1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2017 Free Electrons 4 * 5 * Authors: 6 * Boris Brezillon <boris.brezillon@free-electrons.com> 7 * Peter Pan <peterpandong@micron.com> 8 */ 9 10 #define pr_fmt(fmt) "nand-bbt: " fmt 11 12 #include <linux/mtd/nand.h> 13 #ifndef __UBOOT__ 14 #include <linux/slab.h> 15 #endif 16 17 /** 18 * nanddev_bbt_init() - Initialize the BBT (Bad Block Table) 19 * @nand: NAND device 20 * 21 * Initialize the in-memory BBT. 22 * 23 * Return: 0 in case of success, a negative error code otherwise. 24 */ 25 int nanddev_bbt_init(struct nand_device *nand) 26 { 27 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS); 28 unsigned int nblocks = nanddev_neraseblocks(nand); 29 unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block, 30 BITS_PER_LONG); 31 32 nand->bbt.cache = kzalloc(nwords, GFP_KERNEL); 33 if (!nand->bbt.cache) 34 return -ENOMEM; 35 36 return 0; 37 } 38 EXPORT_SYMBOL_GPL(nanddev_bbt_init); 39 40 /** 41 * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table) 42 * @nand: NAND device 43 * 44 * Undoes what has been done in nanddev_bbt_init() 45 */ 46 void nanddev_bbt_cleanup(struct nand_device *nand) 47 { 48 kfree(nand->bbt.cache); 49 } 50 EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup); 51 52 /** 53 * nanddev_bbt_update() - Update a BBT 54 * @nand: nand device 55 * 56 * Update the BBT. Currently a NOP function since on-flash bbt is not yet 57 * supported. 58 * 59 * Return: 0 in case of success, a negative error code otherwise. 60 */ 61 int nanddev_bbt_update(struct nand_device *nand) 62 { 63 return 0; 64 } 65 EXPORT_SYMBOL_GPL(nanddev_bbt_update); 66 67 /** 68 * nanddev_bbt_get_block_status() - Return the status of an eraseblock 69 * @nand: nand device 70 * @entry: the BBT entry 71 * 72 * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry 73 * is bigger than the BBT size. 74 */ 75 int nanddev_bbt_get_block_status(const struct nand_device *nand, 76 unsigned int entry) 77 { 78 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS); 79 unsigned long *pos = nand->bbt.cache + 80 ((entry * bits_per_block) / BITS_PER_LONG); 81 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG; 82 unsigned long status; 83 84 if (entry >= nanddev_neraseblocks(nand)) 85 return -ERANGE; 86 87 status = pos[0] >> offs; 88 if (bits_per_block + offs > BITS_PER_LONG) 89 status |= pos[1] << (BITS_PER_LONG - offs); 90 91 return status & GENMASK(bits_per_block - 1, 0); 92 } 93 EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status); 94 95 /** 96 * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the 97 * in-memory BBT 98 * @nand: nand device 99 * @entry: the BBT entry to update 100 * @status: the new status 101 * 102 * Update an entry of the in-memory BBT. If you want to push the updated BBT 103 * the NAND you should call nanddev_bbt_update(). 104 * 105 * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT 106 * size. 107 */ 108 int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry, 109 enum nand_bbt_block_status status) 110 { 111 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS); 112 unsigned long *pos = nand->bbt.cache + 113 ((entry * bits_per_block) / BITS_PER_LONG); 114 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG; 115 unsigned long val = status & GENMASK(bits_per_block - 1, 0); 116 117 if (entry >= nanddev_neraseblocks(nand)) 118 return -ERANGE; 119 120 pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs); 121 pos[0] |= val << offs; 122 123 if (bits_per_block + offs > BITS_PER_LONG) { 124 unsigned int rbits = bits_per_block + offs - BITS_PER_LONG; 125 126 pos[1] &= ~GENMASK(rbits - 1, 0); 127 pos[1] |= val >> rbits; 128 } 129 130 return 0; 131 } 132 EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status); 133