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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * MTD device concatenation layer
4 *
5 * Copyright © 2002 Robert Kaiser <[email protected]>
6 * Copyright © 2002-2010 David Woodhouse <[email protected]>
7 *
8 * NAND support by Christian Gan <[email protected]>
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/sched.h>
15#include <linux/types.h>
16#include <linux/backing-dev.h>
17
18#include <linux/mtd/mtd.h>
19#include <linux/mtd/concat.h>
20
21#include <asm/div64.h>
22
23/*
24 * how to calculate the size required for the above structure,
25 * including the pointer array subdev points to:
26 */
27#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \
28 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
29
30/*
31 * Given a pointer to the MTD object in the mtd_concat structure,
32 * we can retrieve the pointer to that structure with this macro.
33 */
34#define CONCAT(x) ((struct mtd_concat *)(x))
35
36/*
37 * MTD methods which look up the relevant subdevice, translate the
38 * effective address and pass through to the subdevice.
39 */
40
41static int
42concat_read(struct mtd_info *mtd, loff_t from, size_t len,
43 size_t * retlen, u_char * buf)
44{
45 struct mtd_concat *concat = CONCAT(mtd);
46 int ret = 0, err;
47 int i;
48
49 for (i = 0; i < concat->num_subdev; i++) {
50 struct mtd_info *subdev = concat->subdev[i];
51 size_t size, retsize;
52
53 if (from >= subdev->size) {
54 /* Not destined for this subdev */
55 size = 0;
56 from -= subdev->size;
57 continue;
58 }
59 if (from + len > subdev->size)
60 /* First part goes into this subdev */
61 size = subdev->size - from;
62 else
63 /* Entire transaction goes into this subdev */
64 size = len;
65
66 err = mtd_read(subdev, from, size, &retsize, buf);
67
68 /* Save information about bitflips! */
69 if (unlikely(err)) {
70 if (mtd_is_eccerr(err)) {
71 mtd->ecc_stats.failed++;
72 ret = err;
73 } else if (mtd_is_bitflip(err)) {
74 mtd->ecc_stats.corrected++;
75 /* Do not overwrite -EBADMSG !! */
76 if (!ret)
77 ret = err;
78 } else
79 return err;
80 }
81
82 *retlen += retsize;
83 len -= size;
84 if (len == 0)
85 return ret;
86
87 buf += size;
88 from = 0;
89 }
90 return -EINVAL;
91}
92
93static int
94concat_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
95 size_t * retlen, const u_char * buf)
96{
97 struct mtd_concat *concat = CONCAT(mtd);
98 int err = -EINVAL;
99 int i;
100 for (i = 0; i < concat->num_subdev; i++) {
101 struct mtd_info *subdev = concat->subdev[i];
102 size_t size, retsize;
103
104 if (to >= subdev->size) {
105 to -= subdev->size;
106 continue;
107 }
108 if (to + len > subdev->size)
109 size = subdev->size - to;
110 else
111 size = len;
112
113 err = mtd_panic_write(subdev, to, size, &retsize, buf);
114 if (err == -EOPNOTSUPP) {
115 printk(KERN_ERR "mtdconcat: Cannot write from panic without panic_write\n");
116 return err;
117 }
118 if (err)
119 break;
120
121 *retlen += retsize;
122 len -= size;
123 if (len == 0)
124 break;
125
126 err = -EINVAL;
127 buf += size;
128 to = 0;
129 }
130 return err;
131}
132
133
134static int
135concat_write(struct mtd_info *mtd, loff_t to, size_t len,
136 size_t * retlen, const u_char * buf)
137{
138 struct mtd_concat *concat = CONCAT(mtd);
139 int err = -EINVAL;
140 int i;
141
142 for (i = 0; i < concat->num_subdev; i++) {
143 struct mtd_info *subdev = concat->subdev[i];
144 size_t size, retsize;
145
146 if (to >= subdev->size) {
147 size = 0;
148 to -= subdev->size;
149 continue;
150 }
151 if (to + len > subdev->size)
152 size = subdev->size - to;
153 else
154 size = len;
155
156 err = mtd_write(subdev, to, size, &retsize, buf);
157 if (err)
158 break;
159
160 *retlen += retsize;
161 len -= size;
162 if (len == 0)
163 break;
164
165 err = -EINVAL;
166 buf += size;
167 to = 0;
168 }
169 return err;
170}
171
172static int
173concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
174 unsigned long count, loff_t to, size_t * retlen)
175{
176 struct mtd_concat *concat = CONCAT(mtd);
177 struct kvec *vecs_copy;
178 unsigned long entry_low, entry_high;
179 size_t total_len = 0;
180 int i;
181 int err = -EINVAL;
182
183 /* Calculate total length of data */
184 for (i = 0; i < count; i++)
185 total_len += vecs[i].iov_len;
186
187 /* Check alignment */
188 if (mtd->writesize > 1) {
189 uint64_t __to = to;
190 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
191 return -EINVAL;
192 }
193
194 /* make a copy of vecs */
195 vecs_copy = kmemdup_array(vecs, count, sizeof(struct kvec), GFP_KERNEL);
196 if (!vecs_copy)
197 return -ENOMEM;
198
199 entry_low = 0;
200 for (i = 0; i < concat->num_subdev; i++) {
201 struct mtd_info *subdev = concat->subdev[i];
202 size_t size, wsize, retsize, old_iov_len;
203
204 if (to >= subdev->size) {
205 to -= subdev->size;
206 continue;
207 }
208
209 size = min_t(uint64_t, total_len, subdev->size - to);
210 wsize = size; /* store for future use */
211
212 entry_high = entry_low;
213 while (entry_high < count) {
214 if (size <= vecs_copy[entry_high].iov_len)
215 break;
216 size -= vecs_copy[entry_high++].iov_len;
217 }
218
219 old_iov_len = vecs_copy[entry_high].iov_len;
220 vecs_copy[entry_high].iov_len = size;
221
222 err = mtd_writev(subdev, &vecs_copy[entry_low],
223 entry_high - entry_low + 1, to, &retsize);
224
225 vecs_copy[entry_high].iov_len = old_iov_len - size;
226 vecs_copy[entry_high].iov_base += size;
227
228 entry_low = entry_high;
229
230 if (err)
231 break;
232
233 *retlen += retsize;
234 total_len -= wsize;
235
236 if (total_len == 0)
237 break;
238
239 err = -EINVAL;
240 to = 0;
241 }
242
243 kfree(vecs_copy);
244 return err;
245}
246
247static int
248concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
249{
250 struct mtd_concat *concat = CONCAT(mtd);
251 struct mtd_oob_ops devops = *ops;
252 int i, err, ret = 0;
253
254 ops->retlen = ops->oobretlen = 0;
255
256 for (i = 0; i < concat->num_subdev; i++) {
257 struct mtd_info *subdev = concat->subdev[i];
258
259 if (from >= subdev->size) {
260 from -= subdev->size;
261 continue;
262 }
263
264 /* partial read ? */
265 if (from + devops.len > subdev->size)
266 devops.len = subdev->size - from;
267
268 err = mtd_read_oob(subdev, from, &devops);
269 ops->retlen += devops.retlen;
270 ops->oobretlen += devops.oobretlen;
271
272 /* Save information about bitflips! */
273 if (unlikely(err)) {
274 if (mtd_is_eccerr(err)) {
275 mtd->ecc_stats.failed++;
276 ret = err;
277 } else if (mtd_is_bitflip(err)) {
278 mtd->ecc_stats.corrected++;
279 /* Do not overwrite -EBADMSG !! */
280 if (!ret)
281 ret = err;
282 } else
283 return err;
284 }
285
286 if (devops.datbuf) {
287 devops.len = ops->len - ops->retlen;
288 if (!devops.len)
289 return ret;
290 devops.datbuf += devops.retlen;
291 }
292 if (devops.oobbuf) {
293 devops.ooblen = ops->ooblen - ops->oobretlen;
294 if (!devops.ooblen)
295 return ret;
296 devops.oobbuf += ops->oobretlen;
297 }
298
299 from = 0;
300 }
301 return -EINVAL;
302}
303
304static int
305concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
306{
307 struct mtd_concat *concat = CONCAT(mtd);
308 struct mtd_oob_ops devops = *ops;
309 int i, err;
310
311 if (!(mtd->flags & MTD_WRITEABLE))
312 return -EROFS;
313
314 ops->retlen = ops->oobretlen = 0;
315
316 for (i = 0; i < concat->num_subdev; i++) {
317 struct mtd_info *subdev = concat->subdev[i];
318
319 if (to >= subdev->size) {
320 to -= subdev->size;
321 continue;
322 }
323
324 /* partial write ? */
325 if (to + devops.len > subdev->size)
326 devops.len = subdev->size - to;
327
328 err = mtd_write_oob(subdev, to, &devops);
329 ops->retlen += devops.retlen;
330 ops->oobretlen += devops.oobretlen;
331 if (err)
332 return err;
333
334 if (devops.datbuf) {
335 devops.len = ops->len - ops->retlen;
336 if (!devops.len)
337 return 0;
338 devops.datbuf += devops.retlen;
339 }
340 if (devops.oobbuf) {
341 devops.ooblen = ops->ooblen - ops->oobretlen;
342 if (!devops.ooblen)
343 return 0;
344 devops.oobbuf += devops.oobretlen;
345 }
346 to = 0;
347 }
348 return -EINVAL;
349}
350
351static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
352{
353 struct mtd_concat *concat = CONCAT(mtd);
354 struct mtd_info *subdev;
355 int i, err;
356 uint64_t length, offset = 0;
357 struct erase_info *erase;
358
359 /*
360 * Check for proper erase block alignment of the to-be-erased area.
361 * It is easier to do this based on the super device's erase
362 * region info rather than looking at each particular sub-device
363 * in turn.
364 */
365 if (!concat->mtd.numeraseregions) {
366 /* the easy case: device has uniform erase block size */
367 if (instr->addr & (concat->mtd.erasesize - 1))
368 return -EINVAL;
369 if (instr->len & (concat->mtd.erasesize - 1))
370 return -EINVAL;
371 } else {
372 /* device has variable erase size */
373 struct mtd_erase_region_info *erase_regions =
374 concat->mtd.eraseregions;
375
376 /*
377 * Find the erase region where the to-be-erased area begins:
378 */
379 for (i = 0; i < concat->mtd.numeraseregions &&
380 instr->addr >= erase_regions[i].offset; i++) ;
381 --i;
382
383 /*
384 * Now erase_regions[i] is the region in which the
385 * to-be-erased area begins. Verify that the starting
386 * offset is aligned to this region's erase size:
387 */
388 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))
389 return -EINVAL;
390
391 /*
392 * now find the erase region where the to-be-erased area ends:
393 */
394 for (; i < concat->mtd.numeraseregions &&
395 (instr->addr + instr->len) >= erase_regions[i].offset;
396 ++i) ;
397 --i;
398 /*
399 * check if the ending offset is aligned to this region's erase size
400 */
401 if (i < 0 || ((instr->addr + instr->len) &
402 (erase_regions[i].erasesize - 1)))
403 return -EINVAL;
404 }
405
406 /* make a local copy of instr to avoid modifying the caller's struct */
407 erase = kmalloc_obj(struct erase_info);
408
409 if (!erase)
410 return -ENOMEM;
411
412 *erase = *instr;
413 length = instr->len;
414
415 /*
416 * find the subdevice where the to-be-erased area begins, adjust
417 * starting offset to be relative to the subdevice start
418 */
419 for (i = 0; i < concat->num_subdev; i++) {
420 subdev = concat->subdev[i];
421 if (subdev->size <= erase->addr) {
422 erase->addr -= subdev->size;
423 offset += subdev->size;
424 } else {
425 break;
426 }
427 }
428
429 /* must never happen since size limit has been verified above */
430 BUG_ON(i >= concat->num_subdev);
431
432 /* now do the erase: */
433 err = 0;
434 for (; length > 0; i++) {
435 /* loop for all subdevices affected by this request */
436 subdev = concat->subdev[i]; /* get current subdevice */
437
438 /* limit length to subdevice's size: */
439 if (erase->addr + length > subdev->size)
440 erase->len = subdev->size - erase->addr;
441 else
442 erase->len = length;
443
444 length -= erase->len;
445 if ((err = mtd_erase(subdev, erase))) {
446 /* sanity check: should never happen since
447 * block alignment has been checked above */
448 BUG_ON(err == -EINVAL);
449 if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
450 instr->fail_addr = erase->fail_addr + offset;
451 break;
452 }
453 /*
454 * erase->addr specifies the offset of the area to be
455 * erased *within the current subdevice*. It can be
456 * non-zero only the first time through this loop, i.e.
457 * for the first subdevice where blocks need to be erased.
458 * All the following erases must begin at the start of the
459 * current subdevice, i.e. at offset zero.
460 */
461 erase->addr = 0;
462 offset += subdev->size;
463 }
464 kfree(erase);
465
466 return err;
467}
468
469static int concat_xxlock(struct mtd_info *mtd, loff_t ofs, uint64_t len,
470 bool is_lock)
471{
472 struct mtd_concat *concat = CONCAT(mtd);
473 int i, err = -EINVAL;
474
475 for (i = 0; i < concat->num_subdev; i++) {
476 struct mtd_info *subdev = concat->subdev[i];
477 uint64_t size;
478
479 if (ofs >= subdev->size) {
480 size = 0;
481 ofs -= subdev->size;
482 continue;
483 }
484 if (ofs + len > subdev->size)
485 size = subdev->size - ofs;
486 else
487 size = len;
488
489 if (is_lock)
490 err = mtd_lock(subdev, ofs, size);
491 else
492 err = mtd_unlock(subdev, ofs, size);
493 if (err)
494 break;
495
496 len -= size;
497 if (len == 0)
498 break;
499
500 err = -EINVAL;
501 ofs = 0;
502 }
503
504 return err;
505}
506
507static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
508{
509 return concat_xxlock(mtd, ofs, len, true);
510}
511
512static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
513{
514 return concat_xxlock(mtd, ofs, len, false);
515}
516
517static int concat_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
518{
519 struct mtd_concat *concat = CONCAT(mtd);
520 int i, err = -EINVAL;
521
522 for (i = 0; i < concat->num_subdev; i++) {
523 struct mtd_info *subdev = concat->subdev[i];
524
525 if (ofs >= subdev->size) {
526 ofs -= subdev->size;
527 continue;
528 }
529
530 if (ofs + len > subdev->size)
531 break;
532
533 return mtd_is_locked(subdev, ofs, len);
534 }
535
536 return err;
537}
538
539static void concat_sync(struct mtd_info *mtd)
540{
541 struct mtd_concat *concat = CONCAT(mtd);
542 int i;
543
544 for (i = 0; i < concat->num_subdev; i++) {
545 struct mtd_info *subdev = concat->subdev[i];
546 mtd_sync(subdev);
547 }
548}
549
550static int concat_suspend(struct mtd_info *mtd)
551{
552 struct mtd_concat *concat = CONCAT(mtd);
553 int i, rc = 0;
554
555 for (i = 0; i < concat->num_subdev; i++) {
556 struct mtd_info *subdev = concat->subdev[i];
557 if ((rc = mtd_suspend(subdev)) < 0)
558 return rc;
559 }
560 return rc;
561}
562
563static void concat_resume(struct mtd_info *mtd)
564{
565 struct mtd_concat *concat = CONCAT(mtd);
566 int i;
567
568 for (i = 0; i < concat->num_subdev; i++) {
569 struct mtd_info *subdev = concat->subdev[i];
570 mtd_resume(subdev);
571 }
572}
573
574static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
575{
576 struct mtd_concat *concat = CONCAT(mtd);
577 int i, res = 0;
578
579 if (!mtd_can_have_bb(concat->subdev[0]))
580 return res;
581
582 for (i = 0; i < concat->num_subdev; i++) {
583 struct mtd_info *subdev = concat->subdev[i];
584
585 if (ofs >= subdev->size) {
586 ofs -= subdev->size;
587 continue;
588 }
589
590 res = mtd_block_isbad(subdev, ofs);
591 break;
592 }
593
594 return res;
595}
596
597static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
598{
599 struct mtd_concat *concat = CONCAT(mtd);
600 int i, err = -EINVAL;
601
602 for (i = 0; i < concat->num_subdev; i++) {
603 struct mtd_info *subdev = concat->subdev[i];
604
605 if (ofs >= subdev->size) {
606 ofs -= subdev->size;
607 continue;
608 }
609
610 err = mtd_block_markbad(subdev, ofs);
611 if (!err)
612 mtd->ecc_stats.badblocks++;
613 break;
614 }
615
616 return err;
617}
618
619/*
620 * This function constructs a virtual MTD device by concatenating
621 * num_devs MTD devices. A pointer to the new device object is
622 * stored to *new_dev upon success. This function does _not_
623 * register any devices: this is the caller's responsibility.
624 */
625struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
626 int num_devs, /* number of subdevices */
627 const char *name)
628{ /* name for the new device */
629 int i;
630 struct mtd_concat *concat;
631 struct mtd_info *subdev_master = NULL;
632 uint32_t max_erasesize, curr_erasesize;
633 int num_erase_region;
634 int max_writebufsize = 0;
635
636 printk(KERN_NOTICE "Concatenating MTD devices:\n");
637 for (i = 0; i < num_devs; i++)
638 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
639 printk(KERN_NOTICE "into device \"%s\"\n", name);
640
641 /* allocate the device structure */
642 concat = kzalloc_flex(*concat, subdev, num_devs);
643 if (!concat) {
644 printk
645 ("memory allocation error while creating concatenated device \"%s\"\n",
646 name);
647 return NULL;
648 }
649
650 /*
651 * Set up the new "super" device's MTD object structure, check for
652 * incompatibilities between the subdevices.
653 */
654 concat->mtd.type = subdev[0]->type;
655 concat->mtd.flags = subdev[0]->flags;
656 concat->mtd.size = subdev[0]->size;
657 concat->mtd.erasesize = subdev[0]->erasesize;
658 concat->mtd.writesize = subdev[0]->writesize;
659
660 for (i = 0; i < num_devs; i++)
661 if (max_writebufsize < subdev[i]->writebufsize)
662 max_writebufsize = subdev[i]->writebufsize;
663 concat->mtd.writebufsize = max_writebufsize;
664
665 concat->mtd.subpage_sft = subdev[0]->subpage_sft;
666 concat->mtd.oobsize = subdev[0]->oobsize;
667 concat->mtd.oobavail = subdev[0]->oobavail;
668
669 subdev_master = mtd_get_master(subdev[0]);
670 if (subdev_master->_writev)
671 concat->mtd._writev = concat_writev;
672 if (subdev_master->_read_oob)
673 concat->mtd._read_oob = concat_read_oob;
674 if (subdev_master->_write_oob)
675 concat->mtd._write_oob = concat_write_oob;
676 if (subdev_master->_block_isbad)
677 concat->mtd._block_isbad = concat_block_isbad;
678 if (subdev_master->_block_markbad)
679 concat->mtd._block_markbad = concat_block_markbad;
680 if (subdev_master->_panic_write)
681 concat->mtd._panic_write = concat_panic_write;
682 if (subdev_master->_read)
683 concat->mtd._read = concat_read;
684 if (subdev_master->_write)
685 concat->mtd._write = concat_write;
686
687 concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
688
689 concat->subdev[0] = subdev[0];
690
691 for (i = 1; i < num_devs; i++) {
692 if (concat->mtd.type != subdev[i]->type) {
693 kfree(concat);
694 printk("Incompatible device type on \"%s\"\n",
695 subdev[i]->name);
696 return NULL;
697 }
698 if (concat->mtd.flags != subdev[i]->flags) {
699 /*
700 * Expect all flags except MTD_WRITEABLE to be
701 * equal on all subdevices.
702 */
703 if ((concat->mtd.flags ^ subdev[i]->
704 flags) & ~MTD_WRITEABLE) {
705 kfree(concat);
706 printk("Incompatible device flags on \"%s\"\n",
707 subdev[i]->name);
708 return NULL;
709 } else
710 /* if writeable attribute differs,
711 make super device writeable */
712 concat->mtd.flags |=
713 subdev[i]->flags & MTD_WRITEABLE;
714 }
715
716 subdev_master = mtd_get_master(subdev[i]);
717 concat->mtd.size += subdev[i]->size;
718 concat->mtd.ecc_stats.badblocks +=
719 subdev[i]->ecc_stats.badblocks;
720 if (concat->mtd.writesize != subdev[i]->writesize ||
721 concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
722 concat->mtd.oobsize != subdev[i]->oobsize ||
723 !concat->mtd._read_oob != !subdev_master->_read_oob ||
724 !concat->mtd._write_oob != !subdev_master->_write_oob) {
725 /*
726 * Check against subdev[i] for data members, because
727 * subdev's attributes may be different from master
728 * mtd device. Check against subdev's master mtd
729 * device for callbacks, because the existence of
730 * subdev's callbacks is decided by master mtd device.
731 */
732 kfree(concat);
733 printk("Incompatible OOB or ECC data on \"%s\"\n",
734 subdev[i]->name);
735 return NULL;
736 }
737 concat->subdev[i] = subdev[i];
738
739 }
740
741 mtd_set_ooblayout(&concat->mtd, subdev[0]->ooblayout);
742
743 concat->num_subdev = num_devs;
744 concat->mtd.name = name;
745
746 concat->mtd._erase = concat_erase;
747 concat->mtd._sync = concat_sync;
748 concat->mtd._lock = concat_lock;
749 concat->mtd._unlock = concat_unlock;
750 concat->mtd._is_locked = concat_is_locked;
751 concat->mtd._suspend = concat_suspend;
752 concat->mtd._resume = concat_resume;
753
754 /*
755 * Combine the erase block size info of the subdevices:
756 *
757 * first, walk the map of the new device and see how
758 * many changes in erase size we have
759 */
760 max_erasesize = curr_erasesize = subdev[0]->erasesize;
761 num_erase_region = 1;
762 for (i = 0; i < num_devs; i++) {
763 if (subdev[i]->numeraseregions == 0) {
764 /* current subdevice has uniform erase size */
765 if (subdev[i]->erasesize != curr_erasesize) {
766 /* if it differs from the last subdevice's erase size, count it */
767 ++num_erase_region;
768 curr_erasesize = subdev[i]->erasesize;
769 if (curr_erasesize > max_erasesize)
770 max_erasesize = curr_erasesize;
771 }
772 } else {
773 /* current subdevice has variable erase size */
774 int j;
775 for (j = 0; j < subdev[i]->numeraseregions; j++) {
776
777 /* walk the list of erase regions, count any changes */
778 if (subdev[i]->eraseregions[j].erasesize !=
779 curr_erasesize) {
780 ++num_erase_region;
781 curr_erasesize =
782 subdev[i]->eraseregions[j].
783 erasesize;
784 if (curr_erasesize > max_erasesize)
785 max_erasesize = curr_erasesize;
786 }
787 }
788 }
789 }
790
791 if (num_erase_region == 1) {
792 /*
793 * All subdevices have the same uniform erase size.
794 * This is easy:
795 */
796 concat->mtd.erasesize = curr_erasesize;
797 concat->mtd.numeraseregions = 0;
798 } else {
799 uint64_t tmp64;
800
801 /*
802 * erase block size varies across the subdevices: allocate
803 * space to store the data describing the variable erase regions
804 */
805 struct mtd_erase_region_info *erase_region_p;
806 uint64_t begin, position;
807
808 concat->mtd.erasesize = max_erasesize;
809 concat->mtd.numeraseregions = num_erase_region;
810 concat->mtd.eraseregions = erase_region_p =
811 kmalloc_objs(struct mtd_erase_region_info, num_erase_region);
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 * 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 tmp64 = position - begin;
838 do_div(tmp64, curr_erasesize);
839 erase_region_p->numblocks = tmp64;
840 begin = position;
841
842 curr_erasesize = subdev[i]->erasesize;
843 ++erase_region_p;
844 }
845 position += subdev[i]->size;
846 } else {
847 /* current subdevice has variable erase size */
848 int j;
849 for (j = 0; j < subdev[i]->numeraseregions; j++) {
850 /* walk the list of erase regions, count any changes */
851 if (subdev[i]->eraseregions[j].
852 erasesize != curr_erasesize) {
853 erase_region_p->offset = begin;
854 erase_region_p->erasesize =
855 curr_erasesize;
856 tmp64 = position - begin;
857 do_div(tmp64, curr_erasesize);
858 erase_region_p->numblocks = tmp64;
859 begin = position;
860
861 curr_erasesize =
862 subdev[i]->eraseregions[j].
863 erasesize;
864 ++erase_region_p;
865 }
866 position +=
867 subdev[i]->eraseregions[j].
868 numblocks * (uint64_t)curr_erasesize;
869 }
870 }
871 }
872 /* Now write the final entry */
873 erase_region_p->offset = begin;
874 erase_region_p->erasesize = curr_erasesize;
875 tmp64 = position - begin;
876 do_div(tmp64, curr_erasesize);
877 erase_region_p->numblocks = tmp64;
878 }
879
880 return &concat->mtd;
881}
882
883/* Cleans the context obtained from mtd_concat_create() */
884void 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
892EXPORT_SYMBOL(mtd_concat_create);
893EXPORT_SYMBOL(mtd_concat_destroy);
894
895MODULE_LICENSE("GPL");
896MODULE_AUTHOR("Robert Kaiser <[email protected]>");
897MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");