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9c3736a3de
Add an intermediate layer to abstract NAND device interface so that some logic can be shared between SPI NANDs, parallel/raw NANDs, OneNANDs, ... Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
131 lines
3.4 KiB
C
131 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2017 Free Electrons
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*
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* Authors:
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* Boris Brezillon <boris.brezillon@free-electrons.com>
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* Peter Pan <peterpandong@micron.com>
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*/
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#define pr_fmt(fmt) "nand-bbt: " fmt
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#include <linux/mtd/nand.h>
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#include <linux/slab.h>
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/**
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* nanddev_bbt_init() - Initialize the BBT (Bad Block Table)
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* @nand: NAND device
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*
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* Initialize the in-memory BBT.
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*
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* Return: 0 in case of success, a negative error code otherwise.
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*/
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int nanddev_bbt_init(struct nand_device *nand)
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{
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unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
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unsigned int nblocks = nanddev_neraseblocks(nand);
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unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block,
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BITS_PER_LONG);
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nand->bbt.cache = kzalloc(nwords, GFP_KERNEL);
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if (!nand->bbt.cache)
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return -ENOMEM;
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return 0;
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}
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EXPORT_SYMBOL_GPL(nanddev_bbt_init);
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/**
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* nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table)
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* @nand: NAND device
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*
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* Undoes what has been done in nanddev_bbt_init()
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*/
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void nanddev_bbt_cleanup(struct nand_device *nand)
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{
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kfree(nand->bbt.cache);
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}
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EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup);
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/**
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* nanddev_bbt_update() - Update a BBT
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* @nand: nand device
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*
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* Update the BBT. Currently a NOP function since on-flash bbt is not yet
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* supported.
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*
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* Return: 0 in case of success, a negative error code otherwise.
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*/
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int nanddev_bbt_update(struct nand_device *nand)
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{
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return 0;
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}
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EXPORT_SYMBOL_GPL(nanddev_bbt_update);
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/**
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* nanddev_bbt_get_block_status() - Return the status of an eraseblock
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* @nand: nand device
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* @entry: the BBT entry
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*
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* Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry
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* is bigger than the BBT size.
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*/
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int nanddev_bbt_get_block_status(const struct nand_device *nand,
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unsigned int entry)
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{
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unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
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unsigned long *pos = nand->bbt.cache +
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((entry * bits_per_block) / BITS_PER_LONG);
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unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
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unsigned long status;
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if (entry >= nanddev_neraseblocks(nand))
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return -ERANGE;
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status = pos[0] >> offs;
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if (bits_per_block + offs > BITS_PER_LONG)
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status |= pos[1] << (BITS_PER_LONG - offs);
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return status & GENMASK(bits_per_block - 1, 0);
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}
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EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status);
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/**
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* nanddev_bbt_set_block_status() - Update the status of an eraseblock in the
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* in-memory BBT
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* @nand: nand device
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* @entry: the BBT entry to update
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* @status: the new status
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*
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* Update an entry of the in-memory BBT. If you want to push the updated BBT
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* the NAND you should call nanddev_bbt_update().
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*
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* Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT
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* size.
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*/
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int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
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enum nand_bbt_block_status status)
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{
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unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
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unsigned long *pos = nand->bbt.cache +
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((entry * bits_per_block) / BITS_PER_LONG);
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unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
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unsigned long val = status & GENMASK(bits_per_block - 1, 0);
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if (entry >= nanddev_neraseblocks(nand))
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return -ERANGE;
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pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs);
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pos[0] |= val << offs;
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if (bits_per_block + offs > BITS_PER_LONG) {
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unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
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pos[1] &= ~GENMASK(rbits - 1, 0);
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pos[1] |= val >> rbits;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);
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