linux/drivers/mtd/nand/nand_bbt.c
Thomas Gleixner 19870da7ea [MTD] NAND: Fix broken bad block scan for 16 bit devices
The previous change to read a single byte from oob breaks the
bad block scan on 16 bit devices, when the byte is on an odd
address. Read the complete oob for now.
Remove the unused arguments from check_short_pattern()
Move the wait for ready function so it is only executed when
consecutive reads happen.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-07-16 09:27:52 +02:00

1113 lines
32 KiB
C

/*
* drivers/mtd/nand_bbt.c
*
* Overview:
* Bad block table support for the NAND driver
*
* Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
*
* $Id: nand_bbt.c,v 1.35 2005/07/15 13:53:47 gleixner Exp $
*
* 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* If one of the bbt's is out of date or does not exist it is (re)created.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 neccecary 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>
/**
* 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_ecc (mtd, from, len, &retlen, buf, NULL, this->autooob);
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%08x\n",
((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
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%08x\n",
((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);
}
}
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;
}
/**
* 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) {
nand_read_raw (mtd, buf, td->pages[0] << this->page_shift, mtd->oobblock, mtd->oobsize);
td->version[0] = buf[mtd->oobblock + 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)) {
nand_read_raw (mtd, buf, md->pages[0] << this->page_shift, mtd->oobblock, mtd->oobsize);
md->version[0] = buf[mtd->oobblock + md->veroffs];
printk (KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", md->pages[0], md->version[0]);
}
return 1;
}
/**
* 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, j, numblocks, len, scanlen;
int startblock;
loff_t from;
size_t readlen, ooblen;
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 = ooblen = 0;
readlen = bd->len;
} else {
/* Full page content should be read */
scanlen = mtd->oobblock + mtd->oobsize;
readlen = len * mtd->oobblock;
ooblen = len * mtd->oobsize;
}
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 = startblock << (this->bbt_erase_shift - 1);
}
for (i = startblock; i < numblocks;) {
int ret;
if (bd->options & NAND_BBT_SCANEMPTY)
if ((ret = nand_read_raw (mtd, buf, from, readlen, ooblen)))
return ret;
for (j = 0; j < len; j++) {
if (!(bd->options & NAND_BBT_SCANEMPTY)) {
size_t retlen;
/* Read the full oob until read_oob is fixed to
* handle single byte reads for 16 bit buswidth */
ret = mtd->read_oob(mtd, from + j * mtd->oobblock,
mtd->oobsize, &retlen, buf);
if (ret)
return ret;
if (check_short_pattern (buf, bd)) {
this->bbt[i >> 3] |= 0x03 << (i & 0x6);
printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
i >> 1, (unsigned int) from);
break;
}
} else {
if (check_pattern (&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {
this->bbt[i >> 3] |= 0x03 << (i & 0x6);
printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
i >> 1, (unsigned int) from);
break;
}
}
}
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 neccecary 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->oobblock + mtd->oobsize;
int bbtblocks;
/* 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;
/* Read first page */
nand_read_raw (mtd, buf, actblock << this->bbt_erase_shift, mtd->oobblock, mtd->oobsize);
if (!check_pattern(buf, scanlen, mtd->oobblock, td)) {
td->pages[i] = actblock << (this->bbt_erase_shift - this->page_shift);
if (td->options & NAND_BBT_VERSION) {
td->version[i] = buf[mtd->oobblock + 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 nand_oobinfo oobinfo;
struct erase_info einfo;
int i, j, res, chip = 0;
int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
int nrchips, bbtoffs, pageoffs;
uint8_t msk[4];
uint8_t rcode = td->reserved_block_code;
size_t retlen, len = 0;
loff_t to;
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;
switch (bits) {
case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01; msk[2] = ~rcode; msk[3] = 0x01; break;
case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01; msk[2] = ~rcode; msk[3] = 0x03; break;
case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C; msk[2] = ~rcode; msk[3] = 0x0f; break;
case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F; msk[2] = ~rcode; msk[3] = 0xff; break;
default: return -EINVAL;
}
bbtoffs = chip * (numblocks >> 2);
to = ((loff_t) page) << this->page_shift;
memcpy (&oobinfo, this->autooob, sizeof(oobinfo));
oobinfo.useecc = MTD_NANDECC_PLACEONLY;
/* 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_ecc (mtd, to, len, &retlen, buf, &buf[len], &oobinfo);
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");
}
/* 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));
/* Preset the bbt's oob area with 0xff */
memset (&buf[len + pageoffs * mtd->oobsize], 0xff,
((len >> this->page_shift) - pageoffs) * mtd->oobsize);
if (td->options & NAND_BBT_VERSION) {
buf[len + (pageoffs * mtd->oobsize) + td->veroffs] = td->version[chip];
}
} else {
/* Calc length */
len = (size_t) (numblocks >> sft);
/* Make it page aligned ! */
len = (len + (mtd->oobblock-1)) & ~(mtd->oobblock-1);
/* Preset the buffer with 0xff */
memset (buf, 0xff, len + (len >> this->page_shift) * mtd->oobsize);
offs = 0;
/* Pattern is located in oob area of first page */
memcpy (&buf[len + td->offs], td->pattern, td->len);
if (td->options & NAND_BBT_VERSION) {
buf[len + 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 = (unsigned long) to;
einfo.len = 1 << this->bbt_erase_shift;
res = nand_erase_nand (mtd, &einfo, 1);
if (res < 0) {
printk (KERN_WARNING "nand_bbt: Error during block erase: %d\n", res);
return res;
}
res = mtd->write_ecc (mtd, to, len, &retlen, buf, &buf[len], &oobinfo);
if (res < 0) {
printk (KERN_WARNING "nand_bbt: Error while writing bad block table %d\n", res);
return res;
}
printk (KERN_DEBUG "Bad block table written to 0x%08x, version 0x%02X\n",
(unsigned int) to, td->version[chip]);
/* Mark it as used */
td->pages[chip] = page;
}
return 0;
}
/**
* 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->data_buf, bd, -1);
}
/**
* check_create - [GENERIC] create and write bbt(s) if neccecary
* @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 neccecary
* Creation is neccecary if no bbt was found for the chip/device
* Update is neccecary 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, 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, (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) */
this->bbt = kmalloc (len, GFP_KERNEL);
if (!this->bbt) {
printk (KERN_ERR "nand_scan_bbt: Out of memory\n");
return -ENOMEM;
}
/* Clear the memory bad block table */
memset (this->bbt, 0x00, len);
/* 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 = kmalloc (len, GFP_KERNEL);
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);
kfree (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;
len = mtd->size >> (this->bbt_erase_shift + 2);
/* 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_SCANEMPTY | NAND_BBT_SCANALLPAGES,
.offs = 5,
.len = 1,
.pattern = scan_ff_pattern
};
static struct nand_bbt_descr largepage_flashbased = {
.options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
.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->oobblock > 512) ?
&largepage_flashbased : &smallpage_flashbased;
}
} else {
this->bbt_td = NULL;
this->bbt_md = NULL;
if (!this->badblock_pattern) {
this->badblock_pattern = (mtd->oobblock > 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);