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>
23 * Our storage structure:
24 * Subdev points to an array of pointers to struct mtd_info objects
25 * which is allocated along with this structure
31 struct mtd_info
**subdev
;
35 * how to calculate the size required for the above structure,
36 * including the pointer array subdev points to:
38 #define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \
39 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
42 * Given a pointer to the MTD object in the mtd_concat structure,
43 * we can retrieve the pointer to that structure with this macro.
45 #define CONCAT(x) ((struct mtd_concat *)(x))
48 * MTD methods which look up the relevant subdevice, translate the
49 * effective address and pass through to the subdevice.
53 concat_read(struct mtd_info
*mtd
, loff_t from
, size_t len
,
54 size_t * retlen
, u_char
* buf
)
56 struct mtd_concat
*concat
= CONCAT(mtd
);
62 for (i
= 0; i
< concat
->num_subdev
; i
++) {
63 struct mtd_info
*subdev
= concat
->subdev
[i
];
66 if (from
>= subdev
->size
) {
67 /* Not destined for this subdev */
72 if (from
+ len
> subdev
->size
)
73 /* First part goes into this subdev */
74 size
= subdev
->size
- from
;
76 /* Entire transaction goes into this subdev */
79 err
= subdev
->read(subdev
, from
, size
, &retsize
, buf
);
97 concat_write(struct mtd_info
*mtd
, loff_t to
, size_t len
,
98 size_t * retlen
, const u_char
* buf
)
100 struct mtd_concat
*concat
= CONCAT(mtd
);
104 if (!(mtd
->flags
& MTD_WRITEABLE
))
109 for (i
= 0; i
< concat
->num_subdev
; i
++) {
110 struct mtd_info
*subdev
= concat
->subdev
[i
];
111 size_t size
, retsize
;
113 if (to
>= subdev
->size
) {
118 if (to
+ len
> subdev
->size
)
119 size
= subdev
->size
- to
;
123 if (!(subdev
->flags
& MTD_WRITEABLE
))
126 err
= subdev
->write(subdev
, to
, size
, &retsize
, buf
);
144 concat_read_ecc(struct mtd_info
*mtd
, loff_t from
, size_t len
,
145 size_t * retlen
, u_char
* buf
, u_char
* eccbuf
,
146 struct nand_oobinfo
*oobsel
)
148 struct mtd_concat
*concat
= CONCAT(mtd
);
154 for (i
= 0; i
< concat
->num_subdev
; i
++) {
155 struct mtd_info
*subdev
= concat
->subdev
[i
];
156 size_t size
, retsize
;
158 if (from
>= subdev
->size
) {
159 /* Not destined for this subdev */
161 from
-= subdev
->size
;
165 if (from
+ len
> subdev
->size
)
166 /* First part goes into this subdev */
167 size
= subdev
->size
- from
;
169 /* Entire transaction goes into this subdev */
172 if (subdev
->read_ecc
)
173 err
= subdev
->read_ecc(subdev
, from
, size
,
174 &retsize
, buf
, eccbuf
, oobsel
);
189 eccbuf
+= subdev
->oobsize
;
190 /* in nand.c at least, eccbufs are
191 tagged with 2 (int)eccstatus'; we
192 must account for these */
193 eccbuf
+= 2 * (sizeof (int));
201 concat_write_ecc(struct mtd_info
*mtd
, loff_t to
, size_t len
,
202 size_t * retlen
, const u_char
* buf
, u_char
* eccbuf
,
203 struct nand_oobinfo
*oobsel
)
205 struct mtd_concat
*concat
= CONCAT(mtd
);
209 if (!(mtd
->flags
& MTD_WRITEABLE
))
214 for (i
= 0; i
< concat
->num_subdev
; i
++) {
215 struct mtd_info
*subdev
= concat
->subdev
[i
];
216 size_t size
, retsize
;
218 if (to
>= subdev
->size
) {
223 if (to
+ len
> subdev
->size
)
224 size
= subdev
->size
- to
;
228 if (!(subdev
->flags
& MTD_WRITEABLE
))
230 else if (subdev
->write_ecc
)
231 err
= subdev
->write_ecc(subdev
, to
, size
,
232 &retsize
, buf
, eccbuf
, oobsel
);
247 eccbuf
+= subdev
->oobsize
;
254 concat_read_oob(struct mtd_info
*mtd
, loff_t from
, size_t len
,
255 size_t * retlen
, u_char
* buf
)
257 struct mtd_concat
*concat
= CONCAT(mtd
);
263 for (i
= 0; i
< concat
->num_subdev
; i
++) {
264 struct mtd_info
*subdev
= concat
->subdev
[i
];
265 size_t size
, retsize
;
267 if (from
>= subdev
->size
) {
268 /* Not destined for this subdev */
270 from
-= subdev
->size
;
273 if (from
+ len
> subdev
->size
)
274 /* First part goes into this subdev */
275 size
= subdev
->size
- from
;
277 /* Entire transaction goes into this subdev */
280 if (subdev
->read_oob
)
281 err
= subdev
->read_oob(subdev
, from
, size
,
302 concat_write_oob(struct mtd_info
*mtd
, loff_t to
, size_t len
,
303 size_t * retlen
, const u_char
* buf
)
305 struct mtd_concat
*concat
= CONCAT(mtd
);
309 if (!(mtd
->flags
& MTD_WRITEABLE
))
314 for (i
= 0; i
< concat
->num_subdev
; i
++) {
315 struct mtd_info
*subdev
= concat
->subdev
[i
];
316 size_t size
, retsize
;
318 if (to
>= subdev
->size
) {
323 if (to
+ len
> subdev
->size
)
324 size
= subdev
->size
- to
;
328 if (!(subdev
->flags
& MTD_WRITEABLE
))
330 else if (subdev
->write_oob
)
331 err
= subdev
->write_oob(subdev
, to
, size
, &retsize
,
351 static void concat_erase_callback(struct erase_info
*instr
)
353 wake_up((wait_queue_head_t
*) instr
->priv
);
356 static int concat_dev_erase(struct mtd_info
*mtd
, struct erase_info
*erase
)
359 wait_queue_head_t waitq
;
360 DECLARE_WAITQUEUE(wait
, current
);
363 * This code was stol^H^H^H^Hinspired by mtdchar.c
365 init_waitqueue_head(&waitq
);
368 erase
->callback
= concat_erase_callback
;
369 erase
->priv
= (unsigned long) &waitq
;
372 * FIXME: Allow INTERRUPTIBLE. Which means
373 * not having the wait_queue head on the stack.
375 err
= mtd
->erase(mtd
, erase
);
377 set_current_state(TASK_UNINTERRUPTIBLE
);
378 add_wait_queue(&waitq
, &wait
);
379 if (erase
->state
!= MTD_ERASE_DONE
380 && erase
->state
!= MTD_ERASE_FAILED
)
382 remove_wait_queue(&waitq
, &wait
);
383 set_current_state(TASK_RUNNING
);
385 err
= (erase
->state
== MTD_ERASE_FAILED
) ? -EIO
: 0;
390 static int concat_erase(struct mtd_info
*mtd
, struct erase_info
*instr
)
392 struct mtd_concat
*concat
= CONCAT(mtd
);
393 struct mtd_info
*subdev
;
395 u_int32_t length
, offset
= 0;
396 struct erase_info
*erase
;
398 if (!(mtd
->flags
& MTD_WRITEABLE
))
401 if (instr
->addr
> concat
->mtd
.size
)
404 if (instr
->len
+ instr
->addr
> concat
->mtd
.size
)
408 * Check for proper erase block alignment of the to-be-erased area.
409 * It is easier to do this based on the super device's erase
410 * region info rather than looking at each particular sub-device
413 if (!concat
->mtd
.numeraseregions
) {
414 /* the easy case: device has uniform erase block size */
415 if (instr
->addr
& (concat
->mtd
.erasesize
- 1))
417 if (instr
->len
& (concat
->mtd
.erasesize
- 1))
420 /* device has variable erase size */
421 struct mtd_erase_region_info
*erase_regions
=
422 concat
->mtd
.eraseregions
;
425 * Find the erase region where the to-be-erased area begins:
427 for (i
= 0; i
< concat
->mtd
.numeraseregions
&&
428 instr
->addr
>= erase_regions
[i
].offset
; i
++) ;
432 * Now erase_regions[i] is the region in which the
433 * to-be-erased area begins. Verify that the starting
434 * offset is aligned to this region's erase size:
436 if (instr
->addr
& (erase_regions
[i
].erasesize
- 1))
440 * now find the erase region where the to-be-erased area ends:
442 for (; i
< concat
->mtd
.numeraseregions
&&
443 (instr
->addr
+ instr
->len
) >= erase_regions
[i
].offset
;
447 * check if the ending offset is aligned to this region's erase size
449 if ((instr
->addr
+ instr
->len
) & (erase_regions
[i
].erasesize
-
454 instr
->fail_addr
= 0xffffffff;
456 /* make a local copy of instr to avoid modifying the caller's struct */
457 erase
= kmalloc(sizeof (struct erase_info
), GFP_KERNEL
);
466 * find the subdevice where the to-be-erased area begins, adjust
467 * starting offset to be relative to the subdevice start
469 for (i
= 0; i
< concat
->num_subdev
; i
++) {
470 subdev
= concat
->subdev
[i
];
471 if (subdev
->size
<= erase
->addr
) {
472 erase
->addr
-= subdev
->size
;
473 offset
+= subdev
->size
;
479 /* must never happen since size limit has been verified above */
480 BUG_ON(i
>= concat
->num_subdev
);
482 /* now do the erase: */
484 for (; length
> 0; i
++) {
485 /* loop for all subdevices affected by this request */
486 subdev
= concat
->subdev
[i
]; /* get current subdevice */
488 /* limit length to subdevice's size: */
489 if (erase
->addr
+ length
> subdev
->size
)
490 erase
->len
= subdev
->size
- erase
->addr
;
494 if (!(subdev
->flags
& MTD_WRITEABLE
)) {
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 BUG_ON(err
== -EINVAL
);
503 if (erase
->fail_addr
!= 0xffffffff)
504 instr
->fail_addr
= erase
->fail_addr
+ offset
;
508 * erase->addr specifies the offset of the area to be
509 * erased *within the current subdevice*. It can be
510 * non-zero only the first time through this loop, i.e.
511 * for the first subdevice where blocks need to be erased.
512 * All the following erases must begin at the start of the
513 * current subdevice, i.e. at offset zero.
516 offset
+= subdev
->size
;
518 instr
->state
= erase
->state
;
524 instr
->callback(instr
);
528 static int concat_lock(struct mtd_info
*mtd
, loff_t ofs
, size_t len
)
530 struct mtd_concat
*concat
= CONCAT(mtd
);
531 int i
, err
= -EINVAL
;
533 if ((len
+ ofs
) > mtd
->size
)
536 for (i
= 0; i
< concat
->num_subdev
; i
++) {
537 struct mtd_info
*subdev
= concat
->subdev
[i
];
540 if (ofs
>= subdev
->size
) {
545 if (ofs
+ len
> subdev
->size
)
546 size
= subdev
->size
- ofs
;
550 err
= subdev
->lock(subdev
, ofs
, size
);
566 static int concat_unlock(struct mtd_info
*mtd
, loff_t ofs
, size_t len
)
568 struct mtd_concat
*concat
= CONCAT(mtd
);
571 if ((len
+ ofs
) > mtd
->size
)
574 for (i
= 0; i
< concat
->num_subdev
; i
++) {
575 struct mtd_info
*subdev
= concat
->subdev
[i
];
578 if (ofs
>= subdev
->size
) {
583 if (ofs
+ len
> subdev
->size
)
584 size
= subdev
->size
- ofs
;
588 err
= subdev
->unlock(subdev
, ofs
, size
);
604 static void concat_sync(struct mtd_info
*mtd
)
606 struct mtd_concat
*concat
= CONCAT(mtd
);
609 for (i
= 0; i
< concat
->num_subdev
; i
++) {
610 struct mtd_info
*subdev
= concat
->subdev
[i
];
611 subdev
->sync(subdev
);
615 static int concat_suspend(struct mtd_info
*mtd
)
617 struct mtd_concat
*concat
= CONCAT(mtd
);
620 for (i
= 0; i
< concat
->num_subdev
; i
++) {
621 struct mtd_info
*subdev
= concat
->subdev
[i
];
622 if ((rc
= subdev
->suspend(subdev
)) < 0)
628 static void concat_resume(struct mtd_info
*mtd
)
630 struct mtd_concat
*concat
= CONCAT(mtd
);
633 for (i
= 0; i
< concat
->num_subdev
; i
++) {
634 struct mtd_info
*subdev
= concat
->subdev
[i
];
635 subdev
->resume(subdev
);
640 * This function constructs a virtual MTD device by concatenating
641 * num_devs MTD devices. A pointer to the new device object is
642 * stored to *new_dev upon success. This function does _not_
643 * register any devices: this is the caller's responsibility.
645 struct mtd_info
*mtd_concat_create(struct mtd_info
*subdev
[], /* subdevices to concatenate */
646 int num_devs
, /* number of subdevices */
648 { /* name for the new device */
651 struct mtd_concat
*concat
;
652 u_int32_t max_erasesize
, curr_erasesize
;
653 int num_erase_region
;
655 printk(KERN_NOTICE
"Concatenating MTD devices:\n");
656 for (i
= 0; i
< num_devs
; i
++)
657 printk(KERN_NOTICE
"(%d): \"%s\"\n", i
, subdev
[i
]->name
);
658 printk(KERN_NOTICE
"into device \"%s\"\n", name
);
660 /* allocate the device structure */
661 size
= SIZEOF_STRUCT_MTD_CONCAT(num_devs
);
662 concat
= kmalloc(size
, GFP_KERNEL
);
665 ("memory allocation error while creating concatenated device \"%s\"\n",
669 memset(concat
, 0, size
);
670 concat
->subdev
= (struct mtd_info
**) (concat
+ 1);
673 * Set up the new "super" device's MTD object structure, check for
674 * incompatibilites between the subdevices.
676 concat
->mtd
.type
= subdev
[0]->type
;
677 concat
->mtd
.flags
= subdev
[0]->flags
;
678 concat
->mtd
.size
= subdev
[0]->size
;
679 concat
->mtd
.erasesize
= subdev
[0]->erasesize
;
680 concat
->mtd
.oobblock
= subdev
[0]->oobblock
;
681 concat
->mtd
.oobsize
= subdev
[0]->oobsize
;
682 concat
->mtd
.ecctype
= subdev
[0]->ecctype
;
683 concat
->mtd
.eccsize
= subdev
[0]->eccsize
;
684 if (subdev
[0]->read_ecc
)
685 concat
->mtd
.read_ecc
= concat_read_ecc
;
686 if (subdev
[0]->write_ecc
)
687 concat
->mtd
.write_ecc
= concat_write_ecc
;
688 if (subdev
[0]->read_oob
)
689 concat
->mtd
.read_oob
= concat_read_oob
;
690 if (subdev
[0]->write_oob
)
691 concat
->mtd
.write_oob
= concat_write_oob
;
693 concat
->subdev
[0] = subdev
[0];
695 for (i
= 1; i
< num_devs
; i
++) {
696 if (concat
->mtd
.type
!= subdev
[i
]->type
) {
698 printk("Incompatible device type on \"%s\"\n",
702 if (concat
->mtd
.flags
!= subdev
[i
]->flags
) {
704 * Expect all flags except MTD_WRITEABLE to be
705 * equal on all subdevices.
707 if ((concat
->mtd
.flags
^ subdev
[i
]->
708 flags
) & ~MTD_WRITEABLE
) {
710 printk("Incompatible device flags on \"%s\"\n",
714 /* if writeable attribute differs,
715 make super device writeable */
717 subdev
[i
]->flags
& MTD_WRITEABLE
;
719 concat
->mtd
.size
+= subdev
[i
]->size
;
720 if (concat
->mtd
.oobblock
!= subdev
[i
]->oobblock
||
721 concat
->mtd
.oobsize
!= subdev
[i
]->oobsize
||
722 concat
->mtd
.ecctype
!= subdev
[i
]->ecctype
||
723 concat
->mtd
.eccsize
!= subdev
[i
]->eccsize
||
724 !concat
->mtd
.read_ecc
!= !subdev
[i
]->read_ecc
||
725 !concat
->mtd
.write_ecc
!= !subdev
[i
]->write_ecc
||
726 !concat
->mtd
.read_oob
!= !subdev
[i
]->read_oob
||
727 !concat
->mtd
.write_oob
!= !subdev
[i
]->write_oob
) {
729 printk("Incompatible OOB or ECC data on \"%s\"\n",
733 concat
->subdev
[i
] = subdev
[i
];
737 concat
->num_subdev
= num_devs
;
738 concat
->mtd
.name
= name
;
741 * NOTE: for now, we do not provide any readv()/writev() methods
742 * because they are messy to implement and they are not
743 * used to a great extent anyway.
745 concat
->mtd
.erase
= concat_erase
;
746 concat
->mtd
.read
= concat_read
;
747 concat
->mtd
.write
= concat_write
;
748 concat
->mtd
.sync
= concat_sync
;
749 concat
->mtd
.lock
= concat_lock
;
750 concat
->mtd
.unlock
= concat_unlock
;
751 concat
->mtd
.suspend
= concat_suspend
;
752 concat
->mtd
.resume
= concat_resume
;
755 * Combine the erase block size info of the subdevices:
757 * first, walk the map of the new device and see how
758 * many changes in erase size we have
760 max_erasesize
= curr_erasesize
= subdev
[0]->erasesize
;
761 num_erase_region
= 1;
762 for (i
= 0; i
< num_devs
; i
++) {
763 if (subdev
[i
]->numeraseregions
== 0) {
764 /* current subdevice has uniform erase size */
765 if (subdev
[i
]->erasesize
!= curr_erasesize
) {
766 /* if it differs from the last subdevice's erase size, count it */
768 curr_erasesize
= subdev
[i
]->erasesize
;
769 if (curr_erasesize
> max_erasesize
)
770 max_erasesize
= curr_erasesize
;
773 /* current subdevice has variable erase size */
775 for (j
= 0; j
< subdev
[i
]->numeraseregions
; j
++) {
777 /* walk the list of erase regions, count any changes */
778 if (subdev
[i
]->eraseregions
[j
].erasesize
!=
782 subdev
[i
]->eraseregions
[j
].
784 if (curr_erasesize
> max_erasesize
)
785 max_erasesize
= curr_erasesize
;
791 if (num_erase_region
== 1) {
793 * All subdevices have the same uniform erase size.
796 concat
->mtd
.erasesize
= curr_erasesize
;
797 concat
->mtd
.numeraseregions
= 0;
800 * erase block size varies across the subdevices: allocate
801 * space to store the data describing the variable erase regions
803 struct mtd_erase_region_info
*erase_region_p
;
804 u_int32_t begin
, position
;
806 concat
->mtd
.erasesize
= max_erasesize
;
807 concat
->mtd
.numeraseregions
= num_erase_region
;
808 concat
->mtd
.eraseregions
= erase_region_p
=
809 kmalloc(num_erase_region
*
810 sizeof (struct mtd_erase_region_info
), GFP_KERNEL
);
811 if (!erase_region_p
) {
814 ("memory allocation error while creating erase region list"
815 " for device \"%s\"\n", name
);
820 * walk the map of the new device once more and fill in
821 * in erase region info:
823 curr_erasesize
= subdev
[0]->erasesize
;
824 begin
= position
= 0;
825 for (i
= 0; i
< num_devs
; i
++) {
826 if (subdev
[i
]->numeraseregions
== 0) {
827 /* current subdevice has uniform erase size */
828 if (subdev
[i
]->erasesize
!= curr_erasesize
) {
830 * fill in an mtd_erase_region_info structure for the area
831 * we have walked so far:
833 erase_region_p
->offset
= begin
;
834 erase_region_p
->erasesize
=
836 erase_region_p
->numblocks
=
837 (position
- begin
) / curr_erasesize
;
840 curr_erasesize
= subdev
[i
]->erasesize
;
843 position
+= subdev
[i
]->size
;
845 /* current subdevice has variable erase size */
847 for (j
= 0; j
< subdev
[i
]->numeraseregions
; j
++) {
848 /* walk the list of erase regions, count any changes */
849 if (subdev
[i
]->eraseregions
[j
].
850 erasesize
!= curr_erasesize
) {
851 erase_region_p
->offset
= begin
;
852 erase_region_p
->erasesize
=
854 erase_region_p
->numblocks
=
856 begin
) / curr_erasesize
;
860 subdev
[i
]->eraseregions
[j
].
865 subdev
[i
]->eraseregions
[j
].
866 numblocks
* curr_erasesize
;
870 /* Now write the final entry */
871 erase_region_p
->offset
= begin
;
872 erase_region_p
->erasesize
= curr_erasesize
;
873 erase_region_p
->numblocks
= (position
- begin
) / curr_erasesize
;
880 * This function destroys an MTD object obtained from concat_mtd_devs()
883 void mtd_concat_destroy(struct mtd_info
*mtd
)
885 struct mtd_concat
*concat
= CONCAT(mtd
);
886 if (concat
->mtd
.numeraseregions
)
887 kfree(concat
->mtd
.eraseregions
);
891 EXPORT_SYMBOL(mtd_concat_create
);
892 EXPORT_SYMBOL(mtd_concat_destroy
);
894 MODULE_LICENSE("GPL");
895 MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
896 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");