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 mtdchar_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 mtdchar_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 } /* mtdchar_open */
 146
 147 /*====================================================================*/
 148
 149 static int mtdchar_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))
 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 } /* mtdchar_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 mtdchar_read(struct file *file, char __user *buf, size_t count,
 188                         loff_t *ppos)
 189 {
 190         struct mtd_file_info *mfi = file->private_data;
 191         struct mtd_info *mtd = mfi->mtd;
 192         size_t retlen;
 193         size_t total_retlen=0;
 194         int ret=0;
 195         int len;
 196         size_t size = count;
 197         char *kbuf;
 198
 199         pr_debug("MTD_read\n");
 200
 201         if (*ppos + count > mtd->size)
 202                 count = mtd->size - *ppos;
 203
 204         if (!count)
 205                 return 0;
 206
 207         kbuf = mtd_kmalloc_up_to(mtd, &size);
 208         if (!kbuf)
 209                 return -ENOMEM;
 210
 211         while (count) {
 212                 len = min_t(size_t, count, size);
 213
 214                 switch (mfi->mode) {
 215                 case MTD_FILE_MODE_OTP_FACTORY:
 216                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 217                                                      &retlen, kbuf);
 218                         break;
 219                 case MTD_FILE_MODE_OTP_USER:
 220                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 221                                                      &retlen, kbuf);
 222                         break;
 223                 case MTD_FILE_MODE_RAW:
 224                 {
 225                         struct mtd_oob_ops ops;
 226
 227                         ops.mode = MTD_OPS_RAW;
 228                         ops.datbuf = kbuf;
 229                         ops.oobbuf = NULL;
 230                         ops.len = len;
 231
 232                         ret = mtd_read_oob(mtd, *ppos, &ops);
 233                         retlen = ops.retlen;
 234                         break;
 235                 }
 236                 default:
 237                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 238                 }
 239                 /* Nand returns -EBADMSG on ECC errors, but it returns
 240                  * the data. For our userspace tools it is important
 241                  * to dump areas with ECC errors!
 242                  * For kernel internal usage it also might return -EUCLEAN
 243                  * to signal the caller that a bitflip has occurred and has
 244                  * been corrected by the ECC algorithm.
 245                  * Userspace software which accesses NAND this way
 246                  * must be aware of the fact that it deals with NAND
 247                  */
 248                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 249                         *ppos += retlen;
 250                         if (copy_to_user(buf, kbuf, retlen)) {
 251                                 kfree(kbuf);
 252                                 return -EFAULT;
 253                         }
 254                         else
 255                                 total_retlen += retlen;
 256
 257                         count -= retlen;
 258                         buf += retlen;
 259                         if (retlen == 0)
 260                                 count = 0;
 261                 }
 262                 else {
 263                         kfree(kbuf);
 264                         return ret;
 265                 }
 266
 267         }
 268
 269         kfree(kbuf);
 270         return total_retlen;
 271 } /* mtdchar_read */
 272
 273 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 274                         loff_t *ppos)
 275 {
 276         struct mtd_file_info *mfi = file->private_data;
 277         struct mtd_info *mtd = mfi->mtd;
 278         size_t size = count;
 279         char *kbuf;
 280         size_t retlen;
 281         size_t total_retlen=0;
 282         int ret=0;
 283         int len;
 284
 285         pr_debug("MTD_write\n");
 286
 287         if (*ppos == mtd->size)
 288                 return -ENOSPC;
 289
 290         if (*ppos + count > mtd->size)
 291                 count = mtd->size - *ppos;
 292
 293         if (!count)
 294                 return 0;
 295
 296         kbuf = mtd_kmalloc_up_to(mtd, &size);
 297         if (!kbuf)
 298                 return -ENOMEM;
 299
 300         while (count) {
 301                 len = min_t(size_t, count, size);
 302
 303                 if (copy_from_user(kbuf, buf, len)) {
 304                         kfree(kbuf);
 305                         return -EFAULT;
 306                 }
 307
 308                 switch (mfi->mode) {
 309                 case MTD_FILE_MODE_OTP_FACTORY:
 310                         ret = -EROFS;
 311                         break;
 312                 case MTD_FILE_MODE_OTP_USER:
 313                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 314                                                       &retlen, kbuf);
 315                         break;
 316
 317                 case MTD_FILE_MODE_RAW:
 318                 {
 319                         struct mtd_oob_ops ops;
 320
 321                         ops.mode = MTD_OPS_RAW;
 322                         ops.datbuf = kbuf;
 323                         ops.oobbuf = NULL;
 324                         ops.ooboffs = 0;
 325                         ops.len = len;
 326
 327                         ret = mtd_write_oob(mtd, *ppos, &ops);
 328                         retlen = ops.retlen;
 329                         break;
 330                 }
 331
 332                 default:
 333                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 334                 }
 335                 if (!ret) {
 336                         *ppos += retlen;
 337                         total_retlen += retlen;
 338                         count -= retlen;
 339                         buf += retlen;
 340                 }
 341                 else {
 342                         kfree(kbuf);
 343                         return ret;
 344                 }
 345         }
 346
 347         kfree(kbuf);
 348         return total_retlen;
 349 } /* mtdchar_write */
 350
 351 /*======================================================================
 352
 353     IOCTL calls for getting device parameters.
 354
 355 ======================================================================*/
 356 static void mtdchar_erase_callback (struct erase_info *instr)
 357 {
 358         wake_up((wait_queue_head_t *)instr->priv);
 359 }
 360
 361 #ifdef CONFIG_HAVE_MTD_OTP
 362 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 363 {
 364         struct mtd_info *mtd = mfi->mtd;
 365         size_t retlen;
 366         int ret = 0;
 367
 368         /*
 369          * Make a fake call to mtd_read_fact_prot_reg() to check if OTP
 370          * operations are supported.
 371          */
 372         if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) == -EOPNOTSUPP)
 373                 return -EOPNOTSUPP;
 374
 375         switch (mode) {
 376         case MTD_OTP_FACTORY:
 377                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 378                 break;
 379         case MTD_OTP_USER:
 380                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 381                 break;
 382         default:
 383                 ret = -EINVAL;
 384         case MTD_OTP_OFF:
 385                 break;
 386         }
 387         return ret;
 388 }
 389 #else
 390 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 391 #endif
 392
 393 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 394         uint64_t start, uint32_t length, void __user *ptr,
 395         uint32_t __user *retp)
 396 {
 397         struct mtd_file_info *mfi = file->private_data;
 398         struct mtd_oob_ops ops;
 399         uint32_t retlen;
 400         int ret = 0;
 401
 402         if (!(file->f_mode & FMODE_WRITE))
 403                 return -EPERM;
 404
 405         if (length > 4096)
 406                 return -EINVAL;
 407
 408         if (!mtd->write_oob)
 409                 ret = -EOPNOTSUPP;
 410         else
 411                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 412
 413         if (ret)
 414                 return ret;
 415
 416         ops.ooblen = length;
 417         ops.ooboffs = start & (mtd->writesize - 1);
 418         ops.datbuf = NULL;
 419         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 420                 MTD_OPS_PLACE_OOB;
 421
 422         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 423                 return -EINVAL;
 424
 425         ops.oobbuf = memdup_user(ptr, length);
 426         if (IS_ERR(ops.oobbuf))
 427                 return PTR_ERR(ops.oobbuf);
 428
 429         start &= ~((uint64_t)mtd->writesize - 1);
 430         ret = mtd_write_oob(mtd, start, &ops);
 431
 432         if (ops.oobretlen > 0xFFFFFFFFU)
 433                 ret = -EOVERFLOW;
 434         retlen = ops.oobretlen;
 435         if (copy_to_user(retp, &retlen, sizeof(length)))
 436                 ret = -EFAULT;
 437
 438         kfree(ops.oobbuf);
 439         return ret;
 440 }
 441
 442 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 443         uint64_t start, uint32_t length, void __user *ptr,
 444         uint32_t __user *retp)
 445 {
 446         struct mtd_file_info *mfi = file->private_data;
 447         struct mtd_oob_ops ops;
 448         int ret = 0;
 449
 450         if (length > 4096)
 451                 return -EINVAL;
 452
 453         if (!access_ok(VERIFY_WRITE, ptr, length))
 454                 return -EFAULT;
 455
 456         ops.ooblen = length;
 457         ops.ooboffs = start & (mtd->writesize - 1);
 458         ops.datbuf = NULL;
 459         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 460                 MTD_OPS_PLACE_OOB;
 461
 462         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 463                 return -EINVAL;
 464
 465         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 466         if (!ops.oobbuf)
 467                 return -ENOMEM;
 468
 469         start &= ~((uint64_t)mtd->writesize - 1);
 470         ret = mtd_read_oob(mtd, start, &ops);
 471
 472         if (put_user(ops.oobretlen, retp))
 473                 ret = -EFAULT;
 474         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 475                                             ops.oobretlen))
 476                 ret = -EFAULT;
 477
 478         kfree(ops.oobbuf);
 479
 480         /*
 481          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 482          * data. For our userspace tools it is important to dump areas
 483          * with ECC errors!
 484          * For kernel internal usage it also might return -EUCLEAN
 485          * to signal the caller that a bitflip has occured and has
 486          * been corrected by the ECC algorithm.
 487          *
 488          * Note: currently the standard NAND function, nand_read_oob_std,
 489          * does not calculate ECC for the OOB area, so do not rely on
 490          * this behavior unless you have replaced it with your own.
 491          */
 492         if (mtd_is_bitflip_or_eccerr(ret))
 493                 return 0;
 494
 495         return ret;
 496 }
 497
 498 /*
 499  * Copies (and truncates, if necessary) data from the larger struct,
 500  * nand_ecclayout, to the smaller, deprecated layout struct,
 501  * nand_ecclayout_user. This is necessary only to support the deprecated
 502  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 503  * nand_ecclayout flexibly (i.e. the struct may change size in new
 504  * releases without requiring major rewrites).
 505  */
 506 static int shrink_ecclayout(const struct nand_ecclayout *from,
 507                 struct nand_ecclayout_user *to)
 508 {
 509         int i;
 510
 511         if (!from || !to)
 512                 return -EINVAL;
 513
 514         memset(to, 0, sizeof(*to));
 515
 516         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 517         for (i = 0; i < to->eccbytes; i++)
 518                 to->eccpos[i] = from->eccpos[i];
 519
 520         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 521                 if (from->oobfree[i].length == 0 &&
 522                                 from->oobfree[i].offset == 0)
 523                         break;
 524                 to->oobavail += from->oobfree[i].length;
 525                 to->oobfree[i] = from->oobfree[i];
 526         }
 527
 528         return 0;
 529 }
 530
 531 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 532                            struct blkpg_ioctl_arg __user *arg)
 533 {
 534         struct blkpg_ioctl_arg a;
 535         struct blkpg_partition p;
 536
 537         if (!capable(CAP_SYS_ADMIN))
 538                 return -EPERM;
 539
 540         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 541                 return -EFAULT;
 542
 543         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 544                 return -EFAULT;
 545
 546         switch (a.op) {
 547         case BLKPG_ADD_PARTITION:
 548
 549                 /* Only master mtd device must be used to add partitions */
 550                 if (mtd_is_partition(mtd))
 551                         return -EINVAL;
 552
 553                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 554
 555         case BLKPG_DEL_PARTITION:
 556
 557                 if (p.pno < 0)
 558                         return -EINVAL;
 559
 560                 return mtd_del_partition(mtd, p.pno);
 561
 562         default:
 563                 return -EINVAL;
 564         }
 565 }
 566
 567 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 568                 struct mtd_write_req __user *argp)
 569 {
 570         struct mtd_write_req req;
 571         struct mtd_oob_ops ops;
 572         void __user *usr_data, *usr_oob;
 573         int ret;
 574
 575         if (copy_from_user(&req, argp, sizeof(req)) ||
 576                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 577                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 578                 return -EFAULT;
 579         if (!mtd->write_oob)
 580                 return -EOPNOTSUPP;
 581
 582         ops.mode = req.mode;
 583         ops.len = (size_t)req.len;
 584         ops.ooblen = (size_t)req.ooblen;
 585         ops.ooboffs = 0;
 586
 587         usr_data = (void __user *)(uintptr_t)req.usr_data;
 588         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 589
 590         if (req.usr_data) {
 591                 ops.datbuf = memdup_user(usr_data, ops.len);
 592                 if (IS_ERR(ops.datbuf))
 593                         return PTR_ERR(ops.datbuf);
 594         } else {
 595                 ops.datbuf = NULL;
 596         }
 597
 598         if (req.usr_oob) {
 599                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 600                 if (IS_ERR(ops.oobbuf)) {
 601                         kfree(ops.datbuf);
 602                         return PTR_ERR(ops.oobbuf);
 603                 }
 604         } else {
 605                 ops.oobbuf = NULL;
 606         }
 607
 608         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 609
 610         kfree(ops.datbuf);
 611         kfree(ops.oobbuf);
 612
 613         return ret;
 614 }
 615
 616 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 617 {
 618         struct mtd_file_info *mfi = file->private_data;
 619         struct mtd_info *mtd = mfi->mtd;
 620         void __user *argp = (void __user *)arg;
 621         int ret = 0;
 622         u_long size;
 623         struct mtd_info_user info;
 624
 625         pr_debug("MTD_ioctl\n");
 626
 627         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 628         if (cmd & IOC_IN) {
 629                 if (!access_ok(VERIFY_READ, argp, size))
 630                         return -EFAULT;
 631         }
 632         if (cmd & IOC_OUT) {
 633                 if (!access_ok(VERIFY_WRITE, argp, size))
 634                         return -EFAULT;
 635         }
 636
 637         switch (cmd) {
 638         case MEMGETREGIONCOUNT:
 639                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 640                         return -EFAULT;
 641                 break;
 642
 643         case MEMGETREGIONINFO:
 644         {
 645                 uint32_t ur_idx;
 646                 struct mtd_erase_region_info *kr;
 647                 struct region_info_user __user *ur = argp;
 648
 649                 if (get_user(ur_idx, &(ur->regionindex)))
 650                         return -EFAULT;
 651
 652                 if (ur_idx >= mtd->numeraseregions)
 653                         return -EINVAL;
 654
 655                 kr = &(mtd->eraseregions[ur_idx]);
 656
 657                 if (put_user(kr->offset, &(ur->offset))
 658                     || put_user(kr->erasesize, &(ur->erasesize))
 659                     || put_user(kr->numblocks, &(ur->numblocks)))
 660                         return -EFAULT;
 661
 662                 break;
 663         }
 664
 665         case MEMGETINFO:
 666                 memset(&info, 0, sizeof(info));
 667                 info.type       = mtd->type;
 668                 info.flags      = mtd->flags;
 669                 info.size       = mtd->size;
 670                 info.erasesize  = mtd->erasesize;
 671                 info.writesize  = mtd->writesize;
 672                 info.oobsize    = mtd->oobsize;
 673                 /* The below field is obsolete */
 674                 info.padding    = 0;
 675                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 676                         return -EFAULT;
 677                 break;
 678
 679         case MEMERASE:
 680         case MEMERASE64:
 681         {
 682                 struct erase_info *erase;
 683
 684                 if(!(file->f_mode & FMODE_WRITE))
 685                         return -EPERM;
 686
 687                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 688                 if (!erase)
 689                         ret = -ENOMEM;
 690                 else {
 691                         wait_queue_head_t waitq;
 692                         DECLARE_WAITQUEUE(wait, current);
 693
 694                         init_waitqueue_head(&waitq);
 695
 696                         if (cmd == MEMERASE64) {
 697                                 struct erase_info_user64 einfo64;
 698
 699                                 if (copy_from_user(&einfo64, argp,
 700                                             sizeof(struct erase_info_user64))) {
 701                                         kfree(erase);
 702                                         return -EFAULT;
 703                                 }
 704                                 erase->addr = einfo64.start;
 705                                 erase->len = einfo64.length;
 706                         } else {
 707                                 struct erase_info_user einfo32;
 708
 709                                 if (copy_from_user(&einfo32, argp,
 710                                             sizeof(struct erase_info_user))) {
 711                                         kfree(erase);
 712                                         return -EFAULT;
 713                                 }
 714                                 erase->addr = einfo32.start;
 715                                 erase->len = einfo32.length;
 716                         }
 717                         erase->mtd = mtd;
 718                         erase->callback = mtdchar_erase_callback;
 719                         erase->priv = (unsigned long)&waitq;
 720
 721                         /*
 722                           FIXME: Allow INTERRUPTIBLE. Which means
 723                           not having the wait_queue head on the stack.
 724
 725                           If the wq_head is on the stack, and we
 726                           leave because we got interrupted, then the
 727                           wq_head is no longer there when the
 728                           callback routine tries to wake us up.
 729                         */
 730                         ret = mtd_erase(mtd, erase);
 731                         if (!ret) {
 732                                 set_current_state(TASK_UNINTERRUPTIBLE);
 733                                 add_wait_queue(&waitq, &wait);
 734                                 if (erase->state != MTD_ERASE_DONE &&
 735                                     erase->state != MTD_ERASE_FAILED)
 736                                         schedule();
 737                                 remove_wait_queue(&waitq, &wait);
 738                                 set_current_state(TASK_RUNNING);
 739
 740                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 741                         }
 742                         kfree(erase);
 743                 }
 744                 break;
 745         }
 746
 747         case MEMWRITEOOB:
 748         {
 749                 struct mtd_oob_buf buf;
 750                 struct mtd_oob_buf __user *buf_user = argp;
 751
 752                 /* NOTE: writes return length to buf_user->length */
 753                 if (copy_from_user(&buf, argp, sizeof(buf)))
 754                         ret = -EFAULT;
 755                 else
 756                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 757                                 buf.ptr, &buf_user->length);
 758                 break;
 759         }
 760
 761         case MEMREADOOB:
 762         {
 763                 struct mtd_oob_buf buf;
 764                 struct mtd_oob_buf __user *buf_user = argp;
 765
 766                 /* NOTE: writes return length to buf_user->start */
 767                 if (copy_from_user(&buf, argp, sizeof(buf)))
 768                         ret = -EFAULT;
 769                 else
 770                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 771                                 buf.ptr, &buf_user->start);
 772                 break;
 773         }
 774
 775         case MEMWRITEOOB64:
 776         {
 777                 struct mtd_oob_buf64 buf;
 778                 struct mtd_oob_buf64 __user *buf_user = argp;
 779
 780                 if (copy_from_user(&buf, argp, sizeof(buf)))
 781                         ret = -EFAULT;
 782                 else
 783                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 784                                 (void __user *)(uintptr_t)buf.usr_ptr,
 785                                 &buf_user->length);
 786                 break;
 787         }
 788
 789         case MEMREADOOB64:
 790         {
 791                 struct mtd_oob_buf64 buf;
 792                 struct mtd_oob_buf64 __user *buf_user = argp;
 793
 794                 if (copy_from_user(&buf, argp, sizeof(buf)))
 795                         ret = -EFAULT;
 796                 else
 797                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 798                                 (void __user *)(uintptr_t)buf.usr_ptr,
 799                                 &buf_user->length);
 800                 break;
 801         }
 802
 803         case MEMWRITE:
 804         {
 805                 ret = mtdchar_write_ioctl(mtd,
 806                       (struct mtd_write_req __user *)arg);
 807                 break;
 808         }
 809
 810         case MEMLOCK:
 811         {
 812                 struct erase_info_user einfo;
 813
 814                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 815                         return -EFAULT;
 816
 817                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 818                 break;
 819         }
 820
 821         case MEMUNLOCK:
 822         {
 823                 struct erase_info_user einfo;
 824
 825                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 826                         return -EFAULT;
 827
 828                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 829                 break;
 830         }
 831
 832         case MEMISLOCKED:
 833         {
 834                 struct erase_info_user einfo;
 835
 836                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 837                         return -EFAULT;
 838
 839                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 840                 break;
 841         }
 842
 843         /* Legacy interface */
 844         case MEMGETOOBSEL:
 845         {
 846                 struct nand_oobinfo oi;
 847
 848                 if (!mtd->ecclayout)
 849                         return -EOPNOTSUPP;
 850                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 851                         return -EINVAL;
 852
 853                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 854                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 855                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 856                        sizeof(oi.oobfree));
 857                 oi.eccbytes = mtd->ecclayout->eccbytes;
 858
 859                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 860                         return -EFAULT;
 861                 break;
 862         }
 863
 864         case MEMGETBADBLOCK:
 865         {
 866                 loff_t offs;
 867
 868                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 869                         return -EFAULT;
 870                 return mtd_block_isbad(mtd, offs);
 871                 break;
 872         }
 873
 874         case MEMSETBADBLOCK:
 875         {
 876                 loff_t offs;
 877
 878                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 879                         return -EFAULT;
 880                 return mtd_block_markbad(mtd, offs);
 881                 break;
 882         }
 883
 884 #ifdef CONFIG_HAVE_MTD_OTP
 885         case OTPSELECT:
 886         {
 887                 int mode;
 888                 if (copy_from_user(&mode, argp, sizeof(int)))
 889                         return -EFAULT;
 890
 891                 mfi->mode = MTD_FILE_MODE_NORMAL;
 892
 893                 ret = otp_select_filemode(mfi, mode);
 894
 895                 file->f_pos = 0;
 896                 break;
 897         }
 898
 899         case OTPGETREGIONCOUNT:
 900         case OTPGETREGIONINFO:
 901         {
 902                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 903                 if (!buf)
 904                         return -ENOMEM;
 905                 switch (mfi->mode) {
 906                 case MTD_FILE_MODE_OTP_FACTORY:
 907                         ret = mtd_get_fact_prot_info(mtd, buf, 4096);
 908                         break;
 909                 case MTD_FILE_MODE_OTP_USER:
 910                         ret = mtd_get_user_prot_info(mtd, buf, 4096);
 911                         break;
 912                 default:
 913                         ret = -EINVAL;
 914                         break;
 915                 }
 916                 if (ret >= 0) {
 917                         if (cmd == OTPGETREGIONCOUNT) {
 918                                 int nbr = ret / sizeof(struct otp_info);
 919                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 920                         } else
 921                                 ret = copy_to_user(argp, buf, ret);
 922                         if (ret)
 923                                 ret = -EFAULT;
 924                 }
 925                 kfree(buf);
 926                 break;
 927         }
 928
 929         case OTPLOCK:
 930         {
 931                 struct otp_info oinfo;
 932
 933                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 934                         return -EINVAL;
 935                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 936                         return -EFAULT;
 937                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 938                 break;
 939         }
 940 #endif
 941
 942         /* This ioctl is being deprecated - it truncates the ECC layout */
 943         case ECCGETLAYOUT:
 944         {
 945                 struct nand_ecclayout_user *usrlay;
 946
 947                 if (!mtd->ecclayout)
 948                         return -EOPNOTSUPP;
 949
 950                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 951                 if (!usrlay)
 952                         return -ENOMEM;
 953
 954                 shrink_ecclayout(mtd->ecclayout, usrlay);
 955
 956                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 957                         ret = -EFAULT;
 958                 kfree(usrlay);
 959                 break;
 960         }
 961
 962         case ECCGETSTATS:
 963         {
 964                 if (copy_to_user(argp, &mtd->ecc_stats,
 965                                  sizeof(struct mtd_ecc_stats)))
 966                         return -EFAULT;
 967                 break;
 968         }
 969
 970         case MTDFILEMODE:
 971         {
 972                 mfi->mode = 0;
 973
 974                 switch(arg) {
 975                 case MTD_FILE_MODE_OTP_FACTORY:
 976                 case MTD_FILE_MODE_OTP_USER:
 977                         ret = otp_select_filemode(mfi, arg);
 978                         break;
 979
 980                 case MTD_FILE_MODE_RAW:
 981                         if (!mtd_has_oob(mtd))
 982                                 return -EOPNOTSUPP;
 983                         mfi->mode = arg;
 984
 985                 case MTD_FILE_MODE_NORMAL:
 986                         break;
 987                 default:
 988                         ret = -EINVAL;
 989                 }
 990                 file->f_pos = 0;
 991                 break;
 992         }
 993
 994         case BLKPG:
 995         {
 996                 ret = mtdchar_blkpg_ioctl(mtd,
 997                       (struct blkpg_ioctl_arg __user *)arg);
 998                 break;
 999         }
1000
1001         case BLKRRPART:
1002         {
1003                 /* No reread partition feature. Just return ok */
1004                 ret = 0;
1005                 break;
1006         }
1007
1008         default:
1009                 ret = -ENOTTY;
1010         }
1011
1012         return ret;
1013 } /* memory_ioctl */
1014
1015 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1016 {
1017         int ret;
1018
1019         mutex_lock(&mtd_mutex);
1020         ret = mtdchar_ioctl(file, cmd, arg);
1021         mutex_unlock(&mtd_mutex);
1022
1023         return ret;
1024 }
1025
1026 #ifdef CONFIG_COMPAT
1027
1028 struct mtd_oob_buf32 {
1029         u_int32_t start;
1030         u_int32_t length;
1031         compat_caddr_t ptr;     /* unsigned char* */
1032 };
1033
1034 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1035 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1036
1037 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1038         unsigned long arg)
1039 {
1040         struct mtd_file_info *mfi = file->private_data;
1041         struct mtd_info *mtd = mfi->mtd;
1042         void __user *argp = compat_ptr(arg);
1043         int ret = 0;
1044
1045         mutex_lock(&mtd_mutex);
1046
1047         switch (cmd) {
1048         case MEMWRITEOOB32:
1049         {
1050                 struct mtd_oob_buf32 buf;
1051                 struct mtd_oob_buf32 __user *buf_user = argp;
1052
1053                 if (copy_from_user(&buf, argp, sizeof(buf)))
1054                         ret = -EFAULT;
1055                 else
1056                         ret = mtdchar_writeoob(file, mtd, buf.start,
1057                                 buf.length, compat_ptr(buf.ptr),
1058                                 &buf_user->length);
1059                 break;
1060         }
1061
1062         case MEMREADOOB32:
1063         {
1064                 struct mtd_oob_buf32 buf;
1065                 struct mtd_oob_buf32 __user *buf_user = argp;
1066
1067                 /* NOTE: writes return length to buf->start */
1068                 if (copy_from_user(&buf, argp, sizeof(buf)))
1069                         ret = -EFAULT;
1070                 else
1071                         ret = mtdchar_readoob(file, mtd, buf.start,
1072                                 buf.length, compat_ptr(buf.ptr),
1073                                 &buf_user->start);
1074                 break;
1075         }
1076         default:
1077                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1078         }
1079
1080         mutex_unlock(&mtd_mutex);
1081
1082         return ret;
1083 }
1084
1085 #endif /* CONFIG_COMPAT */
1086
1087 /*
1088  * try to determine where a shared mapping can be made
1089  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1090  *   mappings)
1091  */
1092 #ifndef CONFIG_MMU
1093 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1094                                            unsigned long addr,
1095                                            unsigned long len,
1096                                            unsigned long pgoff,
1097                                            unsigned long flags)
1098 {
1099         struct mtd_file_info *mfi = file->private_data;
1100         struct mtd_info *mtd = mfi->mtd;
1101         unsigned long offset;
1102         int ret;
1103
1104         if (addr != 0)
1105                 return (unsigned long) -EINVAL;
1106
1107         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1108                 return (unsigned long) -EINVAL;
1109
1110         offset = pgoff << PAGE_SHIFT;
1111         if (offset > mtd->size - len)
1112                 return (unsigned long) -EINVAL;
1113
1114         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1115         return ret == -EOPNOTSUPP ? -ENOSYS : ret;
1116 }
1117 #endif
1118
1119 /*
1120  * set up a mapping for shared memory segments
1121  */
1122 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1123 {
1124 #ifdef CONFIG_MMU
1125         struct mtd_file_info *mfi = file->private_data;
1126         struct mtd_info *mtd = mfi->mtd;
1127         struct map_info *map = mtd->priv;
1128         unsigned long start;
1129         unsigned long off;
1130         u32 len;
1131
1132         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1133                 off = vma->vm_pgoff << PAGE_SHIFT;
1134                 start = map->phys;
1135                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1136                 start &= PAGE_MASK;
1137                 if ((vma->vm_end - vma->vm_start + off) > len)
1138                         return -EINVAL;
1139
1140                 off += start;
1141                 vma->vm_pgoff = off >> PAGE_SHIFT;
1142                 vma->vm_flags |= VM_IO | VM_RESERVED;
1143
1144 #ifdef pgprot_noncached
1145                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1146                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1147 #endif
1148                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1149                                        vma->vm_end - vma->vm_start,
1150                                        vma->vm_page_prot))
1151                         return -EAGAIN;
1152
1153                 return 0;
1154         }
1155         return -ENOSYS;
1156 #else
1157         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1158 #endif
1159 }
1160
1161 static const struct file_operations mtd_fops = {
1162         .owner          = THIS_MODULE,
1163         .llseek         = mtdchar_lseek,
1164         .read           = mtdchar_read,
1165         .write          = mtdchar_write,
1166         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1167 #ifdef CONFIG_COMPAT
1168         .compat_ioctl   = mtdchar_compat_ioctl,
1169 #endif
1170         .open           = mtdchar_open,
1171         .release        = mtdchar_close,
1172         .mmap           = mtdchar_mmap,
1173 #ifndef CONFIG_MMU
1174         .get_unmapped_area = mtdchar_get_unmapped_area,
1175 #endif
1176 };
1177
1178 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1179                                 int flags, const char *dev_name, void *data)
1180 {
1181         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1182 }
1183
1184 static struct file_system_type mtd_inodefs_type = {
1185        .name = "mtd_inodefs",
1186        .mount = mtd_inodefs_mount,
1187        .kill_sb = kill_anon_super,
1188 };
1189
1190 static void mtdchar_notify_add(struct mtd_info *mtd)
1191 {
1192 }
1193
1194 static void mtdchar_notify_remove(struct mtd_info *mtd)
1195 {
1196         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1197
1198         if (mtd_ino) {
1199                 /* Destroy the inode if it exists */
1200                 clear_nlink(mtd_ino);
1201                 iput(mtd_ino);
1202         }
1203 }
1204
1205 static struct mtd_notifier mtdchar_notifier = {
1206         .add = mtdchar_notify_add,
1207         .remove = mtdchar_notify_remove,
1208 };
1209
1210 static int __init init_mtdchar(void)
1211 {
1212         int ret;
1213
1214         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1215                                    "mtd", &mtd_fops);
1216         if (ret < 0) {
1217                 pr_notice("Can't allocate major number %d for "
1218                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1219                 return ret;
1220         }
1221
1222         ret = register_filesystem(&mtd_inodefs_type);
1223         if (ret) {
1224                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1225                 goto err_unregister_chdev;
1226         }
1227
1228         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1229         if (IS_ERR(mtd_inode_mnt)) {
1230                 ret = PTR_ERR(mtd_inode_mnt);
1231                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1232                 goto err_unregister_filesystem;
1233         }
1234         register_mtd_user(&mtdchar_notifier);
1235
1236         return ret;
1237
1238 err_unregister_filesystem:
1239         unregister_filesystem(&mtd_inodefs_type);
1240 err_unregister_chdev:
1241         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1242         return ret;
1243 }
1244
1245 static void __exit cleanup_mtdchar(void)
1246 {
1247         unregister_mtd_user(&mtdchar_notifier);
1248         kern_unmount(mtd_inode_mnt);
1249         unregister_filesystem(&mtd_inodefs_type);
1250         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1251 }
1252
1253 module_init(init_mtdchar);
1254 module_exit(cleanup_mtdchar);
1255
1256 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1257
1258 MODULE_LICENSE("GPL");
1259 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1260 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1261 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);