1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2017 Free Electrons
6 * Boris Brezillon <boris.brezillon@free-electrons.com>
7 * Peter Pan <peterpandong@micron.com>
10 #define pr_fmt(fmt) "nand-bbt: " fmt
12 #include <linux/mtd/nand.h>
14 #include <linux/slab.h>
18 * nanddev_bbt_init() - Initialize the BBT (Bad Block Table)
21 * Initialize the in-memory BBT.
23 * Return: 0 in case of success, a negative error code otherwise.
25 int nanddev_bbt_init(struct nand_device *nand)
27 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
28 unsigned int nblocks = nanddev_neraseblocks(nand);
29 unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block,
32 nand->bbt.cache = kzalloc(nwords, GFP_KERNEL);
38 EXPORT_SYMBOL_GPL(nanddev_bbt_init);
41 * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table)
44 * Undoes what has been done in nanddev_bbt_init()
46 void nanddev_bbt_cleanup(struct nand_device *nand)
48 kfree(nand->bbt.cache);
50 EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup);
53 * nanddev_bbt_update() - Update a BBT
56 * Update the BBT. Currently a NOP function since on-flash bbt is not yet
59 * Return: 0 in case of success, a negative error code otherwise.
61 int nanddev_bbt_update(struct nand_device *nand)
65 EXPORT_SYMBOL_GPL(nanddev_bbt_update);
68 * nanddev_bbt_get_block_status() - Return the status of an eraseblock
70 * @entry: the BBT entry
72 * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry
73 * is bigger than the BBT size.
75 int nanddev_bbt_get_block_status(const struct nand_device *nand,
78 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
79 unsigned long *pos = nand->bbt.cache +
80 ((entry * bits_per_block) / BITS_PER_LONG);
81 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
84 if (entry >= nanddev_neraseblocks(nand))
87 status = pos[0] >> offs;
88 if (bits_per_block + offs > BITS_PER_LONG)
89 status |= pos[1] << (BITS_PER_LONG - offs);
91 return status & GENMASK(bits_per_block - 1, 0);
93 EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status);
96 * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the
99 * @entry: the BBT entry to update
100 * @status: the new status
102 * Update an entry of the in-memory BBT. If you want to push the updated BBT
103 * the NAND you should call nanddev_bbt_update().
105 * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT
108 int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
109 enum nand_bbt_block_status status)
111 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
112 unsigned long *pos = nand->bbt.cache +
113 ((entry * bits_per_block) / BITS_PER_LONG);
114 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
115 unsigned long val = status & GENMASK(bits_per_block - 1, 0);
117 if (entry >= nanddev_neraseblocks(nand))
120 pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs);
121 pos[0] |= val << offs;
123 if (bits_per_block + offs > BITS_PER_LONG) {
124 unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
126 pos[1] &= ~GENMASK(rbits - 1, 0);
127 pos[1] |= val >> rbits;
132 EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);