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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_panic_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 for (i = 0; i < concat->num_subdev; i++) {
113 struct mtd_info *subdev = concat->subdev[i];
114 size_t size, retsize;
115
116 if (to >= subdev->size) {
117 to -= subdev->size;
118 continue;
119 }
120 if (to + len > subdev->size)
121 size = subdev->size - to;
122 else
123 size = len;
124
125 err = mtd_panic_write(subdev, to, size, &retsize, buf);
126 if (err == -EOPNOTSUPP) {
127 printk(KERN_ERR "mtdconcat: Cannot write from panic without panic_write\n");
128 return err;
129 }
130 if (err)
131 break;
132
133 *retlen += retsize;
134 len -= size;
135 if (len == 0)
136 break;
137
138 err = -EINVAL;
139 buf += size;
140 to = 0;
141 }
142 return err;
143}
144
145
146static int
147concat_write(struct mtd_info *mtd, loff_t to, size_t len,
148 size_t * retlen, const u_char * buf)
149{
150 struct mtd_concat *concat = CONCAT(mtd);
151 int err = -EINVAL;
152 int i;
153
154 for (i = 0; i < concat->num_subdev; i++) {
155 struct mtd_info *subdev = concat->subdev[i];
156 size_t size, retsize;
157
158 if (to >= subdev->size) {
159 size = 0;
160 to -= subdev->size;
161 continue;
162 }
163 if (to + len > subdev->size)
164 size = subdev->size - to;
165 else
166 size = len;
167
168 err = mtd_write(subdev, to, size, &retsize, buf);
169 if (err)
170 break;
171
172 *retlen += retsize;
173 len -= size;
174 if (len == 0)
175 break;
176
177 err = -EINVAL;
178 buf += size;
179 to = 0;
180 }
181 return err;
182}
183
184static int
185concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
186 unsigned long count, loff_t to, size_t * retlen)
187{
188 struct mtd_concat *concat = CONCAT(mtd);
189 struct kvec *vecs_copy;
190 unsigned long entry_low, entry_high;
191 size_t total_len = 0;
192 int i;
193 int err = -EINVAL;
194
195 /* Calculate total length of data */
196 for (i = 0; i < count; i++)
197 total_len += vecs[i].iov_len;
198
199 /* Check alignment */
200 if (mtd->writesize > 1) {
201 uint64_t __to = to;
202 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
203 return -EINVAL;
204 }
205
206 /* make a copy of vecs */
207 vecs_copy = kmemdup(vecs, sizeof(struct kvec) * count, GFP_KERNEL);
208 if (!vecs_copy)
209 return -ENOMEM;
210
211 entry_low = 0;
212 for (i = 0; i < concat->num_subdev; i++) {
213 struct mtd_info *subdev = concat->subdev[i];
214 size_t size, wsize, retsize, old_iov_len;
215
216 if (to >= subdev->size) {
217 to -= subdev->size;
218 continue;
219 }
220
221 size = min_t(uint64_t, total_len, subdev->size - to);
222 wsize = size; /* store for future use */
223
224 entry_high = entry_low;
225 while (entry_high < count) {
226 if (size <= vecs_copy[entry_high].iov_len)
227 break;
228 size -= vecs_copy[entry_high++].iov_len;
229 }
230
231 old_iov_len = vecs_copy[entry_high].iov_len;
232 vecs_copy[entry_high].iov_len = size;
233
234 err = mtd_writev(subdev, &vecs_copy[entry_low],
235 entry_high - entry_low + 1, to, &retsize);
236
237 vecs_copy[entry_high].iov_len = old_iov_len - size;
238 vecs_copy[entry_high].iov_base += size;
239
240 entry_low = entry_high;
241
242 if (err)
243 break;
244
245 *retlen += retsize;
246 total_len -= wsize;
247
248 if (total_len == 0)
249 break;
250
251 err = -EINVAL;
252 to = 0;
253 }
254
255 kfree(vecs_copy);
256 return err;
257}
258
259static int
260concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
261{
262 struct mtd_concat *concat = CONCAT(mtd);
263 struct mtd_oob_ops devops = *ops;
264 int i, err, ret = 0;
265
266 ops->retlen = ops->oobretlen = 0;
267
268 for (i = 0; i < concat->num_subdev; i++) {
269 struct mtd_info *subdev = concat->subdev[i];
270
271 if (from >= subdev->size) {
272 from -= subdev->size;
273 continue;
274 }
275
276 /* partial read ? */
277 if (from + devops.len > subdev->size)
278 devops.len = subdev->size - from;
279
280 err = mtd_read_oob(subdev, from, &devops);
281 ops->retlen += devops.retlen;
282 ops->oobretlen += devops.oobretlen;
283
284 /* Save information about bitflips! */
285 if (unlikely(err)) {
286 if (mtd_is_eccerr(err)) {
287 mtd->ecc_stats.failed++;
288 ret = err;
289 } else if (mtd_is_bitflip(err)) {
290 mtd->ecc_stats.corrected++;
291 /* Do not overwrite -EBADMSG !! */
292 if (!ret)
293 ret = err;
294 } else
295 return err;
296 }
297
298 if (devops.datbuf) {
299 devops.len = ops->len - ops->retlen;
300 if (!devops.len)
301 return ret;
302 devops.datbuf += devops.retlen;
303 }
304 if (devops.oobbuf) {
305 devops.ooblen = ops->ooblen - ops->oobretlen;
306 if (!devops.ooblen)
307 return ret;
308 devops.oobbuf += ops->oobretlen;
309 }
310
311 from = 0;
312 }
313 return -EINVAL;
314}
315
316static int
317concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
318{
319 struct mtd_concat *concat = CONCAT(mtd);
320 struct mtd_oob_ops devops = *ops;
321 int i, err;
322
323 if (!(mtd->flags & MTD_WRITEABLE))
324 return -EROFS;
325
326 ops->retlen = ops->oobretlen = 0;
327
328 for (i = 0; i < concat->num_subdev; i++) {
329 struct mtd_info *subdev = concat->subdev[i];
330
331 if (to >= subdev->size) {
332 to -= subdev->size;
333 continue;
334 }
335
336 /* partial write ? */
337 if (to + devops.len > subdev->size)
338 devops.len = subdev->size - to;
339
340 err = mtd_write_oob(subdev, to, &devops);
341 ops->retlen += devops.retlen;
342 ops->oobretlen += devops.oobretlen;
343 if (err)
344 return err;
345
346 if (devops.datbuf) {
347 devops.len = ops->len - ops->retlen;
348 if (!devops.len)
349 return 0;
350 devops.datbuf += devops.retlen;
351 }
352 if (devops.oobbuf) {
353 devops.ooblen = ops->ooblen - ops->oobretlen;
354 if (!devops.ooblen)
355 return 0;
356 devops.oobbuf += devops.oobretlen;
357 }
358 to = 0;
359 }
360 return -EINVAL;
361}
362
363static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
364{
365 struct mtd_concat *concat = CONCAT(mtd);
366 struct mtd_info *subdev;
367 int i, err;
368 uint64_t length, offset = 0;
369 struct erase_info *erase;
370
371 /*
372 * Check for proper erase block alignment of the to-be-erased area.
373 * It is easier to do this based on the super device's erase
374 * region info rather than looking at each particular sub-device
375 * in turn.
376 */
377 if (!concat->mtd.numeraseregions) {
378 /* the easy case: device has uniform erase block size */
379 if (instr->addr & (concat->mtd.erasesize - 1))
380 return -EINVAL;
381 if (instr->len & (concat->mtd.erasesize - 1))
382 return -EINVAL;
383 } else {
384 /* device has variable erase size */
385 struct mtd_erase_region_info *erase_regions =
386 concat->mtd.eraseregions;
387
388 /*
389 * Find the erase region where the to-be-erased area begins:
390 */
391 for (i = 0; i < concat->mtd.numeraseregions &&
392 instr->addr >= erase_regions[i].offset; i++) ;
393 --i;
394
395 /*
396 * Now erase_regions[i] is the region in which the
397 * to-be-erased area begins. Verify that the starting
398 * offset is aligned to this region's erase size:
399 */
400 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))
401 return -EINVAL;
402
403 /*
404 * now find the erase region where the to-be-erased area ends:
405 */
406 for (; i < concat->mtd.numeraseregions &&
407 (instr->addr + instr->len) >= erase_regions[i].offset;
408 ++i) ;
409 --i;
410 /*
411 * check if the ending offset is aligned to this region's erase size
412 */
413 if (i < 0 || ((instr->addr + instr->len) &
414 (erase_regions[i].erasesize - 1)))
415 return -EINVAL;
416 }
417
418 /* make a local copy of instr to avoid modifying the caller's struct */
419 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
420
421 if (!erase)
422 return -ENOMEM;
423
424 *erase = *instr;
425 length = instr->len;
426
427 /*
428 * find the subdevice where the to-be-erased area begins, adjust
429 * starting offset to be relative to the subdevice start
430 */
431 for (i = 0; i < concat->num_subdev; i++) {
432 subdev = concat->subdev[i];
433 if (subdev->size <= erase->addr) {
434 erase->addr -= subdev->size;
435 offset += subdev->size;
436 } else {
437 break;
438 }
439 }
440
441 /* must never happen since size limit has been verified above */
442 BUG_ON(i >= concat->num_subdev);
443
444 /* now do the erase: */
445 err = 0;
446 for (; length > 0; i++) {
447 /* loop for all subdevices affected by this request */
448 subdev = concat->subdev[i]; /* get current subdevice */
449
450 /* limit length to subdevice's size: */
451 if (erase->addr + length > subdev->size)
452 erase->len = subdev->size - erase->addr;
453 else
454 erase->len = length;
455
456 length -= erase->len;
457 if ((err = mtd_erase(subdev, erase))) {
458 /* sanity check: should never happen since
459 * block alignment has been checked above */
460 BUG_ON(err == -EINVAL);
461 if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
462 instr->fail_addr = erase->fail_addr + offset;
463 break;
464 }
465 /*
466 * erase->addr specifies the offset of the area to be
467 * erased *within the current subdevice*. It can be
468 * non-zero only the first time through this loop, i.e.
469 * for the first subdevice where blocks need to be erased.
470 * All the following erases must begin at the start of the
471 * current subdevice, i.e. at offset zero.
472 */
473 erase->addr = 0;
474 offset += subdev->size;
475 }
476 kfree(erase);
477
478 return err;
479}
480
481static int concat_xxlock(struct mtd_info *mtd, loff_t ofs, uint64_t len,
482 bool is_lock)
483{
484 struct mtd_concat *concat = CONCAT(mtd);
485 int i, err = -EINVAL;
486
487 for (i = 0; i < concat->num_subdev; i++) {
488 struct mtd_info *subdev = concat->subdev[i];
489 uint64_t size;
490
491 if (ofs >= subdev->size) {
492 size = 0;
493 ofs -= subdev->size;
494 continue;
495 }
496 if (ofs + len > subdev->size)
497 size = subdev->size - ofs;
498 else
499 size = len;
500
501 if (is_lock)
502 err = mtd_lock(subdev, ofs, size);
503 else
504 err = mtd_unlock(subdev, ofs, size);
505 if (err)
506 break;
507
508 len -= size;
509 if (len == 0)
510 break;
511
512 err = -EINVAL;
513 ofs = 0;
514 }
515
516 return err;
517}
518
519static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
520{
521 return concat_xxlock(mtd, ofs, len, true);
522}
523
524static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
525{
526 return concat_xxlock(mtd, ofs, len, false);
527}
528
529static int concat_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
530{
531 struct mtd_concat *concat = CONCAT(mtd);
532 int i, err = -EINVAL;
533
534 for (i = 0; i < concat->num_subdev; i++) {
535 struct mtd_info *subdev = concat->subdev[i];
536
537 if (ofs >= subdev->size) {
538 ofs -= subdev->size;
539 continue;
540 }
541
542 if (ofs + len > subdev->size)
543 break;
544
545 return mtd_is_locked(subdev, ofs, len);
546 }
547
548 return err;
549}
550
551static void concat_sync(struct mtd_info *mtd)
552{
553 struct mtd_concat *concat = CONCAT(mtd);
554 int i;
555
556 for (i = 0; i < concat->num_subdev; i++) {
557 struct mtd_info *subdev = concat->subdev[i];
558 mtd_sync(subdev);
559 }
560}
561
562static int concat_suspend(struct mtd_info *mtd)
563{
564 struct mtd_concat *concat = CONCAT(mtd);
565 int i, rc = 0;
566
567 for (i = 0; i < concat->num_subdev; i++) {
568 struct mtd_info *subdev = concat->subdev[i];
569 if ((rc = mtd_suspend(subdev)) < 0)
570 return rc;
571 }
572 return rc;
573}
574
575static void concat_resume(struct mtd_info *mtd)
576{
577 struct mtd_concat *concat = CONCAT(mtd);
578 int i;
579
580 for (i = 0; i < concat->num_subdev; i++) {
581 struct mtd_info *subdev = concat->subdev[i];
582 mtd_resume(subdev);
583 }
584}
585
586static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
587{
588 struct mtd_concat *concat = CONCAT(mtd);
589 int i, res = 0;
590
591 if (!mtd_can_have_bb(concat->subdev[0]))
592 return res;
593
594 for (i = 0; i < concat->num_subdev; i++) {
595 struct mtd_info *subdev = concat->subdev[i];
596
597 if (ofs >= subdev->size) {
598 ofs -= subdev->size;
599 continue;
600 }
601
602 res = mtd_block_isbad(subdev, ofs);
603 break;
604 }
605
606 return res;
607}
608
609static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
610{
611 struct mtd_concat *concat = CONCAT(mtd);
612 int i, err = -EINVAL;
613
614 for (i = 0; i < concat->num_subdev; i++) {
615 struct mtd_info *subdev = concat->subdev[i];
616
617 if (ofs >= subdev->size) {
618 ofs -= subdev->size;
619 continue;
620 }
621
622 err = mtd_block_markbad(subdev, ofs);
623 if (!err)
624 mtd->ecc_stats.badblocks++;
625 break;
626 }
627
628 return err;
629}
630
631/*
632 * This function constructs a virtual MTD device by concatenating
633 * num_devs MTD devices. A pointer to the new device object is
634 * stored to *new_dev upon success. This function does _not_
635 * register any devices: this is the caller's responsibility.
636 */
637struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
638 int num_devs, /* number of subdevices */
639 const char *name)
640{ /* name for the new device */
641 int i;
642 size_t size;
643 struct mtd_concat *concat;
644 struct mtd_info *subdev_master = NULL;
645 uint32_t max_erasesize, curr_erasesize;
646 int num_erase_region;
647 int max_writebufsize = 0;
648
649 printk(KERN_NOTICE "Concatenating MTD devices:\n");
650 for (i = 0; i < num_devs; i++)
651 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
652 printk(KERN_NOTICE "into device \"%s\"\n", name);
653
654 /* allocate the device structure */
655 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
656 concat = kzalloc(size, GFP_KERNEL);
657 if (!concat) {
658 printk
659 ("memory allocation error while creating concatenated device \"%s\"\n",
660 name);
661 return NULL;
662 }
663 concat->subdev = (struct mtd_info **) (concat + 1);
664
665 /*
666 * Set up the new "super" device's MTD object structure, check for
667 * incompatibilities between the subdevices.
668 */
669 concat->mtd.type = subdev[0]->type;
670 concat->mtd.flags = subdev[0]->flags;
671 concat->mtd.size = subdev[0]->size;
672 concat->mtd.erasesize = subdev[0]->erasesize;
673 concat->mtd.writesize = subdev[0]->writesize;
674
675 for (i = 0; i < num_devs; i++)
676 if (max_writebufsize < subdev[i]->writebufsize)
677 max_writebufsize = subdev[i]->writebufsize;
678 concat->mtd.writebufsize = max_writebufsize;
679
680 concat->mtd.subpage_sft = subdev[0]->subpage_sft;
681 concat->mtd.oobsize = subdev[0]->oobsize;
682 concat->mtd.oobavail = subdev[0]->oobavail;
683
684 subdev_master = mtd_get_master(subdev[0]);
685 if (subdev_master->_writev)
686 concat->mtd._writev = concat_writev;
687 if (subdev_master->_read_oob)
688 concat->mtd._read_oob = concat_read_oob;
689 if (subdev_master->_write_oob)
690 concat->mtd._write_oob = concat_write_oob;
691 if (subdev_master->_block_isbad)
692 concat->mtd._block_isbad = concat_block_isbad;
693 if (subdev_master->_block_markbad)
694 concat->mtd._block_markbad = concat_block_markbad;
695 if (subdev_master->_panic_write)
696 concat->mtd._panic_write = concat_panic_write;
697 if (subdev_master->_read)
698 concat->mtd._read = concat_read;
699 if (subdev_master->_write)
700 concat->mtd._write = concat_write;
701
702 concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
703
704 concat->subdev[0] = subdev[0];
705
706 for (i = 1; i < num_devs; i++) {
707 if (concat->mtd.type != subdev[i]->type) {
708 kfree(concat);
709 printk("Incompatible device type on \"%s\"\n",
710 subdev[i]->name);
711 return NULL;
712 }
713 if (concat->mtd.flags != subdev[i]->flags) {
714 /*
715 * Expect all flags except MTD_WRITEABLE to be
716 * equal on all subdevices.
717 */
718 if ((concat->mtd.flags ^ subdev[i]->
719 flags) & ~MTD_WRITEABLE) {
720 kfree(concat);
721 printk("Incompatible device flags on \"%s\"\n",
722 subdev[i]->name);
723 return NULL;
724 } else
725 /* if writeable attribute differs,
726 make super device writeable */
727 concat->mtd.flags |=
728 subdev[i]->flags & MTD_WRITEABLE;
729 }
730
731 subdev_master = mtd_get_master(subdev[i]);
732 concat->mtd.size += subdev[i]->size;
733 concat->mtd.ecc_stats.badblocks +=
734 subdev[i]->ecc_stats.badblocks;
735 if (concat->mtd.writesize != subdev[i]->writesize ||
736 concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
737 concat->mtd.oobsize != subdev[i]->oobsize ||
738 !concat->mtd._read_oob != !subdev_master->_read_oob ||
739 !concat->mtd._write_oob != !subdev_master->_write_oob) {
740 /*
741 * Check against subdev[i] for data members, because
742 * subdev's attributes may be different from master
743 * mtd device. Check against subdev's master mtd
744 * device for callbacks, because the existence of
745 * subdev's callbacks is decided by master mtd device.
746 */
747 kfree(concat);
748 printk("Incompatible OOB or ECC data on \"%s\"\n",
749 subdev[i]->name);
750 return NULL;
751 }
752 concat->subdev[i] = subdev[i];
753
754 }
755
756 mtd_set_ooblayout(&concat->mtd, subdev[0]->ooblayout);
757
758 concat->num_subdev = num_devs;
759 concat->mtd.name = name;
760
761 concat->mtd._erase = concat_erase;
762 concat->mtd._sync = concat_sync;
763 concat->mtd._lock = concat_lock;
764 concat->mtd._unlock = concat_unlock;
765 concat->mtd._is_locked = concat_is_locked;
766 concat->mtd._suspend = concat_suspend;
767 concat->mtd._resume = concat_resume;
768
769 /*
770 * Combine the erase block size info of the subdevices:
771 *
772 * first, walk the map of the new device and see how
773 * many changes in erase size we have
774 */
775 max_erasesize = curr_erasesize = subdev[0]->erasesize;
776 num_erase_region = 1;
777 for (i = 0; i < num_devs; i++) {
778 if (subdev[i]->numeraseregions == 0) {
779 /* current subdevice has uniform erase size */
780 if (subdev[i]->erasesize != curr_erasesize) {
781 /* if it differs from the last subdevice's erase size, count it */
782 ++num_erase_region;
783 curr_erasesize = subdev[i]->erasesize;
784 if (curr_erasesize > max_erasesize)
785 max_erasesize = curr_erasesize;
786 }
787 } else {
788 /* current subdevice has variable erase size */
789 int j;
790 for (j = 0; j < subdev[i]->numeraseregions; j++) {
791
792 /* walk the list of erase regions, count any changes */
793 if (subdev[i]->eraseregions[j].erasesize !=
794 curr_erasesize) {
795 ++num_erase_region;
796 curr_erasesize =
797 subdev[i]->eraseregions[j].
798 erasesize;
799 if (curr_erasesize > max_erasesize)
800 max_erasesize = curr_erasesize;
801 }
802 }
803 }
804 }
805
806 if (num_erase_region == 1) {
807 /*
808 * All subdevices have the same uniform erase size.
809 * This is easy:
810 */
811 concat->mtd.erasesize = curr_erasesize;
812 concat->mtd.numeraseregions = 0;
813 } else {
814 uint64_t tmp64;
815
816 /*
817 * erase block size varies across the subdevices: allocate
818 * space to store the data describing the variable erase regions
819 */
820 struct mtd_erase_region_info *erase_region_p;
821 uint64_t begin, position;
822
823 concat->mtd.erasesize = max_erasesize;
824 concat->mtd.numeraseregions = num_erase_region;
825 concat->mtd.eraseregions = erase_region_p =
826 kmalloc_array(num_erase_region,
827 sizeof(struct mtd_erase_region_info),
828 GFP_KERNEL);
829 if (!erase_region_p) {
830 kfree(concat);
831 printk
832 ("memory allocation error while creating erase region list"
833 " for device \"%s\"\n", name);
834 return NULL;
835 }
836
837 /*
838 * walk the map of the new device once more and fill in
839 * erase region info:
840 */
841 curr_erasesize = subdev[0]->erasesize;
842 begin = position = 0;
843 for (i = 0; i < num_devs; i++) {
844 if (subdev[i]->numeraseregions == 0) {
845 /* current subdevice has uniform erase size */
846 if (subdev[i]->erasesize != curr_erasesize) {
847 /*
848 * fill in an mtd_erase_region_info structure for the area
849 * we have walked so far:
850 */
851 erase_region_p->offset = begin;
852 erase_region_p->erasesize =
853 curr_erasesize;
854 tmp64 = position - begin;
855 do_div(tmp64, curr_erasesize);
856 erase_region_p->numblocks = tmp64;
857 begin = position;
858
859 curr_erasesize = subdev[i]->erasesize;
860 ++erase_region_p;
861 }
862 position += subdev[i]->size;
863 } else {
864 /* current subdevice has variable erase size */
865 int j;
866 for (j = 0; j < subdev[i]->numeraseregions; j++) {
867 /* walk the list of erase regions, count any changes */
868 if (subdev[i]->eraseregions[j].
869 erasesize != curr_erasesize) {
870 erase_region_p->offset = begin;
871 erase_region_p->erasesize =
872 curr_erasesize;
873 tmp64 = position - begin;
874 do_div(tmp64, curr_erasesize);
875 erase_region_p->numblocks = tmp64;
876 begin = position;
877
878 curr_erasesize =
879 subdev[i]->eraseregions[j].
880 erasesize;
881 ++erase_region_p;
882 }
883 position +=
884 subdev[i]->eraseregions[j].
885 numblocks * (uint64_t)curr_erasesize;
886 }
887 }
888 }
889 /* Now write the final entry */
890 erase_region_p->offset = begin;
891 erase_region_p->erasesize = curr_erasesize;
892 tmp64 = position - begin;
893 do_div(tmp64, curr_erasesize);
894 erase_region_p->numblocks = tmp64;
895 }
896
897 return &concat->mtd;
898}
899
900/* Cleans the context obtained from mtd_concat_create() */
901void mtd_concat_destroy(struct mtd_info *mtd)
902{
903 struct mtd_concat *concat = CONCAT(mtd);
904 if (concat->mtd.numeraseregions)
905 kfree(concat->mtd.eraseregions);
906 kfree(concat);
907}
908
909EXPORT_SYMBOL(mtd_concat_create);
910EXPORT_SYMBOL(mtd_concat_destroy);
911
912MODULE_LICENSE("GPL");
913MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
914MODULE_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 *retlen = 0;
76
77 for (i = 0; i < concat->num_subdev; i++) {
78 struct mtd_info *subdev = concat->subdev[i];
79 size_t size, retsize;
80
81 if (from >= subdev->size) {
82 /* Not destined for this subdev */
83 size = 0;
84 from -= subdev->size;
85 continue;
86 }
87 if (from + len > subdev->size)
88 /* First part goes into this subdev */
89 size = subdev->size - from;
90 else
91 /* Entire transaction goes into this subdev */
92 size = len;
93
94 err = subdev->read(subdev, from, size, &retsize, buf);
95
96 /* Save information about bitflips! */
97 if (unlikely(err)) {
98 if (err == -EBADMSG) {
99 mtd->ecc_stats.failed++;
100 ret = err;
101 } else if (err == -EUCLEAN) {
102 mtd->ecc_stats.corrected++;
103 /* Do not overwrite -EBADMSG !! */
104 if (!ret)
105 ret = err;
106 } else
107 return err;
108 }
109
110 *retlen += retsize;
111 len -= size;
112 if (len == 0)
113 return ret;
114
115 buf += size;
116 from = 0;
117 }
118 return -EINVAL;
119}
120
121static int
122concat_write(struct mtd_info *mtd, loff_t to, size_t len,
123 size_t * retlen, const u_char * buf)
124{
125 struct mtd_concat *concat = CONCAT(mtd);
126 int err = -EINVAL;
127 int i;
128
129 if (!(mtd->flags & MTD_WRITEABLE))
130 return -EROFS;
131
132 *retlen = 0;
133
134 for (i = 0; i < concat->num_subdev; i++) {
135 struct mtd_info *subdev = concat->subdev[i];
136 size_t size, retsize;
137
138 if (to >= subdev->size) {
139 size = 0;
140 to -= subdev->size;
141 continue;
142 }
143 if (to + len > subdev->size)
144 size = subdev->size - to;
145 else
146 size = len;
147
148 if (!(subdev->flags & MTD_WRITEABLE))
149 err = -EROFS;
150 else
151 err = subdev->write(subdev, to, size, &retsize, buf);
152
153 if (err)
154 break;
155
156 *retlen += retsize;
157 len -= size;
158 if (len == 0)
159 break;
160
161 err = -EINVAL;
162 buf += size;
163 to = 0;
164 }
165 return err;
166}
167
168static int
169concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
170 unsigned long count, loff_t to, size_t * retlen)
171{
172 struct mtd_concat *concat = CONCAT(mtd);
173 struct kvec *vecs_copy;
174 unsigned long entry_low, entry_high;
175 size_t total_len = 0;
176 int i;
177 int err = -EINVAL;
178
179 if (!(mtd->flags & MTD_WRITEABLE))
180 return -EROFS;
181
182 *retlen = 0;
183
184 /* Calculate total length of data */
185 for (i = 0; i < count; i++)
186 total_len += vecs[i].iov_len;
187
188 /* Do not allow write past end of device */
189 if ((to + total_len) > mtd->size)
190 return -EINVAL;
191
192 /* Check alignment */
193 if (mtd->writesize > 1) {
194 uint64_t __to = to;
195 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
196 return -EINVAL;
197 }
198
199 /* make a copy of vecs */
200 vecs_copy = kmemdup(vecs, sizeof(struct kvec) * count, GFP_KERNEL);
201 if (!vecs_copy)
202 return -ENOMEM;
203
204 entry_low = 0;
205 for (i = 0; i < concat->num_subdev; i++) {
206 struct mtd_info *subdev = concat->subdev[i];
207 size_t size, wsize, retsize, old_iov_len;
208
209 if (to >= subdev->size) {
210 to -= subdev->size;
211 continue;
212 }
213
214 size = min_t(uint64_t, total_len, subdev->size - to);
215 wsize = size; /* store for future use */
216
217 entry_high = entry_low;
218 while (entry_high < count) {
219 if (size <= vecs_copy[entry_high].iov_len)
220 break;
221 size -= vecs_copy[entry_high++].iov_len;
222 }
223
224 old_iov_len = vecs_copy[entry_high].iov_len;
225 vecs_copy[entry_high].iov_len = size;
226
227 if (!(subdev->flags & MTD_WRITEABLE))
228 err = -EROFS;
229 else
230 err = subdev->writev(subdev, &vecs_copy[entry_low],
231 entry_high - entry_low + 1, to, &retsize);
232
233 vecs_copy[entry_high].iov_len = old_iov_len - size;
234 vecs_copy[entry_high].iov_base += size;
235
236 entry_low = entry_high;
237
238 if (err)
239 break;
240
241 *retlen += retsize;
242 total_len -= wsize;
243
244 if (total_len == 0)
245 break;
246
247 err = -EINVAL;
248 to = 0;
249 }
250
251 kfree(vecs_copy);
252 return err;
253}
254
255static int
256concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
257{
258 struct mtd_concat *concat = CONCAT(mtd);
259 struct mtd_oob_ops devops = *ops;
260 int i, err, ret = 0;
261
262 ops->retlen = ops->oobretlen = 0;
263
264 for (i = 0; i < concat->num_subdev; i++) {
265 struct mtd_info *subdev = concat->subdev[i];
266
267 if (from >= subdev->size) {
268 from -= subdev->size;
269 continue;
270 }
271
272 /* partial read ? */
273 if (from + devops.len > subdev->size)
274 devops.len = subdev->size - from;
275
276 err = subdev->read_oob(subdev, from, &devops);
277 ops->retlen += devops.retlen;
278 ops->oobretlen += devops.oobretlen;
279
280 /* Save information about bitflips! */
281 if (unlikely(err)) {
282 if (err == -EBADMSG) {
283 mtd->ecc_stats.failed++;
284 ret = err;
285 } else if (err == -EUCLEAN) {
286 mtd->ecc_stats.corrected++;
287 /* Do not overwrite -EBADMSG !! */
288 if (!ret)
289 ret = err;
290 } else
291 return err;
292 }
293
294 if (devops.datbuf) {
295 devops.len = ops->len - ops->retlen;
296 if (!devops.len)
297 return ret;
298 devops.datbuf += devops.retlen;
299 }
300 if (devops.oobbuf) {
301 devops.ooblen = ops->ooblen - ops->oobretlen;
302 if (!devops.ooblen)
303 return ret;
304 devops.oobbuf += ops->oobretlen;
305 }
306
307 from = 0;
308 }
309 return -EINVAL;
310}
311
312static int
313concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
314{
315 struct mtd_concat *concat = CONCAT(mtd);
316 struct mtd_oob_ops devops = *ops;
317 int i, err;
318
319 if (!(mtd->flags & MTD_WRITEABLE))
320 return -EROFS;
321
322 ops->retlen = ops->oobretlen = 0;
323
324 for (i = 0; i < concat->num_subdev; i++) {
325 struct mtd_info *subdev = concat->subdev[i];
326
327 if (to >= subdev->size) {
328 to -= subdev->size;
329 continue;
330 }
331
332 /* partial write ? */
333 if (to + devops.len > subdev->size)
334 devops.len = subdev->size - to;
335
336 err = subdev->write_oob(subdev, to, &devops);
337 ops->retlen += devops.oobretlen;
338 if (err)
339 return err;
340
341 if (devops.datbuf) {
342 devops.len = ops->len - ops->retlen;
343 if (!devops.len)
344 return 0;
345 devops.datbuf += devops.retlen;
346 }
347 if (devops.oobbuf) {
348 devops.ooblen = ops->ooblen - ops->oobretlen;
349 if (!devops.ooblen)
350 return 0;
351 devops.oobbuf += devops.oobretlen;
352 }
353 to = 0;
354 }
355 return -EINVAL;
356}
357
358static void concat_erase_callback(struct erase_info *instr)
359{
360 wake_up((wait_queue_head_t *) instr->priv);
361}
362
363static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
364{
365 int err;
366 wait_queue_head_t waitq;
367 DECLARE_WAITQUEUE(wait, current);
368
369 /*
370 * This code was stol^H^H^H^Hinspired by mtdchar.c
371 */
372 init_waitqueue_head(&waitq);
373
374 erase->mtd = mtd;
375 erase->callback = concat_erase_callback;
376 erase->priv = (unsigned long) &waitq;
377
378 /*
379 * FIXME: Allow INTERRUPTIBLE. Which means
380 * not having the wait_queue head on the stack.
381 */
382 err = mtd->erase(mtd, erase);
383 if (!err) {
384 set_current_state(TASK_UNINTERRUPTIBLE);
385 add_wait_queue(&waitq, &wait);
386 if (erase->state != MTD_ERASE_DONE
387 && erase->state != MTD_ERASE_FAILED)
388 schedule();
389 remove_wait_queue(&waitq, &wait);
390 set_current_state(TASK_RUNNING);
391
392 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
393 }
394 return err;
395}
396
397static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
398{
399 struct mtd_concat *concat = CONCAT(mtd);
400 struct mtd_info *subdev;
401 int i, err;
402 uint64_t length, offset = 0;
403 struct erase_info *erase;
404
405 if (!(mtd->flags & MTD_WRITEABLE))
406 return -EROFS;
407
408 if (instr->addr > concat->mtd.size)
409 return -EINVAL;
410
411 if (instr->len + instr->addr > concat->mtd.size)
412 return -EINVAL;
413
414 /*
415 * Check for proper erase block alignment of the to-be-erased area.
416 * It is easier to do this based on the super device's erase
417 * region info rather than looking at each particular sub-device
418 * in turn.
419 */
420 if (!concat->mtd.numeraseregions) {
421 /* the easy case: device has uniform erase block size */
422 if (instr->addr & (concat->mtd.erasesize - 1))
423 return -EINVAL;
424 if (instr->len & (concat->mtd.erasesize - 1))
425 return -EINVAL;
426 } else {
427 /* device has variable erase size */
428 struct mtd_erase_region_info *erase_regions =
429 concat->mtd.eraseregions;
430
431 /*
432 * Find the erase region where the to-be-erased area begins:
433 */
434 for (i = 0; i < concat->mtd.numeraseregions &&
435 instr->addr >= erase_regions[i].offset; i++) ;
436 --i;
437
438 /*
439 * Now erase_regions[i] is the region in which the
440 * to-be-erased area begins. Verify that the starting
441 * offset is aligned to this region's erase size:
442 */
443 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))
444 return -EINVAL;
445
446 /*
447 * now find the erase region where the to-be-erased area ends:
448 */
449 for (; i < concat->mtd.numeraseregions &&
450 (instr->addr + instr->len) >= erase_regions[i].offset;
451 ++i) ;
452 --i;
453 /*
454 * check if the ending offset is aligned to this region's erase size
455 */
456 if (i < 0 || ((instr->addr + instr->len) &
457 (erase_regions[i].erasesize - 1)))
458 return -EINVAL;
459 }
460
461 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
462
463 /* make a local copy of instr to avoid modifying the caller's struct */
464 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
465
466 if (!erase)
467 return -ENOMEM;
468
469 *erase = *instr;
470 length = instr->len;
471
472 /*
473 * find the subdevice where the to-be-erased area begins, adjust
474 * starting offset to be relative to the subdevice start
475 */
476 for (i = 0; i < concat->num_subdev; i++) {
477 subdev = concat->subdev[i];
478 if (subdev->size <= erase->addr) {
479 erase->addr -= subdev->size;
480 offset += subdev->size;
481 } else {
482 break;
483 }
484 }
485
486 /* must never happen since size limit has been verified above */
487 BUG_ON(i >= concat->num_subdev);
488
489 /* now do the erase: */
490 err = 0;
491 for (; length > 0; i++) {
492 /* loop for all subdevices affected by this request */
493 subdev = concat->subdev[i]; /* get current subdevice */
494
495 /* limit length to subdevice's size: */
496 if (erase->addr + length > subdev->size)
497 erase->len = subdev->size - erase->addr;
498 else
499 erase->len = length;
500
501 if (!(subdev->flags & MTD_WRITEABLE)) {
502 err = -EROFS;
503 break;
504 }
505 length -= erase->len;
506 if ((err = concat_dev_erase(subdev, erase))) {
507 /* sanity check: should never happen since
508 * block alignment has been checked above */
509 BUG_ON(err == -EINVAL);
510 if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
511 instr->fail_addr = erase->fail_addr + offset;
512 break;
513 }
514 /*
515 * erase->addr specifies the offset of the area to be
516 * erased *within the current subdevice*. It can be
517 * non-zero only the first time through this loop, i.e.
518 * for the first subdevice where blocks need to be erased.
519 * All the following erases must begin at the start of the
520 * current subdevice, i.e. at offset zero.
521 */
522 erase->addr = 0;
523 offset += subdev->size;
524 }
525 instr->state = erase->state;
526 kfree(erase);
527 if (err)
528 return err;
529
530 if (instr->callback)
531 instr->callback(instr);
532 return 0;
533}
534
535static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
536{
537 struct mtd_concat *concat = CONCAT(mtd);
538 int i, err = -EINVAL;
539
540 if ((len + ofs) > mtd->size)
541 return -EINVAL;
542
543 for (i = 0; i < concat->num_subdev; i++) {
544 struct mtd_info *subdev = concat->subdev[i];
545 uint64_t size;
546
547 if (ofs >= subdev->size) {
548 size = 0;
549 ofs -= subdev->size;
550 continue;
551 }
552 if (ofs + len > subdev->size)
553 size = subdev->size - ofs;
554 else
555 size = len;
556
557 if (subdev->lock) {
558 err = subdev->lock(subdev, ofs, size);
559 if (err)
560 break;
561 } else
562 err = -EOPNOTSUPP;
563
564 len -= size;
565 if (len == 0)
566 break;
567
568 err = -EINVAL;
569 ofs = 0;
570 }
571
572 return err;
573}
574
575static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
576{
577 struct mtd_concat *concat = CONCAT(mtd);
578 int i, err = 0;
579
580 if ((len + ofs) > mtd->size)
581 return -EINVAL;
582
583 for (i = 0; i < concat->num_subdev; i++) {
584 struct mtd_info *subdev = concat->subdev[i];
585 uint64_t size;
586
587 if (ofs >= subdev->size) {
588 size = 0;
589 ofs -= subdev->size;
590 continue;
591 }
592 if (ofs + len > subdev->size)
593 size = subdev->size - ofs;
594 else
595 size = len;
596
597 if (subdev->unlock) {
598 err = subdev->unlock(subdev, ofs, size);
599 if (err)
600 break;
601 } else
602 err = -EOPNOTSUPP;
603
604 len -= size;
605 if (len == 0)
606 break;
607
608 err = -EINVAL;
609 ofs = 0;
610 }
611
612 return err;
613}
614
615static void concat_sync(struct mtd_info *mtd)
616{
617 struct mtd_concat *concat = CONCAT(mtd);
618 int i;
619
620 for (i = 0; i < concat->num_subdev; i++) {
621 struct mtd_info *subdev = concat->subdev[i];
622 subdev->sync(subdev);
623 }
624}
625
626static int concat_suspend(struct mtd_info *mtd)
627{
628 struct mtd_concat *concat = CONCAT(mtd);
629 int i, rc = 0;
630
631 for (i = 0; i < concat->num_subdev; i++) {
632 struct mtd_info *subdev = concat->subdev[i];
633 if ((rc = subdev->suspend(subdev)) < 0)
634 return rc;
635 }
636 return rc;
637}
638
639static void concat_resume(struct mtd_info *mtd)
640{
641 struct mtd_concat *concat = CONCAT(mtd);
642 int i;
643
644 for (i = 0; i < concat->num_subdev; i++) {
645 struct mtd_info *subdev = concat->subdev[i];
646 subdev->resume(subdev);
647 }
648}
649
650static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
651{
652 struct mtd_concat *concat = CONCAT(mtd);
653 int i, res = 0;
654
655 if (!concat->subdev[0]->block_isbad)
656 return res;
657
658 if (ofs > mtd->size)
659 return -EINVAL;
660
661 for (i = 0; i < concat->num_subdev; i++) {
662 struct mtd_info *subdev = concat->subdev[i];
663
664 if (ofs >= subdev->size) {
665 ofs -= subdev->size;
666 continue;
667 }
668
669 res = subdev->block_isbad(subdev, ofs);
670 break;
671 }
672
673 return res;
674}
675
676static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
677{
678 struct mtd_concat *concat = CONCAT(mtd);
679 int i, err = -EINVAL;
680
681 if (!concat->subdev[0]->block_markbad)
682 return 0;
683
684 if (ofs > mtd->size)
685 return -EINVAL;
686
687 for (i = 0; i < concat->num_subdev; i++) {
688 struct mtd_info *subdev = concat->subdev[i];
689
690 if (ofs >= subdev->size) {
691 ofs -= subdev->size;
692 continue;
693 }
694
695 err = subdev->block_markbad(subdev, ofs);
696 if (!err)
697 mtd->ecc_stats.badblocks++;
698 break;
699 }
700
701 return err;
702}
703
704/*
705 * try to support NOMMU mmaps on concatenated devices
706 * - we don't support subdev spanning as we can't guarantee it'll work
707 */
708static unsigned long concat_get_unmapped_area(struct mtd_info *mtd,
709 unsigned long len,
710 unsigned long offset,
711 unsigned long flags)
712{
713 struct mtd_concat *concat = CONCAT(mtd);
714 int i;
715
716 for (i = 0; i < concat->num_subdev; i++) {
717 struct mtd_info *subdev = concat->subdev[i];
718
719 if (offset >= subdev->size) {
720 offset -= subdev->size;
721 continue;
722 }
723
724 /* we've found the subdev over which the mapping will reside */
725 if (offset + len > subdev->size)
726 return (unsigned long) -EINVAL;
727
728 if (subdev->get_unmapped_area)
729 return subdev->get_unmapped_area(subdev, len, offset,
730 flags);
731
732 break;
733 }
734
735 return (unsigned long) -ENOSYS;
736}
737
738/*
739 * This function constructs a virtual MTD device by concatenating
740 * num_devs MTD devices. A pointer to the new device object is
741 * stored to *new_dev upon success. This function does _not_
742 * register any devices: this is the caller's responsibility.
743 */
744struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
745 int num_devs, /* number of subdevices */
746 const char *name)
747{ /* name for the new device */
748 int i;
749 size_t size;
750 struct mtd_concat *concat;
751 uint32_t max_erasesize, curr_erasesize;
752 int num_erase_region;
753 int max_writebufsize = 0;
754
755 printk(KERN_NOTICE "Concatenating MTD devices:\n");
756 for (i = 0; i < num_devs; i++)
757 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
758 printk(KERN_NOTICE "into device \"%s\"\n", name);
759
760 /* allocate the device structure */
761 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
762 concat = kzalloc(size, GFP_KERNEL);
763 if (!concat) {
764 printk
765 ("memory allocation error while creating concatenated device \"%s\"\n",
766 name);
767 return NULL;
768 }
769 concat->subdev = (struct mtd_info **) (concat + 1);
770
771 /*
772 * Set up the new "super" device's MTD object structure, check for
773 * incompatibilites between the subdevices.
774 */
775 concat->mtd.type = subdev[0]->type;
776 concat->mtd.flags = subdev[0]->flags;
777 concat->mtd.size = subdev[0]->size;
778 concat->mtd.erasesize = subdev[0]->erasesize;
779 concat->mtd.writesize = subdev[0]->writesize;
780
781 for (i = 0; i < num_devs; i++)
782 if (max_writebufsize < subdev[i]->writebufsize)
783 max_writebufsize = subdev[i]->writebufsize;
784 concat->mtd.writebufsize = max_writebufsize;
785
786 concat->mtd.subpage_sft = subdev[0]->subpage_sft;
787 concat->mtd.oobsize = subdev[0]->oobsize;
788 concat->mtd.oobavail = subdev[0]->oobavail;
789 if (subdev[0]->writev)
790 concat->mtd.writev = concat_writev;
791 if (subdev[0]->read_oob)
792 concat->mtd.read_oob = concat_read_oob;
793 if (subdev[0]->write_oob)
794 concat->mtd.write_oob = concat_write_oob;
795 if (subdev[0]->block_isbad)
796 concat->mtd.block_isbad = concat_block_isbad;
797 if (subdev[0]->block_markbad)
798 concat->mtd.block_markbad = concat_block_markbad;
799
800 concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
801
802 concat->mtd.backing_dev_info = subdev[0]->backing_dev_info;
803
804 concat->subdev[0] = subdev[0];
805
806 for (i = 1; i < num_devs; i++) {
807 if (concat->mtd.type != subdev[i]->type) {
808 kfree(concat);
809 printk("Incompatible device type on \"%s\"\n",
810 subdev[i]->name);
811 return NULL;
812 }
813 if (concat->mtd.flags != subdev[i]->flags) {
814 /*
815 * Expect all flags except MTD_WRITEABLE to be
816 * equal on all subdevices.
817 */
818 if ((concat->mtd.flags ^ subdev[i]->
819 flags) & ~MTD_WRITEABLE) {
820 kfree(concat);
821 printk("Incompatible device flags on \"%s\"\n",
822 subdev[i]->name);
823 return NULL;
824 } else
825 /* if writeable attribute differs,
826 make super device writeable */
827 concat->mtd.flags |=
828 subdev[i]->flags & MTD_WRITEABLE;
829 }
830
831 /* only permit direct mapping if the BDIs are all the same
832 * - copy-mapping is still permitted
833 */
834 if (concat->mtd.backing_dev_info !=
835 subdev[i]->backing_dev_info)
836 concat->mtd.backing_dev_info =
837 &default_backing_dev_info;
838
839 concat->mtd.size += subdev[i]->size;
840 concat->mtd.ecc_stats.badblocks +=
841 subdev[i]->ecc_stats.badblocks;
842 if (concat->mtd.writesize != subdev[i]->writesize ||
843 concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
844 concat->mtd.oobsize != subdev[i]->oobsize ||
845 !concat->mtd.read_oob != !subdev[i]->read_oob ||
846 !concat->mtd.write_oob != !subdev[i]->write_oob) {
847 kfree(concat);
848 printk("Incompatible OOB or ECC data on \"%s\"\n",
849 subdev[i]->name);
850 return NULL;
851 }
852 concat->subdev[i] = subdev[i];
853
854 }
855
856 concat->mtd.ecclayout = subdev[0]->ecclayout;
857
858 concat->num_subdev = num_devs;
859 concat->mtd.name = name;
860
861 concat->mtd.erase = concat_erase;
862 concat->mtd.read = concat_read;
863 concat->mtd.write = concat_write;
864 concat->mtd.sync = concat_sync;
865 concat->mtd.lock = concat_lock;
866 concat->mtd.unlock = concat_unlock;
867 concat->mtd.suspend = concat_suspend;
868 concat->mtd.resume = concat_resume;
869 concat->mtd.get_unmapped_area = concat_get_unmapped_area;
870
871 /*
872 * Combine the erase block size info of the subdevices:
873 *
874 * first, walk the map of the new device and see how
875 * many changes in erase size we have
876 */
877 max_erasesize = curr_erasesize = subdev[0]->erasesize;
878 num_erase_region = 1;
879 for (i = 0; i < num_devs; i++) {
880 if (subdev[i]->numeraseregions == 0) {
881 /* current subdevice has uniform erase size */
882 if (subdev[i]->erasesize != curr_erasesize) {
883 /* if it differs from the last subdevice's erase size, count it */
884 ++num_erase_region;
885 curr_erasesize = subdev[i]->erasesize;
886 if (curr_erasesize > max_erasesize)
887 max_erasesize = curr_erasesize;
888 }
889 } else {
890 /* current subdevice has variable erase size */
891 int j;
892 for (j = 0; j < subdev[i]->numeraseregions; j++) {
893
894 /* walk the list of erase regions, count any changes */
895 if (subdev[i]->eraseregions[j].erasesize !=
896 curr_erasesize) {
897 ++num_erase_region;
898 curr_erasesize =
899 subdev[i]->eraseregions[j].
900 erasesize;
901 if (curr_erasesize > max_erasesize)
902 max_erasesize = curr_erasesize;
903 }
904 }
905 }
906 }
907
908 if (num_erase_region == 1) {
909 /*
910 * All subdevices have the same uniform erase size.
911 * This is easy:
912 */
913 concat->mtd.erasesize = curr_erasesize;
914 concat->mtd.numeraseregions = 0;
915 } else {
916 uint64_t tmp64;
917
918 /*
919 * erase block size varies across the subdevices: allocate
920 * space to store the data describing the variable erase regions
921 */
922 struct mtd_erase_region_info *erase_region_p;
923 uint64_t begin, position;
924
925 concat->mtd.erasesize = max_erasesize;
926 concat->mtd.numeraseregions = num_erase_region;
927 concat->mtd.eraseregions = erase_region_p =
928 kmalloc(num_erase_region *
929 sizeof (struct mtd_erase_region_info), GFP_KERNEL);
930 if (!erase_region_p) {
931 kfree(concat);
932 printk
933 ("memory allocation error while creating erase region list"
934 " for device \"%s\"\n", name);
935 return NULL;
936 }
937
938 /*
939 * walk the map of the new device once more and fill in
940 * in erase region info:
941 */
942 curr_erasesize = subdev[0]->erasesize;
943 begin = position = 0;
944 for (i = 0; i < num_devs; i++) {
945 if (subdev[i]->numeraseregions == 0) {
946 /* current subdevice has uniform erase size */
947 if (subdev[i]->erasesize != curr_erasesize) {
948 /*
949 * fill in an mtd_erase_region_info structure for the area
950 * we have walked so far:
951 */
952 erase_region_p->offset = begin;
953 erase_region_p->erasesize =
954 curr_erasesize;
955 tmp64 = position - begin;
956 do_div(tmp64, curr_erasesize);
957 erase_region_p->numblocks = tmp64;
958 begin = position;
959
960 curr_erasesize = subdev[i]->erasesize;
961 ++erase_region_p;
962 }
963 position += subdev[i]->size;
964 } else {
965 /* current subdevice has variable erase size */
966 int j;
967 for (j = 0; j < subdev[i]->numeraseregions; j++) {
968 /* walk the list of erase regions, count any changes */
969 if (subdev[i]->eraseregions[j].
970 erasesize != curr_erasesize) {
971 erase_region_p->offset = begin;
972 erase_region_p->erasesize =
973 curr_erasesize;
974 tmp64 = position - begin;
975 do_div(tmp64, curr_erasesize);
976 erase_region_p->numblocks = tmp64;
977 begin = position;
978
979 curr_erasesize =
980 subdev[i]->eraseregions[j].
981 erasesize;
982 ++erase_region_p;
983 }
984 position +=
985 subdev[i]->eraseregions[j].
986 numblocks * (uint64_t)curr_erasesize;
987 }
988 }
989 }
990 /* Now write the final entry */
991 erase_region_p->offset = begin;
992 erase_region_p->erasesize = curr_erasesize;
993 tmp64 = position - begin;
994 do_div(tmp64, curr_erasesize);
995 erase_region_p->numblocks = tmp64;
996 }
997
998 return &concat->mtd;
999}
1000
1001/*
1002 * This function destroys an MTD object obtained from concat_mtd_devs()
1003 */
1004
1005void mtd_concat_destroy(struct mtd_info *mtd)
1006{
1007 struct mtd_concat *concat = CONCAT(mtd);
1008 if (concat->mtd.numeraseregions)
1009 kfree(concat->mtd.eraseregions);
1010 kfree(concat);
1011}
1012
1013EXPORT_SYMBOL(mtd_concat_create);
1014EXPORT_SYMBOL(mtd_concat_destroy);
1015
1016MODULE_LICENSE("GPL");
1017MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
1018MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");