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 <common.h>
13 #include <linux/mtd/nand.h>
14 #ifndef __UBOOT__
15 #include <linux/slab.h>
16 #endif
17
18 /**
19 * nanddev_bbt_init() - Initialize the BBT (Bad Block Table)
20 * @nand: NAND device
21 *
22 * Initialize the in-memory BBT.
23 *
24 * Return: 0 in case of success, a negative error code otherwise.
25 */
nanddev_bbt_init(struct nand_device * nand)26 int nanddev_bbt_init(struct nand_device *nand)
27 {
28 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
29 unsigned int nblocks = nanddev_neraseblocks(nand);
30 unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block,
31 BITS_PER_LONG);
32
33 nand->bbt.cache = kzalloc(nwords, GFP_KERNEL);
34 if (!nand->bbt.cache)
35 return -ENOMEM;
36
37 return 0;
38 }
39 EXPORT_SYMBOL_GPL(nanddev_bbt_init);
40
41 /**
42 * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table)
43 * @nand: NAND device
44 *
45 * Undoes what has been done in nanddev_bbt_init()
46 */
nanddev_bbt_cleanup(struct nand_device * nand)47 void nanddev_bbt_cleanup(struct nand_device *nand)
48 {
49 kfree(nand->bbt.cache);
50 }
51 EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup);
52
53 /**
54 * nanddev_bbt_update() - Update a BBT
55 * @nand: nand device
56 *
57 * Update the BBT. Currently a NOP function since on-flash bbt is not yet
58 * supported.
59 *
60 * Return: 0 in case of success, a negative error code otherwise.
61 */
nanddev_bbt_update(struct nand_device * nand)62 int nanddev_bbt_update(struct nand_device *nand)
63 {
64 return 0;
65 }
66 EXPORT_SYMBOL_GPL(nanddev_bbt_update);
67
68 /**
69 * nanddev_bbt_get_block_status() - Return the status of an eraseblock
70 * @nand: nand device
71 * @entry: the BBT entry
72 *
73 * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry
74 * is bigger than the BBT size.
75 */
nanddev_bbt_get_block_status(const struct nand_device * nand,unsigned int entry)76 int nanddev_bbt_get_block_status(const struct nand_device *nand,
77 unsigned int entry)
78 {
79 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
80 unsigned long *pos = nand->bbt.cache +
81 ((entry * bits_per_block) / BITS_PER_LONG);
82 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
83 unsigned long status;
84
85 if (entry >= nanddev_neraseblocks(nand))
86 return -ERANGE;
87
88 status = pos[0] >> offs;
89 if (bits_per_block + offs > BITS_PER_LONG)
90 status |= pos[1] << (BITS_PER_LONG - offs);
91
92 return status & GENMASK(bits_per_block - 1, 0);
93 }
94 EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status);
95
96 /**
97 * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the
98 * in-memory BBT
99 * @nand: nand device
100 * @entry: the BBT entry to update
101 * @status: the new status
102 *
103 * Update an entry of the in-memory BBT. If you want to push the updated BBT
104 * the NAND you should call nanddev_bbt_update().
105 *
106 * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT
107 * size.
108 */
nanddev_bbt_set_block_status(struct nand_device * nand,unsigned int entry,enum nand_bbt_block_status status)109 int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
110 enum nand_bbt_block_status status)
111 {
112 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
113 unsigned long *pos = nand->bbt.cache +
114 ((entry * bits_per_block) / BITS_PER_LONG);
115 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
116 unsigned long val = status & GENMASK(bits_per_block - 1, 0);
117
118 if (entry >= nanddev_neraseblocks(nand))
119 return -ERANGE;
120
121 pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs);
122 pos[0] |= val << offs;
123
124 if (bits_per_block + offs > BITS_PER_LONG) {
125 unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
126
127 pos[1] &= ~GENMASK(rbits - 1, 0);
128 pos[1] |= val >> rbits;
129 }
130
131 return 0;
132 }
133 EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);
134