drivers/mtd/mtdchar.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/fs.h>
   8 #include <linux/mm.h>
   9 #include <linux/err.h>
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/sched.h>
  15 #include <linux/mutex.h>
  16 #include <linux/backing-dev.h>
  17 #include <linux/compat.h>
  18 #include <linux/mount.h>
  19 #include <linux/blkpg.h>
  20 #include <linux/magic.h>
  21 #include <linux/major.h>
  22 #include <linux/mtd/mtd.h>
  23 #include <linux/mtd/partitions.h>
  24 #include <linux/mtd/map.h>
  25
  26 #include <linux/uaccess.h>
  27
  28 #include "mtdcore.h"
  29
  30 static DEFINE_MUTEX(mtd_mutex);
  31
  32 /*
  33  * Data structure to hold the pointer to the mtd device as well
  34  * as mode information of various use cases.
  35  */
  36 struct mtd_file_info {
  37         struct mtd_info *mtd;
  38         enum mtd_file_modes mode;
  39 };
  40
  41 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  42 {
  43         struct mtd_file_info *mfi = file->private_data;
  44         return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  45 }
  46
  47 static int mtdchar_open(struct inode *inode, struct file *file)
  48 {
  49         int minor = iminor(inode);
  50         int devnum = minor >> 1;
  51         int ret = 0;
  52         struct mtd_info *mtd;
  53         struct mtd_file_info *mfi;
  54
  55         pr_debug("MTD_open\n");
  56
  57         /* You can't open the RO devices RW */
  58         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  59                 return -EACCES;
  60
  61         mutex_lock(&mtd_mutex);
  62         mtd = get_mtd_device(NULL, devnum);
  63
  64         if (IS_ERR(mtd)) {
  65                 ret = PTR_ERR(mtd);
  66                 goto out;
  67         }
  68
  69         if (mtd->type == MTD_ABSENT) {
  70                 ret = -ENODEV;
  71                 goto out1;
  72         }
  73
  74         /* You can't open it RW if it's not a writeable device */
  75         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
  76                 ret = -EACCES;
  77                 goto out1;
  78         }
  79
  80         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
  81         if (!mfi) {
  82                 ret = -ENOMEM;
  83                 goto out1;
  84         }
  85         mfi->mtd = mtd;
  86         file->private_data = mfi;
  87         mutex_unlock(&mtd_mutex);
  88         return 0;
  89
  90 out1:
  91         put_mtd_device(mtd);
  92 out:
  93         mutex_unlock(&mtd_mutex);
  94         return ret;
  95 } /* mtdchar_open */
  96
  97 /*====================================================================*/
  98
  99 static int mtdchar_close(struct inode *inode, struct file *file)
 100 {
 101         struct mtd_file_info *mfi = file->private_data;
 102         struct mtd_info *mtd = mfi->mtd;
 103
 104         pr_debug("MTD_close\n");
 105
 106         /* Only sync if opened RW */
 107         if ((file->f_mode & FMODE_WRITE))
 108                 mtd_sync(mtd);
 109
 110         put_mtd_device(mtd);
 111         file->private_data = NULL;
 112         kfree(mfi);
 113
 114         return 0;
 115 } /* mtdchar_close */
 116
 117 /* Back in June 2001, dwmw2 wrote:
 118  *
 119  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 120  *   userspace buffer down and use it directly with readv/writev.
 121  *
 122  * The implementation below, using mtd_kmalloc_up_to, mitigates
 123  * allocation failures when the system is under low-memory situations
 124  * or if memory is highly fragmented at the cost of reducing the
 125  * performance of the requested transfer due to a smaller buffer size.
 126  *
 127  * A more complex but more memory-efficient implementation based on
 128  * get_user_pages and iovecs to cover extents of those pages is a
 129  * longer-term goal, as intimated by dwmw2 above. However, for the
 130  * write case, this requires yet more complex head and tail transfer
 131  * handling when those head and tail offsets and sizes are such that
 132  * alignment requirements are not met in the NAND subdriver.
 133  */
 134
 135 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 136                         loff_t *ppos)
 137 {
 138         struct mtd_file_info *mfi = file->private_data;
 139         struct mtd_info *mtd = mfi->mtd;
 140         size_t retlen;
 141         size_t total_retlen=0;
 142         int ret=0;
 143         int len;
 144         size_t size = count;
 145         char *kbuf;
 146
 147         pr_debug("MTD_read\n");
 148
 149         if (*ppos + count > mtd->size) {
 150                 if (*ppos < mtd->size)
 151                         count = mtd->size - *ppos;
 152                 else
 153                         count = 0;
 154         }
 155
 156         if (!count)
 157                 return 0;
 158
 159         kbuf = mtd_kmalloc_up_to(mtd, &size);
 160         if (!kbuf)
 161                 return -ENOMEM;
 162
 163         while (count) {
 164                 len = min_t(size_t, count, size);
 165
 166                 switch (mfi->mode) {
 167                 case MTD_FILE_MODE_OTP_FACTORY:
 168                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 169                                                      &retlen, kbuf);
 170                         break;
 171                 case MTD_FILE_MODE_OTP_USER:
 172                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 173                                                      &retlen, kbuf);
 174                         break;
 175                 case MTD_FILE_MODE_RAW:
 176                 {
 177                         struct mtd_oob_ops ops = {};
 178
 179                         ops.mode = MTD_OPS_RAW;
 180                         ops.datbuf = kbuf;
 181                         ops.oobbuf = NULL;
 182                         ops.len = len;
 183
 184                         ret = mtd_read_oob(mtd, *ppos, &ops);
 185                         retlen = ops.retlen;
 186                         break;
 187                 }
 188                 default:
 189                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 190                 }
 191                 /* Nand returns -EBADMSG on ECC errors, but it returns
 192                  * the data. For our userspace tools it is important
 193                  * to dump areas with ECC errors!
 194                  * For kernel internal usage it also might return -EUCLEAN
 195                  * to signal the caller that a bitflip has occurred and has
 196                  * been corrected by the ECC algorithm.
 197                  * Userspace software which accesses NAND this way
 198                  * must be aware of the fact that it deals with NAND
 199                  */
 200                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 201                         *ppos += retlen;
 202                         if (copy_to_user(buf, kbuf, retlen)) {
 203                                 kfree(kbuf);
 204                                 return -EFAULT;
 205                         }
 206                         else
 207                                 total_retlen += retlen;
 208
 209                         count -= retlen;
 210                         buf += retlen;
 211                         if (retlen == 0)
 212                                 count = 0;
 213                 }
 214                 else {
 215                         kfree(kbuf);
 216                         return ret;
 217                 }
 218
 219         }
 220
 221         kfree(kbuf);
 222         return total_retlen;
 223 } /* mtdchar_read */
 224
 225 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 226                         loff_t *ppos)
 227 {
 228         struct mtd_file_info *mfi = file->private_data;
 229         struct mtd_info *mtd = mfi->mtd;
 230         size_t size = count;
 231         char *kbuf;
 232         size_t retlen;
 233         size_t total_retlen=0;
 234         int ret=0;
 235         int len;
 236
 237         pr_debug("MTD_write\n");
 238
 239         if (*ppos >= mtd->size)
 240                 return -ENOSPC;
 241
 242         if (*ppos + count > mtd->size)
 243                 count = mtd->size - *ppos;
 244
 245         if (!count)
 246                 return 0;
 247
 248         kbuf = mtd_kmalloc_up_to(mtd, &size);
 249         if (!kbuf)
 250                 return -ENOMEM;
 251
 252         while (count) {
 253                 len = min_t(size_t, count, size);
 254
 255                 if (copy_from_user(kbuf, buf, len)) {
 256                         kfree(kbuf);
 257                         return -EFAULT;
 258                 }
 259
 260                 switch (mfi->mode) {
 261                 case MTD_FILE_MODE_OTP_FACTORY:
 262                         ret = -EROFS;
 263                         break;
 264                 case MTD_FILE_MODE_OTP_USER:
 265                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 266                                                       &retlen, kbuf);
 267                         break;
 268
 269                 case MTD_FILE_MODE_RAW:
 270                 {
 271                         struct mtd_oob_ops ops = {};
 272
 273                         ops.mode = MTD_OPS_RAW;
 274                         ops.datbuf = kbuf;
 275                         ops.oobbuf = NULL;
 276                         ops.ooboffs = 0;
 277                         ops.len = len;
 278
 279                         ret = mtd_write_oob(mtd, *ppos, &ops);
 280                         retlen = ops.retlen;
 281                         break;
 282                 }
 283
 284                 default:
 285                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 286                 }
 287
 288                 /*
 289                  * Return -ENOSPC only if no data could be written at all.
 290                  * Otherwise just return the number of bytes that actually
 291                  * have been written.
 292                  */
 293                 if ((ret == -ENOSPC) && (total_retlen))
 294                         break;
 295
 296                 if (!ret) {
 297                         *ppos += retlen;
 298                         total_retlen += retlen;
 299                         count -= retlen;
 300                         buf += retlen;
 301                 }
 302                 else {
 303                         kfree(kbuf);
 304                         return ret;
 305                 }
 306         }
 307
 308         kfree(kbuf);
 309         return total_retlen;
 310 } /* mtdchar_write */
 311
 312 /*======================================================================
 313
 314     IOCTL calls for getting device parameters.
 315
 316 ======================================================================*/
 317
 318 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 319 {
 320         struct mtd_info *mtd = mfi->mtd;
 321         size_t retlen;
 322
 323         switch (mode) {
 324         case MTD_OTP_FACTORY:
 325                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 326                                 -EOPNOTSUPP)
 327                         return -EOPNOTSUPP;
 328
 329                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 330                 break;
 331         case MTD_OTP_USER:
 332                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 333                                 -EOPNOTSUPP)
 334                         return -EOPNOTSUPP;
 335
 336                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 337                 break;
 338         case MTD_OTP_OFF:
 339                 mfi->mode = MTD_FILE_MODE_NORMAL;
 340                 break;
 341         default:
 342                 return -EINVAL;
 343         }
 344
 345         return 0;
 346 }
 347
 348 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 349         uint64_t start, uint32_t length, void __user *ptr,
 350         uint32_t __user *retp)
 351 {
 352         struct mtd_file_info *mfi = file->private_data;
 353         struct mtd_oob_ops ops = {};
 354         uint32_t retlen;
 355         int ret = 0;
 356
 357         if (!(file->f_mode & FMODE_WRITE))
 358                 return -EPERM;
 359
 360         if (length > 4096)
 361                 return -EINVAL;
 362
 363         if (!mtd->_write_oob)
 364                 return -EOPNOTSUPP;
 365
 366         ops.ooblen = length;
 367         ops.ooboffs = start & (mtd->writesize - 1);
 368         ops.datbuf = NULL;
 369         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 370                 MTD_OPS_PLACE_OOB;
 371
 372         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 373                 return -EINVAL;
 374
 375         ops.oobbuf = memdup_user(ptr, length);
 376         if (IS_ERR(ops.oobbuf))
 377                 return PTR_ERR(ops.oobbuf);
 378
 379         start &= ~((uint64_t)mtd->writesize - 1);
 380         ret = mtd_write_oob(mtd, start, &ops);
 381
 382         if (ops.oobretlen > 0xFFFFFFFFU)
 383                 ret = -EOVERFLOW;
 384         retlen = ops.oobretlen;
 385         if (copy_to_user(retp, &retlen, sizeof(length)))
 386                 ret = -EFAULT;
 387
 388         kfree(ops.oobbuf);
 389         return ret;
 390 }
 391
 392 static int mtdchar_readoob(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_file_info *mfi = file->private_data;
 397         struct mtd_oob_ops ops = {};
 398         int ret = 0;
 399
 400         if (length > 4096)
 401                 return -EINVAL;
 402
 403         ops.ooblen = length;
 404         ops.ooboffs = start & (mtd->writesize - 1);
 405         ops.datbuf = NULL;
 406         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 407                 MTD_OPS_PLACE_OOB;
 408
 409         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 410                 return -EINVAL;
 411
 412         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 413         if (!ops.oobbuf)
 414                 return -ENOMEM;
 415
 416         start &= ~((uint64_t)mtd->writesize - 1);
 417         ret = mtd_read_oob(mtd, start, &ops);
 418
 419         if (put_user(ops.oobretlen, retp))
 420                 ret = -EFAULT;
 421         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 422                                             ops.oobretlen))
 423                 ret = -EFAULT;
 424
 425         kfree(ops.oobbuf);
 426
 427         /*
 428          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 429          * data. For our userspace tools it is important to dump areas
 430          * with ECC errors!
 431          * For kernel internal usage it also might return -EUCLEAN
 432          * to signal the caller that a bitflip has occurred and has
 433          * been corrected by the ECC algorithm.
 434          *
 435          * Note: currently the standard NAND function, nand_read_oob_std,
 436          * does not calculate ECC for the OOB area, so do not rely on
 437          * this behavior unless you have replaced it with your own.
 438          */
 439         if (mtd_is_bitflip_or_eccerr(ret))
 440                 return 0;
 441
 442         return ret;
 443 }
 444
 445 /*
 446  * Copies (and truncates, if necessary) OOB layout information to the
 447  * deprecated layout struct, nand_ecclayout_user. This is necessary only to
 448  * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
 449  * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
 450  * can describe any kind of OOB layout with almost zero overhead from a
 451  * memory usage point of view).
 452  */
 453 static int shrink_ecclayout(struct mtd_info *mtd,
 454                             struct nand_ecclayout_user *to)
 455 {
 456         struct mtd_oob_region oobregion;
 457         int i, section = 0, ret;
 458
 459         if (!mtd || !to)
 460                 return -EINVAL;
 461
 462         memset(to, 0, sizeof(*to));
 463
 464         to->eccbytes = 0;
 465         for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
 466                 u32 eccpos;
 467
 468                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 469                 if (ret < 0) {
 470                         if (ret != -ERANGE)
 471                                 return ret;
 472
 473                         break;
 474                 }
 475
 476                 eccpos = oobregion.offset;
 477                 for (; i < MTD_MAX_ECCPOS_ENTRIES &&
 478                        eccpos < oobregion.offset + oobregion.length; i++) {
 479                         to->eccpos[i] = eccpos++;
 480                         to->eccbytes++;
 481                 }
 482         }
 483
 484         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 485                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 486                 if (ret < 0) {
 487                         if (ret != -ERANGE)
 488                                 return ret;
 489
 490                         break;
 491                 }
 492
 493                 to->oobfree[i].offset = oobregion.offset;
 494                 to->oobfree[i].length = oobregion.length;
 495                 to->oobavail += to->oobfree[i].length;
 496         }
 497
 498         return 0;
 499 }
 500
 501 static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
 502 {
 503         struct mtd_oob_region oobregion;
 504         int i, section = 0, ret;
 505
 506         if (!mtd || !to)
 507                 return -EINVAL;
 508
 509         memset(to, 0, sizeof(*to));
 510
 511         to->eccbytes = 0;
 512         for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
 513                 u32 eccpos;
 514
 515                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 516                 if (ret < 0) {
 517                         if (ret != -ERANGE)
 518                                 return ret;
 519
 520                         break;
 521                 }
 522
 523                 if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
 524                         return -EINVAL;
 525
 526                 eccpos = oobregion.offset;
 527                 for (; eccpos < oobregion.offset + oobregion.length; i++) {
 528                         to->eccpos[i] = eccpos++;
 529                         to->eccbytes++;
 530                 }
 531         }
 532
 533         for (i = 0; i < 8; i++) {
 534                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 535                 if (ret < 0) {
 536                         if (ret != -ERANGE)
 537                                 return ret;
 538
 539                         break;
 540                 }
 541
 542                 to->oobfree[i][0] = oobregion.offset;
 543                 to->oobfree[i][1] = oobregion.length;
 544         }
 545
 546         to->useecc = MTD_NANDECC_AUTOPLACE;
 547
 548         return 0;
 549 }
 550
 551 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 552                                struct blkpg_ioctl_arg *arg)
 553 {
 554         struct blkpg_partition p;
 555
 556         if (!capable(CAP_SYS_ADMIN))
 557                 return -EPERM;
 558
 559         if (copy_from_user(&p, arg->data, sizeof(p)))
 560                 return -EFAULT;
 561
 562         switch (arg->op) {
 563         case BLKPG_ADD_PARTITION:
 564
 565                 /* Only master mtd device must be used to add partitions */
 566                 if (mtd_is_partition(mtd))
 567                         return -EINVAL;
 568
 569                 /* Sanitize user input */
 570                 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 571
 572                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 573
 574         case BLKPG_DEL_PARTITION:
 575
 576                 if (p.pno < 0)
 577                         return -EINVAL;
 578
 579                 return mtd_del_partition(mtd, p.pno);
 580
 581         default:
 582                 return -EINVAL;
 583         }
 584 }
 585
 586 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 587                 struct mtd_write_req __user *argp)
 588 {
 589         struct mtd_write_req req;
 590         struct mtd_oob_ops ops = {};
 591         const void __user *usr_data, *usr_oob;
 592         int ret;
 593
 594         if (copy_from_user(&req, argp, sizeof(req)))
 595                 return -EFAULT;
 596
 597         usr_data = (const void __user *)(uintptr_t)req.usr_data;
 598         usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 599
 600         if (!mtd->_write_oob)
 601                 return -EOPNOTSUPP;
 602
 603         ops.mode = req.mode;
 604         ops.len = (size_t)req.len;
 605         ops.ooblen = (size_t)req.ooblen;
 606         ops.ooboffs = 0;
 607
 608         if (usr_data) {
 609                 ops.datbuf = memdup_user(usr_data, ops.len);
 610                 if (IS_ERR(ops.datbuf))
 611                         return PTR_ERR(ops.datbuf);
 612         } else {
 613                 ops.datbuf = NULL;
 614         }
 615
 616         if (usr_oob) {
 617                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 618                 if (IS_ERR(ops.oobbuf)) {
 619                         kfree(ops.datbuf);
 620                         return PTR_ERR(ops.oobbuf);
 621                 }
 622         } else {
 623                 ops.oobbuf = NULL;
 624         }
 625
 626         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 627
 628         kfree(ops.datbuf);
 629         kfree(ops.oobbuf);
 630
 631         return ret;
 632 }
 633
 634 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 635 {
 636         struct mtd_file_info *mfi = file->private_data;
 637         struct mtd_info *mtd = mfi->mtd;
 638         void __user *argp = (void __user *)arg;
 639         int ret = 0;
 640         struct mtd_info_user info;
 641
 642         pr_debug("MTD_ioctl\n");
 643
 644         switch (cmd) {
 645         case MEMGETREGIONCOUNT:
 646                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 647                         return -EFAULT;
 648                 break;
 649
 650         case MEMGETREGIONINFO:
 651         {
 652                 uint32_t ur_idx;
 653                 struct mtd_erase_region_info *kr;
 654                 struct region_info_user __user *ur = argp;
 655
 656                 if (get_user(ur_idx, &(ur->regionindex)))
 657                         return -EFAULT;
 658
 659                 if (ur_idx >= mtd->numeraseregions)
 660                         return -EINVAL;
 661
 662                 kr = &(mtd->eraseregions[ur_idx]);
 663
 664                 if (put_user(kr->offset, &(ur->offset))
 665                     || put_user(kr->erasesize, &(ur->erasesize))
 666                     || put_user(kr->numblocks, &(ur->numblocks)))
 667                         return -EFAULT;
 668
 669                 break;
 670         }
 671
 672         case MEMGETINFO:
 673                 memset(&info, 0, sizeof(info));
 674                 info.type       = mtd->type;
 675                 info.flags      = mtd->flags;
 676                 info.size       = mtd->size;
 677                 info.erasesize  = mtd->erasesize;
 678                 info.writesize  = mtd->writesize;
 679                 info.oobsize    = mtd->oobsize;
 680                 /* The below field is obsolete */
 681                 info.padding    = 0;
 682                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 683                         return -EFAULT;
 684                 break;
 685
 686         case MEMERASE:
 687         case MEMERASE64:
 688         {
 689                 struct erase_info *erase;
 690
 691                 if(!(file->f_mode & FMODE_WRITE))
 692                         return -EPERM;
 693
 694                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 695                 if (!erase)
 696                         ret = -ENOMEM;
 697                 else {
 698                         if (cmd == MEMERASE64) {
 699                                 struct erase_info_user64 einfo64;
 700
 701                                 if (copy_from_user(&einfo64, argp,
 702                                             sizeof(struct erase_info_user64))) {
 703                                         kfree(erase);
 704                                         return -EFAULT;
 705                                 }
 706                                 erase->addr = einfo64.start;
 707                                 erase->len = einfo64.length;
 708                         } else {
 709                                 struct erase_info_user einfo32;
 710
 711                                 if (copy_from_user(&einfo32, argp,
 712                                             sizeof(struct erase_info_user))) {
 713                                         kfree(erase);
 714                                         return -EFAULT;
 715                                 }
 716                                 erase->addr = einfo32.start;
 717                                 erase->len = einfo32.length;
 718                         }
 719
 720                         ret = mtd_erase(mtd, erase);
 721                         kfree(erase);
 722                 }
 723                 break;
 724         }
 725
 726         case MEMWRITEOOB:
 727         {
 728                 struct mtd_oob_buf buf;
 729                 struct mtd_oob_buf __user *buf_user = argp;
 730
 731                 /* NOTE: writes return length to buf_user->length */
 732                 if (copy_from_user(&buf, argp, sizeof(buf)))
 733                         ret = -EFAULT;
 734                 else
 735                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 736                                 buf.ptr, &buf_user->length);
 737                 break;
 738         }
 739
 740         case MEMREADOOB:
 741         {
 742                 struct mtd_oob_buf buf;
 743                 struct mtd_oob_buf __user *buf_user = argp;
 744
 745                 /* NOTE: writes return length to buf_user->start */
 746                 if (copy_from_user(&buf, argp, sizeof(buf)))
 747                         ret = -EFAULT;
 748                 else
 749                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 750                                 buf.ptr, &buf_user->start);
 751                 break;
 752         }
 753
 754         case MEMWRITEOOB64:
 755         {
 756                 struct mtd_oob_buf64 buf;
 757                 struct mtd_oob_buf64 __user *buf_user = argp;
 758
 759                 if (copy_from_user(&buf, argp, sizeof(buf)))
 760                         ret = -EFAULT;
 761                 else
 762                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 763                                 (void __user *)(uintptr_t)buf.usr_ptr,
 764                                 &buf_user->length);
 765                 break;
 766         }
 767
 768         case MEMREADOOB64:
 769         {
 770                 struct mtd_oob_buf64 buf;
 771                 struct mtd_oob_buf64 __user *buf_user = argp;
 772
 773                 if (copy_from_user(&buf, argp, sizeof(buf)))
 774                         ret = -EFAULT;
 775                 else
 776                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 777                                 (void __user *)(uintptr_t)buf.usr_ptr,
 778                                 &buf_user->length);
 779                 break;
 780         }
 781
 782         case MEMWRITE:
 783         {
 784                 ret = mtdchar_write_ioctl(mtd,
 785                       (struct mtd_write_req __user *)arg);
 786                 break;
 787         }
 788
 789         case MEMLOCK:
 790         {
 791                 struct erase_info_user einfo;
 792
 793                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 794                         return -EFAULT;
 795
 796                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 797                 break;
 798         }
 799
 800         case MEMUNLOCK:
 801         {
 802                 struct erase_info_user einfo;
 803
 804                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 805                         return -EFAULT;
 806
 807                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 808                 break;
 809         }
 810
 811         case MEMISLOCKED:
 812         {
 813                 struct erase_info_user einfo;
 814
 815                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 816                         return -EFAULT;
 817
 818                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 819                 break;
 820         }
 821
 822         /* Legacy interface */
 823         case MEMGETOOBSEL:
 824         {
 825                 struct nand_oobinfo oi;
 826
 827                 if (!mtd->ooblayout)
 828                         return -EOPNOTSUPP;
 829
 830                 ret = get_oobinfo(mtd, &oi);
 831                 if (ret)
 832                         return ret;
 833
 834                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 835                         return -EFAULT;
 836                 break;
 837         }
 838
 839         case MEMGETBADBLOCK:
 840         {
 841                 loff_t offs;
 842
 843                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 844                         return -EFAULT;
 845                 return mtd_block_isbad(mtd, offs);
 846                 break;
 847         }
 848
 849         case MEMSETBADBLOCK:
 850         {
 851                 loff_t offs;
 852
 853                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 854                         return -EFAULT;
 855                 return mtd_block_markbad(mtd, offs);
 856                 break;
 857         }
 858
 859         case OTPSELECT:
 860         {
 861                 int mode;
 862                 if (copy_from_user(&mode, argp, sizeof(int)))
 863                         return -EFAULT;
 864
 865                 mfi->mode = MTD_FILE_MODE_NORMAL;
 866
 867                 ret = otp_select_filemode(mfi, mode);
 868
 869                 file->f_pos = 0;
 870                 break;
 871         }
 872
 873         case OTPGETREGIONCOUNT:
 874         case OTPGETREGIONINFO:
 875         {
 876                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 877                 size_t retlen;
 878                 if (!buf)
 879                         return -ENOMEM;
 880                 switch (mfi->mode) {
 881                 case MTD_FILE_MODE_OTP_FACTORY:
 882                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 883                         break;
 884                 case MTD_FILE_MODE_OTP_USER:
 885                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 886                         break;
 887                 default:
 888                         ret = -EINVAL;
 889                         break;
 890                 }
 891                 if (!ret) {
 892                         if (cmd == OTPGETREGIONCOUNT) {
 893                                 int nbr = retlen / sizeof(struct otp_info);
 894                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 895                         } else
 896                                 ret = copy_to_user(argp, buf, retlen);
 897                         if (ret)
 898                                 ret = -EFAULT;
 899                 }
 900                 kfree(buf);
 901                 break;
 902         }
 903
 904         case OTPLOCK:
 905         {
 906                 struct otp_info oinfo;
 907
 908                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 909                         return -EINVAL;
 910                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 911                         return -EFAULT;
 912                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 913                 break;
 914         }
 915
 916         /* This ioctl is being deprecated - it truncates the ECC layout */
 917         case ECCGETLAYOUT:
 918         {
 919                 struct nand_ecclayout_user *usrlay;
 920
 921                 if (!mtd->ooblayout)
 922                         return -EOPNOTSUPP;
 923
 924                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 925                 if (!usrlay)
 926                         return -ENOMEM;
 927
 928                 shrink_ecclayout(mtd, usrlay);
 929
 930                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 931                         ret = -EFAULT;
 932                 kfree(usrlay);
 933                 break;
 934         }
 935
 936         case ECCGETSTATS:
 937         {
 938                 if (copy_to_user(argp, &mtd->ecc_stats,
 939                                  sizeof(struct mtd_ecc_stats)))
 940                         return -EFAULT;
 941                 break;
 942         }
 943
 944         case MTDFILEMODE:
 945         {
 946                 mfi->mode = 0;
 947
 948                 switch(arg) {
 949                 case MTD_FILE_MODE_OTP_FACTORY:
 950                 case MTD_FILE_MODE_OTP_USER:
 951                         ret = otp_select_filemode(mfi, arg);
 952                         break;
 953
 954                 case MTD_FILE_MODE_RAW:
 955                         if (!mtd_has_oob(mtd))
 956                                 return -EOPNOTSUPP;
 957                         mfi->mode = arg;
 958
 959                 case MTD_FILE_MODE_NORMAL:
 960                         break;
 961                 default:
 962                         ret = -EINVAL;
 963                 }
 964                 file->f_pos = 0;
 965                 break;
 966         }
 967
 968         case BLKPG:
 969         {
 970                 struct blkpg_ioctl_arg __user *blk_arg = argp;
 971                 struct blkpg_ioctl_arg a;
 972
 973                 if (copy_from_user(&a, blk_arg, sizeof(a)))
 974                         ret = -EFAULT;
 975                 else
 976                         ret = mtdchar_blkpg_ioctl(mtd, &a);
 977                 break;
 978         }
 979
 980         case BLKRRPART:
 981         {
 982                 /* No reread partition feature. Just return ok */
 983                 ret = 0;
 984                 break;
 985         }
 986
 987         default:
 988                 ret = -ENOTTY;
 989         }
 990
 991         return ret;
 992 } /* memory_ioctl */
 993
 994 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 995 {
 996         int ret;
 997
 998         mutex_lock(&mtd_mutex);
 999         ret = mtdchar_ioctl(file, cmd, arg);
1000         mutex_unlock(&mtd_mutex);
1001
1002         return ret;
1003 }
1004
1005 #ifdef CONFIG_COMPAT
1006
1007 struct mtd_oob_buf32 {
1008         u_int32_t start;
1009         u_int32_t length;
1010         compat_caddr_t ptr;     /* unsigned char* */
1011 };
1012
1013 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1014 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1015
1016 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1017         unsigned long arg)
1018 {
1019         struct mtd_file_info *mfi = file->private_data;
1020         struct mtd_info *mtd = mfi->mtd;
1021         void __user *argp = compat_ptr(arg);
1022         int ret = 0;
1023
1024         mutex_lock(&mtd_mutex);
1025
1026         switch (cmd) {
1027         case MEMWRITEOOB32:
1028         {
1029                 struct mtd_oob_buf32 buf;
1030                 struct mtd_oob_buf32 __user *buf_user = argp;
1031
1032                 if (copy_from_user(&buf, argp, sizeof(buf)))
1033                         ret = -EFAULT;
1034                 else
1035                         ret = mtdchar_writeoob(file, mtd, buf.start,
1036                                 buf.length, compat_ptr(buf.ptr),
1037                                 &buf_user->length);
1038                 break;
1039         }
1040
1041         case MEMREADOOB32:
1042         {
1043                 struct mtd_oob_buf32 buf;
1044                 struct mtd_oob_buf32 __user *buf_user = argp;
1045
1046                 /* NOTE: writes return length to buf->start */
1047                 if (copy_from_user(&buf, argp, sizeof(buf)))
1048                         ret = -EFAULT;
1049                 else
1050                         ret = mtdchar_readoob(file, mtd, buf.start,
1051                                 buf.length, compat_ptr(buf.ptr),
1052                                 &buf_user->start);
1053                 break;
1054         }
1055
1056         case BLKPG:
1057         {
1058                 /* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1059                 struct blkpg_compat_ioctl_arg __user *uarg = argp;
1060                 struct blkpg_compat_ioctl_arg compat_arg;
1061                 struct blkpg_ioctl_arg a;
1062
1063                 if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1064                         ret = -EFAULT;
1065                         break;
1066                 }
1067
1068                 memset(&a, 0, sizeof(a));
1069                 a.op = compat_arg.op;
1070                 a.flags = compat_arg.flags;
1071                 a.datalen = compat_arg.datalen;
1072                 a.data = compat_ptr(compat_arg.data);
1073
1074                 ret = mtdchar_blkpg_ioctl(mtd, &a);
1075                 break;
1076         }
1077
1078         default:
1079                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1080         }
1081
1082         mutex_unlock(&mtd_mutex);
1083
1084         return ret;
1085 }
1086
1087 #endif /* CONFIG_COMPAT */
1088
1089 /*
1090  * try to determine where a shared mapping can be made
1091  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1092  *   mappings)
1093  */
1094 #ifndef CONFIG_MMU
1095 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1096                                            unsigned long addr,
1097                                            unsigned long len,
1098                                            unsigned long pgoff,
1099                                            unsigned long flags)
1100 {
1101         struct mtd_file_info *mfi = file->private_data;
1102         struct mtd_info *mtd = mfi->mtd;
1103         unsigned long offset;
1104         int ret;
1105
1106         if (addr != 0)
1107                 return (unsigned long) -EINVAL;
1108
1109         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1110                 return (unsigned long) -EINVAL;
1111
1112         offset = pgoff << PAGE_SHIFT;
1113         if (offset > mtd->size - len)
1114                 return (unsigned long) -EINVAL;
1115
1116         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1117         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1118 }
1119
1120 static unsigned mtdchar_mmap_capabilities(struct file *file)
1121 {
1122         struct mtd_file_info *mfi = file->private_data;
1123
1124         return mtd_mmap_capabilities(mfi->mtd);
1125 }
1126 #endif
1127
1128 /*
1129  * set up a mapping for shared memory segments
1130  */
1131 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1132 {
1133 #ifdef CONFIG_MMU
1134         struct mtd_file_info *mfi = file->private_data;
1135         struct mtd_info *mtd = mfi->mtd;
1136         struct map_info *map = mtd->priv;
1137
1138         /* This is broken because it assumes the MTD device is map-based
1139            and that mtd->priv is a valid struct map_info.  It should be
1140            replaced with something that uses the mtd_get_unmapped_area()
1141            operation properly. */
1142         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1143 #ifdef pgprot_noncached
1144                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1145                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1146 #endif
1147                 return vm_iomap_memory(vma, map->phys, map->size);
1148         }
1149         return -ENODEV;
1150 #else
1151         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1152 #endif
1153 }
1154
1155 static const struct file_operations mtd_fops = {
1156         .owner          = THIS_MODULE,
1157         .llseek         = mtdchar_lseek,
1158         .read           = mtdchar_read,
1159         .write          = mtdchar_write,
1160         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1161 #ifdef CONFIG_COMPAT
1162         .compat_ioctl   = mtdchar_compat_ioctl,
1163 #endif
1164         .open           = mtdchar_open,
1165         .release        = mtdchar_close,
1166         .mmap           = mtdchar_mmap,
1167 #ifndef CONFIG_MMU
1168         .get_unmapped_area = mtdchar_get_unmapped_area,
1169         .mmap_capabilities = mtdchar_mmap_capabilities,
1170 #endif
1171 };
1172
1173 int __init init_mtdchar(void)
1174 {
1175         int ret;
1176
1177         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1178                                    "mtd", &mtd_fops);
1179         if (ret < 0) {
1180                 pr_err("Can't allocate major number %d for MTD\n",
1181                        MTD_CHAR_MAJOR);
1182                 return ret;
1183         }
1184
1185         return ret;
1186 }
1187
1188 void __exit cleanup_mtdchar(void)
1189 {
1190         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1191 }
1192
1193 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);