4  *   Bad block table support for the NAND driver
10  * When nand_scan_bbt is called, then it tries to find the bad block table
13  * marked good / bad blocks. This information is used to create a memory BBT.
14  * Once a new bad block is discovered then the "factory" information is updated
21  * If the tables are not versioned, then we "or" the bad block information.
24  * good / bad blocks and the bad block tables are created.
29  * The auto generated bad block table is located in the last good blocks
40  * 00b:		block is factory marked bad
41  * 01b, 10b:	block is marked bad due to wear
43  * The memory bad block table uses the following scheme:
45  * 01b:		block is marked bad due to wear
47  * 11b:		block is factory marked bad
49  * Multichip devices like DOC store the bad block info per floor.
104  * Check for a pattern at the given place. Used to search bad block tables and
105  * good / bad block identifiers.
124  * Check for a pattern at the given place. Used to search bad block tables and
125  * good / bad block identifiers. Same as check_pattern, but no optional empty
156  * read_bbt - [GENERIC] Read the bad block table starting from page
164  * Read the bad block table starting from page.
229 				pr_info("nand_read_bbt: bad block at 0x%012llx\n",  in read_bbt()
232 				/* Factory marked bad or worn out? */  in read_bbt()
249  * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
252  * @td: descriptor for the bad block table
256  * Read the bad block table for all chips starting at a given page. We assume
380  * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
383  * @td: descriptor for the bad block table
384  * @md:	descriptor for the bad block table mirror
386  * Read the bad block table(s) for all chips starting at a given page. We
399 		pr_info("Bad block table at page %d, version 0x%02X\n",  in read_abs_bbts()
408 		pr_info("Bad block table at page %d, version 0x%02X\n",  in read_abs_bbts()
450 /* Check if a potential BBT block is marked as bad */
457 	 * No need to check for a bad BBT block if the BBM area overlaps with  in bbt_block_checkbad()
458 	 * the bad block table marker area in OOB since writing a BBM here  in bbt_block_checkbad()
459 	 * invalidates the bad block table marker anyway.  in bbt_block_checkbad()
466 	 * There is no point in checking for a bad block marker if writing  in bbt_block_checkbad()
480  * create_bbt - [GENERIC] Create a bad block table by scanning the device
483  * @bd: descriptor for the good/bad block search pattern
487  * Create a bad block table by scanning the device for the given good/bad block
498 	pr_info("Scanning device for bad blocks\n");  in create_bbt()
527 			pr_warn("Bad eraseblock %d at 0x%012llx\n",  in create_bbt()
538  * search_bbt - [GENERIC] scan the device for a specific bad block table
541  * @td: descriptor for the bad block table
543  * Read the bad block table by searching for a given ident pattern. Search is
547  * the bad block information of this chip. This is necessary to provide support
591 			/* Check if block is marked bad */  in search_bbt()
611 			pr_warn("Bad block table not found for chip %d\n", i);  in search_bbt()
613 			pr_info("Bad block table found at page %d, version 0x%02X\n",  in search_bbt()
620  * search_read_bbts - [GENERIC] scan the device for bad block table(s)
623  * @td: descriptor for the bad block table
624  * @md: descriptor for the bad block table mirror
626  * Search and read the bad block table(s).
649  * all blocks are already used of marked bad. If td->pages[chip] was already
673 	 * Automatic placement of the bad block table. Search direction  in get_bbt_block()
687 		/* Check, if the block is bad */  in get_bbt_block()
705  * mark_bbt_block_bad - Mark one of the block reserved for BBT bad
711  * Blocks reserved for BBT can become bad. This functions is an helper to mark
712  * such blocks as bad. It takes care of updating the in-memory BBT, marking the
713  * block as bad using a bad block marker and invalidating the associated
728 		pr_warn("nand_bbt: error %d while marking block %d bad\n",  in mark_bbt_block_bad()
735  * write_bbt - [GENERIC] (Re)write the bad block table
738  * @td: descriptor for the bad block table
739  * @md: descriptor for the bad block table mirror
742  * (Re)write the bad block table.
767 	/* Write bad block table per chip rather than per device? */  in write_bbt()
788 			pr_err("No space left to write bad block table\n");  in write_bbt()
828 					pr_info("nand_bbt: error reading block for writing the bad block table\n");  in write_bbt()
831 				pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");  in write_bbt()
909 		pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",  in write_bbt()
918 	pr_warn("nand_bbt: error while writing bad block table %d\n", res);  in write_bbt()
923  * nand_memory_bbt - [GENERIC] create a memory based bad block table
925  * @bd: descriptor for the good/bad block search pattern
928  * manufacturer / software marked good / bad blocks.
942  * @bd: descriptor for the good/bad block search pattern
1003 			/* Create the bad block table by scanning the device? */  in check_create()
1049 		/* Write the bad block table to the device? */  in check_create()
1056 		/* Write the mirror bad block table to the device? */  in check_create()
1067  * nand_update_bbt - update bad block table(s)
1071  * The function updates the bad block table(s).
1105 	/* Write the bad block table to the device? */  in nand_update_bbt()
1111 	/* Write the mirror bad block table to the device? */  in nand_update_bbt()
1122  * mark_bbt_region - [GENERIC] mark the bad block table regions
1124  * @td: bad block table descriptor
1126  * The bad block table regions are marked as "bad" to prevent accidental
1183  * verify_bbt_descr - verify the bad block description
1187  * This functions performs a few sanity checks on the bad block description
1232  * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1234  * @bd: descriptor for the good/bad block search pattern
1236  * The function checks, if a bad block table(s) is/are already available. If
1237  * not it scans the device for manufacturer marked good / bad blocks and writes
1238  * the bad block table(s) to the selected place.
1240  * The bad block table memory is allocated here. It must be freed by calling
1253 	 * Allocate memory (2bit per block) and clear the memory bad block  in nand_scan_bbt()
1262 	 * memory based bad block table.  in nand_scan_bbt()
1287 		/* Search the bad block table using a pattern in oob */  in nand_scan_bbt()
1312  * Define some generic bad / good block scan pattern which are used
1313  * while scanning a device for factory marked good / bad blocks.
1375 		pr_warn("Bad block pattern already allocated; not replacing\n");  in nand_create_badblock_pattern()
1391  * nand_create_bbt - [NAND Interface] Select a default bad block table for the device
1394  * This function selects the default bad block table support for the device and
1401 	/* Is a flash based bad block table requested? */  in nand_create_bbt()
1442  * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1445  * @allowbbt: allow access to bad block table region
1472  * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1474  * @offs: offset of the bad block
1482 	/* Mark bad block in memory */  in nand_markbad_bbt()
1485 	/* Update flash-based bad block table */  in nand_markbad_bbt()