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 #include <linux/blkpg.h>
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/partitions.h>
  36 #include <linux/mtd/map.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 #define MTD_INODE_FS_MAGIC 0x11307854
  41 static DEFINE_MUTEX(mtd_mutex);
  42 static struct vfsmount *mtd_inode_mnt __read_mostly;
  43
  44 /*
  45  * Data structure to hold the pointer to the mtd device as well
  46  * as mode information ofr various use cases.
  47  */
  48 struct mtd_file_info {
  49         struct mtd_info *mtd;
  50         struct inode *ino;
  51         enum mtd_file_modes mode;
  52 };
  53
  54 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  55 {
  56         struct mtd_file_info *mfi = file->private_data;
  57         struct mtd_info *mtd = mfi->mtd;
  58
  59         switch (orig) {
  60         case SEEK_SET:
  61                 break;
  62         case SEEK_CUR:
  63                 offset += file->f_pos;
  64                 break;
  65         case SEEK_END:
  66                 offset += mtd->size;
  67                 break;
  68         default:
  69                 return -EINVAL;
  70         }
  71
  72         if (offset >= 0 && offset <= mtd->size)
  73                 return file->f_pos = offset;
  74
  75         return -EINVAL;
  76 }
  77
  78
  79
  80 static int mtd_open(struct inode *inode, struct file *file)
  81 {
  82         int minor = iminor(inode);
  83         int devnum = minor >> 1;
  84         int ret = 0;
  85         struct mtd_info *mtd;
  86         struct mtd_file_info *mfi;
  87         struct inode *mtd_ino;
  88
  89         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  90
  91         /* You can't open the RO devices RW */
  92         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  93                 return -EACCES;
  94
  95         mutex_lock(&mtd_mutex);
  96         mtd = get_mtd_device(NULL, devnum);
  97
  98         if (IS_ERR(mtd)) {
  99                 ret = PTR_ERR(mtd);
 100                 goto out;
 101         }
 102
 103         if (mtd->type == MTD_ABSENT) {
 104                 put_mtd_device(mtd);
 105                 ret = -ENODEV;
 106                 goto out;
 107         }
 108
 109         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 110         if (!mtd_ino) {
 111                 put_mtd_device(mtd);
 112                 ret = -ENOMEM;
 113                 goto out;
 114         }
 115         if (mtd_ino->i_state & I_NEW) {
 116                 mtd_ino->i_private = mtd;
 117                 mtd_ino->i_mode = S_IFCHR;
 118                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 119                 unlock_new_inode(mtd_ino);
 120         }
 121         file->f_mapping = mtd_ino->i_mapping;
 122
 123         /* You can't open it RW if it's not a writeable device */
 124         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 125                 iput(mtd_ino);
 126                 put_mtd_device(mtd);
 127                 ret = -EACCES;
 128                 goto out;
 129         }
 130
 131         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 132         if (!mfi) {
 133                 iput(mtd_ino);
 134                 put_mtd_device(mtd);
 135                 ret = -ENOMEM;
 136                 goto out;
 137         }
 138         mfi->ino = mtd_ino;
 139         mfi->mtd = mtd;
 140         file->private_data = mfi;
 141
 142 out:
 143         mutex_unlock(&mtd_mutex);
 144         return ret;
 145 } /* mtd_open */
 146
 147 /*====================================================================*/
 148
 149 static int mtd_close(struct inode *inode, struct file *file)
 150 {
 151         struct mtd_file_info *mfi = file->private_data;
 152         struct mtd_info *mtd = mfi->mtd;
 153
 154         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 155
 156         /* Only sync if opened RW */
 157         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 158                 mtd->sync(mtd);
 159
 160         iput(mfi->ino);
 161
 162         put_mtd_device(mtd);
 163         file->private_data = NULL;
 164         kfree(mfi);
 165
 166         return 0;
 167 } /* mtd_close */
 168
 169 /* Back in June 2001, dwmw2 wrote:
 170  *
 171  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 172  *   userspace buffer down and use it directly with readv/writev.
 173  *
 174  * The implementation below, using mtd_kmalloc_up_to, mitigates
 175  * allocation failures when the system is under low-memory situations
 176  * or if memory is highly fragmented at the cost of reducing the
 177  * performance of the requested transfer due to a smaller buffer size.
 178  *
 179  * A more complex but more memory-efficient implementation based on
 180  * get_user_pages and iovecs to cover extents of those pages is a
 181  * longer-term goal, as intimated by dwmw2 above. However, for the
 182  * write case, this requires yet more complex head and tail transfer
 183  * handling when those head and tail offsets and sizes are such that
 184  * alignment requirements are not met in the NAND subdriver.
 185  */
 186
 187 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 188 {
 189         struct mtd_file_info *mfi = file->private_data;
 190         struct mtd_info *mtd = mfi->mtd;
 191         size_t retlen=0;
 192         size_t total_retlen=0;
 193         int ret=0;
 194         int len;
 195         size_t size = count;
 196         char *kbuf;
 197
 198         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 199
 200         if (*ppos + count > mtd->size)
 201                 count = mtd->size - *ppos;
 202
 203         if (!count)
 204                 return 0;
 205
 206         kbuf = mtd_kmalloc_up_to(mtd, &size);
 207         if (!kbuf)
 208                 return -ENOMEM;
 209
 210         while (count) {
 211                 len = min_t(size_t, count, size);
 212
 213                 switch (mfi->mode) {
 214                 case MTD_MODE_OTP_FACTORY:
 215                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 216                         break;
 217                 case MTD_MODE_OTP_USER:
 218                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 219                         break;
 220                 case MTD_MODE_RAW:
 221                 {
 222                         struct mtd_oob_ops ops;
 223
 224                         ops.mode = MTD_OOB_RAW;
 225                         ops.datbuf = kbuf;
 226                         ops.oobbuf = NULL;
 227                         ops.len = len;
 228
 229                         ret = mtd->read_oob(mtd, *ppos, &ops);
 230                         retlen = ops.retlen;
 231                         break;
 232                 }
 233                 default:
 234                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 235                 }
 236                 /* Nand returns -EBADMSG on ecc errors, but it returns
 237                  * the data. For our userspace tools it is important
 238                  * to dump areas with ecc errors !
 239                  * For kernel internal usage it also might return -EUCLEAN
 240                  * to signal the caller that a bitflip has occurred and has
 241                  * been corrected by the ECC algorithm.
 242                  * Userspace software which accesses NAND this way
 243                  * must be aware of the fact that it deals with NAND
 244                  */
 245                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 246                         *ppos += retlen;
 247                         if (copy_to_user(buf, kbuf, retlen)) {
 248                                 kfree(kbuf);
 249                                 return -EFAULT;
 250                         }
 251                         else
 252                                 total_retlen += retlen;
 253
 254                         count -= retlen;
 255                         buf += retlen;
 256                         if (retlen == 0)
 257                                 count = 0;
 258                 }
 259                 else {
 260                         kfree(kbuf);
 261                         return ret;
 262                 }
 263
 264         }
 265
 266         kfree(kbuf);
 267         return total_retlen;
 268 } /* mtd_read */
 269
 270 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 271 {
 272         struct mtd_file_info *mfi = file->private_data;
 273         struct mtd_info *mtd = mfi->mtd;
 274         size_t size = count;
 275         char *kbuf;
 276         size_t retlen;
 277         size_t total_retlen=0;
 278         int ret=0;
 279         int len;
 280
 281         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 282
 283         if (*ppos == mtd->size)
 284                 return -ENOSPC;
 285
 286         if (*ppos + count > mtd->size)
 287                 count = mtd->size - *ppos;
 288
 289         if (!count)
 290                 return 0;
 291
 292         kbuf = mtd_kmalloc_up_to(mtd, &size);
 293         if (!kbuf)
 294                 return -ENOMEM;
 295
 296         while (count) {
 297                 len = min_t(size_t, count, size);
 298
 299                 if (copy_from_user(kbuf, buf, len)) {
 300                         kfree(kbuf);
 301                         return -EFAULT;
 302                 }
 303
 304                 switch (mfi->mode) {
 305                 case MTD_MODE_OTP_FACTORY:
 306                         ret = -EROFS;
 307                         break;
 308                 case MTD_MODE_OTP_USER:
 309                         if (!mtd->write_user_prot_reg) {
 310                                 ret = -EOPNOTSUPP;
 311                                 break;
 312                         }
 313                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 314                         break;
 315
 316                 case MTD_MODE_RAW:
 317                 {
 318                         struct mtd_oob_ops ops;
 319
 320                         ops.mode = MTD_OOB_RAW;
 321                         ops.datbuf = kbuf;
 322                         ops.oobbuf = NULL;
 323                         ops.len = len;
 324
 325                         ret = mtd->write_oob(mtd, *ppos, &ops);
 326                         retlen = ops.retlen;
 327                         break;
 328                 }
 329
 330                 default:
 331                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 332                 }
 333                 if (!ret) {
 334                         *ppos += retlen;
 335                         total_retlen += retlen;
 336                         count -= retlen;
 337                         buf += retlen;
 338                 }
 339                 else {
 340                         kfree(kbuf);
 341                         return ret;
 342                 }
 343         }
 344
 345         kfree(kbuf);
 346         return total_retlen;
 347 } /* mtd_write */
 348
 349 /*======================================================================
 350
 351     IOCTL calls for getting device parameters.
 352
 353 ======================================================================*/
 354 static void mtdchar_erase_callback (struct erase_info *instr)
 355 {
 356         wake_up((wait_queue_head_t *)instr->priv);
 357 }
 358
 359 #ifdef CONFIG_HAVE_MTD_OTP
 360 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 361 {
 362         struct mtd_info *mtd = mfi->mtd;
 363         int ret = 0;
 364
 365         switch (mode) {
 366         case MTD_OTP_FACTORY:
 367                 if (!mtd->read_fact_prot_reg)
 368                         ret = -EOPNOTSUPP;
 369                 else
 370                         mfi->mode = MTD_MODE_OTP_FACTORY;
 371                 break;
 372         case MTD_OTP_USER:
 373                 if (!mtd->read_fact_prot_reg)
 374                         ret = -EOPNOTSUPP;
 375                 else
 376                         mfi->mode = MTD_MODE_OTP_USER;
 377                 break;
 378         default:
 379                 ret = -EINVAL;
 380         case MTD_OTP_OFF:
 381                 break;
 382         }
 383         return ret;
 384 }
 385 #else
 386 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 387 #endif
 388
 389 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 390         uint64_t start, uint32_t length, void __user *ptr,
 391         uint32_t __user *retp)
 392 {
 393         struct mtd_oob_ops ops;
 394         uint32_t retlen;
 395         int ret = 0;
 396
 397         if (!(file->f_mode & FMODE_WRITE))
 398                 return -EPERM;
 399
 400         if (length > 4096)
 401                 return -EINVAL;
 402
 403         if (!mtd->write_oob)
 404                 ret = -EOPNOTSUPP;
 405         else
 406                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 407
 408         if (ret)
 409                 return ret;
 410
 411         ops.ooblen = length;
 412         ops.ooboffs = start & (mtd->oobsize - 1);
 413         ops.datbuf = NULL;
 414         ops.mode = MTD_OOB_PLACE;
 415
 416         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 417                 return -EINVAL;
 418
 419         ops.oobbuf = memdup_user(ptr, length);
 420         if (IS_ERR(ops.oobbuf))
 421                 return PTR_ERR(ops.oobbuf);
 422
 423         start &= ~((uint64_t)mtd->oobsize - 1);
 424         ret = mtd->write_oob(mtd, start, &ops);
 425
 426         if (ops.oobretlen > 0xFFFFFFFFU)
 427                 ret = -EOVERFLOW;
 428         retlen = ops.oobretlen;
 429         if (copy_to_user(retp, &retlen, sizeof(length)))
 430                 ret = -EFAULT;
 431
 432         kfree(ops.oobbuf);
 433         return ret;
 434 }
 435
 436 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 437         uint32_t length, void __user *ptr, uint32_t __user *retp)
 438 {
 439         struct mtd_oob_ops ops;
 440         int ret = 0;
 441
 442         if (length > 4096)
 443                 return -EINVAL;
 444
 445         if (!mtd->read_oob)
 446                 ret = -EOPNOTSUPP;
 447         else
 448                 ret = access_ok(VERIFY_WRITE, ptr,
 449                                 length) ? 0 : -EFAULT;
 450         if (ret)
 451                 return ret;
 452
 453         ops.ooblen = length;
 454         ops.ooboffs = start & (mtd->oobsize - 1);
 455         ops.datbuf = NULL;
 456         ops.mode = MTD_OOB_PLACE;
 457
 458         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 459                 return -EINVAL;
 460
 461         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 462         if (!ops.oobbuf)
 463                 return -ENOMEM;
 464
 465         start &= ~((uint64_t)mtd->oobsize - 1);
 466         ret = mtd->read_oob(mtd, start, &ops);
 467
 468         if (put_user(ops.oobretlen, retp))
 469                 ret = -EFAULT;
 470         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 471                                             ops.oobretlen))
 472                 ret = -EFAULT;
 473
 474         kfree(ops.oobbuf);
 475         return ret;
 476 }
 477
 478 /*
 479  * Copies (and truncates, if necessary) data from the larger struct,
 480  * nand_ecclayout, to the smaller, deprecated layout struct,
 481  * nand_ecclayout_user. This is necessary only to suppport the deprecated
 482  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 483  * nand_ecclayout flexibly (i.e. the struct may change size in new
 484  * releases without requiring major rewrites).
 485  */
 486 static int shrink_ecclayout(const struct nand_ecclayout *from,
 487                 struct nand_ecclayout_user *to)
 488 {
 489         int i;
 490
 491         if (!from || !to)
 492                 return -EINVAL;
 493
 494         memset(to, 0, sizeof(*to));
 495
 496         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 497         for (i = 0; i < to->eccbytes; i++)
 498                 to->eccpos[i] = from->eccpos[i];
 499
 500         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 501                 if (from->oobfree[i].length == 0 &&
 502                                 from->oobfree[i].offset == 0)
 503                         break;
 504                 to->oobavail += from->oobfree[i].length;
 505                 to->oobfree[i] = from->oobfree[i];
 506         }
 507
 508         return 0;
 509 }
 510
 511 #ifdef CONFIG_MTD_PARTITIONS
 512 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
 513                            struct blkpg_ioctl_arg __user *arg)
 514 {
 515         struct blkpg_ioctl_arg a;
 516         struct blkpg_partition p;
 517
 518         if (!capable(CAP_SYS_ADMIN))
 519                 return -EPERM;
 520
 521         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 522                 return -EFAULT;
 523
 524         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 525                 return -EFAULT;
 526
 527         switch (a.op) {
 528         case BLKPG_ADD_PARTITION:
 529
 530                 /* Only master mtd device must be used to add partitions */
 531                 if (mtd_is_partition(mtd))
 532                         return -EINVAL;
 533
 534                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 535
 536         case BLKPG_DEL_PARTITION:
 537
 538                 if (p.pno < 0)
 539                         return -EINVAL;
 540
 541                 return mtd_del_partition(mtd, p.pno);
 542
 543         default:
 544                 return -EINVAL;
 545         }
 546 }
 547 #endif
 548
 549
 550 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 551 {
 552         struct mtd_file_info *mfi = file->private_data;
 553         struct mtd_info *mtd = mfi->mtd;
 554         void __user *argp = (void __user *)arg;
 555         int ret = 0;
 556         u_long size;
 557         struct mtd_info_user info;
 558
 559         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 560
 561         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 562         if (cmd & IOC_IN) {
 563                 if (!access_ok(VERIFY_READ, argp, size))
 564                         return -EFAULT;
 565         }
 566         if (cmd & IOC_OUT) {
 567                 if (!access_ok(VERIFY_WRITE, argp, size))
 568                         return -EFAULT;
 569         }
 570
 571         switch (cmd) {
 572         case MEMGETREGIONCOUNT:
 573                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 574                         return -EFAULT;
 575                 break;
 576
 577         case MEMGETREGIONINFO:
 578         {
 579                 uint32_t ur_idx;
 580                 struct mtd_erase_region_info *kr;
 581                 struct region_info_user __user *ur = argp;
 582
 583                 if (get_user(ur_idx, &(ur->regionindex)))
 584                         return -EFAULT;
 585
 586                 if (ur_idx >= mtd->numeraseregions)
 587                         return -EINVAL;
 588
 589                 kr = &(mtd->eraseregions[ur_idx]);
 590
 591                 if (put_user(kr->offset, &(ur->offset))
 592                     || put_user(kr->erasesize, &(ur->erasesize))
 593                     || put_user(kr->numblocks, &(ur->numblocks)))
 594                         return -EFAULT;
 595
 596                 break;
 597         }
 598
 599         case MEMGETINFO:
 600                 memset(&info, 0, sizeof(info));
 601                 info.type       = mtd->type;
 602                 info.flags      = mtd->flags;
 603                 info.size       = mtd->size;
 604                 info.erasesize  = mtd->erasesize;
 605                 info.writesize  = mtd->writesize;
 606                 info.oobsize    = mtd->oobsize;
 607                 /* The below fields are obsolete */
 608                 info.ecctype    = -1;
 609                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 610                         return -EFAULT;
 611                 break;
 612
 613         case MEMERASE:
 614         case MEMERASE64:
 615         {
 616                 struct erase_info *erase;
 617
 618                 if(!(file->f_mode & FMODE_WRITE))
 619                         return -EPERM;
 620
 621                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 622                 if (!erase)
 623                         ret = -ENOMEM;
 624                 else {
 625                         wait_queue_head_t waitq;
 626                         DECLARE_WAITQUEUE(wait, current);
 627
 628                         init_waitqueue_head(&waitq);
 629
 630                         if (cmd == MEMERASE64) {
 631                                 struct erase_info_user64 einfo64;
 632
 633                                 if (copy_from_user(&einfo64, argp,
 634                                             sizeof(struct erase_info_user64))) {
 635                                         kfree(erase);
 636                                         return -EFAULT;
 637                                 }
 638                                 erase->addr = einfo64.start;
 639                                 erase->len = einfo64.length;
 640                         } else {
 641                                 struct erase_info_user einfo32;
 642
 643                                 if (copy_from_user(&einfo32, argp,
 644                                             sizeof(struct erase_info_user))) {
 645                                         kfree(erase);
 646                                         return -EFAULT;
 647                                 }
 648                                 erase->addr = einfo32.start;
 649                                 erase->len = einfo32.length;
 650                         }
 651                         erase->mtd = mtd;
 652                         erase->callback = mtdchar_erase_callback;
 653                         erase->priv = (unsigned long)&waitq;
 654
 655                         /*
 656                           FIXME: Allow INTERRUPTIBLE. Which means
 657                           not having the wait_queue head on the stack.
 658
 659                           If the wq_head is on the stack, and we
 660                           leave because we got interrupted, then the
 661                           wq_head is no longer there when the
 662                           callback routine tries to wake us up.
 663                         */
 664                         ret = mtd->erase(mtd, erase);
 665                         if (!ret) {
 666                                 set_current_state(TASK_UNINTERRUPTIBLE);
 667                                 add_wait_queue(&waitq, &wait);
 668                                 if (erase->state != MTD_ERASE_DONE &&
 669                                     erase->state != MTD_ERASE_FAILED)
 670                                         schedule();
 671                                 remove_wait_queue(&waitq, &wait);
 672                                 set_current_state(TASK_RUNNING);
 673
 674                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 675                         }
 676                         kfree(erase);
 677                 }
 678                 break;
 679         }
 680
 681         case MEMWRITEOOB:
 682         {
 683                 struct mtd_oob_buf buf;
 684                 struct mtd_oob_buf __user *buf_user = argp;
 685
 686                 /* NOTE: writes return length to buf_user->length */
 687                 if (copy_from_user(&buf, argp, sizeof(buf)))
 688                         ret = -EFAULT;
 689                 else
 690                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 691                                 buf.ptr, &buf_user->length);
 692                 break;
 693         }
 694
 695         case MEMREADOOB:
 696         {
 697                 struct mtd_oob_buf buf;
 698                 struct mtd_oob_buf __user *buf_user = argp;
 699
 700                 /* NOTE: writes return length to buf_user->start */
 701                 if (copy_from_user(&buf, argp, sizeof(buf)))
 702                         ret = -EFAULT;
 703                 else
 704                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 705                                 buf.ptr, &buf_user->start);
 706                 break;
 707         }
 708
 709         case MEMWRITEOOB64:
 710         {
 711                 struct mtd_oob_buf64 buf;
 712                 struct mtd_oob_buf64 __user *buf_user = argp;
 713
 714                 if (copy_from_user(&buf, argp, sizeof(buf)))
 715                         ret = -EFAULT;
 716                 else
 717                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 718                                 (void __user *)(uintptr_t)buf.usr_ptr,
 719                                 &buf_user->length);
 720                 break;
 721         }
 722
 723         case MEMREADOOB64:
 724         {
 725                 struct mtd_oob_buf64 buf;
 726                 struct mtd_oob_buf64 __user *buf_user = argp;
 727
 728                 if (copy_from_user(&buf, argp, sizeof(buf)))
 729                         ret = -EFAULT;
 730                 else
 731                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 732                                 (void __user *)(uintptr_t)buf.usr_ptr,
 733                                 &buf_user->length);
 734                 break;
 735         }
 736
 737         case MEMLOCK:
 738         {
 739                 struct erase_info_user einfo;
 740
 741                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 742                         return -EFAULT;
 743
 744                 if (!mtd->lock)
 745                         ret = -EOPNOTSUPP;
 746                 else
 747                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 748                 break;
 749         }
 750
 751         case MEMUNLOCK:
 752         {
 753                 struct erase_info_user einfo;
 754
 755                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 756                         return -EFAULT;
 757
 758                 if (!mtd->unlock)
 759                         ret = -EOPNOTSUPP;
 760                 else
 761                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 762                 break;
 763         }
 764
 765         case MEMISLOCKED:
 766         {
 767                 struct erase_info_user einfo;
 768
 769                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 770                         return -EFAULT;
 771
 772                 if (!mtd->is_locked)
 773                         ret = -EOPNOTSUPP;
 774                 else
 775                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 776                 break;
 777         }
 778
 779         /* Legacy interface */
 780         case MEMGETOOBSEL:
 781         {
 782                 struct nand_oobinfo oi;
 783
 784                 if (!mtd->ecclayout)
 785                         return -EOPNOTSUPP;
 786                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 787                         return -EINVAL;
 788
 789                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 790                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 791                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 792                        sizeof(oi.oobfree));
 793                 oi.eccbytes = mtd->ecclayout->eccbytes;
 794
 795                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 796                         return -EFAULT;
 797                 break;
 798         }
 799
 800         case MEMGETBADBLOCK:
 801         {
 802                 loff_t offs;
 803
 804                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 805                         return -EFAULT;
 806                 if (!mtd->block_isbad)
 807                         ret = -EOPNOTSUPP;
 808                 else
 809                         return mtd->block_isbad(mtd, offs);
 810                 break;
 811         }
 812
 813         case MEMSETBADBLOCK:
 814         {
 815                 loff_t offs;
 816
 817                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 818                         return -EFAULT;
 819                 if (!mtd->block_markbad)
 820                         ret = -EOPNOTSUPP;
 821                 else
 822                         return mtd->block_markbad(mtd, offs);
 823                 break;
 824         }
 825
 826 #ifdef CONFIG_HAVE_MTD_OTP
 827         case OTPSELECT:
 828         {
 829                 int mode;
 830                 if (copy_from_user(&mode, argp, sizeof(int)))
 831                         return -EFAULT;
 832
 833                 mfi->mode = MTD_MODE_NORMAL;
 834
 835                 ret = otp_select_filemode(mfi, mode);
 836
 837                 file->f_pos = 0;
 838                 break;
 839         }
 840
 841         case OTPGETREGIONCOUNT:
 842         case OTPGETREGIONINFO:
 843         {
 844                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 845                 if (!buf)
 846                         return -ENOMEM;
 847                 ret = -EOPNOTSUPP;
 848                 switch (mfi->mode) {
 849                 case MTD_MODE_OTP_FACTORY:
 850                         if (mtd->get_fact_prot_info)
 851                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 852                         break;
 853                 case MTD_MODE_OTP_USER:
 854                         if (mtd->get_user_prot_info)
 855                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 856                         break;
 857                 default:
 858                         break;
 859                 }
 860                 if (ret >= 0) {
 861                         if (cmd == OTPGETREGIONCOUNT) {
 862                                 int nbr = ret / sizeof(struct otp_info);
 863                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 864                         } else
 865                                 ret = copy_to_user(argp, buf, ret);
 866                         if (ret)
 867                                 ret = -EFAULT;
 868                 }
 869                 kfree(buf);
 870                 break;
 871         }
 872
 873         case OTPLOCK:
 874         {
 875                 struct otp_info oinfo;
 876
 877                 if (mfi->mode != MTD_MODE_OTP_USER)
 878                         return -EINVAL;
 879                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 880                         return -EFAULT;
 881                 if (!mtd->lock_user_prot_reg)
 882                         return -EOPNOTSUPP;
 883                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 884                 break;
 885         }
 886 #endif
 887
 888         /* This ioctl is being deprecated - it truncates the ecc layout */
 889         case ECCGETLAYOUT:
 890         {
 891                 struct nand_ecclayout_user *usrlay;
 892
 893                 if (!mtd->ecclayout)
 894                         return -EOPNOTSUPP;
 895
 896                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 897                 if (!usrlay)
 898                         return -ENOMEM;
 899
 900                 shrink_ecclayout(mtd->ecclayout, usrlay);
 901
 902                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 903                         ret = -EFAULT;
 904                 kfree(usrlay);
 905                 break;
 906         }
 907
 908         case ECCGETSTATS:
 909         {
 910                 if (copy_to_user(argp, &mtd->ecc_stats,
 911                                  sizeof(struct mtd_ecc_stats)))
 912                         return -EFAULT;
 913                 break;
 914         }
 915
 916         case MTDFILEMODE:
 917         {
 918                 mfi->mode = 0;
 919
 920                 switch(arg) {
 921                 case MTD_MODE_OTP_FACTORY:
 922                 case MTD_MODE_OTP_USER:
 923                         ret = otp_select_filemode(mfi, arg);
 924                         break;
 925
 926                 case MTD_MODE_RAW:
 927                         if (!mtd->read_oob || !mtd->write_oob)
 928                                 return -EOPNOTSUPP;
 929                         mfi->mode = arg;
 930
 931                 case MTD_MODE_NORMAL:
 932                         break;
 933                 default:
 934                         ret = -EINVAL;
 935                 }
 936                 file->f_pos = 0;
 937                 break;
 938         }
 939
 940 #ifdef CONFIG_MTD_PARTITIONS
 941         case BLKPG:
 942         {
 943                 ret = mtd_blkpg_ioctl(mtd,
 944                       (struct blkpg_ioctl_arg __user *)arg);
 945                 break;
 946         }
 947
 948         case BLKRRPART:
 949         {
 950                 /* No reread partition feature. Just return ok */
 951                 ret = 0;
 952                 break;
 953         }
 954 #endif
 955
 956         default:
 957                 ret = -ENOTTY;
 958         }
 959
 960         return ret;
 961 } /* memory_ioctl */
 962
 963 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 964 {
 965         int ret;
 966
 967         mutex_lock(&mtd_mutex);
 968         ret = mtd_ioctl(file, cmd, arg);
 969         mutex_unlock(&mtd_mutex);
 970
 971         return ret;
 972 }
 973
 974 #ifdef CONFIG_COMPAT
 975
 976 struct mtd_oob_buf32 {
 977         u_int32_t start;
 978         u_int32_t length;
 979         compat_caddr_t ptr;     /* unsigned char* */
 980 };
 981
 982 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 983 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 984
 985 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 986         unsigned long arg)
 987 {
 988         struct mtd_file_info *mfi = file->private_data;
 989         struct mtd_info *mtd = mfi->mtd;
 990         void __user *argp = compat_ptr(arg);
 991         int ret = 0;
 992
 993         mutex_lock(&mtd_mutex);
 994
 995         switch (cmd) {
 996         case MEMWRITEOOB32:
 997         {
 998                 struct mtd_oob_buf32 buf;
 999                 struct mtd_oob_buf32 __user *buf_user = argp;
1000
1001                 if (copy_from_user(&buf, argp, sizeof(buf)))
1002                         ret = -EFAULT;
1003                 else
1004                         ret = mtd_do_writeoob(file, mtd, buf.start,
1005                                 buf.length, compat_ptr(buf.ptr),
1006                                 &buf_user->length);
1007                 break;
1008         }
1009
1010         case MEMREADOOB32:
1011         {
1012                 struct mtd_oob_buf32 buf;
1013                 struct mtd_oob_buf32 __user *buf_user = argp;
1014
1015                 /* NOTE: writes return length to buf->start */
1016                 if (copy_from_user(&buf, argp, sizeof(buf)))
1017                         ret = -EFAULT;
1018                 else
1019                         ret = mtd_do_readoob(mtd, buf.start,
1020                                 buf.length, compat_ptr(buf.ptr),
1021                                 &buf_user->start);
1022                 break;
1023         }
1024         default:
1025                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1026         }
1027
1028         mutex_unlock(&mtd_mutex);
1029
1030         return ret;
1031 }
1032
1033 #endif /* CONFIG_COMPAT */
1034
1035 /*
1036  * try to determine where a shared mapping can be made
1037  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1038  *   mappings)
1039  */
1040 #ifndef CONFIG_MMU
1041 static unsigned long mtd_get_unmapped_area(struct file *file,
1042                                            unsigned long addr,
1043                                            unsigned long len,
1044                                            unsigned long pgoff,
1045                                            unsigned long flags)
1046 {
1047         struct mtd_file_info *mfi = file->private_data;
1048         struct mtd_info *mtd = mfi->mtd;
1049
1050         if (mtd->get_unmapped_area) {
1051                 unsigned long offset;
1052
1053                 if (addr != 0)
1054                         return (unsigned long) -EINVAL;
1055
1056                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1057                         return (unsigned long) -EINVAL;
1058
1059                 offset = pgoff << PAGE_SHIFT;
1060                 if (offset > mtd->size - len)
1061                         return (unsigned long) -EINVAL;
1062
1063                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1064         }
1065
1066         /* can't map directly */
1067         return (unsigned long) -ENOSYS;
1068 }
1069 #endif
1070
1071 /*
1072  * set up a mapping for shared memory segments
1073  */
1074 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1075 {
1076 #ifdef CONFIG_MMU
1077         struct mtd_file_info *mfi = file->private_data;
1078         struct mtd_info *mtd = mfi->mtd;
1079         struct map_info *map = mtd->priv;
1080         unsigned long start;
1081         unsigned long off;
1082         u32 len;
1083
1084         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1085                 off = vma->vm_pgoff << PAGE_SHIFT;
1086                 start = map->phys;
1087                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1088                 start &= PAGE_MASK;
1089                 if ((vma->vm_end - vma->vm_start + off) > len)
1090                         return -EINVAL;
1091
1092                 off += start;
1093                 vma->vm_pgoff = off >> PAGE_SHIFT;
1094                 vma->vm_flags |= VM_IO | VM_RESERVED;
1095
1096 #ifdef pgprot_noncached
1097                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1098                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1099 #endif
1100                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1101                                        vma->vm_end - vma->vm_start,
1102                                        vma->vm_page_prot))
1103                         return -EAGAIN;
1104
1105                 return 0;
1106         }
1107         return -ENOSYS;
1108 #else
1109         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1110 #endif
1111 }
1112
1113 static const struct file_operations mtd_fops = {
1114         .owner          = THIS_MODULE,
1115         .llseek         = mtd_lseek,
1116         .read           = mtd_read,
1117         .write          = mtd_write,
1118         .unlocked_ioctl = mtd_unlocked_ioctl,
1119 #ifdef CONFIG_COMPAT
1120         .compat_ioctl   = mtd_compat_ioctl,
1121 #endif
1122         .open           = mtd_open,
1123         .release        = mtd_close,
1124         .mmap           = mtd_mmap,
1125 #ifndef CONFIG_MMU
1126         .get_unmapped_area = mtd_get_unmapped_area,
1127 #endif
1128 };
1129
1130 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1131                                 int flags, const char *dev_name, void *data)
1132 {
1133         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1134 }
1135
1136 static struct file_system_type mtd_inodefs_type = {
1137        .name = "mtd_inodefs",
1138        .mount = mtd_inodefs_mount,
1139        .kill_sb = kill_anon_super,
1140 };
1141
1142 static void mtdchar_notify_add(struct mtd_info *mtd)
1143 {
1144 }
1145
1146 static void mtdchar_notify_remove(struct mtd_info *mtd)
1147 {
1148         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1149
1150         if (mtd_ino) {
1151                 /* Destroy the inode if it exists */
1152                 mtd_ino->i_nlink = 0;
1153                 iput(mtd_ino);
1154         }
1155 }
1156
1157 static struct mtd_notifier mtdchar_notifier = {
1158         .add = mtdchar_notify_add,
1159         .remove = mtdchar_notify_remove,
1160 };
1161
1162 static int __init init_mtdchar(void)
1163 {
1164         int ret;
1165
1166         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1167                                    "mtd", &mtd_fops);
1168         if (ret < 0) {
1169                 pr_notice("Can't allocate major number %d for "
1170                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1171                 return ret;
1172         }
1173
1174         ret = register_filesystem(&mtd_inodefs_type);
1175         if (ret) {
1176                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1177                 goto err_unregister_chdev;
1178         }
1179
1180         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1181         if (IS_ERR(mtd_inode_mnt)) {
1182                 ret = PTR_ERR(mtd_inode_mnt);
1183                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1184                 goto err_unregister_filesystem;
1185         }
1186         register_mtd_user(&mtdchar_notifier);
1187
1188         return ret;
1189
1190 err_unregister_filesystem:
1191         unregister_filesystem(&mtd_inodefs_type);
1192 err_unregister_chdev:
1193         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1194         return ret;
1195 }
1196
1197 static void __exit cleanup_mtdchar(void)
1198 {
1199         unregister_mtd_user(&mtdchar_notifier);
1200         mntput(mtd_inode_mnt);
1201         unregister_filesystem(&mtd_inodefs_type);
1202         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1203 }
1204
1205 module_init(init_mtdchar);
1206 module_exit(cleanup_mtdchar);
1207
1208 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1209
1210 MODULE_LICENSE("GPL");
1211 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1212 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1213 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);