LXR linux/include/linux/mtd/bbm.h

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 *  NAND family Bad Block Management (BBM) header file
   4 *    - Bad Block Table (BBT) implementation
   5 *
   6 *  Copyright © 2005 Samsung Electronics
   7 *  Kyungmin Park <kyungmin.park@samsung.com>
   8 *
   9 *  Copyright © 2000-2005
  10 *  Thomas Gleixner <tglx@linuxtronix.de>
  11 */
  12#ifndef __LINUX_MTD_BBM_H
  13#define __LINUX_MTD_BBM_H
  14
  15/* The maximum number of NAND chips in an array */
  16#define NAND_MAX_CHIPS          8
  17
  18/**
  19 * struct nand_bbt_descr - bad block table descriptor
  20 * @options:    options for this descriptor
  21 * @pages:      the page(s) where we find the bbt, used with option BBT_ABSPAGE
  22 *              when bbt is searched, then we store the found bbts pages here.
  23 *              Its an array and supports up to 8 chips now
  24 * @offs:       offset of the pattern in the oob area of the page
  25 * @veroffs:    offset of the bbt version counter in the oob are of the page
  26 * @version:    version read from the bbt page during scan
  27 * @len:        length of the pattern, if 0 no pattern check is performed
  28 * @maxblocks:  maximum number of blocks to search for a bbt. This number of
  29 *              blocks is reserved at the end of the device where the tables are
  30 *              written.
  31 * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
  32 *              bad) block in the stored bbt
  33 * @pattern:    pattern to identify bad block table or factory marked good /
  34 *              bad blocks, can be NULL, if len = 0
  35 *
  36 * Descriptor for the bad block table marker and the descriptor for the
  37 * pattern which identifies good and bad blocks. The assumption is made
  38 * that the pattern and the version count are always located in the oob area
  39 * of the first block.
  40 */
  41struct nand_bbt_descr {
  42        int options;
  43        int pages[NAND_MAX_CHIPS];
  44        int offs;
  45        int veroffs;
  46        uint8_t version[NAND_MAX_CHIPS];
  47        int len;
  48        int maxblocks;
  49        int reserved_block_code;
  50        uint8_t *pattern;
  51};
  52
  53/* Options for the bad block table descriptors */
  54
  55/* The number of bits used per block in the bbt on the device */
  56#define NAND_BBT_NRBITS_MSK     0x0000000F
  57#define NAND_BBT_1BIT           0x00000001
  58#define NAND_BBT_2BIT           0x00000002
  59#define NAND_BBT_4BIT           0x00000004
  60#define NAND_BBT_8BIT           0x00000008
  61/* The bad block table is in the last good block of the device */
  62#define NAND_BBT_LASTBLOCK      0x00000010
  63/* The bbt is at the given page, else we must scan for the bbt */
  64#define NAND_BBT_ABSPAGE        0x00000020
  65/* bbt is stored per chip on multichip devices */
  66#define NAND_BBT_PERCHIP        0x00000080
  67/* bbt has a version counter at offset veroffs */
  68#define NAND_BBT_VERSION        0x00000100
  69/* Create a bbt if none exists */
  70#define NAND_BBT_CREATE         0x00000200
  71/*
  72 * Create an empty BBT with no vendor information. Vendor's information may be
  73 * unavailable, for example, if the NAND controller has a different data and OOB
  74 * layout or if this information is already purged. Must be used in conjunction
  75 * with NAND_BBT_CREATE.
  76 */
  77#define NAND_BBT_CREATE_EMPTY   0x00000400
  78/* Write bbt if neccecary */
  79#define NAND_BBT_WRITE          0x00002000
  80/* Read and write back block contents when writing bbt */
  81#define NAND_BBT_SAVECONTENT    0x00004000
  82
  83/*
  84 * Use a flash based bad block table. By default, OOB identifier is saved in
  85 * OOB area. This option is passed to the default bad block table function.
  86 */
  87#define NAND_BBT_USE_FLASH      0x00020000
  88/*
  89 * Do not store flash based bad block table marker in the OOB area; store it
  90 * in-band.
  91 */
  92#define NAND_BBT_NO_OOB         0x00040000
  93/*
  94 * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
  95 * entire spare area. Must be used with NAND_BBT_USE_FLASH.
  96 */
  97#define NAND_BBT_NO_OOB_BBM     0x00080000
  98
  99/*
 100 * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
 101 * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
 102 * in nand_chip.bbt_options.
 103 */
 104#define NAND_BBT_DYNAMICSTRUCT  0x80000000
 105
 106/* The maximum number of blocks to scan for a bbt */
 107#define NAND_BBT_SCAN_MAXBLOCKS 4
 108
 109/*
 110 * Bad block scanning errors
 111 */
 112#define ONENAND_BBT_READ_ERROR          1
 113#define ONENAND_BBT_READ_ECC_ERROR      2
 114#define ONENAND_BBT_READ_FATAL_ERROR    4
 115
 116/**
 117 * struct bbm_info - [GENERIC] Bad Block Table data structure
 118 * @bbt_erase_shift:    [INTERN] number of address bits in a bbt entry
 119 * @options:            options for this descriptor
 120 * @bbt:                [INTERN] bad block table pointer
 121 * @isbad_bbt:          function to determine if a block is bad
 122 * @badblock_pattern:   [REPLACEABLE] bad block scan pattern used for
 123 *                      initial bad block scan
 124 * @priv:               [OPTIONAL] pointer to private bbm date
 125 */
 126struct bbm_info {
 127        int bbt_erase_shift;
 128        int options;
 129
 130        uint8_t *bbt;
 131
 132        int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
 133
 134        /* TODO Add more NAND specific fileds */
 135        struct nand_bbt_descr *badblock_pattern;
 136
 137        void *priv;
 138};
 139
 140/* OneNAND BBT interface */
 141extern int onenand_default_bbt(struct mtd_info *mtd);
 142
 143#endif  /* __LINUX_MTD_BBM_H */
 144