mtd: rawnand: onfi: Avoid doing a copy of the parameter page

There is no need for copying the parameter page, playing with
pointers does the trick.

There is not functional change.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200428094302.14624-7-miquel.raynal@bootlin.com

drivers/mtd/nand/raw/nand_onfi.c

@@ -143,7 +143,7 @@ int nand_onfi_detect(struct nand_chip *chip)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	struct nand_memory_organization *memorg;
-	struct nand_onfi_params *p;
+	struct nand_onfi_params *p = NULL, *pbuf;
 	struct onfi_params *onfi;
 	int onfi_version = 0;
 	char id[4];
@@ -158,8 +158,8 @@ int nand_onfi_detect(struct nand_chip *chip)
 		return 0;
 
 	/* ONFI chip: allocate a buffer to hold its parameter page */
-	p = kzalloc((sizeof(*p) * ONFI_PARAM_PAGES), GFP_KERNEL);
-	if (!p)
+	pbuf = kzalloc((sizeof(*pbuf) * ONFI_PARAM_PAGES), GFP_KERNEL);
+	if (!pbuf)
 		return -ENOMEM;
 
 	ret = nand_read_param_page_op(chip, 0, NULL, 0);
@@ -169,16 +169,15 @@ int nand_onfi_detect(struct nand_chip *chip)
 	}
 
 	for (i = 0; i < ONFI_PARAM_PAGES; i++) {
-		ret = nand_read_data_op(chip, &p[i], sizeof(*p), true);
+		ret = nand_read_data_op(chip, &pbuf[i], sizeof(*pbuf), true);
 		if (ret) {
 			ret = 0;
 			goto free_onfi_param_page;
 		}
 
-		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)&p[i], 254);
-		if (crc == le16_to_cpu(p[i].crc)) {
-			if (i)
-				memcpy(p, &p[i], sizeof(*p));
+		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)&pbuf[i], 254);
+		if (crc == le16_to_cpu(pbuf[i].crc)) {
+			p = &pbuf[i];
 			break;
 		}
 	}
@@ -188,17 +187,18 @@ int nand_onfi_detect(struct nand_chip *chip)
 		unsigned int j;
 
 		for (j = 0; j < ONFI_PARAM_PAGES; j++)
-			srcbufs[j] = p + j;
+			srcbufs[j] = pbuf + j;
 
 		pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
-		nand_bit_wise_majority(srcbufs, ONFI_PARAM_PAGES, p,
-				       sizeof(*p));
+		nand_bit_wise_majority(srcbufs, ONFI_PARAM_PAGES, pbuf,
+				       sizeof(*pbuf));
 
-		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)p, 254);
-		if (crc != le16_to_cpu(p->crc)) {
+		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)pbuf, 254);
+		if (crc != le16_to_cpu(pbuf->crc)) {
 			pr_err("ONFI parameter recovery failed, aborting\n");
 			goto free_onfi_param_page;
 		}
+		p = pbuf;
 	}
 
 	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
@@ -306,14 +306,14 @@ int nand_onfi_detect(struct nand_chip *chip)
 	chip->parameters.onfi = onfi;
 
 	/* Identification done, free the full ONFI parameter page and exit */
-	kfree(p);
+	kfree(pbuf);
 
 	return 1;
 
 free_model:
 	kfree(chip->parameters.model);
 free_onfi_param_page:
-	kfree(p);
+	kfree(pbuf);
 
 	return ret;
 }