[PATCH v2 04/51] mtd: nand: simplify nand_bch_init() usage

Boris Brezillon
2016-02-04T10:29:32Z

nand_bch_init() requires several arguments which could directly be deduced
from the mtd device. Get rid of those useless parameters.

nand_bch_init() is also requiring the caller to provide a proper eccbytes
value, while this value could be deduced from the ecc.size and
ecc.strength value. Fallback to eccbytes calculation when it is set to 0.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/mtd/nand/nand_base.c | 6 ++----
drivers/mtd/nand/nand_bch.c | 27 +++++++++++++++++----------
drivers/mtd/nand/omap2.c | 28 ++++++++++++----------------
include/linux/mtd/nand_bch.h | 8 ++------
4 files changed, 33 insertions(+), 36 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 7f21719..572369d 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4279,10 +4279,8 @@ int nand_scan_tail(struct mtd_info *mtd)
}

/* See nand_bch_init() for details. */
- ecc->bytes = DIV_ROUND_UP(
- ecc->strength * fls(8 * ecc->size), 8);
- ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes,
- &ecc->layout);
+ ecc->bytes = 0;
+ ecc->priv = nand_bch_init(mtd);
if (!ecc->priv) {
pr_warn("BCH ECC initialization failed!\n");
BUG();
diff --git a/drivers/mtd/nand/nand_bch.c b/drivers/mtd/nand/nand_bch.c
index a87c1b6..b585bae 100644
--- a/drivers/mtd/nand/nand_bch.c
+++ b/drivers/mtd/nand/nand_bch.c
@@ -107,9 +107,6 @@ EXPORT_SYMBOL(nand_bch_correct_data);
/**
* nand_bch_init - [NAND Interface] Initialize NAND BCH error correction
* @mtd: MTD block structure
- * @eccsize: ecc block size in bytes
- * @eccbytes: ecc length in bytes
- * @ecclayout: output default layout
*
* Returns:
* a pointer to a new NAND BCH control structure, or NULL upon failure
@@ -123,14 +120,21 @@ EXPORT_SYMBOL(nand_bch_correct_data);
* @eccsize = 512 (thus, m=13 is the smallest integer such that 2^m-1 > 512*8)
* @eccbytes = 7 (7 bytes are required to store m*t = 13*4 = 52 bits)
*/
-struct nand_bch_control *
-nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
- struct nand_ecclayout **ecclayout)
+struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
{
+ struct nand_chip *nand = mtd_to_nand(mtd);
unsigned int m, t, eccsteps, i;
- struct nand_ecclayout *layout;
+ struct nand_ecclayout *layout = nand->ecc.layout;
struct nand_bch_control *nbc = NULL;
unsigned char *erased_page;
+ unsigned int eccsize = nand->ecc.size;
+ unsigned int eccbytes = nand->ecc.bytes;
+ unsigned int eccstrength = nand->ecc.strength;
+
+ if (!eccbytes && eccstrength) {
+ eccbytes = DIV_ROUND_UP(eccstrength * fls(8 * eccsize), 8);
+ nand->ecc.bytes = eccbytes;
+ }

if (!eccsize || !eccbytes) {
printk(KERN_WARNING "ecc parameters not supplied\n");
@@ -158,7 +162,7 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
eccsteps = mtd->writesize/eccsize;

/* if no ecc placement scheme was provided, build one */
- if (!*ecclayout) {
+ if (!layout) {

/* handle large page devices only */
if (mtd->oobsize < 64) {
@@ -184,7 +188,7 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
layout->oobfree[0].offset = 2;
layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes;

- *ecclayout = layout;
+ nand->ecc.layout = layout;
}

/* sanity checks */
@@ -192,7 +196,7 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
printk(KERN_WARNING "eccsize %u is too large\n", eccsize);
goto fail;
}
- if ((*ecclayout)->eccbytes != (eccsteps*eccbytes)) {
+ if (layout->eccbytes != (eccsteps*eccbytes)) {
printk(KERN_WARNING "invalid ecc layout\n");
goto fail;
}
@@ -216,6 +220,9 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
for (i = 0; i < eccbytes; i++)
nbc->eccmask[i] ^= 0xff;

+ if (!eccstrength)
+ nand->ecc.strength = (eccbytes * 8) / fls(8 * eccsize);
+
return nbc;
fail:
nand_bch_free(nbc);
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index c553f78..0749ca1 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1807,13 +1807,19 @@ static int omap_nand_probe(struct platform_device *pdev)
goto return_error;
}

+ /*
+ * Bail out earlier to let NAND_ECC_SOFT code create its own
+ * ecclayout instead of using ours.
+ */
+ if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW) {
+ nand_chip->ecc.mode = NAND_ECC_SOFT;
+ goto scan_tail;
+ }
+
/* populate MTD interface based on ECC scheme */
ecclayout = &info->oobinfo;
+ nand_chip->ecc.layout = ecclayout;
switch (info->ecc_opt) {
- case OMAP_ECC_HAM1_CODE_SW:
- nand_chip->ecc.mode = NAND_ECC_SOFT;
- break;
-
case OMAP_ECC_HAM1_CODE_HW:
pr_info("nand: using OMAP_ECC_HAM1_CODE_HW\n");
nand_chip->ecc.mode = NAND_ECC_HW;
@@ -1861,10 +1867,7 @@ static int omap_nand_probe(struct platform_device *pdev)
ecclayout->oobfree->offset = 1 +
ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
/* software bch library is used for locating errors */
- nand_chip->ecc.priv = nand_bch_init(mtd,
- nand_chip->ecc.size,
- nand_chip->ecc.bytes,
- &ecclayout);
+ nand_chip->ecc.priv = nand_bch_init(mtd);
if (!nand_chip->ecc.priv) {
dev_err(&info->pdev->dev, "unable to use BCH library\n");
err = -EINVAL;
@@ -1925,10 +1928,7 @@ static int omap_nand_probe(struct platform_device *pdev)
ecclayout->oobfree->offset = 1 +
ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
/* software bch library is used for locating errors */
- nand_chip->ecc.priv = nand_bch_init(mtd,
- nand_chip->ecc.size,
- nand_chip->ecc.bytes,
- &ecclayout);
+ nand_chip->ecc.priv = nand_bch_init(mtd);
if (!nand_chip->ecc.priv) {
dev_err(&info->pdev->dev, "unable to use BCH library\n");
err = -EINVAL;
@@ -2002,9 +2002,6 @@ static int omap_nand_probe(struct platform_device *pdev)
goto return_error;
}

- if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW)
- goto scan_tail;
-
/* all OOB bytes from oobfree->offset till end off OOB are free */
ecclayout->oobfree->length = mtd->oobsize - ecclayout->oobfree->offset;
/* check if NAND device's OOB is enough to store ECC signatures */
@@ -2015,7 +2012,6 @@ static int omap_nand_probe(struct platform_device *pdev)
err = -EINVAL;
goto return_error;
}
- nand_chip->ecc.layout = ecclayout;

scan_tail:
/* second phase scan */
diff --git a/include/linux/mtd/nand_bch.h b/include/linux/mtd/nand_bch.h
index fb0bc34..98f20ef 100644
--- a/include/linux/mtd/nand_bch.h
+++ b/include/linux/mtd/nand_bch.h
@@ -32,9 +32,7 @@ int nand_bch_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc,
/*
* Initialize BCH encoder/decoder
*/
-struct nand_bch_control *
-nand_bch_init(struct mtd_info *mtd, unsigned int eccsize,
- unsigned int eccbytes, struct nand_ecclayout **ecclayout);
+struct nand_bch_control *nand_bch_init(struct mtd_info *mtd);
/*
* Release BCH encoder/decoder resources
*/
@@ -58,9 +56,7 @@ nand_bch_correct_data(struct mtd_info *mtd, unsigned char *buf,
return -ENOTSUPP;
}

-static inline struct nand_bch_control *
-nand_bch_init(struct mtd_info *mtd, unsigned int eccsize,
- unsigned int eccbytes, struct nand_ecclayout **ecclayout)
+static inline struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
{
return NULL;
}
--
2.1.4