/* * drivers/mtd/nand_bbt.c * * Overview: * Bad block table support for the NAND driver * * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Description: * * When nand_scan_bbt is called, then it tries to find the bad block table * depending on the options in the BBT descriptor(s). If 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 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 * If one of the BBTs is out of date or does not exist it is (re)created.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/nand.h> #include <linux/mtd/nand_ecc.h> #include <linux/bitops.h> #include <linux/delay.h> #include <linux/vmalloc.h> static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td) { int ret; ret = memcmp(buf, td->pattern, td->len); if (!ret) return ret; return -1; } /** * check_pattern - [GENERIC] check if a pattern is in the buffer * @buf: the buffer to search * @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; if (td->options & NAND_BBT_NO_OOB) return check_pattern_no_oob(buf, td); end = paglen + td->offs; if (td->options & NAND_BBT_SCANEMPTY) { for (i = 0; i < end; i++) { 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; } /** * add_marker_len - compute the length of the marker in data area * @td: BBT descriptor used for computation * * The length will be 0 if the markeris located in OOB area. */ static u32 add_marker_len(struct nand_bbt_descr *td) { u32 len; if (!(td->options & NAND_BBT_NO_OOB)) return 0; len = td->len; if (td->options & NAND_BBT_VERSION) len++; return len; } /** * read_bbt - [GENERIC] Read the bad block table starting from page * @mtd: MTD device structure * @buf: temporary buffer * @page: the starting page * @num: the number of bbt descriptors to read * @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, i, j, act = 0; struct nand_chip *this = mtd->priv; size_t retlen, len, totlen; loff_t from; int bits = td->options & NAND_BBT_NRBITS_MSK; uint8_t msk = (uint8_t) ((1 << bits) - 1); u32 marker_len; int reserved_block_code = td->reserved_block_code; totlen = (num * bits) >> 3; marker_len = add_marker_len(td); from = ((loff_t) page) << this->page_shift; while (totlen) { len = min(totlen, (size_t) (1 << this->bbt_erase_shift)); if (marker_len) { /* * In case the BBT marker is not in the OOB area it * will be just in the first page. */ len -= marker_len; from += marker_len; marker_len = 0; } res = mtd->read(mtd, from, len, &retlen, buf); if (res < 0) { if (retlen != len) { printk(KERN_INFO "nand_bbt: Error reading bad block table\n"); return res; } printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n"); } /* Analyse data */ for (i = 0; i < len; i++) { uint8_t dat = buf[i]; for (j = 0; j < 8; j += bits, act += 2) { uint8_t tmp = (dat >> j) & msk; if (tmp == msk) continue; if (reserved_block_code && (tmp == reserved_block_code)) { printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n", (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06); mtd->ecc_stats.bbtblocks++; continue; } /* * Leave it for now, if it's matured we can * move this message to MTD_DEBUG_LEVEL0. */ printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%012llx\n", (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); /* Factory marked bad or worn out? */ if (tmp == 0) this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06); else this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06); mtd->ecc_stats.badblocks++; } } totlen -= len; from += len; } return 0; } /** * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page * @mtd: MTD device structure * @buf: temporary buffer * @td: descriptor for the bad block table * @chip: read the table for a specific chip, -1 read all chips; aplies 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_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs, struct nand_bbt_descr *td) { size_t retlen; size_t len; len = td->len; if (td->options & NAND_BBT_VERSION) len++; return mtd->read(mtd, offs, len, &retlen, buf); } /* Scan read raw data from flash */ static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs, size_t len) { struct mtd_oob_ops ops; int res; ops.mode = MTD_OOB_RAW; ops.ooboffs = 0; ops.ooblen = mtd->oobsize; while (len > 0) { if (len <= mtd->writesize) { ops.oobbuf = buf + len; ops.datbuf = buf; ops.len = len; return mtd->read_oob(mtd, offs, &ops); } else { ops.oobbuf = buf + mtd->writesize; ops.datbuf = buf; ops.len = mtd->writesize; res = mtd->read_oob(mtd, offs, &ops); if (res) return res; } buf += mtd->oobsize + mtd->writesize; len -= mtd->writesize; } return 0; } static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs, size_t len, struct nand_bbt_descr *td) { if (td->options & NAND_BBT_NO_OOB) return scan_read_raw_data(mtd, buf, offs, td); else return scan_read_raw_oob(mtd, buf, offs, len); } /* Scan write data with oob to flash */ static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len, uint8_t *buf, uint8_t *oob) { struct mtd_oob_ops ops; ops.mode = MTD_OOB_PLACE; ops.ooboffs = 0; ops.ooblen = mtd->oobsize; ops.datbuf = buf; ops.oobbuf = oob; ops.len = len; return mtd->write_oob(mtd, offs, &ops); } 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 int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md) { struct nand_chip *this = mtd->priv; /* Read the primary version, if available */ if (td->options & NAND_BBT_VERSION) { scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift, mtd->writesize, td); td->version[0] = buf[bbt_get_ver_offs(mtd, td)]; printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", td->pages[0], td->version[0]); } /* Read the mirror version, if available */ if (md && (md->options & NAND_BBT_VERSION)) { scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift, mtd->writesize, td); md->version[0] = buf[bbt_get_ver_offs(mtd, md)]; printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", md->pages[0], md->version[0]); } return 1; } /* Scan a given block full */ static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd, loff_t offs, uint8_t *buf, size_t readlen, int scanlen, int len) { int ret, j; ret = scan_read_raw_oob(mtd, buf, offs, readlen); if (ret) return ret; for (j = 0; j < len; j++, buf += scanlen) { if (check_pattern(buf, scanlen, mtd->writesize, bd)) return 1; } return 0; } /* Scan a given block partially */ static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd, loff_t offs, uint8_t *buf, int len) { struct mtd_oob_ops ops; int j, ret; ops.ooblen = mtd->oobsize; ops.oobbuf = buf; ops.ooboffs = 0; ops.datbuf = NULL; ops.mode = MTD_OOB_PLACE; for (j = 0; j < len; j++) { /* * Read the full oob until read_oob is fixed to handle single * byte reads for 16 bit buswidth. */ ret = mtd->read_oob(mtd, offs, &ops); if (ret) return ret; if (check_short_pattern(buf, bd)) return 1; offs += mtd->writesize; } return 0; } /** * create_bbt - [GENERIC] Create a bad block table by scanning the device * @mtd: MTD device structure * @buf: temporary buffer * @bd: descriptor for the good/bad block search pattern * @chip: create the table for a specific chip, -1 read all chips; applies only * if NAND_BBT_PERCHIP option is set * * Create a bad block table by scanning the device for the given good/bad block * identify pattern. */ static int create_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd, int chip) { struct nand_chip *this = mtd->priv; int i, numblocks, len, scanlen; int startblock; loff_t from; size_t readlen; printk(KERN_INFO "Scanning device for bad blocks\n"); if (bd->options & NAND_BBT_SCANALLPAGES) len = 1 << (this->bbt_erase_shift - this->page_shift); else if (bd->options & NAND_BBT_SCAN2NDPAGE) len = 2; else len = 1; if (!(bd->options & NAND_BBT_SCANEMPTY)) { /* We need only read few bytes from the OOB area */ scanlen = 0; readlen = bd->len; } else { /* Full page content should be read */ scanlen = mtd->writesize + mtd->oobsize; readlen = len * mtd->writesize; } if (chip == -1) { /* * Note that numblocks is 2 * (real numblocks) here, see i+=2 * below as it makes shifting and masking less painful */ numblocks = mtd->size >> (this->bbt_erase_shift - 1); startblock = 0; from = 0; } else { if (chip >= this->numchips) { printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n", chip + 1, this->numchips); return -EINVAL; } numblocks = this->chipsize >> (this->bbt_erase_shift - 1); startblock = chip * numblocks; numblocks += startblock; from = (loff_t)startblock << (this->bbt_erase_shift - 1); } if (this->bbt_options & NAND_BBT_SCANLASTPAGE) from += mtd->erasesize - (mtd->writesize * len); for (i = startblock; i < numblocks;) { int ret; BUG_ON(bd->options & NAND_BBT_NO_OOB); if (bd->options & NAND_BBT_SCANALLPAGES) ret = scan_block_full(mtd, bd, from, buf, readlen, scanlen, len); else ret = scan_block_fast(mtd, bd, from, buf, len); if (ret < 0) return ret; if (ret) { this->bbt[i >> 3] |= 0x03 << (i & 0x6); printk(KERN_WARNING "Bad eraseblock %d at 0x%012llx\n", i >> 1, (unsigned long long)from); mtd->ecc_stats.badblocks++; } i += 2; from += (1 << this->bbt_erase_shift); } return 0; } /** * search_bbt - [GENERIC] scan the device for a specific bad block table * @mtd: MTD device structure * @buf: temporary buffer * @td: descriptor for the bad block table * * Read the bad block table by searching for a given ident pattern. Search is * preformed either from the beginning up or from the end of the device * downwards. The search starts always at the start of a block. If the option * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains * the bad block information of this chip. This is necessary to provide support * for certain DOC devices. * * The bbt ident pattern resides in the oob area of the first page in a block. */ static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td) { struct nand_chip *this = mtd->priv; int i, chips; int bits, startblock, block, dir; int scanlen = mtd->writesize + mtd->oobsize; int bbtblocks; int blocktopage = this->bbt_erase_shift - this->page_shift; /* Search direction top -> down? */ if (td->options & NAND_BBT_LASTBLOCK) { startblock = (mtd->size >> this->bbt_erase_shift) - 1; dir = -1; } else { startblock = 0; dir = 1; } /* Do we have a bbt per chip? */ if (td->options & NAND_BBT_PERCHIP) { chips = this->numchips; bbtblocks = this->chipsize >> this->bbt_erase_shift; startblock &= bbtblocks - 1; } else { chips = 1; bbtblocks = mtd->size >> this->bbt_erase_shift; } /* Number of bits for each erase block in the bbt */ bits = td->options & NAND_BBT_NRBITS_MSK; for (i = 0; i < chips; i++) { /* Reset version information */ td->version[i] = 0; td->pages[i] = -1; /* Scan the maximum number of blocks */ for (block = 0; block < td->maxblocks; block++) { int actblock = startblock + dir * block; loff_t offs = (loff_t)actblock << this->bbt_erase_shift; /* Read first page */ scan_read_raw(mtd, buf, offs, mtd->writesize, 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) printk(KERN_WARNING "Bad block table not found for chip %d\n", i); else printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i], td->version[i]); } return 0; } /** * search_read_bbts - [GENERIC] scan the device for bad block table(s) * @mtd: MTD device structure * @buf: temporary buffer * @td: descriptor for the bad block table * @md: descriptor for the bad block table mirror * * Search and read the bad block table(s). */ static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md) { /* Search the primary table */ search_bbt(mtd, buf, td); /* Search the mirror table */ if (md) search_bbt(mtd, buf, md); /* Force result check */ return 1; } /** * write_bbt - [GENERIC] (Re)write the bad block table * @mtd: MTD device structure * @buf: temporary buffer * @td: descriptor for the bad block table * @md: descriptor for the bad block table mirror * @chipsel: selector for a specific chip, -1 for all * * (Re)write the bad block table. */ static int write_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md, int chipsel) { struct nand_chip *this = mtd->priv; struct erase_info einfo; int i, j, res, chip = 0; int bits, startblock, dir, page, offs, numblocks, sft, sftmsk; int nrchips, bbtoffs, pageoffs, ooboffs; uint8_t msk[4]; uint8_t rcode = td->reserved_block_code; size_t retlen, len = 0; loff_t to; struct mtd_oob_ops ops; ops.ooblen = mtd->oobsize; ops.ooboffs = 0; ops.datbuf = NULL; ops.mode = MTD_OOB_PLACE; if (!rcode) rcode = 0xff; /* Write bad block table per chip rather than per device? */ if (td->options & NAND_BBT_PERCHIP) { numblocks = (int)(this->chipsize >> this->bbt_erase_shift); /* Full device write or specific chip? */ if (chipsel == -1) { nrchips = this->numchips; } else { nrchips = chipsel + 1; chip = chipsel; } } else { numblocks = (int)(mtd->size >> this->bbt_erase_shift); nrchips = 1; } /* Loop through the chips */ for (; chip < nrchips; chip++) { /* * There was already a version of the table, reuse the page * This applies for absolute placement too, as we have the * page nr. in td->pages. */ if (td->pages[chip] != -1) { page = td->pages[chip]; goto write; } /* * Automatic placement of the bad block table. Search direction * top -> down? */ if (td->options & NAND_BBT_LASTBLOCK) { startblock = numblocks * (chip + 1) - 1; dir = -1; } else { startblock = chip * numblocks; dir = 1; } for (i = 0; i < td->maxblocks; i++) { int block = startblock + dir * i; /* Check, if the block is bad */ switch ((this->bbt[block >> 2] >> (2 * (block & 0x03))) & 0x03) { case 0x01: case 0x03: continue; } page = block << (this->bbt_erase_shift - this->page_shift); /* Check, if the block is used by the mirror table */ if (!md || md->pages[chip] != page) goto write; } printk(KERN_ERR "No space left to write bad block table\n"); return -ENOSPC; write: /* Set up shift count and masks for the flash table */ bits = td->options & NAND_BBT_NRBITS_MSK; msk[2] = ~rcode; switch (bits) { case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01; msk[3] = 0x01; break; case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01; msk[3] = 0x03; break; case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C; msk[3] = 0x0f; break; case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F; msk[3] = 0xff; break; default: return -EINVAL; } bbtoffs = chip * (numblocks >> 2); to = ((loff_t) page) << this->page_shift; /* Must we save the block contents? */ if (td->options & NAND_BBT_SAVECONTENT) { /* Make it block aligned */ to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1)); len = 1 << this->bbt_erase_shift; res = mtd->read(mtd, to, len, &retlen, buf); if (res < 0) { if (retlen != len) { printk(KERN_INFO "nand_bbt: Error " "reading block for writing " "the bad block table\n"); return res; } printk(KERN_WARNING "nand_bbt: ECC error " "while reading block for writing " "bad block table\n"); } /* Read oob data */ ops.ooblen = (len >> this->page_shift) * mtd->oobsize; ops.oobbuf = &buf[len]; res = mtd->read_oob(mtd, to + mtd->writesize, &ops); if (res < 0 || ops.oobretlen != ops.ooblen) goto outerr; /* Calc the byte offset in the buffer */ pageoffs = page - (int)(to >> this->page_shift); offs = pageoffs << this->page_shift; /* Preset the bbt area with 0xff */ memset(&buf[offs], 0xff, (size_t) (numblocks >> sft)); ooboffs = len + (pageoffs * mtd->oobsize); } else 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; printk(KERN_DEBUG "Bad block table written to 0x%012llx, version " "0x%02X\n", (unsigned long long)to, td->version[chip]); /* Mark it as used */ td->pages[chip] = page; } return 0; outerr: printk(KERN_WARNING "nand_bbt: Error while writing bad block table %d\n", res); return res; } /** * nand_memory_bbt - [GENERIC] create a memory based bad block table * @mtd: MTD device structure * @bd: descriptor for the good/bad block search pattern * * The function creates a memory based bbt by scanning the device for * manufacturer / software marked good / bad blocks. */ static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) { struct nand_chip *this = mtd->priv; bd->options &= ~NAND_BBT_SCANEMPTY; return create_bbt(mtd, this->buffers->databuf, bd, -1); } /** * check_create - [GENERIC] create and write bbt(s) if necessary * @mtd: MTD device structure * @buf: temporary buffer * @bd: descriptor for the good/bad block search pattern * * The function checks the results of the previous call to read_bbt and creates * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found * for the chip/device. Update is necessary if one of the tables is missing or * the version nr. of one table is less than the other. */ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd) { int i, chips, writeops, chipsel, res; struct nand_chip *this = mtd->priv; struct nand_bbt_descr *td = this->bbt_td; struct nand_bbt_descr *md = this->bbt_md; struct nand_bbt_descr *rd, *rd2; /* Do we have a bbt per chip? */ if (td->options & NAND_BBT_PERCHIP) chips = this->numchips; else chips = 1; for (i = 0; i < chips; i++) { writeops = 0; rd = NULL; rd2 = NULL; /* Per chip or per device? */ chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1; /* Mirrored table available? */ 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) */ if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY)) create_bbt(mtd, buf, bd, chipsel); td->version[i] = 1; if (md) md->version[i] = 1; writecheck: /* Read back first? */ if (rd) read_abs_bbt(mtd, buf, rd, chipsel); /* If they weren't versioned, read both */ if (rd2) read_abs_bbt(mtd, buf, rd2, chipsel); /* Write the bad block table to the device? */ if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { res = write_bbt(mtd, buf, td, md, chipsel); if (res < 0) return res; } /* Write the mirror bad block table to the device? */ if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) { res = write_bbt(mtd, buf, md, td, chipsel); if (res < 0) return res; } } return 0; } /** * mark_bbt_regions - [GENERIC] mark the bad block table regions * @mtd: MTD device structure * @td: bad block table descriptor * * The bad block table regions are marked as "bad" to prevent accidental * erasures / writes. The regions are identified by the mark 0x02. */ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td) { struct nand_chip *this = mtd->priv; int i, j, chips, block, nrblocks, update; uint8_t oldval, newval; /* Do we have a bbt per chip? */ if (td->options & NAND_BBT_PERCHIP) { chips = this->numchips; nrblocks = (int)(this->chipsize >> this->bbt_erase_shift); } else { chips = 1; nrblocks = (int)(mtd->size >> this->bbt_erase_shift); } for (i = 0; i < chips; i++) { if ((td->options & NAND_BBT_ABSPAGE) || !(td->options & NAND_BBT_WRITE)) { if (td->pages[i] == -1) continue; block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift); block <<= 1; oldval = this->bbt[(block >> 3)]; newval = oldval | (0x2 << (block & 0x06)); this->bbt[(block >> 3)] = newval; if ((oldval != newval) && td->reserved_block_code) nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1)); continue; } update = 0; if (td->options & NAND_BBT_LASTBLOCK) block = ((i + 1) * nrblocks) - td->maxblocks; else block = i * nrblocks; block <<= 1; for (j = 0; j < td->maxblocks; j++) { oldval = this->bbt[(block >> 3)]; newval = oldval | (0x2 << (block & 0x06)); this->bbt[(block >> 3)] = newval; if (oldval != newval) update = 1; block += 2; } /* * If we want reserved blocks to be recorded to flash, and some * new ones have been marked, then we need to update the stored * bbts. This should only happen once. */ if (update && td->reserved_block_code) nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1)); } } /** * 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) { printk(KERN_ERR "nand_scan_bbt: Out of memory\n"); return -ENOMEM; } /* * If no primary table decriptor is given, scan the device to build a * memory based bad block table. */ if (!td) { if ((res = nand_memory_bbt(mtd, bd))) { printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n"); kfree(this->bbt); this->bbt = NULL; } return res; } 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) { printk(KERN_ERR "nand_bbt: Out of memory\n"); kfree(this->bbt); this->bbt = NULL; return -ENOMEM; } /* Is the bbt at a given page? */ if (td->options & NAND_BBT_ABSPAGE) { res = read_abs_bbts(mtd, buf, td, md); } else { /* Search the bad block table using a pattern in oob */ res = search_read_bbts(mtd, buf, td, md); } if (res) res = check_create(mtd, buf, bd); /* Prevent the bbt regions from erasing / writing */ mark_bbt_region(mtd, td); if (md) mark_bbt_region(mtd, md); vfree(buf); return res; } /** * nand_update_bbt - [NAND Interface] update bad block table(s) * @mtd: MTD device structure * @offs: the offset of the newly marked block * * The function updates the bad block table(s). */ int nand_update_bbt(struct mtd_info *mtd, loff_t offs) { struct nand_chip *this = mtd->priv; int len, res = 0, writeops = 0; int chip, chipsel; uint8_t *buf; struct nand_bbt_descr *td = this->bbt_td; struct nand_bbt_descr *md = this->bbt_md; if (!this->bbt || !td) return -EINVAL; /* Allocate a temporary buffer for one eraseblock incl. oob */ len = (1 << this->bbt_erase_shift); len += (len >> this->page_shift) * mtd->oobsize; buf = kmalloc(len, GFP_KERNEL); if (!buf) { printk(KERN_ERR "nand_update_bbt: Out of memory\n"); return -ENOMEM; } writeops = md != NULL ? 0x03 : 0x01; /* Do we have a bbt per chip? */ if (td->options & NAND_BBT_PERCHIP) { chip = (int)(offs >> this->chip_shift); chipsel = chip; } else { chip = 0; chipsel = -1; } td->version[chip]++; if (md) md->version[chip]++; /* Write the bad block table to the device? */ if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { res = write_bbt(mtd, buf, td, md, chipsel); if (res < 0) goto out; } /* Write the mirror bad block table to the device? */ if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) { res = write_bbt(mtd, buf, md, td, chipsel); } out: kfree(buf); return res; } /* * Define some generic bad / good block scan pattern which are used * while scanning a device for factory marked good / bad blocks. */ static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; static 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 }; static struct nand_bbt_descr bbt_main_no_bbt_descr = { .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP | NAND_BBT_NO_OOB, .len = 4, .veroffs = 4, .maxblocks = 4, .pattern = bbt_pattern }; static struct nand_bbt_descr bbt_mirror_no_bbt_descr = { .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP | NAND_BBT_NO_OOB, .len = 4, .veroffs = 4, .maxblocks = 4, .pattern = mirror_pattern }; /** * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure * @this: NAND chip to create descriptor for * * This function allocates and initializes a nand_bbt_descr for BBM detection * based on the properties of "this". The new descriptor is stored in * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when * passed to this function. */ static int nand_create_default_bbt_descr(struct nand_chip *this) { struct nand_bbt_descr *bd; if (this->badblock_pattern) { printk(KERN_WARNING "BBT descr already allocated; not replacing.\n"); return -EINVAL; } bd = kzalloc(sizeof(*bd), GFP_KERNEL); if (!bd) { printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n"); return -ENOMEM; } bd->options = this->bbt_options; bd->offs = this->badblockpos; bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1; bd->pattern = scan_ff_pattern; bd->options |= NAND_BBT_DYNAMICSTRUCT; this->badblock_pattern = bd; return 0; } /** * nand_default_bbt - [NAND Interface] Select a default bad block table for the device * @mtd: MTD device structure * * 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->bbt_options |= NAND_BBT_USE_FLASH; return nand_scan_bbt(mtd, &agand_flashbased); } /* 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_bbt_descr; this->bbt_md = &bbt_mirror_no_bbt_descr; } else { this->bbt_td = &bbt_main_descr; this->bbt_md = &bbt_mirror_descr; } } } else { this->bbt_td = NULL; this->bbt_md = NULL; } if (!this->badblock_pattern) nand_create_default_bbt_descr(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; 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);