diff mbox

[12/12] mtd: nand-bbt: move nand_bbt.c to mtd folder

Message ID 87F60714EC601C4C83DFF1D2E3D390A0326CC91F@NTXXIAMBX02.xacn.micron.com
State Superseded
Headers show

Commit Message

Peter Pan 潘栋 (peterpandong) Sept. 25, 2015, 6:48 a.m. UTC
Since struct nand_chip is removed from nand_bbt.c, BBT is now
shareable. Both NAND and SPI NAND can use it. So move nand_bbt.c
from nand/ foler to mtd/ folder and create MTD_NAND_BBT config.
Both NAND and SPI NAND should depend on MTD_NAND_BBT.

Signed-off-by: Peter Pan <peterpandong@micron.com>
---
 drivers/mtd/Kconfig         |    7 +
 drivers/mtd/Makefile        |    1 +
 drivers/mtd/nand/Kconfig    |    2 +-
 drivers/mtd/nand/Makefile   |    2 +-
 drivers/mtd/nand/nand_bbt.c | 1289 -------------------------------------------
 drivers/mtd/nand_bbt.c      | 1289 +++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 1299 insertions(+), 1291 deletions(-)
 delete mode 100644 drivers/mtd/nand/nand_bbt.c
 create mode 100644 drivers/mtd/nand_bbt.c

Comments

Brian Norris Sept. 25, 2015, 5:37 p.m. UTC | #1
Hi Peter,

First of all, thanks for taking the time to try to address my
long-delayed comments. I hope to give this a proper look soon. (I also
hope you can fix the email threading soon! I know that's a pain...)

But first, a simpler comment:

On Fri, Sep 25, 2015 at 06:48:05AM +0000, Peter Pan 潘栋 (peterpandong) wrote:
> Since struct nand_chip is removed from nand_bbt.c, BBT is now
> shareable. Both NAND and SPI NAND can use it. So move nand_bbt.c
> from nand/ foler to mtd/ folder and create MTD_NAND_BBT config.
> Both NAND and SPI NAND should depend on MTD_NAND_BBT.
> 
> Signed-off-by: Peter Pan <peterpandong@micron.com>
> ---
>  drivers/mtd/Kconfig         |    7 +
>  drivers/mtd/Makefile        |    1 +
>  drivers/mtd/nand/Kconfig    |    2 +-
>  drivers/mtd/nand/Makefile   |    2 +-
>  drivers/mtd/nand/nand_bbt.c | 1289 -------------------------------------------
>  drivers/mtd/nand_bbt.c      | 1289 +++++++++++++++++++++++++++++++++++++++++++
>  6 files changed, 1299 insertions(+), 1291 deletions(-)
>  delete mode 100644 drivers/mtd/nand/nand_bbt.c
>  create mode 100644 drivers/mtd/nand_bbt.c
> 
[...]
> diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
> deleted file mode 100644
> index 47c1084..0000000
> --- a/drivers/mtd/nand/nand_bbt.c
> +++ /dev/null
> @@ -1,1289 +0,0 @@

[snip deleting entire file]

> diff --git a/drivers/mtd/nand_bbt.c b/drivers/mtd/nand_bbt.c
> new file mode 100644
> index 0000000..47c1084
> --- /dev/null
> +++ b/drivers/mtd/nand_bbt.c
> @@ -0,0 +1,1289 @@

[snip adding the whole file again -- exactly the same I hope?]

When moving files, it helps if you can use the '-M' (or
'--find-renames') option to git-format-patch. That will give much
smaller output that's easier to review. And if you had to change
anything in the move, it should also help highlight exactly what
changed, instead of including the entire file "diff".

Regards,
Brian

P.S. Incidentally, this should also work around your issues with the
copyright symbol. But then, I suspect that some people have used these
sorts of non-ASCII characters just to fish out issues with mail
clients/MTAs like yours :)
Peter Pan 潘栋 (peterpandong) Sept. 28, 2015, 8:37 a.m. UTC | #2
Hi Brian,

Thanks for your reply.

On Fri, Sep 25, 2015 at 06:48:05AM +0000, Brian Norris < computersforpeace@gmail.com >
wrote:
> Hi Peter,

> 

> First of all, thanks for taking the time to try to address my

> long-delayed comments. I hope to give this a proper look soon. (I also

> hope you can fix the email threading soon! I know that's a pain...)


Sorry for bringing inconvenience . I'm working on this now. I'm trying to enable
git-send-email on my server. Once it done, I will resend this series. But please look
at this series first if you have time.

> 

> But first, a simpler comment:

> 

> On Fri, Sep 25, 2015 at 06:48:05AM +0000, Peter Pan 潘栋 (peterpandong)

> wrote:

> > Since struct nand_chip is removed from nand_bbt.c, BBT is now

> > shareable. Both NAND and SPI NAND can use it. So move nand_bbt.c

> > from nand/ foler to mtd/ folder and create MTD_NAND_BBT config.

> > Both NAND and SPI NAND should depend on MTD_NAND_BBT.

> >

> > Signed-off-by: Peter Pan <peterpandong@micron.com>

> > ---

> >  drivers/mtd/Kconfig         |    7 +

> >  drivers/mtd/Makefile        |    1 +

> >  drivers/mtd/nand/Kconfig    |    2 +-

> >  drivers/mtd/nand/Makefile   |    2 +-

> >  drivers/mtd/nand/nand_bbt.c | 1289 -------------------------------------------

> >  drivers/mtd/nand_bbt.c      | 1289

> +++++++++++++++++++++++++++++++++++++++++++

> >  6 files changed, 1299 insertions(+), 1291 deletions(-)

> >  delete mode 100644 drivers/mtd/nand/nand_bbt.c

> >  create mode 100644 drivers/mtd/nand_bbt.c

> >

> [...]

> > diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c

> > deleted file mode 100644

> > index 47c1084..0000000

> > --- a/drivers/mtd/nand/nand_bbt.c

> > +++ /dev/null

> > @@ -1,1289 +0,0 @@

> 

> [snip deleting entire file]

> 

> > diff --git a/drivers/mtd/nand_bbt.c b/drivers/mtd/nand_bbt.c

> > new file mode 100644

> > index 0000000..47c1084

> > --- /dev/null

> > +++ b/drivers/mtd/nand_bbt.c

> > @@ -0,0 +1,1289 @@

> 

> [snip adding the whole file again -- exactly the same I hope?]


Yes. The whole file is exactly the same.

> 

> When moving files, it helps if you can use the '-M' (or

> '--find-renames') option to git-format-patch. That will give much

> smaller output that's easier to review. And if you had to change

> anything in the move, it should also help highlight exactly what

> changed, instead of including the entire file "diff".


Thanks a lot for your suggestion. I'm quite new with patch submit.
So please feel free to point out my missing/mistake. Thanks in advance.

> 

> Regards,

> Brian

> 

> P.S. Incidentally, this should also work around your issues with the

> copyright symbol. But then, I suspect that some people have used these

> sorts of non-ASCII characters just to fish out issues with mail

> clients/MTAs like yours :)
diff mbox

Patch

diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index a03ad29..eb6a33c 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -322,6 +322,13 @@  config MTD_PARTITIONED_MASTER
 	  the parent of the partition device be the master device, rather than
 	  what lies behind the master.
 
+config MTD_NAND_BBT
+	tristate "Bad Block Table support for NAND based devices"
+	depends on MTD
+	help
+	  Since struct nand_chip is removed from nand_bbt.c, BBT is now
+	  shareable. Both NAND and SPI NAND can use it.
+
 source "drivers/mtd/chips/Kconfig"
 
 source "drivers/mtd/maps/Kconfig"
diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 99bb9a1..55aed6f 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -26,6 +26,7 @@  obj-$(CONFIG_SSFDC)		+= ssfdc.o
 obj-$(CONFIG_SM_FTL)		+= sm_ftl.o
 obj-$(CONFIG_MTD_OOPS)		+= mtdoops.o
 obj-$(CONFIG_MTD_SWAP)		+= mtdswap.o
+obj-$(CONFIG_MTD_NAND_BBT)	+= nand_bbt.o
 
 nftl-objs		:= nftlcore.o nftlmount.o
 inftl-objs		:= inftlcore.o inftlmount.o
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 3324281..6ca3a6f 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -12,7 +12,7 @@  config MTD_NAND_ECC_SMC
 
 menuconfig MTD_NAND
 	tristate "NAND Device Support"
-	depends on MTD
+	depends on MTD && MTD_NAND_BBT
 	select MTD_NAND_IDS
 	select MTD_NAND_ECC
 	help
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 075a027..c6887d0 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -55,4 +55,4 @@  obj-$(CONFIG_MTD_NAND_SUNXI)		+= sunxi_nand.o
 obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
 obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
 
-nand-objs := nand_base.o nand_bbt.o nand_timings.o
+nand-objs := nand_base.o nand_timings.o
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
deleted file mode 100644
index 47c1084..0000000
--- a/drivers/mtd/nand/nand_bbt.c
+++ /dev/null
@@ -1,1289 +0,0 @@ 
-/*
- *  Overview:
- *   Bad block table support for the NAND driver
- *
- *  Copyright ? 2004 Thomas Gleixner (tglx@linutronix.de)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * Description:
- *
- * When nand_scan_bbt is called, then it tries to find the bad block table
- * depending on the options in the BBT descriptor(s). If no flash based BBT
- * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
- * marked good / bad blocks. This information is used to create a memory BBT.
- * Once a new bad block is discovered then the "factory" information is updated
- * on the device.
- * If a flash based BBT is specified then the function first tries to find the
- * BBT on flash. If a BBT is found then the contents are read and the memory
- * based BBT is created. If a mirrored BBT is selected then the mirror is
- * searched too and the versions are compared. If the mirror has a greater
- * version number, then the mirror BBT is used to build the memory based BBT.
- * If the tables are not versioned, then we "or" the bad block information.
- * If one of the BBTs is out of date or does not exist it is (re)created.
- * If no BBT exists at all then the device is scanned for factory marked
- * good / bad blocks and the bad block tables are created.
- *
- * For manufacturer created BBTs like the one found on M-SYS DOC devices
- * the BBT is searched and read but never created
- *
- * The auto generated bad block table is located in the last good blocks
- * of the device. The table is mirrored, so it can be updated eventually.
- * The table is marked in the OOB area with an ident pattern and a version
- * number which indicates which of both tables is more up to date. If the NAND
- * controller needs the complete OOB area for the ECC information then the
- * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
- * course): it moves the ident pattern and the version byte into the data area
- * and the OOB area will remain untouched.
- *
- * The table uses 2 bits per block
- * 11b:		block is good
- * 00b:		block is factory marked bad
- * 01b, 10b:	block is marked bad due to wear
- *
- * The memory bad block table uses the following scheme:
- * 00b:		block is good
- * 01b:		block is marked bad due to wear
- * 10b:		block is reserved (to protect the bbt area)
- * 11b:		block is factory marked bad
- *
- * Multichip devices like DOC store the bad block info per floor.
- *
- * Following assumptions are made:
- * - bbts start at a page boundary, if autolocated on a block boundary
- * - the space necessary for a bbt in FLASH does not exceed a block boundary
- *
- */
-
-#include <linux/slab.h>
-#include <linux/types.h>
-#include <linux/mtd/mtd.h>
-#include <linux/mtd/nand_bbt.h>
-#include <linux/bitops.h>
-#include <linux/delay.h>
-#include <linux/vmalloc.h>
-#include <linux/export.h>
-#include <linux/string.h>
-
-#define BBT_BLOCK_GOOD		0x00
-#define BBT_BLOCK_WORN		0x01
-#define BBT_BLOCK_RESERVED	0x02
-#define BBT_BLOCK_FACTORY_BAD	0x03
-
-#define BBT_ENTRY_MASK		0x03
-#define BBT_ENTRY_SHIFT		2
-
-static int nand_update_bbt(struct nand_bbt *bbt, loff_t offs);
-
-static inline uint8_t bbt_get_entry(struct nand_bbt *bbt, int block)
-{
-	uint8_t entry = bbt->bbt[block >> BBT_ENTRY_SHIFT];
-	entry >>= (block & BBT_ENTRY_MASK) * 2;
-	return entry & BBT_ENTRY_MASK;
-}
-
-static inline void bbt_mark_entry(struct nand_bbt *bbt, int block,
-		uint8_t mark)
-{
-	uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);
-	bbt->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
-}
-
-static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
-{
-	if (memcmp(buf, td->pattern, td->len))
-		return -1;
-	return 0;
-}
-
-/**
- * check_pattern - [GENERIC] check if a pattern is in the buffer
- * @buf: the buffer to search
- * @len: the length of buffer to search
- * @paglen: the pagelength
- * @td: search pattern descriptor
- *
- * Check for a pattern at the given place. Used to search bad block tables and
- * good / bad block identifiers.
- */
-static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
-{
-	if (td->options & NAND_BBT_NO_OOB)
-		return check_pattern_no_oob(buf, td);
-
-	/* Compare the pattern */
-	if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
-		return -1;
-
-	return 0;
-}
-
-/**
- * add_marker_len - compute the length of the marker in data area
- * @td: BBT descriptor used for computation
- *
- * The length will be 0 if the marker is located in OOB area.
- */
-static u32 add_marker_len(struct nand_bbt_descr *td)
-{
-	u32 len;
-
-	if (!(td->options & NAND_BBT_NO_OOB))
-		return 0;
-
-	len = td->len;
-	if (td->options & NAND_BBT_VERSION)
-		len++;
-	return len;
-}
-
-/**
- * read_bbt - [GENERIC] Read the bad block table starting from page
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- * @page: the starting page
- * @num: the number of bbt descriptors to read
- * @td: the bbt describtion table
- * @offs: block number offset in the table
- *
- * Read the bad block table starting from page.
- */
-static int read_bbt(struct nand_bbt *bbt, uint8_t *buf, int page, int num,
-		struct nand_bbt_descr *td, int offs)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int res, ret = 0, i, j, act = 0;
-	size_t retlen, len, totlen;
-	loff_t from;
-	int bits = td->options & NAND_BBT_NRBITS_MSK;
-	uint8_t msk = (uint8_t)((1 << bits) - 1);
-	u32 marker_len;
-	int reserved_block_code = td->reserved_block_code;
-
-	totlen = (num * bits) >> 3;
-	marker_len = add_marker_len(td);
-	from = ((loff_t)page) << bbt->page_shift;
-
-	while (totlen) {
-		len = min(totlen, (size_t)(1 << bbt->bbt_erase_shift));
-		if (marker_len) {
-			/*
-			 * In case the BBT marker is not in the OOB area it
-			 * will be just in the first page.
-			 */
-			len -= marker_len;
-			from += marker_len;
-			marker_len = 0;
-		}
-		res = mtd_read(mtd, from, len, &retlen, buf);
-		if (res < 0) {
-			if (mtd_is_eccerr(res)) {
-				pr_info("nand_bbt: ECC error in BBT at 0x%012llx\n",
-					from & ~mtd->writesize);
-				return res;
-			} else if (mtd_is_bitflip(res)) {
-				pr_info("nand_bbt: corrected error in BBT at 0x%012llx\n",
-					from & ~mtd->writesize);
-				ret = res;
-			} else {
-				pr_info("nand_bbt: error reading BBT\n");
-				return res;
-			}
-		}
-
-		/* Analyse data */
-		for (i = 0; i < len; i++) {
-			uint8_t dat = buf[i];
-			for (j = 0; j < 8; j += bits, act++) {
-				uint8_t tmp = (dat >> j) & msk;
-				if (tmp == msk)
-					continue;
-				if (reserved_block_code && (tmp == reserved_block_code)) {
-					pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
-						 (loff_t)(offs + act) <<
-						 bbt->bbt_erase_shift);
-					bbt_mark_entry(bbt, offs + act,
-							BBT_BLOCK_RESERVED);
-					mtd->ecc_stats.bbtblocks++;
-					continue;
-				}
-				/*
-				 * Leave it for now, if it's matured we can
-				 * move this message to pr_debug.
-				 */
-				pr_info("nand_read_bbt: bad block at 0x%012llx\n",
-					 (loff_t)(offs + act) <<
-					 bbt->bbt_erase_shift);
-				/* Factory marked bad or worn out? */
-				if (tmp == 0)
-					bbt_mark_entry(bbt, offs + act,
-							BBT_BLOCK_FACTORY_BAD);
-				else
-					bbt_mark_entry(bbt, offs + act,
-							BBT_BLOCK_WORN);
-				mtd->ecc_stats.badblocks++;
-			}
-		}
-		totlen -= len;
-		from += len;
-	}
-	return ret;
-}
-
-/**
- * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- * @td: descriptor for the bad block table
- * @chip: read the table for a specific chip, -1 read all chips; applies only if
- *        NAND_BBT_PERCHIP option is set
- *
- * Read the bad block table for all chips starting at a given page. We assume
- * that the bbt bits are in consecutive order.
- */
-static int read_abs_bbt(struct nand_bbt *bbt, uint8_t *buf, struct nand_bbt_descr *td, int chip)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int res = 0, i;
-
-	if (td->options & NAND_BBT_PERCHIP) {
-		int offs = 0;
-		for (i = 0; i < bbt->numchips; i++) {
-			if (chip == -1 || chip == i)
-				res = read_bbt(bbt, buf, td->pages[i],
-					bbt->chipsize >> bbt->bbt_erase_shift,
-					td, offs);
-			if (res)
-				return res;
-			offs += bbt->chipsize >> bbt->bbt_erase_shift;
-		}
-	} else {
-		res = read_bbt(bbt, buf, td->pages[0],
-				mtd->size >> bbt->bbt_erase_shift, td, 0);
-		if (res)
-			return res;
-	}
-	return 0;
-}
-
-/* BBT marker is in the first page, no OOB */
-static int scan_read_data(struct nand_bbt *bbt, uint8_t *buf, loff_t offs,
-			 struct nand_bbt_descr *td)
-{
-	size_t retlen;
-	size_t len;
-
-	len = td->len;
-	if (td->options & NAND_BBT_VERSION)
-		len++;
-
-	return mtd_read(bbt->mtd, offs, len, &retlen, buf);
-}
-
-/**
- * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- * @offs: offset at which to scan
- * @len: length of data region to read
- *
- * Scan read data from data+OOB. May traverse multiple pages, interleaving
- * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
- * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
- */
-static int scan_read_oob(struct nand_bbt *bbt, uint8_t *buf, loff_t offs,
-			 size_t len)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	struct mtd_oob_ops ops;
-	int res, ret = 0;
-
-	ops.mode = MTD_OPS_PLACE_OOB;
-	ops.ooboffs = 0;
-	ops.ooblen = mtd->oobsize;
-
-	while (len > 0) {
-		ops.datbuf = buf;
-		ops.len = min(len, (size_t)mtd->writesize);
-		ops.oobbuf = buf + ops.len;
-
-		res = mtd_read_oob(mtd, offs, &ops);
-		if (res) {
-			if (!mtd_is_bitflip_or_eccerr(res))
-				return res;
-			else if (mtd_is_eccerr(res) || !ret)
-				ret = res;
-		}
-
-		buf += mtd->oobsize + mtd->writesize;
-		len -= mtd->writesize;
-		offs += mtd->writesize;
-	}
-	return ret;
-}
-
-static int scan_read(struct nand_bbt *bbt, uint8_t *buf, loff_t offs,
-			 size_t len, struct nand_bbt_descr *td)
-{
-	if (td->options & NAND_BBT_NO_OOB)
-		return scan_read_data(bbt, buf, offs, td);
-	else
-		return scan_read_oob(bbt, buf, offs, len);
-}
-
-/* Scan write data with oob to flash */
-static int scan_write_bbt(struct nand_bbt *bbt, loff_t offs, size_t len,
-			  uint8_t *buf, uint8_t *oob)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	struct mtd_oob_ops ops;
-
-	ops.mode = MTD_OPS_PLACE_OOB;
-	ops.ooboffs = 0;
-	ops.ooblen = mtd->oobsize;
-	ops.datbuf = buf;
-	ops.oobbuf = oob;
-	ops.len = len;
-
-	return mtd_write_oob(mtd, offs, &ops);
-}
-
-static u32 bbt_get_ver_offs(struct nand_bbt *bbt, struct nand_bbt_descr *td)
-{
-	u32 ver_offs = td->veroffs;
-
-	if (!(td->options & NAND_BBT_NO_OOB))
-		ver_offs += bbt->mtd->writesize;
-	return ver_offs;
-}
-
-/**
- * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- * @td: descriptor for the bad block table
- * @md:	descriptor for the bad block table mirror
- *
- * Read the bad block table(s) for all chips starting at a given page. We
- * assume that the bbt bits are in consecutive order.
- */
-static void read_abs_bbts(struct nand_bbt *bbt, uint8_t *buf,
-			  struct nand_bbt_descr *td, struct nand_bbt_descr *md)
-{
-	struct mtd_info *mtd = bbt->mtd;
-
-	/* Read the primary version, if available */
-	if (td->options & NAND_BBT_VERSION) {
-		scan_read(bbt, buf, (loff_t)td->pages[0] << bbt->page_shift,
-			      mtd->writesize, td);
-		td->version[0] = buf[bbt_get_ver_offs(bbt, td)];
-		pr_info("Bad block table at page %d, version 0x%02X\n",
-			 td->pages[0], td->version[0]);
-	}
-
-	/* Read the mirror version, if available */
-	if (md && (md->options & NAND_BBT_VERSION)) {
-		scan_read(bbt, buf, (loff_t)md->pages[0] << bbt->page_shift,
-			      mtd->writesize, md);
-		md->version[0] = buf[bbt_get_ver_offs(bbt, md)];
-		pr_info("Bad block table at page %d, version 0x%02X\n",
-			 md->pages[0], md->version[0]);
-	}
-}
-
-/**
- * create_bbt - [GENERIC] Create a bad block table by scanning the device
- * @bbt: NAND BBT structure
- * @chip: create the table for a specific chip, -1 read all chips; applies only
- *        if NAND_BBT_PERCHIP option is set
- *
- * Create a bad block table by scanning the device for the given good/bad block
- * identify pattern.
- */
-static int create_bbt(struct nand_bbt *bbt, int chip)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int i, startblock, numblocks;
-	loff_t from;
-
-	pr_info("Scanning device for bad blocks\n");
-
-	if (chip == -1) {
-		numblocks = mtd->size >> bbt->bbt_erase_shift;
-		startblock = 0;
-		from = 0;
-	} else {
-		if (chip >= bbt->numchips) {
-			pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
-			       chip + 1, bbt->numchips);
-			return -EINVAL;
-		}
-		numblocks = bbt->chipsize >> bbt->bbt_erase_shift;
-		startblock = chip * numblocks;
-		numblocks += startblock;
-		from = (loff_t)startblock << bbt->bbt_erase_shift;
-	}
-
-	for (i = startblock; i < numblocks; i++) {
-		int ret;
-
-		ret = bbt->is_bad_bbm(mtd, from);
-		if (ret < 0)
-			return ret;
-
-		if (ret) {
-			bbt_mark_entry(bbt, i, BBT_BLOCK_FACTORY_BAD);
-			pr_warn("Bad eraseblock %d at 0x%012llx\n",
-				i, (unsigned long long)from);
-			mtd->ecc_stats.badblocks++;
-		}
-
-		from += (1 << bbt->bbt_erase_shift);
-	}
-	return 0;
-}
-
-/**
- * search_bbt - [GENERIC] scan the device for a specific bad block table
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- * @td: descriptor for the bad block table
- *
- * Read the bad block table by searching for a given ident pattern. Search is
- * preformed either from the beginning up or from the end of the device
- * downwards. The search starts always at the start of a block. If the option
- * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
- * the bad block information of this chip. This is necessary to provide support
- * for certain DOC devices.
- *
- * The bbt ident pattern resides in the oob area of the first page in a block.
- */
-static int search_bbt(struct nand_bbt *bbt, uint8_t *buf, struct nand_bbt_descr *td)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int i, chips;
-	int startblock, block, dir;
-	int scanlen = mtd->writesize + mtd->oobsize;
-	int bbtblocks;
-	int blocktopage = bbt->bbt_erase_shift - bbt->page_shift;
-
-	/* Search direction top -> down? */
-	if (td->options & NAND_BBT_LASTBLOCK) {
-		startblock = (mtd->size >> bbt->bbt_erase_shift) - 1;
-		dir = -1;
-	} else {
-		startblock = 0;
-		dir = 1;
-	}
-
-	/* Do we have a bbt per chip? */
-	if (td->options & NAND_BBT_PERCHIP) {
-		chips = bbt->numchips;
-		bbtblocks = bbt->chipsize >> bbt->bbt_erase_shift;
-		startblock &= bbtblocks - 1;
-	} else {
-		chips = 1;
-		bbtblocks = mtd->size >> bbt->bbt_erase_shift;
-	}
-
-	for (i = 0; i < chips; i++) {
-		/* Reset version information */
-		td->version[i] = 0;
-		td->pages[i] = -1;
-		/* Scan the maximum number of blocks */
-		for (block = 0; block < td->maxblocks; block++) {
-
-			int actblock = startblock + dir * block;
-			loff_t offs = (loff_t)actblock << bbt->bbt_erase_shift;
-
-			/* Read first page */
-			scan_read(bbt, buf, offs, mtd->writesize, td);
-			if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
-				td->pages[i] = actblock << blocktopage;
-				if (td->options & NAND_BBT_VERSION) {
-					offs = bbt_get_ver_offs(bbt, td);
-					td->version[i] = buf[offs];
-				}
-				break;
-			}
-		}
-		startblock += bbt->chipsize >> bbt->bbt_erase_shift;
-	}
-	/* Check, if we found a bbt for each requested chip */
-	for (i = 0; i < chips; i++) {
-		if (td->pages[i] == -1)
-			pr_warn("Bad block table not found for chip %d\n", i);
-		else
-			pr_info("Bad block table found at page %d, version 0x%02X\n",
-				td->pages[i], td->version[i]);
-	}
-	return 0;
-}
-
-/**
- * search_read_bbts - [GENERIC] scan the device for bad block table(s)
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- * @td: descriptor for the bad block table
- * @md: descriptor for the bad block table mirror
- *
- * Search and read the bad block table(s).
- */
-static void search_read_bbts(struct nand_bbt *bbt, uint8_t *buf,
-			     struct nand_bbt_descr *td,
-			     struct nand_bbt_descr *md)
-{
-	/* Search the primary table */
-	search_bbt(bbt, buf, td);
-
-	/* Search the mirror table */
-	if (md)
-		search_bbt(bbt, buf, md);
-}
-
-/**
- * write_bbt - [GENERIC] (Re)write the bad block table
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- * @td: descriptor for the bad block table
- * @md: descriptor for the bad block table mirror
- * @chipsel: selector for a specific chip, -1 for all
- *
- * (Re)write the bad block table.
- */
-static int write_bbt(struct nand_bbt *bbt, uint8_t *buf,
-		     struct nand_bbt_descr *td, struct nand_bbt_descr *md,
-		     int chipsel)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int i, res, chip = 0;
-	int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
-	int nrchips, pageoffs, ooboffs;
-	uint8_t msk[4];
-	uint8_t rcode = td->reserved_block_code;
-	size_t retlen, len = 0;
-	loff_t to;
-	struct mtd_oob_ops ops;
-
-	ops.ooblen = mtd->oobsize;
-	ops.ooboffs = 0;
-	ops.datbuf = NULL;
-	ops.mode = MTD_OPS_PLACE_OOB;
-
-	if (!rcode)
-		rcode = 0xff;
-	/* Write bad block table per chip rather than per device? */
-	if (td->options & NAND_BBT_PERCHIP) {
-		numblocks = (int)(bbt->chipsize >> bbt->bbt_erase_shift);
-		/* Full device write or specific chip? */
-		if (chipsel == -1) {
-			nrchips = bbt->numchips;
-		} else {
-			nrchips = chipsel + 1;
-			chip = chipsel;
-		}
-	} else {
-		numblocks = (int)(mtd->size >> bbt->bbt_erase_shift);
-		nrchips = 1;
-	}
-
-	/* Loop through the chips */
-	for (; chip < nrchips; chip++) {
-		/*
-		 * There was already a version of the table, reuse the page
-		 * This applies for absolute placement too, as we have the
-		 * page nr. in td->pages.
-		 */
-		if (td->pages[chip] != -1) {
-			page = td->pages[chip];
-			goto write;
-		}
-
-		/*
-		 * Automatic placement of the bad block table. Search direction
-		 * top -> down?
-		 */
-		if (td->options & NAND_BBT_LASTBLOCK) {
-			startblock = numblocks * (chip + 1) - 1;
-			dir = -1;
-		} else {
-			startblock = chip * numblocks;
-			dir = 1;
-		}
-
-		for (i = 0; i < td->maxblocks; i++) {
-			int block = startblock + dir * i;
-			/* Check, if the block is bad */
-			switch (bbt_get_entry(bbt, block)) {
-			case BBT_BLOCK_WORN:
-			case BBT_BLOCK_FACTORY_BAD:
-				continue;
-			}
-			page = block <<
-				(bbt->bbt_erase_shift - bbt->page_shift);
-			/* Check, if the block is used by the mirror table */
-			if (!md || md->pages[chip] != page)
-				goto write;
-		}
-		pr_err("No space left to write bad block table\n");
-		return -ENOSPC;
-	write:
-
-		/* Set up shift count and masks for the flash table */
-		bits = td->options & NAND_BBT_NRBITS_MSK;
-		msk[2] = ~rcode;
-		switch (bits) {
-		case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
-			msk[3] = 0x01;
-			break;
-		case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
-			msk[3] = 0x03;
-			break;
-		case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
-			msk[3] = 0x0f;
-			break;
-		case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
-			msk[3] = 0xff;
-			break;
-		default: return -EINVAL;
-		}
-
-		to = ((loff_t)page) << bbt->page_shift;
-
-		/* Must we save the block contents? */
-		if (td->options & NAND_BBT_SAVECONTENT) {
-			/* Make it block aligned */
-			to &= ~(((loff_t)1 << bbt->bbt_erase_shift) - 1);
-			len = 1 << bbt->bbt_erase_shift;
-			res = mtd_read(mtd, to, len, &retlen, buf);
-			if (res < 0) {
-				if (retlen != len) {
-					pr_info("nand_bbt: error reading block for writing the bad block table\n");
-					return res;
-				}
-				pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
-			}
-			/* Read oob data */
-			ops.ooblen = (len >> bbt->page_shift) * mtd->oobsize;
-			ops.oobbuf = &buf[len];
-			res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
-			if (res < 0 || ops.oobretlen != ops.ooblen)
-				goto outerr;
-
-			/* Calc the byte offset in the buffer */
-			pageoffs = page - (int)(to >> bbt->page_shift);
-			offs = pageoffs << bbt->page_shift;
-			/* Preset the bbt area with 0xff */
-			memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
-			ooboffs = len + (pageoffs * mtd->oobsize);
-
-		} else if (td->options & NAND_BBT_NO_OOB) {
-			ooboffs = 0;
-			offs = td->len;
-			/* The version byte */
-			if (td->options & NAND_BBT_VERSION)
-				offs++;
-			/* Calc length */
-			len = (size_t)(numblocks >> sft);
-			len += offs;
-			/* Make it page aligned! */
-			len = ALIGN(len, mtd->writesize);
-			/* Preset the buffer with 0xff */
-			memset(buf, 0xff, len);
-			/* Pattern is located at the begin of first page */
-			memcpy(buf, td->pattern, td->len);
-		} else {
-			/* Calc length */
-			len = (size_t)(numblocks >> sft);
-			/* Make it page aligned! */
-			len = ALIGN(len, mtd->writesize);
-			/* Preset the buffer with 0xff */
-			memset(buf, 0xff, len +
-			       (len >> bbt->page_shift) * mtd->oobsize);
-			offs = 0;
-			ooboffs = len;
-			/* Pattern is located in oob area of first page */
-			memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
-		}
-
-		if (td->options & NAND_BBT_VERSION)
-			buf[ooboffs + td->veroffs] = td->version[chip];
-
-		/* Walk through the memory table */
-		for (i = 0; i < numblocks; i++) {
-			uint8_t dat;
-			int sftcnt = (i << (3 - sft)) & sftmsk;
-			dat = bbt_get_entry(bbt, chip * numblocks + i);
-			/* Do not store the reserved bbt blocks! */
-			buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
-		}
-
-		res = bbt->erase(mtd, to);
-		if (res < 0)
-			goto outerr;
-
-		res = scan_write_bbt(bbt, to, len, buf,
-				td->options & NAND_BBT_NO_OOB ? NULL :
-				&buf[len]);
-		if (res < 0)
-			goto outerr;
-
-		pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
-			 (unsigned long long)to, td->version[chip]);
-
-		/* Mark it as used */
-		td->pages[chip] = page;
-	}
-	return 0;
-
- outerr:
-	pr_warn("nand_bbt: error while writing bad block table %d\n", res);
-	return res;
-}
-
-/**
- * nand_memory_bbt - [GENERIC] create a memory based bad block table
- * @bbt: NAND BBT structure
- *
- * The function creates a memory based bbt by scanning the device for
- * manufacturer / software marked good / bad blocks.
- */
-static inline int nand_memory_bbt(struct nand_bbt *bbt)
-{
-	return create_bbt(bbt, -1);
-}
-
-/**
- * check_create - [GENERIC] create and write bbt(s) if necessary
- * @bbt: NAND BBT structure
- * @buf: temporary buffer
- *
- * The function checks the results of the previous call to read_bbt and creates
- * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
- * for the chip/device. Update is necessary if one of the tables is missing or
- * the version nr. of one table is less than the other.
- */
-static int check_create(struct nand_bbt *bbt, uint8_t *buf)
-{
-	int i, chips, writeops, create, chipsel, res, res2;
-	struct nand_bbt_descr *td = bbt->bbt_td;
-	struct nand_bbt_descr *md = bbt->bbt_md;
-	struct nand_bbt_descr *rd, *rd2;
-
-	/* Do we have a bbt per chip? */
-	if (td->options & NAND_BBT_PERCHIP)
-		chips = bbt->numchips;
-	else
-		chips = 1;
-
-	for (i = 0; i < chips; i++) {
-		writeops = 0;
-		create = 0;
-		rd = NULL;
-		rd2 = NULL;
-		res = res2 = 0;
-		/* Per chip or per device? */
-		chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
-		/* Mirrored table available? */
-		if (md) {
-			if (td->pages[i] == -1 && md->pages[i] == -1) {
-				create = 1;
-				writeops = 0x03;
-			} else if (td->pages[i] == -1) {
-				rd = md;
-				writeops = 0x01;
-			} else if (md->pages[i] == -1) {
-				rd = td;
-				writeops = 0x02;
-			} else if (td->version[i] == md->version[i]) {
-				rd = td;
-				if (!(td->options & NAND_BBT_VERSION))
-					rd2 = md;
-			} else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
-				rd = td;
-				writeops = 0x02;
-			} else {
-				rd = md;
-				writeops = 0x01;
-			}
-		} else {
-			if (td->pages[i] == -1) {
-				create = 1;
-				writeops = 0x01;
-			} else {
-				rd = td;
-			}
-		}
-
-		if (create) {
-			/* Create the bad block table by scanning the device? */
-			if (!(td->options & NAND_BBT_CREATE))
-				continue;
-
-			/* Create the table in memory by scanning the chip(s) */
-			if (!(bbt->bbt_options & NAND_BBT_CREATE_EMPTY))
-				create_bbt(bbt, chipsel);
-
-			td->version[i] = 1;
-			if (md)
-				md->version[i] = 1;
-		}
-
-		/* Read back first? */
-		if (rd) {
-			res = read_abs_bbt(bbt, buf, rd, chipsel);
-			if (mtd_is_eccerr(res)) {
-				/* Mark table as invalid */
-				rd->pages[i] = -1;
-				rd->version[i] = 0;
-				i--;
-				continue;
-			}
-		}
-		/* If they weren't versioned, read both */
-		if (rd2) {
-			res2 = read_abs_bbt(bbt, buf, rd2, chipsel);
-			if (mtd_is_eccerr(res2)) {
-				/* Mark table as invalid */
-				rd2->pages[i] = -1;
-				rd2->version[i] = 0;
-				i--;
-				continue;
-			}
-		}
-
-		/* Scrub the flash table(s)? */
-		if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
-			writeops = 0x03;
-
-		/* Update version numbers before writing */
-		if (md) {
-			td->version[i] = max(td->version[i], md->version[i]);
-			md->version[i] = td->version[i];
-		}
-
-		/* Write the bad block table to the device? */
-		if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
-			res = write_bbt(bbt, buf, td, md, chipsel);
-			if (res < 0)
-				return res;
-		}
-
-		/* Write the mirror bad block table to the device? */
-		if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
-			res = write_bbt(bbt, buf, md, td, chipsel);
-			if (res < 0)
-				return res;
-		}
-	}
-	return 0;
-}
-
-/**
- * mark_bbt_regions - [GENERIC] mark the bad block table regions
- * @bbt: NAND BBT structure
- * @td: bad block table descriptor
- *
- * The bad block table regions are marked as "bad" to prevent accidental
- * erasures / writes. The regions are identified by the mark 0x02.
- */
-static void mark_bbt_region(struct nand_bbt *bbt, struct nand_bbt_descr *td)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int i, j, chips, block, nrblocks, update;
-	uint8_t oldval;
-
-	/* Do we have a bbt per chip? */
-	if (td->options & NAND_BBT_PERCHIP) {
-		chips = bbt->numchips;
-		nrblocks = (int)(bbt->chipsize >> bbt->bbt_erase_shift);
-	} else {
-		chips = 1;
-		nrblocks = (int)(mtd->size >> bbt->bbt_erase_shift);
-	}
-
-	for (i = 0; i < chips; i++) {
-		if ((td->options & NAND_BBT_ABSPAGE) ||
-		    !(td->options & NAND_BBT_WRITE)) {
-			if (td->pages[i] == -1)
-				continue;
-			block = td->pages[i] >> (bbt->bbt_erase_shift - bbt->page_shift);
-			oldval = bbt_get_entry(bbt, block);
-			bbt_mark_entry(bbt, block, BBT_BLOCK_RESERVED);
-			if ((oldval != BBT_BLOCK_RESERVED) &&
-					td->reserved_block_code)
-				nand_update_bbt(bbt, (loff_t)block <<
-						bbt->bbt_erase_shift);
-			continue;
-		}
-		update = 0;
-		if (td->options & NAND_BBT_LASTBLOCK)
-			block = ((i + 1) * nrblocks) - td->maxblocks;
-		else
-			block = i * nrblocks;
-		for (j = 0; j < td->maxblocks; j++) {
-			oldval = bbt_get_entry(bbt, block);
-			bbt_mark_entry(bbt, block, BBT_BLOCK_RESERVED);
-			if (oldval != BBT_BLOCK_RESERVED)
-				update = 1;
-			block++;
-		}
-		/*
-		 * If we want reserved blocks to be recorded to flash, and some
-		 * new ones have been marked, then we need to update the stored
-		 * bbts.  This should only happen once.
-		 */
-		if (update && td->reserved_block_code)
-			nand_update_bbt(bbt, (loff_t)(block - 1) <<
-					bbt->bbt_erase_shift);
-	}
-}
-
-/**
- * verify_bbt_descr - verify the bad block description
- * @bbt: NAND BBT structure
- * @bd: the table to verify
- *
- * This functions performs a few sanity checks on the bad block description
- * table.
- */
-static void verify_bbt_descr(struct nand_bbt *bbt, struct nand_bbt_descr *bd)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	u32 pattern_len;
-	u32 bits;
-	u32 table_size;
-
-	if (!bd)
-		return;
-
-	pattern_len = bd->len;
-	bits = bd->options & NAND_BBT_NRBITS_MSK;
-
-	BUG_ON((bbt->bbt_options & NAND_BBT_NO_OOB) &&
-			!(bbt->bbt_options & NAND_BBT_USE_FLASH));
-	BUG_ON(!bits);
-
-	if (bd->options & NAND_BBT_VERSION)
-		pattern_len++;
-
-	if (bd->options & NAND_BBT_NO_OOB) {
-		BUG_ON(!(bbt->bbt_options & NAND_BBT_USE_FLASH));
-		BUG_ON(!(bbt->bbt_options & NAND_BBT_NO_OOB));
-		BUG_ON(bd->offs);
-		if (bd->options & NAND_BBT_VERSION)
-			BUG_ON(bd->veroffs != bd->len);
-		BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
-	}
-
-	if (bd->options & NAND_BBT_PERCHIP)
-		table_size = bbt->chipsize >> bbt->bbt_erase_shift;
-	else
-		table_size = mtd->size >> bbt->bbt_erase_shift;
-	table_size >>= 3;
-	table_size *= bits;
-	if (bd->options & NAND_BBT_NO_OOB)
-		table_size += pattern_len;
-	BUG_ON(table_size > (1 << bbt->bbt_erase_shift));
-}
-
-/**
- * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
- * @bbt: NAND BBT structure
- *
- * The function checks, if a bad block table(s) is/are already available. If
- * not it scans the device for manufacturer marked good / bad blocks and writes
- * the bad block table(s) to the selected place.
- *
- * The bad block table memory is allocated here. It must be freed by calling
- * the nand_free_bbt function.
- */
-static int nand_scan_bbt(struct nand_bbt *bbt)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int len, res = 0;
-	uint8_t *buf;
-	struct nand_bbt_descr *td = bbt->bbt_td;
-	struct nand_bbt_descr *md = bbt->bbt_md;
-
-	len = mtd->size >> (bbt->bbt_erase_shift + 2);
-	/*
-	 * Allocate memory (2bit per block) and clear the memory bad block
-	 * table.
-	 */
-	bbt->bbt = kzalloc(len, GFP_KERNEL);
-	if (!bbt->bbt)
-		return -ENOMEM;
-
-	/*
-	 * If no primary table decriptor is given, scan the device to build a
-	 * memory based bad block table.
-	 */
-	if (!td) {
-		if ((res = nand_memory_bbt(bbt))) {
-			pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
-			goto err;
-		}
-		return 0;
-	}
-	verify_bbt_descr(bbt, td);
-	verify_bbt_descr(bbt, md);
-
-	/* Allocate a temporary buffer for one eraseblock incl. oob */
-	len = (1 << bbt->bbt_erase_shift);
-	len += (len >> bbt->page_shift) * mtd->oobsize;
-	buf = vmalloc(len);
-	if (!buf) {
-		res = -ENOMEM;
-		goto err;
-	}
-
-	/* Is the bbt at a given page? */
-	if (td->options & NAND_BBT_ABSPAGE) {
-		read_abs_bbts(bbt, buf, td, md);
-	} else {
-		/* Search the bad block table using a pattern in oob */
-		search_read_bbts(bbt, buf, td, md);
-	}
-
-	res = check_create(bbt, buf);
-	if (res)
-		goto err;
-
-	/* Prevent the bbt regions from erasing / writing */
-	mark_bbt_region(bbt, td);
-	if (md)
-		mark_bbt_region(bbt, md);
-
-	vfree(buf);
-	return 0;
-
-err:
-	kfree(bbt->bbt);
-	bbt->bbt = NULL;
-	return res;
-}
-
-/**
- * nand_update_bbt - update bad block table(s)
- * @bbt: NAND BBT structure
- * @offs: the offset of the newly marked block
- *
- * The function updates the bad block table(s).
- */
-static int nand_update_bbt(struct nand_bbt *bbt, loff_t offs)
-{
-	struct mtd_info *mtd = bbt->mtd;
-	int len, res = 0;
-	int chip, chipsel;
-	uint8_t *buf;
-	struct nand_bbt_descr *td = bbt->bbt_td;
-	struct nand_bbt_descr *md = bbt->bbt_md;
-
-	if (!bbt->bbt || !td)
-		return -EINVAL;
-
-	/* Allocate a temporary buffer for one eraseblock incl. oob */
-	len = (1 << bbt->bbt_erase_shift);
-	len += (len >> bbt->page_shift) * mtd->oobsize;
-	buf = kmalloc(len, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	/* Do we have a bbt per chip? */
-	if (td->options & NAND_BBT_PERCHIP) {
-		chip = (int)(offs >> bbt->chip_shift);
-		chipsel = chip;
-	} else {
-		chip = 0;
-		chipsel = -1;
-	}
-
-	td->version[chip]++;
-	if (md)
-		md->version[chip]++;
-
-	/* Write the bad block table to the device? */
-	if (td->options & NAND_BBT_WRITE) {
-		res = write_bbt(bbt, buf, td, md, chipsel);
-		if (res < 0)
-			goto out;
-	}
-	/* Write the mirror bad block table to the device? */
-	if (md && (md->options & NAND_BBT_WRITE)) {
-		res = write_bbt(bbt, buf, md, td, chipsel);
-	}
-
- out:
-	kfree(buf);
-	return res;
-}
-
-/* Generic flash bbt descriptors */
-static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
-static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
-
-static struct nand_bbt_descr bbt_main_descr = {
-	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
-	.offs =	8,
-	.len = 4,
-	.veroffs = 12,
-	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
-	.pattern = bbt_pattern
-};
-
-static struct nand_bbt_descr bbt_mirror_descr = {
-	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
-	.offs =	8,
-	.len = 4,
-	.veroffs = 12,
-	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
-	.pattern = mirror_pattern
-};
-
-static struct nand_bbt_descr bbt_main_no_oob_descr = {
-	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
-		| NAND_BBT_NO_OOB,
-	.len = 4,
-	.veroffs = 4,
-	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
-	.pattern = bbt_pattern
-};
-
-static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
-	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
-		| NAND_BBT_NO_OOB,
-	.len = 4,
-	.veroffs = 4,
-	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
-	.pattern = mirror_pattern
-};
-
-/**
- * nand_bbt_init - [NAND BBT Interface] Initialize and locate/create a bad block
- * table
- * @bbt: NAND BBT structure
- *
- * This function selects the default bad block table support for the device and
- * scans for an existing table, or else creates one.
- */
-int nand_bbt_init(struct nand_bbt *bbt)
-{
-	/* Is a flash based bad block table requested? */
-	if (bbt->bbt_options & NAND_BBT_USE_FLASH) {
-		/* Use the default pattern descriptors */
-		if (!bbt->bbt_td) {
-			if (bbt->bbt_options & NAND_BBT_NO_OOB) {
-				bbt->bbt_td = &bbt_main_no_oob_descr;
-				bbt->bbt_md = &bbt_mirror_no_oob_descr;
-			} else {
-				bbt->bbt_td = &bbt_main_descr;
-				bbt->bbt_md = &bbt_mirror_descr;
-			}
-		}
-	} else {
-		bbt->bbt_td = NULL;
-		bbt->bbt_md = NULL;
-	}
-
-	return nand_scan_bbt(bbt);
-}
-EXPORT_SYMBOL(nand_bbt_init);
-
-void nand_bbt_release(struct nand_bbt *bbt)
-{
-	kfree(bbt->bbt);
-}
-EXPORT_SYMBOL(nand_bbt_release);
-
-/**
- * nand_bbt_isreserved - [NAND BBT Interface] Check if a block is reserved
- * @bbt: NAND BBT structure
- * @offs: offset in the device
- */
-int nand_bbt_isreserved(struct nand_bbt *bbt, loff_t offs)
-{
-	int block;
-
-	block = (int)(offs >> bbt->bbt_erase_shift);
-	return bbt_get_entry(bbt, block) == BBT_BLOCK_RESERVED;
-}
-EXPORT_SYMBOL(nand_bbt_isreserved);
-
-/**
- * nand_bbt_isbad - [NAND BBT Interface] Check if a block is bad
- * @bbt: NAND BBT structure
- * @offs: offset in the device
- */
-int nand_bbt_isbad(struct nand_bbt *bbt, loff_t offs)
-{
-	int block, res;
-
-	block = (int)(offs >> bbt->bbt_erase_shift);
-	res = bbt_get_entry(bbt, block);
-
-	pr_debug("nand_bbt_isbad(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
-		 (unsigned int)offs, block, res);
-
-	switch (res) {
-	case BBT_BLOCK_GOOD:
-	case BBT_BLOCK_RESERVED:
-		return 0;
-	case BBT_BLOCK_WORN:
-	case BBT_BLOCK_FACTORY_BAD:
-	default:
-		return 1;
-	}
-}
-EXPORT_SYMBOL(nand_bbt_isbad);
-
-/**
- * nand_bbt_update_mark - update mark in the BBT
- * @bbt: NAND BBT structure
- * @offs: offset of the bad block
- * @mark: block type mark
- */
-static int nand_bbt_update_mark(struct nand_bbt *bbt, loff_t offs, uint8_t mark)
-{
-	int block, ret = 0;
-
-	block = (int)(offs >> bbt->bbt_erase_shift);
-
-	/* Mark bad block in memory */
-	bbt_mark_entry(bbt, block, mark);
-
-	/* Update flash-based bad block table */
-	if (bbt->bbt_options & NAND_BBT_USE_FLASH)
-		ret = nand_update_bbt(bbt, offs);
-
-	return ret;
-}
-
-/**
- * nand_bbt_markbad - [NAND BBT Interface] Mark a block bad in the BBT
- * @bbt: NAND BBT structure
- * @offs: offset of the bad block
- */
-int nand_bbt_markbad(struct nand_bbt *bbt, loff_t offs)
-{
-	return nand_bbt_update_mark(bbt, offs, BBT_BLOCK_WORN);
-}
-EXPORT_SYMBOL(nand_bbt_markbad);
-
-/**
- * nand_bbt_markbad_factory - [NAND BBT Interface] Mark a block as factory bad
- * in the BBT
- * @bbt: NAND BBT structure
- * @offs: offset of the bad block
- */
-int nand_bbt_markbad_factory(struct nand_bbt *bbt, loff_t offs)
-{
-	return nand_bbt_update_mark(bbt, offs, BBT_BLOCK_FACTORY_BAD);
-}
-EXPORT_SYMBOL(nand_bbt_markbad_factory);
diff --git a/drivers/mtd/nand_bbt.c b/drivers/mtd/nand_bbt.c
new file mode 100644
index 0000000..47c1084
--- /dev/null
+++ b/drivers/mtd/nand_bbt.c
@@ -0,0 +1,1289 @@ 
+/*
+ *  Overview:
+ *   Bad block table support for the NAND driver
+ *
+ *  Copyright ? 2004 Thomas Gleixner (tglx@linutronix.de)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Description:
+ *
+ * When nand_scan_bbt is called, then it tries to find the bad block table
+ * depending on the options in the BBT descriptor(s). If no flash based BBT
+ * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
+ * marked good / bad blocks. This information is used to create a memory BBT.
+ * Once a new bad block is discovered then the "factory" information is updated
+ * on the device.
+ * If a flash based BBT is specified then the function first tries to find the
+ * BBT on flash. If a BBT is found then the contents are read and the memory
+ * based BBT is created. If a mirrored BBT is selected then the mirror is
+ * searched too and the versions are compared. If the mirror has a greater
+ * version number, then the mirror BBT is used to build the memory based BBT.
+ * If the tables are not versioned, then we "or" the bad block information.
+ * If one of the BBTs is out of date or does not exist it is (re)created.
+ * If no BBT exists at all then the device is scanned for factory marked
+ * good / bad blocks and the bad block tables are created.
+ *
+ * For manufacturer created BBTs like the one found on M-SYS DOC devices
+ * the BBT is searched and read but never created
+ *
+ * The auto generated bad block table is located in the last good blocks
+ * of the device. The table is mirrored, so it can be updated eventually.
+ * The table is marked in the OOB area with an ident pattern and a version
+ * number which indicates which of both tables is more up to date. If the NAND
+ * controller needs the complete OOB area for the ECC information then the
+ * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
+ * course): it moves the ident pattern and the version byte into the data area
+ * and the OOB area will remain untouched.
+ *
+ * The table uses 2 bits per block
+ * 11b:		block is good
+ * 00b:		block is factory marked bad
+ * 01b, 10b:	block is marked bad due to wear
+ *
+ * The memory bad block table uses the following scheme:
+ * 00b:		block is good
+ * 01b:		block is marked bad due to wear
+ * 10b:		block is reserved (to protect the bbt area)
+ * 11b:		block is factory marked bad
+ *
+ * Multichip devices like DOC store the bad block info per floor.
+ *
+ * Following assumptions are made:
+ * - bbts start at a page boundary, if autolocated on a block boundary
+ * - the space necessary for a bbt in FLASH does not exceed a block boundary
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand_bbt.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/vmalloc.h>
+#include <linux/export.h>
+#include <linux/string.h>
+
+#define BBT_BLOCK_GOOD		0x00
+#define BBT_BLOCK_WORN		0x01
+#define BBT_BLOCK_RESERVED	0x02
+#define BBT_BLOCK_FACTORY_BAD	0x03
+
+#define BBT_ENTRY_MASK		0x03
+#define BBT_ENTRY_SHIFT		2
+
+static int nand_update_bbt(struct nand_bbt *bbt, loff_t offs);
+
+static inline uint8_t bbt_get_entry(struct nand_bbt *bbt, int block)
+{
+	uint8_t entry = bbt->bbt[block >> BBT_ENTRY_SHIFT];
+	entry >>= (block & BBT_ENTRY_MASK) * 2;
+	return entry & BBT_ENTRY_MASK;
+}
+
+static inline void bbt_mark_entry(struct nand_bbt *bbt, int block,
+		uint8_t mark)
+{
+	uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);
+	bbt->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
+}
+
+static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
+{
+	if (memcmp(buf, td->pattern, td->len))
+		return -1;
+	return 0;
+}
+
+/**
+ * check_pattern - [GENERIC] check if a pattern is in the buffer
+ * @buf: the buffer to search
+ * @len: the length of buffer to search
+ * @paglen: the pagelength
+ * @td: search pattern descriptor
+ *
+ * Check for a pattern at the given place. Used to search bad block tables and
+ * good / bad block identifiers.
+ */
+static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
+{
+	if (td->options & NAND_BBT_NO_OOB)
+		return check_pattern_no_oob(buf, td);
+
+	/* Compare the pattern */
+	if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
+		return -1;
+
+	return 0;
+}
+
+/**
+ * add_marker_len - compute the length of the marker in data area
+ * @td: BBT descriptor used for computation
+ *
+ * The length will be 0 if the marker is located in OOB area.
+ */
+static u32 add_marker_len(struct nand_bbt_descr *td)
+{
+	u32 len;
+
+	if (!(td->options & NAND_BBT_NO_OOB))
+		return 0;
+
+	len = td->len;
+	if (td->options & NAND_BBT_VERSION)
+		len++;
+	return len;
+}
+
+/**
+ * read_bbt - [GENERIC] Read the bad block table starting from page
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ * @page: the starting page
+ * @num: the number of bbt descriptors to read
+ * @td: the bbt describtion table
+ * @offs: block number offset in the table
+ *
+ * Read the bad block table starting from page.
+ */
+static int read_bbt(struct nand_bbt *bbt, uint8_t *buf, int page, int num,
+		struct nand_bbt_descr *td, int offs)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int res, ret = 0, i, j, act = 0;
+	size_t retlen, len, totlen;
+	loff_t from;
+	int bits = td->options & NAND_BBT_NRBITS_MSK;
+	uint8_t msk = (uint8_t)((1 << bits) - 1);
+	u32 marker_len;
+	int reserved_block_code = td->reserved_block_code;
+
+	totlen = (num * bits) >> 3;
+	marker_len = add_marker_len(td);
+	from = ((loff_t)page) << bbt->page_shift;
+
+	while (totlen) {
+		len = min(totlen, (size_t)(1 << bbt->bbt_erase_shift));
+		if (marker_len) {
+			/*
+			 * In case the BBT marker is not in the OOB area it
+			 * will be just in the first page.
+			 */
+			len -= marker_len;
+			from += marker_len;
+			marker_len = 0;
+		}
+		res = mtd_read(mtd, from, len, &retlen, buf);
+		if (res < 0) {
+			if (mtd_is_eccerr(res)) {
+				pr_info("nand_bbt: ECC error in BBT at 0x%012llx\n",
+					from & ~mtd->writesize);
+				return res;
+			} else if (mtd_is_bitflip(res)) {
+				pr_info("nand_bbt: corrected error in BBT at 0x%012llx\n",
+					from & ~mtd->writesize);
+				ret = res;
+			} else {
+				pr_info("nand_bbt: error reading BBT\n");
+				return res;
+			}
+		}
+
+		/* Analyse data */
+		for (i = 0; i < len; i++) {
+			uint8_t dat = buf[i];
+			for (j = 0; j < 8; j += bits, act++) {
+				uint8_t tmp = (dat >> j) & msk;
+				if (tmp == msk)
+					continue;
+				if (reserved_block_code && (tmp == reserved_block_code)) {
+					pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
+						 (loff_t)(offs + act) <<
+						 bbt->bbt_erase_shift);
+					bbt_mark_entry(bbt, offs + act,
+							BBT_BLOCK_RESERVED);
+					mtd->ecc_stats.bbtblocks++;
+					continue;
+				}
+				/*
+				 * Leave it for now, if it's matured we can
+				 * move this message to pr_debug.
+				 */
+				pr_info("nand_read_bbt: bad block at 0x%012llx\n",
+					 (loff_t)(offs + act) <<
+					 bbt->bbt_erase_shift);
+				/* Factory marked bad or worn out? */
+				if (tmp == 0)
+					bbt_mark_entry(bbt, offs + act,
+							BBT_BLOCK_FACTORY_BAD);
+				else
+					bbt_mark_entry(bbt, offs + act,
+							BBT_BLOCK_WORN);
+				mtd->ecc_stats.badblocks++;
+			}
+		}
+		totlen -= len;
+		from += len;
+	}
+	return ret;
+}
+
+/**
+ * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @chip: read the table for a specific chip, -1 read all chips; applies only if
+ *        NAND_BBT_PERCHIP option is set
+ *
+ * Read the bad block table for all chips starting at a given page. We assume
+ * that the bbt bits are in consecutive order.
+ */
+static int read_abs_bbt(struct nand_bbt *bbt, uint8_t *buf, struct nand_bbt_descr *td, int chip)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int res = 0, i;
+
+	if (td->options & NAND_BBT_PERCHIP) {
+		int offs = 0;
+		for (i = 0; i < bbt->numchips; i++) {
+			if (chip == -1 || chip == i)
+				res = read_bbt(bbt, buf, td->pages[i],
+					bbt->chipsize >> bbt->bbt_erase_shift,
+					td, offs);
+			if (res)
+				return res;
+			offs += bbt->chipsize >> bbt->bbt_erase_shift;
+		}
+	} else {
+		res = read_bbt(bbt, buf, td->pages[0],
+				mtd->size >> bbt->bbt_erase_shift, td, 0);
+		if (res)
+			return res;
+	}
+	return 0;
+}
+
+/* BBT marker is in the first page, no OOB */
+static int scan_read_data(struct nand_bbt *bbt, uint8_t *buf, loff_t offs,
+			 struct nand_bbt_descr *td)
+{
+	size_t retlen;
+	size_t len;
+
+	len = td->len;
+	if (td->options & NAND_BBT_VERSION)
+		len++;
+
+	return mtd_read(bbt->mtd, offs, len, &retlen, buf);
+}
+
+/**
+ * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ * @offs: offset at which to scan
+ * @len: length of data region to read
+ *
+ * Scan read data from data+OOB. May traverse multiple pages, interleaving
+ * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
+ * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
+ */
+static int scan_read_oob(struct nand_bbt *bbt, uint8_t *buf, loff_t offs,
+			 size_t len)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	struct mtd_oob_ops ops;
+	int res, ret = 0;
+
+	ops.mode = MTD_OPS_PLACE_OOB;
+	ops.ooboffs = 0;
+	ops.ooblen = mtd->oobsize;
+
+	while (len > 0) {
+		ops.datbuf = buf;
+		ops.len = min(len, (size_t)mtd->writesize);
+		ops.oobbuf = buf + ops.len;
+
+		res = mtd_read_oob(mtd, offs, &ops);
+		if (res) {
+			if (!mtd_is_bitflip_or_eccerr(res))
+				return res;
+			else if (mtd_is_eccerr(res) || !ret)
+				ret = res;
+		}
+
+		buf += mtd->oobsize + mtd->writesize;
+		len -= mtd->writesize;
+		offs += mtd->writesize;
+	}
+	return ret;
+}
+
+static int scan_read(struct nand_bbt *bbt, uint8_t *buf, loff_t offs,
+			 size_t len, struct nand_bbt_descr *td)
+{
+	if (td->options & NAND_BBT_NO_OOB)
+		return scan_read_data(bbt, buf, offs, td);
+	else
+		return scan_read_oob(bbt, buf, offs, len);
+}
+
+/* Scan write data with oob to flash */
+static int scan_write_bbt(struct nand_bbt *bbt, loff_t offs, size_t len,
+			  uint8_t *buf, uint8_t *oob)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	struct mtd_oob_ops ops;
+
+	ops.mode = MTD_OPS_PLACE_OOB;
+	ops.ooboffs = 0;
+	ops.ooblen = mtd->oobsize;
+	ops.datbuf = buf;
+	ops.oobbuf = oob;
+	ops.len = len;
+
+	return mtd_write_oob(mtd, offs, &ops);
+}
+
+static u32 bbt_get_ver_offs(struct nand_bbt *bbt, struct nand_bbt_descr *td)
+{
+	u32 ver_offs = td->veroffs;
+
+	if (!(td->options & NAND_BBT_NO_OOB))
+		ver_offs += bbt->mtd->writesize;
+	return ver_offs;
+}
+
+/**
+ * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @md:	descriptor for the bad block table mirror
+ *
+ * Read the bad block table(s) for all chips starting at a given page. We
+ * assume that the bbt bits are in consecutive order.
+ */
+static void read_abs_bbts(struct nand_bbt *bbt, uint8_t *buf,
+			  struct nand_bbt_descr *td, struct nand_bbt_descr *md)
+{
+	struct mtd_info *mtd = bbt->mtd;
+
+	/* Read the primary version, if available */
+	if (td->options & NAND_BBT_VERSION) {
+		scan_read(bbt, buf, (loff_t)td->pages[0] << bbt->page_shift,
+			      mtd->writesize, td);
+		td->version[0] = buf[bbt_get_ver_offs(bbt, td)];
+		pr_info("Bad block table at page %d, version 0x%02X\n",
+			 td->pages[0], td->version[0]);
+	}
+
+	/* Read the mirror version, if available */
+	if (md && (md->options & NAND_BBT_VERSION)) {
+		scan_read(bbt, buf, (loff_t)md->pages[0] << bbt->page_shift,
+			      mtd->writesize, md);
+		md->version[0] = buf[bbt_get_ver_offs(bbt, md)];
+		pr_info("Bad block table at page %d, version 0x%02X\n",
+			 md->pages[0], md->version[0]);
+	}
+}
+
+/**
+ * create_bbt - [GENERIC] Create a bad block table by scanning the device
+ * @bbt: NAND BBT structure
+ * @chip: create the table for a specific chip, -1 read all chips; applies only
+ *        if NAND_BBT_PERCHIP option is set
+ *
+ * Create a bad block table by scanning the device for the given good/bad block
+ * identify pattern.
+ */
+static int create_bbt(struct nand_bbt *bbt, int chip)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int i, startblock, numblocks;
+	loff_t from;
+
+	pr_info("Scanning device for bad blocks\n");
+
+	if (chip == -1) {
+		numblocks = mtd->size >> bbt->bbt_erase_shift;
+		startblock = 0;
+		from = 0;
+	} else {
+		if (chip >= bbt->numchips) {
+			pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
+			       chip + 1, bbt->numchips);
+			return -EINVAL;
+		}
+		numblocks = bbt->chipsize >> bbt->bbt_erase_shift;
+		startblock = chip * numblocks;
+		numblocks += startblock;
+		from = (loff_t)startblock << bbt->bbt_erase_shift;
+	}
+
+	for (i = startblock; i < numblocks; i++) {
+		int ret;
+
+		ret = bbt->is_bad_bbm(mtd, from);
+		if (ret < 0)
+			return ret;
+
+		if (ret) {
+			bbt_mark_entry(bbt, i, BBT_BLOCK_FACTORY_BAD);
+			pr_warn("Bad eraseblock %d at 0x%012llx\n",
+				i, (unsigned long long)from);
+			mtd->ecc_stats.badblocks++;
+		}
+
+		from += (1 << bbt->bbt_erase_shift);
+	}
+	return 0;
+}
+
+/**
+ * search_bbt - [GENERIC] scan the device for a specific bad block table
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ *
+ * Read the bad block table by searching for a given ident pattern. Search is
+ * preformed either from the beginning up or from the end of the device
+ * downwards. The search starts always at the start of a block. If the option
+ * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
+ * the bad block information of this chip. This is necessary to provide support
+ * for certain DOC devices.
+ *
+ * The bbt ident pattern resides in the oob area of the first page in a block.
+ */
+static int search_bbt(struct nand_bbt *bbt, uint8_t *buf, struct nand_bbt_descr *td)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int i, chips;
+	int startblock, block, dir;
+	int scanlen = mtd->writesize + mtd->oobsize;
+	int bbtblocks;
+	int blocktopage = bbt->bbt_erase_shift - bbt->page_shift;
+
+	/* Search direction top -> down? */
+	if (td->options & NAND_BBT_LASTBLOCK) {
+		startblock = (mtd->size >> bbt->bbt_erase_shift) - 1;
+		dir = -1;
+	} else {
+		startblock = 0;
+		dir = 1;
+	}
+
+	/* Do we have a bbt per chip? */
+	if (td->options & NAND_BBT_PERCHIP) {
+		chips = bbt->numchips;
+		bbtblocks = bbt->chipsize >> bbt->bbt_erase_shift;
+		startblock &= bbtblocks - 1;
+	} else {
+		chips = 1;
+		bbtblocks = mtd->size >> bbt->bbt_erase_shift;
+	}
+
+	for (i = 0; i < chips; i++) {
+		/* Reset version information */
+		td->version[i] = 0;
+		td->pages[i] = -1;
+		/* Scan the maximum number of blocks */
+		for (block = 0; block < td->maxblocks; block++) {
+
+			int actblock = startblock + dir * block;
+			loff_t offs = (loff_t)actblock << bbt->bbt_erase_shift;
+
+			/* Read first page */
+			scan_read(bbt, buf, offs, mtd->writesize, td);
+			if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
+				td->pages[i] = actblock << blocktopage;
+				if (td->options & NAND_BBT_VERSION) {
+					offs = bbt_get_ver_offs(bbt, td);
+					td->version[i] = buf[offs];
+				}
+				break;
+			}
+		}
+		startblock += bbt->chipsize >> bbt->bbt_erase_shift;
+	}
+	/* Check, if we found a bbt for each requested chip */
+	for (i = 0; i < chips; i++) {
+		if (td->pages[i] == -1)
+			pr_warn("Bad block table not found for chip %d\n", i);
+		else
+			pr_info("Bad block table found at page %d, version 0x%02X\n",
+				td->pages[i], td->version[i]);
+	}
+	return 0;
+}
+
+/**
+ * search_read_bbts - [GENERIC] scan the device for bad block table(s)
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @md: descriptor for the bad block table mirror
+ *
+ * Search and read the bad block table(s).
+ */
+static void search_read_bbts(struct nand_bbt *bbt, uint8_t *buf,
+			     struct nand_bbt_descr *td,
+			     struct nand_bbt_descr *md)
+{
+	/* Search the primary table */
+	search_bbt(bbt, buf, td);
+
+	/* Search the mirror table */
+	if (md)
+		search_bbt(bbt, buf, md);
+}
+
+/**
+ * write_bbt - [GENERIC] (Re)write the bad block table
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @md: descriptor for the bad block table mirror
+ * @chipsel: selector for a specific chip, -1 for all
+ *
+ * (Re)write the bad block table.
+ */
+static int write_bbt(struct nand_bbt *bbt, uint8_t *buf,
+		     struct nand_bbt_descr *td, struct nand_bbt_descr *md,
+		     int chipsel)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int i, res, chip = 0;
+	int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
+	int nrchips, pageoffs, ooboffs;
+	uint8_t msk[4];
+	uint8_t rcode = td->reserved_block_code;
+	size_t retlen, len = 0;
+	loff_t to;
+	struct mtd_oob_ops ops;
+
+	ops.ooblen = mtd->oobsize;
+	ops.ooboffs = 0;
+	ops.datbuf = NULL;
+	ops.mode = MTD_OPS_PLACE_OOB;
+
+	if (!rcode)
+		rcode = 0xff;
+	/* Write bad block table per chip rather than per device? */
+	if (td->options & NAND_BBT_PERCHIP) {
+		numblocks = (int)(bbt->chipsize >> bbt->bbt_erase_shift);
+		/* Full device write or specific chip? */
+		if (chipsel == -1) {
+			nrchips = bbt->numchips;
+		} else {
+			nrchips = chipsel + 1;
+			chip = chipsel;
+		}
+	} else {
+		numblocks = (int)(mtd->size >> bbt->bbt_erase_shift);
+		nrchips = 1;
+	}
+
+	/* Loop through the chips */
+	for (; chip < nrchips; chip++) {
+		/*
+		 * There was already a version of the table, reuse the page
+		 * This applies for absolute placement too, as we have the
+		 * page nr. in td->pages.
+		 */
+		if (td->pages[chip] != -1) {
+			page = td->pages[chip];
+			goto write;
+		}
+
+		/*
+		 * Automatic placement of the bad block table. Search direction
+		 * top -> down?
+		 */
+		if (td->options & NAND_BBT_LASTBLOCK) {
+			startblock = numblocks * (chip + 1) - 1;
+			dir = -1;
+		} else {
+			startblock = chip * numblocks;
+			dir = 1;
+		}
+
+		for (i = 0; i < td->maxblocks; i++) {
+			int block = startblock + dir * i;
+			/* Check, if the block is bad */
+			switch (bbt_get_entry(bbt, block)) {
+			case BBT_BLOCK_WORN:
+			case BBT_BLOCK_FACTORY_BAD:
+				continue;
+			}
+			page = block <<
+				(bbt->bbt_erase_shift - bbt->page_shift);
+			/* Check, if the block is used by the mirror table */
+			if (!md || md->pages[chip] != page)
+				goto write;
+		}
+		pr_err("No space left to write bad block table\n");
+		return -ENOSPC;
+	write:
+
+		/* Set up shift count and masks for the flash table */
+		bits = td->options & NAND_BBT_NRBITS_MSK;
+		msk[2] = ~rcode;
+		switch (bits) {
+		case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
+			msk[3] = 0x01;
+			break;
+		case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
+			msk[3] = 0x03;
+			break;
+		case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
+			msk[3] = 0x0f;
+			break;
+		case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
+			msk[3] = 0xff;
+			break;
+		default: return -EINVAL;
+		}
+
+		to = ((loff_t)page) << bbt->page_shift;
+
+		/* Must we save the block contents? */
+		if (td->options & NAND_BBT_SAVECONTENT) {
+			/* Make it block aligned */
+			to &= ~(((loff_t)1 << bbt->bbt_erase_shift) - 1);
+			len = 1 << bbt->bbt_erase_shift;
+			res = mtd_read(mtd, to, len, &retlen, buf);
+			if (res < 0) {
+				if (retlen != len) {
+					pr_info("nand_bbt: error reading block for writing the bad block table\n");
+					return res;
+				}
+				pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
+			}
+			/* Read oob data */
+			ops.ooblen = (len >> bbt->page_shift) * mtd->oobsize;
+			ops.oobbuf = &buf[len];
+			res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
+			if (res < 0 || ops.oobretlen != ops.ooblen)
+				goto outerr;
+
+			/* Calc the byte offset in the buffer */
+			pageoffs = page - (int)(to >> bbt->page_shift);
+			offs = pageoffs << bbt->page_shift;
+			/* Preset the bbt area with 0xff */
+			memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
+			ooboffs = len + (pageoffs * mtd->oobsize);
+
+		} else if (td->options & NAND_BBT_NO_OOB) {
+			ooboffs = 0;
+			offs = td->len;
+			/* The version byte */
+			if (td->options & NAND_BBT_VERSION)
+				offs++;
+			/* Calc length */
+			len = (size_t)(numblocks >> sft);
+			len += offs;
+			/* Make it page aligned! */
+			len = ALIGN(len, mtd->writesize);
+			/* Preset the buffer with 0xff */
+			memset(buf, 0xff, len);
+			/* Pattern is located at the begin of first page */
+			memcpy(buf, td->pattern, td->len);
+		} else {
+			/* Calc length */
+			len = (size_t)(numblocks >> sft);
+			/* Make it page aligned! */
+			len = ALIGN(len, mtd->writesize);
+			/* Preset the buffer with 0xff */
+			memset(buf, 0xff, len +
+			       (len >> bbt->page_shift) * mtd->oobsize);
+			offs = 0;
+			ooboffs = len;
+			/* Pattern is located in oob area of first page */
+			memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
+		}
+
+		if (td->options & NAND_BBT_VERSION)
+			buf[ooboffs + td->veroffs] = td->version[chip];
+
+		/* Walk through the memory table */
+		for (i = 0; i < numblocks; i++) {
+			uint8_t dat;
+			int sftcnt = (i << (3 - sft)) & sftmsk;
+			dat = bbt_get_entry(bbt, chip * numblocks + i);
+			/* Do not store the reserved bbt blocks! */
+			buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
+		}
+
+		res = bbt->erase(mtd, to);
+		if (res < 0)
+			goto outerr;
+
+		res = scan_write_bbt(bbt, to, len, buf,
+				td->options & NAND_BBT_NO_OOB ? NULL :
+				&buf[len]);
+		if (res < 0)
+			goto outerr;
+
+		pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
+			 (unsigned long long)to, td->version[chip]);
+
+		/* Mark it as used */
+		td->pages[chip] = page;
+	}
+	return 0;
+
+ outerr:
+	pr_warn("nand_bbt: error while writing bad block table %d\n", res);
+	return res;
+}
+
+/**
+ * nand_memory_bbt - [GENERIC] create a memory based bad block table
+ * @bbt: NAND BBT structure
+ *
+ * The function creates a memory based bbt by scanning the device for
+ * manufacturer / software marked good / bad blocks.
+ */
+static inline int nand_memory_bbt(struct nand_bbt *bbt)
+{
+	return create_bbt(bbt, -1);
+}
+
+/**
+ * check_create - [GENERIC] create and write bbt(s) if necessary
+ * @bbt: NAND BBT structure
+ * @buf: temporary buffer
+ *
+ * The function checks the results of the previous call to read_bbt and creates
+ * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
+ * for the chip/device. Update is necessary if one of the tables is missing or
+ * the version nr. of one table is less than the other.
+ */
+static int check_create(struct nand_bbt *bbt, uint8_t *buf)
+{
+	int i, chips, writeops, create, chipsel, res, res2;
+	struct nand_bbt_descr *td = bbt->bbt_td;
+	struct nand_bbt_descr *md = bbt->bbt_md;
+	struct nand_bbt_descr *rd, *rd2;
+
+	/* Do we have a bbt per chip? */
+	if (td->options & NAND_BBT_PERCHIP)
+		chips = bbt->numchips;
+	else
+		chips = 1;
+
+	for (i = 0; i < chips; i++) {
+		writeops = 0;
+		create = 0;
+		rd = NULL;
+		rd2 = NULL;
+		res = res2 = 0;
+		/* Per chip or per device? */
+		chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
+		/* Mirrored table available? */
+		if (md) {
+			if (td->pages[i] == -1 && md->pages[i] == -1) {
+				create = 1;
+				writeops = 0x03;
+			} else if (td->pages[i] == -1) {
+				rd = md;
+				writeops = 0x01;
+			} else if (md->pages[i] == -1) {
+				rd = td;
+				writeops = 0x02;
+			} else if (td->version[i] == md->version[i]) {
+				rd = td;
+				if (!(td->options & NAND_BBT_VERSION))
+					rd2 = md;
+			} else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
+				rd = td;
+				writeops = 0x02;
+			} else {
+				rd = md;
+				writeops = 0x01;
+			}
+		} else {
+			if (td->pages[i] == -1) {
+				create = 1;
+				writeops = 0x01;
+			} else {
+				rd = td;
+			}
+		}
+
+		if (create) {
+			/* Create the bad block table by scanning the device? */
+			if (!(td->options & NAND_BBT_CREATE))
+				continue;
+
+			/* Create the table in memory by scanning the chip(s) */
+			if (!(bbt->bbt_options & NAND_BBT_CREATE_EMPTY))
+				create_bbt(bbt, chipsel);
+
+			td->version[i] = 1;
+			if (md)
+				md->version[i] = 1;
+		}
+
+		/* Read back first? */
+		if (rd) {
+			res = read_abs_bbt(bbt, buf, rd, chipsel);
+			if (mtd_is_eccerr(res)) {
+				/* Mark table as invalid */
+				rd->pages[i] = -1;
+				rd->version[i] = 0;
+				i--;
+				continue;
+			}
+		}
+		/* If they weren't versioned, read both */
+		if (rd2) {
+			res2 = read_abs_bbt(bbt, buf, rd2, chipsel);
+			if (mtd_is_eccerr(res2)) {
+				/* Mark table as invalid */
+				rd2->pages[i] = -1;
+				rd2->version[i] = 0;
+				i--;
+				continue;
+			}
+		}
+
+		/* Scrub the flash table(s)? */
+		if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
+			writeops = 0x03;
+
+		/* Update version numbers before writing */
+		if (md) {
+			td->version[i] = max(td->version[i], md->version[i]);
+			md->version[i] = td->version[i];
+		}
+
+		/* Write the bad block table to the device? */
+		if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
+			res = write_bbt(bbt, buf, td, md, chipsel);
+			if (res < 0)
+				return res;
+		}
+
+		/* Write the mirror bad block table to the device? */
+		if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
+			res = write_bbt(bbt, buf, md, td, chipsel);
+			if (res < 0)
+				return res;
+		}
+	}
+	return 0;
+}
+
+/**
+ * mark_bbt_regions - [GENERIC] mark the bad block table regions
+ * @bbt: NAND BBT structure
+ * @td: bad block table descriptor
+ *
+ * The bad block table regions are marked as "bad" to prevent accidental
+ * erasures / writes. The regions are identified by the mark 0x02.
+ */
+static void mark_bbt_region(struct nand_bbt *bbt, struct nand_bbt_descr *td)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int i, j, chips, block, nrblocks, update;
+	uint8_t oldval;
+
+	/* Do we have a bbt per chip? */
+	if (td->options & NAND_BBT_PERCHIP) {
+		chips = bbt->numchips;
+		nrblocks = (int)(bbt->chipsize >> bbt->bbt_erase_shift);
+	} else {
+		chips = 1;
+		nrblocks = (int)(mtd->size >> bbt->bbt_erase_shift);
+	}
+
+	for (i = 0; i < chips; i++) {
+		if ((td->options & NAND_BBT_ABSPAGE) ||
+		    !(td->options & NAND_BBT_WRITE)) {
+			if (td->pages[i] == -1)
+				continue;
+			block = td->pages[i] >> (bbt->bbt_erase_shift - bbt->page_shift);
+			oldval = bbt_get_entry(bbt, block);
+			bbt_mark_entry(bbt, block, BBT_BLOCK_RESERVED);
+			if ((oldval != BBT_BLOCK_RESERVED) &&
+					td->reserved_block_code)
+				nand_update_bbt(bbt, (loff_t)block <<
+						bbt->bbt_erase_shift);
+			continue;
+		}
+		update = 0;
+		if (td->options & NAND_BBT_LASTBLOCK)
+			block = ((i + 1) * nrblocks) - td->maxblocks;
+		else
+			block = i * nrblocks;
+		for (j = 0; j < td->maxblocks; j++) {
+			oldval = bbt_get_entry(bbt, block);
+			bbt_mark_entry(bbt, block, BBT_BLOCK_RESERVED);
+			if (oldval != BBT_BLOCK_RESERVED)
+				update = 1;
+			block++;
+		}
+		/*
+		 * If we want reserved blocks to be recorded to flash, and some
+		 * new ones have been marked, then we need to update the stored
+		 * bbts.  This should only happen once.
+		 */
+		if (update && td->reserved_block_code)
+			nand_update_bbt(bbt, (loff_t)(block - 1) <<
+					bbt->bbt_erase_shift);
+	}
+}
+
+/**
+ * verify_bbt_descr - verify the bad block description
+ * @bbt: NAND BBT structure
+ * @bd: the table to verify
+ *
+ * This functions performs a few sanity checks on the bad block description
+ * table.
+ */
+static void verify_bbt_descr(struct nand_bbt *bbt, struct nand_bbt_descr *bd)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	u32 pattern_len;
+	u32 bits;
+	u32 table_size;
+
+	if (!bd)
+		return;
+
+	pattern_len = bd->len;
+	bits = bd->options & NAND_BBT_NRBITS_MSK;
+
+	BUG_ON((bbt->bbt_options & NAND_BBT_NO_OOB) &&
+			!(bbt->bbt_options & NAND_BBT_USE_FLASH));
+	BUG_ON(!bits);
+
+	if (bd->options & NAND_BBT_VERSION)
+		pattern_len++;
+
+	if (bd->options & NAND_BBT_NO_OOB) {
+		BUG_ON(!(bbt->bbt_options & NAND_BBT_USE_FLASH));
+		BUG_ON(!(bbt->bbt_options & NAND_BBT_NO_OOB));
+		BUG_ON(bd->offs);
+		if (bd->options & NAND_BBT_VERSION)
+			BUG_ON(bd->veroffs != bd->len);
+		BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
+	}
+
+	if (bd->options & NAND_BBT_PERCHIP)
+		table_size = bbt->chipsize >> bbt->bbt_erase_shift;
+	else
+		table_size = mtd->size >> bbt->bbt_erase_shift;
+	table_size >>= 3;
+	table_size *= bits;
+	if (bd->options & NAND_BBT_NO_OOB)
+		table_size += pattern_len;
+	BUG_ON(table_size > (1 << bbt->bbt_erase_shift));
+}
+
+/**
+ * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
+ * @bbt: NAND BBT structure
+ *
+ * The function checks, if a bad block table(s) is/are already available. If
+ * not it scans the device for manufacturer marked good / bad blocks and writes
+ * the bad block table(s) to the selected place.
+ *
+ * The bad block table memory is allocated here. It must be freed by calling
+ * the nand_free_bbt function.
+ */
+static int nand_scan_bbt(struct nand_bbt *bbt)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int len, res = 0;
+	uint8_t *buf;
+	struct nand_bbt_descr *td = bbt->bbt_td;
+	struct nand_bbt_descr *md = bbt->bbt_md;
+
+	len = mtd->size >> (bbt->bbt_erase_shift + 2);
+	/*
+	 * Allocate memory (2bit per block) and clear the memory bad block
+	 * table.
+	 */
+	bbt->bbt = kzalloc(len, GFP_KERNEL);
+	if (!bbt->bbt)
+		return -ENOMEM;
+
+	/*
+	 * If no primary table decriptor is given, scan the device to build a
+	 * memory based bad block table.
+	 */
+	if (!td) {
+		if ((res = nand_memory_bbt(bbt))) {
+			pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
+			goto err;
+		}
+		return 0;
+	}
+	verify_bbt_descr(bbt, td);
+	verify_bbt_descr(bbt, md);
+
+	/* Allocate a temporary buffer for one eraseblock incl. oob */
+	len = (1 << bbt->bbt_erase_shift);
+	len += (len >> bbt->page_shift) * mtd->oobsize;
+	buf = vmalloc(len);
+	if (!buf) {
+		res = -ENOMEM;
+		goto err;
+	}
+
+	/* Is the bbt at a given page? */
+	if (td->options & NAND_BBT_ABSPAGE) {
+		read_abs_bbts(bbt, buf, td, md);
+	} else {
+		/* Search the bad block table using a pattern in oob */
+		search_read_bbts(bbt, buf, td, md);
+	}
+
+	res = check_create(bbt, buf);
+	if (res)
+		goto err;
+
+	/* Prevent the bbt regions from erasing / writing */
+	mark_bbt_region(bbt, td);
+	if (md)
+		mark_bbt_region(bbt, md);
+
+	vfree(buf);
+	return 0;
+
+err:
+	kfree(bbt->bbt);
+	bbt->bbt = NULL;
+	return res;
+}
+
+/**
+ * nand_update_bbt - update bad block table(s)
+ * @bbt: NAND BBT structure
+ * @offs: the offset of the newly marked block
+ *
+ * The function updates the bad block table(s).
+ */
+static int nand_update_bbt(struct nand_bbt *bbt, loff_t offs)
+{
+	struct mtd_info *mtd = bbt->mtd;
+	int len, res = 0;
+	int chip, chipsel;
+	uint8_t *buf;
+	struct nand_bbt_descr *td = bbt->bbt_td;
+	struct nand_bbt_descr *md = bbt->bbt_md;
+
+	if (!bbt->bbt || !td)
+		return -EINVAL;
+
+	/* Allocate a temporary buffer for one eraseblock incl. oob */
+	len = (1 << bbt->bbt_erase_shift);
+	len += (len >> bbt->page_shift) * mtd->oobsize;
+	buf = kmalloc(len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Do we have a bbt per chip? */
+	if (td->options & NAND_BBT_PERCHIP) {
+		chip = (int)(offs >> bbt->chip_shift);
+		chipsel = chip;
+	} else {
+		chip = 0;
+		chipsel = -1;
+	}
+
+	td->version[chip]++;
+	if (md)
+		md->version[chip]++;
+
+	/* Write the bad block table to the device? */
+	if (td->options & NAND_BBT_WRITE) {
+		res = write_bbt(bbt, buf, td, md, chipsel);
+		if (res < 0)
+			goto out;
+	}
+	/* Write the mirror bad block table to the device? */
+	if (md && (md->options & NAND_BBT_WRITE)) {
+		res = write_bbt(bbt, buf, md, td, chipsel);
+	}
+
+ out:
+	kfree(buf);
+	return res;
+}
+
+/* Generic flash bbt descriptors */
+static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
+static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
+
+static struct nand_bbt_descr bbt_main_descr = {
+	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+	.offs =	8,
+	.len = 4,
+	.veroffs = 12,
+	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
+	.pattern = bbt_pattern
+};
+
+static struct nand_bbt_descr bbt_mirror_descr = {
+	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+	.offs =	8,
+	.len = 4,
+	.veroffs = 12,
+	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
+	.pattern = mirror_pattern
+};
+
+static struct nand_bbt_descr bbt_main_no_oob_descr = {
+	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
+		| NAND_BBT_NO_OOB,
+	.len = 4,
+	.veroffs = 4,
+	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
+	.pattern = bbt_pattern
+};
+
+static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
+	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
+		| NAND_BBT_NO_OOB,
+	.len = 4,
+	.veroffs = 4,
+	.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
+	.pattern = mirror_pattern
+};
+
+/**
+ * nand_bbt_init - [NAND BBT Interface] Initialize and locate/create a bad block
+ * table
+ * @bbt: NAND BBT structure
+ *
+ * This function selects the default bad block table support for the device and
+ * scans for an existing table, or else creates one.
+ */
+int nand_bbt_init(struct nand_bbt *bbt)
+{
+	/* Is a flash based bad block table requested? */
+	if (bbt->bbt_options & NAND_BBT_USE_FLASH) {
+		/* Use the default pattern descriptors */
+		if (!bbt->bbt_td) {
+			if (bbt->bbt_options & NAND_BBT_NO_OOB) {
+				bbt->bbt_td = &bbt_main_no_oob_descr;
+				bbt->bbt_md = &bbt_mirror_no_oob_descr;
+			} else {
+				bbt->bbt_td = &bbt_main_descr;
+				bbt->bbt_md = &bbt_mirror_descr;
+			}
+		}
+	} else {
+		bbt->bbt_td = NULL;
+		bbt->bbt_md = NULL;
+	}
+
+	return nand_scan_bbt(bbt);
+}
+EXPORT_SYMBOL(nand_bbt_init);
+
+void nand_bbt_release(struct nand_bbt *bbt)
+{
+	kfree(bbt->bbt);
+}
+EXPORT_SYMBOL(nand_bbt_release);
+
+/**
+ * nand_bbt_isreserved - [NAND BBT Interface] Check if a block is reserved
+ * @bbt: NAND BBT structure
+ * @offs: offset in the device
+ */
+int nand_bbt_isreserved(struct nand_bbt *bbt, loff_t offs)
+{
+	int block;
+
+	block = (int)(offs >> bbt->bbt_erase_shift);
+	return bbt_get_entry(bbt, block) == BBT_BLOCK_RESERVED;
+}
+EXPORT_SYMBOL(nand_bbt_isreserved);
+
+/**
+ * nand_bbt_isbad - [NAND BBT Interface] Check if a block is bad
+ * @bbt: NAND BBT structure
+ * @offs: offset in the device
+ */
+int nand_bbt_isbad(struct nand_bbt *bbt, loff_t offs)
+{
+	int block, res;
+
+	block = (int)(offs >> bbt->bbt_erase_shift);
+	res = bbt_get_entry(bbt, block);
+
+	pr_debug("nand_bbt_isbad(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
+		 (unsigned int)offs, block, res);
+
+	switch (res) {
+	case BBT_BLOCK_GOOD:
+	case BBT_BLOCK_RESERVED:
+		return 0;
+	case BBT_BLOCK_WORN:
+	case BBT_BLOCK_FACTORY_BAD:
+	default:
+		return 1;
+	}
+}
+EXPORT_SYMBOL(nand_bbt_isbad);
+
+/**
+ * nand_bbt_update_mark - update mark in the BBT
+ * @bbt: NAND BBT structure
+ * @offs: offset of the bad block
+ * @mark: block type mark
+ */
+static int nand_bbt_update_mark(struct nand_bbt *bbt, loff_t offs, uint8_t mark)
+{
+	int block, ret = 0;
+
+	block = (int)(offs >> bbt->bbt_erase_shift);
+
+	/* Mark bad block in memory */
+	bbt_mark_entry(bbt, block, mark);
+
+	/* Update flash-based bad block table */
+	if (bbt->bbt_options & NAND_BBT_USE_FLASH)
+		ret = nand_update_bbt(bbt, offs);
+
+	return ret;
+}
+
+/**
+ * nand_bbt_markbad - [NAND BBT Interface] Mark a block bad in the BBT
+ * @bbt: NAND BBT structure
+ * @offs: offset of the bad block
+ */
+int nand_bbt_markbad(struct nand_bbt *bbt, loff_t offs)
+{
+	return nand_bbt_update_mark(bbt, offs, BBT_BLOCK_WORN);
+}
+EXPORT_SYMBOL(nand_bbt_markbad);
+
+/**
+ * nand_bbt_markbad_factory - [NAND BBT Interface] Mark a block as factory bad
+ * in the BBT
+ * @bbt: NAND BBT structure
+ * @offs: offset of the bad block
+ */
+int nand_bbt_markbad_factory(struct nand_bbt *bbt, loff_t offs)
+{
+	return nand_bbt_update_mark(bbt, offs, BBT_BLOCK_FACTORY_BAD);
+}
+EXPORT_SYMBOL(nand_bbt_markbad_factory);