/*
* drivers/mtd/nand_bbt.c
*
* Overview:
* Bad block table support for the NAND driver
*
* Copyright (C) 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 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* If one of the bbt's is out of date or does not exist it is (re)created.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
* 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 autogenerated 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 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.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/compatmac.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/vmalloc.h>
/**
* 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.
* If the SCAN_EMPTY option is set then check, if all bytes except the
* pattern area contain 0xff
*
*/
static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
{
int i, end = 0;
uint8_t *p = buf;
end = paglen + td->offs;
if (td->options & NAND_BBT_SCANEMPTY) {
for (i = 0; i < end; i++) {
if (p[i] != 0xff)
return -1;
}
}
p += end;
/* 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;
for (i = end; i < len; i++) {
if (*p++ != 0xff)
return -1;
}
}
return 0;
}
/**
* 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)
{
int i;
uint8_t *p = buf;
/* Compare the pattern */
for (i = 0; i < td->len; i++) {
if (p[td->offs + i] != td->pattern[i])
return -1;
}
return 0;
}
/**
* 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
* @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)
{
int res, i, j, act = 0;
struct nand_chip *this = mtd->priv;
size_t retlen, len, totlen;
loff_t from;
uint8_t msk = (uint8_t) ((1 << bits) - 1);
totlen = (num * bits) >> 3;
from = ((loff_t) page) << this->page_shift;
while (totlen) {
len = min(totlen, (size_t) (1 << this->bbt_erase_shift));
res = mtd->read(mtd, from, len, &retlen, buf);
if (res < 0) {
if (retlen != len) {
printk(KERN_INFO "nand_bbt: Error reading bad block table\n");
return res;
}
printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
}
/* Analyse data */
for (i = 0; i < len; i++) {
uint8_t dat = buf[i];
for (j = 0; j < 8; j += bits, act += 2) {
uint8_t tmp = (dat >> j) & msk;
if (tmp == msk)
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);
this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
mtd->ecc_stats.bbtblocks++;
continue;
}
/* 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);
/* Factory marked bad or worn out ? */
if (tmp == 0)
this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
else
this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
mtd->ecc_stats.badblocks++;
}
}
totlen -= len;
from += len;
}
return 0;
}
/**
* read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
* @mtd: MTD device 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 mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
{
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);
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);
if (res)
return res;
}
return 0;
}
/*
* Scan read raw data from flash
*/
static int scan_read_raw(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;
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;
}
/*
* Scan write data with oob to flash
*/
static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
uint8_t *buf, uint8_t *oob)
{
struct mtd_oob_ops ops;
ops.mode = MTD_OOB_PLACE;
ops.ooboffs = 0;
ops.ooblen = mtd->oobsize;
ops.datbuf = buf;
ops.oobbuf = oob;
ops.len = len;
return mtd->write_oob(mtd, offs, &ops);
}
/**
* read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
* @mtd: MTD device 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 int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
struct nand_bbt_descr *td, struct nand_bbt_descr *md)
{
struct nand_chip *this = mtd->priv;
/* 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];
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];
printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
md->pages[0], md->version[0]);
}
return 1;
}
/*
* Scan a given block full
*/
static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
loff_t offs, uint8_t *buf, size_t readlen,
int scanlen, int len)
{
int ret, j;
ret = scan_read_raw(mtd, buf, offs, readlen);
if (ret)
return ret;
for (j = 0; j < len; j++, buf += scanlen) {
if (check_pattern(buf, scanlen, mtd->writesize, bd))
return 1;
}
return 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 len)
{
struct mtd_oob_ops ops;
int j, ret;
ops.ooblen = mtd->oobsize;
ops.oobbuf = buf;
ops.ooboffs = 0;
ops.datbuf = NULL;
ops.mode = MTD_OOB_PLACE;
for (j = 0; j < len; 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);
if (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
* @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)
{
struct nand_chip *this = mtd->priv;
int i, numblocks, len, scanlen;
int startblock;
loff_t from;
size_t readlen;
printk(KERN_INFO "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;
}
if (!(bd->options & NAND_BBT_SCANEMPTY)) {
/* We need only read few bytes from the OOB area */
scanlen = 0;
readlen = bd->len;
} else {
/* Full page content should be read */
scanlen = mtd->writesize + mtd->oobsize;
readlen = len * mtd->writesize;
}
if (chip == -1) {
/* Note that numblocks is 2 * (real numblocks) here, see i+=2
* below as it makes shifting and masking less painful */
numblocks = mtd->size >> (this->bbt_erase_shift - 1);
startblock = 0;
from = 0;
} else {
if (chip >= this->numchips) {
printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
chip + 1, this->numchips);
return -EINVAL;
}
numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
startblock = chip * numblocks;
numblocks += startblock;
from = (loff_t)startblock << (this->bbt_erase_shift - 1);
}
if (this->options & NAND_BB_LAST_PAGE)
from += mtd->erasesize - (mtd->writesize * len);
for (i = startblock; i < numblocks;) {
int ret;
if (bd->options & NAND_BBT_SCANALLPAGES)
ret = scan_block_full(mtd, bd, from, buf, readlen,
scanlen, len);
else
ret = scan_block_fast(mtd, bd, from, buf, len);
if (ret < 0)
return ret;
if (ret) {
this->bbt[i >> 3] |= 0x03 << (i & 0x6);
printk(KERN_WARNING "Bad eraseblock %d at 0x%012llx\n",
i >> 1, (unsigned long long)from);
mtd->ecc_stats.badblocks++;
}
i += 2;
from += (1 << this->bbt_erase_shift);
}
return 0;
}
/**
* search_bbt - [GENERIC] scan the device for a specific bad block table
* @mtd: MTD device 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 mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
{
struct nand_chip *this = mtd->priv;
int i, chips;
int bits, startblock, block, dir;
int scanlen = mtd->writesize + mtd->oobsize;
int bbtblocks;
int blocktopage = this->bbt_erase_shift - this->page_shift;
/* Search direction top -> down ? */
if (td->options & NAND_BBT_LASTBLOCK) {
startblock = (mtd->size >> this->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 = this->numchips;
bbtblocks = this->chipsize >> this->bbt_erase_shift;
startblock &= bbtblocks - 1;
} else {
chips = 1;
bbtblocks = mtd->size >> this->bbt_erase_shift;
}
/* Number of bits for each erase block in the bbt */
bits = td->options & NAND_BBT_NRBITS_MSK;
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 << this->bbt_erase_shift;
/* Read first page */
scan_read_raw(mtd, buf, offs, mtd->writesize);
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];
}
break;
}
}
startblock += this->chipsize >> this->bbt_erase_shift;
}
/* Check, if we found a bbt for each requested chip */
for (i = 0; i < chips; i++) {
if (td->pages[i] == -1)
printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
else
printk(KERN_DEBUG "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)
* @mtd: MTD device 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 int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
{
/* Search the primary table */
search_bbt(mtd, buf, td);
/* Search the mirror table */
if (md)
search_bbt(mtd, buf, md);
/* Force result check */
return 1;
}
/**
* write_bbt - [GENERIC] (Re)write the bad block table
*
* @mtd: MTD device 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 mtd_info *mtd, 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;
int i, j, res, chip = 0;
int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
int nrchips, bbtoffs, 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_OOB_PLACE;
if (!rcode)
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);
/* Full device write or specific chip ? */
if (chipsel == -1) {
nrchips = this->numchips;
} else {
nrchips = chipsel + 1;
chip = chipsel;
}
} else {
numblocks = (int)(mtd->size >> this->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 ((this->bbt[block >> 2] >>
(2 * (block & 0x03))) & 0x03) {
case 0x01:
case 0x03:
continue;
}
page = block <<
(this->bbt_erase_shift - this->page_shift);
/* Check, if the block is used by the mirror table */
if (!md || md->pages[chip] != page)
goto write;
}
printk(KERN_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;
}
bbtoffs = chip * (numblocks >> 2);
to = ((loff_t) page) << this->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;
res = mtd->read(mtd, to, len, &retlen, buf);
if (res < 0) {
if (retlen != len) {
printk(KERN_INFO "nand_bbt: Error "
"reading block for writing "
"the bad block table\n");
return res;
}
printk(KERN_WARNING "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.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;
/* Preset the bbt area with 0xff */
memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
ooboffs = len + (pageoffs * mtd->oobsize);
} else {
/* Calc length */
len = (size_t) (numblocks >> sft);
/* Make it page aligned ! */
len = (len + (mtd->writesize - 1)) &
~(mtd->writesize - 1);
/* Preset the buffer with 0xff */
memset(buf, 0xff, len +
(len >> this->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;) {
uint8_t dat;
dat = this->bbt[bbtoffs + (i >> 2)];
for (j = 0; j < 4; j++, i++) {
int sftcnt = (i << (3 - sft)) & sftmsk;
/* Do not store the reserved bbt blocks ! */
buf[offs + (i >> sft)] &=
~(msk[dat & 0x03] << sftcnt);
dat >>= 2;
}
}
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);
if (res < 0)
goto outerr;
res = scan_write_bbt(mtd, to, len, buf, &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]);
/* Mark it as used */
td->pages[chip] = page;
}
return 0;
outerr:
printk(KERN_WARNING
"nand_bbt: Error while writing bad block table %d\n", res);
return res;
}
/**
* nand_memory_bbt - [GENERIC] create a memory based bad block table
* @mtd: MTD device structure
* @bd: descriptor for the good/bad block search pattern
*
* 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)
{
struct nand_chip *this = mtd->priv;
bd->options &= ~NAND_BBT_SCANEMPTY;
return create_bbt(mtd, this->buffers->databuf, bd, -1);
}
/**
* check_create - [GENERIC] create and write bbt(s) if necessary
* @mtd: MTD device 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)
{
int i, chips, writeops, chipsel, res;
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 *rd, *rd2;
/* Do we have a bbt per chip ? */
if (td->options & NAND_BBT_PERCHIP)
chips = this->numchips;
else
chips = 1;
for (i = 0; i < chips; i++) {
writeops = 0;
rd = NULL;
rd2 = NULL;
/* Per chip or per device ? */
chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
/* Mirrored table avilable ? */
if (md) {
if (td->pages[i] == -1 && md->pages[i] == -1) {
writeops = 0x03;
goto create;
}
if (td->pages[i] == -1) {
rd = md;
td->version[i] = md->version[i];
writeops = 1;
goto writecheck;
}
if (md->pages[i] == -1) {
rd = td;
md->version[i] = td->version[i];
writeops = 2;
goto writecheck;
}
if (td->version[i] == md->version[i]) {
rd = td;
if (!(td->options & NAND_BBT_VERSION))
rd2 = md;
goto writecheck;
}
if (((int8_t) (td->version[i] - md->version[i])) > 0) {
rd = td;
md->version[i] = td->version[i];
writeops = 2;
} else {
rd = md;
td->version[i] = md->version[i];
writeops = 1;
}
goto writecheck;
} else {
if (td->pages[i] == -1) {
writeops = 0x01;
goto create;
}
rd = td;
goto writecheck;
}
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) */
create_bbt(mtd, buf, bd, chipsel);
td->version[i] = 1;
if (md)
md->version[i] = 1;
writecheck:
/* read back first ? */
if (rd)
read_abs_bbt(mtd, buf, rd, chipsel);
/* If they weren't versioned, read both. */
if (rd2)
read_abs_bbt(mtd, buf, rd2, chipsel);
/* Write the bad block table to the device ? */
if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
res = write_bbt(mtd, 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);
if (res < 0)
return res;
}
}
return 0;
}
/**
* mark_bbt_regions - [GENERIC] mark the bad block table regions
* @mtd: MTD device 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)
{
struct nand_chip *this = mtd->priv;
int i, j, chips, block, nrblocks, update;
uint8_t oldval, newval;
/* Do we have a bbt per chip ? */
if (td->options & NAND_BBT_PERCHIP) {
chips = this->numchips;
nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
} else {
chips = 1;
nrblocks = (int)(mtd->size >> this->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] >> (this->bbt_erase_shift - this->page_shift);
block <<= 1;
oldval = this->bbt[(block >> 3)];
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));
continue;
}
update = 0;
if (td->options & NAND_BBT_LASTBLOCK)
block = ((i + 1) * nrblocks) - td->maxblocks;
else
block = i * nrblocks;
block <<= 1;
for (j = 0; j < td->maxblocks; j++) {
oldval = this->bbt[(block >> 3)];
newval = oldval | (0x2 << (block & 0x06));
this->bbt[(block >> 3)] = newval;
if (oldval != newval)
update = 1;
block += 2;
}
/* 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(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
}
}
/**
* 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
*
* 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.
*
*/
int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
{
struct nand_chip *this = mtd->priv;
int len, res = 0;
uint8_t *buf;
struct nand_bbt_descr *td = this->bbt_td;
struct nand_bbt_descr *md = this->bbt_md;
len = mtd->size >> (this->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) {
printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
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(mtd, bd))) {
printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
kfree(this->bbt);
this->bbt = NULL;
}
return res;
}
/* Allocate a temporary buffer for one eraseblock incl. oob */
len = (1 << this->bbt_erase_shift);
len += (len >> this->page_shift) * mtd->oobsize;
buf = vmalloc(len);
if (!buf) {
printk(KERN_ERR "nand_bbt: Out of memory\n");
kfree(this->bbt);
this->bbt = NULL;
return -ENOMEM;
}
/* Is the bbt at a given page ? */
if (td->options & NAND_BBT_ABSPAGE) {
res = read_abs_bbts(mtd, buf, td, md);
} else {
/* Search the bad block table using a pattern in oob */
res = search_read_bbts(mtd, buf, td, md);
}
if (res)
res = check_create(mtd, buf, bd);
/* Prevent the bbt regions from erasing / writing */
mark_bbt_region(mtd, td);
if (md)
mark_bbt_region(mtd, md);
vfree(buf);
return res;
}
/**
* nand_update_bbt - [NAND Interface] update bad block table(s)
* @mtd: MTD device structure
* @offs: the offset of the newly marked block
*
* The function updates the bad block table(s)
*/
int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
{
struct nand_chip *this = mtd->priv;
int len, res = 0, writeops = 0;
int chip, chipsel;
uint8_t *buf;
struct nand_bbt_descr *td = this->bbt_td;
struct nand_bbt_descr *md = this->bbt_md;
if (!this->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;
buf = kmalloc(len, GFP_KERNEL);
if (!buf) {
printk(KERN_ERR "nand_update_bbt: Out of memory\n");
return -ENOMEM;
}
writeops = md != NULL ? 0x03 : 0x01;
/* Do we have a bbt per chip ? */
if (td->options & NAND_BBT_PERCHIP) {
chip = (int)(offs >> this->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 ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
res = write_bbt(mtd, buf, td, md, chipsel);
if (res < 0)
goto out;
}
/* 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);
}
out:
kfree(buf);
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 };
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 = {
.options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
.offs = 0x20,
.len = 6,
.pattern = scan_agand_pattern
};
/* Generic flash bbt decriptors
*/
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 = 4,
.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 = 4,
.pattern = mirror_pattern
};
/**
* nand_default_bbt - [NAND Interface] Select a default bad block table for the device
* @mtd: MTD device structure
*
* This function selects the default bad block table
* support for the device and calls the nand_scan_bbt function
*
*/
int nand_default_bbt(struct mtd_info *mtd)
{
struct nand_chip *this = mtd->priv;
/* Default for AG-AND. We must use a flash based
* bad block table as the devices have factory marked
* _good_ blocks. Erasing those blocks leads to loss
* of the good / bad information, so we _must_ store
* this information in a good / bad table during
* startup
*/
if (this->options & NAND_IS_AND) {
/* Use the default pattern descriptors */
if (!this->bbt_td) {
this->bbt_td = &bbt_main_descr;
this->bbt_md = &bbt_mirror_descr;
}
this->options |= NAND_USE_FLASH_BBT;
return nand_scan_bbt(mtd, &agand_flashbased);
}
/* Is a flash based bad block table requested ? */
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;
}
} else {
this->bbt_td = NULL;
this->bbt_md = NULL;
if (!this->badblock_pattern) {
this->badblock_pattern = (mtd->writesize > 512) ?
&largepage_memorybased : &smallpage_memorybased;
}
}
return nand_scan_bbt(mtd, this->badblock_pattern);
}
/**
* nand_isbad_bbt - [NAND Interface] Check if a block is bad
* @mtd: MTD device 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)
{
struct nand_chip *this = mtd->priv;
int block;
uint8_t res;
/* Get block number * 2 */
block = (int)(offs >> (this->bbt_erase_shift - 1));
res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
DEBUG(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:
return 0;
case 0x01:
return 1;
case 0x02:
return allowbbt ? 0 : 1;
}
return 1;
}
EXPORT_SYMBOL(nand_scan_bbt);
EXPORT_SYMBOL(nand_default_bbt);
