drivers/mtd/mtdchar.c

   1 /*
   2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  *
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/err.h>
  24 #include <linux/init.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/sched.h>
  29 #include <linux/smp_lock.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/compat.h>
  32 #include <linux/mount.h>
  33
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/map.h>
  36 #include <linux/mtd/compatmac.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 #define MTD_INODE_FS_MAGIC 0x11307854
  41 static struct vfsmount *mtd_inode_mnt __read_mostly;
  42
  43 /*
  44  * Data structure to hold the pointer to the mtd device as well
  45  * as mode information ofr various use cases.
  46  */
  47 struct mtd_file_info {
  48         struct mtd_info *mtd;
  49         struct inode *ino;
  50         enum mtd_file_modes mode;
  51 };
  52
  53 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  54 {
  55         struct mtd_file_info *mfi = file->private_data;
  56         struct mtd_info *mtd = mfi->mtd;
  57
  58         switch (orig) {
  59         case SEEK_SET:
  60                 break;
  61         case SEEK_CUR:
  62                 offset += file->f_pos;
  63                 break;
  64         case SEEK_END:
  65                 offset += mtd->size;
  66                 break;
  67         default:
  68                 return -EINVAL;
  69         }
  70
  71         if (offset >= 0 && offset <= mtd->size)
  72                 return file->f_pos = offset;
  73
  74         return -EINVAL;
  75 }
  76
  77
  78
  79 static int mtd_open(struct inode *inode, struct file *file)
  80 {
  81         int minor = iminor(inode);
  82         int devnum = minor >> 1;
  83         int ret = 0;
  84         struct mtd_info *mtd;
  85         struct mtd_file_info *mfi;
  86         struct inode *mtd_ino;
  87
  88         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  89
  90         /* You can't open the RO devices RW */
  91         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  92                 return -EACCES;
  93
  94         lock_kernel();
  95         mtd = get_mtd_device(NULL, devnum);
  96
  97         if (IS_ERR(mtd)) {
  98                 ret = PTR_ERR(mtd);
  99                 goto out;
 100         }
 101
 102         if (mtd->type == MTD_ABSENT) {
 103                 put_mtd_device(mtd);
 104                 ret = -ENODEV;
 105                 goto out;
 106         }
 107
 108         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 109         if (!mtd_ino) {
 110                 put_mtd_device(mtd);
 111                 ret = -ENOMEM;
 112                 goto out;
 113         }
 114         if (mtd_ino->i_state & I_NEW) {
 115                 mtd_ino->i_private = mtd;
 116                 mtd_ino->i_mode = S_IFCHR;
 117                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 118                 unlock_new_inode(mtd_ino);
 119         }
 120         file->f_mapping = mtd_ino->i_mapping;
 121
 122         /* You can't open it RW if it's not a writeable device */
 123         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 124                 iput(mtd_ino);
 125                 put_mtd_device(mtd);
 126                 ret = -EACCES;
 127                 goto out;
 128         }
 129
 130         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 131         if (!mfi) {
 132                 iput(mtd_ino);
 133                 put_mtd_device(mtd);
 134                 ret = -ENOMEM;
 135                 goto out;
 136         }
 137         mfi->ino = mtd_ino;
 138         mfi->mtd = mtd;
 139         file->private_data = mfi;
 140
 141 out:
 142         unlock_kernel();
 143         return ret;
 144 } /* mtd_open */
 145
 146 /*====================================================================*/
 147
 148 static int mtd_close(struct inode *inode, struct file *file)
 149 {
 150         struct mtd_file_info *mfi = file->private_data;
 151         struct mtd_info *mtd = mfi->mtd;
 152
 153         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 154
 155         /* Only sync if opened RW */
 156         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 157                 mtd->sync(mtd);
 158
 159         iput(mfi->ino);
 160
 161         put_mtd_device(mtd);
 162         file->private_data = NULL;
 163         kfree(mfi);
 164
 165         return 0;
 166 } /* mtd_close */
 167
 168 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 169    userspace buffer down and use it directly with readv/writev.
 170 */
 171 #define MAX_KMALLOC_SIZE 0x20000
 172
 173 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 174 {
 175         struct mtd_file_info *mfi = file->private_data;
 176         struct mtd_info *mtd = mfi->mtd;
 177         size_t retlen=0;
 178         size_t total_retlen=0;
 179         int ret=0;
 180         int len;
 181         char *kbuf;
 182
 183         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 184
 185         if (*ppos + count > mtd->size)
 186                 count = mtd->size - *ppos;
 187
 188         if (!count)
 189                 return 0;
 190
 191         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 192            and pass them directly to the MTD functions */
 193
 194         if (count > MAX_KMALLOC_SIZE)
 195                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 196         else
 197                 kbuf=kmalloc(count, GFP_KERNEL);
 198
 199         if (!kbuf)
 200                 return -ENOMEM;
 201
 202         while (count) {
 203
 204                 if (count > MAX_KMALLOC_SIZE)
 205                         len = MAX_KMALLOC_SIZE;
 206                 else
 207                         len = count;
 208
 209                 switch (mfi->mode) {
 210                 case MTD_MODE_OTP_FACTORY:
 211                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 212                         break;
 213                 case MTD_MODE_OTP_USER:
 214                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 215                         break;
 216                 case MTD_MODE_RAW:
 217                 {
 218                         struct mtd_oob_ops ops;
 219
 220                         ops.mode = MTD_OOB_RAW;
 221                         ops.datbuf = kbuf;
 222                         ops.oobbuf = NULL;
 223                         ops.len = len;
 224
 225                         ret = mtd->read_oob(mtd, *ppos, &ops);
 226                         retlen = ops.retlen;
 227                         break;
 228                 }
 229                 default:
 230                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 231                 }
 232                 /* Nand returns -EBADMSG on ecc errors, but it returns
 233                  * the data. For our userspace tools it is important
 234                  * to dump areas with ecc errors !
 235                  * For kernel internal usage it also might return -EUCLEAN
 236                  * to signal the caller that a bitflip has occured and has
 237                  * been corrected by the ECC algorithm.
 238                  * Userspace software which accesses NAND this way
 239                  * must be aware of the fact that it deals with NAND
 240                  */
 241                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 242                         *ppos += retlen;
 243                         if (copy_to_user(buf, kbuf, retlen)) {
 244                                 kfree(kbuf);
 245                                 return -EFAULT;
 246                         }
 247                         else
 248                                 total_retlen += retlen;
 249
 250                         count -= retlen;
 251                         buf += retlen;
 252                         if (retlen == 0)
 253                                 count = 0;
 254                 }
 255                 else {
 256                         kfree(kbuf);
 257                         return ret;
 258                 }
 259
 260         }
 261
 262         kfree(kbuf);
 263         return total_retlen;
 264 } /* mtd_read */
 265
 266 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 267 {
 268         struct mtd_file_info *mfi = file->private_data;
 269         struct mtd_info *mtd = mfi->mtd;
 270         char *kbuf;
 271         size_t retlen;
 272         size_t total_retlen=0;
 273         int ret=0;
 274         int len;
 275
 276         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 277
 278         if (*ppos == mtd->size)
 279                 return -ENOSPC;
 280
 281         if (*ppos + count > mtd->size)
 282                 count = mtd->size - *ppos;
 283
 284         if (!count)
 285                 return 0;
 286
 287         if (count > MAX_KMALLOC_SIZE)
 288                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 289         else
 290                 kbuf=kmalloc(count, GFP_KERNEL);
 291
 292         if (!kbuf)
 293                 return -ENOMEM;
 294
 295         while (count) {
 296
 297                 if (count > MAX_KMALLOC_SIZE)
 298                         len = MAX_KMALLOC_SIZE;
 299                 else
 300                         len = count;
 301
 302                 if (copy_from_user(kbuf, buf, len)) {
 303                         kfree(kbuf);
 304                         return -EFAULT;
 305                 }
 306
 307                 switch (mfi->mode) {
 308                 case MTD_MODE_OTP_FACTORY:
 309                         ret = -EROFS;
 310                         break;
 311                 case MTD_MODE_OTP_USER:
 312                         if (!mtd->write_user_prot_reg) {
 313                                 ret = -EOPNOTSUPP;
 314                                 break;
 315                         }
 316                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 317                         break;
 318
 319                 case MTD_MODE_RAW:
 320                 {
 321                         struct mtd_oob_ops ops;
 322
 323                         ops.mode = MTD_OOB_RAW;
 324                         ops.datbuf = kbuf;
 325                         ops.oobbuf = NULL;
 326                         ops.len = len;
 327
 328                         ret = mtd->write_oob(mtd, *ppos, &ops);
 329                         retlen = ops.retlen;
 330                         break;
 331                 }
 332
 333                 default:
 334                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 335                 }
 336                 if (!ret) {
 337                         *ppos += retlen;
 338                         total_retlen += retlen;
 339                         count -= retlen;
 340                         buf += retlen;
 341                 }
 342                 else {
 343                         kfree(kbuf);
 344                         return ret;
 345                 }
 346         }
 347
 348         kfree(kbuf);
 349         return total_retlen;
 350 } /* mtd_write */
 351
 352 /*======================================================================
 353
 354     IOCTL calls for getting device parameters.
 355
 356 ======================================================================*/
 357 static void mtdchar_erase_callback (struct erase_info *instr)
 358 {
 359         wake_up((wait_queue_head_t *)instr->priv);
 360 }
 361
 362 #ifdef CONFIG_HAVE_MTD_OTP
 363 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 364 {
 365         struct mtd_info *mtd = mfi->mtd;
 366         int ret = 0;
 367
 368         switch (mode) {
 369         case MTD_OTP_FACTORY:
 370                 if (!mtd->read_fact_prot_reg)
 371                         ret = -EOPNOTSUPP;
 372                 else
 373                         mfi->mode = MTD_MODE_OTP_FACTORY;
 374                 break;
 375         case MTD_OTP_USER:
 376                 if (!mtd->read_fact_prot_reg)
 377                         ret = -EOPNOTSUPP;
 378                 else
 379                         mfi->mode = MTD_MODE_OTP_USER;
 380                 break;
 381         default:
 382                 ret = -EINVAL;
 383         case MTD_OTP_OFF:
 384                 break;
 385         }
 386         return ret;
 387 }
 388 #else
 389 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 390 #endif
 391
 392 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 393         uint64_t start, uint32_t length, void __user *ptr,
 394         uint32_t __user *retp)
 395 {
 396         struct mtd_oob_ops ops;
 397         uint32_t retlen;
 398         int ret = 0;
 399
 400         if (!(file->f_mode & FMODE_WRITE))
 401                 return -EPERM;
 402
 403         if (length > 4096)
 404                 return -EINVAL;
 405
 406         if (!mtd->write_oob)
 407                 ret = -EOPNOTSUPP;
 408         else
 409                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 410
 411         if (ret)
 412                 return ret;
 413
 414         ops.ooblen = length;
 415         ops.ooboffs = start & (mtd->oobsize - 1);
 416         ops.datbuf = NULL;
 417         ops.mode = MTD_OOB_PLACE;
 418
 419         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 420                 return -EINVAL;
 421
 422         ops.oobbuf = memdup_user(ptr, length);
 423         if (IS_ERR(ops.oobbuf))
 424                 return PTR_ERR(ops.oobbuf);
 425
 426         start &= ~((uint64_t)mtd->oobsize - 1);
 427         ret = mtd->write_oob(mtd, start, &ops);
 428
 429         if (ops.oobretlen > 0xFFFFFFFFU)
 430                 ret = -EOVERFLOW;
 431         retlen = ops.oobretlen;
 432         if (copy_to_user(retp, &retlen, sizeof(length)))
 433                 ret = -EFAULT;
 434
 435         kfree(ops.oobbuf);
 436         return ret;
 437 }
 438
 439 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 440         uint32_t length, void __user *ptr, uint32_t __user *retp)
 441 {
 442         struct mtd_oob_ops ops;
 443         int ret = 0;
 444
 445         if (length > 4096)
 446                 return -EINVAL;
 447
 448         if (!mtd->read_oob)
 449                 ret = -EOPNOTSUPP;
 450         else
 451                 ret = access_ok(VERIFY_WRITE, ptr,
 452                                 length) ? 0 : -EFAULT;
 453         if (ret)
 454                 return ret;
 455
 456         ops.ooblen = length;
 457         ops.ooboffs = start & (mtd->oobsize - 1);
 458         ops.datbuf = NULL;
 459         ops.mode = MTD_OOB_PLACE;
 460
 461         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 462                 return -EINVAL;
 463
 464         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 465         if (!ops.oobbuf)
 466                 return -ENOMEM;
 467
 468         start &= ~((uint64_t)mtd->oobsize - 1);
 469         ret = mtd->read_oob(mtd, start, &ops);
 470
 471         if (put_user(ops.oobretlen, retp))
 472                 ret = -EFAULT;
 473         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 474                                             ops.oobretlen))
 475                 ret = -EFAULT;
 476
 477         kfree(ops.oobbuf);
 478         return ret;
 479 }
 480
 481 static int mtd_ioctl(struct inode *inode, struct file *file,
 482                      u_int cmd, u_long arg)
 483 {
 484         struct mtd_file_info *mfi = file->private_data;
 485         struct mtd_info *mtd = mfi->mtd;
 486         void __user *argp = (void __user *)arg;
 487         int ret = 0;
 488         u_long size;
 489         struct mtd_info_user info;
 490
 491         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 492
 493         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 494         if (cmd & IOC_IN) {
 495                 if (!access_ok(VERIFY_READ, argp, size))
 496                         return -EFAULT;
 497         }
 498         if (cmd & IOC_OUT) {
 499                 if (!access_ok(VERIFY_WRITE, argp, size))
 500                         return -EFAULT;
 501         }
 502
 503         switch (cmd) {
 504         case MEMGETREGIONCOUNT:
 505                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 506                         return -EFAULT;
 507                 break;
 508
 509         case MEMGETREGIONINFO:
 510         {
 511                 uint32_t ur_idx;
 512                 struct mtd_erase_region_info *kr;
 513                 struct region_info_user __user *ur = argp;
 514
 515                 if (get_user(ur_idx, &(ur->regionindex)))
 516                         return -EFAULT;
 517
 518                 kr = &(mtd->eraseregions[ur_idx]);
 519
 520                 if (put_user(kr->offset, &(ur->offset))
 521                     || put_user(kr->erasesize, &(ur->erasesize))
 522                     || put_user(kr->numblocks, &(ur->numblocks)))
 523                         return -EFAULT;
 524
 525                 break;
 526         }
 527
 528         case MEMGETINFO:
 529                 info.type       = mtd->type;
 530                 info.flags      = mtd->flags;
 531                 info.size       = mtd->size;
 532                 info.erasesize  = mtd->erasesize;
 533                 info.writesize  = mtd->writesize;
 534                 info.oobsize    = mtd->oobsize;
 535                 /* The below fields are obsolete */
 536                 info.ecctype    = -1;
 537                 info.eccsize    = 0;
 538                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 539                         return -EFAULT;
 540                 break;
 541
 542         case MEMERASE:
 543         case MEMERASE64:
 544         {
 545                 struct erase_info *erase;
 546
 547                 if(!(file->f_mode & FMODE_WRITE))
 548                         return -EPERM;
 549
 550                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 551                 if (!erase)
 552                         ret = -ENOMEM;
 553                 else {
 554                         wait_queue_head_t waitq;
 555                         DECLARE_WAITQUEUE(wait, current);
 556
 557                         init_waitqueue_head(&waitq);
 558
 559                         if (cmd == MEMERASE64) {
 560                                 struct erase_info_user64 einfo64;
 561
 562                                 if (copy_from_user(&einfo64, argp,
 563                                             sizeof(struct erase_info_user64))) {
 564                                         kfree(erase);
 565                                         return -EFAULT;
 566                                 }
 567                                 erase->addr = einfo64.start;
 568                                 erase->len = einfo64.length;
 569                         } else {
 570                                 struct erase_info_user einfo32;
 571
 572                                 if (copy_from_user(&einfo32, argp,
 573                                             sizeof(struct erase_info_user))) {
 574                                         kfree(erase);
 575                                         return -EFAULT;
 576                                 }
 577                                 erase->addr = einfo32.start;
 578                                 erase->len = einfo32.length;
 579                         }
 580                         erase->mtd = mtd;
 581                         erase->callback = mtdchar_erase_callback;
 582                         erase->priv = (unsigned long)&waitq;
 583
 584                         /*
 585                           FIXME: Allow INTERRUPTIBLE. Which means
 586                           not having the wait_queue head on the stack.
 587
 588                           If the wq_head is on the stack, and we
 589                           leave because we got interrupted, then the
 590                           wq_head is no longer there when the
 591                           callback routine tries to wake us up.
 592                         */
 593                         ret = mtd->erase(mtd, erase);
 594                         if (!ret) {
 595                                 set_current_state(TASK_UNINTERRUPTIBLE);
 596                                 add_wait_queue(&waitq, &wait);
 597                                 if (erase->state != MTD_ERASE_DONE &&
 598                                     erase->state != MTD_ERASE_FAILED)
 599                                         schedule();
 600                                 remove_wait_queue(&waitq, &wait);
 601                                 set_current_state(TASK_RUNNING);
 602
 603                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 604                         }
 605                         kfree(erase);
 606                 }
 607                 break;
 608         }
 609
 610         case MEMWRITEOOB:
 611         {
 612                 struct mtd_oob_buf buf;
 613                 struct mtd_oob_buf __user *buf_user = argp;
 614
 615                 /* NOTE: writes return length to buf_user->length */
 616                 if (copy_from_user(&buf, argp, sizeof(buf)))
 617                         ret = -EFAULT;
 618                 else
 619                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 620                                 buf.ptr, &buf_user->length);
 621                 break;
 622         }
 623
 624         case MEMREADOOB:
 625         {
 626                 struct mtd_oob_buf buf;
 627                 struct mtd_oob_buf __user *buf_user = argp;
 628
 629                 /* NOTE: writes return length to buf_user->start */
 630                 if (copy_from_user(&buf, argp, sizeof(buf)))
 631                         ret = -EFAULT;
 632                 else
 633                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 634                                 buf.ptr, &buf_user->start);
 635                 break;
 636         }
 637
 638         case MEMWRITEOOB64:
 639         {
 640                 struct mtd_oob_buf64 buf;
 641                 struct mtd_oob_buf64 __user *buf_user = argp;
 642
 643                 if (copy_from_user(&buf, argp, sizeof(buf)))
 644                         ret = -EFAULT;
 645                 else
 646                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 647                                 (void __user *)(uintptr_t)buf.usr_ptr,
 648                                 &buf_user->length);
 649                 break;
 650         }
 651
 652         case MEMREADOOB64:
 653         {
 654                 struct mtd_oob_buf64 buf;
 655                 struct mtd_oob_buf64 __user *buf_user = argp;
 656
 657                 if (copy_from_user(&buf, argp, sizeof(buf)))
 658                         ret = -EFAULT;
 659                 else
 660                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 661                                 (void __user *)(uintptr_t)buf.usr_ptr,
 662                                 &buf_user->length);
 663                 break;
 664         }
 665
 666         case MEMLOCK:
 667         {
 668                 struct erase_info_user einfo;
 669
 670                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 671                         return -EFAULT;
 672
 673                 if (!mtd->lock)
 674                         ret = -EOPNOTSUPP;
 675                 else
 676                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 677                 break;
 678         }
 679
 680         case MEMUNLOCK:
 681         {
 682                 struct erase_info_user einfo;
 683
 684                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 685                         return -EFAULT;
 686
 687                 if (!mtd->unlock)
 688                         ret = -EOPNOTSUPP;
 689                 else
 690                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 691                 break;
 692         }
 693
 694         case MEMISLOCKED:
 695         {
 696                 struct erase_info_user einfo;
 697
 698                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 699                         return -EFAULT;
 700
 701                 if (!mtd->is_locked)
 702                         ret = -EOPNOTSUPP;
 703                 else
 704                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 705                 break;
 706         }
 707
 708         /* Legacy interface */
 709         case MEMGETOOBSEL:
 710         {
 711                 struct nand_oobinfo oi;
 712
 713                 if (!mtd->ecclayout)
 714                         return -EOPNOTSUPP;
 715                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 716                         return -EINVAL;
 717
 718                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 719                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 720                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 721                        sizeof(oi.oobfree));
 722                 oi.eccbytes = mtd->ecclayout->eccbytes;
 723
 724                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 725                         return -EFAULT;
 726                 break;
 727         }
 728
 729         case MEMGETBADBLOCK:
 730         {
 731                 loff_t offs;
 732
 733                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 734                         return -EFAULT;
 735                 if (!mtd->block_isbad)
 736                         ret = -EOPNOTSUPP;
 737                 else
 738                         return mtd->block_isbad(mtd, offs);
 739                 break;
 740         }
 741
 742         case MEMSETBADBLOCK:
 743         {
 744                 loff_t offs;
 745
 746                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 747                         return -EFAULT;
 748                 if (!mtd->block_markbad)
 749                         ret = -EOPNOTSUPP;
 750                 else
 751                         return mtd->block_markbad(mtd, offs);
 752                 break;
 753         }
 754
 755 #ifdef CONFIG_HAVE_MTD_OTP
 756         case OTPSELECT:
 757         {
 758                 int mode;
 759                 if (copy_from_user(&mode, argp, sizeof(int)))
 760                         return -EFAULT;
 761
 762                 mfi->mode = MTD_MODE_NORMAL;
 763
 764                 ret = otp_select_filemode(mfi, mode);
 765
 766                 file->f_pos = 0;
 767                 break;
 768         }
 769
 770         case OTPGETREGIONCOUNT:
 771         case OTPGETREGIONINFO:
 772         {
 773                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 774                 if (!buf)
 775                         return -ENOMEM;
 776                 ret = -EOPNOTSUPP;
 777                 switch (mfi->mode) {
 778                 case MTD_MODE_OTP_FACTORY:
 779                         if (mtd->get_fact_prot_info)
 780                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 781                         break;
 782                 case MTD_MODE_OTP_USER:
 783                         if (mtd->get_user_prot_info)
 784                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 785                         break;
 786                 default:
 787                         break;
 788                 }
 789                 if (ret >= 0) {
 790                         if (cmd == OTPGETREGIONCOUNT) {
 791                                 int nbr = ret / sizeof(struct otp_info);
 792                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 793                         } else
 794                                 ret = copy_to_user(argp, buf, ret);
 795                         if (ret)
 796                                 ret = -EFAULT;
 797                 }
 798                 kfree(buf);
 799                 break;
 800         }
 801
 802         case OTPLOCK:
 803         {
 804                 struct otp_info oinfo;
 805
 806                 if (mfi->mode != MTD_MODE_OTP_USER)
 807                         return -EINVAL;
 808                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 809                         return -EFAULT;
 810                 if (!mtd->lock_user_prot_reg)
 811                         return -EOPNOTSUPP;
 812                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 813                 break;
 814         }
 815 #endif
 816
 817         case ECCGETLAYOUT:
 818         {
 819                 if (!mtd->ecclayout)
 820                         return -EOPNOTSUPP;
 821
 822                 if (copy_to_user(argp, mtd->ecclayout,
 823                                  sizeof(struct nand_ecclayout)))
 824                         return -EFAULT;
 825                 break;
 826         }
 827
 828         case ECCGETSTATS:
 829         {
 830                 if (copy_to_user(argp, &mtd->ecc_stats,
 831                                  sizeof(struct mtd_ecc_stats)))
 832                         return -EFAULT;
 833                 break;
 834         }
 835
 836         case MTDFILEMODE:
 837         {
 838                 mfi->mode = 0;
 839
 840                 switch(arg) {
 841                 case MTD_MODE_OTP_FACTORY:
 842                 case MTD_MODE_OTP_USER:
 843                         ret = otp_select_filemode(mfi, arg);
 844                         break;
 845
 846                 case MTD_MODE_RAW:
 847                         if (!mtd->read_oob || !mtd->write_oob)
 848                                 return -EOPNOTSUPP;
 849                         mfi->mode = arg;
 850
 851                 case MTD_MODE_NORMAL:
 852                         break;
 853                 default:
 854                         ret = -EINVAL;
 855                 }
 856                 file->f_pos = 0;
 857                 break;
 858         }
 859
 860         default:
 861                 ret = -ENOTTY;
 862         }
 863
 864         return ret;
 865 } /* memory_ioctl */
 866
 867 #ifdef CONFIG_COMPAT
 868
 869 struct mtd_oob_buf32 {
 870         u_int32_t start;
 871         u_int32_t length;
 872         compat_caddr_t ptr;     /* unsigned char* */
 873 };
 874
 875 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 876 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 877
 878 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 879         unsigned long arg)
 880 {
 881         struct inode *inode = file->f_path.dentry->d_inode;
 882         struct mtd_file_info *mfi = file->private_data;
 883         struct mtd_info *mtd = mfi->mtd;
 884         void __user *argp = compat_ptr(arg);
 885         int ret = 0;
 886
 887         lock_kernel();
 888
 889         switch (cmd) {
 890         case MEMWRITEOOB32:
 891         {
 892                 struct mtd_oob_buf32 buf;
 893                 struct mtd_oob_buf32 __user *buf_user = argp;
 894
 895                 if (copy_from_user(&buf, argp, sizeof(buf)))
 896                         ret = -EFAULT;
 897                 else
 898                         ret = mtd_do_writeoob(file, mtd, buf.start,
 899                                 buf.length, compat_ptr(buf.ptr),
 900                                 &buf_user->length);
 901                 break;
 902         }
 903
 904         case MEMREADOOB32:
 905         {
 906                 struct mtd_oob_buf32 buf;
 907                 struct mtd_oob_buf32 __user *buf_user = argp;
 908
 909                 /* NOTE: writes return length to buf->start */
 910                 if (copy_from_user(&buf, argp, sizeof(buf)))
 911                         ret = -EFAULT;
 912                 else
 913                         ret = mtd_do_readoob(mtd, buf.start,
 914                                 buf.length, compat_ptr(buf.ptr),
 915                                 &buf_user->start);
 916                 break;
 917         }
 918         default:
 919                 ret = mtd_ioctl(inode, file, cmd, (unsigned long)argp);
 920         }
 921
 922         unlock_kernel();
 923
 924         return ret;
 925 }
 926
 927 #endif /* CONFIG_COMPAT */
 928
 929 /*
 930  * try to determine where a shared mapping can be made
 931  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 932  *   mappings)
 933  */
 934 #ifndef CONFIG_MMU
 935 static unsigned long mtd_get_unmapped_area(struct file *file,
 936                                            unsigned long addr,
 937                                            unsigned long len,
 938                                            unsigned long pgoff,
 939                                            unsigned long flags)
 940 {
 941         struct mtd_file_info *mfi = file->private_data;
 942         struct mtd_info *mtd = mfi->mtd;
 943
 944         if (mtd->get_unmapped_area) {
 945                 unsigned long offset;
 946
 947                 if (addr != 0)
 948                         return (unsigned long) -EINVAL;
 949
 950                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
 951                         return (unsigned long) -EINVAL;
 952
 953                 offset = pgoff << PAGE_SHIFT;
 954                 if (offset > mtd->size - len)
 955                         return (unsigned long) -EINVAL;
 956
 957                 return mtd->get_unmapped_area(mtd, len, offset, flags);
 958         }
 959
 960         /* can't map directly */
 961         return (unsigned long) -ENOSYS;
 962 }
 963 #endif
 964
 965 /*
 966  * set up a mapping for shared memory segments
 967  */
 968 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 969 {
 970 #ifdef CONFIG_MMU
 971         struct mtd_file_info *mfi = file->private_data;
 972         struct mtd_info *mtd = mfi->mtd;
 973         struct map_info *map = mtd->priv;
 974         unsigned long start;
 975         unsigned long off;
 976         u32 len;
 977
 978         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
 979                 off = vma->vm_pgoff << PAGE_SHIFT;
 980                 start = map->phys;
 981                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
 982                 start &= PAGE_MASK;
 983                 if ((vma->vm_end - vma->vm_start + off) > len)
 984                         return -EINVAL;
 985
 986                 off += start;
 987                 vma->vm_pgoff = off >> PAGE_SHIFT;
 988                 vma->vm_flags |= VM_IO | VM_RESERVED;
 989
 990 #ifdef pgprot_noncached
 991                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
 992                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 993 #endif
 994                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
 995                                        vma->vm_end - vma->vm_start,
 996                                        vma->vm_page_prot))
 997                         return -EAGAIN;
 998
 999                 return 0;
1000         }
1001         return -ENOSYS;
1002 #else
1003         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1004 #endif
1005 }
1006
1007 static const struct file_operations mtd_fops = {
1008         .owner          = THIS_MODULE,
1009         .llseek         = mtd_lseek,
1010         .read           = mtd_read,
1011         .write          = mtd_write,
1012         .ioctl          = mtd_ioctl,
1013 #ifdef CONFIG_COMPAT
1014         .compat_ioctl   = mtd_compat_ioctl,
1015 #endif
1016         .open           = mtd_open,
1017         .release        = mtd_close,
1018         .mmap           = mtd_mmap,
1019 #ifndef CONFIG_MMU
1020         .get_unmapped_area = mtd_get_unmapped_area,
1021 #endif
1022 };
1023
1024 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
1025                                const char *dev_name, void *data,
1026                                struct vfsmount *mnt)
1027 {
1028         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
1029                              mnt);
1030 }
1031
1032 static struct file_system_type mtd_inodefs_type = {
1033        .name = "mtd_inodefs",
1034        .get_sb = mtd_inodefs_get_sb,
1035        .kill_sb = kill_anon_super,
1036 };
1037
1038 static void mtdchar_notify_add(struct mtd_info *mtd)
1039 {
1040 }
1041
1042 static void mtdchar_notify_remove(struct mtd_info *mtd)
1043 {
1044         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1045
1046         if (mtd_ino) {
1047                 /* Destroy the inode if it exists */
1048                 mtd_ino->i_nlink = 0;
1049                 iput(mtd_ino);
1050         }
1051 }
1052
1053 static struct mtd_notifier mtdchar_notifier = {
1054         .add = mtdchar_notify_add,
1055         .remove = mtdchar_notify_remove,
1056 };
1057
1058 static int __init init_mtdchar(void)
1059 {
1060         int ret;
1061
1062         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1063                                    "mtd", &mtd_fops);
1064         if (ret < 0) {
1065                 pr_notice("Can't allocate major number %d for "
1066                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1067                 return ret;
1068         }
1069
1070         ret = register_filesystem(&mtd_inodefs_type);
1071         if (ret) {
1072                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1073                 goto err_unregister_chdev;
1074         }
1075
1076         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1077         if (IS_ERR(mtd_inode_mnt)) {
1078                 ret = PTR_ERR(mtd_inode_mnt);
1079                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1080                 goto err_unregister_filesystem;
1081         }
1082         register_mtd_user(&mtdchar_notifier);
1083
1084         return ret;
1085
1086 err_unregister_filesystem:
1087         unregister_filesystem(&mtd_inodefs_type);
1088 err_unregister_chdev:
1089         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1090         return ret;
1091 }
1092
1093 static void __exit cleanup_mtdchar(void)
1094 {
1095         unregister_mtd_user(&mtdchar_notifier);
1096         mntput(mtd_inode_mnt);
1097         unregister_filesystem(&mtd_inodefs_type);
1098         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1099 }
1100
1101 module_init(init_mtdchar);
1102 module_exit(cleanup_mtdchar);
1103
1104 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1105
1106 MODULE_LICENSE("GPL");
1107 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1108 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1109 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);