Let's continue introducing the generic ECC engine abstraction in the
NAND subsystem by instantiating a second ECC engine: software
Hamming.
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
drivers/mtd/nand/ecc-sw-hamming.c | 208 ++++++++++++++++++++++++
drivers/mtd/nand/raw/nand_base.c | 25 +--
include/linux/mtd/nand-ecc-sw-hamming.h | 15 ++
3 files changed, 231 insertions(+), 17 deletions(-)
diff --git a/drivers/mtd/nand/ecc-sw-hamming.c b/drivers/mtd/nand/ecc-sw-hamming.c
index 8494e68814bc..a524747458a8 100644
--- a/drivers/mtd/nand/ecc-sw-hamming.c
+++ b/drivers/mtd/nand/ecc-sw-hamming.c
@@ -17,6 +17,7 @@
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mtd/nand.h>
#include <linux/mtd/nand-ecc-sw-hamming.h>
#include <asm/byteorder.h>
@@ -464,6 +465,213 @@ int nand_ecc_sw_hamming_correct(struct nand_device *nand, unsigned char *buf,
}
EXPORT_SYMBOL(nand_ecc_sw_hamming_correct);
+int nand_ecc_sw_hamming_init_ctx(struct nand_device *nand)
+{
+ struct nand_ecc_props *conf = &nand->ecc.ctx.conf;
+ struct nand_ecc_sw_hamming_conf *engine_conf;
+ struct mtd_info *mtd = nanddev_to_mtd(nand);
+
+ if (!mtd->ooblayout) {
+ switch (mtd->oobsize) {
+ case 8:
+ case 16:
+ mtd_set_ooblayout(mtd, &nand_ooblayout_sp_ops);
+ break;
+ case 64:
+ case 128:
+ mtd_set_ooblayout(mtd, &nand_ooblayout_lp_hamming_ops);
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+ }
+
+ conf->provider = NAND_SOFT_ECC_ENGINE;
+ conf->algo = NAND_ECC_HAMMING;
+ conf->step_size = nand->ecc.user_conf.step_size;
+ conf->strength = 1;
+
+ /* Use the strongest configuration by default */
+ if (conf->step_size != 256 && conf->step_size != 512)
+ conf->step_size = 256;
+
+ engine_conf = kzalloc(sizeof(*engine_conf), GFP_KERNEL);
+ if (!engine_conf)
+ return -ENOMEM;
+
+ engine_conf->code_size = 3;
+ engine_conf->nsteps = mtd->writesize / conf->step_size;
+ engine_conf->calc_buf = kzalloc(sizeof(mtd->oobsize), GFP_KERNEL);
+ engine_conf->code_buf = kzalloc(sizeof(mtd->oobsize), GFP_KERNEL);
+ if (!engine_conf->calc_buf || !engine_conf->code_buf) {
+ kfree(engine_conf);
+ return -ENOMEM;
+ }
+
+ nand->ecc.ctx.priv = engine_conf;
+ nand->ecc.ctx.total = engine_conf->nsteps * engine_conf->code_size;
+
+ return 0;
+}
+EXPORT_SYMBOL(nand_ecc_sw_hamming_init_ctx);
+
+void nand_ecc_sw_hamming_cleanup_ctx(struct nand_device *nand)
+{
+ struct nand_ecc_sw_hamming_conf *engine_conf = nand->ecc.ctx.priv;
+
+ if (engine_conf) {
+ kfree(engine_conf->calc_buf);
+ kfree(engine_conf->code_buf);
+ }
+
+ kfree(engine_conf);
+}
+EXPORT_SYMBOL(nand_ecc_sw_hamming_cleanup_ctx);
+
+static int nand_ecc_sw_hamming_prepare_io_req(struct nand_device *nand,
+ struct nand_page_io_req *req,
+ void *oobbuf)
+{
+ struct nand_ecc_sw_hamming_conf *engine_conf = nand->ecc.ctx.priv;
+ struct mtd_info *mtd = nanddev_to_mtd(nand);
+ int eccsize = nand->ecc.ctx.conf.step_size;
+ int eccbytes = engine_conf->code_size;
+ int eccsteps = engine_conf->nsteps;
+ int total = nand->ecc.ctx.total;
+ u8 *ecccalc = engine_conf->calc_buf;
+ const u8 *data = req->databuf.out;
+ int i, ret;
+
+ /* Ensure the OOB buffer is empty before using it */
+ if (req->oobbuf.in)
+ memset(req->oobbuf.in, 0xff, nanddev_per_page_oobsize(nand));
+
+ if (req->mode == MTD_OPS_RAW)
+ return 0;
+
+ /* This engine does not provide BBM/free OOB bytes protection */
+ if (!req->datalen)
+ return 0;
+
+ /*
+ * Ensure OOB area is fully read/written otherwise the software
+ * correction cannot apply.
+ */
+ engine_conf->reqooblen = req->ooblen;
+ req->ooblen = nanddev_per_page_oobsize(nand);
+
+ /* No preparation for page read */
+ if (req->type == NAND_PAGE_READ)
+ return 0;
+
+ /* Preparation for page write: derive the ECC bytes and place them */
+ for (i = 0; eccsteps; eccsteps--, i += eccbytes, data += eccsize)
+ nand_ecc_sw_hamming_calculate(nand, data, &ecccalc[i]);
+
+ ret = mtd_ooblayout_set_eccbytes(mtd, ecccalc, oobbuf, 0, total);
+
+ /* Also place user data OOB bytes in the free area, if any */
+ if (engine_conf->reqooblen) {
+ if (req->mode == MTD_OPS_AUTO_OOB)
+ mtd_ooblayout_set_databytes(mtd, req->oobbuf.out,
+ oobbuf,
+ req->ooboffs,
+ req->ooblen);
+ else
+ memcpy(oobbuf + req->ooboffs, req->oobbuf.out,
+ req->ooblen);
+ }
+
+ return ret;
+}
+
+static int nand_ecc_sw_hamming_finish_io_req(struct nand_device *nand,
+ struct nand_page_io_req *req,
+ void *oobbuf)
+{
+ struct nand_ecc_sw_hamming_conf *engine_conf = nand->ecc.ctx.priv;
+ struct mtd_info *mtd = nanddev_to_mtd(nand);
+ int eccsize = nand->ecc.ctx.conf.step_size;
+ int total = nand->ecc.ctx.total;
+ int eccbytes = engine_conf->code_size;
+ int eccsteps = engine_conf->nsteps;
+ u8 *ecccalc = engine_conf->calc_buf;
+ u8 *ecccode = engine_conf->code_buf;
+ unsigned int max_bitflips = 0;
+ u8 *data = req->databuf.in;
+ int i, ret;
+
+ if (req->mode == MTD_OPS_RAW)
+ return 0;
+
+ /* This engine does not provide BBM/free OOB bytes protection */
+ if (!req->datalen)
+ return 0;
+
+ /* Don't mess up with the upper layer: restore the request OOB length */
+ req->ooblen = engine_conf->reqooblen;
+
+ /* Nothing more to do for page write */
+ if (req->type == NAND_PAGE_WRITE)
+ return 0;
+
+ /* Finish a page read: retrieve the (raw) ECC bytes*/
+ ret = mtd_ooblayout_get_eccbytes(mtd, ecccode, oobbuf, 0, total);
+ if (ret)
+ return ret;
+
+ /* Calculate the ECC bytes */
+ for (i = 0; eccsteps; eccsteps--, i += eccbytes, data += eccsize)
+ nand_ecc_sw_hamming_calculate(nand, data, &ecccalc[i]);
+
+ eccsteps = engine_conf->nsteps;
+
+ /* Finish a page read: compare and correct */
+ for (eccsteps = engine_conf->nsteps, i = 0, data = req->databuf.in;
+ eccsteps;
+ eccsteps--, i += eccbytes, data += eccsize) {
+ int stat = nand_ecc_sw_hamming_correct(nand, data,
+ &ecccode[i],
+ &ecccalc[i]);
+ if (stat < 0) {
+ mtd->ecc_stats.failed++;
+ } else {
+ mtd->ecc_stats.corrected += stat;
+ max_bitflips = max_t(unsigned int, max_bitflips, stat);
+ }
+ }
+
+ /* Format the OOB buffer that will be returned to the user */
+ if (req->ooblen) {
+ if (req->mode == MTD_OPS_AUTO_OOB)
+ mtd_ooblayout_get_databytes(mtd, oobbuf,
+ req->oobbuf.in,
+ req->ooboffs, req->ooblen);
+ else
+ memcpy(req->oobbuf.in, oobbuf + req->ooboffs,
+ req->ooblen);
+ }
+
+ return max_bitflips;
+}
+
+static struct nand_ecc_engine_ops nand_ecc_sw_hamming_engine_ops = {
+ .init_ctx = nand_ecc_sw_hamming_init_ctx,
+ .cleanup_ctx = nand_ecc_sw_hamming_cleanup_ctx,
+ .prepare_io_req = nand_ecc_sw_hamming_prepare_io_req,
+ .finish_io_req = nand_ecc_sw_hamming_finish_io_req,
+};
+
+static struct nand_ecc_engine nand_ecc_sw_hamming_engine = {
+ .ops = &nand_ecc_sw_hamming_engine_ops,
+};
+
+struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void)
+{
+ return &nand_ecc_sw_hamming_engine;
+}
+EXPORT_SYMBOL(nand_ecc_sw_hamming_get_engine);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Frans Meulenbroeks <fransmeulenbroeks@xxxxxxxxx>");
MODULE_DESCRIPTION("NAND software Hamming ECC support");
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 22416334357a..a0f23051cc21 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -4834,34 +4834,24 @@ static void nand_scan_ident_cleanup(struct nand_chip *chip)
int rawnand_sw_hamming_init(struct nand_chip *chip)
{
- struct mtd_info *mtd = nand_to_mtd(chip);
struct nand_ecc_sw_hamming_conf *engine_conf;
struct nand_device *base = &chip->base;
+ int ret;
base->ecc.user_conf.provider = NAND_SOFT_ECC_ENGINE;
base->ecc.user_conf.algo = NAND_ECC_HAMMING;
base->ecc.user_conf.strength = chip->ecc.strength;
base->ecc.user_conf.step_size = chip->ecc.size;
- if (base->ecc.user_conf.strength != 1 ||
- (base->ecc.user_conf.step_size != 256 &&
- base->ecc.user_conf.step_size != 512)) {
- pr_err("%s: unsupported strength or step size\n", __func__);
- return -EINVAL;
- }
+ ret = nand_ecc_sw_hamming_init_ctx(base);
+ if (ret)
+ return ret;
- engine_conf = kzalloc(sizeof(*engine_conf), GFP_KERNEL);
- if (!engine_conf)
- return -ENOMEM;
-
- engine_conf->code_size = 3;
- engine_conf->nsteps = mtd->writesize / base->ecc.user_conf.step_size;
+ engine_conf = base->ecc.ctx.priv;
if (chip->ecc.options & NAND_ECC_SOFT_HAMMING_SM_ORDER)
engine_conf->sm_order = true;
- base->ecc.ctx.priv = engine_conf;
-
chip->ecc.size = base->ecc.ctx.conf.step_size;
chip->ecc.strength = base->ecc.ctx.conf.strength;
chip->ecc.total = base->ecc.ctx.total;
@@ -4897,7 +4887,7 @@ void rawnand_sw_hamming_cleanup(struct nand_chip *chip)
{
struct nand_device *base = &chip->base;
- kfree(base->ecc.ctx.priv);
+ nand_ecc_sw_hamming_cleanup_ctx(base);
}
EXPORT_SYMBOL(rawnand_sw_hamming_cleanup);
@@ -5361,7 +5351,8 @@ static int nand_scan_tail(struct nand_chip *chip)
* If no default placement scheme is given, select an appropriate one.
*/
if (!mtd->ooblayout &&
- !(ecc->mode == NAND_SOFT_ECC_ENGINE && ecc->algo == NAND_ECC_BCH)) {
+ !(ecc->mode == NAND_SOFT_ECC_ENGINE && ecc->algo == NAND_ECC_BCH) &&
+ !(ecc->mode == NAND_SOFT_ECC_ENGINE && ecc->algo == NAND_ECC_HAMMING)) {
switch (mtd->oobsize) {
case 8:
case 16:
diff --git a/include/linux/mtd/nand-ecc-sw-hamming.h b/include/linux/mtd/nand-ecc-sw-hamming.h
index 9de80d324cfa..3ae51bd2e2ab 100644
--- a/include/linux/mtd/nand-ecc-sw-hamming.h
+++ b/include/linux/mtd/nand-ecc-sw-hamming.h
@@ -32,6 +32,8 @@ struct nand_ecc_sw_hamming_conf {
#if IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING)
+int nand_ecc_sw_hamming_init_ctx(struct nand_device *nand);
+void nand_ecc_sw_hamming_cleanup_ctx(struct nand_device *nand);
int ecc_sw_hamming_calculate(const unsigned char *buf, unsigned int step_size,
unsigned char *code, bool sm_order);
int nand_ecc_sw_hamming_calculate(struct nand_device *nand,
@@ -43,9 +45,17 @@ int ecc_sw_hamming_correct(unsigned char *buf, unsigned char *read_ecc,
int nand_ecc_sw_hamming_correct(struct nand_device *nand, unsigned char *buf,
unsigned char *read_ecc,
unsigned char *calc_ecc);
+struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void);
#else /* !CONFIG_MTD_NAND_ECC_SW_HAMMING */
+static inline int nand_ecc_sw_hamming_init_ctx(struct nand_device *nand)
+{
+ return -ENOTSUPP;
+}
+
+static inline void nand_ecc_sw_hamming_cleanup_ctx(struct nand_device *nand) {}
+
static inline int ecc_sw_hamming_calculate(const unsigned char *buf,
unsigned int step_size,
unsigned char *code, bool sm_order)
@@ -76,6 +86,11 @@ static inline int nand_ecc_sw_hamming_correct(struct nand_device *nand,
return -ENOTSUPP;
}
+static inline struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void)
+{
+ return NULL;
+}
+
#endif /* CONFIG_MTD_NAND_ECC_SW_HAMMING */
#endif /* __MTD_NAND_ECC_SW_HAMMING_H__ */
--
2.20.1
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[PATCH v3 27/40] mtd: nand: ecc: Create the software Hamming engine instance
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- Subject: [PATCH v3 27/40] mtd: nand: ecc: Create the software Hamming engine instance
- From: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
- Date: Thu, 19 Sep 2019 21:31:27 +0200
- Cc: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>, Julien Su <juliensu@xxxxxxxxxxx>, Schrempf Frieder <frieder.schrempf@xxxxxxxxxx>, Paul Cercueil <paul@xxxxxxxxxxxxxxx>, Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>, linux-mtd@xxxxxxxxxxxxxxxxxxx, Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx>, Miquel Raynal <miquel.raynal@xxxxxxxxxxx>, Mason Yang <masonccyang@xxxxxxxxxxx>, linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
- In-reply-to: <20190919193141.7865-1-miquel.raynal@bootlin.com>
- References: <20190919193141.7865-1-miquel.raynal@bootlin.com>
- References:
- [PATCH v3 00/40] Introduce the generic ECC engine abstraction
- From: Miquel Raynal
- [PATCH v3 00/40] Introduce the generic ECC engine abstraction
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