drivers/mtd/mtdchar.c

   1 /*
   2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  *
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/err.h>
  24 #include <linux/init.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/sched.h>
  29 #include <linux/mutex.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/compat.h>
  32 #include <linux/mount.h>
  33 #include <linux/blkpg.h>
  34 #include <linux/magic.h>
  35 #include <linux/mtd/mtd.h>
  36 #include <linux/mtd/partitions.h>
  37 #include <linux/mtd/map.h>
  38
  39 #include <asm/uaccess.h>
  40
  41 static DEFINE_MUTEX(mtd_mutex);
  42
  43 /*
  44  * Data structure to hold the pointer to the mtd device as well
  45  * as mode information of various use cases.
  46  */
  47 struct mtd_file_info {
  48         struct mtd_info *mtd;
  49         struct inode *ino;
  50         enum mtd_file_modes mode;
  51 };
  52
  53 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  54 {
  55         struct mtd_file_info *mfi = file->private_data;
  56         struct mtd_info *mtd = mfi->mtd;
  57
  58         switch (orig) {
  59         case SEEK_SET:
  60                 break;
  61         case SEEK_CUR:
  62                 offset += file->f_pos;
  63                 break;
  64         case SEEK_END:
  65                 offset += mtd->size;
  66                 break;
  67         default:
  68                 return -EINVAL;
  69         }
  70
  71         if (offset >= 0 && offset <= mtd->size)
  72                 return file->f_pos = offset;
  73
  74         return -EINVAL;
  75 }
  76
  77 static int count;
  78 static struct vfsmount *mnt;
  79 static struct file_system_type mtd_inodefs_type;
  80
  81 static int mtdchar_open(struct inode *inode, struct file *file)
  82 {
  83         int minor = iminor(inode);
  84         int devnum = minor >> 1;
  85         int ret = 0;
  86         struct mtd_info *mtd;
  87         struct mtd_file_info *mfi;
  88         struct inode *mtd_ino;
  89
  90         pr_debug("MTD_open\n");
  91
  92         /* You can't open the RO devices RW */
  93         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  94                 return -EACCES;
  95
  96         ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
  97         if (ret)
  98                 return ret;
  99
 100         mutex_lock(&mtd_mutex);
 101         mtd = get_mtd_device(NULL, devnum);
 102
 103         if (IS_ERR(mtd)) {
 104                 ret = PTR_ERR(mtd);
 105                 goto out;
 106         }
 107
 108         if (mtd->type == MTD_ABSENT) {
 109                 put_mtd_device(mtd);
 110                 ret = -ENODEV;
 111                 goto out;
 112         }
 113
 114         mtd_ino = iget_locked(mnt->mnt_sb, devnum);
 115         if (!mtd_ino) {
 116                 put_mtd_device(mtd);
 117                 ret = -ENOMEM;
 118                 goto out;
 119         }
 120         if (mtd_ino->i_state & I_NEW) {
 121                 mtd_ino->i_private = mtd;
 122                 mtd_ino->i_mode = S_IFCHR;
 123                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 124                 unlock_new_inode(mtd_ino);
 125         }
 126         file->f_mapping = mtd_ino->i_mapping;
 127
 128         /* You can't open it RW if it's not a writeable device */
 129         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 130                 iput(mtd_ino);
 131                 put_mtd_device(mtd);
 132                 ret = -EACCES;
 133                 goto out;
 134         }
 135
 136         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 137         if (!mfi) {
 138                 iput(mtd_ino);
 139                 put_mtd_device(mtd);
 140                 ret = -ENOMEM;
 141                 goto out;
 142         }
 143         mfi->ino = mtd_ino;
 144         mfi->mtd = mtd;
 145         file->private_data = mfi;
 146
 147 out:
 148         mutex_unlock(&mtd_mutex);
 149         simple_release_fs(&mnt, &count);
 150         return ret;
 151 } /* mtdchar_open */
 152
 153 /*====================================================================*/
 154
 155 static int mtdchar_close(struct inode *inode, struct file *file)
 156 {
 157         struct mtd_file_info *mfi = file->private_data;
 158         struct mtd_info *mtd = mfi->mtd;
 159
 160         pr_debug("MTD_close\n");
 161
 162         /* Only sync if opened RW */
 163         if ((file->f_mode & FMODE_WRITE))
 164                 mtd_sync(mtd);
 165
 166         iput(mfi->ino);
 167
 168         put_mtd_device(mtd);
 169         file->private_data = NULL;
 170         kfree(mfi);
 171         simple_release_fs(&mnt, &count);
 172
 173         return 0;
 174 } /* mtdchar_close */
 175
 176 /* Back in June 2001, dwmw2 wrote:
 177  *
 178  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 179  *   userspace buffer down and use it directly with readv/writev.
 180  *
 181  * The implementation below, using mtd_kmalloc_up_to, mitigates
 182  * allocation failures when the system is under low-memory situations
 183  * or if memory is highly fragmented at the cost of reducing the
 184  * performance of the requested transfer due to a smaller buffer size.
 185  *
 186  * A more complex but more memory-efficient implementation based on
 187  * get_user_pages and iovecs to cover extents of those pages is a
 188  * longer-term goal, as intimated by dwmw2 above. However, for the
 189  * write case, this requires yet more complex head and tail transfer
 190  * handling when those head and tail offsets and sizes are such that
 191  * alignment requirements are not met in the NAND subdriver.
 192  */
 193
 194 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 195                         loff_t *ppos)
 196 {
 197         struct mtd_file_info *mfi = file->private_data;
 198         struct mtd_info *mtd = mfi->mtd;
 199         size_t retlen;
 200         size_t total_retlen=0;
 201         int ret=0;
 202         int len;
 203         size_t size = count;
 204         char *kbuf;
 205
 206         pr_debug("MTD_read\n");
 207
 208         if (*ppos + count > mtd->size)
 209                 count = mtd->size - *ppos;
 210
 211         if (!count)
 212                 return 0;
 213
 214         kbuf = mtd_kmalloc_up_to(mtd, &size);
 215         if (!kbuf)
 216                 return -ENOMEM;
 217
 218         while (count) {
 219                 len = min_t(size_t, count, size);
 220
 221                 switch (mfi->mode) {
 222                 case MTD_FILE_MODE_OTP_FACTORY:
 223                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 224                                                      &retlen, kbuf);
 225                         break;
 226                 case MTD_FILE_MODE_OTP_USER:
 227                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 228                                                      &retlen, kbuf);
 229                         break;
 230                 case MTD_FILE_MODE_RAW:
 231                 {
 232                         struct mtd_oob_ops ops;
 233
 234                         ops.mode = MTD_OPS_RAW;
 235                         ops.datbuf = kbuf;
 236                         ops.oobbuf = NULL;
 237                         ops.len = len;
 238
 239                         ret = mtd_read_oob(mtd, *ppos, &ops);
 240                         retlen = ops.retlen;
 241                         break;
 242                 }
 243                 default:
 244                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 245                 }
 246                 /* Nand returns -EBADMSG on ECC errors, but it returns
 247                  * the data. For our userspace tools it is important
 248                  * to dump areas with ECC errors!
 249                  * For kernel internal usage it also might return -EUCLEAN
 250                  * to signal the caller that a bitflip has occurred and has
 251                  * been corrected by the ECC algorithm.
 252                  * Userspace software which accesses NAND this way
 253                  * must be aware of the fact that it deals with NAND
 254                  */
 255                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 256                         *ppos += retlen;
 257                         if (copy_to_user(buf, kbuf, retlen)) {
 258                                 kfree(kbuf);
 259                                 return -EFAULT;
 260                         }
 261                         else
 262                                 total_retlen += retlen;
 263
 264                         count -= retlen;
 265                         buf += retlen;
 266                         if (retlen == 0)
 267                                 count = 0;
 268                 }
 269                 else {
 270                         kfree(kbuf);
 271                         return ret;
 272                 }
 273
 274         }
 275
 276         kfree(kbuf);
 277         return total_retlen;
 278 } /* mtdchar_read */
 279
 280 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 281                         loff_t *ppos)
 282 {
 283         struct mtd_file_info *mfi = file->private_data;
 284         struct mtd_info *mtd = mfi->mtd;
 285         size_t size = count;
 286         char *kbuf;
 287         size_t retlen;
 288         size_t total_retlen=0;
 289         int ret=0;
 290         int len;
 291
 292         pr_debug("MTD_write\n");
 293
 294         if (*ppos == mtd->size)
 295                 return -ENOSPC;
 296
 297         if (*ppos + count > mtd->size)
 298                 count = mtd->size - *ppos;
 299
 300         if (!count)
 301                 return 0;
 302
 303         kbuf = mtd_kmalloc_up_to(mtd, &size);
 304         if (!kbuf)
 305                 return -ENOMEM;
 306
 307         while (count) {
 308                 len = min_t(size_t, count, size);
 309
 310                 if (copy_from_user(kbuf, buf, len)) {
 311                         kfree(kbuf);
 312                         return -EFAULT;
 313                 }
 314
 315                 switch (mfi->mode) {
 316                 case MTD_FILE_MODE_OTP_FACTORY:
 317                         ret = -EROFS;
 318                         break;
 319                 case MTD_FILE_MODE_OTP_USER:
 320                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 321                                                       &retlen, kbuf);
 322                         break;
 323
 324                 case MTD_FILE_MODE_RAW:
 325                 {
 326                         struct mtd_oob_ops ops;
 327
 328                         ops.mode = MTD_OPS_RAW;
 329                         ops.datbuf = kbuf;
 330                         ops.oobbuf = NULL;
 331                         ops.ooboffs = 0;
 332                         ops.len = len;
 333
 334                         ret = mtd_write_oob(mtd, *ppos, &ops);
 335                         retlen = ops.retlen;
 336                         break;
 337                 }
 338
 339                 default:
 340                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 341                 }
 342                 if (!ret) {
 343                         *ppos += retlen;
 344                         total_retlen += retlen;
 345                         count -= retlen;
 346                         buf += retlen;
 347                 }
 348                 else {
 349                         kfree(kbuf);
 350                         return ret;
 351                 }
 352         }
 353
 354         kfree(kbuf);
 355         return total_retlen;
 356 } /* mtdchar_write */
 357
 358 /*======================================================================
 359
 360     IOCTL calls for getting device parameters.
 361
 362 ======================================================================*/
 363 static void mtdchar_erase_callback (struct erase_info *instr)
 364 {
 365         wake_up((wait_queue_head_t *)instr->priv);
 366 }
 367
 368 #ifdef CONFIG_HAVE_MTD_OTP
 369 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 370 {
 371         struct mtd_info *mtd = mfi->mtd;
 372         size_t retlen;
 373         int ret = 0;
 374
 375         /*
 376          * Make a fake call to mtd_read_fact_prot_reg() to check if OTP
 377          * operations are supported.
 378          */
 379         if (mtd_read_fact_prot_reg(mtd, -1, -1, &retlen, NULL) == -EOPNOTSUPP)
 380                 return -EOPNOTSUPP;
 381
 382         switch (mode) {
 383         case MTD_OTP_FACTORY:
 384                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 385                 break;
 386         case MTD_OTP_USER:
 387                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 388                 break;
 389         default:
 390                 ret = -EINVAL;
 391         case MTD_OTP_OFF:
 392                 break;
 393         }
 394         return ret;
 395 }
 396 #else
 397 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 398 #endif
 399
 400 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 401         uint64_t start, uint32_t length, void __user *ptr,
 402         uint32_t __user *retp)
 403 {
 404         struct mtd_file_info *mfi = file->private_data;
 405         struct mtd_oob_ops ops;
 406         uint32_t retlen;
 407         int ret = 0;
 408
 409         if (!(file->f_mode & FMODE_WRITE))
 410                 return -EPERM;
 411
 412         if (length > 4096)
 413                 return -EINVAL;
 414
 415         if (!mtd->_write_oob)
 416                 ret = -EOPNOTSUPP;
 417         else
 418                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 419
 420         if (ret)
 421                 return ret;
 422
 423         ops.ooblen = length;
 424         ops.ooboffs = start & (mtd->writesize - 1);
 425         ops.datbuf = NULL;
 426         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 427                 MTD_OPS_PLACE_OOB;
 428
 429         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 430                 return -EINVAL;
 431
 432         ops.oobbuf = memdup_user(ptr, length);
 433         if (IS_ERR(ops.oobbuf))
 434                 return PTR_ERR(ops.oobbuf);
 435
 436         start &= ~((uint64_t)mtd->writesize - 1);
 437         ret = mtd_write_oob(mtd, start, &ops);
 438
 439         if (ops.oobretlen > 0xFFFFFFFFU)
 440                 ret = -EOVERFLOW;
 441         retlen = ops.oobretlen;
 442         if (copy_to_user(retp, &retlen, sizeof(length)))
 443                 ret = -EFAULT;
 444
 445         kfree(ops.oobbuf);
 446         return ret;
 447 }
 448
 449 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 450         uint64_t start, uint32_t length, void __user *ptr,
 451         uint32_t __user *retp)
 452 {
 453         struct mtd_file_info *mfi = file->private_data;
 454         struct mtd_oob_ops ops;
 455         int ret = 0;
 456
 457         if (length > 4096)
 458                 return -EINVAL;
 459
 460         if (!access_ok(VERIFY_WRITE, ptr, length))
 461                 return -EFAULT;
 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                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 825                 break;
 826         }
 827
 828         case MEMUNLOCK:
 829         {
 830                 struct erase_info_user einfo;
 831
 832                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 833                         return -EFAULT;
 834
 835                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 836                 break;
 837         }
 838
 839         case MEMISLOCKED:
 840         {
 841                 struct erase_info_user einfo;
 842
 843                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 844                         return -EFAULT;
 845
 846                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 847                 break;
 848         }
 849
 850         /* Legacy interface */
 851         case MEMGETOOBSEL:
 852         {
 853                 struct nand_oobinfo oi;
 854
 855                 if (!mtd->ecclayout)
 856                         return -EOPNOTSUPP;
 857                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 858                         return -EINVAL;
 859
 860                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 861                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 862                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 863                        sizeof(oi.oobfree));
 864                 oi.eccbytes = mtd->ecclayout->eccbytes;
 865
 866                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 867                         return -EFAULT;
 868                 break;
 869         }
 870
 871         case MEMGETBADBLOCK:
 872         {
 873                 loff_t offs;
 874
 875                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 876                         return -EFAULT;
 877                 return mtd_block_isbad(mtd, offs);
 878                 break;
 879         }
 880
 881         case MEMSETBADBLOCK:
 882         {
 883                 loff_t offs;
 884
 885                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 886                         return -EFAULT;
 887                 return mtd_block_markbad(mtd, offs);
 888                 break;
 889         }
 890
 891 #ifdef CONFIG_HAVE_MTD_OTP
 892         case OTPSELECT:
 893         {
 894                 int mode;
 895                 if (copy_from_user(&mode, argp, sizeof(int)))
 896                         return -EFAULT;
 897
 898                 mfi->mode = MTD_FILE_MODE_NORMAL;
 899
 900                 ret = otp_select_filemode(mfi, mode);
 901
 902                 file->f_pos = 0;
 903                 break;
 904         }
 905
 906         case OTPGETREGIONCOUNT:
 907         case OTPGETREGIONINFO:
 908         {
 909                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 910                 if (!buf)
 911                         return -ENOMEM;
 912                 switch (mfi->mode) {
 913                 case MTD_FILE_MODE_OTP_FACTORY:
 914                         ret = mtd_get_fact_prot_info(mtd, buf, 4096);
 915                         break;
 916                 case MTD_FILE_MODE_OTP_USER:
 917                         ret = mtd_get_user_prot_info(mtd, buf, 4096);
 918                         break;
 919                 default:
 920                         ret = -EINVAL;
 921                         break;
 922                 }
 923                 if (ret >= 0) {
 924                         if (cmd == OTPGETREGIONCOUNT) {
 925                                 int nbr = ret / sizeof(struct otp_info);
 926                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 927                         } else
 928                                 ret = copy_to_user(argp, buf, ret);
 929                         if (ret)
 930                                 ret = -EFAULT;
 931                 }
 932                 kfree(buf);
 933                 break;
 934         }
 935
 936         case OTPLOCK:
 937         {
 938                 struct otp_info oinfo;
 939
 940                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 941                         return -EINVAL;
 942                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 943                         return -EFAULT;
 944                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 945                 break;
 946         }
 947 #endif
 948
 949         /* This ioctl is being deprecated - it truncates the ECC layout */
 950         case ECCGETLAYOUT:
 951         {
 952                 struct nand_ecclayout_user *usrlay;
 953
 954                 if (!mtd->ecclayout)
 955                         return -EOPNOTSUPP;
 956
 957                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 958                 if (!usrlay)
 959                         return -ENOMEM;
 960
 961                 shrink_ecclayout(mtd->ecclayout, usrlay);
 962
 963                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 964                         ret = -EFAULT;
 965                 kfree(usrlay);
 966                 break;
 967         }
 968
 969         case ECCGETSTATS:
 970         {
 971                 if (copy_to_user(argp, &mtd->ecc_stats,
 972                                  sizeof(struct mtd_ecc_stats)))
 973                         return -EFAULT;
 974                 break;
 975         }
 976
 977         case MTDFILEMODE:
 978         {
 979                 mfi->mode = 0;
 980
 981                 switch(arg) {
 982                 case MTD_FILE_MODE_OTP_FACTORY:
 983                 case MTD_FILE_MODE_OTP_USER:
 984                         ret = otp_select_filemode(mfi, arg);
 985                         break;
 986
 987                 case MTD_FILE_MODE_RAW:
 988                         if (!mtd_has_oob(mtd))
 989                                 return -EOPNOTSUPP;
 990                         mfi->mode = arg;
 991
 992                 case MTD_FILE_MODE_NORMAL:
 993                         break;
 994                 default:
 995                         ret = -EINVAL;
 996                 }
 997                 file->f_pos = 0;
 998                 break;
 999         }
1000
1001         case BLKPG:
1002         {
1003                 ret = mtdchar_blkpg_ioctl(mtd,
1004                       (struct blkpg_ioctl_arg __user *)arg);
1005                 break;
1006         }
1007
1008         case BLKRRPART:
1009         {
1010                 /* No reread partition feature. Just return ok */
1011                 ret = 0;
1012                 break;
1013         }
1014
1015         default:
1016                 ret = -ENOTTY;
1017         }
1018
1019         return ret;
1020 } /* memory_ioctl */
1021
1022 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1023 {
1024         int ret;
1025
1026         mutex_lock(&mtd_mutex);
1027         ret = mtdchar_ioctl(file, cmd, arg);
1028         mutex_unlock(&mtd_mutex);
1029
1030         return ret;
1031 }
1032
1033 #ifdef CONFIG_COMPAT
1034
1035 struct mtd_oob_buf32 {
1036         u_int32_t start;
1037         u_int32_t length;
1038         compat_caddr_t ptr;     /* unsigned char* */
1039 };
1040
1041 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1042 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1043
1044 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1045         unsigned long arg)
1046 {
1047         struct mtd_file_info *mfi = file->private_data;
1048         struct mtd_info *mtd = mfi->mtd;
1049         void __user *argp = compat_ptr(arg);
1050         int ret = 0;
1051
1052         mutex_lock(&mtd_mutex);
1053
1054         switch (cmd) {
1055         case MEMWRITEOOB32:
1056         {
1057                 struct mtd_oob_buf32 buf;
1058                 struct mtd_oob_buf32 __user *buf_user = argp;
1059
1060                 if (copy_from_user(&buf, argp, sizeof(buf)))
1061                         ret = -EFAULT;
1062                 else
1063                         ret = mtdchar_writeoob(file, mtd, buf.start,
1064                                 buf.length, compat_ptr(buf.ptr),
1065                                 &buf_user->length);
1066                 break;
1067         }
1068
1069         case MEMREADOOB32:
1070         {
1071                 struct mtd_oob_buf32 buf;
1072                 struct mtd_oob_buf32 __user *buf_user = argp;
1073
1074                 /* NOTE: writes return length to buf->start */
1075                 if (copy_from_user(&buf, argp, sizeof(buf)))
1076                         ret = -EFAULT;
1077                 else
1078                         ret = mtdchar_readoob(file, mtd, buf.start,
1079                                 buf.length, compat_ptr(buf.ptr),
1080                                 &buf_user->start);
1081                 break;
1082         }
1083         default:
1084                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1085         }
1086
1087         mutex_unlock(&mtd_mutex);
1088
1089         return ret;
1090 }
1091
1092 #endif /* CONFIG_COMPAT */
1093
1094 /*
1095  * try to determine where a shared mapping can be made
1096  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1097  *   mappings)
1098  */
1099 #ifndef CONFIG_MMU
1100 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1101                                            unsigned long addr,
1102                                            unsigned long len,
1103                                            unsigned long pgoff,
1104                                            unsigned long flags)
1105 {
1106         struct mtd_file_info *mfi = file->private_data;
1107         struct mtd_info *mtd = mfi->mtd;
1108         unsigned long offset;
1109         int ret;
1110
1111         if (addr != 0)
1112                 return (unsigned long) -EINVAL;
1113
1114         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1115                 return (unsigned long) -EINVAL;
1116
1117         offset = pgoff << PAGE_SHIFT;
1118         if (offset > mtd->size - len)
1119                 return (unsigned long) -EINVAL;
1120
1121         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1122         return ret == -EOPNOTSUPP ? -ENOSYS : ret;
1123 }
1124 #endif
1125
1126 /*
1127  * set up a mapping for shared memory segments
1128  */
1129 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1130 {
1131 #ifdef CONFIG_MMU
1132         struct mtd_file_info *mfi = file->private_data;
1133         struct mtd_info *mtd = mfi->mtd;
1134         struct map_info *map = mtd->priv;
1135         unsigned long start;
1136         unsigned long off;
1137         u32 len;
1138
1139         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1140                 off = vma->vm_pgoff << PAGE_SHIFT;
1141                 start = map->phys;
1142                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1143                 start &= PAGE_MASK;
1144                 if ((vma->vm_end - vma->vm_start + off) > len)
1145                         return -EINVAL;
1146
1147                 off += start;
1148                 vma->vm_pgoff = off >> PAGE_SHIFT;
1149                 vma->vm_flags |= VM_IO | VM_RESERVED;
1150
1151 #ifdef pgprot_noncached
1152                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1153                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1154 #endif
1155                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1156                                        vma->vm_end - vma->vm_start,
1157                                        vma->vm_page_prot))
1158                         return -EAGAIN;
1159
1160                 return 0;
1161         }
1162         return -ENOSYS;
1163 #else
1164         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1165 #endif
1166 }
1167
1168 static const struct file_operations mtd_fops = {
1169         .owner          = THIS_MODULE,
1170         .llseek         = mtdchar_lseek,
1171         .read           = mtdchar_read,
1172         .write          = mtdchar_write,
1173         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1174 #ifdef CONFIG_COMPAT
1175         .compat_ioctl   = mtdchar_compat_ioctl,
1176 #endif
1177         .open           = mtdchar_open,
1178         .release        = mtdchar_close,
1179         .mmap           = mtdchar_mmap,
1180 #ifndef CONFIG_MMU
1181         .get_unmapped_area = mtdchar_get_unmapped_area,
1182 #endif
1183 };
1184
1185 static const struct super_operations mtd_ops = {
1186         .drop_inode = generic_delete_inode,
1187         .statfs = simple_statfs,
1188 };
1189
1190 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1191                                 int flags, const char *dev_name, void *data)
1192 {
1193         return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1194 }
1195
1196 static struct file_system_type mtd_inodefs_type = {
1197        .name = "mtd_inodefs",
1198        .mount = mtd_inodefs_mount,
1199        .kill_sb = kill_anon_super,
1200 };
1201
1202 static int __init init_mtdchar(void)
1203 {
1204         int ret;
1205
1206         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1207                                    "mtd", &mtd_fops);
1208         if (ret < 0) {
1209                 pr_notice("Can't allocate major number %d for "
1210                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1211                 return ret;
1212         }
1213
1214         ret = register_filesystem(&mtd_inodefs_type);
1215         if (ret) {
1216                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1217                 goto err_unregister_chdev;
1218         }
1219         return ret;
1220
1221 err_unregister_chdev:
1222         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1223         return ret;
1224 }
1225
1226 static void __exit cleanup_mtdchar(void)
1227 {
1228         unregister_filesystem(&mtd_inodefs_type);
1229         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1230 }
1231
1232 module_init(init_mtdchar);
1233 module_exit(cleanup_mtdchar);
1234
1235 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1236
1237 MODULE_LICENSE("GPL");
1238 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1239 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1240 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);