提交 9c3736a3 编写于 作者: B Boris Brezillon

mtd: nand: Add core infrastructure to deal with NAND devices

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: NBoris Brezillon <boris.brezillon@bootlin.com>
上级 93db446a
config MTD_NAND_CORE
tristate
source "drivers/mtd/nand/raw/Kconfig"
# SPDX-License-Identifier: GPL-2.0
nandcore-objs := core.o bbt.o
obj-$(CONFIG_MTD_NAND_CORE) += nandcore.o
obj-y += raw/
// 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 = kzalloc(nwords, 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);
// 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: " fmt
#include <linux/module.h>
#include <linux/mtd/nand.h>
/**
* nanddev_isbad() - Check if a block is bad
* @nand: NAND device
* @pos: position pointing to the block we want to check
*
* Return: true if the block is bad, false otherwise.
*/
bool nanddev_isbad(struct nand_device *nand, const struct nand_pos *pos)
{
if (nanddev_bbt_is_initialized(nand)) {
unsigned int entry;
int status;
entry = nanddev_bbt_pos_to_entry(nand, pos);
status = nanddev_bbt_get_block_status(nand, entry);
/* Lazy block status retrieval */
if (status == NAND_BBT_BLOCK_STATUS_UNKNOWN) {
if (nand->ops->isbad(nand, pos))
status = NAND_BBT_BLOCK_FACTORY_BAD;
else
status = NAND_BBT_BLOCK_GOOD;
nanddev_bbt_set_block_status(nand, entry, status);
}
if (status == NAND_BBT_BLOCK_WORN ||
status == NAND_BBT_BLOCK_FACTORY_BAD)
return true;
return false;
}
return nand->ops->isbad(nand, pos);
}
EXPORT_SYMBOL_GPL(nanddev_isbad);
/**
* nanddev_markbad() - Mark a block as bad
* @nand: NAND device
* @block: block to mark bad
*
* Mark a block bad. This function is updating the BBT if available and
* calls the low-level markbad hook (nand->ops->markbad()).
*
* Return: 0 in case of success, a negative error code otherwise.
*/
int nanddev_markbad(struct nand_device *nand, const struct nand_pos *pos)
{
struct mtd_info *mtd = nanddev_to_mtd(nand);
unsigned int entry;
int ret = 0;
if (nanddev_isbad(nand, pos))
return 0;
ret = nand->ops->markbad(nand, pos);
if (ret)
pr_warn("failed to write BBM to block @%llx (err = %d)\n",
nanddev_pos_to_offs(nand, pos), ret);
if (!nanddev_bbt_is_initialized(nand))
goto out;
entry = nanddev_bbt_pos_to_entry(nand, pos);
ret = nanddev_bbt_set_block_status(nand, entry, NAND_BBT_BLOCK_WORN);
if (ret)
goto out;
ret = nanddev_bbt_update(nand);
out:
if (!ret)
mtd->ecc_stats.badblocks++;
return ret;
}
EXPORT_SYMBOL_GPL(nanddev_markbad);
/**
* nanddev_isreserved() - Check whether an eraseblock is reserved or not
* @nand: NAND device
* @pos: NAND position to test
*
* Checks whether the eraseblock pointed by @pos is reserved or not.
*
* Return: true if the eraseblock is reserved, false otherwise.
*/
bool nanddev_isreserved(struct nand_device *nand, const struct nand_pos *pos)
{
unsigned int entry;
int status;
if (!nanddev_bbt_is_initialized(nand))
return false;
/* Return info from the table */
entry = nanddev_bbt_pos_to_entry(nand, pos);
status = nanddev_bbt_get_block_status(nand, entry);
return status == NAND_BBT_BLOCK_RESERVED;
}
EXPORT_SYMBOL_GPL(nanddev_isreserved);
/**
* nanddev_erase() - Erase a NAND portion
* @nand: NAND device
* @block: eraseblock to erase
*
* Erases @block if it's not bad.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
int nanddev_erase(struct nand_device *nand, const struct nand_pos *pos)
{
if (nanddev_isbad(nand, pos) || nanddev_isreserved(nand, pos)) {
pr_warn("attempt to erase a bad/reserved block @%llx\n",
nanddev_pos_to_offs(nand, pos));
return -EIO;
}
return nand->ops->erase(nand, pos);
}
EXPORT_SYMBOL_GPL(nanddev_erase);
/**
* nanddev_mtd_erase() - Generic mtd->_erase() implementation for NAND devices
* @mtd: MTD device
* @einfo: erase request
*
* This is a simple mtd->_erase() implementation iterating over all blocks
* concerned by @einfo and calling nand->ops->erase() on each of them.
*
* Note that mtd->_erase should not be directly assigned to this helper,
* because there's no locking here. NAND specialized layers should instead
* implement there own wrapper around nanddev_mtd_erase() taking the
* appropriate lock before calling nanddev_mtd_erase().
*
* Return: 0 in case of success, a negative error code otherwise.
*/
int nanddev_mtd_erase(struct mtd_info *mtd, struct erase_info *einfo)
{
struct nand_device *nand = mtd_to_nanddev(mtd);
struct nand_pos pos, last;
int ret;
nanddev_offs_to_pos(nand, einfo->addr, &pos);
nanddev_offs_to_pos(nand, einfo->addr + einfo->len - 1, &last);
while (nanddev_pos_cmp(&pos, &last) <= 0) {
ret = nanddev_erase(nand, &pos);
if (ret) {
einfo->fail_addr = nanddev_pos_to_offs(nand, &pos);
einfo->state = MTD_ERASE_FAILED;
return ret;
}
nanddev_pos_next_eraseblock(nand, &pos);
}
einfo->state = MTD_ERASE_DONE;
return 0;
}
EXPORT_SYMBOL_GPL(nanddev_mtd_erase);
/**
* nanddev_init() - Initialize a NAND device
* @nand: NAND device
* @memorg: NAND memory organization descriptor
* @ops: NAND device operations
*
* Initializes a NAND device object. Consistency checks are done on @memorg and
* @ops. Also takes care of initializing the BBT.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
int nanddev_init(struct nand_device *nand, const struct nand_ops *ops,
struct module *owner)
{
struct mtd_info *mtd = nanddev_to_mtd(nand);
struct nand_memory_organization *memorg = nanddev_get_memorg(nand);
if (!nand || !ops)
return -EINVAL;
if (!ops->erase || !ops->markbad || !ops->isbad)
return -EINVAL;
if (!memorg->bits_per_cell || !memorg->pagesize ||
!memorg->pages_per_eraseblock || !memorg->eraseblocks_per_lun ||
!memorg->planes_per_lun || !memorg->luns_per_target ||
!memorg->ntargets)
return -EINVAL;
nand->rowconv.eraseblock_addr_shift =
fls(memorg->pages_per_eraseblock - 1);
nand->rowconv.lun_addr_shift = fls(memorg->eraseblocks_per_lun - 1) +
nand->rowconv.eraseblock_addr_shift;
nand->ops = ops;
mtd->type = memorg->bits_per_cell == 1 ?
MTD_NANDFLASH : MTD_MLCNANDFLASH;
mtd->flags = MTD_CAP_NANDFLASH;
mtd->erasesize = memorg->pagesize * memorg->pages_per_eraseblock;
mtd->writesize = memorg->pagesize;
mtd->writebufsize = memorg->pagesize;
mtd->oobsize = memorg->oobsize;
mtd->size = nanddev_size(nand);
mtd->owner = owner;
return nanddev_bbt_init(nand);
}
EXPORT_SYMBOL_GPL(nanddev_init);
/**
* nanddev_cleanup() - Release resources allocated in nanddev_init()
* @nand: NAND device
*
* Basically undoes what has been done in nanddev_init().
*/
void nanddev_cleanup(struct nand_device *nand)
{
if (nanddev_bbt_is_initialized(nand))
nanddev_bbt_cleanup(nand);
}
EXPORT_SYMBOL_GPL(nanddev_cleanup);
MODULE_DESCRIPTION("Generic NAND framework");
MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
MODULE_LICENSE("GPL v2");
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