mtd: spi-nor: Move erase_map to 'struct spi_nor_flash_parameter'

All flash parameters and settings should reside inside
'struct spi_nor_flash_parameter'. Move the SMPT parsed erase map
from 'struct spi_nor' to 'struct spi_nor_flash_parameter'.

Please note that there is a roll-back mechanism for the flash
parameter and settings, for cases when SFDP parser fails. The SFDP
parser receives a Stack allocated copy of nor->params, called
sfdp_params, and uses it to retrieve the serial flash discoverable
parameters. JESD216 SFDP is a standard and has a higher priority
than the default initialized flash parameters, so will overwrite the
sfdp_params data when needed. All SFDP code uses the local copy of
nor->params, that will overwrite it in the end, if the parser succeds.

Saving and restoring the nor->params.erase_map is no longer needed,
since the SFDP code does not touch it.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>

Author: ambarus

drivers/mtd/spi-nor/spi-nor.c

@@ -600,7 +600,7 @@ static void spi_nor_set_4byte_opcodes(struct spi_nor *nor)
 	nor->erase_opcode = spi_nor_convert_3to4_erase(nor->erase_opcode);
 
 	if (!spi_nor_has_uniform_erase(nor)) {
-		struct spi_nor_erase_map *map = &nor->erase_map;
+		struct spi_nor_erase_map *map = &nor->params.erase_map;
 		struct spi_nor_erase_type *erase;
 		int i;
 
@@ -1133,7 +1133,7 @@ static int spi_nor_init_erase_cmd_list(struct spi_nor *nor,
 				       struct list_head *erase_list,
 				       u64 addr, u32 len)
 {
-	const struct spi_nor_erase_map *map = &nor->erase_map;
+	const struct spi_nor_erase_map *map = &nor->params.erase_map;
 	const struct spi_nor_erase_type *erase, *prev_erase = NULL;
 	struct spi_nor_erase_region *region;
 	struct spi_nor_erase_command *cmd = NULL;
@@ -3328,7 +3328,7 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 			      const struct sfdp_parameter_header *bfpt_header,
 			      struct spi_nor_flash_parameter *params)
 {
-	struct spi_nor_erase_map *map = &nor->erase_map;
+	struct spi_nor_erase_map *map = &params->erase_map;
 	struct spi_nor_erase_type *erase_type = map->erase_type;
 	struct sfdp_bfpt bfpt;
 	size_t len;
@@ -3409,7 +3409,7 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 	 * Erase Types defined in the bfpt table.
 	 */
 	erase_mask = 0;
-	memset(&nor->erase_map, 0, sizeof(nor->erase_map));
+	memset(&params->erase_map, 0, sizeof(params->erase_map));
 	for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_erases); i++) {
 		const struct sfdp_bfpt_erase *er = &sfdp_bfpt_erases[i];
 		u32 erasesize;
@@ -3684,14 +3684,18 @@ spi_nor_region_check_overlay(struct spi_nor_erase_region *region,
 /**
  * spi_nor_init_non_uniform_erase_map() - initialize the non-uniform erase map
  * @nor:	pointer to a 'struct spi_nor'
+ * @params:     pointer to a duplicate 'struct spi_nor_flash_parameter' that is
+ *              used for storing SFDP parsed data
  * @smpt:	pointer to the sector map parameter table
  *
  * Return: 0 on success, -errno otherwise.
  */
-static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
-					      const u32 *smpt)
+static int
+spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
+				   struct spi_nor_flash_parameter *params,
+				   const u32 *smpt)
 {
-	struct spi_nor_erase_map *map = &nor->erase_map;
+	struct spi_nor_erase_map *map = &params->erase_map;
 	struct spi_nor_erase_type *erase = map->erase_type;
 	struct spi_nor_erase_region *region;
 	u64 offset;
@@ -3770,6 +3774,8 @@ static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
  * spi_nor_parse_smpt() - parse Sector Map Parameter Table
  * @nor:		pointer to a 'struct spi_nor'
  * @smpt_header:	sector map parameter table header
+ * @params:		pointer to a duplicate 'struct spi_nor_flash_parameter'
+ *                      that is used for storing SFDP parsed data
  *
  * This table is optional, but when available, we parse it to identify the
  * location and size of sectors within the main data array of the flash memory
@@ -3778,7 +3784,8 @@ static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
  * Return: 0 on success, -errno otherwise.
  */
 static int spi_nor_parse_smpt(struct spi_nor *nor,
-			      const struct sfdp_parameter_header *smpt_header)
+			      const struct sfdp_parameter_header *smpt_header,
+			      struct spi_nor_flash_parameter *params)
 {
 	const u32 *sector_map;
 	u32 *smpt;
@@ -3807,11 +3814,11 @@ static int spi_nor_parse_smpt(struct spi_nor *nor,
 		goto out;
 	}
 
-	ret = spi_nor_init_non_uniform_erase_map(nor, sector_map);
+	ret = spi_nor_init_non_uniform_erase_map(nor, params, sector_map);
 	if (ret)
 		goto out;
 
-	spi_nor_regions_sort_erase_types(&nor->erase_map);
+	spi_nor_regions_sort_erase_types(&params->erase_map);
 	/* fall through */
 out:
 	kfree(smpt);
@@ -3867,7 +3874,7 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
 		{ 0u /* not used */,		BIT(12) },
 	};
 	struct spi_nor_pp_command *params_pp = params->page_programs;
-	struct spi_nor_erase_map *map = &nor->erase_map;
+	struct spi_nor_erase_map *map = &params->erase_map;
 	struct spi_nor_erase_type *erase_type = map->erase_type;
 	u32 *dwords;
 	size_t len;
@@ -4097,7 +4104,7 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
 
 		switch (SFDP_PARAM_HEADER_ID(param_header)) {
 		case SFDP_SECTOR_MAP_ID:
-			err = spi_nor_parse_smpt(nor, param_header);
+			err = spi_nor_parse_smpt(nor, param_header, params);
 			break;
 
 		case SFDP_4BAIT_ID:
@@ -4129,7 +4136,7 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
 static int spi_nor_init_params(struct spi_nor *nor)
 {
 	struct spi_nor_flash_parameter *params = &nor->params;
-	struct spi_nor_erase_map *map = &nor->erase_map;
+	struct spi_nor_erase_map *map = &params->erase_map;
 	const struct flash_info *info = nor->info;
 	u8 i, erase_mask;
 
@@ -4229,17 +4236,12 @@ static int spi_nor_init_params(struct spi_nor *nor)
 	if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
 	    !(info->flags & SPI_NOR_SKIP_SFDP)) {
 		struct spi_nor_flash_parameter sfdp_params;
-		struct spi_nor_erase_map prev_map;
 
 		memcpy(&sfdp_params, params, sizeof(sfdp_params));
-		memcpy(&prev_map, &nor->erase_map, sizeof(prev_map));
 
 		if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
 			nor->addr_width = 0;
 			nor->flags &= ~SNOR_F_4B_OPCODES;
-			/* restore previous erase map */
-			memcpy(&nor->erase_map, &prev_map,
-			       sizeof(nor->erase_map));
 		} else {
 			memcpy(params, &sfdp_params, sizeof(*params));
 		}
@@ -4353,7 +4355,7 @@ spi_nor_select_uniform_erase(struct spi_nor_erase_map *map,
 
 static int spi_nor_select_erase(struct spi_nor *nor, u32 wanted_size)
 {
-	struct spi_nor_erase_map *map = &nor->erase_map;
+	struct spi_nor_erase_map *map = &nor->params.erase_map;
 	const struct spi_nor_erase_type *erase = NULL;
 	struct mtd_info *mtd = &nor->mtd;
 	int i;

include/linux/mtd/spi-nor.h

@@ -479,6 +479,8 @@ struct spi_nor;
  *                      in the array, the higher priority.
  * @page_programs:	page program capabilities ordered by priority: the
  *                      higher index in the array, the higher priority.
+ * @erase_map:		the erase map parsed from the SFDP Sector Map Parameter
+ *                      Table.
  * @quad_enable:	enables SPI NOR quad mode.
  */
 struct spi_nor_flash_parameter {
@@ -489,6 +491,8 @@ struct spi_nor_flash_parameter {
 	struct spi_nor_read_command	reads[SNOR_CMD_READ_MAX];
 	struct spi_nor_pp_command	page_programs[SNOR_CMD_PP_MAX];
 
+	struct spi_nor_erase_map        erase_map;
+
 	int (*quad_enable)(struct spi_nor *nor);
 };
 
@@ -519,7 +523,6 @@ struct flash_info;
  * @read_proto:		the SPI protocol for read operations
  * @write_proto:	the SPI protocol for write operations
  * @reg_proto		the SPI protocol for read_reg/write_reg/erase operations
- * @erase_map:		the erase map of the SPI NOR
  * @prepare:		[OPTIONAL] do some preparations for the
  *			read/write/erase/lock/unlock operations
  * @unprepare:		[OPTIONAL] do some post work after the
@@ -562,7 +565,6 @@ struct spi_nor {
 	enum spi_nor_protocol	reg_proto;
 	bool			sst_write_second;
 	u32			flags;
-	struct spi_nor_erase_map	erase_map;
 
 	int (*prepare)(struct spi_nor *nor, enum spi_nor_ops ops);
 	void (*unprepare)(struct spi_nor *nor, enum spi_nor_ops ops);
@@ -610,7 +612,7 @@ spi_nor_region_mark_overlay(struct spi_nor_erase_region *region)
 
 static bool __maybe_unused spi_nor_has_uniform_erase(const struct spi_nor *nor)
 {
-	return !!nor->erase_map.uniform_erase_type;
+	return !!nor->params.erase_map.uniform_erase_type;
 }
 
 static inline void spi_nor_set_flash_node(struct spi_nor *nor,