projects / deliverable / linux.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
[MTD] NAND Replace oobinfo by ecclayout
[deliverable/linux.git] / drivers / mtd / mtdconcat.c
CommitLineData
1da177e4
LT		 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 *
97894cda 10 * $Id: mtdconcat.c,v 1.11 2005/11/07 11:14:20 gleixner Exp $
1da177e4
LT		 11 */
12
1da177e4 13#include <linux/kernel.h>
15fdc52f 14#include <linux/module.h>
1da177e4 15#include <linux/slab.h>
15fdc52f
TG		 16#include <linux/sched.h>
17#include <linux/types.h>
18
1da177e4
LT		 19#include <linux/mtd/mtd.h>
20#include <linux/mtd/concat.h>
21
6c8b44ab
AM		 22#include <asm/div64.h>
23
1da177e4
LT		 24/*
25 * Our storage structure:
26 * Subdev points to an array of pointers to struct mtd_info objects
27 * which is allocated along with this structure
28 *
29 */
30struct mtd_concat {
31 struct mtd_info mtd;
32 int num_subdev;
33 struct mtd_info **subdev;
34};
35
36/*
37 * how to calculate the size required for the above structure,
38 * including the pointer array subdev points to:
39 */
40#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \
41 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
42
43/*
44 * Given a pointer to the MTD object in the mtd_concat structure,
45 * we can retrieve the pointer to that structure with this macro.
46 */
47#define CONCAT(x) ((struct mtd_concat *)(x))
48
97894cda 49/*
1da177e4
LT		 50 * MTD methods which look up the relevant subdevice, translate the
51 * effective address and pass through to the subdevice.
52 */
53
54static int
55concat_read(struct mtd_info *mtd, loff_t from, size_t len,
56 size_t * retlen, u_char * buf)
57{
58 struct mtd_concat *concat = CONCAT(mtd);
59 int err = -EINVAL;
60 int i;
61
62 *retlen = 0;
63
64 for (i = 0; i < concat->num_subdev; i++) {
65 struct mtd_info *subdev = concat->subdev[i];
66 size_t size, retsize;
67
68 if (from >= subdev->size) {
69 /* Not destined for this subdev */
70 size = 0;
71 from -= subdev->size;
72 continue;
73 }
74 if (from + len > subdev->size)
75 /* First part goes into this subdev */
76 size = subdev->size - from;
77 else
78 /* Entire transaction goes into this subdev */
79 size = len;
80
81 err = subdev->read(subdev, from, size, &retsize, buf);
82
83 if (err)
84 break;
85
86 *retlen += retsize;
87 len -= size;
88 if (len == 0)
89 break;
90
91 err = -EINVAL;
92 buf += size;
93 from = 0;
94 }
95 return err;
96}
97
98static int
99concat_write(struct mtd_info *mtd, loff_t to, size_t len,
100 size_t * retlen, const u_char * buf)
101{
102 struct mtd_concat *concat = CONCAT(mtd);
103 int err = -EINVAL;
104 int i;
105
106 if (!(mtd->flags & MTD_WRITEABLE))
107 return -EROFS;
108
109 *retlen = 0;
110
111 for (i = 0; i < concat->num_subdev; i++) {
112 struct mtd_info *subdev = concat->subdev[i];
113 size_t size, retsize;
114
115 if (to >= subdev->size) {
116 size = 0;
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 if (!(subdev->flags & MTD_WRITEABLE))
126 err = -EROFS;
127 else
128 err = subdev->write(subdev, to, size, &retsize, buf);
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
e8d32937 145static int
9d8522df
TG		 146concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
147 unsigned long count, loff_t to, size_t * retlen)
e8d32937
AB		 148{
149 struct mtd_concat *concat = CONCAT(mtd);
150 struct kvec *vecs_copy;
151 unsigned long entry_low, entry_high;
152 size_t total_len = 0;
153 int i;
154 int err = -EINVAL;
155
156 if (!(mtd->flags & MTD_WRITEABLE))
157 return -EROFS;
158
159 *retlen = 0;
160
161 /* Calculate total length of data */
162 for (i = 0; i < count; i++)
163 total_len += vecs[i].iov_len;
164
165 /* Do not allow write past end of device */
166 if ((to + total_len) > mtd->size)
167 return -EINVAL;
168
169 /* Check alignment */
28318776 170 if (mtd->writesize > 1) {
6c8b44ab 171 loff_t __to = to;
28318776 172 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
e8d32937 173 return -EINVAL;
6c8b44ab 174 }
e8d32937
AB		 175
176 /* make a copy of vecs */
177 vecs_copy = kmalloc(sizeof(struct kvec) * count, GFP_KERNEL);
178 if (!vecs_copy)
179 return -ENOMEM;
180 memcpy(vecs_copy, vecs, sizeof(struct kvec) * count);
181
182 entry_low = 0;
183 for (i = 0; i < concat->num_subdev; i++) {
184 struct mtd_info *subdev = concat->subdev[i];
185 size_t size, wsize, retsize, old_iov_len;
186
187 if (to >= subdev->size) {
188 to -= subdev->size;
189 continue;
190 }
191
192 size = min(total_len, (size_t)(subdev->size - to));
193 wsize = size; /* store for future use */
194
195 entry_high = entry_low;
196 while (entry_high < count) {
197 if (size <= vecs_copy[entry_high].iov_len)
198 break;
199 size -= vecs_copy[entry_high++].iov_len;
200 }
201
202 old_iov_len = vecs_copy[entry_high].iov_len;
203 vecs_copy[entry_high].iov_len = size;
204
205 if (!(subdev->flags & MTD_WRITEABLE))
206 err = -EROFS;
e8d32937
AB		 207 else
208 err = subdev->writev(subdev, &vecs_copy[entry_low],
209 entry_high - entry_low + 1, to, &retsize);
210
211 vecs_copy[entry_high].iov_len = old_iov_len - size;
212 vecs_copy[entry_high].iov_base += size;
213
214 entry_low = entry_high;
215
216 if (err)
217 break;
218
219 *retlen += retsize;
220 total_len -= wsize;
e8d32937
AB		 221
222 if (total_len == 0)
223 break;
224
225 err = -EINVAL;
226 to = 0;
227 }
228
229 kfree(vecs_copy);
230 return err;
231}
232
1da177e4
LT		 233static int
234concat_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
235 size_t * retlen, u_char * buf)
236{
237 struct mtd_concat *concat = CONCAT(mtd);
238 int err = -EINVAL;
239 int i;
240
241 *retlen = 0;
242
243 for (i = 0; i < concat->num_subdev; i++) {
244 struct mtd_info *subdev = concat->subdev[i];
245 size_t size, retsize;
246
247 if (from >= subdev->size) {
248 /* Not destined for this subdev */
249 size = 0;
250 from -= subdev->size;
251 continue;
252 }
253 if (from + len > subdev->size)
254 /* First part goes into this subdev */
255 size = subdev->size - from;
256 else
257 /* Entire transaction goes into this subdev */
258 size = len;
259
260 if (subdev->read_oob)
261 err = subdev->read_oob(subdev, from, size,
262 &retsize, buf);
263 else
264 err = -EINVAL;
265
266 if (err)
267 break;
268
269 *retlen += retsize;
270 len -= size;
271 if (len == 0)
272 break;
273
274 err = -EINVAL;
275 buf += size;
276 from = 0;
277 }
278 return err;
279}
280
281static int
282concat_write_oob(struct mtd_info *mtd, loff_t to, size_t len,
283 size_t * retlen, const u_char * buf)
284{
285 struct mtd_concat *concat = CONCAT(mtd);
286 int err = -EINVAL;
287 int i;
288
289 if (!(mtd->flags & MTD_WRITEABLE))
290 return -EROFS;
291
292 *retlen = 0;
293
294 for (i = 0; i < concat->num_subdev; i++) {
295 struct mtd_info *subdev = concat->subdev[i];
296 size_t size, retsize;
297
298 if (to >= subdev->size) {
299 size = 0;
300 to -= subdev->size;
301 continue;
302 }
303 if (to + len > subdev->size)
304 size = subdev->size - to;
305 else
306 size = len;
307
308 if (!(subdev->flags & MTD_WRITEABLE))
309 err = -EROFS;
310 else if (subdev->write_oob)
311 err = subdev->write_oob(subdev, to, size, &retsize,
312 buf);
313 else
314 err = -EINVAL;
315
316 if (err)
317 break;
318
319 *retlen += retsize;
320 len -= size;
321 if (len == 0)
322 break;
323
324 err = -EINVAL;
325 buf += size;
326 to = 0;
327 }
328 return err;
329}
330
331static void concat_erase_callback(struct erase_info *instr)
332{
333 wake_up((wait_queue_head_t *) instr->priv);
334}
335
336static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
337{
338 int err;
339 wait_queue_head_t waitq;
340 DECLARE_WAITQUEUE(wait, current);
341
342 /*
343 * This code was stol^H^H^H^Hinspired by mtdchar.c
344 */
345 init_waitqueue_head(&waitq);
346
347 erase->mtd = mtd;
348 erase->callback = concat_erase_callback;
349 erase->priv = (unsigned long) &waitq;
350
351 /*
352 * FIXME: Allow INTERRUPTIBLE. Which means
353 * not having the wait_queue head on the stack.
354 */
355 err = mtd->erase(mtd, erase);
356 if (!err) {
357 set_current_state(TASK_UNINTERRUPTIBLE);
358 add_wait_queue(&waitq, &wait);
359 if (erase->state != MTD_ERASE_DONE
360 && erase->state != MTD_ERASE_FAILED)
361 schedule();
362 remove_wait_queue(&waitq, &wait);
363 set_current_state(TASK_RUNNING);
364
365 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
366 }
367 return err;
368}
369
370static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
371{
372 struct mtd_concat *concat = CONCAT(mtd);
373 struct mtd_info *subdev;
374 int i, err;
375 u_int32_t length, offset = 0;
376 struct erase_info *erase;
377
378 if (!(mtd->flags & MTD_WRITEABLE))
379 return -EROFS;
380
381 if (instr->addr > concat->mtd.size)
382 return -EINVAL;
383
384 if (instr->len + instr->addr > concat->mtd.size)
385 return -EINVAL;
386
387 /*
388 * Check for proper erase block alignment of the to-be-erased area.
389 * It is easier to do this based on the super device's erase
390 * region info rather than looking at each particular sub-device
391 * in turn.
392 */
393 if (!concat->mtd.numeraseregions) {
394 /* the easy case: device has uniform erase block size */
395 if (instr->addr & (concat->mtd.erasesize - 1))
396 return -EINVAL;
397 if (instr->len & (concat->mtd.erasesize - 1))
398 return -EINVAL;
399 } else {
400 /* device has variable erase size */
401 struct mtd_erase_region_info *erase_regions =
402 concat->mtd.eraseregions;
403
404 /*
405 * Find the erase region where the to-be-erased area begins:
406 */
407 for (i = 0; i < concat->mtd.numeraseregions &&
408 instr->addr >= erase_regions[i].offset; i++) ;
409 --i;
410
411 /*
412 * Now erase_regions[i] is the region in which the
413 * to-be-erased area begins. Verify that the starting
414 * offset is aligned to this region's erase size:
415 */
416 if (instr->addr & (erase_regions[i].erasesize - 1))
417 return -EINVAL;
418
419 /*
420 * now find the erase region where the to-be-erased area ends:
421 */
422 for (; i < concat->mtd.numeraseregions &&
423 (instr->addr + instr->len) >= erase_regions[i].offset;
424 ++i) ;
425 --i;
426 /*
427 * check if the ending offset is aligned to this region's erase size
428 */
429 if ((instr->addr + instr->len) & (erase_regions[i].erasesize -
430 1))
431 return -EINVAL;
432 }
433
434 instr->fail_addr = 0xffffffff;
435
436 /* make a local copy of instr to avoid modifying the caller's struct */
437 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
438
439 if (!erase)
440 return -ENOMEM;
441
442 *erase = *instr;
443 length = instr->len;
444
445 /*
446 * find the subdevice where the to-be-erased area begins, adjust
447 * starting offset to be relative to the subdevice start
448 */
449 for (i = 0; i < concat->num_subdev; i++) {
450 subdev = concat->subdev[i];
451 if (subdev->size <= erase->addr) {
452 erase->addr -= subdev->size;
453 offset += subdev->size;
454 } else {
455 break;
456 }
457 }
458
459 /* must never happen since size limit has been verified above */
373ebfbf 460 BUG_ON(i >= concat->num_subdev);
1da177e4
LT		 461
462 /* now do the erase: */
463 err = 0;
464 for (; length > 0; i++) {
465 /* loop for all subdevices affected by this request */
466 subdev = concat->subdev[i]; /* get current subdevice */
467
468 /* limit length to subdevice's size: */
469 if (erase->addr + length > subdev->size)
470 erase->len = subdev->size - erase->addr;
471 else
472 erase->len = length;
473
474 if (!(subdev->flags & MTD_WRITEABLE)) {
475 err = -EROFS;
476 break;
477 }
478 length -= erase->len;
479 if ((err = concat_dev_erase(subdev, erase))) {
480 /* sanity check: should never happen since
481 * block alignment has been checked above */
373ebfbf 482 BUG_ON(err == -EINVAL);
1da177e4
LT		 483 if (erase->fail_addr != 0xffffffff)
484 instr->fail_addr = erase->fail_addr + offset;
485 break;
486 }
487 /*
488 * erase->addr specifies the offset of the area to be
489 * erased *within the current subdevice*. It can be
490 * non-zero only the first time through this loop, i.e.
491 * for the first subdevice where blocks need to be erased.
492 * All the following erases must begin at the start of the
493 * current subdevice, i.e. at offset zero.
494 */
495 erase->addr = 0;
496 offset += subdev->size;
497 }
498 instr->state = erase->state;
499 kfree(erase);
500 if (err)
501 return err;
502
503 if (instr->callback)
504 instr->callback(instr);
505 return 0;
506}
507
508static int concat_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
509{
510 struct mtd_concat *concat = CONCAT(mtd);
511 int i, err = -EINVAL;
512
513 if ((len + ofs) > mtd->size)
514 return -EINVAL;
515
516 for (i = 0; i < concat->num_subdev; i++) {
517 struct mtd_info *subdev = concat->subdev[i];
518 size_t size;
519
520 if (ofs >= subdev->size) {
521 size = 0;
522 ofs -= subdev->size;
523 continue;
524 }
525 if (ofs + len > subdev->size)
526 size = subdev->size - ofs;
527 else
528 size = len;
529
530 err = subdev->lock(subdev, ofs, size);
531
532 if (err)
533 break;
534
535 len -= size;
536 if (len == 0)
537 break;
538
539 err = -EINVAL;
540 ofs = 0;
541 }
542
543 return err;
544}
545
546static int concat_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
547{
548 struct mtd_concat *concat = CONCAT(mtd);
549 int i, err = 0;
550
551 if ((len + ofs) > mtd->size)
552 return -EINVAL;
553
554 for (i = 0; i < concat->num_subdev; i++) {
555 struct mtd_info *subdev = concat->subdev[i];
556 size_t size;
557
558 if (ofs >= subdev->size) {
559 size = 0;
560 ofs -= subdev->size;
561 continue;
562 }
563 if (ofs + len > subdev->size)
564 size = subdev->size - ofs;
565 else
566 size = len;
567
568 err = subdev->unlock(subdev, ofs, size);
569
570 if (err)
571 break;
572
573 len -= size;
574 if (len == 0)
575 break;
576
577 err = -EINVAL;
578 ofs = 0;
579 }
580
581 return err;
582}
583
584static void concat_sync(struct mtd_info *mtd)
585{
586 struct mtd_concat *concat = CONCAT(mtd);
587 int i;
588
589 for (i = 0; i < concat->num_subdev; i++) {
590 struct mtd_info *subdev = concat->subdev[i];
591 subdev->sync(subdev);
592 }
593}
594
595static int concat_suspend(struct mtd_info *mtd)
596{
597 struct mtd_concat *concat = CONCAT(mtd);
598 int i, rc = 0;
599
600 for (i = 0; i < concat->num_subdev; i++) {
601 struct mtd_info *subdev = concat->subdev[i];
602 if ((rc = subdev->suspend(subdev)) < 0)
603 return rc;
604 }
605 return rc;
606}
607
608static void concat_resume(struct mtd_info *mtd)
609{
610 struct mtd_concat *concat = CONCAT(mtd);
611 int i;
612
613 for (i = 0; i < concat->num_subdev; i++) {
614 struct mtd_info *subdev = concat->subdev[i];
615 subdev->resume(subdev);
616 }
617}
618
e8d32937
AB		 619static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
620{
621 struct mtd_concat *concat = CONCAT(mtd);
622 int i, res = 0;
623
624 if (!concat->subdev[0]->block_isbad)
625 return res;
626
627 if (ofs > mtd->size)
628 return -EINVAL;
629
630 for (i = 0; i < concat->num_subdev; i++) {
631 struct mtd_info *subdev = concat->subdev[i];
632
633 if (ofs >= subdev->size) {
634 ofs -= subdev->size;
635 continue;
636 }
637
638 res = subdev->block_isbad(subdev, ofs);
639 break;
640 }
641
642 return res;
643}
644
645static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
646{
647 struct mtd_concat *concat = CONCAT(mtd);
648 int i, err = -EINVAL;
649
650 if (!concat->subdev[0]->block_markbad)
651 return 0;
652
653 if (ofs > mtd->size)
654 return -EINVAL;
655
656 for (i = 0; i < concat->num_subdev; i++) {
657 struct mtd_info *subdev = concat->subdev[i];
658
659 if (ofs >= subdev->size) {
660 ofs -= subdev->size;
661 continue;
662 }
663
664 err = subdev->block_markbad(subdev, ofs);
665 break;
666 }
667
668 return err;
669}
670
1da177e4
LT		 671/*
672 * This function constructs a virtual MTD device by concatenating
673 * num_devs MTD devices. A pointer to the new device object is
674 * stored to *new_dev upon success. This function does _not_
675 * register any devices: this is the caller's responsibility.
676 */
677struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
678 int num_devs, /* number of subdevices */
679 char *name)
680{ /* name for the new device */
681 int i;
682 size_t size;
683 struct mtd_concat *concat;
684 u_int32_t max_erasesize, curr_erasesize;
685 int num_erase_region;
686
687 printk(KERN_NOTICE "Concatenating MTD devices:\n");
688 for (i = 0; i < num_devs; i++)
689 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
690 printk(KERN_NOTICE "into device \"%s\"\n", name);
691
692 /* allocate the device structure */
693 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
694 concat = kmalloc(size, GFP_KERNEL);
695 if (!concat) {
696 printk
697 ("memory allocation error while creating concatenated device \"%s\"\n",
698 name);
699 return NULL;
700 }
701 memset(concat, 0, size);
702 concat->subdev = (struct mtd_info **) (concat + 1);
703
704 /*
705 * Set up the new "super" device's MTD object structure, check for
706 * incompatibilites between the subdevices.
707 */
708 concat->mtd.type = subdev[0]->type;
709 concat->mtd.flags = subdev[0]->flags;
710 concat->mtd.size = subdev[0]->size;
711 concat->mtd.erasesize = subdev[0]->erasesize;
28318776 712 concat->mtd.writesize = subdev[0]->writesize;
1da177e4
LT		 713 concat->mtd.oobsize = subdev[0]->oobsize;
714 concat->mtd.ecctype = subdev[0]->ecctype;
715 concat->mtd.eccsize = subdev[0]->eccsize;
e8d32937
AB		 716 if (subdev[0]->writev)
717 concat->mtd.writev = concat_writev;
1da177e4
LT		 718 if (subdev[0]->read_oob)
719 concat->mtd.read_oob = concat_read_oob;
720 if (subdev[0]->write_oob)
721 concat->mtd.write_oob = concat_write_oob;
e8d32937
AB		 722 if (subdev[0]->block_isbad)
723 concat->mtd.block_isbad = concat_block_isbad;
724 if (subdev[0]->block_markbad)
725 concat->mtd.block_markbad = concat_block_markbad;
1da177e4
LT		 726
727 concat->subdev[0] = subdev[0];
728
729 for (i = 1; i < num_devs; i++) {
730 if (concat->mtd.type != subdev[i]->type) {
731 kfree(concat);
732 printk("Incompatible device type on \"%s\"\n",
733 subdev[i]->name);
734 return NULL;
735 }
736 if (concat->mtd.flags != subdev[i]->flags) {
737 /*
738 * Expect all flags except MTD_WRITEABLE to be
739 * equal on all subdevices.
740 */
741 if ((concat->mtd.flags ^ subdev[i]->
742 flags) & ~MTD_WRITEABLE) {
743 kfree(concat);
744 printk("Incompatible device flags on \"%s\"\n",
745 subdev[i]->name);
746 return NULL;
747 } else
748 /* if writeable attribute differs,
749 make super device writeable */
750 concat->mtd.flags |=
751 subdev[i]->flags & MTD_WRITEABLE;
752 }
753 concat->mtd.size += subdev[i]->size;
28318776 754 if (concat->mtd.writesize != subdev[i]->writesize ||
1da177e4
LT		 755 concat->mtd.oobsize != subdev[i]->oobsize ||
756 concat->mtd.ecctype != subdev[i]->ecctype ||
757 concat->mtd.eccsize != subdev[i]->eccsize ||
1da177e4
LT		 758 !concat->mtd.read_oob != !subdev[i]->read_oob ||
759 !concat->mtd.write_oob != !subdev[i]->write_oob) {
760 kfree(concat);
761 printk("Incompatible OOB or ECC data on \"%s\"\n",
762 subdev[i]->name);
763 return NULL;
764 }
765 concat->subdev[i] = subdev[i];
766
767 }
768
5bd34c09 769 concat->mtd.ecclayout = subdev[0]->ecclayout;
e8d32937 770
1da177e4
LT		 771 concat->num_subdev = num_devs;
772 concat->mtd.name = name;
773
1da177e4
LT		 774 concat->mtd.erase = concat_erase;
775 concat->mtd.read = concat_read;
776 concat->mtd.write = concat_write;
777 concat->mtd.sync = concat_sync;
778 concat->mtd.lock = concat_lock;
779 concat->mtd.unlock = concat_unlock;
780 concat->mtd.suspend = concat_suspend;
781 concat->mtd.resume = concat_resume;
782
783 /*
784 * Combine the erase block size info of the subdevices:
785 *
786 * first, walk the map of the new device and see how
787 * many changes in erase size we have
788 */
789 max_erasesize = curr_erasesize = subdev[0]->erasesize;
790 num_erase_region = 1;
791 for (i = 0; i < num_devs; i++) {
792 if (subdev[i]->numeraseregions == 0) {
793 /* current subdevice has uniform erase size */
794 if (subdev[i]->erasesize != curr_erasesize) {
795 /* if it differs from the last subdevice's erase size, count it */
796 ++num_erase_region;
797 curr_erasesize = subdev[i]->erasesize;
798 if (curr_erasesize > max_erasesize)
799 max_erasesize = curr_erasesize;
800 }
801 } else {
802 /* current subdevice has variable erase size */
803 int j;
804 for (j = 0; j < subdev[i]->numeraseregions; j++) {
805
806 /* walk the list of erase regions, count any changes */
807 if (subdev[i]->eraseregions[j].erasesize !=
808 curr_erasesize) {
809 ++num_erase_region;
810 curr_erasesize =
811 subdev[i]->eraseregions[j].
812 erasesize;
813 if (curr_erasesize > max_erasesize)
814 max_erasesize = curr_erasesize;
815 }
816 }
817 }
818 }
819
820 if (num_erase_region == 1) {
821 /*
822 * All subdevices have the same uniform erase size.
823 * This is easy:
824 */
825 concat->mtd.erasesize = curr_erasesize;
826 concat->mtd.numeraseregions = 0;
827 } else {
828 /*
829 * erase block size varies across the subdevices: allocate
830 * space to store the data describing the variable erase regions
831 */
832 struct mtd_erase_region_info *erase_region_p;
833 u_int32_t begin, position;
834
835 concat->mtd.erasesize = max_erasesize;
836 concat->mtd.numeraseregions = num_erase_region;
837 concat->mtd.eraseregions = erase_region_p =
838 kmalloc(num_erase_region *
839 sizeof (struct mtd_erase_region_info), GFP_KERNEL);
840 if (!erase_region_p) {
841 kfree(concat);
842 printk
843 ("memory allocation error while creating erase region list"
844 " for device \"%s\"\n", name);
845 return NULL;
846 }
847
848 /*
849 * walk the map of the new device once more and fill in
850 * in erase region info:
851 */
852 curr_erasesize = subdev[0]->erasesize;
853 begin = position = 0;
854 for (i = 0; i < num_devs; i++) {
855 if (subdev[i]->numeraseregions == 0) {
856 /* current subdevice has uniform erase size */
857 if (subdev[i]->erasesize != curr_erasesize) {
858 /*
859 * fill in an mtd_erase_region_info structure for the area
860 * we have walked so far:
861 */
862 erase_region_p->offset = begin;
863 erase_region_p->erasesize =
864 curr_erasesize;
865 erase_region_p->numblocks =
866 (position - begin) / curr_erasesize;
867 begin = position;
868
869 curr_erasesize = subdev[i]->erasesize;
870 ++erase_region_p;
871 }
872 position += subdev[i]->size;
873 } else {
874 /* current subdevice has variable erase size */
875 int j;
876 for (j = 0; j < subdev[i]->numeraseregions; j++) {
877 /* walk the list of erase regions, count any changes */
878 if (subdev[i]->eraseregions[j].
879 erasesize != curr_erasesize) {
880 erase_region_p->offset = begin;
881 erase_region_p->erasesize =
882 curr_erasesize;
883 erase_region_p->numblocks =
884 (position -
885 begin) / curr_erasesize;
886 begin = position;
887
888 curr_erasesize =
889 subdev[i]->eraseregions[j].
890 erasesize;
891 ++erase_region_p;
892 }
893 position +=
894 subdev[i]->eraseregions[j].
895 numblocks * curr_erasesize;
896 }
897 }
898 }
899 /* Now write the final entry */
900 erase_region_p->offset = begin;
901 erase_region_p->erasesize = curr_erasesize;
902 erase_region_p->numblocks = (position - begin) / curr_erasesize;
903 }
904
905 return &concat->mtd;
906}
907
97894cda 908/*
1da177e4
LT		 909 * This function destroys an MTD object obtained from concat_mtd_devs()
910 */
911
912void mtd_concat_destroy(struct mtd_info *mtd)
913{
914 struct mtd_concat *concat = CONCAT(mtd);
915 if (concat->mtd.numeraseregions)
916 kfree(concat->mtd.eraseregions);
917 kfree(concat);
918}
919
920EXPORT_SYMBOL(mtd_concat_create);
921EXPORT_SYMBOL(mtd_concat_destroy);
922
923MODULE_LICENSE("GPL");
924MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
925MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");
Linux kernel - Deliverables
This page took 0.163877 seconds and 5 git commands to generate.