drivers/mtd/mtdchar.c

   1 /*
   2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  *
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/err.h>
  24 #include <linux/init.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/sched.h>
  29 #include <linux/mutex.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/compat.h>
  32 #include <linux/mount.h>
  33 #include <linux/blkpg.h>
  34 #include <linux/magic.h>
  35 #include <linux/major.h>
  36 #include <linux/mtd/mtd.h>
  37 #include <linux/mtd/partitions.h>
  38 #include <linux/mtd/map.h>
  39
  40 #include <asm/uaccess.h>
  41
  42 #include "mtdcore.h"
  43
  44 static DEFINE_MUTEX(mtd_mutex);
  45
  46 /*
  47  * Data structure to hold the pointer to the mtd device as well
  48  * as mode information of various use cases.
  49  */
  50 struct mtd_file_info {
  51         struct mtd_info *mtd;
  52         enum mtd_file_modes mode;
  53 };
  54
  55 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  56 {
  57         struct mtd_file_info *mfi = file->private_data;
  58         return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  59 }
  60
  61 static int mtdchar_open(struct inode *inode, struct file *file)
  62 {
  63         int minor = iminor(inode);
  64         int devnum = minor >> 1;
  65         int ret = 0;
  66         struct mtd_info *mtd;
  67         struct mtd_file_info *mfi;
  68
  69         pr_debug("MTD_open\n");
  70
  71         /* You can't open the RO devices RW */
  72         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  73                 return -EACCES;
  74
  75         mutex_lock(&mtd_mutex);
  76         mtd = get_mtd_device(NULL, devnum);
  77
  78         if (IS_ERR(mtd)) {
  79                 ret = PTR_ERR(mtd);
  80                 goto out;
  81         }
  82
  83         if (mtd->type == MTD_ABSENT) {
  84                 ret = -ENODEV;
  85                 goto out1;
  86         }
  87
  88         /* You can't open it RW if it's not a writeable device */
  89         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
  90                 ret = -EACCES;
  91                 goto out1;
  92         }
  93
  94         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
  95         if (!mfi) {
  96                 ret = -ENOMEM;
  97                 goto out1;
  98         }
  99         mfi->mtd = mtd;
 100         file->private_data = mfi;
 101         mutex_unlock(&mtd_mutex);
 102         return 0;
 103
 104 out1:
 105         put_mtd_device(mtd);
 106 out:
 107         mutex_unlock(&mtd_mutex);
 108         return ret;
 109 } /* mtdchar_open */
 110
 111 /*====================================================================*/
 112
 113 static int mtdchar_close(struct inode *inode, struct file *file)
 114 {
 115         struct mtd_file_info *mfi = file->private_data;
 116         struct mtd_info *mtd = mfi->mtd;
 117
 118         pr_debug("MTD_close\n");
 119
 120         /* Only sync if opened RW */
 121         if ((file->f_mode & FMODE_WRITE))
 122                 mtd_sync(mtd);
 123
 124         put_mtd_device(mtd);
 125         file->private_data = NULL;
 126         kfree(mfi);
 127
 128         return 0;
 129 } /* mtdchar_close */
 130
 131 /* Back in June 2001, dwmw2 wrote:
 132  *
 133  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 134  *   userspace buffer down and use it directly with readv/writev.
 135  *
 136  * The implementation below, using mtd_kmalloc_up_to, mitigates
 137  * allocation failures when the system is under low-memory situations
 138  * or if memory is highly fragmented at the cost of reducing the
 139  * performance of the requested transfer due to a smaller buffer size.
 140  *
 141  * A more complex but more memory-efficient implementation based on
 142  * get_user_pages and iovecs to cover extents of those pages is a
 143  * longer-term goal, as intimated by dwmw2 above. However, for the
 144  * write case, this requires yet more complex head and tail transfer
 145  * handling when those head and tail offsets and sizes are such that
 146  * alignment requirements are not met in the NAND subdriver.
 147  */
 148
 149 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 150                         loff_t *ppos)
 151 {
 152         struct mtd_file_info *mfi = file->private_data;
 153         struct mtd_info *mtd = mfi->mtd;
 154         size_t retlen;
 155         size_t total_retlen=0;
 156         int ret=0;
 157         int len;
 158         size_t size = count;
 159         char *kbuf;
 160
 161         pr_debug("MTD_read\n");
 162
 163         if (*ppos + count > mtd->size)
 164                 count = mtd->size - *ppos;
 165
 166         if (!count)
 167                 return 0;
 168
 169         kbuf = mtd_kmalloc_up_to(mtd, &size);
 170         if (!kbuf)
 171                 return -ENOMEM;
 172
 173         while (count) {
 174                 len = min_t(size_t, count, size);
 175
 176                 switch (mfi->mode) {
 177                 case MTD_FILE_MODE_OTP_FACTORY:
 178                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 179                                                      &retlen, kbuf);
 180                         break;
 181                 case MTD_FILE_MODE_OTP_USER:
 182                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 183                                                      &retlen, kbuf);
 184                         break;
 185                 case MTD_FILE_MODE_RAW:
 186                 {
 187                         struct mtd_oob_ops ops;
 188
 189                         ops.mode = MTD_OPS_RAW;
 190                         ops.datbuf = kbuf;
 191                         ops.oobbuf = NULL;
 192                         ops.len = len;
 193
 194                         ret = mtd_read_oob(mtd, *ppos, &ops);
 195                         retlen = ops.retlen;
 196                         break;
 197                 }
 198                 default:
 199                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 200                 }
 201                 /* Nand returns -EBADMSG on ECC errors, but it returns
 202                  * the data. For our userspace tools it is important
 203                  * to dump areas with ECC errors!
 204                  * For kernel internal usage it also might return -EUCLEAN
 205                  * to signal the caller that a bitflip has occurred and has
 206                  * been corrected by the ECC algorithm.
 207                  * Userspace software which accesses NAND this way
 208                  * must be aware of the fact that it deals with NAND
 209                  */
 210                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 211                         *ppos += retlen;
 212                         if (copy_to_user(buf, kbuf, retlen)) {
 213                                 kfree(kbuf);
 214                                 return -EFAULT;
 215                         }
 216                         else
 217                                 total_retlen += retlen;
 218
 219                         count -= retlen;
 220                         buf += retlen;
 221                         if (retlen == 0)
 222                                 count = 0;
 223                 }
 224                 else {
 225                         kfree(kbuf);
 226                         return ret;
 227                 }
 228
 229         }
 230
 231         kfree(kbuf);
 232         return total_retlen;
 233 } /* mtdchar_read */
 234
 235 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 236                         loff_t *ppos)
 237 {
 238         struct mtd_file_info *mfi = file->private_data;
 239         struct mtd_info *mtd = mfi->mtd;
 240         size_t size = count;
 241         char *kbuf;
 242         size_t retlen;
 243         size_t total_retlen=0;
 244         int ret=0;
 245         int len;
 246
 247         pr_debug("MTD_write\n");
 248
 249         if (*ppos == mtd->size)
 250                 return -ENOSPC;
 251
 252         if (*ppos + count > mtd->size)
 253                 count = mtd->size - *ppos;
 254
 255         if (!count)
 256                 return 0;
 257
 258         kbuf = mtd_kmalloc_up_to(mtd, &size);
 259         if (!kbuf)
 260                 return -ENOMEM;
 261
 262         while (count) {
 263                 len = min_t(size_t, count, size);
 264
 265                 if (copy_from_user(kbuf, buf, len)) {
 266                         kfree(kbuf);
 267                         return -EFAULT;
 268                 }
 269
 270                 switch (mfi->mode) {
 271                 case MTD_FILE_MODE_OTP_FACTORY:
 272                         ret = -EROFS;
 273                         break;
 274                 case MTD_FILE_MODE_OTP_USER:
 275                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 276                                                       &retlen, kbuf);
 277                         break;
 278
 279                 case MTD_FILE_MODE_RAW:
 280                 {
 281                         struct mtd_oob_ops ops;
 282
 283                         ops.mode = MTD_OPS_RAW;
 284                         ops.datbuf = kbuf;
 285                         ops.oobbuf = NULL;
 286                         ops.ooboffs = 0;
 287                         ops.len = len;
 288
 289                         ret = mtd_write_oob(mtd, *ppos, &ops);
 290                         retlen = ops.retlen;
 291                         break;
 292                 }
 293
 294                 default:
 295                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 296                 }
 297
 298                 /*
 299                  * Return -ENOSPC only if no data could be written at all.
 300                  * Otherwise just return the number of bytes that actually
 301                  * have been written.
 302                  */
 303                 if ((ret == -ENOSPC) && (total_retlen))
 304                         break;
 305
 306                 if (!ret) {
 307                         *ppos += retlen;
 308                         total_retlen += retlen;
 309                         count -= retlen;
 310                         buf += retlen;
 311                 }
 312                 else {
 313                         kfree(kbuf);
 314                         return ret;
 315                 }
 316         }
 317
 318         kfree(kbuf);
 319         return total_retlen;
 320 } /* mtdchar_write */
 321
 322 /*======================================================================
 323
 324     IOCTL calls for getting device parameters.
 325
 326 ======================================================================*/
 327 static void mtdchar_erase_callback (struct erase_info *instr)
 328 {
 329         wake_up((wait_queue_head_t *)instr->priv);
 330 }
 331
 332 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 333 {
 334         struct mtd_info *mtd = mfi->mtd;
 335         size_t retlen;
 336
 337         switch (mode) {
 338         case MTD_OTP_FACTORY:
 339                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 340                                 -EOPNOTSUPP)
 341                         return -EOPNOTSUPP;
 342
 343                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 344                 break;
 345         case MTD_OTP_USER:
 346                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 347                                 -EOPNOTSUPP)
 348                         return -EOPNOTSUPP;
 349
 350                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 351                 break;
 352         case MTD_OTP_OFF:
 353                 mfi->mode = MTD_FILE_MODE_NORMAL;
 354                 break;
 355         default:
 356                 return -EINVAL;
 357         }
 358
 359         return 0;
 360 }
 361
 362 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 363         uint64_t start, uint32_t length, void __user *ptr,
 364         uint32_t __user *retp)
 365 {
 366         struct mtd_file_info *mfi = file->private_data;
 367         struct mtd_oob_ops ops;
 368         uint32_t retlen;
 369         int ret = 0;
 370
 371         if (!(file->f_mode & FMODE_WRITE))
 372                 return -EPERM;
 373
 374         if (length > 4096)
 375                 return -EINVAL;
 376
 377         if (!mtd->_write_oob)
 378                 ret = -EOPNOTSUPP;
 379         else
 380                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 381
 382         if (ret)
 383                 return ret;
 384
 385         ops.ooblen = length;
 386         ops.ooboffs = start & (mtd->writesize - 1);
 387         ops.datbuf = NULL;
 388         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 389                 MTD_OPS_PLACE_OOB;
 390
 391         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 392                 return -EINVAL;
 393
 394         ops.oobbuf = memdup_user(ptr, length);
 395         if (IS_ERR(ops.oobbuf))
 396                 return PTR_ERR(ops.oobbuf);
 397
 398         start &= ~((uint64_t)mtd->writesize - 1);
 399         ret = mtd_write_oob(mtd, start, &ops);
 400
 401         if (ops.oobretlen > 0xFFFFFFFFU)
 402                 ret = -EOVERFLOW;
 403         retlen = ops.oobretlen;
 404         if (copy_to_user(retp, &retlen, sizeof(length)))
 405                 ret = -EFAULT;
 406
 407         kfree(ops.oobbuf);
 408         return ret;
 409 }
 410
 411 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 412         uint64_t start, uint32_t length, void __user *ptr,
 413         uint32_t __user *retp)
 414 {
 415         struct mtd_file_info *mfi = file->private_data;
 416         struct mtd_oob_ops ops;
 417         int ret = 0;
 418
 419         if (length > 4096)
 420                 return -EINVAL;
 421
 422         if (!access_ok(VERIFY_WRITE, ptr, length))
 423                 return -EFAULT;
 424
 425         ops.ooblen = length;
 426         ops.ooboffs = start & (mtd->writesize - 1);
 427         ops.datbuf = NULL;
 428         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 429                 MTD_OPS_PLACE_OOB;
 430
 431         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 432                 return -EINVAL;
 433
 434         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 435         if (!ops.oobbuf)
 436                 return -ENOMEM;
 437
 438         start &= ~((uint64_t)mtd->writesize - 1);
 439         ret = mtd_read_oob(mtd, start, &ops);
 440
 441         if (put_user(ops.oobretlen, retp))
 442                 ret = -EFAULT;
 443         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 444                                             ops.oobretlen))
 445                 ret = -EFAULT;
 446
 447         kfree(ops.oobbuf);
 448
 449         /*
 450          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 451          * data. For our userspace tools it is important to dump areas
 452          * with ECC errors!
 453          * For kernel internal usage it also might return -EUCLEAN
 454          * to signal the caller that a bitflip has occured and has
 455          * been corrected by the ECC algorithm.
 456          *
 457          * Note: currently the standard NAND function, nand_read_oob_std,
 458          * does not calculate ECC for the OOB area, so do not rely on
 459          * this behavior unless you have replaced it with your own.
 460          */
 461         if (mtd_is_bitflip_or_eccerr(ret))
 462                 return 0;
 463
 464         return ret;
 465 }
 466
 467 /*
 468  * Copies (and truncates, if necessary) data from the larger struct,
 469  * nand_ecclayout, to the smaller, deprecated layout struct,
 470  * nand_ecclayout_user. This is necessary only to support the deprecated
 471  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 472  * nand_ecclayout flexibly (i.e. the struct may change size in new
 473  * releases without requiring major rewrites).
 474  */
 475 static int shrink_ecclayout(const struct nand_ecclayout *from,
 476                 struct nand_ecclayout_user *to)
 477 {
 478         int i;
 479
 480         if (!from || !to)
 481                 return -EINVAL;
 482
 483         memset(to, 0, sizeof(*to));
 484
 485         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 486         for (i = 0; i < to->eccbytes; i++)
 487                 to->eccpos[i] = from->eccpos[i];
 488
 489         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 490                 if (from->oobfree[i].length == 0 &&
 491                                 from->oobfree[i].offset == 0)
 492                         break;
 493                 to->oobavail += from->oobfree[i].length;
 494                 to->oobfree[i] = from->oobfree[i];
 495         }
 496
 497         return 0;
 498 }
 499
 500 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 501                            struct blkpg_ioctl_arg __user *arg)
 502 {
 503         struct blkpg_ioctl_arg a;
 504         struct blkpg_partition p;
 505
 506         if (!capable(CAP_SYS_ADMIN))
 507                 return -EPERM;
 508
 509         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 510                 return -EFAULT;
 511
 512         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 513                 return -EFAULT;
 514
 515         switch (a.op) {
 516         case BLKPG_ADD_PARTITION:
 517
 518                 /* Only master mtd device must be used to add partitions */
 519                 if (mtd_is_partition(mtd))
 520                         return -EINVAL;
 521
 522                 /* Sanitize user input */
 523                 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 524
 525                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 526
 527         case BLKPG_DEL_PARTITION:
 528
 529                 if (p.pno < 0)
 530                         return -EINVAL;
 531
 532                 return mtd_del_partition(mtd, p.pno);
 533
 534         default:
 535                 return -EINVAL;
 536         }
 537 }
 538
 539 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 540                 struct mtd_write_req __user *argp)
 541 {
 542         struct mtd_write_req req;
 543         struct mtd_oob_ops ops;
 544         const void __user *usr_data, *usr_oob;
 545         int ret;
 546
 547         if (copy_from_user(&req, argp, sizeof(req)))
 548                 return -EFAULT;
 549
 550         usr_data = (const void __user *)(uintptr_t)req.usr_data;
 551         usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 552         if (!access_ok(VERIFY_READ, usr_data, req.len) ||
 553             !access_ok(VERIFY_READ, usr_oob, req.ooblen))
 554                 return -EFAULT;
 555
 556         if (!mtd->_write_oob)
 557                 return -EOPNOTSUPP;
 558
 559         ops.mode = req.mode;
 560         ops.len = (size_t)req.len;
 561         ops.ooblen = (size_t)req.ooblen;
 562         ops.ooboffs = 0;
 563
 564         if (usr_data) {
 565                 ops.datbuf = memdup_user(usr_data, ops.len);
 566                 if (IS_ERR(ops.datbuf))
 567                         return PTR_ERR(ops.datbuf);
 568         } else {
 569                 ops.datbuf = NULL;
 570         }
 571
 572         if (usr_oob) {
 573                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 574                 if (IS_ERR(ops.oobbuf)) {
 575                         kfree(ops.datbuf);
 576                         return PTR_ERR(ops.oobbuf);
 577                 }
 578         } else {
 579                 ops.oobbuf = NULL;
 580         }
 581
 582         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 583
 584         kfree(ops.datbuf);
 585         kfree(ops.oobbuf);
 586
 587         return ret;
 588 }
 589
 590 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 591 {
 592         struct mtd_file_info *mfi = file->private_data;
 593         struct mtd_info *mtd = mfi->mtd;
 594         void __user *argp = (void __user *)arg;
 595         int ret = 0;
 596         u_long size;
 597         struct mtd_info_user info;
 598
 599         pr_debug("MTD_ioctl\n");
 600
 601         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 602         if (cmd & IOC_IN) {
 603                 if (!access_ok(VERIFY_READ, argp, size))
 604                         return -EFAULT;
 605         }
 606         if (cmd & IOC_OUT) {
 607                 if (!access_ok(VERIFY_WRITE, argp, size))
 608                         return -EFAULT;
 609         }
 610
 611         switch (cmd) {
 612         case MEMGETREGIONCOUNT:
 613                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 614                         return -EFAULT;
 615                 break;
 616
 617         case MEMGETREGIONINFO:
 618         {
 619                 uint32_t ur_idx;
 620                 struct mtd_erase_region_info *kr;
 621                 struct region_info_user __user *ur = argp;
 622
 623                 if (get_user(ur_idx, &(ur->regionindex)))
 624                         return -EFAULT;
 625
 626                 if (ur_idx >= mtd->numeraseregions)
 627                         return -EINVAL;
 628
 629                 kr = &(mtd->eraseregions[ur_idx]);
 630
 631                 if (put_user(kr->offset, &(ur->offset))
 632                     || put_user(kr->erasesize, &(ur->erasesize))
 633                     || put_user(kr->numblocks, &(ur->numblocks)))
 634                         return -EFAULT;
 635
 636                 break;
 637         }
 638
 639         case MEMGETINFO:
 640                 memset(&info, 0, sizeof(info));
 641                 info.type       = mtd->type;
 642                 info.flags      = mtd->flags;
 643                 info.size       = mtd->size;
 644                 info.erasesize  = mtd->erasesize;
 645                 info.writesize  = mtd->writesize;
 646                 info.oobsize    = mtd->oobsize;
 647                 /* The below field is obsolete */
 648                 info.padding    = 0;
 649                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 650                         return -EFAULT;
 651                 break;
 652
 653         case MEMERASE:
 654         case MEMERASE64:
 655         {
 656                 struct erase_info *erase;
 657
 658                 if(!(file->f_mode & FMODE_WRITE))
 659                         return -EPERM;
 660
 661                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 662                 if (!erase)
 663                         ret = -ENOMEM;
 664                 else {
 665                         wait_queue_head_t waitq;
 666                         DECLARE_WAITQUEUE(wait, current);
 667
 668                         init_waitqueue_head(&waitq);
 669
 670                         if (cmd == MEMERASE64) {
 671                                 struct erase_info_user64 einfo64;
 672
 673                                 if (copy_from_user(&einfo64, argp,
 674                                             sizeof(struct erase_info_user64))) {
 675                                         kfree(erase);
 676                                         return -EFAULT;
 677                                 }
 678                                 erase->addr = einfo64.start;
 679                                 erase->len = einfo64.length;
 680                         } else {
 681                                 struct erase_info_user einfo32;
 682
 683                                 if (copy_from_user(&einfo32, argp,
 684                                             sizeof(struct erase_info_user))) {
 685                                         kfree(erase);
 686                                         return -EFAULT;
 687                                 }
 688                                 erase->addr = einfo32.start;
 689                                 erase->len = einfo32.length;
 690                         }
 691                         erase->mtd = mtd;
 692                         erase->callback = mtdchar_erase_callback;
 693                         erase->priv = (unsigned long)&waitq;
 694
 695                         /*
 696                           FIXME: Allow INTERRUPTIBLE. Which means
 697                           not having the wait_queue head on the stack.
 698
 699                           If the wq_head is on the stack, and we
 700                           leave because we got interrupted, then the
 701                           wq_head is no longer there when the
 702                           callback routine tries to wake us up.
 703                         */
 704                         ret = mtd_erase(mtd, erase);
 705                         if (!ret) {
 706                                 set_current_state(TASK_UNINTERRUPTIBLE);
 707                                 add_wait_queue(&waitq, &wait);
 708                                 if (erase->state != MTD_ERASE_DONE &&
 709                                     erase->state != MTD_ERASE_FAILED)
 710                                         schedule();
 711                                 remove_wait_queue(&waitq, &wait);
 712                                 set_current_state(TASK_RUNNING);
 713
 714                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 715                         }
 716                         kfree(erase);
 717                 }
 718                 break;
 719         }
 720
 721         case MEMWRITEOOB:
 722         {
 723                 struct mtd_oob_buf buf;
 724                 struct mtd_oob_buf __user *buf_user = argp;
 725
 726                 /* NOTE: writes return length to buf_user->length */
 727                 if (copy_from_user(&buf, argp, sizeof(buf)))
 728                         ret = -EFAULT;
 729                 else
 730                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 731                                 buf.ptr, &buf_user->length);
 732                 break;
 733         }
 734
 735         case MEMREADOOB:
 736         {
 737                 struct mtd_oob_buf buf;
 738                 struct mtd_oob_buf __user *buf_user = argp;
 739
 740                 /* NOTE: writes return length to buf_user->start */
 741                 if (copy_from_user(&buf, argp, sizeof(buf)))
 742                         ret = -EFAULT;
 743                 else
 744                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 745                                 buf.ptr, &buf_user->start);
 746                 break;
 747         }
 748
 749         case MEMWRITEOOB64:
 750         {
 751                 struct mtd_oob_buf64 buf;
 752                 struct mtd_oob_buf64 __user *buf_user = argp;
 753
 754                 if (copy_from_user(&buf, argp, sizeof(buf)))
 755                         ret = -EFAULT;
 756                 else
 757                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 758                                 (void __user *)(uintptr_t)buf.usr_ptr,
 759                                 &buf_user->length);
 760                 break;
 761         }
 762
 763         case MEMREADOOB64:
 764         {
 765                 struct mtd_oob_buf64 buf;
 766                 struct mtd_oob_buf64 __user *buf_user = argp;
 767
 768                 if (copy_from_user(&buf, argp, sizeof(buf)))
 769                         ret = -EFAULT;
 770                 else
 771                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 772                                 (void __user *)(uintptr_t)buf.usr_ptr,
 773                                 &buf_user->length);
 774                 break;
 775         }
 776
 777         case MEMWRITE:
 778         {
 779                 ret = mtdchar_write_ioctl(mtd,
 780                       (struct mtd_write_req __user *)arg);
 781                 break;
 782         }
 783
 784         case MEMLOCK:
 785         {
 786                 struct erase_info_user einfo;
 787
 788                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 789                         return -EFAULT;
 790
 791                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 792                 break;
 793         }
 794
 795         case MEMUNLOCK:
 796         {
 797                 struct erase_info_user einfo;
 798
 799                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 800                         return -EFAULT;
 801
 802                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 803                 break;
 804         }
 805
 806         case MEMISLOCKED:
 807         {
 808                 struct erase_info_user einfo;
 809
 810                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 811                         return -EFAULT;
 812
 813                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 814                 break;
 815         }
 816
 817         /* Legacy interface */
 818         case MEMGETOOBSEL:
 819         {
 820                 struct nand_oobinfo oi;
 821
 822                 if (!mtd->ecclayout)
 823                         return -EOPNOTSUPP;
 824                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 825                         return -EINVAL;
 826
 827                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 828                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 829                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 830                        sizeof(oi.oobfree));
 831                 oi.eccbytes = mtd->ecclayout->eccbytes;
 832
 833                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 834                         return -EFAULT;
 835                 break;
 836         }
 837
 838         case MEMGETBADBLOCK:
 839         {
 840                 loff_t offs;
 841
 842                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 843                         return -EFAULT;
 844                 return mtd_block_isbad(mtd, offs);
 845                 break;
 846         }
 847
 848         case MEMSETBADBLOCK:
 849         {
 850                 loff_t offs;
 851
 852                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 853                         return -EFAULT;
 854                 return mtd_block_markbad(mtd, offs);
 855                 break;
 856         }
 857
 858         case OTPSELECT:
 859         {
 860                 int mode;
 861                 if (copy_from_user(&mode, argp, sizeof(int)))
 862                         return -EFAULT;
 863
 864                 mfi->mode = MTD_FILE_MODE_NORMAL;
 865
 866                 ret = otp_select_filemode(mfi, mode);
 867
 868                 file->f_pos = 0;
 869                 break;
 870         }
 871
 872         case OTPGETREGIONCOUNT:
 873         case OTPGETREGIONINFO:
 874         {
 875                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 876                 size_t retlen;
 877                 if (!buf)
 878                         return -ENOMEM;
 879                 switch (mfi->mode) {
 880                 case MTD_FILE_MODE_OTP_FACTORY:
 881                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 882                         break;
 883                 case MTD_FILE_MODE_OTP_USER:
 884                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 885                         break;
 886                 default:
 887                         ret = -EINVAL;
 888                         break;
 889                 }
 890                 if (!ret) {
 891                         if (cmd == OTPGETREGIONCOUNT) {
 892                                 int nbr = retlen / sizeof(struct otp_info);
 893                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 894                         } else
 895                                 ret = copy_to_user(argp, buf, retlen);
 896                         if (ret)
 897                                 ret = -EFAULT;
 898                 }
 899                 kfree(buf);
 900                 break;
 901         }
 902
 903         case OTPLOCK:
 904         {
 905                 struct otp_info oinfo;
 906
 907                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 908                         return -EINVAL;
 909                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 910                         return -EFAULT;
 911                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 912                 break;
 913         }
 914
 915         /* This ioctl is being deprecated - it truncates the ECC layout */
 916         case ECCGETLAYOUT:
 917         {
 918                 struct nand_ecclayout_user *usrlay;
 919
 920                 if (!mtd->ecclayout)
 921                         return -EOPNOTSUPP;
 922
 923                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 924                 if (!usrlay)
 925                         return -ENOMEM;
 926
 927                 shrink_ecclayout(mtd->ecclayout, usrlay);
 928
 929                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 930                         ret = -EFAULT;
 931                 kfree(usrlay);
 932                 break;
 933         }
 934
 935         case ECCGETSTATS:
 936         {
 937                 if (copy_to_user(argp, &mtd->ecc_stats,
 938                                  sizeof(struct mtd_ecc_stats)))
 939                         return -EFAULT;
 940                 break;
 941         }
 942
 943         case MTDFILEMODE:
 944         {
 945                 mfi->mode = 0;
 946
 947                 switch(arg) {
 948                 case MTD_FILE_MODE_OTP_FACTORY:
 949                 case MTD_FILE_MODE_OTP_USER:
 950                         ret = otp_select_filemode(mfi, arg);
 951                         break;
 952
 953                 case MTD_FILE_MODE_RAW:
 954                         if (!mtd_has_oob(mtd))
 955                                 return -EOPNOTSUPP;
 956                         mfi->mode = arg;
 957
 958                 case MTD_FILE_MODE_NORMAL:
 959                         break;
 960                 default:
 961                         ret = -EINVAL;
 962                 }
 963                 file->f_pos = 0;
 964                 break;
 965         }
 966
 967         case BLKPG:
 968         {
 969                 ret = mtdchar_blkpg_ioctl(mtd,
 970                       (struct blkpg_ioctl_arg __user *)arg);
 971                 break;
 972         }
 973
 974         case BLKRRPART:
 975         {
 976                 /* No reread partition feature. Just return ok */
 977                 ret = 0;
 978                 break;
 979         }
 980
 981         default:
 982                 ret = -ENOTTY;
 983         }
 984
 985         return ret;
 986 } /* memory_ioctl */
 987
 988 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 989 {
 990         int ret;
 991
 992         mutex_lock(&mtd_mutex);
 993         ret = mtdchar_ioctl(file, cmd, arg);
 994         mutex_unlock(&mtd_mutex);
 995
 996         return ret;
 997 }
 998
 999 #ifdef CONFIG_COMPAT
1000
1001 struct mtd_oob_buf32 {
1002         u_int32_t start;
1003         u_int32_t length;
1004         compat_caddr_t ptr;     /* unsigned char* */
1005 };
1006
1007 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1008 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1009
1010 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1011         unsigned long arg)
1012 {
1013         struct mtd_file_info *mfi = file->private_data;
1014         struct mtd_info *mtd = mfi->mtd;
1015         void __user *argp = compat_ptr(arg);
1016         int ret = 0;
1017
1018         mutex_lock(&mtd_mutex);
1019
1020         switch (cmd) {
1021         case MEMWRITEOOB32:
1022         {
1023                 struct mtd_oob_buf32 buf;
1024                 struct mtd_oob_buf32 __user *buf_user = argp;
1025
1026                 if (copy_from_user(&buf, argp, sizeof(buf)))
1027                         ret = -EFAULT;
1028                 else
1029                         ret = mtdchar_writeoob(file, mtd, buf.start,
1030                                 buf.length, compat_ptr(buf.ptr),
1031                                 &buf_user->length);
1032                 break;
1033         }
1034
1035         case MEMREADOOB32:
1036         {
1037                 struct mtd_oob_buf32 buf;
1038                 struct mtd_oob_buf32 __user *buf_user = argp;
1039
1040                 /* NOTE: writes return length to buf->start */
1041                 if (copy_from_user(&buf, argp, sizeof(buf)))
1042                         ret = -EFAULT;
1043                 else
1044                         ret = mtdchar_readoob(file, mtd, buf.start,
1045                                 buf.length, compat_ptr(buf.ptr),
1046                                 &buf_user->start);
1047                 break;
1048         }
1049         default:
1050                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1051         }
1052
1053         mutex_unlock(&mtd_mutex);
1054
1055         return ret;
1056 }
1057
1058 #endif /* CONFIG_COMPAT */
1059
1060 /*
1061  * try to determine where a shared mapping can be made
1062  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1063  *   mappings)
1064  */
1065 #ifndef CONFIG_MMU
1066 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1067                                            unsigned long addr,
1068                                            unsigned long len,
1069                                            unsigned long pgoff,
1070                                            unsigned long flags)
1071 {
1072         struct mtd_file_info *mfi = file->private_data;
1073         struct mtd_info *mtd = mfi->mtd;
1074         unsigned long offset;
1075         int ret;
1076
1077         if (addr != 0)
1078                 return (unsigned long) -EINVAL;
1079
1080         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1081                 return (unsigned long) -EINVAL;
1082
1083         offset = pgoff << PAGE_SHIFT;
1084         if (offset > mtd->size - len)
1085                 return (unsigned long) -EINVAL;
1086
1087         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1088         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1089 }
1090
1091 static unsigned mtdchar_mmap_capabilities(struct file *file)
1092 {
1093         struct mtd_file_info *mfi = file->private_data;
1094
1095         return mtd_mmap_capabilities(mfi->mtd);
1096 }
1097 #endif
1098
1099 /*
1100  * set up a mapping for shared memory segments
1101  */
1102 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1103 {
1104 #ifdef CONFIG_MMU
1105         struct mtd_file_info *mfi = file->private_data;
1106         struct mtd_info *mtd = mfi->mtd;
1107         struct map_info *map = mtd->priv;
1108
1109         /* This is broken because it assumes the MTD device is map-based
1110            and that mtd->priv is a valid struct map_info.  It should be
1111            replaced with something that uses the mtd_get_unmapped_area()
1112            operation properly. */
1113         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1114 #ifdef pgprot_noncached
1115                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1116                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1117 #endif
1118                 return vm_iomap_memory(vma, map->phys, map->size);
1119         }
1120         return -ENODEV;
1121 #else
1122         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1123 #endif
1124 }
1125
1126 static const struct file_operations mtd_fops = {
1127         .owner          = THIS_MODULE,
1128         .llseek         = mtdchar_lseek,
1129         .read           = mtdchar_read,
1130         .write          = mtdchar_write,
1131         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1132 #ifdef CONFIG_COMPAT
1133         .compat_ioctl   = mtdchar_compat_ioctl,
1134 #endif
1135         .open           = mtdchar_open,
1136         .release        = mtdchar_close,
1137         .mmap           = mtdchar_mmap,
1138 #ifndef CONFIG_MMU
1139         .get_unmapped_area = mtdchar_get_unmapped_area,
1140         .mmap_capabilities = mtdchar_mmap_capabilities,
1141 #endif
1142 };
1143
1144 int __init init_mtdchar(void)
1145 {
1146         int ret;
1147
1148         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1149                                    "mtd", &mtd_fops);
1150         if (ret < 0) {
1151                 pr_err("Can't allocate major number %d for MTD\n",
1152                        MTD_CHAR_MAJOR);
1153                 return ret;
1154         }
1155
1156         return ret;
1157 }
1158
1159 void __exit cleanup_mtdchar(void)
1160 {
1161         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1162 }
1163
1164 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);