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 <linux/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                 return -EOPNOTSUPP;
 379
 380         ops.ooblen = length;
 381         ops.ooboffs = start & (mtd->writesize - 1);
 382         ops.datbuf = NULL;
 383         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 384                 MTD_OPS_PLACE_OOB;
 385
 386         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 387                 return -EINVAL;
 388
 389         ops.oobbuf = memdup_user(ptr, length);
 390         if (IS_ERR(ops.oobbuf))
 391                 return PTR_ERR(ops.oobbuf);
 392
 393         start &= ~((uint64_t)mtd->writesize - 1);
 394         ret = mtd_write_oob(mtd, start, &ops);
 395
 396         if (ops.oobretlen > 0xFFFFFFFFU)
 397                 ret = -EOVERFLOW;
 398         retlen = ops.oobretlen;
 399         if (copy_to_user(retp, &retlen, sizeof(length)))
 400                 ret = -EFAULT;
 401
 402         kfree(ops.oobbuf);
 403         return ret;
 404 }
 405
 406 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 407         uint64_t start, uint32_t length, void __user *ptr,
 408         uint32_t __user *retp)
 409 {
 410         struct mtd_file_info *mfi = file->private_data;
 411         struct mtd_oob_ops ops;
 412         int ret = 0;
 413
 414         if (length > 4096)
 415                 return -EINVAL;
 416
 417         ops.ooblen = length;
 418         ops.ooboffs = start & (mtd->writesize - 1);
 419         ops.datbuf = NULL;
 420         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 421                 MTD_OPS_PLACE_OOB;
 422
 423         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 424                 return -EINVAL;
 425
 426         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 427         if (!ops.oobbuf)
 428                 return -ENOMEM;
 429
 430         start &= ~((uint64_t)mtd->writesize - 1);
 431         ret = mtd_read_oob(mtd, start, &ops);
 432
 433         if (put_user(ops.oobretlen, retp))
 434                 ret = -EFAULT;
 435         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 436                                             ops.oobretlen))
 437                 ret = -EFAULT;
 438
 439         kfree(ops.oobbuf);
 440
 441         /*
 442          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 443          * data. For our userspace tools it is important to dump areas
 444          * with ECC errors!
 445          * For kernel internal usage it also might return -EUCLEAN
 446          * to signal the caller that a bitflip has occurred and has
 447          * been corrected by the ECC algorithm.
 448          *
 449          * Note: currently the standard NAND function, nand_read_oob_std,
 450          * does not calculate ECC for the OOB area, so do not rely on
 451          * this behavior unless you have replaced it with your own.
 452          */
 453         if (mtd_is_bitflip_or_eccerr(ret))
 454                 return 0;
 455
 456         return ret;
 457 }
 458
 459 /*
 460  * Copies (and truncates, if necessary) OOB layout information to the
 461  * deprecated layout struct, nand_ecclayout_user. This is necessary only to
 462  * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
 463  * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
 464  * can describe any kind of OOB layout with almost zero overhead from a
 465  * memory usage point of view).
 466  */
 467 static int shrink_ecclayout(struct mtd_info *mtd,
 468                             struct nand_ecclayout_user *to)
 469 {
 470         struct mtd_oob_region oobregion;
 471         int i, section = 0, ret;
 472
 473         if (!mtd || !to)
 474                 return -EINVAL;
 475
 476         memset(to, 0, sizeof(*to));
 477
 478         to->eccbytes = 0;
 479         for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
 480                 u32 eccpos;
 481
 482                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 483                 if (ret < 0) {
 484                         if (ret != -ERANGE)
 485                                 return ret;
 486
 487                         break;
 488                 }
 489
 490                 eccpos = oobregion.offset;
 491                 for (; i < MTD_MAX_ECCPOS_ENTRIES &&
 492                        eccpos < oobregion.offset + oobregion.length; i++) {
 493                         to->eccpos[i] = eccpos++;
 494                         to->eccbytes++;
 495                 }
 496         }
 497
 498         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 499                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 500                 if (ret < 0) {
 501                         if (ret != -ERANGE)
 502                                 return ret;
 503
 504                         break;
 505                 }
 506
 507                 to->oobfree[i].offset = oobregion.offset;
 508                 to->oobfree[i].length = oobregion.length;
 509                 to->oobavail += to->oobfree[i].length;
 510         }
 511
 512         return 0;
 513 }
 514
 515 static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
 516 {
 517         struct mtd_oob_region oobregion;
 518         int i, section = 0, ret;
 519
 520         if (!mtd || !to)
 521                 return -EINVAL;
 522
 523         memset(to, 0, sizeof(*to));
 524
 525         to->eccbytes = 0;
 526         for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
 527                 u32 eccpos;
 528
 529                 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 530                 if (ret < 0) {
 531                         if (ret != -ERANGE)
 532                                 return ret;
 533
 534                         break;
 535                 }
 536
 537                 if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
 538                         return -EINVAL;
 539
 540                 eccpos = oobregion.offset;
 541                 for (; eccpos < oobregion.offset + oobregion.length; i++) {
 542                         to->eccpos[i] = eccpos++;
 543                         to->eccbytes++;
 544                 }
 545         }
 546
 547         for (i = 0; i < 8; i++) {
 548                 ret = mtd_ooblayout_free(mtd, i, &oobregion);
 549                 if (ret < 0) {
 550                         if (ret != -ERANGE)
 551                                 return ret;
 552
 553                         break;
 554                 }
 555
 556                 to->oobfree[i][0] = oobregion.offset;
 557                 to->oobfree[i][1] = oobregion.length;
 558         }
 559
 560         to->useecc = MTD_NANDECC_AUTOPLACE;
 561
 562         return 0;
 563 }
 564
 565 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 566                                struct blkpg_ioctl_arg *arg)
 567 {
 568         struct blkpg_partition p;
 569
 570         if (!capable(CAP_SYS_ADMIN))
 571                 return -EPERM;
 572
 573         if (copy_from_user(&p, arg->data, sizeof(p)))
 574                 return -EFAULT;
 575
 576         switch (arg->op) {
 577         case BLKPG_ADD_PARTITION:
 578
 579                 /* Only master mtd device must be used to add partitions */
 580                 if (mtd_is_partition(mtd))
 581                         return -EINVAL;
 582
 583                 /* Sanitize user input */
 584                 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 585
 586                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 587
 588         case BLKPG_DEL_PARTITION:
 589
 590                 if (p.pno < 0)
 591                         return -EINVAL;
 592
 593                 return mtd_del_partition(mtd, p.pno);
 594
 595         default:
 596                 return -EINVAL;
 597         }
 598 }
 599
 600 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 601                 struct mtd_write_req __user *argp)
 602 {
 603         struct mtd_write_req req;
 604         struct mtd_oob_ops ops;
 605         const void __user *usr_data, *usr_oob;
 606         int ret;
 607
 608         if (copy_from_user(&req, argp, sizeof(req)))
 609                 return -EFAULT;
 610
 611         usr_data = (const void __user *)(uintptr_t)req.usr_data;
 612         usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 613
 614         if (!mtd->_write_oob)
 615                 return -EOPNOTSUPP;
 616
 617         ops.mode = req.mode;
 618         ops.len = (size_t)req.len;
 619         ops.ooblen = (size_t)req.ooblen;
 620         ops.ooboffs = 0;
 621
 622         if (usr_data) {
 623                 ops.datbuf = memdup_user(usr_data, ops.len);
 624                 if (IS_ERR(ops.datbuf))
 625                         return PTR_ERR(ops.datbuf);
 626         } else {
 627                 ops.datbuf = NULL;
 628         }
 629
 630         if (usr_oob) {
 631                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 632                 if (IS_ERR(ops.oobbuf)) {
 633                         kfree(ops.datbuf);
 634                         return PTR_ERR(ops.oobbuf);
 635                 }
 636         } else {
 637                 ops.oobbuf = NULL;
 638         }
 639
 640         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 641
 642         kfree(ops.datbuf);
 643         kfree(ops.oobbuf);
 644
 645         return ret;
 646 }
 647
 648 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 649 {
 650         struct mtd_file_info *mfi = file->private_data;
 651         struct mtd_info *mtd = mfi->mtd;
 652         void __user *argp = (void __user *)arg;
 653         int ret = 0;
 654         struct mtd_info_user info;
 655
 656         pr_debug("MTD_ioctl\n");
 657
 658         switch (cmd) {
 659         case MEMGETREGIONCOUNT:
 660                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 661                         return -EFAULT;
 662                 break;
 663
 664         case MEMGETREGIONINFO:
 665         {
 666                 uint32_t ur_idx;
 667                 struct mtd_erase_region_info *kr;
 668                 struct region_info_user __user *ur = argp;
 669
 670                 if (get_user(ur_idx, &(ur->regionindex)))
 671                         return -EFAULT;
 672
 673                 if (ur_idx >= mtd->numeraseregions)
 674                         return -EINVAL;
 675
 676                 kr = &(mtd->eraseregions[ur_idx]);
 677
 678                 if (put_user(kr->offset, &(ur->offset))
 679                     || put_user(kr->erasesize, &(ur->erasesize))
 680                     || put_user(kr->numblocks, &(ur->numblocks)))
 681                         return -EFAULT;
 682
 683                 break;
 684         }
 685
 686         case MEMGETINFO:
 687                 memset(&info, 0, sizeof(info));
 688                 info.type       = mtd->type;
 689                 info.flags      = mtd->flags;
 690                 info.size       = mtd->size;
 691                 info.erasesize  = mtd->erasesize;
 692                 info.writesize  = mtd->writesize;
 693                 info.oobsize    = mtd->oobsize;
 694                 /* The below field is obsolete */
 695                 info.padding    = 0;
 696                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 697                         return -EFAULT;
 698                 break;
 699
 700         case MEMERASE:
 701         case MEMERASE64:
 702         {
 703                 struct erase_info *erase;
 704
 705                 if(!(file->f_mode & FMODE_WRITE))
 706                         return -EPERM;
 707
 708                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 709                 if (!erase)
 710                         ret = -ENOMEM;
 711                 else {
 712                         wait_queue_head_t waitq;
 713                         DECLARE_WAITQUEUE(wait, current);
 714
 715                         init_waitqueue_head(&waitq);
 716
 717                         if (cmd == MEMERASE64) {
 718                                 struct erase_info_user64 einfo64;
 719
 720                                 if (copy_from_user(&einfo64, argp,
 721                                             sizeof(struct erase_info_user64))) {
 722                                         kfree(erase);
 723                                         return -EFAULT;
 724                                 }
 725                                 erase->addr = einfo64.start;
 726                                 erase->len = einfo64.length;
 727                         } else {
 728                                 struct erase_info_user einfo32;
 729
 730                                 if (copy_from_user(&einfo32, argp,
 731                                             sizeof(struct erase_info_user))) {
 732                                         kfree(erase);
 733                                         return -EFAULT;
 734                                 }
 735                                 erase->addr = einfo32.start;
 736                                 erase->len = einfo32.length;
 737                         }
 738                         erase->mtd = mtd;
 739                         erase->callback = mtdchar_erase_callback;
 740                         erase->priv = (unsigned long)&waitq;
 741
 742                         /*
 743                           FIXME: Allow INTERRUPTIBLE. Which means
 744                           not having the wait_queue head on the stack.
 745
 746                           If the wq_head is on the stack, and we
 747                           leave because we got interrupted, then the
 748                           wq_head is no longer there when the
 749                           callback routine tries to wake us up.
 750                         */
 751                         ret = mtd_erase(mtd, erase);
 752                         if (!ret) {
 753                                 set_current_state(TASK_UNINTERRUPTIBLE);
 754                                 add_wait_queue(&waitq, &wait);
 755                                 if (erase->state != MTD_ERASE_DONE &&
 756                                     erase->state != MTD_ERASE_FAILED)
 757                                         schedule();
 758                                 remove_wait_queue(&waitq, &wait);
 759                                 set_current_state(TASK_RUNNING);
 760
 761                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 762                         }
 763                         kfree(erase);
 764                 }
 765                 break;
 766         }
 767
 768         case MEMWRITEOOB:
 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->length */
 774                 if (copy_from_user(&buf, argp, sizeof(buf)))
 775                         ret = -EFAULT;
 776                 else
 777                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 778                                 buf.ptr, &buf_user->length);
 779                 break;
 780         }
 781
 782         case MEMREADOOB:
 783         {
 784                 struct mtd_oob_buf buf;
 785                 struct mtd_oob_buf __user *buf_user = argp;
 786
 787                 /* NOTE: writes return length to buf_user->start */
 788                 if (copy_from_user(&buf, argp, sizeof(buf)))
 789                         ret = -EFAULT;
 790                 else
 791                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 792                                 buf.ptr, &buf_user->start);
 793                 break;
 794         }
 795
 796         case MEMWRITEOOB64:
 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_writeoob(file, mtd, buf.start, buf.length,
 805                                 (void __user *)(uintptr_t)buf.usr_ptr,
 806                                 &buf_user->length);
 807                 break;
 808         }
 809
 810         case MEMREADOOB64:
 811         {
 812                 struct mtd_oob_buf64 buf;
 813                 struct mtd_oob_buf64 __user *buf_user = argp;
 814
 815                 if (copy_from_user(&buf, argp, sizeof(buf)))
 816                         ret = -EFAULT;
 817                 else
 818                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 819                                 (void __user *)(uintptr_t)buf.usr_ptr,
 820                                 &buf_user->length);
 821                 break;
 822         }
 823
 824         case MEMWRITE:
 825         {
 826                 ret = mtdchar_write_ioctl(mtd,
 827                       (struct mtd_write_req __user *)arg);
 828                 break;
 829         }
 830
 831         case MEMLOCK:
 832         {
 833                 struct erase_info_user einfo;
 834
 835                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 836                         return -EFAULT;
 837
 838                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 839                 break;
 840         }
 841
 842         case MEMUNLOCK:
 843         {
 844                 struct erase_info_user einfo;
 845
 846                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 847                         return -EFAULT;
 848
 849                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 850                 break;
 851         }
 852
 853         case MEMISLOCKED:
 854         {
 855                 struct erase_info_user einfo;
 856
 857                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 858                         return -EFAULT;
 859
 860                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 861                 break;
 862         }
 863
 864         /* Legacy interface */
 865         case MEMGETOOBSEL:
 866         {
 867                 struct nand_oobinfo oi;
 868
 869                 if (!mtd->ooblayout)
 870                         return -EOPNOTSUPP;
 871
 872                 ret = get_oobinfo(mtd, &oi);
 873                 if (ret)
 874                         return ret;
 875
 876                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 877                         return -EFAULT;
 878                 break;
 879         }
 880
 881         case MEMGETBADBLOCK:
 882         {
 883                 loff_t offs;
 884
 885                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 886                         return -EFAULT;
 887                 return mtd_block_isbad(mtd, offs);
 888                 break;
 889         }
 890
 891         case MEMSETBADBLOCK:
 892         {
 893                 loff_t offs;
 894
 895                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 896                         return -EFAULT;
 897                 return mtd_block_markbad(mtd, offs);
 898                 break;
 899         }
 900
 901         case OTPSELECT:
 902         {
 903                 int mode;
 904                 if (copy_from_user(&mode, argp, sizeof(int)))
 905                         return -EFAULT;
 906
 907                 mfi->mode = MTD_FILE_MODE_NORMAL;
 908
 909                 ret = otp_select_filemode(mfi, mode);
 910
 911                 file->f_pos = 0;
 912                 break;
 913         }
 914
 915         case OTPGETREGIONCOUNT:
 916         case OTPGETREGIONINFO:
 917         {
 918                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 919                 size_t retlen;
 920                 if (!buf)
 921                         return -ENOMEM;
 922                 switch (mfi->mode) {
 923                 case MTD_FILE_MODE_OTP_FACTORY:
 924                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 925                         break;
 926                 case MTD_FILE_MODE_OTP_USER:
 927                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 928                         break;
 929                 default:
 930                         ret = -EINVAL;
 931                         break;
 932                 }
 933                 if (!ret) {
 934                         if (cmd == OTPGETREGIONCOUNT) {
 935                                 int nbr = retlen / sizeof(struct otp_info);
 936                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 937                         } else
 938                                 ret = copy_to_user(argp, buf, retlen);
 939                         if (ret)
 940                                 ret = -EFAULT;
 941                 }
 942                 kfree(buf);
 943                 break;
 944         }
 945
 946         case OTPLOCK:
 947         {
 948                 struct otp_info oinfo;
 949
 950                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 951                         return -EINVAL;
 952                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 953                         return -EFAULT;
 954                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 955                 break;
 956         }
 957
 958         /* This ioctl is being deprecated - it truncates the ECC layout */
 959         case ECCGETLAYOUT:
 960         {
 961                 struct nand_ecclayout_user *usrlay;
 962
 963                 if (!mtd->ooblayout)
 964                         return -EOPNOTSUPP;
 965
 966                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 967                 if (!usrlay)
 968                         return -ENOMEM;
 969
 970                 shrink_ecclayout(mtd, usrlay);
 971
 972                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 973                         ret = -EFAULT;
 974                 kfree(usrlay);
 975                 break;
 976         }
 977
 978         case ECCGETSTATS:
 979         {
 980                 if (copy_to_user(argp, &mtd->ecc_stats,
 981                                  sizeof(struct mtd_ecc_stats)))
 982                         return -EFAULT;
 983                 break;
 984         }
 985
 986         case MTDFILEMODE:
 987         {
 988                 mfi->mode = 0;
 989
 990                 switch(arg) {
 991                 case MTD_FILE_MODE_OTP_FACTORY:
 992                 case MTD_FILE_MODE_OTP_USER:
 993                         ret = otp_select_filemode(mfi, arg);
 994                         break;
 995
 996                 case MTD_FILE_MODE_RAW:
 997                         if (!mtd_has_oob(mtd))
 998                                 return -EOPNOTSUPP;
 999                         mfi->mode = arg;
1000
1001                 case MTD_FILE_MODE_NORMAL:
1002                         break;
1003                 default:
1004                         ret = -EINVAL;
1005                 }
1006                 file->f_pos = 0;
1007                 break;
1008         }
1009
1010         case BLKPG:
1011         {
1012                 struct blkpg_ioctl_arg __user *blk_arg = argp;
1013                 struct blkpg_ioctl_arg a;
1014
1015                 if (copy_from_user(&a, blk_arg, sizeof(a)))
1016                         ret = -EFAULT;
1017                 else
1018                         ret = mtdchar_blkpg_ioctl(mtd, &a);
1019                 break;
1020         }
1021
1022         case BLKRRPART:
1023         {
1024                 /* No reread partition feature. Just return ok */
1025                 ret = 0;
1026                 break;
1027         }
1028
1029         default:
1030                 ret = -ENOTTY;
1031         }
1032
1033         return ret;
1034 } /* memory_ioctl */
1035
1036 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1037 {
1038         int ret;
1039
1040         mutex_lock(&mtd_mutex);
1041         ret = mtdchar_ioctl(file, cmd, arg);
1042         mutex_unlock(&mtd_mutex);
1043
1044         return ret;
1045 }
1046
1047 #ifdef CONFIG_COMPAT
1048
1049 struct mtd_oob_buf32 {
1050         u_int32_t start;
1051         u_int32_t length;
1052         compat_caddr_t ptr;     /* unsigned char* */
1053 };
1054
1055 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1056 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1057
1058 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1059         unsigned long arg)
1060 {
1061         struct mtd_file_info *mfi = file->private_data;
1062         struct mtd_info *mtd = mfi->mtd;
1063         void __user *argp = compat_ptr(arg);
1064         int ret = 0;
1065
1066         mutex_lock(&mtd_mutex);
1067
1068         switch (cmd) {
1069         case MEMWRITEOOB32:
1070         {
1071                 struct mtd_oob_buf32 buf;
1072                 struct mtd_oob_buf32 __user *buf_user = argp;
1073
1074                 if (copy_from_user(&buf, argp, sizeof(buf)))
1075                         ret = -EFAULT;
1076                 else
1077                         ret = mtdchar_writeoob(file, mtd, buf.start,
1078                                 buf.length, compat_ptr(buf.ptr),
1079                                 &buf_user->length);
1080                 break;
1081         }
1082
1083         case MEMREADOOB32:
1084         {
1085                 struct mtd_oob_buf32 buf;
1086                 struct mtd_oob_buf32 __user *buf_user = argp;
1087
1088                 /* NOTE: writes return length to buf->start */
1089                 if (copy_from_user(&buf, argp, sizeof(buf)))
1090                         ret = -EFAULT;
1091                 else
1092                         ret = mtdchar_readoob(file, mtd, buf.start,
1093                                 buf.length, compat_ptr(buf.ptr),
1094                                 &buf_user->start);
1095                 break;
1096         }
1097
1098         case BLKPG:
1099         {
1100                 /* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1101                 struct blkpg_compat_ioctl_arg __user *uarg = argp;
1102                 struct blkpg_compat_ioctl_arg compat_arg;
1103                 struct blkpg_ioctl_arg a;
1104
1105                 if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1106                         ret = -EFAULT;
1107                         break;
1108                 }
1109
1110                 memset(&a, 0, sizeof(a));
1111                 a.op = compat_arg.op;
1112                 a.flags = compat_arg.flags;
1113                 a.datalen = compat_arg.datalen;
1114                 a.data = compat_ptr(compat_arg.data);
1115
1116                 ret = mtdchar_blkpg_ioctl(mtd, &a);
1117                 break;
1118         }
1119
1120         default:
1121                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1122         }
1123
1124         mutex_unlock(&mtd_mutex);
1125
1126         return ret;
1127 }
1128
1129 #endif /* CONFIG_COMPAT */
1130
1131 /*
1132  * try to determine where a shared mapping can be made
1133  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1134  *   mappings)
1135  */
1136 #ifndef CONFIG_MMU
1137 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1138                                            unsigned long addr,
1139                                            unsigned long len,
1140                                            unsigned long pgoff,
1141                                            unsigned long flags)
1142 {
1143         struct mtd_file_info *mfi = file->private_data;
1144         struct mtd_info *mtd = mfi->mtd;
1145         unsigned long offset;
1146         int ret;
1147
1148         if (addr != 0)
1149                 return (unsigned long) -EINVAL;
1150
1151         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1152                 return (unsigned long) -EINVAL;
1153
1154         offset = pgoff << PAGE_SHIFT;
1155         if (offset > mtd->size - len)
1156                 return (unsigned long) -EINVAL;
1157
1158         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1159         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1160 }
1161
1162 static unsigned mtdchar_mmap_capabilities(struct file *file)
1163 {
1164         struct mtd_file_info *mfi = file->private_data;
1165
1166         return mtd_mmap_capabilities(mfi->mtd);
1167 }
1168 #endif
1169
1170 /*
1171  * set up a mapping for shared memory segments
1172  */
1173 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1174 {
1175 #ifdef CONFIG_MMU
1176         struct mtd_file_info *mfi = file->private_data;
1177         struct mtd_info *mtd = mfi->mtd;
1178         struct map_info *map = mtd->priv;
1179
1180         /* This is broken because it assumes the MTD device is map-based
1181            and that mtd->priv is a valid struct map_info.  It should be
1182            replaced with something that uses the mtd_get_unmapped_area()
1183            operation properly. */
1184         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1185 #ifdef pgprot_noncached
1186                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1187                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1188 #endif
1189                 return vm_iomap_memory(vma, map->phys, map->size);
1190         }
1191         return -ENODEV;
1192 #else
1193         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1194 #endif
1195 }
1196
1197 static const struct file_operations mtd_fops = {
1198         .owner          = THIS_MODULE,
1199         .llseek         = mtdchar_lseek,
1200         .read           = mtdchar_read,
1201         .write          = mtdchar_write,
1202         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1203 #ifdef CONFIG_COMPAT
1204         .compat_ioctl   = mtdchar_compat_ioctl,
1205 #endif
1206         .open           = mtdchar_open,
1207         .release        = mtdchar_close,
1208         .mmap           = mtdchar_mmap,
1209 #ifndef CONFIG_MMU
1210         .get_unmapped_area = mtdchar_get_unmapped_area,
1211         .mmap_capabilities = mtdchar_mmap_capabilities,
1212 #endif
1213 };
1214
1215 int __init init_mtdchar(void)
1216 {
1217         int ret;
1218
1219         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1220                                    "mtd", &mtd_fops);
1221         if (ret < 0) {
1222                 pr_err("Can't allocate major number %d for MTD\n",
1223                        MTD_CHAR_MAJOR);
1224                 return ret;
1225         }
1226
1227         return ret;
1228 }
1229
1230 void __exit cleanup_mtdchar(void)
1231 {
1232         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1233 }
1234
1235 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);