From 9c3736a3de21d916a6af0594418b85a112f4bef6 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Mon, 5 Feb 2018 23:02:05 +0100 Subject: 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: Boris Brezillon --- drivers/mtd/nand/Kconfig | 3 + drivers/mtd/nand/Makefile | 3 + drivers/mtd/nand/bbt.c | 130 ++++++++++++++++++++++++ drivers/mtd/nand/core.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 380 insertions(+) create mode 100644 drivers/mtd/nand/bbt.c create mode 100644 drivers/mtd/nand/core.c (limited to 'drivers/mtd') diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig index 6d53734..1c1a1f4 100644 --- a/drivers/mtd/nand/Kconfig +++ b/drivers/mtd/nand/Kconfig @@ -1 +1,4 @@ +config MTD_NAND_CORE + tristate + source "drivers/mtd/nand/raw/Kconfig" diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile index 32af716..a72d3cb 100644 --- a/drivers/mtd/nand/Makefile +++ b/drivers/mtd/nand/Makefile @@ -1,3 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +nandcore-objs := core.o bbt.o +obj-$(CONFIG_MTD_NAND_CORE) += nandcore.o + obj-y += raw/ diff --git a/drivers/mtd/nand/bbt.c b/drivers/mtd/nand/bbt.c new file mode 100644 index 0000000..56cde38 --- /dev/null +++ b/drivers/mtd/nand/bbt.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2017 Free Electrons + * + * Authors: + * Boris Brezillon + * Peter Pan + */ + +#define pr_fmt(fmt) "nand-bbt: " fmt + +#include +#include + +/** + * 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); diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c new file mode 100644 index 0000000..f237a68 --- /dev/null +++ b/drivers/mtd/nand/core.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2017 Free Electrons + * + * Authors: + * Boris Brezillon + * Peter Pan + */ + +#define pr_fmt(fmt) "nand: " fmt + +#include +#include + +/** + * 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 "); +MODULE_LICENSE("GPL v2"); -- cgit v1.1