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/mtd/mtd.h>
  35 #include <linux/mtd/partitions.h>
  36 #include <linux/mtd/map.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 #define MTD_INODE_FS_MAGIC 0x11307854
  41 static DEFINE_MUTEX(mtd_mutex);
  42 static struct vfsmount *mtd_inode_mnt __read_mostly;
  43
  44 /*
  45  * Data structure to hold the pointer to the mtd device as well
  46  * as mode information of various use cases.
  47  */
  48 struct mtd_file_info {
  49         struct mtd_info *mtd;
  50         struct inode *ino;
  51         enum mtd_file_modes mode;
  52 };
  53
  54 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  55 {
  56         struct mtd_file_info *mfi = file->private_data;
  57         struct mtd_info *mtd = mfi->mtd;
  58
  59         switch (orig) {
  60         case SEEK_SET:
  61                 break;
  62         case SEEK_CUR:
  63                 offset += file->f_pos;
  64                 break;
  65         case SEEK_END:
  66                 offset += mtd->size;
  67                 break;
  68         default:
  69                 return -EINVAL;
  70         }
  71
  72         if (offset >= 0 && offset <= mtd->size)
  73                 return file->f_pos = offset;
  74
  75         return -EINVAL;
  76 }
  77
  78
  79
  80 static int mtd_open(struct inode *inode, struct file *file)
  81 {
  82         int minor = iminor(inode);
  83         int devnum = minor >> 1;
  84         int ret = 0;
  85         struct mtd_info *mtd;
  86         struct mtd_file_info *mfi;
  87         struct inode *mtd_ino;
  88
  89         pr_debug("MTD_open\n");
  90
  91         /* You can't open the RO devices RW */
  92         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  93                 return -EACCES;
  94
  95         mutex_lock(&mtd_mutex);
  96         mtd = get_mtd_device(NULL, devnum);
  97
  98         if (IS_ERR(mtd)) {
  99                 ret = PTR_ERR(mtd);
 100                 goto out;
 101         }
 102
 103         if (mtd->type == MTD_ABSENT) {
 104                 put_mtd_device(mtd);
 105                 ret = -ENODEV;
 106                 goto out;
 107         }
 108
 109         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 110         if (!mtd_ino) {
 111                 put_mtd_device(mtd);
 112                 ret = -ENOMEM;
 113                 goto out;
 114         }
 115         if (mtd_ino->i_state & I_NEW) {
 116                 mtd_ino->i_private = mtd;
 117                 mtd_ino->i_mode = S_IFCHR;
 118                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 119                 unlock_new_inode(mtd_ino);
 120         }
 121         file->f_mapping = mtd_ino->i_mapping;
 122
 123         /* You can't open it RW if it's not a writeable device */
 124         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 125                 iput(mtd_ino);
 126                 put_mtd_device(mtd);
 127                 ret = -EACCES;
 128                 goto out;
 129         }
 130
 131         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 132         if (!mfi) {
 133                 iput(mtd_ino);
 134                 put_mtd_device(mtd);
 135                 ret = -ENOMEM;
 136                 goto out;
 137         }
 138         mfi->ino = mtd_ino;
 139         mfi->mtd = mtd;
 140         file->private_data = mfi;
 141
 142 out:
 143         mutex_unlock(&mtd_mutex);
 144         return ret;
 145 } /* mtd_open */
 146
 147 /*====================================================================*/
 148
 149 static int mtd_close(struct inode *inode, struct file *file)
 150 {
 151         struct mtd_file_info *mfi = file->private_data;
 152         struct mtd_info *mtd = mfi->mtd;
 153
 154         pr_debug("MTD_close\n");
 155
 156         /* Only sync if opened RW */
 157         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 158                 mtd->sync(mtd);
 159
 160         iput(mfi->ino);
 161
 162         put_mtd_device(mtd);
 163         file->private_data = NULL;
 164         kfree(mfi);
 165
 166         return 0;
 167 } /* mtd_close */
 168
 169 /* Back in June 2001, dwmw2 wrote:
 170  *
 171  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 172  *   userspace buffer down and use it directly with readv/writev.
 173  *
 174  * The implementation below, using mtd_kmalloc_up_to, mitigates
 175  * allocation failures when the system is under low-memory situations
 176  * or if memory is highly fragmented at the cost of reducing the
 177  * performance of the requested transfer due to a smaller buffer size.
 178  *
 179  * A more complex but more memory-efficient implementation based on
 180  * get_user_pages and iovecs to cover extents of those pages is a
 181  * longer-term goal, as intimated by dwmw2 above. However, for the
 182  * write case, this requires yet more complex head and tail transfer
 183  * handling when those head and tail offsets and sizes are such that
 184  * alignment requirements are not met in the NAND subdriver.
 185  */
 186
 187 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 188 {
 189         struct mtd_file_info *mfi = file->private_data;
 190         struct mtd_info *mtd = mfi->mtd;
 191         size_t retlen=0;
 192         size_t total_retlen=0;
 193         int ret=0;
 194         int len;
 195         size_t size = count;
 196         char *kbuf;
 197
 198         pr_debug("MTD_read\n");
 199
 200         if (*ppos + count > mtd->size)
 201                 count = mtd->size - *ppos;
 202
 203         if (!count)
 204                 return 0;
 205
 206         kbuf = mtd_kmalloc_up_to(mtd, &size);
 207         if (!kbuf)
 208                 return -ENOMEM;
 209
 210         while (count) {
 211                 len = min_t(size_t, count, size);
 212
 213                 switch (mfi->mode) {
 214                 case MTD_FILE_MODE_OTP_FACTORY:
 215                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 216                         break;
 217                 case MTD_FILE_MODE_OTP_USER:
 218                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 219                         break;
 220                 case MTD_FILE_MODE_RAW:
 221                 {
 222                         struct mtd_oob_ops ops;
 223
 224                         ops.mode = MTD_OPS_RAW;
 225                         ops.datbuf = kbuf;
 226                         ops.oobbuf = NULL;
 227                         ops.len = len;
 228
 229                         ret = mtd->read_oob(mtd, *ppos, &ops);
 230                         retlen = ops.retlen;
 231                         break;
 232                 }
 233                 default:
 234                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 235                 }
 236                 /* Nand returns -EBADMSG on ECC errors, but it returns
 237                  * the data. For our userspace tools it is important
 238                  * to dump areas with ECC errors!
 239                  * For kernel internal usage it also might return -EUCLEAN
 240                  * to signal the caller that a bitflip has occurred and has
 241                  * been corrected by the ECC algorithm.
 242                  * Userspace software which accesses NAND this way
 243                  * must be aware of the fact that it deals with NAND
 244                  */
 245                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 246                         *ppos += retlen;
 247                         if (copy_to_user(buf, kbuf, retlen)) {
 248                                 kfree(kbuf);
 249                                 return -EFAULT;
 250                         }
 251                         else
 252                                 total_retlen += retlen;
 253
 254                         count -= retlen;
 255                         buf += retlen;
 256                         if (retlen == 0)
 257                                 count = 0;
 258                 }
 259                 else {
 260                         kfree(kbuf);
 261                         return ret;
 262                 }
 263
 264         }
 265
 266         kfree(kbuf);
 267         return total_retlen;
 268 } /* mtd_read */
 269
 270 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 271 {
 272         struct mtd_file_info *mfi = file->private_data;
 273         struct mtd_info *mtd = mfi->mtd;
 274         size_t size = count;
 275         char *kbuf;
 276         size_t retlen;
 277         size_t total_retlen=0;
 278         int ret=0;
 279         int len;
 280
 281         pr_debug("MTD_write\n");
 282
 283         if (*ppos == mtd->size)
 284                 return -ENOSPC;
 285
 286         if (*ppos + count > mtd->size)
 287                 count = mtd->size - *ppos;
 288
 289         if (!count)
 290                 return 0;
 291
 292         kbuf = mtd_kmalloc_up_to(mtd, &size);
 293         if (!kbuf)
 294                 return -ENOMEM;
 295
 296         while (count) {
 297                 len = min_t(size_t, count, size);
 298
 299                 if (copy_from_user(kbuf, buf, len)) {
 300                         kfree(kbuf);
 301                         return -EFAULT;
 302                 }
 303
 304                 switch (mfi->mode) {
 305                 case MTD_FILE_MODE_OTP_FACTORY:
 306                         ret = -EROFS;
 307                         break;
 308                 case MTD_FILE_MODE_OTP_USER:
 309                         if (!mtd->write_user_prot_reg) {
 310                                 ret = -EOPNOTSUPP;
 311                                 break;
 312                         }
 313                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 314                         break;
 315
 316                 case MTD_FILE_MODE_RAW:
 317                 {
 318                         struct mtd_oob_ops ops;
 319
 320                         ops.mode = MTD_OPS_RAW;
 321                         ops.datbuf = kbuf;
 322                         ops.oobbuf = NULL;
 323                         ops.ooboffs = 0;
 324                         ops.len = len;
 325
 326                         ret = mtd->write_oob(mtd, *ppos, &ops);
 327                         retlen = ops.retlen;
 328                         break;
 329                 }
 330
 331                 default:
 332                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 333                 }
 334                 if (!ret) {
 335                         *ppos += retlen;
 336                         total_retlen += retlen;
 337                         count -= retlen;
 338                         buf += retlen;
 339                 }
 340                 else {
 341                         kfree(kbuf);
 342                         return ret;
 343                 }
 344         }
 345
 346         kfree(kbuf);
 347         return total_retlen;
 348 } /* mtd_write */
 349
 350 /*======================================================================
 351
 352     IOCTL calls for getting device parameters.
 353
 354 ======================================================================*/
 355 static void mtdchar_erase_callback (struct erase_info *instr)
 356 {
 357         wake_up((wait_queue_head_t *)instr->priv);
 358 }
 359
 360 #ifdef CONFIG_HAVE_MTD_OTP
 361 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 362 {
 363         struct mtd_info *mtd = mfi->mtd;
 364         int ret = 0;
 365
 366         switch (mode) {
 367         case MTD_OTP_FACTORY:
 368                 if (!mtd->read_fact_prot_reg)
 369                         ret = -EOPNOTSUPP;
 370                 else
 371                         mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 372                 break;
 373         case MTD_OTP_USER:
 374                 if (!mtd->read_fact_prot_reg)
 375                         ret = -EOPNOTSUPP;
 376                 else
 377                         mfi->mode = MTD_FILE_MODE_OTP_USER;
 378                 break;
 379         default:
 380                 ret = -EINVAL;
 381         case MTD_OTP_OFF:
 382                 break;
 383         }
 384         return ret;
 385 }
 386 #else
 387 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 388 #endif
 389
 390 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 391         uint64_t start, uint32_t length, void __user *ptr,
 392         uint32_t __user *retp)
 393 {
 394         struct mtd_file_info *mfi = file->private_data;
 395         struct mtd_oob_ops ops;
 396         uint32_t retlen;
 397         int ret = 0;
 398
 399         if (!(file->f_mode & FMODE_WRITE))
 400                 return -EPERM;
 401
 402         if (length > 4096)
 403                 return -EINVAL;
 404
 405         if (!mtd->write_oob)
 406                 ret = -EOPNOTSUPP;
 407         else
 408                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 409
 410         if (ret)
 411                 return ret;
 412
 413         ops.ooblen = length;
 414         ops.ooboffs = start & (mtd->writesize - 1);
 415         ops.datbuf = NULL;
 416         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 417                 MTD_OPS_PLACE_OOB;
 418
 419         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 420                 return -EINVAL;
 421
 422         ops.oobbuf = memdup_user(ptr, length);
 423         if (IS_ERR(ops.oobbuf))
 424                 return PTR_ERR(ops.oobbuf);
 425
 426         start &= ~((uint64_t)mtd->writesize - 1);
 427         ret = mtd->write_oob(mtd, start, &ops);
 428
 429         if (ops.oobretlen > 0xFFFFFFFFU)
 430                 ret = -EOVERFLOW;
 431         retlen = ops.oobretlen;
 432         if (copy_to_user(retp, &retlen, sizeof(length)))
 433                 ret = -EFAULT;
 434
 435         kfree(ops.oobbuf);
 436         return ret;
 437 }
 438
 439 static int mtd_do_readoob(struct file *file, struct mtd_info *mtd,
 440         uint64_t start, uint32_t length, void __user *ptr,
 441         uint32_t __user *retp)
 442 {
 443         struct mtd_file_info *mfi = file->private_data;
 444         struct mtd_oob_ops ops;
 445         int ret = 0;
 446
 447         if (length > 4096)
 448                 return -EINVAL;
 449
 450         if (!mtd->read_oob)
 451                 ret = -EOPNOTSUPP;
 452         else
 453                 ret = access_ok(VERIFY_WRITE, ptr,
 454                                 length) ? 0 : -EFAULT;
 455         if (ret)
 456                 return ret;
 457
 458         ops.ooblen = length;
 459         ops.ooboffs = start & (mtd->writesize - 1);
 460         ops.datbuf = NULL;
 461         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 462                 MTD_OPS_PLACE_OOB;
 463
 464         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 465                 return -EINVAL;
 466
 467         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 468         if (!ops.oobbuf)
 469                 return -ENOMEM;
 470
 471         start &= ~((uint64_t)mtd->writesize - 1);
 472         ret = mtd->read_oob(mtd, start, &ops);
 473
 474         if (put_user(ops.oobretlen, retp))
 475                 ret = -EFAULT;
 476         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 477                                             ops.oobretlen))
 478                 ret = -EFAULT;
 479
 480         kfree(ops.oobbuf);
 481
 482         /*
 483          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 484          * data. For our userspace tools it is important to dump areas
 485          * with ECC errors!
 486          * For kernel internal usage it also might return -EUCLEAN
 487          * to signal the caller that a bitflip has occured and has
 488          * been corrected by the ECC algorithm.
 489          *
 490          * Note: currently the standard NAND function, nand_read_oob_std,
 491          * does not calculate ECC for the OOB area, so do not rely on
 492          * this behavior unless you have replaced it with your own.
 493          */
 494         if (mtd_is_bitflip_or_eccerr(ret))
 495                 return 0;
 496
 497         return ret;
 498 }
 499
 500 /*
 501  * Copies (and truncates, if necessary) data from the larger struct,
 502  * nand_ecclayout, to the smaller, deprecated layout struct,
 503  * nand_ecclayout_user. This is necessary only to support the deprecated
 504  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 505  * nand_ecclayout flexibly (i.e. the struct may change size in new
 506  * releases without requiring major rewrites).
 507  */
 508 static int shrink_ecclayout(const struct nand_ecclayout *from,
 509                 struct nand_ecclayout_user *to)
 510 {
 511         int i;
 512
 513         if (!from || !to)
 514                 return -EINVAL;
 515
 516         memset(to, 0, sizeof(*to));
 517
 518         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 519         for (i = 0; i < to->eccbytes; i++)
 520                 to->eccpos[i] = from->eccpos[i];
 521
 522         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 523                 if (from->oobfree[i].length == 0 &&
 524                                 from->oobfree[i].offset == 0)
 525                         break;
 526                 to->oobavail += from->oobfree[i].length;
 527                 to->oobfree[i] = from->oobfree[i];
 528         }
 529
 530         return 0;
 531 }
 532
 533 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
 534                            struct blkpg_ioctl_arg __user *arg)
 535 {
 536         struct blkpg_ioctl_arg a;
 537         struct blkpg_partition p;
 538
 539         if (!capable(CAP_SYS_ADMIN))
 540                 return -EPERM;
 541
 542         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 543                 return -EFAULT;
 544
 545         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 546                 return -EFAULT;
 547
 548         switch (a.op) {
 549         case BLKPG_ADD_PARTITION:
 550
 551                 /* Only master mtd device must be used to add partitions */
 552                 if (mtd_is_partition(mtd))
 553                         return -EINVAL;
 554
 555                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 556
 557         case BLKPG_DEL_PARTITION:
 558
 559                 if (p.pno < 0)
 560                         return -EINVAL;
 561
 562                 return mtd_del_partition(mtd, p.pno);
 563
 564         default:
 565                 return -EINVAL;
 566         }
 567 }
 568
 569 static int mtd_write_ioctl(struct mtd_info *mtd,
 570                 struct mtd_write_req __user *argp)
 571 {
 572         struct mtd_write_req req;
 573         struct mtd_oob_ops ops;
 574         void __user *usr_data, *usr_oob;
 575         int ret;
 576
 577         if (copy_from_user(&req, argp, sizeof(req)) ||
 578                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 579                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 580                 return -EFAULT;
 581         if (!mtd->write_oob)
 582                 return -EOPNOTSUPP;
 583
 584         ops.mode = req.mode;
 585         ops.len = (size_t)req.len;
 586         ops.ooblen = (size_t)req.ooblen;
 587         ops.ooboffs = 0;
 588
 589         usr_data = (void __user *)(uintptr_t)req.usr_data;
 590         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 591
 592         if (req.usr_data) {
 593                 ops.datbuf = memdup_user(usr_data, ops.len);
 594                 if (IS_ERR(ops.datbuf))
 595                         return PTR_ERR(ops.datbuf);
 596         } else {
 597                 ops.datbuf = NULL;
 598         }
 599
 600         if (req.usr_oob) {
 601                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 602                 if (IS_ERR(ops.oobbuf)) {
 603                         kfree(ops.datbuf);
 604                         return PTR_ERR(ops.oobbuf);
 605                 }
 606         } else {
 607                 ops.oobbuf = NULL;
 608         }
 609
 610         ret = mtd->write_oob(mtd, (loff_t)req.start, &ops);
 611
 612         kfree(ops.datbuf);
 613         kfree(ops.oobbuf);
 614
 615         return ret;
 616 }
 617
 618 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 619 {
 620         struct mtd_file_info *mfi = file->private_data;
 621         struct mtd_info *mtd = mfi->mtd;
 622         void __user *argp = (void __user *)arg;
 623         int ret = 0;
 624         u_long size;
 625         struct mtd_info_user info;
 626
 627         pr_debug("MTD_ioctl\n");
 628
 629         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 630         if (cmd & IOC_IN) {
 631                 if (!access_ok(VERIFY_READ, argp, size))
 632                         return -EFAULT;
 633         }
 634         if (cmd & IOC_OUT) {
 635                 if (!access_ok(VERIFY_WRITE, argp, size))
 636                         return -EFAULT;
 637         }
 638
 639         switch (cmd) {
 640         case MEMGETREGIONCOUNT:
 641                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 642                         return -EFAULT;
 643                 break;
 644
 645         case MEMGETREGIONINFO:
 646         {
 647                 uint32_t ur_idx;
 648                 struct mtd_erase_region_info *kr;
 649                 struct region_info_user __user *ur = argp;
 650
 651                 if (get_user(ur_idx, &(ur->regionindex)))
 652                         return -EFAULT;
 653
 654                 if (ur_idx >= mtd->numeraseregions)
 655                         return -EINVAL;
 656
 657                 kr = &(mtd->eraseregions[ur_idx]);
 658
 659                 if (put_user(kr->offset, &(ur->offset))
 660                     || put_user(kr->erasesize, &(ur->erasesize))
 661                     || put_user(kr->numblocks, &(ur->numblocks)))
 662                         return -EFAULT;
 663
 664                 break;
 665         }
 666
 667         case MEMGETINFO:
 668                 memset(&info, 0, sizeof(info));
 669                 info.type       = mtd->type;
 670                 info.flags      = mtd->flags;
 671                 info.size       = mtd->size;
 672                 info.erasesize  = mtd->erasesize;
 673                 info.writesize  = mtd->writesize;
 674                 info.oobsize    = mtd->oobsize;
 675                 /* The below field is obsolete */
 676                 info.padding    = 0;
 677                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 678                         return -EFAULT;
 679                 break;
 680
 681         case MEMERASE:
 682         case MEMERASE64:
 683         {
 684                 struct erase_info *erase;
 685
 686                 if(!(file->f_mode & FMODE_WRITE))
 687                         return -EPERM;
 688
 689                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 690                 if (!erase)
 691                         ret = -ENOMEM;
 692                 else {
 693                         wait_queue_head_t waitq;
 694                         DECLARE_WAITQUEUE(wait, current);
 695
 696                         init_waitqueue_head(&waitq);
 697
 698                         if (cmd == MEMERASE64) {
 699                                 struct erase_info_user64 einfo64;
 700
 701                                 if (copy_from_user(&einfo64, argp,
 702                                             sizeof(struct erase_info_user64))) {
 703                                         kfree(erase);
 704                                         return -EFAULT;
 705                                 }
 706                                 erase->addr = einfo64.start;
 707                                 erase->len = einfo64.length;
 708                         } else {
 709                                 struct erase_info_user einfo32;
 710
 711                                 if (copy_from_user(&einfo32, argp,
 712                                             sizeof(struct erase_info_user))) {
 713                                         kfree(erase);
 714                                         return -EFAULT;
 715                                 }
 716                                 erase->addr = einfo32.start;
 717                                 erase->len = einfo32.length;
 718                         }
 719                         erase->mtd = mtd;
 720                         erase->callback = mtdchar_erase_callback;
 721                         erase->priv = (unsigned long)&waitq;
 722
 723                         /*
 724                           FIXME: Allow INTERRUPTIBLE. Which means
 725                           not having the wait_queue head on the stack.
 726
 727                           If the wq_head is on the stack, and we
 728                           leave because we got interrupted, then the
 729                           wq_head is no longer there when the
 730                           callback routine tries to wake us up.
 731                         */
 732                         ret = mtd->erase(mtd, erase);
 733                         if (!ret) {
 734                                 set_current_state(TASK_UNINTERRUPTIBLE);
 735                                 add_wait_queue(&waitq, &wait);
 736                                 if (erase->state != MTD_ERASE_DONE &&
 737                                     erase->state != MTD_ERASE_FAILED)
 738                                         schedule();
 739                                 remove_wait_queue(&waitq, &wait);
 740                                 set_current_state(TASK_RUNNING);
 741
 742                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 743                         }
 744                         kfree(erase);
 745                 }
 746                 break;
 747         }
 748
 749         case MEMWRITEOOB:
 750         {
 751                 struct mtd_oob_buf buf;
 752                 struct mtd_oob_buf __user *buf_user = argp;
 753
 754                 /* NOTE: writes return length to buf_user->length */
 755                 if (copy_from_user(&buf, argp, sizeof(buf)))
 756                         ret = -EFAULT;
 757                 else
 758                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 759                                 buf.ptr, &buf_user->length);
 760                 break;
 761         }
 762
 763         case MEMREADOOB:
 764         {
 765                 struct mtd_oob_buf buf;
 766                 struct mtd_oob_buf __user *buf_user = argp;
 767
 768                 /* NOTE: writes return length to buf_user->start */
 769                 if (copy_from_user(&buf, argp, sizeof(buf)))
 770                         ret = -EFAULT;
 771                 else
 772                         ret = mtd_do_readoob(file, mtd, buf.start, buf.length,
 773                                 buf.ptr, &buf_user->start);
 774                 break;
 775         }
 776
 777         case MEMWRITEOOB64:
 778         {
 779                 struct mtd_oob_buf64 buf;
 780                 struct mtd_oob_buf64 __user *buf_user = argp;
 781
 782                 if (copy_from_user(&buf, argp, sizeof(buf)))
 783                         ret = -EFAULT;
 784                 else
 785                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 786                                 (void __user *)(uintptr_t)buf.usr_ptr,
 787                                 &buf_user->length);
 788                 break;
 789         }
 790
 791         case MEMREADOOB64:
 792         {
 793                 struct mtd_oob_buf64 buf;
 794                 struct mtd_oob_buf64 __user *buf_user = argp;
 795
 796                 if (copy_from_user(&buf, argp, sizeof(buf)))
 797                         ret = -EFAULT;
 798                 else
 799                         ret = mtd_do_readoob(file, mtd, buf.start, buf.length,
 800                                 (void __user *)(uintptr_t)buf.usr_ptr,
 801                                 &buf_user->length);
 802                 break;
 803         }
 804
 805         case MEMWRITE:
 806         {
 807                 ret = mtd_write_ioctl(mtd,
 808                       (struct mtd_write_req __user *)arg);
 809                 break;
 810         }
 811
 812         case MEMLOCK:
 813         {
 814                 struct erase_info_user einfo;
 815
 816                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 817                         return -EFAULT;
 818
 819                 if (!mtd->lock)
 820                         ret = -EOPNOTSUPP;
 821                 else
 822                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 823                 break;
 824         }
 825
 826         case MEMUNLOCK:
 827         {
 828                 struct erase_info_user einfo;
 829
 830                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 831                         return -EFAULT;
 832
 833                 if (!mtd->unlock)
 834                         ret = -EOPNOTSUPP;
 835                 else
 836                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 837                 break;
 838         }
 839
 840         case MEMISLOCKED:
 841         {
 842                 struct erase_info_user einfo;
 843
 844                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 845                         return -EFAULT;
 846
 847                 if (!mtd->is_locked)
 848                         ret = -EOPNOTSUPP;
 849                 else
 850                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 851                 break;
 852         }
 853
 854         /* Legacy interface */
 855         case MEMGETOOBSEL:
 856         {
 857                 struct nand_oobinfo oi;
 858
 859                 if (!mtd->ecclayout)
 860                         return -EOPNOTSUPP;
 861                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 862                         return -EINVAL;
 863
 864                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 865                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 866                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 867                        sizeof(oi.oobfree));
 868                 oi.eccbytes = mtd->ecclayout->eccbytes;
 869
 870                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 871                         return -EFAULT;
 872                 break;
 873         }
 874
 875         case MEMGETBADBLOCK:
 876         {
 877                 loff_t offs;
 878
 879                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 880                         return -EFAULT;
 881                 if (!mtd->block_isbad)
 882                         ret = -EOPNOTSUPP;
 883                 else
 884                         return mtd->block_isbad(mtd, offs);
 885                 break;
 886         }
 887
 888         case MEMSETBADBLOCK:
 889         {
 890                 loff_t offs;
 891
 892                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 893                         return -EFAULT;
 894                 if (!mtd->block_markbad)
 895                         ret = -EOPNOTSUPP;
 896                 else
 897                         return mtd->block_markbad(mtd, offs);
 898                 break;
 899         }
 900
 901 #ifdef CONFIG_HAVE_MTD_OTP
 902         case OTPSELECT:
 903         {
 904                 int mode;
 905                 if (copy_from_user(&mode, argp, sizeof(int)))
 906                         return -EFAULT;
 907
 908                 mfi->mode = MTD_FILE_MODE_NORMAL;
 909
 910                 ret = otp_select_filemode(mfi, mode);
 911
 912                 file->f_pos = 0;
 913                 break;
 914         }
 915
 916         case OTPGETREGIONCOUNT:
 917         case OTPGETREGIONINFO:
 918         {
 919                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 920                 if (!buf)
 921                         return -ENOMEM;
 922                 ret = -EOPNOTSUPP;
 923                 switch (mfi->mode) {
 924                 case MTD_FILE_MODE_OTP_FACTORY:
 925                         if (mtd->get_fact_prot_info)
 926                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 927                         break;
 928                 case MTD_FILE_MODE_OTP_USER:
 929                         if (mtd->get_user_prot_info)
 930                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 931                         break;
 932                 default:
 933                         break;
 934                 }
 935                 if (ret >= 0) {
 936                         if (cmd == OTPGETREGIONCOUNT) {
 937                                 int nbr = ret / sizeof(struct otp_info);
 938                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 939                         } else
 940                                 ret = copy_to_user(argp, buf, ret);
 941                         if (ret)
 942                                 ret = -EFAULT;
 943                 }
 944                 kfree(buf);
 945                 break;
 946         }
 947
 948         case OTPLOCK:
 949         {
 950                 struct otp_info oinfo;
 951
 952                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 953                         return -EINVAL;
 954                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 955                         return -EFAULT;
 956                 if (!mtd->lock_user_prot_reg)
 957                         return -EOPNOTSUPP;
 958                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 959                 break;
 960         }
 961 #endif
 962
 963         /* This ioctl is being deprecated - it truncates the ECC layout */
 964         case ECCGETLAYOUT:
 965         {
 966                 struct nand_ecclayout_user *usrlay;
 967
 968                 if (!mtd->ecclayout)
 969                         return -EOPNOTSUPP;
 970
 971                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 972                 if (!usrlay)
 973                         return -ENOMEM;
 974
 975                 shrink_ecclayout(mtd->ecclayout, usrlay);
 976
 977                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 978                         ret = -EFAULT;
 979                 kfree(usrlay);
 980                 break;
 981         }
 982
 983         case ECCGETSTATS:
 984         {
 985                 if (copy_to_user(argp, &mtd->ecc_stats,
 986                                  sizeof(struct mtd_ecc_stats)))
 987                         return -EFAULT;
 988                 break;
 989         }
 990
 991         case MTDFILEMODE:
 992         {
 993                 mfi->mode = 0;
 994
 995                 switch(arg) {
 996                 case MTD_FILE_MODE_OTP_FACTORY:
 997                 case MTD_FILE_MODE_OTP_USER:
 998                         ret = otp_select_filemode(mfi, arg);
 999                         break;
1000
1001                 case MTD_FILE_MODE_RAW:
1002                         if (!mtd->read_oob || !mtd->write_oob)
1003                                 return -EOPNOTSUPP;
1004                         mfi->mode = arg;
1005
1006                 case MTD_FILE_MODE_NORMAL:
1007                         break;
1008                 default:
1009                         ret = -EINVAL;
1010                 }
1011                 file->f_pos = 0;
1012                 break;
1013         }
1014
1015         case BLKPG:
1016         {
1017                 ret = mtd_blkpg_ioctl(mtd,
1018                       (struct blkpg_ioctl_arg __user *)arg);
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 mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1037 {
1038         int ret;
1039
1040         mutex_lock(&mtd_mutex);
1041         ret = mtd_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 mtd_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 = mtd_do_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 = mtd_do_readoob(file, mtd, buf.start,
1093                                 buf.length, compat_ptr(buf.ptr),
1094                                 &buf_user->start);
1095                 break;
1096         }
1097         default:
1098                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1099         }
1100
1101         mutex_unlock(&mtd_mutex);
1102
1103         return ret;
1104 }
1105
1106 #endif /* CONFIG_COMPAT */
1107
1108 /*
1109  * try to determine where a shared mapping can be made
1110  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1111  *   mappings)
1112  */
1113 #ifndef CONFIG_MMU
1114 static unsigned long mtd_get_unmapped_area(struct file *file,
1115                                            unsigned long addr,
1116                                            unsigned long len,
1117                                            unsigned long pgoff,
1118                                            unsigned long flags)
1119 {
1120         struct mtd_file_info *mfi = file->private_data;
1121         struct mtd_info *mtd = mfi->mtd;
1122
1123         if (mtd->get_unmapped_area) {
1124                 unsigned long offset;
1125
1126                 if (addr != 0)
1127                         return (unsigned long) -EINVAL;
1128
1129                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1130                         return (unsigned long) -EINVAL;
1131
1132                 offset = pgoff << PAGE_SHIFT;
1133                 if (offset > mtd->size - len)
1134                         return (unsigned long) -EINVAL;
1135
1136                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1137         }
1138
1139         /* can't map directly */
1140         return (unsigned long) -ENOSYS;
1141 }
1142 #endif
1143
1144 /*
1145  * set up a mapping for shared memory segments
1146  */
1147 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1148 {
1149 #ifdef CONFIG_MMU
1150         struct mtd_file_info *mfi = file->private_data;
1151         struct mtd_info *mtd = mfi->mtd;
1152         struct map_info *map = mtd->priv;
1153         unsigned long start;
1154         unsigned long off;
1155         u32 len;
1156
1157         /* This is broken because it assumes the MTD device is map-based
1158            and that mtd->priv is a valid struct map_info.  It should be
1159            replaced with something that uses the mtd_get_unmapped_area()
1160            operation properly. */
1161         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1162                 off = vma->vm_pgoff << PAGE_SHIFT;
1163                 start = map->phys;
1164                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1165                 start &= PAGE_MASK;
1166                 if ((vma->vm_end - vma->vm_start + off) > len)
1167                         return -EINVAL;
1168
1169                 off += start;
1170                 vma->vm_pgoff = off >> PAGE_SHIFT;
1171                 vma->vm_flags |= VM_IO | VM_RESERVED;
1172
1173 #ifdef pgprot_noncached
1174                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1175                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1176 #endif
1177                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1178                                        vma->vm_end - vma->vm_start,
1179                                        vma->vm_page_prot))
1180                         return -EAGAIN;
1181
1182                 return 0;
1183         }
1184         return -ENOSYS;
1185 #else
1186         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1187 #endif
1188 }
1189
1190 static const struct file_operations mtd_fops = {
1191         .owner          = THIS_MODULE,
1192         .llseek         = mtd_lseek,
1193         .read           = mtd_read,
1194         .write          = mtd_write,
1195         .unlocked_ioctl = mtd_unlocked_ioctl,
1196 #ifdef CONFIG_COMPAT
1197         .compat_ioctl   = mtd_compat_ioctl,
1198 #endif
1199         .open           = mtd_open,
1200         .release        = mtd_close,
1201         .mmap           = mtd_mmap,
1202 #ifndef CONFIG_MMU
1203         .get_unmapped_area = mtd_get_unmapped_area,
1204 #endif
1205 };
1206
1207 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1208                                 int flags, const char *dev_name, void *data)
1209 {
1210         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1211 }
1212
1213 static struct file_system_type mtd_inodefs_type = {
1214        .name = "mtd_inodefs",
1215        .mount = mtd_inodefs_mount,
1216        .kill_sb = kill_anon_super,
1217 };
1218
1219 static void mtdchar_notify_add(struct mtd_info *mtd)
1220 {
1221 }
1222
1223 static void mtdchar_notify_remove(struct mtd_info *mtd)
1224 {
1225         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1226
1227         if (mtd_ino) {
1228                 /* Destroy the inode if it exists */
1229                 clear_nlink(mtd_ino);
1230                 iput(mtd_ino);
1231         }
1232 }
1233
1234 static struct mtd_notifier mtdchar_notifier = {
1235         .add = mtdchar_notify_add,
1236         .remove = mtdchar_notify_remove,
1237 };
1238
1239 static int __init init_mtdchar(void)
1240 {
1241         int ret;
1242
1243         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1244                                    "mtd", &mtd_fops);
1245         if (ret < 0) {
1246                 pr_notice("Can't allocate major number %d for "
1247                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1248                 return ret;
1249         }
1250
1251         ret = register_filesystem(&mtd_inodefs_type);
1252         if (ret) {
1253                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1254                 goto err_unregister_chdev;
1255         }
1256
1257         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1258         if (IS_ERR(mtd_inode_mnt)) {
1259                 ret = PTR_ERR(mtd_inode_mnt);
1260                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1261                 goto err_unregister_filesystem;
1262         }
1263         register_mtd_user(&mtdchar_notifier);
1264
1265         return ret;
1266
1267 err_unregister_filesystem:
1268         unregister_filesystem(&mtd_inodefs_type);
1269 err_unregister_chdev:
1270         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1271         return ret;
1272 }
1273
1274 static void __exit cleanup_mtdchar(void)
1275 {
1276         unregister_mtd_user(&mtdchar_notifier);
1277         kern_unmount(mtd_inode_mnt);
1278         unregister_filesystem(&mtd_inodefs_type);
1279         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1280 }
1281
1282 module_init(init_mtdchar);
1283 module_exit(cleanup_mtdchar);
1284
1285 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1286
1287 MODULE_LICENSE("GPL");
1288 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1289 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1290 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);