[PATCH v4 1/3] mtd: Add support for Linux slc-mode for MLC NAND

16 Dec 2021

From: Chris Morgan macromorgan@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 have tested these patches extensively on the NTC CHIP for both
SKHynix and Toshiba MLC NAND versions. I have been able to boot from a
ubifs partition from a vmlinuz, initramfs, devicetree, and boot.scr
from said partition. I have also been able to create a new empty
partition from within U-Boot.
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.
Thank you.
Signed-off-by: Chris Morgan macromorgan@hotmail.com
---
 cmd/mtdparts.c                   |  20 ++
 drivers/mtd/mtdcore.c            | 563 +++++++++++++++++++++++++------
 drivers/mtd/mtdcore.h            |   1 -
 drivers/mtd/mtdpart.c            |   7 +
 drivers/mtd/nand/raw/nand_base.c |  50 +++
 include/linux/mtd/mtd.h          | 190 ++++++++++-
 include/linux/mtd/partitions.h   |  24 +-
 include/mtd/mtd-abi.h            |   1 +
 8 files changed, 732 insertions(+), 124 deletions(-)

diff --git a/cmd/mtdparts.c b/cmd/mtdparts.c
index 3048700778..5c1ad09bf5 100644
--- a/cmd/mtdparts.c
+++ b/cmd/mtdparts.c
@@ -110,6 +110,10 @@ DECLARE_GLOBAL_DATA_PTR;
  * field for read-only partitions */
 #define MTD_WRITEABLE_CMD		1
+/* this flag needs to be set in part_info struct mask_flags
+ * field for slc-emulation partitions */
+#define MTD_SLC_ON_MLC_EMULATION_CMD	1
+
 /* default values for mtdids and mtdparts variables */
 #if !defined(MTDIDS_DEFAULT)
 #ifdef CONFIG_MTDIDS_DEFAULT
@@ -662,6 +666,11 @@ static int part_parse(const char *const partdef, const char **ret, struct part_i
    	p += 2;
    }
+	if (strncmp(p, "slc", 3) == 0) {
+		mask_flags |= MTD_SLC_ON_MLC_EMULATION_CMD;
+		p += 3;
+	}
+
    /* check for next partition definition */
    if (*p == ',') {
    	if (size == SIZE_REMAINING) {
@@ -1171,6 +1180,17 @@ static int generate_mtdparts(char *buf, u32 buflen)
    			maxlen -= 2;
    		}
+			/* slc mask flag */
+			if (part->mask_flags && MTD_SLC_ON_MLC_EMULATION_CMD) {
+				len = 3;
+				if (len > maxlen)
+					goto cleanup;
+				*(p++) = 's';
+				*(p++) = 'l';
+				*(p++) = 'c';
+				maxlen -= 3;
+			}
+
    		/* print ',' separator if there are other partitions
    		 * following */
    		if (dev->num_parts > part_cnt) {
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 1d45fb55c7..e45a306a42 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
@@ -750,20 +881,28 @@ EXPORT_SYMBOL_GPL(get_mtd_device);
int __get_mtd_device(struct mtd_info *mtd)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
    int err;
-	if (!try_module_get(mtd->owner))
+	if (!try_module_get(master->owner))
    	return -ENODEV;
-	if (mtd->_get_device) {
-		err = mtd->_get_device(mtd);
+	if (master->_get_device) {
+		err = master->_get_device(mtd);
if (err) {
-			module_put(mtd->owner);
+			module_put(master->owner);
    		return err;
    	}
    }
-	mtd->usecount++;
+
+	master->usecount++;
+
+	while (mtd->parent) {
+		mtd->usecount++;
+		mtd = mtd->parent;
+	}
+
    return 0;
 }
 EXPORT_SYMBOL_GPL(__get_mtd_device);
@@ -896,28 +1035,66 @@ EXPORT_SYMBOL_GPL(put_mtd_device);
void __put_mtd_device(struct mtd_info *mtd)
 {
-	--mtd->usecount;
-	BUG_ON(mtd->usecount < 0);
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	while (mtd->parent) {
+		--mtd->usecount;
+		BUG_ON(mtd->usecount < 0);
+		mtd = mtd->parent;
+	}
+
+	master->usecount--;
-	if (mtd->_put_device)
-		mtd->_put_device(mtd);
+	if (master->_put_device)
+		master->_put_device(master);
-	module_put(mtd->owner);
+	module_put(master->owner);
 }
 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);
+	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;
+
    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;
-	if (!instr->len) {
-		instr->state = MTD_ERASE_DONE;
+
+	if (!instr->len)
    	return 0;
+
+	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;
    }
-	return mtd->_erase(mtd, instr);
+
+	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;
+		}
+	}
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_erase);
@@ -928,30 +1105,36 @@ EXPORT_SYMBOL_GPL(mtd_erase);
 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
          void **virt, resource_size_t *phys)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
    *retlen = 0;
    *virt = NULL;
    if (phys)
    	*phys = 0;
-	if (!mtd->_point)
+	if (!master->_point)
    	return -EOPNOTSUPP;
    if (from < 0 || from > mtd->size || len > mtd->size - from)
    	return -EINVAL;
    if (!len)
    	return 0;
-	return mtd->_point(mtd, from, len, retlen, virt, phys);
+
+	from = mtd_get_master_ofs(mtd, from);
+	return master->_point(master, from, len, retlen, virt, phys);
 }
 EXPORT_SYMBOL_GPL(mtd_point);
/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
 {
-	if (!mtd->_point)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_point)
    	return -EOPNOTSUPP;
    if (from < 0 || from > mtd->size || len > mtd->size - from)
    	return -EINVAL;
    if (!len)
    	return 0;
-	return mtd->_unpoint(mtd, from, len);
+	return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
 }
 EXPORT_SYMBOL_GPL(mtd_unpoint);
 #endif
@@ -972,68 +1155,54 @@ unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
 }
 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
+static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
+				 const struct mtd_ecc_stats *old_stats)
+{
+	struct mtd_ecc_stats diff;
+
+	if (master == mtd)
+		return;
+
+	diff = master->ecc_stats;
+	diff.failed -= old_stats->failed;
+	diff.corrected -= old_stats->corrected;
+
+	while (mtd->parent) {
+		mtd->ecc_stats.failed += diff.failed;
+		mtd->ecc_stats.corrected += diff.corrected;
+		mtd = mtd->parent;
+	}
+}
+
 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
         u_char *buf)
 {
-	int ret_code;
-	*retlen = 0;
-	if (from < 0 || from > mtd->size || len > mtd->size - from)
-		return -EINVAL;
-	if (!len)
-		return 0;
+	struct mtd_oob_ops ops = {
+		.len = len,
+		.datbuf = buf,
+	};
+	int ret;
-	/*
-	 * In the absence of an error, drivers return a non-negative integer
-	 * representing the maximum number of bitflips that were corrected on
-	 * any one ecc region (if applicable; zero otherwise).
-	 */
-	if (mtd->_read) {
-		ret_code = mtd->_read(mtd, from, len, retlen, buf);
-	} else if (mtd->_read_oob) {
-		struct mtd_oob_ops ops = {
-			.len = len,
-			.datbuf = buf,
-		};
-
-		ret_code = mtd->_read_oob(mtd, from, &ops);
-		*retlen = ops.retlen;
-	} else {
-		return -ENOTSUPP;
-	}
+	ret = mtd_read_oob(mtd, from, &ops);
+	*retlen = ops.retlen;
-	if (unlikely(ret_code < 0))
-		return ret_code;
-	if (mtd->ecc_strength == 0)
-		return 0;	/* device lacks ecc */
-	return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_read);
int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
          const u_char *buf)
 {
-	*retlen = 0;
-	if (to < 0 || to > mtd->size || len > mtd->size - to)
-		return -EINVAL;
-	if ((!mtd->_write && !mtd->_write_oob) ||
-	    !(mtd->flags & MTD_WRITEABLE))
-		return -EROFS;
-	if (!len)
-		return 0;
-
-	if (!mtd->_write) {
-		struct mtd_oob_ops ops = {
-			.len = len,
-			.datbuf = (u8 *)buf,
-		};
-		int ret;
+	struct mtd_oob_ops ops = {
+		.len = len,
+		.datbuf = (u8 *)buf,
+	};
+	int ret;
-		ret = mtd->_write_oob(mtd, to, &ops);
-		*retlen = ops.retlen;
-		return ret;
-	}
+	ret = mtd_write_oob(mtd, to, &ops);
+	*retlen = ops.retlen;
-	return mtd->_write(mtd, to, len, retlen, buf);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_write);
@@ -1047,8 +1216,10 @@ EXPORT_SYMBOL_GPL(mtd_write);
 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
    	    const u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
    *retlen = 0;
-	if (!mtd->_panic_write)
+	if (!master->_panic_write)
    	return -EOPNOTSUPP;
    if (to < 0 || to > mtd->size || len > mtd->size - to)
    	return -EINVAL;
@@ -1056,7 +1227,8 @@ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
    	return -EROFS;
    if (!len)
    	return 0;
-	return mtd->_panic_write(mtd, to, len, retlen, buf);
+	return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
+				    retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_panic_write);
@@ -1093,9 +1265,107 @@ 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);
+	struct mtd_ecc_stats old_stats = master->ecc_stats;
    int ret_code;
+
    ops->retlen = ops->oobretlen = 0;
ret_code = mtd_check_oob_ops(mtd, from, ops);
@@ -1103,14 +1373,15 @@ int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
    	return ret_code;
/* Check the validity of a potential fallback on mtd->_read */
-	if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
+	if (!master->_read_oob && (!master->_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);
+
+	mtd_update_ecc_stats(mtd, master, &old_stats);
/*
     * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
@@ -1129,6 +1400,7 @@ EXPORT_SYMBOL_GPL(mtd_read_oob);
 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
    			struct mtd_oob_ops *ops)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
    int ret;
ops->retlen = ops->oobretlen = 0;
@@ -1141,14 +1413,14 @@ int mtd_write_oob(struct mtd_info *mtd, loff_t to,
    	return ret;
/* Check the validity of a potential fallback on mtd->_write */
-	if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
+	if (!master->_write_oob && (!master->_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);
@@ -1171,15 +1443,17 @@ EXPORT_SYMBOL_GPL(mtd_write_oob);
 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
    	      struct mtd_oob_region *oobecc)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
    memset(oobecc, 0, sizeof(*oobecc));
-	if (!mtd || section < 0)
+	if (!master || section < 0)
    	return -EINVAL;
-	if (!mtd->ooblayout || !mtd->ooblayout->ecc)
+	if (!master->ooblayout || !master->ooblayout->ecc)
    	return -ENOTSUPP;
-	return mtd->ooblayout->ecc(mtd, section, oobecc);
+	return master->ooblayout->ecc(master, section, oobecc);
 }
 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
@@ -1203,15 +1477,17 @@ EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
    	       struct mtd_oob_region *oobfree)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
    memset(oobfree, 0, sizeof(*oobfree));
-	if (!mtd || section < 0)
+	if (!master || section < 0)
    	return -EINVAL;
-	if (!mtd->ooblayout || !mtd->ooblayout->rfree)
+	if (!master->ooblayout || !master->ooblayout->rfree)
    	return -ENOTSUPP;
-	return mtd->ooblayout->rfree(mtd, section, oobfree);
+	return master->ooblayout->rfree(master, section, oobfree);
 }
 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
@@ -1520,60 +1796,69 @@ EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
    		   struct otp_info *buf)
 {
-	if (!mtd->_get_fact_prot_info)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_get_fact_prot_info)
    	return -EOPNOTSUPP;
    if (!len)
    	return 0;
-	return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
+	return master->_get_fact_prot_info(master, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
    		   size_t *retlen, u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
    *retlen = 0;
-	if (!mtd->_read_fact_prot_reg)
+	if (!master->_read_fact_prot_reg)
    	return -EOPNOTSUPP;
    if (!len)
    	return 0;
-	return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
+	return master->_read_fact_prot_reg(master, from, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
    		   struct otp_info *buf)
 {
-	if (!mtd->_get_user_prot_info)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_get_user_prot_info)
    	return -EOPNOTSUPP;
    if (!len)
    	return 0;
-	return mtd->_get_user_prot_info(mtd, len, retlen, buf);
+	return master->_get_user_prot_info(master, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
    		   size_t *retlen, u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
    *retlen = 0;
-	if (!mtd->_read_user_prot_reg)
+	if (!master->_read_user_prot_reg)
    	return -EOPNOTSUPP;
    if (!len)
    	return 0;
-	return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
+	return master->_read_user_prot_reg(master, from, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
    		    size_t *retlen, u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
    int ret;
*retlen = 0;
-	if (!mtd->_write_user_prot_reg)
+	if (!master->_write_user_prot_reg)
    	return -EOPNOTSUPP;
    if (!len)
    	return 0;
-	ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
+	ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
    if (ret)
    	return ret;
@@ -1587,80 +1872,129 @@ EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
 {
-	if (!mtd->_lock_user_prot_reg)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_lock_user_prot_reg)
    	return -EOPNOTSUPP;
    if (!len)
    	return 0;
-	return mtd->_lock_user_prot_reg(mtd, from, len);
+	return master->_lock_user_prot_reg(master, from, len);
 }
 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);
+	int ret;
+
+	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;
+
+	ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
+	if (ret)
+		return ret;
+
+	while (mtd->parent) {
+		mtd->ecc_stats.badblocks++;
+		mtd = mtd->parent;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mtd_block_markbad);
@@ -1711,12 +2045,17 @@ static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
           unsigned long count, loff_t to, size_t *retlen)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
    *retlen = 0;
    if (!(mtd->flags & MTD_WRITEABLE))
    	return -EROFS;
-	if (!mtd->_writev)
+
+	if (!master->_writev)
    	return default_mtd_writev(mtd, vecs, count, to, retlen);
-	return mtd->_writev(mtd, vecs, count, to, retlen);
+
+	return master->_writev(master, vecs, count,
+			       mtd_get_master_ofs(mtd, to), retlen);
 }
 EXPORT_SYMBOL_GPL(mtd_writev);
diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index 1d181a1045..73f8f21271 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -10,7 +10,6 @@ int del_mtd_device(struct mtd_info *mtd);
 int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
 int del_mtd_partitions(struct mtd_info *);
 int parse_mtd_partitions(struct mtd_info *master, const char * const *types,
-			 struct mtd_partition **pparts,
    		 struct mtd_part_parser_data *data);
int __init init_mtdchar(void);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index a435ce6d07..092853e872 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) {
@@ -580,6 +586,7 @@ 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 f7616985d9..8a148863bd 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -105,6 +105,56 @@ 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 7455400981..d8f65c49fb 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -132,6 +132,82 @@ 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
@@ -147,6 +223,43 @@ struct nand_ecclayout {
struct module;	/* only needed for owner field in mtd_info */
+/**
+ * struct mtd_part - MTD partition specific fields
+ *
+ * @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)
+ *
+ * This struct is embedded in mtd_info and contains partition-specific
+ * properties/fields.
+ */
+struct mtd_part {
+	struct list_head node;
+	u64 offset;
+	u64 size;
+	u32 flags;
+};
+
+/**
+ * struct mtd_master - MTD master specific fields
+ *
+ * @partitions_lock: lock protecting accesses to the partition list. Protects
+ *		     not only the master partition list, but also all
+ *		     sub-partitions.
+ * @suspended: et to 1 when the device is suspended, 0 otherwise
+ *
+ * This struct is embedded in mtd_info and contains master-specific
+ * properties/fields. The master is the root MTD device from the MTD partition
+ * point of view.
+ */
+struct mtd_master {
+	struct mutex partitions_lock;
+	unsigned int suspended : 1;
+};
+
 struct mtd_info {
    u_char type;
    uint32_t flags;
@@ -210,6 +323,9 @@ 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;
@@ -328,8 +444,31 @@ struct mtd_info {
     * MTD device can itself be a partition).
     */
    struct list_head partitions;
+
+	union {
+		struct mtd_part part;
+		struct mtd_master master;
+	};
 };
+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)
 {
@@ -390,11 +529,22 @@ 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,
@@ -432,8 +582,10 @@ int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
static inline void mtd_sync(struct mtd_info *mtd)
 {
-	if (mtd->_sync)
-		mtd->_sync(mtd);
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (master->_sync)
+		master->_sync(master);
 }
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
@@ -446,13 +598,15 @@ int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
 #ifndef __UBOOT__
 static inline int mtd_suspend(struct mtd_info *mtd)
 {
-	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
+	struct mtd_info *master = mtd_get_master(mtd);
+	return master->_suspend ? master->_suspend(master) : 0;
 }
static inline void mtd_resume(struct mtd_info *mtd)
 {
-	if (mtd->_resume)
-		mtd->_resume(mtd);
+	struct mtd_info *master = mtd_get_master(mtd);
+	if (master->_resume)
+		master->_resume(master);
 }
 #endif
@@ -486,9 +640,29 @@ 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;
+	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
+
+	return master->_read_oob && master->_write_oob;
 }
static inline int mtd_type_is_nand(const struct mtd_info *mtd)
@@ -498,7 +672,9 @@ static inline int mtd_type_is_nand(const struct mtd_info *mtd)
static inline int mtd_can_have_bb(const struct mtd_info *mtd)
 {
-	return !!mtd->_block_isbad;
+	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
+
+	return !!master->_block_isbad;
 }
/* Kernel-side ioctl definitions */
diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
index 0f5a233266..06b36c6881 100644
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -20,6 +20,12 @@
  *
  * For each partition, these fields are available:
  * name: string that will be used to label the partition's MTD device.
+ * types: some partitions can be containers using specific format to describe
+ *	embedded subpartitions / volumes. E.g. many home routers use "firmware"
+ *	partition that contains at least kernel and rootfs. In such case an
+ *	extra parser is needed that will detect these dynamic partitions and
+ *	report them to the MTD subsystem. If set this property stores an array
+ *	of parser names to use when looking for subpartitions.
  * size: the partition size; if defined as MTDPART_SIZ_FULL, the partition
  *	will extend to the end of the master MTD device.
  * offset: absolute starting position within the master MTD device; if
@@ -31,6 +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).
@@ -38,9 +45,11 @@
struct mtd_partition {
    const char *name;		/* identifier string */
+	const char *const *types;	/* names of parsers to use if any */
    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) */
 };
@@ -53,7 +62,6 @@ struct mtd_partition {
 struct mtd_info;
 struct device_node;
-#ifndef __UBOOT__
 /**
  * struct mtd_part_parser_data - used to pass data to MTD partition parsers.
  * @origin: for RedBoot, start address of MTD device
@@ -64,7 +72,6 @@ struct mtd_part_parser_data {
    struct device_node *of_node;
 };
-
 /*
  * Functions dealing with the various ways of partitioning the space
  */
@@ -73,13 +80,22 @@ struct mtd_part_parser {
    struct list_head list;
    struct module *owner;
    const char *name;
-	int (*parse_fn)(struct mtd_info *, struct mtd_partition **,
+	const struct udevice_id *of_match_table;
+	int (*parse_fn)(struct mtd_info *, const struct mtd_partition **,
    		struct mtd_part_parser_data *);
+	void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
+};
+
+/* Container for passing around a set of parsed partitions */
+struct mtd_partitions {
+	const struct mtd_partition *parts;
+	int nr_parts;
+	const struct mtd_part_parser *parser;
 };
+
 extern void register_mtd_parser(struct mtd_part_parser *parser);
 extern void deregister_mtd_parser(struct mtd_part_parser *parser);
-#endif
int mtd_add_partition(struct mtd_info *master, const char *name,
    	      long long offset, long long length);
diff --git a/include/mtd/mtd-abi.h b/include/mtd/mtd-abi.h
index ea244fbaeb..96850aff93 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


    