openwrt/package/boot/uboot-mediatek/patches/100-07-mtd-nmbm-add-support-for-mtd.patch

From 0524995f07fcd216a1a7e267fdb5cf2b0ede8489 Mon Sep 17 00:00:00 2001
From: Weijie Gao <weijie.gao@mediatek.com>
Date: Mon, 25 Jul 2022 10:42:12 +0800
Subject: [PATCH 41/71] mtd: nmbm: add support for mtd

Add support to create NMBM based on MTD devices

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
---
 drivers/mtd/nmbm/Kconfig    |   5 +
 drivers/mtd/nmbm/Makefile   |   1 +
 drivers/mtd/nmbm/nmbm-mtd.c | 890 ++++++++++++++++++++++++++++++++++++
 include/nmbm/nmbm-mtd.h     |  27 ++
 4 files changed, 923 insertions(+)
 create mode 100644 drivers/mtd/nmbm/nmbm-mtd.c
 create mode 100644 include/nmbm/nmbm-mtd.h

--- a/drivers/mtd/nmbm/Kconfig
+++ b/drivers/mtd/nmbm/Kconfig
@@ -27,3 +27,8 @@ config NMBM_LOG_LEVEL_NONE
 	bool "5 - None"
 
 endchoice
+
+config NMBM_MTD
+	bool "Enable MTD based NAND mapping block management"
+	default n
+	depends on NMBM
--- a/drivers/mtd/nmbm/Makefile
+++ b/drivers/mtd/nmbm/Makefile
@@ -3,3 +3,4 @@
 # (C) Copyright 2020 MediaTek Inc. All rights reserved.
 
 obj-$(CONFIG_NMBM) += nmbm-core.o
+obj-$(CONFIG_NMBM_MTD) += nmbm-mtd.o
--- /dev/null
+++ b/drivers/mtd/nmbm/nmbm-mtd.c
@@ -0,0 +1,890 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include <linux/list.h>
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/mtd/mtd.h>
+#include <jffs2/load_kernel.h>
+#include <watchdog.h>
+
+#include "nmbm-debug.h"
+
+#define NMBM_UPPER_MTD_NAME	"nmbm"
+
+static uint32_t nmbm_id_cnt;
+static LIST_HEAD(nmbm_devs);
+
+struct nmbm_mtd {
+	struct mtd_info upper;
+	char *name;
+	uint32_t id;
+
+	struct mtd_info *lower;
+
+	struct nmbm_instance *ni;
+	uint8_t *page_cache;
+
+	struct list_head node;
+};
+
+static int nmbm_lower_read_page(void *arg, uint64_t addr, void *buf, void *oob,
+				enum nmbm_oob_mode mode)
+{
+	struct nmbm_mtd *nm = arg;
+	struct mtd_oob_ops ops;
+	int ret;
+
+	memset(&ops, 0, sizeof(ops));
+
+	switch (mode) {
+	case NMBM_MODE_PLACE_OOB:
+		ops.mode = MTD_OPS_PLACE_OOB;
+		break;
+	case NMBM_MODE_AUTO_OOB:
+		ops.mode = MTD_OPS_AUTO_OOB;
+		break;
+	case NMBM_MODE_RAW:
+		ops.mode = MTD_OPS_RAW;
+		break;
+	default:
+		pr_debug("%s: unsupported NMBM mode: %u\n", __func__, mode);
+		return -ENOTSUPP;
+	}
+
+	if (buf) {
+		ops.datbuf = buf;
+		ops.len = nm->lower->writesize;
+	}
+
+	if (oob) {
+		ops.oobbuf = oob;
+		ops.ooblen = mtd_oobavail(nm->lower, &ops);
+	}
+
+	ret = mtd_read_oob(nm->lower, addr, &ops);
+	nm->upper.ecc_stats.corrected = nm->lower->ecc_stats.corrected;
+	nm->upper.ecc_stats.failed = nm->lower->ecc_stats.failed;
+
+	/* Report error on failure (including ecc error) */
+	if (ret < 0 && ret != -EUCLEAN)
+		return ret;
+
+	/*
+	 * Since mtd_read_oob() won't report exact bitflips, what we can know
+	 * is whether bitflips exceeds the threshold.
+	 * We want the -EUCLEAN to be passed to the upper layer, but not the
+	 * error value itself. To achieve this, report bitflips above the
+	 * threshold.
+	 */
+
+	if (ret == -EUCLEAN) {
+		return min_t(u32, nm->lower->bitflip_threshold + 1,
+			     nm->lower->ecc_strength);
+	}
+
+	/* For bitflips less than the threshold, return 0 */
+
+	return 0;
+}
+
+static int nmbm_lower_write_page(void *arg, uint64_t addr, const void *buf,
+				 const void *oob, enum nmbm_oob_mode mode)
+{
+	struct nmbm_mtd *nm = arg;
+	struct mtd_oob_ops ops;
+
+	memset(&ops, 0, sizeof(ops));
+
+	switch (mode) {
+	case NMBM_MODE_PLACE_OOB:
+		ops.mode = MTD_OPS_PLACE_OOB;
+		break;
+	case NMBM_MODE_AUTO_OOB:
+		ops.mode = MTD_OPS_AUTO_OOB;
+		break;
+	case NMBM_MODE_RAW:
+		ops.mode = MTD_OPS_RAW;
+		break;
+	default:
+		pr_debug("%s: unsupported NMBM mode: %u\n", __func__, mode);
+		return -ENOTSUPP;
+	}
+
+	if (buf) {
+		ops.datbuf = (uint8_t *)buf;
+		ops.len = nm->lower->writesize;
+	}
+
+	if (oob) {
+		ops.oobbuf = (uint8_t *)oob;
+		ops.ooblen = mtd_oobavail(nm->lower, &ops);
+	}
+
+	return mtd_write_oob(nm->lower, addr, &ops);
+}
+
+static int nmbm_lower_erase_block(void *arg, uint64_t addr)
+{
+	struct nmbm_mtd *nm = arg;
+	struct erase_info ei;
+
+	memset(&ei, 0, sizeof(ei));
+
+	ei.mtd = nm->lower;
+	ei.addr = addr;
+	ei.len = nm->lower->erasesize;
+
+	return mtd_erase(nm->lower, &ei);
+}
+
+static int nmbm_lower_is_bad_block(void *arg, uint64_t addr)
+{
+	struct nmbm_mtd *nm = arg;
+
+	return mtd_block_isbad(nm->lower, addr);
+}
+
+static int nmbm_lower_mark_bad_block(void *arg, uint64_t addr)
+{
+	struct nmbm_mtd *nm = arg;
+
+	return mtd_block_markbad(nm->lower, addr);
+}
+
+static void nmbm_lower_log(void *arg, enum nmbm_log_category level,
+			   const char *fmt, va_list ap)
+{
+	vprintf(fmt, ap);
+}
+
+static int nmbm_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
+			 size_t *retlen, u_char *buf)
+{
+	struct nmbm_mtd *nm = container_of(mtd, struct nmbm_mtd, upper);
+
+	/* Do not allow read past end of device */
+	if ((from + len) > mtd->size) {
+		pr_debug("%s: attempt to write beyond end of device\n",
+			 __func__);
+		return -EINVAL;
+	}
+
+	return nmbm_read_range(nm->ni, from, len, buf, MTD_OPS_PLACE_OOB,
+			       retlen);
+}
+
+static int nmbm_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+			  size_t *retlen, const u_char *buf)
+{
+	struct nmbm_mtd *nm = container_of(mtd, struct nmbm_mtd, upper);
+
+	/* Do not allow write past end of device */
+	if ((to + len) > mtd->size) {
+		pr_debug("%s: attempt to write beyond end of device\n",
+			 __func__);
+		return -EINVAL;
+	}
+
+	return nmbm_write_range(nm->ni, to, len, buf, MTD_OPS_PLACE_OOB,
+				retlen);
+}
+
+static int nmbm_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct nmbm_mtd *nm = container_of(mtd, struct nmbm_mtd, upper);
+	int ret;
+
+	instr->state = MTD_ERASING;
+
+	ret = nmbm_erase_block_range(nm->ni, instr->addr, instr->len,
+				     &instr->fail_addr);
+	if (ret)
+		instr->state = MTD_ERASE_FAILED;
+	else
+		instr->state = MTD_ERASE_DONE;
+
+	if (!ret)
+		/* FIXME */
+		/* mtd_erase_callback(instr); */
+		return ret;
+	else
+		ret = -EIO;
+
+	return ret;
+}
+
+static int nmbm_mtd_read_data(struct nmbm_mtd *nm, uint64_t addr,
+			      struct mtd_oob_ops *ops, enum nmbm_oob_mode mode)
+{
+	size_t len, ooblen, maxooblen, chklen;
+	uint32_t col, ooboffs;
+	uint8_t *datcache, *oobcache;
+	bool has_ecc_err = false;
+	int ret, max_bitflips = 0;
+
+	col = addr & nm->lower->writesize_mask;
+	addr &= ~nm->lower->writesize_mask;
+	maxooblen = mtd_oobavail(nm->lower, ops);
+	ooboffs = ops->ooboffs;
+	ooblen = ops->ooblen;
+	len = ops->len;
+
+	datcache = len ? nm->page_cache : NULL;
+	oobcache = ooblen ? nm->page_cache + nm->lower->writesize : NULL;
+
+	ops->oobretlen = 0;
+	ops->retlen = 0;
+
+	while (len || ooblen) {
+		WATCHDOG_RESET();
+
+		ret = nmbm_read_single_page(nm->ni, addr, datcache, oobcache,
+					    mode);
+		if (ret < 0 && ret != -EBADMSG)
+			return ret;
+
+		/* Continue reading on ecc error */
+		if (ret == -EBADMSG)
+			has_ecc_err = true;
+
+		/* Record the maximum bitflips between pages */
+		if (ret > max_bitflips)
+			max_bitflips = ret;
+
+		if (len) {
+			/* Move data */
+			chklen = nm->lower->writesize - col;
+			if (chklen > len)
+				chklen = len;
+
+			memcpy(ops->datbuf + ops->retlen, datcache + col,
+			       chklen);
+			len -= chklen;
+			col = 0; /* (col + chklen) %  */
+			ops->retlen += chklen;
+		}
+
+		if (ooblen) {
+			/* Move oob */
+			chklen = maxooblen - ooboffs;
+			if (chklen > ooblen)
+				chklen = ooblen;
+
+			memcpy(ops->oobbuf + ops->oobretlen, oobcache + ooboffs,
+			       chklen);
+			ooblen -= chklen;
+			ooboffs = 0; /* (ooboffs + chklen) % maxooblen; */
+			ops->oobretlen += chklen;
+		}
+
+		addr += nm->lower->writesize;
+	}
+
+	if (has_ecc_err)
+		return -EBADMSG;
+
+	return max_bitflips;
+}
+
+static int nmbm_mtd_read_oob(struct mtd_info *mtd, loff_t from,
+			     struct mtd_oob_ops *ops)
+{
+	struct nmbm_mtd *nm = container_of(mtd, struct nmbm_mtd, upper);
+	uint32_t maxooblen;
+	enum nmbm_oob_mode mode;
+
+	if (!ops->oobbuf && !ops->datbuf) {
+		if (ops->ooblen || ops->len)
+			return -EINVAL;
+
+		return 0;
+	}
+
+	switch (ops->mode) {
+	case MTD_OPS_PLACE_OOB:
+		mode = NMBM_MODE_PLACE_OOB;
+		break;
+	case MTD_OPS_AUTO_OOB:
+		mode = NMBM_MODE_AUTO_OOB;
+		break;
+	case MTD_OPS_RAW:
+		mode = NMBM_MODE_RAW;
+		break;
+	default:
+		pr_debug("%s: unsupported oob mode: %u\n", __func__, ops->mode);
+		return -ENOTSUPP;
+	}
+
+	maxooblen = mtd_oobavail(mtd, ops);
+
+	/* Do not allow read past end of device */
+	if (ops->datbuf && (from + ops->len) > mtd->size) {
+		pr_debug("%s: attempt to read beyond end of device\n",
+			 __func__);
+		return -EINVAL;
+	}
+
+	if (!ops->oobbuf) {
+		/* Optimized for reading data only */
+		return nmbm_read_range(nm->ni, from, ops->len, ops->datbuf,
+				       mode, &ops->retlen);
+	}
+
+	if (unlikely(ops->ooboffs >= maxooblen)) {
+		pr_debug("%s: attempt to start read outside oob\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	if (unlikely(from >= mtd->size ||
+	    ops->ooboffs + ops->ooblen > ((mtd->size >> mtd->writesize_shift) -
+	    (from >> mtd->writesize_shift)) * maxooblen)) {
+		pr_debug("%s: attempt to read beyond end of device\n",
+				__func__);
+		return -EINVAL;
+	}
+
+	return nmbm_mtd_read_data(nm, from, ops, mode);
+}
+
+static int nmbm_mtd_write_data(struct nmbm_mtd *nm, uint64_t addr,
+			       struct mtd_oob_ops *ops, enum nmbm_oob_mode mode)
+{
+	size_t len, ooblen, maxooblen, chklen;
+	uint32_t col, ooboffs;
+	uint8_t *datcache, *oobcache;
+	int ret;
+
+	col = addr & nm->lower->writesize_mask;
+	addr &= ~nm->lower->writesize_mask;
+	maxooblen = mtd_oobavail(nm->lower, ops);
+	ooboffs = ops->ooboffs;
+	ooblen = ops->ooblen;
+	len = ops->len;
+
+	datcache = len ? nm->page_cache : NULL;
+	oobcache = ooblen ? nm->page_cache + nm->lower->writesize : NULL;
+
+	ops->oobretlen = 0;
+	ops->retlen = 0;
+
+	while (len || ooblen) {
+		WATCHDOG_RESET();
+
+		if (len) {
+			/* Move data */
+			chklen = nm->lower->writesize - col;
+			if (chklen > len)
+				chklen = len;
+
+			memset(datcache, 0xff, col);
+			memcpy(datcache + col, ops->datbuf + ops->retlen,
+			       chklen);
+			memset(datcache + col + chklen, 0xff,
+			       nm->lower->writesize - col - chklen);
+			len -= chklen;
+			col = 0; /* (col + chklen) %  */
+			ops->retlen += chklen;
+		}
+
+		if (ooblen) {
+			/* Move oob */
+			chklen = maxooblen - ooboffs;
+			if (chklen > ooblen)
+				chklen = ooblen;
+
+			memset(oobcache, 0xff, ooboffs);
+			memcpy(oobcache + ooboffs,
+			       ops->oobbuf + ops->oobretlen, chklen);
+			memset(oobcache + ooboffs + chklen, 0xff,
+			       nm->lower->oobsize - ooboffs - chklen);
+			ooblen -= chklen;
+			ooboffs = 0; /* (ooboffs + chklen) % maxooblen; */
+			ops->oobretlen += chklen;
+		}
+
+		ret = nmbm_write_single_page(nm->ni, addr, datcache, oobcache,
+					     mode);
+		if (ret)
+			return ret;
+
+		addr += nm->lower->writesize;
+	}
+
+	return 0;
+}
+
+static int nmbm_mtd_write_oob(struct mtd_info *mtd, loff_t to,
+			      struct mtd_oob_ops *ops)
+{
+	struct nmbm_mtd *nm = container_of(mtd, struct nmbm_mtd, upper);
+	enum nmbm_oob_mode mode;
+	uint32_t maxooblen;
+
+	if (!ops->oobbuf && !ops->datbuf) {
+		if (ops->ooblen || ops->len)
+			return -EINVAL;
+
+		return 0;
+	}
+
+	switch (ops->mode) {
+	case MTD_OPS_PLACE_OOB:
+		mode = NMBM_MODE_PLACE_OOB;
+		break;
+	case MTD_OPS_AUTO_OOB:
+		mode = NMBM_MODE_AUTO_OOB;
+		break;
+	case MTD_OPS_RAW:
+		mode = NMBM_MODE_RAW;
+		break;
+	default:
+		pr_debug("%s: unsupported oob mode: %u\n", __func__,
+			 ops->mode);
+		return -ENOTSUPP;
+	}
+
+	maxooblen = mtd_oobavail(mtd, ops);
+
+	/* Do not allow write past end of device */
+	if (ops->datbuf && (to + ops->len) > mtd->size) {
+		pr_debug("%s: attempt to write beyond end of device\n",
+			 __func__);
+		return -EINVAL;
+	}
+
+	if (!ops->oobbuf) {
+		/* Optimized for writing data only */
+		return nmbm_write_range(nm->ni, to, ops->len, ops->datbuf,
+					mode, &ops->retlen);
+	}
+
+	if (unlikely(ops->ooboffs >= maxooblen)) {
+		pr_debug("%s: attempt to start write outside oob\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	if (unlikely(to >= mtd->size ||
+	    ops->ooboffs + ops->ooblen > ((mtd->size >> mtd->writesize_shift) -
+	    (to >> mtd->writesize_shift)) * maxooblen)) {
+		pr_debug("%s: attempt to write beyond end of device\n",
+				__func__);
+		return -EINVAL;
+	}
+
+	return nmbm_mtd_write_data(nm, to, ops, mode);
+}
+
+static int nmbm_mtd_block_isbad(struct mtd_info *mtd, loff_t offs)
+{
+	struct nmbm_mtd *nm = container_of(mtd, struct nmbm_mtd, upper);
+
+	return nmbm_check_bad_block(nm->ni, offs);
+}
+
+static int nmbm_mtd_block_markbad(struct mtd_info *mtd, loff_t offs)
+{
+	struct nmbm_mtd *nm = container_of(mtd, struct nmbm_mtd, upper);
+
+	return nmbm_mark_bad_block(nm->ni, offs);
+}
+
+int nmbm_attach_mtd(struct mtd_info *lower, int flags, uint32_t max_ratio,
+		    uint32_t max_reserved_blocks, struct mtd_info **upper)
+{
+	struct nmbm_lower_device nld;
+	struct nmbm_instance *ni;
+	struct mtd_info *mtd;
+	struct nmbm_mtd *nm;
+	size_t namelen, alloc_size;
+	int ret;
+
+	if (!lower)
+		return -EINVAL;
+
+	if (lower->type != MTD_NANDFLASH || lower->flags != MTD_CAP_NANDFLASH)
+		return -ENOTSUPP;
+
+	namelen = strlen(NMBM_UPPER_MTD_NAME) + 16;
+
+	nm = calloc(sizeof(*nm) + lower->writesize + lower->oobsize + namelen + 1, 1);
+	if (!nm)
+		return -ENOMEM;
+
+	nm->lower = lower;
+	nm->name = (char *)nm + sizeof(*nm);
+	nm->page_cache = (uint8_t *)nm->name + namelen + 1;
+
+	nm->id = nmbm_id_cnt++;
+	snprintf(nm->name, namelen + 1, "%s%u", NMBM_UPPER_MTD_NAME, nm->id);
+
+	memset(&nld, 0, sizeof(nld));
+
+	nld.flags = flags;
+	nld.max_ratio = max_ratio;
+	nld.max_reserved_blocks = max_reserved_blocks;
+
+	nld.size = lower->size;
+	nld.erasesize = lower->erasesize;
+	nld.writesize = lower->writesize;
+	nld.oobsize = lower->oobsize;
+	nld.oobavail = lower->oobavail;
+
+	nld.arg = nm;
+	nld.read_page = nmbm_lower_read_page;
+	nld.write_page = nmbm_lower_write_page;
+	nld.erase_block = nmbm_lower_erase_block;
+	nld.is_bad_block = nmbm_lower_is_bad_block;
+	nld.mark_bad_block = nmbm_lower_mark_bad_block;
+
+	nld.logprint = nmbm_lower_log;
+
+	alloc_size = nmbm_calc_structure_size(&nld);
+	ni = calloc(alloc_size, 1);
+	if (!ni) {
+		free(nm);
+		return -ENOMEM;
+	}
+
+	ret = nmbm_attach(&nld, ni);
+	if (ret) {
+		free(ni);
+		free(nm);
+		return ret;
+	}
+
+	nm->ni = ni;
+
+	/* Initialize upper mtd */
+	mtd = &nm->upper;
+
+	mtd->name = nm->name;
+	mtd->type = MTD_DEV_TYPE_NMBM;
+	mtd->flags = lower->flags;
+
+	mtd->size = (uint64_t)ni->data_block_count * ni->lower.erasesize;
+	mtd->erasesize = lower->erasesize;
+	mtd->writesize = lower->writesize;
+	mtd->writebufsize = lower->writesize;
+	mtd->oobsize = lower->oobsize;
+	mtd->oobavail = lower->oobavail;
+
+	mtd->erasesize_shift = lower->erasesize_shift;
+	mtd->writesize_shift = lower->writesize_shift;
+	mtd->erasesize_mask = lower->erasesize_mask;
+	mtd->writesize_mask = lower->writesize_mask;
+
+	mtd->bitflip_threshold = lower->bitflip_threshold;
+
+	/* XXX: should this be duplicated? */
+	mtd->ooblayout = lower->ooblayout;
+	mtd->ecclayout = lower->ecclayout;
+
+	mtd->ecc_step_size = lower->ecc_step_size;
+	mtd->ecc_strength = lower->ecc_strength;
+
+	mtd->numeraseregions = lower->numeraseregions;
+	mtd->eraseregions = lower->eraseregions;
+
+	mtd->_read = nmbm_mtd_read;
+	mtd->_write = nmbm_mtd_write;
+	mtd->_erase = nmbm_mtd_erase;
+	mtd->_read_oob = nmbm_mtd_read_oob;
+	mtd->_write_oob = nmbm_mtd_write_oob;
+	mtd->_block_isbad = nmbm_mtd_block_isbad;
+	mtd->_block_markbad = nmbm_mtd_block_markbad;
+
+	*upper = mtd;
+
+	list_add_tail(&nm->node, &nmbm_devs);
+
+	return 0;
+}
+
+int nmbm_free_mtd(struct mtd_info *upper)
+{
+	struct nmbm_mtd *pos;
+
+	if (!upper)
+		return -EINVAL;
+
+	list_for_each_entry(pos, &nmbm_devs, node) {
+		if (&pos->upper == upper) {
+			list_del(&pos->node);
+
+			nmbm_detach(pos->ni);
+			free(pos->ni);
+			free(pos);
+
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
+struct mtd_info *nmbm_mtd_get_upper_by_index(uint32_t index)
+{
+	struct nmbm_mtd *nm;
+
+	list_for_each_entry(nm, &nmbm_devs, node) {
+		if (nm->id == index)
+			return &nm->upper;
+	}
+
+	return NULL;
+}
+
+struct mtd_info *nmbm_mtd_get_upper(struct mtd_info *lower)
+{
+	struct nmbm_mtd *nm;
+
+	list_for_each_entry(nm, &nmbm_devs, node) {
+		if (nm->lower == lower)
+			return &nm->upper;
+	}
+
+	return NULL;
+}
+
+void nmbm_mtd_list_devices(void)
+{
+	struct nmbm_mtd *nm;
+
+	printf("Index   NMBM device         Lower device\n");
+	printf("========================================\n");
+
+	list_for_each_entry(nm, &nmbm_devs, node) {
+		printf("%-8u%-20s%s\n", nm->id, nm->name, nm->lower->name);
+	}
+}
+
+int nmbm_mtd_print_info(const char *name)
+{
+	struct nmbm_mtd *nm;
+	bool found = false;
+
+	list_for_each_entry(nm, &nmbm_devs, node) {
+		if (!strcmp(nm->name, name)) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		printf("Error: NMBM device '%s' not found\n", name);
+		return -ENODEV;
+	}
+
+	printf("%s:\n", name);
+	printf("Total blocks:                  %u\n", nm->ni->block_count);
+	printf("Data blocks:                   %u\n", nm->ni->data_block_count);
+	printf("Management start block:        %u\n", nm->ni->mgmt_start_ba);
+	printf("Info table size:               0x%x\n", nm->ni->info_table_size);
+
+	if (nm->ni->main_table_ba)
+		printf("Main info table start block:   %u\n", nm->ni->main_table_ba);
+	else
+		printf("Main info table start block:   Not exist\n");
+
+	if (nm->ni->backup_table_ba)
+		printf("Backup info table start block: %u\n", nm->ni->backup_table_ba);
+	else
+		printf("Backup info table start block: Not exist\n");
+
+	printf("Signature block:               %u\n", nm->ni->signature_ba);
+	printf("Mapping blocks top address:    %u\n", nm->ni->mapping_blocks_top_ba);
+	printf("Mapping blocks limit address:  %u\n", nm->ni->mapping_blocks_ba);
+
+	return 0;
+}
+
+static const char nmbm_block_legends[] = {
+	[NMBM_BLOCK_GOOD_DATA] = '-',
+	[NMBM_BLOCK_GOOD_MGMT] = '+',
+	[NMBM_BLOCK_BAD] = 'B',
+	[NMBM_BLOCK_MAIN_INFO_TABLE] = 'I',
+	[NMBM_BLOCK_BACKUP_INFO_TABLE] = 'i',
+	[NMBM_BLOCK_REMAPPED] = 'M',
+	[NMBM_BLOCK_SIGNATURE] = 'S',
+};
+
+int nmbm_mtd_print_states(const char *name)
+{
+	struct nmbm_mtd *nm;
+	enum nmmb_block_type bt;
+	bool found = false;
+	uint32_t i;
+
+	list_for_each_entry(nm, &nmbm_devs, node) {
+		if (!strcmp(nm->name, name)) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		printf("Error: NMBM device '%s' not found\n", name);
+		return -ENODEV;
+	}
+
+	printf("Physical blocks:\n");
+	printf("\n");
+
+	printf("Legends:\n");
+	printf("  -     Good data block\n");
+	printf("  +     Good management block\n");
+	printf("  B     Bad block\n");
+	printf("  I     Main info table\n");
+	printf("  i     Backup info table\n");
+	printf("  M     Remapped spare block\n");
+	printf("  S     Signature block\n");
+	printf("\n");
+
+	for (i = 0; i < nm->ni->block_count; i++) {
+		if (i % 64 == 0)
+			printf("    ");
+
+		bt = nmbm_debug_get_phys_block_type(nm->ni, i);
+		if (bt < __NMBM_BLOCK_TYPE_MAX)
+			putc(nmbm_block_legends[bt]);
+		else
+			putc('?');
+
+		if (i % 64 == 63)
+			printf("\n");
+	}
+
+	printf("\n");
+	printf("Logical blocks:\n");
+	printf("\n");
+
+	printf("Legends:\n");
+	printf("  -     Good block\n");
+	printf("  +     Initially remapped block\n");
+	printf("  M     Remapped block\n");
+	printf("  B     Bad/Unmapped block\n");
+	printf("\n");
+
+	for (i = 0; i < nm->ni->data_block_count; i++) {
+		if (i % 64 == 0)
+			printf("    ");
+
+		if (nm->ni->block_mapping[i] < 0)
+			putc('B');
+		else if (nm->ni->block_mapping[i] == i)
+			putc('-');
+		else if (nm->ni->block_mapping[i] < nm->ni->data_block_count)
+			putc('+');
+		else if (nm->ni->block_mapping[i] > nm->ni->mapping_blocks_top_ba &&
+			 nm->ni->block_mapping[i] < nm->ni->signature_ba)
+			putc('M');
+		else
+			putc('?');
+
+		if (i % 64 == 63)
+			printf("\n");
+	}
+
+	return 0;
+}
+
+int nmbm_mtd_print_bad_blocks(const char *name)
+{
+	struct nmbm_mtd *nm;
+	bool found = false;
+	uint32_t i;
+
+	list_for_each_entry(nm, &nmbm_devs, node) {
+		if (!strcmp(nm->name, name)) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		printf("Error: NMBM device '%s' not found\n", name);
+		return -ENODEV;
+	}
+
+	printf("Physical blocks:\n");
+
+	for (i = 0; i < nm->ni->block_count; i++) {
+		switch (nmbm_debug_get_block_state(nm->ni, i)) {
+		case BLOCK_ST_BAD:
+			printf("%-12u [0x%08llx] - Bad\n", i,
+			       (uint64_t)i << nm->ni->erasesize_shift);
+			break;
+		case BLOCK_ST_NEED_REMAP:
+			printf("%-12u [0x%08llx] - Awaiting remapping\n", i,
+			       (uint64_t)i << nm->ni->erasesize_shift);
+			break;
+		}
+	}
+
+	printf("\n");
+	printf("Logical blocks:\n");
+
+	for (i = 0; i < nm->ni->data_block_count; i++) {
+		if (nm->ni->block_mapping[i] < 0) {
+			printf("%-12u [0x%08llx] - Bad\n", i,
+			       (uint64_t)i << nm->ni->erasesize_shift);
+		}
+	}
+
+	return 0;
+}
+
+int nmbm_mtd_print_mappings(const char *name, int printall)
+{
+	struct nmbm_mtd *nm;
+	bool found = false;
+	int32_t pb;
+	uint32_t i;
+
+	list_for_each_entry(nm, &nmbm_devs, node) {
+		if (!strcmp(nm->name, name)) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		printf("Error: NMBM device '%s' not found\n", name);
+		return -ENODEV;
+	}
+
+	printf("Logical Block       Physical Block\n");
+	printf("==================================\n");
+
+	if (!printall) {
+		for (i = 0; i < nm->ni->data_block_count; i++) {
+			pb = nm->ni->block_mapping[i];
+			if (pb < 0)
+				printf("%-20uUnmapped\n", i);
+			else if ((uint32_t)pb > nm->ni->mapping_blocks_top_ba &&
+				(uint32_t)pb < nm->ni->signature_ba)
+				printf("%-20u%u\n", i, pb);
+		}
+
+		return 0;
+	}
+
+	for (i = 0; i < nm->ni->data_block_count; i++) {
+		pb = nm->ni->block_mapping[i];
+
+		if (pb >= 0)
+			printf("%-20u%u\n", i, pb);
+		else
+			printf("%-20uUnmapped\n", i);
+	}
+
+	return 0;
+}
--- /dev/null
+++ b/include/nmbm/nmbm-mtd.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#ifndef _NMBM_MTD_H_
+#define _NMBM_MTD_H_
+
+#include <linux/mtd/mtd.h>
+
+int nmbm_attach_mtd(struct mtd_info *lower, int flags, uint32_t max_ratio,
+		    uint32_t max_reserved_blocks, struct mtd_info **upper);
+
+int nmbm_free_mtd(struct mtd_info *upper);
+
+struct mtd_info *nmbm_mtd_get_upper_by_index(uint32_t index);
+struct mtd_info *nmbm_mtd_get_upper(struct mtd_info *lower);
+
+void nmbm_mtd_list_devices(void);
+int nmbm_mtd_print_info(const char *name);
+int nmbm_mtd_print_states(const char *name);
+int nmbm_mtd_print_bad_blocks(const char *name);
+int nmbm_mtd_print_mappings(const char *name, int printall);
+
+#endif /* _NMBM_MTD_H_ */