mtd: rawnand: get rid of the ONFI parameter page in nand_chip

The NAND chip parameter page is statically allocated within the
nand_chip structure, which reserves a lot of space. Even not ONFI nor
JEDEC chips have it embedded. Also, only a few parameters are actually
read from the parameter page after the detection.

Now that there is a small nand_parameters structure that hold all needed
ONFI parameters, remove the ONFI page from the nand_chip structure by
just allocating it during the identification phase and removing it right
after.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

drivers/mtd/nand/raw/nand_base.c

@@ -5101,7 +5101,7 @@ static int nand_flash_detect_ext_param_page(struct nand_chip *chip,
 static int nand_flash_detect_onfi(struct nand_chip *chip)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
-	struct nand_onfi_params *p = &chip->onfi_params;
+	struct nand_onfi_params *p;
 	char id[4];
 	int i, ret, val;
 
@@ -5110,14 +5110,23 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
 	if (ret || strncmp(id, "ONFI", 4))
 		return 0;
 
+	/* ONFI chip: allocate a buffer to hold its parameter page */
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
 	ret = nand_read_param_page_op(chip, 0, NULL, 0);
-	if (ret)
-		return 0;
+	if (ret) {
+		ret = 0;
+		goto free_onfi_param_page;
+	}
 
 	for (i = 0; i < 3; i++) {
 		ret = nand_read_data_op(chip, p, sizeof(*p), true);
-		if (ret)
-			return 0;
+		if (ret) {
+			ret = 0;
+			goto free_onfi_param_page;
+		}
 
 		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
 				le16_to_cpu(p->crc)) {
@@ -5127,7 +5136,7 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
 
 	if (i == 3) {
 		pr_err("Could not find valid ONFI parameter page; aborting\n");
-		return 0;
+		goto free_onfi_param_page;
 	}
 
 	/* Check version */
@@ -5145,7 +5154,9 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
 
 	if (!chip->parameters.onfi.version) {
 		pr_info("unsupported ONFI version: %d\n", val);
-		return 0;
+		goto free_onfi_param_page;
+	} else {
+		ret = 1;
 	}
 
 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
@@ -5217,7 +5228,9 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
 	memcpy(chip->parameters.onfi.vendor, p->vendor,
 	       sizeof(p->vendor));
 
-	return 1;
+free_onfi_param_page:
+	kfree(p);
+	return ret;
 }
 
 /*
@@ -5612,7 +5625,10 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
 	chip->parameters.onfi.version = 0;
 	if (!type->name || !type->pagesize) {
 		/* Check if the chip is ONFI compliant */
-		if (nand_flash_detect_onfi(chip))
+		ret = nand_flash_detect_onfi(chip);
+		if (ret < 0)
+			return ret;
+		else if (ret)
 			goto ident_done;
 
 		/* Check if the chip is JEDEC compliant */

include/linux/mtd/rawnand.h

@@ -1200,8 +1200,6 @@ int nand_op_parser_exec_op(struct nand_chip *chip,
  *			currently in data_buf.
  * @subpagesize:	[INTERN] holds the subpagesize
  * @id:			[INTERN] holds NAND ID
- * @onfi_params:	[INTERN] holds the ONFI page parameter when ONFI is
- *			supported, 0 otherwise.
  * @parameters:		[INTERN] holds generic parameters under an easily
  *			readable form.
  * @max_bb_per_die:	[INTERN] the max number of bad blocks each die of a
@@ -1282,7 +1280,6 @@ struct nand_chip {
 	int badblockbits;
 
 	struct nand_id id;
-	struct nand_onfi_params	onfi_params;
 	struct nand_parameters parameters;
 	u16 max_bb_per_die;
 	u32 blocks_per_die;