Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * $Id: mtdchar.c,v 1.66 2005/01/05 18:05:11 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(¬ifier); |
| 50 | } |
| 51 | |
| 52 | static inline void mtdchar_devfs_exit(void) |
| 53 | { |
| 54 | unregister_mtd_user(¬ifier); |
| 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 = 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 = 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 = 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 | /* Nand returns -EBADMSG on ecc errors, but it returns |
| 183 | * the data. For our userspace tools it is important |
| 184 | * to dump areas with ecc errors ! |
| 185 | * Userspace software which accesses NAND this way |
| 186 | * must be aware of the fact that it deals with NAND |
| 187 | */ |
| 188 | if (!ret || (ret == -EBADMSG)) { |
| 189 | *ppos += retlen; |
| 190 | if (copy_to_user(buf, kbuf, retlen)) { |
| 191 | kfree(kbuf); |
| 192 | return -EFAULT; |
| 193 | } |
| 194 | else |
| 195 | total_retlen += retlen; |
| 196 | |
| 197 | count -= retlen; |
| 198 | buf += retlen; |
| 199 | } |
| 200 | else { |
| 201 | kfree(kbuf); |
| 202 | return ret; |
| 203 | } |
| 204 | |
| 205 | kfree(kbuf); |
| 206 | } |
| 207 | |
| 208 | return total_retlen; |
| 209 | } /* mtd_read */ |
| 210 | |
| 211 | static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos) |
| 212 | { |
| 213 | struct mtd_info *mtd = file->private_data; |
| 214 | char *kbuf; |
| 215 | size_t retlen; |
| 216 | size_t total_retlen=0; |
| 217 | int ret=0; |
| 218 | int len; |
| 219 | |
| 220 | DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n"); |
| 221 | |
| 222 | if (*ppos == mtd->size) |
| 223 | return -ENOSPC; |
| 224 | |
| 225 | if (*ppos + count > mtd->size) |
| 226 | count = mtd->size - *ppos; |
| 227 | |
| 228 | if (!count) |
| 229 | return 0; |
| 230 | |
| 231 | while (count) { |
| 232 | if (count > MAX_KMALLOC_SIZE) |
| 233 | len = MAX_KMALLOC_SIZE; |
| 234 | else |
| 235 | len = count; |
| 236 | |
| 237 | kbuf=kmalloc(len,GFP_KERNEL); |
| 238 | if (!kbuf) { |
| 239 | printk("kmalloc is null\n"); |
| 240 | return -ENOMEM; |
| 241 | } |
| 242 | |
| 243 | if (copy_from_user(kbuf, buf, len)) { |
| 244 | kfree(kbuf); |
| 245 | return -EFAULT; |
| 246 | } |
| 247 | |
| 248 | ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf); |
| 249 | if (!ret) { |
| 250 | *ppos += retlen; |
| 251 | total_retlen += retlen; |
| 252 | count -= retlen; |
| 253 | buf += retlen; |
| 254 | } |
| 255 | else { |
| 256 | kfree(kbuf); |
| 257 | return ret; |
| 258 | } |
| 259 | |
| 260 | kfree(kbuf); |
| 261 | } |
| 262 | |
| 263 | return total_retlen; |
| 264 | } /* mtd_write */ |
| 265 | |
| 266 | /*====================================================================== |
| 267 | |
| 268 | IOCTL calls for getting device parameters. |
| 269 | |
| 270 | ======================================================================*/ |
| 271 | static void mtdchar_erase_callback (struct erase_info *instr) |
| 272 | { |
| 273 | wake_up((wait_queue_head_t *)instr->priv); |
| 274 | } |
| 275 | |
| 276 | static int mtd_ioctl(struct inode *inode, struct file *file, |
| 277 | u_int cmd, u_long arg) |
| 278 | { |
| 279 | struct mtd_info *mtd = file->private_data; |
| 280 | void __user *argp = (void __user *)arg; |
| 281 | int ret = 0; |
| 282 | u_long size; |
| 283 | |
| 284 | DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n"); |
| 285 | |
| 286 | size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT; |
| 287 | if (cmd & IOC_IN) { |
| 288 | if (!access_ok(VERIFY_READ, argp, size)) |
| 289 | return -EFAULT; |
| 290 | } |
| 291 | if (cmd & IOC_OUT) { |
| 292 | if (!access_ok(VERIFY_WRITE, argp, size)) |
| 293 | return -EFAULT; |
| 294 | } |
| 295 | |
| 296 | switch (cmd) { |
| 297 | case MEMGETREGIONCOUNT: |
| 298 | if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int))) |
| 299 | return -EFAULT; |
| 300 | break; |
| 301 | |
| 302 | case MEMGETREGIONINFO: |
| 303 | { |
| 304 | struct region_info_user ur; |
| 305 | |
| 306 | if (copy_from_user(&ur, argp, sizeof(struct region_info_user))) |
| 307 | return -EFAULT; |
| 308 | |
| 309 | if (ur.regionindex >= mtd->numeraseregions) |
| 310 | return -EINVAL; |
| 311 | if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]), |
| 312 | sizeof(struct mtd_erase_region_info))) |
| 313 | return -EFAULT; |
| 314 | break; |
| 315 | } |
| 316 | |
| 317 | case MEMGETINFO: |
| 318 | if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user))) |
| 319 | return -EFAULT; |
| 320 | break; |
| 321 | |
| 322 | case MEMERASE: |
| 323 | { |
| 324 | struct erase_info *erase; |
| 325 | |
| 326 | if(!(file->f_mode & 2)) |
| 327 | return -EPERM; |
| 328 | |
| 329 | erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL); |
| 330 | if (!erase) |
| 331 | ret = -ENOMEM; |
| 332 | else { |
| 333 | wait_queue_head_t waitq; |
| 334 | DECLARE_WAITQUEUE(wait, current); |
| 335 | |
| 336 | init_waitqueue_head(&waitq); |
| 337 | |
| 338 | memset (erase,0,sizeof(struct erase_info)); |
| 339 | if (copy_from_user(&erase->addr, argp, |
| 340 | sizeof(struct erase_info_user))) { |
| 341 | kfree(erase); |
| 342 | return -EFAULT; |
| 343 | } |
| 344 | erase->mtd = mtd; |
| 345 | erase->callback = mtdchar_erase_callback; |
| 346 | erase->priv = (unsigned long)&waitq; |
| 347 | |
| 348 | /* |
| 349 | FIXME: Allow INTERRUPTIBLE. Which means |
| 350 | not having the wait_queue head on the stack. |
| 351 | |
| 352 | If the wq_head is on the stack, and we |
| 353 | leave because we got interrupted, then the |
| 354 | wq_head is no longer there when the |
| 355 | callback routine tries to wake us up. |
| 356 | */ |
| 357 | ret = mtd->erase(mtd, erase); |
| 358 | if (!ret) { |
| 359 | set_current_state(TASK_UNINTERRUPTIBLE); |
| 360 | add_wait_queue(&waitq, &wait); |
| 361 | if (erase->state != MTD_ERASE_DONE && |
| 362 | erase->state != MTD_ERASE_FAILED) |
| 363 | schedule(); |
| 364 | remove_wait_queue(&waitq, &wait); |
| 365 | set_current_state(TASK_RUNNING); |
| 366 | |
| 367 | ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0; |
| 368 | } |
| 369 | kfree(erase); |
| 370 | } |
| 371 | break; |
| 372 | } |
| 373 | |
| 374 | case MEMWRITEOOB: |
| 375 | { |
| 376 | struct mtd_oob_buf buf; |
| 377 | void *databuf; |
| 378 | ssize_t retlen; |
| 379 | |
| 380 | if(!(file->f_mode & 2)) |
| 381 | return -EPERM; |
| 382 | |
| 383 | if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf))) |
| 384 | return -EFAULT; |
| 385 | |
| 386 | if (buf.length > 0x4096) |
| 387 | return -EINVAL; |
| 388 | |
| 389 | if (!mtd->write_oob) |
| 390 | ret = -EOPNOTSUPP; |
| 391 | else |
| 392 | ret = access_ok(VERIFY_READ, buf.ptr, |
| 393 | buf.length) ? 0 : EFAULT; |
| 394 | |
| 395 | if (ret) |
| 396 | return ret; |
| 397 | |
| 398 | databuf = kmalloc(buf.length, GFP_KERNEL); |
| 399 | if (!databuf) |
| 400 | return -ENOMEM; |
| 401 | |
| 402 | if (copy_from_user(databuf, buf.ptr, buf.length)) { |
| 403 | kfree(databuf); |
| 404 | return -EFAULT; |
| 405 | } |
| 406 | |
| 407 | ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf); |
| 408 | |
| 409 | if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t))) |
| 410 | ret = -EFAULT; |
| 411 | |
| 412 | kfree(databuf); |
| 413 | break; |
| 414 | |
| 415 | } |
| 416 | |
| 417 | case MEMREADOOB: |
| 418 | { |
| 419 | struct mtd_oob_buf buf; |
| 420 | void *databuf; |
| 421 | ssize_t retlen; |
| 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->read_oob) |
| 430 | ret = -EOPNOTSUPP; |
| 431 | else |
| 432 | ret = access_ok(VERIFY_WRITE, 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 | ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf); |
| 443 | |
| 444 | if (put_user(retlen, (uint32_t __user *)argp)) |
| 445 | ret = -EFAULT; |
| 446 | else if (retlen && copy_to_user(buf.ptr, databuf, retlen)) |
| 447 | ret = -EFAULT; |
| 448 | |
| 449 | kfree(databuf); |
| 450 | break; |
| 451 | } |
| 452 | |
| 453 | case MEMLOCK: |
| 454 | { |
| 455 | struct erase_info_user info; |
| 456 | |
| 457 | if (copy_from_user(&info, argp, sizeof(info))) |
| 458 | return -EFAULT; |
| 459 | |
| 460 | if (!mtd->lock) |
| 461 | ret = -EOPNOTSUPP; |
| 462 | else |
| 463 | ret = mtd->lock(mtd, info.start, info.length); |
| 464 | break; |
| 465 | } |
| 466 | |
| 467 | case MEMUNLOCK: |
| 468 | { |
| 469 | struct erase_info_user info; |
| 470 | |
| 471 | if (copy_from_user(&info, argp, sizeof(info))) |
| 472 | return -EFAULT; |
| 473 | |
| 474 | if (!mtd->unlock) |
| 475 | ret = -EOPNOTSUPP; |
| 476 | else |
| 477 | ret = mtd->unlock(mtd, info.start, info.length); |
| 478 | break; |
| 479 | } |
| 480 | |
| 481 | case MEMSETOOBSEL: |
| 482 | { |
| 483 | if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo))) |
| 484 | return -EFAULT; |
| 485 | break; |
| 486 | } |
| 487 | |
| 488 | case MEMGETOOBSEL: |
| 489 | { |
| 490 | if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo))) |
| 491 | return -EFAULT; |
| 492 | break; |
| 493 | } |
| 494 | |
| 495 | case MEMGETBADBLOCK: |
| 496 | { |
| 497 | loff_t offs; |
| 498 | |
| 499 | if (copy_from_user(&offs, argp, sizeof(loff_t))) |
| 500 | return -EFAULT; |
| 501 | if (!mtd->block_isbad) |
| 502 | ret = -EOPNOTSUPP; |
| 503 | else |
| 504 | return mtd->block_isbad(mtd, offs); |
| 505 | break; |
| 506 | } |
| 507 | |
| 508 | case MEMSETBADBLOCK: |
| 509 | { |
| 510 | loff_t offs; |
| 511 | |
| 512 | if (copy_from_user(&offs, argp, sizeof(loff_t))) |
| 513 | return -EFAULT; |
| 514 | if (!mtd->block_markbad) |
| 515 | ret = -EOPNOTSUPP; |
| 516 | else |
| 517 | return mtd->block_markbad(mtd, offs); |
| 518 | break; |
| 519 | } |
| 520 | |
| 521 | default: |
| 522 | ret = -ENOTTY; |
| 523 | } |
| 524 | |
| 525 | return ret; |
| 526 | } /* memory_ioctl */ |
| 527 | |
| 528 | static struct file_operations mtd_fops = { |
| 529 | .owner = THIS_MODULE, |
| 530 | .llseek = mtd_lseek, |
| 531 | .read = mtd_read, |
| 532 | .write = mtd_write, |
| 533 | .ioctl = mtd_ioctl, |
| 534 | .open = mtd_open, |
| 535 | .release = mtd_close, |
| 536 | }; |
| 537 | |
| 538 | static int __init init_mtdchar(void) |
| 539 | { |
| 540 | if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) { |
| 541 | printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n", |
| 542 | MTD_CHAR_MAJOR); |
| 543 | return -EAGAIN; |
| 544 | } |
| 545 | |
| 546 | mtdchar_devfs_init(); |
| 547 | return 0; |
| 548 | } |
| 549 | |
| 550 | static void __exit cleanup_mtdchar(void) |
| 551 | { |
| 552 | mtdchar_devfs_exit(); |
| 553 | unregister_chrdev(MTD_CHAR_MAJOR, "mtd"); |
| 554 | } |
| 555 | |
| 556 | module_init(init_mtdchar); |
| 557 | module_exit(cleanup_mtdchar); |
| 558 | |
| 559 | |
| 560 | MODULE_LICENSE("GPL"); |
| 561 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); |
| 562 | MODULE_DESCRIPTION("Direct character-device access to MTD devices"); |