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 mtdchar_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 mtdchar_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 } /* mtdchar_open */
 146
 147 /*====================================================================*/
 148
 149 static int mtdchar_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 } /* mtdchar_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 mtdchar_read(struct file *file, char __user *buf, size_t count,
 188                         loff_t *ppos)
 189 {
 190         struct mtd_file_info *mfi = file->private_data;
 191         struct mtd_info *mtd = mfi->mtd;
 192         size_t retlen=0;
 193         size_t total_retlen=0;
 194         int ret=0;
 195         int len;
 196         size_t size = count;
 197         char *kbuf;
 198
 199         pr_debug("MTD_read\n");
 200
 201         if (*ppos + count > mtd->size)
 202                 count = mtd->size - *ppos;
 203
 204         if (!count)
 205                 return 0;
 206
 207         kbuf = mtd_kmalloc_up_to(mtd, &size);
 208         if (!kbuf)
 209                 return -ENOMEM;
 210
 211         while (count) {
 212                 len = min_t(size_t, count, size);
 213
 214                 switch (mfi->mode) {
 215                 case MTD_FILE_MODE_OTP_FACTORY:
 216                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 217                         break;
 218                 case MTD_FILE_MODE_OTP_USER:
 219                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 220                         break;
 221                 case MTD_FILE_MODE_RAW:
 222                 {
 223                         struct mtd_oob_ops ops;
 224
 225                         ops.mode = MTD_OPS_RAW;
 226                         ops.datbuf = kbuf;
 227                         ops.oobbuf = NULL;
 228                         ops.len = len;
 229
 230                         ret = mtd->read_oob(mtd, *ppos, &ops);
 231                         retlen = ops.retlen;
 232                         break;
 233                 }
 234                 default:
 235                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 236                 }
 237                 /* Nand returns -EBADMSG on ECC errors, but it returns
 238                  * the data. For our userspace tools it is important
 239                  * to dump areas with ECC errors!
 240                  * For kernel internal usage it also might return -EUCLEAN
 241                  * to signal the caller that a bitflip has occurred and has
 242                  * been corrected by the ECC algorithm.
 243                  * Userspace software which accesses NAND this way
 244                  * must be aware of the fact that it deals with NAND
 245                  */
 246                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 247                         *ppos += retlen;
 248                         if (copy_to_user(buf, kbuf, retlen)) {
 249                                 kfree(kbuf);
 250                                 return -EFAULT;
 251                         }
 252                         else
 253                                 total_retlen += retlen;
 254
 255                         count -= retlen;
 256                         buf += retlen;
 257                         if (retlen == 0)
 258                                 count = 0;
 259                 }
 260                 else {
 261                         kfree(kbuf);
 262                         return ret;
 263                 }
 264
 265         }
 266
 267         kfree(kbuf);
 268         return total_retlen;
 269 } /* mtdchar_read */
 270
 271 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 272                         loff_t *ppos)
 273 {
 274         struct mtd_file_info *mfi = file->private_data;
 275         struct mtd_info *mtd = mfi->mtd;
 276         size_t size = count;
 277         char *kbuf;
 278         size_t retlen;
 279         size_t total_retlen=0;
 280         int ret=0;
 281         int len;
 282
 283         pr_debug("MTD_write\n");
 284
 285         if (*ppos == mtd->size)
 286                 return -ENOSPC;
 287
 288         if (*ppos + count > mtd->size)
 289                 count = mtd->size - *ppos;
 290
 291         if (!count)
 292                 return 0;
 293
 294         kbuf = mtd_kmalloc_up_to(mtd, &size);
 295         if (!kbuf)
 296                 return -ENOMEM;
 297
 298         while (count) {
 299                 len = min_t(size_t, count, size);
 300
 301                 if (copy_from_user(kbuf, buf, len)) {
 302                         kfree(kbuf);
 303                         return -EFAULT;
 304                 }
 305
 306                 switch (mfi->mode) {
 307                 case MTD_FILE_MODE_OTP_FACTORY:
 308                         ret = -EROFS;
 309                         break;
 310                 case MTD_FILE_MODE_OTP_USER:
 311                         if (!mtd->write_user_prot_reg) {
 312                                 ret = -EOPNOTSUPP;
 313                                 break;
 314                         }
 315                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 316                         break;
 317
 318                 case MTD_FILE_MODE_RAW:
 319                 {
 320                         struct mtd_oob_ops ops;
 321
 322                         ops.mode = MTD_OPS_RAW;
 323                         ops.datbuf = kbuf;
 324                         ops.oobbuf = NULL;
 325                         ops.ooboffs = 0;
 326                         ops.len = len;
 327
 328                         ret = mtd->write_oob(mtd, *ppos, &ops);
 329                         retlen = ops.retlen;
 330                         break;
 331                 }
 332
 333                 default:
 334                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 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 #ifdef CONFIG_HAVE_MTD_OTP
 363 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 364 {
 365         struct mtd_info *mtd = mfi->mtd;
 366         int ret = 0;
 367
 368         switch (mode) {
 369         case MTD_OTP_FACTORY:
 370                 if (!mtd->read_fact_prot_reg)
 371                         ret = -EOPNOTSUPP;
 372                 else
 373                         mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 374                 break;
 375         case MTD_OTP_USER:
 376                 if (!mtd->read_fact_prot_reg)
 377                         ret = -EOPNOTSUPP;
 378                 else
 379                         mfi->mode = MTD_FILE_MODE_OTP_USER;
 380                 break;
 381         default:
 382                 ret = -EINVAL;
 383         case MTD_OTP_OFF:
 384                 break;
 385         }
 386         return ret;
 387 }
 388 #else
 389 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 390 #endif
 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 (!mtd->read_oob)
 453                 ret = -EOPNOTSUPP;
 454         else
 455                 ret = access_ok(VERIFY_WRITE, ptr,
 456                                 length) ? 0 : -EFAULT;
 457         if (ret)
 458                 return ret;
 459
 460         ops.ooblen = length;
 461         ops.ooboffs = start & (mtd->writesize - 1);
 462         ops.datbuf = NULL;
 463         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 464                 MTD_OPS_PLACE_OOB;
 465
 466         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 467                 return -EINVAL;
 468
 469         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 470         if (!ops.oobbuf)
 471                 return -ENOMEM;
 472
 473         start &= ~((uint64_t)mtd->writesize - 1);
 474         ret = mtd->read_oob(mtd, start, &ops);
 475
 476         if (put_user(ops.oobretlen, retp))
 477                 ret = -EFAULT;
 478         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 479                                             ops.oobretlen))
 480                 ret = -EFAULT;
 481
 482         kfree(ops.oobbuf);
 483
 484         /*
 485          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 486          * data. For our userspace tools it is important to dump areas
 487          * with ECC errors!
 488          * For kernel internal usage it also might return -EUCLEAN
 489          * to signal the caller that a bitflip has occured and has
 490          * been corrected by the ECC algorithm.
 491          *
 492          * Note: currently the standard NAND function, nand_read_oob_std,
 493          * does not calculate ECC for the OOB area, so do not rely on
 494          * this behavior unless you have replaced it with your own.
 495          */
 496         if (mtd_is_bitflip_or_eccerr(ret))
 497                 return 0;
 498
 499         return ret;
 500 }
 501
 502 /*
 503  * Copies (and truncates, if necessary) data from the larger struct,
 504  * nand_ecclayout, to the smaller, deprecated layout struct,
 505  * nand_ecclayout_user. This is necessary only to support the deprecated
 506  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 507  * nand_ecclayout flexibly (i.e. the struct may change size in new
 508  * releases without requiring major rewrites).
 509  */
 510 static int shrink_ecclayout(const struct nand_ecclayout *from,
 511                 struct nand_ecclayout_user *to)
 512 {
 513         int i;
 514
 515         if (!from || !to)
 516                 return -EINVAL;
 517
 518         memset(to, 0, sizeof(*to));
 519
 520         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 521         for (i = 0; i < to->eccbytes; i++)
 522                 to->eccpos[i] = from->eccpos[i];
 523
 524         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 525                 if (from->oobfree[i].length == 0 &&
 526                                 from->oobfree[i].offset == 0)
 527                         break;
 528                 to->oobavail += from->oobfree[i].length;
 529                 to->oobfree[i] = from->oobfree[i];
 530         }
 531
 532         return 0;
 533 }
 534
 535 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 536                            struct blkpg_ioctl_arg __user *arg)
 537 {
 538         struct blkpg_ioctl_arg a;
 539         struct blkpg_partition p;
 540
 541         if (!capable(CAP_SYS_ADMIN))
 542                 return -EPERM;
 543
 544         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 545                 return -EFAULT;
 546
 547         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 548                 return -EFAULT;
 549
 550         switch (a.op) {
 551         case BLKPG_ADD_PARTITION:
 552
 553                 /* Only master mtd device must be used to add partitions */
 554                 if (mtd_is_partition(mtd))
 555                         return -EINVAL;
 556
 557                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
 558
 559         case BLKPG_DEL_PARTITION:
 560
 561                 if (p.pno < 0)
 562                         return -EINVAL;
 563
 564                 return mtd_del_partition(mtd, p.pno);
 565
 566         default:
 567                 return -EINVAL;
 568         }
 569 }
 570
 571 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 572                 struct mtd_write_req __user *argp)
 573 {
 574         struct mtd_write_req req;
 575         struct mtd_oob_ops ops;
 576         void __user *usr_data, *usr_oob;
 577         int ret;
 578
 579         if (copy_from_user(&req, argp, sizeof(req)) ||
 580                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 581                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 582                 return -EFAULT;
 583         if (!mtd->write_oob)
 584                 return -EOPNOTSUPP;
 585
 586         ops.mode = req.mode;
 587         ops.len = (size_t)req.len;
 588         ops.ooblen = (size_t)req.ooblen;
 589         ops.ooboffs = 0;
 590
 591         usr_data = (void __user *)(uintptr_t)req.usr_data;
 592         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 593
 594         if (req.usr_data) {
 595                 ops.datbuf = memdup_user(usr_data, ops.len);
 596                 if (IS_ERR(ops.datbuf))
 597                         return PTR_ERR(ops.datbuf);
 598         } else {
 599                 ops.datbuf = NULL;
 600         }
 601
 602         if (req.usr_oob) {
 603                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 604                 if (IS_ERR(ops.oobbuf)) {
 605                         kfree(ops.datbuf);
 606                         return PTR_ERR(ops.oobbuf);
 607                 }
 608         } else {
 609                 ops.oobbuf = NULL;
 610         }
 611
 612         ret = mtd->write_oob(mtd, (loff_t)req.start, &ops);
 613
 614         kfree(ops.datbuf);
 615         kfree(ops.oobbuf);
 616
 617         return ret;
 618 }
 619
 620 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 621 {
 622         struct mtd_file_info *mfi = file->private_data;
 623         struct mtd_info *mtd = mfi->mtd;
 624         void __user *argp = (void __user *)arg;
 625         int ret = 0;
 626         u_long size;
 627         struct mtd_info_user info;
 628
 629         pr_debug("MTD_ioctl\n");
 630
 631         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 632         if (cmd & IOC_IN) {
 633                 if (!access_ok(VERIFY_READ, argp, size))
 634                         return -EFAULT;
 635         }
 636         if (cmd & IOC_OUT) {
 637                 if (!access_ok(VERIFY_WRITE, argp, size))
 638                         return -EFAULT;
 639         }
 640
 641         switch (cmd) {
 642         case MEMGETREGIONCOUNT:
 643                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 644                         return -EFAULT;
 645                 break;
 646
 647         case MEMGETREGIONINFO:
 648         {
 649                 uint32_t ur_idx;
 650                 struct mtd_erase_region_info *kr;
 651                 struct region_info_user __user *ur = argp;
 652
 653                 if (get_user(ur_idx, &(ur->regionindex)))
 654                         return -EFAULT;
 655
 656                 if (ur_idx >= mtd->numeraseregions)
 657                         return -EINVAL;
 658
 659                 kr = &(mtd->eraseregions[ur_idx]);
 660
 661                 if (put_user(kr->offset, &(ur->offset))
 662                     || put_user(kr->erasesize, &(ur->erasesize))
 663                     || put_user(kr->numblocks, &(ur->numblocks)))
 664                         return -EFAULT;
 665
 666                 break;
 667         }
 668
 669         case MEMGETINFO:
 670                 memset(&info, 0, sizeof(info));
 671                 info.type       = mtd->type;
 672                 info.flags      = mtd->flags;
 673                 info.size       = mtd->size;
 674                 info.erasesize  = mtd->erasesize;
 675                 info.writesize  = mtd->writesize;
 676                 info.oobsize    = mtd->oobsize;
 677                 /* The below field is obsolete */
 678                 info.padding    = 0;
 679                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 680                         return -EFAULT;
 681                 break;
 682
 683         case MEMERASE:
 684         case MEMERASE64:
 685         {
 686                 struct erase_info *erase;
 687
 688                 if(!(file->f_mode & FMODE_WRITE))
 689                         return -EPERM;
 690
 691                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 692                 if (!erase)
 693                         ret = -ENOMEM;
 694                 else {
 695                         wait_queue_head_t waitq;
 696                         DECLARE_WAITQUEUE(wait, current);
 697
 698                         init_waitqueue_head(&waitq);
 699
 700                         if (cmd == MEMERASE64) {
 701                                 struct erase_info_user64 einfo64;
 702
 703                                 if (copy_from_user(&einfo64, argp,
 704                                             sizeof(struct erase_info_user64))) {
 705                                         kfree(erase);
 706                                         return -EFAULT;
 707                                 }
 708                                 erase->addr = einfo64.start;
 709                                 erase->len = einfo64.length;
 710                         } else {
 711                                 struct erase_info_user einfo32;
 712
 713                                 if (copy_from_user(&einfo32, argp,
 714                                             sizeof(struct erase_info_user))) {
 715                                         kfree(erase);
 716                                         return -EFAULT;
 717                                 }
 718                                 erase->addr = einfo32.start;
 719                                 erase->len = einfo32.length;
 720                         }
 721                         erase->mtd = mtd;
 722                         erase->callback = mtdchar_erase_callback;
 723                         erase->priv = (unsigned long)&waitq;
 724
 725                         /*
 726                           FIXME: Allow INTERRUPTIBLE. Which means
 727                           not having the wait_queue head on the stack.
 728
 729                           If the wq_head is on the stack, and we
 730                           leave because we got interrupted, then the
 731                           wq_head is no longer there when the
 732                           callback routine tries to wake us up.
 733                         */
 734                         ret = mtd_erase(mtd, erase);
 735                         if (!ret) {
 736                                 set_current_state(TASK_UNINTERRUPTIBLE);
 737                                 add_wait_queue(&waitq, &wait);
 738                                 if (erase->state != MTD_ERASE_DONE &&
 739                                     erase->state != MTD_ERASE_FAILED)
 740                                         schedule();
 741                                 remove_wait_queue(&waitq, &wait);
 742                                 set_current_state(TASK_RUNNING);
 743
 744                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 745                         }
 746                         kfree(erase);
 747                 }
 748                 break;
 749         }
 750
 751         case MEMWRITEOOB:
 752         {
 753                 struct mtd_oob_buf buf;
 754                 struct mtd_oob_buf __user *buf_user = argp;
 755
 756                 /* NOTE: writes return length to buf_user->length */
 757                 if (copy_from_user(&buf, argp, sizeof(buf)))
 758                         ret = -EFAULT;
 759                 else
 760                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 761                                 buf.ptr, &buf_user->length);
 762                 break;
 763         }
 764
 765         case MEMREADOOB:
 766         {
 767                 struct mtd_oob_buf buf;
 768                 struct mtd_oob_buf __user *buf_user = argp;
 769
 770                 /* NOTE: writes return length to buf_user->start */
 771                 if (copy_from_user(&buf, argp, sizeof(buf)))
 772                         ret = -EFAULT;
 773                 else
 774                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 775                                 buf.ptr, &buf_user->start);
 776                 break;
 777         }
 778
 779         case MEMWRITEOOB64:
 780         {
 781                 struct mtd_oob_buf64 buf;
 782                 struct mtd_oob_buf64 __user *buf_user = argp;
 783
 784                 if (copy_from_user(&buf, argp, sizeof(buf)))
 785                         ret = -EFAULT;
 786                 else
 787                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 788                                 (void __user *)(uintptr_t)buf.usr_ptr,
 789                                 &buf_user->length);
 790                 break;
 791         }
 792
 793         case MEMREADOOB64:
 794         {
 795                 struct mtd_oob_buf64 buf;
 796                 struct mtd_oob_buf64 __user *buf_user = argp;
 797
 798                 if (copy_from_user(&buf, argp, sizeof(buf)))
 799                         ret = -EFAULT;
 800                 else
 801                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 802                                 (void __user *)(uintptr_t)buf.usr_ptr,
 803                                 &buf_user->length);
 804                 break;
 805         }
 806
 807         case MEMWRITE:
 808         {
 809                 ret = mtdchar_write_ioctl(mtd,
 810                       (struct mtd_write_req __user *)arg);
 811                 break;
 812         }
 813
 814         case MEMLOCK:
 815         {
 816                 struct erase_info_user einfo;
 817
 818                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 819                         return -EFAULT;
 820
 821                 if (!mtd->lock)
 822                         ret = -EOPNOTSUPP;
 823                 else
 824                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 825                 break;
 826         }
 827
 828         case MEMUNLOCK:
 829         {
 830                 struct erase_info_user einfo;
 831
 832                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 833                         return -EFAULT;
 834
 835                 if (!mtd->unlock)
 836                         ret = -EOPNOTSUPP;
 837                 else
 838                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 839                 break;
 840         }
 841
 842         case MEMISLOCKED:
 843         {
 844                 struct erase_info_user einfo;
 845
 846                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 847                         return -EFAULT;
 848
 849                 if (!mtd->is_locked)
 850                         ret = -EOPNOTSUPP;
 851                 else
 852                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 853                 break;
 854         }
 855
 856         /* Legacy interface */
 857         case MEMGETOOBSEL:
 858         {
 859                 struct nand_oobinfo oi;
 860
 861                 if (!mtd->ecclayout)
 862                         return -EOPNOTSUPP;
 863                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 864                         return -EINVAL;
 865
 866                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 867                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 868                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 869                        sizeof(oi.oobfree));
 870                 oi.eccbytes = mtd->ecclayout->eccbytes;
 871
 872                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 873                         return -EFAULT;
 874                 break;
 875         }
 876
 877         case MEMGETBADBLOCK:
 878         {
 879                 loff_t offs;
 880
 881                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 882                         return -EFAULT;
 883                 if (!mtd->block_isbad)
 884                         ret = -EOPNOTSUPP;
 885                 else
 886                         return mtd->block_isbad(mtd, offs);
 887                 break;
 888         }
 889
 890         case MEMSETBADBLOCK:
 891         {
 892                 loff_t offs;
 893
 894                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 895                         return -EFAULT;
 896                 if (!mtd->block_markbad)
 897                         ret = -EOPNOTSUPP;
 898                 else
 899                         return mtd->block_markbad(mtd, offs);
 900                 break;
 901         }
 902
 903 #ifdef CONFIG_HAVE_MTD_OTP
 904         case OTPSELECT:
 905         {
 906                 int mode;
 907                 if (copy_from_user(&mode, argp, sizeof(int)))
 908                         return -EFAULT;
 909
 910                 mfi->mode = MTD_FILE_MODE_NORMAL;
 911
 912                 ret = otp_select_filemode(mfi, mode);
 913
 914                 file->f_pos = 0;
 915                 break;
 916         }
 917
 918         case OTPGETREGIONCOUNT:
 919         case OTPGETREGIONINFO:
 920         {
 921                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 922                 if (!buf)
 923                         return -ENOMEM;
 924                 ret = -EOPNOTSUPP;
 925                 switch (mfi->mode) {
 926                 case MTD_FILE_MODE_OTP_FACTORY:
 927                         if (mtd->get_fact_prot_info)
 928                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 929                         break;
 930                 case MTD_FILE_MODE_OTP_USER:
 931                         if (mtd->get_user_prot_info)
 932                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 933                         break;
 934                 default:
 935                         break;
 936                 }
 937                 if (ret >= 0) {
 938                         if (cmd == OTPGETREGIONCOUNT) {
 939                                 int nbr = ret / sizeof(struct otp_info);
 940                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 941                         } else
 942                                 ret = copy_to_user(argp, buf, ret);
 943                         if (ret)
 944                                 ret = -EFAULT;
 945                 }
 946                 kfree(buf);
 947                 break;
 948         }
 949
 950         case OTPLOCK:
 951         {
 952                 struct otp_info oinfo;
 953
 954                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 955                         return -EINVAL;
 956                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 957                         return -EFAULT;
 958                 if (!mtd->lock_user_prot_reg)
 959                         return -EOPNOTSUPP;
 960                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 961                 break;
 962         }
 963 #endif
 964
 965         /* This ioctl is being deprecated - it truncates the ECC layout */
 966         case ECCGETLAYOUT:
 967         {
 968                 struct nand_ecclayout_user *usrlay;
 969
 970                 if (!mtd->ecclayout)
 971                         return -EOPNOTSUPP;
 972
 973                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 974                 if (!usrlay)
 975                         return -ENOMEM;
 976
 977                 shrink_ecclayout(mtd->ecclayout, usrlay);
 978
 979                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 980                         ret = -EFAULT;
 981                 kfree(usrlay);
 982                 break;
 983         }
 984
 985         case ECCGETSTATS:
 986         {
 987                 if (copy_to_user(argp, &mtd->ecc_stats,
 988                                  sizeof(struct mtd_ecc_stats)))
 989                         return -EFAULT;
 990                 break;
 991         }
 992
 993         case MTDFILEMODE:
 994         {
 995                 mfi->mode = 0;
 996
 997                 switch(arg) {
 998                 case MTD_FILE_MODE_OTP_FACTORY:
 999                 case MTD_FILE_MODE_OTP_USER:
1000                         ret = otp_select_filemode(mfi, arg);
1001                         break;
1002
1003                 case MTD_FILE_MODE_RAW:
1004                         if (!mtd->read_oob || !mtd->write_oob)
1005                                 return -EOPNOTSUPP;
1006                         mfi->mode = arg;
1007
1008                 case MTD_FILE_MODE_NORMAL:
1009                         break;
1010                 default:
1011                         ret = -EINVAL;
1012                 }
1013                 file->f_pos = 0;
1014                 break;
1015         }
1016
1017         case BLKPG:
1018         {
1019                 ret = mtdchar_blkpg_ioctl(mtd,
1020                       (struct blkpg_ioctl_arg __user *)arg);
1021                 break;
1022         }
1023
1024         case BLKRRPART:
1025         {
1026                 /* No reread partition feature. Just return ok */
1027                 ret = 0;
1028                 break;
1029         }
1030
1031         default:
1032                 ret = -ENOTTY;
1033         }
1034
1035         return ret;
1036 } /* memory_ioctl */
1037
1038 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1039 {
1040         int ret;
1041
1042         mutex_lock(&mtd_mutex);
1043         ret = mtdchar_ioctl(file, cmd, arg);
1044         mutex_unlock(&mtd_mutex);
1045
1046         return ret;
1047 }
1048
1049 #ifdef CONFIG_COMPAT
1050
1051 struct mtd_oob_buf32 {
1052         u_int32_t start;
1053         u_int32_t length;
1054         compat_caddr_t ptr;     /* unsigned char* */
1055 };
1056
1057 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1058 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1059
1060 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1061         unsigned long arg)
1062 {
1063         struct mtd_file_info *mfi = file->private_data;
1064         struct mtd_info *mtd = mfi->mtd;
1065         void __user *argp = compat_ptr(arg);
1066         int ret = 0;
1067
1068         mutex_lock(&mtd_mutex);
1069
1070         switch (cmd) {
1071         case MEMWRITEOOB32:
1072         {
1073                 struct mtd_oob_buf32 buf;
1074                 struct mtd_oob_buf32 __user *buf_user = argp;
1075
1076                 if (copy_from_user(&buf, argp, sizeof(buf)))
1077                         ret = -EFAULT;
1078                 else
1079                         ret = mtdchar_writeoob(file, mtd, buf.start,
1080                                 buf.length, compat_ptr(buf.ptr),
1081                                 &buf_user->length);
1082                 break;
1083         }
1084
1085         case MEMREADOOB32:
1086         {
1087                 struct mtd_oob_buf32 buf;
1088                 struct mtd_oob_buf32 __user *buf_user = argp;
1089
1090                 /* NOTE: writes return length to buf->start */
1091                 if (copy_from_user(&buf, argp, sizeof(buf)))
1092                         ret = -EFAULT;
1093                 else
1094                         ret = mtdchar_readoob(file, mtd, buf.start,
1095                                 buf.length, compat_ptr(buf.ptr),
1096                                 &buf_user->start);
1097                 break;
1098         }
1099         default:
1100                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1101         }
1102
1103         mutex_unlock(&mtd_mutex);
1104
1105         return ret;
1106 }
1107
1108 #endif /* CONFIG_COMPAT */
1109
1110 /*
1111  * try to determine where a shared mapping can be made
1112  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1113  *   mappings)
1114  */
1115 #ifndef CONFIG_MMU
1116 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1117                                            unsigned long addr,
1118                                            unsigned long len,
1119                                            unsigned long pgoff,
1120                                            unsigned long flags)
1121 {
1122         struct mtd_file_info *mfi = file->private_data;
1123         struct mtd_info *mtd = mfi->mtd;
1124
1125         if (mtd->get_unmapped_area) {
1126                 unsigned long offset;
1127
1128                 if (addr != 0)
1129                         return (unsigned long) -EINVAL;
1130
1131                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1132                         return (unsigned long) -EINVAL;
1133
1134                 offset = pgoff << PAGE_SHIFT;
1135                 if (offset > mtd->size - len)
1136                         return (unsigned long) -EINVAL;
1137
1138                 return mtd_get_unmapped_area(mtd, len, offset, flags);
1139         }
1140
1141         /* can't map directly */
1142         return (unsigned long) -ENOSYS;
1143 }
1144 #endif
1145
1146 /*
1147  * set up a mapping for shared memory segments
1148  */
1149 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1150 {
1151 #ifdef CONFIG_MMU
1152         struct mtd_file_info *mfi = file->private_data;
1153         struct mtd_info *mtd = mfi->mtd;
1154         struct map_info *map = mtd->priv;
1155         unsigned long start;
1156         unsigned long off;
1157         u32 len;
1158
1159         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1160                 off = vma->vm_pgoff << PAGE_SHIFT;
1161                 start = map->phys;
1162                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1163                 start &= PAGE_MASK;
1164                 if ((vma->vm_end - vma->vm_start + off) > len)
1165                         return -EINVAL;
1166
1167                 off += start;
1168                 vma->vm_pgoff = off >> PAGE_SHIFT;
1169                 vma->vm_flags |= VM_IO | VM_RESERVED;
1170
1171 #ifdef pgprot_noncached
1172                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1173                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1174 #endif
1175                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1176                                        vma->vm_end - vma->vm_start,
1177                                        vma->vm_page_prot))
1178                         return -EAGAIN;
1179
1180                 return 0;
1181         }
1182         return -ENOSYS;
1183 #else
1184         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1185 #endif
1186 }
1187
1188 static const struct file_operations mtd_fops = {
1189         .owner          = THIS_MODULE,
1190         .llseek         = mtdchar_lseek,
1191         .read           = mtdchar_read,
1192         .write          = mtdchar_write,
1193         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1194 #ifdef CONFIG_COMPAT
1195         .compat_ioctl   = mtdchar_compat_ioctl,
1196 #endif
1197         .open           = mtdchar_open,
1198         .release        = mtdchar_close,
1199         .mmap           = mtdchar_mmap,
1200 #ifndef CONFIG_MMU
1201         .get_unmapped_area = mtdchar_get_unmapped_area,
1202 #endif
1203 };
1204
1205 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1206                                 int flags, const char *dev_name, void *data)
1207 {
1208         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1209 }
1210
1211 static struct file_system_type mtd_inodefs_type = {
1212        .name = "mtd_inodefs",
1213        .mount = mtd_inodefs_mount,
1214        .kill_sb = kill_anon_super,
1215 };
1216
1217 static void mtdchar_notify_add(struct mtd_info *mtd)
1218 {
1219 }
1220
1221 static void mtdchar_notify_remove(struct mtd_info *mtd)
1222 {
1223         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1224
1225         if (mtd_ino) {
1226                 /* Destroy the inode if it exists */
1227                 clear_nlink(mtd_ino);
1228                 iput(mtd_ino);
1229         }
1230 }
1231
1232 static struct mtd_notifier mtdchar_notifier = {
1233         .add = mtdchar_notify_add,
1234         .remove = mtdchar_notify_remove,
1235 };
1236
1237 static int __init init_mtdchar(void)
1238 {
1239         int ret;
1240
1241         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1242                                    "mtd", &mtd_fops);
1243         if (ret < 0) {
1244                 pr_notice("Can't allocate major number %d for "
1245                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1246                 return ret;
1247         }
1248
1249         ret = register_filesystem(&mtd_inodefs_type);
1250         if (ret) {
1251                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1252                 goto err_unregister_chdev;
1253         }
1254
1255         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1256         if (IS_ERR(mtd_inode_mnt)) {
1257                 ret = PTR_ERR(mtd_inode_mnt);
1258                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1259                 goto err_unregister_filesystem;
1260         }
1261         register_mtd_user(&mtdchar_notifier);
1262
1263         return ret;
1264
1265 err_unregister_filesystem:
1266         unregister_filesystem(&mtd_inodefs_type);
1267 err_unregister_chdev:
1268         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1269         return ret;
1270 }
1271
1272 static void __exit cleanup_mtdchar(void)
1273 {
1274         unregister_mtd_user(&mtdchar_notifier);
1275         kern_unmount(mtd_inode_mnt);
1276         unregister_filesystem(&mtd_inodefs_type);
1277         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1278 }
1279
1280 module_init(init_mtdchar);
1281 module_exit(cleanup_mtdchar);
1282
1283 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1284
1285 MODULE_LICENSE("GPL");
1286 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1287 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1288 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);