nand: Merge changes to BBT from Linux nand driver

[backport from linux commit 02f8c6aee8df3cdc935e9bdd4f2d020306035dbe]

This patch synchronizes the nand driver with the Linux 3.0 state.

Signed-off-by: Christian Hitz <christian.hitz@aizo.com>
Cc: Scott Wood <scottwood@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

1 files changed, 328 insertions, 99 deletions

diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index ded652be3..2b730e09c 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -13,27 +13,36 @@
  * 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 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
- * than the mirror bbt is used to build the memory based bbt.
+ * depending on the options in the BBT descriptor(s). If no flash based BBT
+ * (NAND_USE_FLASH_BBT) 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 than 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- * If one of the bbt's is out of date or does not exist it is (re)created.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
+ * If one of the BBTs is out of date or does not exist it is (re)created.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
+ * For manufacturer created BBTs like the one found on M-SYS DOC devices
+ * the BBT is searched and read but never created
  *
- * The autogenerated bad block table is located in the last good blocks
+ * 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.
+ * 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_USE_FLASH_BBT_NO_OOB should be used: 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
+ * 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:
@@ -55,9 +64,21 @@
 #include <linux/mtd/compat.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/bitops.h>
 
 #include <asm/errno.h>
 
+static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
+{
+	int ret;
+
+	ret = memcmp(buf, td->pattern, td->len);
+	if (!ret)
+		return ret;
+	return -1;
+}
+
 /**
  * check_pattern - [GENERIC] check if a pattern is in the buffer
  * @buf:	the buffer to search
@@ -76,6 +97,9 @@ static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_desc
 	int i, end = 0;
 	uint8_t *p = buf;
 
+	if (td->options & NAND_BBT_NO_OOB)
+		return check_pattern_no_oob(buf, td);
+
 	end = paglen + td->offs;
 	if (td->options & NAND_BBT_SCANEMPTY) {
 		for (i = 0; i < end; i++) {
@@ -91,6 +115,28 @@ static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_desc
 			return -1;
 	}
 
+	/* Check both positions 1 and 6 for pattern? */
+	if (td->options & NAND_BBT_SCANBYTE1AND6) {
+		if (td->options & NAND_BBT_SCANEMPTY) {
+			p += td->len;
+			end += NAND_SMALL_BADBLOCK_POS - td->offs;
+			/* Check region between positions 1 and 6 */
+			for (i = 0; i < NAND_SMALL_BADBLOCK_POS - td->offs - td->len;
+					i++) {
+				if (*p++ != 0xff)
+					return -1;
+			}
+		}
+		else {
+			p += NAND_SMALL_BADBLOCK_POS - td->offs;
+		}
+		/* Compare the pattern */
+		for (i = 0; i < td->len; i++) {
+			if (p[i] != td->pattern[i])
+				return -1;
+		}
+	}
+
 	if (td->options & NAND_BBT_SCANEMPTY) {
 		p += td->len;
 		end += td->len;
@@ -122,36 +168,74 @@ static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
 		if (p[td->offs + i] != td->pattern[i])
 			return -1;
 	}
+	/* Need to check location 1 AND 6? */
+	if (td->options & NAND_BBT_SCANBYTE1AND6) {
+		for (i = 0; i < td->len; i++) {
+			if (p[NAND_SMALL_BADBLOCK_POS + i] != td->pattern[i])
+				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 markeris 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
  * @mtd:	MTD device structure
  * @buf:	temporary buffer
  * @page:	the starting page
  * @num:	the number of bbt descriptors to read
- * @bits:	number of bits per block
+ * @td:		the bbt describtion table
  * @offs:	offset in the memory table
- * @reserved_block_code:	Pattern to identify reserved blocks
  *
  * Read the bad block table starting from page.
  *
  */
 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
-		    int bits, int offs, int reserved_block_code)
+		struct nand_bbt_descr *td, int offs)
 {
 	int res, 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;
 	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) << this->page_shift;
 
 	while (totlen) {
 		len = min(totlen, (size_t) (1 << this->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 (retlen != len) {
@@ -170,9 +254,7 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
 					continue;
 				if (reserved_block_code && (tmp == reserved_block_code)) {
 					printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n",
-						(loff_t)((offs << 2) +
-						(act >> 1)) <<
-						this->bbt_erase_shift);
+					       (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
 					this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
 					mtd->ecc_stats.bbtblocks++;
 					continue;
@@ -180,8 +262,7 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
 				/* Leave it for now, if its matured we can move this
 				 * message to MTD_DEBUG_LEVEL0 */
 				printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%012llx\n",
-					(loff_t)((offs << 2) + (act >> 1)) <<
-					this->bbt_erase_shift);
+				       (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
 				/* Factory marked bad or worn out ? */
 				if (tmp == 0)
 					this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
@@ -211,20 +292,21 @@ static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 {
 	struct nand_chip *this = mtd->priv;
 	int res = 0, i;
-	int bits;
 
-	bits = td->options & NAND_BBT_NRBITS_MSK;
 	if (td->options & NAND_BBT_PERCHIP) {
 		int offs = 0;
 		for (i = 0; i < this->numchips; i++) {
 			if (chip == -1 || chip == i)
-				res = read_bbt (mtd, buf, td->pages[i], this->chipsize >> this->bbt_erase_shift, bits, offs, td->reserved_block_code);
+				res = read_bbt(mtd, buf, td->pages[i],
+					this->chipsize >> this->bbt_erase_shift,
+					td, offs);
 			if (res)
 				return res;
 			offs += this->chipsize >> (this->bbt_erase_shift + 2);
 		}
 	} else {
-		res = read_bbt (mtd, buf, td->pages[0], mtd->size >> this->bbt_erase_shift, bits, 0, td->reserved_block_code);
+		res = read_bbt(mtd, buf, td->pages[0],
+				mtd->size >> this->bbt_erase_shift, td, 0);
 		if (res)
 			return res;
 	}
@@ -232,21 +314,64 @@ 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_raw_data(struct mtd_info *mtd, 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(mtd, offs, len, &retlen, buf);
+}
+
+/*
  * Scan read raw data from flash
  */
-static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
+static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
 			 size_t len)
 {
 	struct mtd_oob_ops ops;
+	int res;
 
 	ops.mode = MTD_OOB_RAW;
 	ops.ooboffs = 0;
 	ops.ooblen = mtd->oobsize;
-	ops.oobbuf = buf;
-	ops.datbuf = buf;
-	ops.len = len;
 
-	return mtd->read_oob(mtd, offs, &ops);
+
+	while (len > 0) {
+		if (len <= mtd->writesize) {
+			ops.oobbuf = buf + len;
+			ops.datbuf = buf;
+			ops.len = len;
+			return mtd->read_oob(mtd, offs, &ops);
+		} else {
+			ops.oobbuf = buf + mtd->writesize;
+			ops.datbuf = buf;
+			ops.len = mtd->writesize;
+			res = mtd->read_oob(mtd, offs, &ops);
+
+			if (res)
+				return res;
+		}
+
+		buf += mtd->oobsize + mtd->writesize;
+		len -= mtd->writesize;
+	}
+	return 0;
+}
+
+static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
+			 size_t len, struct nand_bbt_descr *td)
+{
+	if (td->options & NAND_BBT_NO_OOB)
+		return scan_read_raw_data(mtd, buf, offs, td);
+	else
+		return scan_read_raw_oob(mtd, buf, offs, len);
 }
 
 /*
@@ -267,6 +392,15 @@ 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)
+{
+	u32 ver_offs = td->veroffs;
+
+	if (!(td->options & NAND_BBT_NO_OOB))
+		ver_offs += mtd->writesize;
+	return ver_offs;
+}
+
 /**
  * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
  * @mtd:	MTD device structure
@@ -285,18 +419,18 @@ static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
 
 	/* Read the primary version, if available */
 	if (td->options & NAND_BBT_VERSION) {
-		scan_read_raw(mtd, buf, (loff_t)td->pages[0] <<
-				this->page_shift, mtd->writesize);
-		td->version[0] = buf[mtd->writesize + td->veroffs];
+		scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
+			      mtd->writesize, td);
+		td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
 		printk(KERN_DEBUG "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_raw(mtd, buf, (loff_t)md->pages[0] <<
-				this->page_shift, mtd->writesize);
-		md->version[0] = buf[mtd->writesize + md->veroffs];
+		scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
+			      mtd->writesize, td);
+		md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
 		printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
 		       md->pages[0], md->version[0]);
 	}
@@ -312,7 +446,7 @@ static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
 {
 	int ret, j;
 
-	ret = scan_read_raw(mtd, buf, offs, readlen);
+	ret = scan_read_raw_oob(mtd, buf, offs, readlen);
 	if (ret)
 		return ret;
 
@@ -376,16 +510,14 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
 	loff_t from;
 	size_t readlen;
 
-	MTDDEBUG (MTD_DEBUG_LEVEL0, "Scanning device for bad blocks\n");
+	MTDDEBUG(MTD_DEBUG_LEVEL0, "Scanning device for bad blocks\n");
 
 	if (bd->options & NAND_BBT_SCANALLPAGES)
 		len = 1 << (this->bbt_erase_shift - this->page_shift);
-	else {
-		if (bd->options & NAND_BBT_SCAN2NDPAGE)
-			len = 2;
-		else
-			len = 1;
-	}
+	else if (bd->options & NAND_BBT_SCAN2NDPAGE)
+		len = 2;
+	else
+		len = 1;
 
 	if (!(bd->options & NAND_BBT_SCANEMPTY)) {
 		/* We need only read few bytes from the OOB area */
@@ -415,9 +547,14 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
 		from = (loff_t)startblock << (this->bbt_erase_shift - 1);
 	}
 
+	if (this->options & NAND_BBT_SCANLASTPAGE)
+		from += mtd->erasesize - (mtd->writesize * len);
+
 	for (i = startblock; i < numblocks;) {
 		int ret;
 
+		BUG_ON(bd->options & NAND_BBT_NO_OOB);
+
 		if (bd->options & NAND_BBT_SCANALLPAGES)
 			ret = scan_block_full(mtd, bd, from, buf, readlen,
 					      scanlen, len);
@@ -429,7 +566,7 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
 
 		if (ret) {
 			this->bbt[i >> 3] |= 0x03 << (i & 0x6);
-			MTDDEBUG (MTD_DEBUG_LEVEL0,
+			MTDDEBUG(MTD_DEBUG_LEVEL0,
 				  "Bad eraseblock %d at 0x%012llx\n",
 				  i >> 1, (unsigned long long)from);
 			mtd->ecc_stats.badblocks++;
@@ -497,11 +634,12 @@ static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr
 			loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
 
 			/* Read first page */
-			scan_read_raw(mtd, buf, offs, mtd->writesize);
+			scan_read_raw(mtd, buf, offs, mtd->writesize, td);
 			if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
 				td->pages[i] = actblock << blocktopage;
 				if (td->options & NAND_BBT_VERSION) {
-					td->version[i] = buf[mtd->writesize + td->veroffs];
+					offs = bbt_get_ver_offs(mtd, td);
+					td->version[i] = buf[offs];
 				}
 				break;
 			}
@@ -685,12 +823,26 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 			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 = (len + (mtd->writesize - 1)) &
-				~(mtd->writesize - 1);
+			len = ALIGN(len, mtd->writesize);
 			/* Preset the buffer with 0xff */
 			memset(buf, 0xff, len +
 			       (len >> this->page_shift)* mtd->oobsize);
@@ -724,13 +876,14 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 		if (res < 0)
 			goto outerr;
 
-		res = scan_write_bbt(mtd, to, len, buf, &buf[len]);
+		res = scan_write_bbt(mtd, to, len, buf,
+				td->options & NAND_BBT_NO_OOB ? NULL :
+				&buf[len]);
 		if (res < 0)
 			goto outerr;
 
-		printk(KERN_DEBUG "Bad block table written to 0x%012llx, "
-		       "version 0x%02X\n", (unsigned long long)to,
-		       td->version[chip]);
+		printk(KERN_DEBUG "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;
@@ -791,7 +944,7 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 		rd2 = NULL;
 		/* Per chip or per device ? */
 		chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
-		/* Mirrored table avilable ? */
+		/* Mirrored table available ? */
 		if (md) {
 			if (td->pages[i] == -1 && md->pages[i] == -1) {
 				writeops = 0x03;
@@ -845,7 +998,8 @@ 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) */
-		create_bbt(mtd, buf, bd, chipsel);
+		if (!(this->options & NAND_CREATE_EMPTY_BBT))
+			create_bbt(mtd, buf, bd, chipsel);
 
 		td->version[i] = 1;
 		if (md)
@@ -910,8 +1064,7 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
 			newval = oldval | (0x2 << (block & 0x06));
 			this->bbt[(block >> 3)] = newval;
 			if ((oldval != newval) && td->reserved_block_code)
-				nand_update_bbt(mtd, (loff_t)block <<
-					(this->bbt_erase_shift - 1));
+				nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));
 			continue;
 		}
 		update = 0;
@@ -932,9 +1085,56 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
 		   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(mtd, (loff_t)(block - 2) <<
-				(this->bbt_erase_shift - 1));
+			nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
+	}
+}
+
+/**
+ * verify_bbt_descr - verify the bad block description
+ * @mtd:	MTD device 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)
+{
+	struct nand_chip *this = mtd->priv;
+	u32 pattern_len;
+	u32 bits;
+	u32 table_size;
+
+	if (!bd)
+		return;
+
+	pattern_len = bd->len;
+	bits = bd->options & NAND_BBT_NRBITS_MSK;
+
+	BUG_ON((this->options & NAND_USE_FLASH_BBT_NO_OOB) &&
+			!(this->options & NAND_USE_FLASH_BBT));
+	BUG_ON(!bits);
+
+	if (bd->options & NAND_BBT_VERSION)
+		pattern_len++;
+
+	if (bd->options & NAND_BBT_NO_OOB) {
+		BUG_ON(!(this->options & NAND_USE_FLASH_BBT));
+		BUG_ON(!(this->options & NAND_USE_FLASH_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 = this->chipsize >> this->bbt_erase_shift;
+	else
+		table_size = mtd->size >> this->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));
 }
 
 /**
@@ -978,6 +1178,8 @@ int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
 		}
 		return res;
 	}
+	verify_bbt_descr(mtd, td);
+	verify_bbt_descr(mtd, md);
 
 	/* Allocate a temporary buffer for one eraseblock incl. oob */
 	len = (1 << this->bbt_erase_shift);
@@ -1073,34 +1275,6 @@ int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
  * while scanning a device for factory marked good / bad blocks. */
 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
 
-static struct nand_bbt_descr smallpage_memorybased = {
-	.options = NAND_BBT_SCAN2NDPAGE,
-	.offs = 5,
-	.len = 1,
-	.pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr largepage_memorybased = {
-	.options = 0,
-	.offs = 0,
-	.len = 2,
-	.pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr smallpage_flashbased = {
-	.options = NAND_BBT_SCAN2NDPAGE,
-	.offs = 5,
-	.len = 1,
-	.pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr largepage_flashbased = {
-	.options = NAND_BBT_SCAN2NDPAGE,
-	.offs = 0,
-	.len = 2,
-	.pattern = scan_ff_pattern
-};
-
 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
 
 static struct nand_bbt_descr agand_flashbased = {
@@ -1135,6 +1309,59 @@ static struct nand_bbt_descr bbt_mirror_descr = {
 	.pattern = mirror_pattern
 };
 
+static struct nand_bbt_descr bbt_main_no_bbt_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 = 4,
+	.pattern = bbt_pattern
+};
+
+static struct nand_bbt_descr bbt_mirror_no_bbt_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 = 4,
+	.pattern = mirror_pattern
+};
+
+#define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
+		NAND_BBT_SCANBYTE1AND6)
+/**
+ * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
+ * @this:	NAND chip to create descriptor for
+ *
+ * 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_default_bbt_descr(struct nand_chip *this)
+{
+	struct nand_bbt_descr *bd;
+	if (this->badblock_pattern) {
+		printk(KERN_WARNING "BBT descr already allocated; not replacing.\n");
+		return -EINVAL;
+	}
+	bd = kzalloc(sizeof(*bd), GFP_KERNEL);
+	if (!bd) {
+		printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n");
+		return -ENOMEM;
+	}
+	bd->options = this->options & BBT_SCAN_OPTIONS;
+	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
@@ -1168,20 +1395,22 @@ int nand_default_bbt(struct mtd_info *mtd)
 	if (this->options & NAND_USE_FLASH_BBT) {
 		/* Use the default pattern descriptors */
 		if (!this->bbt_td) {
-			this->bbt_td = &bbt_main_descr;
-			this->bbt_md = &bbt_mirror_descr;
-		}
-		if (!this->badblock_pattern) {
-			this->badblock_pattern = (mtd->writesize > 512) ? &largepage_flashbased : &smallpage_flashbased;
+			if (this->options & NAND_USE_FLASH_BBT_NO_OOB) {
+				this->bbt_td = &bbt_main_no_bbt_descr;
+				this->bbt_md = &bbt_mirror_no_bbt_descr;
+			} else {
+				this->bbt_td = &bbt_main_descr;
+				this->bbt_md = &bbt_mirror_descr;
+			}
 		}
 	} else {
 		this->bbt_td = NULL;
 		this->bbt_md = NULL;
-		if (!this->badblock_pattern) {
-			this->badblock_pattern = (mtd->writesize > 512) ?
-			    &largepage_memorybased : &smallpage_memorybased;
-		}
 	}
+
+	if (!this->badblock_pattern)
+		nand_create_default_bbt_descr(this);
+
 	return nand_scan_bbt(mtd, this->badblock_pattern);
 }
 
@@ -1202,8 +1431,8 @@ int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
 	block = (int)(offs >> (this->bbt_erase_shift - 1));
 	res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
 
-	MTDDEBUG (MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
-	          "(block %d) 0x%02x\n", (unsigned int)offs, res, block >> 1);
+	MTDDEBUG(MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
+	      (unsigned int)offs, block >> 1, res);
 
 	switch ((int)res) {
 	case 0x00: