464 }
 465
 466 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 467 {
 468         struct mtd_file_info *mfi = file->private_data;
 469         struct mtd_info *mtd = mfi->mtd;
 470         void __user *argp = (void __user *)arg;
 471         int ret = 0;
 472         u_long size;
 473         struct mtd_info_user info;
 474
 475         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 476
 477         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 478         if (cmd & IOC_IN) {
 479                 if (!access_ok(VERIFY_READ, argp, size))
 480                         return -EFAULT;
 481         }
 482         if (cmd & IOC_OUT) {
 483                 if (!access_ok(VERIFY_WRITE, argp, size))
 484                         return -EFAULT;
 485         }
 486
 487         switch (cmd) {
 488         case MEMGETREGIONCOUNT:
 489                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 490                         return -EFAULT;
 491                 break;
 492
 493         case MEMGETREGIONINFO:
 494         {
 495                 uint32_t ur_idx;
 496                 struct mtd_erase_region_info *kr;
 497                 struct region_info_user __user *ur = argp;
 498
 499                 if (get_user(ur_idx, &(ur->regionindex)))
 500                         return -EFAULT;
 501
 502                 kr = &(mtd->eraseregions[ur_idx]);
 503
 504                 if (put_user(kr->offset, &(ur->offset))
 505                     || put_user(kr->erasesize, &(ur->erasesize))
 506                     || put_user(kr->numblocks, &(ur->numblocks)))
 507                         return -EFAULT;
 508
 509                 break;
 510         }
 511
 512         case MEMGETINFO:
 513                 info.type       = mtd->type;
 514                 info.flags      = mtd->flags;
 515                 info.size       = mtd->size;
 516                 info.erasesize  = mtd->erasesize;
 517                 info.writesize  = mtd->writesize;
 518                 info.oobsize    = mtd->oobsize;
 519                 /* The below fields are obsolete */
 520                 info.ecctype    = -1;
 521                 info.eccsize    = 0;
 522                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 523                         return -EFAULT;
 524                 break;
 525
 526         case MEMERASE:
 527         case MEMERASE64:
 528         {
 529                 struct erase_info *erase;
 530
 531                 if(!(file->f_mode & FMODE_WRITE))
 532                         return -EPERM;
 533
 534                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 535                 if (!erase)
 536                         ret = -ENOMEM;
 537                 else {
 538                         wait_queue_head_t waitq;
 539                         DECLARE_WAITQUEUE(wait, current);
 540
 541                         init_waitqueue_head(&waitq);
 542
 543                         if (cmd == MEMERASE64) {
 544                                 struct erase_info_user64 einfo64;
 545
 546                                 if (copy_from_user(&einfo64, argp,
 547                                             sizeof(struct erase_info_user64))) {
 548                                         kfree(erase);
 549                                         return -EFAULT;
 550                                 }
 551                                 erase->addr = einfo64.start;
 552                                 erase->len = einfo64.length;
 553                         } else {
 554                                 struct erase_info_user einfo32;
 555
 556                                 if (copy_from_user(&einfo32, argp,
 557                                             sizeof(struct erase_info_user))) {
 558                                         kfree(erase);
 559                                         return -EFAULT;
 560                                 }
 561                                 erase->addr = einfo32.start;
 562                                 erase->len = einfo32.length;
 563                         }
 564                         erase->mtd = mtd;
 565                         erase->callback = mtdchar_erase_callback;
 566                         erase->priv = (unsigned long)&waitq;
 567
 568                         /*
 569                           FIXME: Allow INTERRUPTIBLE. Which means
 570                           not having the wait_queue head on the stack.
 571
 572                           If the wq_head is on the stack, and we
 573                           leave because we got interrupted, then the
 574                           wq_head is no longer there when the
 575                           callback routine tries to wake us up.
 576                         */
 577                         ret = mtd->erase(mtd, erase);
 578                         if (!ret) {
 579                                 set_current_state(TASK_UNINTERRUPTIBLE);
 580                                 add_wait_queue(&waitq, &wait);
 581                                 if (erase->state != MTD_ERASE_DONE &&
 582                                     erase->state != MTD_ERASE_FAILED)
 583                                         schedule();
 584                                 remove_wait_queue(&waitq, &wait);
 585                                 set_current_state(TASK_RUNNING);
 586
 587                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 588                         }
 589                         kfree(erase);
 590                 }
 591                 break;
 592         }
 593
 594         case MEMWRITEOOB:
 595         {
 596                 struct mtd_oob_buf buf;
 597                 struct mtd_oob_buf __user *buf_user = argp;
 598
 599                 /* NOTE: writes return length to buf_user->length */
 600                 if (copy_from_user(&buf, argp, sizeof(buf)))
 601                         ret = -EFAULT;
 602                 else
 603                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 604                                 buf.ptr, &buf_user->length);
 605                 break;
 606         }
 607
 608         case MEMREADOOB:
 609         {
 610                 struct mtd_oob_buf buf;
 611                 struct mtd_oob_buf __user *buf_user = argp;
 612
 613                 /* NOTE: writes return length to buf_user->start */
 614                 if (copy_from_user(&buf, argp, sizeof(buf)))
 615                         ret = -EFAULT;
 616                 else
 617                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 618                                 buf.ptr, &buf_user->start);
 619                 break;
 620         }
 621
 622         case MEMWRITEOOB64:
 623         {
 624                 struct mtd_oob_buf64 buf;
 625                 struct mtd_oob_buf64 __user *buf_user = argp;
 626
 627                 if (copy_from_user(&buf, argp, sizeof(buf)))
 628                         ret = -EFAULT;
 629                 else
 630                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 631                                 (void __user *)(uintptr_t)buf.usr_ptr,
 632                                 &buf_user->length);
 633                 break;
 634         }
 635
 636         case MEMREADOOB64:
 637         {
 638                 struct mtd_oob_buf64 buf;
 639                 struct mtd_oob_buf64 __user *buf_user = argp;
 640
 641                 if (copy_from_user(&buf, argp, sizeof(buf)))
 642                         ret = -EFAULT;
 643                 else
 644                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 645                                 (void __user *)(uintptr_t)buf.usr_ptr,
 646                                 &buf_user->length);
 647                 break;
 648         }
 649
 650         case MEMLOCK:
 651         {
 652                 struct erase_info_user einfo;
 653
 654                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 655                         return -EFAULT;
 656
 657                 if (!mtd->lock)
 658                         ret = -EOPNOTSUPP;
 659                 else
 660                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 661                 break;
 662         }
 663
 664         case MEMUNLOCK:
 665         {
 666                 struct erase_info_user einfo;
 667
 668                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 669                         return -EFAULT;
 670
 671                 if (!mtd->unlock)
 672                         ret = -EOPNOTSUPP;
 673                 else
 674                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 675                 break;
 676         }
 677
 678         /* Legacy interface */
 679         case MEMGETOOBSEL:
 680         {
 681                 struct nand_oobinfo oi;
 682
 683                 if (!mtd->ecclayout)
 684                         return -EOPNOTSUPP;
 685                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 686                         return -EINVAL;
 687
 688                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 689                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 690                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 691                        sizeof(oi.oobfree));
 692                 oi.eccbytes = mtd->ecclayout->eccbytes;
 693
 694                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 695                         return -EFAULT;
 696                 break;
 697         }
 698
 699         case MEMGETBADBLOCK:
 700         {
 701                 loff_t offs;
 702
 703                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 704                         return -EFAULT;
 705                 if (!mtd->block_isbad)
 706                         ret = -EOPNOTSUPP;
 707                 else
 708                         return mtd->block_isbad(mtd, offs);
 709                 break;
 710         }
 711
 712         case MEMSETBADBLOCK:
 713         {
 714                 loff_t offs;
 715
 716                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 717                         return -EFAULT;
 718                 if (!mtd->block_markbad)
 719                         ret = -EOPNOTSUPP;
 720                 else
 721                         return mtd->block_markbad(mtd, offs);
 722                 break;
 723         }
 724
 725 #ifdef CONFIG_HAVE_MTD_OTP
 726         case OTPSELECT:
 727         {
 728                 int mode;
 729                 if (copy_from_user(&mode, argp, sizeof(int)))
 730                         return -EFAULT;
 731
 732                 mfi->mode = MTD_MODE_NORMAL;
 733
 734                 ret = otp_select_filemode(mfi, mode);
 735
 736                 file->f_pos = 0;
 737                 break;
 738         }
 739
 740         case OTPGETREGIONCOUNT:
 741         case OTPGETREGIONINFO:
 742         {
 743                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 744                 if (!buf)
 745                         return -ENOMEM;
 746                 ret = -EOPNOTSUPP;
 747                 switch (mfi->mode) {
 748                 case MTD_MODE_OTP_FACTORY:
 749                         if (mtd->get_fact_prot_info)
 750                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 751                         break;
 752                 case MTD_MODE_OTP_USER:
 753                         if (mtd->get_user_prot_info)
 754                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 755                         break;
 756                 default:
 757                         break;
 758                 }
 759                 if (ret >= 0) {
 760                         if (cmd == OTPGETREGIONCOUNT) {
 761                                 int nbr = ret / sizeof(struct otp_info);
 762                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 763                         } else
 764                                 ret = copy_to_user(argp, buf, ret);
 765                         if (ret)
 766                                 ret = -EFAULT;
 767                 }
 768                 kfree(buf);
 769                 break;
 770         }
 771
 772         case OTPLOCK:
 773         {
 774                 struct otp_info oinfo;
 775
 776                 if (mfi->mode != MTD_MODE_OTP_USER)
 777                         return -EINVAL;
 778                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 779                         return -EFAULT;
 780                 if (!mtd->lock_user_prot_reg)
 781                         return -EOPNOTSUPP;
 782                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 783                 break;
 784         }
 785 #endif
 786
 787         case ECCGETLAYOUT:
 788         {
 789                 if (!mtd->ecclayout)
 790                         return -EOPNOTSUPP;
 791
 792                 if (copy_to_user(argp, mtd->ecclayout,
 793                                  sizeof(struct nand_ecclayout)))
 794                         return -EFAULT;
 795                 break;
 796         }
 797
 798         case ECCGETSTATS:
 799         {
 800                 if (copy_to_user(argp, &mtd->ecc_stats,
 801                                  sizeof(struct mtd_ecc_stats)))
 802                         return -EFAULT;
 803                 break;
 804         }
 805
 806         case MTDFILEMODE:
 807         {
 808                 mfi->mode = 0;
 809
 810                 switch(arg) {
 811                 case MTD_MODE_OTP_FACTORY:
 812                 case MTD_MODE_OTP_USER:
 813                         ret = otp_select_filemode(mfi, arg);
 814                         break;
 815
 816                 case MTD_MODE_RAW:
 817                         if (!mtd->read_oob || !mtd->write_oob)
 818                                 return -EOPNOTSUPP;
 819                         mfi->mode = arg;
 820
 821                 case MTD_MODE_NORMAL:
 822                         break;
 823                 default:
 824                         ret = -EINVAL;
 825                 }
 826                 file->f_pos = 0;
 827                 break;
 828         }
 829
 830         default:
 831                 ret = -ENOTTY;
 832         }
 833
 834         return ret;
 835 } /* memory_ioctl */
 836
 837 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 838 {
 839         int ret;
 840
 841         lock_kernel();
 842         ret = mtd_ioctl(file, cmd, arg);
 843         unlock_kernel();
 844
 845         return ret;
 846 }
 847
 848 #ifdef CONFIG_COMPAT
 849
 850 struct mtd_oob_buf32 {
 851         u_int32_t start;
 852         u_int32_t length;
 853         compat_caddr_t ptr;     /* unsigned char* */
 854 };
 855
 856 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 857 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 858
 859 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 860         unsigned long arg)
 861 {
 862         struct mtd_file_info *mfi = file->private_data;
 863         struct mtd_info *mtd = mfi->mtd;
 864         void __user *argp = compat_ptr(arg);
 865         int ret = 0;
 866
 867         lock_kernel();
 868
 869         switch (cmd) {
 870         case MEMWRITEOOB32:
 871         {
 872                 struct mtd_oob_buf32 buf;
 873                 struct mtd_oob_buf32 __user *buf_user = argp;
 874
 875                 if (copy_from_user(&buf, argp, sizeof(buf)))
 876                         ret = -EFAULT;
 877                 else
 878                         ret = mtd_do_writeoob(file, mtd, buf.start,
 879                                 buf.length, compat_ptr(buf.ptr),
 880                                 &buf_user->length);
 881                 break;
 882         }
 883
 884         case MEMREADOOB32:
 885         {
 886                 struct mtd_oob_buf32 buf;
 887                 struct mtd_oob_buf32 __user *buf_user = argp;
 888
 889                 /* NOTE: writes return length to buf->start */
 890                 if (copy_from_user(&buf, argp, sizeof(buf)))
 891                         ret = -EFAULT;
 892                 else
 893                         ret = mtd_do_readoob(mtd, buf.start,
 894                                 buf.length, compat_ptr(buf.ptr),
 895                                 &buf_user->start);
 896                 break;
 897         }
 898         default:
 899                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
 900         }
 901
 902         unlock_kernel();
 903
 904         return ret;
 905 }
 906
 907 #endif /* CONFIG_COMPAT */
 908
 909 /*
 910  * try to determine where a shared mapping can be made
 911  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 912  *   mappings)
 913  */
 914 #ifndef CONFIG_MMU
 915 static unsigned long mtd_get_unmapped_area(struct file *file,
 916                                            unsigned long addr,
 917                                            unsigned long len,
 918                                            unsigned long pgoff,
 919                                            unsigned long flags)
 920 {
 921         struct mtd_file_info *mfi = file->private_data;
 922         struct mtd_info *mtd = mfi->mtd;
 923
 924         if (mtd->get_unmapped_area) {
 925                 unsigned long offset;
 926
 927                 if (addr != 0)
 928                         return (unsigned long) -EINVAL;
 929
 930                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
 931                         return (unsigned long) -EINVAL;
 932
 933                 offset = pgoff << PAGE_SHIFT;
 934                 if (offset > mtd->size - len)
 935                         return (unsigned long) -EINVAL;
 936
 937                 return mtd->get_unmapped_area(mtd, len, offset, flags);
 938         }
 939
 940         /* can't map directly */
 941         return (unsigned long) -ENOSYS;
 942 }
 943 #endif
 944
 945 /*
 946  * set up a mapping for shared memory segments
 947  */
 948 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 949 {
 950 #ifdef CONFIG_MMU
 951         struct mtd_file_info *mfi = file->private_data;
 952         struct mtd_info *mtd = mfi->mtd;
 953
 954         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
 955                 return 0;
 956         return -ENOSYS;
 957 #else
 958         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
 959 #endif
 960 }
 961
 962 static const struct file_operations mtd_fops = {
 963         .owner          = THIS_MODULE,
 964         .llseek         = mtd_lseek,
 965         .read           = mtd_read,
 966         .write          = mtd_write,
 967         .unlocked_ioctl = mtd_unlocked_ioctl,
 968 #ifdef CONFIG_COMPAT
 969         .compat_ioctl   = mtd_compat_ioctl,
 970 #endif
 971         .open           = mtd_open,
 972         .release        = mtd_close,
 973         .mmap           = mtd_mmap,
 974 #ifndef CONFIG_MMU
 975         .get_unmapped_area = mtd_get_unmapped_area,
 976 #endif
 977 };
 978
 979 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
 980                                const char *dev_name, void *data,
 981                                struct vfsmount *mnt)
 982 {
 983         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
 984                              mnt);
 985 }
 986
 987 static struct file_system_type mtd_inodefs_type = {
 988        .name = "mtd_inodefs",
 989        .get_sb = mtd_inodefs_get_sb,
 990        .kill_sb = kill_anon_super,
 991 };
 992
 993 static void mtdchar_notify_add(struct mtd_info *mtd)
 994 {
 995 }
 996
 997 static void mtdchar_notify_remove(struct mtd_info *mtd)
 998 {
 999         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1000
1001         if (mtd_ino) {
1002                 /* Destroy the inode if it exists */
1003                 mtd_ino->i_nlink = 0;
1004                 iput(mtd_ino);
1005         }
1006 }
1007
1008 static struct mtd_notifier mtdchar_notifier = {
1009         .add = mtdchar_notify_add,
1010         .remove = mtdchar_notify_remove,
1011 };
1012
1013 static int __init init_mtdchar(void)
1014 {
1015         int ret;
1016
1017         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1018                                    "mtd", &mtd_fops);
1019         if (ret < 0) {
1020                 pr_notice("Can't allocate major number %d for "
1021                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1022                 return ret;
1023         }
1024
1025         ret = register_filesystem(&mtd_inodefs_type);
1026         if (ret) {
1027                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1028                 goto err_unregister_chdev;
1029         }
1030
1031         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1032         if (IS_ERR(mtd_inode_mnt)) {
1033                 ret = PTR_ERR(mtd_inode_mnt);
1034                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1035                 goto err_unregister_filesystem;
1036         }
1037         register_mtd_user(&mtdchar_notifier);
1038
1039         return ret;
1040
1041 err_unregister_filesystem:
1042         unregister_filesystem(&mtd_inodefs_type);
1043 err_unregister_chdev:
1044         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1045         return ret;
1046 }
1047
1048 static void __exit cleanup_mtdchar(void)
1049 {
1050         unregister_mtd_user(&mtdchar_notifier);
1051         mntput(mtd_inode_mnt);
1052         unregister_filesystem(&mtd_inodefs_type);
1053         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1054 }
1055
1056 module_init(init_mtdchar);
1057 module_exit(cleanup_mtdchar);
1058
1059 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1060
1061 MODULE_LICENSE("GPL");
1062 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1063 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1064 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);