1 /* 2 * MTD device concatenation layer 3 * 4 * (C) 2002 Robert Kaiser <rkaiser@sysgo.de> 5 * 6 * NAND support by Christian Gan <cgan@iders.ca> 7 * 8 * This code is GPL 9 * 10 * $Id: mtdconcat.c,v 1.9 2004/06/30 15:17:41 dbrown Exp $ 11 */ 12 13 #include <linux/module.h> 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/slab.h> 17 18 #include <linux/mtd/mtd.h> 19 #include <linux/mtd/concat.h> 20 21 /* 22 * Our storage structure: 23 * Subdev points to an array of pointers to struct mtd_info objects 24 * which is allocated along with this structure 25 * 26 */ 27 struct mtd_concat { 28 struct mtd_info mtd; 29 int num_subdev; 30 struct mtd_info **subdev; 31 }; 32 33 /* 34 * how to calculate the size required for the above structure, 35 * including the pointer array subdev points to: 36 */ 37 #define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \ 38 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *))) 39 40 /* 41 * Given a pointer to the MTD object in the mtd_concat structure, 42 * we can retrieve the pointer to that structure with this macro. 43 */ 44 #define CONCAT(x) ((struct mtd_concat *)(x)) 45 46 /* 47 * MTD methods which look up the relevant subdevice, translate the 48 * effective address and pass through to the subdevice. 49 */ 50 51 static int 52 concat_read(struct mtd_info *mtd, loff_t from, size_t len, 53 size_t * retlen, u_char * buf) 54 { 55 struct mtd_concat *concat = CONCAT(mtd); 56 int err = -EINVAL; 57 int i; 58 59 *retlen = 0; 60 61 for (i = 0; i < concat->num_subdev; i++) { 62 struct mtd_info *subdev = concat->subdev[i]; 63 size_t size, retsize; 64 65 if (from >= subdev->size) { 66 /* Not destined for this subdev */ 67 size = 0; 68 from -= subdev->size; 69 continue; 70 } 71 if (from + len > subdev->size) 72 /* First part goes into this subdev */ 73 size = subdev->size - from; 74 else 75 /* Entire transaction goes into this subdev */ 76 size = len; 77 78 err = subdev->read(subdev, from, size, &retsize, buf); 79 80 if (err) 81 break; 82 83 *retlen += retsize; 84 len -= size; 85 if (len == 0) 86 break; 87 88 err = -EINVAL; 89 buf += size; 90 from = 0; 91 } 92 return err; 93 } 94 95 static int 96 concat_write(struct mtd_info *mtd, loff_t to, size_t len, 97 size_t * retlen, const u_char * buf) 98 { 99 struct mtd_concat *concat = CONCAT(mtd); 100 int err = -EINVAL; 101 int i; 102 103 if (!(mtd->flags & MTD_WRITEABLE)) 104 return -EROFS; 105 106 *retlen = 0; 107 108 for (i = 0; i < concat->num_subdev; i++) { 109 struct mtd_info *subdev = concat->subdev[i]; 110 size_t size, retsize; 111 112 if (to >= subdev->size) { 113 size = 0; 114 to -= subdev->size; 115 continue; 116 } 117 if (to + len > subdev->size) 118 size = subdev->size - to; 119 else 120 size = len; 121 122 if (!(subdev->flags & MTD_WRITEABLE)) 123 err = -EROFS; 124 else 125 err = subdev->write(subdev, to, size, &retsize, buf); 126 127 if (err) 128 break; 129 130 *retlen += retsize; 131 len -= size; 132 if (len == 0) 133 break; 134 135 err = -EINVAL; 136 buf += size; 137 to = 0; 138 } 139 return err; 140 } 141 142 static int 143 concat_read_ecc(struct mtd_info *mtd, loff_t from, size_t len, 144 size_t * retlen, u_char * buf, u_char * eccbuf, 145 struct nand_oobinfo *oobsel) 146 { 147 struct mtd_concat *concat = CONCAT(mtd); 148 int err = -EINVAL; 149 int i; 150 151 *retlen = 0; 152 153 for (i = 0; i < concat->num_subdev; i++) { 154 struct mtd_info *subdev = concat->subdev[i]; 155 size_t size, retsize; 156 157 if (from >= subdev->size) { 158 /* Not destined for this subdev */ 159 size = 0; 160 from -= subdev->size; 161 continue; 162 } 163 164 if (from + len > subdev->size) 165 /* First part goes into this subdev */ 166 size = subdev->size - from; 167 else 168 /* Entire transaction goes into this subdev */ 169 size = len; 170 171 if (subdev->read_ecc) 172 err = subdev->read_ecc(subdev, from, size, 173 &retsize, buf, eccbuf, oobsel); 174 else 175 err = -EINVAL; 176 177 if (err) 178 break; 179 180 *retlen += retsize; 181 len -= size; 182 if (len == 0) 183 break; 184 185 err = -EINVAL; 186 buf += size; 187 if (eccbuf) { 188 eccbuf += subdev->oobsize; 189 /* in nand.c at least, eccbufs are 190 tagged with 2 (int)eccstatus'; we 191 must account for these */ 192 eccbuf += 2 * (sizeof (int)); 193 } 194 from = 0; 195 } 196 return err; 197 } 198 199 static int 200 concat_write_ecc(struct mtd_info *mtd, loff_t to, size_t len, 201 size_t * retlen, const u_char * buf, u_char * eccbuf, 202 struct nand_oobinfo *oobsel) 203 { 204 struct mtd_concat *concat = CONCAT(mtd); 205 int err = -EINVAL; 206 int i; 207 208 if (!(mtd->flags & MTD_WRITEABLE)) 209 return -EROFS; 210 211 *retlen = 0; 212 213 for (i = 0; i < concat->num_subdev; i++) { 214 struct mtd_info *subdev = concat->subdev[i]; 215 size_t size, retsize; 216 217 if (to >= subdev->size) { 218 size = 0; 219 to -= subdev->size; 220 continue; 221 } 222 if (to + len > subdev->size) 223 size = subdev->size - to; 224 else 225 size = len; 226 227 if (!(subdev->flags & MTD_WRITEABLE)) 228 err = -EROFS; 229 else if (subdev->write_ecc) 230 err = subdev->write_ecc(subdev, to, size, 231 &retsize, buf, eccbuf, oobsel); 232 else 233 err = -EINVAL; 234 235 if (err) 236 break; 237 238 *retlen += retsize; 239 len -= size; 240 if (len == 0) 241 break; 242 243 err = -EINVAL; 244 buf += size; 245 if (eccbuf) 246 eccbuf += subdev->oobsize; 247 to = 0; 248 } 249 return err; 250 } 251 252 static int 253 concat_read_oob(struct mtd_info *mtd, loff_t from, size_t len, 254 size_t * retlen, u_char * buf) 255 { 256 struct mtd_concat *concat = CONCAT(mtd); 257 int err = -EINVAL; 258 int i; 259 260 *retlen = 0; 261 262 for (i = 0; i < concat->num_subdev; i++) { 263 struct mtd_info *subdev = concat->subdev[i]; 264 size_t size, retsize; 265 266 if (from >= subdev->size) { 267 /* Not destined for this subdev */ 268 size = 0; 269 from -= subdev->size; 270 continue; 271 } 272 if (from + len > subdev->size) 273 /* First part goes into this subdev */ 274 size = subdev->size - from; 275 else 276 /* Entire transaction goes into this subdev */ 277 size = len; 278 279 if (subdev->read_oob) 280 err = subdev->read_oob(subdev, from, size, 281 &retsize, buf); 282 else 283 err = -EINVAL; 284 285 if (err) 286 break; 287 288 *retlen += retsize; 289 len -= size; 290 if (len == 0) 291 break; 292 293 err = -EINVAL; 294 buf += size; 295 from = 0; 296 } 297 return err; 298 } 299 300 static int 301 concat_write_oob(struct mtd_info *mtd, loff_t to, size_t len, 302 size_t * retlen, const u_char * buf) 303 { 304 struct mtd_concat *concat = CONCAT(mtd); 305 int err = -EINVAL; 306 int i; 307 308 if (!(mtd->flags & MTD_WRITEABLE)) 309 return -EROFS; 310 311 *retlen = 0; 312 313 for (i = 0; i < concat->num_subdev; i++) { 314 struct mtd_info *subdev = concat->subdev[i]; 315 size_t size, retsize; 316 317 if (to >= subdev->size) { 318 size = 0; 319 to -= subdev->size; 320 continue; 321 } 322 if (to + len > subdev->size) 323 size = subdev->size - to; 324 else 325 size = len; 326 327 if (!(subdev->flags & MTD_WRITEABLE)) 328 err = -EROFS; 329 else if (subdev->write_oob) 330 err = subdev->write_oob(subdev, to, size, &retsize, 331 buf); 332 else 333 err = -EINVAL; 334 335 if (err) 336 break; 337 338 *retlen += retsize; 339 len -= size; 340 if (len == 0) 341 break; 342 343 err = -EINVAL; 344 buf += size; 345 to = 0; 346 } 347 return err; 348 } 349 350 static void concat_erase_callback(struct erase_info *instr) 351 { 352 wake_up((wait_queue_head_t *) instr->priv); 353 } 354 355 static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase) 356 { 357 int err; 358 wait_queue_head_t waitq; 359 DECLARE_WAITQUEUE(wait, current); 360 361 /* 362 * This code was stol^H^H^H^Hinspired by mtdchar.c 363 */ 364 init_waitqueue_head(&waitq); 365 366 erase->mtd = mtd; 367 erase->callback = concat_erase_callback; 368 erase->priv = (unsigned long) &waitq; 369 370 /* 371 * FIXME: Allow INTERRUPTIBLE. Which means 372 * not having the wait_queue head on the stack. 373 */ 374 err = mtd->erase(mtd, erase); 375 if (!err) { 376 set_current_state(TASK_UNINTERRUPTIBLE); 377 add_wait_queue(&waitq, &wait); 378 if (erase->state != MTD_ERASE_DONE 379 && erase->state != MTD_ERASE_FAILED) 380 schedule(); 381 remove_wait_queue(&waitq, &wait); 382 set_current_state(TASK_RUNNING); 383 384 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0; 385 } 386 return err; 387 } 388 389 static int concat_erase(struct mtd_info *mtd, struct erase_info *instr) 390 { 391 struct mtd_concat *concat = CONCAT(mtd); 392 struct mtd_info *subdev; 393 int i, err; 394 u_int32_t length, offset = 0; 395 struct erase_info *erase; 396 397 if (!(mtd->flags & MTD_WRITEABLE)) 398 return -EROFS; 399 400 if (instr->addr > concat->mtd.size) 401 return -EINVAL; 402 403 if (instr->len + instr->addr > concat->mtd.size) 404 return -EINVAL; 405 406 /* 407 * Check for proper erase block alignment of the to-be-erased area. 408 * It is easier to do this based on the super device's erase 409 * region info rather than looking at each particular sub-device 410 * in turn. 411 */ 412 if (!concat->mtd.numeraseregions) { 413 /* the easy case: device has uniform erase block size */ 414 if (instr->addr & (concat->mtd.erasesize - 1)) 415 return -EINVAL; 416 if (instr->len & (concat->mtd.erasesize - 1)) 417 return -EINVAL; 418 } else { 419 /* device has variable erase size */ 420 struct mtd_erase_region_info *erase_regions = 421 concat->mtd.eraseregions; 422 423 /* 424 * Find the erase region where the to-be-erased area begins: 425 */ 426 for (i = 0; i < concat->mtd.numeraseregions && 427 instr->addr >= erase_regions[i].offset; i++) ; 428 --i; 429 430 /* 431 * Now erase_regions[i] is the region in which the 432 * to-be-erased area begins. Verify that the starting 433 * offset is aligned to this region's erase size: 434 */ 435 if (instr->addr & (erase_regions[i].erasesize - 1)) 436 return -EINVAL; 437 438 /* 439 * now find the erase region where the to-be-erased area ends: 440 */ 441 for (; i < concat->mtd.numeraseregions && 442 (instr->addr + instr->len) >= erase_regions[i].offset; 443 ++i) ; 444 --i; 445 /* 446 * check if the ending offset is aligned to this region's erase size 447 */ 448 if ((instr->addr + instr->len) & (erase_regions[i].erasesize - 449 1)) 450 return -EINVAL; 451 } 452 453 instr->fail_addr = 0xffffffff; 454 455 /* make a local copy of instr to avoid modifying the caller's struct */ 456 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL); 457 458 if (!erase) 459 return -ENOMEM; 460 461 *erase = *instr; 462 length = instr->len; 463 464 /* 465 * find the subdevice where the to-be-erased area begins, adjust 466 * starting offset to be relative to the subdevice start 467 */ 468 for (i = 0; i < concat->num_subdev; i++) { 469 subdev = concat->subdev[i]; 470 if (subdev->size <= erase->addr) { 471 erase->addr -= subdev->size; 472 offset += subdev->size; 473 } else { 474 break; 475 } 476 } 477 478 /* must never happen since size limit has been verified above */ 479 if (i >= concat->num_subdev) 480 BUG(); 481 482 /* now do the erase: */ 483 err = 0; 484 for (; length > 0; i++) { 485 /* loop for all subdevices affected by this request */ 486 subdev = concat->subdev[i]; /* get current subdevice */ 487 488 /* limit length to subdevice's size: */ 489 if (erase->addr + length > subdev->size) 490 erase->len = subdev->size - erase->addr; 491 else 492 erase->len = length; 493 494 if (!(subdev->flags & MTD_WRITEABLE)) { 495 err = -EROFS; 496 break; 497 } 498 length -= erase->len; 499 if ((err = concat_dev_erase(subdev, erase))) { 500 /* sanity check: should never happen since 501 * block alignment has been checked above */ 502 if (err == -EINVAL) 503 BUG(); 504 if (erase->fail_addr != 0xffffffff) 505 instr->fail_addr = erase->fail_addr + offset; 506 break; 507 } 508 /* 509 * erase->addr specifies the offset of the area to be 510 * erased *within the current subdevice*. It can be 511 * non-zero only the first time through this loop, i.e. 512 * for the first subdevice where blocks need to be erased. 513 * All the following erases must begin at the start of the 514 * current subdevice, i.e. at offset zero. 515 */ 516 erase->addr = 0; 517 offset += subdev->size; 518 } 519 instr->state = erase->state; 520 kfree(erase); 521 if (err) 522 return err; 523 524 if (instr->callback) 525 instr->callback(instr); 526 return 0; 527 } 528 529 static int concat_lock(struct mtd_info *mtd, loff_t ofs, size_t len) 530 { 531 struct mtd_concat *concat = CONCAT(mtd); 532 int i, err = -EINVAL; 533 534 if ((len + ofs) > mtd->size) 535 return -EINVAL; 536 537 for (i = 0; i < concat->num_subdev; i++) { 538 struct mtd_info *subdev = concat->subdev[i]; 539 size_t size; 540 541 if (ofs >= subdev->size) { 542 size = 0; 543 ofs -= subdev->size; 544 continue; 545 } 546 if (ofs + len > subdev->size) 547 size = subdev->size - ofs; 548 else 549 size = len; 550 551 err = subdev->lock(subdev, ofs, size); 552 553 if (err) 554 break; 555 556 len -= size; 557 if (len == 0) 558 break; 559 560 err = -EINVAL; 561 ofs = 0; 562 } 563 564 return err; 565 } 566 567 static int concat_unlock(struct mtd_info *mtd, loff_t ofs, size_t len) 568 { 569 struct mtd_concat *concat = CONCAT(mtd); 570 int i, err = 0; 571 572 if ((len + ofs) > mtd->size) 573 return -EINVAL; 574 575 for (i = 0; i < concat->num_subdev; i++) { 576 struct mtd_info *subdev = concat->subdev[i]; 577 size_t size; 578 579 if (ofs >= subdev->size) { 580 size = 0; 581 ofs -= subdev->size; 582 continue; 583 } 584 if (ofs + len > subdev->size) 585 size = subdev->size - ofs; 586 else 587 size = len; 588 589 err = subdev->unlock(subdev, ofs, size); 590 591 if (err) 592 break; 593 594 len -= size; 595 if (len == 0) 596 break; 597 598 err = -EINVAL; 599 ofs = 0; 600 } 601 602 return err; 603 } 604 605 static void concat_sync(struct mtd_info *mtd) 606 { 607 struct mtd_concat *concat = CONCAT(mtd); 608 int i; 609 610 for (i = 0; i < concat->num_subdev; i++) { 611 struct mtd_info *subdev = concat->subdev[i]; 612 subdev->sync(subdev); 613 } 614 } 615 616 static int concat_suspend(struct mtd_info *mtd) 617 { 618 struct mtd_concat *concat = CONCAT(mtd); 619 int i, rc = 0; 620 621 for (i = 0; i < concat->num_subdev; i++) { 622 struct mtd_info *subdev = concat->subdev[i]; 623 if ((rc = subdev->suspend(subdev)) < 0) 624 return rc; 625 } 626 return rc; 627 } 628 629 static void concat_resume(struct mtd_info *mtd) 630 { 631 struct mtd_concat *concat = CONCAT(mtd); 632 int i; 633 634 for (i = 0; i < concat->num_subdev; i++) { 635 struct mtd_info *subdev = concat->subdev[i]; 636 subdev->resume(subdev); 637 } 638 } 639 640 /* 641 * This function constructs a virtual MTD device by concatenating 642 * num_devs MTD devices. A pointer to the new device object is 643 * stored to *new_dev upon success. This function does _not_ 644 * register any devices: this is the caller's responsibility. 645 */ 646 struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */ 647 int num_devs, /* number of subdevices */ 648 char *name) 649 { /* name for the new device */ 650 int i; 651 size_t size; 652 struct mtd_concat *concat; 653 u_int32_t max_erasesize, curr_erasesize; 654 int num_erase_region; 655 656 printk(KERN_NOTICE "Concatenating MTD devices:\n"); 657 for (i = 0; i < num_devs; i++) 658 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name); 659 printk(KERN_NOTICE "into device \"%s\"\n", name); 660 661 /* allocate the device structure */ 662 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs); 663 concat = kmalloc(size, GFP_KERNEL); 664 if (!concat) { 665 printk 666 ("memory allocation error while creating concatenated device \"%s\"\n", 667 name); 668 return NULL; 669 } 670 memset(concat, 0, size); 671 concat->subdev = (struct mtd_info **) (concat + 1); 672 673 /* 674 * Set up the new "super" device's MTD object structure, check for 675 * incompatibilites between the subdevices. 676 */ 677 concat->mtd.type = subdev[0]->type; 678 concat->mtd.flags = subdev[0]->flags; 679 concat->mtd.size = subdev[0]->size; 680 concat->mtd.erasesize = subdev[0]->erasesize; 681 concat->mtd.oobblock = subdev[0]->oobblock; 682 concat->mtd.oobsize = subdev[0]->oobsize; 683 concat->mtd.ecctype = subdev[0]->ecctype; 684 concat->mtd.eccsize = subdev[0]->eccsize; 685 if (subdev[0]->read_ecc) 686 concat->mtd.read_ecc = concat_read_ecc; 687 if (subdev[0]->write_ecc) 688 concat->mtd.write_ecc = concat_write_ecc; 689 if (subdev[0]->read_oob) 690 concat->mtd.read_oob = concat_read_oob; 691 if (subdev[0]->write_oob) 692 concat->mtd.write_oob = concat_write_oob; 693 694 concat->subdev[0] = subdev[0]; 695 696 for (i = 1; i < num_devs; i++) { 697 if (concat->mtd.type != subdev[i]->type) { 698 kfree(concat); 699 printk("Incompatible device type on \"%s\"\n", 700 subdev[i]->name); 701 return NULL; 702 } 703 if (concat->mtd.flags != subdev[i]->flags) { 704 /* 705 * Expect all flags except MTD_WRITEABLE to be 706 * equal on all subdevices. 707 */ 708 if ((concat->mtd.flags ^ subdev[i]-> 709 flags) & ~MTD_WRITEABLE) { 710 kfree(concat); 711 printk("Incompatible device flags on \"%s\"\n", 712 subdev[i]->name); 713 return NULL; 714 } else 715 /* if writeable attribute differs, 716 make super device writeable */ 717 concat->mtd.flags |= 718 subdev[i]->flags & MTD_WRITEABLE; 719 } 720 concat->mtd.size += subdev[i]->size; 721 if (concat->mtd.oobblock != subdev[i]->oobblock || 722 concat->mtd.oobsize != subdev[i]->oobsize || 723 concat->mtd.ecctype != subdev[i]->ecctype || 724 concat->mtd.eccsize != subdev[i]->eccsize || 725 !concat->mtd.read_ecc != !subdev[i]->read_ecc || 726 !concat->mtd.write_ecc != !subdev[i]->write_ecc || 727 !concat->mtd.read_oob != !subdev[i]->read_oob || 728 !concat->mtd.write_oob != !subdev[i]->write_oob) { 729 kfree(concat); 730 printk("Incompatible OOB or ECC data on \"%s\"\n", 731 subdev[i]->name); 732 return NULL; 733 } 734 concat->subdev[i] = subdev[i]; 735 736 } 737 738 concat->num_subdev = num_devs; 739 concat->mtd.name = name; 740 741 /* 742 * NOTE: for now, we do not provide any readv()/writev() methods 743 * because they are messy to implement and they are not 744 * used to a great extent anyway. 745 */ 746 concat->mtd.erase = concat_erase; 747 concat->mtd.read = concat_read; 748 concat->mtd.write = concat_write; 749 concat->mtd.sync = concat_sync; 750 concat->mtd.lock = concat_lock; 751 concat->mtd.unlock = concat_unlock; 752 concat->mtd.suspend = concat_suspend; 753 concat->mtd.resume = concat_resume; 754 755 /* 756 * Combine the erase block size info of the subdevices: 757 * 758 * first, walk the map of the new device and see how 759 * many changes in erase size we have 760 */ 761 max_erasesize = curr_erasesize = subdev[0]->erasesize; 762 num_erase_region = 1; 763 for (i = 0; i < num_devs; i++) { 764 if (subdev[i]->numeraseregions == 0) { 765 /* current subdevice has uniform erase size */ 766 if (subdev[i]->erasesize != curr_erasesize) { 767 /* if it differs from the last subdevice's erase size, count it */ 768 ++num_erase_region; 769 curr_erasesize = subdev[i]->erasesize; 770 if (curr_erasesize > max_erasesize) 771 max_erasesize = curr_erasesize; 772 } 773 } else { 774 /* current subdevice has variable erase size */ 775 int j; 776 for (j = 0; j < subdev[i]->numeraseregions; j++) { 777 778 /* walk the list of erase regions, count any changes */ 779 if (subdev[i]->eraseregions[j].erasesize != 780 curr_erasesize) { 781 ++num_erase_region; 782 curr_erasesize = 783 subdev[i]->eraseregions[j]. 784 erasesize; 785 if (curr_erasesize > max_erasesize) 786 max_erasesize = curr_erasesize; 787 } 788 } 789 } 790 } 791 792 if (num_erase_region == 1) { 793 /* 794 * All subdevices have the same uniform erase size. 795 * This is easy: 796 */ 797 concat->mtd.erasesize = curr_erasesize; 798 concat->mtd.numeraseregions = 0; 799 } else { 800 /* 801 * erase block size varies across the subdevices: allocate 802 * space to store the data describing the variable erase regions 803 */ 804 struct mtd_erase_region_info *erase_region_p; 805 u_int32_t begin, position; 806 807 concat->mtd.erasesize = max_erasesize; 808 concat->mtd.numeraseregions = num_erase_region; 809 concat->mtd.eraseregions = erase_region_p = 810 kmalloc(num_erase_region * 811 sizeof (struct mtd_erase_region_info), GFP_KERNEL); 812 if (!erase_region_p) { 813 kfree(concat); 814 printk 815 ("memory allocation error while creating erase region list" 816 " for device \"%s\"\n", name); 817 return NULL; 818 } 819 820 /* 821 * walk the map of the new device once more and fill in 822 * in erase region info: 823 */ 824 curr_erasesize = subdev[0]->erasesize; 825 begin = position = 0; 826 for (i = 0; i < num_devs; i++) { 827 if (subdev[i]->numeraseregions == 0) { 828 /* current subdevice has uniform erase size */ 829 if (subdev[i]->erasesize != curr_erasesize) { 830 /* 831 * fill in an mtd_erase_region_info structure for the area 832 * we have walked so far: 833 */ 834 erase_region_p->offset = begin; 835 erase_region_p->erasesize = 836 curr_erasesize; 837 erase_region_p->numblocks = 838 (position - begin) / curr_erasesize; 839 begin = position; 840 841 curr_erasesize = subdev[i]->erasesize; 842 ++erase_region_p; 843 } 844 position += subdev[i]->size; 845 } else { 846 /* current subdevice has variable erase size */ 847 int j; 848 for (j = 0; j < subdev[i]->numeraseregions; j++) { 849 /* walk the list of erase regions, count any changes */ 850 if (subdev[i]->eraseregions[j]. 851 erasesize != curr_erasesize) { 852 erase_region_p->offset = begin; 853 erase_region_p->erasesize = 854 curr_erasesize; 855 erase_region_p->numblocks = 856 (position - 857 begin) / curr_erasesize; 858 begin = position; 859 860 curr_erasesize = 861 subdev[i]->eraseregions[j]. 862 erasesize; 863 ++erase_region_p; 864 } 865 position += 866 subdev[i]->eraseregions[j]. 867 numblocks * curr_erasesize; 868 } 869 } 870 } 871 /* Now write the final entry */ 872 erase_region_p->offset = begin; 873 erase_region_p->erasesize = curr_erasesize; 874 erase_region_p->numblocks = (position - begin) / curr_erasesize; 875 } 876 877 return &concat->mtd; 878 } 879 880 /* 881 * This function destroys an MTD object obtained from concat_mtd_devs() 882 */ 883 884 void mtd_concat_destroy(struct mtd_info *mtd) 885 { 886 struct mtd_concat *concat = CONCAT(mtd); 887 if (concat->mtd.numeraseregions) 888 kfree(concat->mtd.eraseregions); 889 kfree(concat); 890 } 891 892 EXPORT_SYMBOL(mtd_concat_create); 893 EXPORT_SYMBOL(mtd_concat_destroy); 894 895 MODULE_LICENSE("GPL"); 896 MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>"); 897 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices"); 898