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-rw-r--r--drivers/mtd/mtdconcat.c897
1 files changed, 897 insertions, 0 deletions
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
new file mode 100644
index 000000000000..8f66d093c80d
--- /dev/null
+++ b/drivers/mtd/mtdconcat.c
@@ -0,0 +1,897 @@
1/*
2 * MTD device concatenation layer
3 *
4 * (C) 2002 Robert Kaiser <rkaiser@sysgo.de>
5 *
6 * NAND support by Christian Gan <cgan@iders.ca>
7 *
8 * This code is GPL
9 *
10 * $Id: mtdconcat.c,v 1.9 2004/06/30 15:17:41 dbrown Exp $
11 */
12
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/kernel.h>
16#include <linux/slab.h>
17
18#include <linux/mtd/mtd.h>
19#include <linux/mtd/concat.h>
20
21/*
22 * Our storage structure:
23 * Subdev points to an array of pointers to struct mtd_info objects
24 * which is allocated along with this structure
25 *
26 */
27struct mtd_concat {
28 struct mtd_info mtd;
29 int num_subdev;
30 struct mtd_info **subdev;
31};
32
33/*
34 * how to calculate the size required for the above structure,
35 * including the pointer array subdev points to:
36 */
37#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \
38 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
39
40/*
41 * Given a pointer to the MTD object in the mtd_concat structure,
42 * we can retrieve the pointer to that structure with this macro.
43 */
44#define CONCAT(x) ((struct mtd_concat *)(x))
45
46/*
47 * MTD methods which look up the relevant subdevice, translate the
48 * effective address and pass through to the subdevice.
49 */
50
51static int
52concat_read(struct mtd_info *mtd, loff_t from, size_t len,
53 size_t * retlen, u_char * buf)
54{
55 struct mtd_concat *concat = CONCAT(mtd);
56 int err = -EINVAL;
57 int i;
58
59 *retlen = 0;
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 = subdev->read(subdev, from, size, &retsize, buf);
79
80 if (err)
81 break;
82
83 *retlen += retsize;
84 len -= size;
85 if (len == 0)
86 break;
87
88 err = -EINVAL;
89 buf += size;
90 from = 0;
91 }
92 return err;
93}
94
95static int
96concat_write(struct mtd_info *mtd, loff_t to, size_t len,
97 size_t * retlen, const u_char * buf)
98{
99 struct mtd_concat *concat = CONCAT(mtd);
100 int err = -EINVAL;
101 int i;
102
103 if (!(mtd->flags & MTD_WRITEABLE))
104 return -EROFS;
105
106 *retlen = 0;
107
108 for (i = 0; i < concat->num_subdev; i++) {
109 struct mtd_info *subdev = concat->subdev[i];
110 size_t size, retsize;
111
112 if (to >= subdev->size) {
113 size = 0;
114 to -= subdev->size;
115 continue;
116 }
117 if (to + len > subdev->size)
118 size = subdev->size - to;
119 else
120 size = len;
121
122 if (!(subdev->flags & MTD_WRITEABLE))
123 err = -EROFS;
124 else
125 err = subdev->write(subdev, to, size, &retsize, buf);
126
127 if (err)
128 break;
129
130 *retlen += retsize;
131 len -= size;
132 if (len == 0)
133 break;
134
135 err = -EINVAL;
136 buf += size;
137 to = 0;
138 }
139 return err;
140}
141
142static int
143concat_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
144 size_t * retlen, u_char * buf, u_char * eccbuf,
145 struct nand_oobinfo *oobsel)
146{
147 struct mtd_concat *concat = CONCAT(mtd);
148 int err = -EINVAL;
149 int i;
150
151 *retlen = 0;
152
153 for (i = 0; i < concat->num_subdev; i++) {
154 struct mtd_info *subdev = concat->subdev[i];
155 size_t size, retsize;
156
157 if (from >= subdev->size) {
158 /* Not destined for this subdev */
159 size = 0;
160 from -= subdev->size;
161 continue;
162 }
163
164 if (from + len > subdev->size)
165 /* First part goes into this subdev */
166 size = subdev->size - from;
167 else
168 /* Entire transaction goes into this subdev */
169 size = len;
170
171 if (subdev->read_ecc)
172 err = subdev->read_ecc(subdev, from, size,
173 &retsize, buf, eccbuf, oobsel);
174 else
175 err = -EINVAL;
176
177 if (err)
178 break;
179
180 *retlen += retsize;
181 len -= size;
182 if (len == 0)
183 break;
184
185 err = -EINVAL;
186 buf += size;
187 if (eccbuf) {
188 eccbuf += subdev->oobsize;
189 /* in nand.c at least, eccbufs are
190 tagged with 2 (int)eccstatus'; we
191 must account for these */
192 eccbuf += 2 * (sizeof (int));
193 }
194 from = 0;
195 }
196 return err;
197}
198
199static int
200concat_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
201 size_t * retlen, const u_char * buf, u_char * eccbuf,
202 struct nand_oobinfo *oobsel)
203{
204 struct mtd_concat *concat = CONCAT(mtd);
205 int err = -EINVAL;
206 int i;
207
208 if (!(mtd->flags & MTD_WRITEABLE))
209 return -EROFS;
210
211 *retlen = 0;
212
213 for (i = 0; i < concat->num_subdev; i++) {
214 struct mtd_info *subdev = concat->subdev[i];
215 size_t size, retsize;
216
217 if (to >= subdev->size) {
218 size = 0;
219 to -= subdev->size;
220 continue;
221 }
222 if (to + len > subdev->size)
223 size = subdev->size - to;
224 else
225 size = len;
226
227 if (!(subdev->flags & MTD_WRITEABLE))
228 err = -EROFS;
229 else if (subdev->write_ecc)
230 err = subdev->write_ecc(subdev, to, size,
231 &retsize, buf, eccbuf, oobsel);
232 else
233 err = -EINVAL;
234
235 if (err)
236 break;
237
238 *retlen += retsize;
239 len -= size;
240 if (len == 0)
241 break;
242
243 err = -EINVAL;
244 buf += size;
245 if (eccbuf)
246 eccbuf += subdev->oobsize;
247 to = 0;
248 }
249 return err;
250}
251
252static int
253concat_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
254 size_t * retlen, u_char * buf)
255{
256 struct mtd_concat *concat = CONCAT(mtd);
257 int err = -EINVAL;
258 int i;
259
260 *retlen = 0;
261
262 for (i = 0; i < concat->num_subdev; i++) {
263 struct mtd_info *subdev = concat->subdev[i];
264 size_t size, retsize;
265
266 if (from >= subdev->size) {
267 /* Not destined for this subdev */
268 size = 0;
269 from -= subdev->size;
270 continue;
271 }
272 if (from + len > subdev->size)
273 /* First part goes into this subdev */
274 size = subdev->size - from;
275 else
276 /* Entire transaction goes into this subdev */
277 size = len;
278
279 if (subdev->read_oob)
280 err = subdev->read_oob(subdev, from, size,
281 &retsize, buf);
282 else
283 err = -EINVAL;
284
285 if (err)
286 break;
287
288 *retlen += retsize;
289 len -= size;
290 if (len == 0)
291 break;
292
293 err = -EINVAL;
294 buf += size;
295 from = 0;
296 }
297 return err;
298}
299
300static int
301concat_write_oob(struct mtd_info *mtd, loff_t to, size_t len,
302 size_t * retlen, const u_char * buf)
303{
304 struct mtd_concat *concat = CONCAT(mtd);
305 int err = -EINVAL;
306 int i;
307
308 if (!(mtd->flags & MTD_WRITEABLE))
309 return -EROFS;
310
311 *retlen = 0;
312
313 for (i = 0; i < concat->num_subdev; i++) {
314 struct mtd_info *subdev = concat->subdev[i];
315 size_t size, retsize;
316
317 if (to >= subdev->size) {
318 size = 0;
319 to -= subdev->size;
320 continue;
321 }
322 if (to + len > subdev->size)
323 size = subdev->size - to;
324 else
325 size = len;
326
327 if (!(subdev->flags & MTD_WRITEABLE))
328 err = -EROFS;
329 else if (subdev->write_oob)
330 err = subdev->write_oob(subdev, to, size, &retsize,
331 buf);
332 else
333 err = -EINVAL;
334
335 if (err)
336 break;
337
338 *retlen += retsize;
339 len -= size;
340 if (len == 0)
341 break;
342
343 err = -EINVAL;
344 buf += size;
345 to = 0;
346 }
347 return err;
348}
349
350static void concat_erase_callback(struct erase_info *instr)
351{
352 wake_up((wait_queue_head_t *) instr->priv);
353}
354
355static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
356{
357 int err;
358 wait_queue_head_t waitq;
359 DECLARE_WAITQUEUE(wait, current);
360
361 /*
362 * This code was stol^H^H^H^Hinspired by mtdchar.c
363 */
364 init_waitqueue_head(&waitq);
365
366 erase->mtd = mtd;
367 erase->callback = concat_erase_callback;
368 erase->priv = (unsigned long) &waitq;
369
370 /*
371 * FIXME: Allow INTERRUPTIBLE. Which means
372 * not having the wait_queue head on the stack.
373 */
374 err = mtd->erase(mtd, erase);
375 if (!err) {
376 set_current_state(TASK_UNINTERRUPTIBLE);
377 add_wait_queue(&waitq, &wait);
378 if (erase->state != MTD_ERASE_DONE
379 && erase->state != MTD_ERASE_FAILED)
380 schedule();
381 remove_wait_queue(&waitq, &wait);
382 set_current_state(TASK_RUNNING);
383
384 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
385 }
386 return err;
387}
388
389static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
390{
391 struct mtd_concat *concat = CONCAT(mtd);
392 struct mtd_info *subdev;
393 int i, err;
394 u_int32_t length, offset = 0;
395 struct erase_info *erase;
396
397 if (!(mtd->flags & MTD_WRITEABLE))
398 return -EROFS;
399
400 if (instr->addr > concat->mtd.size)
401 return -EINVAL;
402
403 if (instr->len + instr->addr > concat->mtd.size)
404 return -EINVAL;
405
406 /*
407 * Check for proper erase block alignment of the to-be-erased area.
408 * It is easier to do this based on the super device's erase
409 * region info rather than looking at each particular sub-device
410 * in turn.
411 */
412 if (!concat->mtd.numeraseregions) {
413 /* the easy case: device has uniform erase block size */
414 if (instr->addr & (concat->mtd.erasesize - 1))
415 return -EINVAL;
416 if (instr->len & (concat->mtd.erasesize - 1))
417 return -EINVAL;
418 } else {
419 /* device has variable erase size */
420 struct mtd_erase_region_info *erase_regions =
421 concat->mtd.eraseregions;
422
423 /*
424 * Find the erase region where the to-be-erased area begins:
425 */
426 for (i = 0; i < concat->mtd.numeraseregions &&
427 instr->addr >= erase_regions[i].offset; i++) ;
428 --i;
429
430 /*
431 * Now erase_regions[i] is the region in which the
432 * to-be-erased area begins. Verify that the starting
433 * offset is aligned to this region's erase size:
434 */
435 if (instr->addr & (erase_regions[i].erasesize - 1))
436 return -EINVAL;
437
438 /*
439 * now find the erase region where the to-be-erased area ends:
440 */
441 for (; i < concat->mtd.numeraseregions &&
442 (instr->addr + instr->len) >= erase_regions[i].offset;
443 ++i) ;
444 --i;
445 /*
446 * check if the ending offset is aligned to this region's erase size
447 */
448 if ((instr->addr + instr->len) & (erase_regions[i].erasesize -
449 1))
450 return -EINVAL;
451 }
452
453 instr->fail_addr = 0xffffffff;
454
455 /* make a local copy of instr to avoid modifying the caller's struct */
456 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
457
458 if (!erase)
459 return -ENOMEM;
460
461 *erase = *instr;
462 length = instr->len;
463
464 /*
465 * find the subdevice where the to-be-erased area begins, adjust
466 * starting offset to be relative to the subdevice start
467 */
468 for (i = 0; i < concat->num_subdev; i++) {
469 subdev = concat->subdev[i];
470 if (subdev->size <= erase->addr) {
471 erase->addr -= subdev->size;
472 offset += subdev->size;
473 } else {
474 break;
475 }
476 }
477
478 /* must never happen since size limit has been verified above */
479 if (i >= concat->num_subdev)
480 BUG();
481
482 /* now do the erase: */
483 err = 0;
484 for (; length > 0; i++) {
485 /* loop for all subdevices affected by this request */
486 subdev = concat->subdev[i]; /* get current subdevice */
487
488 /* limit length to subdevice's size: */
489 if (erase->addr + length > subdev->size)
490 erase->len = subdev->size - erase->addr;
491 else
492 erase->len = length;
493
494 if (!(subdev->flags & MTD_WRITEABLE)) {
495 err = -EROFS;
496 break;
497 }
498 length -= erase->len;
499 if ((err = concat_dev_erase(subdev, erase))) {
500 /* sanity check: should never happen since
501 * block alignment has been checked above */
502 if (err == -EINVAL)
503 BUG();
504 if (erase->fail_addr != 0xffffffff)
505 instr->fail_addr = erase->fail_addr + offset;
506 break;
507 }
508 /*
509 * erase->addr specifies the offset of the area to be
510 * erased *within the current subdevice*. It can be
511 * non-zero only the first time through this loop, i.e.
512 * for the first subdevice where blocks need to be erased.
513 * All the following erases must begin at the start of the
514 * current subdevice, i.e. at offset zero.
515 */
516 erase->addr = 0;
517 offset += subdev->size;
518 }
519 instr->state = erase->state;
520 kfree(erase);
521 if (err)
522 return err;
523
524 if (instr->callback)
525 instr->callback(instr);
526 return 0;
527}
528
529static int concat_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
530{
531 struct mtd_concat *concat = CONCAT(mtd);
532 int i, err = -EINVAL;
533
534 if ((len + ofs) > mtd->size)
535 return -EINVAL;
536
537 for (i = 0; i < concat->num_subdev; i++) {
538 struct mtd_info *subdev = concat->subdev[i];
539 size_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 = subdev->lock(subdev, ofs, size);
552
553 if (err)
554 break;
555
556 len -= size;
557 if (len == 0)
558 break;
559
560 err = -EINVAL;
561 ofs = 0;
562 }
563
564 return err;
565}
566
567static int concat_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
568{
569 struct mtd_concat *concat = CONCAT(mtd);
570 int i, err = 0;
571
572 if ((len + ofs) > mtd->size)
573 return -EINVAL;
574
575 for (i = 0; i < concat->num_subdev; i++) {
576 struct mtd_info *subdev = concat->subdev[i];
577 size_t size;
578
579 if (ofs >= subdev->size) {
580 size = 0;
581 ofs -= subdev->size;
582 continue;
583 }
584 if (ofs + len > subdev->size)
585 size = subdev->size - ofs;
586 else
587 size = len;
588
589 err = subdev->unlock(subdev, ofs, size);
590
591 if (err)
592 break;
593
594 len -= size;
595 if (len == 0)
596 break;
597
598 err = -EINVAL;
599 ofs = 0;
600 }
601
602 return err;
603}
604
605static void concat_sync(struct mtd_info *mtd)
606{
607 struct mtd_concat *concat = CONCAT(mtd);
608 int i;
609
610 for (i = 0; i < concat->num_subdev; i++) {
611 struct mtd_info *subdev = concat->subdev[i];
612 subdev->sync(subdev);
613 }
614}
615
616static int concat_suspend(struct mtd_info *mtd)
617{
618 struct mtd_concat *concat = CONCAT(mtd);
619 int i, rc = 0;
620
621 for (i = 0; i < concat->num_subdev; i++) {
622 struct mtd_info *subdev = concat->subdev[i];
623 if ((rc = subdev->suspend(subdev)) < 0)
624 return rc;
625 }
626 return rc;
627}
628
629static void concat_resume(struct mtd_info *mtd)
630{
631 struct mtd_concat *concat = CONCAT(mtd);
632 int i;
633
634 for (i = 0; i < concat->num_subdev; i++) {
635 struct mtd_info *subdev = concat->subdev[i];
636 subdev->resume(subdev);
637 }
638}
639
640/*
641 * This function constructs a virtual MTD device by concatenating
642 * num_devs MTD devices. A pointer to the new device object is
643 * stored to *new_dev upon success. This function does _not_
644 * register any devices: this is the caller's responsibility.
645 */
646struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
647 int num_devs, /* number of subdevices */
648 char *name)
649{ /* name for the new device */
650 int i;
651 size_t size;
652 struct mtd_concat *concat;
653 u_int32_t max_erasesize, curr_erasesize;
654 int num_erase_region;
655
656 printk(KERN_NOTICE "Concatenating MTD devices:\n");
657 for (i = 0; i < num_devs; i++)
658 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
659 printk(KERN_NOTICE "into device \"%s\"\n", name);
660
661 /* allocate the device structure */
662 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
663 concat = kmalloc(size, GFP_KERNEL);
664 if (!concat) {
665 printk
666 ("memory allocation error while creating concatenated device \"%s\"\n",
667 name);
668 return NULL;
669 }
670 memset(concat, 0, size);
671 concat->subdev = (struct mtd_info **) (concat + 1);
672
673 /*
674 * Set up the new "super" device's MTD object structure, check for
675 * incompatibilites between the subdevices.
676 */
677 concat->mtd.type = subdev[0]->type;
678 concat->mtd.flags = subdev[0]->flags;
679 concat->mtd.size = subdev[0]->size;
680 concat->mtd.erasesize = subdev[0]->erasesize;
681 concat->mtd.oobblock = subdev[0]->oobblock;
682 concat->mtd.oobsize = subdev[0]->oobsize;
683 concat->mtd.ecctype = subdev[0]->ecctype;
684 concat->mtd.eccsize = subdev[0]->eccsize;
685 if (subdev[0]->read_ecc)
686 concat->mtd.read_ecc = concat_read_ecc;
687 if (subdev[0]->write_ecc)
688 concat->mtd.write_ecc = concat_write_ecc;
689 if (subdev[0]->read_oob)
690 concat->mtd.read_oob = concat_read_oob;
691 if (subdev[0]->write_oob)
692 concat->mtd.write_oob = concat_write_oob;
693
694 concat->subdev[0] = subdev[0];
695
696 for (i = 1; i < num_devs; i++) {
697 if (concat->mtd.type != subdev[i]->type) {
698 kfree(concat);
699 printk("Incompatible device type on \"%s\"\n",
700 subdev[i]->name);
701 return NULL;
702 }
703 if (concat->mtd.flags != subdev[i]->flags) {
704 /*
705 * Expect all flags except MTD_WRITEABLE to be
706 * equal on all subdevices.
707 */
708 if ((concat->mtd.flags ^ subdev[i]->
709 flags) & ~MTD_WRITEABLE) {
710 kfree(concat);
711 printk("Incompatible device flags on \"%s\"\n",
712 subdev[i]->name);
713 return NULL;
714 } else
715 /* if writeable attribute differs,
716 make super device writeable */
717 concat->mtd.flags |=
718 subdev[i]->flags & MTD_WRITEABLE;
719 }
720 concat->mtd.size += subdev[i]->size;
721 if (concat->mtd.oobblock != subdev[i]->oobblock ||
722 concat->mtd.oobsize != subdev[i]->oobsize ||
723 concat->mtd.ecctype != subdev[i]->ecctype ||
724 concat->mtd.eccsize != subdev[i]->eccsize ||
725 !concat->mtd.read_ecc != !subdev[i]->read_ecc ||
726 !concat->mtd.write_ecc != !subdev[i]->write_ecc ||
727 !concat->mtd.read_oob != !subdev[i]->read_oob ||
728 !concat->mtd.write_oob != !subdev[i]->write_oob) {
729 kfree(concat);
730 printk("Incompatible OOB or ECC data on \"%s\"\n",
731 subdev[i]->name);
732 return NULL;
733 }
734 concat->subdev[i] = subdev[i];
735
736 }
737
738 concat->num_subdev = num_devs;
739 concat->mtd.name = name;
740
741 /*
742 * NOTE: for now, we do not provide any readv()/writev() methods
743 * because they are messy to implement and they are not
744 * used to a great extent anyway.
745 */
746 concat->mtd.erase = concat_erase;
747 concat->mtd.read = concat_read;
748 concat->mtd.write = concat_write;
749 concat->mtd.sync = concat_sync;
750 concat->mtd.lock = concat_lock;
751 concat->mtd.unlock = concat_unlock;
752 concat->mtd.suspend = concat_suspend;
753 concat->mtd.resume = concat_resume;
754
755 /*
756 * Combine the erase block size info of the subdevices:
757 *
758 * first, walk the map of the new device and see how
759 * many changes in erase size we have
760 */
761 max_erasesize = curr_erasesize = subdev[0]->erasesize;
762 num_erase_region = 1;
763 for (i = 0; i < num_devs; i++) {
764 if (subdev[i]->numeraseregions == 0) {
765 /* current subdevice has uniform erase size */
766 if (subdev[i]->erasesize != curr_erasesize) {
767 /* if it differs from the last subdevice's erase size, count it */
768 ++num_erase_region;
769 curr_erasesize = subdev[i]->erasesize;
770 if (curr_erasesize > max_erasesize)
771 max_erasesize = curr_erasesize;
772 }
773 } else {
774 /* current subdevice has variable erase size */
775 int j;
776 for (j = 0; j < subdev[i]->numeraseregions; j++) {
777
778 /* walk the list of erase regions, count any changes */
779 if (subdev[i]->eraseregions[j].erasesize !=
780 curr_erasesize) {
781 ++num_erase_region;
782 curr_erasesize =
783 subdev[i]->eraseregions[j].
784 erasesize;
785 if (curr_erasesize > max_erasesize)
786 max_erasesize = curr_erasesize;
787 }
788 }
789 }
790 }
791
792 if (num_erase_region == 1) {
793 /*
794 * All subdevices have the same uniform erase size.
795 * This is easy:
796 */
797 concat->mtd.erasesize = curr_erasesize;
798 concat->mtd.numeraseregions = 0;
799 } else {
800 /*
801 * erase block size varies across the subdevices: allocate
802 * space to store the data describing the variable erase regions
803 */
804 struct mtd_erase_region_info *erase_region_p;
805 u_int32_t begin, position;
806
807 concat->mtd.erasesize = max_erasesize;
808 concat->mtd.numeraseregions = num_erase_region;
809 concat->mtd.eraseregions = erase_region_p =
810 kmalloc(num_erase_region *
811 sizeof (struct mtd_erase_region_info), GFP_KERNEL);
812 if (!erase_region_p) {
813 kfree(concat);
814 printk
815 ("memory allocation error while creating erase region list"
816 " for device \"%s\"\n", name);
817 return NULL;
818 }
819
820 /*
821 * walk the map of the new device once more and fill in
822 * in erase region info:
823 */
824 curr_erasesize = subdev[0]->erasesize;
825 begin = position = 0;
826 for (i = 0; i < num_devs; i++) {
827 if (subdev[i]->numeraseregions == 0) {
828 /* current subdevice has uniform erase size */
829 if (subdev[i]->erasesize != curr_erasesize) {
830 /*
831 * fill in an mtd_erase_region_info structure for the area
832 * we have walked so far:
833 */
834 erase_region_p->offset = begin;
835 erase_region_p->erasesize =
836 curr_erasesize;
837 erase_region_p->numblocks =
838 (position - begin) / curr_erasesize;
839 begin = position;
840
841 curr_erasesize = subdev[i]->erasesize;
842 ++erase_region_p;
843 }
844 position += subdev[i]->size;
845 } else {
846 /* current subdevice has variable erase size */
847 int j;
848 for (j = 0; j < subdev[i]->numeraseregions; j++) {
849 /* walk the list of erase regions, count any changes */
850 if (subdev[i]->eraseregions[j].
851 erasesize != curr_erasesize) {
852 erase_region_p->offset = begin;
853 erase_region_p->erasesize =
854 curr_erasesize;
855 erase_region_p->numblocks =
856 (position -
857 begin) / curr_erasesize;
858 begin = position;
859
860 curr_erasesize =
861 subdev[i]->eraseregions[j].
862 erasesize;
863 ++erase_region_p;
864 }
865 position +=
866 subdev[i]->eraseregions[j].
867 numblocks * curr_erasesize;
868 }
869 }
870 }
871 /* Now write the final entry */
872 erase_region_p->offset = begin;
873 erase_region_p->erasesize = curr_erasesize;
874 erase_region_p->numblocks = (position - begin) / curr_erasesize;
875 }
876
877 return &concat->mtd;
878}
879
880/*
881 * This function destroys an MTD object obtained from concat_mtd_devs()
882 */
883
884void mtd_concat_destroy(struct mtd_info *mtd)
885{
886 struct mtd_concat *concat = CONCAT(mtd);
887 if (concat->mtd.numeraseregions)
888 kfree(concat->mtd.eraseregions);
889 kfree(concat);
890}
891
892EXPORT_SYMBOL(mtd_concat_create);
893EXPORT_SYMBOL(mtd_concat_destroy);
894
895MODULE_LICENSE("GPL");
896MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
897MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-08 11:56:28 -0500