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