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 <dm/devres.h>
14 #include <linux/bitops.h>
15 #include <linux/mtd/nand.h>
16 #ifndef __UBOOT__
17 #include <linux/slab.h>
18 #endif
19
20 /**
21 * nanddev_bbt_init() - Initialize the BBT (Bad Block Table)
22 * @nand: NAND device
23 *
24 * Initialize the in-memory BBT.
25 *
26 * Return: 0 in case of success, a negative error code otherwise.
27 */
nanddev_bbt_init(struct nand_device * nand)28 int nanddev_bbt_init(struct nand_device *nand)
29 {
30 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
31 unsigned int nblocks = nanddev_neraseblocks(nand);
32 unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block,
33 BITS_PER_LONG);
34
35 nand->bbt.cache = kzalloc(nwords, GFP_KERNEL);
36 if (!nand->bbt.cache)
37 return -ENOMEM;
38
39 return 0;
40 }
41 EXPORT_SYMBOL_GPL(nanddev_bbt_init);
42
43 /**
44 * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table)
45 * @nand: NAND device
46 *
47 * Undoes what has been done in nanddev_bbt_init()
48 */
nanddev_bbt_cleanup(struct nand_device * nand)49 void nanddev_bbt_cleanup(struct nand_device *nand)
50 {
51 kfree(nand->bbt.cache);
52 }
53 EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup);
54
55 /**
56 * nanddev_bbt_update() - Update a BBT
57 * @nand: nand device
58 *
59 * Update the BBT. Currently a NOP function since on-flash bbt is not yet
60 * supported.
61 *
62 * Return: 0 in case of success, a negative error code otherwise.
63 */
nanddev_bbt_update(struct nand_device * nand)64 int nanddev_bbt_update(struct nand_device *nand)
65 {
66 return 0;
67 }
68 EXPORT_SYMBOL_GPL(nanddev_bbt_update);
69
70 /**
71 * nanddev_bbt_get_block_status() - Return the status of an eraseblock
72 * @nand: nand device
73 * @entry: the BBT entry
74 *
75 * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry
76 * is bigger than the BBT size.
77 */
nanddev_bbt_get_block_status(const struct nand_device * nand,unsigned int entry)78 int nanddev_bbt_get_block_status(const struct nand_device *nand,
79 unsigned int entry)
80 {
81 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
82 unsigned long *pos = nand->bbt.cache +
83 ((entry * bits_per_block) / BITS_PER_LONG);
84 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
85 unsigned long status;
86
87 if (entry >= nanddev_neraseblocks(nand))
88 return -ERANGE;
89
90 status = pos[0] >> offs;
91 if (bits_per_block + offs > BITS_PER_LONG)
92 status |= pos[1] << (BITS_PER_LONG - offs);
93
94 return status & GENMASK(bits_per_block - 1, 0);
95 }
96 EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status);
97
98 /**
99 * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the
100 * in-memory BBT
101 * @nand: nand device
102 * @entry: the BBT entry to update
103 * @status: the new status
104 *
105 * Update an entry of the in-memory BBT. If you want to push the updated BBT
106 * the NAND you should call nanddev_bbt_update().
107 *
108 * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT
109 * size.
110 */
nanddev_bbt_set_block_status(struct nand_device * nand,unsigned int entry,enum nand_bbt_block_status status)111 int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
112 enum nand_bbt_block_status status)
113 {
114 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
115 unsigned long *pos = nand->bbt.cache +
116 ((entry * bits_per_block) / BITS_PER_LONG);
117 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
118 unsigned long val = status & GENMASK(bits_per_block - 1, 0);
119
120 if (entry >= nanddev_neraseblocks(nand))
121 return -ERANGE;
122
123 pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs);
124 pos[0] |= val << offs;
125
126 if (bits_per_block + offs > BITS_PER_LONG) {
127 unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
128
129 pos[1] &= ~GENMASK(rbits - 1, 0);
130 pos[1] |= val >> (bits_per_block - rbits);
131 }
132
133 return 0;
134 }
135 EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);
136