root/drivers/mtd/nand/core.c

DEFINITIONS

1. nanddev_isbad
2. nanddev_markbad
3. nanddev_isreserved
4. nanddev_erase
5. nanddev_mtd_erase
6. nanddev_mtd_max_bad_blocks
7. nanddev_init
8. nanddev_cleanup

   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 (nanddev_bbt_is_initialized(nand)) {
  25                 unsigned int entry;
  26                 int status;
  27 
  28                 entry = nanddev_bbt_pos_to_entry(nand, pos);
  29                 status = nanddev_bbt_get_block_status(nand, entry);
  30                 /* Lazy block status retrieval */
  31                 if (status == NAND_BBT_BLOCK_STATUS_UNKNOWN) {
  32                         if (nand->ops->isbad(nand, pos))
  33                                 status = NAND_BBT_BLOCK_FACTORY_BAD;
  34                         else
  35                                 status = NAND_BBT_BLOCK_GOOD;
  36 
  37                         nanddev_bbt_set_block_status(nand, entry, status);
  38                 }
  39 
  40                 if (status == NAND_BBT_BLOCK_WORN ||
  41                     status == NAND_BBT_BLOCK_FACTORY_BAD)
  42                         return true;
  43 
  44                 return false;
  45         }
  46 
  47         return nand->ops->isbad(nand, pos);
  48 }
  49 EXPORT_SYMBOL_GPL(nanddev_isbad);
  50 
  51 /**
  52  * nanddev_markbad() - Mark a block as bad
  53  * @nand: NAND device
  54  * @pos: position of the block to mark bad
  55  *
  56  * Mark a block bad. This function is updating the BBT if available and
  57  * calls the low-level markbad hook (nand->ops->markbad()).
  58  *
  59  * Return: 0 in case of success, a negative error code otherwise.
  60  */
  61 int nanddev_markbad(struct nand_device *nand, const struct nand_pos *pos)
  62 {
  63         struct mtd_info *mtd = nanddev_to_mtd(nand);
  64         unsigned int entry;
  65         int ret = 0;
  66 
  67         if (nanddev_isbad(nand, pos))
  68                 return 0;
  69 
  70         ret = nand->ops->markbad(nand, pos);
  71         if (ret)
  72                 pr_warn("failed to write BBM to block @%llx (err = %d)\n",
  73                         nanddev_pos_to_offs(nand, pos), ret);
  74 
  75         if (!nanddev_bbt_is_initialized(nand))
  76                 goto out;
  77 
  78         entry = nanddev_bbt_pos_to_entry(nand, pos);
  79         ret = nanddev_bbt_set_block_status(nand, entry, NAND_BBT_BLOCK_WORN);
  80         if (ret)
  81                 goto out;
  82 
  83         ret = nanddev_bbt_update(nand);
  84 
  85 out:
  86         if (!ret)
  87                 mtd->ecc_stats.badblocks++;
  88 
  89         return ret;
  90 }
  91 EXPORT_SYMBOL_GPL(nanddev_markbad);
  92 
  93 /**
  94  * nanddev_isreserved() - Check whether an eraseblock is reserved or not
  95  * @nand: NAND device
  96  * @pos: NAND position to test
  97  *
  98  * Checks whether the eraseblock pointed by @pos is reserved or not.
  99  *
 100  * Return: true if the eraseblock is reserved, false otherwise.
 101  */
 102 bool nanddev_isreserved(struct nand_device *nand, const struct nand_pos *pos)
 103 {
 104         unsigned int entry;
 105         int status;
 106 
 107         if (!nanddev_bbt_is_initialized(nand))
 108                 return false;
 109 
 110         /* Return info from the table */
 111         entry = nanddev_bbt_pos_to_entry(nand, pos);
 112         status = nanddev_bbt_get_block_status(nand, entry);
 113         return status == NAND_BBT_BLOCK_RESERVED;
 114 }
 115 EXPORT_SYMBOL_GPL(nanddev_isreserved);
 116 
 117 /**
 118  * nanddev_erase() - Erase a NAND portion
 119  * @nand: NAND device
 120  * @pos: position of the block to erase
 121  *
 122  * Erases the block if it's not bad.
 123  *
 124  * Return: 0 in case of success, a negative error code otherwise.
 125  */
 126 int nanddev_erase(struct nand_device *nand, const struct nand_pos *pos)
 127 {
 128         if (nanddev_isbad(nand, pos) || nanddev_isreserved(nand, pos)) {
 129                 pr_warn("attempt to erase a bad/reserved block @%llx\n",
 130                         nanddev_pos_to_offs(nand, pos));
 131                 return -EIO;
 132         }
 133 
 134         return nand->ops->erase(nand, pos);
 135 }
 136 EXPORT_SYMBOL_GPL(nanddev_erase);
 137 
 138 /**
 139  * nanddev_mtd_erase() - Generic mtd->_erase() implementation for NAND devices
 140  * @mtd: MTD device
 141  * @einfo: erase request
 142  *
 143  * This is a simple mtd->_erase() implementation iterating over all blocks
 144  * concerned by @einfo and calling nand->ops->erase() on each of them.
 145  *
 146  * Note that mtd->_erase should not be directly assigned to this helper,
 147  * because there's no locking here. NAND specialized layers should instead
 148  * implement there own wrapper around nanddev_mtd_erase() taking the
 149  * appropriate lock before calling nanddev_mtd_erase().
 150  *
 151  * Return: 0 in case of success, a negative error code otherwise.
 152  */
 153 int nanddev_mtd_erase(struct mtd_info *mtd, struct erase_info *einfo)
 154 {
 155         struct nand_device *nand = mtd_to_nanddev(mtd);
 156         struct nand_pos pos, last;
 157         int ret;
 158 
 159         nanddev_offs_to_pos(nand, einfo->addr, &pos);
 160         nanddev_offs_to_pos(nand, einfo->addr + einfo->len - 1, &last);
 161         while (nanddev_pos_cmp(&pos, &last) <= 0) {
 162                 ret = nanddev_erase(nand, &pos);
 163                 if (ret) {
 164                         einfo->fail_addr = nanddev_pos_to_offs(nand, &pos);
 165 
 166                         return ret;
 167                 }
 168 
 169                 nanddev_pos_next_eraseblock(nand, &pos);
 170         }
 171 
 172         return 0;
 173 }
 174 EXPORT_SYMBOL_GPL(nanddev_mtd_erase);
 175 
 176 /**
 177  * nanddev_mtd_max_bad_blocks() - Get the maximum number of bad eraseblock on
 178  *                                a specific region of the NAND device
 179  * @mtd: MTD device
 180  * @offs: offset of the NAND region
 181  * @len: length of the NAND region
 182  *
 183  * Default implementation for mtd->_max_bad_blocks(). Only works if
 184  * nand->memorg.max_bad_eraseblocks_per_lun is > 0.
 185  *
 186  * Return: a positive number encoding the maximum number of eraseblocks on a
 187  * portion of memory, a negative error code otherwise.
 188  */
 189 int nanddev_mtd_max_bad_blocks(struct mtd_info *mtd, loff_t offs, size_t len)
 190 {
 191         struct nand_device *nand = mtd_to_nanddev(mtd);
 192         struct nand_pos pos, end;
 193         unsigned int max_bb = 0;
 194 
 195         if (!nand->memorg.max_bad_eraseblocks_per_lun)
 196                 return -ENOTSUPP;
 197 
 198         nanddev_offs_to_pos(nand, offs, &pos);
 199         nanddev_offs_to_pos(nand, offs + len, &end);
 200 
 201         for (nanddev_offs_to_pos(nand, offs, &pos);
 202              nanddev_pos_cmp(&pos, &end) < 0;
 203              nanddev_pos_next_lun(nand, &pos))
 204                 max_bb += nand->memorg.max_bad_eraseblocks_per_lun;
 205 
 206         return max_bb;
 207 }
 208 EXPORT_SYMBOL_GPL(nanddev_mtd_max_bad_blocks);
 209 
 210 /**
 211  * nanddev_init() - Initialize a NAND device
 212  * @nand: NAND device
 213  * @ops: NAND device operations
 214  * @owner: NAND device owner
 215  *
 216  * Initializes a NAND device object. Consistency checks are done on @ops and
 217  * @nand->memorg. Also takes care of initializing the BBT.
 218  *
 219  * Return: 0 in case of success, a negative error code otherwise.
 220  */
 221 int nanddev_init(struct nand_device *nand, const struct nand_ops *ops,
 222                  struct module *owner)
 223 {
 224         struct mtd_info *mtd = nanddev_to_mtd(nand);
 225         struct nand_memory_organization *memorg = nanddev_get_memorg(nand);
 226 
 227         if (!nand || !ops)
 228                 return -EINVAL;
 229 
 230         if (!ops->erase || !ops->markbad || !ops->isbad)
 231                 return -EINVAL;
 232 
 233         if (!memorg->bits_per_cell || !memorg->pagesize ||
 234             !memorg->pages_per_eraseblock || !memorg->eraseblocks_per_lun ||
 235             !memorg->planes_per_lun || !memorg->luns_per_target ||
 236             !memorg->ntargets)
 237                 return -EINVAL;
 238 
 239         nand->rowconv.eraseblock_addr_shift =
 240                                         fls(memorg->pages_per_eraseblock - 1);
 241         nand->rowconv.lun_addr_shift = fls(memorg->eraseblocks_per_lun - 1) +
 242                                        nand->rowconv.eraseblock_addr_shift;
 243 
 244         nand->ops = ops;
 245 
 246         mtd->type = memorg->bits_per_cell == 1 ?
 247                     MTD_NANDFLASH : MTD_MLCNANDFLASH;
 248         mtd->flags = MTD_CAP_NANDFLASH;
 249         mtd->erasesize = memorg->pagesize * memorg->pages_per_eraseblock;
 250         mtd->writesize = memorg->pagesize;
 251         mtd->writebufsize = memorg->pagesize;
 252         mtd->oobsize = memorg->oobsize;
 253         mtd->size = nanddev_size(nand);
 254         mtd->owner = owner;
 255 
 256         return nanddev_bbt_init(nand);
 257 }
 258 EXPORT_SYMBOL_GPL(nanddev_init);
 259 
 260 /**
 261  * nanddev_cleanup() - Release resources allocated in nanddev_init()
 262  * @nand: NAND device
 263  *
 264  * Basically undoes what has been done in nanddev_init().
 265  */
 266 void nanddev_cleanup(struct nand_device *nand)
 267 {
 268         if (nanddev_bbt_is_initialized(nand))
 269                 nanddev_bbt_cleanup(nand);
 270 }
 271 EXPORT_SYMBOL_GPL(nanddev_cleanup);
 272 
 273 MODULE_DESCRIPTION("Generic NAND framework");
 274 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 275 MODULE_LICENSE("GPL v2");