/*
* 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, log_num, phymax;
loff_t block_adr;
u8 *oob;
int i, ret;
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");
