mtd: rawnand: get rid of the JEDEC 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 can held
generic parameters, remove the JEDEC page from the nand_chip structure
by just allocating it during the identification phase and removing it
right after.

Signed-off-by: Miquel Raynal <[email protected]>
Signed-off-by: Boris Brezillon <[email protected]>

Author: miquelraynal

drivers/mtd/nand/raw/nand_base.c

@@ -5226,8 +5226,9 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
 static int nand_flash_detect_jedec(struct nand_chip *chip)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
-	struct nand_jedec_params *p = &chip->jedec_params;
+	struct nand_jedec_params *p;
 	struct jedec_ecc_info *ecc;
+	int jedec_version = 0;
 	char id[5];
 	int i, val, ret;
 
@@ -5236,14 +5237,23 @@ static int nand_flash_detect_jedec(struct nand_chip *chip)
 	if (ret || strncmp(id, "JEDEC", sizeof(id)))
 		return 0;
 
+	/* JEDEC 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, 0x40, NULL, 0);
-	if (ret)
-		return 0;
+	if (ret) {
+		ret = 0;
+		goto free_jedec_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_jedec_param_page;
+		}
 
 		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) ==
 				le16_to_cpu(p->crc))
@@ -5252,19 +5262,19 @@ static int nand_flash_detect_jedec(struct nand_chip *chip)
 
 	if (i == 3) {
 		pr_err("Could not find valid JEDEC parameter page; aborting\n");
-		return 0;
+		goto free_jedec_param_page;
 	}
 
 	/* Check version */
 	val = le16_to_cpu(p->revision);
 	if (val & (1 << 2))
-		chip->jedec_version = 10;
+		jedec_version = 10;
 	else if (val & (1 << 1))
-		chip->jedec_version = 1; /* vendor specific version */
+		jedec_version = 1; /* vendor specific version */
 
-	if (!chip->jedec_version) {
+	if (!jedec_version) {
 		pr_info("unsupported JEDEC version: %d\n", val);
-		return 0;
+		goto free_jedec_param_page;
 	}
 
 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
@@ -5285,7 +5295,7 @@ static int nand_flash_detect_jedec(struct nand_chip *chip)
 	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
 	chip->bits_per_cell = p->bits_per_cell;
 
-	if (jedec_feature(chip) & JEDEC_FEATURE_16_BIT_BUS)
+	if (le16_to_cpu(p->features) & JEDEC_FEATURE_16_BIT_BUS)
 		chip->options |= NAND_BUSWIDTH_16;
 
 	/* ECC info */
@@ -5298,7 +5308,9 @@ static int nand_flash_detect_jedec(struct nand_chip *chip)
 		pr_warn("Invalid codeword size\n");
 	}
 
-	return 1;
+free_jedec_param_page:
+	kfree(p);
+	return ret;
 }
 
 /*
@@ -5604,7 +5616,10 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
 			goto ident_done;
 
 		/* Check if the chip is JEDEC compliant */
-		if (nand_flash_detect_jedec(chip))
+		ret = nand_flash_detect_jedec(chip);
+		if (ret < 0)
+			return ret;
+		else if (ret)
 			goto ident_done;
 	}
 

include/linux/mtd/rawnand.h

@@ -1200,12 +1200,8 @@ int nand_op_parser_exec_op(struct nand_chip *chip,
  *			currently in data_buf.
  * @subpagesize:	[INTERN] holds the subpagesize
  * @id:			[INTERN] holds NAND ID
- * @jedec_version:	[INTERN] holds the chip JEDEC version (BCD encoded),
- *			non 0 if JEDEC supported.
  * @onfi_params:	[INTERN] holds the ONFI page parameter when ONFI is
  *			supported, 0 otherwise.
- * @jedec_params:	[INTERN] holds the JEDEC parameter page when JEDEC 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
@@ -1286,11 +1282,7 @@ struct nand_chip {
 	int badblockbits;
 
 	struct nand_id id;
-	int jedec_version;
-	union {
-		struct nand_onfi_params	onfi_params;
-		struct nand_jedec_params jedec_params;
-	};
+	struct nand_onfi_params	onfi_params;
 	struct nand_parameters parameters;
 	u16 max_bb_per_die;
 	u32 blocks_per_die;
@@ -1621,13 +1613,6 @@ static inline int nand_opcode_8bits(unsigned int command)
 	return 0;
 }
 
-/* return the supported JEDEC features. */
-static inline int jedec_feature(struct nand_chip *chip)
-{
-	return chip->jedec_version ? le16_to_cpu(chip->jedec_params.features)
-		: 0;
-}
-
 /* get timing characteristics from ONFI timing mode. */
 const struct nand_sdr_timings *onfi_async_timing_mode_to_sdr_timings(int mode);