xref: /linux/include/linux/mtd/bbm.h (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d)
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  */
41 struct 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  */
126 struct 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 */
141 extern int onenand_default_bbt(struct mtd_info *mtd);
142 
143 #endif	/* __LINUX_MTD_BBM_H */
144