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 /*
  31  * Data structure to hold the pointer to the mtd device as well
  32  * as mode information of various use cases.
  33  */
  34 struct mtd_file_info {
  35         struct mtd_info *mtd;
  36         enum mtd_file_modes mode;
  37 };
  38
  39 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  40 {
  41         struct mtd_file_info *mfi = file->private_data;
  42         return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  43 }
  44
  45 static int mtdchar_open(struct inode *inode, struct file *file)
  46 {
  47         int minor = iminor(inode);
  48         int devnum = minor >> 1;
  49         int ret = 0;
  50         struct mtd_info *mtd;
  51         struct mtd_file_info *mfi;
  52
  53         pr_debug("MTD_open\n");
  54
  55         /* You can't open the RO devices RW */
  56         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  57                 return -EACCES;
  58
  59         mtd = get_mtd_device(NULL, devnum);
  60
  61         if (IS_ERR(mtd))
  62                 return PTR_ERR(mtd);
  63
  64         if (mtd->type == MTD_ABSENT) {
  65                 ret = -ENODEV;
  66                 goto out1;
  67         }
  68
  69         /* You can't open it RW if it's not a writeable device */
  70         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
  71                 ret = -EACCES;
  72                 goto out1;
  73         }
  74
  75         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
  76         if (!mfi) {
  77                 ret = -ENOMEM;
  78                 goto out1;
  79         }
  80         mfi->mtd = mtd;
  81         file->private_data = mfi;
  82         return 0;
  83
  84 out1:
  85         put_mtd_device(mtd);
  86         return ret;
  87 } /* mtdchar_open */
  88
  89 /*====================================================================*/
  90
  91 static int mtdchar_close(struct inode *inode, struct file *file)
  92 {
  93         struct mtd_file_info *mfi = file->private_data;
  94         struct mtd_info *mtd = mfi->mtd;
  95
  96         pr_debug("MTD_close\n");
  97
  98         /* Only sync if opened RW */
  99         if ((file->f_mode & FMODE_WRITE))
 100                 mtd_sync(mtd);
 101
 102         put_mtd_device(mtd);
 103         file->private_data = NULL;
 104         kfree(mfi);
 105
 106         return 0;
 107 } /* mtdchar_close */
 108
 109 /* Back in June 2001, dwmw2 wrote:
 110  *
 111  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 112  *   userspace buffer down and use it directly with readv/writev.
 113  *
 114  * The implementation below, using mtd_kmalloc_up_to, mitigates
 115  * allocation failures when the system is under low-memory situations
 116  * or if memory is highly fragmented at the cost of reducing the
 117  * performance of the requested transfer due to a smaller buffer size.
 118  *
 119  * A more complex but more memory-efficient implementation based on
 120  * get_user_pages and iovecs to cover extents of those pages is a
 121  * longer-term goal, as intimated by dwmw2 above. However, for the
 122  * write case, this requires yet more complex head and tail transfer
 123  * handling when those head and tail offsets and sizes are such that
 124  * alignment requirements are not met in the NAND subdriver.
 125  */
 126
 127 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 128                         loff_t *ppos)
 129 {
 130         struct mtd_file_info *mfi = file->private_data;
 131         struct mtd_info *mtd = mfi->mtd;
 132         size_t retlen;
 133         size_t total_retlen=0;
 134         int ret=0;
 135         int len;
 136         size_t size = count;
 137         char *kbuf;
 138
 139         pr_debug("MTD_read\n");
 140
 141         if (*ppos + count > mtd->size) {
 142                 if (*ppos < mtd->size)
 143                         count = mtd->size - *ppos;
 144                 else
 145                         count = 0;
 146         }
 147
 148         if (!count)
 149                 return 0;
 150
 151         kbuf = mtd_kmalloc_up_to(mtd, &size);
 152         if (!kbuf)
 153                 return -ENOMEM;
 154
 155         while (count) {
 156                 len = min_t(size_t, count, size);
 157
 158                 switch (mfi->mode) {
 159                 case MTD_FILE_MODE_OTP_FACTORY:
 160                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 161                                                      &retlen, kbuf);
 162                         break;
 163                 case MTD_FILE_MODE_OTP_USER:
 164                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 165                                                      &retlen, kbuf);
 166                         break;
 167                 case MTD_FILE_MODE_RAW:
 168                 {
 169                         struct mtd_oob_ops ops = {};
 170
 171                         ops.mode = MTD_OPS_RAW;
 172                         ops.datbuf = kbuf;
 173                         ops.oobbuf = NULL;
 174                         ops.len = len;
 175
 176                         ret = mtd_read_oob(mtd, *ppos, &ops);
 177                         retlen = ops.retlen;
 178                         break;
 179                 }
 180                 default:
 181                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 182                 }
 183                 /* Nand returns -EBADMSG on ECC errors, but it returns
 184                  * the data. For our userspace tools it is important
 185                  * to dump areas with ECC errors!
 186                  * For kernel internal usage it also might return -EUCLEAN
 187                  * to signal the caller that a bitflip has occurred and has
 188                  * been corrected by the ECC algorithm.
 189                  * Userspace software which accesses NAND this way
 190                  * must be aware of the fact that it deals with NAND
 191                  */
 192                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 193                         *ppos += retlen;
 194                         if (copy_to_user(buf, kbuf, retlen)) {
 195                                 kfree(kbuf);
 196                                 return -EFAULT;
 197                         }
 198                         else
 199                                 total_retlen += retlen;
 200
 201                         count -= retlen;
 202                         buf += retlen;
 203                         if (retlen == 0)
 204                                 count = 0;
 205                 }
 206                 else {
 207                         kfree(kbuf);
 208                         return ret;
 209                 }
 210
 211         }
 212
 213         kfree(kbuf);
 214         return total_retlen;
 215 } /* mtdchar_read */
 216
 217 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 218                         loff_t *ppos)
 219 {
 220         struct mtd_file_info *mfi = file->private_data;
 221         struct mtd_info *mtd = mfi->mtd;
 222         size_t size = count;
 223         char *kbuf;
 224         size_t retlen;
 225         size_t total_retlen=0;
 226         int ret=0;
 227         int len;
 228
 229         pr_debug("MTD_write\n");
 230
 231         if (*ppos >= mtd->size)
 232                 return -ENOSPC;
 233
 234         if (*ppos + count > mtd->size)
 235                 count = mtd->size - *ppos;
 236
 237         if (!count)
 238                 return 0;
 239
 240         kbuf = mtd_kmalloc_up_to(mtd, &size);
 241         if (!kbuf)
 242                 return -ENOMEM;
 243
 244         while (count) {
 245                 len = min_t(size_t, count, size);
 246
 247                 if (copy_from_user(kbuf, buf, len)) {
 248                         kfree(kbuf);
 249                         return -EFAULT;
 250                 }
 251
 252                 switch (mfi->mode) {
 253                 case MTD_FILE_MODE_OTP_FACTORY:
 254                         ret = -EROFS;
 255                         break;
 256                 case MTD_FILE_MODE_OTP_USER:
 257                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 258                                                       &retlen, kbuf);
 259                         break;
 260
 261                 case MTD_FILE_MODE_RAW:
 262                 {
 263                         struct mtd_oob_ops ops = {};
 264
 265                         ops.mode = MTD_OPS_RAW;
 266                         ops.datbuf = kbuf;
 267                         ops.oobbuf = NULL;
 268                         ops.ooboffs = 0;
 269                         ops.len = len;
 270
 271                         ret = mtd_write_oob(mtd, *ppos, &ops);
 272                         retlen = ops.retlen;
 273                         break;
 274                 }
 275
 276                 default:
 277                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 278                 }
 279
 280                 /*
 281                  * Return -ENOSPC only if no data could be written at all.
 282                  * Otherwise just return the number of bytes that actually
 283                  * have been written.
 284                  */
 285                 if ((ret == -ENOSPC) && (total_retlen))
 286                         break;
 287
 288                 if (!ret) {
 289                         *ppos += retlen;
 290                         total_retlen += retlen;
 291                         count -= retlen;
 292                         buf += retlen;
 293                 }
 294                 else {
 295                         kfree(kbuf);
 296                         return ret;
 297                 }
 298         }
 299
 300         kfree(kbuf);
 301         return total_retlen;
 302 } /* mtdchar_write */
 303
 304 /*======================================================================
 305
 306     IOCTL calls for getting device parameters.
 307
 308 ======================================================================*/
 309
 310 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 311 {
 312         struct mtd_info *mtd = mfi->mtd;
 313         size_t retlen;
 314
 315         switch (mode) {
 316         case MTD_OTP_FACTORY:
 317                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 318                                 -EOPNOTSUPP)
 319                         return -EOPNOTSUPP;
 320
 321                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 322                 break;
 323         case MTD_OTP_USER:
 324                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 325                                 -EOPNOTSUPP)
 326                         return -EOPNOTSUPP;
 327
 328                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 329                 break;
 330         case MTD_OTP_OFF:
 331                 mfi->mode = MTD_FILE_MODE_NORMAL;
 332                 break;
 333         default:
 334                 return -EINVAL;
 335         }
 336
 337         return 0;
 338 }
 339
 340 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 341         uint64_t start, uint32_t length, void __user *ptr,
 342         uint32_t __user *retp)
 343 {
 344         struct mtd_info *master  = mtd_get_master(mtd);
 345         struct mtd_file_info *mfi = file->private_data;
 346         struct mtd_oob_ops ops = {};
 347         uint32_t retlen;
 348         int ret = 0;
 349
 350         if (length > 4096)
 351                 return -EINVAL;
 352
 353         if (!master->_write_oob)
 354                 return -EOPNOTSUPP;
 355
 356         ops.ooblen = length;
 357         ops.ooboffs = start & (mtd->writesize - 1);
 358         ops.datbuf = NULL;
 359         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 360                 MTD_OPS_PLACE_OOB;
 361
 362         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 363                 return -EINVAL;
 364
 365         ops.oobbuf = memdup_user(ptr, length);
 366         if (IS_ERR(ops.oobbuf))
 367                 return PTR_ERR(ops.oobbuf);
 368
 369         start &= ~((uint64_t)mtd->writesize - 1);
 370         ret = mtd_write_oob(mtd, start, &ops);
 371
 372         if (ops.oobretlen > 0xFFFFFFFFU)
 373                 ret = -EOVERFLOW;
 374         retlen = ops.oobretlen;
 375         if (copy_to_user(retp, &retlen, sizeof(length)))
 376                 ret = -EFAULT;
 377
 378         kfree(ops.oobbuf);
 379         return ret;
 380 }
 381
 382 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 383         uint64_t start, uint32_t length, void __user *ptr,
 384         uint32_t __user *retp)
 385 {
 386         struct mtd_file_info *mfi = file->private_data;
 387         struct mtd_oob_ops ops = {};
 388         int ret = 0;
 389
 390         if (length > 4096)
 391                 return -EINVAL;
 392
 393         ops.ooblen = length;
 394         ops.ooboffs = start & (mtd->writesize - 1);
 395         ops.datbuf = NULL;
 396         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 397                 MTD_OPS_PLACE_OOB;
 398
 399         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 400                 return -EINVAL;
 401
 402         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 403         if (!ops.oobbuf)
 404                 return -ENOMEM;
 405
 406         start &= ~((uint64_t)mtd->writesize - 1);
 407         ret = mtd_read_oob(mtd, start, &ops);
 408
 409         if (put_user(ops.oobretlen, retp))
 410                 ret = -EFAULT;
 411         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 412                                             ops.oobretlen))
 413                 ret = -EFAULT;
 414
 415         kfree(ops.oobbuf);
 416
 417         /*
 418          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 419          * data. For our userspace tools it is important to dump areas
 420          * with ECC errors!
 421          * For kernel internal usage it also might return -EUCLEAN
 422          * to signal the caller that a bitflip has occurred and has
 423          * been corrected by the ECC algorithm.
 424          *
 425          * Note: currently the standard NAND function, nand_read_oob_std,
 426          * does not calculate ECC for the OOB area, so do not rely on
 427          * this behavior unless you have replaced it with your own.
 428          */
 429         if (mtd_is_bitflip_or_eccerr(ret))
 430                 return 0;
 431
 432         return ret;
 433 }
 434
 435 /*
 436  * Copies (and truncates, if necessary) OOB layout information to the
 437  * deprecated layout struct, nand_ecclayout_user. This is necessary only to
 438  * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
 439  * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
 440  * can describe any kind of OOB layout with almost zero overhead from a
 441  * memory usage point of view).
 442  */
 443 static int shrink_ecclayout(struct mtd_info *mtd,
 444                             struct nand_ecclayout_user *to)
 445 {
 446         struct mtd_oob_region oobregion;
 447         int i, section = 0, ret;
 448
 449         if (!mtd || !to)
 450                 return -EINVAL;
 451
 452         memset(to, 0, sizeof(*to));
 453
 454         to->eccbytes = 0;
 455         for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
 456                 u32 eccpos;
 457
 458                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 459                 if (ret < 0) {
 460                         if (ret != -ERANGE)
 461                                 return ret;
 462
 463                         break;
 464                 }
 465
 466                 eccpos = oobregion.offset;
 467                 for (; i < MTD_MAX_ECCPOS_ENTRIES &&
 468                        eccpos < oobregion.offset + oobregion.length; i++) {
 469                         to->eccpos[i] = eccpos++;
 470                         to->eccbytes++;
 471                 }
 472         }
 473
 474         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 475                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 476                 if (ret < 0) {
 477                         if (ret != -ERANGE)
 478                                 return ret;
 479
 480                         break;
 481                 }
 482
 483                 to->oobfree[i].offset = oobregion.offset;
 484                 to->oobfree[i].length = oobregion.length;
 485                 to->oobavail += to->oobfree[i].length;
 486         }
 487
 488         return 0;
 489 }
 490
 491 static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
 492 {
 493         struct mtd_oob_region oobregion;
 494         int i, section = 0, ret;
 495
 496         if (!mtd || !to)
 497                 return -EINVAL;
 498
 499         memset(to, 0, sizeof(*to));
 500
 501         to->eccbytes = 0;
 502         for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
 503                 u32 eccpos;
 504
 505                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 506                 if (ret < 0) {
 507                         if (ret != -ERANGE)
 508                                 return ret;
 509
 510                         break;
 511                 }
 512
 513                 if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
 514                         return -EINVAL;
 515
 516                 eccpos = oobregion.offset;
 517                 for (; eccpos < oobregion.offset + oobregion.length; i++) {
 518                         to->eccpos[i] = eccpos++;
 519                         to->eccbytes++;
 520                 }
 521         }
 522
 523         for (i = 0; i < 8; i++) {
 524                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 525                 if (ret < 0) {
 526                         if (ret != -ERANGE)
 527                                 return ret;
 528
 529                         break;
 530                 }
 531
 532                 to->oobfree[i][0] = oobregion.offset;
 533                 to->oobfree[i][1] = oobregion.length;
 534         }
 535
 536         to->useecc = MTD_NANDECC_AUTOPLACE;
 537
 538         return 0;
 539 }
 540
 541 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 542                                struct blkpg_ioctl_arg *arg)
 543 {
 544         struct blkpg_partition p;
 545
 546         if (!capable(CAP_SYS_ADMIN))
 547                 return -EPERM;
 548
 549         if (copy_from_user(&p, arg->data, sizeof(p)))
 550                 return -EFAULT;
 551
 552         switch (arg->op) {
 553         case BLKPG_ADD_PARTITION:
 554
 555                 /* Only master mtd device must be used to add partitions */
 556                 if (mtd_is_partition(mtd))
 557                         return -EINVAL;
 558
 559                 /* Sanitize user input */
 560                 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 561
 562                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 563
 564         case BLKPG_DEL_PARTITION:
 565
 566                 if (p.pno < 0)
 567                         return -EINVAL;
 568
 569                 return mtd_del_partition(mtd, p.pno);
 570
 571         default:
 572                 return -EINVAL;
 573         }
 574 }
 575
 576 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 577                 struct mtd_write_req __user *argp)
 578 {
 579         struct mtd_info *master = mtd_get_master(mtd);
 580         struct mtd_write_req req;
 581         struct mtd_oob_ops ops = {};
 582         const void __user *usr_data, *usr_oob;
 583         int ret;
 584
 585         if (copy_from_user(&req, argp, sizeof(req)))
 586                 return -EFAULT;
 587
 588         usr_data = (const void __user *)(uintptr_t)req.usr_data;
 589         usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 590
 591         if (!master->_write_oob)
 592                 return -EOPNOTSUPP;
 593         ops.mode = req.mode;
 594         ops.len = (size_t)req.len;
 595         ops.ooblen = (size_t)req.ooblen;
 596         ops.ooboffs = 0;
 597
 598         if (usr_data) {
 599                 ops.datbuf = memdup_user(usr_data, ops.len);
 600                 if (IS_ERR(ops.datbuf))
 601                         return PTR_ERR(ops.datbuf);
 602         } else {
 603                 ops.datbuf = NULL;
 604         }
 605
 606         if (usr_oob) {
 607                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 608                 if (IS_ERR(ops.oobbuf)) {
 609                         kfree(ops.datbuf);
 610                         return PTR_ERR(ops.oobbuf);
 611                 }
 612         } else {
 613                 ops.oobbuf = NULL;
 614         }
 615
 616         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 617
 618         kfree(ops.datbuf);
 619         kfree(ops.oobbuf);
 620
 621         return ret;
 622 }
 623
 624 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 625 {
 626         struct mtd_file_info *mfi = file->private_data;
 627         struct mtd_info *mtd = mfi->mtd;
 628         struct mtd_info *master = mtd_get_master(mtd);
 629         void __user *argp = (void __user *)arg;
 630         int ret = 0;
 631         struct mtd_info_user info;
 632
 633         pr_debug("MTD_ioctl\n");
 634
 635         /*
 636          * Check the file mode to require "dangerous" commands to have write
 637          * permissions.
 638          */
 639         switch (cmd) {
 640         /* "safe" commands */
 641         case MEMGETREGIONCOUNT:
 642         case MEMGETREGIONINFO:
 643         case MEMGETINFO:
 644         case MEMREADOOB:
 645         case MEMREADOOB64:
 646         case MEMISLOCKED:
 647         case MEMGETOOBSEL:
 648         case MEMGETBADBLOCK:
 649         case OTPSELECT:
 650         case OTPGETREGIONCOUNT:
 651         case OTPGETREGIONINFO:
 652         case ECCGETLAYOUT:
 653         case ECCGETSTATS:
 654         case MTDFILEMODE:
 655         case BLKPG:
 656         case BLKRRPART:
 657                 break;
 658
 659         /* "dangerous" commands */
 660         case MEMERASE:
 661         case MEMERASE64:
 662         case MEMLOCK:
 663         case MEMUNLOCK:
 664         case MEMSETBADBLOCK:
 665         case MEMWRITEOOB:
 666         case MEMWRITEOOB64:
 667         case MEMWRITE:
 668         case OTPLOCK:
 669         case OTPERASE:
 670                 if (!(file->f_mode & FMODE_WRITE))
 671                         return -EPERM;
 672                 break;
 673
 674         default:
 675                 return -ENOTTY;
 676         }
 677
 678         switch (cmd) {
 679         case MEMGETREGIONCOUNT:
 680                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 681                         return -EFAULT;
 682                 break;
 683
 684         case MEMGETREGIONINFO:
 685         {
 686                 uint32_t ur_idx;
 687                 struct mtd_erase_region_info *kr;
 688                 struct region_info_user __user *ur = argp;
 689
 690                 if (get_user(ur_idx, &(ur->regionindex)))
 691                         return -EFAULT;
 692
 693                 if (ur_idx >= mtd->numeraseregions)
 694                         return -EINVAL;
 695
 696                 kr = &(mtd->eraseregions[ur_idx]);
 697
 698                 if (put_user(kr->offset, &(ur->offset))
 699                     || put_user(kr->erasesize, &(ur->erasesize))
 700                     || put_user(kr->numblocks, &(ur->numblocks)))
 701                         return -EFAULT;
 702
 703                 break;
 704         }
 705
 706         case MEMGETINFO:
 707                 memset(&info, 0, sizeof(info));
 708                 info.type       = mtd->type;
 709                 info.flags      = mtd->flags;
 710                 info.size       = mtd->size;
 711                 info.erasesize  = mtd->erasesize;
 712                 info.writesize  = mtd->writesize;
 713                 info.oobsize    = mtd->oobsize;
 714                 /* The below field is obsolete */
 715                 info.padding    = 0;
 716                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 717                         return -EFAULT;
 718                 break;
 719
 720         case MEMERASE:
 721         case MEMERASE64:
 722         {
 723                 struct erase_info *erase;
 724
 725                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 726                 if (!erase)
 727                         ret = -ENOMEM;
 728                 else {
 729                         if (cmd == MEMERASE64) {
 730                                 struct erase_info_user64 einfo64;
 731
 732                                 if (copy_from_user(&einfo64, argp,
 733                                             sizeof(struct erase_info_user64))) {
 734                                         kfree(erase);
 735                                         return -EFAULT;
 736                                 }
 737                                 erase->addr = einfo64.start;
 738                                 erase->len = einfo64.length;
 739                         } else {
 740                                 struct erase_info_user einfo32;
 741
 742                                 if (copy_from_user(&einfo32, argp,
 743                                             sizeof(struct erase_info_user))) {
 744                                         kfree(erase);
 745                                         return -EFAULT;
 746                                 }
 747                                 erase->addr = einfo32.start;
 748                                 erase->len = einfo32.length;
 749                         }
 750
 751                         ret = mtd_erase(mtd, erase);
 752                         kfree(erase);
 753                 }
 754                 break;
 755         }
 756
 757         case MEMWRITEOOB:
 758         {
 759                 struct mtd_oob_buf buf;
 760                 struct mtd_oob_buf __user *buf_user = argp;
 761
 762                 /* NOTE: writes return length to buf_user->length */
 763                 if (copy_from_user(&buf, argp, sizeof(buf)))
 764                         ret = -EFAULT;
 765                 else
 766                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 767                                 buf.ptr, &buf_user->length);
 768                 break;
 769         }
 770
 771         case MEMREADOOB:
 772         {
 773                 struct mtd_oob_buf buf;
 774                 struct mtd_oob_buf __user *buf_user = argp;
 775
 776                 /* NOTE: writes return length to buf_user->start */
 777                 if (copy_from_user(&buf, argp, sizeof(buf)))
 778                         ret = -EFAULT;
 779                 else
 780                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 781                                 buf.ptr, &buf_user->start);
 782                 break;
 783         }
 784
 785         case MEMWRITEOOB64:
 786         {
 787                 struct mtd_oob_buf64 buf;
 788                 struct mtd_oob_buf64 __user *buf_user = argp;
 789
 790                 if (copy_from_user(&buf, argp, sizeof(buf)))
 791                         ret = -EFAULT;
 792                 else
 793                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 794                                 (void __user *)(uintptr_t)buf.usr_ptr,
 795                                 &buf_user->length);
 796                 break;
 797         }
 798
 799         case MEMREADOOB64:
 800         {
 801                 struct mtd_oob_buf64 buf;
 802                 struct mtd_oob_buf64 __user *buf_user = argp;
 803
 804                 if (copy_from_user(&buf, argp, sizeof(buf)))
 805                         ret = -EFAULT;
 806                 else
 807                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 808                                 (void __user *)(uintptr_t)buf.usr_ptr,
 809                                 &buf_user->length);
 810                 break;
 811         }
 812
 813         case MEMWRITE:
 814         {
 815                 ret = mtdchar_write_ioctl(mtd,
 816                       (struct mtd_write_req __user *)arg);
 817                 break;
 818         }
 819
 820         case MEMLOCK:
 821         {
 822                 struct erase_info_user einfo;
 823
 824                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 825                         return -EFAULT;
 826
 827                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 828                 break;
 829         }
 830
 831         case MEMUNLOCK:
 832         {
 833                 struct erase_info_user einfo;
 834
 835                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 836                         return -EFAULT;
 837
 838                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 839                 break;
 840         }
 841
 842         case MEMISLOCKED:
 843         {
 844                 struct erase_info_user einfo;
 845
 846                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 847                         return -EFAULT;
 848
 849                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 850                 break;
 851         }
 852
 853         /* Legacy interface */
 854         case MEMGETOOBSEL:
 855         {
 856                 struct nand_oobinfo oi;
 857
 858                 if (!master->ooblayout)
 859                         return -EOPNOTSUPP;
 860
 861                 ret = get_oobinfo(mtd, &oi);
 862                 if (ret)
 863                         return ret;
 864
 865                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 866                         return -EFAULT;
 867                 break;
 868         }
 869
 870         case MEMGETBADBLOCK:
 871         {
 872                 loff_t offs;
 873
 874                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 875                         return -EFAULT;
 876                 return mtd_block_isbad(mtd, offs);
 877         }
 878
 879         case MEMSETBADBLOCK:
 880         {
 881                 loff_t offs;
 882
 883                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 884                         return -EFAULT;
 885                 return mtd_block_markbad(mtd, offs);
 886         }
 887
 888         case OTPSELECT:
 889         {
 890                 int mode;
 891                 if (copy_from_user(&mode, argp, sizeof(int)))
 892                         return -EFAULT;
 893
 894                 mfi->mode = MTD_FILE_MODE_NORMAL;
 895
 896                 ret = otp_select_filemode(mfi, mode);
 897
 898                 file->f_pos = 0;
 899                 break;
 900         }
 901
 902         case OTPGETREGIONCOUNT:
 903         case OTPGETREGIONINFO:
 904         {
 905                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 906                 size_t retlen;
 907                 if (!buf)
 908                         return -ENOMEM;
 909                 switch (mfi->mode) {
 910                 case MTD_FILE_MODE_OTP_FACTORY:
 911                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 912                         break;
 913                 case MTD_FILE_MODE_OTP_USER:
 914                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 915                         break;
 916                 default:
 917                         ret = -EINVAL;
 918                         break;
 919                 }
 920                 if (!ret) {
 921                         if (cmd == OTPGETREGIONCOUNT) {
 922                                 int nbr = retlen / sizeof(struct otp_info);
 923                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 924                         } else
 925                                 ret = copy_to_user(argp, buf, retlen);
 926                         if (ret)
 927                                 ret = -EFAULT;
 928                 }
 929                 kfree(buf);
 930                 break;
 931         }
 932
 933         case OTPLOCK:
 934         case OTPERASE:
 935         {
 936                 struct otp_info oinfo;
 937
 938                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 939                         return -EINVAL;
 940                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 941                         return -EFAULT;
 942                 if (cmd == OTPLOCK)
 943                         ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 944                 else
 945                         ret = mtd_erase_user_prot_reg(mtd, oinfo.start, oinfo.length);
 946                 break;
 947         }
 948
 949         /* This ioctl is being deprecated - it truncates the ECC layout */
 950         case ECCGETLAYOUT:
 951         {
 952                 struct nand_ecclayout_user *usrlay;
 953
 954                 if (!master->ooblayout)
 955                         return -EOPNOTSUPP;
 956
 957                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 958                 if (!usrlay)
 959                         return -ENOMEM;
 960
 961                 shrink_ecclayout(mtd, usrlay);
 962
 963                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 964                         ret = -EFAULT;
 965                 kfree(usrlay);
 966                 break;
 967         }
 968
 969         case ECCGETSTATS:
 970         {
 971                 if (copy_to_user(argp, &mtd->ecc_stats,
 972                                  sizeof(struct mtd_ecc_stats)))
 973                         return -EFAULT;
 974                 break;
 975         }
 976
 977         case MTDFILEMODE:
 978         {
 979                 mfi->mode = 0;
 980
 981                 switch(arg) {
 982                 case MTD_FILE_MODE_OTP_FACTORY:
 983                 case MTD_FILE_MODE_OTP_USER:
 984                         ret = otp_select_filemode(mfi, arg);
 985                         break;
 986
 987                 case MTD_FILE_MODE_RAW:
 988                         if (!mtd_has_oob(mtd))
 989                                 return -EOPNOTSUPP;
 990                         mfi->mode = arg;
 991                         break;
 992
 993                 case MTD_FILE_MODE_NORMAL:
 994                         break;
 995                 default:
 996                         ret = -EINVAL;
 997                 }
 998                 file->f_pos = 0;
 999                 break;
1000         }
1001
1002         case BLKPG:
1003         {
1004                 struct blkpg_ioctl_arg __user *blk_arg = argp;
1005                 struct blkpg_ioctl_arg a;
1006
1007                 if (copy_from_user(&a, blk_arg, sizeof(a)))
1008                         ret = -EFAULT;
1009                 else
1010                         ret = mtdchar_blkpg_ioctl(mtd, &a);
1011                 break;
1012         }
1013
1014         case BLKRRPART:
1015         {
1016                 /* No reread partition feature. Just return ok */
1017                 ret = 0;
1018                 break;
1019         }
1020         }
1021
1022         return ret;
1023 } /* memory_ioctl */
1024
1025 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1026 {
1027         struct mtd_file_info *mfi = file->private_data;
1028         struct mtd_info *mtd = mfi->mtd;
1029         struct mtd_info *master = mtd_get_master(mtd);
1030         int ret;
1031
1032         mutex_lock(&master->master.chrdev_lock);
1033         ret = mtdchar_ioctl(file, cmd, arg);
1034         mutex_unlock(&master->master.chrdev_lock);
1035
1036         return ret;
1037 }
1038
1039 #ifdef CONFIG_COMPAT
1040
1041 struct mtd_oob_buf32 {
1042         u_int32_t start;
1043         u_int32_t length;
1044         compat_caddr_t ptr;     /* unsigned char* */
1045 };
1046
1047 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1048 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1049
1050 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1051         unsigned long arg)
1052 {
1053         struct mtd_file_info *mfi = file->private_data;
1054         struct mtd_info *mtd = mfi->mtd;
1055         struct mtd_info *master = mtd_get_master(mtd);
1056         void __user *argp = compat_ptr(arg);
1057         int ret = 0;
1058
1059         mutex_lock(&master->master.chrdev_lock);
1060
1061         switch (cmd) {
1062         case MEMWRITEOOB32:
1063         {
1064                 struct mtd_oob_buf32 buf;
1065                 struct mtd_oob_buf32 __user *buf_user = argp;
1066
1067                 if (!(file->f_mode & FMODE_WRITE)) {
1068                         ret = -EPERM;
1069                         break;
1070                 }
1071
1072                 if (copy_from_user(&buf, argp, sizeof(buf)))
1073                         ret = -EFAULT;
1074                 else
1075                         ret = mtdchar_writeoob(file, mtd, buf.start,
1076                                 buf.length, compat_ptr(buf.ptr),
1077                                 &buf_user->length);
1078                 break;
1079         }
1080
1081         case MEMREADOOB32:
1082         {
1083                 struct mtd_oob_buf32 buf;
1084                 struct mtd_oob_buf32 __user *buf_user = argp;
1085
1086                 /* NOTE: writes return length to buf->start */
1087                 if (copy_from_user(&buf, argp, sizeof(buf)))
1088                         ret = -EFAULT;
1089                 else
1090                         ret = mtdchar_readoob(file, mtd, buf.start,
1091                                 buf.length, compat_ptr(buf.ptr),
1092                                 &buf_user->start);
1093                 break;
1094         }
1095
1096         case BLKPG:
1097         {
1098                 /* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1099                 struct blkpg_compat_ioctl_arg __user *uarg = argp;
1100                 struct blkpg_compat_ioctl_arg compat_arg;
1101                 struct blkpg_ioctl_arg a;
1102
1103                 if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1104                         ret = -EFAULT;
1105                         break;
1106                 }
1107
1108                 memset(&a, 0, sizeof(a));
1109                 a.op = compat_arg.op;
1110                 a.flags = compat_arg.flags;
1111                 a.datalen = compat_arg.datalen;
1112                 a.data = compat_ptr(compat_arg.data);
1113
1114                 ret = mtdchar_blkpg_ioctl(mtd, &a);
1115                 break;
1116         }
1117
1118         default:
1119                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1120         }
1121
1122         mutex_unlock(&master->master.chrdev_lock);
1123
1124         return ret;
1125 }
1126
1127 #endif /* CONFIG_COMPAT */
1128
1129 /*
1130  * try to determine where a shared mapping can be made
1131  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1132  *   mappings)
1133  */
1134 #ifndef CONFIG_MMU
1135 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1136                                            unsigned long addr,
1137                                            unsigned long len,
1138                                            unsigned long pgoff,
1139                                            unsigned long flags)
1140 {
1141         struct mtd_file_info *mfi = file->private_data;
1142         struct mtd_info *mtd = mfi->mtd;
1143         unsigned long offset;
1144         int ret;
1145
1146         if (addr != 0)
1147                 return (unsigned long) -EINVAL;
1148
1149         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1150                 return (unsigned long) -EINVAL;
1151
1152         offset = pgoff << PAGE_SHIFT;
1153         if (offset > mtd->size - len)
1154                 return (unsigned long) -EINVAL;
1155
1156         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1157         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1158 }
1159
1160 static unsigned mtdchar_mmap_capabilities(struct file *file)
1161 {
1162         struct mtd_file_info *mfi = file->private_data;
1163
1164         return mtd_mmap_capabilities(mfi->mtd);
1165 }
1166 #endif
1167
1168 /*
1169  * set up a mapping for shared memory segments
1170  */
1171 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1172 {
1173 #ifdef CONFIG_MMU
1174         struct mtd_file_info *mfi = file->private_data;
1175         struct mtd_info *mtd = mfi->mtd;
1176         struct map_info *map = mtd->priv;
1177
1178         /* This is broken because it assumes the MTD device is map-based
1179            and that mtd->priv is a valid struct map_info.  It should be
1180            replaced with something that uses the mtd_get_unmapped_area()
1181            operation properly. */
1182         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1183 #ifdef pgprot_noncached
1184                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1185                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1186 #endif
1187                 return vm_iomap_memory(vma, map->phys, map->size);
1188         }
1189         return -ENODEV;
1190 #else
1191         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1192 #endif
1193 }
1194
1195 static const struct file_operations mtd_fops = {
1196         .owner          = THIS_MODULE,
1197         .llseek         = mtdchar_lseek,
1198         .read           = mtdchar_read,
1199         .write          = mtdchar_write,
1200         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1201 #ifdef CONFIG_COMPAT
1202         .compat_ioctl   = mtdchar_compat_ioctl,
1203 #endif
1204         .open           = mtdchar_open,
1205         .release        = mtdchar_close,
1206         .mmap           = mtdchar_mmap,
1207 #ifndef CONFIG_MMU
1208         .get_unmapped_area = mtdchar_get_unmapped_area,
1209         .mmap_capabilities = mtdchar_mmap_capabilities,
1210 #endif
1211 };
1212
1213 int __init init_mtdchar(void)
1214 {
1215         int ret;
1216
1217         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1218                                    "mtd", &mtd_fops);
1219         if (ret < 0) {
1220                 pr_err("Can't allocate major number %d for MTD\n",
1221                        MTD_CHAR_MAJOR);
1222                 return ret;
1223         }
1224
1225         return ret;
1226 }
1227
1228 void __exit cleanup_mtdchar(void)
1229 {
1230         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1231 }
1232
1233 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);