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