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 #include "mtdcore.h"
  42
  43 static DEFINE_MUTEX(mtd_mutex);
  44
  45 /*
  46  * Data structure to hold the pointer to the mtd device as well
  47  * as mode information of various use cases.
  48  */
  49 struct mtd_file_info {
  50         struct mtd_info *mtd;
  51         struct inode *ino;
  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 count;
  62 static struct vfsmount *mnt;
  63 static struct file_system_type mtd_inodefs_type;
  64
  65 static int mtdchar_open(struct inode *inode, struct file *file)
  66 {
  67         int minor = iminor(inode);
  68         int devnum = minor >> 1;
  69         int ret = 0;
  70         struct mtd_info *mtd;
  71         struct mtd_file_info *mfi;
  72         struct inode *mtd_ino;
  73
  74         pr_debug("MTD_open\n");
  75
  76         /* You can't open the RO devices RW */
  77         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  78                 return -EACCES;
  79
  80         ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
  81         if (ret)
  82                 return ret;
  83
  84         mutex_lock(&mtd_mutex);
  85         mtd = get_mtd_device(NULL, devnum);
  86
  87         if (IS_ERR(mtd)) {
  88                 ret = PTR_ERR(mtd);
  89                 goto out;
  90         }
  91
  92         if (mtd->type == MTD_ABSENT) {
  93                 ret = -ENODEV;
  94                 goto out1;
  95         }
  96
  97         mtd_ino = iget_locked(mnt->mnt_sb, devnum);
  98         if (!mtd_ino) {
  99                 ret = -ENOMEM;
 100                 goto out1;
 101         }
 102         if (mtd_ino->i_state & I_NEW) {
 103                 mtd_ino->i_private = mtd;
 104                 mtd_ino->i_mode = S_IFCHR;
 105                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 106                 unlock_new_inode(mtd_ino);
 107         }
 108         file->f_mapping = mtd_ino->i_mapping;
 109
 110         /* You can't open it RW if it's not a writeable device */
 111         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 112                 ret = -EACCES;
 113                 goto out2;
 114         }
 115
 116         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 117         if (!mfi) {
 118                 ret = -ENOMEM;
 119                 goto out2;
 120         }
 121         mfi->ino = mtd_ino;
 122         mfi->mtd = mtd;
 123         file->private_data = mfi;
 124         mutex_unlock(&mtd_mutex);
 125         return 0;
 126
 127 out2:
 128         iput(mtd_ino);
 129 out1:
 130         put_mtd_device(mtd);
 131 out:
 132         mutex_unlock(&mtd_mutex);
 133         simple_release_fs(&mnt, &count);
 134         return ret;
 135 } /* mtdchar_open */
 136
 137 /*====================================================================*/
 138
 139 static int mtdchar_close(struct inode *inode, struct file *file)
 140 {
 141         struct mtd_file_info *mfi = file->private_data;
 142         struct mtd_info *mtd = mfi->mtd;
 143
 144         pr_debug("MTD_close\n");
 145
 146         /* Only sync if opened RW */
 147         if ((file->f_mode & FMODE_WRITE))
 148                 mtd_sync(mtd);
 149
 150         iput(mfi->ino);
 151
 152         put_mtd_device(mtd);
 153         file->private_data = NULL;
 154         kfree(mfi);
 155         simple_release_fs(&mnt, &count);
 156
 157         return 0;
 158 } /* mtdchar_close */
 159
 160 /* Back in June 2001, dwmw2 wrote:
 161  *
 162  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 163  *   userspace buffer down and use it directly with readv/writev.
 164  *
 165  * The implementation below, using mtd_kmalloc_up_to, mitigates
 166  * allocation failures when the system is under low-memory situations
 167  * or if memory is highly fragmented at the cost of reducing the
 168  * performance of the requested transfer due to a smaller buffer size.
 169  *
 170  * A more complex but more memory-efficient implementation based on
 171  * get_user_pages and iovecs to cover extents of those pages is a
 172  * longer-term goal, as intimated by dwmw2 above. However, for the
 173  * write case, this requires yet more complex head and tail transfer
 174  * handling when those head and tail offsets and sizes are such that
 175  * alignment requirements are not met in the NAND subdriver.
 176  */
 177
 178 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 179                         loff_t *ppos)
 180 {
 181         struct mtd_file_info *mfi = file->private_data;
 182         struct mtd_info *mtd = mfi->mtd;
 183         size_t retlen;
 184         size_t total_retlen=0;
 185         int ret=0;
 186         int len;
 187         size_t size = count;
 188         char *kbuf;
 189
 190         pr_debug("MTD_read\n");
 191
 192         if (*ppos + count > mtd->size)
 193                 count = mtd->size - *ppos;
 194
 195         if (!count)
 196                 return 0;
 197
 198         kbuf = mtd_kmalloc_up_to(mtd, &size);
 199         if (!kbuf)
 200                 return -ENOMEM;
 201
 202         while (count) {
 203                 len = min_t(size_t, count, size);
 204
 205                 switch (mfi->mode) {
 206                 case MTD_FILE_MODE_OTP_FACTORY:
 207                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 208                                                      &retlen, kbuf);
 209                         break;
 210                 case MTD_FILE_MODE_OTP_USER:
 211                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 212                                                      &retlen, kbuf);
 213                         break;
 214                 case MTD_FILE_MODE_RAW:
 215                 {
 216                         struct mtd_oob_ops ops;
 217
 218                         ops.mode = MTD_OPS_RAW;
 219                         ops.datbuf = kbuf;
 220                         ops.oobbuf = NULL;
 221                         ops.len = len;
 222
 223                         ret = mtd_read_oob(mtd, *ppos, &ops);
 224                         retlen = ops.retlen;
 225                         break;
 226                 }
 227                 default:
 228                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 229                 }
 230                 /* Nand returns -EBADMSG on ECC errors, but it returns
 231                  * the data. For our userspace tools it is important
 232                  * to dump areas with ECC errors!
 233                  * For kernel internal usage it also might return -EUCLEAN
 234                  * to signal the caller that a bitflip has occurred and has
 235                  * been corrected by the ECC algorithm.
 236                  * Userspace software which accesses NAND this way
 237                  * must be aware of the fact that it deals with NAND
 238                  */
 239                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 240                         *ppos += retlen;
 241                         if (copy_to_user(buf, kbuf, retlen)) {
 242                                 kfree(kbuf);
 243                                 return -EFAULT;
 244                         }
 245                         else
 246                                 total_retlen += retlen;
 247
 248                         count -= retlen;
 249                         buf += retlen;
 250                         if (retlen == 0)
 251                                 count = 0;
 252                 }
 253                 else {
 254                         kfree(kbuf);
 255                         return ret;
 256                 }
 257
 258         }
 259
 260         kfree(kbuf);
 261         return total_retlen;
 262 } /* mtdchar_read */
 263
 264 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 265                         loff_t *ppos)
 266 {
 267         struct mtd_file_info *mfi = file->private_data;
 268         struct mtd_info *mtd = mfi->mtd;
 269         size_t size = count;
 270         char *kbuf;
 271         size_t retlen;
 272         size_t total_retlen=0;
 273         int ret=0;
 274         int len;
 275
 276         pr_debug("MTD_write\n");
 277
 278         if (*ppos == mtd->size)
 279                 return -ENOSPC;
 280
 281         if (*ppos + count > mtd->size)
 282                 count = mtd->size - *ppos;
 283
 284         if (!count)
 285                 return 0;
 286
 287         kbuf = mtd_kmalloc_up_to(mtd, &size);
 288         if (!kbuf)
 289                 return -ENOMEM;
 290
 291         while (count) {
 292                 len = min_t(size_t, count, size);
 293
 294                 if (copy_from_user(kbuf, buf, len)) {
 295                         kfree(kbuf);
 296                         return -EFAULT;
 297                 }
 298
 299                 switch (mfi->mode) {
 300                 case MTD_FILE_MODE_OTP_FACTORY:
 301                         ret = -EROFS;
 302                         break;
 303                 case MTD_FILE_MODE_OTP_USER:
 304                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 305                                                       &retlen, kbuf);
 306                         break;
 307
 308                 case MTD_FILE_MODE_RAW:
 309                 {
 310                         struct mtd_oob_ops ops;
 311
 312                         ops.mode = MTD_OPS_RAW;
 313                         ops.datbuf = kbuf;
 314                         ops.oobbuf = NULL;
 315                         ops.ooboffs = 0;
 316                         ops.len = len;
 317
 318                         ret = mtd_write_oob(mtd, *ppos, &ops);
 319                         retlen = ops.retlen;
 320                         break;
 321                 }
 322
 323                 default:
 324                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 325                 }
 326                 if (!ret) {
 327                         *ppos += retlen;
 328                         total_retlen += retlen;
 329                         count -= retlen;
 330                         buf += retlen;
 331                 }
 332                 else {
 333                         kfree(kbuf);
 334                         return ret;
 335                 }
 336         }
 337
 338         kfree(kbuf);
 339         return total_retlen;
 340 } /* mtdchar_write */
 341
 342 /*======================================================================
 343
 344     IOCTL calls for getting device parameters.
 345
 346 ======================================================================*/
 347 static void mtdchar_erase_callback (struct erase_info *instr)
 348 {
 349         wake_up((wait_queue_head_t *)instr->priv);
 350 }
 351
 352 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 353 {
 354         struct mtd_info *mtd = mfi->mtd;
 355         size_t retlen;
 356
 357         switch (mode) {
 358         case MTD_OTP_FACTORY:
 359                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 360                                 -EOPNOTSUPP)
 361                         return -EOPNOTSUPP;
 362
 363                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 364                 break;
 365         case MTD_OTP_USER:
 366                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 367                                 -EOPNOTSUPP)
 368                         return -EOPNOTSUPP;
 369
 370                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 371                 break;
 372         case MTD_OTP_OFF:
 373                 mfi->mode = MTD_FILE_MODE_NORMAL;
 374                 break;
 375         default:
 376                 return -EINVAL;
 377         }
 378
 379         return 0;
 380 }
 381
 382 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 383         uint64_t start, uint32_t length, void __user *ptr,
 384         uint32_t __user *retp)
 385 {
 386         struct mtd_file_info *mfi = file->private_data;
 387         struct mtd_oob_ops ops;
 388         uint32_t retlen;
 389         int ret = 0;
 390
 391         if (!(file->f_mode & FMODE_WRITE))
 392                 return -EPERM;
 393
 394         if (length > 4096)
 395                 return -EINVAL;
 396
 397         if (!mtd->_write_oob)
 398                 ret = -EOPNOTSUPP;
 399         else
 400                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 401
 402         if (ret)
 403                 return ret;
 404
 405         ops.ooblen = length;
 406         ops.ooboffs = start & (mtd->writesize - 1);
 407         ops.datbuf = NULL;
 408         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 409                 MTD_OPS_PLACE_OOB;
 410
 411         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 412                 return -EINVAL;
 413
 414         ops.oobbuf = memdup_user(ptr, length);
 415         if (IS_ERR(ops.oobbuf))
 416                 return PTR_ERR(ops.oobbuf);
 417
 418         start &= ~((uint64_t)mtd->writesize - 1);
 419         ret = mtd_write_oob(mtd, start, &ops);
 420
 421         if (ops.oobretlen > 0xFFFFFFFFU)
 422                 ret = -EOVERFLOW;
 423         retlen = ops.oobretlen;
 424         if (copy_to_user(retp, &retlen, sizeof(length)))
 425                 ret = -EFAULT;
 426
 427         kfree(ops.oobbuf);
 428         return ret;
 429 }
 430
 431 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 432         uint64_t start, uint32_t length, void __user *ptr,
 433         uint32_t __user *retp)
 434 {
 435         struct mtd_file_info *mfi = file->private_data;
 436         struct mtd_oob_ops ops;
 437         int ret = 0;
 438
 439         if (length > 4096)
 440                 return -EINVAL;
 441
 442         if (!access_ok(VERIFY_WRITE, ptr, length))
 443                 return -EFAULT;
 444
 445         ops.ooblen = length;
 446         ops.ooboffs = start & (mtd->writesize - 1);
 447         ops.datbuf = NULL;
 448         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 449                 MTD_OPS_PLACE_OOB;
 450
 451         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 452                 return -EINVAL;
 453
 454         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 455         if (!ops.oobbuf)
 456                 return -ENOMEM;
 457
 458         start &= ~((uint64_t)mtd->writesize - 1);
 459         ret = mtd_read_oob(mtd, start, &ops);
 460
 461         if (put_user(ops.oobretlen, retp))
 462                 ret = -EFAULT;
 463         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 464                                             ops.oobretlen))
 465                 ret = -EFAULT;
 466
 467         kfree(ops.oobbuf);
 468
 469         /*
 470          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 471          * data. For our userspace tools it is important to dump areas
 472          * with ECC errors!
 473          * For kernel internal usage it also might return -EUCLEAN
 474          * to signal the caller that a bitflip has occured and has
 475          * been corrected by the ECC algorithm.
 476          *
 477          * Note: currently the standard NAND function, nand_read_oob_std,
 478          * does not calculate ECC for the OOB area, so do not rely on
 479          * this behavior unless you have replaced it with your own.
 480          */
 481         if (mtd_is_bitflip_or_eccerr(ret))
 482                 return 0;
 483
 484         return ret;
 485 }
 486
 487 /*
 488  * Copies (and truncates, if necessary) data from the larger struct,
 489  * nand_ecclayout, to the smaller, deprecated layout struct,
 490  * nand_ecclayout_user. This is necessary only to support the deprecated
 491  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 492  * nand_ecclayout flexibly (i.e. the struct may change size in new
 493  * releases without requiring major rewrites).
 494  */
 495 static int shrink_ecclayout(const struct nand_ecclayout *from,
 496                 struct nand_ecclayout_user *to)
 497 {
 498         int i;
 499
 500         if (!from || !to)
 501                 return -EINVAL;
 502
 503         memset(to, 0, sizeof(*to));
 504
 505         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 506         for (i = 0; i < to->eccbytes; i++)
 507                 to->eccpos[i] = from->eccpos[i];
 508
 509         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 510                 if (from->oobfree[i].length == 0 &&
 511                                 from->oobfree[i].offset == 0)
 512                         break;
 513                 to->oobavail += from->oobfree[i].length;
 514                 to->oobfree[i] = from->oobfree[i];
 515         }
 516
 517         return 0;
 518 }
 519
 520 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 521                            struct blkpg_ioctl_arg __user *arg)
 522 {
 523         struct blkpg_ioctl_arg a;
 524         struct blkpg_partition p;
 525
 526         if (!capable(CAP_SYS_ADMIN))
 527                 return -EPERM;
 528
 529         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 530                 return -EFAULT;
 531
 532         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 533                 return -EFAULT;
 534
 535         switch (a.op) {
 536         case BLKPG_ADD_PARTITION:
 537
 538                 /* Only master mtd device must be used to add partitions */
 539                 if (mtd_is_partition(mtd))
 540                         return -EINVAL;
 541
 542                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 543
 544         case BLKPG_DEL_PARTITION:
 545
 546                 if (p.pno < 0)
 547                         return -EINVAL;
 548
 549                 return mtd_del_partition(mtd, p.pno);
 550
 551         default:
 552                 return -EINVAL;
 553         }
 554 }
 555
 556 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 557                 struct mtd_write_req __user *argp)
 558 {
 559         struct mtd_write_req req;
 560         struct mtd_oob_ops ops;
 561         void __user *usr_data, *usr_oob;
 562         int ret;
 563
 564         if (copy_from_user(&req, argp, sizeof(req)) ||
 565                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 566                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 567                 return -EFAULT;
 568         if (!mtd->_write_oob)
 569                 return -EOPNOTSUPP;
 570
 571         ops.mode = req.mode;
 572         ops.len = (size_t)req.len;
 573         ops.ooblen = (size_t)req.ooblen;
 574         ops.ooboffs = 0;
 575
 576         usr_data = (void __user *)(uintptr_t)req.usr_data;
 577         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 578
 579         if (req.usr_data) {
 580                 ops.datbuf = memdup_user(usr_data, ops.len);
 581                 if (IS_ERR(ops.datbuf))
 582                         return PTR_ERR(ops.datbuf);
 583         } else {
 584                 ops.datbuf = NULL;
 585         }
 586
 587         if (req.usr_oob) {
 588                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 589                 if (IS_ERR(ops.oobbuf)) {
 590                         kfree(ops.datbuf);
 591                         return PTR_ERR(ops.oobbuf);
 592                 }
 593         } else {
 594                 ops.oobbuf = NULL;
 595         }
 596
 597         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 598
 599         kfree(ops.datbuf);
 600         kfree(ops.oobbuf);
 601
 602         return ret;
 603 }
 604
 605 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 606 {
 607         struct mtd_file_info *mfi = file->private_data;
 608         struct mtd_info *mtd = mfi->mtd;
 609         void __user *argp = (void __user *)arg;
 610         int ret = 0;
 611         u_long size;
 612         struct mtd_info_user info;
 613
 614         pr_debug("MTD_ioctl\n");
 615
 616         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 617         if (cmd & IOC_IN) {
 618                 if (!access_ok(VERIFY_READ, argp, size))
 619                         return -EFAULT;
 620         }
 621         if (cmd & IOC_OUT) {
 622                 if (!access_ok(VERIFY_WRITE, argp, size))
 623                         return -EFAULT;
 624         }
 625
 626         switch (cmd) {
 627         case MEMGETREGIONCOUNT:
 628                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 629                         return -EFAULT;
 630                 break;
 631
 632         case MEMGETREGIONINFO:
 633         {
 634                 uint32_t ur_idx;
 635                 struct mtd_erase_region_info *kr;
 636                 struct region_info_user __user *ur = argp;
 637
 638                 if (get_user(ur_idx, &(ur->regionindex)))
 639                         return -EFAULT;
 640
 641                 if (ur_idx >= mtd->numeraseregions)
 642                         return -EINVAL;
 643
 644                 kr = &(mtd->eraseregions[ur_idx]);
 645
 646                 if (put_user(kr->offset, &(ur->offset))
 647                     || put_user(kr->erasesize, &(ur->erasesize))
 648                     || put_user(kr->numblocks, &(ur->numblocks)))
 649                         return -EFAULT;
 650
 651                 break;
 652         }
 653
 654         case MEMGETINFO:
 655                 memset(&info, 0, sizeof(info));
 656                 info.type       = mtd->type;
 657                 info.flags      = mtd->flags;
 658                 info.size       = mtd->size;
 659                 info.erasesize  = mtd->erasesize;
 660                 info.writesize  = mtd->writesize;
 661                 info.oobsize    = mtd->oobsize;
 662                 /* The below field is obsolete */
 663                 info.padding    = 0;
 664                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 665                         return -EFAULT;
 666                 break;
 667
 668         case MEMERASE:
 669         case MEMERASE64:
 670         {
 671                 struct erase_info *erase;
 672
 673                 if(!(file->f_mode & FMODE_WRITE))
 674                         return -EPERM;
 675
 676                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 677                 if (!erase)
 678                         ret = -ENOMEM;
 679                 else {
 680                         wait_queue_head_t waitq;
 681                         DECLARE_WAITQUEUE(wait, current);
 682
 683                         init_waitqueue_head(&waitq);
 684
 685                         if (cmd == MEMERASE64) {
 686                                 struct erase_info_user64 einfo64;
 687
 688                                 if (copy_from_user(&einfo64, argp,
 689                                             sizeof(struct erase_info_user64))) {
 690                                         kfree(erase);
 691                                         return -EFAULT;
 692                                 }
 693                                 erase->addr = einfo64.start;
 694                                 erase->len = einfo64.length;
 695                         } else {
 696                                 struct erase_info_user einfo32;
 697
 698                                 if (copy_from_user(&einfo32, argp,
 699                                             sizeof(struct erase_info_user))) {
 700                                         kfree(erase);
 701                                         return -EFAULT;
 702                                 }
 703                                 erase->addr = einfo32.start;
 704                                 erase->len = einfo32.length;
 705                         }
 706                         erase->mtd = mtd;
 707                         erase->callback = mtdchar_erase_callback;
 708                         erase->priv = (unsigned long)&waitq;
 709
 710                         /*
 711                           FIXME: Allow INTERRUPTIBLE. Which means
 712                           not having the wait_queue head on the stack.
 713
 714                           If the wq_head is on the stack, and we
 715                           leave because we got interrupted, then the
 716                           wq_head is no longer there when the
 717                           callback routine tries to wake us up.
 718                         */
 719                         ret = mtd_erase(mtd, erase);
 720                         if (!ret) {
 721                                 set_current_state(TASK_UNINTERRUPTIBLE);
 722                                 add_wait_queue(&waitq, &wait);
 723                                 if (erase->state != MTD_ERASE_DONE &&
 724                                     erase->state != MTD_ERASE_FAILED)
 725                                         schedule();
 726                                 remove_wait_queue(&waitq, &wait);
 727                                 set_current_state(TASK_RUNNING);
 728
 729                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 730                         }
 731                         kfree(erase);
 732                 }
 733                 break;
 734         }
 735
 736         case MEMWRITEOOB:
 737         {
 738                 struct mtd_oob_buf buf;
 739                 struct mtd_oob_buf __user *buf_user = argp;
 740
 741                 /* NOTE: writes return length to buf_user->length */
 742                 if (copy_from_user(&buf, argp, sizeof(buf)))
 743                         ret = -EFAULT;
 744                 else
 745                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 746                                 buf.ptr, &buf_user->length);
 747                 break;
 748         }
 749
 750         case MEMREADOOB:
 751         {
 752                 struct mtd_oob_buf buf;
 753                 struct mtd_oob_buf __user *buf_user = argp;
 754
 755                 /* NOTE: writes return length to buf_user->start */
 756                 if (copy_from_user(&buf, argp, sizeof(buf)))
 757                         ret = -EFAULT;
 758                 else
 759                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 760                                 buf.ptr, &buf_user->start);
 761                 break;
 762         }
 763
 764         case MEMWRITEOOB64:
 765         {
 766                 struct mtd_oob_buf64 buf;
 767                 struct mtd_oob_buf64 __user *buf_user = argp;
 768
 769                 if (copy_from_user(&buf, argp, sizeof(buf)))
 770                         ret = -EFAULT;
 771                 else
 772                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 773                                 (void __user *)(uintptr_t)buf.usr_ptr,
 774                                 &buf_user->length);
 775                 break;
 776         }
 777
 778         case MEMREADOOB64:
 779         {
 780                 struct mtd_oob_buf64 buf;
 781                 struct mtd_oob_buf64 __user *buf_user = argp;
 782
 783                 if (copy_from_user(&buf, argp, sizeof(buf)))
 784                         ret = -EFAULT;
 785                 else
 786                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 787                                 (void __user *)(uintptr_t)buf.usr_ptr,
 788                                 &buf_user->length);
 789                 break;
 790         }
 791
 792         case MEMWRITE:
 793         {
 794                 ret = mtdchar_write_ioctl(mtd,
 795                       (struct mtd_write_req __user *)arg);
 796                 break;
 797         }
 798
 799         case MEMLOCK:
 800         {
 801                 struct erase_info_user einfo;
 802
 803                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 804                         return -EFAULT;
 805
 806                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 807                 break;
 808         }
 809
 810         case MEMUNLOCK:
 811         {
 812                 struct erase_info_user einfo;
 813
 814                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 815                         return -EFAULT;
 816
 817                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 818                 break;
 819         }
 820
 821         case MEMISLOCKED:
 822         {
 823                 struct erase_info_user einfo;
 824
 825                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 826                         return -EFAULT;
 827
 828                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 829                 break;
 830         }
 831
 832         /* Legacy interface */
 833         case MEMGETOOBSEL:
 834         {
 835                 struct nand_oobinfo oi;
 836
 837                 if (!mtd->ecclayout)
 838                         return -EOPNOTSUPP;
 839                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 840                         return -EINVAL;
 841
 842                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 843                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 844                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 845                        sizeof(oi.oobfree));
 846                 oi.eccbytes = mtd->ecclayout->eccbytes;
 847
 848                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 849                         return -EFAULT;
 850                 break;
 851         }
 852
 853         case MEMGETBADBLOCK:
 854         {
 855                 loff_t offs;
 856
 857                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 858                         return -EFAULT;
 859                 return mtd_block_isbad(mtd, offs);
 860                 break;
 861         }
 862
 863         case MEMSETBADBLOCK:
 864         {
 865                 loff_t offs;
 866
 867                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 868                         return -EFAULT;
 869                 return mtd_block_markbad(mtd, offs);
 870                 break;
 871         }
 872
 873         case OTPSELECT:
 874         {
 875                 int mode;
 876                 if (copy_from_user(&mode, argp, sizeof(int)))
 877                         return -EFAULT;
 878
 879                 mfi->mode = MTD_FILE_MODE_NORMAL;
 880
 881                 ret = otp_select_filemode(mfi, mode);
 882
 883                 file->f_pos = 0;
 884                 break;
 885         }
 886
 887         case OTPGETREGIONCOUNT:
 888         case OTPGETREGIONINFO:
 889         {
 890                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 891                 if (!buf)
 892                         return -ENOMEM;
 893                 switch (mfi->mode) {
 894                 case MTD_FILE_MODE_OTP_FACTORY:
 895                         ret = mtd_get_fact_prot_info(mtd, buf, 4096);
 896                         break;
 897                 case MTD_FILE_MODE_OTP_USER:
 898                         ret = mtd_get_user_prot_info(mtd, buf, 4096);
 899                         break;
 900                 default:
 901                         ret = -EINVAL;
 902                         break;
 903                 }
 904                 if (ret >= 0) {
 905                         if (cmd == OTPGETREGIONCOUNT) {
 906                                 int nbr = ret / sizeof(struct otp_info);
 907                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 908                         } else
 909                                 ret = copy_to_user(argp, buf, ret);
 910                         if (ret)
 911                                 ret = -EFAULT;
 912                 }
 913                 kfree(buf);
 914                 break;
 915         }
 916
 917         case OTPLOCK:
 918         {
 919                 struct otp_info oinfo;
 920
 921                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 922                         return -EINVAL;
 923                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 924                         return -EFAULT;
 925                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 926                 break;
 927         }
 928
 929         /* This ioctl is being deprecated - it truncates the ECC layout */
 930         case ECCGETLAYOUT:
 931         {
 932                 struct nand_ecclayout_user *usrlay;
 933
 934                 if (!mtd->ecclayout)
 935                         return -EOPNOTSUPP;
 936
 937                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 938                 if (!usrlay)
 939                         return -ENOMEM;
 940
 941                 shrink_ecclayout(mtd->ecclayout, usrlay);
 942
 943                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 944                         ret = -EFAULT;
 945                 kfree(usrlay);
 946                 break;
 947         }
 948
 949         case ECCGETSTATS:
 950         {
 951                 if (copy_to_user(argp, &mtd->ecc_stats,
 952                                  sizeof(struct mtd_ecc_stats)))
 953                         return -EFAULT;
 954                 break;
 955         }
 956
 957         case MTDFILEMODE:
 958         {
 959                 mfi->mode = 0;
 960
 961                 switch(arg) {
 962                 case MTD_FILE_MODE_OTP_FACTORY:
 963                 case MTD_FILE_MODE_OTP_USER:
 964                         ret = otp_select_filemode(mfi, arg);
 965                         break;
 966
 967                 case MTD_FILE_MODE_RAW:
 968                         if (!mtd_has_oob(mtd))
 969                                 return -EOPNOTSUPP;
 970                         mfi->mode = arg;
 971
 972                 case MTD_FILE_MODE_NORMAL:
 973                         break;
 974                 default:
 975                         ret = -EINVAL;
 976                 }
 977                 file->f_pos = 0;
 978                 break;
 979         }
 980
 981         case BLKPG:
 982         {
 983                 ret = mtdchar_blkpg_ioctl(mtd,
 984                       (struct blkpg_ioctl_arg __user *)arg);
 985                 break;
 986         }
 987
 988         case BLKRRPART:
 989         {
 990                 /* No reread partition feature. Just return ok */
 991                 ret = 0;
 992                 break;
 993         }
 994
 995         default:
 996                 ret = -ENOTTY;
 997         }
 998
 999         return ret;
1000 } /* memory_ioctl */
1001
1002 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1003 {
1004         int ret;
1005
1006         mutex_lock(&mtd_mutex);
1007         ret = mtdchar_ioctl(file, cmd, arg);
1008         mutex_unlock(&mtd_mutex);
1009
1010         return ret;
1011 }
1012
1013 #ifdef CONFIG_COMPAT
1014
1015 struct mtd_oob_buf32 {
1016         u_int32_t start;
1017         u_int32_t length;
1018         compat_caddr_t ptr;     /* unsigned char* */
1019 };
1020
1021 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1022 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1023
1024 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1025         unsigned long arg)
1026 {
1027         struct mtd_file_info *mfi = file->private_data;
1028         struct mtd_info *mtd = mfi->mtd;
1029         void __user *argp = compat_ptr(arg);
1030         int ret = 0;
1031
1032         mutex_lock(&mtd_mutex);
1033
1034         switch (cmd) {
1035         case MEMWRITEOOB32:
1036         {
1037                 struct mtd_oob_buf32 buf;
1038                 struct mtd_oob_buf32 __user *buf_user = argp;
1039
1040                 if (copy_from_user(&buf, argp, sizeof(buf)))
1041                         ret = -EFAULT;
1042                 else
1043                         ret = mtdchar_writeoob(file, mtd, buf.start,
1044                                 buf.length, compat_ptr(buf.ptr),
1045                                 &buf_user->length);
1046                 break;
1047         }
1048
1049         case MEMREADOOB32:
1050         {
1051                 struct mtd_oob_buf32 buf;
1052                 struct mtd_oob_buf32 __user *buf_user = argp;
1053
1054                 /* NOTE: writes return length to buf->start */
1055                 if (copy_from_user(&buf, argp, sizeof(buf)))
1056                         ret = -EFAULT;
1057                 else
1058                         ret = mtdchar_readoob(file, mtd, buf.start,
1059                                 buf.length, compat_ptr(buf.ptr),
1060                                 &buf_user->start);
1061                 break;
1062         }
1063         default:
1064                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1065         }
1066
1067         mutex_unlock(&mtd_mutex);
1068
1069         return ret;
1070 }
1071
1072 #endif /* CONFIG_COMPAT */
1073
1074 /*
1075  * try to determine where a shared mapping can be made
1076  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1077  *   mappings)
1078  */
1079 #ifndef CONFIG_MMU
1080 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1081                                            unsigned long addr,
1082                                            unsigned long len,
1083                                            unsigned long pgoff,
1084                                            unsigned long flags)
1085 {
1086         struct mtd_file_info *mfi = file->private_data;
1087         struct mtd_info *mtd = mfi->mtd;
1088         unsigned long offset;
1089         int ret;
1090
1091         if (addr != 0)
1092                 return (unsigned long) -EINVAL;
1093
1094         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1095                 return (unsigned long) -EINVAL;
1096
1097         offset = pgoff << PAGE_SHIFT;
1098         if (offset > mtd->size - len)
1099                 return (unsigned long) -EINVAL;
1100
1101         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1102         return ret == -EOPNOTSUPP ? -ENOSYS : ret;
1103 }
1104 #endif
1105
1106 /*
1107  * set up a mapping for shared memory segments
1108  */
1109 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1110 {
1111 #ifdef CONFIG_MMU
1112         struct mtd_file_info *mfi = file->private_data;
1113         struct mtd_info *mtd = mfi->mtd;
1114         struct map_info *map = mtd->priv;
1115
1116         /* This is broken because it assumes the MTD device is map-based
1117            and that mtd->priv is a valid struct map_info.  It should be
1118            replaced with something that uses the mtd_get_unmapped_area()
1119            operation properly. */
1120         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1121 #ifdef pgprot_noncached
1122                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1123                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1124 #endif
1125                 return vm_iomap_memory(vma, map->phys, map->size);
1126         }
1127         return -ENOSYS;
1128 #else
1129         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1130 #endif
1131 }
1132
1133 static const struct file_operations mtd_fops = {
1134         .owner          = THIS_MODULE,
1135         .llseek         = mtdchar_lseek,
1136         .read           = mtdchar_read,
1137         .write          = mtdchar_write,
1138         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1139 #ifdef CONFIG_COMPAT
1140         .compat_ioctl   = mtdchar_compat_ioctl,
1141 #endif
1142         .open           = mtdchar_open,
1143         .release        = mtdchar_close,
1144         .mmap           = mtdchar_mmap,
1145 #ifndef CONFIG_MMU
1146         .get_unmapped_area = mtdchar_get_unmapped_area,
1147 #endif
1148 };
1149
1150 static const struct super_operations mtd_ops = {
1151         .drop_inode = generic_delete_inode,
1152         .statfs = simple_statfs,
1153 };
1154
1155 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1156                                 int flags, const char *dev_name, void *data)
1157 {
1158         return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1159 }
1160
1161 static struct file_system_type mtd_inodefs_type = {
1162        .name = "mtd_inodefs",
1163        .mount = mtd_inodefs_mount,
1164        .kill_sb = kill_anon_super,
1165 };
1166 MODULE_ALIAS_FS("mtd_inodefs");
1167
1168 int __init init_mtdchar(void)
1169 {
1170         int ret;
1171
1172         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1173                                    "mtd", &mtd_fops);
1174         if (ret < 0) {
1175                 pr_err("Can't allocate major number %d for MTD\n",
1176                        MTD_CHAR_MAJOR);
1177                 return ret;
1178         }
1179
1180         ret = register_filesystem(&mtd_inodefs_type);
1181         if (ret) {
1182                 pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1183                        ret);
1184                 goto err_unregister_chdev;
1185         }
1186
1187         return ret;
1188
1189 err_unregister_chdev:
1190         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1191         return ret;
1192 }
1193
1194 void __exit cleanup_mtdchar(void)
1195 {
1196         unregister_filesystem(&mtd_inodefs_type);
1197         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1198 }
1199
1200 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);