diff options
Diffstat (limited to 'target/linux/generic/files/drivers/mtd/nand/mtk_bmt_bbt.c')
| -rw-r--r-- | target/linux/generic/files/drivers/mtd/nand/mtk_bmt_bbt.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/target/linux/generic/files/drivers/mtd/nand/mtk_bmt_bbt.c b/target/linux/generic/files/drivers/mtd/nand/mtk_bmt_bbt.c new file mode 100644 index 0000000000..fe1040802e --- /dev/null +++ b/target/linux/generic/files/drivers/mtd/nand/mtk_bmt_bbt.c @@ -0,0 +1,203 @@ +/* + * 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" + +static bool +bbt_block_is_bad(u16 block) +{ + u8 cur = bmtd.bbt_buf[block / 4]; + + return cur & (3 << ((block % 4) * 2)); +} + +static void +bbt_set_block_state(u16 block, bool bad) +{ + u8 mask = (3 << ((block % 4) * 2)); + + if (bad) + bmtd.bbt_buf[block / 4] |= mask; + else + bmtd.bbt_buf[block / 4] &= ~mask; + + bbt_nand_erase(bmtd.bmt_blk_idx); + write_bmt(bmtd.bmt_blk_idx, bmtd.bbt_buf); +} + +static u16 +get_mapping_block_index_bbt(int block) +{ + int start, end, ofs; + int bad_blocks = 0; + int i; + + if (!mapping_block_in_range(block, &start, &end)) + return block; + + start >>= bmtd.blk_shift; + end >>= bmtd.blk_shift; + /* skip bad blocks within the mapping range */ + ofs = block - start; + for (i = start; i < end; i++) { + if (bbt_block_is_bad(i)) + bad_blocks++; + else if (ofs) + ofs--; + else + break; + } + + if (i < end) + return i; + + /* when overflowing, remap remaining blocks to bad ones */ + for (i = end - 1; bad_blocks > 0; i--) { + if (!bbt_block_is_bad(i)) + continue; + + bad_blocks--; + if (bad_blocks <= ofs) + return i; + } + + return block; +} + +static bool remap_block_bbt(u16 block, u16 mapped_blk, int copy_len) +{ + int start, end; + u16 new_blk; + + if (!mapping_block_in_range(block, &start, &end)) + return false; + + bbt_set_block_state(mapped_blk, true); + + new_blk = get_mapping_block_index_bbt(block); + bbt_nand_erase(new_blk); + if (copy_len > 0) + bbt_nand_copy(new_blk, mapped_blk, copy_len); + + return false; +} + +static void +unmap_block_bbt(u16 block) +{ + bbt_set_block_state(block, false); +} + +static int +mtk_bmt_read_bbt(void) +{ + u8 oob_buf[8]; + int i; + + for (i = bmtd.total_blks - 1; i >= bmtd.total_blks - 5; i--) { + u32 page = i << (bmtd.blk_shift - bmtd.pg_shift); + + if (bbt_nand_read(page, bmtd.bbt_buf, bmtd.pg_size, + oob_buf, sizeof(oob_buf))) { + pr_info("read_bbt: could not read block %d\n", i); + continue; + } + + if (oob_buf[0] != 0xff) { + pr_info("read_bbt: bad block at %d\n", i); + continue; + } + + if (memcmp(&oob_buf[1], "mtknand", 7) != 0) { + pr_info("read_bbt: signature mismatch in block %d\n", i); + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1, oob_buf, 8, 1); + continue; + } + + pr_info("read_bbt: found bbt at block %d\n", i); + bmtd.bmt_blk_idx = i; + return 0; + } + + return -EIO; +} + + +static int +mtk_bmt_init_bbt(struct device_node *np) +{ + int buf_size = round_up(bmtd.total_blks >> 2, bmtd.blk_size); + int ret; + + bmtd.bbt_buf = kmalloc(buf_size, GFP_KERNEL); + if (!bmtd.bbt_buf) + return -ENOMEM; + + memset(bmtd.bbt_buf, 0xff, buf_size); + bmtd.mtd->size -= 4 * bmtd.mtd->erasesize; + + ret = mtk_bmt_read_bbt(); + if (ret) + return ret; + + bmtd.bmt_pgs = buf_size / bmtd.pg_size; + + return 0; +} + +static int mtk_bmt_debug_bbt(void *data, u64 val) +{ + char buf[5]; + int i, k; + + switch (val) { + case 0: + for (i = 0; i < bmtd.total_blks; i += 4) { + u8 cur = bmtd.bbt_buf[i / 4]; + + for (k = 0; k < 4; k++, cur >>= 2) + buf[k] = (cur & 3) ? 'B' : '.'; + + buf[4] = 0; + printk("[%06x] %s\n", i * bmtd.blk_size, buf); + } + break; + case 100: +#if 0 + for (i = bmtd.bmt_blk_idx; i < bmtd.total_blks - 1; i++) + bbt_nand_erase(bmtd.bmt_blk_idx); +#endif + + bmtd.bmt_blk_idx = bmtd.total_blks - 1; + bbt_nand_erase(bmtd.bmt_blk_idx); + write_bmt(bmtd.bmt_blk_idx, bmtd.bbt_buf); + break; + default: + break; + } + return 0; +} + +const struct mtk_bmt_ops mtk_bmt_bbt_ops = { + .sig = "mtknand", + .sig_len = 7, + .init = mtk_bmt_init_bbt, + .remap_block = remap_block_bbt, + .unmap_block = unmap_block_bbt, + .get_mapping_block = get_mapping_block_index_bbt, + .debug = mtk_bmt_debug_bbt, +}; |