mtd: nand: ecc-bch: Stop exporting the private structure

The NAND BCH control structure has nothing to do outside of this
driver, all users of the nand_bch_init/free() functions just save it
to chip->ecc.priv so do it in this driver directly and return a
regular error code instead.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200929230124.31491-5-miquel.raynal@bootlin.com

drivers/mtd/nand/ecc-sw-bch.c

@@ -90,7 +90,7 @@ EXPORT_SYMBOL(nand_bch_correct_data);
 
 /**
  * nand_bch_init - Initialize software BCH ECC engine
- * @mtd: MTD device
+ * @chip: NAND chip object
  *
  * Returns: a pointer to a new NAND BCH control structure, or NULL upon failure
  *
@@ -105,24 +105,24 @@ 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)
+int nand_bch_init(struct nand_chip *chip)
 {
-	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct mtd_info *mtd = nand_to_mtd(chip);
 	unsigned int m, t, eccsteps, i;
 	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;
+	unsigned int eccsize = chip->ecc.size;
+	unsigned int eccbytes = chip->ecc.bytes;
+	unsigned int eccstrength = chip->ecc.strength;
 
 	if (!eccbytes && eccstrength) {
 		eccbytes = DIV_ROUND_UP(eccstrength * fls(8 * eccsize), 8);
-		nand->ecc.bytes = eccbytes;
+		chip->ecc.bytes = eccbytes;
 	}
 
 	if (!eccsize || !eccbytes) {
 		pr_warn("ecc parameters not supplied\n");
-		goto fail;
+		return -EINVAL;
 	}
 
 	m = fls(1+8*eccsize);
@@ -130,7 +130,9 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 
 	nbc = kzalloc(sizeof(*nbc), GFP_KERNEL);
 	if (!nbc)
-		goto fail;
+		return -ENOMEM;
+
+	chip->ecc.priv = nbc;
 
 	nbc->bch = bch_init(m, t, 0, false);
 	if (!nbc->bch)
@@ -165,9 +167,9 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 	 * FIXME: we should probably rework the sequencing in nand_scan_tail()
 	 * to avoid setting those fields twice.
 	 */
-	nand->ecc.steps = eccsteps;
-	nand->ecc.total = eccsteps * eccbytes;
-	nand->base.ecc.ctx.total = nand->ecc.total;
+	chip->ecc.steps = eccsteps;
+	chip->ecc.total = eccsteps * eccbytes;
+	nand->base.ecc.ctx.total = chip->ecc.total;
 	if (mtd_ooblayout_count_eccbytes(mtd) != (eccsteps*eccbytes)) {
 		pr_warn("invalid ecc layout\n");
 		goto fail;
@@ -193,12 +195,12 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 		nbc->eccmask[i] ^= 0xff;
 
 	if (!eccstrength)
-		nand->ecc.strength = (eccbytes * 8) / fls(8 * eccsize);
+		chip->ecc.strength = (eccbytes * 8) / fls(8 * eccsize);
 
-	return nbc;
+	return 0;
 fail:
-	nand_bch_free(nbc);
-	return NULL;
+	nand_bch_free(chip);
+	return -EINVAL;
 }
 EXPORT_SYMBOL(nand_bch_init);
 
@@ -206,8 +208,10 @@ EXPORT_SYMBOL(nand_bch_init);
  * nand_bch_free - Release NAND BCH ECC resources
  * @nbc: NAND BCH control structure
  */
-void nand_bch_free(struct nand_bch_control *nbc)
+void nand_bch_free(struct nand_chip *chip)
 {
+	struct nand_bch_control *nbc = chip->ecc.priv;
+
 	if (nbc) {
 		bch_free(nbc->bch);
 		kfree(nbc->errloc);

drivers/mtd/nand/raw/fsmc_nand.c

@@ -942,7 +942,7 @@ static int fsmc_nand_attach_chip(struct nand_chip *nand)
 
 	/*
 	 * Don't set layout for BCH4 SW ECC. This will be
-	 * generated later in nand_bch_init() later.
+	 * generated later during BCH initialization.
 	 */
 	if (nand->ecc.engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST) {
 		switch (mtd->oobsize) {

drivers/mtd/nand/raw/nand_base.c

@@ -5203,6 +5203,7 @@ static int nand_set_ecc_soft_ops(struct nand_chip *chip)
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	struct nand_device *nanddev = mtd_to_nanddev(mtd);
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	int ret;
 
 	if (WARN_ON(ecc->engine_type != NAND_ECC_ENGINE_TYPE_SOFT))
 		return -EINVAL;
@@ -5289,13 +5290,14 @@ static int nand_set_ecc_soft_ops(struct nand_chip *chip)
 			ecc->strength = bytes * 8 / fls(8 * ecc->size);
 		}
 
-		/* See nand_bch_init() for details. */
+		/* See the software BCH ECC initialization for details */
 		ecc->bytes = 0;
-		ecc->priv = nand_bch_init(mtd);
-		if (!ecc->priv) {
+		ret = nand_bch_init(chip);
+		if (ret) {
 			WARN(1, "BCH ECC initialization failed!\n");
-			return -EINVAL;
+			return ret;
 		}
+
 		return 0;
 	default:
 		WARN(1, "Unsupported ECC algorithm!\n");
@@ -5955,7 +5957,7 @@ void nand_cleanup(struct nand_chip *chip)
 {
 	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT &&
 	    chip->ecc.algo == NAND_ECC_ALGO_BCH)
-		nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
+		nand_bch_free(chip);
 
 	nanddev_cleanup(&chip->base);
 

drivers/mtd/nand/raw/omap2.c

@@ -2047,10 +2047,10 @@ static int omap_nand_attach_chip(struct nand_chip *chip)
 		/* Reserve one byte for the OMAP marker */
 		oobbytes_per_step	= chip->ecc.bytes + 1;
 		/* Software BCH library is used for locating errors */
-		chip->ecc.priv		= nand_bch_init(mtd);
-		if (!chip->ecc.priv) {
+		err = nand_bch_init(chip);
+		if (err) {
 			dev_err(dev, "Unable to use BCH library\n");
-			return -EINVAL;
+			return err;
 		}
 		break;
 
@@ -2089,10 +2089,10 @@ static int omap_nand_attach_chip(struct nand_chip *chip)
 		/* Reserve one byte for the OMAP marker */
 		oobbytes_per_step	= chip->ecc.bytes + 1;
 		/* Software BCH library is used for locating errors */
-		chip->ecc.priv		= nand_bch_init(mtd);
-		if (!chip->ecc.priv) {
+		err = nand_bch_init(chip);
+		if (err) {
 			dev_err(dev, "unable to use BCH library\n");
-			return -EINVAL;
+			return err;
 		}
 		break;
 
@@ -2272,7 +2272,7 @@ static int omap_nand_probe(struct platform_device *pdev)
 	if (!IS_ERR_OR_NULL(info->dma))
 		dma_release_channel(info->dma);
 	if (nand_chip->ecc.priv) {
-		nand_bch_free(nand_chip->ecc.priv);
+		nand_bch_free(nand_chip);
 		nand_chip->ecc.priv = NULL;
 	}
 	return err;
@@ -2286,7 +2286,7 @@ static int omap_nand_remove(struct platform_device *pdev)
 	int ret;
 
 	if (nand_chip->ecc.priv) {
-		nand_bch_free(nand_chip->ecc.priv);
+		nand_bch_free(nand_chip);
 		nand_chip->ecc.priv = NULL;
 	}
 	if (info->dma)

include/linux/mtd/nand-ecc-sw-bch.h

@@ -10,7 +10,6 @@
 
 struct mtd_info;
 struct nand_chip;
-struct nand_bch_control;
 
 #if IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_BCH)
 
@@ -30,11 +29,11 @@ int nand_bch_correct_data(struct nand_chip *chip, u_char *dat,
 /*
  * Initialize BCH encoder/decoder
  */
-struct nand_bch_control *nand_bch_init(struct mtd_info *mtd);
+int nand_bch_init(struct nand_chip *chip);
 /*
  * Release BCH encoder/decoder resources
  */
-void nand_bch_free(struct nand_bch_control *nbc);
+void nand_bch_free(struct nand_chip *chip);
 
 #else /* !CONFIG_MTD_NAND_ECC_SW_BCH */
 
@@ -54,12 +53,12 @@ nand_bch_correct_data(struct nand_chip *chip, unsigned char *buf,
 	return -ENOTSUPP;
 }
 
-static inline struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
+static inline int nand_bch_init(struct nand_chip *chip)
 {
-	return NULL;
+	return -ENOTSUPP;
 }
 
-static inline void nand_bch_free(struct nand_bch_control *nbc) {}
+static inline void nand_bch_free(struct nand_chip *chip) {}
 
 #endif /* CONFIG_MTD_NAND_ECC_SW_BCH */