linux/drivers/mtd/mtdconcat.c
Felix Radensky 431e1ecabd mtd: mtdconcat: fix NAND OOB write
Currently mtdconcat is broken for NAND. An attemtpt to create
JFFS2 filesystem on concatenation of several NAND devices fails
with OOB write errors. This patch fixes that problem.

Signed-off-by: Felix Radensky <felix@embedded-sol.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2011-05-25 01:54:50 +01:00

1018 lines
24 KiB
C

/*
* MTD device concatenation layer
*
* Copyright © 2002 Robert Kaiser <rkaiser@sysgo.de>
* Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org>
*
* NAND support by Christian Gan <cgan@iders.ca>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/backing-dev.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/concat.h>
#include <asm/div64.h>
/*
* Our storage structure:
* Subdev points to an array of pointers to struct mtd_info objects
* which is allocated along with this structure
*
*/
struct mtd_concat {
struct mtd_info mtd;
int num_subdev;
struct mtd_info **subdev;
};
/*
* how to calculate the size required for the above structure,
* including the pointer array subdev points to:
*/
#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \
((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
/*
* Given a pointer to the MTD object in the mtd_concat structure,
* we can retrieve the pointer to that structure with this macro.
*/
#define CONCAT(x) ((struct mtd_concat *)(x))
/*
* MTD methods which look up the relevant subdevice, translate the
* effective address and pass through to the subdevice.
*/
static int
concat_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t * retlen, u_char * buf)
{
struct mtd_concat *concat = CONCAT(mtd);
int ret = 0, err;
int i;
*retlen = 0;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
size_t size, retsize;
if (from >= subdev->size) {
/* Not destined for this subdev */
size = 0;
from -= subdev->size;
continue;
}
if (from + len > subdev->size)
/* First part goes into this subdev */
size = subdev->size - from;
else
/* Entire transaction goes into this subdev */
size = len;
err = subdev->read(subdev, from, size, &retsize, buf);
/* Save information about bitflips! */
if (unlikely(err)) {
if (err == -EBADMSG) {
mtd->ecc_stats.failed++;
ret = err;
} else if (err == -EUCLEAN) {
mtd->ecc_stats.corrected++;
/* Do not overwrite -EBADMSG !! */
if (!ret)
ret = err;
} else
return err;
}
*retlen += retsize;
len -= size;
if (len == 0)
return ret;
buf += size;
from = 0;
}
return -EINVAL;
}
static int
concat_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t * retlen, const u_char * buf)
{
struct mtd_concat *concat = CONCAT(mtd);
int err = -EINVAL;
int i;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
*retlen = 0;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
size_t size, retsize;
if (to >= subdev->size) {
size = 0;
to -= subdev->size;
continue;
}
if (to + len > subdev->size)
size = subdev->size - to;
else
size = len;
if (!(subdev->flags & MTD_WRITEABLE))
err = -EROFS;
else
err = subdev->write(subdev, to, size, &retsize, buf);
if (err)
break;
*retlen += retsize;
len -= size;
if (len == 0)
break;
err = -EINVAL;
buf += size;
to = 0;
}
return err;
}
static int
concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t * retlen)
{
struct mtd_concat *concat = CONCAT(mtd);
struct kvec *vecs_copy;
unsigned long entry_low, entry_high;
size_t total_len = 0;
int i;
int err = -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
*retlen = 0;
/* Calculate total length of data */
for (i = 0; i < count; i++)
total_len += vecs[i].iov_len;
/* Do not allow write past end of device */
if ((to + total_len) > mtd->size)
return -EINVAL;
/* Check alignment */
if (mtd->writesize > 1) {
uint64_t __to = to;
if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
return -EINVAL;
}
/* make a copy of vecs */
vecs_copy = kmemdup(vecs, sizeof(struct kvec) * count, GFP_KERNEL);
if (!vecs_copy)
return -ENOMEM;
entry_low = 0;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
size_t size, wsize, retsize, old_iov_len;
if (to >= subdev->size) {
to -= subdev->size;
continue;
}
size = min_t(uint64_t, total_len, subdev->size - to);
wsize = size; /* store for future use */
entry_high = entry_low;
while (entry_high < count) {
if (size <= vecs_copy[entry_high].iov_len)
break;
size -= vecs_copy[entry_high++].iov_len;
}
old_iov_len = vecs_copy[entry_high].iov_len;
vecs_copy[entry_high].iov_len = size;
if (!(subdev->flags & MTD_WRITEABLE))
err = -EROFS;
else
err = subdev->writev(subdev, &vecs_copy[entry_low],
entry_high - entry_low + 1, to, &retsize);
vecs_copy[entry_high].iov_len = old_iov_len - size;
vecs_copy[entry_high].iov_base += size;
entry_low = entry_high;
if (err)
break;
*retlen += retsize;
total_len -= wsize;
if (total_len == 0)
break;
err = -EINVAL;
to = 0;
}
kfree(vecs_copy);
return err;
}
static int
concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
{
struct mtd_concat *concat = CONCAT(mtd);
struct mtd_oob_ops devops = *ops;
int i, err, ret = 0;
ops->retlen = ops->oobretlen = 0;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
if (from >= subdev->size) {
from -= subdev->size;
continue;
}
/* partial read ? */
if (from + devops.len > subdev->size)
devops.len = subdev->size - from;
err = subdev->read_oob(subdev, from, &devops);
ops->retlen += devops.retlen;
ops->oobretlen += devops.oobretlen;
/* Save information about bitflips! */
if (unlikely(err)) {
if (err == -EBADMSG) {
mtd->ecc_stats.failed++;
ret = err;
} else if (err == -EUCLEAN) {
mtd->ecc_stats.corrected++;
/* Do not overwrite -EBADMSG !! */
if (!ret)
ret = err;
} else
return err;
}
if (devops.datbuf) {
devops.len = ops->len - ops->retlen;
if (!devops.len)
return ret;
devops.datbuf += devops.retlen;
}
if (devops.oobbuf) {
devops.ooblen = ops->ooblen - ops->oobretlen;
if (!devops.ooblen)
return ret;
devops.oobbuf += ops->oobretlen;
}
from = 0;
}
return -EINVAL;
}
static int
concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
{
struct mtd_concat *concat = CONCAT(mtd);
struct mtd_oob_ops devops = *ops;
int i, err;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
ops->retlen = ops->oobretlen = 0;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
if (to >= subdev->size) {
to -= subdev->size;
continue;
}
/* partial write ? */
if (to + devops.len > subdev->size)
devops.len = subdev->size - to;
err = subdev->write_oob(subdev, to, &devops);
ops->retlen += devops.oobretlen;
if (err)
return err;
if (devops.datbuf) {
devops.len = ops->len - ops->retlen;
if (!devops.len)
return 0;
devops.datbuf += devops.retlen;
}
if (devops.oobbuf) {
devops.ooblen = ops->ooblen - ops->oobretlen;
if (!devops.ooblen)
return 0;
devops.oobbuf += devops.oobretlen;
}
to = 0;
}
return -EINVAL;
}
static void concat_erase_callback(struct erase_info *instr)
{
wake_up((wait_queue_head_t *) instr->priv);
}
static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
{
int err;
wait_queue_head_t waitq;
DECLARE_WAITQUEUE(wait, current);
/*
* This code was stol^H^H^H^Hinspired by mtdchar.c
*/
init_waitqueue_head(&waitq);
erase->mtd = mtd;
erase->callback = concat_erase_callback;
erase->priv = (unsigned long) &waitq;
/*
* FIXME: Allow INTERRUPTIBLE. Which means
* not having the wait_queue head on the stack.
*/
err = mtd->erase(mtd, erase);
if (!err) {
set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(&waitq, &wait);
if (erase->state != MTD_ERASE_DONE
&& erase->state != MTD_ERASE_FAILED)
schedule();
remove_wait_queue(&waitq, &wait);
set_current_state(TASK_RUNNING);
err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
}
return err;
}
static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
{
struct mtd_concat *concat = CONCAT(mtd);
struct mtd_info *subdev;
int i, err;
uint64_t length, offset = 0;
struct erase_info *erase;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (instr->addr > concat->mtd.size)
return -EINVAL;
if (instr->len + instr->addr > concat->mtd.size)
return -EINVAL;
/*
* Check for proper erase block alignment of the to-be-erased area.
* It is easier to do this based on the super device's erase
* region info rather than looking at each particular sub-device
* in turn.
*/
if (!concat->mtd.numeraseregions) {
/* the easy case: device has uniform erase block size */
if (instr->addr & (concat->mtd.erasesize - 1))
return -EINVAL;
if (instr->len & (concat->mtd.erasesize - 1))
return -EINVAL;
} else {
/* device has variable erase size */
struct mtd_erase_region_info *erase_regions =
concat->mtd.eraseregions;
/*
* Find the erase region where the to-be-erased area begins:
*/
for (i = 0; i < concat->mtd.numeraseregions &&
instr->addr >= erase_regions[i].offset; i++) ;
--i;
/*
* Now erase_regions[i] is the region in which the
* to-be-erased area begins. Verify that the starting
* offset is aligned to this region's erase size:
*/
if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))
return -EINVAL;
/*
* now find the erase region where the to-be-erased area ends:
*/
for (; i < concat->mtd.numeraseregions &&
(instr->addr + instr->len) >= erase_regions[i].offset;
++i) ;
--i;
/*
* check if the ending offset is aligned to this region's erase size
*/
if (i < 0 || ((instr->addr + instr->len) &
(erase_regions[i].erasesize - 1)))
return -EINVAL;
}
instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
/* make a local copy of instr to avoid modifying the caller's struct */
erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
if (!erase)
return -ENOMEM;
*erase = *instr;
length = instr->len;
/*
* find the subdevice where the to-be-erased area begins, adjust
* starting offset to be relative to the subdevice start
*/
for (i = 0; i < concat->num_subdev; i++) {
subdev = concat->subdev[i];
if (subdev->size <= erase->addr) {
erase->addr -= subdev->size;
offset += subdev->size;
} else {
break;
}
}
/* must never happen since size limit has been verified above */
BUG_ON(i >= concat->num_subdev);
/* now do the erase: */
err = 0;
for (; length > 0; i++) {
/* loop for all subdevices affected by this request */
subdev = concat->subdev[i]; /* get current subdevice */
/* limit length to subdevice's size: */
if (erase->addr + length > subdev->size)
erase->len = subdev->size - erase->addr;
else
erase->len = length;
if (!(subdev->flags & MTD_WRITEABLE)) {
err = -EROFS;
break;
}
length -= erase->len;
if ((err = concat_dev_erase(subdev, erase))) {
/* sanity check: should never happen since
* block alignment has been checked above */
BUG_ON(err == -EINVAL);
if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
instr->fail_addr = erase->fail_addr + offset;
break;
}
/*
* erase->addr specifies the offset of the area to be
* erased *within the current subdevice*. It can be
* non-zero only the first time through this loop, i.e.
* for the first subdevice where blocks need to be erased.
* All the following erases must begin at the start of the
* current subdevice, i.e. at offset zero.
*/
erase->addr = 0;
offset += subdev->size;
}
instr->state = erase->state;
kfree(erase);
if (err)
return err;
if (instr->callback)
instr->callback(instr);
return 0;
}
static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_concat *concat = CONCAT(mtd);
int i, err = -EINVAL;
if ((len + ofs) > mtd->size)
return -EINVAL;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
uint64_t size;
if (ofs >= subdev->size) {
size = 0;
ofs -= subdev->size;
continue;
}
if (ofs + len > subdev->size)
size = subdev->size - ofs;
else
size = len;
if (subdev->lock) {
err = subdev->lock(subdev, ofs, size);
if (err)
break;
} else
err = -EOPNOTSUPP;
len -= size;
if (len == 0)
break;
err = -EINVAL;
ofs = 0;
}
return err;
}
static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_concat *concat = CONCAT(mtd);
int i, err = 0;
if ((len + ofs) > mtd->size)
return -EINVAL;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
uint64_t size;
if (ofs >= subdev->size) {
size = 0;
ofs -= subdev->size;
continue;
}
if (ofs + len > subdev->size)
size = subdev->size - ofs;
else
size = len;
if (subdev->unlock) {
err = subdev->unlock(subdev, ofs, size);
if (err)
break;
} else
err = -EOPNOTSUPP;
len -= size;
if (len == 0)
break;
err = -EINVAL;
ofs = 0;
}
return err;
}
static void concat_sync(struct mtd_info *mtd)
{
struct mtd_concat *concat = CONCAT(mtd);
int i;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
subdev->sync(subdev);
}
}
static int concat_suspend(struct mtd_info *mtd)
{
struct mtd_concat *concat = CONCAT(mtd);
int i, rc = 0;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
if ((rc = subdev->suspend(subdev)) < 0)
return rc;
}
return rc;
}
static void concat_resume(struct mtd_info *mtd)
{
struct mtd_concat *concat = CONCAT(mtd);
int i;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
subdev->resume(subdev);
}
}
static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_concat *concat = CONCAT(mtd);
int i, res = 0;
if (!concat->subdev[0]->block_isbad)
return res;
if (ofs > mtd->size)
return -EINVAL;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
if (ofs >= subdev->size) {
ofs -= subdev->size;
continue;
}
res = subdev->block_isbad(subdev, ofs);
break;
}
return res;
}
static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_concat *concat = CONCAT(mtd);
int i, err = -EINVAL;
if (!concat->subdev[0]->block_markbad)
return 0;
if (ofs > mtd->size)
return -EINVAL;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
if (ofs >= subdev->size) {
ofs -= subdev->size;
continue;
}
err = subdev->block_markbad(subdev, ofs);
if (!err)
mtd->ecc_stats.badblocks++;
break;
}
return err;
}
/*
* try to support NOMMU mmaps on concatenated devices
* - we don't support subdev spanning as we can't guarantee it'll work
*/
static unsigned long concat_get_unmapped_area(struct mtd_info *mtd,
unsigned long len,
unsigned long offset,
unsigned long flags)
{
struct mtd_concat *concat = CONCAT(mtd);
int i;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
if (offset >= subdev->size) {
offset -= subdev->size;
continue;
}
/* we've found the subdev over which the mapping will reside */
if (offset + len > subdev->size)
return (unsigned long) -EINVAL;
if (subdev->get_unmapped_area)
return subdev->get_unmapped_area(subdev, len, offset,
flags);
break;
}
return (unsigned long) -ENOSYS;
}
/*
* This function constructs a virtual MTD device by concatenating
* num_devs MTD devices. A pointer to the new device object is
* stored to *new_dev upon success. This function does _not_
* register any devices: this is the caller's responsibility.
*/
struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */
int num_devs, /* number of subdevices */
const char *name)
{ /* name for the new device */
int i;
size_t size;
struct mtd_concat *concat;
uint32_t max_erasesize, curr_erasesize;
int num_erase_region;
int max_writebufsize = 0;
printk(KERN_NOTICE "Concatenating MTD devices:\n");
for (i = 0; i < num_devs; i++)
printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
printk(KERN_NOTICE "into device \"%s\"\n", name);
/* allocate the device structure */
size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
concat = kzalloc(size, GFP_KERNEL);
if (!concat) {
printk
("memory allocation error while creating concatenated device \"%s\"\n",
name);
return NULL;
}
concat->subdev = (struct mtd_info **) (concat + 1);
/*
* Set up the new "super" device's MTD object structure, check for
* incompatibilites between the subdevices.
*/
concat->mtd.type = subdev[0]->type;
concat->mtd.flags = subdev[0]->flags;
concat->mtd.size = subdev[0]->size;
concat->mtd.erasesize = subdev[0]->erasesize;
concat->mtd.writesize = subdev[0]->writesize;
for (i = 0; i < num_devs; i++)
if (max_writebufsize < subdev[i]->writebufsize)
max_writebufsize = subdev[i]->writebufsize;
concat->mtd.writebufsize = max_writebufsize;
concat->mtd.subpage_sft = subdev[0]->subpage_sft;
concat->mtd.oobsize = subdev[0]->oobsize;
concat->mtd.oobavail = subdev[0]->oobavail;
if (subdev[0]->writev)
concat->mtd.writev = concat_writev;
if (subdev[0]->read_oob)
concat->mtd.read_oob = concat_read_oob;
if (subdev[0]->write_oob)
concat->mtd.write_oob = concat_write_oob;
if (subdev[0]->block_isbad)
concat->mtd.block_isbad = concat_block_isbad;
if (subdev[0]->block_markbad)
concat->mtd.block_markbad = concat_block_markbad;
concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
concat->mtd.backing_dev_info = subdev[0]->backing_dev_info;
concat->subdev[0] = subdev[0];
for (i = 1; i < num_devs; i++) {
if (concat->mtd.type != subdev[i]->type) {
kfree(concat);
printk("Incompatible device type on \"%s\"\n",
subdev[i]->name);
return NULL;
}
if (concat->mtd.flags != subdev[i]->flags) {
/*
* Expect all flags except MTD_WRITEABLE to be
* equal on all subdevices.
*/
if ((concat->mtd.flags ^ subdev[i]->
flags) & ~MTD_WRITEABLE) {
kfree(concat);
printk("Incompatible device flags on \"%s\"\n",
subdev[i]->name);
return NULL;
} else
/* if writeable attribute differs,
make super device writeable */
concat->mtd.flags |=
subdev[i]->flags & MTD_WRITEABLE;
}
/* only permit direct mapping if the BDIs are all the same
* - copy-mapping is still permitted
*/
if (concat->mtd.backing_dev_info !=
subdev[i]->backing_dev_info)
concat->mtd.backing_dev_info =
&default_backing_dev_info;
concat->mtd.size += subdev[i]->size;
concat->mtd.ecc_stats.badblocks +=
subdev[i]->ecc_stats.badblocks;
if (concat->mtd.writesize != subdev[i]->writesize ||
concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
concat->mtd.oobsize != subdev[i]->oobsize ||
!concat->mtd.read_oob != !subdev[i]->read_oob ||
!concat->mtd.write_oob != !subdev[i]->write_oob) {
kfree(concat);
printk("Incompatible OOB or ECC data on \"%s\"\n",
subdev[i]->name);
return NULL;
}
concat->subdev[i] = subdev[i];
}
concat->mtd.ecclayout = subdev[0]->ecclayout;
concat->num_subdev = num_devs;
concat->mtd.name = name;
concat->mtd.erase = concat_erase;
concat->mtd.read = concat_read;
concat->mtd.write = concat_write;
concat->mtd.sync = concat_sync;
concat->mtd.lock = concat_lock;
concat->mtd.unlock = concat_unlock;
concat->mtd.suspend = concat_suspend;
concat->mtd.resume = concat_resume;
concat->mtd.get_unmapped_area = concat_get_unmapped_area;
/*
* Combine the erase block size info of the subdevices:
*
* first, walk the map of the new device and see how
* many changes in erase size we have
*/
max_erasesize = curr_erasesize = subdev[0]->erasesize;
num_erase_region = 1;
for (i = 0; i < num_devs; i++) {
if (subdev[i]->numeraseregions == 0) {
/* current subdevice has uniform erase size */
if (subdev[i]->erasesize != curr_erasesize) {
/* if it differs from the last subdevice's erase size, count it */
++num_erase_region;
curr_erasesize = subdev[i]->erasesize;
if (curr_erasesize > max_erasesize)
max_erasesize = curr_erasesize;
}
} else {
/* current subdevice has variable erase size */
int j;
for (j = 0; j < subdev[i]->numeraseregions; j++) {
/* walk the list of erase regions, count any changes */
if (subdev[i]->eraseregions[j].erasesize !=
curr_erasesize) {
++num_erase_region;
curr_erasesize =
subdev[i]->eraseregions[j].
erasesize;
if (curr_erasesize > max_erasesize)
max_erasesize = curr_erasesize;
}
}
}
}
if (num_erase_region == 1) {
/*
* All subdevices have the same uniform erase size.
* This is easy:
*/
concat->mtd.erasesize = curr_erasesize;
concat->mtd.numeraseregions = 0;
} else {
uint64_t tmp64;
/*
* erase block size varies across the subdevices: allocate
* space to store the data describing the variable erase regions
*/
struct mtd_erase_region_info *erase_region_p;
uint64_t begin, position;
concat->mtd.erasesize = max_erasesize;
concat->mtd.numeraseregions = num_erase_region;
concat->mtd.eraseregions = erase_region_p =
kmalloc(num_erase_region *
sizeof (struct mtd_erase_region_info), GFP_KERNEL);
if (!erase_region_p) {
kfree(concat);
printk
("memory allocation error while creating erase region list"
" for device \"%s\"\n", name);
return NULL;
}
/*
* walk the map of the new device once more and fill in
* in erase region info:
*/
curr_erasesize = subdev[0]->erasesize;
begin = position = 0;
for (i = 0; i < num_devs; i++) {
if (subdev[i]->numeraseregions == 0) {
/* current subdevice has uniform erase size */
if (subdev[i]->erasesize != curr_erasesize) {
/*
* fill in an mtd_erase_region_info structure for the area
* we have walked so far:
*/
erase_region_p->offset = begin;
erase_region_p->erasesize =
curr_erasesize;
tmp64 = position - begin;
do_div(tmp64, curr_erasesize);
erase_region_p->numblocks = tmp64;
begin = position;
curr_erasesize = subdev[i]->erasesize;
++erase_region_p;
}
position += subdev[i]->size;
} else {
/* current subdevice has variable erase size */
int j;
for (j = 0; j < subdev[i]->numeraseregions; j++) {
/* walk the list of erase regions, count any changes */
if (subdev[i]->eraseregions[j].
erasesize != curr_erasesize) {
erase_region_p->offset = begin;
erase_region_p->erasesize =
curr_erasesize;
tmp64 = position - begin;
do_div(tmp64, curr_erasesize);
erase_region_p->numblocks = tmp64;
begin = position;
curr_erasesize =
subdev[i]->eraseregions[j].
erasesize;
++erase_region_p;
}
position +=
subdev[i]->eraseregions[j].
numblocks * (uint64_t)curr_erasesize;
}
}
}
/* Now write the final entry */
erase_region_p->offset = begin;
erase_region_p->erasesize = curr_erasesize;
tmp64 = position - begin;
do_div(tmp64, curr_erasesize);
erase_region_p->numblocks = tmp64;
}
return &concat->mtd;
}
/*
* This function destroys an MTD object obtained from concat_mtd_devs()
*/
void mtd_concat_destroy(struct mtd_info *mtd)
{
struct mtd_concat *concat = CONCAT(mtd);
if (concat->mtd.numeraseregions)
kfree(concat->mtd.eraseregions);
kfree(concat);
}
EXPORT_SYMBOL(mtd_concat_create);
EXPORT_SYMBOL(mtd_concat_destroy);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");