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