drivers/mtd/mtdchar.c

   1 /*
   2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  *
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/err.h>
  24 #include <linux/init.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/sched.h>
  29 #include <linux/mutex.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/compat.h>
  32 #include <linux/mount.h>
  33 #include <linux/blkpg.h>
  34 #include <linux/magic.h>
  35 #include <linux/major.h>
  36 #include <linux/mtd/mtd.h>
  37 #include <linux/mtd/partitions.h>
  38 #include <linux/mtd/map.h>
  39
  40 #include <asm/uaccess.h>
  41
  42 #include "mtdcore.h"
  43
  44 static DEFINE_MUTEX(mtd_mutex);
  45
  46 /*
  47  * Data structure to hold the pointer to the mtd device as well
  48  * as mode information of various use cases.
  49  */
  50 struct mtd_file_info {
  51         struct mtd_info *mtd;
  52         enum mtd_file_modes mode;
  53 };
  54
  55 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  56 {
  57         struct mtd_file_info *mfi = file->private_data;
  58         return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  59 }
  60
  61 static int mtdchar_open(struct inode *inode, struct file *file)
  62 {
  63         int minor = iminor(inode);
  64         int devnum = minor >> 1;
  65         int ret = 0;
  66         struct mtd_info *mtd;
  67         struct mtd_file_info *mfi;
  68
  69         pr_debug("MTD_open\n");
  70
  71         /* You can't open the RO devices RW */
  72         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  73                 return -EACCES;
  74
  75         mutex_lock(&mtd_mutex);
  76         mtd = get_mtd_device(NULL, devnum);
  77
  78         if (IS_ERR(mtd)) {
  79                 ret = PTR_ERR(mtd);
  80                 goto out;
  81         }
  82
  83         if (mtd->type == MTD_ABSENT) {
  84                 ret = -ENODEV;
  85                 goto out1;
  86         }
  87
  88         /* You can't open it RW if it's not a writeable device */
  89         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
  90                 ret = -EACCES;
  91                 goto out1;
  92         }
  93
  94         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
  95         if (!mfi) {
  96                 ret = -ENOMEM;
  97                 goto out1;
  98         }
  99         mfi->mtd = mtd;
 100         file->private_data = mfi;
 101         mutex_unlock(&mtd_mutex);
 102         return 0;
 103
 104 out1:
 105         put_mtd_device(mtd);
 106 out:
 107         mutex_unlock(&mtd_mutex);
 108         return ret;
 109 } /* mtdchar_open */
 110
 111 /*====================================================================*/
 112
 113 static int mtdchar_close(struct inode *inode, struct file *file)
 114 {
 115         struct mtd_file_info *mfi = file->private_data;
 116         struct mtd_info *mtd = mfi->mtd;
 117
 118         pr_debug("MTD_close\n");
 119
 120         /* Only sync if opened RW */
 121         if ((file->f_mode & FMODE_WRITE))
 122                 mtd_sync(mtd);
 123
 124         put_mtd_device(mtd);
 125         file->private_data = NULL;
 126         kfree(mfi);
 127
 128         return 0;
 129 } /* mtdchar_close */
 130
 131 /* Back in June 2001, dwmw2 wrote:
 132  *
 133  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 134  *   userspace buffer down and use it directly with readv/writev.
 135  *
 136  * The implementation below, using mtd_kmalloc_up_to, mitigates
 137  * allocation failures when the system is under low-memory situations
 138  * or if memory is highly fragmented at the cost of reducing the
 139  * performance of the requested transfer due to a smaller buffer size.
 140  *
 141  * A more complex but more memory-efficient implementation based on
 142  * get_user_pages and iovecs to cover extents of those pages is a
 143  * longer-term goal, as intimated by dwmw2 above. However, for the
 144  * write case, this requires yet more complex head and tail transfer
 145  * handling when those head and tail offsets and sizes are such that
 146  * alignment requirements are not met in the NAND subdriver.
 147  */
 148
 149 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 150                         loff_t *ppos)
 151 {
 152         struct mtd_file_info *mfi = file->private_data;
 153         struct mtd_info *mtd = mfi->mtd;
 154         size_t retlen;
 155         size_t total_retlen=0;
 156         int ret=0;
 157         int len;
 158         size_t size = count;
 159         char *kbuf;
 160
 161         pr_debug("MTD_read\n");
 162
 163         if (*ppos + count > mtd->size)
 164                 count = mtd->size - *ppos;
 165
 166         if (!count)
 167                 return 0;
 168
 169         kbuf = mtd_kmalloc_up_to(mtd, &size);
 170         if (!kbuf)
 171                 return -ENOMEM;
 172
 173         while (count) {
 174                 len = min_t(size_t, count, size);
 175
 176                 switch (mfi->mode) {
 177                 case MTD_FILE_MODE_OTP_FACTORY:
 178                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 179                                                      &retlen, kbuf);
 180                         break;
 181                 case MTD_FILE_MODE_OTP_USER:
 182                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 183                                                      &retlen, kbuf);
 184                         break;
 185                 case MTD_FILE_MODE_RAW:
 186                 {
 187                         struct mtd_oob_ops ops;
 188
 189                         ops.mode = MTD_OPS_RAW;
 190                         ops.datbuf = kbuf;
 191                         ops.oobbuf = NULL;
 192                         ops.len = len;
 193
 194                         ret = mtd_read_oob(mtd, *ppos, &ops);
 195                         retlen = ops.retlen;
 196                         break;
 197                 }
 198                 default:
 199                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 200                 }
 201                 /* Nand returns -EBADMSG on ECC errors, but it returns
 202                  * the data. For our userspace tools it is important
 203                  * to dump areas with ECC errors!
 204                  * For kernel internal usage it also might return -EUCLEAN
 205                  * to signal the caller that a bitflip has occurred and has
 206                  * been corrected by the ECC algorithm.
 207                  * Userspace software which accesses NAND this way
 208                  * must be aware of the fact that it deals with NAND
 209                  */
 210                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 211                         *ppos += retlen;
 212                         if (copy_to_user(buf, kbuf, retlen)) {
 213                                 kfree(kbuf);
 214                                 return -EFAULT;
 215                         }
 216                         else
 217                                 total_retlen += retlen;
 218
 219                         count -= retlen;
 220                         buf += retlen;
 221                         if (retlen == 0)
 222                                 count = 0;
 223                 }
 224                 else {
 225                         kfree(kbuf);
 226                         return ret;
 227                 }
 228
 229         }
 230
 231         kfree(kbuf);
 232         return total_retlen;
 233 } /* mtdchar_read */
 234
 235 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 236                         loff_t *ppos)
 237 {
 238         struct mtd_file_info *mfi = file->private_data;
 239         struct mtd_info *mtd = mfi->mtd;
 240         size_t size = count;
 241         char *kbuf;
 242         size_t retlen;
 243         size_t total_retlen=0;
 244         int ret=0;
 245         int len;
 246
 247         pr_debug("MTD_write\n");
 248
 249         if (*ppos == mtd->size)
 250                 return -ENOSPC;
 251
 252         if (*ppos + count > mtd->size)
 253                 count = mtd->size - *ppos;
 254
 255         if (!count)
 256                 return 0;
 257
 258         kbuf = mtd_kmalloc_up_to(mtd, &size);
 259         if (!kbuf)
 260                 return -ENOMEM;
 261
 262         while (count) {
 263                 len = min_t(size_t, count, size);
 264
 265                 if (copy_from_user(kbuf, buf, len)) {
 266                         kfree(kbuf);
 267                         return -EFAULT;
 268                 }
 269
 270                 switch (mfi->mode) {
 271                 case MTD_FILE_MODE_OTP_FACTORY:
 272                         ret = -EROFS;
 273                         break;
 274                 case MTD_FILE_MODE_OTP_USER:
 275                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 276                                                       &retlen, kbuf);
 277                         break;
 278
 279                 case MTD_FILE_MODE_RAW:
 280                 {
 281                         struct mtd_oob_ops ops;
 282
 283                         ops.mode = MTD_OPS_RAW;
 284                         ops.datbuf = kbuf;
 285                         ops.oobbuf = NULL;
 286                         ops.ooboffs = 0;
 287                         ops.len = len;
 288
 289                         ret = mtd_write_oob(mtd, *ppos, &ops);
 290                         retlen = ops.retlen;
 291                         break;
 292                 }
 293
 294                 default:
 295                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 296                 }
 297
 298                 /*
 299                  * Return -ENOSPC only if no data could be written at all.
 300                  * Otherwise just return the number of bytes that actually
 301                  * have been written.
 302                  */
 303                 if ((ret == -ENOSPC) && (total_retlen))
 304                         break;
 305
 306                 if (!ret) {
 307                         *ppos += retlen;
 308                         total_retlen += retlen;
 309                         count -= retlen;
 310                         buf += retlen;
 311                 }
 312                 else {
 313                         kfree(kbuf);
 314                         return ret;
 315                 }
 316         }
 317
 318         kfree(kbuf);
 319         return total_retlen;
 320 } /* mtdchar_write */
 321
 322 /*======================================================================
 323
 324     IOCTL calls for getting device parameters.
 325
 326 ======================================================================*/
 327 static void mtdchar_erase_callback (struct erase_info *instr)
 328 {
 329         wake_up((wait_queue_head_t *)instr->priv);
 330 }
 331
 332 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 333 {
 334         struct mtd_info *mtd = mfi->mtd;
 335         size_t retlen;
 336
 337         switch (mode) {
 338         case MTD_OTP_FACTORY:
 339                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 340                                 -EOPNOTSUPP)
 341                         return -EOPNOTSUPP;
 342
 343                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 344                 break;
 345         case MTD_OTP_USER:
 346                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 347                                 -EOPNOTSUPP)
 348                         return -EOPNOTSUPP;
 349
 350                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 351                 break;
 352         case MTD_OTP_OFF:
 353                 mfi->mode = MTD_FILE_MODE_NORMAL;
 354                 break;
 355         default:
 356                 return -EINVAL;
 357         }
 358
 359         return 0;
 360 }
 361
 362 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 363         uint64_t start, uint32_t length, void __user *ptr,
 364         uint32_t __user *retp)
 365 {
 366         struct mtd_file_info *mfi = file->private_data;
 367         struct mtd_oob_ops ops;
 368         uint32_t retlen;
 369         int ret = 0;
 370
 371         if (!(file->f_mode & FMODE_WRITE))
 372                 return -EPERM;
 373
 374         if (length > 4096)
 375                 return -EINVAL;
 376
 377         if (!mtd->_write_oob)
 378                 ret = -EOPNOTSUPP;
 379         else
 380                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 381
 382         if (ret)
 383                 return ret;
 384
 385         ops.ooblen = length;
 386         ops.ooboffs = start & (mtd->writesize - 1);
 387         ops.datbuf = NULL;
 388         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 389                 MTD_OPS_PLACE_OOB;
 390
 391         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 392                 return -EINVAL;
 393
 394         ops.oobbuf = memdup_user(ptr, length);
 395         if (IS_ERR(ops.oobbuf))
 396                 return PTR_ERR(ops.oobbuf);
 397
 398         start &= ~((uint64_t)mtd->writesize - 1);
 399         ret = mtd_write_oob(mtd, start, &ops);
 400
 401         if (ops.oobretlen > 0xFFFFFFFFU)
 402                 ret = -EOVERFLOW;
 403         retlen = ops.oobretlen;
 404         if (copy_to_user(retp, &retlen, sizeof(length)))
 405                 ret = -EFAULT;
 406
 407         kfree(ops.oobbuf);
 408         return ret;
 409 }
 410
 411 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 412         uint64_t start, uint32_t length, void __user *ptr,
 413         uint32_t __user *retp)
 414 {
 415         struct mtd_file_info *mfi = file->private_data;
 416         struct mtd_oob_ops ops;
 417         int ret = 0;
 418
 419         if (length > 4096)
 420                 return -EINVAL;
 421
 422         if (!access_ok(VERIFY_WRITE, ptr, length))
 423                 return -EFAULT;
 424
 425         ops.ooblen = length;
 426         ops.ooboffs = start & (mtd->writesize - 1);
 427         ops.datbuf = NULL;
 428         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 429                 MTD_OPS_PLACE_OOB;
 430
 431         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 432                 return -EINVAL;
 433
 434         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 435         if (!ops.oobbuf)
 436                 return -ENOMEM;
 437
 438         start &= ~((uint64_t)mtd->writesize - 1);
 439         ret = mtd_read_oob(mtd, start, &ops);
 440
 441         if (put_user(ops.oobretlen, retp))
 442                 ret = -EFAULT;
 443         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 444                                             ops.oobretlen))
 445                 ret = -EFAULT;
 446
 447         kfree(ops.oobbuf);
 448
 449         /*
 450          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 451          * data. For our userspace tools it is important to dump areas
 452          * with ECC errors!
 453          * For kernel internal usage it also might return -EUCLEAN
 454          * to signal the caller that a bitflip has occured and has
 455          * been corrected by the ECC algorithm.
 456          *
 457          * Note: currently the standard NAND function, nand_read_oob_std,
 458          * does not calculate ECC for the OOB area, so do not rely on
 459          * this behavior unless you have replaced it with your own.
 460          */
 461         if (mtd_is_bitflip_or_eccerr(ret))
 462                 return 0;
 463
 464         return ret;
 465 }
 466
 467 /*
 468  * Copies (and truncates, if necessary) OOB layout information to the
 469  * deprecated layout struct, nand_ecclayout_user. This is necessary only to
 470  * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
 471  * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
 472  * can describe any kind of OOB layout with almost zero overhead from a
 473  * memory usage point of view).
 474  */
 475 static int shrink_ecclayout(struct mtd_info *mtd,
 476                             struct nand_ecclayout_user *to)
 477 {
 478         struct mtd_oob_region oobregion;
 479         int i, section = 0, ret;
 480
 481         if (!mtd || !to)
 482                 return -EINVAL;
 483
 484         memset(to, 0, sizeof(*to));
 485
 486         to->eccbytes = 0;
 487         for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
 488                 u32 eccpos;
 489
 490                 ret = mtd_ooblayout_ecc(mtd, section, &oobregion);
 491                 if (ret < 0) {
 492                         if (ret != -ERANGE)
 493                                 return ret;
 494
 495                         break;
 496                 }
 497
 498                 eccpos = oobregion.offset;
 499                 for (; i < MTD_MAX_ECCPOS_ENTRIES &&
 500                        eccpos < oobregion.offset + oobregion.length; i++) {
 501                         to->eccpos[i] = eccpos++;
 502                         to->eccbytes++;
 503                 }
 504         }
 505
 506         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 507                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 508                 if (ret < 0) {
 509                         if (ret != -ERANGE)
 510                                 return ret;
 511
 512                         break;
 513                 }
 514
 515                 to->oobfree[i].offset = oobregion.offset;
 516                 to->oobfree[i].length = oobregion.length;
 517                 to->oobavail += to->oobfree[i].length;
 518         }
 519
 520         return 0;
 521 }
 522
 523 static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
 524 {
 525         struct mtd_oob_region oobregion;
 526         int i, section = 0, ret;
 527
 528         if (!mtd || !to)
 529                 return -EINVAL;
 530
 531         memset(to, 0, sizeof(*to));
 532
 533         to->eccbytes = 0;
 534         for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
 535                 u32 eccpos;
 536
 537                 ret = mtd_ooblayout_ecc(mtd, section, &oobregion);
 538                 if (ret < 0) {
 539                         if (ret != -ERANGE)
 540                                 return ret;
 541
 542                         break;
 543                 }
 544
 545                 if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
 546                         return -EINVAL;
 547
 548                 eccpos = oobregion.offset;
 549                 for (; eccpos < oobregion.offset + oobregion.length; i++) {
 550                         to->eccpos[i] = eccpos++;
 551                         to->eccbytes++;
 552                 }
 553         }
 554
 555         for (i = 0; i < 8; i++) {
 556                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 557                 if (ret < 0) {
 558                         if (ret != -ERANGE)
 559                                 return ret;
 560
 561                         break;
 562                 }
 563
 564                 to->oobfree[i][0] = oobregion.offset;
 565                 to->oobfree[i][1] = oobregion.length;
 566         }
 567
 568         to->useecc = MTD_NANDECC_AUTOPLACE;
 569
 570         return 0;
 571 }
 572
 573 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 574                                struct blkpg_ioctl_arg *arg)
 575 {
 576         struct blkpg_partition p;
 577
 578         if (!capable(CAP_SYS_ADMIN))
 579                 return -EPERM;
 580
 581         if (copy_from_user(&p, arg->data, sizeof(p)))
 582                 return -EFAULT;
 583
 584         switch (arg->op) {
 585         case BLKPG_ADD_PARTITION:
 586
 587                 /* Only master mtd device must be used to add partitions */
 588                 if (mtd_is_partition(mtd))
 589                         return -EINVAL;
 590
 591                 /* Sanitize user input */
 592                 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 593
 594                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 595
 596         case BLKPG_DEL_PARTITION:
 597
 598                 if (p.pno < 0)
 599                         return -EINVAL;
 600
 601                 return mtd_del_partition(mtd, p.pno);
 602
 603         default:
 604                 return -EINVAL;
 605         }
 606 }
 607
 608 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 609                 struct mtd_write_req __user *argp)
 610 {
 611         struct mtd_write_req req;
 612         struct mtd_oob_ops ops;
 613         const void __user *usr_data, *usr_oob;
 614         int ret;
 615
 616         if (copy_from_user(&req, argp, sizeof(req)))
 617                 return -EFAULT;
 618
 619         usr_data = (const void __user *)(uintptr_t)req.usr_data;
 620         usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 621         if (!access_ok(VERIFY_READ, usr_data, req.len) ||
 622             !access_ok(VERIFY_READ, usr_oob, req.ooblen))
 623                 return -EFAULT;
 624
 625         if (!mtd->_write_oob)
 626                 return -EOPNOTSUPP;
 627
 628         ops.mode = req.mode;
 629         ops.len = (size_t)req.len;
 630         ops.ooblen = (size_t)req.ooblen;
 631         ops.ooboffs = 0;
 632
 633         if (usr_data) {
 634                 ops.datbuf = memdup_user(usr_data, ops.len);
 635                 if (IS_ERR(ops.datbuf))
 636                         return PTR_ERR(ops.datbuf);
 637         } else {
 638                 ops.datbuf = NULL;
 639         }
 640
 641         if (usr_oob) {
 642                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 643                 if (IS_ERR(ops.oobbuf)) {
 644                         kfree(ops.datbuf);
 645                         return PTR_ERR(ops.oobbuf);
 646                 }
 647         } else {
 648                 ops.oobbuf = NULL;
 649         }
 650
 651         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 652
 653         kfree(ops.datbuf);
 654         kfree(ops.oobbuf);
 655
 656         return ret;
 657 }
 658
 659 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 660 {
 661         struct mtd_file_info *mfi = file->private_data;
 662         struct mtd_info *mtd = mfi->mtd;
 663         void __user *argp = (void __user *)arg;
 664         int ret = 0;
 665         u_long size;
 666         struct mtd_info_user info;
 667
 668         pr_debug("MTD_ioctl\n");
 669
 670         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 671         if (cmd & IOC_IN) {
 672                 if (!access_ok(VERIFY_READ, argp, size))
 673                         return -EFAULT;
 674         }
 675         if (cmd & IOC_OUT) {
 676                 if (!access_ok(VERIFY_WRITE, argp, size))
 677                         return -EFAULT;
 678         }
 679
 680         switch (cmd) {
 681         case MEMGETREGIONCOUNT:
 682                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 683                         return -EFAULT;
 684                 break;
 685
 686         case MEMGETREGIONINFO:
 687         {
 688                 uint32_t ur_idx;
 689                 struct mtd_erase_region_info *kr;
 690                 struct region_info_user __user *ur = argp;
 691
 692                 if (get_user(ur_idx, &(ur->regionindex)))
 693                         return -EFAULT;
 694
 695                 if (ur_idx >= mtd->numeraseregions)
 696                         return -EINVAL;
 697
 698                 kr = &(mtd->eraseregions[ur_idx]);
 699
 700                 if (put_user(kr->offset, &(ur->offset))
 701                     || put_user(kr->erasesize, &(ur->erasesize))
 702                     || put_user(kr->numblocks, &(ur->numblocks)))
 703                         return -EFAULT;
 704
 705                 break;
 706         }
 707
 708         case MEMGETINFO:
 709                 memset(&info, 0, sizeof(info));
 710                 info.type       = mtd->type;
 711                 info.flags      = mtd->flags;
 712                 info.size       = mtd->size;
 713                 info.erasesize  = mtd->erasesize;
 714                 info.writesize  = mtd->writesize;
 715                 info.oobsize    = mtd->oobsize;
 716                 /* The below field is obsolete */
 717                 info.padding    = 0;
 718                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 719                         return -EFAULT;
 720                 break;
 721
 722         case MEMERASE:
 723         case MEMERASE64:
 724         {
 725                 struct erase_info *erase;
 726
 727                 if(!(file->f_mode & FMODE_WRITE))
 728                         return -EPERM;
 729
 730                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 731                 if (!erase)
 732                         ret = -ENOMEM;
 733                 else {
 734                         wait_queue_head_t waitq;
 735                         DECLARE_WAITQUEUE(wait, current);
 736
 737                         init_waitqueue_head(&waitq);
 738
 739                         if (cmd == MEMERASE64) {
 740                                 struct erase_info_user64 einfo64;
 741
 742                                 if (copy_from_user(&einfo64, argp,
 743                                             sizeof(struct erase_info_user64))) {
 744                                         kfree(erase);
 745                                         return -EFAULT;
 746                                 }
 747                                 erase->addr = einfo64.start;
 748                                 erase->len = einfo64.length;
 749                         } else {
 750                                 struct erase_info_user einfo32;
 751
 752                                 if (copy_from_user(&einfo32, argp,
 753                                             sizeof(struct erase_info_user))) {
 754                                         kfree(erase);
 755                                         return -EFAULT;
 756                                 }
 757                                 erase->addr = einfo32.start;
 758                                 erase->len = einfo32.length;
 759                         }
 760                         erase->mtd = mtd;
 761                         erase->callback = mtdchar_erase_callback;
 762                         erase->priv = (unsigned long)&waitq;
 763
 764                         /*
 765                           FIXME: Allow INTERRUPTIBLE. Which means
 766                           not having the wait_queue head on the stack.
 767
 768                           If the wq_head is on the stack, and we
 769                           leave because we got interrupted, then the
 770                           wq_head is no longer there when the
 771                           callback routine tries to wake us up.
 772                         */
 773                         ret = mtd_erase(mtd, erase);
 774                         if (!ret) {
 775                                 set_current_state(TASK_UNINTERRUPTIBLE);
 776                                 add_wait_queue(&waitq, &wait);
 777                                 if (erase->state != MTD_ERASE_DONE &&
 778                                     erase->state != MTD_ERASE_FAILED)
 779                                         schedule();
 780                                 remove_wait_queue(&waitq, &wait);
 781                                 set_current_state(TASK_RUNNING);
 782
 783                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 784                         }
 785                         kfree(erase);
 786                 }
 787                 break;
 788         }
 789
 790         case MEMWRITEOOB:
 791         {
 792                 struct mtd_oob_buf buf;
 793                 struct mtd_oob_buf __user *buf_user = argp;
 794
 795                 /* NOTE: writes return length to buf_user->length */
 796                 if (copy_from_user(&buf, argp, sizeof(buf)))
 797                         ret = -EFAULT;
 798                 else
 799                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 800                                 buf.ptr, &buf_user->length);
 801                 break;
 802         }
 803
 804         case MEMREADOOB:
 805         {
 806                 struct mtd_oob_buf buf;
 807                 struct mtd_oob_buf __user *buf_user = argp;
 808
 809                 /* NOTE: writes return length to buf_user->start */
 810                 if (copy_from_user(&buf, argp, sizeof(buf)))
 811                         ret = -EFAULT;
 812                 else
 813                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 814                                 buf.ptr, &buf_user->start);
 815                 break;
 816         }
 817
 818         case MEMWRITEOOB64:
 819         {
 820                 struct mtd_oob_buf64 buf;
 821                 struct mtd_oob_buf64 __user *buf_user = argp;
 822
 823                 if (copy_from_user(&buf, argp, sizeof(buf)))
 824                         ret = -EFAULT;
 825                 else
 826                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 827                                 (void __user *)(uintptr_t)buf.usr_ptr,
 828                                 &buf_user->length);
 829                 break;
 830         }
 831
 832         case MEMREADOOB64:
 833         {
 834                 struct mtd_oob_buf64 buf;
 835                 struct mtd_oob_buf64 __user *buf_user = argp;
 836
 837                 if (copy_from_user(&buf, argp, sizeof(buf)))
 838                         ret = -EFAULT;
 839                 else
 840                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 841                                 (void __user *)(uintptr_t)buf.usr_ptr,
 842                                 &buf_user->length);
 843                 break;
 844         }
 845
 846         case MEMWRITE:
 847         {
 848                 ret = mtdchar_write_ioctl(mtd,
 849                       (struct mtd_write_req __user *)arg);
 850                 break;
 851         }
 852
 853         case MEMLOCK:
 854         {
 855                 struct erase_info_user einfo;
 856
 857                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 858                         return -EFAULT;
 859
 860                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 861                 break;
 862         }
 863
 864         case MEMUNLOCK:
 865         {
 866                 struct erase_info_user einfo;
 867
 868                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 869                         return -EFAULT;
 870
 871                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 872                 break;
 873         }
 874
 875         case MEMISLOCKED:
 876         {
 877                 struct erase_info_user einfo;
 878
 879                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 880                         return -EFAULT;
 881
 882                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 883                 break;
 884         }
 885
 886         /* Legacy interface */
 887         case MEMGETOOBSEL:
 888         {
 889                 struct nand_oobinfo oi;
 890
 891                 if (!mtd->ooblayout)
 892                         return -EOPNOTSUPP;
 893
 894                 ret = get_oobinfo(mtd, &oi);
 895                 if (ret)
 896                         return ret;
 897
 898                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 899                         return -EFAULT;
 900                 break;
 901         }
 902
 903         case MEMGETBADBLOCK:
 904         {
 905                 loff_t offs;
 906
 907                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 908                         return -EFAULT;
 909                 return mtd_block_isbad(mtd, offs);
 910                 break;
 911         }
 912
 913         case MEMSETBADBLOCK:
 914         {
 915                 loff_t offs;
 916
 917                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 918                         return -EFAULT;
 919                 return mtd_block_markbad(mtd, offs);
 920                 break;
 921         }
 922
 923         case OTPSELECT:
 924         {
 925                 int mode;
 926                 if (copy_from_user(&mode, argp, sizeof(int)))
 927                         return -EFAULT;
 928
 929                 mfi->mode = MTD_FILE_MODE_NORMAL;
 930
 931                 ret = otp_select_filemode(mfi, mode);
 932
 933                 file->f_pos = 0;
 934                 break;
 935         }
 936
 937         case OTPGETREGIONCOUNT:
 938         case OTPGETREGIONINFO:
 939         {
 940                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 941                 size_t retlen;
 942                 if (!buf)
 943                         return -ENOMEM;
 944                 switch (mfi->mode) {
 945                 case MTD_FILE_MODE_OTP_FACTORY:
 946                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 947                         break;
 948                 case MTD_FILE_MODE_OTP_USER:
 949                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 950                         break;
 951                 default:
 952                         ret = -EINVAL;
 953                         break;
 954                 }
 955                 if (!ret) {
 956                         if (cmd == OTPGETREGIONCOUNT) {
 957                                 int nbr = retlen / sizeof(struct otp_info);
 958                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 959                         } else
 960                                 ret = copy_to_user(argp, buf, retlen);
 961                         if (ret)
 962                                 ret = -EFAULT;
 963                 }
 964                 kfree(buf);
 965                 break;
 966         }
 967
 968         case OTPLOCK:
 969         {
 970                 struct otp_info oinfo;
 971
 972                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 973                         return -EINVAL;
 974                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 975                         return -EFAULT;
 976                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 977                 break;
 978         }
 979
 980         /* This ioctl is being deprecated - it truncates the ECC layout */
 981         case ECCGETLAYOUT:
 982         {
 983                 struct nand_ecclayout_user *usrlay;
 984
 985                 if (!mtd->ooblayout)
 986                         return -EOPNOTSUPP;
 987
 988                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 989                 if (!usrlay)
 990                         return -ENOMEM;
 991
 992                 shrink_ecclayout(mtd, usrlay);
 993
 994                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 995                         ret = -EFAULT;
 996                 kfree(usrlay);
 997                 break;
 998         }
 999
1000         case ECCGETSTATS:
1001         {
1002                 if (copy_to_user(argp, &mtd->ecc_stats,
1003                                  sizeof(struct mtd_ecc_stats)))
1004                         return -EFAULT;
1005                 break;
1006         }
1007
1008         case MTDFILEMODE:
1009         {
1010                 mfi->mode = 0;
1011
1012                 switch(arg) {
1013                 case MTD_FILE_MODE_OTP_FACTORY:
1014                 case MTD_FILE_MODE_OTP_USER:
1015                         ret = otp_select_filemode(mfi, arg);
1016                         break;
1017
1018                 case MTD_FILE_MODE_RAW:
1019                         if (!mtd_has_oob(mtd))
1020                                 return -EOPNOTSUPP;
1021                         mfi->mode = arg;
1022
1023                 case MTD_FILE_MODE_NORMAL:
1024                         break;
1025                 default:
1026                         ret = -EINVAL;
1027                 }
1028                 file->f_pos = 0;
1029                 break;
1030         }
1031
1032         case BLKPG:
1033         {
1034                 struct blkpg_ioctl_arg __user *blk_arg = argp;
1035                 struct blkpg_ioctl_arg a;
1036
1037                 if (copy_from_user(&a, blk_arg, sizeof(a)))
1038                         ret = -EFAULT;
1039                 else
1040                         ret = mtdchar_blkpg_ioctl(mtd, &a);
1041                 break;
1042         }
1043
1044         case BLKRRPART:
1045         {
1046                 /* No reread partition feature. Just return ok */
1047                 ret = 0;
1048                 break;
1049         }
1050
1051         default:
1052                 ret = -ENOTTY;
1053         }
1054
1055         return ret;
1056 } /* memory_ioctl */
1057
1058 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1059 {
1060         int ret;
1061
1062         mutex_lock(&mtd_mutex);
1063         ret = mtdchar_ioctl(file, cmd, arg);
1064         mutex_unlock(&mtd_mutex);
1065
1066         return ret;
1067 }
1068
1069 #ifdef CONFIG_COMPAT
1070
1071 struct mtd_oob_buf32 {
1072         u_int32_t start;
1073         u_int32_t length;
1074         compat_caddr_t ptr;     /* unsigned char* */
1075 };
1076
1077 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1078 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1079
1080 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1081         unsigned long arg)
1082 {
1083         struct mtd_file_info *mfi = file->private_data;
1084         struct mtd_info *mtd = mfi->mtd;
1085         void __user *argp = compat_ptr(arg);
1086         int ret = 0;
1087
1088         mutex_lock(&mtd_mutex);
1089
1090         switch (cmd) {
1091         case MEMWRITEOOB32:
1092         {
1093                 struct mtd_oob_buf32 buf;
1094                 struct mtd_oob_buf32 __user *buf_user = argp;
1095
1096                 if (copy_from_user(&buf, argp, sizeof(buf)))
1097                         ret = -EFAULT;
1098                 else
1099                         ret = mtdchar_writeoob(file, mtd, buf.start,
1100                                 buf.length, compat_ptr(buf.ptr),
1101                                 &buf_user->length);
1102                 break;
1103         }
1104
1105         case MEMREADOOB32:
1106         {
1107                 struct mtd_oob_buf32 buf;
1108                 struct mtd_oob_buf32 __user *buf_user = argp;
1109
1110                 /* NOTE: writes return length to buf->start */
1111                 if (copy_from_user(&buf, argp, sizeof(buf)))
1112                         ret = -EFAULT;
1113                 else
1114                         ret = mtdchar_readoob(file, mtd, buf.start,
1115                                 buf.length, compat_ptr(buf.ptr),
1116                                 &buf_user->start);
1117                 break;
1118         }
1119
1120         case BLKPG:
1121         {
1122                 /* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1123                 struct blkpg_compat_ioctl_arg __user *uarg = argp;
1124                 struct blkpg_compat_ioctl_arg compat_arg;
1125                 struct blkpg_ioctl_arg a;
1126
1127                 if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1128                         ret = -EFAULT;
1129                         break;
1130                 }
1131
1132                 memset(&a, 0, sizeof(a));
1133                 a.op = compat_arg.op;
1134                 a.flags = compat_arg.flags;
1135                 a.datalen = compat_arg.datalen;
1136                 a.data = compat_ptr(compat_arg.data);
1137
1138                 ret = mtdchar_blkpg_ioctl(mtd, &a);
1139                 break;
1140         }
1141
1142         default:
1143                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1144         }
1145
1146         mutex_unlock(&mtd_mutex);
1147
1148         return ret;
1149 }
1150
1151 #endif /* CONFIG_COMPAT */
1152
1153 /*
1154  * try to determine where a shared mapping can be made
1155  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1156  *   mappings)
1157  */
1158 #ifndef CONFIG_MMU
1159 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1160                                            unsigned long addr,
1161                                            unsigned long len,
1162                                            unsigned long pgoff,
1163                                            unsigned long flags)
1164 {
1165         struct mtd_file_info *mfi = file->private_data;
1166         struct mtd_info *mtd = mfi->mtd;
1167         unsigned long offset;
1168         int ret;
1169
1170         if (addr != 0)
1171                 return (unsigned long) -EINVAL;
1172
1173         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1174                 return (unsigned long) -EINVAL;
1175
1176         offset = pgoff << PAGE_SHIFT;
1177         if (offset > mtd->size - len)
1178                 return (unsigned long) -EINVAL;
1179
1180         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1181         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1182 }
1183
1184 static unsigned mtdchar_mmap_capabilities(struct file *file)
1185 {
1186         struct mtd_file_info *mfi = file->private_data;
1187
1188         return mtd_mmap_capabilities(mfi->mtd);
1189 }
1190 #endif
1191
1192 /*
1193  * set up a mapping for shared memory segments
1194  */
1195 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1196 {
1197 #ifdef CONFIG_MMU
1198         struct mtd_file_info *mfi = file->private_data;
1199         struct mtd_info *mtd = mfi->mtd;
1200         struct map_info *map = mtd->priv;
1201
1202         /* This is broken because it assumes the MTD device is map-based
1203            and that mtd->priv is a valid struct map_info.  It should be
1204            replaced with something that uses the mtd_get_unmapped_area()
1205            operation properly. */
1206         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1207 #ifdef pgprot_noncached
1208                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1209                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1210 #endif
1211                 return vm_iomap_memory(vma, map->phys, map->size);
1212         }
1213         return -ENODEV;
1214 #else
1215         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1216 #endif
1217 }
1218
1219 static const struct file_operations mtd_fops = {
1220         .owner          = THIS_MODULE,
1221         .llseek         = mtdchar_lseek,
1222         .read           = mtdchar_read,
1223         .write          = mtdchar_write,
1224         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1225 #ifdef CONFIG_COMPAT
1226         .compat_ioctl   = mtdchar_compat_ioctl,
1227 #endif
1228         .open           = mtdchar_open,
1229         .release        = mtdchar_close,
1230         .mmap           = mtdchar_mmap,
1231 #ifndef CONFIG_MMU
1232         .get_unmapped_area = mtdchar_get_unmapped_area,
1233         .mmap_capabilities = mtdchar_mmap_capabilities,
1234 #endif
1235 };
1236
1237 int __init init_mtdchar(void)
1238 {
1239         int ret;
1240
1241         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1242                                    "mtd", &mtd_fops);
1243         if (ret < 0) {
1244                 pr_err("Can't allocate major number %d for MTD\n",
1245                        MTD_CHAR_MAJOR);
1246                 return ret;
1247         }
1248
1249         return ret;
1250 }
1251
1252 void __exit cleanup_mtdchar(void)
1253 {
1254         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1255 }
1256
1257 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);