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_cleanup(). 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 */