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.retlen; 315 ops->oobretlen += devops.oobretlen; 316 if (err) 317 return err; 318 319 if (devops.datbuf) { 320 devops.len = ops->len - ops->retlen; 321 if (!devops.len) 322 return 0; 323 devops.datbuf += devops.retlen; 324 } 325 if (devops.oobbuf) { 326 devops.ooblen = ops->ooblen - ops->oobretlen; 327 if (!devops.ooblen) 328 return 0; 329 devops.oobbuf += devops.oobretlen; 330 } 331 to = 0; 332 } 333 return -EINVAL; 334} 335 336static void concat_erase_callback(struct erase_info *instr) 337{ 338 wake_up((wait_queue_head_t *) instr->priv); 339} 340 341static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase) 342{ 343 int err; 344 wait_queue_head_t waitq; 345 DECLARE_WAITQUEUE(wait, current); 346 347 /* 348 * This code was stol^H^H^H^Hinspired by mtdchar.c 349 */ 350 init_waitqueue_head(&waitq); 351 352 erase->mtd = mtd; 353 erase->callback = concat_erase_callback; 354 erase->priv = (unsigned long) &waitq; 355 356 /* 357 * FIXME: Allow INTERRUPTIBLE. Which means 358 * not having the wait_queue head on the stack. 359 */ 360 err = mtd_erase(mtd, erase); 361 if (!err) { 362 set_current_state(TASK_UNINTERRUPTIBLE); 363 add_wait_queue(&waitq, &wait); 364 if (erase->state != MTD_ERASE_DONE 365 && erase->state != MTD_ERASE_FAILED) 366 schedule(); 367 remove_wait_queue(&waitq, &wait); 368 set_current_state(TASK_RUNNING); 369 370 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0; 371 } 372 return err; 373} 374 375static int concat_erase(struct mtd_info *mtd, struct erase_info *instr) 376{ 377 struct mtd_concat *concat = CONCAT(mtd); 378 struct mtd_info *subdev; 379 int i, err; 380 uint64_t length, offset = 0; 381 struct erase_info *erase; 382 383 /* 384 * Check for proper erase block alignment of the to-be-erased area. 385 * It is easier to do this based on the super device's erase 386 * region info rather than looking at each particular sub-device 387 * in turn. 388 */ 389 if (!concat->mtd.numeraseregions) { 390 /* the easy case: device has uniform erase block size */ 391 if (instr->addr & (concat->mtd.erasesize - 1)) 392 return -EINVAL; 393 if (instr->len & (concat->mtd.erasesize - 1)) 394 return -EINVAL; 395 } else { 396 /* device has variable erase size */ 397 struct mtd_erase_region_info *erase_regions = 398 concat->mtd.eraseregions; 399 400 /* 401 * Find the erase region where the to-be-erased area begins: 402 */ 403 for (i = 0; i < concat->mtd.numeraseregions && 404 instr->addr >= erase_regions[i].offset; i++) ; 405 --i; 406 407 /* 408 * Now erase_regions[i] is the region in which the 409 * to-be-erased area begins. Verify that the starting 410 * offset is aligned to this region's erase size: 411 */ 412 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1)) 413 return -EINVAL; 414 415 /* 416 * now find the erase region where the to-be-erased area ends: 417 */ 418 for (; i < concat->mtd.numeraseregions && 419 (instr->addr + instr->len) >= erase_regions[i].offset; 420 ++i) ; 421 --i; 422 /* 423 * check if the ending offset is aligned to this region's erase size 424 */ 425 if (i < 0 || ((instr->addr + instr->len) & 426 (erase_regions[i].erasesize - 1))) 427 return -EINVAL; 428 } 429 430 /* make a local copy of instr to avoid modifying the caller's struct */ 431 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL); 432 433 if (!erase) 434 return -ENOMEM; 435 436 *erase = *instr; 437 length = instr->len; 438 439 /* 440 * find the subdevice where the to-be-erased area begins, adjust 441 * starting offset to be relative to the subdevice start 442 */ 443 for (i = 0; i < concat->num_subdev; i++) { 444 subdev = concat->subdev[i]; 445 if (subdev->size <= erase->addr) { 446 erase->addr -= subdev->size; 447 offset += subdev->size; 448 } else { 449 break; 450 } 451 } 452 453 /* must never happen since size limit has been verified above */ 454 BUG_ON(i >= concat->num_subdev); 455 456 /* now do the erase: */ 457 err = 0; 458 for (; length > 0; i++) { 459 /* loop for all subdevices affected by this request */ 460 subdev = concat->subdev[i]; /* get current subdevice */ 461 462 /* limit length to subdevice's size: */ 463 if (erase->addr + length > subdev->size) 464 erase->len = subdev->size - erase->addr; 465 else 466 erase->len = length; 467 468 length -= erase->len; 469 if ((err = concat_dev_erase(subdev, erase))) { 470 /* sanity check: should never happen since 471 * block alignment has been checked above */ 472 BUG_ON(err == -EINVAL); 473 if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN) 474 instr->fail_addr = erase->fail_addr + offset; 475 break; 476 } 477 /* 478 * erase->addr specifies the offset of the area to be 479 * erased *within the current subdevice*. It can be 480 * non-zero only the first time through this loop, i.e. 481 * for the first subdevice where blocks need to be erased. 482 * All the following erases must begin at the start of the 483 * current subdevice, i.e. at offset zero. 484 */ 485 erase->addr = 0; 486 offset += subdev->size; 487 } 488 instr->state = erase->state; 489 kfree(erase); 490 if (err) 491 return err; 492 493 if (instr->callback) 494 instr->callback(instr); 495 return 0; 496} 497 498static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 499{ 500 struct mtd_concat *concat = CONCAT(mtd); 501 int i, err = -EINVAL; 502 503 for (i = 0; i < concat->num_subdev; i++) { 504 struct mtd_info *subdev = concat->subdev[i]; 505 uint64_t size; 506 507 if (ofs >= subdev->size) { 508 size = 0; 509 ofs -= subdev->size; 510 continue; 511 } 512 if (ofs + len > subdev->size) 513 size = subdev->size - ofs; 514 else 515 size = len; 516 517 err = mtd_lock(subdev, ofs, size); 518 if (err) 519 break; 520 521 len -= size; 522 if (len == 0) 523 break; 524 525 err = -EINVAL; 526 ofs = 0; 527 } 528 529 return err; 530} 531 532static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 533{ 534 struct mtd_concat *concat = CONCAT(mtd); 535 int i, err = 0; 536 537 for (i = 0; i < concat->num_subdev; i++) { 538 struct mtd_info *subdev = concat->subdev[i]; 539 uint64_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 = mtd_unlock(subdev, ofs, size); 552 if (err) 553 break; 554 555 len -= size; 556 if (len == 0) 557 break; 558 559 err = -EINVAL; 560 ofs = 0; 561 } 562 563 return err; 564} 565 566static void concat_sync(struct mtd_info *mtd) 567{ 568 struct mtd_concat *concat = CONCAT(mtd); 569 int i; 570 571 for (i = 0; i < concat->num_subdev; i++) { 572 struct mtd_info *subdev = concat->subdev[i]; 573 mtd_sync(subdev); 574 } 575} 576 577static int concat_suspend(struct mtd_info *mtd) 578{ 579 struct mtd_concat *concat = CONCAT(mtd); 580 int i, rc = 0; 581 582 for (i = 0; i < concat->num_subdev; i++) { 583 struct mtd_info *subdev = concat->subdev[i]; 584 if ((rc = mtd_suspend(subdev)) < 0) 585 return rc; 586 } 587 return rc; 588} 589 590static void concat_resume(struct mtd_info *mtd) 591{ 592 struct mtd_concat *concat = CONCAT(mtd); 593 int i; 594 595 for (i = 0; i < concat->num_subdev; i++) { 596 struct mtd_info *subdev = concat->subdev[i]; 597 mtd_resume(subdev); 598 } 599} 600 601static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs) 602{ 603 struct mtd_concat *concat = CONCAT(mtd); 604 int i, res = 0; 605 606 if (!mtd_can_have_bb(concat->subdev[0])) 607 return res; 608 609 for (i = 0; i < concat->num_subdev; i++) { 610 struct mtd_info *subdev = concat->subdev[i]; 611 612 if (ofs >= subdev->size) { 613 ofs -= subdev->size; 614 continue; 615 } 616 617 res = mtd_block_isbad(subdev, ofs); 618 break; 619 } 620 621 return res; 622} 623 624static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs) 625{ 626 struct mtd_concat *concat = CONCAT(mtd); 627 int i, err = -EINVAL; 628 629 for (i = 0; i < concat->num_subdev; i++) { 630 struct mtd_info *subdev = concat->subdev[i]; 631 632 if (ofs >= subdev->size) { 633 ofs -= subdev->size; 634 continue; 635 } 636 637 err = mtd_block_markbad(subdev, ofs); 638 if (!err) 639 mtd->ecc_stats.badblocks++; 640 break; 641 } 642 643 return err; 644} 645 646/* 647 * try to support NOMMU mmaps on concatenated devices 648 * - we don't support subdev spanning as we can't guarantee it'll work 649 */ 650static unsigned long concat_get_unmapped_area(struct mtd_info *mtd, 651 unsigned long len, 652 unsigned long offset, 653 unsigned long flags) 654{ 655 struct mtd_concat *concat = CONCAT(mtd); 656 int i; 657 658 for (i = 0; i < concat->num_subdev; i++) { 659 struct mtd_info *subdev = concat->subdev[i]; 660 661 if (offset >= subdev->size) { 662 offset -= subdev->size; 663 continue; 664 } 665 666 return mtd_get_unmapped_area(subdev, len, offset, flags); 667 } 668 669 return (unsigned long) -ENOSYS; 670} 671 672/* 673 * This function constructs a virtual MTD device by concatenating 674 * num_devs MTD devices. A pointer to the new device object is 675 * stored to *new_dev upon success. This function does _not_ 676 * register any devices: this is the caller's responsibility. 677 */ 678struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */ 679 int num_devs, /* number of subdevices */ 680 const char *name) 681{ /* name for the new device */ 682 int i; 683 size_t size; 684 struct mtd_concat *concat; 685 uint32_t max_erasesize, curr_erasesize; 686 int num_erase_region; 687 int max_writebufsize = 0; 688 689 printk(KERN_NOTICE "Concatenating MTD devices:\n"); 690 for (i = 0; i < num_devs; i++) 691 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name); 692 printk(KERN_NOTICE "into device \"%s\"\n", name); 693 694 /* allocate the device structure */ 695 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs); 696 concat = kzalloc(size, GFP_KERNEL); 697 if (!concat) { 698 printk 699 ("memory allocation error while creating concatenated device \"%s\"\n", 700 name); 701 return NULL; 702 } 703 concat->subdev = (struct mtd_info **) (concat + 1); 704 705 /* 706 * Set up the new "super" device's MTD object structure, check for 707 * incompatibilities between the subdevices. 708 */ 709 concat->mtd.type = subdev[0]->type; 710 concat->mtd.flags = subdev[0]->flags; 711 concat->mtd.size = subdev[0]->size; 712 concat->mtd.erasesize = subdev[0]->erasesize; 713 concat->mtd.writesize = subdev[0]->writesize; 714 715 for (i = 0; i < num_devs; i++) 716 if (max_writebufsize < subdev[i]->writebufsize) 717 max_writebufsize = subdev[i]->writebufsize; 718 concat->mtd.writebufsize = max_writebufsize; 719 720 concat->mtd.subpage_sft = subdev[0]->subpage_sft; 721 concat->mtd.oobsize = subdev[0]->oobsize; 722 concat->mtd.oobavail = subdev[0]->oobavail; 723 if (subdev[0]->_writev) 724 concat->mtd._writev = concat_writev; 725 if (subdev[0]->_read_oob) 726 concat->mtd._read_oob = concat_read_oob; 727 if (subdev[0]->_write_oob) 728 concat->mtd._write_oob = concat_write_oob; 729 if (subdev[0]->_block_isbad) 730 concat->mtd._block_isbad = concat_block_isbad; 731 if (subdev[0]->_block_markbad) 732 concat->mtd._block_markbad = concat_block_markbad; 733 734 concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks; 735 736 concat->subdev[0] = subdev[0]; 737 738 for (i = 1; i < num_devs; i++) { 739 if (concat->mtd.type != subdev[i]->type) { 740 kfree(concat); 741 printk("Incompatible device type on \"%s\"\n", 742 subdev[i]->name); 743 return NULL; 744 } 745 if (concat->mtd.flags != subdev[i]->flags) { 746 /* 747 * Expect all flags except MTD_WRITEABLE to be 748 * equal on all subdevices. 749 */ 750 if ((concat->mtd.flags ^ subdev[i]-> 751 flags) & ~MTD_WRITEABLE) { 752 kfree(concat); 753 printk("Incompatible device flags on \"%s\"\n", 754 subdev[i]->name); 755 return NULL; 756 } else 757 /* if writeable attribute differs, 758 make super device writeable */ 759 concat->mtd.flags |= 760 subdev[i]->flags & MTD_WRITEABLE; 761 } 762 763 concat->mtd.size += subdev[i]->size; 764 concat->mtd.ecc_stats.badblocks += 765 subdev[i]->ecc_stats.badblocks; 766 if (concat->mtd.writesize != subdev[i]->writesize || 767 concat->mtd.subpage_sft != subdev[i]->subpage_sft || 768 concat->mtd.oobsize != subdev[i]->oobsize || 769 !concat->mtd._read_oob != !subdev[i]->_read_oob || 770 !concat->mtd._write_oob != !subdev[i]->_write_oob) { 771 kfree(concat); 772 printk("Incompatible OOB or ECC data on \"%s\"\n", 773 subdev[i]->name); 774 return NULL; 775 } 776 concat->subdev[i] = subdev[i]; 777 778 } 779 780 concat->mtd.ecclayout = subdev[0]->ecclayout; 781 782 concat->num_subdev = num_devs; 783 concat->mtd.name = name; 784 785 concat->mtd._erase = concat_erase; 786 concat->mtd._read = concat_read; 787 concat->mtd._write = concat_write; 788 concat->mtd._sync = concat_sync; 789 concat->mtd._lock = concat_lock; 790 concat->mtd._unlock = concat_unlock; 791 concat->mtd._suspend = concat_suspend; 792 concat->mtd._resume = concat_resume; 793 concat->mtd._get_unmapped_area = concat_get_unmapped_area; 794 795 /* 796 * Combine the erase block size info of the subdevices: 797 * 798 * first, walk the map of the new device and see how 799 * many changes in erase size we have 800 */ 801 max_erasesize = curr_erasesize = subdev[0]->erasesize; 802 num_erase_region = 1; 803 for (i = 0; i < num_devs; i++) { 804 if (subdev[i]->numeraseregions == 0) { 805 /* current subdevice has uniform erase size */ 806 if (subdev[i]->erasesize != curr_erasesize) { 807 /* if it differs from the last subdevice's erase size, count it */ 808 ++num_erase_region; 809 curr_erasesize = subdev[i]->erasesize; 810 if (curr_erasesize > max_erasesize) 811 max_erasesize = curr_erasesize; 812 } 813 } else { 814 /* current subdevice has variable erase size */ 815 int j; 816 for (j = 0; j < subdev[i]->numeraseregions; j++) { 817 818 /* walk the list of erase regions, count any changes */ 819 if (subdev[i]->eraseregions[j].erasesize != 820 curr_erasesize) { 821 ++num_erase_region; 822 curr_erasesize = 823 subdev[i]->eraseregions[j]. 824 erasesize; 825 if (curr_erasesize > max_erasesize) 826 max_erasesize = curr_erasesize; 827 } 828 } 829 } 830 } 831 832 if (num_erase_region == 1) { 833 /* 834 * All subdevices have the same uniform erase size. 835 * This is easy: 836 */ 837 concat->mtd.erasesize = curr_erasesize; 838 concat->mtd.numeraseregions = 0; 839 } else { 840 uint64_t tmp64; 841 842 /* 843 * erase block size varies across the subdevices: allocate 844 * space to store the data describing the variable erase regions 845 */ 846 struct mtd_erase_region_info *erase_region_p; 847 uint64_t begin, position; 848 849 concat->mtd.erasesize = max_erasesize; 850 concat->mtd.numeraseregions = num_erase_region; 851 concat->mtd.eraseregions = erase_region_p = 852 kmalloc(num_erase_region * 853 sizeof (struct mtd_erase_region_info), GFP_KERNEL); 854 if (!erase_region_p) { 855 kfree(concat); 856 printk 857 ("memory allocation error while creating erase region list" 858 " for device \"%s\"\n", name); 859 return NULL; 860 } 861 862 /* 863 * walk the map of the new device once more and fill in 864 * in erase region info: 865 */ 866 curr_erasesize = subdev[0]->erasesize; 867 begin = position = 0; 868 for (i = 0; i < num_devs; i++) { 869 if (subdev[i]->numeraseregions == 0) { 870 /* current subdevice has uniform erase size */ 871 if (subdev[i]->erasesize != curr_erasesize) { 872 /* 873 * fill in an mtd_erase_region_info structure for the area 874 * we have walked so far: 875 */ 876 erase_region_p->offset = begin; 877 erase_region_p->erasesize = 878 curr_erasesize; 879 tmp64 = position - begin; 880 do_div(tmp64, curr_erasesize); 881 erase_region_p->numblocks = tmp64; 882 begin = position; 883 884 curr_erasesize = subdev[i]->erasesize; 885 ++erase_region_p; 886 } 887 position += subdev[i]->size; 888 } else { 889 /* current subdevice has variable erase size */ 890 int j; 891 for (j = 0; j < subdev[i]->numeraseregions; j++) { 892 /* walk the list of erase regions, count any changes */ 893 if (subdev[i]->eraseregions[j]. 894 erasesize != curr_erasesize) { 895 erase_region_p->offset = begin; 896 erase_region_p->erasesize = 897 curr_erasesize; 898 tmp64 = position - begin; 899 do_div(tmp64, curr_erasesize); 900 erase_region_p->numblocks = tmp64; 901 begin = position; 902 903 curr_erasesize = 904 subdev[i]->eraseregions[j]. 905 erasesize; 906 ++erase_region_p; 907 } 908 position += 909 subdev[i]->eraseregions[j]. 910 numblocks * (uint64_t)curr_erasesize; 911 } 912 } 913 } 914 /* Now write the final entry */ 915 erase_region_p->offset = begin; 916 erase_region_p->erasesize = curr_erasesize; 917 tmp64 = position - begin; 918 do_div(tmp64, curr_erasesize); 919 erase_region_p->numblocks = tmp64; 920 } 921 922 return &concat->mtd; 923} 924 925/* 926 * This function destroys an MTD object obtained from concat_mtd_devs() 927 */ 928 929void mtd_concat_destroy(struct mtd_info *mtd) 930{ 931 struct mtd_concat *concat = CONCAT(mtd); 932 if (concat->mtd.numeraseregions) 933 kfree(concat->mtd.eraseregions); 934 kfree(concat); 935} 936 937EXPORT_SYMBOL(mtd_concat_create); 938EXPORT_SYMBOL(mtd_concat_destroy); 939 940MODULE_LICENSE("GPL"); 941MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>"); 942MODULE_DESCRIPTION("Generic support for concatenating of MTD devices"); 943