129 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2017 Free Electrons4 *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: " fmt11 12#include <linux/mtd/nand.h>13#include <linux/slab.h>14 15/**16 * nanddev_bbt_init() - Initialize the BBT (Bad Block Table)17 * @nand: NAND device18 *19 * Initialize the in-memory BBT.20 *21 * Return: 0 in case of success, a negative error code otherwise.22 */23int nanddev_bbt_init(struct nand_device *nand)24{25 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);26 unsigned int nblocks = nanddev_neraseblocks(nand);27 28 nand->bbt.cache = bitmap_zalloc(nblocks * bits_per_block, GFP_KERNEL);29 if (!nand->bbt.cache)30 return -ENOMEM;31 32 return 0;33}34EXPORT_SYMBOL_GPL(nanddev_bbt_init);35 36/**37 * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table)38 * @nand: NAND device39 *40 * Undoes what has been done in nanddev_bbt_init()41 */42void nanddev_bbt_cleanup(struct nand_device *nand)43{44 bitmap_free(nand->bbt.cache);45}46EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup);47 48/**49 * nanddev_bbt_update() - Update a BBT50 * @nand: nand device51 *52 * Update the BBT. Currently a NOP function since on-flash bbt is not yet53 * supported.54 *55 * Return: 0 in case of success, a negative error code otherwise.56 */57int nanddev_bbt_update(struct nand_device *nand)58{59 return 0;60}61EXPORT_SYMBOL_GPL(nanddev_bbt_update);62 63/**64 * nanddev_bbt_get_block_status() - Return the status of an eraseblock65 * @nand: nand device66 * @entry: the BBT entry67 *68 * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry69 * is bigger than the BBT size.70 */71int nanddev_bbt_get_block_status(const struct nand_device *nand,72 unsigned int entry)73{74 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);75 unsigned long *pos = nand->bbt.cache +76 ((entry * bits_per_block) / BITS_PER_LONG);77 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;78 unsigned long status;79 80 if (entry >= nanddev_neraseblocks(nand))81 return -ERANGE;82 83 status = pos[0] >> offs;84 if (bits_per_block + offs > BITS_PER_LONG)85 status |= pos[1] << (BITS_PER_LONG - offs);86 87 return status & GENMASK(bits_per_block - 1, 0);88}89EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status);90 91/**92 * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the93 * in-memory BBT94 * @nand: nand device95 * @entry: the BBT entry to update96 * @status: the new status97 *98 * Update an entry of the in-memory BBT. If you want to push the updated BBT99 * the NAND you should call nanddev_bbt_update().100 *101 * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT102 * size.103 */104int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,105 enum nand_bbt_block_status status)106{107 unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);108 unsigned long *pos = nand->bbt.cache +109 ((entry * bits_per_block) / BITS_PER_LONG);110 unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;111 unsigned long val = status & GENMASK(bits_per_block - 1, 0);112 113 if (entry >= nanddev_neraseblocks(nand))114 return -ERANGE;115 116 pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs);117 pos[0] |= val << offs;118 119 if (bits_per_block + offs > BITS_PER_LONG) {120 unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;121 122 pos[1] &= ~GENMASK(rbits - 1, 0);123 pos[1] |= val >> (bits_per_block - rbits);124 }125 126 return 0;127}128EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);129