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         struct inode *ino;
  53         enum mtd_file_modes mode;
  54 };
  55
  56 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  57 {
  58         struct mtd_file_info *mfi = file->private_data;
  59         return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  60 }
  61
  62 static int count;
  63 static struct vfsmount *mnt;
  64 static struct file_system_type mtd_inodefs_type;
  65
  66 static int mtdchar_open(struct inode *inode, struct file *file)
  67 {
  68         int minor = iminor(inode);
  69         int devnum = minor >> 1;
  70         int ret = 0;
  71         struct mtd_info *mtd;
  72         struct mtd_file_info *mfi;
  73         struct inode *mtd_ino;
  74
  75         pr_debug("MTD_open\n");
  76
  77         /* You can't open the RO devices RW */
  78         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  79                 return -EACCES;
  80
  81         ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
  82         if (ret)
  83                 return ret;
  84
  85         mutex_lock(&mtd_mutex);
  86         mtd = get_mtd_device(NULL, devnum);
  87
  88         if (IS_ERR(mtd)) {
  89                 ret = PTR_ERR(mtd);
  90                 goto out;
  91         }
  92
  93         if (mtd->type == MTD_ABSENT) {
  94                 ret = -ENODEV;
  95                 goto out1;
  96         }
  97
  98         mtd_ino = iget_locked(mnt->mnt_sb, devnum);
  99         if (!mtd_ino) {
 100                 ret = -ENOMEM;
 101                 goto out1;
 102         }
 103         if (mtd_ino->i_state & I_NEW) {
 104                 mtd_ino->i_private = mtd;
 105                 mtd_ino->i_mode = S_IFCHR;
 106                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 107                 unlock_new_inode(mtd_ino);
 108         }
 109         file->f_mapping = mtd_ino->i_mapping;
 110
 111         /* You can't open it RW if it's not a writeable device */
 112         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 113                 ret = -EACCES;
 114                 goto out2;
 115         }
 116
 117         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 118         if (!mfi) {
 119                 ret = -ENOMEM;
 120                 goto out2;
 121         }
 122         mfi->ino = mtd_ino;
 123         mfi->mtd = mtd;
 124         file->private_data = mfi;
 125         mutex_unlock(&mtd_mutex);
 126         return 0;
 127
 128 out2:
 129         iput(mtd_ino);
 130 out1:
 131         put_mtd_device(mtd);
 132 out:
 133         mutex_unlock(&mtd_mutex);
 134         simple_release_fs(&mnt, &count);
 135         return ret;
 136 } /* mtdchar_open */
 137
 138 /*====================================================================*/
 139
 140 static int mtdchar_close(struct inode *inode, struct file *file)
 141 {
 142         struct mtd_file_info *mfi = file->private_data;
 143         struct mtd_info *mtd = mfi->mtd;
 144
 145         pr_debug("MTD_close\n");
 146
 147         /* Only sync if opened RW */
 148         if ((file->f_mode & FMODE_WRITE))
 149                 mtd_sync(mtd);
 150
 151         iput(mfi->ino);
 152
 153         put_mtd_device(mtd);
 154         file->private_data = NULL;
 155         kfree(mfi);
 156         simple_release_fs(&mnt, &count);
 157
 158         return 0;
 159 } /* mtdchar_close */
 160
 161 /* Back in June 2001, dwmw2 wrote:
 162  *
 163  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 164  *   userspace buffer down and use it directly with readv/writev.
 165  *
 166  * The implementation below, using mtd_kmalloc_up_to, mitigates
 167  * allocation failures when the system is under low-memory situations
 168  * or if memory is highly fragmented at the cost of reducing the
 169  * performance of the requested transfer due to a smaller buffer size.
 170  *
 171  * A more complex but more memory-efficient implementation based on
 172  * get_user_pages and iovecs to cover extents of those pages is a
 173  * longer-term goal, as intimated by dwmw2 above. However, for the
 174  * write case, this requires yet more complex head and tail transfer
 175  * handling when those head and tail offsets and sizes are such that
 176  * alignment requirements are not met in the NAND subdriver.
 177  */
 178
 179 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 180                         loff_t *ppos)
 181 {
 182         struct mtd_file_info *mfi = file->private_data;
 183         struct mtd_info *mtd = mfi->mtd;
 184         size_t retlen;
 185         size_t total_retlen=0;
 186         int ret=0;
 187         int len;
 188         size_t size = count;
 189         char *kbuf;
 190
 191         pr_debug("MTD_read\n");
 192
 193         if (*ppos + count > mtd->size)
 194                 count = mtd->size - *ppos;
 195
 196         if (!count)
 197                 return 0;
 198
 199         kbuf = mtd_kmalloc_up_to(mtd, &size);
 200         if (!kbuf)
 201                 return -ENOMEM;
 202
 203         while (count) {
 204                 len = min_t(size_t, count, size);
 205
 206                 switch (mfi->mode) {
 207                 case MTD_FILE_MODE_OTP_FACTORY:
 208                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 209                                                      &retlen, kbuf);
 210                         break;
 211                 case MTD_FILE_MODE_OTP_USER:
 212                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 213                                                      &retlen, kbuf);
 214                         break;
 215                 case MTD_FILE_MODE_RAW:
 216                 {
 217                         struct mtd_oob_ops ops;
 218
 219                         ops.mode = MTD_OPS_RAW;
 220                         ops.datbuf = kbuf;
 221                         ops.oobbuf = NULL;
 222                         ops.len = len;
 223
 224                         ret = mtd_read_oob(mtd, *ppos, &ops);
 225                         retlen = ops.retlen;
 226                         break;
 227                 }
 228                 default:
 229                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 230                 }
 231                 /* Nand returns -EBADMSG on ECC errors, but it returns
 232                  * the data. For our userspace tools it is important
 233                  * to dump areas with ECC errors!
 234                  * For kernel internal usage it also might return -EUCLEAN
 235                  * to signal the caller that a bitflip has occurred and has
 236                  * been corrected by the ECC algorithm.
 237                  * Userspace software which accesses NAND this way
 238                  * must be aware of the fact that it deals with NAND
 239                  */
 240                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 241                         *ppos += retlen;
 242                         if (copy_to_user(buf, kbuf, retlen)) {
 243                                 kfree(kbuf);
 244                                 return -EFAULT;
 245                         }
 246                         else
 247                                 total_retlen += retlen;
 248
 249                         count -= retlen;
 250                         buf += retlen;
 251                         if (retlen == 0)
 252                                 count = 0;
 253                 }
 254                 else {
 255                         kfree(kbuf);
 256                         return ret;
 257                 }
 258
 259         }
 260
 261         kfree(kbuf);
 262         return total_retlen;
 263 } /* mtdchar_read */
 264
 265 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 266                         loff_t *ppos)
 267 {
 268         struct mtd_file_info *mfi = file->private_data;
 269         struct mtd_info *mtd = mfi->mtd;
 270         size_t size = count;
 271         char *kbuf;
 272         size_t retlen;
 273         size_t total_retlen=0;
 274         int ret=0;
 275         int len;
 276
 277         pr_debug("MTD_write\n");
 278
 279         if (*ppos == mtd->size)
 280                 return -ENOSPC;
 281
 282         if (*ppos + count > mtd->size)
 283                 count = mtd->size - *ppos;
 284
 285         if (!count)
 286                 return 0;
 287
 288         kbuf = mtd_kmalloc_up_to(mtd, &size);
 289         if (!kbuf)
 290                 return -ENOMEM;
 291
 292         while (count) {
 293                 len = min_t(size_t, count, size);
 294
 295                 if (copy_from_user(kbuf, buf, len)) {
 296                         kfree(kbuf);
 297                         return -EFAULT;
 298                 }
 299
 300                 switch (mfi->mode) {
 301                 case MTD_FILE_MODE_OTP_FACTORY:
 302                         ret = -EROFS;
 303                         break;
 304                 case MTD_FILE_MODE_OTP_USER:
 305                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 306                                                       &retlen, kbuf);
 307                         break;
 308
 309                 case MTD_FILE_MODE_RAW:
 310                 {
 311                         struct mtd_oob_ops ops;
 312
 313                         ops.mode = MTD_OPS_RAW;
 314                         ops.datbuf = kbuf;
 315                         ops.oobbuf = NULL;
 316                         ops.ooboffs = 0;
 317                         ops.len = len;
 318
 319                         ret = mtd_write_oob(mtd, *ppos, &ops);
 320                         retlen = ops.retlen;
 321                         break;
 322                 }
 323
 324                 default:
 325                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 326                 }
 327
 328                 /*
 329                  * Return -ENOSPC only if no data could be written at all.
 330                  * Otherwise just return the number of bytes that actually
 331                  * have been written.
 332                  */
 333                 if ((ret == -ENOSPC) && (total_retlen))
 334                         break;
 335
 336                 if (!ret) {
 337                         *ppos += retlen;
 338                         total_retlen += retlen;
 339                         count -= retlen;
 340                         buf += retlen;
 341                 }
 342                 else {
 343                         kfree(kbuf);
 344                         return ret;
 345                 }
 346         }
 347
 348         kfree(kbuf);
 349         return total_retlen;
 350 } /* mtdchar_write */
 351
 352 /*======================================================================
 353
 354     IOCTL calls for getting device parameters.
 355
 356 ======================================================================*/
 357 static void mtdchar_erase_callback (struct erase_info *instr)
 358 {
 359         wake_up((wait_queue_head_t *)instr->priv);
 360 }
 361
 362 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 363 {
 364         struct mtd_info *mtd = mfi->mtd;
 365         size_t retlen;
 366
 367         switch (mode) {
 368         case MTD_OTP_FACTORY:
 369                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 370                                 -EOPNOTSUPP)
 371                         return -EOPNOTSUPP;
 372
 373                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 374                 break;
 375         case MTD_OTP_USER:
 376                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 377                                 -EOPNOTSUPP)
 378                         return -EOPNOTSUPP;
 379
 380                 mfi->mode = MTD_FILE_MODE_OTP_USER;
 381                 break;
 382         case MTD_OTP_OFF:
 383                 mfi->mode = MTD_FILE_MODE_NORMAL;
 384                 break;
 385         default:
 386                 return -EINVAL;
 387         }
 388
 389         return 0;
 390 }
 391
 392 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 393         uint64_t start, uint32_t length, void __user *ptr,
 394         uint32_t __user *retp)
 395 {
 396         struct mtd_file_info *mfi = file->private_data;
 397         struct mtd_oob_ops ops;
 398         uint32_t retlen;
 399         int ret = 0;
 400
 401         if (!(file->f_mode & FMODE_WRITE))
 402                 return -EPERM;
 403
 404         if (length > 4096)
 405                 return -EINVAL;
 406
 407         if (!mtd->_write_oob)
 408                 ret = -EOPNOTSUPP;
 409         else
 410                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 411
 412         if (ret)
 413                 return ret;
 414
 415         ops.ooblen = length;
 416         ops.ooboffs = start & (mtd->writesize - 1);
 417         ops.datbuf = NULL;
 418         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 419                 MTD_OPS_PLACE_OOB;
 420
 421         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 422                 return -EINVAL;
 423
 424         ops.oobbuf = memdup_user(ptr, length);
 425         if (IS_ERR(ops.oobbuf))
 426                 return PTR_ERR(ops.oobbuf);
 427
 428         start &= ~((uint64_t)mtd->writesize - 1);
 429         ret = mtd_write_oob(mtd, start, &ops);
 430
 431         if (ops.oobretlen > 0xFFFFFFFFU)
 432                 ret = -EOVERFLOW;
 433         retlen = ops.oobretlen;
 434         if (copy_to_user(retp, &retlen, sizeof(length)))
 435                 ret = -EFAULT;
 436
 437         kfree(ops.oobbuf);
 438         return ret;
 439 }
 440
 441 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 442         uint64_t start, uint32_t length, void __user *ptr,
 443         uint32_t __user *retp)
 444 {
 445         struct mtd_file_info *mfi = file->private_data;
 446         struct mtd_oob_ops ops;
 447         int ret = 0;
 448
 449         if (length > 4096)
 450                 return -EINVAL;
 451
 452         if (!access_ok(VERIFY_WRITE, ptr, length))
 453                 return -EFAULT;
 454
 455         ops.ooblen = length;
 456         ops.ooboffs = start & (mtd->writesize - 1);
 457         ops.datbuf = NULL;
 458         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 459                 MTD_OPS_PLACE_OOB;
 460
 461         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 462                 return -EINVAL;
 463
 464         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 465         if (!ops.oobbuf)
 466                 return -ENOMEM;
 467
 468         start &= ~((uint64_t)mtd->writesize - 1);
 469         ret = mtd_read_oob(mtd, start, &ops);
 470
 471         if (put_user(ops.oobretlen, retp))
 472                 ret = -EFAULT;
 473         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 474                                             ops.oobretlen))
 475                 ret = -EFAULT;
 476
 477         kfree(ops.oobbuf);
 478
 479         /*
 480          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 481          * data. For our userspace tools it is important to dump areas
 482          * with ECC errors!
 483          * For kernel internal usage it also might return -EUCLEAN
 484          * to signal the caller that a bitflip has occured and has
 485          * been corrected by the ECC algorithm.
 486          *
 487          * Note: currently the standard NAND function, nand_read_oob_std,
 488          * does not calculate ECC for the OOB area, so do not rely on
 489          * this behavior unless you have replaced it with your own.
 490          */
 491         if (mtd_is_bitflip_or_eccerr(ret))
 492                 return 0;
 493
 494         return ret;
 495 }
 496
 497 /*
 498  * Copies (and truncates, if necessary) data from the larger struct,
 499  * nand_ecclayout, to the smaller, deprecated layout struct,
 500  * nand_ecclayout_user. This is necessary only to support the deprecated
 501  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 502  * nand_ecclayout flexibly (i.e. the struct may change size in new
 503  * releases without requiring major rewrites).
 504  */
 505 static int shrink_ecclayout(const struct nand_ecclayout *from,
 506                 struct nand_ecclayout_user *to)
 507 {
 508         int i;
 509
 510         if (!from || !to)
 511                 return -EINVAL;
 512
 513         memset(to, 0, sizeof(*to));
 514
 515         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 516         for (i = 0; i < to->eccbytes; i++)
 517                 to->eccpos[i] = from->eccpos[i];
 518
 519         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 520                 if (from->oobfree[i].length == 0 &&
 521                                 from->oobfree[i].offset == 0)
 522                         break;
 523                 to->oobavail += from->oobfree[i].length;
 524                 to->oobfree[i] = from->oobfree[i];
 525         }
 526
 527         return 0;
 528 }
 529
 530 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 531                            struct blkpg_ioctl_arg __user *arg)
 532 {
 533         struct blkpg_ioctl_arg a;
 534         struct blkpg_partition p;
 535
 536         if (!capable(CAP_SYS_ADMIN))
 537                 return -EPERM;
 538
 539         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 540                 return -EFAULT;
 541
 542         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 543                 return -EFAULT;
 544
 545         switch (a.op) {
 546         case BLKPG_ADD_PARTITION:
 547
 548                 /* Only master mtd device must be used to add partitions */
 549                 if (mtd_is_partition(mtd))
 550                         return -EINVAL;
 551
 552                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 553
 554         case BLKPG_DEL_PARTITION:
 555
 556                 if (p.pno < 0)
 557                         return -EINVAL;
 558
 559                 return mtd_del_partition(mtd, p.pno);
 560
 561         default:
 562                 return -EINVAL;
 563         }
 564 }
 565
 566 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 567                 struct mtd_write_req __user *argp)
 568 {
 569         struct mtd_write_req req;
 570         struct mtd_oob_ops ops;
 571         void __user *usr_data, *usr_oob;
 572         int ret;
 573
 574         if (copy_from_user(&req, argp, sizeof(req)) ||
 575                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 576                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 577                 return -EFAULT;
 578         if (!mtd->_write_oob)
 579                 return -EOPNOTSUPP;
 580
 581         ops.mode = req.mode;
 582         ops.len = (size_t)req.len;
 583         ops.ooblen = (size_t)req.ooblen;
 584         ops.ooboffs = 0;
 585
 586         usr_data = (void __user *)(uintptr_t)req.usr_data;
 587         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 588
 589         if (req.usr_data) {
 590                 ops.datbuf = memdup_user(usr_data, ops.len);
 591                 if (IS_ERR(ops.datbuf))
 592                         return PTR_ERR(ops.datbuf);
 593         } else {
 594                 ops.datbuf = NULL;
 595         }
 596
 597         if (req.usr_oob) {
 598                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 599                 if (IS_ERR(ops.oobbuf)) {
 600                         kfree(ops.datbuf);
 601                         return PTR_ERR(ops.oobbuf);
 602                 }
 603         } else {
 604                 ops.oobbuf = NULL;
 605         }
 606
 607         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 608
 609         kfree(ops.datbuf);
 610         kfree(ops.oobbuf);
 611
 612         return ret;
 613 }
 614
 615 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 616 {
 617         struct mtd_file_info *mfi = file->private_data;
 618         struct mtd_info *mtd = mfi->mtd;
 619         void __user *argp = (void __user *)arg;
 620         int ret = 0;
 621         u_long size;
 622         struct mtd_info_user info;
 623
 624         pr_debug("MTD_ioctl\n");
 625
 626         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 627         if (cmd & IOC_IN) {
 628                 if (!access_ok(VERIFY_READ, argp, size))
 629                         return -EFAULT;
 630         }
 631         if (cmd & IOC_OUT) {
 632                 if (!access_ok(VERIFY_WRITE, argp, size))
 633                         return -EFAULT;
 634         }
 635
 636         switch (cmd) {
 637         case MEMGETREGIONCOUNT:
 638                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 639                         return -EFAULT;
 640                 break;
 641
 642         case MEMGETREGIONINFO:
 643         {
 644                 uint32_t ur_idx;
 645                 struct mtd_erase_region_info *kr;
 646                 struct region_info_user __user *ur = argp;
 647
 648                 if (get_user(ur_idx, &(ur->regionindex)))
 649                         return -EFAULT;
 650
 651                 if (ur_idx >= mtd->numeraseregions)
 652                         return -EINVAL;
 653
 654                 kr = &(mtd->eraseregions[ur_idx]);
 655
 656                 if (put_user(kr->offset, &(ur->offset))
 657                     || put_user(kr->erasesize, &(ur->erasesize))
 658                     || put_user(kr->numblocks, &(ur->numblocks)))
 659                         return -EFAULT;
 660
 661                 break;
 662         }
 663
 664         case MEMGETINFO:
 665                 memset(&info, 0, sizeof(info));
 666                 info.type       = mtd->type;
 667                 info.flags      = mtd->flags;
 668                 info.size       = mtd->size;
 669                 info.erasesize  = mtd->erasesize;
 670                 info.writesize  = mtd->writesize;
 671                 info.oobsize    = mtd->oobsize;
 672                 /* The below field is obsolete */
 673                 info.padding    = 0;
 674                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 675                         return -EFAULT;
 676                 break;
 677
 678         case MEMERASE:
 679         case MEMERASE64:
 680         {
 681                 struct erase_info *erase;
 682
 683                 if(!(file->f_mode & FMODE_WRITE))
 684                         return -EPERM;
 685
 686                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 687                 if (!erase)
 688                         ret = -ENOMEM;
 689                 else {
 690                         wait_queue_head_t waitq;
 691                         DECLARE_WAITQUEUE(wait, current);
 692
 693                         init_waitqueue_head(&waitq);
 694
 695                         if (cmd == MEMERASE64) {
 696                                 struct erase_info_user64 einfo64;
 697
 698                                 if (copy_from_user(&einfo64, argp,
 699                                             sizeof(struct erase_info_user64))) {
 700                                         kfree(erase);
 701                                         return -EFAULT;
 702                                 }
 703                                 erase->addr = einfo64.start;
 704                                 erase->len = einfo64.length;
 705                         } else {
 706                                 struct erase_info_user einfo32;
 707
 708                                 if (copy_from_user(&einfo32, argp,
 709                                             sizeof(struct erase_info_user))) {
 710                                         kfree(erase);
 711                                         return -EFAULT;
 712                                 }
 713                                 erase->addr = einfo32.start;
 714                                 erase->len = einfo32.length;
 715                         }
 716                         erase->mtd = mtd;
 717                         erase->callback = mtdchar_erase_callback;
 718                         erase->priv = (unsigned long)&waitq;
 719
 720                         /*
 721                           FIXME: Allow INTERRUPTIBLE. Which means
 722                           not having the wait_queue head on the stack.
 723
 724                           If the wq_head is on the stack, and we
 725                           leave because we got interrupted, then the
 726                           wq_head is no longer there when the
 727                           callback routine tries to wake us up.
 728                         */
 729                         ret = mtd_erase(mtd, erase);
 730                         if (!ret) {
 731                                 set_current_state(TASK_UNINTERRUPTIBLE);
 732                                 add_wait_queue(&waitq, &wait);
 733                                 if (erase->state != MTD_ERASE_DONE &&
 734                                     erase->state != MTD_ERASE_FAILED)
 735                                         schedule();
 736                                 remove_wait_queue(&waitq, &wait);
 737                                 set_current_state(TASK_RUNNING);
 738
 739                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 740                         }
 741                         kfree(erase);
 742                 }
 743                 break;
 744         }
 745
 746         case MEMWRITEOOB:
 747         {
 748                 struct mtd_oob_buf buf;
 749                 struct mtd_oob_buf __user *buf_user = argp;
 750
 751                 /* NOTE: writes return length to buf_user->length */
 752                 if (copy_from_user(&buf, argp, sizeof(buf)))
 753                         ret = -EFAULT;
 754                 else
 755                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 756                                 buf.ptr, &buf_user->length);
 757                 break;
 758         }
 759
 760         case MEMREADOOB:
 761         {
 762                 struct mtd_oob_buf buf;
 763                 struct mtd_oob_buf __user *buf_user = argp;
 764
 765                 /* NOTE: writes return length to buf_user->start */
 766                 if (copy_from_user(&buf, argp, sizeof(buf)))
 767                         ret = -EFAULT;
 768                 else
 769                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 770                                 buf.ptr, &buf_user->start);
 771                 break;
 772         }
 773
 774         case MEMWRITEOOB64:
 775         {
 776                 struct mtd_oob_buf64 buf;
 777                 struct mtd_oob_buf64 __user *buf_user = argp;
 778
 779                 if (copy_from_user(&buf, argp, sizeof(buf)))
 780                         ret = -EFAULT;
 781                 else
 782                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 783                                 (void __user *)(uintptr_t)buf.usr_ptr,
 784                                 &buf_user->length);
 785                 break;
 786         }
 787
 788         case MEMREADOOB64:
 789         {
 790                 struct mtd_oob_buf64 buf;
 791                 struct mtd_oob_buf64 __user *buf_user = argp;
 792
 793                 if (copy_from_user(&buf, argp, sizeof(buf)))
 794                         ret = -EFAULT;
 795                 else
 796                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 797                                 (void __user *)(uintptr_t)buf.usr_ptr,
 798                                 &buf_user->length);
 799                 break;
 800         }
 801
 802         case MEMWRITE:
 803         {
 804                 ret = mtdchar_write_ioctl(mtd,
 805                       (struct mtd_write_req __user *)arg);
 806                 break;
 807         }
 808
 809         case MEMLOCK:
 810         {
 811                 struct erase_info_user einfo;
 812
 813                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 814                         return -EFAULT;
 815
 816                 ret = mtd_lock(mtd, einfo.start, einfo.length);
 817                 break;
 818         }
 819
 820         case MEMUNLOCK:
 821         {
 822                 struct erase_info_user einfo;
 823
 824                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 825                         return -EFAULT;
 826
 827                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
 828                 break;
 829         }
 830
 831         case MEMISLOCKED:
 832         {
 833                 struct erase_info_user einfo;
 834
 835                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 836                         return -EFAULT;
 837
 838                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 839                 break;
 840         }
 841
 842         /* Legacy interface */
 843         case MEMGETOOBSEL:
 844         {
 845                 struct nand_oobinfo oi;
 846
 847                 if (!mtd->ecclayout)
 848                         return -EOPNOTSUPP;
 849                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 850                         return -EINVAL;
 851
 852                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 853                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 854                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 855                        sizeof(oi.oobfree));
 856                 oi.eccbytes = mtd->ecclayout->eccbytes;
 857
 858                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 859                         return -EFAULT;
 860                 break;
 861         }
 862
 863         case MEMGETBADBLOCK:
 864         {
 865                 loff_t offs;
 866
 867                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 868                         return -EFAULT;
 869                 return mtd_block_isbad(mtd, offs);
 870                 break;
 871         }
 872
 873         case MEMSETBADBLOCK:
 874         {
 875                 loff_t offs;
 876
 877                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 878                         return -EFAULT;
 879                 return mtd_block_markbad(mtd, offs);
 880                 break;
 881         }
 882
 883         case OTPSELECT:
 884         {
 885                 int mode;
 886                 if (copy_from_user(&mode, argp, sizeof(int)))
 887                         return -EFAULT;
 888
 889                 mfi->mode = MTD_FILE_MODE_NORMAL;
 890
 891                 ret = otp_select_filemode(mfi, mode);
 892
 893                 file->f_pos = 0;
 894                 break;
 895         }
 896
 897         case OTPGETREGIONCOUNT:
 898         case OTPGETREGIONINFO:
 899         {
 900                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 901                 size_t retlen;
 902                 if (!buf)
 903                         return -ENOMEM;
 904                 switch (mfi->mode) {
 905                 case MTD_FILE_MODE_OTP_FACTORY:
 906                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 907                         break;
 908                 case MTD_FILE_MODE_OTP_USER:
 909                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 910                         break;
 911                 default:
 912                         ret = -EINVAL;
 913                         break;
 914                 }
 915                 if (!ret) {
 916                         if (cmd == OTPGETREGIONCOUNT) {
 917                                 int nbr = retlen / sizeof(struct otp_info);
 918                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 919                         } else
 920                                 ret = copy_to_user(argp, buf, retlen);
 921                         if (ret)
 922                                 ret = -EFAULT;
 923                 }
 924                 kfree(buf);
 925                 break;
 926         }
 927
 928         case OTPLOCK:
 929         {
 930                 struct otp_info oinfo;
 931
 932                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 933                         return -EINVAL;
 934                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 935                         return -EFAULT;
 936                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 937                 break;
 938         }
 939
 940         /* This ioctl is being deprecated - it truncates the ECC layout */
 941         case ECCGETLAYOUT:
 942         {
 943                 struct nand_ecclayout_user *usrlay;
 944
 945                 if (!mtd->ecclayout)
 946                         return -EOPNOTSUPP;
 947
 948                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 949                 if (!usrlay)
 950                         return -ENOMEM;
 951
 952                 shrink_ecclayout(mtd->ecclayout, usrlay);
 953
 954                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 955                         ret = -EFAULT;
 956                 kfree(usrlay);
 957                 break;
 958         }
 959
 960         case ECCGETSTATS:
 961         {
 962                 if (copy_to_user(argp, &mtd->ecc_stats,
 963                                  sizeof(struct mtd_ecc_stats)))
 964                         return -EFAULT;
 965                 break;
 966         }
 967
 968         case MTDFILEMODE:
 969         {
 970                 mfi->mode = 0;
 971
 972                 switch(arg) {
 973                 case MTD_FILE_MODE_OTP_FACTORY:
 974                 case MTD_FILE_MODE_OTP_USER:
 975                         ret = otp_select_filemode(mfi, arg);
 976                         break;
 977
 978                 case MTD_FILE_MODE_RAW:
 979                         if (!mtd_has_oob(mtd))
 980                                 return -EOPNOTSUPP;
 981                         mfi->mode = arg;
 982
 983                 case MTD_FILE_MODE_NORMAL:
 984                         break;
 985                 default:
 986                         ret = -EINVAL;
 987                 }
 988                 file->f_pos = 0;
 989                 break;
 990         }
 991
 992         case BLKPG:
 993         {
 994                 ret = mtdchar_blkpg_ioctl(mtd,
 995                       (struct blkpg_ioctl_arg __user *)arg);
 996                 break;
 997         }
 998
 999         case BLKRRPART:
1000         {
1001                 /* No reread partition feature. Just return ok */
1002                 ret = 0;
1003                 break;
1004         }
1005
1006         default:
1007                 ret = -ENOTTY;
1008         }
1009
1010         return ret;
1011 } /* memory_ioctl */
1012
1013 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1014 {
1015         int ret;
1016
1017         mutex_lock(&mtd_mutex);
1018         ret = mtdchar_ioctl(file, cmd, arg);
1019         mutex_unlock(&mtd_mutex);
1020
1021         return ret;
1022 }
1023
1024 #ifdef CONFIG_COMPAT
1025
1026 struct mtd_oob_buf32 {
1027         u_int32_t start;
1028         u_int32_t length;
1029         compat_caddr_t ptr;     /* unsigned char* */
1030 };
1031
1032 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1033 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1034
1035 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1036         unsigned long arg)
1037 {
1038         struct mtd_file_info *mfi = file->private_data;
1039         struct mtd_info *mtd = mfi->mtd;
1040         void __user *argp = compat_ptr(arg);
1041         int ret = 0;
1042
1043         mutex_lock(&mtd_mutex);
1044
1045         switch (cmd) {
1046         case MEMWRITEOOB32:
1047         {
1048                 struct mtd_oob_buf32 buf;
1049                 struct mtd_oob_buf32 __user *buf_user = argp;
1050
1051                 if (copy_from_user(&buf, argp, sizeof(buf)))
1052                         ret = -EFAULT;
1053                 else
1054                         ret = mtdchar_writeoob(file, mtd, buf.start,
1055                                 buf.length, compat_ptr(buf.ptr),
1056                                 &buf_user->length);
1057                 break;
1058         }
1059
1060         case MEMREADOOB32:
1061         {
1062                 struct mtd_oob_buf32 buf;
1063                 struct mtd_oob_buf32 __user *buf_user = argp;
1064
1065                 /* NOTE: writes return length to buf->start */
1066                 if (copy_from_user(&buf, argp, sizeof(buf)))
1067                         ret = -EFAULT;
1068                 else
1069                         ret = mtdchar_readoob(file, mtd, buf.start,
1070                                 buf.length, compat_ptr(buf.ptr),
1071                                 &buf_user->start);
1072                 break;
1073         }
1074         default:
1075                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1076         }
1077
1078         mutex_unlock(&mtd_mutex);
1079
1080         return ret;
1081 }
1082
1083 #endif /* CONFIG_COMPAT */
1084
1085 /*
1086  * try to determine where a shared mapping can be made
1087  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1088  *   mappings)
1089  */
1090 #ifndef CONFIG_MMU
1091 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1092                                            unsigned long addr,
1093                                            unsigned long len,
1094                                            unsigned long pgoff,
1095                                            unsigned long flags)
1096 {
1097         struct mtd_file_info *mfi = file->private_data;
1098         struct mtd_info *mtd = mfi->mtd;
1099         unsigned long offset;
1100         int ret;
1101
1102         if (addr != 0)
1103                 return (unsigned long) -EINVAL;
1104
1105         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1106                 return (unsigned long) -EINVAL;
1107
1108         offset = pgoff << PAGE_SHIFT;
1109         if (offset > mtd->size - len)
1110                 return (unsigned long) -EINVAL;
1111
1112         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1113         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1114 }
1115 #endif
1116
1117 /*
1118  * set up a mapping for shared memory segments
1119  */
1120 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1121 {
1122 #ifdef CONFIG_MMU
1123         struct mtd_file_info *mfi = file->private_data;
1124         struct mtd_info *mtd = mfi->mtd;
1125         struct map_info *map = mtd->priv;
1126
1127         /* This is broken because it assumes the MTD device is map-based
1128            and that mtd->priv is a valid struct map_info.  It should be
1129            replaced with something that uses the mtd_get_unmapped_area()
1130            operation properly. */
1131         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1132 #ifdef pgprot_noncached
1133                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1134                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1135 #endif
1136                 return vm_iomap_memory(vma, map->phys, map->size);
1137         }
1138         return -ENODEV;
1139 #else
1140         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1141 #endif
1142 }
1143
1144 static const struct file_operations mtd_fops = {
1145         .owner          = THIS_MODULE,
1146         .llseek         = mtdchar_lseek,
1147         .read           = mtdchar_read,
1148         .write          = mtdchar_write,
1149         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1150 #ifdef CONFIG_COMPAT
1151         .compat_ioctl   = mtdchar_compat_ioctl,
1152 #endif
1153         .open           = mtdchar_open,
1154         .release        = mtdchar_close,
1155         .mmap           = mtdchar_mmap,
1156 #ifndef CONFIG_MMU
1157         .get_unmapped_area = mtdchar_get_unmapped_area,
1158 #endif
1159 };
1160
1161 static const struct super_operations mtd_ops = {
1162         .drop_inode = generic_delete_inode,
1163         .statfs = simple_statfs,
1164 };
1165
1166 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1167                                 int flags, const char *dev_name, void *data)
1168 {
1169         return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1170 }
1171
1172 static struct file_system_type mtd_inodefs_type = {
1173        .name = "mtd_inodefs",
1174        .mount = mtd_inodefs_mount,
1175        .kill_sb = kill_anon_super,
1176 };
1177 MODULE_ALIAS_FS("mtd_inodefs");
1178
1179 int __init init_mtdchar(void)
1180 {
1181         int ret;
1182
1183         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1184                                    "mtd", &mtd_fops);
1185         if (ret < 0) {
1186                 pr_err("Can't allocate major number %d for MTD\n",
1187                        MTD_CHAR_MAJOR);
1188                 return ret;
1189         }
1190
1191         ret = register_filesystem(&mtd_inodefs_type);
1192         if (ret) {
1193                 pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1194                        ret);
1195                 goto err_unregister_chdev;
1196         }
1197
1198         return ret;
1199
1200 err_unregister_chdev:
1201         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1202         return ret;
1203 }
1204
1205 void __exit cleanup_mtdchar(void)
1206 {
1207         unregister_filesystem(&mtd_inodefs_type);
1208         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1209 }
1210
1211 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);