1 files changed, 513 insertions, 0 deletions
diff --git a/target/linux/generic/files/drivers/mtd/nand/mtk_bmt_v2.c b/target/linux/generic/files/drivers/mtd/nand/mtk_bmt_v2.c
new file mode 100644
index 0000000000..b7ce7e2ca8
--- /dev/null
+++ b/target/linux/generic/files/drivers/mtd/nand/mtk_bmt_v2.c
@@ -0,0 +1,513 @@
+/*
+ * Copyright (c) 2017 MediaTek Inc.
+ * Author: Xiangsheng Hou <xiangsheng.hou@mediatek.com>
+ * Copyright (c) 2020-2022 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/kernel.h>
+#include <linux/slab.h>
+#include "mtk_bmt.h"
+
+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;
+};
+
+/* Maximum 8k blocks */
+#define BBPOOL_RATIO		2
+#define BB_TABLE_MAX	bmtd.table_size
+#define BMT_TABLE_MAX	(BB_TABLE_MAX * BBPOOL_RATIO / 100)
+#define BMT_TBL_DEF_VAL	0x0
+
+static inline struct bbmt *bmt_tbl(struct bbbt *bbbt)
+{
+	return (struct bbmt *)&bbbt->bb_tbl[bmtd.table_size];
+}
+
+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), bmtd.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 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 struct bbbt *scan_bmt(u16 block)
+{
+	u8 fdm[4];
+
+	if (block < bmtd.pool_lba)
+		return NULL;
+
+	if (read_bmt(block, bmtd.bbt_buf, fdm, sizeof(fdm)))
+		return scan_bmt(block - 1);
+
+	if (is_valid_bmt(bmtd.bbt_buf, fdm)) {
+		bmtd.bmt_blk_idx = get_bmt_index(bmt_tbl((struct bbbt *)bmtd.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 *)bmtd.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 remap_block_v2(u16 block, u16 mapped_block, int copy_len)
+{
+	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;
+
+	/* Erase new block */
+	bbt_nand_erase(mapped_blk);
+	if (copy_len > 0)
+		bbt_nand_copy(mapped_blk, block, copy_len);
+
+	bmtd.bmt_blk_idx = upload_bmt(bbt, bmtd.bmt_blk_idx);
+
+	return true;
+}
+
+static u16 get_mapping_block_index_v2(int block)
+{
+	int start, end;
+
+	if (block >= bmtd.pool_lba)
+		return block;
+
+	if (!mapping_block_in_range(block, &start, &end))
+		return block;
+
+	return bmtd.bbt->bb_tbl[block];
+}
+
+static void
+unmap_block_v2(u16 block)
+{
+	bmtd.bbt->bb_tbl[block] = block;
+	bmtd.bmt_blk_idx = upload_bmt(bmtd.bbt, bmtd.bmt_blk_idx);
+}
+
+static unsigned long *
+mtk_bmt_get_mapping_mask(void)
+{
+	struct bbmt *bbmt = bmt_tbl(bmtd.bbt);
+	int main_blocks = bmtd.mtd->size >> bmtd.blk_shift;
+	unsigned long *used;
+	int i, k;
+
+	used = kcalloc(sizeof(unsigned long), BIT_WORD(bmtd.bmt_blk_idx) + 1, GFP_KERNEL);
+	if (!used)
+		return NULL;
+
+	for (i = 1; i < main_blocks; i++) {
+		if (bmtd.bbt->bb_tbl[i] == i)
+			continue;
+
+		for (k = 0; k < bmtd.bmt_blk_idx; k++) {
+			if (bmtd.bbt->bb_tbl[i] != bbmt[k].block)
+				continue;
+
+			set_bit(k, used);
+			break;
+		}
+	}
+
+	return used;
+}
+
+static int mtk_bmt_debug_v2(void *data, u64 val)
+{
+	struct bbmt *bbmt = bmt_tbl(bmtd.bbt);
+	struct mtd_info *mtd = bmtd.mtd;
+	unsigned long *used;
+	int main_blocks = mtd->size >> bmtd.blk_shift;
+	int n_remap = 0;
+	int i;
+
+	used = mtk_bmt_get_mapping_mask();
+	if (!used)
+		return -ENOMEM;
+
+	switch (val) {
+	case 0:
+		for (i = 1; i < main_blocks; i++) {
+			if (bmtd.bbt->bb_tbl[i] == i)
+				continue;
+
+			printk("remap [%x->%x]\n", i, bmtd.bbt->bb_tbl[i]);
+			n_remap++;
+		}
+		for (i = 0; i <= bmtd.bmt_blk_idx; i++) {
+			char c;
+
+			switch (bbmt[i].mapped) {
+			case NO_MAPPED:
+				continue;
+			case NORMAL_MAPPED:
+				c = 'm';
+				if (test_bit(i, used))
+					c = 'M';
+				break;
+			case BMT_MAPPED:
+				c = 'B';
+				break;
+			default:
+				c = 'X';
+				break;
+			}
+			printk("[%x:%c] = 0x%x\n", i, c, bbmt[i].block);
+		}
+		break;
+	case 100:
+		for (i = 0; i <= bmtd.bmt_blk_idx; i++) {
+			if (bbmt[i].mapped != NORMAL_MAPPED)
+				continue;
+
+			if (test_bit(i, used))
+				continue;
+
+			n_remap++;
+			bbmt[i].mapped = NO_MAPPED;
+			printk("free block [%d:%x]\n", i, bbmt[i].block);
+		}
+		if (n_remap)
+			bmtd.bmt_blk_idx = upload_bmt(bmtd.bbt, bmtd.bmt_blk_idx);
+		break;
+	}
+
+	kfree(used);
+
+	return 0;
+}
+
+static int mtk_bmt_init_v2(struct device_node *np)
+{
+	u32 bmt_pool_size, bmt_table_size;
+	u32 bufsz, block;
+	u16 pmt_block;
+
+	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.table_size = bmt_table_size;
+
+	pmt_block = bmtd.total_blks - bmt_pool_size - 2;
+
+	bmtd.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.bb_max = bmtd.total_blks * BBPOOL_RATIO / 100;
+
+	bufsz = round_up(sizeof(struct bbbt) +
+			 bmt_table_size * sizeof(struct bbmt), bmtd.pg_size);
+	bmtd.bmt_pgs = bufsz >> bmtd.pg_shift;
+
+	bmtd.bbt_buf = kzalloc(bufsz, GFP_KERNEL);
+	if (!bmtd.bbt_buf)
+		return -ENOMEM;
+
+	memset(bmtd.bbt_buf, 0xff, bufsz);
+
+	/* Scanning start from the first page of the last block
+	 * of whole flash
+	 */
+	bmtd.bbt = scan_bmt(bmtd.total_blks - 1);
+	if (!bmtd.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");
+			return -1;
+		}
+
+		bmtd.bbt = (struct bbbt *)bmtd.bbt_buf;
+		memset(bmt_tbl(bmtd.bbt), BMT_TBL_DEF_VAL,
+		       bmtd.table_size * sizeof(struct bbmt));
+
+		if (scan_bad_blocks(bmtd.bbt))
+			return -1;
+
+		/* BMT always in the last valid block in pool */
+		bmtd.bmt_blk_idx = upload_bmt(bmtd.bbt, bmtd.bmt_blk_idx);
+		block = bmt_tbl(bmtd.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)
+			return -1;
+	}
+
+	return 0;
+}
+
+
+const struct mtk_bmt_ops mtk_bmt_v2_ops = {
+	.sig = "bmt",
+	.sig_len = 3,
+	.init = mtk_bmt_init_v2,
+	.remap_block = remap_block_v2,
+	.unmap_block = unmap_block_v2,
+	.get_mapping_block = get_mapping_block_index_v2,
+	.debug = mtk_bmt_debug_v2,
+};