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
);
83 /* Save information about bitflips! */
85 if (err
== -EBADMSG
) {
86 mtd
->ecc_stats
.failed
++;
88 } else if (err
== -EUCLEAN
) {
89 mtd
->ecc_stats
.corrected
++;
90 /* Do not overwrite -EBADMSG !! */
109 concat_write(struct mtd_info
*mtd
, loff_t to
, size_t len
,
110 size_t * retlen
, const u_char
* buf
)
112 struct mtd_concat
*concat
= CONCAT(mtd
);
116 if (!(mtd
->flags
& MTD_WRITEABLE
))
121 for (i
= 0; i
< concat
->num_subdev
; i
++) {
122 struct mtd_info
*subdev
= concat
->subdev
[i
];
123 size_t size
, retsize
;
125 if (to
>= subdev
->size
) {
130 if (to
+ len
> subdev
->size
)
131 size
= subdev
->size
- to
;
135 if (!(subdev
->flags
& MTD_WRITEABLE
))
138 err
= subdev
->write(subdev
, to
, size
, &retsize
, buf
);
156 concat_writev(struct mtd_info
*mtd
, const struct kvec
*vecs
,
157 unsigned long count
, loff_t to
, size_t * retlen
)
159 struct mtd_concat
*concat
= CONCAT(mtd
);
160 struct kvec
*vecs_copy
;
161 unsigned long entry_low
, entry_high
;
162 size_t total_len
= 0;
166 if (!(mtd
->flags
& MTD_WRITEABLE
))
171 /* Calculate total length of data */
172 for (i
= 0; i
< count
; i
++)
173 total_len
+= vecs
[i
].iov_len
;
175 /* Do not allow write past end of device */
176 if ((to
+ total_len
) > mtd
->size
)
179 /* Check alignment */
180 if (mtd
->writesize
> 1) {
182 if (do_div(__to
, mtd
->writesize
) || (total_len
% mtd
->writesize
))
186 /* make a copy of vecs */
187 vecs_copy
= kmalloc(sizeof(struct kvec
) * count
, GFP_KERNEL
);
190 memcpy(vecs_copy
, vecs
, sizeof(struct kvec
) * count
);
193 for (i
= 0; i
< concat
->num_subdev
; i
++) {
194 struct mtd_info
*subdev
= concat
->subdev
[i
];
195 size_t size
, wsize
, retsize
, old_iov_len
;
197 if (to
>= subdev
->size
) {
202 size
= min(total_len
, (size_t)(subdev
->size
- to
));
203 wsize
= size
; /* store for future use */
205 entry_high
= entry_low
;
206 while (entry_high
< count
) {
207 if (size
<= vecs_copy
[entry_high
].iov_len
)
209 size
-= vecs_copy
[entry_high
++].iov_len
;
212 old_iov_len
= vecs_copy
[entry_high
].iov_len
;
213 vecs_copy
[entry_high
].iov_len
= size
;
215 if (!(subdev
->flags
& MTD_WRITEABLE
))
218 err
= subdev
->writev(subdev
, &vecs_copy
[entry_low
],
219 entry_high
- entry_low
+ 1, to
, &retsize
);
221 vecs_copy
[entry_high
].iov_len
= old_iov_len
- size
;
222 vecs_copy
[entry_high
].iov_base
+= size
;
224 entry_low
= entry_high
;
244 concat_read_oob(struct mtd_info
*mtd
, loff_t from
, struct mtd_oob_ops
*ops
)
246 struct mtd_concat
*concat
= CONCAT(mtd
);
247 struct mtd_oob_ops devops
= *ops
;
250 ops
->retlen
= ops
->oobretlen
= 0;
252 for (i
= 0; i
< concat
->num_subdev
; i
++) {
253 struct mtd_info
*subdev
= concat
->subdev
[i
];
255 if (from
>= subdev
->size
) {
256 from
-= subdev
->size
;
261 if (from
+ devops
.len
> subdev
->size
)
262 devops
.len
= subdev
->size
- from
;
264 err
= subdev
->read_oob(subdev
, from
, &devops
);
265 ops
->retlen
+= devops
.retlen
;
266 ops
->oobretlen
+= devops
.oobretlen
;
268 /* Save information about bitflips! */
270 if (err
== -EBADMSG
) {
271 mtd
->ecc_stats
.failed
++;
273 } else if (err
== -EUCLEAN
) {
274 mtd
->ecc_stats
.corrected
++;
275 /* Do not overwrite -EBADMSG !! */
283 devops
.len
= ops
->len
- ops
->retlen
;
286 devops
.datbuf
+= devops
.retlen
;
289 devops
.ooblen
= ops
->ooblen
- ops
->oobretlen
;
292 devops
.oobbuf
+= ops
->oobretlen
;
301 concat_write_oob(struct mtd_info
*mtd
, loff_t to
, struct mtd_oob_ops
*ops
)
303 struct mtd_concat
*concat
= CONCAT(mtd
);
304 struct mtd_oob_ops devops
= *ops
;
307 if (!(mtd
->flags
& MTD_WRITEABLE
))
312 for (i
= 0; i
< concat
->num_subdev
; i
++) {
313 struct mtd_info
*subdev
= concat
->subdev
[i
];
315 if (to
>= subdev
->size
) {
320 /* partial write ? */
321 if (to
+ devops
.len
> subdev
->size
)
322 devops
.len
= subdev
->size
- to
;
324 err
= subdev
->write_oob(subdev
, to
, &devops
);
325 ops
->retlen
+= devops
.retlen
;
330 devops
.len
= ops
->len
- ops
->retlen
;
333 devops
.datbuf
+= devops
.retlen
;
336 devops
.ooblen
= ops
->ooblen
- ops
->oobretlen
;
339 devops
.oobbuf
+= devops
.oobretlen
;
346 static void concat_erase_callback(struct erase_info
*instr
)
348 wake_up((wait_queue_head_t
*) instr
->priv
);
351 static int concat_dev_erase(struct mtd_info
*mtd
, struct erase_info
*erase
)
354 wait_queue_head_t waitq
;
355 DECLARE_WAITQUEUE(wait
, current
);
358 * This code was stol^H^H^H^Hinspired by mtdchar.c
360 init_waitqueue_head(&waitq
);
363 erase
->callback
= concat_erase_callback
;
364 erase
->priv
= (unsigned long) &waitq
;
367 * FIXME: Allow INTERRUPTIBLE. Which means
368 * not having the wait_queue head on the stack.
370 err
= mtd
->erase(mtd
, erase
);
372 set_current_state(TASK_UNINTERRUPTIBLE
);
373 add_wait_queue(&waitq
, &wait
);
374 if (erase
->state
!= MTD_ERASE_DONE
375 && erase
->state
!= MTD_ERASE_FAILED
)
377 remove_wait_queue(&waitq
, &wait
);
378 set_current_state(TASK_RUNNING
);
380 err
= (erase
->state
== MTD_ERASE_FAILED
) ? -EIO
: 0;
385 static int concat_erase(struct mtd_info
*mtd
, struct erase_info
*instr
)
387 struct mtd_concat
*concat
= CONCAT(mtd
);
388 struct mtd_info
*subdev
;
390 u_int32_t length
, offset
= 0;
391 struct erase_info
*erase
;
393 if (!(mtd
->flags
& MTD_WRITEABLE
))
396 if (instr
->addr
> concat
->mtd
.size
)
399 if (instr
->len
+ instr
->addr
> concat
->mtd
.size
)
403 * Check for proper erase block alignment of the to-be-erased area.
404 * It is easier to do this based on the super device's erase
405 * region info rather than looking at each particular sub-device
408 if (!concat
->mtd
.numeraseregions
) {
409 /* the easy case: device has uniform erase block size */
410 if (instr
->addr
& (concat
->mtd
.erasesize
- 1))
412 if (instr
->len
& (concat
->mtd
.erasesize
- 1))
415 /* device has variable erase size */
416 struct mtd_erase_region_info
*erase_regions
=
417 concat
->mtd
.eraseregions
;
420 * Find the erase region where the to-be-erased area begins:
422 for (i
= 0; i
< concat
->mtd
.numeraseregions
&&
423 instr
->addr
>= erase_regions
[i
].offset
; i
++) ;
427 * Now erase_regions[i] is the region in which the
428 * to-be-erased area begins. Verify that the starting
429 * offset is aligned to this region's erase size:
431 if (instr
->addr
& (erase_regions
[i
].erasesize
- 1))
435 * now find the erase region where the to-be-erased area ends:
437 for (; i
< concat
->mtd
.numeraseregions
&&
438 (instr
->addr
+ instr
->len
) >= erase_regions
[i
].offset
;
442 * check if the ending offset is aligned to this region's erase size
444 if ((instr
->addr
+ instr
->len
) & (erase_regions
[i
].erasesize
-
449 instr
->fail_addr
= 0xffffffff;
451 /* make a local copy of instr to avoid modifying the caller's struct */
452 erase
= kmalloc(sizeof (struct erase_info
), GFP_KERNEL
);
461 * find the subdevice where the to-be-erased area begins, adjust
462 * starting offset to be relative to the subdevice start
464 for (i
= 0; i
< concat
->num_subdev
; i
++) {
465 subdev
= concat
->subdev
[i
];
466 if (subdev
->size
<= erase
->addr
) {
467 erase
->addr
-= subdev
->size
;
468 offset
+= subdev
->size
;
474 /* must never happen since size limit has been verified above */
475 BUG_ON(i
>= concat
->num_subdev
);
477 /* now do the erase: */
479 for (; length
> 0; i
++) {
480 /* loop for all subdevices affected by this request */
481 subdev
= concat
->subdev
[i
]; /* get current subdevice */
483 /* limit length to subdevice's size: */
484 if (erase
->addr
+ length
> subdev
->size
)
485 erase
->len
= subdev
->size
- erase
->addr
;
489 if (!(subdev
->flags
& MTD_WRITEABLE
)) {
493 length
-= erase
->len
;
494 if ((err
= concat_dev_erase(subdev
, erase
))) {
495 /* sanity check: should never happen since
496 * block alignment has been checked above */
497 BUG_ON(err
== -EINVAL
);
498 if (erase
->fail_addr
!= 0xffffffff)
499 instr
->fail_addr
= erase
->fail_addr
+ offset
;
503 * erase->addr specifies the offset of the area to be
504 * erased *within the current subdevice*. It can be
505 * non-zero only the first time through this loop, i.e.
506 * for the first subdevice where blocks need to be erased.
507 * All the following erases must begin at the start of the
508 * current subdevice, i.e. at offset zero.
511 offset
+= subdev
->size
;
513 instr
->state
= erase
->state
;
519 instr
->callback(instr
);
523 static int concat_lock(struct mtd_info
*mtd
, loff_t ofs
, size_t len
)
525 struct mtd_concat
*concat
= CONCAT(mtd
);
526 int i
, err
= -EINVAL
;
528 if ((len
+ ofs
) > mtd
->size
)
531 for (i
= 0; i
< concat
->num_subdev
; i
++) {
532 struct mtd_info
*subdev
= concat
->subdev
[i
];
535 if (ofs
>= subdev
->size
) {
540 if (ofs
+ len
> subdev
->size
)
541 size
= subdev
->size
- ofs
;
545 err
= subdev
->lock(subdev
, ofs
, size
);
561 static int concat_unlock(struct mtd_info
*mtd
, loff_t ofs
, size_t len
)
563 struct mtd_concat
*concat
= CONCAT(mtd
);
566 if ((len
+ ofs
) > mtd
->size
)
569 for (i
= 0; i
< concat
->num_subdev
; i
++) {
570 struct mtd_info
*subdev
= concat
->subdev
[i
];
573 if (ofs
>= subdev
->size
) {
578 if (ofs
+ len
> subdev
->size
)
579 size
= subdev
->size
- ofs
;
583 err
= subdev
->unlock(subdev
, ofs
, size
);
599 static void concat_sync(struct mtd_info
*mtd
)
601 struct mtd_concat
*concat
= CONCAT(mtd
);
604 for (i
= 0; i
< concat
->num_subdev
; i
++) {
605 struct mtd_info
*subdev
= concat
->subdev
[i
];
606 subdev
->sync(subdev
);
610 static int concat_suspend(struct mtd_info
*mtd
)
612 struct mtd_concat
*concat
= CONCAT(mtd
);
615 for (i
= 0; i
< concat
->num_subdev
; i
++) {
616 struct mtd_info
*subdev
= concat
->subdev
[i
];
617 if ((rc
= subdev
->suspend(subdev
)) < 0)
623 static void concat_resume(struct mtd_info
*mtd
)
625 struct mtd_concat
*concat
= CONCAT(mtd
);
628 for (i
= 0; i
< concat
->num_subdev
; i
++) {
629 struct mtd_info
*subdev
= concat
->subdev
[i
];
630 subdev
->resume(subdev
);
634 static int concat_block_isbad(struct mtd_info
*mtd
, loff_t ofs
)
636 struct mtd_concat
*concat
= CONCAT(mtd
);
639 if (!concat
->subdev
[0]->block_isbad
)
645 for (i
= 0; i
< concat
->num_subdev
; i
++) {
646 struct mtd_info
*subdev
= concat
->subdev
[i
];
648 if (ofs
>= subdev
->size
) {
653 res
= subdev
->block_isbad(subdev
, ofs
);
660 static int concat_block_markbad(struct mtd_info
*mtd
, loff_t ofs
)
662 struct mtd_concat
*concat
= CONCAT(mtd
);
663 int i
, err
= -EINVAL
;
665 if (!concat
->subdev
[0]->block_markbad
)
671 for (i
= 0; i
< concat
->num_subdev
; i
++) {
672 struct mtd_info
*subdev
= concat
->subdev
[i
];
674 if (ofs
>= subdev
->size
) {
679 err
= subdev
->block_markbad(subdev
, ofs
);
681 mtd
->ecc_stats
.badblocks
++;
689 * This function constructs a virtual MTD device by concatenating
690 * num_devs MTD devices. A pointer to the new device object is
691 * stored to *new_dev upon success. This function does _not_
692 * register any devices: this is the caller's responsibility.
694 struct mtd_info
*mtd_concat_create(struct mtd_info
*subdev
[], /* subdevices to concatenate */
695 int num_devs
, /* number of subdevices */
697 { /* name for the new device */
700 struct mtd_concat
*concat
;
701 u_int32_t max_erasesize
, curr_erasesize
;
702 int num_erase_region
;
704 printk(KERN_NOTICE
"Concatenating MTD devices:\n");
705 for (i
= 0; i
< num_devs
; i
++)
706 printk(KERN_NOTICE
"(%d): \"%s\"\n", i
, subdev
[i
]->name
);
707 printk(KERN_NOTICE
"into device \"%s\"\n", name
);
709 /* allocate the device structure */
710 size
= SIZEOF_STRUCT_MTD_CONCAT(num_devs
);
711 concat
= kzalloc(size
, GFP_KERNEL
);
714 ("memory allocation error while creating concatenated device \"%s\"\n",
718 concat
->subdev
= (struct mtd_info
**) (concat
+ 1);
721 * Set up the new "super" device's MTD object structure, check for
722 * incompatibilites between the subdevices.
724 concat
->mtd
.type
= subdev
[0]->type
;
725 concat
->mtd
.flags
= subdev
[0]->flags
;
726 concat
->mtd
.size
= subdev
[0]->size
;
727 concat
->mtd
.erasesize
= subdev
[0]->erasesize
;
728 concat
->mtd
.writesize
= subdev
[0]->writesize
;
729 concat
->mtd
.subpage_sft
= subdev
[0]->subpage_sft
;
730 concat
->mtd
.oobsize
= subdev
[0]->oobsize
;
731 concat
->mtd
.oobavail
= subdev
[0]->oobavail
;
732 if (subdev
[0]->writev
)
733 concat
->mtd
.writev
= concat_writev
;
734 if (subdev
[0]->read_oob
)
735 concat
->mtd
.read_oob
= concat_read_oob
;
736 if (subdev
[0]->write_oob
)
737 concat
->mtd
.write_oob
= concat_write_oob
;
738 if (subdev
[0]->block_isbad
)
739 concat
->mtd
.block_isbad
= concat_block_isbad
;
740 if (subdev
[0]->block_markbad
)
741 concat
->mtd
.block_markbad
= concat_block_markbad
;
743 concat
->mtd
.ecc_stats
.badblocks
= subdev
[0]->ecc_stats
.badblocks
;
745 concat
->subdev
[0] = subdev
[0];
747 for (i
= 1; i
< num_devs
; i
++) {
748 if (concat
->mtd
.type
!= subdev
[i
]->type
) {
750 printk("Incompatible device type on \"%s\"\n",
754 if (concat
->mtd
.flags
!= subdev
[i
]->flags
) {
756 * Expect all flags except MTD_WRITEABLE to be
757 * equal on all subdevices.
759 if ((concat
->mtd
.flags
^ subdev
[i
]->
760 flags
) & ~MTD_WRITEABLE
) {
762 printk("Incompatible device flags on \"%s\"\n",
766 /* if writeable attribute differs,
767 make super device writeable */
769 subdev
[i
]->flags
& MTD_WRITEABLE
;
771 concat
->mtd
.size
+= subdev
[i
]->size
;
772 concat
->mtd
.ecc_stats
.badblocks
+=
773 subdev
[i
]->ecc_stats
.badblocks
;
774 if (concat
->mtd
.writesize
!= subdev
[i
]->writesize
||
775 concat
->mtd
.subpage_sft
!= subdev
[i
]->subpage_sft
||
776 concat
->mtd
.oobsize
!= subdev
[i
]->oobsize
||
777 !concat
->mtd
.read_oob
!= !subdev
[i
]->read_oob
||
778 !concat
->mtd
.write_oob
!= !subdev
[i
]->write_oob
) {
780 printk("Incompatible OOB or ECC data on \"%s\"\n",
784 concat
->subdev
[i
] = subdev
[i
];
788 concat
->mtd
.ecclayout
= subdev
[0]->ecclayout
;
790 concat
->num_subdev
= num_devs
;
791 concat
->mtd
.name
= name
;
793 concat
->mtd
.erase
= concat_erase
;
794 concat
->mtd
.read
= concat_read
;
795 concat
->mtd
.write
= concat_write
;
796 concat
->mtd
.sync
= concat_sync
;
797 concat
->mtd
.lock
= concat_lock
;
798 concat
->mtd
.unlock
= concat_unlock
;
799 concat
->mtd
.suspend
= concat_suspend
;
800 concat
->mtd
.resume
= concat_resume
;
803 * Combine the erase block size info of the subdevices:
805 * first, walk the map of the new device and see how
806 * many changes in erase size we have
808 max_erasesize
= curr_erasesize
= subdev
[0]->erasesize
;
809 num_erase_region
= 1;
810 for (i
= 0; i
< num_devs
; i
++) {
811 if (subdev
[i
]->numeraseregions
== 0) {
812 /* current subdevice has uniform erase size */
813 if (subdev
[i
]->erasesize
!= curr_erasesize
) {
814 /* if it differs from the last subdevice's erase size, count it */
816 curr_erasesize
= subdev
[i
]->erasesize
;
817 if (curr_erasesize
> max_erasesize
)
818 max_erasesize
= curr_erasesize
;
821 /* current subdevice has variable erase size */
823 for (j
= 0; j
< subdev
[i
]->numeraseregions
; j
++) {
825 /* walk the list of erase regions, count any changes */
826 if (subdev
[i
]->eraseregions
[j
].erasesize
!=
830 subdev
[i
]->eraseregions
[j
].
832 if (curr_erasesize
> max_erasesize
)
833 max_erasesize
= curr_erasesize
;
839 if (num_erase_region
== 1) {
841 * All subdevices have the same uniform erase size.
844 concat
->mtd
.erasesize
= curr_erasesize
;
845 concat
->mtd
.numeraseregions
= 0;
848 * erase block size varies across the subdevices: allocate
849 * space to store the data describing the variable erase regions
851 struct mtd_erase_region_info
*erase_region_p
;
852 u_int32_t begin
, position
;
854 concat
->mtd
.erasesize
= max_erasesize
;
855 concat
->mtd
.numeraseregions
= num_erase_region
;
856 concat
->mtd
.eraseregions
= erase_region_p
=
857 kmalloc(num_erase_region
*
858 sizeof (struct mtd_erase_region_info
), GFP_KERNEL
);
859 if (!erase_region_p
) {
862 ("memory allocation error while creating erase region list"
863 " for device \"%s\"\n", name
);
868 * walk the map of the new device once more and fill in
869 * in erase region info:
871 curr_erasesize
= subdev
[0]->erasesize
;
872 begin
= position
= 0;
873 for (i
= 0; i
< num_devs
; i
++) {
874 if (subdev
[i
]->numeraseregions
== 0) {
875 /* current subdevice has uniform erase size */
876 if (subdev
[i
]->erasesize
!= curr_erasesize
) {
878 * fill in an mtd_erase_region_info structure for the area
879 * we have walked so far:
881 erase_region_p
->offset
= begin
;
882 erase_region_p
->erasesize
=
884 erase_region_p
->numblocks
=
885 (position
- begin
) / curr_erasesize
;
888 curr_erasesize
= subdev
[i
]->erasesize
;
891 position
+= subdev
[i
]->size
;
893 /* current subdevice has variable erase size */
895 for (j
= 0; j
< subdev
[i
]->numeraseregions
; j
++) {
896 /* walk the list of erase regions, count any changes */
897 if (subdev
[i
]->eraseregions
[j
].
898 erasesize
!= curr_erasesize
) {
899 erase_region_p
->offset
= begin
;
900 erase_region_p
->erasesize
=
902 erase_region_p
->numblocks
=
904 begin
) / curr_erasesize
;
908 subdev
[i
]->eraseregions
[j
].
913 subdev
[i
]->eraseregions
[j
].
914 numblocks
* curr_erasesize
;
918 /* Now write the final entry */
919 erase_region_p
->offset
= begin
;
920 erase_region_p
->erasesize
= curr_erasesize
;
921 erase_region_p
->numblocks
= (position
- begin
) / curr_erasesize
;
928 * This function destroys an MTD object obtained from concat_mtd_devs()
931 void mtd_concat_destroy(struct mtd_info
*mtd
)
933 struct mtd_concat
*concat
= CONCAT(mtd
);
934 if (concat
->mtd
.numeraseregions
)
935 kfree(concat
->mtd
.eraseregions
);
939 EXPORT_SYMBOL(mtd_concat_create
);
940 EXPORT_SYMBOL(mtd_concat_destroy
);
942 MODULE_LICENSE("GPL");
943 MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
944 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");
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