From 9e3307a169537a6adc30b13bf9063e94990a5493 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Sun, 3 May 2020 17:53:37 +0200 Subject: [PATCH] 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 +++++++++++++++++++++++++++++++++++++---- drivers/mtd/mtdpart.c | 54 +++++++----- include/linux/mtd/mtd.h | 7 +- include/linux/mtd/partitions.h | 2 + include/uapi/mtd/mtd-abi.h | 1 + 5 files changed, 213 insertions(+), 40 deletions(-) diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 2916674..50437b4 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; diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index 3f60256..c3575b6 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -35,9 +35,12 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, const struct mtd_partition *part, int partno, uint64_t cur_offset) { - int wr_alignment = (parent->flags & MTD_NO_ERASE) ? parent->writesize : - parent->erasesize; - struct mtd_info *child, *master = mtd_get_master(parent); + struct mtd_info *master = mtd_get_master(parent); + int wr_alignment = (parent->flags & MTD_NO_ERASE) ? + master->writesize : master->erasesize; + u64 parent_size = mtd_is_partition(parent) ? + parent->part.size : parent->size; + struct mtd_info *child; u32 remainder; char *name; u64 tmp; @@ -56,8 +59,9 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, /* set up the MTD object for this partition */ child->type = parent->type; child->part.flags = parent->flags & ~part->mask_flags; + child->part.flags |= part->add_flags; child->flags = child->part.flags; - child->size = part->size; + child->part.size = part->size; child->writesize = parent->writesize; child->writebufsize = parent->writebufsize; child->oobsize = parent->oobsize; @@ -98,29 +102,29 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, } if (child->part.offset == MTDPART_OFS_RETAIN) { child->part.offset = cur_offset; - if (parent->size - child->part.offset >= child->size) { - child->size = parent->size - child->part.offset - - child->size; + if (parent_size - child->part.offset >= child->part.size) { + child->part.size = parent_size - child->part.offset - + child->part.size; } else { printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n", - part->name, parent->size - child->part.offset, - child->size); + part->name, parent_size - child->part.offset, + child->part.size); /* register to preserve ordering */ goto out_register; } } - if (child->size == MTDPART_SIZ_FULL) - child->size = parent->size - child->part.offset; + if (child->part.size == MTDPART_SIZ_FULL) + child->part.size = parent_size - child->part.offset; printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", - child->part.offset, child->part.offset + child->size, + child->part.offset, child->part.offset + child->part.size, child->name); /* let's do some sanity checks */ - if (child->part.offset >= parent->size) { + if (child->part.offset >= parent_size) { /* let's register it anyway to preserve ordering */ child->part.offset = 0; - child->size = 0; + child->part.size = 0; /* Initialize ->erasesize to make add_mtd_device() happy. */ child->erasesize = parent->erasesize; @@ -128,15 +132,16 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, part->name); goto out_register; } - if (child->part.offset + child->size > parent->size) { - child->size = parent->size - child->part.offset; + if (child->part.offset + child->part.size > parent->size) { + child->part.size = parent_size - child->part.offset; printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n", - part->name, parent->name, child->size); + part->name, parent->name, child->part.size); } + if (parent->numeraseregions > 1) { /* Deal with variable erase size stuff */ int i, max = parent->numeraseregions; - u64 end = child->part.offset + child->size; + u64 end = child->part.offset + child->part.size; struct mtd_erase_region_info *regions = parent->eraseregions; /* Find the first erase regions which is part of this @@ -156,7 +161,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, BUG_ON(child->erasesize == 0); } else { /* Single erase size */ - child->erasesize = parent->erasesize; + child->erasesize = master->erasesize; } /* @@ -178,7 +183,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, part->name); } - tmp = mtd_get_master_ofs(child, 0) + child->size; + tmp = mtd_get_master_ofs(child, 0) + child->part.size; remainder = do_div(tmp, wr_alignment); if ((child->flags & MTD_WRITEABLE) && remainder) { child->flags &= ~MTD_WRITEABLE; @@ -186,6 +191,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, part->name); } + child->size = child->part.size; child->ecc_step_size = parent->ecc_step_size; child->ecc_strength = parent->ecc_strength; child->bitflip_threshold = parent->bitflip_threshold; @@ -193,7 +199,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, if (master->_block_isbad) { uint64_t offs = 0; - while (offs < child->size) { + while (offs < child->part.size) { if (mtd_block_isreserved(child, offs)) child->ecc_stats.bbtblocks++; else if (mtd_block_isbad(child, offs)) @@ -234,6 +240,8 @@ int mtd_add_partition(struct mtd_info *parent, const char *name, long long offset, long long length) { struct mtd_info *master = mtd_get_master(parent); + u64 parent_size = mtd_is_partition(parent) ? + parent->part.size : parent->size; struct mtd_partition part; struct mtd_info *child; int ret = 0; @@ -244,7 +252,7 @@ int mtd_add_partition(struct mtd_info *parent, const char *name, return -EINVAL; if (length == MTDPART_SIZ_FULL) - length = parent->size - offset; + length = parent_size - offset; if (length <= 0) return -EINVAL; @@ -419,7 +427,7 @@ int add_mtd_partitions(struct mtd_info *parent, /* Look for subpartitions */ parse_mtd_partitions(child, parts[i].types, NULL); - cur_offset = child->part.offset + child->size; + cur_offset = child->part.offset + child->part.size; } return 0; diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 2d1f4a6..157357e 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -200,6 +200,8 @@ struct mtd_debug_info { * * @node: list node used to add an MTD partition to the parent partition list * @offset: offset of the partition relatively to the parent offset + * @size: partition size. Should be equal to mtd->size unless + * MTD_SLC_ON_MLC_EMULATION is set * @flags: original flags (before the mtdpart logic decided to tweak them based * on flash constraints, like eraseblock/pagesize alignment) * @@ -209,6 +211,7 @@ struct mtd_debug_info { struct mtd_part { struct list_head node; u64 offset; + u64 size; u32 flags; }; @@ -622,7 +625,9 @@ static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd) static inline int mtd_wunit_per_eb(struct mtd_info *mtd) { - return mtd->erasesize / mtd->writesize; + struct mtd_info *master = mtd_get_master(mtd); + + return master->erasesize / mtd->writesize; } static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs) diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h index e545c050..b74a539 100644 --- a/include/linux/mtd/partitions.h +++ b/include/linux/mtd/partitions.h @@ -37,6 +37,7 @@ * master MTD flag set for the corresponding MTD partition. * For example, to force a read-only partition, simply adding * MTD_WRITEABLE to the mask_flags will do the trick. + * add_flags: contains flags to add to the parent flags * * Note: writeable partitions require their size and offset be * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK). @@ -48,6 +49,7 @@ struct mtd_partition { uint64_t size; /* partition size */ uint64_t offset; /* offset within the master MTD space */ uint32_t mask_flags; /* master MTD flags to mask out for this partition */ + uint32_t add_flags; /* flags to add to the partition */ struct device_node *of_node; }; diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h index 47ffe32..4b48fbf 100644 --- a/include/uapi/mtd/mtd-abi.h +++ b/include/uapi/mtd/mtd-abi.h @@ -104,6 +104,7 @@ struct mtd_write_req { #define MTD_BIT_WRITEABLE 0x800 /* Single bits can be flipped */ #define MTD_NO_ERASE 0x1000 /* No erase necessary */ #define MTD_POWERUP_LOCK 0x2000 /* Always locked after reset */ +#define MTD_SLC_ON_MLC_EMULATION 0x4000 /* Emulate SLC behavior on MLC NANDs */ /* Some common devices / combinations of capabilities */ #define MTD_CAP_ROM 0 -- 2.7.4