/*
* drivers/mtd/nand_bbt.c
*
* Overview:
* Bad block table support for the NAND driver
*
* Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Description:
*
* When nand_scan_bbt is called, then it tries to find the bad block table
* depending on the options in the BBT descriptor(s). If no flash based BBT
* (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
* marked good / bad blocks. This information is used to create a memory BBT.
* Once a new bad block is discovered then the "factory" information is updated
* on the device.
* If a flash based BBT is specified then the function first tries to find the
* BBT on flash. If a BBT is found then the contents are read and the memory
* based BBT is created. If a mirrored BBT is selected then the mirror is
* searched too and the versions are compared. If the mirror has a greater
* version number, then the mirror BBT is used to build the memory based BBT.
* If the tables are not versioned, then we "or" the bad block information.
* If one of the BBTs is out of date or does not exist it is (re)created.
* If no BBT exists at all then the device is scanned for factory marked
* good / bad blocks and the bad block tables are created.
*
* For manufacturer created BBTs like the one found on M-SYS DOC devices
* the BBT is searched and read but never created
*
* The auto generated bad block table is located in the last good blocks
* of the device. The table is mirrored, so it can be updated eventually.
* The table is marked in the OOB area with an ident pattern and a version
* number which indicates which of both tables is more up to date. If the NAND
* controller needs the complete OOB area for the ECC information then the
* option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
* course): it moves the ident pattern and the version byte into the data area
* and the OOB area will remain untouched.
*
* The table uses 2 bits per block
* 11b: block is good
* 00b: block is factory marked bad
* 01b, 10b: block is marked bad due to wear
*
* The memory bad block table uses the following scheme:
* 00b: block is good
* 01b: block is marked bad due to wear
* 10b: block is reserved (to protect the bbt area)
* 11b: block is factory marked bad
*
* Multichip devices like DOC store the bad block info per floor.
*
* Following assumptions are made:
* - bbts start at a page boundary, if autolocated on a block boundary
* - the space necessary for a bbt in FLASH does not exceed a block boundary
*
*/
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/bbm.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <linux/string.h>
static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
{
if (memcmp(buf, td->pattern, td->len))
return -1;
return 0;
}
/**
* check_pattern - [GENERIC] check if a pattern is in the buffer
* @buf: the buffer to search
* @len: the length of buffer to search
* @paglen: the pagelength
* @td: search pattern descriptor
*
* Check for a pattern at the given place. Used to search bad block tables and
* good / bad block identifiers. 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 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)
if (memchr_inv(p, 0xff, end))
return -1;
p += end;
/* Compare the pattern */
if (memcmp(p, td->pattern, td->len))
return -1;
if (td->options & NAND_BBT_SCANEMPTY) {
p += td->len;
end += td->len;
if (memchr_inv(p, 0xff, len - end))
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)
{
/* 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
*
* The length will be 0 if the marker is located in OOB area.
*/
static u32 add_marker_len(struct nand_bbt_descr *td)
{
u32 len;
if (!(td->options & NAND_BBT_NO_OOB))
return 0;
len = td->len;
if (td->options & NAND_BBT_VERSION)
len++;
return len;
}
/**
* read_bbt - [GENERIC] Read the bad block table starting from page
* @mtd: MTD device structure
* @buf: temporary buffer
* @page: the starting page
* @num: the number of bbt descriptors to read
* @td: the bbt describtion table
* @offs: offset in the memory table
*
* Read the bad block table starting from page.
*/
static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
struct nand_bbt_descr *td, int offs)
{
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;
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 (mtd_is_eccerr(res)) {
pr_info("nand_bbt: ECC error in BBT at "
"0x%012llx\n", from & ~mtd->writesize);
return res;
} else if (mtd_is_bitflip(res)) {
pr_info("nand_bbt: corrected error in BBT at "
"0x%012llx\n", from & ~mtd->writesize);
ret = res;
} else {
pr_info("nand_bbt: error reading BBT\n");
return res;
}
}
/* Analyse data */
for (i = 0; i < len; i++) {
uint8_t dat = buf[i];
for (j = 0; j < 8; j += bits, act += 2) {
uint8_t tmp = (dat >> j) & msk;
if (tmp == msk)
continue;
if (reserved_block_code && (tmp == reserved_block_code)) {
pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
(loff_t)((offs << 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 it's matured we can
* move this message to pr_debug.
*/
pr_info("nand_read_bbt: bad block at 0x%012llx\n",
(loff_t)((offs << 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 ret;
}
/**
* 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;
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,
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, td, 0);
if (res)
return res;
}
return 0;
}
/* BBT marker is in the first page, no OOB */
static int scan_read_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_oob - [GENERIC] Scan data+OOB region to buffer
* @mtd: MTD device structure
* @buf: temporary buffer
* @offs: offset at which to scan
* @len: length of data region to read
*
* Scan read data from data+OOB. May traverse multiple pages, interleaving
* page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
* ECC condition (error or bitflip). May quit on the first (non-ECC) error.
*/
static int scan_read_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
size_t len)
{
struct mtd_oob_ops ops;
int res, ret = 0;
ops.mode = MTD_OPS_PLACE_OOB;
ops.ooboffs = 0;
ops.ooblen = mtd->oobsize;
while (len > 0) {
ops.datbuf = buf;
ops.len = min(len, (size_t)mtd->writesize);
ops.oobbuf = buf + ops.len;
res = mtd_read_oob(mtd, offs, &ops);
if (res) {
if (!mtd_is_bitflip_or_eccerr(res))
return res;
else if (mtd_is_eccerr(res) || !ret)
ret = res;
}
buf += mtd->oobsize + mtd->writesize;
len -= mtd->writesize;
offs += mtd->writesize;
}
return ret;
}
static int scan_read(struct 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_data(mtd, buf, offs, td);
else
return scan_read_oob(mtd, buf, offs, len);
}
/* 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_OPS_PLACE_OOB;
ops.ooboffs = 0;
ops.ooblen = mtd->oobsize;
ops.datbuf = buf;
ops.oobbuf = oob;
ops.len = len;
return mtd_write_oob(mtd, offs, &ops);
}
static u32 bbt_get_ver_offs(struct 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
* @buf: temporary buffer
* @td: descriptor for the bad block table
* @md: descriptor for the bad block table mirror
*
* Read the bad block table(s) for all chips starting at a given page. We
* assume that the bbt bits are in consecutive order.
*/
static void read_abs_bbts(struct 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(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
mtd->writesize, td);
td->version[0] = buf[bbt_get_ver_offs(mtd, 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,
mtd->writesize, md);
md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
pr_info("Bad block table at page %d, version 0x%02X\n",
md->pages[0], md->version[0]);
}
}
/* 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 numpages)
{
int ret, j;
ret = scan_read_oob(mtd, buf, offs, readlen);
/* Ignore ECC errors when checking for BBM */
if (ret && !mtd_is_bitflip_or_eccerr(ret))
return ret;
for (j = 0; j < numpages; 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 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
* @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, numpages, scanlen;
int startblock;
loff_t from;
size_t readlen;
pr_info("Scanning device for bad blocks\n");
if (bd->options & NAND_BBT_SCANALLPAGES)
numpages = 1 << (this->bbt_erase_shift - this->page_shift);
else if (bd->options & NAND_BBT_SCAN2NDPAGE)
numpages = 2;
else
numpages = 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 = numpages * 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) {
pr_warn("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->bbt_options & NAND_BBT_SCANLASTPAGE)
from += mtd->erasesize - (mtd->writesize * numpages);
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, numpages);
else
ret = scan_block_fast(mtd, bd, from, buf, numpages);
if (ret < 0)
return ret;
if (ret) {
this->bbt[i >> 3] |= 0x03 << (i & 0x6);
pr_warn("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(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) {
offs = bbt_get_ver_offs(mtd, td);
td->version[i] = buf[offs];
}
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)
pr_warn("Bad block table not found for chip %d\n", i);
else
pr_info("Bad block table found at page %d, version "
"0x%02X\n", td->pages[i], td->version[i]);
}
return 0;
}
/**
* search_read_bbts - [GENERIC] scan the device for bad block table(s)
* @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 void 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);
}
/**
* 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_OPS_PLACE_OOB;
if (!rcode)
rcode = 0xff;
/* Write bad block table per chip rather than per device? */
if (td->options & NAND_BBT_PERCHIP) {
numblocks = (int)(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;
}
pr_err("No space left to write bad block table\n");
return -ENOSPC;
write:
/* Set up shift count and masks for the flash table */
bits = td->options & NAND_BBT_NRBITS_MSK;
msk[2] = ~rcode;
switch (bits) {
case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
msk[3] = 0x01;
break;
case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
msk[3] = 0x03;
break;
case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
msk[3] = 0x0f;
break;
case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
msk[3] = 0xff;
break;
default: return -EINVAL;
}
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) {
pr_info("nand_bbt: error reading block "
"for writing the bad block table\n");
return res;
}
pr_warn("nand_bbt: ECC error while reading "
"block for writing bad block table\n");
}
/* Read oob data */
ops.ooblen = (len >> 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 if (td->options & NAND_BBT_NO_OOB) {
ooboffs = 0;
offs = td->len;
/* The version byte */
if (td->options & NAND_BBT_VERSION)
offs++;
/* Calc length */
len = (size_t)(numblocks >> sft);
len += offs;
/* Make it page aligned! */
len = ALIGN(len, mtd->writesize);
/* Preset the buffer with 0xff */
memset(buf, 0xff, len);
/* Pattern is located at the begin of first page */
memcpy(buf, td->pattern, td->len);
} else {
/* Calc length */
len = (size_t)(numblocks >> sft);
/* Make it page aligned! */
len = ALIGN(len, mtd->writesize);
/* Preset the buffer with 0xff */
memset(buf, 0xff, len +
(len >> 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,
td->options & NAND_BBT_NO_OOB ? NULL :
&buf[len]);
if (res < 0)
goto outerr;
pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
(unsigned long long)to, td->version[chip]);
/* Mark it as used */
td->pages[chip] = page;
}
return 0;
outerr:
pr_warn("nand_bbt: error while writing bad block table %d\n", res);
return res;
}
/**
* nand_memory_bbt - [GENERIC] create a memory based bad block table
* @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, 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 *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;
create = 0;
rd = NULL;
rd2 = NULL;
res = res2 = 0;
/* Per chip or per device? */
chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
/* Mirrored table available? */
if (md) {
if (td->pages[i] == -1 && md->pages[i] == -1) {
create = 1;
writeops = 0x03;
} else if (td->pages[i] == -1) {
rd = md;
writeops = 0x01;
} else if (md->pages[i] == -1) {
rd = td;
writeops = 0x02;
} else if (td->version[i] == md->version[i]) {
rd = td;
if (!(td->options & NAND_BBT_VERSION))
rd2 = md;
} else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
rd = td;
writeops = 0x02;
} else {
rd = md;
writeops = 0x01;
}
} else {
if (td->pages[i] == -1) {
create = 1;
writeops = 0x01;
} else {
rd = td;
}
}
if (create) {
/* Create the bad block table by scanning the device? */
if (!(td->options & NAND_BBT_CREATE))
continue;
/* Create the table in memory by scanning the chip(s) */
if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
create_bbt(mtd, buf, bd, chipsel);
td->version[i] = 1;
if (md)
md->version[i] = 1;
}
/* Read back first? */
if (rd) {
res = read_abs_bbt(mtd, buf, rd, chipsel);
if (mtd_is_eccerr(res)) {
/* Mark table as invalid */
rd->pages[i] = -1;
rd->version[i] = 0;
i--;
continue;
}
}
/* If they weren't versioned, read both */
if (rd2) {
res2 = read_abs_bbt(mtd, buf, rd2, chipsel);
if (mtd_is_eccerr(res2)) {
/* Mark table as invalid */
rd2->pages[i] = -1;
rd2->version[i] = 0;
i--;
continue;
}
}
/* Scrub the flash table(s)? */
if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
writeops = 0x03;
/* Update version numbers before writing */
if (md) {
td->version[i] = max(td->version[i], md->version[i]);
md->version[i] = td->version[i];
}
/* Write the bad block table to the device? */
if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
res = write_bbt(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));
}
}
/**
* 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->bbt_options & NAND_BBT_NO_OOB) &&
!(this->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(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));
}
/**
* 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)
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))) {
pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
kfree(this->bbt);
this->bbt = NULL;
}
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);
len += (len >> this->page_shift) * mtd->oobsize;
buf = vmalloc(len);
if (!buf) {
kfree(this->bbt);
this->bbt = NULL;
return -ENOMEM;
}
/* Is the bbt at a given page? */
if (td->options & NAND_BBT_ABSPAGE) {
read_abs_bbts(mtd, buf, td, md);
} else {
/* Search the bad block table using a pattern in oob */
search_read_bbts(mtd, buf, td, md);
}
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;
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)
return -ENOMEM;
/* 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 (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 (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 };
/* Generic flash bbt descriptors */
static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
static struct nand_bbt_descr bbt_main_descr = {
.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
.offs = 8,
.len = 4,
.veroffs = 12,
.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
.pattern = bbt_pattern
};
static struct nand_bbt_descr bbt_mirror_descr = {
.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
.offs = 8,
.len = 4,
.veroffs = 12,
.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
.pattern = mirror_pattern
};
static struct nand_bbt_descr bbt_main_no_oob_descr = {
.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
| NAND_BBT_NO_OOB,
.len = 4,
.veroffs = 4,
.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
.pattern = bbt_pattern
};
static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
| NAND_BBT_NO_OOB,
.len = 4,
.veroffs = 4,
.maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
.pattern = mirror_pattern
};
#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
*
* 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
*
* 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;
/* Is a flash based bad block table requested? */
if (this->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;
} 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)
nand_create_badblock_pattern(this);
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;
pr_debug("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);
EXPORT_SYMBOL_GPL(nand_update_bbt);