[PATCH 1/1] mtd: nand_bbt: separate struct nand_chip from nand_bbt.c

Peter Pan 潘栋 (peterpandong) peterpandong at micron.com
Fri May 15 00:31:47 PDT 2015


Currently nand_bbt.c is tied with struct nand_chip, and it makes other
NAND family chips hard to use nand_bbt.c. Maybe it's the reason why
onenand has own bbt(onenand_bbt.c).

Parameterize a few relevant device detail information into a new
nand_bbt struct, and set some hooks for chip specified part. Allocate
and initialize struct nand_bbt in nand_base.c.

Most of the patch is borrowed from Brian Norris <computersforpeace at gmail.com>.
http://git.infradead.org/users/norris/linux-mtd.git/shortlog/refs/heads/nand-bbt

Signed-off-by: Peter Pan <peterpandong at micron.com>
Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 drivers/mtd/nand/docg4.c     |   8 +-
 drivers/mtd/nand/nand_base.c | 145 +++++++++++-
 drivers/mtd/nand/nand_bbt.c  | 518 +++++++++++++++++--------------------------
 include/linux/mtd/bbm.h      |  96 +-------
 include/linux/mtd/nand.h     |  11 +-
 include/linux/mtd/nand_bbt.h | 160 +++++++++++++
 6 files changed, 516 insertions(+), 422 deletions(-)
 create mode 100644 include/linux/mtd/nand_bbt.h

diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c
index 510c12d..ec83d9a 100644
--- a/drivers/mtd/nand/docg4.c
+++ b/drivers/mtd/nand/docg4.c
@@ -1037,7 +1037,7 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
 	 * operation after device power-up.  The above read ensures it never is.
 	 * Ugly, I know.
 	 */
-	if (nand->bbt == NULL)  /* no memory-based bbt */
+	if (nand->nand_bbt == NULL)  /* no memory-based bbt */
 		goto exit;
 
 	if (mtd->ecc_stats.failed > eccfailed_stats) {
@@ -1064,7 +1064,11 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
 		unsigned long bits = ~buf[i];
 		for_each_set_bit(bitnum, &bits, 8) {
 			int badblock = block + 7 - bitnum;
-			nand->bbt[badblock / 4] |=
+			/*
+			 * Should we create a mark factory bad block interface
+			 * for this?
+			 */
+			nand->nand_bbt->bbt[badblock / 4] |=
 				0x03 << ((badblock % 4) * 2);
 			mtd->ecc_stats.badblocks++;
 			dev_notice(doc->dev, "factory-marked bad block: %d\n",
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 0afe763..8bd8aa5 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -98,6 +98,9 @@ static int nand_get_device(struct mtd_info *mtd, int new_state);
 static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
 			     struct mtd_oob_ops *ops);
 
+static int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
+			   int allowbbt);
+
 /*
  * For devices which display every fart in the system on a separate LED. Is
  * compiled away when LED support is disabled.
@@ -451,8 +454,8 @@ static int nand_block_markbad_lowlevel(struct mtd_info *mtd, loff_t ofs)
 	}
 
 	/* Mark block bad in BBT */
-	if (chip->bbt) {
-		res = nand_markbad_bbt(mtd, ofs);
+	if (chip->nand_bbt) {
+		res = nand_bbt_markbad(chip->nand_bbt, ofs);
 		if (!ret)
 			ret = res;
 	}
@@ -494,10 +497,10 @@ static int nand_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 {
 	struct nand_chip *chip = mtd->priv;
 
-	if (!chip->bbt)
+	if (!chip->nand_bbt)
 		return 0;
 	/* Return info from the table */
-	return nand_isreserved_bbt(mtd, ofs);
+	return nand_bbt_isreserved(chip->nand_bbt, ofs);
 }
 
 /**
@@ -514,12 +517,18 @@ static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
 			       int allowbbt)
 {
 	struct nand_chip *chip = mtd->priv;
+	struct nand_bbt *bbt = chip->nand_bbt;
 
-	if (!chip->bbt)
+	if (!bbt)
 		return chip->block_bad(mtd, ofs, getchip);
 
 	/* Return info from the table */
-	return nand_isbad_bbt(mtd, ofs, allowbbt);
+	if (nand_bbt_isbad(bbt, ofs))
+		return 1;
+	else if (allowbbt)
+		return 0;
+	else
+		return nand_bbt_isreserved(bbt, ofs);
 }
 
 /**
@@ -2730,7 +2739,7 @@ static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
  *
  * Erase one ore more blocks.
  */
-int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
+static int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
 		    int allowbbt)
 {
 	int page, status, pages_per_block, ret, chipnr;
@@ -2837,6 +2846,122 @@ erase_exit:
 	return ret;
 }
 
+/* NAND BBT helper - erase a block, including reserved blocks */
+static int nand_bbt_erase_block(struct mtd_info *mtd, loff_t addr)
+{
+	struct erase_info einfo;
+	struct nand_chip *chip = mtd->priv;
+
+	memset(&einfo, 0, sizeof(einfo));
+	einfo.mtd = mtd;
+	einfo.addr = addr;
+	einfo.len = 1ULL << chip->phys_erase_shift;
+
+	return nand_erase_nand(mtd, &einfo, 1);
+}
+
+static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
+#define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
+/**
+ * nand_create_factory_badblock_pattern - [INTERN] Creates a BBT descriptor
+ * structure for factory bad block marker
+ * @chip: NAND chip to create descriptor for
+ *
+ * This function allocates and initializes a badblock_pattern for factory bad
+ * block marker based on the properties of @chip when chip.badblock_pattern
+ * is NULL.
+ */
+static int nand_create_factory_badblock_pattern(struct nand_chip *chip)
+{
+	struct nand_bbt_descr *bd;
+
+	if (chip->badblock_pattern) {
+		pr_warn("Bad block pattern already allocated; not replacing\n");
+		return -EINVAL;
+	}
+	bd = kzalloc(sizeof(*bd), GFP_KERNEL);
+	if (!bd)
+		return -ENOMEM;
+	bd->options = chip->bbt_options & BADBLOCK_SCAN_MASK;
+	bd->offs = chip->badblockpos;
+	bd->len = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
+	bd->pattern = scan_ff_pattern;
+	bd->options |= NAND_BADBLOCK_PATTERN_ALLOC;
+	chip->badblock_pattern = bd;
+
+	return 0;
+}
+
+static int nand_is_bad_bbm(struct mtd_info *mtd, loff_t addr)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mtd_oob_ops ops;
+	struct nand_bbt_descr *bd = chip->badblock_pattern;
+	int j, ret;
+	int numpages;
+
+	if (bd->options & NAND_BBT_SCAN2NDPAGE)
+		numpages = 2;
+	else
+		numpages = 1;
+
+	if (bd->options & NAND_BBT_SCANLASTPAGE)
+		addr += mtd->erasesize - (mtd->writesize * numpages);
+
+	ops.ooblen = mtd->oobsize;
+	ops.oobbuf = chip->buffers->databuf;
+	ops.ooboffs = 0;
+	ops.datbuf = NULL;
+	ops.mode = MTD_OPS_PLACE_OOB;
+
+	for (j = 0; j < numpages; j++) {
+		/*
+		 * Read the full oob until read_oob is fixed to handle single
+		 * byte reads for 16 bit buswidth.
+		 */
+		ret = nand_do_read_oob(mtd, addr, &ops);
+		/* Ignore ECC errors when checking for BBM */
+		if (ret && !mtd_is_bitflip_or_eccerr(ret))
+			return ret;
+
+		if (memcmp(chip->buffers->databuf + bd->offs,
+				bd->pattern, bd->len))
+			return 1;
+
+		addr += mtd->writesize;
+	}
+
+	return 0;
+}
+
+static int nand_default_bbt(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct nand_bbt *bbt = kzalloc(sizeof(struct nand_bbt), GFP_KERNEL);
+
+	if (!bbt)
+		return -ENOMEM;
+
+	bbt->bbt_options = chip->bbt_options;
+	bbt->mtd = mtd;
+	bbt->numchips = chip->numchips;
+	bbt->chipsize = chip->chipsize;
+	bbt->chip_shift = chip->chip_shift;
+	bbt->bbt_erase_shift = chip->phys_erase_shift;
+	bbt->page_shift = chip->page_shift;
+	bbt->bbt_td = chip->bbt_td;
+	bbt->bbt_md = chip->bbt_md;
+	bbt->is_bad_bbm = nand_is_bad_bbm;
+	bbt->erase = nand_bbt_erase_block;
+	chip->nand_bbt = bbt;
+
+	if (!chip->badblock_pattern &&
+		nand_create_factory_badblock_pattern(chip))
+		return -ENOMEM;
+
+	return nand_bbt_init(chip->nand_bbt);
+}
+
 /**
  * nand_sync - [MTD Interface] sync
  * @mtd: MTD device structure
@@ -4252,13 +4377,15 @@ void nand_release(struct mtd_info *mtd)
 	mtd_device_unregister(mtd);
 
 	/* Free bad block table memory */
-	kfree(chip->bbt);
+	if (chip->nand_bbt)
+		nand_bbt_release(chip->nand_bbt);
+	kfree(chip->nand_bbt);
 	if (!(chip->options & NAND_OWN_BUFFERS))
 		kfree(chip->buffers);
 
 	/* Free bad block descriptor memory */
 	if (chip->badblock_pattern && chip->badblock_pattern->options
-			& NAND_BBT_DYNAMICSTRUCT)
+				& NAND_BADBLOCK_PATTERN_ALLOC)
 		kfree(chip->badblock_pattern);
 }
 EXPORT_SYMBOL_GPL(nand_release);
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index 2c4fa1a..0dd6d5e 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -62,8 +62,7 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/mtd/mtd.h>
-#include <linux/mtd/bbm.h>
-#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_bbt.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/vmalloc.h>
@@ -78,20 +77,20 @@
 #define BBT_ENTRY_MASK		0x03
 #define BBT_ENTRY_SHIFT		2
 
-static int nand_update_bbt(struct mtd_info *mtd, loff_t offs);
+static int nand_update_bbt(struct nand_bbt *bbt, loff_t offs);
 
-static inline uint8_t bbt_get_entry(struct nand_chip *chip, int block)
+static inline uint8_t bbt_get_entry(struct nand_bbt *bbt, int block)
 {
-	uint8_t entry = chip->bbt[block >> BBT_ENTRY_SHIFT];
+	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_chip *chip, int block,
+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);
-	chip->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
+	bbt->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
 }
 
 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
@@ -124,23 +123,6 @@ static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_desc
 }
 
 /**
- * check_short_pattern - [GENERIC] check if a pattern is in the buffer
- * @buf: the buffer to search
- * @td:	search pattern descriptor
- *
- * Check for a pattern at the given place. Used to search bad block tables and
- * good / bad block identifiers. Same as check_pattern, but no optional empty
- * check.
- */
-static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
-{
-	/* Compare the pattern */
-	if (memcmp(buf + 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
  *
@@ -161,7 +143,7 @@ static u32 add_marker_len(struct nand_bbt_descr *td)
 
 /**
  * read_bbt - [GENERIC] Read the bad block table starting from page
- * @mtd: MTD device structure
+ * @bbt: NAND BBT structure
  * @buf: temporary buffer
  * @page: the starting page
  * @num: the number of bbt descriptors to read
@@ -170,11 +152,11 @@ static u32 add_marker_len(struct nand_bbt_descr *td)
  *
  * Read the bad block table starting from page.
  */
-static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
+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;
-	struct nand_chip *this = mtd->priv;
 	size_t retlen, len, totlen;
 	loff_t from;
 	int bits = td->options & NAND_BBT_NRBITS_MSK;
@@ -184,10 +166,10 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
 
 	totlen = (num * bits) >> 3;
 	marker_len = add_marker_len(td);
-	from = ((loff_t)page) << this->page_shift;
+	from = ((loff_t)page) << bbt->page_shift;
 
 	while (totlen) {
-		len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
+		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
@@ -223,8 +205,8 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
 				if (reserved_block_code && (tmp == reserved_block_code)) {
 					pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
 						 (loff_t)(offs + act) <<
-						 this->bbt_erase_shift);
-					bbt_mark_entry(this, offs + act,
+						 bbt->bbt_erase_shift);
+					bbt_mark_entry(bbt, offs + act,
 							BBT_BLOCK_RESERVED);
 					mtd->ecc_stats.bbtblocks++;
 					continue;
@@ -235,13 +217,13 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
 				 */
 				pr_info("nand_read_bbt: bad block at 0x%012llx\n",
 					 (loff_t)(offs + act) <<
-					 this->bbt_erase_shift);
+					 bbt->bbt_erase_shift);
 				/* Factory marked bad or worn out? */
 				if (tmp == 0)
-					bbt_mark_entry(this, offs + act,
+					bbt_mark_entry(bbt, offs + act,
 							BBT_BLOCK_FACTORY_BAD);
 				else
-					bbt_mark_entry(this, offs + act,
+					bbt_mark_entry(bbt, offs + act,
 							BBT_BLOCK_WORN);
 				mtd->ecc_stats.badblocks++;
 			}
@@ -254,7 +236,7 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
 
 /**
  * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
- * @mtd: MTD device structure
+ * @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
@@ -263,25 +245,26 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
  * 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 mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
+static int read_abs_bbt(struct nand_bbt *bbt, uint8_t *buf,
+			struct nand_bbt_descr *td, int chip)
 {
-	struct nand_chip *this = mtd->priv;
+	struct mtd_info *mtd = bbt->mtd;
 	int res = 0, i;
 
 	if (td->options & NAND_BBT_PERCHIP) {
 		int offs = 0;
-		for (i = 0; i < this->numchips; i++) {
+		for (i = 0; i < bbt->numchips; i++) {
 			if (chip == -1 || chip == i)
-				res = read_bbt(mtd, buf, td->pages[i],
-					this->chipsize >> this->bbt_erase_shift,
+				res = read_bbt(bbt, buf, td->pages[i],
+					bbt->chipsize >> bbt->bbt_erase_shift,
 					td, offs);
 			if (res)
 				return res;
-			offs += this->chipsize >> this->bbt_erase_shift;
+			offs += bbt->chipsize >> bbt->bbt_erase_shift;
 		}
 	} else {
-		res = read_bbt(mtd, buf, td->pages[0],
-				mtd->size >> this->bbt_erase_shift, td, 0);
+		res = read_bbt(bbt, buf, td->pages[0],
+				mtd->size >> bbt->bbt_erase_shift, td, 0);
 		if (res)
 			return res;
 	}
@@ -289,7 +272,7 @@ static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 }
 
 /* BBT marker is in the first page, no OOB */
-static int scan_read_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
+static int scan_read_data(struct nand_bbt *bbt, uint8_t *buf, loff_t offs,
 			 struct nand_bbt_descr *td)
 {
 	size_t retlen;
@@ -299,12 +282,12 @@ static int scan_read_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
 	if (td->options & NAND_BBT_VERSION)
 		len++;
 
-	return mtd_read(mtd, offs, len, &retlen, buf);
+	return mtd_read(bbt->mtd, offs, len, &retlen, buf);
 }
 
 /**
  * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
- * @mtd: MTD device structure
+ * @bbt: NAND BBT structure
  * @buf: temporary buffer
  * @offs: offset at which to scan
  * @len: length of data region to read
@@ -313,9 +296,10 @@ static int scan_read_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
  * 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 mtd_info *mtd, uint8_t *buf, loff_t offs,
+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;
 
@@ -343,13 +327,13 @@ static int scan_read_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
 	return ret;
 }
 
-static int scan_read(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
+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(mtd, buf, offs, td);
+		return scan_read_data(bbt, buf, offs, td);
 	else
-		return scan_read_oob(mtd, buf, offs, len);
+		return scan_read_oob(bbt, buf, offs, len);
 }
 
 /* Scan write data with oob to flash */
@@ -368,8 +352,9 @@ static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
 	return mtd_write_oob(mtd, offs, &ops);
 }
 
-static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
+static u32 bbt_get_ver_offs(struct nand_bbt *bbt, struct nand_bbt_descr *td)
 {
+	struct mtd_info *mtd = bbt->mtd;
 	u32 ver_offs = td->veroffs;
 
 	if (!(td->options & NAND_BBT_NO_OOB))
@@ -379,7 +364,7 @@ static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
 
 /**
  * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
- * @mtd: MTD device structure
+ * @bbt: NAND BBT structure
  * @buf: temporary buffer
  * @td: descriptor for the bad block table
  * @md:	descriptor for the bad block table mirror
@@ -387,130 +372,85 @@ static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
  * 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 mtd_info *mtd, uint8_t *buf,
+static void read_abs_bbts(struct nand_bbt *bbt, uint8_t *buf,
 			  struct nand_bbt_descr *td, struct nand_bbt_descr *md)
 {
-	struct nand_chip *this = mtd->priv;
+	struct mtd_info *mtd = bbt->mtd;
 
 	/* Read the primary version, if available */
 	if (td->options & NAND_BBT_VERSION) {
-		scan_read(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
+		scan_read(bbt, buf, (loff_t)td->pages[0] << bbt->page_shift,
 			      mtd->writesize, td);
-		td->version[0] = buf[bbt_get_ver_offs(mtd, 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(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
+		scan_read(bbt, buf, (loff_t)md->pages[0] << bbt->page_shift,
 			      mtd->writesize, md);
-		md->version[0] = buf[bbt_get_ver_offs(mtd, 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]);
 	}
 }
 
-/* Scan a given block partially */
-static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
-			   loff_t offs, uint8_t *buf, int numpages)
-{
-	struct mtd_oob_ops ops;
-	int j, ret;
-
-	ops.ooblen = mtd->oobsize;
-	ops.oobbuf = buf;
-	ops.ooboffs = 0;
-	ops.datbuf = NULL;
-	ops.mode = MTD_OPS_PLACE_OOB;
-
-	for (j = 0; j < numpages; j++) {
-		/*
-		 * Read the full oob until read_oob is fixed to handle single
-		 * byte reads for 16 bit buswidth.
-		 */
-		ret = mtd_read_oob(mtd, offs, &ops);
-		/* Ignore ECC errors when checking for BBM */
-		if (ret && !mtd_is_bitflip_or_eccerr(ret))
-			return ret;
-
-		if (check_short_pattern(buf, bd))
-			return 1;
-
-		offs += mtd->writesize;
-	}
-	return 0;
-}
-
 /**
  * create_bbt - [GENERIC] Create a bad block table by scanning the device
- * @mtd: MTD device structure
- * @buf: temporary buffer
- * @bd: descriptor for the good/bad block search pattern
+ * @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 mtd_info *mtd, uint8_t *buf,
-	struct nand_bbt_descr *bd, int chip)
+static int create_bbt(struct nand_bbt *bbt, int chip)
 {
-	struct nand_chip *this = mtd->priv;
-	int i, numblocks, numpages;
-	int startblock;
+	struct mtd_info *mtd = bbt->mtd;
+	int i, startblock, numblocks;
 	loff_t from;
 
 	pr_info("Scanning device for bad blocks\n");
 
-	if (bd->options & NAND_BBT_SCAN2NDPAGE)
-		numpages = 2;
-	else
-		numpages = 1;
-
 	if (chip == -1) {
-		numblocks = mtd->size >> this->bbt_erase_shift;
+		numblocks = mtd->size >> bbt->bbt_erase_shift;
 		startblock = 0;
 		from = 0;
 	} else {
-		if (chip >= this->numchips) {
+		if (chip >= bbt->numchips) {
 			pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
-			       chip + 1, this->numchips);
+			       chip + 1, bbt->numchips);
 			return -EINVAL;
 		}
-		numblocks = this->chipsize >> this->bbt_erase_shift;
+		numblocks = bbt->chipsize >> bbt->bbt_erase_shift;
 		startblock = chip * numblocks;
 		numblocks += startblock;
-		from = (loff_t)startblock << this->bbt_erase_shift;
+		from = (loff_t)startblock << bbt->bbt_erase_shift;
 	}
 
-	if (this->bbt_options & NAND_BBT_SCANLASTPAGE)
-		from += mtd->erasesize - (mtd->writesize * numpages);
-
 	for (i = startblock; i < numblocks; i++) {
 		int ret;
 
-		BUG_ON(bd->options & NAND_BBT_NO_OOB);
-
-		ret = scan_block_fast(mtd, bd, from, buf, numpages);
+		ret = bbt->is_bad_bbm(mtd, from);
 		if (ret < 0)
 			return ret;
 
 		if (ret) {
-			bbt_mark_entry(this, i, BBT_BLOCK_FACTORY_BAD);
+			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 << this->bbt_erase_shift);
+		from += (1 << bbt->bbt_erase_shift);
 	}
 	return 0;
 }
 
 /**
  * search_bbt - [GENERIC] scan the device for a specific bad block table
- * @mtd: MTD device structure
+ * @bbt: NAND BBT structure
  * @buf: temporary buffer
  * @td: descriptor for the bad block table
  *
@@ -523,18 +463,19 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
  *
  * The bbt ident pattern resides in the oob area of the first page in a block.
  */
-static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
+static int search_bbt(struct nand_bbt *bbt, uint8_t *buf,
+			struct nand_bbt_descr *td)
 {
-	struct nand_chip *this = mtd->priv;
+	struct mtd_info *mtd = bbt->mtd;
 	int i, chips;
 	int startblock, block, dir;
 	int scanlen = mtd->writesize + mtd->oobsize;
 	int bbtblocks;
-	int blocktopage = this->bbt_erase_shift - this->page_shift;
+	int blocktopage = bbt->bbt_erase_shift - bbt->page_shift;
 
 	/* Search direction top -> down? */
 	if (td->options & NAND_BBT_LASTBLOCK) {
-		startblock = (mtd->size >> this->bbt_erase_shift) - 1;
+		startblock = (mtd->size >> bbt->bbt_erase_shift) - 1;
 		dir = -1;
 	} else {
 		startblock = 0;
@@ -543,12 +484,12 @@ static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr
 
 	/* Do we have a bbt per chip? */
 	if (td->options & NAND_BBT_PERCHIP) {
-		chips = this->numchips;
-		bbtblocks = this->chipsize >> this->bbt_erase_shift;
+		chips = bbt->numchips;
+		bbtblocks = bbt->chipsize >> bbt->bbt_erase_shift;
 		startblock &= bbtblocks - 1;
 	} else {
 		chips = 1;
-		bbtblocks = mtd->size >> this->bbt_erase_shift;
+		bbtblocks = mtd->size >> bbt->bbt_erase_shift;
 	}
 
 	for (i = 0; i < chips; i++) {
@@ -559,20 +500,20 @@ static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr
 		for (block = 0; block < td->maxblocks; block++) {
 
 			int actblock = startblock + dir * block;
-			loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
+			loff_t offs = (loff_t)actblock << bbt->bbt_erase_shift;
 
 			/* Read first page */
-			scan_read(mtd, buf, offs, mtd->writesize, td);
+			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(mtd, td);
+					offs = bbt_get_ver_offs(bbt, td);
 					td->version[i] = buf[offs];
 				}
 				break;
 			}
 		}
-		startblock += this->chipsize >> this->bbt_erase_shift;
+		startblock += bbt->chipsize >> bbt->bbt_erase_shift;
 	}
 	/* Check, if we found a bbt for each requested chip */
 	for (i = 0; i < chips; i++) {
@@ -587,28 +528,28 @@ static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr
 
 /**
  * search_read_bbts - [GENERIC] scan the device for bad block table(s)
- * @mtd: MTD device structure
+ * @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 mtd_info *mtd, uint8_t *buf,
+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(mtd, buf, td);
+	search_bbt(bbt, buf, td);
 
 	/* Search the mirror table */
 	if (md)
-		search_bbt(mtd, buf, md);
+		search_bbt(bbt, buf, md);
 }
 
 /**
  * write_bbt - [GENERIC] (Re)write the bad block table
- * @mtd: MTD device structure
+ * @bbt: NAND BBT structure
  * @buf: temporary buffer
  * @td: descriptor for the bad block table
  * @md: descriptor for the bad block table mirror
@@ -616,12 +557,11 @@ static void search_read_bbts(struct mtd_info *mtd, uint8_t *buf,
  *
  * (Re)write the bad block table.
  */
-static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
+static int write_bbt(struct nand_bbt *bbt, uint8_t *buf,
 		     struct nand_bbt_descr *td, struct nand_bbt_descr *md,
 		     int chipsel)
 {
-	struct nand_chip *this = mtd->priv;
-	struct erase_info einfo;
+	struct mtd_info *mtd = bbt->mtd;
 	int i, res, chip = 0;
 	int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
 	int nrchips, pageoffs, ooboffs;
@@ -640,16 +580,16 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 		rcode = 0xff;
 	/* Write bad block table per chip rather than per device? */
 	if (td->options & NAND_BBT_PERCHIP) {
-		numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
+		numblocks = (int)(bbt->chipsize >> bbt->bbt_erase_shift);
 		/* Full device write or specific chip? */
 		if (chipsel == -1) {
-			nrchips = this->numchips;
+			nrchips = bbt->numchips;
 		} else {
 			nrchips = chipsel + 1;
 			chip = chipsel;
 		}
 	} else {
-		numblocks = (int)(mtd->size >> this->bbt_erase_shift);
+		numblocks = (int)(mtd->size >> bbt->bbt_erase_shift);
 		nrchips = 1;
 	}
 
@@ -680,13 +620,13 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 		for (i = 0; i < td->maxblocks; i++) {
 			int block = startblock + dir * i;
 			/* Check, if the block is bad */
-			switch (bbt_get_entry(this, block)) {
+			switch (bbt_get_entry(bbt, block)) {
 			case BBT_BLOCK_WORN:
 			case BBT_BLOCK_FACTORY_BAD:
 				continue;
 			}
 			page = block <<
-				(this->bbt_erase_shift - this->page_shift);
+				(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;
@@ -714,13 +654,13 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 		default: return -EINVAL;
 		}
 
-		to = ((loff_t)page) << this->page_shift;
+		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 << this->bbt_erase_shift) - 1);
-			len = 1 << this->bbt_erase_shift;
+			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) {
@@ -730,15 +670,15 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 				pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
 			}
 			/* Read oob data */
-			ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
+			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 >> this->page_shift);
-			offs = pageoffs << this->page_shift;
+			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);
@@ -765,7 +705,7 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 			len = ALIGN(len, mtd->writesize);
 			/* Preset the buffer with 0xff */
 			memset(buf, 0xff, len +
-			       (len >> this->page_shift)* mtd->oobsize);
+			       (len >> bbt->page_shift) * mtd->oobsize);
 			offs = 0;
 			ooboffs = len;
 			/* Pattern is located in oob area of first page */
@@ -779,16 +719,12 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 		for (i = 0; i < numblocks; i++) {
 			uint8_t dat;
 			int sftcnt = (i << (3 - sft)) & sftmsk;
-			dat = bbt_get_entry(this, chip * numblocks + i);
+			dat = bbt_get_entry(bbt, chip * numblocks + i);
 			/* Do not store the reserved bbt blocks! */
 			buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
 		}
 
-		memset(&einfo, 0, sizeof(einfo));
-		einfo.mtd = mtd;
-		einfo.addr = to;
-		einfo.len = 1 << this->bbt_erase_shift;
-		res = nand_erase_nand(mtd, &einfo, 1);
+		res = bbt->erase(mtd, to);
 		if (res < 0)
 			goto outerr;
 
@@ -813,41 +749,36 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 
 /**
  * nand_memory_bbt - [GENERIC] create a memory based bad block table
- * @mtd: MTD device structure
- * @bd: descriptor for the good/bad block search pattern
+ * @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 mtd_info *mtd, struct nand_bbt_descr *bd)
+static inline int nand_memory_bbt(struct nand_bbt *bbt)
 {
-	struct nand_chip *this = mtd->priv;
-
-	return create_bbt(mtd, this->buffers->databuf, bd, -1);
+	return create_bbt(bbt, -1);
 }
 
 /**
  * check_create - [GENERIC] create and write bbt(s) if necessary
- * @mtd: MTD device structure
+ * @bbt: NAND BBT structure
  * @buf: temporary buffer
- * @bd: descriptor for the good/bad block search pattern
  *
  * 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 mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
+static int check_create(struct nand_bbt *bbt, uint8_t *buf)
 {
 	int i, chips, writeops, create, chipsel, res, res2;
-	struct nand_chip *this = mtd->priv;
-	struct nand_bbt_descr *td = this->bbt_td;
-	struct nand_bbt_descr *md = this->bbt_md;
+	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 = this->numchips;
+		chips = bbt->numchips;
 	else
 		chips = 1;
 
@@ -896,8 +827,8 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 				continue;
 
 			/* Create the table in memory by scanning the chip(s) */
-			if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
-				create_bbt(mtd, buf, bd, chipsel);
+			if (!(bbt->bbt_options & NAND_BBT_CREATE_EMPTY))
+				create_bbt(bbt, chipsel);
 
 			td->version[i] = 1;
 			if (md)
@@ -906,7 +837,7 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 
 		/* Read back first? */
 		if (rd) {
-			res = read_abs_bbt(mtd, buf, rd, chipsel);
+			res = read_abs_bbt(bbt, buf, rd, chipsel);
 			if (mtd_is_eccerr(res)) {
 				/* Mark table as invalid */
 				rd->pages[i] = -1;
@@ -917,7 +848,7 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 		}
 		/* If they weren't versioned, read both */
 		if (rd2) {
-			res2 = read_abs_bbt(mtd, buf, rd2, chipsel);
+			res2 = read_abs_bbt(bbt, buf, rd2, chipsel);
 			if (mtd_is_eccerr(res2)) {
 				/* Mark table as invalid */
 				rd2->pages[i] = -1;
@@ -939,14 +870,14 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 
 		/* Write the bad block table to the device? */
 		if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
-			res = write_bbt(mtd, buf, td, md, chipsel);
+			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(mtd, buf, md, td, chipsel);
+			res = write_bbt(bbt, buf, md, td, chipsel);
 			if (res < 0)
 				return res;
 		}
@@ -956,25 +887,25 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 
 /**
  * mark_bbt_regions - [GENERIC] mark the bad block table regions
- * @mtd: MTD device structure
+ * @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 mtd_info *mtd, struct nand_bbt_descr *td)
+static void mark_bbt_region(struct nand_bbt *bbt, struct nand_bbt_descr *td)
 {
-	struct nand_chip *this = mtd->priv;
+	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 = this->numchips;
-		nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
+		chips = bbt->numchips;
+		nrblocks = (int)(bbt->chipsize >> bbt->bbt_erase_shift);
 	} else {
 		chips = 1;
-		nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
+		nrblocks = (int)(mtd->size >> bbt->bbt_erase_shift);
 	}
 
 	for (i = 0; i < chips; i++) {
@@ -982,13 +913,14 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
 		    !(td->options & NAND_BBT_WRITE)) {
 			if (td->pages[i] == -1)
 				continue;
-			block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
-			oldval = bbt_get_entry(this, block);
-			bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
+			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(mtd, (loff_t)block <<
-						this->bbt_erase_shift);
+				nand_update_bbt(bbt, (loff_t)block <<
+						bbt->bbt_erase_shift);
 			continue;
 		}
 		update = 0;
@@ -997,8 +929,8 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
 		else
 			block = i * nrblocks;
 		for (j = 0; j < td->maxblocks; j++) {
-			oldval = bbt_get_entry(this, block);
-			bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
+			oldval = bbt_get_entry(bbt, block);
+			bbt_mark_entry(bbt, block, BBT_BLOCK_RESERVED);
 			if (oldval != BBT_BLOCK_RESERVED)
 				update = 1;
 			block++;
@@ -1009,22 +941,22 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
 		 * bbts.  This should only happen once.
 		 */
 		if (update && td->reserved_block_code)
-			nand_update_bbt(mtd, (loff_t)(block - 1) <<
-					this->bbt_erase_shift);
+			nand_update_bbt(bbt, (loff_t)(block - 1) <<
+					bbt->bbt_erase_shift);
 	}
 }
 
 /**
  * verify_bbt_descr - verify the bad block description
- * @mtd: MTD device structure
+ * @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 mtd_info *mtd, struct nand_bbt_descr *bd)
+static void verify_bbt_descr(struct nand_bbt *bbt, struct nand_bbt_descr *bd)
 {
-	struct nand_chip *this = mtd->priv;
+	struct mtd_info *mtd = bbt->mtd;
 	u32 pattern_len;
 	u32 bits;
 	u32 table_size;
@@ -1035,16 +967,16 @@ static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
 	pattern_len = bd->len;
 	bits = bd->options & NAND_BBT_NRBITS_MSK;
 
-	BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
-			!(this->bbt_options & NAND_BBT_USE_FLASH));
+	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(!(this->bbt_options & NAND_BBT_USE_FLASH));
-		BUG_ON(!(this->bbt_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);
@@ -1052,20 +984,19 @@ static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
 	}
 
 	if (bd->options & NAND_BBT_PERCHIP)
-		table_size = this->chipsize >> this->bbt_erase_shift;
+		table_size = bbt->chipsize >> bbt->bbt_erase_shift;
 	else
-		table_size = mtd->size >> this->bbt_erase_shift;
+		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 << this->bbt_erase_shift));
+	BUG_ON(table_size > (1 << bbt->bbt_erase_shift));
 }
 
 /**
  * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
- * @mtd: MTD device structure
- * @bd: descriptor for the good/bad block search pattern
+ * @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
@@ -1074,21 +1005,21 @@ static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
  * 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 mtd_info *mtd, struct nand_bbt_descr *bd)
+static int nand_scan_bbt(struct nand_bbt *bbt)
 {
-	struct nand_chip *this = mtd->priv;
+	struct mtd_info *mtd = bbt->mtd;
 	int len, res;
 	uint8_t *buf;
-	struct nand_bbt_descr *td = this->bbt_td;
-	struct nand_bbt_descr *md = this->bbt_md;
+	struct nand_bbt_descr *td = bbt->bbt_td;
+	struct nand_bbt_descr *md = bbt->bbt_md;
 
-	len = mtd->size >> (this->bbt_erase_shift + 2);
+	len = mtd->size >> (bbt->bbt_erase_shift + 2);
 	/*
 	 * Allocate memory (2bit per block) and clear the memory bad block
 	 * table.
 	 */
-	this->bbt = kzalloc(len, GFP_KERNEL);
-	if (!this->bbt)
+	bbt->bbt = kzalloc(len, GFP_KERNEL);
+	if (!bbt->bbt)
 		return -ENOMEM;
 
 	/*
@@ -1096,18 +1027,19 @@ static int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
 	 * memory based bad block table.
 	 */
 	if (!td) {
-		if ((res = nand_memory_bbt(mtd, bd))) {
+		res = nand_memory_bbt(bbt);
+		if (res) {
 			pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
 			goto err;
 		}
 		return 0;
 	}
-	verify_bbt_descr(mtd, td);
-	verify_bbt_descr(mtd, md);
+	verify_bbt_descr(bbt, td);
+	verify_bbt_descr(bbt, md);
 
 	/* Allocate a temporary buffer for one eraseblock incl. oob */
-	len = (1 << this->bbt_erase_shift);
-	len += (len >> this->page_shift) * mtd->oobsize;
+	len = (1 << bbt->bbt_erase_shift);
+	len += (len >> bbt->page_shift) * mtd->oobsize;
 	buf = vmalloc(len);
 	if (!buf) {
 		res = -ENOMEM;
@@ -1116,59 +1048,59 @@ static int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
 
 	/* Is the bbt at a given page? */
 	if (td->options & NAND_BBT_ABSPAGE) {
-		read_abs_bbts(mtd, buf, td, md);
+		read_abs_bbts(bbt, buf, td, md);
 	} else {
 		/* Search the bad block table using a pattern in oob */
-		search_read_bbts(mtd, buf, td, md);
+		search_read_bbts(bbt, buf, td, md);
 	}
 
-	res = check_create(mtd, buf, bd);
+	res = check_create(bbt, buf);
 	if (res)
 		goto err;
 
 	/* Prevent the bbt regions from erasing / writing */
-	mark_bbt_region(mtd, td);
+	mark_bbt_region(bbt, td);
 	if (md)
-		mark_bbt_region(mtd, md);
+		mark_bbt_region(bbt, md);
 
 	vfree(buf);
 	return 0;
 
 err:
-	kfree(this->bbt);
-	this->bbt = NULL;
+	kfree(bbt->bbt);
+	bbt->bbt = NULL;
 	return res;
 }
 
 /**
  * nand_update_bbt - update bad block table(s)
- * @mtd: MTD device structure
+ * @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 mtd_info *mtd, loff_t offs)
+static int nand_update_bbt(struct nand_bbt *bbt, loff_t offs)
 {
-	struct nand_chip *this = mtd->priv;
+	struct mtd_info *mtd = bbt->mtd;
 	int len, res = 0;
 	int chip, chipsel;
 	uint8_t *buf;
-	struct nand_bbt_descr *td = this->bbt_td;
-	struct nand_bbt_descr *md = this->bbt_md;
+	struct nand_bbt_descr *td = bbt->bbt_td;
+	struct nand_bbt_descr *md = bbt->bbt_md;
 
-	if (!this->bbt || !td)
+	if (!bbt->bbt || !td)
 		return -EINVAL;
 
 	/* Allocate a temporary buffer for one eraseblock incl. oob */
-	len = (1 << this->bbt_erase_shift);
-	len += (len >> this->page_shift) * mtd->oobsize;
+	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 >> this->chip_shift);
+		chip = (int)(offs >> bbt->chip_shift);
 		chipsel = chip;
 	} else {
 		chip = 0;
@@ -1181,13 +1113,13 @@ static int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
 
 	/* Write the bad block table to the device? */
 	if (td->options & NAND_BBT_WRITE) {
-		res = write_bbt(mtd, buf, td, md, chipsel);
+		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(mtd, buf, md, td, chipsel);
+		res = write_bbt(bbt, buf, md, td, chipsel);
 	}
 
  out:
@@ -1195,12 +1127,6 @@ static int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
 	return res;
 }
 
-/*
- * Define some generic bad / good block scan pattern which are used
- * while scanning a device for factory marked good / bad blocks.
- */
-static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
-
 /* Generic flash bbt descriptors */
 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
@@ -1245,135 +1171,103 @@ static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
 	.pattern = mirror_pattern
 };
 
-#define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
 /**
- * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
- * @this: NAND chip to create descriptor for
+ * nand_bbt_init - [NAND Interface] Initialize and locate/create a bad block
+ * table
  *
- * This function allocates and initializes a nand_bbt_descr for BBM detection
- * based on the properties of @this. The new descriptor is stored in
- * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
- * passed to this function.
- */
-static int nand_create_badblock_pattern(struct nand_chip *this)
-{
-	struct nand_bbt_descr *bd;
-	if (this->badblock_pattern) {
-		pr_warn("Bad block pattern already allocated; not replacing\n");
-		return -EINVAL;
-	}
-	bd = kzalloc(sizeof(*bd), GFP_KERNEL);
-	if (!bd)
-		return -ENOMEM;
-	bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
-	bd->offs = this->badblockpos;
-	bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
-	bd->pattern = scan_ff_pattern;
-	bd->options |= NAND_BBT_DYNAMICSTRUCT;
-	this->badblock_pattern = bd;
-	return 0;
-}
-
-/**
- * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
- * @mtd: MTD device structure
+ * @bbt: NAND BBT structure
  *
  * This function selects the default bad block table support for the device and
- * calls the nand_scan_bbt function.
+ * scans for an existing table, or else creates one.
  */
-int nand_default_bbt(struct mtd_info *mtd)
+int nand_bbt_init(struct nand_bbt *bbt)
 {
-	struct nand_chip *this = mtd->priv;
-	int ret;
-
 	/* Is a flash based bad block table requested? */
-	if (this->bbt_options & NAND_BBT_USE_FLASH) {
+	if (bbt->bbt_options & NAND_BBT_USE_FLASH) {
 		/* Use the default pattern descriptors */
-		if (!this->bbt_td) {
-			if (this->bbt_options & NAND_BBT_NO_OOB) {
-				this->bbt_td = &bbt_main_no_oob_descr;
-				this->bbt_md = &bbt_mirror_no_oob_descr;
+		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 {
-				this->bbt_td = &bbt_main_descr;
-				this->bbt_md = &bbt_mirror_descr;
+				bbt->bbt_td = &bbt_main_descr;
+				bbt->bbt_md = &bbt_mirror_descr;
 			}
 		}
 	} else {
-		this->bbt_td = NULL;
-		this->bbt_md = NULL;
+		bbt->bbt_td = NULL;
+		bbt->bbt_md = NULL;
 	}
 
-	if (!this->badblock_pattern) {
-		ret = nand_create_badblock_pattern(this);
-		if (ret)
-			return ret;
-	}
+	return nand_scan_bbt(bbt);
+}
+EXPORT_SYMBOL(nand_bbt_init);
 
-	return nand_scan_bbt(mtd, this->badblock_pattern);
+void nand_bbt_release(struct nand_bbt *bbt)
+{
+	kfree(bbt->bbt);
 }
+EXPORT_SYMBOL(nand_bbt_release);
 
 /**
- * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
- * @mtd: MTD device structure
+ * nand_bbt_isreserved - [NAND Interface] Check if a block is reserved
+ * @bbt: NAND BBT structure
  * @offs: offset in the device
  */
-int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs)
+int nand_bbt_isreserved(struct nand_bbt *bbt, loff_t offs)
 {
-	struct nand_chip *this = mtd->priv;
 	int block;
 
-	block = (int)(offs >> this->bbt_erase_shift);
-	return bbt_get_entry(this, block) == BBT_BLOCK_RESERVED;
+	block = (int)(offs >> bbt->bbt_erase_shift);
+	return bbt_get_entry(bbt, block) == BBT_BLOCK_RESERVED;
 }
+EXPORT_SYMBOL(nand_bbt_isreserved);
 
 /**
- * nand_isbad_bbt - [NAND Interface] Check if a block is bad
- * @mtd: MTD device structure
+ * nand_bbt_isbad - [NAND Interface] Check if a block is bad
+ * @bbt: NAND BBT structure
  * @offs: offset in the device
- * @allowbbt: allow access to bad block table region
  */
-int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
+int nand_bbt_isbad(struct nand_bbt *bbt, loff_t offs)
 {
-	struct nand_chip *this = mtd->priv;
 	int block, res;
 
-	block = (int)(offs >> this->bbt_erase_shift);
-	res = bbt_get_entry(this, block);
+	block = (int)(offs >> bbt->bbt_erase_shift);
+	res = bbt_get_entry(bbt, block);
 
-	pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
+	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;
-	case BBT_BLOCK_RESERVED:
-		return allowbbt ? 0 : 1;
 	}
-	return 1;
 }
+EXPORT_SYMBOL(nand_bbt_isbad);
 
 /**
- * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
- * @mtd: MTD device structure
+ * nand_bbt_markbad - [NAND Interface] Mark a block bad in the BBT
+ * @bbt: NAND BBT structure
  * @offs: offset of the bad block
  */
-int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs)
+int nand_bbt_markbad(struct nand_bbt *bbt, loff_t offs)
 {
-	struct nand_chip *this = mtd->priv;
 	int block, ret = 0;
 
-	block = (int)(offs >> this->bbt_erase_shift);
+	block = (int)(offs >> bbt->bbt_erase_shift);
 
 	/* Mark bad block in memory */
-	bbt_mark_entry(this, block, BBT_BLOCK_WORN);
+	bbt_mark_entry(bbt, block, BBT_BLOCK_WORN);
 
 	/* Update flash-based bad block table */
-	if (this->bbt_options & NAND_BBT_USE_FLASH)
-		ret = nand_update_bbt(mtd, offs);
+	if (bbt->bbt_options & NAND_BBT_USE_FLASH)
+		ret = nand_update_bbt(bbt, offs);
 
 	return ret;
 }
-
-EXPORT_SYMBOL(nand_scan_bbt);
+EXPORT_SYMBOL(nand_bbt_markbad);
diff --git a/include/linux/mtd/bbm.h b/include/linux/mtd/bbm.h
index 36bb6a5..fb751d9 100644
--- a/include/linux/mtd/bbm.h
+++ b/include/linux/mtd/bbm.h
@@ -28,102 +28,8 @@
 #ifndef __LINUX_MTD_BBM_H
 #define __LINUX_MTD_BBM_H
 
-/* The maximum number of NAND chips in an array */
-#define NAND_MAX_CHIPS		8
+#include <linux/mtd/nand_bbt.h>
 
-/**
- * struct nand_bbt_descr - bad block table descriptor
- * @options:	options for this descriptor
- * @pages:	the page(s) where we find the bbt, used with option BBT_ABSPAGE
- *		when bbt is searched, then we store the found bbts pages here.
- *		Its an array and supports up to 8 chips now
- * @offs:	offset of the pattern in the oob area of the page
- * @veroffs:	offset of the bbt version counter in the oob are of the page
- * @version:	version read from the bbt page during scan
- * @len:	length of the pattern, if 0 no pattern check is performed
- * @maxblocks:	maximum number of blocks to search for a bbt. This number of
- *		blocks is reserved at the end of the device where the tables are
- *		written.
- * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
- *              bad) block in the stored bbt
- * @pattern:	pattern to identify bad block table or factory marked good /
- *		bad blocks, can be NULL, if len = 0
- *
- * Descriptor for the bad block table marker and the descriptor for the
- * pattern which identifies good and bad blocks. The assumption is made
- * that the pattern and the version count are always located in the oob area
- * of the first block.
- */
-struct nand_bbt_descr {
-	int options;
-	int pages[NAND_MAX_CHIPS];
-	int offs;
-	int veroffs;
-	uint8_t version[NAND_MAX_CHIPS];
-	int len;
-	int maxblocks;
-	int reserved_block_code;
-	uint8_t *pattern;
-};
-
-/* Options for the bad block table descriptors */
-
-/* The number of bits used per block in the bbt on the device */
-#define NAND_BBT_NRBITS_MSK	0x0000000F
-#define NAND_BBT_1BIT		0x00000001
-#define NAND_BBT_2BIT		0x00000002
-#define NAND_BBT_4BIT		0x00000004
-#define NAND_BBT_8BIT		0x00000008
-/* The bad block table is in the last good block of the device */
-#define NAND_BBT_LASTBLOCK	0x00000010
-/* The bbt is at the given page, else we must scan for the bbt */
-#define NAND_BBT_ABSPAGE	0x00000020
-/* bbt is stored per chip on multichip devices */
-#define NAND_BBT_PERCHIP	0x00000080
-/* bbt has a version counter at offset veroffs */
-#define NAND_BBT_VERSION	0x00000100
-/* Create a bbt if none exists */
-#define NAND_BBT_CREATE		0x00000200
-/*
- * Create an empty BBT with no vendor information. Vendor's information may be
- * unavailable, for example, if the NAND controller has a different data and OOB
- * layout or if this information is already purged. Must be used in conjunction
- * with NAND_BBT_CREATE.
- */
-#define NAND_BBT_CREATE_EMPTY	0x00000400
-/* Write bbt if neccecary */
-#define NAND_BBT_WRITE		0x00002000
-/* Read and write back block contents when writing bbt */
-#define NAND_BBT_SAVECONTENT	0x00004000
-/* Search good / bad pattern on the first and the second page */
-#define NAND_BBT_SCAN2NDPAGE	0x00008000
-/* Search good / bad pattern on the last page of the eraseblock */
-#define NAND_BBT_SCANLASTPAGE	0x00010000
-/*
- * Use a flash based bad block table. By default, OOB identifier is saved in
- * OOB area. This option is passed to the default bad block table function.
- */
-#define NAND_BBT_USE_FLASH	0x00020000
-/*
- * Do not store flash based bad block table marker in the OOB area; store it
- * in-band.
- */
-#define NAND_BBT_NO_OOB		0x00040000
-/*
- * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
- * entire spare area. Must be used with NAND_BBT_USE_FLASH.
- */
-#define NAND_BBT_NO_OOB_BBM	0x00080000
-
-/*
- * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
- * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
- * in nand_chip.bbt_options.
- */
-#define NAND_BBT_DYNAMICSTRUCT	0x80000000
-
-/* The maximum number of blocks to scan for a bbt */
-#define NAND_BBT_SCAN_MAXBLOCKS	4
 
 /*
  * Constants for oob configuration
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 6c51876..fbd3007 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -192,6 +192,12 @@ typedef enum {
 /* Nand scan has allocated controller struct */
 #define NAND_CONTROLLER_ALLOC	0x80000000
 
+/*
+ * Flag to mark that the badblock_pattern is allocated dynamicaly and must
+ * be freed in nand_release().
+ */
+#define NAND_BADBLOCK_PATTERN_ALLOC	0x08000000
+
 /* Cell info constants */
 #define NAND_CI_CHIPNR_MSK	0x03
 #define NAND_CI_CELLTYPE_MSK	0x0C
@@ -711,7 +717,7 @@ struct nand_chip {
 	struct nand_buffers *buffers;
 	struct nand_hw_control hwcontrol;
 
-	uint8_t *bbt;
+	struct nand_bbt *nand_bbt;
 	struct nand_bbt_descr *bbt_td;
 	struct nand_bbt_descr *bbt_md;
 
@@ -833,12 +839,9 @@ struct nand_manufacturers {
 extern struct nand_flash_dev nand_flash_ids[];
 extern struct nand_manufacturers nand_manuf_ids[];
 
-extern int nand_default_bbt(struct mtd_info *mtd);
 extern int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs);
 extern int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs);
 extern int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt);
-extern int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
-			   int allowbbt);
 extern int nand_do_read(struct mtd_info *mtd, loff_t from, size_t len,
 			size_t *retlen, uint8_t *buf);
 
diff --git a/include/linux/mtd/nand_bbt.h b/include/linux/mtd/nand_bbt.h
new file mode 100644
index 0000000..03ee0eb
--- /dev/null
+++ b/include/linux/mtd/nand_bbt.h
@@ -0,0 +1,160 @@
+/*
+ *  NAND family Bad Block Table support
+ *
+ *  Copyright © 2015 Broadcom Corporation
+ *  Brian Norris <computersforpeace at gmail.com>
+ *
+ * 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.
+ *
+ */
+#ifndef __LINUX_MTD_NAND_BBT_H
+#define __LINUX_MTD_NAND_BBT_H
+
+struct mtd_info;
+
+/* The maximum number of NAND chips in an array */
+#define NAND_MAX_CHIPS		8
+
+/**
+ * struct nand_bbt_descr - bad block table descriptor
+ * @options:	options for this descriptor
+ * @pages:	the page(s) where we find the bbt, used with option BBT_ABSPAGE
+ *		when bbt is searched, then we store the found bbts pages here.
+ *		Its an array and supports up to 8 chips now
+ * @offs:	offset of the pattern in the oob area of the page
+ * @veroffs:	offset of the bbt version counter in the oob are of the page
+ * @version:	version read from the bbt page during scan
+ * @len:	length of the pattern, if 0 no pattern check is performed
+ * @maxblocks:	maximum number of blocks to search for a bbt. This number of
+ *		blocks is reserved at the end of the device where the tables are
+ *		written.
+ * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
+ *              bad) block in the stored bbt
+ * @pattern:	pattern to identify bad block table or factory marked good /
+ *		bad blocks, can be NULL, if len = 0
+ *
+ * Descriptor for the bad block table marker and the descriptor for the
+ * pattern which identifies good and bad blocks. The assumption is made
+ * that the pattern and the version count are always located in the oob area
+ * of the first block.
+ */
+struct nand_bbt_descr {
+	int options;
+	int pages[NAND_MAX_CHIPS];
+	int offs;
+	int veroffs;
+	uint8_t version[NAND_MAX_CHIPS];
+	int len;
+	int maxblocks;
+	int reserved_block_code;
+	uint8_t *pattern;
+};
+
+/* Options for the bad block table descriptors */
+
+/* The number of bits used per block in the bbt on the device */
+#define NAND_BBT_NRBITS_MSK	0x0000000F
+#define NAND_BBT_1BIT		0x00000001
+#define NAND_BBT_2BIT		0x00000002
+#define NAND_BBT_4BIT		0x00000004
+#define NAND_BBT_8BIT		0x00000008
+/* The bad block table is in the last good block of the device */
+#define NAND_BBT_LASTBLOCK	0x00000010
+/* The bbt is at the given page, else we must scan for the bbt */
+#define NAND_BBT_ABSPAGE	0x00000020
+/* bbt is stored per chip on multichip devices */
+#define NAND_BBT_PERCHIP	0x00000080
+/* bbt has a version counter at offset veroffs */
+#define NAND_BBT_VERSION	0x00000100
+/* Create a bbt if none exists */
+#define NAND_BBT_CREATE		0x00000200
+/*
+ * Create an empty BBT with no vendor information. Vendor's information may be
+ * unavailable, for example, if the NAND controller has a different data and OOB
+ * layout or if this information is already purged. Must be used in conjunction
+ * with NAND_BBT_CREATE.
+ */
+#define NAND_BBT_CREATE_EMPTY	0x00000400
+/* Write bbt if necessary */
+#define NAND_BBT_WRITE		0x00002000
+/* Read and write back block contents when writing bbt */
+#define NAND_BBT_SAVECONTENT	0x00004000
+/* Search good / bad pattern on the first and the second page */
+#define NAND_BBT_SCAN2NDPAGE	0x00008000
+/* Search good / bad pattern on the last page of the eraseblock */
+#define NAND_BBT_SCANLASTPAGE	0x00010000
+/*
+ * Use a flash based bad block table. By default, OOB identifier is saved in
+ * OOB area. This option is passed to the default bad block table function.
+ */
+#define NAND_BBT_USE_FLASH	0x00020000
+/*
+ * Do not store flash based bad block table marker in the OOB area; store it
+ * in-band.
+ */
+#define NAND_BBT_NO_OOB		0x00040000
+/*
+ * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
+ * entire spare area. Must be used with NAND_BBT_USE_FLASH.
+ */
+#define NAND_BBT_NO_OOB_BBM	0x00080000
+
+/* The maximum number of blocks to scan for a bbt */
+#define NAND_BBT_SCAN_MAXBLOCKS	4
+
+struct nand_bbt {
+	struct mtd_info *mtd;
+
+	/*
+	 * This is important to abstract out of nand_bbt.c and provide
+	 * separately in nand_base.c and spi-nand-base.c -- it's sort of
+	 * duplicated in nand_block_bad() (nand_base) and
+	 * scan_block_fast() (nand_bbt) right now
+	 *
+	 * Note that this also means nand_chip.badblock_pattern should
+	 * be removed from nand_bbt.c
+	 */
+	int (*is_bad_bbm)(struct mtd_info *mtd, loff_t ofs);
+
+	/* Only required if the driver wants to attempt to program new
+	 * bad block markers that imitate the factory-marked BBMs */
+	int (*mark_bad_bbm)(struct mtd_info *mtd, loff_t ofs);
+
+	/* Erase a block, bypassing reserved checks */
+	int (*erase)(struct mtd_info *mtd, loff_t ofs);
+
+	unsigned int bbt_options;
+
+	/* Only required for NAND_BBT_PERCHIP */
+	int numchips;
+
+	/* Discourage new customer usages here; suggest usage of the
+	 * relevant NAND_BBT_* options instead */
+	struct nand_bbt_descr *bbt_td;
+	struct nand_bbt_descr *bbt_md;
+
+	/* The rest are filled in by nand_bbt_init() */
+
+	u64 chipsize;
+	int chip_shift;
+	int bbt_erase_shift;
+	int page_shift;
+
+	u8 *bbt;
+};
+
+int nand_bbt_init(struct nand_bbt *bbt);
+void nand_bbt_release(struct nand_bbt *bbt);
+int nand_bbt_markbad(struct nand_bbt *bbt, loff_t offs);
+int nand_bbt_isreserved(struct nand_bbt *bbt, loff_t offs);
+int nand_bbt_isbad(struct nand_bbt *bbt, loff_t offs);
+
+#endif	/* __LINUX_MTD_NAND_BBT_H */
-- 
1.9.1


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