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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
87590e26 KP |
2 | /* |
3 | * linux/drivers/mtd/onenand/onenand_bbt.c | |
4 | * | |
5 | * Bad Block Table support for the OneNAND driver | |
6 | * | |
7 | * Copyright(c) 2005 Samsung Electronics | |
8 | * Kyungmin Park <kyungmin.park@samsung.com> | |
9 | * | |
10 | * Derived from nand_bbt.c | |
11 | * | |
12 | * TODO: | |
13 | * Split BBT core and chip specific BBT. | |
14 | */ | |
15 | ||
16 | #include <linux/slab.h> | |
17 | #include <linux/mtd/mtd.h> | |
18 | #include <linux/mtd/onenand.h> | |
f3bcc017 | 19 | #include <linux/export.h> |
87590e26 KP |
20 | |
21 | /** | |
22 | * check_short_pattern - [GENERIC] check if a pattern is in the buffer | |
23 | * @param buf the buffer to search | |
24 | * @param len the length of buffer to search | |
25 | * @param paglen the pagelength | |
26 | * @param td search pattern descriptor | |
27 | * | |
28 | * Check for a pattern at the given place. Used to search bad block | |
29 | * tables and good / bad block identifiers. Same as check_pattern, but | |
30 | * no optional empty check and the pattern is expected to start | |
31 | * at offset 0. | |
32 | * | |
33 | */ | |
34 | static int check_short_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td) | |
35 | { | |
36 | int i; | |
37 | uint8_t *p = buf; | |
38 | ||
39 | /* Compare the pattern */ | |
40 | for (i = 0; i < td->len; i++) { | |
41 | if (p[i] != td->pattern[i]) | |
42 | return -1; | |
43 | } | |
44 | return 0; | |
45 | } | |
46 | ||
47 | /** | |
48 | * create_bbt - [GENERIC] Create a bad block table by scanning the device | |
49 | * @param mtd MTD device structure | |
50 | * @param buf temporary buffer | |
51 | * @param bd descriptor for the good/bad block search pattern | |
52 | * @param chip create the table for a specific chip, -1 read all chips. | |
53 | * Applies only if NAND_BBT_PERCHIP option is set | |
54 | * | |
55 | * Create a bad block table by scanning the device | |
56 | * for the given good/bad block identify pattern | |
57 | */ | |
58 | static int create_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd, int chip) | |
59 | { | |
60 | struct onenand_chip *this = mtd->priv; | |
61 | struct bbm_info *bbm = this->bbm; | |
62 | int i, j, numblocks, len, scanlen; | |
63 | int startblock; | |
64 | loff_t from; | |
65 | size_t readlen, ooblen; | |
211ac75f | 66 | struct mtd_oob_ops ops; |
5988af23 | 67 | int rgn; |
87590e26 KP |
68 | |
69 | printk(KERN_INFO "Scanning device for bad blocks\n"); | |
70 | ||
ec255e34 | 71 | len = 2; |
87590e26 KP |
72 | |
73 | /* We need only read few bytes from the OOB area */ | |
74 | scanlen = ooblen = 0; | |
75 | readlen = bd->len; | |
76 | ||
77 | /* chip == -1 case only */ | |
78 | /* Note that numblocks is 2 * (real numblocks) here; | |
79 | * see i += 2 below as it makses shifting and masking less painful | |
80 | */ | |
5988af23 | 81 | numblocks = this->chipsize >> (bbm->bbt_erase_shift - 1); |
87590e26 KP |
82 | startblock = 0; |
83 | from = 0; | |
84 | ||
0612b9dd | 85 | ops.mode = MTD_OPS_PLACE_OOB; |
211ac75f KP |
86 | ops.ooblen = readlen; |
87 | ops.oobbuf = buf; | |
88 | ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0; | |
89 | ||
87590e26 KP |
90 | for (i = startblock; i < numblocks; ) { |
91 | int ret; | |
92 | ||
93 | for (j = 0; j < len; j++) { | |
87590e26 KP |
94 | /* No need to read pages fully, |
95 | * just read required OOB bytes */ | |
01039e4e RT |
96 | ret = onenand_bbt_read_oob(mtd, |
97 | from + j * this->writesize + bd->offs, &ops); | |
87590e26 | 98 | |
f6272487 | 99 | /* If it is a initial bad block, just ignore it */ |
211ac75f KP |
100 | if (ret == ONENAND_BBT_READ_FATAL_ERROR) |
101 | return -EIO; | |
87590e26 | 102 | |
01039e4e RT |
103 | if (ret || check_short_pattern(&buf[j * scanlen], |
104 | scanlen, this->writesize, bd)) { | |
87590e26 | 105 | bbm->bbt[i >> 3] |= 0x03 << (i & 0x6); |
e0c1a921 AH |
106 | printk(KERN_INFO "OneNAND eraseblock %d is an " |
107 | "initial bad block\n", i >> 1); | |
f4f91ac3 | 108 | mtd->ecc_stats.badblocks++; |
87590e26 KP |
109 | break; |
110 | } | |
111 | } | |
112 | i += 2; | |
5988af23 RH |
113 | |
114 | if (FLEXONENAND(this)) { | |
115 | rgn = flexonenand_region(mtd, from); | |
116 | from += mtd->eraseregions[rgn].erasesize; | |
117 | } else | |
118 | from += (1 << bbm->bbt_erase_shift); | |
87590e26 KP |
119 | } |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | ||
125 | /** | |
126 | * onenand_memory_bbt - [GENERIC] create a memory based bad block table | |
127 | * @param mtd MTD device structure | |
128 | * @param bd descriptor for the good/bad block search pattern | |
129 | * | |
130 | * The function creates a memory based bbt by scanning the device | |
131 | * for manufacturer / software marked good / bad blocks | |
132 | */ | |
133 | static inline int onenand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd) | |
134 | { | |
532a37cf | 135 | struct onenand_chip *this = mtd->priv; |
87590e26 | 136 | |
532a37cf | 137 | return create_bbt(mtd, this->page_buf, bd, -1); |
87590e26 KP |
138 | } |
139 | ||
140 | /** | |
141 | * onenand_isbad_bbt - [OneNAND Interface] Check if a block is bad | |
142 | * @param mtd MTD device structure | |
143 | * @param offs offset in the device | |
144 | * @param allowbbt allow access to bad block table region | |
145 | */ | |
146 | static int onenand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt) | |
147 | { | |
148 | struct onenand_chip *this = mtd->priv; | |
149 | struct bbm_info *bbm = this->bbm; | |
150 | int block; | |
151 | uint8_t res; | |
152 | ||
153 | /* Get block number * 2 */ | |
5988af23 | 154 | block = (int) (onenand_block(this, offs) << 1); |
87590e26 KP |
155 | res = (bbm->bbt[block >> 3] >> (block & 0x06)) & 0x03; |
156 | ||
289c0522 | 157 | pr_debug("onenand_isbad_bbt: bbt info for offs 0x%08x: (block %d) 0x%02x\n", |
87590e26 KP |
158 | (unsigned int) offs, block >> 1, res); |
159 | ||
160 | switch ((int) res) { | |
161 | case 0x00: return 0; | |
162 | case 0x01: return 1; | |
163 | case 0x02: return allowbbt ? 0 : 1; | |
164 | } | |
165 | ||
166 | return 1; | |
167 | } | |
168 | ||
169 | /** | |
170 | * onenand_scan_bbt - [OneNAND Interface] scan, find, read and maybe create bad block table(s) | |
171 | * @param mtd MTD device structure | |
172 | * @param bd descriptor for the good/bad block search pattern | |
173 | * | |
174 | * The function checks, if a bad block table(s) is/are already | |
175 | * available. If not it scans the device for manufacturer | |
176 | * marked good / bad blocks and writes the bad block table(s) to | |
177 | * the selected place. | |
178 | * | |
f00b0046 AH |
179 | * The bad block table memory is allocated here. It is freed |
180 | * by the onenand_release function. | |
87590e26 KP |
181 | * |
182 | */ | |
fd2a2f20 | 183 | static int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) |
87590e26 KP |
184 | { |
185 | struct onenand_chip *this = mtd->priv; | |
186 | struct bbm_info *bbm = this->bbm; | |
187 | int len, ret = 0; | |
188 | ||
5988af23 | 189 | len = this->chipsize >> (this->erase_shift + 2); |
95b93a0c BY |
190 | /* Allocate memory (2bit per block) and clear the memory bad block table */ |
191 | bbm->bbt = kzalloc(len, GFP_KERNEL); | |
0870066d | 192 | if (!bbm->bbt) |
87590e26 | 193 | return -ENOMEM; |
87590e26 KP |
194 | |
195 | /* Set the bad block position */ | |
196 | bbm->badblockpos = ONENAND_BADBLOCK_POS; | |
197 | ||
198 | /* Set erase shift */ | |
199 | bbm->bbt_erase_shift = this->erase_shift; | |
200 | ||
201 | if (!bbm->isbad_bbt) | |
202 | bbm->isbad_bbt = onenand_isbad_bbt; | |
203 | ||
204 | /* Scan the device to build a memory based bad block table */ | |
205 | if ((ret = onenand_memory_bbt(mtd, bd))) { | |
206 | printk(KERN_ERR "onenand_scan_bbt: Can't scan flash and build the RAM-based BBT\n"); | |
207 | kfree(bbm->bbt); | |
208 | bbm->bbt = NULL; | |
209 | } | |
210 | ||
211 | return ret; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Define some generic bad / good block scan pattern which are used | |
216 | * while scanning a device for factory marked good / bad blocks. | |
217 | */ | |
218 | static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; | |
219 | ||
220 | static struct nand_bbt_descr largepage_memorybased = { | |
221 | .options = 0, | |
222 | .offs = 0, | |
223 | .len = 2, | |
224 | .pattern = scan_ff_pattern, | |
225 | }; | |
226 | ||
227 | /** | |
228 | * onenand_default_bbt - [OneNAND Interface] Select a default bad block table for the device | |
229 | * @param mtd MTD device structure | |
230 | * | |
231 | * This function selects the default bad block table | |
232 | * support for the device and calls the onenand_scan_bbt function | |
233 | */ | |
234 | int onenand_default_bbt(struct mtd_info *mtd) | |
235 | { | |
236 | struct onenand_chip *this = mtd->priv; | |
237 | struct bbm_info *bbm; | |
238 | ||
95b93a0c | 239 | this->bbm = kzalloc(sizeof(struct bbm_info), GFP_KERNEL); |
87590e26 KP |
240 | if (!this->bbm) |
241 | return -ENOMEM; | |
242 | ||
243 | bbm = this->bbm; | |
244 | ||
87590e26 KP |
245 | /* 1KB page has same configuration as 2KB page */ |
246 | if (!bbm->badblock_pattern) | |
247 | bbm->badblock_pattern = &largepage_memorybased; | |
248 | ||
249 | return onenand_scan_bbt(mtd, bbm->badblock_pattern); | |
250 | } |