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