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) && 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 } /* 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                         if (!mtd->write_user_prot_reg) {
 314                                 ret = -EOPNOTSUPP;
 315                                 break;
 316                         }
 317                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 318                                                       &retlen, kbuf);
 319                         break;
 320
 321                 case MTD_FILE_MODE_RAW:
 322                 {
 323                         struct mtd_oob_ops ops;
 324
 325                         ops.mode = MTD_OPS_RAW;
 326                         ops.datbuf = kbuf;
 327                         ops.oobbuf = NULL;
 328                         ops.ooboffs = 0;
 329                         ops.len = len;
 330
 331                         ret = mtd_write_oob(mtd, *ppos, &ops);
 332                         retlen = ops.retlen;
 333                         break;
 334                 }
 335
 336                 default:
 337                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 338                 }
 339                 if (!ret) {
 340                         *ppos += retlen;
 341                         total_retlen += retlen;
 342                         count -= retlen;
 343                         buf += retlen;
 344                 }
 345                 else {
 346                         kfree(kbuf);
 347                         return ret;
 348                 }
 349         }
 350
 351         kfree(kbuf);
 352         return total_retlen;
 353 } /* mtdchar_write */
 354
 355 /*======================================================================
 356
 357     IOCTL calls for getting device parameters.
 358
 359 ======================================================================*/
 360 static void mtdchar_erase_callback (struct erase_info *instr)
 361 {
 362         wake_up((wait_queue_head_t *)instr->priv);
 363 }
 364
 365 #ifdef CONFIG_HAVE_MTD_OTP
 366 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 367 {
 368         struct mtd_info *mtd = mfi->mtd;
 369         int ret = 0;
 370
 371         switch (mode) {
 372         case MTD_OTP_FACTORY:
 373                 if (!mtd->read_fact_prot_reg)
 374                         ret = -EOPNOTSUPP;
 375                 else
 376                         mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 377                 break;
 378         case MTD_OTP_USER:
 379                 if (!mtd->read_fact_prot_reg)
 380                         ret = -EOPNOTSUPP;
 381                 else
 382                         mfi->mode = MTD_FILE_MODE_OTP_USER;
 383                 break;
 384         default:
 385                 ret = -EINVAL;
 386         case MTD_OTP_OFF:
 387                 break;
 388         }
 389         return ret;
 390 }
 391 #else
 392 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 393 #endif
 394
 395 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 396         uint64_t start, uint32_t length, void __user *ptr,
 397         uint32_t __user *retp)
 398 {
 399         struct mtd_file_info *mfi = file->private_data;
 400         struct mtd_oob_ops ops;
 401         uint32_t retlen;
 402         int ret = 0;
 403
 404         if (!(file->f_mode & FMODE_WRITE))
 405                 return -EPERM;
 406
 407         if (length > 4096)
 408                 return -EINVAL;
 409
 410         if (!mtd->write_oob)
 411                 ret = -EOPNOTSUPP;
 412         else
 413                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 414
 415         if (ret)
 416                 return ret;
 417
 418         ops.ooblen = length;
 419         ops.ooboffs = start & (mtd->writesize - 1);
 420         ops.datbuf = NULL;
 421         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 422                 MTD_OPS_PLACE_OOB;
 423
 424         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 425                 return -EINVAL;
 426
 427         ops.oobbuf = memdup_user(ptr, length);
 428         if (IS_ERR(ops.oobbuf))
 429                 return PTR_ERR(ops.oobbuf);
 430
 431         start &= ~((uint64_t)mtd->writesize - 1);
 432         ret = mtd_write_oob(mtd, start, &ops);
 433
 434         if (ops.oobretlen > 0xFFFFFFFFU)
 435                 ret = -EOVERFLOW;
 436         retlen = ops.oobretlen;
 437         if (copy_to_user(retp, &retlen, sizeof(length)))
 438                 ret = -EFAULT;
 439
 440         kfree(ops.oobbuf);
 441         return ret;
 442 }
 443
 444 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 445         uint64_t start, uint32_t length, void __user *ptr,
 446         uint32_t __user *retp)
 447 {
 448         struct mtd_file_info *mfi = file->private_data;
 449         struct mtd_oob_ops ops;
 450         int ret = 0;
 451
 452         if (length > 4096)
 453                 return -EINVAL;
 454
 455         if (!mtd->read_oob)
 456                 ret = -EOPNOTSUPP;
 457         else
 458                 ret = access_ok(VERIFY_WRITE, ptr,
 459                                 length) ? 0 : -EFAULT;
 460         if (ret)
 461                 return ret;
 462
 463         ops.ooblen = length;
 464         ops.ooboffs = start & (mtd->writesize - 1);
 465         ops.datbuf = NULL;
 466         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 467                 MTD_OPS_PLACE_OOB;
 468
 469         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 470                 return -EINVAL;
 471
 472         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 473         if (!ops.oobbuf)
 474                 return -ENOMEM;
 475
 476         start &= ~((uint64_t)mtd->writesize - 1);
 477         ret = mtd_read_oob(mtd, start, &ops);
 478
 479         if (put_user(ops.oobretlen, retp))
 480                 ret = -EFAULT;
 481         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 482                                             ops.oobretlen))
 483                 ret = -EFAULT;
 484
 485         kfree(ops.oobbuf);
 486
 487         /*
 488          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 489          * data. For our userspace tools it is important to dump areas
 490          * with ECC errors!
 491          * For kernel internal usage it also might return -EUCLEAN
 492          * to signal the caller that a bitflip has occured and has
 493          * been corrected by the ECC algorithm.
 494          *
 495          * Note: currently the standard NAND function, nand_read_oob_std,
 496          * does not calculate ECC for the OOB area, so do not rely on
 497          * this behavior unless you have replaced it with your own.
 498          */
 499         if (mtd_is_bitflip_or_eccerr(ret))
 500                 return 0;
 501
 502         return ret;
 503 }
 504
 505 /*
 506  * Copies (and truncates, if necessary) data from the larger struct,
 507  * nand_ecclayout, to the smaller, deprecated layout struct,
 508  * nand_ecclayout_user. This is necessary only to support the deprecated
 509  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 510  * nand_ecclayout flexibly (i.e. the struct may change size in new
 511  * releases without requiring major rewrites).
 512  */
 513 static int shrink_ecclayout(const struct nand_ecclayout *from,
 514                 struct nand_ecclayout_user *to)
 515 {
 516         int i;
 517
 518         if (!from || !to)
 519                 return -EINVAL;
 520
 521         memset(to, 0, sizeof(*to));
 522
 523         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 524         for (i = 0; i < to->eccbytes; i++)
 525                 to->eccpos[i] = from->eccpos[i];
 526
 527         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 528                 if (from->oobfree[i].length == 0 &&
 529                                 from->oobfree[i].offset == 0)
 530                         break;
 531                 to->oobavail += from->oobfree[i].length;
 532                 to->oobfree[i] = from->oobfree[i];
 533         }
 534
 535         return 0;
 536 }
 537
 538 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 539                            struct blkpg_ioctl_arg __user *arg)
 540 {
 541         struct blkpg_ioctl_arg a;
 542         struct blkpg_partition p;
 543
 544         if (!capable(CAP_SYS_ADMIN))
 545                 return -EPERM;
 546
 547         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 548                 return -EFAULT;
 549
 550         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 551                 return -EFAULT;
 552
 553         switch (a.op) {
 554         case BLKPG_ADD_PARTITION:
 555
 556                 /* Only master mtd device must be used to add partitions */
 557                 if (mtd_is_partition(mtd))
 558                         return -EINVAL;
 559
 560                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 561
 562         case BLKPG_DEL_PARTITION:
 563
 564                 if (p.pno < 0)
 565                         return -EINVAL;
 566
 567                 return mtd_del_partition(mtd, p.pno);
 568
 569         default:
 570                 return -EINVAL;
 571         }
 572 }
 573
 574 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 575                 struct mtd_write_req __user *argp)
 576 {
 577         struct mtd_write_req req;
 578         struct mtd_oob_ops ops;
 579         void __user *usr_data, *usr_oob;
 580         int ret;
 581
 582         if (copy_from_user(&req, argp, sizeof(req)) ||
 583                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 584                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 585                 return -EFAULT;
 586         if (!mtd->write_oob)
 587                 return -EOPNOTSUPP;
 588
 589         ops.mode = req.mode;
 590         ops.len = (size_t)req.len;
 591         ops.ooblen = (size_t)req.ooblen;
 592         ops.ooboffs = 0;
 593
 594         usr_data = (void __user *)(uintptr_t)req.usr_data;
 595         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 596
 597         if (req.usr_data) {
 598                 ops.datbuf = memdup_user(usr_data, ops.len);
 599                 if (IS_ERR(ops.datbuf))
 600                         return PTR_ERR(ops.datbuf);
 601         } else {
 602                 ops.datbuf = NULL;
 603         }
 604
 605         if (req.usr_oob) {
 606                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 607                 if (IS_ERR(ops.oobbuf)) {
 608                         kfree(ops.datbuf);
 609                         return PTR_ERR(ops.oobbuf);
 610                 }
 611         } else {
 612                 ops.oobbuf = NULL;
 613         }
 614
 615         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 616
 617         kfree(ops.datbuf);
 618         kfree(ops.oobbuf);
 619
 620         return ret;
 621 }
 622
 623 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 624 {
 625         struct mtd_file_info *mfi = file->private_data;
 626         struct mtd_info *mtd = mfi->mtd;
 627         void __user *argp = (void __user *)arg;
 628         int ret = 0;
 629         u_long size;
 630         struct mtd_info_user info;
 631
 632         pr_debug("MTD_ioctl\n");
 633
 634         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 635         if (cmd & IOC_IN) {
 636                 if (!access_ok(VERIFY_READ, argp, size))
 637                         return -EFAULT;
 638         }
 639         if (cmd & IOC_OUT) {
 640                 if (!access_ok(VERIFY_WRITE, argp, size))
 641                         return -EFAULT;
 642         }
 643
 644         switch (cmd) {
 645         case MEMGETREGIONCOUNT:
 646                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 647                         return -EFAULT;
 648                 break;
 649
 650         case MEMGETREGIONINFO:
 651         {
 652                 uint32_t ur_idx;
 653                 struct mtd_erase_region_info *kr;
 654                 struct region_info_user __user *ur = argp;
 655
 656                 if (get_user(ur_idx, &(ur->regionindex)))
 657                         return -EFAULT;
 658
 659                 if (ur_idx >= mtd->numeraseregions)
 660                         return -EINVAL;
 661
 662                 kr = &(mtd->eraseregions[ur_idx]);
 663
 664                 if (put_user(kr->offset, &(ur->offset))
 665                     || put_user(kr->erasesize, &(ur->erasesize))
 666                     || put_user(kr->numblocks, &(ur->numblocks)))
 667                         return -EFAULT;
 668
 669                 break;
 670         }
 671
 672         case MEMGETINFO:
 673                 memset(&info, 0, sizeof(info));
 674                 info.type       = mtd->type;
 675                 info.flags      = mtd->flags;
 676                 info.size       = mtd->size;
 677                 info.erasesize  = mtd->erasesize;
 678                 info.writesize  = mtd->writesize;
 679                 info.oobsize    = mtd->oobsize;
 680                 /* The below field is obsolete */
 681                 info.padding    = 0;
 682                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 683                         return -EFAULT;
 684                 break;
 685
 686         case MEMERASE:
 687         case MEMERASE64:
 688         {
 689                 struct erase_info *erase;
 690
 691                 if(!(file->f_mode & FMODE_WRITE))
 692                         return -EPERM;
 693
 694                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 695                 if (!erase)
 696                         ret = -ENOMEM;
 697                 else {
 698                         wait_queue_head_t waitq;
 699                         DECLARE_WAITQUEUE(wait, current);
 700
 701                         init_waitqueue_head(&waitq);
 702
 703                         if (cmd == MEMERASE64) {
 704                                 struct erase_info_user64 einfo64;
 705
 706                                 if (copy_from_user(&einfo64, argp,
 707                                             sizeof(struct erase_info_user64))) {
 708                                         kfree(erase);
 709                                         return -EFAULT;
 710                                 }
 711                                 erase->addr = einfo64.start;
 712                                 erase->len = einfo64.length;
 713                         } else {
 714                                 struct erase_info_user einfo32;
 715
 716                                 if (copy_from_user(&einfo32, argp,
 717                                             sizeof(struct erase_info_user))) {
 718                                         kfree(erase);
 719                                         return -EFAULT;
 720                                 }
 721                                 erase->addr = einfo32.start;
 722                                 erase->len = einfo32.length;
 723                         }
 724                         erase->mtd = mtd;
 725                         erase->callback = mtdchar_erase_callback;
 726                         erase->priv = (unsigned long)&waitq;
 727
 728                         /*
 729                           FIXME: Allow INTERRUPTIBLE. Which means
 730                           not having the wait_queue head on the stack.
 731
 732                           If the wq_head is on the stack, and we
 733                           leave because we got interrupted, then the
 734                           wq_head is no longer there when the
 735                           callback routine tries to wake us up.
 736                         */
 737                         ret = mtd_erase(mtd, erase);
 738                         if (!ret) {
 739                                 set_current_state(TASK_UNINTERRUPTIBLE);
 740                                 add_wait_queue(&waitq, &wait);
 741                                 if (erase->state != MTD_ERASE_DONE &&
 742                                     erase->state != MTD_ERASE_FAILED)
 743                                         schedule();
 744                                 remove_wait_queue(&waitq, &wait);
 745                                 set_current_state(TASK_RUNNING);
 746
 747                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 748                         }
 749                         kfree(erase);
 750                 }
 751                 break;
 752         }
 753
 754         case MEMWRITEOOB:
 755         {
 756                 struct mtd_oob_buf buf;
 757                 struct mtd_oob_buf __user *buf_user = argp;
 758
 759                 /* NOTE: writes return length to buf_user->length */
 760                 if (copy_from_user(&buf, argp, sizeof(buf)))
 761                         ret = -EFAULT;
 762                 else
 763                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 764                                 buf.ptr, &buf_user->length);
 765                 break;
 766         }
 767
 768         case MEMREADOOB:
 769         {
 770                 struct mtd_oob_buf buf;
 771                 struct mtd_oob_buf __user *buf_user = argp;
 772
 773                 /* NOTE: writes return length to buf_user->start */
 774                 if (copy_from_user(&buf, argp, sizeof(buf)))
 775                         ret = -EFAULT;
 776                 else
 777                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 778                                 buf.ptr, &buf_user->start);
 779                 break;
 780         }
 781
 782         case MEMWRITEOOB64:
 783         {
 784                 struct mtd_oob_buf64 buf;
 785                 struct mtd_oob_buf64 __user *buf_user = argp;
 786
 787                 if (copy_from_user(&buf, argp, sizeof(buf)))
 788                         ret = -EFAULT;
 789                 else
 790                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 791                                 (void __user *)(uintptr_t)buf.usr_ptr,
 792                                 &buf_user->length);
 793                 break;
 794         }
 795
 796         case MEMREADOOB64:
 797         {
 798                 struct mtd_oob_buf64 buf;
 799                 struct mtd_oob_buf64 __user *buf_user = argp;
 800
 801                 if (copy_from_user(&buf, argp, sizeof(buf)))
 802                         ret = -EFAULT;
 803                 else
 804                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 805                                 (void __user *)(uintptr_t)buf.usr_ptr,
 806                                 &buf_user->length);
 807                 break;
 808         }
 809
 810         case MEMWRITE:
 811         {
 812                 ret = mtdchar_write_ioctl(mtd,
 813                       (struct mtd_write_req __user *)arg);
 814                 break;
 815         }
 816
 817         case MEMLOCK:
 818         {
 819                 struct erase_info_user einfo;
 820
 821                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 822                         return -EFAULT;
 823
 824                 if (!mtd->lock)
 825                         ret = -EOPNOTSUPP;
 826                 else
 827                         ret = mtd_lock(mtd, einfo.start, einfo.length);
 828                 break;
 829         }
 830
 831         case MEMUNLOCK:
 832         {
 833                 struct erase_info_user einfo;
 834
 835                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 836                         return -EFAULT;
 837
 838                 if (!mtd->unlock)
 839                         ret = -EOPNOTSUPP;
 840                 else
 841                         ret = mtd_unlock(mtd, einfo.start, einfo.length);
 842                 break;
 843         }
 844
 845         case MEMISLOCKED:
 846         {
 847                 struct erase_info_user einfo;
 848
 849                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 850                         return -EFAULT;
 851
 852                 if (!mtd->is_locked)
 853                         ret = -EOPNOTSUPP;
 854                 else
 855                         ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 856                 break;
 857         }
 858
 859         /* Legacy interface */
 860         case MEMGETOOBSEL:
 861         {
 862                 struct nand_oobinfo oi;
 863
 864                 if (!mtd->ecclayout)
 865                         return -EOPNOTSUPP;
 866                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 867                         return -EINVAL;
 868
 869                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 870                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 871                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 872                        sizeof(oi.oobfree));
 873                 oi.eccbytes = mtd->ecclayout->eccbytes;
 874
 875                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 876                         return -EFAULT;
 877                 break;
 878         }
 879
 880         case MEMGETBADBLOCK:
 881         {
 882                 loff_t offs;
 883
 884                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 885                         return -EFAULT;
 886                 if (!mtd->block_isbad)
 887                         ret = -EOPNOTSUPP;
 888                 else
 889                         return mtd_block_isbad(mtd, offs);
 890                 break;
 891         }
 892
 893         case MEMSETBADBLOCK:
 894         {
 895                 loff_t offs;
 896
 897                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 898                         return -EFAULT;
 899                 if (!mtd->block_markbad)
 900                         ret = -EOPNOTSUPP;
 901                 else
 902                         return mtd_block_markbad(mtd, offs);
 903                 break;
 904         }
 905
 906 #ifdef CONFIG_HAVE_MTD_OTP
 907         case OTPSELECT:
 908         {
 909                 int mode;
 910                 if (copy_from_user(&mode, argp, sizeof(int)))
 911                         return -EFAULT;
 912
 913                 mfi->mode = MTD_FILE_MODE_NORMAL;
 914
 915                 ret = otp_select_filemode(mfi, mode);
 916
 917                 file->f_pos = 0;
 918                 break;
 919         }
 920
 921         case OTPGETREGIONCOUNT:
 922         case OTPGETREGIONINFO:
 923         {
 924                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 925                 if (!buf)
 926                         return -ENOMEM;
 927                 ret = -EOPNOTSUPP;
 928                 switch (mfi->mode) {
 929                 case MTD_FILE_MODE_OTP_FACTORY:
 930                         if (mtd->get_fact_prot_info)
 931                                 ret = mtd_get_fact_prot_info(mtd, buf, 4096);
 932                         break;
 933                 case MTD_FILE_MODE_OTP_USER:
 934                         if (mtd->get_user_prot_info)
 935                                 ret = mtd_get_user_prot_info(mtd, buf, 4096);
 936                         break;
 937                 default:
 938                         break;
 939                 }
 940                 if (ret >= 0) {
 941                         if (cmd == OTPGETREGIONCOUNT) {
 942                                 int nbr = ret / sizeof(struct otp_info);
 943                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 944                         } else
 945                                 ret = copy_to_user(argp, buf, ret);
 946                         if (ret)
 947                                 ret = -EFAULT;
 948                 }
 949                 kfree(buf);
 950                 break;
 951         }
 952
 953         case OTPLOCK:
 954         {
 955                 struct otp_info oinfo;
 956
 957                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 958                         return -EINVAL;
 959                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 960                         return -EFAULT;
 961                 if (!mtd->lock_user_prot_reg)
 962                         return -EOPNOTSUPP;
 963                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 964                 break;
 965         }
 966 #endif
 967
 968         /* This ioctl is being deprecated - it truncates the ECC layout */
 969         case ECCGETLAYOUT:
 970         {
 971                 struct nand_ecclayout_user *usrlay;
 972
 973                 if (!mtd->ecclayout)
 974                         return -EOPNOTSUPP;
 975
 976                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 977                 if (!usrlay)
 978                         return -ENOMEM;
 979
 980                 shrink_ecclayout(mtd->ecclayout, usrlay);
 981
 982                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 983                         ret = -EFAULT;
 984                 kfree(usrlay);
 985                 break;
 986         }
 987
 988         case ECCGETSTATS:
 989         {
 990                 if (copy_to_user(argp, &mtd->ecc_stats,
 991                                  sizeof(struct mtd_ecc_stats)))
 992                         return -EFAULT;
 993                 break;
 994         }
 995
 996         case MTDFILEMODE:
 997         {
 998                 mfi->mode = 0;
 999
1000                 switch(arg) {
1001                 case MTD_FILE_MODE_OTP_FACTORY:
1002                 case MTD_FILE_MODE_OTP_USER:
1003                         ret = otp_select_filemode(mfi, arg);
1004                         break;
1005
1006                 case MTD_FILE_MODE_RAW:
1007                         if (!mtd_has_oob(mtd))
1008                                 return -EOPNOTSUPP;
1009                         mfi->mode = arg;
1010
1011                 case MTD_FILE_MODE_NORMAL:
1012                         break;
1013                 default:
1014                         ret = -EINVAL;
1015                 }
1016                 file->f_pos = 0;
1017                 break;
1018         }
1019
1020         case BLKPG:
1021         {
1022                 ret = mtdchar_blkpg_ioctl(mtd,
1023                       (struct blkpg_ioctl_arg __user *)arg);
1024                 break;
1025         }
1026
1027         case BLKRRPART:
1028         {
1029                 /* No reread partition feature. Just return ok */
1030                 ret = 0;
1031                 break;
1032         }
1033
1034         default:
1035                 ret = -ENOTTY;
1036         }
1037
1038         return ret;
1039 } /* memory_ioctl */
1040
1041 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1042 {
1043         int ret;
1044
1045         mutex_lock(&mtd_mutex);
1046         ret = mtdchar_ioctl(file, cmd, arg);
1047         mutex_unlock(&mtd_mutex);
1048
1049         return ret;
1050 }
1051
1052 #ifdef CONFIG_COMPAT
1053
1054 struct mtd_oob_buf32 {
1055         u_int32_t start;
1056         u_int32_t length;
1057         compat_caddr_t ptr;     /* unsigned char* */
1058 };
1059
1060 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1061 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1062
1063 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1064         unsigned long arg)
1065 {
1066         struct mtd_file_info *mfi = file->private_data;
1067         struct mtd_info *mtd = mfi->mtd;
1068         void __user *argp = compat_ptr(arg);
1069         int ret = 0;
1070
1071         mutex_lock(&mtd_mutex);
1072
1073         switch (cmd) {
1074         case MEMWRITEOOB32:
1075         {
1076                 struct mtd_oob_buf32 buf;
1077                 struct mtd_oob_buf32 __user *buf_user = argp;
1078
1079                 if (copy_from_user(&buf, argp, sizeof(buf)))
1080                         ret = -EFAULT;
1081                 else
1082                         ret = mtdchar_writeoob(file, mtd, buf.start,
1083                                 buf.length, compat_ptr(buf.ptr),
1084                                 &buf_user->length);
1085                 break;
1086         }
1087
1088         case MEMREADOOB32:
1089         {
1090                 struct mtd_oob_buf32 buf;
1091                 struct mtd_oob_buf32 __user *buf_user = argp;
1092
1093                 /* NOTE: writes return length to buf->start */
1094                 if (copy_from_user(&buf, argp, sizeof(buf)))
1095                         ret = -EFAULT;
1096                 else
1097                         ret = mtdchar_readoob(file, mtd, buf.start,
1098                                 buf.length, compat_ptr(buf.ptr),
1099                                 &buf_user->start);
1100                 break;
1101         }
1102         default:
1103                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1104         }
1105
1106         mutex_unlock(&mtd_mutex);
1107
1108         return ret;
1109 }
1110
1111 #endif /* CONFIG_COMPAT */
1112
1113 /*
1114  * try to determine where a shared mapping can be made
1115  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1116  *   mappings)
1117  */
1118 #ifndef CONFIG_MMU
1119 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1120                                            unsigned long addr,
1121                                            unsigned long len,
1122                                            unsigned long pgoff,
1123                                            unsigned long flags)
1124 {
1125         struct mtd_file_info *mfi = file->private_data;
1126         struct mtd_info *mtd = mfi->mtd;
1127         unsigned long offset;
1128         int ret;
1129
1130         if (addr != 0)
1131                 return (unsigned long) -EINVAL;
1132
1133         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1134                 return (unsigned long) -EINVAL;
1135
1136         offset = pgoff << PAGE_SHIFT;
1137         if (offset > mtd->size - len)
1138                 return (unsigned long) -EINVAL;
1139
1140         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1141         return ret == -EOPNOTSUPP ? -ENOSYS : ret;
1142 }
1143 #endif
1144
1145 /*
1146  * set up a mapping for shared memory segments
1147  */
1148 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1149 {
1150 #ifdef CONFIG_MMU
1151         struct mtd_file_info *mfi = file->private_data;
1152         struct mtd_info *mtd = mfi->mtd;
1153         struct map_info *map = mtd->priv;
1154         unsigned long start;
1155         unsigned long off;
1156         u32 len;
1157
1158         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1159                 off = vma->vm_pgoff << PAGE_SHIFT;
1160                 start = map->phys;
1161                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1162                 start &= PAGE_MASK;
1163                 if ((vma->vm_end - vma->vm_start + off) > len)
1164                         return -EINVAL;
1165
1166                 off += start;
1167                 vma->vm_pgoff = off >> PAGE_SHIFT;
1168                 vma->vm_flags |= VM_IO | VM_RESERVED;
1169
1170 #ifdef pgprot_noncached
1171                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1172                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1173 #endif
1174                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1175                                        vma->vm_end - vma->vm_start,
1176                                        vma->vm_page_prot))
1177                         return -EAGAIN;
1178
1179                 return 0;
1180         }
1181         return -ENOSYS;
1182 #else
1183         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1184 #endif
1185 }
1186
1187 static const struct file_operations mtd_fops = {
1188         .owner          = THIS_MODULE,
1189         .llseek         = mtdchar_lseek,
1190         .read           = mtdchar_read,
1191         .write          = mtdchar_write,
1192         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1193 #ifdef CONFIG_COMPAT
1194         .compat_ioctl   = mtdchar_compat_ioctl,
1195 #endif
1196         .open           = mtdchar_open,
1197         .release        = mtdchar_close,
1198         .mmap           = mtdchar_mmap,
1199 #ifndef CONFIG_MMU
1200         .get_unmapped_area = mtdchar_get_unmapped_area,
1201 #endif
1202 };
1203
1204 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1205                                 int flags, const char *dev_name, void *data)
1206 {
1207         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1208 }
1209
1210 static struct file_system_type mtd_inodefs_type = {
1211        .name = "mtd_inodefs",
1212        .mount = mtd_inodefs_mount,
1213        .kill_sb = kill_anon_super,
1214 };
1215
1216 static void mtdchar_notify_add(struct mtd_info *mtd)
1217 {
1218 }
1219
1220 static void mtdchar_notify_remove(struct mtd_info *mtd)
1221 {
1222         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1223
1224         if (mtd_ino) {
1225                 /* Destroy the inode if it exists */
1226                 clear_nlink(mtd_ino);
1227                 iput(mtd_ino);
1228         }
1229 }
1230
1231 static struct mtd_notifier mtdchar_notifier = {
1232         .add = mtdchar_notify_add,
1233         .remove = mtdchar_notify_remove,
1234 };
1235
1236 static int __init init_mtdchar(void)
1237 {
1238         int ret;
1239
1240         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1241                                    "mtd", &mtd_fops);
1242         if (ret < 0) {
1243                 pr_notice("Can't allocate major number %d for "
1244                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1245                 return ret;
1246         }
1247
1248         ret = register_filesystem(&mtd_inodefs_type);
1249         if (ret) {
1250                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1251                 goto err_unregister_chdev;
1252         }
1253
1254         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1255         if (IS_ERR(mtd_inode_mnt)) {
1256                 ret = PTR_ERR(mtd_inode_mnt);
1257                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1258                 goto err_unregister_filesystem;
1259         }
1260         register_mtd_user(&mtdchar_notifier);
1261
1262         return ret;
1263
1264 err_unregister_filesystem:
1265         unregister_filesystem(&mtd_inodefs_type);
1266 err_unregister_chdev:
1267         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1268         return ret;
1269 }
1270
1271 static void __exit cleanup_mtdchar(void)
1272 {
1273         unregister_mtd_user(&mtdchar_notifier);
1274         kern_unmount(mtd_inode_mnt);
1275         unregister_filesystem(&mtd_inodefs_type);
1276         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1277 }
1278
1279 module_init(init_mtdchar);
1280 module_exit(cleanup_mtdchar);
1281
1282 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1283
1284 MODULE_LICENSE("GPL");
1285 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1286 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1287 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);