Arve Hjønnevåg | 3de69a7 | 2010-05-18 20:35:30 -0700 | [diff] [blame] | 1 | /* |
| 2 | * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. |
| 3 | * |
| 4 | * Copyright (C) 2002-2010 Aleph One Ltd. |
| 5 | * for Toby Churchill Ltd and Brightstar Engineering |
| 6 | * |
| 7 | * Created by Charles Manning <charles@aleph1.co.uk> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | */ |
| 13 | |
| 14 | #include "yaffs_guts.h" |
| 15 | #include "yaffs_tagscompat.h" |
| 16 | #include "yaffs_ecc.h" |
| 17 | #include "yaffs_getblockinfo.h" |
| 18 | #include "yaffs_trace.h" |
| 19 | |
| 20 | static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk); |
| 21 | |
| 22 | |
| 23 | /********** Tags ECC calculations *********/ |
| 24 | |
| 25 | void yaffs_calc_ecc(const u8 * data, struct yaffs_spare *spare) |
| 26 | { |
| 27 | yaffs_ecc_cacl(data, spare->ecc1); |
| 28 | yaffs_ecc_cacl(&data[256], spare->ecc2); |
| 29 | } |
| 30 | |
| 31 | void yaffs_calc_tags_ecc(struct yaffs_tags *tags) |
| 32 | { |
| 33 | /* Calculate an ecc */ |
| 34 | |
| 35 | unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes; |
| 36 | unsigned i, j; |
| 37 | unsigned ecc = 0; |
| 38 | unsigned bit = 0; |
| 39 | |
| 40 | tags->ecc = 0; |
| 41 | |
| 42 | for (i = 0; i < 8; i++) { |
| 43 | for (j = 1; j & 0xff; j <<= 1) { |
| 44 | bit++; |
| 45 | if (b[i] & j) |
| 46 | ecc ^= bit; |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | tags->ecc = ecc; |
| 51 | |
| 52 | } |
| 53 | |
| 54 | int yaffs_check_tags_ecc(struct yaffs_tags *tags) |
| 55 | { |
| 56 | unsigned ecc = tags->ecc; |
| 57 | |
| 58 | yaffs_calc_tags_ecc(tags); |
| 59 | |
| 60 | ecc ^= tags->ecc; |
| 61 | |
| 62 | if (ecc && ecc <= 64) { |
| 63 | /* TODO: Handle the failure better. Retire? */ |
| 64 | unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes; |
| 65 | |
| 66 | ecc--; |
| 67 | |
| 68 | b[ecc / 8] ^= (1 << (ecc & 7)); |
| 69 | |
| 70 | /* Now recvalc the ecc */ |
| 71 | yaffs_calc_tags_ecc(tags); |
| 72 | |
| 73 | return 1; /* recovered error */ |
| 74 | } else if (ecc) { |
| 75 | /* Wierd ecc failure value */ |
| 76 | /* TODO Need to do somethiong here */ |
| 77 | return -1; /* unrecovered error */ |
| 78 | } |
| 79 | |
| 80 | return 0; |
| 81 | } |
| 82 | |
| 83 | /********** Tags **********/ |
| 84 | |
| 85 | static void yaffs_load_tags_to_spare(struct yaffs_spare *spare_ptr, |
| 86 | struct yaffs_tags *tags_ptr) |
| 87 | { |
| 88 | union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr; |
| 89 | |
| 90 | yaffs_calc_tags_ecc(tags_ptr); |
| 91 | |
| 92 | spare_ptr->tb0 = tu->as_bytes[0]; |
| 93 | spare_ptr->tb1 = tu->as_bytes[1]; |
| 94 | spare_ptr->tb2 = tu->as_bytes[2]; |
| 95 | spare_ptr->tb3 = tu->as_bytes[3]; |
| 96 | spare_ptr->tb4 = tu->as_bytes[4]; |
| 97 | spare_ptr->tb5 = tu->as_bytes[5]; |
| 98 | spare_ptr->tb6 = tu->as_bytes[6]; |
| 99 | spare_ptr->tb7 = tu->as_bytes[7]; |
| 100 | } |
| 101 | |
| 102 | static void yaffs_get_tags_from_spare(struct yaffs_dev *dev, |
| 103 | struct yaffs_spare *spare_ptr, |
| 104 | struct yaffs_tags *tags_ptr) |
| 105 | { |
| 106 | union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr; |
| 107 | int result; |
| 108 | |
| 109 | tu->as_bytes[0] = spare_ptr->tb0; |
| 110 | tu->as_bytes[1] = spare_ptr->tb1; |
| 111 | tu->as_bytes[2] = spare_ptr->tb2; |
| 112 | tu->as_bytes[3] = spare_ptr->tb3; |
| 113 | tu->as_bytes[4] = spare_ptr->tb4; |
| 114 | tu->as_bytes[5] = spare_ptr->tb5; |
| 115 | tu->as_bytes[6] = spare_ptr->tb6; |
| 116 | tu->as_bytes[7] = spare_ptr->tb7; |
| 117 | |
| 118 | result = yaffs_check_tags_ecc(tags_ptr); |
| 119 | if (result > 0) |
| 120 | dev->n_tags_ecc_fixed++; |
| 121 | else if (result < 0) |
| 122 | dev->n_tags_ecc_unfixed++; |
| 123 | } |
| 124 | |
| 125 | static void yaffs_spare_init(struct yaffs_spare *spare) |
| 126 | { |
| 127 | memset(spare, 0xFF, sizeof(struct yaffs_spare)); |
| 128 | } |
| 129 | |
| 130 | static int yaffs_wr_nand(struct yaffs_dev *dev, |
| 131 | int nand_chunk, const u8 * data, |
| 132 | struct yaffs_spare *spare) |
| 133 | { |
| 134 | if (nand_chunk < dev->param.start_block * dev->param.chunks_per_block) { |
| 135 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 136 | "**>> yaffs chunk %d is not valid", |
| 137 | nand_chunk); |
| 138 | return YAFFS_FAIL; |
| 139 | } |
| 140 | |
| 141 | return dev->param.write_chunk_fn(dev, nand_chunk, data, spare); |
| 142 | } |
| 143 | |
| 144 | static int yaffs_rd_chunk_nand(struct yaffs_dev *dev, |
| 145 | int nand_chunk, |
| 146 | u8 * data, |
| 147 | struct yaffs_spare *spare, |
| 148 | enum yaffs_ecc_result *ecc_result, |
| 149 | int correct_errors) |
| 150 | { |
| 151 | int ret_val; |
| 152 | struct yaffs_spare local_spare; |
| 153 | |
| 154 | if (!spare && data) { |
| 155 | /* If we don't have a real spare, then we use a local one. */ |
| 156 | /* Need this for the calculation of the ecc */ |
| 157 | spare = &local_spare; |
| 158 | } |
| 159 | |
| 160 | if (!dev->param.use_nand_ecc) { |
| 161 | ret_val = |
| 162 | dev->param.read_chunk_fn(dev, nand_chunk, data, spare); |
| 163 | if (data && correct_errors) { |
| 164 | /* Do ECC correction */ |
| 165 | /* Todo handle any errors */ |
| 166 | int ecc_result1, ecc_result2; |
| 167 | u8 calc_ecc[3]; |
| 168 | |
| 169 | yaffs_ecc_cacl(data, calc_ecc); |
| 170 | ecc_result1 = |
| 171 | yaffs_ecc_correct(data, spare->ecc1, calc_ecc); |
| 172 | yaffs_ecc_cacl(&data[256], calc_ecc); |
| 173 | ecc_result2 = |
| 174 | yaffs_ecc_correct(&data[256], spare->ecc2, |
| 175 | calc_ecc); |
| 176 | |
| 177 | if (ecc_result1 > 0) { |
| 178 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 179 | "**>>yaffs ecc error fix performed on chunk %d:0", |
| 180 | nand_chunk); |
| 181 | dev->n_ecc_fixed++; |
| 182 | } else if (ecc_result1 < 0) { |
| 183 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 184 | "**>>yaffs ecc error unfixed on chunk %d:0", |
| 185 | nand_chunk); |
| 186 | dev->n_ecc_unfixed++; |
| 187 | } |
| 188 | |
| 189 | if (ecc_result2 > 0) { |
| 190 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 191 | "**>>yaffs ecc error fix performed on chunk %d:1", |
| 192 | nand_chunk); |
| 193 | dev->n_ecc_fixed++; |
| 194 | } else if (ecc_result2 < 0) { |
| 195 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 196 | "**>>yaffs ecc error unfixed on chunk %d:1", |
| 197 | nand_chunk); |
| 198 | dev->n_ecc_unfixed++; |
| 199 | } |
| 200 | |
| 201 | if (ecc_result1 || ecc_result2) { |
| 202 | /* We had a data problem on this page */ |
| 203 | yaffs_handle_rd_data_error(dev, nand_chunk); |
| 204 | } |
| 205 | |
| 206 | if (ecc_result1 < 0 || ecc_result2 < 0) |
| 207 | *ecc_result = YAFFS_ECC_RESULT_UNFIXED; |
| 208 | else if (ecc_result1 > 0 || ecc_result2 > 0) |
| 209 | *ecc_result = YAFFS_ECC_RESULT_FIXED; |
| 210 | else |
| 211 | *ecc_result = YAFFS_ECC_RESULT_NO_ERROR; |
| 212 | } |
| 213 | } else { |
| 214 | /* Must allocate enough memory for spare+2*sizeof(int) */ |
| 215 | /* for ecc results from device. */ |
| 216 | struct yaffs_nand_spare nspare; |
| 217 | |
| 218 | memset(&nspare, 0, sizeof(nspare)); |
| 219 | |
| 220 | ret_val = dev->param.read_chunk_fn(dev, nand_chunk, data, |
| 221 | (struct yaffs_spare *) |
| 222 | &nspare); |
| 223 | memcpy(spare, &nspare, sizeof(struct yaffs_spare)); |
| 224 | if (data && correct_errors) { |
| 225 | if (nspare.eccres1 > 0) { |
| 226 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 227 | "**>>mtd ecc error fix performed on chunk %d:0", |
| 228 | nand_chunk); |
| 229 | } else if (nspare.eccres1 < 0) { |
| 230 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 231 | "**>>mtd ecc error unfixed on chunk %d:0", |
| 232 | nand_chunk); |
| 233 | } |
| 234 | |
| 235 | if (nspare.eccres2 > 0) { |
| 236 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 237 | "**>>mtd ecc error fix performed on chunk %d:1", |
| 238 | nand_chunk); |
| 239 | } else if (nspare.eccres2 < 0) { |
| 240 | yaffs_trace(YAFFS_TRACE_ERROR, |
| 241 | "**>>mtd ecc error unfixed on chunk %d:1", |
| 242 | nand_chunk); |
| 243 | } |
| 244 | |
| 245 | if (nspare.eccres1 || nspare.eccres2) { |
| 246 | /* We had a data problem on this page */ |
| 247 | yaffs_handle_rd_data_error(dev, nand_chunk); |
| 248 | } |
| 249 | |
| 250 | if (nspare.eccres1 < 0 || nspare.eccres2 < 0) |
| 251 | *ecc_result = YAFFS_ECC_RESULT_UNFIXED; |
| 252 | else if (nspare.eccres1 > 0 || nspare.eccres2 > 0) |
| 253 | *ecc_result = YAFFS_ECC_RESULT_FIXED; |
| 254 | else |
| 255 | *ecc_result = YAFFS_ECC_RESULT_NO_ERROR; |
| 256 | |
| 257 | } |
| 258 | } |
| 259 | return ret_val; |
| 260 | } |
| 261 | |
| 262 | /* |
| 263 | * Functions for robustisizing |
| 264 | */ |
| 265 | |
| 266 | static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk) |
| 267 | { |
| 268 | int flash_block = nand_chunk / dev->param.chunks_per_block; |
| 269 | |
| 270 | /* Mark the block for retirement */ |
| 271 | yaffs_get_block_info(dev, |
| 272 | flash_block + dev->block_offset)->needs_retiring = |
| 273 | 1; |
| 274 | yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS, |
| 275 | "**>>Block %d marked for retirement", |
| 276 | flash_block); |
| 277 | |
| 278 | /* TODO: |
| 279 | * Just do a garbage collection on the affected block |
| 280 | * then retire the block |
| 281 | * NB recursion |
| 282 | */ |
| 283 | } |
| 284 | |
| 285 | int yaffs_tags_compat_wr(struct yaffs_dev *dev, |
| 286 | int nand_chunk, |
| 287 | const u8 * data, const struct yaffs_ext_tags *ext_tags) |
| 288 | { |
| 289 | struct yaffs_spare spare; |
| 290 | struct yaffs_tags tags; |
| 291 | |
| 292 | yaffs_spare_init(&spare); |
| 293 | |
| 294 | if (ext_tags->is_deleted) |
| 295 | spare.page_status = 0; |
| 296 | else { |
| 297 | tags.obj_id = ext_tags->obj_id; |
| 298 | tags.chunk_id = ext_tags->chunk_id; |
| 299 | |
| 300 | tags.n_bytes_lsb = ext_tags->n_bytes & 0x3ff; |
| 301 | |
| 302 | if (dev->data_bytes_per_chunk >= 1024) |
| 303 | tags.n_bytes_msb = (ext_tags->n_bytes >> 10) & 3; |
| 304 | else |
| 305 | tags.n_bytes_msb = 3; |
| 306 | |
| 307 | tags.serial_number = ext_tags->serial_number; |
| 308 | |
| 309 | if (!dev->param.use_nand_ecc && data) |
| 310 | yaffs_calc_ecc(data, &spare); |
| 311 | |
| 312 | yaffs_load_tags_to_spare(&spare, &tags); |
| 313 | |
| 314 | } |
| 315 | |
| 316 | return yaffs_wr_nand(dev, nand_chunk, data, &spare); |
| 317 | } |
| 318 | |
| 319 | int yaffs_tags_compat_rd(struct yaffs_dev *dev, |
| 320 | int nand_chunk, |
| 321 | u8 * data, struct yaffs_ext_tags *ext_tags) |
| 322 | { |
| 323 | |
| 324 | struct yaffs_spare spare; |
| 325 | struct yaffs_tags tags; |
| 326 | enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_UNKNOWN; |
| 327 | |
| 328 | static struct yaffs_spare spare_ff; |
| 329 | static int init; |
| 330 | |
| 331 | if (!init) { |
| 332 | memset(&spare_ff, 0xFF, sizeof(spare_ff)); |
| 333 | init = 1; |
| 334 | } |
| 335 | |
| 336 | if (yaffs_rd_chunk_nand(dev, nand_chunk, data, &spare, &ecc_result, 1)) { |
| 337 | /* ext_tags may be NULL */ |
| 338 | if (ext_tags) { |
| 339 | |
| 340 | int deleted = |
| 341 | (hweight8(spare.page_status) < 7) ? 1 : 0; |
| 342 | |
| 343 | ext_tags->is_deleted = deleted; |
| 344 | ext_tags->ecc_result = ecc_result; |
| 345 | ext_tags->block_bad = 0; /* We're reading it */ |
| 346 | /* therefore it is not a bad block */ |
| 347 | ext_tags->chunk_used = |
| 348 | (memcmp(&spare_ff, &spare, sizeof(spare_ff)) != |
| 349 | 0) ? 1 : 0; |
| 350 | |
| 351 | if (ext_tags->chunk_used) { |
| 352 | yaffs_get_tags_from_spare(dev, &spare, &tags); |
| 353 | |
| 354 | ext_tags->obj_id = tags.obj_id; |
| 355 | ext_tags->chunk_id = tags.chunk_id; |
| 356 | ext_tags->n_bytes = tags.n_bytes_lsb; |
| 357 | |
| 358 | if (dev->data_bytes_per_chunk >= 1024) |
| 359 | ext_tags->n_bytes |= |
| 360 | (((unsigned)tags. |
| 361 | n_bytes_msb) << 10); |
| 362 | |
| 363 | ext_tags->serial_number = tags.serial_number; |
| 364 | } |
| 365 | } |
| 366 | |
| 367 | return YAFFS_OK; |
| 368 | } else { |
| 369 | return YAFFS_FAIL; |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | int yaffs_tags_compat_mark_bad(struct yaffs_dev *dev, int flash_block) |
| 374 | { |
| 375 | |
| 376 | struct yaffs_spare spare; |
| 377 | |
| 378 | memset(&spare, 0xff, sizeof(struct yaffs_spare)); |
| 379 | |
| 380 | spare.block_status = 'Y'; |
| 381 | |
| 382 | yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block, NULL, |
| 383 | &spare); |
| 384 | yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block + 1, |
| 385 | NULL, &spare); |
| 386 | |
| 387 | return YAFFS_OK; |
| 388 | |
| 389 | } |
| 390 | |
| 391 | int yaffs_tags_compat_query_block(struct yaffs_dev *dev, |
| 392 | int block_no, |
| 393 | enum yaffs_block_state *state, |
| 394 | u32 * seq_number) |
| 395 | { |
| 396 | |
| 397 | struct yaffs_spare spare0, spare1; |
| 398 | static struct yaffs_spare spare_ff; |
| 399 | static int init; |
| 400 | enum yaffs_ecc_result dummy; |
| 401 | |
| 402 | if (!init) { |
| 403 | memset(&spare_ff, 0xFF, sizeof(spare_ff)); |
| 404 | init = 1; |
| 405 | } |
| 406 | |
| 407 | *seq_number = 0; |
| 408 | |
| 409 | yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block, NULL, |
| 410 | &spare0, &dummy, 1); |
| 411 | yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block + 1, |
| 412 | NULL, &spare1, &dummy, 1); |
| 413 | |
| 414 | if (hweight8(spare0.block_status & spare1.block_status) < 7) |
| 415 | *state = YAFFS_BLOCK_STATE_DEAD; |
| 416 | else if (memcmp(&spare_ff, &spare0, sizeof(spare_ff)) == 0) |
| 417 | *state = YAFFS_BLOCK_STATE_EMPTY; |
| 418 | else |
| 419 | *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING; |
| 420 | |
| 421 | return YAFFS_OK; |
| 422 | } |