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);
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);
99 concat_write(struct mtd_info *mtd, loff_t to, size_t len,
100 size_t * retlen, const u_char * buf)
102 struct mtd_concat *concat = CONCAT(mtd);
106 if (!(mtd->flags & MTD_WRITEABLE))
111 for (i = 0; i < concat->num_subdev; i++) {
112 struct mtd_info *subdev = concat->subdev[i];
113 size_t size, retsize;
115 if (to >= subdev->size) {
120 if (to + len > subdev->size)
121 size = subdev->size - to;
125 if (!(subdev->flags & MTD_WRITEABLE))
128 err = subdev->write(subdev, to, size, &retsize, buf);
146 concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
147 unsigned long count, loff_t to, size_t * retlen)
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;
156 if (!(mtd->flags & MTD_WRITEABLE))
161 /* Calculate total length of data */
162 for (i = 0; i < count; i++)
163 total_len += vecs[i].iov_len;
165 /* Do not allow write past end of device */
166 if ((to + total_len) > mtd->size)
169 /* Check alignment */
170 if (mtd->writesize > 1) {
172 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
176 /* make a copy of vecs */
177 vecs_copy = kmalloc(sizeof(struct kvec) * count, GFP_KERNEL);
180 memcpy(vecs_copy, vecs, sizeof(struct kvec) * count);
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;
187 if (to >= subdev->size) {
192 size = min(total_len, (size_t)(subdev->size - to));
193 wsize = size; /* store for future use */
195 entry_high = entry_low;
196 while (entry_high < count) {
197 if (size <= vecs_copy[entry_high].iov_len)
199 size -= vecs_copy[entry_high++].iov_len;
202 old_iov_len = vecs_copy[entry_high].iov_len;
203 vecs_copy[entry_high].iov_len = size;
205 if (!(subdev->flags & MTD_WRITEABLE))
208 err = subdev->writev(subdev, &vecs_copy[entry_low],
209 entry_high - entry_low + 1, to, &retsize);
211 vecs_copy[entry_high].iov_len = old_iov_len - size;
212 vecs_copy[entry_high].iov_base += size;
214 entry_low = entry_high;
234 concat_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
235 size_t * retlen, u_char * buf)
237 struct mtd_concat *concat = CONCAT(mtd);
243 for (i = 0; i < concat->num_subdev; i++) {
244 struct mtd_info *subdev = concat->subdev[i];
245 size_t size, retsize;
247 if (from >= subdev->size) {
248 /* Not destined for this subdev */
250 from -= subdev->size;
253 if (from + len > subdev->size)
254 /* First part goes into this subdev */
255 size = subdev->size - from;
257 /* Entire transaction goes into this subdev */
260 if (subdev->read_oob)
261 err = subdev->read_oob(subdev, from, size,
282 concat_write_oob(struct mtd_info *mtd, loff_t to, size_t len,
283 size_t * retlen, const u_char * buf)
285 struct mtd_concat *concat = CONCAT(mtd);
289 if (!(mtd->flags & MTD_WRITEABLE))
294 for (i = 0; i < concat->num_subdev; i++) {
295 struct mtd_info *subdev = concat->subdev[i];
296 size_t size, retsize;
298 if (to >= subdev->size) {
303 if (to + len > subdev->size)
304 size = subdev->size - to;
308 if (!(subdev->flags & MTD_WRITEABLE))
310 else if (subdev->write_oob)
311 err = subdev->write_oob(subdev, to, size, &retsize,
331 static void concat_erase_callback(struct erase_info *instr)
333 wake_up((wait_queue_head_t *) instr->priv);
336 static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
339 wait_queue_head_t waitq;
340 DECLARE_WAITQUEUE(wait, current);
343 * This code was stol^H^H^H^Hinspired by mtdchar.c
345 init_waitqueue_head(&waitq);
348 erase->callback = concat_erase_callback;
349 erase->priv = (unsigned long) &waitq;
352 * FIXME: Allow INTERRUPTIBLE. Which means
353 * not having the wait_queue head on the stack.
355 err = mtd->erase(mtd, erase);
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)
362 remove_wait_queue(&waitq, &wait);
363 set_current_state(TASK_RUNNING);
365 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
370 static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
372 struct mtd_concat *concat = CONCAT(mtd);
373 struct mtd_info *subdev;
375 u_int32_t length, offset = 0;
376 struct erase_info *erase;
378 if (!(mtd->flags & MTD_WRITEABLE))
381 if (instr->addr > concat->mtd.size)
384 if (instr->len + instr->addr > concat->mtd.size)
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
393 if (!concat->mtd.numeraseregions) {
394 /* the easy case: device has uniform erase block size */
395 if (instr->addr & (concat->mtd.erasesize - 1))
397 if (instr->len & (concat->mtd.erasesize - 1))
400 /* device has variable erase size */
401 struct mtd_erase_region_info *erase_regions =
402 concat->mtd.eraseregions;
405 * Find the erase region where the to-be-erased area begins:
407 for (i = 0; i < concat->mtd.numeraseregions &&
408 instr->addr >= erase_regions[i].offset; i++) ;
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:
416 if (instr->addr & (erase_regions[i].erasesize - 1))
420 * now find the erase region where the to-be-erased area ends:
422 for (; i < concat->mtd.numeraseregions &&
423 (instr->addr + instr->len) >= erase_regions[i].offset;
427 * check if the ending offset is aligned to this region's erase size
429 if ((instr->addr + instr->len) & (erase_regions[i].erasesize -
434 instr->fail_addr = 0xffffffff;
436 /* make a local copy of instr to avoid modifying the caller's struct */
437 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
446 * find the subdevice where the to-be-erased area begins, adjust
447 * starting offset to be relative to the subdevice start
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;
459 /* must never happen since size limit has been verified above */
460 BUG_ON(i >= concat->num_subdev);
462 /* now do the erase: */
464 for (; length > 0; i++) {
465 /* loop for all subdevices affected by this request */
466 subdev = concat->subdev[i]; /* get current subdevice */
468 /* limit length to subdevice's size: */
469 if (erase->addr + length > subdev->size)
470 erase->len = subdev->size - erase->addr;
474 if (!(subdev->flags & MTD_WRITEABLE)) {
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 */
482 BUG_ON(err == -EINVAL);
483 if (erase->fail_addr != 0xffffffff)
484 instr->fail_addr = erase->fail_addr + offset;
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.
496 offset += subdev->size;
498 instr->state = erase->state;
504 instr->callback(instr);
508 static int concat_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
510 struct mtd_concat *concat = CONCAT(mtd);
511 int i, err = -EINVAL;
513 if ((len + ofs) > mtd->size)
516 for (i = 0; i < concat->num_subdev; i++) {
517 struct mtd_info *subdev = concat->subdev[i];
520 if (ofs >= subdev->size) {
525 if (ofs + len > subdev->size)
526 size = subdev->size - ofs;
530 err = subdev->lock(subdev, ofs, size);
546 static int concat_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
548 struct mtd_concat *concat = CONCAT(mtd);
551 if ((len + ofs) > mtd->size)
554 for (i = 0; i < concat->num_subdev; i++) {
555 struct mtd_info *subdev = concat->subdev[i];
558 if (ofs >= subdev->size) {
563 if (ofs + len > subdev->size)
564 size = subdev->size - ofs;
568 err = subdev->unlock(subdev, ofs, size);
584 static void concat_sync(struct mtd_info *mtd)
586 struct mtd_concat *concat = CONCAT(mtd);
589 for (i = 0; i < concat->num_subdev; i++) {
590 struct mtd_info *subdev = concat->subdev[i];
591 subdev->sync(subdev);
595 static int concat_suspend(struct mtd_info *mtd)
597 struct mtd_concat *concat = CONCAT(mtd);
600 for (i = 0; i < concat->num_subdev; i++) {
601 struct mtd_info *subdev = concat->subdev[i];
602 if ((rc = subdev->suspend(subdev)) < 0)
608 static void concat_resume(struct mtd_info *mtd)
610 struct mtd_concat *concat = CONCAT(mtd);
613 for (i = 0; i < concat->num_subdev; i++) {
614 struct mtd_info *subdev = concat->subdev[i];
615 subdev->resume(subdev);
619 static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
621 struct mtd_concat *concat = CONCAT(mtd);
624 if (!concat->subdev[0]->block_isbad)
630 for (i = 0; i < concat->num_subdev; i++) {
631 struct mtd_info *subdev = concat->subdev[i];
633 if (ofs >= subdev->size) {
638 res = subdev->block_isbad(subdev, ofs);
645 static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
647 struct mtd_concat *concat = CONCAT(mtd);
648 int i, err = -EINVAL;
650 if (!concat->subdev[0]->block_markbad)
656 for (i = 0; i < concat->num_subdev; i++) {
657 struct mtd_info *subdev = concat->subdev[i];
659 if (ofs >= subdev->size) {
664 err = subdev->block_markbad(subdev, ofs);
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.
677 struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
678 int num_devs, /* number of subdevices */
680 { /* name for the new device */
683 struct mtd_concat *concat;
684 u_int32_t max_erasesize, curr_erasesize;
685 int num_erase_region;
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);
692 /* allocate the device structure */
693 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
694 concat = kmalloc(size, GFP_KERNEL);
697 ("memory allocation error while creating concatenated device \"%s\"\n",
701 memset(concat, 0, size);
702 concat->subdev = (struct mtd_info **) (concat + 1);
705 * Set up the new "super" device's MTD object structure, check for
706 * incompatibilites between the subdevices.
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;
712 concat->mtd.writesize = subdev[0]->writesize;
713 concat->mtd.oobsize = subdev[0]->oobsize;
714 concat->mtd.ecctype = subdev[0]->ecctype;
715 concat->mtd.eccsize = subdev[0]->eccsize;
716 if (subdev[0]->writev)
717 concat->mtd.writev = concat_writev;
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;
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;
727 concat->subdev[0] = subdev[0];
729 for (i = 1; i < num_devs; i++) {
730 if (concat->mtd.type != subdev[i]->type) {
732 printk("Incompatible device type on \"%s\"\n",
736 if (concat->mtd.flags != subdev[i]->flags) {
738 * Expect all flags except MTD_WRITEABLE to be
739 * equal on all subdevices.
741 if ((concat->mtd.flags ^ subdev[i]->
742 flags) & ~MTD_WRITEABLE) {
744 printk("Incompatible device flags on \"%s\"\n",
748 /* if writeable attribute differs,
749 make super device writeable */
751 subdev[i]->flags & MTD_WRITEABLE;
753 concat->mtd.size += subdev[i]->size;
754 if (concat->mtd.writesize != subdev[i]->writesize ||
755 concat->mtd.oobsize != subdev[i]->oobsize ||
756 concat->mtd.ecctype != subdev[i]->ecctype ||
757 concat->mtd.eccsize != subdev[i]->eccsize ||
758 !concat->mtd.read_oob != !subdev[i]->read_oob ||
759 !concat->mtd.write_oob != !subdev[i]->write_oob) {
761 printk("Incompatible OOB or ECC data on \"%s\"\n",
765 concat->subdev[i] = subdev[i];
769 if(concat->mtd.type == MTD_NANDFLASH)
770 memcpy(&concat->mtd.oobinfo, &subdev[0]->oobinfo,
771 sizeof(struct nand_oobinfo));
773 concat->num_subdev = num_devs;
774 concat->mtd.name = name;
776 concat->mtd.erase = concat_erase;
777 concat->mtd.read = concat_read;
778 concat->mtd.write = concat_write;
779 concat->mtd.sync = concat_sync;
780 concat->mtd.lock = concat_lock;
781 concat->mtd.unlock = concat_unlock;
782 concat->mtd.suspend = concat_suspend;
783 concat->mtd.resume = concat_resume;
786 * Combine the erase block size info of the subdevices:
788 * first, walk the map of the new device and see how
789 * many changes in erase size we have
791 max_erasesize = curr_erasesize = subdev[0]->erasesize;
792 num_erase_region = 1;
793 for (i = 0; i < num_devs; i++) {
794 if (subdev[i]->numeraseregions == 0) {
795 /* current subdevice has uniform erase size */
796 if (subdev[i]->erasesize != curr_erasesize) {
797 /* if it differs from the last subdevice's erase size, count it */
799 curr_erasesize = subdev[i]->erasesize;
800 if (curr_erasesize > max_erasesize)
801 max_erasesize = curr_erasesize;
804 /* current subdevice has variable erase size */
806 for (j = 0; j < subdev[i]->numeraseregions; j++) {
808 /* walk the list of erase regions, count any changes */
809 if (subdev[i]->eraseregions[j].erasesize !=
813 subdev[i]->eraseregions[j].
815 if (curr_erasesize > max_erasesize)
816 max_erasesize = curr_erasesize;
822 if (num_erase_region == 1) {
824 * All subdevices have the same uniform erase size.
827 concat->mtd.erasesize = curr_erasesize;
828 concat->mtd.numeraseregions = 0;
831 * erase block size varies across the subdevices: allocate
832 * space to store the data describing the variable erase regions
834 struct mtd_erase_region_info *erase_region_p;
835 u_int32_t begin, position;
837 concat->mtd.erasesize = max_erasesize;
838 concat->mtd.numeraseregions = num_erase_region;
839 concat->mtd.eraseregions = erase_region_p =
840 kmalloc(num_erase_region *
841 sizeof (struct mtd_erase_region_info), GFP_KERNEL);
842 if (!erase_region_p) {
845 ("memory allocation error while creating erase region list"
846 " for device \"%s\"\n", name);
851 * walk the map of the new device once more and fill in
852 * in erase region info:
854 curr_erasesize = subdev[0]->erasesize;
855 begin = position = 0;
856 for (i = 0; i < num_devs; i++) {
857 if (subdev[i]->numeraseregions == 0) {
858 /* current subdevice has uniform erase size */
859 if (subdev[i]->erasesize != curr_erasesize) {
861 * fill in an mtd_erase_region_info structure for the area
862 * we have walked so far:
864 erase_region_p->offset = begin;
865 erase_region_p->erasesize =
867 erase_region_p->numblocks =
868 (position - begin) / curr_erasesize;
871 curr_erasesize = subdev[i]->erasesize;
874 position += subdev[i]->size;
876 /* current subdevice has variable erase size */
878 for (j = 0; j < subdev[i]->numeraseregions; j++) {
879 /* walk the list of erase regions, count any changes */
880 if (subdev[i]->eraseregions[j].
881 erasesize != curr_erasesize) {
882 erase_region_p->offset = begin;
883 erase_region_p->erasesize =
885 erase_region_p->numblocks =
887 begin) / curr_erasesize;
891 subdev[i]->eraseregions[j].
896 subdev[i]->eraseregions[j].
897 numblocks * curr_erasesize;
901 /* Now write the final entry */
902 erase_region_p->offset = begin;
903 erase_region_p->erasesize = curr_erasesize;
904 erase_region_p->numblocks = (position - begin) / curr_erasesize;
911 * This function destroys an MTD object obtained from concat_mtd_devs()
914 void mtd_concat_destroy(struct mtd_info *mtd)
916 struct mtd_concat *concat = CONCAT(mtd);
917 if (concat->mtd.numeraseregions)
918 kfree(concat->mtd.eraseregions);
922 EXPORT_SYMBOL(mtd_concat_create);
923 EXPORT_SYMBOL(mtd_concat_destroy);
925 MODULE_LICENSE("GPL");
926 MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
927 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");