drivers/mtd/mtdchar.c

   1 /*
   2  * $Id: mtdchar.c,v 1.64 2004/08/09 13:59:46 dwmw2 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 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  63 {
  64         struct mtd_info *mtd=(struct mtd_info *)file->private_data;
  65
  66         switch (orig) {
  67         case 0:
  68                 /* SEEK_SET */
  69                 file->f_pos = offset;
  70                 break;
  71         case 1:
  72                 /* SEEK_CUR */
  73                 file->f_pos += offset;
  74                 break;
  75         case 2:
  76                 /* SEEK_END */
  77                 file->f_pos =mtd->size + offset;
  78                 break;
  79         default:
  80                 return -EINVAL;
  81         }
  82
  83         if (file->f_pos < 0)
  84                 file->f_pos = 0;
  85         else if (file->f_pos >= mtd->size)
  86                 file->f_pos = mtd->size - 1;
  87
  88         return file->f_pos;
  89 }
  90
  91
  92
  93 static int mtd_open(struct inode *inode, struct file *file)
  94 {
  95         int minor = iminor(inode);
  96         int devnum = minor >> 1;
  97         struct mtd_info *mtd;
  98
  99         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 100
 101         if (devnum >= MAX_MTD_DEVICES)
 102                 return -ENODEV;
 103
 104         /* You can't open the RO devices RW */
 105         if ((file->f_mode & 2) && (minor & 1))
 106                 return -EACCES;
 107
 108         mtd = get_mtd_device(NULL, devnum);
 109
 110         if (!mtd)
 111                 return -ENODEV;
 112
 113         if (MTD_ABSENT == mtd->type) {
 114                 put_mtd_device(mtd);
 115                 return -ENODEV;
 116         }
 117
 118         file->private_data = mtd;
 119
 120         /* You can't open it RW if it's not a writeable device */
 121         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
 122                 put_mtd_device(mtd);
 123                 return -EACCES;
 124         }
 125
 126         return 0;
 127 } /* mtd_open */
 128
 129 /*====================================================================*/
 130
 131 static int mtd_close(struct inode *inode, struct file *file)
 132 {
 133         struct mtd_info *mtd;
 134
 135         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 136
 137         mtd = (struct mtd_info *)file->private_data;
 138
 139         if (mtd->sync)
 140                 mtd->sync(mtd);
 141
 142         put_mtd_device(mtd);
 143
 144         return 0;
 145 } /* mtd_close */
 146
 147 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 148    userspace buffer down and use it directly with readv/writev.
 149 */
 150 #define MAX_KMALLOC_SIZE 0x20000
 151
 152 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 153 {
 154         struct mtd_info *mtd = (struct mtd_info *)file->private_data;
 155         size_t retlen=0;
 156         size_t total_retlen=0;
 157         int ret=0;
 158         int len;
 159         char *kbuf;
 160
 161         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 162
 163         if (*ppos + count > mtd->size)
 164                 count = mtd->size - *ppos;
 165
 166         if (!count)
 167                 return 0;
 168
 169         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 170            and pass them directly to the MTD functions */
 171         while (count) {
 172                 if (count > MAX_KMALLOC_SIZE)
 173                         len = MAX_KMALLOC_SIZE;
 174                 else
 175                         len = count;
 176
 177                 kbuf=kmalloc(len,GFP_KERNEL);
 178                 if (!kbuf)
 179                         return -ENOMEM;
 180
 181                 ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 182                 if (!ret) {
 183                         *ppos += retlen;
 184                         if (copy_to_user(buf, kbuf, retlen)) {
 185                                 kfree(kbuf);
 186                                 return -EFAULT;
 187                         }
 188                         else
 189                                 total_retlen += retlen;
 190
 191                         count -= retlen;
 192                         buf += retlen;
 193                 }
 194                 else {
 195                         kfree(kbuf);
 196                         return ret;
 197                 }
 198
 199                 kfree(kbuf);
 200         }
 201
 202         return total_retlen;
 203 } /* mtd_read */
 204
 205 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 206 {
 207         struct mtd_info *mtd = (struct mtd_info *)file->private_data;
 208         char *kbuf;
 209         size_t retlen;
 210         size_t total_retlen=0;
 211         int ret=0;
 212         int len;
 213
 214         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 215
 216         if (*ppos == mtd->size)
 217                 return -ENOSPC;
 218
 219         if (*ppos + count > mtd->size)
 220                 count = mtd->size - *ppos;
 221
 222         if (!count)
 223                 return 0;
 224
 225         while (count) {
 226                 if (count > MAX_KMALLOC_SIZE)
 227                         len = MAX_KMALLOC_SIZE;
 228                 else
 229                         len = count;
 230
 231                 kbuf=kmalloc(len,GFP_KERNEL);
 232                 if (!kbuf) {
 233                         printk("kmalloc is null\n");
 234                         return -ENOMEM;
 235                 }
 236
 237                 if (copy_from_user(kbuf, buf, len)) {
 238                         kfree(kbuf);
 239                         return -EFAULT;
 240                 }
 241
 242                 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 243                 if (!ret) {
 244                         *ppos += retlen;
 245                         total_retlen += retlen;
 246                         count -= retlen;
 247                         buf += retlen;
 248                 }
 249                 else {
 250                         kfree(kbuf);
 251                         return ret;
 252                 }
 253
 254                 kfree(kbuf);
 255         }
 256
 257         return total_retlen;
 258 } /* mtd_write */
 259
 260 /*======================================================================
 261
 262     IOCTL calls for getting device parameters.
 263
 264 ======================================================================*/
 265 static void mtdchar_erase_callback (struct erase_info *instr)
 266 {
 267         wake_up((wait_queue_head_t *)instr->priv);
 268 }
 269
 270 static int mtd_ioctl(struct inode *inode, struct file *file,
 271                      u_int cmd, u_long arg)
 272 {
 273         struct mtd_info *mtd = (struct mtd_info *)file->private_data;
 274         void __user *argp = (void __user *)arg;
 275         int ret = 0;
 276         u_long size;
 277
 278         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 279
 280         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 281         if (cmd & IOC_IN) {
 282                 ret = verify_area(VERIFY_READ, argp, size);
 283                 if (ret) return ret;
 284         }
 285         if (cmd & IOC_OUT) {
 286                 ret = verify_area(VERIFY_WRITE, argp, size);
 287                 if (ret) return ret;
 288         }
 289
 290         switch (cmd) {
 291         case MEMGETREGIONCOUNT:
 292                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 293                         return -EFAULT;
 294                 break;
 295
 296         case MEMGETREGIONINFO:
 297         {
 298                 struct region_info_user ur;
 299
 300                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 301                         return -EFAULT;
 302
 303                 if (ur.regionindex >= mtd->numeraseregions)
 304                         return -EINVAL;
 305                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 306                                 sizeof(struct mtd_erase_region_info)))
 307                         return -EFAULT;
 308                 break;
 309         }
 310
 311         case MEMGETINFO:
 312                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 313                         return -EFAULT;
 314                 break;
 315
 316         case MEMERASE:
 317         {
 318                 struct erase_info *erase;
 319
 320                 if(!(file->f_mode & 2))
 321                         return -EPERM;
 322
 323                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 324                 if (!erase)
 325                         ret = -ENOMEM;
 326                 else {
 327                         wait_queue_head_t waitq;
 328                         DECLARE_WAITQUEUE(wait, current);
 329
 330                         init_waitqueue_head(&waitq);
 331
 332                         memset (erase,0,sizeof(struct erase_info));
 333                         if (copy_from_user(&erase->addr, argp,
 334                                     sizeof(struct erase_info_user))) {
 335                                 kfree(erase);
 336                                 return -EFAULT;
 337                         }
 338                         erase->mtd = mtd;
 339                         erase->callback = mtdchar_erase_callback;
 340                         erase->priv = (unsigned long)&waitq;
 341
 342                         /*
 343                           FIXME: Allow INTERRUPTIBLE. Which means
 344                           not having the wait_queue head on the stack.
 345
 346                           If the wq_head is on the stack, and we
 347                           leave because we got interrupted, then the
 348                           wq_head is no longer there when the
 349                           callback routine tries to wake us up.
 350                         */
 351                         ret = mtd->erase(mtd, erase);
 352                         if (!ret) {
 353                                 set_current_state(TASK_UNINTERRUPTIBLE);
 354                                 add_wait_queue(&waitq, &wait);
 355                                 if (erase->state != MTD_ERASE_DONE &&
 356                                     erase->state != MTD_ERASE_FAILED)
 357                                         schedule();
 358                                 remove_wait_queue(&waitq, &wait);
 359                                 set_current_state(TASK_RUNNING);
 360
 361                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 362                         }
 363                         kfree(erase);
 364                 }
 365                 break;
 366         }
 367
 368         case MEMWRITEOOB:
 369         {
 370                 struct mtd_oob_buf buf;
 371                 void *databuf;
 372                 ssize_t retlen;
 373
 374                 if(!(file->f_mode & 2))
 375                         return -EPERM;
 376
 377                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 378                         return -EFAULT;
 379
 380                 if (buf.length > 0x4096)
 381                         return -EINVAL;
 382
 383                 if (!mtd->write_oob)
 384                         ret = -EOPNOTSUPP;
 385                 else
 386                         ret = verify_area(VERIFY_READ, buf.ptr, buf.length);
 387
 388                 if (ret)
 389                         return ret;
 390
 391                 databuf = kmalloc(buf.length, GFP_KERNEL);
 392                 if (!databuf)
 393                         return -ENOMEM;
 394
 395                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 396                         kfree(databuf);
 397                         return -EFAULT;
 398                 }
 399
 400                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 401
 402                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 403                         ret = -EFAULT;
 404
 405                 kfree(databuf);
 406                 break;
 407
 408         }
 409
 410         case MEMREADOOB:
 411         {
 412                 struct mtd_oob_buf buf;
 413                 void *databuf;
 414                 ssize_t retlen;
 415
 416                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 417                         return -EFAULT;
 418
 419                 if (buf.length > 0x4096)
 420                         return -EINVAL;
 421
 422                 if (!mtd->read_oob)
 423                         ret = -EOPNOTSUPP;
 424                 else
 425                         ret = verify_area(VERIFY_WRITE, buf.ptr, buf.length);
 426
 427                 if (ret)
 428                         return ret;
 429
 430                 databuf = kmalloc(buf.length, GFP_KERNEL);
 431                 if (!databuf)
 432                         return -ENOMEM;
 433
 434                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 435
 436                 if (put_user(retlen, (uint32_t __user *)argp))
 437                         ret = -EFAULT;
 438                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 439                         ret = -EFAULT;
 440
 441                 kfree(databuf);
 442                 break;
 443         }
 444
 445         case MEMLOCK:
 446         {
 447                 struct erase_info_user info;
 448
 449                 if (copy_from_user(&info, argp, sizeof(info)))
 450                         return -EFAULT;
 451
 452                 if (!mtd->lock)
 453                         ret = -EOPNOTSUPP;
 454                 else
 455                         ret = mtd->lock(mtd, info.start, info.length);
 456                 break;
 457         }
 458
 459         case MEMUNLOCK:
 460         {
 461                 struct erase_info_user info;
 462
 463                 if (copy_from_user(&info, argp, sizeof(info)))
 464                         return -EFAULT;
 465
 466                 if (!mtd->unlock)
 467                         ret = -EOPNOTSUPP;
 468                 else
 469                         ret = mtd->unlock(mtd, info.start, info.length);
 470                 break;
 471         }
 472
 473         case MEMSETOOBSEL:
 474         {
 475                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
 476                         return -EFAULT;
 477                 break;
 478         }
 479
 480         case MEMGETOOBSEL:
 481         {
 482                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
 483                         return -EFAULT;
 484                 break;
 485         }
 486
 487         case MEMGETBADBLOCK:
 488         {
 489                 loff_t offs;
 490
 491                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 492                         return -EFAULT;
 493                 if (!mtd->block_isbad)
 494                         ret = -EOPNOTSUPP;
 495                 else
 496                         return mtd->block_isbad(mtd, offs);
 497                 break;
 498         }
 499
 500         case MEMSETBADBLOCK:
 501         {
 502                 loff_t offs;
 503
 504                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 505                         return -EFAULT;
 506                 if (!mtd->block_markbad)
 507                         ret = -EOPNOTSUPP;
 508                 else
 509                         return mtd->block_markbad(mtd, offs);
 510                 break;
 511         }
 512
 513         default:
 514                 ret = -ENOTTY;
 515         }
 516
 517         return ret;
 518 } /* memory_ioctl */
 519
 520 static struct file_operations mtd_fops = {
 521         .owner          = THIS_MODULE,
 522         .llseek         = mtd_lseek,
 523         .read           = mtd_read,
 524         .write          = mtd_write,
 525         .ioctl          = mtd_ioctl,
 526         .open           = mtd_open,
 527         .release        = mtd_close,
 528 };
 529
 530 static int __init init_mtdchar(void)
 531 {
 532         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 533                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 534                        MTD_CHAR_MAJOR);
 535                 return -EAGAIN;
 536         }
 537
 538         mtdchar_devfs_init();
 539         return 0;
 540 }
 541
 542 static void __exit cleanup_mtdchar(void)
 543 {
 544         mtdchar_devfs_exit();
 545         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 546 }
 547
 548 module_init(init_mtdchar);
 549 module_exit(cleanup_mtdchar);
 550
 551
 552 MODULE_LICENSE("GPL");
 553 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 554 MODULE_DESCRIPTION("Direct character-device access to MTD devices");