drivers/mtd/mtdchar.c

   1 /*
   2  * Copyright © 1999-2010 David Woodhouse <[email protected]>
   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 ofr various use cases.
  47  */
  48 struct mtd_file_info {
  49         struct mtd_info *mtd;
  50         struct inode *ino;
  51         enum mtd_file_modes mode;
  52 };
  53
  54 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  55 {
  56         struct mtd_file_info *mfi = file->private_data;
  57         struct mtd_info *mtd = mfi->mtd;
  58
  59         switch (orig) {
  60         case SEEK_SET:
  61                 break;
  62         case SEEK_CUR:
  63                 offset += file->f_pos;
  64                 break;
  65         case SEEK_END:
  66                 offset += mtd->size;
  67                 break;
  68         default:
  69                 return -EINVAL;
  70         }
  71
  72         if (offset >= 0 && offset <= mtd->size)
  73                 return file->f_pos = offset;
  74
  75         return -EINVAL;
  76 }
  77
  78
  79
  80 static int mtd_open(struct inode *inode, struct file *file)
  81 {
  82         int minor = iminor(inode);
  83         int devnum = minor >> 1;
  84         int ret = 0;
  85         struct mtd_info *mtd;
  86         struct mtd_file_info *mfi;
  87         struct inode *mtd_ino;
  88
  89         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  90
  91         /* You can't open the RO devices RW */
  92         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  93                 return -EACCES;
  94
  95         mutex_lock(&mtd_mutex);
  96         mtd = get_mtd_device(NULL, devnum);
  97
  98         if (IS_ERR(mtd)) {
  99                 ret = PTR_ERR(mtd);
 100                 goto out;
 101         }
 102
 103         if (mtd->type == MTD_ABSENT) {
 104                 put_mtd_device(mtd);
 105                 ret = -ENODEV;
 106                 goto out;
 107         }
 108
 109         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 110         if (!mtd_ino) {
 111                 put_mtd_device(mtd);
 112                 ret = -ENOMEM;
 113                 goto out;
 114         }
 115         if (mtd_ino->i_state & I_NEW) {
 116                 mtd_ino->i_private = mtd;
 117                 mtd_ino->i_mode = S_IFCHR;
 118                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 119                 unlock_new_inode(mtd_ino);
 120         }
 121         file->f_mapping = mtd_ino->i_mapping;
 122
 123         /* You can't open it RW if it's not a writeable device */
 124         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 125                 iput(mtd_ino);
 126                 put_mtd_device(mtd);
 127                 ret = -EACCES;
 128                 goto out;
 129         }
 130
 131         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 132         if (!mfi) {
 133                 iput(mtd_ino);
 134                 put_mtd_device(mtd);
 135                 ret = -ENOMEM;
 136                 goto out;
 137         }
 138         mfi->ino = mtd_ino;
 139         mfi->mtd = mtd;
 140         file->private_data = mfi;
 141
 142 out:
 143         mutex_unlock(&mtd_mutex);
 144         return ret;
 145 } /* mtd_open */
 146
 147 /*====================================================================*/
 148
 149 static int mtd_close(struct inode *inode, struct file *file)
 150 {
 151         struct mtd_file_info *mfi = file->private_data;
 152         struct mtd_info *mtd = mfi->mtd;
 153
 154         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 155
 156         /* Only sync if opened RW */
 157         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 158                 mtd->sync(mtd);
 159
 160         iput(mfi->ino);
 161
 162         put_mtd_device(mtd);
 163         file->private_data = NULL;
 164         kfree(mfi);
 165
 166         return 0;
 167 } /* mtd_close */
 168
 169 /* Back in June 2001, dwmw2 wrote:
 170  *
 171  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 172  *   userspace buffer down and use it directly with readv/writev.
 173  *
 174  * The implementation below, using mtd_kmalloc_up_to, mitigates
 175  * allocation failures when the system is under low-memory situations
 176  * or if memory is highly fragmented at the cost of reducing the
 177  * performance of the requested transfer due to a smaller buffer size.
 178  *
 179  * A more complex but more memory-efficient implementation based on
 180  * get_user_pages and iovecs to cover extents of those pages is a
 181  * longer-term goal, as intimated by dwmw2 above. However, for the
 182  * write case, this requires yet more complex head and tail transfer
 183  * handling when those head and tail offsets and sizes are such that
 184  * alignment requirements are not met in the NAND subdriver.
 185  */
 186
 187 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 188 {
 189         struct mtd_file_info *mfi = file->private_data;
 190         struct mtd_info *mtd = mfi->mtd;
 191         size_t retlen=0;
 192         size_t total_retlen=0;
 193         int ret=0;
 194         int len;
 195         size_t size = count;
 196         char *kbuf;
 197
 198         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 199
 200         if (*ppos + count > mtd->size)
 201                 count = mtd->size - *ppos;
 202
 203         if (!count)
 204                 return 0;
 205
 206         kbuf = mtd_kmalloc_up_to(mtd, &size);
 207         if (!kbuf)
 208                 return -ENOMEM;
 209
 210         while (count) {
 211                 len = min_t(size_t, count, size);
 212
 213                 switch (mfi->mode) {
 214                 case MTD_MODE_OTP_FACTORY:
 215                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 216                         break;
 217                 case MTD_MODE_OTP_USER:
 218                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 219                         break;
 220                 case MTD_MODE_RAW:
 221                 {
 222                         struct mtd_oob_ops ops;
 223
 224                         ops.mode = MTD_OOB_RAW;
 225                         ops.datbuf = kbuf;
 226                         ops.oobbuf = NULL;
 227                         ops.len = len;
 228
 229                         ret = mtd->read_oob(mtd, *ppos, &ops);
 230                         retlen = ops.retlen;
 231                         break;
 232                 }
 233                 default:
 234                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 235                 }
 236                 /* Nand returns -EBADMSG on ecc errors, but it returns
 237                  * the data. For our userspace tools it is important
 238                  * to dump areas with ecc errors !
 239                  * For kernel internal usage it also might return -EUCLEAN
 240                  * to signal the caller that a bitflip has occurred and has
 241                  * been corrected by the ECC algorithm.
 242                  * Userspace software which accesses NAND this way
 243                  * must be aware of the fact that it deals with NAND
 244                  */
 245                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 246                         *ppos += retlen;
 247                         if (copy_to_user(buf, kbuf, retlen)) {
 248                                 kfree(kbuf);
 249                                 return -EFAULT;
 250                         }
 251                         else
 252                                 total_retlen += retlen;
 253
 254                         count -= retlen;
 255                         buf += retlen;
 256                         if (retlen == 0)
 257                                 count = 0;
 258                 }
 259                 else {
 260                         kfree(kbuf);
 261                         return ret;
 262                 }
 263
 264         }
 265
 266         kfree(kbuf);
 267         return total_retlen;
 268 } /* mtd_read */
 269
 270 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 271 {
 272         struct mtd_file_info *mfi = file->private_data;
 273         struct mtd_info *mtd = mfi->mtd;
 274         size_t size = count;
 275         char *kbuf;
 276         size_t retlen;
 277         size_t total_retlen=0;
 278         int ret=0;
 279         int len;
 280
 281         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 282
 283         if (*ppos == mtd->size)
 284                 return -ENOSPC;
 285
 286         if (*ppos + count > mtd->size)
 287                 count = mtd->size - *ppos;
 288
 289         if (!count)
 290                 return 0;
 291
 292         kbuf = mtd_kmalloc_up_to(mtd, &size);
 293         if (!kbuf)
 294                 return -ENOMEM;
 295
 296         while (count) {
 297                 len = min_t(size_t, count, size);
 298
 299                 if (copy_from_user(kbuf, buf, len)) {
 300                         kfree(kbuf);
 301                         return -EFAULT;
 302                 }
 303
 304                 switch (mfi->mode) {
 305                 case MTD_MODE_OTP_FACTORY:
 306                         ret = -EROFS;
 307                         break;
 308                 case MTD_MODE_OTP_USER:
 309                         if (!mtd->write_user_prot_reg) {
 310                                 ret = -EOPNOTSUPP;
 311                                 break;
 312                         }
 313                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 314                         break;
 315
 316                 case MTD_MODE_RAW:
 317                 {
 318                         struct mtd_oob_ops ops;
 319
 320                         ops.mode = MTD_OOB_RAW;
 321                         ops.datbuf = kbuf;
 322                         ops.oobbuf = NULL;
 323                         ops.len = len;
 324
 325                         ret = mtd->write_oob(mtd, *ppos, &ops);
 326                         retlen = ops.retlen;
 327                         break;
 328                 }
 329
 330                 default:
 331                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 332                 }
 333                 if (!ret) {
 334                         *ppos += retlen;
 335                         total_retlen += retlen;
 336                         count -= retlen;
 337                         buf += retlen;
 338                 }
 339                 else {
 340                         kfree(kbuf);
 341                         return ret;
 342                 }
 343         }
 344
 345         kfree(kbuf);
 346         return total_retlen;
 347 } /* mtd_write */
 348
 349 /*======================================================================
 350
 351     IOCTL calls for getting device parameters.
 352
 353 ======================================================================*/
 354 static void mtdchar_erase_callback (struct erase_info *instr)
 355 {
 356         wake_up((wait_queue_head_t *)instr->priv);
 357 }
 358
 359 #ifdef CONFIG_HAVE_MTD_OTP
 360 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 361 {
 362         struct mtd_info *mtd = mfi->mtd;
 363         int ret = 0;
 364
 365         switch (mode) {
 366         case MTD_OTP_FACTORY:
 367                 if (!mtd->read_fact_prot_reg)
 368                         ret = -EOPNOTSUPP;
 369                 else
 370                         mfi->mode = MTD_MODE_OTP_FACTORY;
 371                 break;
 372         case MTD_OTP_USER:
 373                 if (!mtd->read_fact_prot_reg)
 374                         ret = -EOPNOTSUPP;
 375                 else
 376                         mfi->mode = MTD_MODE_OTP_USER;
 377                 break;
 378         default:
 379                 ret = -EINVAL;
 380         case MTD_OTP_OFF:
 381                 break;
 382         }
 383         return ret;
 384 }
 385 #else
 386 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 387 #endif
 388
 389 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 390         uint64_t start, uint32_t length, void __user *ptr,
 391         uint32_t __user *retp)
 392 {
 393         struct mtd_oob_ops ops;
 394         uint32_t retlen;
 395         int ret = 0;
 396
 397         if (!(file->f_mode & FMODE_WRITE))
 398                 return -EPERM;
 399
 400         if (length > 4096)
 401                 return -EINVAL;
 402
 403         if (!mtd->write_oob)
 404                 ret = -EOPNOTSUPP;
 405         else
 406                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 407
 408         if (ret)
 409                 return ret;
 410
 411         ops.ooblen = length;
 412         ops.ooboffs = start & (mtd->oobsize - 1);
 413         ops.datbuf = NULL;
 414         ops.mode = MTD_OOB_PLACE;
 415
 416         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 417                 return -EINVAL;
 418
 419         ops.oobbuf = memdup_user(ptr, length);
 420         if (IS_ERR(ops.oobbuf))
 421                 return PTR_ERR(ops.oobbuf);
 422
 423         start &= ~((uint64_t)mtd->oobsize - 1);
 424         ret = mtd->write_oob(mtd, start, &ops);
 425
 426         if (ops.oobretlen > 0xFFFFFFFFU)
 427                 ret = -EOVERFLOW;
 428         retlen = ops.oobretlen;
 429         if (copy_to_user(retp, &retlen, sizeof(length)))
 430                 ret = -EFAULT;
 431
 432         kfree(ops.oobbuf);
 433         return ret;
 434 }
 435
 436 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 437         uint32_t length, void __user *ptr, uint32_t __user *retp)
 438 {
 439         struct mtd_oob_ops ops;
 440         int ret = 0;
 441
 442         if (length > 4096)
 443                 return -EINVAL;
 444
 445         if (!mtd->read_oob)
 446                 ret = -EOPNOTSUPP;
 447         else
 448                 ret = access_ok(VERIFY_WRITE, ptr,
 449                                 length) ? 0 : -EFAULT;
 450         if (ret)
 451                 return ret;
 452
 453         ops.ooblen = length;
 454         ops.ooboffs = start & (mtd->oobsize - 1);
 455         ops.datbuf = NULL;
 456         ops.mode = MTD_OOB_PLACE;
 457
 458         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 459                 return -EINVAL;
 460
 461         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 462         if (!ops.oobbuf)
 463                 return -ENOMEM;
 464
 465         start &= ~((uint64_t)mtd->oobsize - 1);
 466         ret = mtd->read_oob(mtd, start, &ops);
 467
 468         if (put_user(ops.oobretlen, retp))
 469                 ret = -EFAULT;
 470         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 471                                             ops.oobretlen))
 472                 ret = -EFAULT;
 473
 474         kfree(ops.oobbuf);
 475         return ret;
 476 }
 477
 478 /*
 479  * Copies (and truncates, if necessary) data from the larger struct,
 480  * nand_ecclayout, to the smaller, deprecated layout struct,
 481  * nand_ecclayout_user. This is necessary only to suppport the deprecated
 482  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 483  * nand_ecclayout flexibly (i.e. the struct may change size in new
 484  * releases without requiring major rewrites).
 485  */
 486 static int shrink_ecclayout(const struct nand_ecclayout *from,
 487                 struct nand_ecclayout_user *to)
 488 {
 489         int i;
 490
 491         if (!from || !to)
 492                 return -EINVAL;
 493
 494         memset(to, 0, sizeof(*to));
 495
 496         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 497         for (i = 0; i < to->eccbytes; i++)
 498                 to->eccpos[i] = from->eccpos[i];
 499
 500         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 501                 if (from->oobfree[i].length == 0 &&
 502                                 from->oobfree[i].offset == 0)
 503                         break;
 504                 to->oobavail += from->oobfree[i].length;
 505                 to->oobfree[i] = from->oobfree[i];
 506         }
 507
 508         return 0;
 509 }
 510
 511 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
 512                            struct blkpg_ioctl_arg __user *arg)
 513 {
 514         struct blkpg_ioctl_arg a;
 515         struct blkpg_partition p;
 516
 517         if (!capable(CAP_SYS_ADMIN))
 518                 return -EPERM;
 519
 520         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 521                 return -EFAULT;
 522
 523         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 524                 return -EFAULT;
 525
 526         switch (a.op) {
 527         case BLKPG_ADD_PARTITION:
 528
 529                 /* Only master mtd device must be used to add partitions */
 530                 if (mtd_is_partition(mtd))
 531                         return -EINVAL;
 532
 533                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 534
 535         case BLKPG_DEL_PARTITION:
 536
 537                 if (p.pno < 0)
 538                         return -EINVAL;
 539
 540                 return mtd_del_partition(mtd, p.pno);
 541
 542         default:
 543                 return -EINVAL;
 544         }
 545 }
 546
 547 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 548 {
 549         struct mtd_file_info *mfi = file->private_data;
 550         struct mtd_info *mtd = mfi->mtd;
 551         void __user *argp = (void __user *)arg;
 552         int ret = 0;
 553         u_long size;
 554         struct mtd_info_user info;
 555
 556         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 557
 558         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 559         if (cmd & IOC_IN) {
 560                 if (!access_ok(VERIFY_READ, argp, size))
 561                         return -EFAULT;
 562         }
 563         if (cmd & IOC_OUT) {
 564                 if (!access_ok(VERIFY_WRITE, argp, size))
 565                         return -EFAULT;
 566         }
 567
 568         switch (cmd) {
 569         case MEMGETREGIONCOUNT:
 570                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 571                         return -EFAULT;
 572                 break;
 573
 574         case MEMGETREGIONINFO:
 575         {
 576                 uint32_t ur_idx;
 577                 struct mtd_erase_region_info *kr;
 578                 struct region_info_user __user *ur = argp;
 579
 580                 if (get_user(ur_idx, &(ur->regionindex)))
 581                         return -EFAULT;
 582
 583                 if (ur_idx >= mtd->numeraseregions)
 584                         return -EINVAL;
 585
 586                 kr = &(mtd->eraseregions[ur_idx]);
 587
 588                 if (put_user(kr->offset, &(ur->offset))
 589                     || put_user(kr->erasesize, &(ur->erasesize))
 590                     || put_user(kr->numblocks, &(ur->numblocks)))
 591                         return -EFAULT;
 592
 593                 break;
 594         }
 595
 596         case MEMGETINFO:
 597                 memset(&info, 0, sizeof(info));
 598                 info.type       = mtd->type;
 599                 info.flags      = mtd->flags;
 600                 info.size       = mtd->size;
 601                 info.erasesize  = mtd->erasesize;
 602                 info.writesize  = mtd->writesize;
 603                 info.oobsize    = mtd->oobsize;
 604                 /* The below fields are obsolete */
 605                 info.ecctype    = -1;
 606                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 607                         return -EFAULT;
 608                 break;
 609
 610         case MEMERASE:
 611         case MEMERASE64:
 612         {
 613                 struct erase_info *erase;
 614
 615                 if(!(file->f_mode & FMODE_WRITE))
 616                         return -EPERM;
 617
 618                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 619                 if (!erase)
 620                         ret = -ENOMEM;
 621                 else {
 622                         wait_queue_head_t waitq;
 623                         DECLARE_WAITQUEUE(wait, current);
 624
 625                         init_waitqueue_head(&waitq);
 626
 627                         if (cmd == MEMERASE64) {
 628                                 struct erase_info_user64 einfo64;
 629
 630                                 if (copy_from_user(&einfo64, argp,
 631                                             sizeof(struct erase_info_user64))) {
 632                                         kfree(erase);
 633                                         return -EFAULT;
 634                                 }
 635                                 erase->addr = einfo64.start;
 636                                 erase->len = einfo64.length;
 637                         } else {
 638                                 struct erase_info_user einfo32;
 639
 640                                 if (copy_from_user(&einfo32, argp,
 641                                             sizeof(struct erase_info_user))) {
 642                                         kfree(erase);
 643                                         return -EFAULT;
 644                                 }
 645                                 erase->addr = einfo32.start;
 646                                 erase->len = einfo32.length;
 647                         }
 648                         erase->mtd = mtd;
 649                         erase->callback = mtdchar_erase_callback;
 650                         erase->priv = (unsigned long)&waitq;
 651
 652                         /*
 653                           FIXME: Allow INTERRUPTIBLE. Which means
 654                           not having the wait_queue head on the stack.
 655
 656                           If the wq_head is on the stack, and we
 657                           leave because we got interrupted, then the
 658                           wq_head is no longer there when the
 659                           callback routine tries to wake us up.
 660                         */
 661                         ret = mtd->erase(mtd, erase);
 662                         if (!ret) {
 663                                 set_current_state(TASK_UNINTERRUPTIBLE);
 664                                 add_wait_queue(&waitq, &wait);
 665                                 if (erase->state != MTD_ERASE_DONE &&
 666                                     erase->state != MTD_ERASE_FAILED)
 667                                         schedule();
 668                                 remove_wait_queue(&waitq, &wait);
 669                                 set_current_state(TASK_RUNNING);
 670
 671                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 672                         }
 673                         kfree(erase);
 674                 }
 675                 break;
 676         }
 677
 678         case MEMWRITEOOB:
 679         {
 680                 struct mtd_oob_buf buf;
 681                 struct mtd_oob_buf __user *buf_user = argp;
 682
 683                 /* NOTE: writes return length to buf_user->length */
 684                 if (copy_from_user(&buf, argp, sizeof(buf)))
 685                         ret = -EFAULT;
 686                 else
 687                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 688                                 buf.ptr, &buf_user->length);
 689                 break;
 690         }
 691
 692         case MEMREADOOB:
 693         {
 694                 struct mtd_oob_buf buf;
 695                 struct mtd_oob_buf __user *buf_user = argp;
 696
 697                 /* NOTE: writes return length to buf_user->start */
 698                 if (copy_from_user(&buf, argp, sizeof(buf)))
 699                         ret = -EFAULT;
 700                 else
 701                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 702                                 buf.ptr, &buf_user->start);
 703                 break;
 704         }
 705
 706         case MEMWRITEOOB64:
 707         {
 708                 struct mtd_oob_buf64 buf;
 709                 struct mtd_oob_buf64 __user *buf_user = argp;
 710
 711                 if (copy_from_user(&buf, argp, sizeof(buf)))
 712                         ret = -EFAULT;
 713                 else
 714                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 715                                 (void __user *)(uintptr_t)buf.usr_ptr,
 716                                 &buf_user->length);
 717                 break;
 718         }
 719
 720         case MEMREADOOB64:
 721         {
 722                 struct mtd_oob_buf64 buf;
 723                 struct mtd_oob_buf64 __user *buf_user = argp;
 724
 725                 if (copy_from_user(&buf, argp, sizeof(buf)))
 726                         ret = -EFAULT;
 727                 else
 728                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 729                                 (void __user *)(uintptr_t)buf.usr_ptr,
 730                                 &buf_user->length);
 731                 break;
 732         }
 733
 734         case MEMLOCK:
 735         {
 736                 struct erase_info_user einfo;
 737
 738                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 739                         return -EFAULT;
 740
 741                 if (!mtd->lock)
 742                         ret = -EOPNOTSUPP;
 743                 else
 744                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 745                 break;
 746         }
 747
 748         case MEMUNLOCK:
 749         {
 750                 struct erase_info_user einfo;
 751
 752                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 753                         return -EFAULT;
 754
 755                 if (!mtd->unlock)
 756                         ret = -EOPNOTSUPP;
 757                 else
 758                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 759                 break;
 760         }
 761
 762         case MEMISLOCKED:
 763         {
 764                 struct erase_info_user einfo;
 765
 766                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 767                         return -EFAULT;
 768
 769                 if (!mtd->is_locked)
 770                         ret = -EOPNOTSUPP;
 771                 else
 772                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 773                 break;
 774         }
 775
 776         /* Legacy interface */
 777         case MEMGETOOBSEL:
 778         {
 779                 struct nand_oobinfo oi;
 780
 781                 if (!mtd->ecclayout)
 782                         return -EOPNOTSUPP;
 783                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 784                         return -EINVAL;
 785
 786                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 787                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 788                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 789                        sizeof(oi.oobfree));
 790                 oi.eccbytes = mtd->ecclayout->eccbytes;
 791
 792                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 793                         return -EFAULT;
 794                 break;
 795         }
 796
 797         case MEMGETBADBLOCK:
 798         {
 799                 loff_t offs;
 800
 801                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 802                         return -EFAULT;
 803                 if (!mtd->block_isbad)
 804                         ret = -EOPNOTSUPP;
 805                 else
 806                         return mtd->block_isbad(mtd, offs);
 807                 break;
 808         }
 809
 810         case MEMSETBADBLOCK:
 811         {
 812                 loff_t offs;
 813
 814                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 815                         return -EFAULT;
 816                 if (!mtd->block_markbad)
 817                         ret = -EOPNOTSUPP;
 818                 else
 819                         return mtd->block_markbad(mtd, offs);
 820                 break;
 821         }
 822
 823 #ifdef CONFIG_HAVE_MTD_OTP
 824         case OTPSELECT:
 825         {
 826                 int mode;
 827                 if (copy_from_user(&mode, argp, sizeof(int)))
 828                         return -EFAULT;
 829
 830                 mfi->mode = MTD_MODE_NORMAL;
 831
 832                 ret = otp_select_filemode(mfi, mode);
 833
 834                 file->f_pos = 0;
 835                 break;
 836         }
 837
 838         case OTPGETREGIONCOUNT:
 839         case OTPGETREGIONINFO:
 840         {
 841                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 842                 if (!buf)
 843                         return -ENOMEM;
 844                 ret = -EOPNOTSUPP;
 845                 switch (mfi->mode) {
 846                 case MTD_MODE_OTP_FACTORY:
 847                         if (mtd->get_fact_prot_info)
 848                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 849                         break;
 850                 case MTD_MODE_OTP_USER:
 851                         if (mtd->get_user_prot_info)
 852                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 853                         break;
 854                 default:
 855                         break;
 856                 }
 857                 if (ret >= 0) {
 858                         if (cmd == OTPGETREGIONCOUNT) {
 859                                 int nbr = ret / sizeof(struct otp_info);
 860                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 861                         } else
 862                                 ret = copy_to_user(argp, buf, ret);
 863                         if (ret)
 864                                 ret = -EFAULT;
 865                 }
 866                 kfree(buf);
 867                 break;
 868         }
 869
 870         case OTPLOCK:
 871         {
 872                 struct otp_info oinfo;
 873
 874                 if (mfi->mode != MTD_MODE_OTP_USER)
 875                         return -EINVAL;
 876                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 877                         return -EFAULT;
 878                 if (!mtd->lock_user_prot_reg)
 879                         return -EOPNOTSUPP;
 880                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 881                 break;
 882         }
 883 #endif
 884
 885         /* This ioctl is being deprecated - it truncates the ecc layout */
 886         case ECCGETLAYOUT:
 887         {
 888                 struct nand_ecclayout_user *usrlay;
 889
 890                 if (!mtd->ecclayout)
 891                         return -EOPNOTSUPP;
 892
 893                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 894                 if (!usrlay)
 895                         return -ENOMEM;
 896
 897                 shrink_ecclayout(mtd->ecclayout, usrlay);
 898
 899                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 900                         ret = -EFAULT;
 901                 kfree(usrlay);
 902                 break;
 903         }
 904
 905         case ECCGETSTATS:
 906         {
 907                 if (copy_to_user(argp, &mtd->ecc_stats,
 908                                  sizeof(struct mtd_ecc_stats)))
 909                         return -EFAULT;
 910                 break;
 911         }
 912
 913         case MTDFILEMODE:
 914         {
 915                 mfi->mode = 0;
 916
 917                 switch(arg) {
 918                 case MTD_MODE_OTP_FACTORY:
 919                 case MTD_MODE_OTP_USER:
 920                         ret = otp_select_filemode(mfi, arg);
 921                         break;
 922
 923                 case MTD_MODE_RAW:
 924                         if (!mtd->read_oob || !mtd->write_oob)
 925                                 return -EOPNOTSUPP;
 926                         mfi->mode = arg;
 927
 928                 case MTD_MODE_NORMAL:
 929                         break;
 930                 default:
 931                         ret = -EINVAL;
 932                 }
 933                 file->f_pos = 0;
 934                 break;
 935         }
 936
 937         case BLKPG:
 938         {
 939                 ret = mtd_blkpg_ioctl(mtd,
 940                       (struct blkpg_ioctl_arg __user *)arg);
 941                 break;
 942         }
 943
 944         case BLKRRPART:
 945         {
 946                 /* No reread partition feature. Just return ok */
 947                 ret = 0;
 948                 break;
 949         }
 950
 951         default:
 952                 ret = -ENOTTY;
 953         }
 954
 955         return ret;
 956 } /* memory_ioctl */
 957
 958 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 959 {
 960         int ret;
 961
 962         mutex_lock(&mtd_mutex);
 963         ret = mtd_ioctl(file, cmd, arg);
 964         mutex_unlock(&mtd_mutex);
 965
 966         return ret;
 967 }
 968
 969 #ifdef CONFIG_COMPAT
 970
 971 struct mtd_oob_buf32 {
 972         u_int32_t start;
 973         u_int32_t length;
 974         compat_caddr_t ptr;     /* unsigned char* */
 975 };
 976
 977 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 978 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 979
 980 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 981         unsigned long arg)
 982 {
 983         struct mtd_file_info *mfi = file->private_data;
 984         struct mtd_info *mtd = mfi->mtd;
 985         void __user *argp = compat_ptr(arg);
 986         int ret = 0;
 987
 988         mutex_lock(&mtd_mutex);
 989
 990         switch (cmd) {
 991         case MEMWRITEOOB32:
 992         {
 993                 struct mtd_oob_buf32 buf;
 994                 struct mtd_oob_buf32 __user *buf_user = argp;
 995
 996                 if (copy_from_user(&buf, argp, sizeof(buf)))
 997                         ret = -EFAULT;
 998                 else
 999                         ret = mtd_do_writeoob(file, mtd, buf.start,
1000                                 buf.length, compat_ptr(buf.ptr),
1001                                 &buf_user->length);
1002                 break;
1003         }
1004
1005         case MEMREADOOB32:
1006         {
1007                 struct mtd_oob_buf32 buf;
1008                 struct mtd_oob_buf32 __user *buf_user = argp;
1009
1010                 /* NOTE: writes return length to buf->start */
1011                 if (copy_from_user(&buf, argp, sizeof(buf)))
1012                         ret = -EFAULT;
1013                 else
1014                         ret = mtd_do_readoob(mtd, buf.start,
1015                                 buf.length, compat_ptr(buf.ptr),
1016                                 &buf_user->start);
1017                 break;
1018         }
1019         default:
1020                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1021         }
1022
1023         mutex_unlock(&mtd_mutex);
1024
1025         return ret;
1026 }
1027
1028 #endif /* CONFIG_COMPAT */
1029
1030 /*
1031  * try to determine where a shared mapping can be made
1032  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1033  *   mappings)
1034  */
1035 #ifndef CONFIG_MMU
1036 static unsigned long mtd_get_unmapped_area(struct file *file,
1037                                            unsigned long addr,
1038                                            unsigned long len,
1039                                            unsigned long pgoff,
1040                                            unsigned long flags)
1041 {
1042         struct mtd_file_info *mfi = file->private_data;
1043         struct mtd_info *mtd = mfi->mtd;
1044
1045         if (mtd->get_unmapped_area) {
1046                 unsigned long offset;
1047
1048                 if (addr != 0)
1049                         return (unsigned long) -EINVAL;
1050
1051                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1052                         return (unsigned long) -EINVAL;
1053
1054                 offset = pgoff << PAGE_SHIFT;
1055                 if (offset > mtd->size - len)
1056                         return (unsigned long) -EINVAL;
1057
1058                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1059         }
1060
1061         /* can't map directly */
1062         return (unsigned long) -ENOSYS;
1063 }
1064 #endif
1065
1066 /*
1067  * set up a mapping for shared memory segments
1068  */
1069 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1070 {
1071 #ifdef CONFIG_MMU
1072         struct mtd_file_info *mfi = file->private_data;
1073         struct mtd_info *mtd = mfi->mtd;
1074         struct map_info *map = mtd->priv;
1075         unsigned long start;
1076         unsigned long off;
1077         u32 len;
1078
1079         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1080                 off = vma->vm_pgoff << PAGE_SHIFT;
1081                 start = map->phys;
1082                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1083                 start &= PAGE_MASK;
1084                 if ((vma->vm_end - vma->vm_start + off) > len)
1085                         return -EINVAL;
1086
1087                 off += start;
1088                 vma->vm_pgoff = off >> PAGE_SHIFT;
1089                 vma->vm_flags |= VM_IO | VM_RESERVED;
1090
1091 #ifdef pgprot_noncached
1092                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1093                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1094 #endif
1095                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1096                                        vma->vm_end - vma->vm_start,
1097                                        vma->vm_page_prot))
1098                         return -EAGAIN;
1099
1100                 return 0;
1101         }
1102         return -ENOSYS;
1103 #else
1104         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1105 #endif
1106 }
1107
1108 static const struct file_operations mtd_fops = {
1109         .owner          = THIS_MODULE,
1110         .llseek         = mtd_lseek,
1111         .read           = mtd_read,
1112         .write          = mtd_write,
1113         .unlocked_ioctl = mtd_unlocked_ioctl,
1114 #ifdef CONFIG_COMPAT
1115         .compat_ioctl   = mtd_compat_ioctl,
1116 #endif
1117         .open           = mtd_open,
1118         .release        = mtd_close,
1119         .mmap           = mtd_mmap,
1120 #ifndef CONFIG_MMU
1121         .get_unmapped_area = mtd_get_unmapped_area,
1122 #endif
1123 };
1124
1125 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1126                                 int flags, const char *dev_name, void *data)
1127 {
1128         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1129 }
1130
1131 static struct file_system_type mtd_inodefs_type = {
1132        .name = "mtd_inodefs",
1133        .mount = mtd_inodefs_mount,
1134        .kill_sb = kill_anon_super,
1135 };
1136
1137 static void mtdchar_notify_add(struct mtd_info *mtd)
1138 {
1139 }
1140
1141 static void mtdchar_notify_remove(struct mtd_info *mtd)
1142 {
1143         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1144
1145         if (mtd_ino) {
1146                 /* Destroy the inode if it exists */
1147                 mtd_ino->i_nlink = 0;
1148                 iput(mtd_ino);
1149         }
1150 }
1151
1152 static struct mtd_notifier mtdchar_notifier = {
1153         .add = mtdchar_notify_add,
1154         .remove = mtdchar_notify_remove,
1155 };
1156
1157 static int __init init_mtdchar(void)
1158 {
1159         int ret;
1160
1161         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1162                                    "mtd", &mtd_fops);
1163         if (ret < 0) {
1164                 pr_notice("Can't allocate major number %d for "
1165                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1166                 return ret;
1167         }
1168
1169         ret = register_filesystem(&mtd_inodefs_type);
1170         if (ret) {
1171                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1172                 goto err_unregister_chdev;
1173         }
1174
1175         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1176         if (IS_ERR(mtd_inode_mnt)) {
1177                 ret = PTR_ERR(mtd_inode_mnt);
1178                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1179                 goto err_unregister_filesystem;
1180         }
1181         register_mtd_user(&mtdchar_notifier);
1182
1183         return ret;
1184
1185 err_unregister_filesystem:
1186         unregister_filesystem(&mtd_inodefs_type);
1187 err_unregister_chdev:
1188         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1189         return ret;
1190 }
1191
1192 static void __exit cleanup_mtdchar(void)
1193 {
1194         unregister_mtd_user(&mtdchar_notifier);
1195         kern_unmount(mtd_inode_mnt);
1196         unregister_filesystem(&mtd_inodefs_type);
1197         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1198 }
1199
1200 module_init(init_mtdchar);
1201 module_exit(cleanup_mtdchar);
1202
1203 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1204
1205 MODULE_LICENSE("GPL");
1206 MODULE_AUTHOR("David Woodhouse <[email protected]>");
1207 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1208 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);