drivers/mtd/mtdchar.c

   1 /*
   2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  *
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/err.h>
  24 #include <linux/init.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/sched.h>
  29 #include <linux/smp_lock.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/compat.h>
  32 #include <linux/mount.h>
  33
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/map.h>
  36
  37 #include <asm/uaccess.h>
  38
  39 #define MTD_INODE_FS_MAGIC 0x11307854
  40 static struct vfsmount *mtd_inode_mnt __read_mostly;
  41
  42 /*
  43  * Data structure to hold the pointer to the mtd device as well
  44  * as mode information ofr various use cases.
  45  */
  46 struct mtd_file_info {
  47         struct mtd_info *mtd;
  48         struct inode *ino;
  49         enum mtd_file_modes mode;
  50 };
  51
  52 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  53 {
  54         struct mtd_file_info *mfi = file->private_data;
  55         struct mtd_info *mtd = mfi->mtd;
  56
  57         switch (orig) {
  58         case SEEK_SET:
  59                 break;
  60         case SEEK_CUR:
  61                 offset += file->f_pos;
  62                 break;
  63         case SEEK_END:
  64                 offset += mtd->size;
  65                 break;
  66         default:
  67                 return -EINVAL;
  68         }
  69
  70         if (offset >= 0 && offset <= mtd->size)
  71                 return file->f_pos = offset;
  72
  73         return -EINVAL;
  74 }
  75
  76
  77
  78 static int mtd_open(struct inode *inode, struct file *file)
  79 {
  80         int minor = iminor(inode);
  81         int devnum = minor >> 1;
  82         int ret = 0;
  83         struct mtd_info *mtd;
  84         struct mtd_file_info *mfi;
  85         struct inode *mtd_ino;
  86
  87         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  88
  89         /* You can't open the RO devices RW */
  90         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  91                 return -EACCES;
  92
  93         lock_kernel();
  94         mtd = get_mtd_device(NULL, devnum);
  95
  96         if (IS_ERR(mtd)) {
  97                 ret = PTR_ERR(mtd);
  98                 goto out;
  99         }
 100
 101         if (mtd->type == MTD_ABSENT) {
 102                 put_mtd_device(mtd);
 103                 ret = -ENODEV;
 104                 goto out;
 105         }
 106
 107         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 108         if (!mtd_ino) {
 109                 put_mtd_device(mtd);
 110                 ret = -ENOMEM;
 111                 goto out;
 112         }
 113         if (mtd_ino->i_state & I_NEW) {
 114                 mtd_ino->i_private = mtd;
 115                 mtd_ino->i_mode = S_IFCHR;
 116                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 117                 unlock_new_inode(mtd_ino);
 118         }
 119         file->f_mapping = mtd_ino->i_mapping;
 120
 121         /* You can't open it RW if it's not a writeable device */
 122         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 123                 iput(mtd_ino);
 124                 put_mtd_device(mtd);
 125                 ret = -EACCES;
 126                 goto out;
 127         }
 128
 129         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 130         if (!mfi) {
 131                 iput(mtd_ino);
 132                 put_mtd_device(mtd);
 133                 ret = -ENOMEM;
 134                 goto out;
 135         }
 136         mfi->ino = mtd_ino;
 137         mfi->mtd = mtd;
 138         file->private_data = mfi;
 139
 140 out:
 141         unlock_kernel();
 142         return ret;
 143 } /* mtd_open */
 144
 145 /*====================================================================*/
 146
 147 static int mtd_close(struct inode *inode, struct file *file)
 148 {
 149         struct mtd_file_info *mfi = file->private_data;
 150         struct mtd_info *mtd = mfi->mtd;
 151
 152         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 153
 154         /* Only sync if opened RW */
 155         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 156                 mtd->sync(mtd);
 157
 158         iput(mfi->ino);
 159
 160         put_mtd_device(mtd);
 161         file->private_data = NULL;
 162         kfree(mfi);
 163
 164         return 0;
 165 } /* mtd_close */
 166
 167 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 168    userspace buffer down and use it directly with readv/writev.
 169 */
 170 #define MAX_KMALLOC_SIZE 0x20000
 171
 172 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 173 {
 174         struct mtd_file_info *mfi = file->private_data;
 175         struct mtd_info *mtd = mfi->mtd;
 176         size_t retlen=0;
 177         size_t total_retlen=0;
 178         int ret=0;
 179         int len;
 180         char *kbuf;
 181
 182         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 183
 184         if (*ppos + count > mtd->size)
 185                 count = mtd->size - *ppos;
 186
 187         if (!count)
 188                 return 0;
 189
 190         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 191            and pass them directly to the MTD functions */
 192
 193         if (count > MAX_KMALLOC_SIZE)
 194                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 195         else
 196                 kbuf=kmalloc(count, GFP_KERNEL);
 197
 198         if (!kbuf)
 199                 return -ENOMEM;
 200
 201         while (count) {
 202
 203                 if (count > MAX_KMALLOC_SIZE)
 204                         len = MAX_KMALLOC_SIZE;
 205                 else
 206                         len = count;
 207
 208                 switch (mfi->mode) {
 209                 case MTD_MODE_OTP_FACTORY:
 210                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 211                         break;
 212                 case MTD_MODE_OTP_USER:
 213                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 214                         break;
 215                 case MTD_MODE_RAW:
 216                 {
 217                         struct mtd_oob_ops ops;
 218
 219                         ops.mode = MTD_OOB_RAW;
 220                         ops.datbuf = kbuf;
 221                         ops.oobbuf = NULL;
 222                         ops.len = len;
 223
 224                         ret = mtd->read_oob(mtd, *ppos, &ops);
 225                         retlen = ops.retlen;
 226                         break;
 227                 }
 228                 default:
 229                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 230                 }
 231                 /* Nand returns -EBADMSG on ecc errors, but it returns
 232                  * the data. For our userspace tools it is important
 233                  * to dump areas with ecc errors !
 234                  * For kernel internal usage it also might return -EUCLEAN
 235                  * to signal the caller that a bitflip has occured and has
 236                  * been corrected by the ECC algorithm.
 237                  * Userspace software which accesses NAND this way
 238                  * must be aware of the fact that it deals with NAND
 239                  */
 240                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 241                         *ppos += retlen;
 242                         if (copy_to_user(buf, kbuf, retlen)) {
 243                                 kfree(kbuf);
 244                                 return -EFAULT;
 245                         }
 246                         else
 247                                 total_retlen += retlen;
 248
 249                         count -= retlen;
 250                         buf += retlen;
 251                         if (retlen == 0)
 252                                 count = 0;
 253                 }
 254                 else {
 255                         kfree(kbuf);
 256                         return ret;
 257                 }
 258
 259         }
 260
 261         kfree(kbuf);
 262         return total_retlen;
 263 } /* mtd_read */
 264
 265 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 266 {
 267         struct mtd_file_info *mfi = file->private_data;
 268         struct mtd_info *mtd = mfi->mtd;
 269         char *kbuf;
 270         size_t retlen;
 271         size_t total_retlen=0;
 272         int ret=0;
 273         int len;
 274
 275         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 276
 277         if (*ppos == mtd->size)
 278                 return -ENOSPC;
 279
 280         if (*ppos + count > mtd->size)
 281                 count = mtd->size - *ppos;
 282
 283         if (!count)
 284                 return 0;
 285
 286         if (count > MAX_KMALLOC_SIZE)
 287                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 288         else
 289                 kbuf=kmalloc(count, GFP_KERNEL);
 290
 291         if (!kbuf)
 292                 return -ENOMEM;
 293
 294         while (count) {
 295
 296                 if (count > MAX_KMALLOC_SIZE)
 297                         len = MAX_KMALLOC_SIZE;
 298                 else
 299                         len = count;
 300
 301                 if (copy_from_user(kbuf, buf, len)) {
 302                         kfree(kbuf);
 303                         return -EFAULT;
 304                 }
 305
 306                 switch (mfi->mode) {
 307                 case MTD_MODE_OTP_FACTORY:
 308                         ret = -EROFS;
 309                         break;
 310                 case MTD_MODE_OTP_USER:
 311                         if (!mtd->write_user_prot_reg) {
 312                                 ret = -EOPNOTSUPP;
 313                                 break;
 314                         }
 315                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 316                         break;
 317
 318                 case MTD_MODE_RAW:
 319                 {
 320                         struct mtd_oob_ops ops;
 321
 322                         ops.mode = MTD_OOB_RAW;
 323                         ops.datbuf = kbuf;
 324                         ops.oobbuf = NULL;
 325                         ops.len = len;
 326
 327                         ret = mtd->write_oob(mtd, *ppos, &ops);
 328                         retlen = ops.retlen;
 329                         break;
 330                 }
 331
 332                 default:
 333                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 334                 }
 335                 if (!ret) {
 336                         *ppos += retlen;
 337                         total_retlen += retlen;
 338                         count -= retlen;
 339                         buf += retlen;
 340                 }
 341                 else {
 342                         kfree(kbuf);
 343                         return ret;
 344                 }
 345         }
 346
 347         kfree(kbuf);
 348         return total_retlen;
 349 } /* mtd_write */
 350
 351 /*======================================================================
 352
 353     IOCTL calls for getting device parameters.
 354
 355 ======================================================================*/
 356 static void mtdchar_erase_callback (struct erase_info *instr)
 357 {
 358         wake_up((wait_queue_head_t *)instr->priv);
 359 }
 360
 361 #ifdef CONFIG_HAVE_MTD_OTP
 362 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 363 {
 364         struct mtd_info *mtd = mfi->mtd;
 365         int ret = 0;
 366
 367         switch (mode) {
 368         case MTD_OTP_FACTORY:
 369                 if (!mtd->read_fact_prot_reg)
 370                         ret = -EOPNOTSUPP;
 371                 else
 372                         mfi->mode = MTD_MODE_OTP_FACTORY;
 373                 break;
 374         case MTD_OTP_USER:
 375                 if (!mtd->read_fact_prot_reg)
 376                         ret = -EOPNOTSUPP;
 377                 else
 378                         mfi->mode = MTD_MODE_OTP_USER;
 379                 break;
 380         default:
 381                 ret = -EINVAL;
 382         case MTD_OTP_OFF:
 383                 break;
 384         }
 385         return ret;
 386 }
 387 #else
 388 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 389 #endif
 390
 391 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 392         uint64_t start, uint32_t length, void __user *ptr,
 393         uint32_t __user *retp)
 394 {
 395         struct mtd_oob_ops ops;
 396         uint32_t retlen;
 397         int ret = 0;
 398
 399         if (!(file->f_mode & FMODE_WRITE))
 400                 return -EPERM;
 401
 402         if (length > 4096)
 403                 return -EINVAL;
 404
 405         if (!mtd->write_oob)
 406                 ret = -EOPNOTSUPP;
 407         else
 408                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 409
 410         if (ret)
 411                 return ret;
 412
 413         ops.ooblen = length;
 414         ops.ooboffs = start & (mtd->oobsize - 1);
 415         ops.datbuf = NULL;
 416         ops.mode = MTD_OOB_PLACE;
 417
 418         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 419                 return -EINVAL;
 420
 421         ops.oobbuf = memdup_user(ptr, length);
 422         if (IS_ERR(ops.oobbuf))
 423                 return PTR_ERR(ops.oobbuf);
 424
 425         start &= ~((uint64_t)mtd->oobsize - 1);
 426         ret = mtd->write_oob(mtd, start, &ops);
 427
 428         if (ops.oobretlen > 0xFFFFFFFFU)
 429                 ret = -EOVERFLOW;
 430         retlen = ops.oobretlen;
 431         if (copy_to_user(retp, &retlen, sizeof(length)))
 432                 ret = -EFAULT;
 433
 434         kfree(ops.oobbuf);
 435         return ret;
 436 }
 437
 438 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 439         uint32_t length, void __user *ptr, uint32_t __user *retp)
 440 {
 441         struct mtd_oob_ops ops;
 442         int ret = 0;
 443
 444         if (length > 4096)
 445                 return -EINVAL;
 446
 447         if (!mtd->read_oob)
 448                 ret = -EOPNOTSUPP;
 449         else
 450                 ret = access_ok(VERIFY_WRITE, ptr,
 451                                 length) ? 0 : -EFAULT;
 452         if (ret)
 453                 return ret;
 454
 455         ops.ooblen = length;
 456         ops.ooboffs = start & (mtd->oobsize - 1);
 457         ops.datbuf = NULL;
 458         ops.mode = MTD_OOB_PLACE;
 459
 460         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 461                 return -EINVAL;
 462
 463         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 464         if (!ops.oobbuf)
 465                 return -ENOMEM;
 466
 467         start &= ~((uint64_t)mtd->oobsize - 1);
 468         ret = mtd->read_oob(mtd, start, &ops);
 469
 470         if (put_user(ops.oobretlen, retp))
 471                 ret = -EFAULT;
 472         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 473                                             ops.oobretlen))
 474                 ret = -EFAULT;
 475
 476         kfree(ops.oobbuf);
 477         return ret;
 478 }
 479
 480 /*
 481  * Copies (and truncates, if necessary) data from the larger struct,
 482  * nand_ecclayout, to the smaller, deprecated layout struct,
 483  * nand_ecclayout_user. This is necessary only to suppport the deprecated
 484  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 485  * nand_ecclayout flexibly (i.e. the struct may change size in new
 486  * releases without requiring major rewrites).
 487  */
 488 static int shrink_ecclayout(const struct nand_ecclayout *from,
 489                 struct nand_ecclayout_user *to)
 490 {
 491         int i;
 492
 493         if (!from || !to)
 494                 return -EINVAL;
 495
 496         memset(to, 0, sizeof(*to));
 497
 498         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 499         for (i = 0; i < to->eccbytes; i++)
 500                 to->eccpos[i] = from->eccpos[i];
 501
 502         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 503                 if (from->oobfree[i].length == 0 &&
 504                                 from->oobfree[i].offset == 0)
 505                         break;
 506                 to->oobavail += from->oobfree[i].length;
 507                 to->oobfree[i] = from->oobfree[i];
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 514 {
 515         struct mtd_file_info *mfi = file->private_data;
 516         struct mtd_info *mtd = mfi->mtd;
 517         void __user *argp = (void __user *)arg;
 518         int ret = 0;
 519         u_long size;
 520         struct mtd_info_user info;
 521
 522         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 523
 524         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 525         if (cmd & IOC_IN) {
 526                 if (!access_ok(VERIFY_READ, argp, size))
 527                         return -EFAULT;
 528         }
 529         if (cmd & IOC_OUT) {
 530                 if (!access_ok(VERIFY_WRITE, argp, size))
 531                         return -EFAULT;
 532         }
 533
 534         switch (cmd) {
 535         case MEMGETREGIONCOUNT:
 536                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 537                         return -EFAULT;
 538                 break;
 539
 540         case MEMGETREGIONINFO:
 541         {
 542                 uint32_t ur_idx;
 543                 struct mtd_erase_region_info *kr;
 544                 struct region_info_user __user *ur = argp;
 545
 546                 if (get_user(ur_idx, &(ur->regionindex)))
 547                         return -EFAULT;
 548
 549                 if (ur_idx >= mtd->numeraseregions)
 550                         return -EINVAL;
 551
 552                 kr = &(mtd->eraseregions[ur_idx]);
 553
 554                 if (put_user(kr->offset, &(ur->offset))
 555                     || put_user(kr->erasesize, &(ur->erasesize))
 556                     || put_user(kr->numblocks, &(ur->numblocks)))
 557                         return -EFAULT;
 558
 559                 break;
 560         }
 561
 562         case MEMGETINFO:
 563                 info.type       = mtd->type;
 564                 info.flags      = mtd->flags;
 565                 info.size       = mtd->size;
 566                 info.erasesize  = mtd->erasesize;
 567                 info.writesize  = mtd->writesize;
 568                 info.oobsize    = mtd->oobsize;
 569                 /* The below fields are obsolete */
 570                 info.ecctype    = -1;
 571                 info.eccsize    = 0;
 572                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 573                         return -EFAULT;
 574                 break;
 575
 576         case MEMERASE:
 577         case MEMERASE64:
 578         {
 579                 struct erase_info *erase;
 580
 581                 if(!(file->f_mode & FMODE_WRITE))
 582                         return -EPERM;
 583
 584                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 585                 if (!erase)
 586                         ret = -ENOMEM;
 587                 else {
 588                         wait_queue_head_t waitq;
 589                         DECLARE_WAITQUEUE(wait, current);
 590
 591                         init_waitqueue_head(&waitq);
 592
 593                         if (cmd == MEMERASE64) {
 594                                 struct erase_info_user64 einfo64;
 595
 596                                 if (copy_from_user(&einfo64, argp,
 597                                             sizeof(struct erase_info_user64))) {
 598                                         kfree(erase);
 599                                         return -EFAULT;
 600                                 }
 601                                 erase->addr = einfo64.start;
 602                                 erase->len = einfo64.length;
 603                         } else {
 604                                 struct erase_info_user einfo32;
 605
 606                                 if (copy_from_user(&einfo32, argp,
 607                                             sizeof(struct erase_info_user))) {
 608                                         kfree(erase);
 609                                         return -EFAULT;
 610                                 }
 611                                 erase->addr = einfo32.start;
 612                                 erase->len = einfo32.length;
 613                         }
 614                         erase->mtd = mtd;
 615                         erase->callback = mtdchar_erase_callback;
 616                         erase->priv = (unsigned long)&waitq;
 617
 618                         /*
 619                           FIXME: Allow INTERRUPTIBLE. Which means
 620                           not having the wait_queue head on the stack.
 621
 622                           If the wq_head is on the stack, and we
 623                           leave because we got interrupted, then the
 624                           wq_head is no longer there when the
 625                           callback routine tries to wake us up.
 626                         */
 627                         ret = mtd->erase(mtd, erase);
 628                         if (!ret) {
 629                                 set_current_state(TASK_UNINTERRUPTIBLE);
 630                                 add_wait_queue(&waitq, &wait);
 631                                 if (erase->state != MTD_ERASE_DONE &&
 632                                     erase->state != MTD_ERASE_FAILED)
 633                                         schedule();
 634                                 remove_wait_queue(&waitq, &wait);
 635                                 set_current_state(TASK_RUNNING);
 636
 637                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 638                         }
 639                         kfree(erase);
 640                 }
 641                 break;
 642         }
 643
 644         case MEMWRITEOOB:
 645         {
 646                 struct mtd_oob_buf buf;
 647                 struct mtd_oob_buf __user *buf_user = argp;
 648
 649                 /* NOTE: writes return length to buf_user->length */
 650                 if (copy_from_user(&buf, argp, sizeof(buf)))
 651                         ret = -EFAULT;
 652                 else
 653                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 654                                 buf.ptr, &buf_user->length);
 655                 break;
 656         }
 657
 658         case MEMREADOOB:
 659         {
 660                 struct mtd_oob_buf buf;
 661                 struct mtd_oob_buf __user *buf_user = argp;
 662
 663                 /* NOTE: writes return length to buf_user->start */
 664                 if (copy_from_user(&buf, argp, sizeof(buf)))
 665                         ret = -EFAULT;
 666                 else
 667                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 668                                 buf.ptr, &buf_user->start);
 669                 break;
 670         }
 671
 672         case MEMWRITEOOB64:
 673         {
 674                 struct mtd_oob_buf64 buf;
 675                 struct mtd_oob_buf64 __user *buf_user = argp;
 676
 677                 if (copy_from_user(&buf, argp, sizeof(buf)))
 678                         ret = -EFAULT;
 679                 else
 680                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 681                                 (void __user *)(uintptr_t)buf.usr_ptr,
 682                                 &buf_user->length);
 683                 break;
 684         }
 685
 686         case MEMREADOOB64:
 687         {
 688                 struct mtd_oob_buf64 buf;
 689                 struct mtd_oob_buf64 __user *buf_user = argp;
 690
 691                 if (copy_from_user(&buf, argp, sizeof(buf)))
 692                         ret = -EFAULT;
 693                 else
 694                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 695                                 (void __user *)(uintptr_t)buf.usr_ptr,
 696                                 &buf_user->length);
 697                 break;
 698         }
 699
 700         case MEMLOCK:
 701         {
 702                 struct erase_info_user einfo;
 703
 704                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 705                         return -EFAULT;
 706
 707                 if (!mtd->lock)
 708                         ret = -EOPNOTSUPP;
 709                 else
 710                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 711                 break;
 712         }
 713
 714         case MEMUNLOCK:
 715         {
 716                 struct erase_info_user einfo;
 717
 718                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 719                         return -EFAULT;
 720
 721                 if (!mtd->unlock)
 722                         ret = -EOPNOTSUPP;
 723                 else
 724                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 725                 break;
 726         }
 727
 728         case MEMISLOCKED:
 729         {
 730                 struct erase_info_user einfo;
 731
 732                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 733                         return -EFAULT;
 734
 735                 if (!mtd->is_locked)
 736                         ret = -EOPNOTSUPP;
 737                 else
 738                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 739                 break;
 740         }
 741
 742         /* Legacy interface */
 743         case MEMGETOOBSEL:
 744         {
 745                 struct nand_oobinfo oi;
 746
 747                 if (!mtd->ecclayout)
 748                         return -EOPNOTSUPP;
 749                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 750                         return -EINVAL;
 751
 752                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 753                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 754                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 755                        sizeof(oi.oobfree));
 756                 oi.eccbytes = mtd->ecclayout->eccbytes;
 757
 758                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 759                         return -EFAULT;
 760                 break;
 761         }
 762
 763         case MEMGETBADBLOCK:
 764         {
 765                 loff_t offs;
 766
 767                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 768                         return -EFAULT;
 769                 if (!mtd->block_isbad)
 770                         ret = -EOPNOTSUPP;
 771                 else
 772                         return mtd->block_isbad(mtd, offs);
 773                 break;
 774         }
 775
 776         case MEMSETBADBLOCK:
 777         {
 778                 loff_t offs;
 779
 780                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 781                         return -EFAULT;
 782                 if (!mtd->block_markbad)
 783                         ret = -EOPNOTSUPP;
 784                 else
 785                         return mtd->block_markbad(mtd, offs);
 786                 break;
 787         }
 788
 789 #ifdef CONFIG_HAVE_MTD_OTP
 790         case OTPSELECT:
 791         {
 792                 int mode;
 793                 if (copy_from_user(&mode, argp, sizeof(int)))
 794                         return -EFAULT;
 795
 796                 mfi->mode = MTD_MODE_NORMAL;
 797
 798                 ret = otp_select_filemode(mfi, mode);
 799
 800                 file->f_pos = 0;
 801                 break;
 802         }
 803
 804         case OTPGETREGIONCOUNT:
 805         case OTPGETREGIONINFO:
 806         {
 807                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 808                 if (!buf)
 809                         return -ENOMEM;
 810                 ret = -EOPNOTSUPP;
 811                 switch (mfi->mode) {
 812                 case MTD_MODE_OTP_FACTORY:
 813                         if (mtd->get_fact_prot_info)
 814                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 815                         break;
 816                 case MTD_MODE_OTP_USER:
 817                         if (mtd->get_user_prot_info)
 818                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 819                         break;
 820                 default:
 821                         break;
 822                 }
 823                 if (ret >= 0) {
 824                         if (cmd == OTPGETREGIONCOUNT) {
 825                                 int nbr = ret / sizeof(struct otp_info);
 826                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 827                         } else
 828                                 ret = copy_to_user(argp, buf, ret);
 829                         if (ret)
 830                                 ret = -EFAULT;
 831                 }
 832                 kfree(buf);
 833                 break;
 834         }
 835
 836         case OTPLOCK:
 837         {
 838                 struct otp_info oinfo;
 839
 840                 if (mfi->mode != MTD_MODE_OTP_USER)
 841                         return -EINVAL;
 842                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 843                         return -EFAULT;
 844                 if (!mtd->lock_user_prot_reg)
 845                         return -EOPNOTSUPP;
 846                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 847                 break;
 848         }
 849 #endif
 850
 851         /* This ioctl is being deprecated - it truncates the ecc layout */
 852         case ECCGETLAYOUT:
 853         {
 854                 struct nand_ecclayout_user *usrlay;
 855
 856                 if (!mtd->ecclayout)
 857                         return -EOPNOTSUPP;
 858
 859                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 860                 if (!usrlay)
 861                         return -ENOMEM;
 862
 863                 shrink_ecclayout(mtd->ecclayout, usrlay);
 864
 865                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 866                         ret = -EFAULT;
 867                 kfree(usrlay);
 868                 break;
 869         }
 870
 871         case ECCGETSTATS:
 872         {
 873                 if (copy_to_user(argp, &mtd->ecc_stats,
 874                                  sizeof(struct mtd_ecc_stats)))
 875                         return -EFAULT;
 876                 break;
 877         }
 878
 879         case MTDFILEMODE:
 880         {
 881                 mfi->mode = 0;
 882
 883                 switch(arg) {
 884                 case MTD_MODE_OTP_FACTORY:
 885                 case MTD_MODE_OTP_USER:
 886                         ret = otp_select_filemode(mfi, arg);
 887                         break;
 888
 889                 case MTD_MODE_RAW:
 890                         if (!mtd->read_oob || !mtd->write_oob)
 891                                 return -EOPNOTSUPP;
 892                         mfi->mode = arg;
 893
 894                 case MTD_MODE_NORMAL:
 895                         break;
 896                 default:
 897                         ret = -EINVAL;
 898                 }
 899                 file->f_pos = 0;
 900                 break;
 901         }
 902
 903         default:
 904                 ret = -ENOTTY;
 905         }
 906
 907         return ret;
 908 } /* memory_ioctl */
 909
 910 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 911 {
 912         int ret;
 913
 914         lock_kernel();
 915         ret = mtd_ioctl(file, cmd, arg);
 916         unlock_kernel();
 917
 918         return ret;
 919 }
 920
 921 #ifdef CONFIG_COMPAT
 922
 923 struct mtd_oob_buf32 {
 924         u_int32_t start;
 925         u_int32_t length;
 926         compat_caddr_t ptr;     /* unsigned char* */
 927 };
 928
 929 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 930 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 931
 932 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 933         unsigned long arg)
 934 {
 935         struct mtd_file_info *mfi = file->private_data;
 936         struct mtd_info *mtd = mfi->mtd;
 937         void __user *argp = compat_ptr(arg);
 938         int ret = 0;
 939
 940         lock_kernel();
 941
 942         switch (cmd) {
 943         case MEMWRITEOOB32:
 944         {
 945                 struct mtd_oob_buf32 buf;
 946                 struct mtd_oob_buf32 __user *buf_user = argp;
 947
 948                 if (copy_from_user(&buf, argp, sizeof(buf)))
 949                         ret = -EFAULT;
 950                 else
 951                         ret = mtd_do_writeoob(file, mtd, buf.start,
 952                                 buf.length, compat_ptr(buf.ptr),
 953                                 &buf_user->length);
 954                 break;
 955         }
 956
 957         case MEMREADOOB32:
 958         {
 959                 struct mtd_oob_buf32 buf;
 960                 struct mtd_oob_buf32 __user *buf_user = argp;
 961
 962                 /* NOTE: writes return length to buf->start */
 963                 if (copy_from_user(&buf, argp, sizeof(buf)))
 964                         ret = -EFAULT;
 965                 else
 966                         ret = mtd_do_readoob(mtd, buf.start,
 967                                 buf.length, compat_ptr(buf.ptr),
 968                                 &buf_user->start);
 969                 break;
 970         }
 971         default:
 972                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
 973         }
 974
 975         unlock_kernel();
 976
 977         return ret;
 978 }
 979
 980 #endif /* CONFIG_COMPAT */
 981
 982 /*
 983  * try to determine where a shared mapping can be made
 984  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 985  *   mappings)
 986  */
 987 #ifndef CONFIG_MMU
 988 static unsigned long mtd_get_unmapped_area(struct file *file,
 989                                            unsigned long addr,
 990                                            unsigned long len,
 991                                            unsigned long pgoff,
 992                                            unsigned long flags)
 993 {
 994         struct mtd_file_info *mfi = file->private_data;
 995         struct mtd_info *mtd = mfi->mtd;
 996
 997         if (mtd->get_unmapped_area) {
 998                 unsigned long offset;
 999
1000                 if (addr != 0)
1001                         return (unsigned long) -EINVAL;
1002
1003                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1004                         return (unsigned long) -EINVAL;
1005
1006                 offset = pgoff << PAGE_SHIFT;
1007                 if (offset > mtd->size - len)
1008                         return (unsigned long) -EINVAL;
1009
1010                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1011         }
1012
1013         /* can't map directly */
1014         return (unsigned long) -ENOSYS;
1015 }
1016 #endif
1017
1018 /*
1019  * set up a mapping for shared memory segments
1020  */
1021 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1022 {
1023 #ifdef CONFIG_MMU
1024         struct mtd_file_info *mfi = file->private_data;
1025         struct mtd_info *mtd = mfi->mtd;
1026         struct map_info *map = mtd->priv;
1027         unsigned long start;
1028         unsigned long off;
1029         u32 len;
1030
1031         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1032                 off = vma->vm_pgoff << PAGE_SHIFT;
1033                 start = map->phys;
1034                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1035                 start &= PAGE_MASK;
1036                 if ((vma->vm_end - vma->vm_start + off) > len)
1037                         return -EINVAL;
1038
1039                 off += start;
1040                 vma->vm_pgoff = off >> PAGE_SHIFT;
1041                 vma->vm_flags |= VM_IO | VM_RESERVED;
1042
1043 #ifdef pgprot_noncached
1044                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1045                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1046 #endif
1047                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1048                                        vma->vm_end - vma->vm_start,
1049                                        vma->vm_page_prot))
1050                         return -EAGAIN;
1051
1052                 return 0;
1053         }
1054         return -ENOSYS;
1055 #else
1056         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1057 #endif
1058 }
1059
1060 static const struct file_operations mtd_fops = {
1061         .owner          = THIS_MODULE,
1062         .llseek         = mtd_lseek,
1063         .read           = mtd_read,
1064         .write          = mtd_write,
1065         .unlocked_ioctl = mtd_unlocked_ioctl,
1066 #ifdef CONFIG_COMPAT
1067         .compat_ioctl   = mtd_compat_ioctl,
1068 #endif
1069         .open           = mtd_open,
1070         .release        = mtd_close,
1071         .mmap           = mtd_mmap,
1072 #ifndef CONFIG_MMU
1073         .get_unmapped_area = mtd_get_unmapped_area,
1074 #endif
1075 };
1076
1077 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
1078                                const char *dev_name, void *data,
1079                                struct vfsmount *mnt)
1080 {
1081         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
1082                              mnt);
1083 }
1084
1085 static struct file_system_type mtd_inodefs_type = {
1086        .name = "mtd_inodefs",
1087        .get_sb = mtd_inodefs_get_sb,
1088        .kill_sb = kill_anon_super,
1089 };
1090
1091 static void mtdchar_notify_add(struct mtd_info *mtd)
1092 {
1093 }
1094
1095 static void mtdchar_notify_remove(struct mtd_info *mtd)
1096 {
1097         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1098
1099         if (mtd_ino) {
1100                 /* Destroy the inode if it exists */
1101                 mtd_ino->i_nlink = 0;
1102                 iput(mtd_ino);
1103         }
1104 }
1105
1106 static struct mtd_notifier mtdchar_notifier = {
1107         .add = mtdchar_notify_add,
1108         .remove = mtdchar_notify_remove,
1109 };
1110
1111 static int __init init_mtdchar(void)
1112 {
1113         int ret;
1114
1115         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1116                                    "mtd", &mtd_fops);
1117         if (ret < 0) {
1118                 pr_notice("Can't allocate major number %d for "
1119                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1120                 return ret;
1121         }
1122
1123         ret = register_filesystem(&mtd_inodefs_type);
1124         if (ret) {
1125                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1126                 goto err_unregister_chdev;
1127         }
1128
1129         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1130         if (IS_ERR(mtd_inode_mnt)) {
1131                 ret = PTR_ERR(mtd_inode_mnt);
1132                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1133                 goto err_unregister_filesystem;
1134         }
1135         register_mtd_user(&mtdchar_notifier);
1136
1137         return ret;
1138
1139 err_unregister_filesystem:
1140         unregister_filesystem(&mtd_inodefs_type);
1141 err_unregister_chdev:
1142         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1143         return ret;
1144 }
1145
1146 static void __exit cleanup_mtdchar(void)
1147 {
1148         unregister_mtd_user(&mtdchar_notifier);
1149         mntput(mtd_inode_mnt);
1150         unregister_filesystem(&mtd_inodefs_type);
1151         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1152 }
1153
1154 module_init(init_mtdchar);
1155 module_exit(cleanup_mtdchar);
1156
1157 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1158
1159 MODULE_LICENSE("GPL");
1160 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1161 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1162 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);