// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2017 Free Electrons * * Authors: * Boris Brezillon <boris.brezillon@free-electrons.com> * Peter Pan <peterpandong@micron.com> */ #define pr_fmt(fmt) "nand-bbt: " fmt #include <linux/mtd/nand.h> #include <linux/slab.h> /** * nanddev_bbt_init() - Initialize the BBT (Bad Block Table) * @nand: NAND device * * Initialize the in-memory BBT. * * Return: 0 in case of success, a negative error code otherwise. */ int nanddev_bbt_init(struct nand_device *nand) { unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS); unsigned int nblocks = nanddev_neraseblocks(nand); unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block, BITS_PER_LONG); nand->bbt.cache = kcalloc(nwords, sizeof(*nand->bbt.cache), GFP_KERNEL); if (!nand->bbt.cache) return -ENOMEM; return 0; } EXPORT_SYMBOL_GPL(nanddev_bbt_init); /** * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table) * @nand: NAND device * * Undoes what has been done in nanddev_bbt_init() */ void nanddev_bbt_cleanup(struct nand_device *nand) { kfree(nand->bbt.cache); } EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup); /** * nanddev_bbt_update() - Update a BBT * @nand: nand device * * Update the BBT. Currently a NOP function since on-flash bbt is not yet * supported. * * Return: 0 in case of success, a negative error code otherwise. */ int nanddev_bbt_update(struct nand_device *nand) { return 0; } EXPORT_SYMBOL_GPL(nanddev_bbt_update); /** * nanddev_bbt_get_block_status() - Return the status of an eraseblock * @nand: nand device * @entry: the BBT entry * * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry * is bigger than the BBT size. */ int nanddev_bbt_get_block_status(const struct nand_device *nand, unsigned int entry) { unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS); unsigned long *pos = nand->bbt.cache + ((entry * bits_per_block) / BITS_PER_LONG); unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG; unsigned long status; if (entry >= nanddev_neraseblocks(nand)) return -ERANGE; status = pos[0] >> offs; if (bits_per_block + offs > BITS_PER_LONG) status |= pos[1] << (BITS_PER_LONG - offs); return status & GENMASK(bits_per_block - 1, 0); } EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status); /** * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the * in-memory BBT * @nand: nand device * @entry: the BBT entry to update * @status: the new status * * Update an entry of the in-memory BBT. If you want to push the updated BBT * the NAND you should call nanddev_bbt_update(). * * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT * size. */ int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry, enum nand_bbt_block_status status) { unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS); unsigned long *pos = nand->bbt.cache + ((entry * bits_per_block) / BITS_PER_LONG); unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG; unsigned long val = status & GENMASK(bits_per_block - 1, 0); if (entry >= nanddev_neraseblocks(nand)) return -ERANGE; pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs); pos[0] |= val << offs; if (bits_per_block + offs > BITS_PER_LONG) { unsigned int rbits = bits_per_block + offs - BITS_PER_LONG; pos[1] &= ~GENMASK(rbits - 1, 0); pos[1] |= val >> rbits; } return 0; } EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);