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         struct inode *ino;
  53         enum mtd_file_modes mode;
  54 };
  55
  56 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  57 {
  58         struct mtd_file_info *mfi = file->private_data;
  59         return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  60 }
  61
  62 static int count;
  63 static struct vfsmount *mnt;
  64 static struct file_system_type mtd_inodefs_type;
  65
  66 static int mtdchar_open(struct inode *inode, struct file *file)
  67 {
  68         int minor = iminor(inode);
  69         int devnum = minor >> 1;
  70         int ret = 0;
  71         struct mtd_info *mtd;
  72         struct mtd_file_info *mfi;
  73         struct inode *mtd_ino;
  74
  75         pr_debug("MTD_open\n");
  76
  77         /* You can't open the RO devices RW */
  78         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  79                 return -EACCES;
  80
  81         ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
  82         if (ret)
  83                 return ret;
  84
  85         mutex_lock(&mtd_mutex);
  86         mtd = get_mtd_device(NULL, devnum);
  87
  88         if (IS_ERR(mtd)) {
  89                 ret = PTR_ERR(mtd);
  90                 goto out;
  91         }
  92
  93         if (mtd->type == MTD_ABSENT) {
  94                 ret = -ENODEV;
  95                 goto out1;
  96         }
  97
  98         mtd_ino = iget_locked(mnt->mnt_sb, devnum);
  99         if (!mtd_ino) {
 100                 ret = -ENOMEM;
 101                 goto out1;
 102         }
 103         if (mtd_ino->i_state & I_NEW) {
 104                 mtd_ino->i_private = mtd;
 105                 mtd_ino->i_mode = S_IFCHR;
 106                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 107                 unlock_new_inode(mtd_ino);
 108         }
 109         file->f_mapping = mtd_ino->i_mapping;
 110
 111         /* You can't open it RW if it's not a writeable device */
 112         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 113                 ret = -EACCES;
 114                 goto out2;
 115         }
 116
 117         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 118         if (!mfi) {
 119                 ret = -ENOMEM;
 120                 goto out2;
 121         }
 122         mfi->ino = mtd_ino;
 123         mfi->mtd = mtd;
 124         file->private_data = mfi;
 125         mutex_unlock(&mtd_mutex);
 126         return 0;
 127
 128 out2:
 129         iput(mtd_ino);
 130 out1:
 131         put_mtd_device(mtd);
 132 out:
 133         mutex_unlock(&mtd_mutex);
 134         simple_release_fs(&mnt, &count);
 135         return ret;
 136 } /* mtdchar_open */
 137
 138 /*====================================================================*/
 139
 140 static int mtdchar_close(struct inode *inode, struct file *file)
 141 {
 142         struct mtd_file_info *mfi = file->private_data;
 143         struct mtd_info *mtd = mfi->mtd;
 144
 145         pr_debug("MTD_close\n");
 146
 147         /* Only sync if opened RW */
 148         if ((file->f_mode & FMODE_WRITE))
 149                 mtd_sync(mtd);
 150
 151         iput(mfi->ino);
 152
 153         put_mtd_device(mtd);
 154         file->private_data = NULL;
 155         kfree(mfi);
 156         simple_release_fs(&mnt, &count);
 157
 158         return 0;
 159 } /* mtdchar_close */
 160
 161 /* Back in June 2001, dwmw2 wrote:
 162  *
 163  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 164  *   userspace buffer down and use it directly with readv/writev.
 165  *
 166  * The implementation below, using mtd_kmalloc_up_to, mitigates
 167  * allocation failures when the system is under low-memory situations
 168  * or if memory is highly fragmented at the cost of reducing the
 169  * performance of the requested transfer due to a smaller buffer size.
 170  *
 171  * A more complex but more memory-efficient implementation based on
 172  * get_user_pages and iovecs to cover extents of those pages is a
 173  * longer-term goal, as intimated by dwmw2 above. However, for the
 174  * write case, this requires yet more complex head and tail transfer
 175  * handling when those head and tail offsets and sizes are such that
 176  * alignment requirements are not met in the NAND subdriver.
 177  */
 178
 179 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 180                         loff_t *ppos)
 181 {
 182         struct mtd_file_info *mfi = file->private_data;
 183         struct mtd_info *mtd = mfi->mtd;
 184         size_t retlen;
 185         size_t total_retlen=0;
 186         int ret=0;
 187         int len;
 188         size_t size = count;
 189         char *kbuf;
 190
 191         pr_debug("MTD_read\n");
 192
 193         if (*ppos + count > mtd->size)
 194                 count = mtd->size - *ppos;
 195
 196         if (!count)
 197                 return 0;
 198
 199         kbuf = mtd_kmalloc_up_to(mtd, &size);
 200         if (!kbuf)
 201                 return -ENOMEM;
 202
 203         while (count) {
 204                 len = min_t(size_t, count, size);
 205
 206                 switch (mfi->mode) {
 207                 case MTD_FILE_MODE_OTP_FACTORY:
 208                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 209                                                      &retlen, kbuf);
 210                         break;
 211                 case MTD_FILE_MODE_OTP_USER:
 212                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 213                                                      &retlen, kbuf);
 214                         break;
 215                 case MTD_FILE_MODE_RAW:
 216                 {
 217                         struct mtd_oob_ops ops;
 218
 219                         ops.mode = MTD_OPS_RAW;
 220                         ops.datbuf = kbuf;
 221                         ops.oobbuf = NULL;
 222                         ops.len = len;
 223
 224                         ret = mtd_read_oob(mtd, *ppos, &ops);
 225                         retlen = ops.retlen;
 226                         break;
 227                 }
 228                 default:
 229                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 230                 }
 231                 /* Nand returns -EBADMSG on ECC errors, but it returns
 232                  * the data. For our userspace tools it is important
 233                  * to dump areas with ECC errors!
 234                  * For kernel internal usage it also might return -EUCLEAN
 235                  * to signal the caller that a bitflip has occurred and has
 236                  * been corrected by the ECC algorithm.
 237                  * Userspace software which accesses NAND this way
 238                  * must be aware of the fact that it deals with NAND
 239                  */
 240                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 241                         *ppos += retlen;
 242                         if (copy_to_user(buf, kbuf, retlen)) {
 243                                 kfree(kbuf);
 244                                 return -EFAULT;
 245                         }
 246                         else
 247                                 total_retlen += retlen;
 248
 249                         count -= retlen;
 250                         buf += retlen;
 251                         if (retlen == 0)
 252                                 count = 0;
 253                 }
 254                 else {
 255                         kfree(kbuf);
 256                         return ret;
 257                 }
 258
 259         }
 260
 261         kfree(kbuf);
 262         return total_retlen;
 263 } /* mtdchar_read */
 264
 265 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 266                         loff_t *ppos)
 267 {
 268         struct mtd_file_info *mfi = file->private_data;
 269         struct mtd_info *mtd = mfi->mtd;
 270         size_t size = count;
 271         char *kbuf;
 272         size_t retlen;
 273         size_t total_retlen=0;
 274         int ret=0;
 275         int len;
 276
 277         pr_debug("MTD_write\n");
 278
 279         if (*ppos == mtd->size)
 280                 return -ENOSPC;
 281
 282         if (*ppos + count > mtd->size)
 283                 count = mtd->size - *ppos;
 284
 285         if (!count)
 286                 return 0;
 287
 288         kbuf = mtd_kmalloc_up_to(mtd, &size);
 289         if (!kbuf)
 290                 return -ENOMEM;
 291
 292         while (count) {
 293                 len = min_t(size_t, count, size);
 294
 295                 if (copy_from_user(kbuf, buf, len)) {
 296                         kfree(kbuf);
 297                         return -EFAULT;
 298                 }
 299
 300                 switch (mfi->mode) {
 301                 case MTD_FILE_MODE_OTP_FACTORY:
 302                         ret = -EROFS;
 303                         break;
 304                 case MTD_FILE_MODE_OTP_USER:
 305                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 306                                                       &retlen, kbuf);
 307                         break;
 308
 309                 case MTD_FILE_MODE_RAW:
 310                 {
 311                         struct mtd_oob_ops ops;
 312
 313                         ops.mode = MTD_OPS_RAW;
 314                         ops.datbuf = kbuf;
 315                         ops.oobbuf = NULL;
 316                         ops.ooboffs = 0;
 317                         ops.len = len;
 318
 319                         ret = mtd_write_oob(mtd, *ppos, &ops);
 320                         retlen = ops.retlen;
 321                         break;
 322                 }
 323
 324                 default:
 325                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 326                 }
 327                 if (!ret) {
 328                         *ppos += retlen;
 329                         total_retlen += retlen;
 330                         count -= retlen;
 331                         buf += retlen;
 332                 }
 333                 else {
 334                         kfree(kbuf);
 335                         return ret;
 336                 }
 337         }
 338
 339         kfree(kbuf);
 340         return total_retlen;
 341 } /* mtdchar_write */
 342
 343 /*======================================================================
 344
 345     IOCTL calls for getting device parameters.
 346
 347 ======================================================================*/
 348 static void mtdchar_erase_callback (struct erase_info *instr)
 349 {
 350         wake_up((wait_queue_head_t *)instr->priv);
 351 }
 352
 353 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 354 {
 355         struct mtd_info *mtd = mfi->mtd;
 356         size_t retlen;
 357
 358         switch (mode) {
 359         case MTD_OTP_FACTORY:
 360                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 361                                 -EOPNOTSUPP)
 362                         return -EOPNOTSUPP;
 363
 364                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 365                 break;
 366         case MTD_OTP_USER:
 367                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 368                                 -EOPNOTSUPP)
 369                         return -EOPNOTSUPP;
 370
 371                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 372                 break;
 373         case MTD_OTP_OFF:
 374                 mfi->mode = MTD_FILE_MODE_NORMAL;
 375                 break;
 376         default:
 377                 return -EINVAL;
 378         }
 379
 380         return 0;
 381 }
 382
 383 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 384         uint64_t start, uint32_t length, void __user *ptr,
 385         uint32_t __user *retp)
 386 {
 387         struct mtd_file_info *mfi = file->private_data;
 388         struct mtd_oob_ops ops;
 389         uint32_t retlen;
 390         int ret = 0;
 391
 392         if (!(file->f_mode & FMODE_WRITE))
 393                 return -EPERM;
 394
 395         if (length > 4096)
 396                 return -EINVAL;
 397
 398         if (!mtd->_write_oob)
 399                 ret = -EOPNOTSUPP;
 400         else
 401                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 402
 403         if (ret)
 404                 return ret;
 405
 406         ops.ooblen = length;
 407         ops.ooboffs = start & (mtd->writesize - 1);
 408         ops.datbuf = NULL;
 409         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 410                 MTD_OPS_PLACE_OOB;
 411
 412         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 413                 return -EINVAL;
 414
 415         ops.oobbuf = memdup_user(ptr, length);
 416         if (IS_ERR(ops.oobbuf))
 417                 return PTR_ERR(ops.oobbuf);
 418
 419         start &= ~((uint64_t)mtd->writesize - 1);
 420         ret = mtd_write_oob(mtd, start, &ops);
 421
 422         if (ops.oobretlen > 0xFFFFFFFFU)
 423                 ret = -EOVERFLOW;
 424         retlen = ops.oobretlen;
 425         if (copy_to_user(retp, &retlen, sizeof(length)))
 426                 ret = -EFAULT;
 427
 428         kfree(ops.oobbuf);
 429         return ret;
 430 }
 431
 432 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 433         uint64_t start, uint32_t length, void __user *ptr,
 434         uint32_t __user *retp)
 435 {
 436         struct mtd_file_info *mfi = file->private_data;
 437         struct mtd_oob_ops ops;
 438         int ret = 0;
 439
 440         if (length > 4096)
 441                 return -EINVAL;
 442
 443         if (!access_ok(VERIFY_WRITE, ptr, length))
 444                 return -EFAULT;
 445
 446         ops.ooblen = length;
 447         ops.ooboffs = start & (mtd->writesize - 1);
 448         ops.datbuf = NULL;
 449         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 450                 MTD_OPS_PLACE_OOB;
 451
 452         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 453                 return -EINVAL;
 454
 455         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 456         if (!ops.oobbuf)
 457                 return -ENOMEM;
 458
 459         start &= ~((uint64_t)mtd->writesize - 1);
 460         ret = mtd_read_oob(mtd, start, &ops);
 461
 462         if (put_user(ops.oobretlen, retp))
 463                 ret = -EFAULT;
 464         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 465                                             ops.oobretlen))
 466                 ret = -EFAULT;
 467
 468         kfree(ops.oobbuf);
 469
 470         /*
 471          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 472          * data. For our userspace tools it is important to dump areas
 473          * with ECC errors!
 474          * For kernel internal usage it also might return -EUCLEAN
 475          * to signal the caller that a bitflip has occured and has
 476          * been corrected by the ECC algorithm.
 477          *
 478          * Note: currently the standard NAND function, nand_read_oob_std,
 479          * does not calculate ECC for the OOB area, so do not rely on
 480          * this behavior unless you have replaced it with your own.
 481          */
 482         if (mtd_is_bitflip_or_eccerr(ret))
 483                 return 0;
 484
 485         return ret;
 486 }
 487
 488 /*
 489  * Copies (and truncates, if necessary) data from the larger struct,
 490  * nand_ecclayout, to the smaller, deprecated layout struct,
 491  * nand_ecclayout_user. This is necessary only to support the deprecated
 492  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 493  * nand_ecclayout flexibly (i.e. the struct may change size in new
 494  * releases without requiring major rewrites).
 495  */
 496 static int shrink_ecclayout(const struct nand_ecclayout *from,
 497                 struct nand_ecclayout_user *to)
 498 {
 499         int i;
 500
 501         if (!from || !to)
 502                 return -EINVAL;
 503
 504         memset(to, 0, sizeof(*to));
 505
 506         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 507         for (i = 0; i < to->eccbytes; i++)
 508                 to->eccpos[i] = from->eccpos[i];
 509
 510         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 511                 if (from->oobfree[i].length == 0 &&
 512                                 from->oobfree[i].offset == 0)
 513                         break;
 514                 to->oobavail += from->oobfree[i].length;
 515                 to->oobfree[i] = from->oobfree[i];
 516         }
 517
 518         return 0;
 519 }
 520
 521 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 522                            struct blkpg_ioctl_arg __user *arg)
 523 {
 524         struct blkpg_ioctl_arg a;
 525         struct blkpg_partition p;
 526
 527         if (!capable(CAP_SYS_ADMIN))
 528                 return -EPERM;
 529
 530         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 531                 return -EFAULT;
 532
 533         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 534                 return -EFAULT;
 535
 536         switch (a.op) {
 537         case BLKPG_ADD_PARTITION:
 538
 539                 /* Only master mtd device must be used to add partitions */
 540                 if (mtd_is_partition(mtd))
 541                         return -EINVAL;
 542
 543                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 544
 545         case BLKPG_DEL_PARTITION:
 546
 547                 if (p.pno < 0)
 548                         return -EINVAL;
 549
 550                 return mtd_del_partition(mtd, p.pno);
 551
 552         default:
 553                 return -EINVAL;
 554         }
 555 }
 556
 557 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 558                 struct mtd_write_req __user *argp)
 559 {
 560         struct mtd_write_req req;
 561         struct mtd_oob_ops ops;
 562         void __user *usr_data, *usr_oob;
 563         int ret;
 564
 565         if (copy_from_user(&req, argp, sizeof(req)) ||
 566                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 567                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 568                 return -EFAULT;
 569         if (!mtd->_write_oob)
 570                 return -EOPNOTSUPP;
 571
 572         ops.mode = req.mode;
 573         ops.len = (size_t)req.len;
 574         ops.ooblen = (size_t)req.ooblen;
 575         ops.ooboffs = 0;
 576
 577         usr_data = (void __user *)(uintptr_t)req.usr_data;
 578         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 579
 580         if (req.usr_data) {
 581                 ops.datbuf = memdup_user(usr_data, ops.len);
 582                 if (IS_ERR(ops.datbuf))
 583                         return PTR_ERR(ops.datbuf);
 584         } else {
 585                 ops.datbuf = NULL;
 586         }
 587
 588         if (req.usr_oob) {
 589                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 590                 if (IS_ERR(ops.oobbuf)) {
 591                         kfree(ops.datbuf);
 592                         return PTR_ERR(ops.oobbuf);
 593                 }
 594         } else {
 595                 ops.oobbuf = NULL;
 596         }
 597
 598         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 599
 600         kfree(ops.datbuf);
 601         kfree(ops.oobbuf);
 602
 603         return ret;
 604 }
 605
 606 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 607 {
 608         struct mtd_file_info *mfi = file->private_data;
 609         struct mtd_info *mtd = mfi->mtd;
 610         void __user *argp = (void __user *)arg;
 611         int ret = 0;
 612         u_long size;
 613         struct mtd_info_user info;
 614
 615         pr_debug("MTD_ioctl\n");
 616
 617         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 618         if (cmd & IOC_IN) {
 619                 if (!access_ok(VERIFY_READ, argp, size))
 620                         return -EFAULT;
 621         }
 622         if (cmd & IOC_OUT) {
 623                 if (!access_ok(VERIFY_WRITE, argp, size))
 624                         return -EFAULT;
 625         }
 626
 627         switch (cmd) {
 628         case MEMGETREGIONCOUNT:
 629                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 630                         return -EFAULT;
 631                 break;
 632
 633         case MEMGETREGIONINFO:
 634         {
 635                 uint32_t ur_idx;
 636                 struct mtd_erase_region_info *kr;
 637                 struct region_info_user __user *ur = argp;
 638
 639                 if (get_user(ur_idx, &(ur->regionindex)))
 640                         return -EFAULT;
 641
 642                 if (ur_idx >= mtd->numeraseregions)
 643                         return -EINVAL;
 644
 645                 kr = &(mtd->eraseregions[ur_idx]);
 646
 647                 if (put_user(kr->offset, &(ur->offset))
 648                     || put_user(kr->erasesize, &(ur->erasesize))
 649                     || put_user(kr->numblocks, &(ur->numblocks)))
 650                         return -EFAULT;
 651
 652                 break;
 653         }
 654
 655         case MEMGETINFO:
 656                 memset(&info, 0, sizeof(info));
 657                 info.type       = mtd->type;
 658                 info.flags      = mtd->flags;
 659                 info.size       = mtd->size;
 660                 info.erasesize  = mtd->erasesize;
 661                 info.writesize  = mtd->writesize;
 662                 info.oobsize    = mtd->oobsize;
 663                 /* The below field is obsolete */
 664                 info.padding    = 0;
 665                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 666                         return -EFAULT;
 667                 break;
 668
 669         case MEMERASE:
 670         case MEMERASE64:
 671         {
 672                 struct erase_info *erase;
 673
 674                 if(!(file->f_mode & FMODE_WRITE))
 675                         return -EPERM;
 676
 677                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 678                 if (!erase)
 679                         ret = -ENOMEM;
 680                 else {
 681                         wait_queue_head_t waitq;
 682                         DECLARE_WAITQUEUE(wait, current);
 683
 684                         init_waitqueue_head(&waitq);
 685
 686                         if (cmd == MEMERASE64) {
 687                                 struct erase_info_user64 einfo64;
 688
 689                                 if (copy_from_user(&einfo64, argp,
 690                                             sizeof(struct erase_info_user64))) {
 691                                         kfree(erase);
 692                                         return -EFAULT;
 693                                 }
 694                                 erase->addr = einfo64.start;
 695                                 erase->len = einfo64.length;
 696                         } else {
 697                                 struct erase_info_user einfo32;
 698
 699                                 if (copy_from_user(&einfo32, argp,
 700                                             sizeof(struct erase_info_user))) {
 701                                         kfree(erase);
 702                                         return -EFAULT;
 703                                 }
 704                                 erase->addr = einfo32.start;
 705                                 erase->len = einfo32.length;
 706                         }
 707                         erase->mtd = mtd;
 708                         erase->callback = mtdchar_erase_callback;
 709                         erase->priv = (unsigned long)&waitq;
 710
 711                         /*
 712                           FIXME: Allow INTERRUPTIBLE. Which means
 713                           not having the wait_queue head on the stack.
 714
 715                           If the wq_head is on the stack, and we
 716                           leave because we got interrupted, then the
 717                           wq_head is no longer there when the
 718                           callback routine tries to wake us up.
 719                         */
 720                         ret = mtd_erase(mtd, erase);
 721                         if (!ret) {
 722                                 set_current_state(TASK_UNINTERRUPTIBLE);
 723                                 add_wait_queue(&waitq, &wait);
 724                                 if (erase->state != MTD_ERASE_DONE &&
 725                                     erase->state != MTD_ERASE_FAILED)
 726                                         schedule();
 727                                 remove_wait_queue(&waitq, &wait);
 728                                 set_current_state(TASK_RUNNING);
 729
 730                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 731                         }
 732                         kfree(erase);
 733                 }
 734                 break;
 735         }
 736
 737         case MEMWRITEOOB:
 738         {
 739                 struct mtd_oob_buf buf;
 740                 struct mtd_oob_buf __user *buf_user = argp;
 741
 742                 /* NOTE: writes return length to buf_user->length */
 743                 if (copy_from_user(&buf, argp, sizeof(buf)))
 744                         ret = -EFAULT;
 745                 else
 746                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 747                                 buf.ptr, &buf_user->length);
 748                 break;
 749         }
 750
 751         case MEMREADOOB:
 752         {
 753                 struct mtd_oob_buf buf;
 754                 struct mtd_oob_buf __user *buf_user = argp;
 755
 756                 /* NOTE: writes return length to buf_user->start */
 757                 if (copy_from_user(&buf, argp, sizeof(buf)))
 758                         ret = -EFAULT;
 759                 else
 760                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 761                                 buf.ptr, &buf_user->start);
 762                 break;
 763         }
 764
 765         case MEMWRITEOOB64:
 766         {
 767                 struct mtd_oob_buf64 buf;
 768                 struct mtd_oob_buf64 __user *buf_user = argp;
 769
 770                 if (copy_from_user(&buf, argp, sizeof(buf)))
 771                         ret = -EFAULT;
 772                 else
 773                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 774                                 (void __user *)(uintptr_t)buf.usr_ptr,
 775                                 &buf_user->length);
 776                 break;
 777         }
 778
 779         case MEMREADOOB64:
 780         {
 781                 struct mtd_oob_buf64 buf;
 782                 struct mtd_oob_buf64 __user *buf_user = argp;
 783
 784                 if (copy_from_user(&buf, argp, sizeof(buf)))
 785                         ret = -EFAULT;
 786                 else
 787                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 788                                 (void __user *)(uintptr_t)buf.usr_ptr,
 789                                 &buf_user->length);
 790                 break;
 791         }
 792
 793         case MEMWRITE:
 794         {
 795                 ret = mtdchar_write_ioctl(mtd,
 796                       (struct mtd_write_req __user *)arg);
 797                 break;
 798         }
 799
 800         case MEMLOCK:
 801         {
 802                 struct erase_info_user einfo;
 803
 804                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 805                         return -EFAULT;
 806
 807                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 808                 break;
 809         }
 810
 811         case MEMUNLOCK:
 812         {
 813                 struct erase_info_user einfo;
 814
 815                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 816                         return -EFAULT;
 817
 818                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 819                 break;
 820         }
 821
 822         case MEMISLOCKED:
 823         {
 824                 struct erase_info_user einfo;
 825
 826                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 827                         return -EFAULT;
 828
 829                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 830                 break;
 831         }
 832
 833         /* Legacy interface */
 834         case MEMGETOOBSEL:
 835         {
 836                 struct nand_oobinfo oi;
 837
 838                 if (!mtd->ecclayout)
 839                         return -EOPNOTSUPP;
 840                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 841                         return -EINVAL;
 842
 843                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 844                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 845                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 846                        sizeof(oi.oobfree));
 847                 oi.eccbytes = mtd->ecclayout->eccbytes;
 848
 849                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 850                         return -EFAULT;
 851                 break;
 852         }
 853
 854         case MEMGETBADBLOCK:
 855         {
 856                 loff_t offs;
 857
 858                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 859                         return -EFAULT;
 860                 return mtd_block_isbad(mtd, offs);
 861                 break;
 862         }
 863
 864         case MEMSETBADBLOCK:
 865         {
 866                 loff_t offs;
 867
 868                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 869                         return -EFAULT;
 870                 return mtd_block_markbad(mtd, offs);
 871                 break;
 872         }
 873
 874         case OTPSELECT:
 875         {
 876                 int mode;
 877                 if (copy_from_user(&mode, argp, sizeof(int)))
 878                         return -EFAULT;
 879
 880                 mfi->mode = MTD_FILE_MODE_NORMAL;
 881
 882                 ret = otp_select_filemode(mfi, mode);
 883
 884                 file->f_pos = 0;
 885                 break;
 886         }
 887
 888         case OTPGETREGIONCOUNT:
 889         case OTPGETREGIONINFO:
 890         {
 891                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 892                 if (!buf)
 893                         return -ENOMEM;
 894                 switch (mfi->mode) {
 895                 case MTD_FILE_MODE_OTP_FACTORY:
 896                         ret = mtd_get_fact_prot_info(mtd, buf, 4096);
 897                         break;
 898                 case MTD_FILE_MODE_OTP_USER:
 899                         ret = mtd_get_user_prot_info(mtd, buf, 4096);
 900                         break;
 901                 default:
 902                         ret = -EINVAL;
 903                         break;
 904                 }
 905                 if (ret >= 0) {
 906                         if (cmd == OTPGETREGIONCOUNT) {
 907                                 int nbr = ret / sizeof(struct otp_info);
 908                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 909                         } else
 910                                 ret = copy_to_user(argp, buf, ret);
 911                         if (ret)
 912                                 ret = -EFAULT;
 913                 }
 914                 kfree(buf);
 915                 break;
 916         }
 917
 918         case OTPLOCK:
 919         {
 920                 struct otp_info oinfo;
 921
 922                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 923                         return -EINVAL;
 924                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 925                         return -EFAULT;
 926                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 927                 break;
 928         }
 929
 930         /* This ioctl is being deprecated - it truncates the ECC layout */
 931         case ECCGETLAYOUT:
 932         {
 933                 struct nand_ecclayout_user *usrlay;
 934
 935                 if (!mtd->ecclayout)
 936                         return -EOPNOTSUPP;
 937
 938                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 939                 if (!usrlay)
 940                         return -ENOMEM;
 941
 942                 shrink_ecclayout(mtd->ecclayout, usrlay);
 943
 944                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 945                         ret = -EFAULT;
 946                 kfree(usrlay);
 947                 break;
 948         }
 949
 950         case ECCGETSTATS:
 951         {
 952                 if (copy_to_user(argp, &mtd->ecc_stats,
 953                                  sizeof(struct mtd_ecc_stats)))
 954                         return -EFAULT;
 955                 break;
 956         }
 957
 958         case MTDFILEMODE:
 959         {
 960                 mfi->mode = 0;
 961
 962                 switch(arg) {
 963                 case MTD_FILE_MODE_OTP_FACTORY:
 964                 case MTD_FILE_MODE_OTP_USER:
 965                         ret = otp_select_filemode(mfi, arg);
 966                         break;
 967
 968                 case MTD_FILE_MODE_RAW:
 969                         if (!mtd_has_oob(mtd))
 970                                 return -EOPNOTSUPP;
 971                         mfi->mode = arg;
 972
 973                 case MTD_FILE_MODE_NORMAL:
 974                         break;
 975                 default:
 976                         ret = -EINVAL;
 977                 }
 978                 file->f_pos = 0;
 979                 break;
 980         }
 981
 982         case BLKPG:
 983         {
 984                 ret = mtdchar_blkpg_ioctl(mtd,
 985                       (struct blkpg_ioctl_arg __user *)arg);
 986                 break;
 987         }
 988
 989         case BLKRRPART:
 990         {
 991                 /* No reread partition feature. Just return ok */
 992                 ret = 0;
 993                 break;
 994         }
 995
 996         default:
 997                 ret = -ENOTTY;
 998         }
 999
1000         return ret;
1001 } /* memory_ioctl */
1002
1003 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1004 {
1005         int ret;
1006
1007         mutex_lock(&mtd_mutex);
1008         ret = mtdchar_ioctl(file, cmd, arg);
1009         mutex_unlock(&mtd_mutex);
1010
1011         return ret;
1012 }
1013
1014 #ifdef CONFIG_COMPAT
1015
1016 struct mtd_oob_buf32 {
1017         u_int32_t start;
1018         u_int32_t length;
1019         compat_caddr_t ptr;     /* unsigned char* */
1020 };
1021
1022 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1023 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1024
1025 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1026         unsigned long arg)
1027 {
1028         struct mtd_file_info *mfi = file->private_data;
1029         struct mtd_info *mtd = mfi->mtd;
1030         void __user *argp = compat_ptr(arg);
1031         int ret = 0;
1032
1033         mutex_lock(&mtd_mutex);
1034
1035         switch (cmd) {
1036         case MEMWRITEOOB32:
1037         {
1038                 struct mtd_oob_buf32 buf;
1039                 struct mtd_oob_buf32 __user *buf_user = argp;
1040
1041                 if (copy_from_user(&buf, argp, sizeof(buf)))
1042                         ret = -EFAULT;
1043                 else
1044                         ret = mtdchar_writeoob(file, mtd, buf.start,
1045                                 buf.length, compat_ptr(buf.ptr),
1046                                 &buf_user->length);
1047                 break;
1048         }
1049
1050         case MEMREADOOB32:
1051         {
1052                 struct mtd_oob_buf32 buf;
1053                 struct mtd_oob_buf32 __user *buf_user = argp;
1054
1055                 /* NOTE: writes return length to buf->start */
1056                 if (copy_from_user(&buf, argp, sizeof(buf)))
1057                         ret = -EFAULT;
1058                 else
1059                         ret = mtdchar_readoob(file, mtd, buf.start,
1060                                 buf.length, compat_ptr(buf.ptr),
1061                                 &buf_user->start);
1062                 break;
1063         }
1064         default:
1065                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1066         }
1067
1068         mutex_unlock(&mtd_mutex);
1069
1070         return ret;
1071 }
1072
1073 #endif /* CONFIG_COMPAT */
1074
1075 /*
1076  * try to determine where a shared mapping can be made
1077  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1078  *   mappings)
1079  */
1080 #ifndef CONFIG_MMU
1081 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1082                                            unsigned long addr,
1083                                            unsigned long len,
1084                                            unsigned long pgoff,
1085                                            unsigned long flags)
1086 {
1087         struct mtd_file_info *mfi = file->private_data;
1088         struct mtd_info *mtd = mfi->mtd;
1089         unsigned long offset;
1090         int ret;
1091
1092         if (addr != 0)
1093                 return (unsigned long) -EINVAL;
1094
1095         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1096                 return (unsigned long) -EINVAL;
1097
1098         offset = pgoff << PAGE_SHIFT;
1099         if (offset > mtd->size - len)
1100                 return (unsigned long) -EINVAL;
1101
1102         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1103         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1104 }
1105 #endif
1106
1107 /*
1108  * set up a mapping for shared memory segments
1109  */
1110 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1111 {
1112 #ifdef CONFIG_MMU
1113         struct mtd_file_info *mfi = file->private_data;
1114         struct mtd_info *mtd = mfi->mtd;
1115         struct map_info *map = mtd->priv;
1116
1117         /* This is broken because it assumes the MTD device is map-based
1118            and that mtd->priv is a valid struct map_info.  It should be
1119            replaced with something that uses the mtd_get_unmapped_area()
1120            operation properly. */
1121         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1122 #ifdef pgprot_noncached
1123                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1124                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1125 #endif
1126                 return vm_iomap_memory(vma, map->phys, map->size);
1127         }
1128         return -ENODEV;
1129 #else
1130         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1131 #endif
1132 }
1133
1134 static const struct file_operations mtd_fops = {
1135         .owner          = THIS_MODULE,
1136         .llseek         = mtdchar_lseek,
1137         .read           = mtdchar_read,
1138         .write          = mtdchar_write,
1139         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1140 #ifdef CONFIG_COMPAT
1141         .compat_ioctl   = mtdchar_compat_ioctl,
1142 #endif
1143         .open           = mtdchar_open,
1144         .release        = mtdchar_close,
1145         .mmap           = mtdchar_mmap,
1146 #ifndef CONFIG_MMU
1147         .get_unmapped_area = mtdchar_get_unmapped_area,
1148 #endif
1149 };
1150
1151 static const struct super_operations mtd_ops = {
1152         .drop_inode = generic_delete_inode,
1153         .statfs = simple_statfs,
1154 };
1155
1156 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1157                                 int flags, const char *dev_name, void *data)
1158 {
1159         return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1160 }
1161
1162 static struct file_system_type mtd_inodefs_type = {
1163        .name = "mtd_inodefs",
1164        .mount = mtd_inodefs_mount,
1165        .kill_sb = kill_anon_super,
1166 };
1167 MODULE_ALIAS_FS("mtd_inodefs");
1168
1169 int __init init_mtdchar(void)
1170 {
1171         int ret;
1172
1173         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1174                                    "mtd", &mtd_fops);
1175         if (ret < 0) {
1176                 pr_err("Can't allocate major number %d for MTD\n",
1177                        MTD_CHAR_MAJOR);
1178                 return ret;
1179         }
1180
1181         ret = register_filesystem(&mtd_inodefs_type);
1182         if (ret) {
1183                 pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1184                        ret);
1185                 goto err_unregister_chdev;
1186         }
1187
1188         return ret;
1189
1190 err_unregister_chdev:
1191         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1192         return ret;
1193 }
1194
1195 void __exit cleanup_mtdchar(void)
1196 {
1197         unregister_filesystem(&mtd_inodefs_type);
1198         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1199 }
1200
1201 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);