linux/mtd/bbm.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  *  NAND family Bad Block Management (BBM) header file
0004  *    - Bad Block Table (BBT) implementation
0005  *
0006  *  Copyright © 2005 Samsung Electronics
0007  *  Kyungmin Park <kyungmin.park@samsung.com>
0008  *
0009  *  Copyright © 2000-2005
0010  *  Thomas Gleixner <tglx@linuxtronix.de>
0011  */
0012 #ifndef __LINUX_MTD_BBM_H
0013 #define __LINUX_MTD_BBM_H
0014
0015 /* The maximum number of NAND chips in an array */
0016 #define NAND_MAX_CHIPS      8
0017
0018 /**
0019  * struct nand_bbt_descr - bad block table descriptor
0020  * @options:    options for this descriptor
0021  * @pages:  the page(s) where we find the bbt, used with option BBT_ABSPAGE
0022  *      when bbt is searched, then we store the found bbts pages here.
0023  *      Its an array and supports up to 8 chips now
0024  * @offs:   offset of the pattern in the oob area of the page
0025  * @veroffs:    offset of the bbt version counter in the oob are of the page
0026  * @version:    version read from the bbt page during scan
0027  * @len:    length of the pattern, if 0 no pattern check is performed
0028  * @maxblocks:  maximum number of blocks to search for a bbt. This number of
0029  *      blocks is reserved at the end of the device where the tables are
0030  *      written.
0031  * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
0032  *              bad) block in the stored bbt
0033  * @pattern:    pattern to identify bad block table or factory marked good /
0034  *      bad blocks, can be NULL, if len = 0
0035  *
0036  * Descriptor for the bad block table marker and the descriptor for the
0037  * pattern which identifies good and bad blocks. The assumption is made
0038  * that the pattern and the version count are always located in the oob area
0039  * of the first block.
0040  */
0041 struct nand_bbt_descr {
0042     int options;
0043     int pages[NAND_MAX_CHIPS];
0044     int offs;
0045     int veroffs;
0046     uint8_t version[NAND_MAX_CHIPS];
0047     int len;
0048     int maxblocks;
0049     int reserved_block_code;
0050     uint8_t *pattern;
0051 };
0052
0053 /* Options for the bad block table descriptors */
0054
0055 /* The number of bits used per block in the bbt on the device */
0056 #define NAND_BBT_NRBITS_MSK 0x0000000F
0057 #define NAND_BBT_1BIT       0x00000001
0058 #define NAND_BBT_2BIT       0x00000002
0059 #define NAND_BBT_4BIT       0x00000004
0060 #define NAND_BBT_8BIT       0x00000008
0061 /* The bad block table is in the last good block of the device */
0062 #define NAND_BBT_LASTBLOCK  0x00000010
0063 /* The bbt is at the given page, else we must scan for the bbt */
0064 #define NAND_BBT_ABSPAGE    0x00000020
0065 /* bbt is stored per chip on multichip devices */
0066 #define NAND_BBT_PERCHIP    0x00000080
0067 /* bbt has a version counter at offset veroffs */
0068 #define NAND_BBT_VERSION    0x00000100
0069 /* Create a bbt if none exists */
0070 #define NAND_BBT_CREATE     0x00000200
0071 /*
0072  * Create an empty BBT with no vendor information. Vendor's information may be
0073  * unavailable, for example, if the NAND controller has a different data and OOB
0074  * layout or if this information is already purged. Must be used in conjunction
0075  * with NAND_BBT_CREATE.
0076  */
0077 #define NAND_BBT_CREATE_EMPTY   0x00000400
0078 /* Write bbt if neccecary */
0079 #define NAND_BBT_WRITE      0x00002000
0080 /* Read and write back block contents when writing bbt */
0081 #define NAND_BBT_SAVECONTENT    0x00004000
0082
0083 /*
0084  * Use a flash based bad block table. By default, OOB identifier is saved in
0085  * OOB area. This option is passed to the default bad block table function.
0086  */
0087 #define NAND_BBT_USE_FLASH  0x00020000
0088 /*
0089  * Do not store flash based bad block table marker in the OOB area; store it
0090  * in-band.
0091  */
0092 #define NAND_BBT_NO_OOB     0x00040000
0093 /*
0094  * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
0095  * entire spare area. Must be used with NAND_BBT_USE_FLASH.
0096  */
0097 #define NAND_BBT_NO_OOB_BBM 0x00080000
0098
0099 /*
0100  * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
0101  * was allocated dynamicaly and must be freed in nand_cleanup(). Has no meaning
0102  * in nand_chip.bbt_options.
0103  */
0104 #define NAND_BBT_DYNAMICSTRUCT  0x80000000
0105
0106 /* The maximum number of blocks to scan for a bbt */
0107 #define NAND_BBT_SCAN_MAXBLOCKS 4
0108
0109 /*
0110  * Bad block scanning errors
0111  */
0112 #define ONENAND_BBT_READ_ERROR      1
0113 #define ONENAND_BBT_READ_ECC_ERROR  2
0114 #define ONENAND_BBT_READ_FATAL_ERROR    4
0115
0116 /**
0117  * struct bbm_info - [GENERIC] Bad Block Table data structure
0118  * @bbt_erase_shift:    [INTERN] number of address bits in a bbt entry
0119  * @options:        options for this descriptor
0120  * @bbt:        [INTERN] bad block table pointer
0121  * @isbad_bbt:      function to determine if a block is bad
0122  * @badblock_pattern:   [REPLACEABLE] bad block scan pattern used for
0123  *          initial bad block scan
0124  * @priv:       [OPTIONAL] pointer to private bbm date
0125  */
0126 struct bbm_info {
0127     int bbt_erase_shift;
0128     int options;
0129
0130     uint8_t *bbt;
0131
0132     int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
0133
0134     /* TODO Add more NAND specific fileds */
0135     struct nand_bbt_descr *badblock_pattern;
0136
0137     void *priv;
0138 };
0139
0140 /* OneNAND BBT interface */
0141 extern int onenand_default_bbt(struct mtd_info *mtd);
0142
0143 #endif  /* __LINUX_MTD_BBM_H */