From 9e3307a169537a6adc30b13bf9063e94990a5493 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Sun, 3 May 2020 17:53:37 +0200 Subject: mtd: Add support for emulated SLC mode on MLC NANDs MLC NANDs can be made a bit more reliable if we only program the lower page of each pair. At least, this solves the paired-pages corruption issue. Signed-off-by: Boris Brezillon Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200503155341.16712-5-miquel.raynal@bootlin.com --- drivers/mtd/mtdcore.c | 189 +++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 173 insertions(+), 16 deletions(-) (limited to 'drivers/mtd/mtdcore.c') diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 2916674208b3..50437b4ffe76 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -617,6 +617,19 @@ int add_mtd_device(struct mtd_info *mtd) !(mtd->flags & MTD_NO_ERASE))) return -EINVAL; + /* + * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the + * master is an MLC NAND and has a proper pairing scheme defined. + * We also reject masters that implement ->_writev() for now, because + * NAND controller drivers don't implement this hook, and adding the + * SLC -> MLC address/length conversion to this path is useless if we + * don't have a user. + */ + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION && + (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH || + !master->pairing || master->_writev)) + return -EINVAL; + mutex_lock(&mtd_table_mutex); i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL); @@ -632,6 +645,14 @@ int add_mtd_device(struct mtd_info *mtd) if (mtd->bitflip_threshold == 0) mtd->bitflip_threshold = mtd->ecc_strength; + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + int ngroups = mtd_pairing_groups(master); + + mtd->erasesize /= ngroups; + mtd->size = (u64)mtd_div_by_eb(mtd->size, master) * + mtd->erasesize; + } + if (is_power_of_2(mtd->erasesize)) mtd->erasesize_shift = ffs(mtd->erasesize) - 1; else @@ -1074,9 +1095,11 @@ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) { struct mtd_info *master = mtd_get_master(mtd); u64 mst_ofs = mtd_get_master_ofs(mtd, 0); + struct erase_info adjinstr; int ret; instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN; + adjinstr = *instr; if (!mtd->erasesize || !master->_erase) return -ENOTSUPP; @@ -1091,12 +1114,27 @@ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) ledtrig_mtd_activity(); - instr->addr += mst_ofs; - ret = master->_erase(master, instr); - if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN) - instr->fail_addr -= mst_ofs; + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) * + master->erasesize; + adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) * + master->erasesize) - + adjinstr.addr; + } + + adjinstr.addr += mst_ofs; + + ret = master->_erase(master, &adjinstr); + + if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) { + instr->fail_addr = adjinstr.fail_addr - mst_ofs; + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + instr->fail_addr = mtd_div_by_eb(instr->fail_addr, + master); + instr->fail_addr *= mtd->erasesize; + } + } - instr->addr -= mst_ofs; return ret; } EXPORT_SYMBOL_GPL(mtd_erase); @@ -1276,6 +1314,101 @@ static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs, return 0; } +static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from, + struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ret; + + from = mtd_get_master_ofs(mtd, from); + if (master->_read_oob) + ret = master->_read_oob(master, from, ops); + else + ret = master->_read(master, from, ops->len, &ops->retlen, + ops->datbuf); + + return ret; +} + +static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to, + struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ret; + + to = mtd_get_master_ofs(mtd, to); + if (master->_write_oob) + ret = master->_write_oob(master, to, ops); + else + ret = master->_write(master, to, ops->len, &ops->retlen, + ops->datbuf); + + return ret; +} + +static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read, + struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ngroups = mtd_pairing_groups(master); + int npairs = mtd_wunit_per_eb(master) / ngroups; + struct mtd_oob_ops adjops = *ops; + unsigned int wunit, oobavail; + struct mtd_pairing_info info; + int max_bitflips = 0; + u32 ebofs, pageofs; + loff_t base, pos; + + ebofs = mtd_mod_by_eb(start, mtd); + base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize; + info.group = 0; + info.pair = mtd_div_by_ws(ebofs, mtd); + pageofs = mtd_mod_by_ws(ebofs, mtd); + oobavail = mtd_oobavail(mtd, ops); + + while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) { + int ret; + + if (info.pair >= npairs) { + info.pair = 0; + base += master->erasesize; + } + + wunit = mtd_pairing_info_to_wunit(master, &info); + pos = mtd_wunit_to_offset(mtd, base, wunit); + + adjops.len = ops->len - ops->retlen; + if (adjops.len > mtd->writesize - pageofs) + adjops.len = mtd->writesize - pageofs; + + adjops.ooblen = ops->ooblen - ops->oobretlen; + if (adjops.ooblen > oobavail - adjops.ooboffs) + adjops.ooblen = oobavail - adjops.ooboffs; + + if (read) { + ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops); + if (ret > 0) + max_bitflips = max(max_bitflips, ret); + } else { + ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops); + } + + if (ret < 0) + return ret; + + max_bitflips = max(max_bitflips, ret); + ops->retlen += adjops.retlen; + ops->oobretlen += adjops.oobretlen; + adjops.datbuf += adjops.retlen; + adjops.oobbuf += adjops.oobretlen; + adjops.ooboffs = 0; + pageofs = 0; + info.pair++; + } + + return max_bitflips; +} + int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) { struct mtd_info *master = mtd_get_master(mtd); @@ -1294,12 +1427,10 @@ int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) if (!master->_read_oob && (!master->_read || ops->oobbuf)) return -EOPNOTSUPP; - from = mtd_get_master_ofs(mtd, from); - if (master->_read_oob) - ret_code = master->_read_oob(master, from, ops); + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ret_code = mtd_io_emulated_slc(mtd, from, true, ops); else - ret_code = master->_read(master, from, ops->len, &ops->retlen, - ops->datbuf); + ret_code = mtd_read_oob_std(mtd, from, ops); mtd_update_ecc_stats(mtd, master, &old_stats); @@ -1338,13 +1469,10 @@ int mtd_write_oob(struct mtd_info *mtd, loff_t to, if (!master->_write_oob && (!master->_write || ops->oobbuf)) return -EOPNOTSUPP; - to = mtd_get_master_ofs(mtd, to); + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + return mtd_io_emulated_slc(mtd, to, false, ops); - if (master->_write_oob) - return master->_write_oob(master, to, ops); - else - return master->_write(master, to, ops->len, &ops->retlen, - ops->datbuf); + return mtd_write_oob_std(mtd, to, ops); } EXPORT_SYMBOL_GPL(mtd_write_oob); @@ -1817,6 +1945,12 @@ int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) return -EINVAL; if (!len) return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; + } + return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len); } EXPORT_SYMBOL_GPL(mtd_lock); @@ -1831,6 +1965,12 @@ int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) return -EINVAL; if (!len) return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; + } + return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len); } EXPORT_SYMBOL_GPL(mtd_unlock); @@ -1845,6 +1985,12 @@ int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len) return -EINVAL; if (!len) return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; + } + return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len); } EXPORT_SYMBOL_GPL(mtd_is_locked); @@ -1857,6 +2003,10 @@ int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs) return -EINVAL; if (!master->_block_isreserved) return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs)); } EXPORT_SYMBOL_GPL(mtd_block_isreserved); @@ -1869,6 +2019,10 @@ int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs) return -EINVAL; if (!master->_block_isbad) return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs)); } EXPORT_SYMBOL_GPL(mtd_block_isbad); @@ -1885,6 +2039,9 @@ int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs) if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs)); if (ret) return ret; -- cgit v1.2.3