summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/nand/core.c
blob: 9c9f8936b63bc37bbcbd7c6d22d6ca85d69f388f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2017 Free Electrons
 *
 * Authors:
 *	Boris Brezillon <boris.brezillon@free-electrons.com>
 *	Peter Pan <peterpandong@micron.com>
 */

#define pr_fmt(fmt)	"nand: " fmt

#include <linux/module.h>
#include <linux/mtd/nand.h>

/**
 * nanddev_isbad() - Check if a block is bad
 * @nand: NAND device
 * @pos: position pointing to the block we want to check
 *
 * Return: true if the block is bad, false otherwise.
 */
bool nanddev_isbad(struct nand_device *nand, const struct nand_pos *pos)
{
	if (nanddev_bbt_is_initialized(nand)) {
		unsigned int entry;
		int status;

		entry = nanddev_bbt_pos_to_entry(nand, pos);
		status = nanddev_bbt_get_block_status(nand, entry);
		/* Lazy block status retrieval */
		if (status == NAND_BBT_BLOCK_STATUS_UNKNOWN) {
			if (nand->ops->isbad(nand, pos))
				status = NAND_BBT_BLOCK_FACTORY_BAD;
			else
				status = NAND_BBT_BLOCK_GOOD;

			nanddev_bbt_set_block_status(nand, entry, status);
		}

		if (status == NAND_BBT_BLOCK_WORN ||
		    status == NAND_BBT_BLOCK_FACTORY_BAD)
			return true;

		return false;
	}

	return nand->ops->isbad(nand, pos);
}
EXPORT_SYMBOL_GPL(nanddev_isbad);

/**
 * nanddev_markbad() - Mark a block as bad
 * @nand: NAND device
 * @pos: position of the block to mark bad
 *
 * Mark a block bad. This function is updating the BBT if available and
 * calls the low-level markbad hook (nand->ops->markbad()).
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
int nanddev_markbad(struct nand_device *nand, const struct nand_pos *pos)
{
	struct mtd_info *mtd = nanddev_to_mtd(nand);
	unsigned int entry;
	int ret = 0;

	if (nanddev_isbad(nand, pos))
		return 0;

	ret = nand->ops->markbad(nand, pos);
	if (ret)
		pr_warn("failed to write BBM to block @%llx (err = %d)\n",
			nanddev_pos_to_offs(nand, pos), ret);

	if (!nanddev_bbt_is_initialized(nand))
		goto out;

	entry = nanddev_bbt_pos_to_entry(nand, pos);
	ret = nanddev_bbt_set_block_status(nand, entry, NAND_BBT_BLOCK_WORN);
	if (ret)
		goto out;

	ret = nanddev_bbt_update(nand);

out:
	if (!ret)
		mtd->ecc_stats.badblocks++;

	return ret;
}
EXPORT_SYMBOL_GPL(nanddev_markbad);

/**
 * nanddev_isreserved() - Check whether an eraseblock is reserved or not
 * @nand: NAND device
 * @pos: NAND position to test
 *
 * Checks whether the eraseblock pointed by @pos is reserved or not.
 *
 * Return: true if the eraseblock is reserved, false otherwise.
 */
bool nanddev_isreserved(struct nand_device *nand, const struct nand_pos *pos)
{
	unsigned int entry;
	int status;

	if (!nanddev_bbt_is_initialized(nand))
		return false;

	/* Return info from the table */
	entry = nanddev_bbt_pos_to_entry(nand, pos);
	status = nanddev_bbt_get_block_status(nand, entry);
	return status == NAND_BBT_BLOCK_RESERVED;
}
EXPORT_SYMBOL_GPL(nanddev_isreserved);

/**
 * nanddev_erase() - Erase a NAND portion
 * @nand: NAND device
 * @pos: position of the block to erase
 *
 * Erases the block if it's not bad.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
int nanddev_erase(struct nand_device *nand, const struct nand_pos *pos)
{
	if (nanddev_isbad(nand, pos) || nanddev_isreserved(nand, pos)) {
		pr_warn("attempt to erase a bad/reserved block @%llx\n",
			nanddev_pos_to_offs(nand, pos));
		return -EIO;
	}

	return nand->ops->erase(nand, pos);
}
EXPORT_SYMBOL_GPL(nanddev_erase);

/**
 * nanddev_mtd_erase() - Generic mtd->_erase() implementation for NAND devices
 * @mtd: MTD device
 * @einfo: erase request
 *
 * This is a simple mtd->_erase() implementation iterating over all blocks
 * concerned by @einfo and calling nand->ops->erase() on each of them.
 *
 * Note that mtd->_erase should not be directly assigned to this helper,
 * because there's no locking here. NAND specialized layers should instead
 * implement there own wrapper around nanddev_mtd_erase() taking the
 * appropriate lock before calling nanddev_mtd_erase().
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
int nanddev_mtd_erase(struct mtd_info *mtd, struct erase_info *einfo)
{
	struct nand_device *nand = mtd_to_nanddev(mtd);
	struct nand_pos pos, last;
	int ret;

	nanddev_offs_to_pos(nand, einfo->addr, &pos);
	nanddev_offs_to_pos(nand, einfo->addr + einfo->len - 1, &last);
	while (nanddev_pos_cmp(&pos, &last) <= 0) {
		ret = nanddev_erase(nand, &pos);
		if (ret) {
			einfo->fail_addr = nanddev_pos_to_offs(nand, &pos);

			return ret;
		}

		nanddev_pos_next_eraseblock(nand, &pos);
	}

	return 0;
}
EXPORT_SYMBOL_GPL(nanddev_mtd_erase);

/**
 * nanddev_init() - Initialize a NAND device
 * @nand: NAND device
 * @ops: NAND device operations
 * @owner: NAND device owner
 *
 * Initializes a NAND device object. Consistency checks are done on @ops and
 * @nand->memorg. Also takes care of initializing the BBT.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
int nanddev_init(struct nand_device *nand, const struct nand_ops *ops,
		 struct module *owner)
{
	struct mtd_info *mtd = nanddev_to_mtd(nand);
	struct nand_memory_organization *memorg = nanddev_get_memorg(nand);

	if (!nand || !ops)
		return -EINVAL;

	if (!ops->erase || !ops->markbad || !ops->isbad)
		return -EINVAL;

	if (!memorg->bits_per_cell || !memorg->pagesize ||
	    !memorg->pages_per_eraseblock || !memorg->eraseblocks_per_lun ||
	    !memorg->planes_per_lun || !memorg->luns_per_target ||
	    !memorg->ntargets)
		return -EINVAL;

	nand->rowconv.eraseblock_addr_shift =
					fls(memorg->pages_per_eraseblock - 1);
	nand->rowconv.lun_addr_shift = fls(memorg->eraseblocks_per_lun - 1) +
				       nand->rowconv.eraseblock_addr_shift;

	nand->ops = ops;

	mtd->type = memorg->bits_per_cell == 1 ?
		    MTD_NANDFLASH : MTD_MLCNANDFLASH;
	mtd->flags = MTD_CAP_NANDFLASH;
	mtd->erasesize = memorg->pagesize * memorg->pages_per_eraseblock;
	mtd->writesize = memorg->pagesize;
	mtd->writebufsize = memorg->pagesize;
	mtd->oobsize = memorg->oobsize;
	mtd->size = nanddev_size(nand);
	mtd->owner = owner;

	return nanddev_bbt_init(nand);
}
EXPORT_SYMBOL_GPL(nanddev_init);

/**
 * nanddev_cleanup() - Release resources allocated in nanddev_init()
 * @nand: NAND device
 *
 * Basically undoes what has been done in nanddev_init().
 */
void nanddev_cleanup(struct nand_device *nand)
{
	if (nanddev_bbt_is_initialized(nand))
		nanddev_bbt_cleanup(nand);
}
EXPORT_SYMBOL_GPL(nanddev_cleanup);

MODULE_DESCRIPTION("Generic NAND framework");
MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
MODULE_LICENSE("GPL v2");