SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/mtd/mtdchar.c

   1 /*
   2  * $Id: mtdchar.c,v 1.68 2005/02/08 19:12:50 nico Exp $
   3  *
   4  * Character-device access to raw MTD devices.
   5  *
   6  */
   7
   8 #include <linux/config.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/mtd/mtd.h>
  12 #include <linux/mtd/compatmac.h>
  13 #include <linux/slab.h>
  14 #include <linux/init.h>
  15 #include <linux/fs.h>
  16 #include <asm/uaccess.h>
  17
  18 #ifdef CONFIG_DEVFS_FS
  19 #include <linux/devfs_fs_kernel.h>
  20
  21 static void mtd_notify_add(struct mtd_info* mtd)
  22 {
  23         if (!mtd)
  24                 return;
  25
  26         devfs_mk_cdev(MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
  27                       S_IFCHR | S_IRUGO | S_IWUGO, "mtd/%d", mtd->index);
  28
  29         devfs_mk_cdev(MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
  30                       S_IFCHR | S_IRUGO, "mtd/%dro", mtd->index);
  31 }
  32
  33 static void mtd_notify_remove(struct mtd_info* mtd)
  34 {
  35         if (!mtd)
  36                 return;
  37         devfs_remove("mtd/%d", mtd->index);
  38         devfs_remove("mtd/%dro", mtd->index);
  39 }
  40
  41 static struct mtd_notifier notifier = {
  42         .add    = mtd_notify_add,
  43         .remove = mtd_notify_remove,
  44 };
  45
  46 static inline void mtdchar_devfs_init(void)
  47 {
  48         devfs_mk_dir("mtd");
  49         register_mtd_user(&notifier);
  50 }
  51
  52 static inline void mtdchar_devfs_exit(void)
  53 {
  54         unregister_mtd_user(&notifier);
  55         devfs_remove("mtd");
  56 }
  57 #else /* !DEVFS */
  58 #define mtdchar_devfs_init() do { } while(0)
  59 #define mtdchar_devfs_exit() do { } while(0)
  60 #endif
  61
  62 /*
  63  * We use file->private_data to store a pointer to the MTDdevice.
  64  * Since alighment is at least 32 bits, we have 2 bits free for OTP
  65  * modes as well.
  66  */
  67
  68 #define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
  69
  70 #define MTD_MODE_OTP_FACT       1
  71 #define MTD_MODE_OTP_USER       2
  72 #define MTD_MODE(file)          ((long)((file)->private_data) & 3)
  73
  74 #define SET_MTD_MODE(file, mode) \
  75         do { long __p = (long)((file)->private_data); \
  76              (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
  77
  78 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  79 {
  80         struct mtd_info *mtd = TO_MTD(file);
  81
  82         switch (orig) {
  83         case 0:
  84                 /* SEEK_SET */
  85                 file->f_pos = offset;
  86                 break;
  87         case 1:
  88                 /* SEEK_CUR */
  89                 file->f_pos += offset;
  90                 break;
  91         case 2:
  92                 /* SEEK_END */
  93                 file->f_pos =mtd->size + offset;
  94                 break;
  95         default:
  96                 return -EINVAL;
  97         }
  98
  99         if (file->f_pos < 0)
 100                 file->f_pos = 0;
 101         else if (file->f_pos >= mtd->size)
 102                 file->f_pos = mtd->size - 1;
 103
 104         return file->f_pos;
 105 }
 106
 107
 108
 109 static int mtd_open(struct inode *inode, struct file *file)
 110 {
 111         int minor = iminor(inode);
 112         int devnum = minor >> 1;
 113         struct mtd_info *mtd;
 114
 115         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 116
 117         if (devnum >= MAX_MTD_DEVICES)
 118                 return -ENODEV;
 119
 120         /* You can't open the RO devices RW */
 121         if ((file->f_mode & 2) && (minor & 1))
 122                 return -EACCES;
 123
 124         mtd = get_mtd_device(NULL, devnum);
 125
 126         if (!mtd)
 127                 return -ENODEV;
 128
 129         if (MTD_ABSENT == mtd->type) {
 130                 put_mtd_device(mtd);
 131                 return -ENODEV;
 132         }
 133
 134         file->private_data = mtd;
 135
 136         /* You can't open it RW if it's not a writeable device */
 137         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
 138                 put_mtd_device(mtd);
 139                 return -EACCES;
 140         }
 141
 142         return 0;
 143 } /* mtd_open */
 144
 145 /*====================================================================*/
 146
 147 static int mtd_close(struct inode *inode, struct file *file)
 148 {
 149         struct mtd_info *mtd;
 150
 151         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 152
 153         mtd = TO_MTD(file);
 154
 155         if (mtd->sync)
 156                 mtd->sync(mtd);
 157
 158         put_mtd_device(mtd);
 159
 160         return 0;
 161 } /* mtd_close */
 162
 163 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 164    userspace buffer down and use it directly with readv/writev.
 165 */
 166 #define MAX_KMALLOC_SIZE 0x20000
 167
 168 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 169 {
 170         struct mtd_info *mtd = TO_MTD(file);
 171         size_t retlen=0;
 172         size_t total_retlen=0;
 173         int ret=0;
 174         int len;
 175         char *kbuf;
 176
 177         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 178
 179         if (*ppos + count > mtd->size)
 180                 count = mtd->size - *ppos;
 181
 182         if (!count)
 183                 return 0;
 184
 185         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 186            and pass them directly to the MTD functions */
 187         while (count) {
 188                 if (count > MAX_KMALLOC_SIZE)
 189                         len = MAX_KMALLOC_SIZE;
 190                 else
 191                         len = count;
 192
 193                 kbuf=kmalloc(len,GFP_KERNEL);
 194                 if (!kbuf)
 195                         return -ENOMEM;
 196
 197                 switch (MTD_MODE(file)) {
 198                 case MTD_MODE_OTP_FACT:
 199                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 200                         break;
 201                 case MTD_MODE_OTP_USER:
 202                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 203                         break;
 204                 default:
 205                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 206                 }
 207                 /* Nand returns -EBADMSG on ecc errors, but it returns
 208                  * the data. For our userspace tools it is important
 209                  * to dump areas with ecc errors !
 210                  * Userspace software which accesses NAND this way
 211                  * must be aware of the fact that it deals with NAND
 212                  */
 213                 if (!ret || (ret == -EBADMSG)) {
 214                         *ppos += retlen;
 215                         if (copy_to_user(buf, kbuf, retlen)) {
 216                                 kfree(kbuf);
 217                                 return -EFAULT;
 218                         }
 219                         else
 220                                 total_retlen += retlen;
 221
 222                         count -= retlen;
 223                         buf += retlen;
 224                         if (retlen == 0)
 225                                 count = 0;
 226                 }
 227                 else {
 228                         kfree(kbuf);
 229                         return ret;
 230                 }
 231
 232                 kfree(kbuf);
 233         }
 234
 235         return total_retlen;
 236 } /* mtd_read */
 237
 238 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 239 {
 240         struct mtd_info *mtd = TO_MTD(file);
 241         char *kbuf;
 242         size_t retlen;
 243         size_t total_retlen=0;
 244         int ret=0;
 245         int len;
 246
 247         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 248
 249         if (*ppos == mtd->size)
 250                 return -ENOSPC;
 251
 252         if (*ppos + count > mtd->size)
 253                 count = mtd->size - *ppos;
 254
 255         if (!count)
 256                 return 0;
 257
 258         while (count) {
 259                 if (count > MAX_KMALLOC_SIZE)
 260                         len = MAX_KMALLOC_SIZE;
 261                 else
 262                         len = count;
 263
 264                 kbuf=kmalloc(len,GFP_KERNEL);
 265                 if (!kbuf) {
 266                         printk("kmalloc is null\n");
 267                         return -ENOMEM;
 268                 }
 269
 270                 if (copy_from_user(kbuf, buf, len)) {
 271                         kfree(kbuf);
 272                         return -EFAULT;
 273                 }
 274
 275                 switch (MTD_MODE(file)) {
 276                 case MTD_MODE_OTP_FACT:
 277                         ret = -EROFS;
 278                         break;
 279                 case MTD_MODE_OTP_USER:
 280                         if (!mtd->write_user_prot_reg) {
 281                                 ret = -EOPNOTSUPP;
 282                                 break;
 283                         }
 284                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 285                         break;
 286                 default:
 287                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 288                 }
 289                 if (!ret) {
 290                         *ppos += retlen;
 291                         total_retlen += retlen;
 292                         count -= retlen;
 293                         buf += retlen;
 294                 }
 295                 else {
 296                         kfree(kbuf);
 297                         return ret;
 298                 }
 299
 300                 kfree(kbuf);
 301         }
 302
 303         return total_retlen;
 304 } /* mtd_write */
 305
 306 /*======================================================================
 307
 308     IOCTL calls for getting device parameters.
 309
 310 ======================================================================*/
 311 static void mtdchar_erase_callback (struct erase_info *instr)
 312 {
 313         wake_up((wait_queue_head_t *)instr->priv);
 314 }
 315
 316 static int mtd_ioctl(struct inode *inode, struct file *file,
 317                      u_int cmd, u_long arg)
 318 {
 319         struct mtd_info *mtd = TO_MTD(file);
 320         void __user *argp = (void __user *)arg;
 321         int ret = 0;
 322         u_long size;
 323
 324         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 325
 326         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 327         if (cmd & IOC_IN) {
 328                 if (!access_ok(VERIFY_READ, argp, size))
 329                         return -EFAULT;
 330         }
 331         if (cmd & IOC_OUT) {
 332                 if (!access_ok(VERIFY_WRITE, argp, size))
 333                         return -EFAULT;
 334         }
 335
 336         switch (cmd) {
 337         case MEMGETREGIONCOUNT:
 338                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 339                         return -EFAULT;
 340                 break;
 341
 342         case MEMGETREGIONINFO:
 343         {
 344                 struct region_info_user ur;
 345
 346                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 347                         return -EFAULT;
 348
 349                 if (ur.regionindex >= mtd->numeraseregions)
 350                         return -EINVAL;
 351                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 352                                 sizeof(struct mtd_erase_region_info)))
 353                         return -EFAULT;
 354                 break;
 355         }
 356
 357         case MEMGETINFO:
 358                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 359                         return -EFAULT;
 360                 break;
 361
 362         case MEMERASE:
 363         {
 364                 struct erase_info *erase;
 365
 366                 if(!(file->f_mode & 2))
 367                         return -EPERM;
 368
 369                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 370                 if (!erase)
 371                         ret = -ENOMEM;
 372                 else {
 373                         wait_queue_head_t waitq;
 374                         DECLARE_WAITQUEUE(wait, current);
 375
 376                         init_waitqueue_head(&waitq);
 377
 378                         memset (erase,0,sizeof(struct erase_info));
 379                         if (copy_from_user(&erase->addr, argp,
 380                                     sizeof(struct erase_info_user))) {
 381                                 kfree(erase);
 382                                 return -EFAULT;
 383                         }
 384                         erase->mtd = mtd;
 385                         erase->callback = mtdchar_erase_callback;
 386                         erase->priv = (unsigned long)&waitq;
 387
 388                         /*
 389                           FIXME: Allow INTERRUPTIBLE. Which means
 390                           not having the wait_queue head on the stack.
 391
 392                           If the wq_head is on the stack, and we
 393                           leave because we got interrupted, then the
 394                           wq_head is no longer there when the
 395                           callback routine tries to wake us up.
 396                         */
 397                         ret = mtd->erase(mtd, erase);
 398                         if (!ret) {
 399                                 set_current_state(TASK_UNINTERRUPTIBLE);
 400                                 add_wait_queue(&waitq, &wait);
 401                                 if (erase->state != MTD_ERASE_DONE &&
 402                                     erase->state != MTD_ERASE_FAILED)
 403                                         schedule();
 404                                 remove_wait_queue(&waitq, &wait);
 405                                 set_current_state(TASK_RUNNING);
 406
 407                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 408                         }
 409                         kfree(erase);
 410                 }
 411                 break;
 412         }
 413
 414         case MEMWRITEOOB:
 415         {
 416                 struct mtd_oob_buf buf;
 417                 void *databuf;
 418                 ssize_t retlen;
 419
 420                 if(!(file->f_mode & 2))
 421                         return -EPERM;
 422
 423                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 424                         return -EFAULT;
 425
 426                 if (buf.length > 0x4096)
 427                         return -EINVAL;
 428
 429                 if (!mtd->write_oob)
 430                         ret = -EOPNOTSUPP;
 431                 else
 432                         ret = access_ok(VERIFY_READ, buf.ptr,
 433                                         buf.length) ? 0 : EFAULT;
 434
 435                 if (ret)
 436                         return ret;
 437
 438                 databuf = kmalloc(buf.length, GFP_KERNEL);
 439                 if (!databuf)
 440                         return -ENOMEM;
 441
 442                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 443                         kfree(databuf);
 444                         return -EFAULT;
 445                 }
 446
 447                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 448
 449                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 450                         ret = -EFAULT;
 451
 452                 kfree(databuf);
 453                 break;
 454
 455         }
 456
 457         case MEMREADOOB:
 458         {
 459                 struct mtd_oob_buf buf;
 460                 void *databuf;
 461                 ssize_t retlen;
 462
 463                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 464                         return -EFAULT;
 465
 466                 if (buf.length > 0x4096)
 467                         return -EINVAL;
 468
 469                 if (!mtd->read_oob)
 470                         ret = -EOPNOTSUPP;
 471                 else
 472                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 473                                         buf.length) ? 0 : -EFAULT;
 474
 475                 if (ret)
 476                         return ret;
 477
 478                 databuf = kmalloc(buf.length, GFP_KERNEL);
 479                 if (!databuf)
 480                         return -ENOMEM;
 481
 482                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 483
 484                 if (put_user(retlen, (uint32_t __user *)argp))
 485                         ret = -EFAULT;
 486                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 487                         ret = -EFAULT;
 488
 489                 kfree(databuf);
 490                 break;
 491         }
 492
 493         case MEMLOCK:
 494         {
 495                 struct erase_info_user info;
 496
 497                 if (copy_from_user(&info, argp, sizeof(info)))
 498                         return -EFAULT;
 499
 500                 if (!mtd->lock)
 501                         ret = -EOPNOTSUPP;
 502                 else
 503                         ret = mtd->lock(mtd, info.start, info.length);
 504                 break;
 505         }
 506
 507         case MEMUNLOCK:
 508         {
 509                 struct erase_info_user info;
 510
 511                 if (copy_from_user(&info, argp, sizeof(info)))
 512                         return -EFAULT;
 513
 514                 if (!mtd->unlock)
 515                         ret = -EOPNOTSUPP;
 516                 else
 517                         ret = mtd->unlock(mtd, info.start, info.length);
 518                 break;
 519         }
 520
 521         case MEMSETOOBSEL:
 522         {
 523                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
 524                         return -EFAULT;
 525                 break;
 526         }
 527
 528         case MEMGETOOBSEL:
 529         {
 530                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
 531                         return -EFAULT;
 532                 break;
 533         }
 534
 535         case MEMGETBADBLOCK:
 536         {
 537                 loff_t offs;
 538
 539                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 540                         return -EFAULT;
 541                 if (!mtd->block_isbad)
 542                         ret = -EOPNOTSUPP;
 543                 else
 544                         return mtd->block_isbad(mtd, offs);
 545                 break;
 546         }
 547
 548         case MEMSETBADBLOCK:
 549         {
 550                 loff_t offs;
 551
 552                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 553                         return -EFAULT;
 554                 if (!mtd->block_markbad)
 555                         ret = -EOPNOTSUPP;
 556                 else
 557                         return mtd->block_markbad(mtd, offs);
 558                 break;
 559         }
 560
 561 #ifdef CONFIG_MTD_OTP
 562         case OTPSELECT:
 563         {
 564                 int mode;
 565                 if (copy_from_user(&mode, argp, sizeof(int)))
 566                         return -EFAULT;
 567                 SET_MTD_MODE(file, 0);
 568                 switch (mode) {
 569                 case MTD_OTP_FACTORY:
 570                         if (!mtd->read_fact_prot_reg)
 571                                 ret = -EOPNOTSUPP;
 572                         else
 573                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
 574                         break;
 575                 case MTD_OTP_USER:
 576                         if (!mtd->read_fact_prot_reg)
 577                                 ret = -EOPNOTSUPP;
 578                         else
 579                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
 580                         break;
 581                 default:
 582                         ret = -EINVAL;
 583                 case MTD_OTP_OFF:
 584                         break;
 585                 }
 586                 break;
 587         }
 588
 589         case OTPGETREGIONCOUNT:
 590         case OTPGETREGIONINFO:
 591         {
 592                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 593                 if (!buf)
 594                         return -ENOMEM;
 595                 ret = -EOPNOTSUPP;
 596                 switch (MTD_MODE(file)) {
 597                 case MTD_MODE_OTP_FACT:
 598                         if (mtd->get_fact_prot_info)
 599                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 600                         break;
 601                 case MTD_MODE_OTP_USER:
 602                         if (mtd->get_user_prot_info)
 603                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 604                         break;
 605                 }
 606                 if (ret >= 0) {
 607                         if (cmd == OTPGETREGIONCOUNT) {
 608                                 int nbr = ret / sizeof(struct otp_info);
 609                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 610                         } else
 611                                 ret = copy_to_user(argp, buf, ret);
 612                         if (ret)
 613                                 ret = -EFAULT;
 614                 }
 615                 kfree(buf);
 616                 break;
 617         }
 618
 619         case OTPLOCK:
 620         {
 621                 struct otp_info info;
 622
 623                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
 624                         return -EINVAL;
 625                 if (copy_from_user(&info, argp, sizeof(info)))
 626                         return -EFAULT;
 627                 if (!mtd->lock_user_prot_reg)
 628                         return -EOPNOTSUPP;
 629                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
 630                 break;
 631         }
 632 #endif
 633
 634         default:
 635                 ret = -ENOTTY;
 636         }
 637
 638         return ret;
 639 } /* memory_ioctl */
 640
 641 static struct file_operations mtd_fops = {
 642         .owner          = THIS_MODULE,
 643         .llseek         = mtd_lseek,
 644         .read           = mtd_read,
 645         .write          = mtd_write,
 646         .ioctl          = mtd_ioctl,
 647         .open           = mtd_open,
 648         .release        = mtd_close,
 649 };
 650
 651 static int __init init_mtdchar(void)
 652 {
 653         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 654                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 655                        MTD_CHAR_MAJOR);
 656                 return -EAGAIN;
 657         }
 658
 659         mtdchar_devfs_init();
 660         return 0;
 661 }
 662
 663 static void __exit cleanup_mtdchar(void)
 664 {
 665         mtdchar_devfs_exit();
 666         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 667 }
 668
 669 module_init(init_mtdchar);
 670 module_exit(cleanup_mtdchar);
 671
 672
 673 MODULE_LICENSE("GPL");
 674 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 675 MODULE_DESCRIPTION("Direct character-device access to MTD devices");