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 file *file, u_int cmd, u_long arg)
 481 {
 482         struct mtd_file_info *mfi = file->private_data;
 483         struct mtd_info *mtd = mfi->mtd;
 484         void __user *argp = (void __user *)arg;
 485         int ret = 0;
 486         u_long size;
 487         struct mtd_info_user info;
 488
 489         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 490
 491         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 492         if (cmd & IOC_IN) {
 493                 if (!access_ok(VERIFY_READ, argp, size))
 494                         return -EFAULT;
 495         }
 496         if (cmd & IOC_OUT) {
 497                 if (!access_ok(VERIFY_WRITE, argp, size))
 498                         return -EFAULT;
 499         }
 500
 501         switch (cmd) {
 502         case MEMGETREGIONCOUNT:
 503                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 504                         return -EFAULT;
 505                 break;
 506
 507         case MEMGETREGIONINFO:
 508         {
 509                 uint32_t ur_idx;
 510                 struct mtd_erase_region_info *kr;
 511                 struct region_info_user __user *ur = argp;
 512
 513                 if (get_user(ur_idx, &(ur->regionindex)))
 514                         return -EFAULT;
 515
 516                 kr = &(mtd->eraseregions[ur_idx]);
 517
 518                 if (put_user(kr->offset, &(ur->offset))
 519                     || put_user(kr->erasesize, &(ur->erasesize))
 520                     || put_user(kr->numblocks, &(ur->numblocks)))
 521                         return -EFAULT;
 522
 523                 break;
 524         }
 525
 526         case MEMGETINFO:
 527                 info.type       = mtd->type;
 528                 info.flags      = mtd->flags;
 529                 info.size       = mtd->size;
 530                 info.erasesize  = mtd->erasesize;
 531                 info.writesize  = mtd->writesize;
 532                 info.oobsize    = mtd->oobsize;
 533                 /* The below fields are obsolete */
 534                 info.ecctype    = -1;
 535                 info.eccsize    = 0;
 536                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 537                         return -EFAULT;
 538                 break;
 539
 540         case MEMERASE:
 541         case MEMERASE64:
 542         {
 543                 struct erase_info *erase;
 544
 545                 if(!(file->f_mode & FMODE_WRITE))
 546                         return -EPERM;
 547
 548                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 549                 if (!erase)
 550                         ret = -ENOMEM;
 551                 else {
 552                         wait_queue_head_t waitq;
 553                         DECLARE_WAITQUEUE(wait, current);
 554
 555                         init_waitqueue_head(&waitq);
 556
 557                         if (cmd == MEMERASE64) {
 558                                 struct erase_info_user64 einfo64;
 559
 560                                 if (copy_from_user(&einfo64, argp,
 561                                             sizeof(struct erase_info_user64))) {
 562                                         kfree(erase);
 563                                         return -EFAULT;
 564                                 }
 565                                 erase->addr = einfo64.start;
 566                                 erase->len = einfo64.length;
 567                         } else {
 568                                 struct erase_info_user einfo32;
 569
 570                                 if (copy_from_user(&einfo32, argp,
 571                                             sizeof(struct erase_info_user))) {
 572                                         kfree(erase);
 573                                         return -EFAULT;
 574                                 }
 575                                 erase->addr = einfo32.start;
 576                                 erase->len = einfo32.length;
 577                         }
 578                         erase->mtd = mtd;
 579                         erase->callback = mtdchar_erase_callback;
 580                         erase->priv = (unsigned long)&waitq;
 581
 582                         /*
 583                           FIXME: Allow INTERRUPTIBLE. Which means
 584                           not having the wait_queue head on the stack.
 585
 586                           If the wq_head is on the stack, and we
 587                           leave because we got interrupted, then the
 588                           wq_head is no longer there when the
 589                           callback routine tries to wake us up.
 590                         */
 591                         ret = mtd->erase(mtd, erase);
 592                         if (!ret) {
 593                                 set_current_state(TASK_UNINTERRUPTIBLE);
 594                                 add_wait_queue(&waitq, &wait);
 595                                 if (erase->state != MTD_ERASE_DONE &&
 596                                     erase->state != MTD_ERASE_FAILED)
 597                                         schedule();
 598                                 remove_wait_queue(&waitq, &wait);
 599                                 set_current_state(TASK_RUNNING);
 600
 601                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 602                         }
 603                         kfree(erase);
 604                 }
 605                 break;
 606         }
 607
 608         case MEMWRITEOOB:
 609         {
 610                 struct mtd_oob_buf buf;
 611                 struct mtd_oob_buf __user *buf_user = argp;
 612
 613                 /* NOTE: writes return length to buf_user->length */
 614                 if (copy_from_user(&buf, argp, sizeof(buf)))
 615                         ret = -EFAULT;
 616                 else
 617                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 618                                 buf.ptr, &buf_user->length);
 619                 break;
 620         }
 621
 622         case MEMREADOOB:
 623         {
 624                 struct mtd_oob_buf buf;
 625                 struct mtd_oob_buf __user *buf_user = argp;
 626
 627                 /* NOTE: writes return length to buf_user->start */
 628                 if (copy_from_user(&buf, argp, sizeof(buf)))
 629                         ret = -EFAULT;
 630                 else
 631                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 632                                 buf.ptr, &buf_user->start);
 633                 break;
 634         }
 635
 636         case MEMWRITEOOB64:
 637         {
 638                 struct mtd_oob_buf64 buf;
 639                 struct mtd_oob_buf64 __user *buf_user = argp;
 640
 641                 if (copy_from_user(&buf, argp, sizeof(buf)))
 642                         ret = -EFAULT;
 643                 else
 644                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 645                                 (void __user *)(uintptr_t)buf.usr_ptr,
 646                                 &buf_user->length);
 647                 break;
 648         }
 649
 650         case MEMREADOOB64:
 651         {
 652                 struct mtd_oob_buf64 buf;
 653                 struct mtd_oob_buf64 __user *buf_user = argp;
 654
 655                 if (copy_from_user(&buf, argp, sizeof(buf)))
 656                         ret = -EFAULT;
 657                 else
 658                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 659                                 (void __user *)(uintptr_t)buf.usr_ptr,
 660                                 &buf_user->length);
 661                 break;
 662         }
 663
 664         case MEMLOCK:
 665         {
 666                 struct erase_info_user einfo;
 667
 668                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 669                         return -EFAULT;
 670
 671                 if (!mtd->lock)
 672                         ret = -EOPNOTSUPP;
 673                 else
 674                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 675                 break;
 676         }
 677
 678         case MEMUNLOCK:
 679         {
 680                 struct erase_info_user einfo;
 681
 682                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 683                         return -EFAULT;
 684
 685                 if (!mtd->unlock)
 686                         ret = -EOPNOTSUPP;
 687                 else
 688                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 689                 break;
 690         }
 691
 692         case MEMISLOCKED:
 693         {
 694                 struct erase_info_user einfo;
 695
 696                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 697                         return -EFAULT;
 698
 699                 if (!mtd->is_locked)
 700                         ret = -EOPNOTSUPP;
 701                 else
 702                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 703                 break;
 704         }
 705
 706         /* Legacy interface */
 707         case MEMGETOOBSEL:
 708         {
 709                 struct nand_oobinfo oi;
 710
 711                 if (!mtd->ecclayout)
 712                         return -EOPNOTSUPP;
 713                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 714                         return -EINVAL;
 715
 716                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 717                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 718                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 719                        sizeof(oi.oobfree));
 720                 oi.eccbytes = mtd->ecclayout->eccbytes;
 721
 722                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 723                         return -EFAULT;
 724                 break;
 725         }
 726
 727         case MEMGETBADBLOCK:
 728         {
 729                 loff_t offs;
 730
 731                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 732                         return -EFAULT;
 733                 if (!mtd->block_isbad)
 734                         ret = -EOPNOTSUPP;
 735                 else
 736                         return mtd->block_isbad(mtd, offs);
 737                 break;
 738         }
 739
 740         case MEMSETBADBLOCK:
 741         {
 742                 loff_t offs;
 743
 744                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 745                         return -EFAULT;
 746                 if (!mtd->block_markbad)
 747                         ret = -EOPNOTSUPP;
 748                 else
 749                         return mtd->block_markbad(mtd, offs);
 750                 break;
 751         }
 752
 753 #ifdef CONFIG_HAVE_MTD_OTP
 754         case OTPSELECT:
 755         {
 756                 int mode;
 757                 if (copy_from_user(&mode, argp, sizeof(int)))
 758                         return -EFAULT;
 759
 760                 mfi->mode = MTD_MODE_NORMAL;
 761
 762                 ret = otp_select_filemode(mfi, mode);
 763
 764                 file->f_pos = 0;
 765                 break;
 766         }
 767
 768         case OTPGETREGIONCOUNT:
 769         case OTPGETREGIONINFO:
 770         {
 771                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 772                 if (!buf)
 773                         return -ENOMEM;
 774                 ret = -EOPNOTSUPP;
 775                 switch (mfi->mode) {
 776                 case MTD_MODE_OTP_FACTORY:
 777                         if (mtd->get_fact_prot_info)
 778                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 779                         break;
 780                 case MTD_MODE_OTP_USER:
 781                         if (mtd->get_user_prot_info)
 782                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 783                         break;
 784                 default:
 785                         break;
 786                 }
 787                 if (ret >= 0) {
 788                         if (cmd == OTPGETREGIONCOUNT) {
 789                                 int nbr = ret / sizeof(struct otp_info);
 790                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 791                         } else
 792                                 ret = copy_to_user(argp, buf, ret);
 793                         if (ret)
 794                                 ret = -EFAULT;
 795                 }
 796                 kfree(buf);
 797                 break;
 798         }
 799
 800         case OTPLOCK:
 801         {
 802                 struct otp_info oinfo;
 803
 804                 if (mfi->mode != MTD_MODE_OTP_USER)
 805                         return -EINVAL;
 806                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 807                         return -EFAULT;
 808                 if (!mtd->lock_user_prot_reg)
 809                         return -EOPNOTSUPP;
 810                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 811                 break;
 812         }
 813 #endif
 814
 815         case ECCGETLAYOUT:
 816         {
 817                 if (!mtd->ecclayout)
 818                         return -EOPNOTSUPP;
 819
 820                 if (copy_to_user(argp, mtd->ecclayout,
 821                                  sizeof(struct nand_ecclayout)))
 822                         return -EFAULT;
 823                 break;
 824         }
 825
 826         case ECCGETSTATS:
 827         {
 828                 if (copy_to_user(argp, &mtd->ecc_stats,
 829                                  sizeof(struct mtd_ecc_stats)))
 830                         return -EFAULT;
 831                 break;
 832         }
 833
 834         case MTDFILEMODE:
 835         {
 836                 mfi->mode = 0;
 837
 838                 switch(arg) {
 839                 case MTD_MODE_OTP_FACTORY:
 840                 case MTD_MODE_OTP_USER:
 841                         ret = otp_select_filemode(mfi, arg);
 842                         break;
 843
 844                 case MTD_MODE_RAW:
 845                         if (!mtd->read_oob || !mtd->write_oob)
 846                                 return -EOPNOTSUPP;
 847                         mfi->mode = arg;
 848
 849                 case MTD_MODE_NORMAL:
 850                         break;
 851                 default:
 852                         ret = -EINVAL;
 853                 }
 854                 file->f_pos = 0;
 855                 break;
 856         }
 857
 858         default:
 859                 ret = -ENOTTY;
 860         }
 861
 862         return ret;
 863 } /* memory_ioctl */
 864
 865 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 866 {
 867         int ret;
 868
 869         lock_kernel();
 870         ret = mtd_ioctl(file, cmd, arg);
 871         unlock_kernel();
 872
 873         return ret;
 874 }
 875
 876 #ifdef CONFIG_COMPAT
 877
 878 struct mtd_oob_buf32 {
 879         u_int32_t start;
 880         u_int32_t length;
 881         compat_caddr_t ptr;     /* unsigned char* */
 882 };
 883
 884 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 885 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 886
 887 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 888         unsigned long arg)
 889 {
 890         struct mtd_file_info *mfi = file->private_data;
 891         struct mtd_info *mtd = mfi->mtd;
 892         void __user *argp = compat_ptr(arg);
 893         int ret = 0;
 894
 895         lock_kernel();
 896
 897         switch (cmd) {
 898         case MEMWRITEOOB32:
 899         {
 900                 struct mtd_oob_buf32 buf;
 901                 struct mtd_oob_buf32 __user *buf_user = argp;
 902
 903                 if (copy_from_user(&buf, argp, sizeof(buf)))
 904                         ret = -EFAULT;
 905                 else
 906                         ret = mtd_do_writeoob(file, mtd, buf.start,
 907                                 buf.length, compat_ptr(buf.ptr),
 908                                 &buf_user->length);
 909                 break;
 910         }
 911
 912         case MEMREADOOB32:
 913         {
 914                 struct mtd_oob_buf32 buf;
 915                 struct mtd_oob_buf32 __user *buf_user = argp;
 916
 917                 /* NOTE: writes return length to buf->start */
 918                 if (copy_from_user(&buf, argp, sizeof(buf)))
 919                         ret = -EFAULT;
 920                 else
 921                         ret = mtd_do_readoob(mtd, buf.start,
 922                                 buf.length, compat_ptr(buf.ptr),
 923                                 &buf_user->start);
 924                 break;
 925         }
 926         default:
 927                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
 928         }
 929
 930         unlock_kernel();
 931
 932         return ret;
 933 }
 934
 935 #endif /* CONFIG_COMPAT */
 936
 937 /*
 938  * try to determine where a shared mapping can be made
 939  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 940  *   mappings)
 941  */
 942 #ifndef CONFIG_MMU
 943 static unsigned long mtd_get_unmapped_area(struct file *file,
 944                                            unsigned long addr,
 945                                            unsigned long len,
 946                                            unsigned long pgoff,
 947                                            unsigned long flags)
 948 {
 949         struct mtd_file_info *mfi = file->private_data;
 950         struct mtd_info *mtd = mfi->mtd;
 951
 952         if (mtd->get_unmapped_area) {
 953                 unsigned long offset;
 954
 955                 if (addr != 0)
 956                         return (unsigned long) -EINVAL;
 957
 958                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
 959                         return (unsigned long) -EINVAL;
 960
 961                 offset = pgoff << PAGE_SHIFT;
 962                 if (offset > mtd->size - len)
 963                         return (unsigned long) -EINVAL;
 964
 965                 return mtd->get_unmapped_area(mtd, len, offset, flags);
 966         }
 967
 968         /* can't map directly */
 969         return (unsigned long) -ENOSYS;
 970 }
 971 #endif
 972
 973 /*
 974  * set up a mapping for shared memory segments
 975  */
 976 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 977 {
 978 #ifdef CONFIG_MMU
 979         struct mtd_file_info *mfi = file->private_data;
 980         struct mtd_info *mtd = mfi->mtd;
 981         struct map_info *map = mtd->priv;
 982         unsigned long start;
 983         unsigned long off;
 984         u32 len;
 985
 986         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
 987                 off = vma->vm_pgoff << PAGE_SHIFT;
 988                 start = map->phys;
 989                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
 990                 start &= PAGE_MASK;
 991                 if ((vma->vm_end - vma->vm_start + off) > len)
 992                         return -EINVAL;
 993
 994                 off += start;
 995                 vma->vm_pgoff = off >> PAGE_SHIFT;
 996                 vma->vm_flags |= VM_IO | VM_RESERVED;
 997
 998 #ifdef pgprot_noncached
 999                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1000                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1001 #endif
1002                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1003                                        vma->vm_end - vma->vm_start,
1004                                        vma->vm_page_prot))
1005                         return -EAGAIN;
1006
1007                 return 0;
1008         }
1009         return -ENOSYS;
1010 #else
1011         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1012 #endif
1013 }
1014
1015 static const struct file_operations mtd_fops = {
1016         .owner          = THIS_MODULE,
1017         .llseek         = mtd_lseek,
1018         .read           = mtd_read,
1019         .write          = mtd_write,
1020         .unlocked_ioctl = mtd_unlocked_ioctl,
1021 #ifdef CONFIG_COMPAT
1022         .compat_ioctl   = mtd_compat_ioctl,
1023 #endif
1024         .open           = mtd_open,
1025         .release        = mtd_close,
1026         .mmap           = mtd_mmap,
1027 #ifndef CONFIG_MMU
1028         .get_unmapped_area = mtd_get_unmapped_area,
1029 #endif
1030 };
1031
1032 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
1033                                const char *dev_name, void *data,
1034                                struct vfsmount *mnt)
1035 {
1036         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
1037                              mnt);
1038 }
1039
1040 static struct file_system_type mtd_inodefs_type = {
1041        .name = "mtd_inodefs",
1042        .get_sb = mtd_inodefs_get_sb,
1043        .kill_sb = kill_anon_super,
1044 };
1045
1046 static void mtdchar_notify_add(struct mtd_info *mtd)
1047 {
1048 }
1049
1050 static void mtdchar_notify_remove(struct mtd_info *mtd)
1051 {
1052         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1053
1054         if (mtd_ino) {
1055                 /* Destroy the inode if it exists */
1056                 mtd_ino->i_nlink = 0;
1057                 iput(mtd_ino);
1058         }
1059 }
1060
1061 static struct mtd_notifier mtdchar_notifier = {
1062         .add = mtdchar_notify_add,
1063         .remove = mtdchar_notify_remove,
1064 };
1065
1066 static int __init init_mtdchar(void)
1067 {
1068         int ret;
1069
1070         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1071                                    "mtd", &mtd_fops);
1072         if (ret < 0) {
1073                 pr_notice("Can't allocate major number %d for "
1074                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1075                 return ret;
1076         }
1077
1078         ret = register_filesystem(&mtd_inodefs_type);
1079         if (ret) {
1080                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1081                 goto err_unregister_chdev;
1082         }
1083
1084         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1085         if (IS_ERR(mtd_inode_mnt)) {
1086                 ret = PTR_ERR(mtd_inode_mnt);
1087                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1088                 goto err_unregister_filesystem;
1089         }
1090         register_mtd_user(&mtdchar_notifier);
1091
1092         return ret;
1093
1094 err_unregister_filesystem:
1095         unregister_filesystem(&mtd_inodefs_type);
1096 err_unregister_chdev:
1097         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1098         return ret;
1099 }
1100
1101 static void __exit cleanup_mtdchar(void)
1102 {
1103         unregister_mtd_user(&mtdchar_notifier);
1104         mntput(mtd_inode_mnt);
1105         unregister_filesystem(&mtd_inodefs_type);
1106         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1107 }
1108
1109 module_init(init_mtdchar);
1110 module_exit(cleanup_mtdchar);
1111
1112 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1113
1114 MODULE_LICENSE("GPL");
1115 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1116 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1117 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);