[RFC 1/2] mtd: Add partial support for Linux slc-mode for MLC NAND
Chris Morgan
macroalpha82 at gmail.com
Fri Sep 17 20:12:33 CEST 2021
From: Chris Morgan <macromorgan at hotmail.com>
Add support for setting the slc-mode parameter for a given MLC NAND
device. This allows a given device to write only to the first set
of paried pages to help reduce data corruption and increase reliability
of the NAND.
I haven't tested these patches extensively yet, but thus far I have
been able to boot a FIT image written directly to an MTD partition
from within Linux via U-boot where the slc-mode parameter is set. I
am not able to attach a ubifs partition generated in Linux with the
slc-mode set.
As I am unfamiliar with NAND and have limited experience with the MTD
subsystems, please let me know what else I can do to improve the driver
(and possibly get it where ubifs can work).
Thank you.
Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
---
drivers/mtd/mtdcore.c | 320 ++++++++++++++++++++++++++++---
drivers/mtd/mtdpart.c | 7 +
drivers/mtd/nand/raw/nand_base.c | 50 +++++
include/linux/mtd/mtd.h | 126 ++++++++++++
include/linux/mtd/partitions.h | 2 +
include/mtd/mtd-abi.h | 1 +
6 files changed, 482 insertions(+), 24 deletions(-)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 0d1f94c6cb..884c95228a 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -397,6 +397,114 @@ static struct device_type mtd_devtype = {
};
#endif
+/**
+ * mtd_wunit_to_pairing_info - get pairing information of a wunit
+ * @mtd: pointer to new MTD device info structure
+ * @wunit: write unit we are interested in
+ * @info: returned pairing information
+ *
+ * Retrieve pairing information associated to the wunit.
+ * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
+ * paired together, and where programming a page may influence the page it is
+ * paired with.
+ * The notion of page is replaced by the term wunit (write-unit) to stay
+ * consistent with the ->writesize field.
+ *
+ * The @wunit argument can be extracted from an absolute offset using
+ * mtd_offset_to_wunit(). @info is filled with the pairing information attached
+ * to @wunit.
+ *
+ * From the pairing info the MTD user can find all the wunits paired with
+ * @wunit using the following loop:
+ *
+ * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
+ * info.pair = i;
+ * mtd_pairing_info_to_wunit(mtd, &info);
+ * ...
+ * }
+ */
+int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
+ struct mtd_pairing_info *info)
+{
+ struct mtd_info *master = mtd_get_master(mtd);
+ int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
+
+ if (wunit < 0 || wunit >= npairs)
+ return -EINVAL;
+
+ if (master->pairing && master->pairing->get_info)
+ return master->pairing->get_info(master, wunit, info);
+
+ info->group = 0;
+ info->pair = wunit;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
+
+/**
+ * mtd_pairing_info_to_wunit - get wunit from pairing information
+ * @mtd: pointer to new MTD device info structure
+ * @info: pairing information struct
+ *
+ * Returns a positive number representing the wunit associated to the info
+ * struct, or a negative error code.
+ *
+ * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
+ * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
+ * doc).
+ *
+ * It can also be used to only program the first page of each pair (i.e.
+ * page attached to group 0), which allows one to use an MLC NAND in
+ * software-emulated SLC mode:
+ *
+ * info.group = 0;
+ * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
+ * for (info.pair = 0; info.pair < npairs; info.pair++) {
+ * wunit = mtd_pairing_info_to_wunit(mtd, &info);
+ * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
+ * mtd->writesize, &retlen, buf + (i * mtd->writesize));
+ * }
+ */
+int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
+ const struct mtd_pairing_info *info)
+{
+ struct mtd_info *master = mtd_get_master(mtd);
+ int ngroups = mtd_pairing_groups(master);
+ int npairs = mtd_wunit_per_eb(master) / ngroups;
+
+ if (!info || info->pair < 0 || info->pair >= npairs ||
+ info->group < 0 || info->group >= ngroups)
+ return -EINVAL;
+
+ if (master->pairing && master->pairing->get_wunit)
+ return mtd->pairing->get_wunit(master, info);
+
+ return info->pair;
+}
+EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
+
+/**
+ * mtd_pairing_groups - get the number of pairing groups
+ * @mtd: pointer to new MTD device info structure
+ *
+ * Returns the number of pairing groups.
+ *
+ * This number is usually equal to the number of bits exposed by a single
+ * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
+ * to iterate over all pages of a given pair.
+ */
+int mtd_pairing_groups(struct mtd_info *mtd)
+{
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->pairing || !master->pairing->ngroups)
+ return 1;
+
+ return master->pairing->ngroups;
+}
+EXPORT_SYMBOL_GPL(mtd_pairing_groups);
+
/**
* add_mtd_device - register an MTD device
* @mtd: pointer to new MTD device info structure
@@ -412,6 +520,7 @@ int add_mtd_device(struct mtd_info *mtd)
#ifndef __UBOOT__
struct mtd_notifier *not;
#endif
+ struct mtd_info *master = mtd_get_master(mtd);
int i, error;
#ifndef __UBOOT__
@@ -431,6 +540,20 @@ int add_mtd_device(struct mtd_info *mtd)
#endif
BUG_ON(mtd->writesize == 0);
+
+ /*
+ * 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))
+ return -EINVAL;
+
mutex_lock(&mtd_table_mutex);
i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
@@ -446,6 +569,14 @@ 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
@@ -880,17 +1011,29 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
*/
int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
+ struct mtd_info *master = mtd_get_master(mtd);
+ struct erase_info adjinstr;
if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
+ adjinstr = *instr;
+
+ 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;
+ }
+
if (!instr->len) {
- instr->state = MTD_ERASE_DONE;
- mtd_erase_callback(instr);
+ adjinstr.state = MTD_ERASE_DONE;
+ mtd_erase_callback(&adjinstr);
return 0;
}
- return mtd->_erase(mtd, instr);
+ return master->_erase(master, &adjinstr);
}
EXPORT_SYMBOL_GPL(mtd_erase);
@@ -1066,6 +1209,101 @@ 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)
{
int ret_code;
@@ -1079,11 +1317,10 @@ int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
return -EOPNOTSUPP;
- if (mtd->_read_oob)
- ret_code = mtd->_read_oob(mtd, from, ops);
+ if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
+ ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
else
- ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
- ops->datbuf);
+ ret_code = mtd_read_oob_std(mtd, from, ops);
/*
* In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
@@ -1117,11 +1354,11 @@ int mtd_write_oob(struct mtd_info *mtd, loff_t to,
if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
return -EOPNOTSUPP;
- if (mtd->_write_oob)
- return mtd->_write_oob(mtd, to, ops);
- else
- return mtd->_write(mtd, to, ops->len, &ops->retlen,
- ops->datbuf);
+ if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
+ return mtd_io_emulated_slc(mtd, to, false, ops);
+
+ return mtd_write_oob_std(mtd, to, ops);
+
}
EXPORT_SYMBOL_GPL(mtd_write_oob);
@@ -1571,69 +1808,104 @@ EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
/* Chip-supported device locking */
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
- if (!mtd->_lock)
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_lock)
return -EOPNOTSUPP;
if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
return -EINVAL;
if (!len)
return 0;
- return mtd->_lock(mtd, ofs, len);
+ 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);
int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
- if (!mtd->_unlock)
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_unlock)
return -EOPNOTSUPP;
if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
return -EINVAL;
if (!len)
return 0;
- return mtd->_unlock(mtd, ofs, len);
+ 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);
int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
- if (!mtd->_is_locked)
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_is_locked)
return -EOPNOTSUPP;
if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
return -EINVAL;
if (!len)
return 0;
- return mtd->_is_locked(mtd, ofs, len);
+ 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);
int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
{
+ struct mtd_info *master = mtd_get_master(mtd);
+
if (ofs < 0 || ofs > mtd->size)
return -EINVAL;
- if (!mtd->_block_isreserved)
+ if (!master->_block_isreserved)
return 0;
- return mtd->_block_isreserved(mtd, ofs);
+ 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);
int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
+ struct mtd_info *master = mtd_get_master(mtd);
+
if (ofs < 0 || ofs > mtd->size)
return -EINVAL;
- if (!mtd->_block_isbad)
+ if (!master->_block_isbad)
return 0;
- return mtd->_block_isbad(mtd, ofs);
+ 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);
int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
- if (!mtd->_block_markbad)
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_block_markbad)
return -EOPNOTSUPP;
if (ofs < 0 || ofs > mtd->size)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
- return mtd->_block_markbad(mtd, ofs);
+ if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
+ ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
+
+ return master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
}
EXPORT_SYMBOL_GPL(mtd_block_markbad);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index d064ac3048..63d14467d4 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -148,6 +148,12 @@ static int mtd_parse_partition(const char **_mtdparts,
mtdparts += 2;
}
+ /* if slc is found use emulated SLC mode on this partition*/
+ if (!strncmp(mtdparts, "slc", 3)) {
+ partition->add_flags |= MTD_SLC_ON_MLC_EMULATION;
+ mtdparts += 3;
+ }
+
/* Check for a potential next partition definition */
if (*mtdparts == ',') {
if (partition->size == MTD_SIZE_REMAINING) {
@@ -591,6 +597,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *master,
/* set up the MTD object for this partition */
slave->type = master->type;
slave->flags = master->flags & ~part->mask_flags;
+ slave->flags |= part->add_flags;
slave->size = part->size;
slave->writesize = master->writesize;
slave->writebufsize = master->writebufsize;
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 3679ee727e..845bf57c53 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -108,6 +108,56 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
*/
DEFINE_LED_TRIGGER(nand_led_trigger);
+static int nand_pairing_dist3_get_info(struct mtd_info *mtd, int page,
+ struct mtd_pairing_info *info)
+{
+ int lastpage = (mtd->erasesize / mtd->writesize) - 1;
+ int dist = 3;
+
+ if (page == lastpage)
+ dist = 2;
+
+ if (!page || (page & 1)) {
+ info->group = 0;
+ info->pair = (page + 1) / 2;
+ } else {
+ info->group = 1;
+ info->pair = (page + 1 - dist) / 2;
+ }
+
+ return 0;
+}
+
+static int nand_pairing_dist3_get_wunit(struct mtd_info *mtd,
+ const struct mtd_pairing_info *info)
+{
+ int lastpair = ((mtd->erasesize / mtd->writesize) - 1) / 2;
+ int page = info->pair * 2;
+ int dist = 3;
+
+ if (!info->group && !info->pair)
+ return 0;
+
+ if (info->pair == lastpair && info->group)
+ dist = 2;
+
+ if (!info->group)
+ page--;
+ else if (info->pair)
+ page += dist - 1;
+
+ if (page >= mtd->erasesize / mtd->writesize)
+ return -EINVAL;
+
+ return page;
+}
+
+const struct mtd_pairing_scheme dist3_pairing_scheme = {
+ .ngroups = 2,
+ .get_info = nand_pairing_dist3_get_info,
+ .get_wunit = nand_pairing_dist3_get_wunit,
+};
+
static int check_offs_len(struct mtd_info *mtd,
loff_t ofs, uint64_t len)
{
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 927854950a..7d63df4130 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -133,6 +133,82 @@ struct mtd_ooblayout_ops {
struct mtd_oob_region *oobfree);
};
+/**
+ * struct mtd_pairing_info - page pairing information
+ *
+ * @pair: pair id
+ * @group: group id
+ *
+ * The term "pair" is used here, even though TLC NANDs might group pages by 3
+ * (3 bits in a single cell). A pair should regroup all pages that are sharing
+ * the same cell. Pairs are then indexed in ascending order.
+ *
+ * @group is defining the position of a page in a given pair. It can also be
+ * seen as the bit position in the cell: page attached to bit 0 belongs to
+ * group 0, page attached to bit 1 belongs to group 1, etc.
+ *
+ * Example:
+ * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
+ *
+ * group-0 group-1
+ *
+ * pair-0 page-0 page-4
+ * pair-1 page-1 page-5
+ * pair-2 page-2 page-8
+ * ...
+ * pair-127 page-251 page-255
+ *
+ *
+ * Note that the "group" and "pair" terms were extracted from Samsung and
+ * Hynix datasheets, and might be referenced under other names in other
+ * datasheets (Micron is describing this concept as "shared pages").
+ */
+struct mtd_pairing_info {
+ int pair;
+ int group;
+};
+
+/**
+ * struct mtd_pairing_scheme - page pairing scheme description
+ *
+ * @ngroups: number of groups. Should be related to the number of bits
+ * per cell.
+ * @get_info: converts a write-unit (page number within an erase block) into
+ * mtd_pairing information (pair + group). This function should
+ * fill the info parameter based on the wunit index or return
+ * -EINVAL if the wunit parameter is invalid.
+ * @get_wunit: converts pairing information into a write-unit (page) number.
+ * This function should return the wunit index pointed by the
+ * pairing information described in the info argument. It should
+ * return -EINVAL, if there's no wunit corresponding to the
+ * passed pairing information.
+ *
+ * See mtd_pairing_info documentation for a detailed explanation of the
+ * pair and group concepts.
+ *
+ * The mtd_pairing_scheme structure provides a generic solution to represent
+ * NAND page pairing scheme. Instead of exposing two big tables to do the
+ * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
+ * implement the ->get_info() and ->get_wunit() functions.
+ *
+ * MTD users will then be able to query these information by using the
+ * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
+ *
+ * @ngroups is here to help MTD users iterating over all the pages in a
+ * given pair. This value can be retrieved by MTD users using the
+ * mtd_pairing_groups() helper.
+ *
+ * Examples are given in the mtd_pairing_info_to_wunit() and
+ * mtd_wunit_to_pairing_info() documentation.
+ */
+struct mtd_pairing_scheme {
+ int ngroups;
+ int (*get_info)(struct mtd_info *mtd, int wunit,
+ struct mtd_pairing_info *info);
+ int (*get_wunit)(struct mtd_info *mtd,
+ const struct mtd_pairing_info *info);
+};
+
/*
* Internal ECC layout control structure. For historical reasons, there is a
* similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
@@ -211,6 +287,9 @@ struct mtd_info {
/* OOB layout description */
const struct mtd_ooblayout_ops *ooblayout;
+ /* NAND pairing scheme, only provided for MLC/TLC NANDs */
+ const struct mtd_pairing_scheme *pairing;
+
/* ECC layout structure pointer - read only! */
struct nand_ecclayout *ecclayout;
@@ -331,6 +410,24 @@ struct mtd_info {
struct list_head partitions;
};
+static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
+{
+ while (mtd->parent)
+ mtd = mtd->parent;
+
+ return mtd;
+}
+
+static inline u64 mtd_get_master_ofs(struct mtd_info *mtd, u64 ofs)
+{
+ while (mtd->parent) {
+ ofs += mtd->offset;
+ mtd = mtd->parent;
+ }
+
+ return ofs;
+}
+
#if IS_ENABLED(CONFIG_DM)
static inline void mtd_set_ofnode(struct mtd_info *mtd, ofnode node)
{
@@ -391,11 +488,22 @@ static inline void mtd_set_ooblayout(struct mtd_info *mtd,
mtd->ooblayout = ooblayout;
}
+static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
+ const struct mtd_pairing_scheme *pairing)
+{
+ mtd->pairing = pairing;
+}
+
static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
{
return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
}
+int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
+ struct mtd_pairing_info *info);
+int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
+ const struct mtd_pairing_info *info);
+int mtd_pairing_groups(struct mtd_info *mtd);
int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
#ifndef __UBOOT__
int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
@@ -487,6 +595,24 @@ static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
return do_div(sz, mtd->writesize);
}
+static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
+{
+ 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)
+{
+ return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
+}
+
+static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
+ int wunit)
+{
+ return base + (wunit * mtd->writesize);
+}
+
static inline int mtd_has_oob(const struct mtd_info *mtd)
{
return mtd->_read_oob && mtd->_write_oob;
diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
index 3822237f2a..8e0f35ce25 100644
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -31,6 +31,7 @@
* 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).
@@ -41,6 +42,7 @@ 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 nand_ecclayout *ecclayout; /* out of band layout for this partition (NAND only) */
};
diff --git a/include/mtd/mtd-abi.h b/include/mtd/mtd-abi.h
index 8d9761050f..2f6ce18795 100644
--- a/include/mtd/mtd-abi.h
+++ b/include/mtd/mtd-abi.h
@@ -94,6 +94,7 @@ 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
--
2.30.2
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