diff options
Diffstat (limited to 'drivers/mtd/nand/nand_bbt.c')
| -rw-r--r-- | drivers/mtd/nand/nand_bbt.c | 1056 |
1 files changed, 1056 insertions, 0 deletions
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c new file mode 100644 index 0000000..9a19497 --- /dev/null +++ b/drivers/mtd/nand/nand_bbt.c @@ -0,0 +1,1056 @@ +/* + * 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 1.28 2004/11/13 10:19:09 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 + * If one of the bbt's is out of date or does not exist it is (re)created.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; + 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; + } + + p += td->len; + end += td->len; + if (td->options & NAND_BBT_SCANEMPTY) { + for (i = end; i < len; i++) { + if (*p++ != 0xff) + 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 void 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; + } + 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; + } + 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;) { + nand_read_raw (mtd, buf, from, readlen, ooblen); + for (j = 0; j < len; j++) { + 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); + } +} + +/** + * 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 int nand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd) +{ + struct nand_chip *this = mtd->priv; + + /* Ensure that we only scan for the pattern and nothing else */ + bd->options = 0; + create_bbt (mtd, this->data_buf, bd, -1); + return 0; +} + +/** + * 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) + return nand_memory_bbt(mtd, bd); + + /* 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 + * + * The memory based patterns just + */ +static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; + +static struct nand_bbt_descr smallpage_memorybased = { + .options = 0, + .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, res, block >> 1); + + 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); |
