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/mutex.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
  37 #include <asm/uaccess.h>
  38
  39 #define MTD_INODE_FS_MAGIC 0x11307854
  40 static DEFINE_MUTEX(mtd_mutex);
  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         mutex_lock(&mtd_mutex);
  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         mutex_unlock(&mtd_mutex);
 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 file *file, u_int cmd, u_long arg)
 482 {
 483         struct mtd_file_info *mfi = file->private_data;
 484         struct mtd_info *mtd = mfi->mtd;
 485         void __user *argp = (void __user *)arg;
 486         int ret = 0;
 487         u_long size;
 488         struct mtd_info_user info;
 489
 490         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 491
 492         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 493         if (cmd & IOC_IN) {
 494                 if (!access_ok(VERIFY_READ, argp, size))
 495                         return -EFAULT;
 496         }
 497         if (cmd & IOC_OUT) {
 498                 if (!access_ok(VERIFY_WRITE, argp, size))
 499                         return -EFAULT;
 500         }
 501
 502         switch (cmd) {
 503         case MEMGETREGIONCOUNT:
 504                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 505                         return -EFAULT;
 506                 break;
 507
 508         case MEMGETREGIONINFO:
 509         {
 510                 uint32_t ur_idx;
 511                 struct mtd_erase_region_info *kr;
 512                 struct region_info_user __user *ur = argp;
 513
 514                 if (get_user(ur_idx, &(ur->regionindex)))
 515                         return -EFAULT;
 516
 517                 kr = &(mtd->eraseregions[ur_idx]);
 518
 519                 if (put_user(kr->offset, &(ur->offset))
 520                     || put_user(kr->erasesize, &(ur->erasesize))
 521                     || put_user(kr->numblocks, &(ur->numblocks)))
 522                         return -EFAULT;
 523
 524                 break;
 525         }
 526
 527         case MEMGETINFO:
 528                 info.type       = mtd->type;
 529                 info.flags      = mtd->flags;
 530                 info.size       = mtd->size;
 531                 info.erasesize  = mtd->erasesize;
 532                 info.writesize  = mtd->writesize;
 533                 info.oobsize    = mtd->oobsize;
 534                 /* The below fields are obsolete */
 535                 info.ecctype    = -1;
 536                 info.eccsize    = 0;
 537                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 538                         return -EFAULT;
 539                 break;
 540
 541         case MEMERASE:
 542         case MEMERASE64:
 543         {
 544                 struct erase_info *erase;
 545
 546                 if(!(file->f_mode & FMODE_WRITE))
 547                         return -EPERM;
 548
 549                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 550                 if (!erase)
 551                         ret = -ENOMEM;
 552                 else {
 553                         wait_queue_head_t waitq;
 554                         DECLARE_WAITQUEUE(wait, current);
 555
 556                         init_waitqueue_head(&waitq);
 557
 558                         if (cmd == MEMERASE64) {
 559                                 struct erase_info_user64 einfo64;
 560
 561                                 if (copy_from_user(&einfo64, argp,
 562                                             sizeof(struct erase_info_user64))) {
 563                                         kfree(erase);
 564                                         return -EFAULT;
 565                                 }
 566                                 erase->addr = einfo64.start;
 567                                 erase->len = einfo64.length;
 568                         } else {
 569                                 struct erase_info_user einfo32;
 570
 571                                 if (copy_from_user(&einfo32, argp,
 572                                             sizeof(struct erase_info_user))) {
 573                                         kfree(erase);
 574                                         return -EFAULT;
 575                                 }
 576                                 erase->addr = einfo32.start;
 577                                 erase->len = einfo32.length;
 578                         }
 579                         erase->mtd = mtd;
 580                         erase->callback = mtdchar_erase_callback;
 581                         erase->priv = (unsigned long)&waitq;
 582
 583                         /*
 584                           FIXME: Allow INTERRUPTIBLE. Which means
 585                           not having the wait_queue head on the stack.
 586
 587                           If the wq_head is on the stack, and we
 588                           leave because we got interrupted, then the
 589                           wq_head is no longer there when the
 590                           callback routine tries to wake us up.
 591                         */
 592                         ret = mtd->erase(mtd, erase);
 593                         if (!ret) {
 594                                 set_current_state(TASK_UNINTERRUPTIBLE);
 595                                 add_wait_queue(&waitq, &wait);
 596                                 if (erase->state != MTD_ERASE_DONE &&
 597                                     erase->state != MTD_ERASE_FAILED)
 598                                         schedule();
 599                                 remove_wait_queue(&waitq, &wait);
 600                                 set_current_state(TASK_RUNNING);
 601
 602                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 603                         }
 604                         kfree(erase);
 605                 }
 606                 break;
 607         }
 608
 609         case MEMWRITEOOB:
 610         {
 611                 struct mtd_oob_buf buf;
 612                 struct mtd_oob_buf __user *buf_user = argp;
 613
 614                 /* NOTE: writes return length to buf_user->length */
 615                 if (copy_from_user(&buf, argp, sizeof(buf)))
 616                         ret = -EFAULT;
 617                 else
 618                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 619                                 buf.ptr, &buf_user->length);
 620                 break;
 621         }
 622
 623         case MEMREADOOB:
 624         {
 625                 struct mtd_oob_buf buf;
 626                 struct mtd_oob_buf __user *buf_user = argp;
 627
 628                 /* NOTE: writes return length to buf_user->start */
 629                 if (copy_from_user(&buf, argp, sizeof(buf)))
 630                         ret = -EFAULT;
 631                 else
 632                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 633                                 buf.ptr, &buf_user->start);
 634                 break;
 635         }
 636
 637         case MEMWRITEOOB64:
 638         {
 639                 struct mtd_oob_buf64 buf;
 640                 struct mtd_oob_buf64 __user *buf_user = argp;
 641
 642                 if (copy_from_user(&buf, argp, sizeof(buf)))
 643                         ret = -EFAULT;
 644                 else
 645                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 646                                 (void __user *)(uintptr_t)buf.usr_ptr,
 647                                 &buf_user->length);
 648                 break;
 649         }
 650
 651         case MEMREADOOB64:
 652         {
 653                 struct mtd_oob_buf64 buf;
 654                 struct mtd_oob_buf64 __user *buf_user = argp;
 655
 656                 if (copy_from_user(&buf, argp, sizeof(buf)))
 657                         ret = -EFAULT;
 658                 else
 659                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 660                                 (void __user *)(uintptr_t)buf.usr_ptr,
 661                                 &buf_user->length);
 662                 break;
 663         }
 664
 665         case MEMLOCK:
 666         {
 667                 struct erase_info_user einfo;
 668
 669                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 670                         return -EFAULT;
 671
 672                 if (!mtd->lock)
 673                         ret = -EOPNOTSUPP;
 674                 else
 675                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 676                 break;
 677         }
 678
 679         case MEMUNLOCK:
 680         {
 681                 struct erase_info_user einfo;
 682
 683                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 684                         return -EFAULT;
 685
 686                 if (!mtd->unlock)
 687                         ret = -EOPNOTSUPP;
 688                 else
 689                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 690                 break;
 691         }
 692
 693         case MEMISLOCKED:
 694         {
 695                 struct erase_info_user einfo;
 696
 697                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 698                         return -EFAULT;
 699
 700                 if (!mtd->is_locked)
 701                         ret = -EOPNOTSUPP;
 702                 else
 703                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 704                 break;
 705         }
 706
 707         /* Legacy interface */
 708         case MEMGETOOBSEL:
 709         {
 710                 struct nand_oobinfo oi;
 711
 712                 if (!mtd->ecclayout)
 713                         return -EOPNOTSUPP;
 714                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 715                         return -EINVAL;
 716
 717                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 718                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 719                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 720                        sizeof(oi.oobfree));
 721                 oi.eccbytes = mtd->ecclayout->eccbytes;
 722
 723                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 724                         return -EFAULT;
 725                 break;
 726         }
 727
 728         case MEMGETBADBLOCK:
 729         {
 730                 loff_t offs;
 731
 732                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 733                         return -EFAULT;
 734                 if (!mtd->block_isbad)
 735                         ret = -EOPNOTSUPP;
 736                 else
 737                         return mtd->block_isbad(mtd, offs);
 738                 break;
 739         }
 740
 741         case MEMSETBADBLOCK:
 742         {
 743                 loff_t offs;
 744
 745                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 746                         return -EFAULT;
 747                 if (!mtd->block_markbad)
 748                         ret = -EOPNOTSUPP;
 749                 else
 750                         return mtd->block_markbad(mtd, offs);
 751                 break;
 752         }
 753
 754 #ifdef CONFIG_HAVE_MTD_OTP
 755         case OTPSELECT:
 756         {
 757                 int mode;
 758                 if (copy_from_user(&mode, argp, sizeof(int)))
 759                         return -EFAULT;
 760
 761                 mfi->mode = MTD_MODE_NORMAL;
 762
 763                 ret = otp_select_filemode(mfi, mode);
 764
 765                 file->f_pos = 0;
 766                 break;
 767         }
 768
 769         case OTPGETREGIONCOUNT:
 770         case OTPGETREGIONINFO:
 771         {
 772                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 773                 if (!buf)
 774                         return -ENOMEM;
 775                 ret = -EOPNOTSUPP;
 776                 switch (mfi->mode) {
 777                 case MTD_MODE_OTP_FACTORY:
 778                         if (mtd->get_fact_prot_info)
 779                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 780                         break;
 781                 case MTD_MODE_OTP_USER:
 782                         if (mtd->get_user_prot_info)
 783                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 784                         break;
 785                 default:
 786                         break;
 787                 }
 788                 if (ret >= 0) {
 789                         if (cmd == OTPGETREGIONCOUNT) {
 790                                 int nbr = ret / sizeof(struct otp_info);
 791                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 792                         } else
 793                                 ret = copy_to_user(argp, buf, ret);
 794                         if (ret)
 795                                 ret = -EFAULT;
 796                 }
 797                 kfree(buf);
 798                 break;
 799         }
 800
 801         case OTPLOCK:
 802         {
 803                 struct otp_info oinfo;
 804
 805                 if (mfi->mode != MTD_MODE_OTP_USER)
 806                         return -EINVAL;
 807                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 808                         return -EFAULT;
 809                 if (!mtd->lock_user_prot_reg)
 810                         return -EOPNOTSUPP;
 811                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 812                 break;
 813         }
 814 #endif
 815
 816         case ECCGETLAYOUT:
 817         {
 818                 if (!mtd->ecclayout)
 819                         return -EOPNOTSUPP;
 820
 821                 if (copy_to_user(argp, mtd->ecclayout,
 822                                  sizeof(struct nand_ecclayout)))
 823                         return -EFAULT;
 824                 break;
 825         }
 826
 827         case ECCGETSTATS:
 828         {
 829                 if (copy_to_user(argp, &mtd->ecc_stats,
 830                                  sizeof(struct mtd_ecc_stats)))
 831                         return -EFAULT;
 832                 break;
 833         }
 834
 835         case MTDFILEMODE:
 836         {
 837                 mfi->mode = 0;
 838
 839                 switch(arg) {
 840                 case MTD_MODE_OTP_FACTORY:
 841                 case MTD_MODE_OTP_USER:
 842                         ret = otp_select_filemode(mfi, arg);
 843                         break;
 844
 845                 case MTD_MODE_RAW:
 846                         if (!mtd->read_oob || !mtd->write_oob)
 847                                 return -EOPNOTSUPP;
 848                         mfi->mode = arg;
 849
 850                 case MTD_MODE_NORMAL:
 851                         break;
 852                 default:
 853                         ret = -EINVAL;
 854                 }
 855                 file->f_pos = 0;
 856                 break;
 857         }
 858
 859         default:
 860                 ret = -ENOTTY;
 861         }
 862
 863         return ret;
 864 } /* memory_ioctl */
 865
 866 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 867 {
 868         int ret;
 869
 870         mutex_lock(&mtd_mutex);
 871         ret = mtd_ioctl(file, cmd, arg);
 872         mutex_unlock(&mtd_mutex);
 873
 874         return ret;
 875 }
 876
 877 #ifdef CONFIG_COMPAT
 878
 879 struct mtd_oob_buf32 {
 880         u_int32_t start;
 881         u_int32_t length;
 882         compat_caddr_t ptr;     /* unsigned char* */
 883 };
 884
 885 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 886 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 887
 888 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 889         unsigned long arg)
 890 {
 891         struct mtd_file_info *mfi = file->private_data;
 892         struct mtd_info *mtd = mfi->mtd;
 893         void __user *argp = compat_ptr(arg);
 894         int ret = 0;
 895
 896         mutex_lock(&mtd_mutex);
 897
 898         switch (cmd) {
 899         case MEMWRITEOOB32:
 900         {
 901                 struct mtd_oob_buf32 buf;
 902                 struct mtd_oob_buf32 __user *buf_user = argp;
 903
 904                 if (copy_from_user(&buf, argp, sizeof(buf)))
 905                         ret = -EFAULT;
 906                 else
 907                         ret = mtd_do_writeoob(file, mtd, buf.start,
 908                                 buf.length, compat_ptr(buf.ptr),
 909                                 &buf_user->length);
 910                 break;
 911         }
 912
 913         case MEMREADOOB32:
 914         {
 915                 struct mtd_oob_buf32 buf;
 916                 struct mtd_oob_buf32 __user *buf_user = argp;
 917
 918                 /* NOTE: writes return length to buf->start */
 919                 if (copy_from_user(&buf, argp, sizeof(buf)))
 920                         ret = -EFAULT;
 921                 else
 922                         ret = mtd_do_readoob(mtd, buf.start,
 923                                 buf.length, compat_ptr(buf.ptr),
 924                                 &buf_user->start);
 925                 break;
 926         }
 927         default:
 928                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
 929         }
 930
 931         mutex_unlock(&mtd_mutex);
 932
 933         return ret;
 934 }
 935
 936 #endif /* CONFIG_COMPAT */
 937
 938 /*
 939  * try to determine where a shared mapping can be made
 940  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 941  *   mappings)
 942  */
 943 #ifndef CONFIG_MMU
 944 static unsigned long mtd_get_unmapped_area(struct file *file,
 945                                            unsigned long addr,
 946                                            unsigned long len,
 947                                            unsigned long pgoff,
 948                                            unsigned long flags)
 949 {
 950         struct mtd_file_info *mfi = file->private_data;
 951         struct mtd_info *mtd = mfi->mtd;
 952
 953         if (mtd->get_unmapped_area) {
 954                 unsigned long offset;
 955
 956                 if (addr != 0)
 957                         return (unsigned long) -EINVAL;
 958
 959                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
 960                         return (unsigned long) -EINVAL;
 961
 962                 offset = pgoff << PAGE_SHIFT;
 963                 if (offset > mtd->size - len)
 964                         return (unsigned long) -EINVAL;
 965
 966                 return mtd->get_unmapped_area(mtd, len, offset, flags);
 967         }
 968
 969         /* can't map directly */
 970         return (unsigned long) -ENOSYS;
 971 }
 972 #endif
 973
 974 /*
 975  * set up a mapping for shared memory segments
 976  */
 977 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 978 {
 979 #ifdef CONFIG_MMU
 980         struct mtd_file_info *mfi = file->private_data;
 981         struct mtd_info *mtd = mfi->mtd;
 982         struct map_info *map = mtd->priv;
 983         unsigned long start;
 984         unsigned long off;
 985         u32 len;
 986
 987         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
 988                 off = vma->vm_pgoff << PAGE_SHIFT;
 989                 start = map->phys;
 990                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
 991                 start &= PAGE_MASK;
 992                 if ((vma->vm_end - vma->vm_start + off) > len)
 993                         return -EINVAL;
 994
 995                 off += start;
 996                 vma->vm_pgoff = off >> PAGE_SHIFT;
 997                 vma->vm_flags |= VM_IO | VM_RESERVED;
 998
 999 #ifdef pgprot_noncached
1000                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1001                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1002 #endif
1003                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1004                                        vma->vm_end - vma->vm_start,
1005                                        vma->vm_page_prot))
1006                         return -EAGAIN;
1007
1008                 return 0;
1009         }
1010         return -ENOSYS;
1011 #else
1012         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1013 #endif
1014 }
1015
1016 static const struct file_operations mtd_fops = {
1017         .owner          = THIS_MODULE,
1018         .llseek         = mtd_lseek,
1019         .read           = mtd_read,
1020         .write          = mtd_write,
1021         .unlocked_ioctl = mtd_unlocked_ioctl,
1022 #ifdef CONFIG_COMPAT
1023         .compat_ioctl   = mtd_compat_ioctl,
1024 #endif
1025         .open           = mtd_open,
1026         .release        = mtd_close,
1027         .mmap           = mtd_mmap,
1028 #ifndef CONFIG_MMU
1029         .get_unmapped_area = mtd_get_unmapped_area,
1030 #endif
1031 };
1032
1033 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
1034                                const char *dev_name, void *data,
1035                                struct vfsmount *mnt)
1036 {
1037         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
1038                              mnt);
1039 }
1040
1041 static struct file_system_type mtd_inodefs_type = {
1042        .name = "mtd_inodefs",
1043        .get_sb = mtd_inodefs_get_sb,
1044        .kill_sb = kill_anon_super,
1045 };
1046
1047 static void mtdchar_notify_add(struct mtd_info *mtd)
1048 {
1049 }
1050
1051 static void mtdchar_notify_remove(struct mtd_info *mtd)
1052 {
1053         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1054
1055         if (mtd_ino) {
1056                 /* Destroy the inode if it exists */
1057                 mtd_ino->i_nlink = 0;
1058                 iput(mtd_ino);
1059         }
1060 }
1061
1062 static struct mtd_notifier mtdchar_notifier = {
1063         .add = mtdchar_notify_add,
1064         .remove = mtdchar_notify_remove,
1065 };
1066
1067 static int __init init_mtdchar(void)
1068 {
1069         int ret;
1070
1071         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1072                                    "mtd", &mtd_fops);
1073         if (ret < 0) {
1074                 pr_notice("Can't allocate major number %d for "
1075                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1076                 return ret;
1077         }
1078
1079         ret = register_filesystem(&mtd_inodefs_type);
1080         if (ret) {
1081                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1082                 goto err_unregister_chdev;
1083         }
1084
1085         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1086         if (IS_ERR(mtd_inode_mnt)) {
1087                 ret = PTR_ERR(mtd_inode_mnt);
1088                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1089                 goto err_unregister_filesystem;
1090         }
1091         register_mtd_user(&mtdchar_notifier);
1092
1093         return ret;
1094
1095 err_unregister_filesystem:
1096         unregister_filesystem(&mtd_inodefs_type);
1097 err_unregister_chdev:
1098         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1099         return ret;
1100 }
1101
1102 static void __exit cleanup_mtdchar(void)
1103 {
1104         unregister_mtd_user(&mtdchar_notifier);
1105         mntput(mtd_inode_mnt);
1106         unregister_filesystem(&mtd_inodefs_type);
1107         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1108 }
1109
1110 module_init(init_mtdchar);
1111 module_exit(cleanup_mtdchar);
1112
1113 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1114
1115 MODULE_LICENSE("GPL");
1116 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1117 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1118 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);