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 #include <linux/blkpg.h>
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/partitions.h>
  36 #include <linux/mtd/map.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 #define MTD_INODE_FS_MAGIC 0x11307854
  41 static struct vfsmount *mtd_inode_mnt __read_mostly;
  42
  43 /*
  44  * Data structure to hold the pointer to the mtd device as well
  45  * as mode information ofr various use cases.
  46  */
  47 struct mtd_file_info {
  48         struct mtd_info *mtd;
  49         struct inode *ino;
  50         enum mtd_file_modes mode;
  51 };
  52
  53 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  54 {
  55         struct mtd_file_info *mfi = file->private_data;
  56         struct mtd_info *mtd = mfi->mtd;
  57
  58         switch (orig) {
  59         case SEEK_SET:
  60                 break;
  61         case SEEK_CUR:
  62                 offset += file->f_pos;
  63                 break;
  64         case SEEK_END:
  65                 offset += mtd->size;
  66                 break;
  67         default:
  68                 return -EINVAL;
  69         }
  70
  71         if (offset >= 0 && offset <= mtd->size)
  72                 return file->f_pos = offset;
  73
  74         return -EINVAL;
  75 }
  76
  77
  78
  79 static int mtd_open(struct inode *inode, struct file *file)
  80 {
  81         int minor = iminor(inode);
  82         int devnum = minor >> 1;
  83         int ret = 0;
  84         struct mtd_info *mtd;
  85         struct mtd_file_info *mfi;
  86         struct inode *mtd_ino;
  87
  88         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  89
  90         /* You can't open the RO devices RW */
  91         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  92                 return -EACCES;
  93
  94         lock_kernel();
  95         mtd = get_mtd_device(NULL, devnum);
  96
  97         if (IS_ERR(mtd)) {
  98                 ret = PTR_ERR(mtd);
  99                 goto out;
 100         }
 101
 102         if (mtd->type == MTD_ABSENT) {
 103                 put_mtd_device(mtd);
 104                 ret = -ENODEV;
 105                 goto out;
 106         }
 107
 108         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 109         if (!mtd_ino) {
 110                 put_mtd_device(mtd);
 111                 ret = -ENOMEM;
 112                 goto out;
 113         }
 114         if (mtd_ino->i_state & I_NEW) {
 115                 mtd_ino->i_private = mtd;
 116                 mtd_ino->i_mode = S_IFCHR;
 117                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 118                 unlock_new_inode(mtd_ino);
 119         }
 120         file->f_mapping = mtd_ino->i_mapping;
 121
 122         /* You can't open it RW if it's not a writeable device */
 123         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 124                 iput(mtd_ino);
 125                 put_mtd_device(mtd);
 126                 ret = -EACCES;
 127                 goto out;
 128         }
 129
 130         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 131         if (!mfi) {
 132                 iput(mtd_ino);
 133                 put_mtd_device(mtd);
 134                 ret = -ENOMEM;
 135                 goto out;
 136         }
 137         mfi->ino = mtd_ino;
 138         mfi->mtd = mtd;
 139         file->private_data = mfi;
 140
 141 out:
 142         unlock_kernel();
 143         return ret;
 144 } /* mtd_open */
 145
 146 /*====================================================================*/
 147
 148 static int mtd_close(struct inode *inode, struct file *file)
 149 {
 150         struct mtd_file_info *mfi = file->private_data;
 151         struct mtd_info *mtd = mfi->mtd;
 152
 153         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 154
 155         /* Only sync if opened RW */
 156         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 157                 mtd->sync(mtd);
 158
 159         iput(mfi->ino);
 160
 161         put_mtd_device(mtd);
 162         file->private_data = NULL;
 163         kfree(mfi);
 164
 165         return 0;
 166 } /* mtd_close */
 167
 168 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 169    userspace buffer down and use it directly with readv/writev.
 170 */
 171 #define MAX_KMALLOC_SIZE 0x20000
 172
 173 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 174 {
 175         struct mtd_file_info *mfi = file->private_data;
 176         struct mtd_info *mtd = mfi->mtd;
 177         size_t retlen=0;
 178         size_t total_retlen=0;
 179         int ret=0;
 180         int len;
 181         char *kbuf;
 182
 183         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 184
 185         if (*ppos + count > mtd->size)
 186                 count = mtd->size - *ppos;
 187
 188         if (!count)
 189                 return 0;
 190
 191         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 192            and pass them directly to the MTD functions */
 193
 194         if (count > MAX_KMALLOC_SIZE)
 195                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 196         else
 197                 kbuf=kmalloc(count, GFP_KERNEL);
 198
 199         if (!kbuf)
 200                 return -ENOMEM;
 201
 202         while (count) {
 203
 204                 if (count > MAX_KMALLOC_SIZE)
 205                         len = MAX_KMALLOC_SIZE;
 206                 else
 207                         len = count;
 208
 209                 switch (mfi->mode) {
 210                 case MTD_MODE_OTP_FACTORY:
 211                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 212                         break;
 213                 case MTD_MODE_OTP_USER:
 214                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 215                         break;
 216                 case MTD_MODE_RAW:
 217                 {
 218                         struct mtd_oob_ops ops;
 219
 220                         ops.mode = MTD_OOB_RAW;
 221                         ops.datbuf = kbuf;
 222                         ops.oobbuf = NULL;
 223                         ops.len = len;
 224
 225                         ret = mtd->read_oob(mtd, *ppos, &ops);
 226                         retlen = ops.retlen;
 227                         break;
 228                 }
 229                 default:
 230                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 231                 }
 232                 /* Nand returns -EBADMSG on ecc errors, but it returns
 233                  * the data. For our userspace tools it is important
 234                  * to dump areas with ecc errors !
 235                  * For kernel internal usage it also might return -EUCLEAN
 236                  * to signal the caller that a bitflip has occured and has
 237                  * been corrected by the ECC algorithm.
 238                  * Userspace software which accesses NAND this way
 239                  * must be aware of the fact that it deals with NAND
 240                  */
 241                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 242                         *ppos += retlen;
 243                         if (copy_to_user(buf, kbuf, retlen)) {
 244                                 kfree(kbuf);
 245                                 return -EFAULT;
 246                         }
 247                         else
 248                                 total_retlen += retlen;
 249
 250                         count -= retlen;
 251                         buf += retlen;
 252                         if (retlen == 0)
 253                                 count = 0;
 254                 }
 255                 else {
 256                         kfree(kbuf);
 257                         return ret;
 258                 }
 259
 260         }
 261
 262         kfree(kbuf);
 263         return total_retlen;
 264 } /* mtd_read */
 265
 266 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 267 {
 268         struct mtd_file_info *mfi = file->private_data;
 269         struct mtd_info *mtd = mfi->mtd;
 270         char *kbuf;
 271         size_t retlen;
 272         size_t total_retlen=0;
 273         int ret=0;
 274         int len;
 275
 276         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 277
 278         if (*ppos == mtd->size)
 279                 return -ENOSPC;
 280
 281         if (*ppos + count > mtd->size)
 282                 count = mtd->size - *ppos;
 283
 284         if (!count)
 285                 return 0;
 286
 287         if (count > MAX_KMALLOC_SIZE)
 288                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 289         else
 290                 kbuf=kmalloc(count, GFP_KERNEL);
 291
 292         if (!kbuf)
 293                 return -ENOMEM;
 294
 295         while (count) {
 296
 297                 if (count > MAX_KMALLOC_SIZE)
 298                         len = MAX_KMALLOC_SIZE;
 299                 else
 300                         len = count;
 301
 302                 if (copy_from_user(kbuf, buf, len)) {
 303                         kfree(kbuf);
 304                         return -EFAULT;
 305                 }
 306
 307                 switch (mfi->mode) {
 308                 case MTD_MODE_OTP_FACTORY:
 309                         ret = -EROFS;
 310                         break;
 311                 case MTD_MODE_OTP_USER:
 312                         if (!mtd->write_user_prot_reg) {
 313                                 ret = -EOPNOTSUPP;
 314                                 break;
 315                         }
 316                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 317                         break;
 318
 319                 case MTD_MODE_RAW:
 320                 {
 321                         struct mtd_oob_ops ops;
 322
 323                         ops.mode = MTD_OOB_RAW;
 324                         ops.datbuf = kbuf;
 325                         ops.oobbuf = NULL;
 326                         ops.len = len;
 327
 328                         ret = mtd->write_oob(mtd, *ppos, &ops);
 329                         retlen = ops.retlen;
 330                         break;
 331                 }
 332
 333                 default:
 334                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 335                 }
 336                 if (!ret) {
 337                         *ppos += retlen;
 338                         total_retlen += retlen;
 339                         count -= retlen;
 340                         buf += retlen;
 341                 }
 342                 else {
 343                         kfree(kbuf);
 344                         return ret;
 345                 }
 346         }
 347
 348         kfree(kbuf);
 349         return total_retlen;
 350 } /* mtd_write */
 351
 352 /*======================================================================
 353
 354     IOCTL calls for getting device parameters.
 355
 356 ======================================================================*/
 357 static void mtdchar_erase_callback (struct erase_info *instr)
 358 {
 359         wake_up((wait_queue_head_t *)instr->priv);
 360 }
 361
 362 #ifdef CONFIG_HAVE_MTD_OTP
 363 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 364 {
 365         struct mtd_info *mtd = mfi->mtd;
 366         int ret = 0;
 367
 368         switch (mode) {
 369         case MTD_OTP_FACTORY:
 370                 if (!mtd->read_fact_prot_reg)
 371                         ret = -EOPNOTSUPP;
 372                 else
 373                         mfi->mode = MTD_MODE_OTP_FACTORY;
 374                 break;
 375         case MTD_OTP_USER:
 376                 if (!mtd->read_fact_prot_reg)
 377                         ret = -EOPNOTSUPP;
 378                 else
 379                         mfi->mode = MTD_MODE_OTP_USER;
 380                 break;
 381         default:
 382                 ret = -EINVAL;
 383         case MTD_OTP_OFF:
 384                 break;
 385         }
 386         return ret;
 387 }
 388 #else
 389 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 390 #endif
 391
 392 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 393         uint64_t start, uint32_t length, void __user *ptr,
 394         uint32_t __user *retp)
 395 {
 396         struct mtd_oob_ops ops;
 397         uint32_t retlen;
 398         int ret = 0;
 399
 400         if (!(file->f_mode & FMODE_WRITE))
 401                 return -EPERM;
 402
 403         if (length > 4096)
 404                 return -EINVAL;
 405
 406         if (!mtd->write_oob)
 407                 ret = -EOPNOTSUPP;
 408         else
 409                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 410
 411         if (ret)
 412                 return ret;
 413
 414         ops.ooblen = length;
 415         ops.ooboffs = start & (mtd->oobsize - 1);
 416         ops.datbuf = NULL;
 417         ops.mode = MTD_OOB_PLACE;
 418
 419         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 420                 return -EINVAL;
 421
 422         ops.oobbuf = memdup_user(ptr, length);
 423         if (IS_ERR(ops.oobbuf))
 424                 return PTR_ERR(ops.oobbuf);
 425
 426         start &= ~((uint64_t)mtd->oobsize - 1);
 427         ret = mtd->write_oob(mtd, start, &ops);
 428
 429         if (ops.oobretlen > 0xFFFFFFFFU)
 430                 ret = -EOVERFLOW;
 431         retlen = ops.oobretlen;
 432         if (copy_to_user(retp, &retlen, sizeof(length)))
 433                 ret = -EFAULT;
 434
 435         kfree(ops.oobbuf);
 436         return ret;
 437 }
 438
 439 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 440         uint32_t length, void __user *ptr, uint32_t __user *retp)
 441 {
 442         struct mtd_oob_ops ops;
 443         int ret = 0;
 444
 445         if (length > 4096)
 446                 return -EINVAL;
 447
 448         if (!mtd->read_oob)
 449                 ret = -EOPNOTSUPP;
 450         else
 451                 ret = access_ok(VERIFY_WRITE, ptr,
 452                                 length) ? 0 : -EFAULT;
 453         if (ret)
 454                 return ret;
 455
 456         ops.ooblen = length;
 457         ops.ooboffs = start & (mtd->oobsize - 1);
 458         ops.datbuf = NULL;
 459         ops.mode = MTD_OOB_PLACE;
 460
 461         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 462                 return -EINVAL;
 463
 464         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 465         if (!ops.oobbuf)
 466                 return -ENOMEM;
 467
 468         start &= ~((uint64_t)mtd->oobsize - 1);
 469         ret = mtd->read_oob(mtd, start, &ops);
 470
 471         if (put_user(ops.oobretlen, retp))
 472                 ret = -EFAULT;
 473         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 474                                             ops.oobretlen))
 475                 ret = -EFAULT;
 476
 477         kfree(ops.oobbuf);
 478         return ret;
 479 }
 480
 481 /*
 482  * Copies (and truncates, if necessary) data from the larger struct,
 483  * nand_ecclayout, to the smaller, deprecated layout struct,
 484  * nand_ecclayout_user. This is necessary only to suppport the deprecated
 485  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 486  * nand_ecclayout flexibly (i.e. the struct may change size in new
 487  * releases without requiring major rewrites).
 488  */
 489 static int shrink_ecclayout(const struct nand_ecclayout *from,
 490                 struct nand_ecclayout_user *to)
 491 {
 492         int i;
 493
 494         if (!from || !to)
 495                 return -EINVAL;
 496
 497         memset(to, 0, sizeof(*to));
 498
 499         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 500         for (i = 0; i < to->eccbytes; i++)
 501                 to->eccpos[i] = from->eccpos[i];
 502
 503         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 504                 if (from->oobfree[i].length == 0 &&
 505                                 from->oobfree[i].offset == 0)
 506                         break;
 507                 to->oobavail += from->oobfree[i].length;
 508                 to->oobfree[i] = from->oobfree[i];
 509         }
 510
 511         return 0;
 512 }
 513
 514 #ifdef CONFIG_MTD_PARTITIONS
 515 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
 516                            struct blkpg_ioctl_arg __user *arg)
 517 {
 518         struct blkpg_ioctl_arg a;
 519         struct blkpg_partition p;
 520
 521         if (!capable(CAP_SYS_ADMIN))
 522                 return -EPERM;
 523
 524         /* Only master mtd device must be used to control partitions */
 525         if (!mtd_is_master(mtd))
 526                 return -EINVAL;
 527
 528         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 529                 return -EFAULT;
 530
 531         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 532                 return -EFAULT;
 533
 534         switch (a.op) {
 535         case BLKPG_ADD_PARTITION:
 536
 537                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 538
 539         case BLKPG_DEL_PARTITION:
 540
 541                 if (p.pno < 0)
 542                         return -EINVAL;
 543
 544                 return mtd_del_partition(mtd, p.pno);
 545
 546         default:
 547                 return -EINVAL;
 548         }
 549 }
 550 #endif
 551
 552
 553 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 554 {
 555         struct mtd_file_info *mfi = file->private_data;
 556         struct mtd_info *mtd = mfi->mtd;
 557         void __user *argp = (void __user *)arg;
 558         int ret = 0;
 559         u_long size;
 560         struct mtd_info_user info;
 561
 562         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 563
 564         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 565         if (cmd & IOC_IN) {
 566                 if (!access_ok(VERIFY_READ, argp, size))
 567                         return -EFAULT;
 568         }
 569         if (cmd & IOC_OUT) {
 570                 if (!access_ok(VERIFY_WRITE, argp, size))
 571                         return -EFAULT;
 572         }
 573
 574         switch (cmd) {
 575         case MEMGETREGIONCOUNT:
 576                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 577                         return -EFAULT;
 578                 break;
 579
 580         case MEMGETREGIONINFO:
 581         {
 582                 uint32_t ur_idx;
 583                 struct mtd_erase_region_info *kr;
 584                 struct region_info_user __user *ur = argp;
 585
 586                 if (get_user(ur_idx, &(ur->regionindex)))
 587                         return -EFAULT;
 588
 589                 if (ur_idx >= mtd->numeraseregions)
 590                         return -EINVAL;
 591
 592                 kr = &(mtd->eraseregions[ur_idx]);
 593
 594                 if (put_user(kr->offset, &(ur->offset))
 595                     || put_user(kr->erasesize, &(ur->erasesize))
 596                     || put_user(kr->numblocks, &(ur->numblocks)))
 597                         return -EFAULT;
 598
 599                 break;
 600         }
 601
 602         case MEMGETINFO:
 603                 info.type       = mtd->type;
 604                 info.flags      = mtd->flags;
 605                 info.size       = mtd->size;
 606                 info.erasesize  = mtd->erasesize;
 607                 info.writesize  = mtd->writesize;
 608                 info.oobsize    = mtd->oobsize;
 609                 /* The below fields are obsolete */
 610                 info.ecctype    = -1;
 611                 info.eccsize    = 0;
 612                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 613                         return -EFAULT;
 614                 break;
 615
 616         case MEMERASE:
 617         case MEMERASE64:
 618         {
 619                 struct erase_info *erase;
 620
 621                 if(!(file->f_mode & FMODE_WRITE))
 622                         return -EPERM;
 623
 624                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 625                 if (!erase)
 626                         ret = -ENOMEM;
 627                 else {
 628                         wait_queue_head_t waitq;
 629                         DECLARE_WAITQUEUE(wait, current);
 630
 631                         init_waitqueue_head(&waitq);
 632
 633                         if (cmd == MEMERASE64) {
 634                                 struct erase_info_user64 einfo64;
 635
 636                                 if (copy_from_user(&einfo64, argp,
 637                                             sizeof(struct erase_info_user64))) {
 638                                         kfree(erase);
 639                                         return -EFAULT;
 640                                 }
 641                                 erase->addr = einfo64.start;
 642                                 erase->len = einfo64.length;
 643                         } else {
 644                                 struct erase_info_user einfo32;
 645
 646                                 if (copy_from_user(&einfo32, argp,
 647                                             sizeof(struct erase_info_user))) {
 648                                         kfree(erase);
 649                                         return -EFAULT;
 650                                 }
 651                                 erase->addr = einfo32.start;
 652                                 erase->len = einfo32.length;
 653                         }
 654                         erase->mtd = mtd;
 655                         erase->callback = mtdchar_erase_callback;
 656                         erase->priv = (unsigned long)&waitq;
 657
 658                         /*
 659                           FIXME: Allow INTERRUPTIBLE. Which means
 660                           not having the wait_queue head on the stack.
 661
 662                           If the wq_head is on the stack, and we
 663                           leave because we got interrupted, then the
 664                           wq_head is no longer there when the
 665                           callback routine tries to wake us up.
 666                         */
 667                         ret = mtd->erase(mtd, erase);
 668                         if (!ret) {
 669                                 set_current_state(TASK_UNINTERRUPTIBLE);
 670                                 add_wait_queue(&waitq, &wait);
 671                                 if (erase->state != MTD_ERASE_DONE &&
 672                                     erase->state != MTD_ERASE_FAILED)
 673                                         schedule();
 674                                 remove_wait_queue(&waitq, &wait);
 675                                 set_current_state(TASK_RUNNING);
 676
 677                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 678                         }
 679                         kfree(erase);
 680                 }
 681                 break;
 682         }
 683
 684         case MEMWRITEOOB:
 685         {
 686                 struct mtd_oob_buf buf;
 687                 struct mtd_oob_buf __user *buf_user = argp;
 688
 689                 /* NOTE: writes return length to buf_user->length */
 690                 if (copy_from_user(&buf, argp, sizeof(buf)))
 691                         ret = -EFAULT;
 692                 else
 693                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 694                                 buf.ptr, &buf_user->length);
 695                 break;
 696         }
 697
 698         case MEMREADOOB:
 699         {
 700                 struct mtd_oob_buf buf;
 701                 struct mtd_oob_buf __user *buf_user = argp;
 702
 703                 /* NOTE: writes return length to buf_user->start */
 704                 if (copy_from_user(&buf, argp, sizeof(buf)))
 705                         ret = -EFAULT;
 706                 else
 707                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 708                                 buf.ptr, &buf_user->start);
 709                 break;
 710         }
 711
 712         case MEMWRITEOOB64:
 713         {
 714                 struct mtd_oob_buf64 buf;
 715                 struct mtd_oob_buf64 __user *buf_user = argp;
 716
 717                 if (copy_from_user(&buf, argp, sizeof(buf)))
 718                         ret = -EFAULT;
 719                 else
 720                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 721                                 (void __user *)(uintptr_t)buf.usr_ptr,
 722                                 &buf_user->length);
 723                 break;
 724         }
 725
 726         case MEMREADOOB64:
 727         {
 728                 struct mtd_oob_buf64 buf;
 729                 struct mtd_oob_buf64 __user *buf_user = argp;
 730
 731                 if (copy_from_user(&buf, argp, sizeof(buf)))
 732                         ret = -EFAULT;
 733                 else
 734                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 735                                 (void __user *)(uintptr_t)buf.usr_ptr,
 736                                 &buf_user->length);
 737                 break;
 738         }
 739
 740         case MEMLOCK:
 741         {
 742                 struct erase_info_user einfo;
 743
 744                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 745                         return -EFAULT;
 746
 747                 if (!mtd->lock)
 748                         ret = -EOPNOTSUPP;
 749                 else
 750                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 751                 break;
 752         }
 753
 754         case MEMUNLOCK:
 755         {
 756                 struct erase_info_user einfo;
 757
 758                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 759                         return -EFAULT;
 760
 761                 if (!mtd->unlock)
 762                         ret = -EOPNOTSUPP;
 763                 else
 764                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 765                 break;
 766         }
 767
 768         case MEMISLOCKED:
 769         {
 770                 struct erase_info_user einfo;
 771
 772                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 773                         return -EFAULT;
 774
 775                 if (!mtd->is_locked)
 776                         ret = -EOPNOTSUPP;
 777                 else
 778                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 779                 break;
 780         }
 781
 782         /* Legacy interface */
 783         case MEMGETOOBSEL:
 784         {
 785                 struct nand_oobinfo oi;
 786
 787                 if (!mtd->ecclayout)
 788                         return -EOPNOTSUPP;
 789                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 790                         return -EINVAL;
 791
 792                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 793                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 794                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 795                        sizeof(oi.oobfree));
 796                 oi.eccbytes = mtd->ecclayout->eccbytes;
 797
 798                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 799                         return -EFAULT;
 800                 break;
 801         }
 802
 803         case MEMGETBADBLOCK:
 804         {
 805                 loff_t offs;
 806
 807                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 808                         return -EFAULT;
 809                 if (!mtd->block_isbad)
 810                         ret = -EOPNOTSUPP;
 811                 else
 812                         return mtd->block_isbad(mtd, offs);
 813                 break;
 814         }
 815
 816         case MEMSETBADBLOCK:
 817         {
 818                 loff_t offs;
 819
 820                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 821                         return -EFAULT;
 822                 if (!mtd->block_markbad)
 823                         ret = -EOPNOTSUPP;
 824                 else
 825                         return mtd->block_markbad(mtd, offs);
 826                 break;
 827         }
 828
 829 #ifdef CONFIG_HAVE_MTD_OTP
 830         case OTPSELECT:
 831         {
 832                 int mode;
 833                 if (copy_from_user(&mode, argp, sizeof(int)))
 834                         return -EFAULT;
 835
 836                 mfi->mode = MTD_MODE_NORMAL;
 837
 838                 ret = otp_select_filemode(mfi, mode);
 839
 840                 file->f_pos = 0;
 841                 break;
 842         }
 843
 844         case OTPGETREGIONCOUNT:
 845         case OTPGETREGIONINFO:
 846         {
 847                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 848                 if (!buf)
 849                         return -ENOMEM;
 850                 ret = -EOPNOTSUPP;
 851                 switch (mfi->mode) {
 852                 case MTD_MODE_OTP_FACTORY:
 853                         if (mtd->get_fact_prot_info)
 854                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 855                         break;
 856                 case MTD_MODE_OTP_USER:
 857                         if (mtd->get_user_prot_info)
 858                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 859                         break;
 860                 default:
 861                         break;
 862                 }
 863                 if (ret >= 0) {
 864                         if (cmd == OTPGETREGIONCOUNT) {
 865                                 int nbr = ret / sizeof(struct otp_info);
 866                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 867                         } else
 868                                 ret = copy_to_user(argp, buf, ret);
 869                         if (ret)
 870                                 ret = -EFAULT;
 871                 }
 872                 kfree(buf);
 873                 break;
 874         }
 875
 876         case OTPLOCK:
 877         {
 878                 struct otp_info oinfo;
 879
 880                 if (mfi->mode != MTD_MODE_OTP_USER)
 881                         return -EINVAL;
 882                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 883                         return -EFAULT;
 884                 if (!mtd->lock_user_prot_reg)
 885                         return -EOPNOTSUPP;
 886                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 887                 break;
 888         }
 889 #endif
 890
 891         /* This ioctl is being deprecated - it truncates the ecc layout */
 892         case ECCGETLAYOUT:
 893         {
 894                 struct nand_ecclayout_user *usrlay;
 895
 896                 if (!mtd->ecclayout)
 897                         return -EOPNOTSUPP;
 898
 899                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 900                 if (!usrlay)
 901                         return -ENOMEM;
 902
 903                 shrink_ecclayout(mtd->ecclayout, usrlay);
 904
 905                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 906                         ret = -EFAULT;
 907                 kfree(usrlay);
 908                 break;
 909         }
 910
 911         case ECCGETSTATS:
 912         {
 913                 if (copy_to_user(argp, &mtd->ecc_stats,
 914                                  sizeof(struct mtd_ecc_stats)))
 915                         return -EFAULT;
 916                 break;
 917         }
 918
 919         case MTDFILEMODE:
 920         {
 921                 mfi->mode = 0;
 922
 923                 switch(arg) {
 924                 case MTD_MODE_OTP_FACTORY:
 925                 case MTD_MODE_OTP_USER:
 926                         ret = otp_select_filemode(mfi, arg);
 927                         break;
 928
 929                 case MTD_MODE_RAW:
 930                         if (!mtd->read_oob || !mtd->write_oob)
 931                                 return -EOPNOTSUPP;
 932                         mfi->mode = arg;
 933
 934                 case MTD_MODE_NORMAL:
 935                         break;
 936                 default:
 937                         ret = -EINVAL;
 938                 }
 939                 file->f_pos = 0;
 940                 break;
 941         }
 942
 943 #ifdef CONFIG_MTD_PARTITIONS
 944         case BLKPG:
 945         {
 946                 ret = mtd_blkpg_ioctl(mtd,
 947                       (struct blkpg_ioctl_arg __user *)arg);
 948                 break;
 949         }
 950
 951         case BLKRRPART:
 952         {
 953                 /* No reread partition feature. Just return ok */
 954                 ret = 0;
 955                 break;
 956         }
 957 #endif
 958
 959         default:
 960                 ret = -ENOTTY;
 961         }
 962
 963         return ret;
 964 } /* memory_ioctl */
 965
 966 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 967 {
 968         int ret;
 969
 970         lock_kernel();
 971         ret = mtd_ioctl(file, cmd, arg);
 972         unlock_kernel();
 973
 974         return ret;
 975 }
 976
 977 #ifdef CONFIG_COMPAT
 978
 979 struct mtd_oob_buf32 {
 980         u_int32_t start;
 981         u_int32_t length;
 982         compat_caddr_t ptr;     /* unsigned char* */
 983 };
 984
 985 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 986 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 987
 988 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 989         unsigned long arg)
 990 {
 991         struct mtd_file_info *mfi = file->private_data;
 992         struct mtd_info *mtd = mfi->mtd;
 993         void __user *argp = compat_ptr(arg);
 994         int ret = 0;
 995
 996         lock_kernel();
 997
 998         switch (cmd) {
 999         case MEMWRITEOOB32:
1000         {
1001                 struct mtd_oob_buf32 buf;
1002                 struct mtd_oob_buf32 __user *buf_user = argp;
1003
1004                 if (copy_from_user(&buf, argp, sizeof(buf)))
1005                         ret = -EFAULT;
1006                 else
1007                         ret = mtd_do_writeoob(file, mtd, buf.start,
1008                                 buf.length, compat_ptr(buf.ptr),
1009                                 &buf_user->length);
1010                 break;
1011         }
1012
1013         case MEMREADOOB32:
1014         {
1015                 struct mtd_oob_buf32 buf;
1016                 struct mtd_oob_buf32 __user *buf_user = argp;
1017
1018                 /* NOTE: writes return length to buf->start */
1019                 if (copy_from_user(&buf, argp, sizeof(buf)))
1020                         ret = -EFAULT;
1021                 else
1022                         ret = mtd_do_readoob(mtd, buf.start,
1023                                 buf.length, compat_ptr(buf.ptr),
1024                                 &buf_user->start);
1025                 break;
1026         }
1027         default:
1028                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1029         }
1030
1031         unlock_kernel();
1032
1033         return ret;
1034 }
1035
1036 #endif /* CONFIG_COMPAT */
1037
1038 /*
1039  * try to determine where a shared mapping can be made
1040  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1041  *   mappings)
1042  */
1043 #ifndef CONFIG_MMU
1044 static unsigned long mtd_get_unmapped_area(struct file *file,
1045                                            unsigned long addr,
1046                                            unsigned long len,
1047                                            unsigned long pgoff,
1048                                            unsigned long flags)
1049 {
1050         struct mtd_file_info *mfi = file->private_data;
1051         struct mtd_info *mtd = mfi->mtd;
1052
1053         if (mtd->get_unmapped_area) {
1054                 unsigned long offset;
1055
1056                 if (addr != 0)
1057                         return (unsigned long) -EINVAL;
1058
1059                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1060                         return (unsigned long) -EINVAL;
1061
1062                 offset = pgoff << PAGE_SHIFT;
1063                 if (offset > mtd->size - len)
1064                         return (unsigned long) -EINVAL;
1065
1066                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1067         }
1068
1069         /* can't map directly */
1070         return (unsigned long) -ENOSYS;
1071 }
1072 #endif
1073
1074 /*
1075  * set up a mapping for shared memory segments
1076  */
1077 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1078 {
1079 #ifdef CONFIG_MMU
1080         struct mtd_file_info *mfi = file->private_data;
1081         struct mtd_info *mtd = mfi->mtd;
1082         struct map_info *map = mtd->priv;
1083         unsigned long start;
1084         unsigned long off;
1085         u32 len;
1086
1087         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1088                 off = vma->vm_pgoff << PAGE_SHIFT;
1089                 start = map->phys;
1090                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1091                 start &= PAGE_MASK;
1092                 if ((vma->vm_end - vma->vm_start + off) > len)
1093                         return -EINVAL;
1094
1095                 off += start;
1096                 vma->vm_pgoff = off >> PAGE_SHIFT;
1097                 vma->vm_flags |= VM_IO | VM_RESERVED;
1098
1099 #ifdef pgprot_noncached
1100                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1101                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1102 #endif
1103                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1104                                        vma->vm_end - vma->vm_start,
1105                                        vma->vm_page_prot))
1106                         return -EAGAIN;
1107
1108                 return 0;
1109         }
1110         return -ENOSYS;
1111 #else
1112         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1113 #endif
1114 }
1115
1116 static const struct file_operations mtd_fops = {
1117         .owner          = THIS_MODULE,
1118         .llseek         = mtd_lseek,
1119         .read           = mtd_read,
1120         .write          = mtd_write,
1121         .unlocked_ioctl = mtd_unlocked_ioctl,
1122 #ifdef CONFIG_COMPAT
1123         .compat_ioctl   = mtd_compat_ioctl,
1124 #endif
1125         .open           = mtd_open,
1126         .release        = mtd_close,
1127         .mmap           = mtd_mmap,
1128 #ifndef CONFIG_MMU
1129         .get_unmapped_area = mtd_get_unmapped_area,
1130 #endif
1131 };
1132
1133 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
1134                                const char *dev_name, void *data,
1135                                struct vfsmount *mnt)
1136 {
1137         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
1138                              mnt);
1139 }
1140
1141 static struct file_system_type mtd_inodefs_type = {
1142        .name = "mtd_inodefs",
1143        .get_sb = mtd_inodefs_get_sb,
1144        .kill_sb = kill_anon_super,
1145 };
1146
1147 static void mtdchar_notify_add(struct mtd_info *mtd)
1148 {
1149 }
1150
1151 static void mtdchar_notify_remove(struct mtd_info *mtd)
1152 {
1153         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1154
1155         if (mtd_ino) {
1156                 /* Destroy the inode if it exists */
1157                 mtd_ino->i_nlink = 0;
1158                 iput(mtd_ino);
1159         }
1160 }
1161
1162 static struct mtd_notifier mtdchar_notifier = {
1163         .add = mtdchar_notify_add,
1164         .remove = mtdchar_notify_remove,
1165 };
1166
1167 static int __init init_mtdchar(void)
1168 {
1169         int ret;
1170
1171         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1172                                    "mtd", &mtd_fops);
1173         if (ret < 0) {
1174                 pr_notice("Can't allocate major number %d for "
1175                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1176                 return ret;
1177         }
1178
1179         ret = register_filesystem(&mtd_inodefs_type);
1180         if (ret) {
1181                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1182                 goto err_unregister_chdev;
1183         }
1184
1185         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1186         if (IS_ERR(mtd_inode_mnt)) {
1187                 ret = PTR_ERR(mtd_inode_mnt);
1188                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1189                 goto err_unregister_filesystem;
1190         }
1191         register_mtd_user(&mtdchar_notifier);
1192
1193         return ret;
1194
1195 err_unregister_filesystem:
1196         unregister_filesystem(&mtd_inodefs_type);
1197 err_unregister_chdev:
1198         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1199         return ret;
1200 }
1201
1202 static void __exit cleanup_mtdchar(void)
1203 {
1204         unregister_mtd_user(&mtdchar_notifier);
1205         mntput(mtd_inode_mnt);
1206         unregister_filesystem(&mtd_inodefs_type);
1207         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1208 }
1209
1210 module_init(init_mtdchar);
1211 module_exit(cleanup_mtdchar);
1212
1213 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1214
1215 MODULE_LICENSE("GPL");
1216 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1217 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1218 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);