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 (length > 4096)
 358                 return -EINVAL;
 359
 360         if (!mtd->_write_oob)
 361                 return -EOPNOTSUPP;
 362
 363         ops.ooblen = length;
 364         ops.ooboffs = start & (mtd->writesize - 1);
 365         ops.datbuf = NULL;
 366         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 367                 MTD_OPS_PLACE_OOB;
 368
 369         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 370                 return -EINVAL;
 371
 372         ops.oobbuf = memdup_user(ptr, length);
 373         if (IS_ERR(ops.oobbuf))
 374                 return PTR_ERR(ops.oobbuf);
 375
 376         start &= ~((uint64_t)mtd->writesize - 1);
 377         ret = mtd_write_oob(mtd, start, &ops);
 378
 379         if (ops.oobretlen > 0xFFFFFFFFU)
 380                 ret = -EOVERFLOW;
 381         retlen = ops.oobretlen;
 382         if (copy_to_user(retp, &retlen, sizeof(length)))
 383                 ret = -EFAULT;
 384
 385         kfree(ops.oobbuf);
 386         return ret;
 387 }
 388
 389 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 390         uint64_t start, uint32_t length, void __user *ptr,
 391         uint32_t __user *retp)
 392 {
 393         struct mtd_file_info *mfi = file->private_data;
 394         struct mtd_oob_ops ops;
 395         int ret = 0;
 396
 397         if (length > 4096)
 398                 return -EINVAL;
 399
 400         ops.ooblen = length;
 401         ops.ooboffs = start & (mtd->writesize - 1);
 402         ops.datbuf = NULL;
 403         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 404                 MTD_OPS_PLACE_OOB;
 405
 406         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 407                 return -EINVAL;
 408
 409         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 410         if (!ops.oobbuf)
 411                 return -ENOMEM;
 412
 413         start &= ~((uint64_t)mtd->writesize - 1);
 414         ret = mtd_read_oob(mtd, start, &ops);
 415
 416         if (put_user(ops.oobretlen, retp))
 417                 ret = -EFAULT;
 418         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 419                                             ops.oobretlen))
 420                 ret = -EFAULT;
 421
 422         kfree(ops.oobbuf);
 423
 424         /*
 425          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 426          * data. For our userspace tools it is important to dump areas
 427          * with ECC errors!
 428          * For kernel internal usage it also might return -EUCLEAN
 429          * to signal the caller that a bitflip has occurred and has
 430          * been corrected by the ECC algorithm.
 431          *
 432          * Note: currently the standard NAND function, nand_read_oob_std,
 433          * does not calculate ECC for the OOB area, so do not rely on
 434          * this behavior unless you have replaced it with your own.
 435          */
 436         if (mtd_is_bitflip_or_eccerr(ret))
 437                 return 0;
 438
 439         return ret;
 440 }
 441
 442 /*
 443  * Copies (and truncates, if necessary) OOB layout information to the
 444  * deprecated layout struct, nand_ecclayout_user. This is necessary only to
 445  * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
 446  * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
 447  * can describe any kind of OOB layout with almost zero overhead from a
 448  * memory usage point of view).
 449  */
 450 static int shrink_ecclayout(struct mtd_info *mtd,
 451                             struct nand_ecclayout_user *to)
 452 {
 453         struct mtd_oob_region oobregion;
 454         int i, section = 0, ret;
 455
 456         if (!mtd || !to)
 457                 return -EINVAL;
 458
 459         memset(to, 0, sizeof(*to));
 460
 461         to->eccbytes = 0;
 462         for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
 463                 u32 eccpos;
 464
 465                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 466                 if (ret < 0) {
 467                         if (ret != -ERANGE)
 468                                 return ret;
 469
 470                         break;
 471                 }
 472
 473                 eccpos = oobregion.offset;
 474                 for (; i < MTD_MAX_ECCPOS_ENTRIES &&
 475                        eccpos < oobregion.offset + oobregion.length; i++) {
 476                         to->eccpos[i] = eccpos++;
 477                         to->eccbytes++;
 478                 }
 479         }
 480
 481         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 482                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 483                 if (ret < 0) {
 484                         if (ret != -ERANGE)
 485                                 return ret;
 486
 487                         break;
 488                 }
 489
 490                 to->oobfree[i].offset = oobregion.offset;
 491                 to->oobfree[i].length = oobregion.length;
 492                 to->oobavail += to->oobfree[i].length;
 493         }
 494
 495         return 0;
 496 }
 497
 498 static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
 499 {
 500         struct mtd_oob_region oobregion;
 501         int i, section = 0, ret;
 502
 503         if (!mtd || !to)
 504                 return -EINVAL;
 505
 506         memset(to, 0, sizeof(*to));
 507
 508         to->eccbytes = 0;
 509         for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
 510                 u32 eccpos;
 511
 512                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 513                 if (ret < 0) {
 514                         if (ret != -ERANGE)
 515                                 return ret;
 516
 517                         break;
 518                 }
 519
 520                 if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
 521                         return -EINVAL;
 522
 523                 eccpos = oobregion.offset;
 524                 for (; eccpos < oobregion.offset + oobregion.length; i++) {
 525                         to->eccpos[i] = eccpos++;
 526                         to->eccbytes++;
 527                 }
 528         }
 529
 530         for (i = 0; i < 8; i++) {
 531                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 532                 if (ret < 0) {
 533                         if (ret != -ERANGE)
 534                                 return ret;
 535
 536                         break;
 537                 }
 538
 539                 to->oobfree[i][0] = oobregion.offset;
 540                 to->oobfree[i][1] = oobregion.length;
 541         }
 542
 543         to->useecc = MTD_NANDECC_AUTOPLACE;
 544
 545         return 0;
 546 }
 547
 548 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 549                                struct blkpg_ioctl_arg *arg)
 550 {
 551         struct blkpg_partition p;
 552
 553         if (!capable(CAP_SYS_ADMIN))
 554                 return -EPERM;
 555
 556         if (copy_from_user(&p, arg->data, sizeof(p)))
 557                 return -EFAULT;
 558
 559         switch (arg->op) {
 560         case BLKPG_ADD_PARTITION:
 561
 562                 /* Only master mtd device must be used to add partitions */
 563                 if (mtd_is_partition(mtd))
 564                         return -EINVAL;
 565
 566                 /* Sanitize user input */
 567                 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 568
 569                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 570
 571         case BLKPG_DEL_PARTITION:
 572
 573                 if (p.pno < 0)
 574                         return -EINVAL;
 575
 576                 return mtd_del_partition(mtd, p.pno);
 577
 578         default:
 579                 return -EINVAL;
 580         }
 581 }
 582
 583 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 584                 struct mtd_write_req __user *argp)
 585 {
 586         struct mtd_write_req req;
 587         struct mtd_oob_ops ops;
 588         const void __user *usr_data, *usr_oob;
 589         int ret;
 590
 591         if (copy_from_user(&req, argp, sizeof(req)))
 592                 return -EFAULT;
 593
 594         usr_data = (const void __user *)(uintptr_t)req.usr_data;
 595         usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 596
 597         if (!mtd->_write_oob)
 598                 return -EOPNOTSUPP;
 599
 600         ops.mode = req.mode;
 601         ops.len = (size_t)req.len;
 602         ops.ooblen = (size_t)req.ooblen;
 603         ops.ooboffs = 0;
 604
 605         if (usr_data) {
 606                 ops.datbuf = memdup_user(usr_data, ops.len);
 607                 if (IS_ERR(ops.datbuf))
 608                         return PTR_ERR(ops.datbuf);
 609         } else {
 610                 ops.datbuf = NULL;
 611         }
 612
 613         if (usr_oob) {
 614                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 615                 if (IS_ERR(ops.oobbuf)) {
 616                         kfree(ops.datbuf);
 617                         return PTR_ERR(ops.oobbuf);
 618                 }
 619         } else {
 620                 ops.oobbuf = NULL;
 621         }
 622
 623         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 624
 625         kfree(ops.datbuf);
 626         kfree(ops.oobbuf);
 627
 628         return ret;
 629 }
 630
 631 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 632 {
 633         struct mtd_file_info *mfi = file->private_data;
 634         struct mtd_info *mtd = mfi->mtd;
 635         void __user *argp = (void __user *)arg;
 636         int ret = 0;
 637         struct mtd_info_user info;
 638
 639         pr_debug("MTD_ioctl\n");
 640
 641         /*
 642          * Check the file mode to require "dangerous" commands to have write
 643          * permissions.
 644          */
 645         switch (cmd) {
 646         /* "safe" commands */
 647         case MEMGETREGIONCOUNT:
 648         case MEMGETREGIONINFO:
 649         case MEMGETINFO:
 650         case MEMREADOOB:
 651         case MEMREADOOB64:
 652         case MEMLOCK:
 653         case MEMUNLOCK:
 654         case MEMISLOCKED:
 655         case MEMGETOOBSEL:
 656         case MEMGETBADBLOCK:
 657         case MEMSETBADBLOCK:
 658         case OTPSELECT:
 659         case OTPGETREGIONCOUNT:
 660         case OTPGETREGIONINFO:
 661         case OTPLOCK:
 662         case ECCGETLAYOUT:
 663         case ECCGETSTATS:
 664         case MTDFILEMODE:
 665         case BLKPG:
 666         case BLKRRPART:
 667                 break;
 668
 669         /* "dangerous" commands */
 670         case MEMERASE:
 671         case MEMERASE64:
 672         case MEMWRITEOOB:
 673         case MEMWRITEOOB64:
 674         case MEMWRITE:
 675                 if (!(file->f_mode & FMODE_WRITE))
 676                         return -EPERM;
 677                 break;
 678
 679         default:
 680                 return -ENOTTY;
 681         }
 682
 683         switch (cmd) {
 684         case MEMGETREGIONCOUNT:
 685                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 686                         return -EFAULT;
 687                 break;
 688
 689         case MEMGETREGIONINFO:
 690         {
 691                 uint32_t ur_idx;
 692                 struct mtd_erase_region_info *kr;
 693                 struct region_info_user __user *ur = argp;
 694
 695                 if (get_user(ur_idx, &(ur->regionindex)))
 696                         return -EFAULT;
 697
 698                 if (ur_idx >= mtd->numeraseregions)
 699                         return -EINVAL;
 700
 701                 kr = &(mtd->eraseregions[ur_idx]);
 702
 703                 if (put_user(kr->offset, &(ur->offset))
 704                     || put_user(kr->erasesize, &(ur->erasesize))
 705                     || put_user(kr->numblocks, &(ur->numblocks)))
 706                         return -EFAULT;
 707
 708                 break;
 709         }
 710
 711         case MEMGETINFO:
 712                 memset(&info, 0, sizeof(info));
 713                 info.type       = mtd->type;
 714                 info.flags      = mtd->flags;
 715                 info.size       = mtd->size;
 716                 info.erasesize  = mtd->erasesize;
 717                 info.writesize  = mtd->writesize;
 718                 info.oobsize    = mtd->oobsize;
 719                 /* The below field is obsolete */
 720                 info.padding    = 0;
 721                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 722                         return -EFAULT;
 723                 break;
 724
 725         case MEMERASE:
 726         case MEMERASE64:
 727         {
 728                 struct erase_info *erase;
 729
 730                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 731                 if (!erase)
 732                         ret = -ENOMEM;
 733                 else {
 734                         if (cmd == MEMERASE64) {
 735                                 struct erase_info_user64 einfo64;
 736
 737                                 if (copy_from_user(&einfo64, argp,
 738                                             sizeof(struct erase_info_user64))) {
 739                                         kfree(erase);
 740                                         return -EFAULT;
 741                                 }
 742                                 erase->addr = einfo64.start;
 743                                 erase->len = einfo64.length;
 744                         } else {
 745                                 struct erase_info_user einfo32;
 746
 747                                 if (copy_from_user(&einfo32, argp,
 748                                             sizeof(struct erase_info_user))) {
 749                                         kfree(erase);
 750                                         return -EFAULT;
 751                                 }
 752                                 erase->addr = einfo32.start;
 753                                 erase->len = einfo32.length;
 754                         }
 755
 756                         ret = mtd_erase(mtd, erase);
 757                         kfree(erase);
 758                 }
 759                 break;
 760         }
 761
 762         case MEMWRITEOOB:
 763         {
 764                 struct mtd_oob_buf buf;
 765                 struct mtd_oob_buf __user *buf_user = argp;
 766
 767                 /* NOTE: writes return length to buf_user->length */
 768                 if (copy_from_user(&buf, argp, sizeof(buf)))
 769                         ret = -EFAULT;
 770                 else
 771                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 772                                 buf.ptr, &buf_user->length);
 773                 break;
 774         }
 775
 776         case MEMREADOOB:
 777         {
 778                 struct mtd_oob_buf buf;
 779                 struct mtd_oob_buf __user *buf_user = argp;
 780
 781                 /* NOTE: writes return length to buf_user->start */
 782                 if (copy_from_user(&buf, argp, sizeof(buf)))
 783                         ret = -EFAULT;
 784                 else
 785                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 786                                 buf.ptr, &buf_user->start);
 787                 break;
 788         }
 789
 790         case MEMWRITEOOB64:
 791         {
 792                 struct mtd_oob_buf64 buf;
 793                 struct mtd_oob_buf64 __user *buf_user = argp;
 794
 795                 if (copy_from_user(&buf, argp, sizeof(buf)))
 796                         ret = -EFAULT;
 797                 else
 798                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 799                                 (void __user *)(uintptr_t)buf.usr_ptr,
 800                                 &buf_user->length);
 801                 break;
 802         }
 803
 804         case MEMREADOOB64:
 805         {
 806                 struct mtd_oob_buf64 buf;
 807                 struct mtd_oob_buf64 __user *buf_user = argp;
 808
 809                 if (copy_from_user(&buf, argp, sizeof(buf)))
 810                         ret = -EFAULT;
 811                 else
 812                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 813                                 (void __user *)(uintptr_t)buf.usr_ptr,
 814                                 &buf_user->length);
 815                 break;
 816         }
 817
 818         case MEMWRITE:
 819         {
 820                 ret = mtdchar_write_ioctl(mtd,
 821                       (struct mtd_write_req __user *)arg);
 822                 break;
 823         }
 824
 825         case MEMLOCK:
 826         {
 827                 struct erase_info_user einfo;
 828
 829                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 830                         return -EFAULT;
 831
 832                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 833                 break;
 834         }
 835
 836         case MEMUNLOCK:
 837         {
 838                 struct erase_info_user einfo;
 839
 840                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 841                         return -EFAULT;
 842
 843                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 844                 break;
 845         }
 846
 847         case MEMISLOCKED:
 848         {
 849                 struct erase_info_user einfo;
 850
 851                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 852                         return -EFAULT;
 853
 854                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 855                 break;
 856         }
 857
 858         /* Legacy interface */
 859         case MEMGETOOBSEL:
 860         {
 861                 struct nand_oobinfo oi;
 862
 863                 if (!mtd->ooblayout)
 864                         return -EOPNOTSUPP;
 865
 866                 ret = get_oobinfo(mtd, &oi);
 867                 if (ret)
 868                         return ret;
 869
 870                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 871                         return -EFAULT;
 872                 break;
 873         }
 874
 875         case MEMGETBADBLOCK:
 876         {
 877                 loff_t offs;
 878
 879                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 880                         return -EFAULT;
 881                 return mtd_block_isbad(mtd, offs);
 882                 break;
 883         }
 884
 885         case MEMSETBADBLOCK:
 886         {
 887                 loff_t offs;
 888
 889                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 890                         return -EFAULT;
 891                 return mtd_block_markbad(mtd, offs);
 892                 break;
 893         }
 894
 895         case OTPSELECT:
 896         {
 897                 int mode;
 898                 if (copy_from_user(&mode, argp, sizeof(int)))
 899                         return -EFAULT;
 900
 901                 mfi->mode = MTD_FILE_MODE_NORMAL;
 902
 903                 ret = otp_select_filemode(mfi, mode);
 904
 905                 file->f_pos = 0;
 906                 break;
 907         }
 908
 909         case OTPGETREGIONCOUNT:
 910         case OTPGETREGIONINFO:
 911         {
 912                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 913                 size_t retlen;
 914                 if (!buf)
 915                         return -ENOMEM;
 916                 switch (mfi->mode) {
 917                 case MTD_FILE_MODE_OTP_FACTORY:
 918                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 919                         break;
 920                 case MTD_FILE_MODE_OTP_USER:
 921                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 922                         break;
 923                 default:
 924                         ret = -EINVAL;
 925                         break;
 926                 }
 927                 if (!ret) {
 928                         if (cmd == OTPGETREGIONCOUNT) {
 929                                 int nbr = retlen / sizeof(struct otp_info);
 930                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 931                         } else
 932                                 ret = copy_to_user(argp, buf, retlen);
 933                         if (ret)
 934                                 ret = -EFAULT;
 935                 }
 936                 kfree(buf);
 937                 break;
 938         }
 939
 940         case OTPLOCK:
 941         {
 942                 struct otp_info oinfo;
 943
 944                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 945                         return -EINVAL;
 946                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 947                         return -EFAULT;
 948                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 949                 break;
 950         }
 951
 952         /* This ioctl is being deprecated - it truncates the ECC layout */
 953         case ECCGETLAYOUT:
 954         {
 955                 struct nand_ecclayout_user *usrlay;
 956
 957                 if (!mtd->ooblayout)
 958                         return -EOPNOTSUPP;
 959
 960                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 961                 if (!usrlay)
 962                         return -ENOMEM;
 963
 964                 shrink_ecclayout(mtd, usrlay);
 965
 966                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 967                         ret = -EFAULT;
 968                 kfree(usrlay);
 969                 break;
 970         }
 971
 972         case ECCGETSTATS:
 973         {
 974                 if (copy_to_user(argp, &mtd->ecc_stats,
 975                                  sizeof(struct mtd_ecc_stats)))
 976                         return -EFAULT;
 977                 break;
 978         }
 979
 980         case MTDFILEMODE:
 981         {
 982                 mfi->mode = 0;
 983
 984                 switch(arg) {
 985                 case MTD_FILE_MODE_OTP_FACTORY:
 986                 case MTD_FILE_MODE_OTP_USER:
 987                         ret = otp_select_filemode(mfi, arg);
 988                         break;
 989
 990                 case MTD_FILE_MODE_RAW:
 991                         if (!mtd_has_oob(mtd))
 992                                 return -EOPNOTSUPP;
 993                         mfi->mode = arg;
 994
 995                 case MTD_FILE_MODE_NORMAL:
 996                         break;
 997                 default:
 998                         ret = -EINVAL;
 999                 }
1000                 file->f_pos = 0;
1001                 break;
1002         }
1003
1004         case BLKPG:
1005         {
1006                 struct blkpg_ioctl_arg __user *blk_arg = argp;
1007                 struct blkpg_ioctl_arg a;
1008
1009                 if (copy_from_user(&a, blk_arg, sizeof(a)))
1010                         ret = -EFAULT;
1011                 else
1012                         ret = mtdchar_blkpg_ioctl(mtd, &a);
1013                 break;
1014         }
1015
1016         case BLKRRPART:
1017         {
1018                 /* No reread partition feature. Just return ok */
1019                 ret = 0;
1020                 break;
1021         }
1022         }
1023
1024         return ret;
1025 } /* memory_ioctl */
1026
1027 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1028 {
1029         int ret;
1030
1031         mutex_lock(&mtd_mutex);
1032         ret = mtdchar_ioctl(file, cmd, arg);
1033         mutex_unlock(&mtd_mutex);
1034
1035         return ret;
1036 }
1037
1038 #ifdef CONFIG_COMPAT
1039
1040 struct mtd_oob_buf32 {
1041         u_int32_t start;
1042         u_int32_t length;
1043         compat_caddr_t ptr;     /* unsigned char* */
1044 };
1045
1046 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1047 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1048
1049 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1050         unsigned long arg)
1051 {
1052         struct mtd_file_info *mfi = file->private_data;
1053         struct mtd_info *mtd = mfi->mtd;
1054         void __user *argp = compat_ptr(arg);
1055         int ret = 0;
1056
1057         mutex_lock(&mtd_mutex);
1058
1059         switch (cmd) {
1060         case MEMWRITEOOB32:
1061         {
1062                 struct mtd_oob_buf32 buf;
1063                 struct mtd_oob_buf32 __user *buf_user = argp;
1064
1065                 if (!(file->f_mode & FMODE_WRITE)) {
1066                         ret = -EPERM;
1067                         break;
1068                 }
1069
1070                 if (copy_from_user(&buf, argp, sizeof(buf)))
1071                         ret = -EFAULT;
1072                 else
1073                         ret = mtdchar_writeoob(file, mtd, buf.start,
1074                                 buf.length, compat_ptr(buf.ptr),
1075                                 &buf_user->length);
1076                 break;
1077         }
1078
1079         case MEMREADOOB32:
1080         {
1081                 struct mtd_oob_buf32 buf;
1082                 struct mtd_oob_buf32 __user *buf_user = argp;
1083
1084                 /* NOTE: writes return length to buf->start */
1085                 if (copy_from_user(&buf, argp, sizeof(buf)))
1086                         ret = -EFAULT;
1087                 else
1088                         ret = mtdchar_readoob(file, mtd, buf.start,
1089                                 buf.length, compat_ptr(buf.ptr),
1090                                 &buf_user->start);
1091                 break;
1092         }
1093
1094         case BLKPG:
1095         {
1096                 /* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1097                 struct blkpg_compat_ioctl_arg __user *uarg = argp;
1098                 struct blkpg_compat_ioctl_arg compat_arg;
1099                 struct blkpg_ioctl_arg a;
1100
1101                 if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1102                         ret = -EFAULT;
1103                         break;
1104                 }
1105
1106                 memset(&a, 0, sizeof(a));
1107                 a.op = compat_arg.op;
1108                 a.flags = compat_arg.flags;
1109                 a.datalen = compat_arg.datalen;
1110                 a.data = compat_ptr(compat_arg.data);
1111
1112                 ret = mtdchar_blkpg_ioctl(mtd, &a);
1113                 break;
1114         }
1115
1116         default:
1117                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1118         }
1119
1120         mutex_unlock(&mtd_mutex);
1121
1122         return ret;
1123 }
1124
1125 #endif /* CONFIG_COMPAT */
1126
1127 /*
1128  * try to determine where a shared mapping can be made
1129  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1130  *   mappings)
1131  */
1132 #ifndef CONFIG_MMU
1133 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1134                                            unsigned long addr,
1135                                            unsigned long len,
1136                                            unsigned long pgoff,
1137                                            unsigned long flags)
1138 {
1139         struct mtd_file_info *mfi = file->private_data;
1140         struct mtd_info *mtd = mfi->mtd;
1141         unsigned long offset;
1142         int ret;
1143
1144         if (addr != 0)
1145                 return (unsigned long) -EINVAL;
1146
1147         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1148                 return (unsigned long) -EINVAL;
1149
1150         offset = pgoff << PAGE_SHIFT;
1151         if (offset > mtd->size - len)
1152                 return (unsigned long) -EINVAL;
1153
1154         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1155         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1156 }
1157
1158 static unsigned mtdchar_mmap_capabilities(struct file *file)
1159 {
1160         struct mtd_file_info *mfi = file->private_data;
1161
1162         return mtd_mmap_capabilities(mfi->mtd);
1163 }
1164 #endif
1165
1166 /*
1167  * set up a mapping for shared memory segments
1168  */
1169 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1170 {
1171 #ifdef CONFIG_MMU
1172         struct mtd_file_info *mfi = file->private_data;
1173         struct mtd_info *mtd = mfi->mtd;
1174         struct map_info *map = mtd->priv;
1175
1176         /* This is broken because it assumes the MTD device is map-based
1177            and that mtd->priv is a valid struct map_info.  It should be
1178            replaced with something that uses the mtd_get_unmapped_area()
1179            operation properly. */
1180         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1181 #ifdef pgprot_noncached
1182                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1183                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1184 #endif
1185                 return vm_iomap_memory(vma, map->phys, map->size);
1186         }
1187         return -ENODEV;
1188 #else
1189         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1190 #endif
1191 }
1192
1193 static const struct file_operations mtd_fops = {
1194         .owner          = THIS_MODULE,
1195         .llseek         = mtdchar_lseek,
1196         .read           = mtdchar_read,
1197         .write          = mtdchar_write,
1198         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1199 #ifdef CONFIG_COMPAT
1200         .compat_ioctl   = mtdchar_compat_ioctl,
1201 #endif
1202         .open           = mtdchar_open,
1203         .release        = mtdchar_close,
1204         .mmap           = mtdchar_mmap,
1205 #ifndef CONFIG_MMU
1206         .get_unmapped_area = mtdchar_get_unmapped_area,
1207         .mmap_capabilities = mtdchar_mmap_capabilities,
1208 #endif
1209 };
1210
1211 int __init init_mtdchar(void)
1212 {
1213         int ret;
1214
1215         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1216                                    "mtd", &mtd_fops);
1217         if (ret < 0) {
1218                 pr_err("Can't allocate major number %d for MTD\n",
1219                        MTD_CHAR_MAJOR);
1220                 return ret;
1221         }
1222
1223         return ret;
1224 }
1225
1226 void __exit cleanup_mtdchar(void)
1227 {
1228         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1229 }
1230
1231 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);