drivers/mtd/nand/core.c

   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: " fmt
  11
  12 #include <linux/module.h>
  13 #include <linux/mtd/nand.h>
  14
  15 /**
  16  * nanddev_isbad() - Check if a block is bad
  17  * @nand: NAND device
  18  * @pos: position pointing to the block we want to check
  19  *
  20  * Return: true if the block is bad, false otherwise.
  21  */
  22 bool nanddev_isbad(struct nand_device *nand, const struct nand_pos *pos)
  23 {
  24         if (mtd_check_expert_analysis_mode())
  25                 return false;
  26
  27         if (nanddev_bbt_is_initialized(nand)) {
  28                 unsigned int entry;
  29                 int status;
  30
  31                 entry = nanddev_bbt_pos_to_entry(nand, pos);
  32                 status = nanddev_bbt_get_block_status(nand, entry);
  33                 /* Lazy block status retrieval */
  34                 if (status == NAND_BBT_BLOCK_STATUS_UNKNOWN) {
  35                         if (nand->ops->isbad(nand, pos))
  36                                 status = NAND_BBT_BLOCK_FACTORY_BAD;
  37                         else
  38                                 status = NAND_BBT_BLOCK_GOOD;
  39
  40                         nanddev_bbt_set_block_status(nand, entry, status);
  41                 }
  42
  43                 if (status == NAND_BBT_BLOCK_WORN ||
  44                     status == NAND_BBT_BLOCK_FACTORY_BAD)
  45                         return true;
  46
  47                 return false;
  48         }
  49
  50         return nand->ops->isbad(nand, pos);
  51 }
  52 EXPORT_SYMBOL_GPL(nanddev_isbad);
  53
  54 /**
  55  * nanddev_markbad() - Mark a block as bad
  56  * @nand: NAND device
  57  * @pos: position of the block to mark bad
  58  *
  59  * Mark a block bad. This function is updating the BBT if available and
  60  * calls the low-level markbad hook (nand->ops->markbad()).
  61  *
  62  * Return: 0 in case of success, a negative error code otherwise.
  63  */
  64 int nanddev_markbad(struct nand_device *nand, const struct nand_pos *pos)
  65 {
  66         struct mtd_info *mtd = nanddev_to_mtd(nand);
  67         unsigned int entry;
  68         int ret = 0;
  69
  70         if (nanddev_isbad(nand, pos))
  71                 return 0;
  72
  73         ret = nand->ops->markbad(nand, pos);
  74         if (ret)
  75                 pr_warn("failed to write BBM to block @%llx (err = %d)\n",
  76                         nanddev_pos_to_offs(nand, pos), ret);
  77
  78         if (!nanddev_bbt_is_initialized(nand))
  79                 goto out;
  80
  81         entry = nanddev_bbt_pos_to_entry(nand, pos);
  82         ret = nanddev_bbt_set_block_status(nand, entry, NAND_BBT_BLOCK_WORN);
  83         if (ret)
  84                 goto out;
  85
  86         ret = nanddev_bbt_update(nand);
  87
  88 out:
  89         if (!ret)
  90                 mtd->ecc_stats.badblocks++;
  91
  92         return ret;
  93 }
  94 EXPORT_SYMBOL_GPL(nanddev_markbad);
  95
  96 /**
  97  * nanddev_isreserved() - Check whether an eraseblock is reserved or not
  98  * @nand: NAND device
  99  * @pos: NAND position to test
 100  *
 101  * Checks whether the eraseblock pointed by @pos is reserved or not.
 102  *
 103  * Return: true if the eraseblock is reserved, false otherwise.
 104  */
 105 bool nanddev_isreserved(struct nand_device *nand, const struct nand_pos *pos)
 106 {
 107         unsigned int entry;
 108         int status;
 109
 110         if (!nanddev_bbt_is_initialized(nand))
 111                 return false;
 112
 113         /* Return info from the table */
 114         entry = nanddev_bbt_pos_to_entry(nand, pos);
 115         status = nanddev_bbt_get_block_status(nand, entry);
 116         return status == NAND_BBT_BLOCK_RESERVED;
 117 }
 118 EXPORT_SYMBOL_GPL(nanddev_isreserved);
 119
 120 /**
 121  * nanddev_erase() - Erase a NAND portion
 122  * @nand: NAND device
 123  * @pos: position of the block to erase
 124  *
 125  * Erases the block if it's not bad.
 126  *
 127  * Return: 0 in case of success, a negative error code otherwise.
 128  */
 129 static int nanddev_erase(struct nand_device *nand, const struct nand_pos *pos)
 130 {
 131         if (nanddev_isbad(nand, pos) || nanddev_isreserved(nand, pos)) {
 132                 pr_warn("attempt to erase a bad/reserved block @%llx\n",
 133                         nanddev_pos_to_offs(nand, pos));
 134                 return -EIO;
 135         }
 136
 137         return nand->ops->erase(nand, pos);
 138 }
 139
 140 /**
 141  * nanddev_mtd_erase() - Generic mtd->_erase() implementation for NAND devices
 142  * @mtd: MTD device
 143  * @einfo: erase request
 144  *
 145  * This is a simple mtd->_erase() implementation iterating over all blocks
 146  * concerned by @einfo and calling nand->ops->erase() on each of them.
 147  *
 148  * Note that mtd->_erase should not be directly assigned to this helper,
 149  * because there's no locking here. NAND specialized layers should instead
 150  * implement there own wrapper around nanddev_mtd_erase() taking the
 151  * appropriate lock before calling nanddev_mtd_erase().
 152  *
 153  * Return: 0 in case of success, a negative error code otherwise.
 154  */
 155 int nanddev_mtd_erase(struct mtd_info *mtd, struct erase_info *einfo)
 156 {
 157         struct nand_device *nand = mtd_to_nanddev(mtd);
 158         struct nand_pos pos, last;
 159         int ret;
 160
 161         nanddev_offs_to_pos(nand, einfo->addr, &pos);
 162         nanddev_offs_to_pos(nand, einfo->addr + einfo->len - 1, &last);
 163         while (nanddev_pos_cmp(&pos, &last) <= 0) {
 164                 ret = nanddev_erase(nand, &pos);
 165                 if (ret) {
 166                         einfo->fail_addr = nanddev_pos_to_offs(nand, &pos);
 167
 168                         return ret;
 169                 }
 170
 171                 nanddev_pos_next_eraseblock(nand, &pos);
 172         }
 173
 174         return 0;
 175 }
 176 EXPORT_SYMBOL_GPL(nanddev_mtd_erase);
 177
 178 /**
 179  * nanddev_mtd_max_bad_blocks() - Get the maximum number of bad eraseblock on
 180  *                                a specific region of the NAND device
 181  * @mtd: MTD device
 182  * @offs: offset of the NAND region
 183  * @len: length of the NAND region
 184  *
 185  * Default implementation for mtd->_max_bad_blocks(). Only works if
 186  * nand->memorg.max_bad_eraseblocks_per_lun is > 0.
 187  *
 188  * Return: a positive number encoding the maximum number of eraseblocks on a
 189  * portion of memory, a negative error code otherwise.
 190  */
 191 int nanddev_mtd_max_bad_blocks(struct mtd_info *mtd, loff_t offs, size_t len)
 192 {
 193         struct nand_device *nand = mtd_to_nanddev(mtd);
 194         struct nand_pos pos, end;
 195         unsigned int max_bb = 0;
 196
 197         if (!nand->memorg.max_bad_eraseblocks_per_lun)
 198                 return -ENOTSUPP;
 199
 200         nanddev_offs_to_pos(nand, offs, &pos);
 201         nanddev_offs_to_pos(nand, offs + len, &end);
 202
 203         for (nanddev_offs_to_pos(nand, offs, &pos);
 204              nanddev_pos_cmp(&pos, &end) < 0;
 205              nanddev_pos_next_lun(nand, &pos))
 206                 max_bb += nand->memorg.max_bad_eraseblocks_per_lun;
 207
 208         return max_bb;
 209 }
 210 EXPORT_SYMBOL_GPL(nanddev_mtd_max_bad_blocks);
 211
 212 /**
 213  * nanddev_get_ecc_engine() - Find and get a suitable ECC engine
 214  * @nand: NAND device
 215  */
 216 static int nanddev_get_ecc_engine(struct nand_device *nand)
 217 {
 218         int engine_type;
 219
 220         /* Read the user desires in terms of ECC engine/configuration */
 221         of_get_nand_ecc_user_config(nand);
 222
 223         engine_type = nand->ecc.user_conf.engine_type;
 224         if (engine_type == NAND_ECC_ENGINE_TYPE_INVALID)
 225                 engine_type = nand->ecc.defaults.engine_type;
 226
 227         switch (engine_type) {
 228         case NAND_ECC_ENGINE_TYPE_NONE:
 229                 return 0;
 230         case NAND_ECC_ENGINE_TYPE_SOFT:
 231                 nand->ecc.engine = nand_ecc_get_sw_engine(nand);
 232                 break;
 233         case NAND_ECC_ENGINE_TYPE_ON_DIE:
 234                 nand->ecc.engine = nand_ecc_get_on_die_hw_engine(nand);
 235                 break;
 236         case NAND_ECC_ENGINE_TYPE_ON_HOST:
 237                 nand->ecc.engine = nand_ecc_get_on_host_hw_engine(nand);
 238                 if (PTR_ERR(nand->ecc.engine) == -EPROBE_DEFER)
 239                         return -EPROBE_DEFER;
 240                 break;
 241         default:
 242                 pr_err("Missing ECC engine type\n");
 243         }
 244
 245         if (!nand->ecc.engine)
 246                 return  -EINVAL;
 247
 248         return 0;
 249 }
 250
 251 /**
 252  * nanddev_put_ecc_engine() - Dettach and put the in-use ECC engine
 253  * @nand: NAND device
 254  */
 255 static int nanddev_put_ecc_engine(struct nand_device *nand)
 256 {
 257         switch (nand->ecc.ctx.conf.engine_type) {
 258         case NAND_ECC_ENGINE_TYPE_ON_HOST:
 259                 nand_ecc_put_on_host_hw_engine(nand);
 260                 break;
 261         case NAND_ECC_ENGINE_TYPE_NONE:
 262         case NAND_ECC_ENGINE_TYPE_SOFT:
 263         case NAND_ECC_ENGINE_TYPE_ON_DIE:
 264         default:
 265                 break;
 266         }
 267
 268         return 0;
 269 }
 270
 271 /**
 272  * nanddev_find_ecc_configuration() - Find a suitable ECC configuration
 273  * @nand: NAND device
 274  */
 275 static int nanddev_find_ecc_configuration(struct nand_device *nand)
 276 {
 277         int ret;
 278
 279         if (!nand->ecc.engine)
 280                 return -ENOTSUPP;
 281
 282         ret = nand_ecc_init_ctx(nand);
 283         if (ret)
 284                 return ret;
 285
 286         if (!nand_ecc_is_strong_enough(nand))
 287                 pr_warn("WARNING: %s: the ECC used on your system is too weak compared to the one required by the NAND chip\n",
 288                         nand->mtd.name);
 289
 290         return 0;
 291 }
 292
 293 /**
 294  * nanddev_ecc_engine_init() - Initialize an ECC engine for the chip
 295  * @nand: NAND device
 296  */
 297 int nanddev_ecc_engine_init(struct nand_device *nand)
 298 {
 299         int ret;
 300
 301         /* Look for the ECC engine to use */
 302         ret = nanddev_get_ecc_engine(nand);
 303         if (ret) {
 304                 if (ret != -EPROBE_DEFER)
 305                         pr_err("No ECC engine found\n");
 306
 307                 return ret;
 308         }
 309
 310         /* No ECC engine requested */
 311         if (!nand->ecc.engine)
 312                 return 0;
 313
 314         /* Configure the engine: balance user input and chip requirements */
 315         ret = nanddev_find_ecc_configuration(nand);
 316         if (ret) {
 317                 pr_err("No suitable ECC configuration\n");
 318                 nanddev_put_ecc_engine(nand);
 319
 320                 return ret;
 321         }
 322
 323         return 0;
 324 }
 325 EXPORT_SYMBOL_GPL(nanddev_ecc_engine_init);
 326
 327 /**
 328  * nanddev_ecc_engine_cleanup() - Cleanup ECC engine initializations
 329  * @nand: NAND device
 330  */
 331 void nanddev_ecc_engine_cleanup(struct nand_device *nand)
 332 {
 333         if (nand->ecc.engine)
 334                 nand_ecc_cleanup_ctx(nand);
 335
 336         nanddev_put_ecc_engine(nand);
 337 }
 338 EXPORT_SYMBOL_GPL(nanddev_ecc_engine_cleanup);
 339
 340 /**
 341  * nanddev_init() - Initialize a NAND device
 342  * @nand: NAND device
 343  * @ops: NAND device operations
 344  * @owner: NAND device owner
 345  *
 346  * Initializes a NAND device object. Consistency checks are done on @ops and
 347  * @nand->memorg. Also takes care of initializing the BBT.
 348  *
 349  * Return: 0 in case of success, a negative error code otherwise.
 350  */
 351 int nanddev_init(struct nand_device *nand, const struct nand_ops *ops,
 352                  struct module *owner)
 353 {
 354         struct mtd_info *mtd = nanddev_to_mtd(nand);
 355         struct nand_memory_organization *memorg = nanddev_get_memorg(nand);
 356
 357         if (!nand || !ops)
 358                 return -EINVAL;
 359
 360         if (!ops->erase || !ops->markbad || !ops->isbad)
 361                 return -EINVAL;
 362
 363         if (!memorg->bits_per_cell || !memorg->pagesize ||
 364             !memorg->pages_per_eraseblock || !memorg->eraseblocks_per_lun ||
 365             !memorg->planes_per_lun || !memorg->luns_per_target ||
 366             !memorg->ntargets)
 367                 return -EINVAL;
 368
 369         nand->rowconv.eraseblock_addr_shift =
 370                                         fls(memorg->pages_per_eraseblock - 1);
 371         nand->rowconv.lun_addr_shift = fls(memorg->eraseblocks_per_lun - 1) +
 372                                        nand->rowconv.eraseblock_addr_shift;
 373
 374         nand->ops = ops;
 375
 376         mtd->type = memorg->bits_per_cell == 1 ?
 377                     MTD_NANDFLASH : MTD_MLCNANDFLASH;
 378         mtd->flags = MTD_CAP_NANDFLASH;
 379         mtd->erasesize = memorg->pagesize * memorg->pages_per_eraseblock;
 380         mtd->writesize = memorg->pagesize;
 381         mtd->writebufsize = memorg->pagesize;
 382         mtd->oobsize = memorg->oobsize;
 383         mtd->size = nanddev_size(nand);
 384         mtd->owner = owner;
 385
 386         return nanddev_bbt_init(nand);
 387 }
 388 EXPORT_SYMBOL_GPL(nanddev_init);
 389
 390 /**
 391  * nanddev_cleanup() - Release resources allocated in nanddev_init()
 392  * @nand: NAND device
 393  *
 394  * Basically undoes what has been done in nanddev_init().
 395  */
 396 void nanddev_cleanup(struct nand_device *nand)
 397 {
 398         if (nanddev_bbt_is_initialized(nand))
 399                 nanddev_bbt_cleanup(nand);
 400 }
 401 EXPORT_SYMBOL_GPL(nanddev_cleanup);
 402
 403 MODULE_DESCRIPTION("Generic NAND framework");
 404 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 405 MODULE_LICENSE("GPL v2");