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git01.mediatek.com / filogic / uboot / 43ec7e0bf5a6483fb69cd9895340a6a44f667847 / . / drivers / mtd / nand / bbt.c
blob: 7e0ad3190c22eaf46202711b8d8117587f1d3eb5 [file] [log] [blame]
Boris Brezillon894380f2018-08-16 17:30:09 +0200[diff] [blame]1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2017 Free Electrons
4 *
5 * Authors:
6 * Boris Brezillon <boris.brezillon@free-electrons.com>
7 * Peter Pan <peterpandong@micron.com>
8 */
9
10#define pr_fmt(fmt) "nand-bbt: " fmt
11
12#include <linux/mtd/nand.h>
13#ifndef __UBOOT__
14#include <linux/slab.h>
15#endif
16
17/**
18 * nanddev_bbt_init() - Initialize the BBT (Bad Block Table)
19 * @nand: NAND device
20 *
21 * Initialize the in-memory BBT.
22 *
23 * Return: 0 in case of success, a negative error code otherwise.
24 */
25int nanddev_bbt_init(struct nand_device *nand)
26{
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,
30 BITS_PER_LONG);
31
32 nand->bbt.cache = kzalloc(nwords, GFP_KERNEL);
33 if (!nand->bbt.cache)
34 return -ENOMEM;
35
36 return 0;
37}
38EXPORT_SYMBOL_GPL(nanddev_bbt_init);
39
40/**
41 * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table)
42 * @nand: NAND device
43 *
44 * Undoes what has been done in nanddev_bbt_init()
45 */
46void nanddev_bbt_cleanup(struct nand_device *nand)
47{
48 kfree(nand->bbt.cache);
49}
50EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup);
51
52/**
53 * nanddev_bbt_update() - Update a BBT
54 * @nand: nand device
55 *
56 * Update the BBT. Currently a NOP function since on-flash bbt is not yet
57 * supported.
58 *
59 * Return: 0 in case of success, a negative error code otherwise.
60 */
61int nanddev_bbt_update(struct nand_device *nand)
62{
63 return 0;
64}
65EXPORT_SYMBOL_GPL(nanddev_bbt_update);
66
67/**
68 * nanddev_bbt_get_block_status() - Return the status of an eraseblock
69 * @nand: nand device
70 * @entry: the BBT entry
71 *
72 * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry
73 * is bigger than the BBT size.
74 */
75int nanddev_bbt_get_block_status(const struct nand_device *nand,
76 unsigned int entry)
77{
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;
82 unsigned long status;
83
84 if (entry >= nanddev_neraseblocks(nand))
85 return -ERANGE;
86
87 status = pos[0] >> offs;
88 if (bits_per_block + offs > BITS_PER_LONG)
89 status |= pos[1] << (BITS_PER_LONG - offs);
90
91 return status & GENMASK(bits_per_block - 1, 0);
92}
93EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status);
94
95/**
96 * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the
97 * in-memory BBT
98 * @nand: nand device
99 * @entry: the BBT entry to update
100 * @status: the new status
101 *
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().
104 *
105 * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT
106 * size.
107 */
108int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
109 enum nand_bbt_block_status status)
110{
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);
116
117 if (entry >= nanddev_neraseblocks(nand))
118 return -ERANGE;
119
120 pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs);
121 pos[0] |= val << offs;
122
123 if (bits_per_block + offs > BITS_PER_LONG) {
124 unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
125
126 pos[1] &= ~GENMASK(rbits - 1, 0);
127 pos[1] |= val >> rbits;
128 }
129
130 return 0;
131}
132EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);