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/mtd/mtd.h>
  35 #include <linux/mtd/partitions.h>
  36 #include <linux/mtd/map.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 #define MTD_INODE_FS_MAGIC 0x11307854
  41 static DEFINE_MUTEX(mtd_mutex);
  42 static struct vfsmount *mtd_inode_mnt __read_mostly;
  43
  44 /*
  45  * Data structure to hold the pointer to the mtd device as well
  46  * as mode information of various use cases.
  47  */
  48 struct mtd_file_info {
  49         struct mtd_info *mtd;
  50         struct inode *ino;
  51         enum mtd_file_modes mode;
  52 };
  53
  54 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  55 {
  56         struct mtd_file_info *mfi = file->private_data;
  57         struct mtd_info *mtd = mfi->mtd;
  58
  59         switch (orig) {
  60         case SEEK_SET:
  61                 break;
  62         case SEEK_CUR:
  63                 offset += file->f_pos;
  64                 break;
  65         case SEEK_END:
  66                 offset += mtd->size;
  67                 break;
  68         default:
  69                 return -EINVAL;
  70         }
  71
  72         if (offset >= 0 && offset <= mtd->size)
  73                 return file->f_pos = offset;
  74
  75         return -EINVAL;
  76 }
  77
  78
  79
  80 static int mtd_open(struct inode *inode, struct file *file)
  81 {
  82         int minor = iminor(inode);
  83         int devnum = minor >> 1;
  84         int ret = 0;
  85         struct mtd_info *mtd;
  86         struct mtd_file_info *mfi;
  87         struct inode *mtd_ino;
  88
  89         pr_debug("MTD_open\n");
  90
  91         /* You can't open the RO devices RW */
  92         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  93                 return -EACCES;
  94
  95         mutex_lock(&mtd_mutex);
  96         mtd = get_mtd_device(NULL, devnum);
  97
  98         if (IS_ERR(mtd)) {
  99                 ret = PTR_ERR(mtd);
 100                 goto out;
 101         }
 102
 103         if (mtd->type == MTD_ABSENT) {
 104                 put_mtd_device(mtd);
 105                 ret = -ENODEV;
 106                 goto out;
 107         }
 108
 109         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 110         if (!mtd_ino) {
 111                 put_mtd_device(mtd);
 112                 ret = -ENOMEM;
 113                 goto out;
 114         }
 115         if (mtd_ino->i_state & I_NEW) {
 116                 mtd_ino->i_private = mtd;
 117                 mtd_ino->i_mode = S_IFCHR;
 118                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 119                 unlock_new_inode(mtd_ino);
 120         }
 121         file->f_mapping = mtd_ino->i_mapping;
 122
 123         /* You can't open it RW if it's not a writeable device */
 124         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 125                 iput(mtd_ino);
 126                 put_mtd_device(mtd);
 127                 ret = -EACCES;
 128                 goto out;
 129         }
 130
 131         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 132         if (!mfi) {
 133                 iput(mtd_ino);
 134                 put_mtd_device(mtd);
 135                 ret = -ENOMEM;
 136                 goto out;
 137         }
 138         mfi->ino = mtd_ino;
 139         mfi->mtd = mtd;
 140         file->private_data = mfi;
 141
 142 out:
 143         mutex_unlock(&mtd_mutex);
 144         return ret;
 145 } /* mtd_open */
 146
 147 /*====================================================================*/
 148
 149 static int mtd_close(struct inode *inode, struct file *file)
 150 {
 151         struct mtd_file_info *mfi = file->private_data;
 152         struct mtd_info *mtd = mfi->mtd;
 153
 154         pr_debug("MTD_close\n");
 155
 156         /* Only sync if opened RW */
 157         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 158                 mtd->sync(mtd);
 159
 160         iput(mfi->ino);
 161
 162         put_mtd_device(mtd);
 163         file->private_data = NULL;
 164         kfree(mfi);
 165
 166         return 0;
 167 } /* mtd_close */
 168
 169 /* Back in June 2001, dwmw2 wrote:
 170  *
 171  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 172  *   userspace buffer down and use it directly with readv/writev.
 173  *
 174  * The implementation below, using mtd_kmalloc_up_to, mitigates
 175  * allocation failures when the system is under low-memory situations
 176  * or if memory is highly fragmented at the cost of reducing the
 177  * performance of the requested transfer due to a smaller buffer size.
 178  *
 179  * A more complex but more memory-efficient implementation based on
 180  * get_user_pages and iovecs to cover extents of those pages is a
 181  * longer-term goal, as intimated by dwmw2 above. However, for the
 182  * write case, this requires yet more complex head and tail transfer
 183  * handling when those head and tail offsets and sizes are such that
 184  * alignment requirements are not met in the NAND subdriver.
 185  */
 186
 187 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 188 {
 189         struct mtd_file_info *mfi = file->private_data;
 190         struct mtd_info *mtd = mfi->mtd;
 191         size_t retlen=0;
 192         size_t total_retlen=0;
 193         int ret=0;
 194         int len;
 195         size_t size = count;
 196         char *kbuf;
 197
 198         pr_debug("MTD_read\n");
 199
 200         if (*ppos + count > mtd->size)
 201                 count = mtd->size - *ppos;
 202
 203         if (!count)
 204                 return 0;
 205
 206         kbuf = mtd_kmalloc_up_to(mtd, &size);
 207         if (!kbuf)
 208                 return -ENOMEM;
 209
 210         while (count) {
 211                 len = min_t(size_t, count, size);
 212
 213                 switch (mfi->mode) {
 214                 case MTD_FILE_MODE_OTP_FACTORY:
 215                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 216                         break;
 217                 case MTD_FILE_MODE_OTP_USER:
 218                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 219                         break;
 220                 case MTD_FILE_MODE_RAW:
 221                 {
 222                         struct mtd_oob_ops ops;
 223
 224                         ops.mode = MTD_OPS_RAW;
 225                         ops.datbuf = kbuf;
 226                         ops.oobbuf = NULL;
 227                         ops.len = len;
 228
 229                         ret = mtd->read_oob(mtd, *ppos, &ops);
 230                         retlen = ops.retlen;
 231                         break;
 232                 }
 233                 default:
 234                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 235                 }
 236                 /* Nand returns -EBADMSG on ECC errors, but it returns
 237                  * the data. For our userspace tools it is important
 238                  * to dump areas with ECC errors!
 239                  * For kernel internal usage it also might return -EUCLEAN
 240                  * to signal the caller that a bitflip has occurred and has
 241                  * been corrected by the ECC algorithm.
 242                  * Userspace software which accesses NAND this way
 243                  * must be aware of the fact that it deals with NAND
 244                  */
 245                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 246                         *ppos += retlen;
 247                         if (copy_to_user(buf, kbuf, retlen)) {
 248                                 kfree(kbuf);
 249                                 return -EFAULT;
 250                         }
 251                         else
 252                                 total_retlen += retlen;
 253
 254                         count -= retlen;
 255                         buf += retlen;
 256                         if (retlen == 0)
 257                                 count = 0;
 258                 }
 259                 else {
 260                         kfree(kbuf);
 261                         return ret;
 262                 }
 263
 264         }
 265
 266         kfree(kbuf);
 267         return total_retlen;
 268 } /* mtd_read */
 269
 270 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 271 {
 272         struct mtd_file_info *mfi = file->private_data;
 273         struct mtd_info *mtd = mfi->mtd;
 274         size_t size = count;
 275         char *kbuf;
 276         size_t retlen;
 277         size_t total_retlen=0;
 278         int ret=0;
 279         int len;
 280
 281         pr_debug("MTD_write\n");
 282
 283         if (*ppos == mtd->size)
 284                 return -ENOSPC;
 285
 286         if (*ppos + count > mtd->size)
 287                 count = mtd->size - *ppos;
 288
 289         if (!count)
 290                 return 0;
 291
 292         kbuf = mtd_kmalloc_up_to(mtd, &size);
 293         if (!kbuf)
 294                 return -ENOMEM;
 295
 296         while (count) {
 297                 len = min_t(size_t, count, size);
 298
 299                 if (copy_from_user(kbuf, buf, len)) {
 300                         kfree(kbuf);
 301                         return -EFAULT;
 302                 }
 303
 304                 switch (mfi->mode) {
 305                 case MTD_FILE_MODE_OTP_FACTORY:
 306                         ret = -EROFS;
 307                         break;
 308                 case MTD_FILE_MODE_OTP_USER:
 309                         if (!mtd->write_user_prot_reg) {
 310                                 ret = -EOPNOTSUPP;
 311                                 break;
 312                         }
 313                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 314                         break;
 315
 316                 case MTD_FILE_MODE_RAW:
 317                 {
 318                         struct mtd_oob_ops ops;
 319
 320                         ops.mode = MTD_OPS_RAW;
 321                         ops.datbuf = kbuf;
 322                         ops.oobbuf = NULL;
 323                         ops.ooboffs = 0;
 324                         ops.len = len;
 325
 326                         ret = mtd->write_oob(mtd, *ppos, &ops);
 327                         retlen = ops.retlen;
 328                         break;
 329                 }
 330
 331                 default:
 332                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 333                 }
 334                 if (!ret) {
 335                         *ppos += retlen;
 336                         total_retlen += retlen;
 337                         count -= retlen;
 338                         buf += retlen;
 339                 }
 340                 else {
 341                         kfree(kbuf);
 342                         return ret;
 343                 }
 344         }
 345
 346         kfree(kbuf);
 347         return total_retlen;
 348 } /* mtd_write */
 349
 350 /*======================================================================
 351
 352     IOCTL calls for getting device parameters.
 353
 354 ======================================================================*/
 355 static void mtdchar_erase_callback (struct erase_info *instr)
 356 {
 357         wake_up((wait_queue_head_t *)instr->priv);
 358 }
 359
 360 #ifdef CONFIG_HAVE_MTD_OTP
 361 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 362 {
 363         struct mtd_info *mtd = mfi->mtd;
 364         int ret = 0;
 365
 366         switch (mode) {
 367         case MTD_OTP_FACTORY:
 368                 if (!mtd->read_fact_prot_reg)
 369                         ret = -EOPNOTSUPP;
 370                 else
 371                         mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 372                 break;
 373         case MTD_OTP_USER:
 374                 if (!mtd->read_fact_prot_reg)
 375                         ret = -EOPNOTSUPP;
 376                 else
 377                         mfi->mode = MTD_FILE_MODE_OTP_USER;
 378                 break;
 379         default:
 380                 ret = -EINVAL;
 381         case MTD_OTP_OFF:
 382                 break;
 383         }
 384         return ret;
 385 }
 386 #else
 387 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 388 #endif
 389
 390 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 391         uint64_t start, uint32_t length, void __user *ptr,
 392         uint32_t __user *retp)
 393 {
 394         struct mtd_file_info *mfi = file->private_data;
 395         struct mtd_oob_ops ops;
 396         uint32_t retlen;
 397         int ret = 0;
 398
 399         if (!(file->f_mode & FMODE_WRITE))
 400                 return -EPERM;
 401
 402         if (length > 4096)
 403                 return -EINVAL;
 404
 405         if (!mtd->write_oob)
 406                 ret = -EOPNOTSUPP;
 407         else
 408                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 409
 410         if (ret)
 411                 return ret;
 412
 413         ops.ooblen = length;
 414         ops.ooboffs = start & (mtd->writesize - 1);
 415         ops.datbuf = NULL;
 416         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 417                 MTD_OPS_PLACE_OOB;
 418
 419         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 420                 return -EINVAL;
 421
 422         ops.oobbuf = memdup_user(ptr, length);
 423         if (IS_ERR(ops.oobbuf))
 424                 return PTR_ERR(ops.oobbuf);
 425
 426         start &= ~((uint64_t)mtd->writesize - 1);
 427         ret = mtd->write_oob(mtd, start, &ops);
 428
 429         if (ops.oobretlen > 0xFFFFFFFFU)
 430                 ret = -EOVERFLOW;
 431         retlen = ops.oobretlen;
 432         if (copy_to_user(retp, &retlen, sizeof(length)))
 433                 ret = -EFAULT;
 434
 435         kfree(ops.oobbuf);
 436         return ret;
 437 }
 438
 439 static int mtd_do_readoob(struct file *file, struct mtd_info *mtd,
 440         uint64_t start, uint32_t length, void __user *ptr,
 441         uint32_t __user *retp)
 442 {
 443         struct mtd_file_info *mfi = file->private_data;
 444         struct mtd_oob_ops ops;
 445         int ret = 0;
 446
 447         if (length > 4096)
 448                 return -EINVAL;
 449
 450         if (!mtd->read_oob)
 451                 ret = -EOPNOTSUPP;
 452         else
 453                 ret = access_ok(VERIFY_WRITE, ptr,
 454                                 length) ? 0 : -EFAULT;
 455         if (ret)
 456                 return ret;
 457
 458         ops.ooblen = length;
 459         ops.ooboffs = start & (mtd->writesize - 1);
 460         ops.datbuf = NULL;
 461         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 462                 MTD_OPS_PLACE_OOB;
 463
 464         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 465                 return -EINVAL;
 466
 467         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 468         if (!ops.oobbuf)
 469                 return -ENOMEM;
 470
 471         start &= ~((uint64_t)mtd->writesize - 1);
 472         ret = mtd->read_oob(mtd, start, &ops);
 473
 474         if (put_user(ops.oobretlen, retp))
 475                 ret = -EFAULT;
 476         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 477                                             ops.oobretlen))
 478                 ret = -EFAULT;
 479
 480         kfree(ops.oobbuf);
 481
 482         /*
 483          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 484          * data. For our userspace tools it is important to dump areas
 485          * with ECC errors!
 486          * For kernel internal usage it also might return -EUCLEAN
 487          * to signal the caller that a bitflip has occured and has
 488          * been corrected by the ECC algorithm.
 489          *
 490          * Note: currently the standard NAND function, nand_read_oob_std,
 491          * does not calculate ECC for the OOB area, so do not rely on
 492          * this behavior unless you have replaced it with your own.
 493          */
 494         if (ret == -EUCLEAN || ret == -EBADMSG)
 495                 return 0;
 496
 497         return ret;
 498 }
 499
 500 /*
 501  * Copies (and truncates, if necessary) data from the larger struct,
 502  * nand_ecclayout, to the smaller, deprecated layout struct,
 503  * nand_ecclayout_user. This is necessary only to support the deprecated
 504  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 505  * nand_ecclayout flexibly (i.e. the struct may change size in new
 506  * releases without requiring major rewrites).
 507  */
 508 static int shrink_ecclayout(const struct nand_ecclayout *from,
 509                 struct nand_ecclayout_user *to)
 510 {
 511         int i;
 512
 513         if (!from || !to)
 514                 return -EINVAL;
 515
 516         memset(to, 0, sizeof(*to));
 517
 518         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 519         for (i = 0; i < to->eccbytes; i++)
 520                 to->eccpos[i] = from->eccpos[i];
 521
 522         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 523                 if (from->oobfree[i].length == 0 &&
 524                                 from->oobfree[i].offset == 0)
 525                         break;
 526                 to->oobavail += from->oobfree[i].length;
 527                 to->oobfree[i] = from->oobfree[i];
 528         }
 529
 530         return 0;
 531 }
 532
 533 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
 534                            struct blkpg_ioctl_arg __user *arg)
 535 {
 536         struct blkpg_ioctl_arg a;
 537         struct blkpg_partition p;
 538
 539         if (!capable(CAP_SYS_ADMIN))
 540                 return -EPERM;
 541
 542         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 543                 return -EFAULT;
 544
 545         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 546                 return -EFAULT;
 547
 548         switch (a.op) {
 549         case BLKPG_ADD_PARTITION:
 550
 551                 /* Only master mtd device must be used to add partitions */
 552                 if (mtd_is_partition(mtd))
 553                         return -EINVAL;
 554
 555                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 556
 557         case BLKPG_DEL_PARTITION:
 558
 559                 if (p.pno < 0)
 560                         return -EINVAL;
 561
 562                 return mtd_del_partition(mtd, p.pno);
 563
 564         default:
 565                 return -EINVAL;
 566         }
 567 }
 568
 569 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 570 {
 571         struct mtd_file_info *mfi = file->private_data;
 572         struct mtd_info *mtd = mfi->mtd;
 573         void __user *argp = (void __user *)arg;
 574         int ret = 0;
 575         u_long size;
 576         struct mtd_info_user info;
 577
 578         pr_debug("MTD_ioctl\n");
 579
 580         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 581         if (cmd & IOC_IN) {
 582                 if (!access_ok(VERIFY_READ, argp, size))
 583                         return -EFAULT;
 584         }
 585         if (cmd & IOC_OUT) {
 586                 if (!access_ok(VERIFY_WRITE, argp, size))
 587                         return -EFAULT;
 588         }
 589
 590         switch (cmd) {
 591         case MEMGETREGIONCOUNT:
 592                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 593                         return -EFAULT;
 594                 break;
 595
 596         case MEMGETREGIONINFO:
 597         {
 598                 uint32_t ur_idx;
 599                 struct mtd_erase_region_info *kr;
 600                 struct region_info_user __user *ur = argp;
 601
 602                 if (get_user(ur_idx, &(ur->regionindex)))
 603                         return -EFAULT;
 604
 605                 if (ur_idx >= mtd->numeraseregions)
 606                         return -EINVAL;
 607
 608                 kr = &(mtd->eraseregions[ur_idx]);
 609
 610                 if (put_user(kr->offset, &(ur->offset))
 611                     || put_user(kr->erasesize, &(ur->erasesize))
 612                     || put_user(kr->numblocks, &(ur->numblocks)))
 613                         return -EFAULT;
 614
 615                 break;
 616         }
 617
 618         case MEMGETINFO:
 619                 memset(&info, 0, sizeof(info));
 620                 info.type       = mtd->type;
 621                 info.flags      = mtd->flags;
 622                 info.size       = mtd->size;
 623                 info.erasesize  = mtd->erasesize;
 624                 info.writesize  = mtd->writesize;
 625                 info.oobsize    = mtd->oobsize;
 626                 /* The below fields are obsolete */
 627                 info.ecctype    = -1;
 628                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 629                         return -EFAULT;
 630                 break;
 631
 632         case MEMERASE:
 633         case MEMERASE64:
 634         {
 635                 struct erase_info *erase;
 636
 637                 if(!(file->f_mode & FMODE_WRITE))
 638                         return -EPERM;
 639
 640                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 641                 if (!erase)
 642                         ret = -ENOMEM;
 643                 else {
 644                         wait_queue_head_t waitq;
 645                         DECLARE_WAITQUEUE(wait, current);
 646
 647                         init_waitqueue_head(&waitq);
 648
 649                         if (cmd == MEMERASE64) {
 650                                 struct erase_info_user64 einfo64;
 651
 652                                 if (copy_from_user(&einfo64, argp,
 653                                             sizeof(struct erase_info_user64))) {
 654                                         kfree(erase);
 655                                         return -EFAULT;
 656                                 }
 657                                 erase->addr = einfo64.start;
 658                                 erase->len = einfo64.length;
 659                         } else {
 660                                 struct erase_info_user einfo32;
 661
 662                                 if (copy_from_user(&einfo32, argp,
 663                                             sizeof(struct erase_info_user))) {
 664                                         kfree(erase);
 665                                         return -EFAULT;
 666                                 }
 667                                 erase->addr = einfo32.start;
 668                                 erase->len = einfo32.length;
 669                         }
 670                         erase->mtd = mtd;
 671                         erase->callback = mtdchar_erase_callback;
 672                         erase->priv = (unsigned long)&waitq;
 673
 674                         /*
 675                           FIXME: Allow INTERRUPTIBLE. Which means
 676                           not having the wait_queue head on the stack.
 677
 678                           If the wq_head is on the stack, and we
 679                           leave because we got interrupted, then the
 680                           wq_head is no longer there when the
 681                           callback routine tries to wake us up.
 682                         */
 683                         ret = mtd->erase(mtd, erase);
 684                         if (!ret) {
 685                                 set_current_state(TASK_UNINTERRUPTIBLE);
 686                                 add_wait_queue(&waitq, &wait);
 687                                 if (erase->state != MTD_ERASE_DONE &&
 688                                     erase->state != MTD_ERASE_FAILED)
 689                                         schedule();
 690                                 remove_wait_queue(&waitq, &wait);
 691                                 set_current_state(TASK_RUNNING);
 692
 693                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 694                         }
 695                         kfree(erase);
 696                 }
 697                 break;
 698         }
 699
 700         case MEMWRITEOOB:
 701         {
 702                 struct mtd_oob_buf buf;
 703                 struct mtd_oob_buf __user *buf_user = argp;
 704
 705                 /* NOTE: writes return length to buf_user->length */
 706                 if (copy_from_user(&buf, argp, sizeof(buf)))
 707                         ret = -EFAULT;
 708                 else
 709                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 710                                 buf.ptr, &buf_user->length);
 711                 break;
 712         }
 713
 714         case MEMREADOOB:
 715         {
 716                 struct mtd_oob_buf buf;
 717                 struct mtd_oob_buf __user *buf_user = argp;
 718
 719                 /* NOTE: writes return length to buf_user->start */
 720                 if (copy_from_user(&buf, argp, sizeof(buf)))
 721                         ret = -EFAULT;
 722                 else
 723                         ret = mtd_do_readoob(file, mtd, buf.start, buf.length,
 724                                 buf.ptr, &buf_user->start);
 725                 break;
 726         }
 727
 728         case MEMWRITEOOB64:
 729         {
 730                 struct mtd_oob_buf64 buf;
 731                 struct mtd_oob_buf64 __user *buf_user = argp;
 732
 733                 if (copy_from_user(&buf, argp, sizeof(buf)))
 734                         ret = -EFAULT;
 735                 else
 736                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 737                                 (void __user *)(uintptr_t)buf.usr_ptr,
 738                                 &buf_user->length);
 739                 break;
 740         }
 741
 742         case MEMREADOOB64:
 743         {
 744                 struct mtd_oob_buf64 buf;
 745                 struct mtd_oob_buf64 __user *buf_user = argp;
 746
 747                 if (copy_from_user(&buf, argp, sizeof(buf)))
 748                         ret = -EFAULT;
 749                 else
 750                         ret = mtd_do_readoob(file, mtd, buf.start, buf.length,
 751                                 (void __user *)(uintptr_t)buf.usr_ptr,
 752                                 &buf_user->length);
 753                 break;
 754         }
 755
 756         case MEMLOCK:
 757         {
 758                 struct erase_info_user einfo;
 759
 760                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 761                         return -EFAULT;
 762
 763                 if (!mtd->lock)
 764                         ret = -EOPNOTSUPP;
 765                 else
 766                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 767                 break;
 768         }
 769
 770         case MEMUNLOCK:
 771         {
 772                 struct erase_info_user einfo;
 773
 774                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 775                         return -EFAULT;
 776
 777                 if (!mtd->unlock)
 778                         ret = -EOPNOTSUPP;
 779                 else
 780                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 781                 break;
 782         }
 783
 784         case MEMISLOCKED:
 785         {
 786                 struct erase_info_user einfo;
 787
 788                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 789                         return -EFAULT;
 790
 791                 if (!mtd->is_locked)
 792                         ret = -EOPNOTSUPP;
 793                 else
 794                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 795                 break;
 796         }
 797
 798         /* Legacy interface */
 799         case MEMGETOOBSEL:
 800         {
 801                 struct nand_oobinfo oi;
 802
 803                 if (!mtd->ecclayout)
 804                         return -EOPNOTSUPP;
 805                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 806                         return -EINVAL;
 807
 808                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 809                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 810                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 811                        sizeof(oi.oobfree));
 812                 oi.eccbytes = mtd->ecclayout->eccbytes;
 813
 814                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 815                         return -EFAULT;
 816                 break;
 817         }
 818
 819         case MEMGETBADBLOCK:
 820         {
 821                 loff_t offs;
 822
 823                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 824                         return -EFAULT;
 825                 if (!mtd->block_isbad)
 826                         ret = -EOPNOTSUPP;
 827                 else
 828                         return mtd->block_isbad(mtd, offs);
 829                 break;
 830         }
 831
 832         case MEMSETBADBLOCK:
 833         {
 834                 loff_t offs;
 835
 836                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 837                         return -EFAULT;
 838                 if (!mtd->block_markbad)
 839                         ret = -EOPNOTSUPP;
 840                 else
 841                         return mtd->block_markbad(mtd, offs);
 842                 break;
 843         }
 844
 845 #ifdef CONFIG_HAVE_MTD_OTP
 846         case OTPSELECT:
 847         {
 848                 int mode;
 849                 if (copy_from_user(&mode, argp, sizeof(int)))
 850                         return -EFAULT;
 851
 852                 mfi->mode = MTD_FILE_MODE_NORMAL;
 853
 854                 ret = otp_select_filemode(mfi, mode);
 855
 856                 file->f_pos = 0;
 857                 break;
 858         }
 859
 860         case OTPGETREGIONCOUNT:
 861         case OTPGETREGIONINFO:
 862         {
 863                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 864                 if (!buf)
 865                         return -ENOMEM;
 866                 ret = -EOPNOTSUPP;
 867                 switch (mfi->mode) {
 868                 case MTD_FILE_MODE_OTP_FACTORY:
 869                         if (mtd->get_fact_prot_info)
 870                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 871                         break;
 872                 case MTD_FILE_MODE_OTP_USER:
 873                         if (mtd->get_user_prot_info)
 874                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 875                         break;
 876                 default:
 877                         break;
 878                 }
 879                 if (ret >= 0) {
 880                         if (cmd == OTPGETREGIONCOUNT) {
 881                                 int nbr = ret / sizeof(struct otp_info);
 882                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 883                         } else
 884                                 ret = copy_to_user(argp, buf, ret);
 885                         if (ret)
 886                                 ret = -EFAULT;
 887                 }
 888                 kfree(buf);
 889                 break;
 890         }
 891
 892         case OTPLOCK:
 893         {
 894                 struct otp_info oinfo;
 895
 896                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 897                         return -EINVAL;
 898                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 899                         return -EFAULT;
 900                 if (!mtd->lock_user_prot_reg)
 901                         return -EOPNOTSUPP;
 902                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 903                 break;
 904         }
 905 #endif
 906
 907         /* This ioctl is being deprecated - it truncates the ECC layout */
 908         case ECCGETLAYOUT:
 909         {
 910                 struct nand_ecclayout_user *usrlay;
 911
 912                 if (!mtd->ecclayout)
 913                         return -EOPNOTSUPP;
 914
 915                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 916                 if (!usrlay)
 917                         return -ENOMEM;
 918
 919                 shrink_ecclayout(mtd->ecclayout, usrlay);
 920
 921                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 922                         ret = -EFAULT;
 923                 kfree(usrlay);
 924                 break;
 925         }
 926
 927         case ECCGETSTATS:
 928         {
 929                 if (copy_to_user(argp, &mtd->ecc_stats,
 930                                  sizeof(struct mtd_ecc_stats)))
 931                         return -EFAULT;
 932                 break;
 933         }
 934
 935         case MTDFILEMODE:
 936         {
 937                 mfi->mode = 0;
 938
 939                 switch(arg) {
 940                 case MTD_FILE_MODE_OTP_FACTORY:
 941                 case MTD_FILE_MODE_OTP_USER:
 942                         ret = otp_select_filemode(mfi, arg);
 943                         break;
 944
 945                 case MTD_FILE_MODE_RAW:
 946                         if (!mtd->read_oob || !mtd->write_oob)
 947                                 return -EOPNOTSUPP;
 948                         mfi->mode = arg;
 949
 950                 case MTD_FILE_MODE_NORMAL:
 951                         break;
 952                 default:
 953                         ret = -EINVAL;
 954                 }
 955                 file->f_pos = 0;
 956                 break;
 957         }
 958
 959         case BLKPG:
 960         {
 961                 ret = mtd_blkpg_ioctl(mtd,
 962                       (struct blkpg_ioctl_arg __user *)arg);
 963                 break;
 964         }
 965
 966         case BLKRRPART:
 967         {
 968                 /* No reread partition feature. Just return ok */
 969                 ret = 0;
 970                 break;
 971         }
 972
 973         default:
 974                 ret = -ENOTTY;
 975         }
 976
 977         return ret;
 978 } /* memory_ioctl */
 979
 980 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 981 {
 982         int ret;
 983
 984         mutex_lock(&mtd_mutex);
 985         ret = mtd_ioctl(file, cmd, arg);
 986         mutex_unlock(&mtd_mutex);
 987
 988         return ret;
 989 }
 990
 991 #ifdef CONFIG_COMPAT
 992
 993 struct mtd_oob_buf32 {
 994         u_int32_t start;
 995         u_int32_t length;
 996         compat_caddr_t ptr;     /* unsigned char* */
 997 };
 998
 999 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1000 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1001
1002 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
1003         unsigned long arg)
1004 {
1005         struct mtd_file_info *mfi = file->private_data;
1006         struct mtd_info *mtd = mfi->mtd;
1007         void __user *argp = compat_ptr(arg);
1008         int ret = 0;
1009
1010         mutex_lock(&mtd_mutex);
1011
1012         switch (cmd) {
1013         case MEMWRITEOOB32:
1014         {
1015                 struct mtd_oob_buf32 buf;
1016                 struct mtd_oob_buf32 __user *buf_user = argp;
1017
1018                 if (copy_from_user(&buf, argp, sizeof(buf)))
1019                         ret = -EFAULT;
1020                 else
1021                         ret = mtd_do_writeoob(file, mtd, buf.start,
1022                                 buf.length, compat_ptr(buf.ptr),
1023                                 &buf_user->length);
1024                 break;
1025         }
1026
1027         case MEMREADOOB32:
1028         {
1029                 struct mtd_oob_buf32 buf;
1030                 struct mtd_oob_buf32 __user *buf_user = argp;
1031
1032                 /* NOTE: writes return length to buf->start */
1033                 if (copy_from_user(&buf, argp, sizeof(buf)))
1034                         ret = -EFAULT;
1035                 else
1036                         ret = mtd_do_readoob(file, mtd, buf.start,
1037                                 buf.length, compat_ptr(buf.ptr),
1038                                 &buf_user->start);
1039                 break;
1040         }
1041         default:
1042                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1043         }
1044
1045         mutex_unlock(&mtd_mutex);
1046
1047         return ret;
1048 }
1049
1050 #endif /* CONFIG_COMPAT */
1051
1052 /*
1053  * try to determine where a shared mapping can be made
1054  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1055  *   mappings)
1056  */
1057 #ifndef CONFIG_MMU
1058 static unsigned long mtd_get_unmapped_area(struct file *file,
1059                                            unsigned long addr,
1060                                            unsigned long len,
1061                                            unsigned long pgoff,
1062                                            unsigned long flags)
1063 {
1064         struct mtd_file_info *mfi = file->private_data;
1065         struct mtd_info *mtd = mfi->mtd;
1066
1067         if (mtd->get_unmapped_area) {
1068                 unsigned long offset;
1069
1070                 if (addr != 0)
1071                         return (unsigned long) -EINVAL;
1072
1073                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1074                         return (unsigned long) -EINVAL;
1075
1076                 offset = pgoff << PAGE_SHIFT;
1077                 if (offset > mtd->size - len)
1078                         return (unsigned long) -EINVAL;
1079
1080                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1081         }
1082
1083         /* can't map directly */
1084         return (unsigned long) -ENOSYS;
1085 }
1086 #endif
1087
1088 /*
1089  * set up a mapping for shared memory segments
1090  */
1091 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1092 {
1093 #ifdef CONFIG_MMU
1094         struct mtd_file_info *mfi = file->private_data;
1095         struct mtd_info *mtd = mfi->mtd;
1096         struct map_info *map = mtd->priv;
1097         unsigned long start;
1098         unsigned long off;
1099         u32 len;
1100
1101         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1102                 off = vma->vm_pgoff << PAGE_SHIFT;
1103                 start = map->phys;
1104                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1105                 start &= PAGE_MASK;
1106                 if ((vma->vm_end - vma->vm_start + off) > len)
1107                         return -EINVAL;
1108
1109                 off += start;
1110                 vma->vm_pgoff = off >> PAGE_SHIFT;
1111                 vma->vm_flags |= VM_IO | VM_RESERVED;
1112
1113 #ifdef pgprot_noncached
1114                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1115                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1116 #endif
1117                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1118                                        vma->vm_end - vma->vm_start,
1119                                        vma->vm_page_prot))
1120                         return -EAGAIN;
1121
1122                 return 0;
1123         }
1124         return -ENOSYS;
1125 #else
1126         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1127 #endif
1128 }
1129
1130 static const struct file_operations mtd_fops = {
1131         .owner          = THIS_MODULE,
1132         .llseek         = mtd_lseek,
1133         .read           = mtd_read,
1134         .write          = mtd_write,
1135         .unlocked_ioctl = mtd_unlocked_ioctl,
1136 #ifdef CONFIG_COMPAT
1137         .compat_ioctl   = mtd_compat_ioctl,
1138 #endif
1139         .open           = mtd_open,
1140         .release        = mtd_close,
1141         .mmap           = mtd_mmap,
1142 #ifndef CONFIG_MMU
1143         .get_unmapped_area = mtd_get_unmapped_area,
1144 #endif
1145 };
1146
1147 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1148                                 int flags, const char *dev_name, void *data)
1149 {
1150         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1151 }
1152
1153 static struct file_system_type mtd_inodefs_type = {
1154        .name = "mtd_inodefs",
1155        .mount = mtd_inodefs_mount,
1156        .kill_sb = kill_anon_super,
1157 };
1158
1159 static void mtdchar_notify_add(struct mtd_info *mtd)
1160 {
1161 }
1162
1163 static void mtdchar_notify_remove(struct mtd_info *mtd)
1164 {
1165         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1166
1167         if (mtd_ino) {
1168                 /* Destroy the inode if it exists */
1169                 mtd_ino->i_nlink = 0;
1170                 iput(mtd_ino);
1171         }
1172 }
1173
1174 static struct mtd_notifier mtdchar_notifier = {
1175         .add = mtdchar_notify_add,
1176         .remove = mtdchar_notify_remove,
1177 };
1178
1179 static int __init init_mtdchar(void)
1180 {
1181         int ret;
1182
1183         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1184                                    "mtd", &mtd_fops);
1185         if (ret < 0) {
1186                 pr_notice("Can't allocate major number %d for "
1187                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1188                 return ret;
1189         }
1190
1191         ret = register_filesystem(&mtd_inodefs_type);
1192         if (ret) {
1193                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1194                 goto err_unregister_chdev;
1195         }
1196
1197         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1198         if (IS_ERR(mtd_inode_mnt)) {
1199                 ret = PTR_ERR(mtd_inode_mnt);
1200                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1201                 goto err_unregister_filesystem;
1202         }
1203         register_mtd_user(&mtdchar_notifier);
1204
1205         return ret;
1206
1207 err_unregister_filesystem:
1208         unregister_filesystem(&mtd_inodefs_type);
1209 err_unregister_chdev:
1210         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1211         return ret;
1212 }
1213
1214 static void __exit cleanup_mtdchar(void)
1215 {
1216         unregister_mtd_user(&mtdchar_notifier);
1217         kern_unmount(mtd_inode_mnt);
1218         unregister_filesystem(&mtd_inodefs_type);
1219         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1220 }
1221
1222 module_init(init_mtdchar);
1223 module_exit(cleanup_mtdchar);
1224
1225 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1226
1227 MODULE_LICENSE("GPL");
1228 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1229 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1230 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);