2 * MTD device concatenation layer
4 * (C) 2002 Robert Kaiser <rkaiser@sysgo.de>
6 * NAND support by Christian Gan <cgan@iders.ca>
10 * $Id: mtdconcat.c,v 1.11 2005/11/07 11:14:20 gleixner Exp $
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
17 #include <linux/types.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/concat.h>
22 #include <asm/div64.h>
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
33 struct mtd_info **subdev;
37 * how to calculate the size required for the above structure,
38 * including the pointer array subdev points to:
40 #define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \
41 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
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.
47 #define CONCAT(x) ((struct mtd_concat *)(x))
50 * MTD methods which look up the relevant subdevice, translate the
51 * effective address and pass through to the subdevice.
55 concat_read(struct mtd_info *mtd, loff_t from, size_t len,
56 size_t * retlen, u_char * buf)
58 struct mtd_concat *concat = CONCAT(mtd);
59 int ret = 0, err = -EINVAL;
64 for (i = 0; i < concat->num_subdev; i++) {
65 struct mtd_info *subdev = concat->subdev[i];
68 if (from >= subdev->size) {
69 /* Not destined for this subdev */
74 if (from + len > subdev->size)
75 /* First part goes into this subdev */
76 size = subdev->size - from;
78 /* Entire transaction goes into this subdev */
81 err = subdev->read(subdev, from, size, &retsize, buf);
83 if (err && (err != -EBADMSG) && (err != -EUCLEAN))
86 /* Save information about bitflips! */
104 return err ? err : ret;
108 concat_write(struct mtd_info *mtd, loff_t to, size_t len,
109 size_t * retlen, const u_char * buf)
111 struct mtd_concat *concat = CONCAT(mtd);
115 if (!(mtd->flags & MTD_WRITEABLE))
120 for (i = 0; i < concat->num_subdev; i++) {
121 struct mtd_info *subdev = concat->subdev[i];
122 size_t size, retsize;
124 if (to >= subdev->size) {
129 if (to + len > subdev->size)
130 size = subdev->size - to;
134 if (!(subdev->flags & MTD_WRITEABLE))
137 err = subdev->write(subdev, to, size, &retsize, buf);
155 concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
156 unsigned long count, loff_t to, size_t * retlen)
158 struct mtd_concat *concat = CONCAT(mtd);
159 struct kvec *vecs_copy;
160 unsigned long entry_low, entry_high;
161 size_t total_len = 0;
165 if (!(mtd->flags & MTD_WRITEABLE))
170 /* Calculate total length of data */
171 for (i = 0; i < count; i++)
172 total_len += vecs[i].iov_len;
174 /* Do not allow write past end of device */
175 if ((to + total_len) > mtd->size)
178 /* Check alignment */
179 if (mtd->writesize > 1) {
181 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
185 /* make a copy of vecs */
186 vecs_copy = kmalloc(sizeof(struct kvec) * count, GFP_KERNEL);
189 memcpy(vecs_copy, vecs, sizeof(struct kvec) * count);
192 for (i = 0; i < concat->num_subdev; i++) {
193 struct mtd_info *subdev = concat->subdev[i];
194 size_t size, wsize, retsize, old_iov_len;
196 if (to >= subdev->size) {
201 size = min(total_len, (size_t)(subdev->size - to));
202 wsize = size; /* store for future use */
204 entry_high = entry_low;
205 while (entry_high < count) {
206 if (size <= vecs_copy[entry_high].iov_len)
208 size -= vecs_copy[entry_high++].iov_len;
211 old_iov_len = vecs_copy[entry_high].iov_len;
212 vecs_copy[entry_high].iov_len = size;
214 if (!(subdev->flags & MTD_WRITEABLE))
217 err = subdev->writev(subdev, &vecs_copy[entry_low],
218 entry_high - entry_low + 1, to, &retsize);
220 vecs_copy[entry_high].iov_len = old_iov_len - size;
221 vecs_copy[entry_high].iov_base += size;
223 entry_low = entry_high;
243 concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
245 struct mtd_concat *concat = CONCAT(mtd);
246 struct mtd_oob_ops devops = *ops;
251 for (i = 0; i < concat->num_subdev; i++) {
252 struct mtd_info *subdev = concat->subdev[i];
254 if (from >= subdev->size) {
255 from -= subdev->size;
260 if (from + devops.len > subdev->size)
261 devops.len = subdev->size - from;
263 err = subdev->read_oob(subdev, from, &devops);
264 ops->retlen += devops.retlen;
268 devops.len = ops->len - ops->retlen;
273 devops.datbuf += devops.retlen;
275 devops.oobbuf += devops.ooblen;
283 concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
285 struct mtd_concat *concat = CONCAT(mtd);
286 struct mtd_oob_ops devops = *ops;
289 if (!(mtd->flags & MTD_WRITEABLE))
294 for (i = 0; i < concat->num_subdev; i++) {
295 struct mtd_info *subdev = concat->subdev[i];
297 if (to >= subdev->size) {
302 /* partial write ? */
303 if (to + devops.len > subdev->size)
304 devops.len = subdev->size - to;
306 err = subdev->write_oob(subdev, to, &devops);
307 ops->retlen += devops.retlen;
311 devops.len = ops->len - ops->retlen;
316 devops.datbuf += devops.retlen;
318 devops.oobbuf += devops.ooblen;
324 static void concat_erase_callback(struct erase_info *instr)
326 wake_up((wait_queue_head_t *) instr->priv);
329 static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
332 wait_queue_head_t waitq;
333 DECLARE_WAITQUEUE(wait, current);
336 * This code was stol^H^H^H^Hinspired by mtdchar.c
338 init_waitqueue_head(&waitq);
341 erase->callback = concat_erase_callback;
342 erase->priv = (unsigned long) &waitq;
345 * FIXME: Allow INTERRUPTIBLE. Which means
346 * not having the wait_queue head on the stack.
348 err = mtd->erase(mtd, erase);
350 set_current_state(TASK_UNINTERRUPTIBLE);
351 add_wait_queue(&waitq, &wait);
352 if (erase->state != MTD_ERASE_DONE
353 && erase->state != MTD_ERASE_FAILED)
355 remove_wait_queue(&waitq, &wait);
356 set_current_state(TASK_RUNNING);
358 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
363 static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
365 struct mtd_concat *concat = CONCAT(mtd);
366 struct mtd_info *subdev;
368 u_int32_t length, offset = 0;
369 struct erase_info *erase;
371 if (!(mtd->flags & MTD_WRITEABLE))
374 if (instr->addr > concat->mtd.size)
377 if (instr->len + instr->addr > concat->mtd.size)
381 * Check for proper erase block alignment of the to-be-erased area.
382 * It is easier to do this based on the super device's erase
383 * region info rather than looking at each particular sub-device
386 if (!concat->mtd.numeraseregions) {
387 /* the easy case: device has uniform erase block size */
388 if (instr->addr & (concat->mtd.erasesize - 1))
390 if (instr->len & (concat->mtd.erasesize - 1))
393 /* device has variable erase size */
394 struct mtd_erase_region_info *erase_regions =
395 concat->mtd.eraseregions;
398 * Find the erase region where the to-be-erased area begins:
400 for (i = 0; i < concat->mtd.numeraseregions &&
401 instr->addr >= erase_regions[i].offset; i++) ;
405 * Now erase_regions[i] is the region in which the
406 * to-be-erased area begins. Verify that the starting
407 * offset is aligned to this region's erase size:
409 if (instr->addr & (erase_regions[i].erasesize - 1))
413 * now find the erase region where the to-be-erased area ends:
415 for (; i < concat->mtd.numeraseregions &&
416 (instr->addr + instr->len) >= erase_regions[i].offset;
420 * check if the ending offset is aligned to this region's erase size
422 if ((instr->addr + instr->len) & (erase_regions[i].erasesize -
427 instr->fail_addr = 0xffffffff;
429 /* make a local copy of instr to avoid modifying the caller's struct */
430 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
439 * find the subdevice where the to-be-erased area begins, adjust
440 * starting offset to be relative to the subdevice start
442 for (i = 0; i < concat->num_subdev; i++) {
443 subdev = concat->subdev[i];
444 if (subdev->size <= erase->addr) {
445 erase->addr -= subdev->size;
446 offset += subdev->size;
452 /* must never happen since size limit has been verified above */
453 BUG_ON(i >= concat->num_subdev);
455 /* now do the erase: */
457 for (; length > 0; i++) {
458 /* loop for all subdevices affected by this request */
459 subdev = concat->subdev[i]; /* get current subdevice */
461 /* limit length to subdevice's size: */
462 if (erase->addr + length > subdev->size)
463 erase->len = subdev->size - erase->addr;
467 if (!(subdev->flags & MTD_WRITEABLE)) {
471 length -= erase->len;
472 if ((err = concat_dev_erase(subdev, erase))) {
473 /* sanity check: should never happen since
474 * block alignment has been checked above */
475 BUG_ON(err == -EINVAL);
476 if (erase->fail_addr != 0xffffffff)
477 instr->fail_addr = erase->fail_addr + offset;
481 * erase->addr specifies the offset of the area to be
482 * erased *within the current subdevice*. It can be
483 * non-zero only the first time through this loop, i.e.
484 * for the first subdevice where blocks need to be erased.
485 * All the following erases must begin at the start of the
486 * current subdevice, i.e. at offset zero.
489 offset += subdev->size;
491 instr->state = erase->state;
497 instr->callback(instr);
501 static int concat_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
503 struct mtd_concat *concat = CONCAT(mtd);
504 int i, err = -EINVAL;
506 if ((len + ofs) > mtd->size)
509 for (i = 0; i < concat->num_subdev; i++) {
510 struct mtd_info *subdev = concat->subdev[i];
513 if (ofs >= subdev->size) {
518 if (ofs + len > subdev->size)
519 size = subdev->size - ofs;
523 err = subdev->lock(subdev, ofs, size);
539 static int concat_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
541 struct mtd_concat *concat = CONCAT(mtd);
544 if ((len + ofs) > mtd->size)
547 for (i = 0; i < concat->num_subdev; i++) {
548 struct mtd_info *subdev = concat->subdev[i];
551 if (ofs >= subdev->size) {
556 if (ofs + len > subdev->size)
557 size = subdev->size - ofs;
561 err = subdev->unlock(subdev, ofs, size);
577 static void concat_sync(struct mtd_info *mtd)
579 struct mtd_concat *concat = CONCAT(mtd);
582 for (i = 0; i < concat->num_subdev; i++) {
583 struct mtd_info *subdev = concat->subdev[i];
584 subdev->sync(subdev);
588 static int concat_suspend(struct mtd_info *mtd)
590 struct mtd_concat *concat = CONCAT(mtd);
593 for (i = 0; i < concat->num_subdev; i++) {
594 struct mtd_info *subdev = concat->subdev[i];
595 if ((rc = subdev->suspend(subdev)) < 0)
601 static void concat_resume(struct mtd_info *mtd)
603 struct mtd_concat *concat = CONCAT(mtd);
606 for (i = 0; i < concat->num_subdev; i++) {
607 struct mtd_info *subdev = concat->subdev[i];
608 subdev->resume(subdev);
612 static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
614 struct mtd_concat *concat = CONCAT(mtd);
617 if (!concat->subdev[0]->block_isbad)
623 for (i = 0; i < concat->num_subdev; i++) {
624 struct mtd_info *subdev = concat->subdev[i];
626 if (ofs >= subdev->size) {
631 res = subdev->block_isbad(subdev, ofs);
638 static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
640 struct mtd_concat *concat = CONCAT(mtd);
641 int i, err = -EINVAL;
643 if (!concat->subdev[0]->block_markbad)
649 for (i = 0; i < concat->num_subdev; i++) {
650 struct mtd_info *subdev = concat->subdev[i];
652 if (ofs >= subdev->size) {
657 err = subdev->block_markbad(subdev, ofs);
665 * This function constructs a virtual MTD device by concatenating
666 * num_devs MTD devices. A pointer to the new device object is
667 * stored to *new_dev upon success. This function does _not_
668 * register any devices: this is the caller's responsibility.
670 struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
671 int num_devs, /* number of subdevices */
673 { /* name for the new device */
676 struct mtd_concat *concat;
677 u_int32_t max_erasesize, curr_erasesize;
678 int num_erase_region;
680 printk(KERN_NOTICE "Concatenating MTD devices:\n");
681 for (i = 0; i < num_devs; i++)
682 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
683 printk(KERN_NOTICE "into device \"%s\"\n", name);
685 /* allocate the device structure */
686 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
687 concat = kmalloc(size, GFP_KERNEL);
690 ("memory allocation error while creating concatenated device \"%s\"\n",
694 memset(concat, 0, size);
695 concat->subdev = (struct mtd_info **) (concat + 1);
698 * Set up the new "super" device's MTD object structure, check for
699 * incompatibilites between the subdevices.
701 concat->mtd.type = subdev[0]->type;
702 concat->mtd.flags = subdev[0]->flags;
703 concat->mtd.size = subdev[0]->size;
704 concat->mtd.erasesize = subdev[0]->erasesize;
705 concat->mtd.writesize = subdev[0]->writesize;
706 concat->mtd.oobsize = subdev[0]->oobsize;
707 concat->mtd.ecctype = subdev[0]->ecctype;
708 concat->mtd.eccsize = subdev[0]->eccsize;
709 if (subdev[0]->writev)
710 concat->mtd.writev = concat_writev;
711 if (subdev[0]->read_oob)
712 concat->mtd.read_oob = concat_read_oob;
713 if (subdev[0]->write_oob)
714 concat->mtd.write_oob = concat_write_oob;
715 if (subdev[0]->block_isbad)
716 concat->mtd.block_isbad = concat_block_isbad;
717 if (subdev[0]->block_markbad)
718 concat->mtd.block_markbad = concat_block_markbad;
720 concat->subdev[0] = subdev[0];
722 for (i = 1; i < num_devs; i++) {
723 if (concat->mtd.type != subdev[i]->type) {
725 printk("Incompatible device type on \"%s\"\n",
729 if (concat->mtd.flags != subdev[i]->flags) {
731 * Expect all flags except MTD_WRITEABLE to be
732 * equal on all subdevices.
734 if ((concat->mtd.flags ^ subdev[i]->
735 flags) & ~MTD_WRITEABLE) {
737 printk("Incompatible device flags on \"%s\"\n",
741 /* if writeable attribute differs,
742 make super device writeable */
744 subdev[i]->flags & MTD_WRITEABLE;
746 concat->mtd.size += subdev[i]->size;
747 if (concat->mtd.writesize != subdev[i]->writesize ||
748 concat->mtd.oobsize != subdev[i]->oobsize ||
749 concat->mtd.ecctype != subdev[i]->ecctype ||
750 concat->mtd.eccsize != subdev[i]->eccsize ||
751 !concat->mtd.read_oob != !subdev[i]->read_oob ||
752 !concat->mtd.write_oob != !subdev[i]->write_oob) {
754 printk("Incompatible OOB or ECC data on \"%s\"\n",
758 concat->subdev[i] = subdev[i];
762 concat->mtd.ecclayout = subdev[0]->ecclayout;
764 concat->num_subdev = num_devs;
765 concat->mtd.name = name;
767 concat->mtd.erase = concat_erase;
768 concat->mtd.read = concat_read;
769 concat->mtd.write = concat_write;
770 concat->mtd.sync = concat_sync;
771 concat->mtd.lock = concat_lock;
772 concat->mtd.unlock = concat_unlock;
773 concat->mtd.suspend = concat_suspend;
774 concat->mtd.resume = concat_resume;
777 * Combine the erase block size info of the subdevices:
779 * first, walk the map of the new device and see how
780 * many changes in erase size we have
782 max_erasesize = curr_erasesize = subdev[0]->erasesize;
783 num_erase_region = 1;
784 for (i = 0; i < num_devs; i++) {
785 if (subdev[i]->numeraseregions == 0) {
786 /* current subdevice has uniform erase size */
787 if (subdev[i]->erasesize != curr_erasesize) {
788 /* if it differs from the last subdevice's erase size, count it */
790 curr_erasesize = subdev[i]->erasesize;
791 if (curr_erasesize > max_erasesize)
792 max_erasesize = curr_erasesize;
795 /* current subdevice has variable erase size */
797 for (j = 0; j < subdev[i]->numeraseregions; j++) {
799 /* walk the list of erase regions, count any changes */
800 if (subdev[i]->eraseregions[j].erasesize !=
804 subdev[i]->eraseregions[j].
806 if (curr_erasesize > max_erasesize)
807 max_erasesize = curr_erasesize;
813 if (num_erase_region == 1) {
815 * All subdevices have the same uniform erase size.
818 concat->mtd.erasesize = curr_erasesize;
819 concat->mtd.numeraseregions = 0;
822 * erase block size varies across the subdevices: allocate
823 * space to store the data describing the variable erase regions
825 struct mtd_erase_region_info *erase_region_p;
826 u_int32_t begin, position;
828 concat->mtd.erasesize = max_erasesize;
829 concat->mtd.numeraseregions = num_erase_region;
830 concat->mtd.eraseregions = erase_region_p =
831 kmalloc(num_erase_region *
832 sizeof (struct mtd_erase_region_info), GFP_KERNEL);
833 if (!erase_region_p) {
836 ("memory allocation error while creating erase region list"
837 " for device \"%s\"\n", name);
842 * walk the map of the new device once more and fill in
843 * in erase region info:
845 curr_erasesize = subdev[0]->erasesize;
846 begin = position = 0;
847 for (i = 0; i < num_devs; i++) {
848 if (subdev[i]->numeraseregions == 0) {
849 /* current subdevice has uniform erase size */
850 if (subdev[i]->erasesize != curr_erasesize) {
852 * fill in an mtd_erase_region_info structure for the area
853 * we have walked so far:
855 erase_region_p->offset = begin;
856 erase_region_p->erasesize =
858 erase_region_p->numblocks =
859 (position - begin) / curr_erasesize;
862 curr_erasesize = subdev[i]->erasesize;
865 position += subdev[i]->size;
867 /* current subdevice has variable erase size */
869 for (j = 0; j < subdev[i]->numeraseregions; j++) {
870 /* walk the list of erase regions, count any changes */
871 if (subdev[i]->eraseregions[j].
872 erasesize != curr_erasesize) {
873 erase_region_p->offset = begin;
874 erase_region_p->erasesize =
876 erase_region_p->numblocks =
878 begin) / curr_erasesize;
882 subdev[i]->eraseregions[j].
887 subdev[i]->eraseregions[j].
888 numblocks * curr_erasesize;
892 /* Now write the final entry */
893 erase_region_p->offset = begin;
894 erase_region_p->erasesize = curr_erasesize;
895 erase_region_p->numblocks = (position - begin) / curr_erasesize;
902 * This function destroys an MTD object obtained from concat_mtd_devs()
905 void mtd_concat_destroy(struct mtd_info *mtd)
907 struct mtd_concat *concat = CONCAT(mtd);
908 if (concat->mtd.numeraseregions)
909 kfree(concat->mtd.eraseregions);
913 EXPORT_SYMBOL(mtd_concat_create);
914 EXPORT_SYMBOL(mtd_concat_destroy);
916 MODULE_LICENSE("GPL");
917 MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
918 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");