kernel: move mediatek BMT support patch to generic patches

Preparation for supporting BMT on MT7621. Move source files to the files/
subdirectory in order to simplify maintenance

Signed-off-by: Felix Fietkau <nbd@nbd.name>

2 files changed, 36 insertions, 871 deletions

diff --git a/target/linux/mediatek/patches-5.10/330-mtk-bmt-support.patch b/target/linux/mediatek/patches-5.10/330-mtk-bmt-support.patch
deleted file mode 100644
index bf70fb75b9..0000000000
--- a/target/linux/mediatek/patches-5.10/330-mtk-bmt-support.patch
+++ /dev/null
@@ -1,871 +0,0 @@
---- a/drivers/mtd/nand/Kconfig
-+++ b/drivers/mtd/nand/Kconfig
-@@ -15,6 +15,10 @@ config MTD_NAND_ECC
-        bool
-        depends on MTD_NAND_CORE
- 
-+config MTD_NAND_MTK_BMT
-+	bool "Support MediaTek NAND Bad-block Management Table"
-+	default n
-+
- endmenu
- 
- endmenu
---- a/drivers/mtd/nand/Makefile
-+++ b/drivers/mtd/nand/Makefile
-@@ -2,6 +2,7 @@
- 
- nandcore-objs := core.o bbt.o
- obj-$(CONFIG_MTD_NAND_CORE) += nandcore.o
-+obj-$(CONFIG_MTD_NAND_MTK_BMT)	+= mtk_bmt.o
- 
- obj-y	+= onenand/
- obj-y	+= raw/
---- /dev/null
-+++ b/drivers/mtd/nand/mtk_bmt.c
-@@ -0,0 +1,788 @@
-+/*
-+ * Copyright (c) 2017 MediaTek Inc.
-+ * Author: Xiangsheng Hou <xiangsheng.hou@mediatek.com>
-+ * Copyright (c) 2020 Felix Fietkau <nbd@nbd.name>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-+ * GNU General Public License for more details.
-+ */
-+
-+#include <linux/slab.h>
-+#include <linux/gfp.h>
-+#include <linux/kernel.h>
-+#include <linux/of.h>
-+#include <linux/mtd/mtd.h>
-+#include <linux/mtd/partitions.h>
-+#include <linux/mtd/mtk_bmt.h>
-+#include <linux/module.h>
-+#include <linux/debugfs.h>
-+
-+#define MAIN_SIGNATURE_OFFSET   0
-+#define OOB_SIGNATURE_OFFSET    1
-+#define BBPOOL_RATIO		2
-+
-+#define BBT_LOG(fmt, ...) pr_debug("[BBT][%s|%d] "fmt"\n", __func__, __LINE__, ##__VA_ARGS__)
-+
-+/* Maximum 8k blocks */
-+#define BB_TABLE_MAX	bmtd.table_size
-+#define BMT_TABLE_MAX	(BB_TABLE_MAX * BBPOOL_RATIO / 100)
-+#define BMT_TBL_DEF_VAL	0x0
-+
-+/*
-+ * Burner Bad Block Table
-+ * --------- Only support SLC Nand Chips!!!!!!!!!!! ----------
-+ */
-+
-+struct bbbt {
-+	char signature[3];
-+	/* This version is used to distinguish the legacy and new algorithm */
-+#define BBMT_VERSION		2
-+	unsigned char version;
-+	/* Below 2 tables will be written in SLC */
-+	u16 bb_tbl[];
-+};
-+
-+struct bbmt {
-+	u16 block;
-+#define NO_MAPPED		0
-+#define NORMAL_MAPPED	1
-+#define BMT_MAPPED		2
-+	u16 mapped;
-+};
-+
-+static struct bmt_desc {
-+	struct mtd_info *mtd;
-+
-+	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
-+			  struct mtd_oob_ops *ops);
-+	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
-+			   struct mtd_oob_ops *ops);
-+	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
-+	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
-+	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
-+
-+	struct bbbt *bbt;
-+
-+	struct dentry *debugfs_dir;
-+
-+	u32 table_size;
-+	u32 pg_size;
-+	u32 blk_size;
-+	u16 pg_shift;
-+	u16 blk_shift;
-+	/* bbt logical address */
-+	u16 pool_lba;
-+	/* bbt physical address */
-+	u16 pool_pba;
-+	/* Maximum count of bad blocks that the vendor guaranteed */
-+	u16 bb_max;
-+	/* Total blocks of the Nand Chip */
-+	u16 total_blks;
-+	/* The block(n) BMT is located at (bmt_tbl[n]) */
-+	u16 bmt_blk_idx;
-+	/* How many pages needs to store 'struct bbbt' */
-+	u32 bmt_pgs;
-+
-+	/* to compensate for driver level remapping */
-+	u8 oob_offset;
-+} bmtd = {0};
-+
-+static unsigned char *nand_bbt_buf;
-+static unsigned char *nand_data_buf;
-+
-+/* -------- Unit conversions -------- */
-+static inline u32 blk_pg(u16 block)
-+{
-+	return (u32)(block << (bmtd.blk_shift - bmtd.pg_shift));
-+}
-+
-+/* -------- Nand operations wrapper -------- */
-+static inline int
-+bbt_nand_read(u32 page, unsigned char *dat, int dat_len,
-+	      unsigned char *fdm, int fdm_len)
-+{
-+	struct mtd_oob_ops ops = {
-+		.mode = MTD_OPS_PLACE_OOB,
-+		.ooboffs = bmtd.oob_offset,
-+		.oobbuf = fdm,
-+		.ooblen = fdm_len,
-+		.datbuf = dat,
-+		.len = dat_len,
-+	};
-+
-+	return bmtd._read_oob(bmtd.mtd, page << bmtd.pg_shift, &ops);
-+}
-+
-+static inline int bbt_nand_erase(u16 block)
-+{
-+	struct mtd_info *mtd = bmtd.mtd;
-+	struct erase_info instr = {
-+		.addr = (loff_t)block << bmtd.blk_shift,
-+		.len = bmtd.blk_size,
-+	};
-+
-+	return bmtd._erase(mtd, &instr);
-+}
-+
-+/* -------- Bad Blocks Management -------- */
-+static inline struct bbmt *bmt_tbl(struct bbbt *bbbt)
-+{
-+	return (struct bbmt *)&bbbt->bb_tbl[bmtd.table_size];
-+}
-+
-+static int
-+read_bmt(u16 block, unsigned char *dat, unsigned char *fdm, int fdm_len)
-+{
-+	u32 len = bmtd.bmt_pgs << bmtd.pg_shift;
-+
-+	return bbt_nand_read(blk_pg(block), dat, len, fdm, fdm_len);
-+}
-+
-+static int write_bmt(u16 block, unsigned char *dat)
-+{
-+	struct mtd_oob_ops ops = {
-+		.mode = MTD_OPS_PLACE_OOB,
-+		.ooboffs = OOB_SIGNATURE_OFFSET + bmtd.oob_offset,
-+		.oobbuf = "bmt",
-+		.ooblen = 3,
-+		.datbuf = dat,
-+		.len = bmtd.bmt_pgs << bmtd.pg_shift,
-+	};
-+	loff_t addr = (loff_t)block << bmtd.blk_shift;
-+
-+	return bmtd._write_oob(bmtd.mtd, addr, &ops);
-+}
-+
-+static u16 find_valid_block(u16 block)
-+{
-+	u8 fdm[4];
-+	int ret;
-+	int loop = 0;
-+
-+retry:
-+	if (block >= bmtd.total_blks)
-+		return 0;
-+
-+	ret = bbt_nand_read(blk_pg(block), nand_data_buf, bmtd.pg_size,
-+			    fdm, sizeof(fdm));
-+	/* Read the 1st byte of FDM to judge whether it's a bad
-+	 * or not
-+	 */
-+	if (ret || fdm[0] != 0xff) {
-+		pr_info("nand: found bad block 0x%x\n", block);
-+		if (loop >= bmtd.bb_max) {
-+			pr_info("nand: FATAL ERR: too many bad blocks!!\n");
-+			return 0;
-+		}
-+
-+		loop++;
-+		block++;
-+		goto retry;
-+	}
-+
-+	return block;
-+}
-+
-+/* Find out all bad blocks, and fill in the mapping table */
-+static int scan_bad_blocks(struct bbbt *bbt)
-+{
-+	int i;
-+	u16 block = 0;
-+
-+	/* First time download, the block0 MUST NOT be a bad block,
-+	 * this is guaranteed by vendor
-+	 */
-+	bbt->bb_tbl[0] = 0;
-+
-+	/*
-+	 * Construct the mapping table of Normal data area(non-PMT/BMTPOOL)
-+	 * G - Good block; B - Bad block
-+	 *			---------------------------
-+	 * physical |G|G|B|G|B|B|G|G|G|G|B|G|B|
-+	 *			---------------------------
-+	 * What bb_tbl[i] looks like:
-+	 *   physical block(i):
-+	 *			 0 1 2 3 4 5 6 7 8 9 a b c
-+	 *   mapped block(bb_tbl[i]):
-+	 *			 0 1 3 6 7 8 9 b ......
-+	 * ATTENTION:
-+	 *		If new bad block ocurred(n), search bmt_tbl to find
-+	 *		a available block(x), and fill in the bb_tbl[n] = x;
-+	 */
-+	for (i = 1; i < bmtd.pool_lba; i++) {
-+		bbt->bb_tbl[i] = find_valid_block(bbt->bb_tbl[i - 1] + 1);
-+		BBT_LOG("bb_tbl[0x%x] = 0x%x", i, bbt->bb_tbl[i]);
-+		if (bbt->bb_tbl[i] == 0)
-+			return -1;
-+	}
-+
-+	/* Physical Block start Address of BMT pool */
-+	bmtd.pool_pba = bbt->bb_tbl[i - 1] + 1;
-+	if (bmtd.pool_pba >= bmtd.total_blks - 2) {
-+		pr_info("nand: FATAL ERR: Too many bad blocks!!\n");
-+		return -1;
-+	}
-+
-+	BBT_LOG("pool_pba=0x%x", bmtd.pool_pba);
-+	i = 0;
-+	block = bmtd.pool_pba;
-+	/*
-+	 * The bmt table is used for runtime bad block mapping
-+	 * G - Good block; B - Bad block
-+	 *			---------------------------
-+	 * physical |G|G|B|G|B|B|G|G|G|G|B|G|B|
-+	 *			---------------------------
-+	 *   block:	 0 1 2 3 4 5 6 7 8 9 a b c
-+	 * What bmt_tbl[i] looks like in initial state:
-+	 *   i:
-+	 *			 0 1 2 3 4 5 6 7
-+	 *   bmt_tbl[i].block:
-+	 *			 0 1 3 6 7 8 9 b
-+	 *   bmt_tbl[i].mapped:
-+	 *			 N N N N N N N B
-+	 *		N - Not mapped(Available)
-+	 *		M - Mapped
-+	 *		B - BMT
-+	 * ATTENTION:
-+	 *		BMT always in the last valid block in pool
-+	 */
-+	while ((block = find_valid_block(block)) != 0) {
-+		bmt_tbl(bbt)[i].block = block;
-+		bmt_tbl(bbt)[i].mapped = NO_MAPPED;
-+		BBT_LOG("bmt_tbl[%d].block = 0x%x", i, block);
-+		block++;
-+		i++;
-+	}
-+
-+	/* i - How many available blocks in pool, which is the length of bmt_tbl[]
-+	 * bmtd.bmt_blk_idx - bmt_tbl[bmtd.bmt_blk_idx].block => the BMT block
-+	 */
-+	bmtd.bmt_blk_idx = i - 1;
-+	bmt_tbl(bbt)[bmtd.bmt_blk_idx].mapped = BMT_MAPPED;
-+
-+	if (i < 1) {
-+		pr_info("nand: FATAL ERR: no space to store BMT!!\n");
-+		return -1;
-+	}
-+
-+	pr_info("[BBT] %d available blocks in BMT pool\n", i);
-+
-+	return 0;
-+}
-+
-+static bool is_valid_bmt(unsigned char *buf, unsigned char *fdm)
-+{
-+	struct bbbt *bbt = (struct bbbt *)buf;
-+	u8 *sig = (u8*)bbt->signature + MAIN_SIGNATURE_OFFSET;
-+
-+
-+	if (memcmp(bbt->signature + MAIN_SIGNATURE_OFFSET, "BMT", 3) == 0 &&
-+		memcmp(fdm + OOB_SIGNATURE_OFFSET, "bmt", 3) == 0) {
-+		if (bbt->version == BBMT_VERSION)
-+			return true;
-+	}
-+	BBT_LOG("[BBT] BMT Version not match,upgrage preloader and uboot please! sig=%02x%02x%02x, fdm=%02x%02x%02x",
-+		sig[0], sig[1], sig[2],
-+		fdm[1], fdm[2], fdm[3]);
-+	return false;
-+}
-+
-+static u16 get_bmt_index(struct bbmt *bmt)
-+{
-+	int i = 0;
-+
-+	while (bmt[i].block != BMT_TBL_DEF_VAL) {
-+		if (bmt[i].mapped == BMT_MAPPED)
-+			return i;
-+		i++;
-+	}
-+	return 0;
-+}
-+
-+static struct bbbt *scan_bmt(u16 block)
-+{
-+	u8 fdm[4];
-+
-+	if (block < bmtd.pool_lba)
-+		return NULL;
-+
-+	if (read_bmt(block, nand_bbt_buf, fdm, sizeof(fdm)))
-+		return scan_bmt(block - 1);
-+
-+	if (is_valid_bmt(nand_bbt_buf, fdm)) {
-+		bmtd.bmt_blk_idx = get_bmt_index(bmt_tbl((struct bbbt *)nand_bbt_buf));
-+		if (bmtd.bmt_blk_idx == 0) {
-+			pr_info("[BBT] FATAL ERR: bmt block index is wrong!\n");
-+			return NULL;
-+		}
-+		pr_info("[BBT] BMT.v2 is found at 0x%x\n", block);
-+		return (struct bbbt *)nand_bbt_buf;
-+	} else
-+		return scan_bmt(block - 1);
-+}
-+
-+/* Write the Burner Bad Block Table to Nand Flash
-+ * n - write BMT to bmt_tbl[n]
-+ */
-+static u16 upload_bmt(struct bbbt *bbt, int n)
-+{
-+	u16 block;
-+
-+retry:
-+	if (n < 0 || bmt_tbl(bbt)[n].mapped == NORMAL_MAPPED) {
-+		pr_info("nand: FATAL ERR: no space to store BMT!\n");
-+		return (u16)-1;
-+	}
-+
-+	block = bmt_tbl(bbt)[n].block;
-+	BBT_LOG("n = 0x%x, block = 0x%x", n, block);
-+	if (bbt_nand_erase(block)) {
-+		bmt_tbl(bbt)[n].block = 0;
-+		/* erase failed, try the previous block: bmt_tbl[n - 1].block */
-+		n--;
-+		goto retry;
-+	}
-+
-+	/* The signature offset is fixed set to 0,
-+	 * oob signature offset is fixed set to 1
-+	 */
-+	memcpy(bbt->signature + MAIN_SIGNATURE_OFFSET, "BMT", 3);
-+	bbt->version = BBMT_VERSION;
-+
-+	if (write_bmt(block, (unsigned char *)bbt)) {
-+		bmt_tbl(bbt)[n].block = 0;
-+
-+		/* write failed, try the previous block in bmt_tbl[n - 1] */
-+		n--;
-+		goto retry;
-+	}
-+
-+	/* Return the current index(n) of BMT pool (bmt_tbl[n]) */
-+	return n;
-+}
-+
-+static u16 find_valid_block_in_pool(struct bbbt *bbt)
-+{
-+	int i;
-+
-+	if (bmtd.bmt_blk_idx == 0)
-+		goto error;
-+
-+	for (i = 0; i < bmtd.bmt_blk_idx; i++) {
-+		if (bmt_tbl(bbt)[i].block != 0 && bmt_tbl(bbt)[i].mapped == NO_MAPPED) {
-+			bmt_tbl(bbt)[i].mapped = NORMAL_MAPPED;
-+			return bmt_tbl(bbt)[i].block;
-+		}
-+	}
-+
-+error:
-+	pr_info("nand: FATAL ERR: BMT pool is run out!\n");
-+	return 0;
-+}
-+
-+/* We met a bad block, mark it as bad and map it to a valid block in pool,
-+ * if it's a write failure, we need to write the data to mapped block
-+ */
-+static bool update_bmt(u16 block)
-+{
-+	u16 mapped_blk;
-+	struct bbbt *bbt;
-+
-+	bbt = bmtd.bbt;
-+	mapped_blk = find_valid_block_in_pool(bbt);
-+	if (mapped_blk == 0)
-+		return false;
-+
-+	/* Map new bad block to available block in pool */
-+	bbt->bb_tbl[block] = mapped_blk;
-+	bmtd.bmt_blk_idx = upload_bmt(bbt, bmtd.bmt_blk_idx);
-+
-+	return true;
-+}
-+
-+u16 get_mapping_block_index(int block)
-+{
-+	int mapping_block;
-+
-+	if (block < bmtd.pool_lba)
-+		mapping_block = bmtd.bbt->bb_tbl[block];
-+	else
-+		mapping_block = block;
-+	BBT_LOG("0x%x mapped to 0x%x", block, mapping_block);
-+
-+	return mapping_block;
-+}
-+
-+static int
-+mtk_bmt_read(struct mtd_info *mtd, loff_t from,
-+	     struct mtd_oob_ops *ops)
-+{
-+	struct mtd_oob_ops cur_ops = *ops;
-+	int retry_count = 0;
-+	loff_t cur_from;
-+	int ret;
-+
-+	ops->retlen = 0;
-+	ops->oobretlen = 0;
-+
-+	while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
-+		u32 offset = from & (bmtd.blk_size - 1);
-+		u32 block = from >> bmtd.blk_shift;
-+		u32 cur_block;
-+
-+		cur_block = get_mapping_block_index(block);
-+		cur_from = ((loff_t)cur_block << bmtd.blk_shift) + offset;
-+
-+		cur_ops.oobretlen = 0;
-+		cur_ops.retlen = 0;
-+		cur_ops.len = min_t(u32, mtd->erasesize - offset,
-+					 ops->len - ops->retlen);
-+		ret = bmtd._read_oob(mtd, cur_from, &cur_ops);
-+		if (ret < 0) {
-+			update_bmt(block);
-+			if (retry_count++ < 10)
-+				continue;
-+
-+			return ret;
-+		}
-+
-+		ops->retlen += cur_ops.retlen;
-+		ops->oobretlen += cur_ops.oobretlen;
-+
-+		cur_ops.ooboffs = 0;
-+		cur_ops.datbuf += cur_ops.retlen;
-+		cur_ops.oobbuf += cur_ops.oobretlen;
-+		cur_ops.ooblen -= cur_ops.oobretlen;
-+
-+		if (!cur_ops.len)
-+			cur_ops.len = mtd->erasesize - offset;
-+
-+		from += cur_ops.len;
-+		retry_count = 0;
-+	}
-+
-+	return 0;
-+}
-+
-+static int
-+mtk_bmt_write(struct mtd_info *mtd, loff_t to,
-+	      struct mtd_oob_ops *ops)
-+{
-+	struct mtd_oob_ops cur_ops = *ops;
-+	int retry_count = 0;
-+	loff_t cur_to;
-+	int ret;
-+
-+	ops->retlen = 0;
-+	ops->oobretlen = 0;
-+
-+	while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
-+		u32 offset = to & (bmtd.blk_size - 1);
-+		u32 block = to >> bmtd.blk_shift;
-+		u32 cur_block;
-+
-+		cur_block = get_mapping_block_index(block);
-+		cur_to = ((loff_t)cur_block << bmtd.blk_shift) + offset;
-+
-+		cur_ops.oobretlen = 0;
-+		cur_ops.retlen = 0;
-+		cur_ops.len = min_t(u32, bmtd.blk_size - offset,
-+					 ops->len - ops->retlen);
-+		ret = bmtd._write_oob(mtd, cur_to, &cur_ops);
-+		if (ret < 0) {
-+			update_bmt(block);
-+			if (retry_count++ < 10)
-+				continue;
-+
-+			return ret;
-+		}
-+
-+		ops->retlen += cur_ops.retlen;
-+		ops->oobretlen += cur_ops.oobretlen;
-+
-+		cur_ops.ooboffs = 0;
-+		cur_ops.datbuf += cur_ops.retlen;
-+		cur_ops.oobbuf += cur_ops.oobretlen;
-+		cur_ops.ooblen -= cur_ops.oobretlen;
-+
-+		if (!cur_ops.len)
-+			cur_ops.len = mtd->erasesize - offset;
-+
-+		to += cur_ops.len;
-+		retry_count = 0;
-+	}
-+
-+	return 0;
-+}
-+
-+static int
-+mtk_bmt_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
-+{
-+	struct erase_info mapped_instr = {
-+		.len = bmtd.blk_size,
-+	};
-+	int retry_count = 0;
-+	u64 start_addr, end_addr;
-+	int ret;
-+	u16 orig_block, block;
-+
-+	start_addr = instr->addr & (~mtd->erasesize_mask);
-+	end_addr = instr->addr + instr->len;
-+
-+	while (start_addr < end_addr) {
-+		orig_block = start_addr >> bmtd.blk_shift;
-+		block = get_mapping_block_index(orig_block);
-+		mapped_instr.addr = (loff_t)block << bmtd.blk_shift;
-+		ret = bmtd._erase(mtd, &mapped_instr);
-+		if (ret) {
-+			update_bmt(orig_block);
-+			if (retry_count++ < 10)
-+				continue;
-+			instr->fail_addr = start_addr;
-+			break;
-+		}
-+		start_addr += mtd->erasesize;
-+		retry_count = 0;
-+	}
-+
-+	return ret;
-+}
-+static int
-+mtk_bmt_block_isbad(struct mtd_info *mtd, loff_t ofs)
-+{
-+	int retry_count = 0;
-+	u16 orig_block = ofs >> bmtd.blk_shift;
-+	u16 block;
-+	int ret;
-+
-+retry:
-+	block = get_mapping_block_index(orig_block);
-+	ret = bmtd._block_isbad(mtd, (loff_t)block << bmtd.blk_shift);
-+	if (ret) {
-+		update_bmt(orig_block);
-+		if (retry_count++ < 10)
-+			goto retry;
-+	}
-+	return ret;
-+}
-+
-+static int
-+mtk_bmt_block_markbad(struct mtd_info *mtd, loff_t ofs)
-+{
-+	u16 orig_block = ofs >> bmtd.blk_shift;
-+	u16 block = get_mapping_block_index(orig_block);
-+	update_bmt(orig_block);
-+	return bmtd._block_markbad(mtd, (loff_t)block << bmtd.blk_shift);
-+}
-+
-+static void
-+mtk_bmt_replace_ops(struct mtd_info *mtd)
-+{
-+	bmtd._read_oob = mtd->_read_oob;
-+	bmtd._write_oob = mtd->_write_oob;
-+	bmtd._erase = mtd->_erase;
-+	bmtd._block_isbad = mtd->_block_isbad;
-+	bmtd._block_markbad = mtd->_block_markbad;
-+
-+	mtd->_read_oob = mtk_bmt_read;
-+	mtd->_write_oob = mtk_bmt_write;
-+	mtd->_erase = mtk_bmt_mtd_erase;
-+	mtd->_block_isbad = mtk_bmt_block_isbad;
-+	mtd->_block_markbad = mtk_bmt_block_markbad;
-+}
-+
-+static int mtk_bmt_debug_mark_good(void *data, u64 val)
-+{
-+	u32 block = val >> bmtd.blk_shift;
-+
-+	bmtd.bbt->bb_tbl[block] = block;
-+	bmtd.bmt_blk_idx = upload_bmt(bmtd.bbt, bmtd.bmt_blk_idx);
-+
-+	return 0;
-+}
-+
-+static int mtk_bmt_debug_mark_bad(void *data, u64 val)
-+{
-+	u32 block = val >> bmtd.blk_shift;
-+
-+	update_bmt(block);
-+
-+	return 0;
-+}
-+
-+DEFINE_DEBUGFS_ATTRIBUTE(fops_mark_good, NULL, mtk_bmt_debug_mark_good, "%llu\n");
-+DEFINE_DEBUGFS_ATTRIBUTE(fops_mark_bad, NULL, mtk_bmt_debug_mark_bad, "%llu\n");
-+
-+static void
-+mtk_bmt_add_debugfs(void)
-+{
-+	struct dentry *dir;
-+
-+	dir = bmtd.debugfs_dir = debugfs_create_dir("mtk-bmt", NULL);
-+	if (!dir)
-+		return;
-+
-+	debugfs_create_file_unsafe("mark_good", S_IWUSR, dir, NULL, &fops_mark_good);
-+	debugfs_create_file_unsafe("mark_bad", S_IWUSR, dir, NULL, &fops_mark_bad);
-+}
-+
-+void mtk_bmt_detach(struct mtd_info *mtd)
-+{
-+	if (bmtd.mtd != mtd)
-+		return;
-+
-+	if (bmtd.debugfs_dir)
-+		debugfs_remove_recursive(bmtd.debugfs_dir);
-+	bmtd.debugfs_dir = NULL;
-+
-+	kfree(nand_bbt_buf);
-+	kfree(nand_data_buf);
-+
-+	mtd->_read_oob = bmtd._read_oob;
-+	mtd->_write_oob = bmtd._write_oob;
-+	mtd->_erase = bmtd._erase;
-+	mtd->_block_isbad = bmtd._block_isbad;
-+	mtd->_block_markbad = bmtd._block_markbad;
-+	mtd->size = bmtd.total_blks << bmtd.blk_shift;
-+
-+	memset(&bmtd, 0, sizeof(bmtd));
-+}
-+
-+/* total_blocks - The total count of blocks that the Nand Chip has */
-+int mtk_bmt_attach(struct mtd_info *mtd)
-+{
-+	struct device_node *np;
-+	struct bbbt *bbt;
-+	u32 bufsz;
-+	u32 block;
-+	u16 total_blocks, pmt_block;
-+	int ret = 0;
-+	u32 bmt_pool_size, bmt_table_size;
-+
-+	if (bmtd.mtd)
-+		return -ENOSPC;
-+
-+	np = mtd_get_of_node(mtd);
-+	if (!np)
-+		return 0;
-+
-+	if (!of_property_read_bool(np, "mediatek,bmt-v2"))
-+		return 0;
-+
-+	if (of_property_read_u32(np, "mediatek,bmt-pool-size",
-+				 &bmt_pool_size) != 0)
-+		bmt_pool_size = 80;
-+
-+	if (of_property_read_u8(np, "mediatek,bmt-oob-offset",
-+				 &bmtd.oob_offset) != 0)
-+		bmtd.oob_offset = 0;
-+
-+	if (of_property_read_u32(np, "mediatek,bmt-table-size",
-+				 &bmt_table_size) != 0)
-+		bmt_table_size = 0x2000U;
-+
-+	bmtd.mtd = mtd;
-+	mtk_bmt_replace_ops(mtd);
-+
-+	bmtd.table_size = bmt_table_size;
-+	bmtd.blk_size = mtd->erasesize;
-+	bmtd.blk_shift = ffs(bmtd.blk_size) - 1;
-+	bmtd.pg_size = mtd->writesize;
-+	bmtd.pg_shift = ffs(bmtd.pg_size) - 1;
-+	total_blocks = mtd->size >> bmtd.blk_shift;
-+	pmt_block = total_blocks - bmt_pool_size - 2;
-+
-+	mtd->size = pmt_block << bmtd.blk_shift;
-+
-+	/*
-+	 *  ---------------------------------------
-+	 * | PMT(2blks) | BMT POOL(totalblks * 2%) |
-+	 *  ---------------------------------------
-+	 * ^            ^
-+	 * |            |
-+	 * pmt_block	pmt_block + 2blocks(pool_lba)
-+	 *
-+	 * ATTETION!!!!!!
-+	 *     The blocks ahead of the boundary block are stored in bb_tbl
-+	 *     and blocks behind are stored in bmt_tbl
-+	 */
-+
-+	bmtd.pool_lba = (u16)(pmt_block + 2);
-+	bmtd.total_blks = total_blocks;
-+	bmtd.bb_max = bmtd.total_blks * BBPOOL_RATIO / 100;
-+
-+	/* 3 buffers we need */
-+	bufsz = round_up(sizeof(struct bbbt) +
-+			 bmt_table_size * sizeof(struct bbmt), bmtd.pg_size);
-+	bmtd.bmt_pgs = bufsz >> bmtd.pg_shift;
-+
-+	nand_bbt_buf = kzalloc(bufsz, GFP_KERNEL);
-+	nand_data_buf = kzalloc(bmtd.pg_size, GFP_KERNEL);
-+
-+	if (!nand_bbt_buf || !nand_data_buf) {
-+		pr_info("nand: FATAL ERR: allocate buffer failed!\n");
-+		ret = -1;
-+		goto error;
-+	}
-+
-+	memset(nand_bbt_buf, 0xff, bufsz);
-+	memset(nand_data_buf, 0xff, bmtd.pg_size);
-+
-+	BBT_LOG("bbtbuf=0x%p(0x%x) dat=0x%p(0x%x)",
-+			nand_bbt_buf, bufsz, nand_data_buf, bmtd.pg_size);
-+	BBT_LOG("pool_lba=0x%x total_blks=0x%x bb_max=0x%x",
-+			bmtd.pool_lba, bmtd.total_blks, bmtd.bb_max);
-+
-+	/* Scanning start from the first page of the last block
-+	 * of whole flash
-+	 */
-+	bbt = scan_bmt(bmtd.total_blks - 1);
-+	if (!bbt) {
-+		/* BMT not found */
-+		if (bmtd.total_blks > BB_TABLE_MAX + BMT_TABLE_MAX) {
-+			pr_info("nand: FATAL: Too many blocks, can not support!\n");
-+			ret = -1;
-+			goto error;
-+		}
-+
-+		bbt = (struct bbbt *)nand_bbt_buf;
-+		memset(bmt_tbl(bbt), BMT_TBL_DEF_VAL, bmtd.table_size * sizeof(struct bbmt));
-+
-+		if (scan_bad_blocks(bbt)) {
-+			ret = -1;
-+			goto error;
-+		}
-+
-+		/* BMT always in the last valid block in pool */
-+		bmtd.bmt_blk_idx = upload_bmt(bbt, bmtd.bmt_blk_idx);
-+		block = bmt_tbl(bbt)[bmtd.bmt_blk_idx].block;
-+		pr_notice("[BBT] BMT.v2 is written into PBA:0x%x\n", block);
-+
-+		if (bmtd.bmt_blk_idx == 0)
-+			pr_info("nand: Warning: no available block in BMT pool!\n");
-+		else if (bmtd.bmt_blk_idx == (u16)-1) {
-+			ret = -1;
-+			goto error;
-+		}
-+	}
-+	mtk_bmt_add_debugfs();
-+
-+	bmtd.bbt = bbt;
-+	return 0;
-+
-+error:
-+	mtk_bmt_detach(mtd);
-+	return ret;
-+}
-+
-+
-+MODULE_LICENSE("GPL");
-+MODULE_AUTHOR("Xiangsheng Hou <xiangsheng.hou@mediatek.com>, Felix Fietkau <nbd@nbd.name>");
-+MODULE_DESCRIPTION("Bad Block mapping management v2 for MediaTek NAND Flash Driver");
-+
---- /dev/null
-+++ b/include/linux/mtd/mtk_bmt.h
-@@ -0,0 +1,18 @@
-+#ifndef __MTK_BMT_H
-+#define __MTK_BMT_H
-+
-+#ifdef CONFIG_MTD_NAND_MTK_BMT
-+int mtk_bmt_attach(struct mtd_info *mtd);
-+void mtk_bmt_detach(struct mtd_info *mtd);
-+#else
-+static inline int mtk_bmt_attach(struct mtd_info *mtd)
-+{
-+	return 0;
-+}
-+
-+static inline void mtk_bmt_detach(struct mtd_info *mtd)
-+{
-+}
-+#endif
-+
-+#endif
---- a/drivers/mtd/mtk-snand/mtk-snand-mtd.c
-+++ b/drivers/mtd/mtk-snand/mtk-snand-mtd.c
-@@ -16,6 +16,7 @@
- #include <linux/dma-mapping.h>
- #include <linux/wait.h>
- #include <linux/mtd/mtd.h>
-+#include <linux/mtd/mtk_bmt.h>
- #include <linux/mtd/partitions.h>
- #include <linux/of_platform.h>
- 
-@@ -612,6 +613,8 @@ static int mtk_snand_probe(struct platfo
- 	mtd->_block_isbad = mtk_snand_mtd_block_isbad;
- 	mtd->_block_markbad = mtk_snand_mtd_block_markbad;
- 
-+	mtk_bmt_attach(mtd);
-+
- 	ret = mtd_device_register(mtd, NULL, 0);
- 	if (ret) {
- 		dev_err(msm->pdev.dev, "failed to register mtd partition\n");
-@@ -623,6 +626,7 @@ static int mtk_snand_probe(struct platfo
- 	return 0;
- 
- errout4:
-+	mtk_bmt_detach(mtd);
- 	devm_kfree(msm->pdev.dev, msm->page_cache);
- 
- errout3:
-@@ -650,6 +654,8 @@ static int mtk_snand_remove(struct platf
- 	if (ret)
- 		return ret;
- 
-+	mtk_bmt_detach(mtd);
-+
- 	mtk_snand_cleanup(msm->snf);
- 
- 	if (msm->irq >= 0)
diff --git a/target/linux/mediatek/patches-5.10/330-mtk-snand-bmt-support.patch b/target/linux/mediatek/patches-5.10/330-mtk-snand-bmt-support.patch
new file mode 100644
index 0000000000..318c8b2873
--- /dev/null
+++ b/target/linux/mediatek/patches-5.10/330-mtk-snand-bmt-support.patch
@@ -0,0 +1,36 @@
+--- a/drivers/mtd/mtk-snand/mtk-snand-mtd.c
++++ b/drivers/mtd/mtk-snand/mtk-snand-mtd.c
+@@ -16,6 +16,7 @@
+ #include <linux/dma-mapping.h>
+ #include <linux/wait.h>
+ #include <linux/mtd/mtd.h>
++#include <linux/mtd/mtk_bmt.h>
+ #include <linux/mtd/partitions.h>
+ #include <linux/of_platform.h>
+ 
+@@ -612,6 +613,8 @@ static int mtk_snand_probe(struct platfo
+ 	mtd->_block_isbad = mtk_snand_mtd_block_isbad;
+ 	mtd->_block_markbad = mtk_snand_mtd_block_markbad;
+ 
++	mtk_bmt_attach(mtd);
++
+ 	ret = mtd_device_register(mtd, NULL, 0);
+ 	if (ret) {
+ 		dev_err(msm->pdev.dev, "failed to register mtd partition\n");
+@@ -623,6 +626,7 @@ static int mtk_snand_probe(struct platfo
+ 	return 0;
+ 
+ errout4:
++	mtk_bmt_detach(mtd);
+ 	devm_kfree(msm->pdev.dev, msm->page_cache);
+ 
+ errout3:
+@@ -650,6 +654,8 @@ static int mtk_snand_remove(struct platf
+ 	if (ret)
+ 		return ret;
+ 
++	mtk_bmt_detach(mtd);
++
+ 	mtk_snand_cleanup(msm->snf);
+ 
+ 	if (msm->irq >= 0)