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 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 170    userspace buffer down and use it directly with readv/writev.
 171 */
 172 #define MAX_KMALLOC_SIZE 0x20000
 173
 174 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 175 {
 176         struct mtd_file_info *mfi = file->private_data;
 177         struct mtd_info *mtd = mfi->mtd;
 178         size_t retlen=0;
 179         size_t total_retlen=0;
 180         int ret=0;
 181         int len;
 182         char *kbuf;
 183
 184         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 185
 186         if (*ppos + count > mtd->size)
 187                 count = mtd->size - *ppos;
 188
 189         if (!count)
 190                 return 0;
 191
 192         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 193            and pass them directly to the MTD functions */
 194
 195         if (count > MAX_KMALLOC_SIZE)
 196                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 197         else
 198                 kbuf=kmalloc(count, GFP_KERNEL);
 199
 200         if (!kbuf)
 201                 return -ENOMEM;
 202
 203         while (count) {
 204
 205                 if (count > MAX_KMALLOC_SIZE)
 206                         len = MAX_KMALLOC_SIZE;
 207                 else
 208                         len = count;
 209
 210                 switch (mfi->mode) {
 211                 case MTD_MODE_OTP_FACTORY:
 212                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 213                         break;
 214                 case MTD_MODE_OTP_USER:
 215                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 216                         break;
 217                 case MTD_MODE_RAW:
 218                 {
 219                         struct mtd_oob_ops ops;
 220
 221                         ops.mode = MTD_OOB_RAW;
 222                         ops.datbuf = kbuf;
 223                         ops.oobbuf = NULL;
 224                         ops.len = len;
 225
 226                         ret = mtd->read_oob(mtd, *ppos, &ops);
 227                         retlen = ops.retlen;
 228                         break;
 229                 }
 230                 default:
 231                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 232                 }
 233                 /* Nand returns -EBADMSG on ecc errors, but it returns
 234                  * the data. For our userspace tools it is important
 235                  * to dump areas with ecc errors !
 236                  * For kernel internal usage it also might return -EUCLEAN
 237                  * to signal the caller that a bitflip has occured and has
 238                  * been corrected by the ECC algorithm.
 239                  * Userspace software which accesses NAND this way
 240                  * must be aware of the fact that it deals with NAND
 241                  */
 242                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 243                         *ppos += retlen;
 244                         if (copy_to_user(buf, kbuf, retlen)) {
 245                                 kfree(kbuf);
 246                                 return -EFAULT;
 247                         }
 248                         else
 249                                 total_retlen += retlen;
 250
 251                         count -= retlen;
 252                         buf += retlen;
 253                         if (retlen == 0)
 254                                 count = 0;
 255                 }
 256                 else {
 257                         kfree(kbuf);
 258                         return ret;
 259                 }
 260
 261         }
 262
 263         kfree(kbuf);
 264         return total_retlen;
 265 } /* mtd_read */
 266
 267 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 268 {
 269         struct mtd_file_info *mfi = file->private_data;
 270         struct mtd_info *mtd = mfi->mtd;
 271         char *kbuf;
 272         size_t retlen;
 273         size_t total_retlen=0;
 274         int ret=0;
 275         int len;
 276
 277         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 278
 279         if (*ppos == mtd->size)
 280                 return -ENOSPC;
 281
 282         if (*ppos + count > mtd->size)
 283                 count = mtd->size - *ppos;
 284
 285         if (!count)
 286                 return 0;
 287
 288         if (count > MAX_KMALLOC_SIZE)
 289                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 290         else
 291                 kbuf=kmalloc(count, GFP_KERNEL);
 292
 293         if (!kbuf)
 294                 return -ENOMEM;
 295
 296         while (count) {
 297
 298                 if (count > MAX_KMALLOC_SIZE)
 299                         len = MAX_KMALLOC_SIZE;
 300                 else
 301                         len = count;
 302
 303                 if (copy_from_user(kbuf, buf, len)) {
 304                         kfree(kbuf);
 305                         return -EFAULT;
 306                 }
 307
 308                 switch (mfi->mode) {
 309                 case MTD_MODE_OTP_FACTORY:
 310                         ret = -EROFS;
 311                         break;
 312                 case MTD_MODE_OTP_USER:
 313                         if (!mtd->write_user_prot_reg) {
 314                                 ret = -EOPNOTSUPP;
 315                                 break;
 316                         }
 317                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 318                         break;
 319
 320                 case MTD_MODE_RAW:
 321                 {
 322                         struct mtd_oob_ops ops;
 323
 324                         ops.mode = MTD_OOB_RAW;
 325                         ops.datbuf = kbuf;
 326                         ops.oobbuf = NULL;
 327                         ops.len = len;
 328
 329                         ret = mtd->write_oob(mtd, *ppos, &ops);
 330                         retlen = ops.retlen;
 331                         break;
 332                 }
 333
 334                 default:
 335                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 336                 }
 337                 if (!ret) {
 338                         *ppos += retlen;
 339                         total_retlen += retlen;
 340                         count -= retlen;
 341                         buf += retlen;
 342                 }
 343                 else {
 344                         kfree(kbuf);
 345                         return ret;
 346                 }
 347         }
 348
 349         kfree(kbuf);
 350         return total_retlen;
 351 } /* mtd_write */
 352
 353 /*======================================================================
 354
 355     IOCTL calls for getting device parameters.
 356
 357 ======================================================================*/
 358 static void mtdchar_erase_callback (struct erase_info *instr)
 359 {
 360         wake_up((wait_queue_head_t *)instr->priv);
 361 }
 362
 363 #ifdef CONFIG_HAVE_MTD_OTP
 364 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 365 {
 366         struct mtd_info *mtd = mfi->mtd;
 367         int ret = 0;
 368
 369         switch (mode) {
 370         case MTD_OTP_FACTORY:
 371                 if (!mtd->read_fact_prot_reg)
 372                         ret = -EOPNOTSUPP;
 373                 else
 374                         mfi->mode = MTD_MODE_OTP_FACTORY;
 375                 break;
 376         case MTD_OTP_USER:
 377                 if (!mtd->read_fact_prot_reg)
 378                         ret = -EOPNOTSUPP;
 379                 else
 380                         mfi->mode = MTD_MODE_OTP_USER;
 381                 break;
 382         default:
 383                 ret = -EINVAL;
 384         case MTD_OTP_OFF:
 385                 break;
 386         }
 387         return ret;
 388 }
 389 #else
 390 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 391 #endif
 392
 393 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 394         uint64_t start, uint32_t length, void __user *ptr,
 395         uint32_t __user *retp)
 396 {
 397         struct mtd_oob_ops ops;
 398         uint32_t retlen;
 399         int ret = 0;
 400
 401         if (!(file->f_mode & FMODE_WRITE))
 402                 return -EPERM;
 403
 404         if (length > 4096)
 405                 return -EINVAL;
 406
 407         if (!mtd->write_oob)
 408                 ret = -EOPNOTSUPP;
 409         else
 410                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 411
 412         if (ret)
 413                 return ret;
 414
 415         ops.ooblen = length;
 416         ops.ooboffs = start & (mtd->oobsize - 1);
 417         ops.datbuf = NULL;
 418         ops.mode = MTD_OOB_PLACE;
 419
 420         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 421                 return -EINVAL;
 422
 423         ops.oobbuf = memdup_user(ptr, length);
 424         if (IS_ERR(ops.oobbuf))
 425                 return PTR_ERR(ops.oobbuf);
 426
 427         start &= ~((uint64_t)mtd->oobsize - 1);
 428         ret = mtd->write_oob(mtd, start, &ops);
 429
 430         if (ops.oobretlen > 0xFFFFFFFFU)
 431                 ret = -EOVERFLOW;
 432         retlen = ops.oobretlen;
 433         if (copy_to_user(retp, &retlen, sizeof(length)))
 434                 ret = -EFAULT;
 435
 436         kfree(ops.oobbuf);
 437         return ret;
 438 }
 439
 440 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 441         uint32_t length, void __user *ptr, uint32_t __user *retp)
 442 {
 443         struct mtd_oob_ops ops;
 444         int ret = 0;
 445
 446         if (length > 4096)
 447                 return -EINVAL;
 448
 449         if (!mtd->read_oob)
 450                 ret = -EOPNOTSUPP;
 451         else
 452                 ret = access_ok(VERIFY_WRITE, ptr,
 453                                 length) ? 0 : -EFAULT;
 454         if (ret)
 455                 return ret;
 456
 457         ops.ooblen = length;
 458         ops.ooboffs = start & (mtd->oobsize - 1);
 459         ops.datbuf = NULL;
 460         ops.mode = MTD_OOB_PLACE;
 461
 462         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 463                 return -EINVAL;
 464
 465         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 466         if (!ops.oobbuf)
 467                 return -ENOMEM;
 468
 469         start &= ~((uint64_t)mtd->oobsize - 1);
 470         ret = mtd->read_oob(mtd, start, &ops);
 471
 472         if (put_user(ops.oobretlen, retp))
 473                 ret = -EFAULT;
 474         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 475                                             ops.oobretlen))
 476                 ret = -EFAULT;
 477
 478         kfree(ops.oobbuf);
 479         return ret;
 480 }
 481
 482 /*
 483  * Copies (and truncates, if necessary) data from the larger struct,
 484  * nand_ecclayout, to the smaller, deprecated layout struct,
 485  * nand_ecclayout_user. This is necessary only to suppport the deprecated
 486  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 487  * nand_ecclayout flexibly (i.e. the struct may change size in new
 488  * releases without requiring major rewrites).
 489  */
 490 static int shrink_ecclayout(const struct nand_ecclayout *from,
 491                 struct nand_ecclayout_user *to)
 492 {
 493         int i;
 494
 495         if (!from || !to)
 496                 return -EINVAL;
 497
 498         memset(to, 0, sizeof(*to));
 499
 500         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 501         for (i = 0; i < to->eccbytes; i++)
 502                 to->eccpos[i] = from->eccpos[i];
 503
 504         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 505                 if (from->oobfree[i].length == 0 &&
 506                                 from->oobfree[i].offset == 0)
 507                         break;
 508                 to->oobavail += from->oobfree[i].length;
 509                 to->oobfree[i] = from->oobfree[i];
 510         }
 511
 512         return 0;
 513 }
 514
 515 #ifdef CONFIG_MTD_PARTITIONS
 516 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
 517                            struct blkpg_ioctl_arg __user *arg)
 518 {
 519         struct blkpg_ioctl_arg a;
 520         struct blkpg_partition p;
 521
 522         if (!capable(CAP_SYS_ADMIN))
 523                 return -EPERM;
 524
 525         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 526                 return -EFAULT;
 527
 528         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 529                 return -EFAULT;
 530
 531         switch (a.op) {
 532         case BLKPG_ADD_PARTITION:
 533
 534                 /* Only master mtd device must be used to add partitions */
 535                 if (mtd_is_partition(mtd))
 536                         return -EINVAL;
 537
 538                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 539
 540         case BLKPG_DEL_PARTITION:
 541
 542                 if (p.pno < 0)
 543                         return -EINVAL;
 544
 545                 return mtd_del_partition(mtd, p.pno);
 546
 547         default:
 548                 return -EINVAL;
 549         }
 550 }
 551 #endif
 552
 553
 554 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 555 {
 556         struct mtd_file_info *mfi = file->private_data;
 557         struct mtd_info *mtd = mfi->mtd;
 558         void __user *argp = (void __user *)arg;
 559         int ret = 0;
 560         u_long size;
 561         struct mtd_info_user info;
 562
 563         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 564
 565         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 566         if (cmd & IOC_IN) {
 567                 if (!access_ok(VERIFY_READ, argp, size))
 568                         return -EFAULT;
 569         }
 570         if (cmd & IOC_OUT) {
 571                 if (!access_ok(VERIFY_WRITE, argp, size))
 572                         return -EFAULT;
 573         }
 574
 575         switch (cmd) {
 576         case MEMGETREGIONCOUNT:
 577                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 578                         return -EFAULT;
 579                 break;
 580
 581         case MEMGETREGIONINFO:
 582         {
 583                 uint32_t ur_idx;
 584                 struct mtd_erase_region_info *kr;
 585                 struct region_info_user __user *ur = argp;
 586
 587                 if (get_user(ur_idx, &(ur->regionindex)))
 588                         return -EFAULT;
 589
 590                 if (ur_idx >= mtd->numeraseregions)
 591                         return -EINVAL;
 592
 593                 kr = &(mtd->eraseregions[ur_idx]);
 594
 595                 if (put_user(kr->offset, &(ur->offset))
 596                     || put_user(kr->erasesize, &(ur->erasesize))
 597                     || put_user(kr->numblocks, &(ur->numblocks)))
 598                         return -EFAULT;
 599
 600                 break;
 601         }
 602
 603         case MEMGETINFO:
 604                 memset(&info, 0, sizeof(info));
 605                 info.type       = mtd->type;
 606                 info.flags      = mtd->flags;
 607                 info.size       = mtd->size;
 608                 info.erasesize  = mtd->erasesize;
 609                 info.writesize  = mtd->writesize;
 610                 info.oobsize    = mtd->oobsize;
 611                 /* The below fields are obsolete */
 612                 info.ecctype    = -1;
 613                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 614                         return -EFAULT;
 615                 break;
 616
 617         case MEMERASE:
 618         case MEMERASE64:
 619         {
 620                 struct erase_info *erase;
 621
 622                 if(!(file->f_mode & FMODE_WRITE))
 623                         return -EPERM;
 624
 625                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 626                 if (!erase)
 627                         ret = -ENOMEM;
 628                 else {
 629                         wait_queue_head_t waitq;
 630                         DECLARE_WAITQUEUE(wait, current);
 631
 632                         init_waitqueue_head(&waitq);
 633
 634                         if (cmd == MEMERASE64) {
 635                                 struct erase_info_user64 einfo64;
 636
 637                                 if (copy_from_user(&einfo64, argp,
 638                                             sizeof(struct erase_info_user64))) {
 639                                         kfree(erase);
 640                                         return -EFAULT;
 641                                 }
 642                                 erase->addr = einfo64.start;
 643                                 erase->len = einfo64.length;
 644                         } else {
 645                                 struct erase_info_user einfo32;
 646
 647                                 if (copy_from_user(&einfo32, argp,
 648                                             sizeof(struct erase_info_user))) {
 649                                         kfree(erase);
 650                                         return -EFAULT;
 651                                 }
 652                                 erase->addr = einfo32.start;
 653                                 erase->len = einfo32.length;
 654                         }
 655                         erase->mtd = mtd;
 656                         erase->callback = mtdchar_erase_callback;
 657                         erase->priv = (unsigned long)&waitq;
 658
 659                         /*
 660                           FIXME: Allow INTERRUPTIBLE. Which means
 661                           not having the wait_queue head on the stack.
 662
 663                           If the wq_head is on the stack, and we
 664                           leave because we got interrupted, then the
 665                           wq_head is no longer there when the
 666                           callback routine tries to wake us up.
 667                         */
 668                         ret = mtd->erase(mtd, erase);
 669                         if (!ret) {
 670                                 set_current_state(TASK_UNINTERRUPTIBLE);
 671                                 add_wait_queue(&waitq, &wait);
 672                                 if (erase->state != MTD_ERASE_DONE &&
 673                                     erase->state != MTD_ERASE_FAILED)
 674                                         schedule();
 675                                 remove_wait_queue(&waitq, &wait);
 676                                 set_current_state(TASK_RUNNING);
 677
 678                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 679                         }
 680                         kfree(erase);
 681                 }
 682                 break;
 683         }
 684
 685         case MEMWRITEOOB:
 686         {
 687                 struct mtd_oob_buf buf;
 688                 struct mtd_oob_buf __user *buf_user = argp;
 689
 690                 /* NOTE: writes return length to buf_user->length */
 691                 if (copy_from_user(&buf, argp, sizeof(buf)))
 692                         ret = -EFAULT;
 693                 else
 694                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 695                                 buf.ptr, &buf_user->length);
 696                 break;
 697         }
 698
 699         case MEMREADOOB:
 700         {
 701                 struct mtd_oob_buf buf;
 702                 struct mtd_oob_buf __user *buf_user = argp;
 703
 704                 /* NOTE: writes return length to buf_user->start */
 705                 if (copy_from_user(&buf, argp, sizeof(buf)))
 706                         ret = -EFAULT;
 707                 else
 708                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 709                                 buf.ptr, &buf_user->start);
 710                 break;
 711         }
 712
 713         case MEMWRITEOOB64:
 714         {
 715                 struct mtd_oob_buf64 buf;
 716                 struct mtd_oob_buf64 __user *buf_user = argp;
 717
 718                 if (copy_from_user(&buf, argp, sizeof(buf)))
 719                         ret = -EFAULT;
 720                 else
 721                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 722                                 (void __user *)(uintptr_t)buf.usr_ptr,
 723                                 &buf_user->length);
 724                 break;
 725         }
 726
 727         case MEMREADOOB64:
 728         {
 729                 struct mtd_oob_buf64 buf;
 730                 struct mtd_oob_buf64 __user *buf_user = argp;
 731
 732                 if (copy_from_user(&buf, argp, sizeof(buf)))
 733                         ret = -EFAULT;
 734                 else
 735                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 736                                 (void __user *)(uintptr_t)buf.usr_ptr,
 737                                 &buf_user->length);
 738                 break;
 739         }
 740
 741         case MEMLOCK:
 742         {
 743                 struct erase_info_user einfo;
 744
 745                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 746                         return -EFAULT;
 747
 748                 if (!mtd->lock)
 749                         ret = -EOPNOTSUPP;
 750                 else
 751                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 752                 break;
 753         }
 754
 755         case MEMUNLOCK:
 756         {
 757                 struct erase_info_user einfo;
 758
 759                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 760                         return -EFAULT;
 761
 762                 if (!mtd->unlock)
 763                         ret = -EOPNOTSUPP;
 764                 else
 765                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 766                 break;
 767         }
 768
 769         case MEMISLOCKED:
 770         {
 771                 struct erase_info_user einfo;
 772
 773                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 774                         return -EFAULT;
 775
 776                 if (!mtd->is_locked)
 777                         ret = -EOPNOTSUPP;
 778                 else
 779                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 780                 break;
 781         }
 782
 783         /* Legacy interface */
 784         case MEMGETOOBSEL:
 785         {
 786                 struct nand_oobinfo oi;
 787
 788                 if (!mtd->ecclayout)
 789                         return -EOPNOTSUPP;
 790                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 791                         return -EINVAL;
 792
 793                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 794                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 795                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 796                        sizeof(oi.oobfree));
 797                 oi.eccbytes = mtd->ecclayout->eccbytes;
 798
 799                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 800                         return -EFAULT;
 801                 break;
 802         }
 803
 804         case MEMGETBADBLOCK:
 805         {
 806                 loff_t offs;
 807
 808                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 809                         return -EFAULT;
 810                 if (!mtd->block_isbad)
 811                         ret = -EOPNOTSUPP;
 812                 else
 813                         return mtd->block_isbad(mtd, offs);
 814                 break;
 815         }
 816
 817         case MEMSETBADBLOCK:
 818         {
 819                 loff_t offs;
 820
 821                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 822                         return -EFAULT;
 823                 if (!mtd->block_markbad)
 824                         ret = -EOPNOTSUPP;
 825                 else
 826                         return mtd->block_markbad(mtd, offs);
 827                 break;
 828         }
 829
 830 #ifdef CONFIG_HAVE_MTD_OTP
 831         case OTPSELECT:
 832         {
 833                 int mode;
 834                 if (copy_from_user(&mode, argp, sizeof(int)))
 835                         return -EFAULT;
 836
 837                 mfi->mode = MTD_MODE_NORMAL;
 838
 839                 ret = otp_select_filemode(mfi, mode);
 840
 841                 file->f_pos = 0;
 842                 break;
 843         }
 844
 845         case OTPGETREGIONCOUNT:
 846         case OTPGETREGIONINFO:
 847         {
 848                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 849                 if (!buf)
 850                         return -ENOMEM;
 851                 ret = -EOPNOTSUPP;
 852                 switch (mfi->mode) {
 853                 case MTD_MODE_OTP_FACTORY:
 854                         if (mtd->get_fact_prot_info)
 855                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 856                         break;
 857                 case MTD_MODE_OTP_USER:
 858                         if (mtd->get_user_prot_info)
 859                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 860                         break;
 861                 default:
 862                         break;
 863                 }
 864                 if (ret >= 0) {
 865                         if (cmd == OTPGETREGIONCOUNT) {
 866                                 int nbr = ret / sizeof(struct otp_info);
 867                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 868                         } else
 869                                 ret = copy_to_user(argp, buf, ret);
 870                         if (ret)
 871                                 ret = -EFAULT;
 872                 }
 873                 kfree(buf);
 874                 break;
 875         }
 876
 877         case OTPLOCK:
 878         {
 879                 struct otp_info oinfo;
 880
 881                 if (mfi->mode != MTD_MODE_OTP_USER)
 882                         return -EINVAL;
 883                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 884                         return -EFAULT;
 885                 if (!mtd->lock_user_prot_reg)
 886                         return -EOPNOTSUPP;
 887                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 888                 break;
 889         }
 890 #endif
 891
 892         /* This ioctl is being deprecated - it truncates the ecc layout */
 893         case ECCGETLAYOUT:
 894         {
 895                 struct nand_ecclayout_user *usrlay;
 896
 897                 if (!mtd->ecclayout)
 898                         return -EOPNOTSUPP;
 899
 900                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 901                 if (!usrlay)
 902                         return -ENOMEM;
 903
 904                 shrink_ecclayout(mtd->ecclayout, usrlay);
 905
 906                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 907                         ret = -EFAULT;
 908                 kfree(usrlay);
 909                 break;
 910         }
 911
 912         case ECCGETSTATS:
 913         {
 914                 if (copy_to_user(argp, &mtd->ecc_stats,
 915                                  sizeof(struct mtd_ecc_stats)))
 916                         return -EFAULT;
 917                 break;
 918         }
 919
 920         case MTDFILEMODE:
 921         {
 922                 mfi->mode = 0;
 923
 924                 switch(arg) {
 925                 case MTD_MODE_OTP_FACTORY:
 926                 case MTD_MODE_OTP_USER:
 927                         ret = otp_select_filemode(mfi, arg);
 928                         break;
 929
 930                 case MTD_MODE_RAW:
 931                         if (!mtd->read_oob || !mtd->write_oob)
 932                                 return -EOPNOTSUPP;
 933                         mfi->mode = arg;
 934
 935                 case MTD_MODE_NORMAL:
 936                         break;
 937                 default:
 938                         ret = -EINVAL;
 939                 }
 940                 file->f_pos = 0;
 941                 break;
 942         }
 943
 944 #ifdef CONFIG_MTD_PARTITIONS
 945         case BLKPG:
 946         {
 947                 ret = mtd_blkpg_ioctl(mtd,
 948                       (struct blkpg_ioctl_arg __user *)arg);
 949                 break;
 950         }
 951
 952         case BLKRRPART:
 953         {
 954                 /* No reread partition feature. Just return ok */
 955                 ret = 0;
 956                 break;
 957         }
 958 #endif
 959
 960         default:
 961                 ret = -ENOTTY;
 962         }
 963
 964         return ret;
 965 } /* memory_ioctl */
 966
 967 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 968 {
 969         int ret;
 970
 971         mutex_lock(&mtd_mutex);
 972         ret = mtd_ioctl(file, cmd, arg);
 973         mutex_unlock(&mtd_mutex);
 974
 975         return ret;
 976 }
 977
 978 #ifdef CONFIG_COMPAT
 979
 980 struct mtd_oob_buf32 {
 981         u_int32_t start;
 982         u_int32_t length;
 983         compat_caddr_t ptr;     /* unsigned char* */
 984 };
 985
 986 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 987 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 988
 989 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 990         unsigned long arg)
 991 {
 992         struct mtd_file_info *mfi = file->private_data;
 993         struct mtd_info *mtd = mfi->mtd;
 994         void __user *argp = compat_ptr(arg);
 995         int ret = 0;
 996
 997         mutex_lock(&mtd_mutex);
 998
 999         switch (cmd) {
1000         case MEMWRITEOOB32:
1001         {
1002                 struct mtd_oob_buf32 buf;
1003                 struct mtd_oob_buf32 __user *buf_user = argp;
1004
1005                 if (copy_from_user(&buf, argp, sizeof(buf)))
1006                         ret = -EFAULT;
1007                 else
1008                         ret = mtd_do_writeoob(file, mtd, buf.start,
1009                                 buf.length, compat_ptr(buf.ptr),
1010                                 &buf_user->length);
1011                 break;
1012         }
1013
1014         case MEMREADOOB32:
1015         {
1016                 struct mtd_oob_buf32 buf;
1017                 struct mtd_oob_buf32 __user *buf_user = argp;
1018
1019                 /* NOTE: writes return length to buf->start */
1020                 if (copy_from_user(&buf, argp, sizeof(buf)))
1021                         ret = -EFAULT;
1022                 else
1023                         ret = mtd_do_readoob(mtd, buf.start,
1024                                 buf.length, compat_ptr(buf.ptr),
1025                                 &buf_user->start);
1026                 break;
1027         }
1028         default:
1029                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1030         }
1031
1032         mutex_unlock(&mtd_mutex);
1033
1034         return ret;
1035 }
1036
1037 #endif /* CONFIG_COMPAT */
1038
1039 /*
1040  * try to determine where a shared mapping can be made
1041  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1042  *   mappings)
1043  */
1044 #ifndef CONFIG_MMU
1045 static unsigned long mtd_get_unmapped_area(struct file *file,
1046                                            unsigned long addr,
1047                                            unsigned long len,
1048                                            unsigned long pgoff,
1049                                            unsigned long flags)
1050 {
1051         struct mtd_file_info *mfi = file->private_data;
1052         struct mtd_info *mtd = mfi->mtd;
1053
1054         if (mtd->get_unmapped_area) {
1055                 unsigned long offset;
1056
1057                 if (addr != 0)
1058                         return (unsigned long) -EINVAL;
1059
1060                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1061                         return (unsigned long) -EINVAL;
1062
1063                 offset = pgoff << PAGE_SHIFT;
1064                 if (offset > mtd->size - len)
1065                         return (unsigned long) -EINVAL;
1066
1067                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1068         }
1069
1070         /* can't map directly */
1071         return (unsigned long) -ENOSYS;
1072 }
1073 #endif
1074
1075 /*
1076  * set up a mapping for shared memory segments
1077  */
1078 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1079 {
1080 #ifdef CONFIG_MMU
1081         struct mtd_file_info *mfi = file->private_data;
1082         struct mtd_info *mtd = mfi->mtd;
1083         struct map_info *map = mtd->priv;
1084         unsigned long start;
1085         unsigned long off;
1086         u32 len;
1087
1088         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1089                 off = vma->vm_pgoff << PAGE_SHIFT;
1090                 start = map->phys;
1091                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1092                 start &= PAGE_MASK;
1093                 if ((vma->vm_end - vma->vm_start + off) > len)
1094                         return -EINVAL;
1095
1096                 off += start;
1097                 vma->vm_pgoff = off >> PAGE_SHIFT;
1098                 vma->vm_flags |= VM_IO | VM_RESERVED;
1099
1100 #ifdef pgprot_noncached
1101                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1102                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1103 #endif
1104                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1105                                        vma->vm_end - vma->vm_start,
1106                                        vma->vm_page_prot))
1107                         return -EAGAIN;
1108
1109                 return 0;
1110         }
1111         return -ENOSYS;
1112 #else
1113         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1114 #endif
1115 }
1116
1117 static const struct file_operations mtd_fops = {
1118         .owner          = THIS_MODULE,
1119         .llseek         = mtd_lseek,
1120         .read           = mtd_read,
1121         .write          = mtd_write,
1122         .unlocked_ioctl = mtd_unlocked_ioctl,
1123 #ifdef CONFIG_COMPAT
1124         .compat_ioctl   = mtd_compat_ioctl,
1125 #endif
1126         .open           = mtd_open,
1127         .release        = mtd_close,
1128         .mmap           = mtd_mmap,
1129 #ifndef CONFIG_MMU
1130         .get_unmapped_area = mtd_get_unmapped_area,
1131 #endif
1132 };
1133
1134 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1135                                 int flags, const char *dev_name, void *data)
1136 {
1137         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1138 }
1139
1140 static struct file_system_type mtd_inodefs_type = {
1141        .name = "mtd_inodefs",
1142        .mount = mtd_inodefs_mount,
1143        .kill_sb = kill_anon_super,
1144 };
1145
1146 static void mtdchar_notify_add(struct mtd_info *mtd)
1147 {
1148 }
1149
1150 static void mtdchar_notify_remove(struct mtd_info *mtd)
1151 {
1152         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1153
1154         if (mtd_ino) {
1155                 /* Destroy the inode if it exists */
1156                 mtd_ino->i_nlink = 0;
1157                 iput(mtd_ino);
1158         }
1159 }
1160
1161 static struct mtd_notifier mtdchar_notifier = {
1162         .add = mtdchar_notify_add,
1163         .remove = mtdchar_notify_remove,
1164 };
1165
1166 static int __init init_mtdchar(void)
1167 {
1168         int ret;
1169
1170         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1171                                    "mtd", &mtd_fops);
1172         if (ret < 0) {
1173                 pr_notice("Can't allocate major number %d for "
1174                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1175                 return ret;
1176         }
1177
1178         ret = register_filesystem(&mtd_inodefs_type);
1179         if (ret) {
1180                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1181                 goto err_unregister_chdev;
1182         }
1183
1184         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1185         if (IS_ERR(mtd_inode_mnt)) {
1186                 ret = PTR_ERR(mtd_inode_mnt);
1187                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1188                 goto err_unregister_filesystem;
1189         }
1190         register_mtd_user(&mtdchar_notifier);
1191
1192         return ret;
1193
1194 err_unregister_filesystem:
1195         unregister_filesystem(&mtd_inodefs_type);
1196 err_unregister_chdev:
1197         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1198         return ret;
1199 }
1200
1201 static void __exit cleanup_mtdchar(void)
1202 {
1203         unregister_mtd_user(&mtdchar_notifier);
1204         mntput(mtd_inode_mnt);
1205         unregister_filesystem(&mtd_inodefs_type);
1206         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1207 }
1208
1209 module_init(init_mtdchar);
1210 module_exit(cleanup_mtdchar);
1211
1212 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1213
1214 MODULE_LICENSE("GPL");
1215 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1216 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1217 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);