diff options
Diffstat (limited to 'drivers/mtd/parsers/sharpslpart.c')
| -rw-r--r-- | drivers/mtd/parsers/sharpslpart.c | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/mtd/parsers/sharpslpart.c b/drivers/mtd/parsers/sharpslpart.c new file mode 100644 index 000000000..671a61845 --- /dev/null +++ b/drivers/mtd/parsers/sharpslpart.c @@ -0,0 +1,399 @@ +/* + * sharpslpart.c - MTD partition parser for NAND flash using the SHARP FTL + * for logical addressing, as used on the PXA models of the SHARP SL Series. + * + * Copyright (C) 2017 Andrea Adami <andrea.adami@gmail.com> + * + * Based on SHARP GPL 2.4 sources: + * http://support.ezaurus.com/developer/source/source_dl.asp + * drivers/mtd/nand/sharp_sl_logical.c + * linux/include/asm-arm/sharp_nand_logical.h + * + * Copyright (C) 2002 SHARP + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/bitops.h> +#include <linux/sizes.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/partitions.h> + +/* oob structure */ +#define NAND_NOOB_LOGADDR_00 8 +#define NAND_NOOB_LOGADDR_01 9 +#define NAND_NOOB_LOGADDR_10 10 +#define NAND_NOOB_LOGADDR_11 11 +#define NAND_NOOB_LOGADDR_20 12 +#define NAND_NOOB_LOGADDR_21 13 + +#define BLOCK_IS_RESERVED 0xffff +#define BLOCK_UNMASK_COMPLEMENT 1 + +/* factory defaults */ +#define SHARPSL_NAND_PARTS 3 +#define SHARPSL_FTL_PART_SIZE (7 * SZ_1M) +#define SHARPSL_PARTINFO1_LADDR 0x00060000 +#define SHARPSL_PARTINFO2_LADDR 0x00064000 + +#define BOOT_MAGIC 0x424f4f54 +#define FSRO_MAGIC 0x4653524f +#define FSRW_MAGIC 0x46535257 + +/** + * struct sharpsl_ftl - Sharp FTL Logical Table + * @logmax: number of logical blocks + * @log2phy: the logical-to-physical table + * + * Structure containing the logical-to-physical translation table + * used by the SHARP SL FTL. + */ +struct sharpsl_ftl { + unsigned int logmax; + unsigned int *log2phy; +}; + +/* verify that the OOB bytes 8 to 15 are free and available for the FTL */ +static int sharpsl_nand_check_ooblayout(struct mtd_info *mtd) +{ + u8 freebytes = 0; + int section = 0; + + while (true) { + struct mtd_oob_region oobfree = { }; + int ret, i; + + ret = mtd_ooblayout_free(mtd, section++, &oobfree); + if (ret) + break; + + if (!oobfree.length || oobfree.offset > 15 || + (oobfree.offset + oobfree.length) < 8) + continue; + + i = oobfree.offset >= 8 ? oobfree.offset : 8; + for (; i < oobfree.offset + oobfree.length && i < 16; i++) + freebytes |= BIT(i - 8); + + if (freebytes == 0xff) + return 0; + } + + return -ENOTSUPP; +} + +static int sharpsl_nand_read_oob(struct mtd_info *mtd, loff_t offs, u8 *buf) +{ + struct mtd_oob_ops ops = { }; + int ret; + + ops.mode = MTD_OPS_PLACE_OOB; + ops.ooblen = mtd->oobsize; + ops.oobbuf = buf; + + ret = mtd_read_oob(mtd, offs, &ops); + if (ret != 0 || mtd->oobsize != ops.oobretlen) + return -1; + + return 0; +} + +/* + * The logical block number assigned to a physical block is stored in the OOB + * of the first page, in 3 16-bit copies with the following layout: + * + * 01234567 89abcdef + * -------- -------- + * ECC BB xyxyxy + * + * When reading we check that the first two copies agree. + * In case of error, matching is tried using the following pairs. + * Reserved values 0xffff mean the block is kept for wear leveling. + * + * 01234567 89abcdef + * -------- -------- + * ECC BB xyxy oob[8]==oob[10] && oob[9]==oob[11] -> byte0=8 byte1=9 + * ECC BB xyxy oob[10]==oob[12] && oob[11]==oob[13] -> byte0=10 byte1=11 + * ECC BB xy xy oob[12]==oob[8] && oob[13]==oob[9] -> byte0=12 byte1=13 + */ +static int sharpsl_nand_get_logical_num(u8 *oob) +{ + u16 us; + int good0, good1; + + if (oob[NAND_NOOB_LOGADDR_00] == oob[NAND_NOOB_LOGADDR_10] && + oob[NAND_NOOB_LOGADDR_01] == oob[NAND_NOOB_LOGADDR_11]) { + good0 = NAND_NOOB_LOGADDR_00; + good1 = NAND_NOOB_LOGADDR_01; + } else if (oob[NAND_NOOB_LOGADDR_10] == oob[NAND_NOOB_LOGADDR_20] && + oob[NAND_NOOB_LOGADDR_11] == oob[NAND_NOOB_LOGADDR_21]) { + good0 = NAND_NOOB_LOGADDR_10; + good1 = NAND_NOOB_LOGADDR_11; + } else if (oob[NAND_NOOB_LOGADDR_20] == oob[NAND_NOOB_LOGADDR_00] && + oob[NAND_NOOB_LOGADDR_21] == oob[NAND_NOOB_LOGADDR_01]) { + good0 = NAND_NOOB_LOGADDR_20; + good1 = NAND_NOOB_LOGADDR_21; + } else { + return -EINVAL; + } + + us = oob[good0] | oob[good1] << 8; + + /* parity check */ + if (hweight16(us) & BLOCK_UNMASK_COMPLEMENT) + return -EINVAL; + + /* reserved */ + if (us == BLOCK_IS_RESERVED) + return BLOCK_IS_RESERVED; + + return (us >> 1) & GENMASK(9, 0); +} + +static int sharpsl_nand_init_ftl(struct mtd_info *mtd, struct sharpsl_ftl *ftl) +{ + unsigned int block_num, phymax; + int i, ret, log_num; + loff_t block_adr; + u8 *oob; + + oob = kzalloc(mtd->oobsize, GFP_KERNEL); + if (!oob) + return -ENOMEM; + + phymax = mtd_div_by_eb(SHARPSL_FTL_PART_SIZE, mtd); + + /* FTL reserves 5% of the blocks + 1 spare */ + ftl->logmax = ((phymax * 95) / 100) - 1; + + ftl->log2phy = kmalloc_array(ftl->logmax, sizeof(*ftl->log2phy), + GFP_KERNEL); + if (!ftl->log2phy) { + ret = -ENOMEM; + goto exit; + } + + /* initialize ftl->log2phy */ + for (i = 0; i < ftl->logmax; i++) + ftl->log2phy[i] = UINT_MAX; + + /* create physical-logical table */ + for (block_num = 0; block_num < phymax; block_num++) { + block_adr = (loff_t)block_num * mtd->erasesize; + + if (mtd_block_isbad(mtd, block_adr)) + continue; + + if (sharpsl_nand_read_oob(mtd, block_adr, oob)) + continue; + + /* get logical block */ + log_num = sharpsl_nand_get_logical_num(oob); + + /* cut-off errors and skip the out-of-range values */ + if (log_num > 0 && log_num < ftl->logmax) { + if (ftl->log2phy[log_num] == UINT_MAX) + ftl->log2phy[log_num] = block_num; + } + } + + pr_info("Sharp SL FTL: %d blocks used (%d logical, %d reserved)\n", + phymax, ftl->logmax, phymax - ftl->logmax); + + ret = 0; +exit: + kfree(oob); + return ret; +} + +static void sharpsl_nand_cleanup_ftl(struct sharpsl_ftl *ftl) +{ + kfree(ftl->log2phy); +} + +static int sharpsl_nand_read_laddr(struct mtd_info *mtd, + loff_t from, + size_t len, + void *buf, + struct sharpsl_ftl *ftl) +{ + unsigned int log_num, final_log_num; + unsigned int block_num; + loff_t block_adr; + loff_t block_ofs; + size_t retlen; + int err; + + log_num = mtd_div_by_eb((u32)from, mtd); + final_log_num = mtd_div_by_eb(((u32)from + len - 1), mtd); + + if (len <= 0 || log_num >= ftl->logmax || final_log_num > log_num) + return -EINVAL; + + block_num = ftl->log2phy[log_num]; + block_adr = (loff_t)block_num * mtd->erasesize; + block_ofs = mtd_mod_by_eb((u32)from, mtd); + + err = mtd_read(mtd, block_adr + block_ofs, len, &retlen, buf); + /* Ignore corrected ECC errors */ + if (mtd_is_bitflip(err)) + err = 0; + + if (!err && retlen != len) + err = -EIO; + + if (err) + pr_err("sharpslpart: error, read failed at %#llx\n", + block_adr + block_ofs); + + return err; +} + +/* + * MTD Partition Parser + * + * Sample values read from SL-C860 + * + * # cat /proc/mtd + * dev: size erasesize name + * mtd0: 006d0000 00020000 "Filesystem" + * mtd1: 00700000 00004000 "smf" + * mtd2: 03500000 00004000 "root" + * mtd3: 04400000 00004000 "home" + * + * PARTITIONINFO1 + * 0x00060000: 00 00 00 00 00 00 70 00 42 4f 4f 54 00 00 00 00 ......p.BOOT.... + * 0x00060010: 00 00 70 00 00 00 c0 03 46 53 52 4f 00 00 00 00 ..p.....FSRO.... + * 0x00060020: 00 00 c0 03 00 00 00 04 46 53 52 57 00 00 00 00 ........FSRW.... + */ +struct sharpsl_nand_partinfo { + __le32 start; + __le32 end; + __be32 magic; + u32 reserved; +}; + +static int sharpsl_nand_read_partinfo(struct mtd_info *master, + loff_t from, + size_t len, + struct sharpsl_nand_partinfo *buf, + struct sharpsl_ftl *ftl) +{ + int ret; + + ret = sharpsl_nand_read_laddr(master, from, len, buf, ftl); + if (ret) + return ret; + + /* check for magics */ + if (be32_to_cpu(buf[0].magic) != BOOT_MAGIC || + be32_to_cpu(buf[1].magic) != FSRO_MAGIC || + be32_to_cpu(buf[2].magic) != FSRW_MAGIC) { + pr_err("sharpslpart: magic values mismatch\n"); + return -EINVAL; + } + + /* fixup for hardcoded value 64 MiB (for older models) */ + buf[2].end = cpu_to_le32(master->size); + + /* extra sanity check */ + if (le32_to_cpu(buf[0].end) <= le32_to_cpu(buf[0].start) || + le32_to_cpu(buf[1].start) < le32_to_cpu(buf[0].end) || + le32_to_cpu(buf[1].end) <= le32_to_cpu(buf[1].start) || + le32_to_cpu(buf[2].start) < le32_to_cpu(buf[1].end) || + le32_to_cpu(buf[2].end) <= le32_to_cpu(buf[2].start)) { + pr_err("sharpslpart: partition sizes mismatch\n"); + return -EINVAL; + } + + return 0; +} + +static int sharpsl_parse_mtd_partitions(struct mtd_info *master, + const struct mtd_partition **pparts, + struct mtd_part_parser_data *data) +{ + struct sharpsl_ftl ftl; + struct sharpsl_nand_partinfo buf[SHARPSL_NAND_PARTS]; + struct mtd_partition *sharpsl_nand_parts; + int err; + + /* check that OOB bytes 8 to 15 used by the FTL are actually free */ + err = sharpsl_nand_check_ooblayout(master); + if (err) + return err; + + /* init logical mgmt (FTL) */ + err = sharpsl_nand_init_ftl(master, &ftl); + if (err) + return err; + + /* read and validate first partition table */ + pr_info("sharpslpart: try reading first partition table\n"); + err = sharpsl_nand_read_partinfo(master, + SHARPSL_PARTINFO1_LADDR, + sizeof(buf), buf, &ftl); + if (err) { + /* fallback: read second partition table */ + pr_warn("sharpslpart: first partition table is invalid, retry using the second\n"); + err = sharpsl_nand_read_partinfo(master, + SHARPSL_PARTINFO2_LADDR, + sizeof(buf), buf, &ftl); + } + + /* cleanup logical mgmt (FTL) */ + sharpsl_nand_cleanup_ftl(&ftl); + + if (err) { + pr_err("sharpslpart: both partition tables are invalid\n"); + return err; + } + + sharpsl_nand_parts = kcalloc(SHARPSL_NAND_PARTS, + sizeof(*sharpsl_nand_parts), + GFP_KERNEL); + if (!sharpsl_nand_parts) + return -ENOMEM; + + /* original names */ + sharpsl_nand_parts[0].name = "smf"; + sharpsl_nand_parts[0].offset = le32_to_cpu(buf[0].start); + sharpsl_nand_parts[0].size = le32_to_cpu(buf[0].end) - + le32_to_cpu(buf[0].start); + + sharpsl_nand_parts[1].name = "root"; + sharpsl_nand_parts[1].offset = le32_to_cpu(buf[1].start); + sharpsl_nand_parts[1].size = le32_to_cpu(buf[1].end) - + le32_to_cpu(buf[1].start); + + sharpsl_nand_parts[2].name = "home"; + sharpsl_nand_parts[2].offset = le32_to_cpu(buf[2].start); + sharpsl_nand_parts[2].size = le32_to_cpu(buf[2].end) - + le32_to_cpu(buf[2].start); + + *pparts = sharpsl_nand_parts; + return SHARPSL_NAND_PARTS; +} + +static struct mtd_part_parser sharpsl_mtd_parser = { + .parse_fn = sharpsl_parse_mtd_partitions, + .name = "sharpslpart", +}; +module_mtd_part_parser(sharpsl_mtd_parser); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Andrea Adami <andrea.adami@gmail.com>"); +MODULE_DESCRIPTION("MTD partitioning for NAND flash on Sharp SL Series"); 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