1/* 2 * MTD device concatenation layer 3 * 4 * Copyright © 2002 Robert Kaiser <rkaiser@sysgo.de> 5 * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org> 6 * 7 * NAND support by Christian Gan <cgan@iders.ca> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 22 * 23 */ 24 25#include <linux/kernel.h> 26#include <linux/module.h> 27#include <linux/slab.h> 28#include <linux/sched.h> 29#include <linux/types.h> 30#include <linux/backing-dev.h> 31 32#include <linux/mtd/mtd.h> 33#include <linux/mtd/concat.h> 34 35#include <asm/div64.h> 36 37/* 38 * Our storage structure: 39 * Subdev points to an array of pointers to struct mtd_info objects 40 * which is allocated along with this structure 41 * 42 */ 43struct mtd_concat { 44 struct mtd_info mtd; 45 int num_subdev; 46 struct mtd_info **subdev; 47}; 48 49/* 50 * how to calculate the size required for the above structure, 51 * including the pointer array subdev points to: 52 */ 53#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \ 54 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *))) 55 56/* 57 * Given a pointer to the MTD object in the mtd_concat structure, 58 * we can retrieve the pointer to that structure with this macro. 59 */ 60#define CONCAT(x) ((struct mtd_concat *)(x)) 61 62/* 63 * MTD methods which look up the relevant subdevice, translate the 64 * effective address and pass through to the subdevice. 65 */ 66 67static int 68concat_read(struct mtd_info *mtd, loff_t from, size_t len, 69 size_t * retlen, u_char * buf) 70{ 71 struct mtd_concat *concat = CONCAT(mtd); 72 int ret = 0, err; 73 int i; 74 75 for (i = 0; i < concat->num_subdev; i++) { 76 struct mtd_info *subdev = concat->subdev[i]; 77 size_t size, retsize; 78 79 if (from >= subdev->size) { 80 /* Not destined for this subdev */ 81 size = 0; 82 from -= subdev->size; 83 continue; 84 } 85 if (from + len > subdev->size) 86 /* First part goes into this subdev */ 87 size = subdev->size - from; 88 else 89 /* Entire transaction goes into this subdev */ 90 size = len; 91 92 err = mtd_read(subdev, from, size, &retsize, buf); 93 94 /* Save information about bitflips! */ 95 if (unlikely(err)) { 96 if (mtd_is_eccerr(err)) { 97 mtd->ecc_stats.failed++; 98 ret = err; 99 } else if (mtd_is_bitflip(err)) { 100 mtd->ecc_stats.corrected++; 101 /* Do not overwrite -EBADMSG !! */ 102 if (!ret) 103 ret = err; 104 } else 105 return err; 106 } 107 108 *retlen += retsize; 109 len -= size; 110 if (len == 0) 111 return ret; 112 113 buf += size; 114 from = 0; 115 } 116 return -EINVAL; 117} 118 119static int 120concat_write(struct mtd_info *mtd, loff_t to, size_t len, 121 size_t * retlen, const u_char * buf) 122{ 123 struct mtd_concat *concat = CONCAT(mtd); 124 int err = -EINVAL; 125 int i; 126 127 for (i = 0; i < concat->num_subdev; i++) { 128 struct mtd_info *subdev = concat->subdev[i]; 129 size_t size, retsize; 130 131 if (to >= subdev->size) { 132 size = 0; 133 to -= subdev->size; 134 continue; 135 } 136 if (to + len > subdev->size) 137 size = subdev->size - to; 138 else 139 size = len; 140 141 err = mtd_write(subdev, to, size, &retsize, buf); 142 if (err) 143 break; 144 145 *retlen += retsize; 146 len -= size; 147 if (len == 0) 148 break; 149 150 err = -EINVAL; 151 buf += size; 152 to = 0; 153 } 154 return err; 155} 156 157static int 158concat_writev(struct mtd_info *mtd, const struct kvec *vecs, 159 unsigned long count, loff_t to, size_t * retlen) 160{ 161 struct mtd_concat *concat = CONCAT(mtd); 162 struct kvec *vecs_copy; 163 unsigned long entry_low, entry_high; 164 size_t total_len = 0; 165 int i; 166 int err = -EINVAL; 167 168 /* Calculate total length of data */ 169 for (i = 0; i < count; i++) 170 total_len += vecs[i].iov_len; 171 172 /* Check alignment */ 173 if (mtd->writesize > 1) { 174 uint64_t __to = to; 175 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize)) 176 return -EINVAL; 177 } 178 179 /* make a copy of vecs */ 180 vecs_copy = kmemdup(vecs, sizeof(struct kvec) * count, GFP_KERNEL); 181 if (!vecs_copy) 182 return -ENOMEM; 183 184 entry_low = 0; 185 for (i = 0; i < concat->num_subdev; i++) { 186 struct mtd_info *subdev = concat->subdev[i]; 187 size_t size, wsize, retsize, old_iov_len; 188 189 if (to >= subdev->size) { 190 to -= subdev->size; 191 continue; 192 } 193 194 size = min_t(uint64_t, total_len, subdev->size - to); 195 wsize = size; /* store for future use */ 196 197 entry_high = entry_low; 198 while (entry_high < count) { 199 if (size <= vecs_copy[entry_high].iov_len) 200 break; 201 size -= vecs_copy[entry_high++].iov_len; 202 } 203 204 old_iov_len = vecs_copy[entry_high].iov_len; 205 vecs_copy[entry_high].iov_len = size; 206 207 err = mtd_writev(subdev, &vecs_copy[entry_low], 208 entry_high - entry_low + 1, to, &retsize); 209 210 vecs_copy[entry_high].iov_len = old_iov_len - size; 211 vecs_copy[entry_high].iov_base += size; 212 213 entry_low = entry_high; 214 215 if (err) 216 break; 217 218 *retlen += retsize; 219 total_len -= wsize; 220 221 if (total_len == 0) 222 break; 223 224 err = -EINVAL; 225 to = 0; 226 } 227 228 kfree(vecs_copy); 229 return err; 230} 231 232static int 233concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) 234{ 235 struct mtd_concat *concat = CONCAT(mtd); 236 struct mtd_oob_ops devops = *ops; 237 int i, err, ret = 0; 238 239 ops->retlen = ops->oobretlen = 0; 240 241 for (i = 0; i < concat->num_subdev; i++) { 242 struct mtd_info *subdev = concat->subdev[i]; 243 244 if (from >= subdev->size) { 245 from -= subdev->size; 246 continue; 247 } 248 249 /* partial read ? */ 250 if (from + devops.len > subdev->size) 251 devops.len = subdev->size - from; 252 253 err = mtd_read_oob(subdev, from, &devops); 254 ops->retlen += devops.retlen; 255 ops->oobretlen += devops.oobretlen; 256 257 /* Save information about bitflips! */ 258 if (unlikely(err)) { 259 if (mtd_is_eccerr(err)) { 260 mtd->ecc_stats.failed++; 261 ret = err; 262 } else if (mtd_is_bitflip(err)) { 263 mtd->ecc_stats.corrected++; 264 /* Do not overwrite -EBADMSG !! */ 265 if (!ret) 266 ret = err; 267 } else 268 return err; 269 } 270 271 if (devops.datbuf) { 272 devops.len = ops->len - ops->retlen; 273 if (!devops.len) 274 return ret; 275 devops.datbuf += devops.retlen; 276 } 277 if (devops.oobbuf) { 278 devops.ooblen = ops->ooblen - ops->oobretlen; 279 if (!devops.ooblen) 280 return ret; 281 devops.oobbuf += ops->oobretlen; 282 } 283 284 from = 0; 285 } 286 return -EINVAL; 287} 288 289static int 290concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops) 291{ 292 struct mtd_concat *concat = CONCAT(mtd); 293 struct mtd_oob_ops devops = *ops; 294 int i, err; 295 296 if (!(mtd->flags & MTD_WRITEABLE)) 297 return -EROFS; 298 299 ops->retlen = ops->oobretlen = 0; 300 301 for (i = 0; i < concat->num_subdev; i++) { 302 struct mtd_info *subdev = concat->subdev[i]; 303 304 if (to >= subdev->size) { 305 to -= subdev->size; 306 continue; 307 } 308 309 /* partial write ? */ 310 if (to + devops.len > subdev->size) 311 devops.len = subdev->size - to; 312 313 err = mtd_write_oob(subdev, to, &devops); 314 ops->retlen += devops.oobretlen; 315 if (err) 316 return err; 317 318 if (devops.datbuf) { 319 devops.len = ops->len - ops->retlen; 320 if (!devops.len) 321 return 0; 322 devops.datbuf += devops.retlen; 323 } 324 if (devops.oobbuf) { 325 devops.ooblen = ops->ooblen - ops->oobretlen; 326 if (!devops.ooblen) 327 return 0; 328 devops.oobbuf += devops.oobretlen; 329 } 330 to = 0; 331 } 332 return -EINVAL; 333} 334 335static void concat_erase_callback(struct erase_info *instr) 336{ 337 wake_up((wait_queue_head_t *) instr->priv); 338} 339 340static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase) 341{ 342 int err; 343 wait_queue_head_t waitq; 344 DECLARE_WAITQUEUE(wait, current); 345 346 /* 347 * This code was stol^H^H^H^Hinspired by mtdchar.c 348 */ 349 init_waitqueue_head(&waitq); 350 351 erase->mtd = mtd; 352 erase->callback = concat_erase_callback; 353 erase->priv = (unsigned long) &waitq; 354 355 /* 356 * FIXME: Allow INTERRUPTIBLE. Which means 357 * not having the wait_queue head on the stack. 358 */ 359 err = mtd_erase(mtd, erase); 360 if (!err) { 361 set_current_state(TASK_UNINTERRUPTIBLE); 362 add_wait_queue(&waitq, &wait); 363 if (erase->state != MTD_ERASE_DONE 364 && erase->state != MTD_ERASE_FAILED) 365 schedule(); 366 remove_wait_queue(&waitq, &wait); 367 set_current_state(TASK_RUNNING); 368 369 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0; 370 } 371 return err; 372} 373 374static int concat_erase(struct mtd_info *mtd, struct erase_info *instr) 375{ 376 struct mtd_concat *concat = CONCAT(mtd); 377 struct mtd_info *subdev; 378 int i, err; 379 uint64_t length, offset = 0; 380 struct erase_info *erase; 381 382 /* 383 * Check for proper erase block alignment of the to-be-erased area. 384 * It is easier to do this based on the super device's erase 385 * region info rather than looking at each particular sub-device 386 * in turn. 387 */ 388 if (!concat->mtd.numeraseregions) { 389 /* the easy case: device has uniform erase block size */ 390 if (instr->addr & (concat->mtd.erasesize - 1)) 391 return -EINVAL; 392 if (instr->len & (concat->mtd.erasesize - 1)) 393 return -EINVAL; 394 } else { 395 /* device has variable erase size */ 396 struct mtd_erase_region_info *erase_regions = 397 concat->mtd.eraseregions; 398 399 /* 400 * Find the erase region where the to-be-erased area begins: 401 */ 402 for (i = 0; i < concat->mtd.numeraseregions && 403 instr->addr >= erase_regions[i].offset; i++) ; 404 --i; 405 406 /* 407 * Now erase_regions[i] is the region in which the 408 * to-be-erased area begins. Verify that the starting 409 * offset is aligned to this region's erase size: 410 */ 411 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1)) 412 return -EINVAL; 413 414 /* 415 * now find the erase region where the to-be-erased area ends: 416 */ 417 for (; i < concat->mtd.numeraseregions && 418 (instr->addr + instr->len) >= erase_regions[i].offset; 419 ++i) ; 420 --i; 421 /* 422 * check if the ending offset is aligned to this region's erase size 423 */ 424 if (i < 0 || ((instr->addr + instr->len) & 425 (erase_regions[i].erasesize - 1))) 426 return -EINVAL; 427 } 428 429 /* make a local copy of instr to avoid modifying the caller's struct */ 430 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL); 431 432 if (!erase) 433 return -ENOMEM; 434 435 *erase = *instr; 436 length = instr->len; 437 438 /* 439 * find the subdevice where the to-be-erased area begins, adjust 440 * starting offset to be relative to the subdevice start 441 */ 442 for (i = 0; i < concat->num_subdev; i++) { 443 subdev = concat->subdev[i]; 444 if (subdev->size <= erase->addr) { 445 erase->addr -= subdev->size; 446 offset += subdev->size; 447 } else { 448 break; 449 } 450 } 451 452 /* must never happen since size limit has been verified above */ 453 BUG_ON(i >= concat->num_subdev); 454 455 /* now do the erase: */ 456 err = 0; 457 for (; length > 0; i++) { 458 /* loop for all subdevices affected by this request */ 459 subdev = concat->subdev[i]; /* get current subdevice */ 460 461 /* limit length to subdevice's size: */ 462 if (erase->addr + length > subdev->size) 463 erase->len = subdev->size - erase->addr; 464 else 465 erase->len = length; 466 467 length -= erase->len; 468 if ((err = concat_dev_erase(subdev, erase))) { 469 /* sanity check: should never happen since 470 * block alignment has been checked above */ 471 BUG_ON(err == -EINVAL); 472 if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN) 473 instr->fail_addr = erase->fail_addr + offset; 474 break; 475 } 476 /* 477 * erase->addr specifies the offset of the area to be 478 * erased *within the current subdevice*. It can be 479 * non-zero only the first time through this loop, i.e. 480 * for the first subdevice where blocks need to be erased. 481 * All the following erases must begin at the start of the 482 * current subdevice, i.e. at offset zero. 483 */ 484 erase->addr = 0; 485 offset += subdev->size; 486 } 487 instr->state = erase->state; 488 kfree(erase); 489 if (err) 490 return err; 491 492 if (instr->callback) 493 instr->callback(instr); 494 return 0; 495} 496 497static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 498{ 499 struct mtd_concat *concat = CONCAT(mtd); 500 int i, err = -EINVAL; 501 502 for (i = 0; i < concat->num_subdev; i++) { 503 struct mtd_info *subdev = concat->subdev[i]; 504 uint64_t size; 505 506 if (ofs >= subdev->size) { 507 size = 0; 508 ofs -= subdev->size; 509 continue; 510 } 511 if (ofs + len > subdev->size) 512 size = subdev->size - ofs; 513 else 514 size = len; 515 516 err = mtd_lock(subdev, ofs, size); 517 if (err) 518 break; 519 520 len -= size; 521 if (len == 0) 522 break; 523 524 err = -EINVAL; 525 ofs = 0; 526 } 527 528 return err; 529} 530 531static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 532{ 533 struct mtd_concat *concat = CONCAT(mtd); 534 int i, err = 0; 535 536 for (i = 0; i < concat->num_subdev; i++) { 537 struct mtd_info *subdev = concat->subdev[i]; 538 uint64_t size; 539 540 if (ofs >= subdev->size) { 541 size = 0; 542 ofs -= subdev->size; 543 continue; 544 } 545 if (ofs + len > subdev->size) 546 size = subdev->size - ofs; 547 else 548 size = len; 549 550 err = mtd_unlock(subdev, ofs, size); 551 if (err) 552 break; 553 554 len -= size; 555 if (len == 0) 556 break; 557 558 err = -EINVAL; 559 ofs = 0; 560 } 561 562 return err; 563} 564 565static void concat_sync(struct mtd_info *mtd) 566{ 567 struct mtd_concat *concat = CONCAT(mtd); 568 int i; 569 570 for (i = 0; i < concat->num_subdev; i++) { 571 struct mtd_info *subdev = concat->subdev[i]; 572 mtd_sync(subdev); 573 } 574} 575 576static int concat_suspend(struct mtd_info *mtd) 577{ 578 struct mtd_concat *concat = CONCAT(mtd); 579 int i, rc = 0; 580 581 for (i = 0; i < concat->num_subdev; i++) { 582 struct mtd_info *subdev = concat->subdev[i]; 583 if ((rc = mtd_suspend(subdev)) < 0) 584 return rc; 585 } 586 return rc; 587} 588 589static void concat_resume(struct mtd_info *mtd) 590{ 591 struct mtd_concat *concat = CONCAT(mtd); 592 int i; 593 594 for (i = 0; i < concat->num_subdev; i++) { 595 struct mtd_info *subdev = concat->subdev[i]; 596 mtd_resume(subdev); 597 } 598} 599 600static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs) 601{ 602 struct mtd_concat *concat = CONCAT(mtd); 603 int i, res = 0; 604 605 if (!mtd_can_have_bb(concat->subdev[0])) 606 return res; 607 608 for (i = 0; i < concat->num_subdev; i++) { 609 struct mtd_info *subdev = concat->subdev[i]; 610 611 if (ofs >= subdev->size) { 612 ofs -= subdev->size; 613 continue; 614 } 615 616 res = mtd_block_isbad(subdev, ofs); 617 break; 618 } 619 620 return res; 621} 622 623static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs) 624{ 625 struct mtd_concat *concat = CONCAT(mtd); 626 int i, err = -EINVAL; 627 628 for (i = 0; i < concat->num_subdev; i++) { 629 struct mtd_info *subdev = concat->subdev[i]; 630 631 if (ofs >= subdev->size) { 632 ofs -= subdev->size; 633 continue; 634 } 635 636 err = mtd_block_markbad(subdev, ofs); 637 if (!err) 638 mtd->ecc_stats.badblocks++; 639 break; 640 } 641 642 return err; 643} 644 645/* 646 * try to support NOMMU mmaps on concatenated devices 647 * - we don't support subdev spanning as we can't guarantee it'll work 648 */ 649static unsigned long concat_get_unmapped_area(struct mtd_info *mtd, 650 unsigned long len, 651 unsigned long offset, 652 unsigned long flags) 653{ 654 struct mtd_concat *concat = CONCAT(mtd); 655 int i; 656 657 for (i = 0; i < concat->num_subdev; i++) { 658 struct mtd_info *subdev = concat->subdev[i]; 659 660 if (offset >= subdev->size) { 661 offset -= subdev->size; 662 continue; 663 } 664 665 return mtd_get_unmapped_area(subdev, len, offset, flags); 666 } 667 668 return (unsigned long) -ENOSYS; 669} 670 671/* 672 * This function constructs a virtual MTD device by concatenating 673 * num_devs MTD devices. A pointer to the new device object is 674 * stored to *new_dev upon success. This function does _not_ 675 * register any devices: this is the caller's responsibility. 676 */ 677struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */ 678 int num_devs, /* number of subdevices */ 679 const char *name) 680{ /* name for the new device */ 681 int i; 682 size_t size; 683 struct mtd_concat *concat; 684 uint32_t max_erasesize, curr_erasesize; 685 int num_erase_region; 686 int max_writebufsize = 0; 687 688 printk(KERN_NOTICE "Concatenating MTD devices:\n"); 689 for (i = 0; i < num_devs; i++) 690 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name); 691 printk(KERN_NOTICE "into device \"%s\"\n", name); 692 693 /* allocate the device structure */ 694 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs); 695 concat = kzalloc(size, GFP_KERNEL); 696 if (!concat) { 697 printk 698 ("memory allocation error while creating concatenated device \"%s\"\n", 699 name); 700 return NULL; 701 } 702 concat->subdev = (struct mtd_info **) (concat + 1); 703 704 /* 705 * Set up the new "super" device's MTD object structure, check for 706 * incompatibilities between the subdevices. 707 */ 708 concat->mtd.type = subdev[0]->type; 709 concat->mtd.flags = subdev[0]->flags; 710 concat->mtd.size = subdev[0]->size; 711 concat->mtd.erasesize = subdev[0]->erasesize; 712 concat->mtd.writesize = subdev[0]->writesize; 713 714 for (i = 0; i < num_devs; i++) 715 if (max_writebufsize < subdev[i]->writebufsize) 716 max_writebufsize = subdev[i]->writebufsize; 717 concat->mtd.writebufsize = max_writebufsize; 718 719 concat->mtd.subpage_sft = subdev[0]->subpage_sft; 720 concat->mtd.oobsize = subdev[0]->oobsize; 721 concat->mtd.oobavail = subdev[0]->oobavail; 722 if (subdev[0]->_writev) 723 concat->mtd._writev = concat_writev; 724 if (subdev[0]->_read_oob) 725 concat->mtd._read_oob = concat_read_oob; 726 if (subdev[0]->_write_oob) 727 concat->mtd._write_oob = concat_write_oob; 728 if (subdev[0]->_block_isbad) 729 concat->mtd._block_isbad = concat_block_isbad; 730 if (subdev[0]->_block_markbad) 731 concat->mtd._block_markbad = concat_block_markbad; 732 733 concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks; 734 735 concat->mtd.backing_dev_info = subdev[0]->backing_dev_info; 736 737 concat->subdev[0] = subdev[0]; 738 739 for (i = 1; i < num_devs; i++) { 740 if (concat->mtd.type != subdev[i]->type) { 741 kfree(concat); 742 printk("Incompatible device type on \"%s\"\n", 743 subdev[i]->name); 744 return NULL; 745 } 746 if (concat->mtd.flags != subdev[i]->flags) { 747 /* 748 * Expect all flags except MTD_WRITEABLE to be 749 * equal on all subdevices. 750 */ 751 if ((concat->mtd.flags ^ subdev[i]-> 752 flags) & ~MTD_WRITEABLE) { 753 kfree(concat); 754 printk("Incompatible device flags on \"%s\"\n", 755 subdev[i]->name); 756 return NULL; 757 } else 758 /* if writeable attribute differs, 759 make super device writeable */ 760 concat->mtd.flags |= 761 subdev[i]->flags & MTD_WRITEABLE; 762 } 763 764 /* only permit direct mapping if the BDIs are all the same 765 * - copy-mapping is still permitted 766 */ 767 if (concat->mtd.backing_dev_info != 768 subdev[i]->backing_dev_info) 769 concat->mtd.backing_dev_info = 770 &default_backing_dev_info; 771 772 concat->mtd.size += subdev[i]->size; 773 concat->mtd.ecc_stats.badblocks += 774 subdev[i]->ecc_stats.badblocks; 775 if (concat->mtd.writesize != subdev[i]->writesize || 776 concat->mtd.subpage_sft != subdev[i]->subpage_sft || 777 concat->mtd.oobsize != subdev[i]->oobsize || 778 !concat->mtd._read_oob != !subdev[i]->_read_oob || 779 !concat->mtd._write_oob != !subdev[i]->_write_oob) { 780 kfree(concat); 781 printk("Incompatible OOB or ECC data on \"%s\"\n", 782 subdev[i]->name); 783 return NULL; 784 } 785 concat->subdev[i] = subdev[i]; 786 787 } 788 789 concat->mtd.ecclayout = subdev[0]->ecclayout; 790 791 concat->num_subdev = num_devs; 792 concat->mtd.name = name; 793 794 concat->mtd._erase = concat_erase; 795 concat->mtd._read = concat_read; 796 concat->mtd._write = concat_write; 797 concat->mtd._sync = concat_sync; 798 concat->mtd._lock = concat_lock; 799 concat->mtd._unlock = concat_unlock; 800 concat->mtd._suspend = concat_suspend; 801 concat->mtd._resume = concat_resume; 802 concat->mtd._get_unmapped_area = concat_get_unmapped_area; 803 804 /* 805 * Combine the erase block size info of the subdevices: 806 * 807 * first, walk the map of the new device and see how 808 * many changes in erase size we have 809 */ 810 max_erasesize = curr_erasesize = subdev[0]->erasesize; 811 num_erase_region = 1; 812 for (i = 0; i < num_devs; i++) { 813 if (subdev[i]->numeraseregions == 0) { 814 /* current subdevice has uniform erase size */ 815 if (subdev[i]->erasesize != curr_erasesize) { 816 /* if it differs from the last subdevice's erase size, count it */ 817 ++num_erase_region; 818 curr_erasesize = subdev[i]->erasesize; 819 if (curr_erasesize > max_erasesize) 820 max_erasesize = curr_erasesize; 821 } 822 } else { 823 /* current subdevice has variable erase size */ 824 int j; 825 for (j = 0; j < subdev[i]->numeraseregions; j++) { 826 827 /* walk the list of erase regions, count any changes */ 828 if (subdev[i]->eraseregions[j].erasesize != 829 curr_erasesize) { 830 ++num_erase_region; 831 curr_erasesize = 832 subdev[i]->eraseregions[j]. 833 erasesize; 834 if (curr_erasesize > max_erasesize) 835 max_erasesize = curr_erasesize; 836 } 837 } 838 } 839 } 840 841 if (num_erase_region == 1) { 842 /* 843 * All subdevices have the same uniform erase size. 844 * This is easy: 845 */ 846 concat->mtd.erasesize = curr_erasesize; 847 concat->mtd.numeraseregions = 0; 848 } else { 849 uint64_t tmp64; 850 851 /* 852 * erase block size varies across the subdevices: allocate 853 * space to store the data describing the variable erase regions 854 */ 855 struct mtd_erase_region_info *erase_region_p; 856 uint64_t begin, position; 857 858 concat->mtd.erasesize = max_erasesize; 859 concat->mtd.numeraseregions = num_erase_region; 860 concat->mtd.eraseregions = erase_region_p = 861 kmalloc(num_erase_region * 862 sizeof (struct mtd_erase_region_info), GFP_KERNEL); 863 if (!erase_region_p) { 864 kfree(concat); 865 printk 866 ("memory allocation error while creating erase region list" 867 " for device \"%s\"\n", name); 868 return NULL; 869 } 870 871 /* 872 * walk the map of the new device once more and fill in 873 * in erase region info: 874 */ 875 curr_erasesize = subdev[0]->erasesize; 876 begin = position = 0; 877 for (i = 0; i < num_devs; i++) { 878 if (subdev[i]->numeraseregions == 0) { 879 /* current subdevice has uniform erase size */ 880 if (subdev[i]->erasesize != curr_erasesize) { 881 /* 882 * fill in an mtd_erase_region_info structure for the area 883 * we have walked so far: 884 */ 885 erase_region_p->offset = begin; 886 erase_region_p->erasesize = 887 curr_erasesize; 888 tmp64 = position - begin; 889 do_div(tmp64, curr_erasesize); 890 erase_region_p->numblocks = tmp64; 891 begin = position; 892 893 curr_erasesize = subdev[i]->erasesize; 894 ++erase_region_p; 895 } 896 position += subdev[i]->size; 897 } else { 898 /* current subdevice has variable erase size */ 899 int j; 900 for (j = 0; j < subdev[i]->numeraseregions; j++) { 901 /* walk the list of erase regions, count any changes */ 902 if (subdev[i]->eraseregions[j]. 903 erasesize != curr_erasesize) { 904 erase_region_p->offset = begin; 905 erase_region_p->erasesize = 906 curr_erasesize; 907 tmp64 = position - begin; 908 do_div(tmp64, curr_erasesize); 909 erase_region_p->numblocks = tmp64; 910 begin = position; 911 912 curr_erasesize = 913 subdev[i]->eraseregions[j]. 914 erasesize; 915 ++erase_region_p; 916 } 917 position += 918 subdev[i]->eraseregions[j]. 919 numblocks * (uint64_t)curr_erasesize; 920 } 921 } 922 } 923 /* Now write the final entry */ 924 erase_region_p->offset = begin; 925 erase_region_p->erasesize = curr_erasesize; 926 tmp64 = position - begin; 927 do_div(tmp64, curr_erasesize); 928 erase_region_p->numblocks = tmp64; 929 } 930 931 return &concat->mtd; 932} 933 934/* 935 * This function destroys an MTD object obtained from concat_mtd_devs() 936 */ 937 938void mtd_concat_destroy(struct mtd_info *mtd) 939{ 940 struct mtd_concat *concat = CONCAT(mtd); 941 if (concat->mtd.numeraseregions) 942 kfree(concat->mtd.eraseregions); 943 kfree(concat); 944} 945 946EXPORT_SYMBOL(mtd_concat_create); 947EXPORT_SYMBOL(mtd_concat_destroy); 948 949MODULE_LICENSE("GPL"); 950MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>"); 951MODULE_DESCRIPTION("Generic support for concatenating of MTD devices"); 952