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// 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 >> (bits_per_block - rbits);
}
return 0;
}
EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);
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