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