[PATCH v3 4/4] mtd: Fallback to ->_read/write_oob() when ->_read/write() is missing
Boris Brezillon
boris.brezillon at free-electrons.com
Mon Jan 8 13:11:28 PST 2018
On Fri, 15 Dec 2017 13:39:54 +0100
Boris Brezillon <boris.brezillon at free-electrons.com> wrote:
> Some MTD sublayers/drivers are implementing ->_read/write_oob() and
> provide dummy wrappers for their ->_read/write() implementations.
> Let the core handle this case instead of duplicating the logic.
Also dropped this patch since it depends on patch 3. I'll send a new
version soon.
>
> Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> Acked-by: Robert Jarzmik <robert.jarzmik at free.fr>
> Acked-by: Brian Norris <computersforpeace at gmail.com>
> ---
> Changes in v3:
> - none
>
> Changes in v2:
> - none
> ---
> drivers/mtd/devices/docg3.c | 65 --------------------------------------
> drivers/mtd/mtdcore.c | 31 ++++++++++++++++--
> drivers/mtd/nand/nand_base.c | 56 --------------------------------
> drivers/mtd/onenand/onenand_base.c | 63 ------------------------------------
> 4 files changed, 29 insertions(+), 186 deletions(-)
>
> diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
> index 0806f72102c0..5fb5e93d1547 100644
> --- a/drivers/mtd/devices/docg3.c
> +++ b/drivers/mtd/devices/docg3.c
> @@ -990,36 +990,6 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from,
> goto out;
> }
>
> -/**
> - * doc_read - Read bytes from flash
> - * @mtd: the device
> - * @from: the offset from first block and first page, in bytes, aligned on page
> - * size
> - * @len: the number of bytes to read (must be a multiple of 4)
> - * @retlen: the number of bytes actually read
> - * @buf: the filled in buffer
> - *
> - * Reads flash memory pages. This function does not read the OOB chunk, but only
> - * the page data.
> - *
> - * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred
> - */
> -static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
> - size_t *retlen, u_char *buf)
> -{
> - struct mtd_oob_ops ops;
> - size_t ret;
> -
> - memset(&ops, 0, sizeof(ops));
> - ops.datbuf = buf;
> - ops.len = len;
> - ops.mode = MTD_OPS_AUTO_OOB;
> -
> - ret = doc_read_oob(mtd, from, &ops);
> - *retlen = ops.retlen;
> - return ret;
> -}
> -
> static int doc_reload_bbt(struct docg3 *docg3)
> {
> int block = DOC_LAYOUT_BLOCK_BBT;
> @@ -1513,39 +1483,6 @@ static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
> return ret;
> }
>
> -/**
> - * doc_write - Write a buffer to the chip
> - * @mtd: the device
> - * @to: the offset from first block and first page, in bytes, aligned on page
> - * size
> - * @len: the number of bytes to write (must be a full page size, ie. 512)
> - * @retlen: the number of bytes actually written (0 or 512)
> - * @buf: the buffer to get bytes from
> - *
> - * Writes data to the chip.
> - *
> - * Returns 0 if write successful, -EIO if write error
> - */
> -static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
> - size_t *retlen, const u_char *buf)
> -{
> - struct docg3 *docg3 = mtd->priv;
> - int ret;
> - struct mtd_oob_ops ops;
> -
> - doc_dbg("doc_write(to=%lld, len=%zu)\n", to, len);
> - ops.datbuf = (char *)buf;
> - ops.len = len;
> - ops.mode = MTD_OPS_PLACE_OOB;
> - ops.oobbuf = NULL;
> - ops.ooblen = 0;
> - ops.ooboffs = 0;
> -
> - ret = doc_write_oob(mtd, to, &ops);
> - *retlen = ops.retlen;
> - return ret;
> -}
> -
> static struct docg3 *sysfs_dev2docg3(struct device *dev,
> struct device_attribute *attr)
> {
> @@ -1866,8 +1803,6 @@ static int __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
> mtd->writebufsize = mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
> mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
> mtd->_erase = doc_erase;
> - mtd->_read = doc_read;
> - mtd->_write = doc_write;
> mtd->_read_oob = doc_read_oob;
> mtd->_write_oob = doc_write_oob;
> mtd->_block_isbad = doc_block_isbad;
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 642c35dde686..d7ab091b36b2 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -1058,7 +1058,20 @@ int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
> * representing the maximum number of bitflips that were corrected on
> * any one ecc region (if applicable; zero otherwise).
> */
> - ret_code = mtd->_read(mtd, from, len, retlen, buf);
> + if (mtd->_read) {
> + ret_code = mtd->_read(mtd, from, len, retlen, buf);
> + } else if (mtd->_read_oob) {
> + struct mtd_oob_ops ops = {
> + .len = len,
> + .datbuf = buf,
> + };
> +
> + ret_code = mtd->_read_oob(mtd, from, &ops);
> + *retlen = ops.retlen;
> + } else {
> + return -ENOTSUPP;
> + }
> +
> if (unlikely(ret_code < 0))
> return ret_code;
> if (mtd->ecc_strength == 0)
> @@ -1073,11 +1086,25 @@ int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
> *retlen = 0;
> if (to < 0 || to >= mtd->size || len > mtd->size - to)
> return -EINVAL;
> - if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
> + if ((!mtd->_write && !mtd->_write_oob) ||
> + !(mtd->flags & MTD_WRITEABLE))
> return -EROFS;
> if (!len)
> return 0;
> ledtrig_mtd_activity();
> +
> + if (!mtd->_write) {
> + struct mtd_oob_ops ops = {
> + .len = len,
> + .datbuf = (u8 *)buf,
> + };
> + int ret;
> +
> + ret = mtd->_write_oob(mtd, to, &ops);
> + *retlen = ops.retlen;
> + return ret;
> + }
> +
> return mtd->_write(mtd, to, len, retlen, buf);
> }
> EXPORT_SYMBOL_GPL(mtd_write);
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index 6135d007a068..889ceadbf607 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -2027,33 +2027,6 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
> }
>
> /**
> - * nand_read - [MTD Interface] MTD compatibility function for nand_do_read_ecc
> - * @mtd: MTD device structure
> - * @from: offset to read from
> - * @len: number of bytes to read
> - * @retlen: pointer to variable to store the number of read bytes
> - * @buf: the databuffer to put data
> - *
> - * Get hold of the chip and call nand_do_read.
> - */
> -static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
> - size_t *retlen, uint8_t *buf)
> -{
> - struct mtd_oob_ops ops;
> - int ret;
> -
> - nand_get_device(mtd, FL_READING);
> - memset(&ops, 0, sizeof(ops));
> - ops.len = len;
> - ops.datbuf = buf;
> - ops.mode = MTD_OPS_PLACE_OOB;
> - ret = nand_do_read_ops(mtd, from, &ops);
> - *retlen = ops.retlen;
> - nand_release_device(mtd);
> - return ret;
> -}
> -
> -/**
> * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
> * @mtd: mtd info structure
> * @chip: nand chip info structure
> @@ -2822,33 +2795,6 @@ static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
> }
>
> /**
> - * nand_write - [MTD Interface] NAND write with ECC
> - * @mtd: MTD device structure
> - * @to: offset to write to
> - * @len: number of bytes to write
> - * @retlen: pointer to variable to store the number of written bytes
> - * @buf: the data to write
> - *
> - * NAND write with ECC.
> - */
> -static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
> - size_t *retlen, const uint8_t *buf)
> -{
> - struct mtd_oob_ops ops;
> - int ret;
> -
> - nand_get_device(mtd, FL_WRITING);
> - memset(&ops, 0, sizeof(ops));
> - ops.len = len;
> - ops.datbuf = (uint8_t *)buf;
> - ops.mode = MTD_OPS_PLACE_OOB;
> - ret = nand_do_write_ops(mtd, to, &ops);
> - *retlen = ops.retlen;
> - nand_release_device(mtd);
> - return ret;
> -}
> -
> -/**
> * nand_do_write_oob - [MTD Interface] NAND write out-of-band
> * @mtd: MTD device structure
> * @to: offset to write to
> @@ -4917,8 +4863,6 @@ int nand_scan_tail(struct mtd_info *mtd)
> mtd->_erase = nand_erase;
> mtd->_point = NULL;
> mtd->_unpoint = NULL;
> - mtd->_read = nand_read;
> - mtd->_write = nand_write;
> mtd->_panic_write = panic_nand_write;
> mtd->_read_oob = nand_read_oob;
> mtd->_write_oob = nand_write_oob;
> diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
> index 1a6d0e367b89..050ba8a87543 100644
> --- a/drivers/mtd/onenand/onenand_base.c
> +++ b/drivers/mtd/onenand/onenand_base.c
> @@ -1448,38 +1448,6 @@ static int onenand_read_oob_nolock(struct mtd_info *mtd, loff_t from,
> }
>
> /**
> - * onenand_read - [MTD Interface] Read data from flash
> - * @param mtd MTD device structure
> - * @param from offset to read from
> - * @param len number of bytes to read
> - * @param retlen pointer to variable to store the number of read bytes
> - * @param buf the databuffer to put data
> - *
> - * Read with ecc
> -*/
> -static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
> - size_t *retlen, u_char *buf)
> -{
> - struct onenand_chip *this = mtd->priv;
> - struct mtd_oob_ops ops = {
> - .len = len,
> - .ooblen = 0,
> - .datbuf = buf,
> - .oobbuf = NULL,
> - };
> - int ret;
> -
> - onenand_get_device(mtd, FL_READING);
> - ret = ONENAND_IS_4KB_PAGE(this) ?
> - onenand_mlc_read_ops_nolock(mtd, from, &ops) :
> - onenand_read_ops_nolock(mtd, from, &ops);
> - onenand_release_device(mtd);
> -
> - *retlen = ops.retlen;
> - return ret;
> -}
> -
> -/**
> * onenand_read_oob - [MTD Interface] Read main and/or out-of-band
> * @param mtd: MTD device structure
> * @param from: offset to read from
> @@ -2129,35 +2097,6 @@ static int onenand_write_oob_nolock(struct mtd_info *mtd, loff_t to,
> }
>
> /**
> - * onenand_write - [MTD Interface] write buffer to FLASH
> - * @param mtd MTD device structure
> - * @param to offset to write to
> - * @param len number of bytes to write
> - * @param retlen pointer to variable to store the number of written bytes
> - * @param buf the data to write
> - *
> - * Write with ECC
> - */
> -static int onenand_write(struct mtd_info *mtd, loff_t to, size_t len,
> - size_t *retlen, const u_char *buf)
> -{
> - struct mtd_oob_ops ops = {
> - .len = len,
> - .ooblen = 0,
> - .datbuf = (u_char *) buf,
> - .oobbuf = NULL,
> - };
> - int ret;
> -
> - onenand_get_device(mtd, FL_WRITING);
> - ret = onenand_write_ops_nolock(mtd, to, &ops);
> - onenand_release_device(mtd);
> -
> - *retlen = ops.retlen;
> - return ret;
> -}
> -
> -/**
> * onenand_write_oob - [MTD Interface] NAND write data and/or out-of-band
> * @param mtd: MTD device structure
> * @param to: offset to write
> @@ -4038,8 +3977,6 @@ int onenand_scan(struct mtd_info *mtd, int maxchips)
> mtd->_erase = onenand_erase;
> mtd->_point = NULL;
> mtd->_unpoint = NULL;
> - mtd->_read = onenand_read;
> - mtd->_write = onenand_write;
> mtd->_read_oob = onenand_read_oob;
> mtd->_write_oob = onenand_write_oob;
> mtd->_panic_write = onenand_panic_write;
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