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Diffstat (limited to '')
-rw-r--r-- | drivers/mtd/nand/bbt.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/mtd/nand/bbt.c b/drivers/mtd/nand/bbt.c new file mode 100644 index 000000000..db4f93a90 --- /dev/null +++ b/drivers/mtd/nand/bbt.c @@ -0,0 +1,128 @@ +// 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); + + nand->bbt.cache = bitmap_zalloc(nblocks * bits_per_block, 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) +{ + bitmap_free(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 >> (bits_per_block - rbits); + } + + return 0; +} +EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status); |