RE: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories

Yogesh Narayan Gaur
2018-10-16T09:51:47Z

Hi Tudor,

This patch is breaking the 1-4-4 Read protocol for the spansion flash "s25fl512s".

Without this patch read request command for Quad mode, 4-byte enable, is coming as 0xEC i.e. SPINOR_OP_READ_1_4_4_4B.
But after applying this patch, read request command for Quad mode is coming as 0x6C i.e. SPINOR_OP_READ_1_1_4_4B.

This flash also supports non-uniform erase.
Can you please check and provide some suggestion?

--
Regards
Yogesh Gaur

> -----Original Message-----
> From: linux-mtd [mailto:linux-mtd-bounces@lists.infradead.org] On Behalf Of
> Tudor Ambarus
> Sent: Tuesday, September 11, 2018 9:10 PM
> To: marek.vasut@gmail.com; dwmw2@infradead.org;
> computersforpeace@gmail.com; boris.brezillon@bootlin.com; richard@nod.at
> Cc: Tudor Ambarus <tudor.ambarus@microchip.com>; linux-
> kernel@vger.kernel.org; nicolas.ferre@microchip.com;
> cyrille.pitchen@microchip.com; linux-mtd@lists.infradead.org; linux-arm-
> kernel@lists.infradead.org; Cristian.Birsan@microchip.com
> Subject: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI NOR
> flash memories
>
> Based on Cyrille Pitchen's patch
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.or
> g%2Flkml%2F2017%2F3%2F22%2F935&amp;data=02%7C01%7Cyogeshnarayan.
> gaur%40nxp.com%7C3c782e52b7fd4a8b9af008d617fd5154%7C686ea1d3bc2b4
> c6fa92cd99c5c301635%7C0%7C0%7C636722774108718782&amp;sdata=szyc%
> 2FTumG6eYAmBd0oW3IL7v1yLh9E1SAZqL%2BCWczOA%3D&amp;reserved=0.
>
> This patch is a transitional patch in introducing the support of SFDP SPI
> memories with non-uniform erase sizes like Spansion s25fs512s.
> Non-uniform erase maps will be used later when initialized based on the SFDP
> data.
>
> Introduce the memory erase map which splits the memory array into one or
> many erase regions. Each erase region supports up to 4 erase types, as defined
> by the JEDEC JESD216B (SFDP) specification.
>
> To be backward compatible, the erase map of uniform SPI NOR flash memories
> is initialized so it contains only one erase region and this erase region supports
> only one erase command. Hence a single size is used to erase any sector/block
> of the memory.
>
> Besides, since the algorithm used to erase sectors on non-uniform SPI NOR flash
> memories is quite expensive, when possible, the erase map is tuned to come
> back to the uniform case.
>
> The 'erase with the best command, move forward and repeat' approach was
> suggested by Cristian Birsan in a brainstorm session, so:
>
> Suggested-by: Cristian Birsan <cristian.birsan@microchip.com>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
> drivers/mtd/spi-nor/spi-nor.c | 594
> +++++++++++++++++++++++++++++++++++++++---
> include/linux/mtd/spi-nor.h | 107 ++++++++
> 2 files changed, 659 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index
> dc8757e..4687345 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -18,6 +18,7 @@
> #include <linux/math64.h>
> #include <linux/sizes.h>
> #include <linux/slab.h>
> +#include <linux/sort.h>
>
> #include <linux/mtd/mtd.h>
> #include <linux/of_platform.h>
> @@ -261,6 +262,18 @@ static void spi_nor_set_4byte_opcodes(struct spi_nor
> *nor,
> nor->read_opcode = spi_nor_convert_3to4_read(nor->read_opcode);
> nor->program_opcode = spi_nor_convert_3to4_program(nor-
> >program_opcode);
> 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_type *erase;
> + int i;
> +
> + for (i = 0; i < SNOR_ERASE_TYPE_MAX; i++) {
> + erase = &map->erase_type[i];
> + erase->opcode =
> + spi_nor_convert_3to4_erase(erase->opcode);
> + }
> + }
> }
>
> /* Enable/disable 4-byte addressing mode. */ @@ -499,6 +512,275 @@ static
> int spi_nor_erase_sector(struct spi_nor *nor, u32 addr) }
>
> /*
> + * spi_nor_div_by_erase_size() - calculate remainder and update new dividend
> + * @erase: pointer to a structure that describes a SPI NOR erase type
> + * @dividend: dividend value
> + * @remainder: pointer to u32 remainder (will be updated)
> + *
> + * Returns two values: remainder and the new dividend */ static u64
> +spi_nor_div_by_erase_size(const struct spi_nor_erase_type *erase,
> + u64 dividend, u32 *remainder)
> +{
> + /* JEDEC JESD216B Standard imposes erase sizes to be power of 2. */
> + *remainder = (u32)dividend & erase->size_mask;
> + return dividend >> erase->size_shift;
> +}
> +
> +/*
> + * spi_nor_find_best_erase_type() - find the best erase type for the
> +given
> + * offset in the serial flash memory and the number of bytes to erase.
> +The
> + * region in which the address fits is expected to be provided.
> + * @map: the erase map of the SPI NOR
> + * @region: pointer to a structure that describes a SPI NOR erase region
> + * @addr: offset in the serial flash memory
> + * @len: number of bytes to erase
> + *
> + * Returns a pointer to the best fitted erase type, NULL otherwise.
> + */
> +static const struct spi_nor_erase_type *
> +spi_nor_find_best_erase_type(const struct spi_nor_erase_map *map,
> + const struct spi_nor_erase_region *region,
> + u64 addr, u32 len)
> +{
> + const struct spi_nor_erase_type *erase;
> + u32 rem;
> + int i;
> + u8 erase_mask = region->offset & SNOR_ERASE_TYPE_MASK;
> +
> + /*
> + * Erase types are ordered by size, with the biggest erase type at
> + * index 0.
> + */
> + for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
> + /* Does the erase region support the tested erase type? */
> + if (!(erase_mask & BIT(i)))
> + continue;
> +
> + erase = &map->erase_type[i];
> +
> + /* Don't erase more than what the user has asked for. */
> + if (erase->size > len)
> + continue;
> +
> + /* Alignment is not mandatory for overlaid regions */
> + if (region->offset & SNOR_OVERLAID_REGION)
> + return erase;
> +
> + spi_nor_div_by_erase_size(erase, addr, &rem);
> + if (rem)
> + continue;
> + else
> + return erase;
> + }
> +
> + return NULL;
> +}
> +
> +/*
> + * spi_nor_region_next() - get the next spi nor region
> + * @region: pointer to a structure that describes a SPI NOR erase region
> + *
> + * Returns the next spi nor region or NULL if last region.
> + */
> +static struct spi_nor_erase_region *
> +spi_nor_region_next(struct spi_nor_erase_region *region) {
> + if (spi_nor_region_is_last(region))
> + return NULL;
> + region++;
> + return region;
> +}
> +
> +/*
> + * spi_nor_find_erase_region() - find the region of the serial flash
> +memory in
> + * which the offset fits
> + * @map: the erase map of the SPI NOR
> + * @addr: offset in the serial flash memory
> + *
> + * Returns pointer to the spi_nor_erase_region struct, ERR_PTR(-errno)
> + * otherwise.
> + */
> +static struct spi_nor_erase_region *
> +spi_nor_find_erase_region(const struct spi_nor_erase_map *map, u64
> +addr) {
> + struct spi_nor_erase_region *region = map->regions;
> + u64 region_start = region->offset & ~SNOR_ERASE_FLAGS_MASK;
> + u64 region_end = region_start + region->size;
> +
> + while (addr < region_start || addr >= region_end) {
> + region = spi_nor_region_next(region);
> + if (!region)
> + return ERR_PTR(-EINVAL);
> +
> + region_start = region->offset & ~SNOR_ERASE_FLAGS_MASK;
> + region_end = region_start + region->size;
> + }
> +
> + return region;
> +}
> +
> +/*
> + * spi_nor_init_erase_cmd() - initialize an erase command
> + * @region: pointer to a structure that describes a SPI NOR erase region
> + * @erase: pointer to a structure that describes a SPI NOR erase type
> + *
> + * Returns the pointer to the allocated erase command, ERR_PTR(-errno)
> + * otherwise.
> + */
> +static struct spi_nor_erase_command *
> +spi_nor_init_erase_cmd(const struct spi_nor_erase_region *region,
> + const struct spi_nor_erase_type *erase) {
> + struct spi_nor_erase_command *cmd;
> +
> + cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
> + if (!cmd)
> + return ERR_PTR(-ENOMEM);
> +
> + INIT_LIST_HEAD(&cmd->list);
> + cmd->opcode = erase->opcode;
> + cmd->count = 1;
> +
> + if (region->offset & SNOR_OVERLAID_REGION)
> + cmd->size = region->size;
> + else
> + cmd->size = erase->size;
> +
> + return cmd;
> +}
> +
> +/*
> + * spi_nor_destroy_erase_cmd_list() - destroy erase command list
> + * @erase_list: list of erase commands
> + */
> +static void spi_nor_destroy_erase_cmd_list(struct list_head
> +*erase_list) {
> + struct spi_nor_erase_command *cmd, *next;
> +
> + list_for_each_entry_safe(cmd, next, erase_list, list) {
> + list_del(&cmd->list);
> + kfree(cmd);
> + }
> +}
> +
> +/*
> + * spi_nor_init_erase_cmd_list() - initialize erase command list
> + * @nor: pointer to a 'struct spi_nor'
> + * @erase_list: list of erase commands to be executed once we validate that
> the
> + * erase can be performed
> + * @addr: offset in the serial flash memory
> + * @len: number of bytes to erase
> + *
> + * Builds the list of best fitted erase commands and verifies if the
> +erase can
> + * be performed.
> + *
> + * Returns 0 on success, -errno otherwise.
> + */
> +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_type *erase, *prev_erase = NULL;
> + struct spi_nor_erase_region *region;
> + struct spi_nor_erase_command *cmd = NULL;
> + u64 region_end;
> + int ret = -EINVAL;
> +
> + region = spi_nor_find_erase_region(map, addr);
> + if (IS_ERR(region))
> + return PTR_ERR(region);
> +
> + region_end = spi_nor_region_end(region);
> +
> + while (len) {
> + erase = spi_nor_find_best_erase_type(map, region, addr, len);
> + if (!erase)
> + goto destroy_erase_cmd_list;
> +
> + if (prev_erase != erase ||
> + region->offset & SNOR_OVERLAID_REGION) {
> + cmd = spi_nor_init_erase_cmd(region, erase);
> + if (IS_ERR(cmd)) {
> + ret = PTR_ERR(cmd);
> + goto destroy_erase_cmd_list;
> + }
> +
> + list_add_tail(&cmd->list, erase_list);
> + } else {
> + cmd->count++;
> + }
> +
> + addr += cmd->size;
> + len -= cmd->size;
> +
> + if (len && addr >= region_end) {
> + region = spi_nor_region_next(region);
> + if (!region)
> + goto destroy_erase_cmd_list;
> + region_end = spi_nor_region_end(region);
> + }
> +
> + prev_erase = erase;
> + }
> +
> + return 0;
> +
> +destroy_erase_cmd_list:
> + spi_nor_destroy_erase_cmd_list(erase_list);
> + return ret;
> +}
> +
> +/*
> + * spi_nor_erase_multi_sectors() - perform a non-uniform erase
> + * @nor: pointer to a 'struct spi_nor'
> + * @addr: offset in the serial flash memory
> + * @len: number of bytes to erase
> + *
> + * Build a list of best fitted erase commands and execute it once we
> + * validate that the erase can be performed.
> + *
> + * Returns 0 on success, -errno otherwise.
> + */
> +static int spi_nor_erase_multi_sectors(struct spi_nor *nor, u64 addr,
> +u32 len) {
> + LIST_HEAD(erase_list);
> + struct spi_nor_erase_command *cmd, *next;
> + int ret;
> +
> + ret = spi_nor_init_erase_cmd_list(nor, &erase_list, addr, len);
> + if (ret)
> + return ret;
> +
> + list_for_each_entry_safe(cmd, next, &erase_list, list) {
> + nor->erase_opcode = cmd->opcode;
> + while (cmd->count) {
> + write_enable(nor);
> +
> + ret = spi_nor_erase_sector(nor, addr);
> + if (ret)
> + goto destroy_erase_cmd_list;
> +
> + addr += cmd->size;
> + cmd->count--;
> +
> + ret = spi_nor_wait_till_ready(nor);
> + if (ret)
> + goto destroy_erase_cmd_list;
> + }
> + list_del(&cmd->list);
> + kfree(cmd);
> + }
> +
> + return 0;
> +
> +destroy_erase_cmd_list:
> + spi_nor_destroy_erase_cmd_list(&erase_list);
> + return ret;
> +}
> +
> +/*
> * Erase an address range on the nor chip. The address range may extend
> * one or more erase sectors. Return an error is there is a problem erasing.
> */
> @@ -512,9 +794,11 @@ static int spi_nor_erase(struct mtd_info *mtd, struct
> erase_info *instr)
> dev_dbg(nor->dev, "at 0x%llx, len %lld\n", (long long)instr->addr,
> (long long)instr->len);
>
> - div_u64_rem(instr->len, mtd->erasesize, &rem);
> - if (rem)
> - return -EINVAL;
> + if (spi_nor_has_uniform_erase(nor)) {
> + div_u64_rem(instr->len, mtd->erasesize, &rem);
> + if (rem)
> + return -EINVAL;
> + }
>
> addr = instr->addr;
> len = instr->len;
> @@ -553,7 +837,7 @@ static int spi_nor_erase(struct mtd_info *mtd, struct
> erase_info *instr)
> */
>
> /* "sector"-at-a-time erase */
> - } else {
> + } else if (spi_nor_has_uniform_erase(nor)) {
> while (len) {
> write_enable(nor);
>
> @@ -568,6 +852,12 @@ static int spi_nor_erase(struct mtd_info *mtd, struct
> erase_info *instr)
> if (ret)
> goto erase_err;
> }
> +
> + /* erase multiple sectors */
> + } else {
> + ret = spi_nor_erase_multi_sectors(nor, addr, len);
> + if (ret)
> + goto erase_err;
> }
>
> write_disable(nor);
> @@ -2190,6 +2480,113 @@ static const struct sfdp_bfpt_erase
> sfdp_bfpt_erases[] = {
>
> static int spi_nor_hwcaps_read2cmd(u32 hwcaps);
>
> +/*
> + * spi_nor_set_erase_type() - set a SPI NOR erase type
> + * @erase: pointer to a structure that describes a SPI NOR erase type
> + * @size: the size of the sector/block erased by the erase type
> + * @opcode: the SPI command op code to erase the sector/block
> + */
> +static void spi_nor_set_erase_type(struct spi_nor_erase_type *erase,
> + u32 size, u8 opcode)
> +{
> + erase->size = size;
> + erase->opcode = opcode;
> + /* JEDEC JESD216B Standard imposes erase sizes to be power of 2. */
> + erase->size_shift = ffs(erase->size) - 1;
> + erase->size_mask = (1 << erase->size_shift) - 1; }
> +
> +/*
> + * spi_nor_set_erase_settings_from_bfpt() - set erase type settings from BFPT
> + * @erase: pointer to a structure that describes a SPI NOR erase type
> + * @size: the size of the sector/block erased by the erase type
> + * @opcode: the SPI command op code to erase the sector/block
> + * @i: erase type index as sorted in the Basic Flash Parameter Table
> + *
> + * The supported Erase Types will be sorted at init in ascending order,
> +with
> + * the smallest Erase Type size being the first member in the
> +erase_type array
> + * of the spi_nor_erase_map structure. Save the Erase Type index as
> +sorted in
> + * the Basic Flash Parameter Table since it will be used later on to
> + * synchronize with the supported Erase Types defined in SFDP optional tables.
> + */
> +static void
> +spi_nor_set_erase_settings_from_bfpt(struct spi_nor_erase_type *erase,
> + u32 size, u8 opcode, u8 i)
> +{
> + erase->idx = i;
> + spi_nor_set_erase_type(erase, size, opcode); }
> +
> +/* spi_nor_map_cmp_erase_type() - compare the map's erase types by size
> + * @l: member in the left half of the map's erase_type array
> + * @r: member in the right half of the map's erase_type array
> + *
> + * Comparison function used in the sort() call to sort in ascending
> +order the
> + * map's erase types, the smallest erase type size being the first
> +member in the
> + * sorted erase_type array.
> + */
> +static int spi_nor_map_cmp_erase_type(const void *l, const void *r) {
> + const struct spi_nor_erase_type *left = l, *right = r;
> +
> + return left->size - right->size;
> +}
> +
> +/*
> + * spi_nor_regions_sort_erase_types() - sort erase types in each region
> + * @map: the erase map of the SPI NOR
> + *
> + * Function assumes that the erase types defined in the erase map are
> +already
> + * sorted in ascending order, with the smallest erase type size being
> +the first
> + * member in the erase_type array. It replicates the sort done for the
> +map's
> + * erase types. Each region's erase bitmask will indicate which erase
> +types are
> + * supported from the sorted erase types defined in the erase map.
> + * Sort the all region's erase type at init in order to speed up the
> +process of
> + * finding the best erase command at runtime.
> + */
> +static void spi_nor_regions_sort_erase_types(struct spi_nor_erase_map
> +*map) {
> + struct spi_nor_erase_region *region = map->regions;
> + struct spi_nor_erase_type *erase_type = map->erase_type;
> + int i;
> + u8 region_erase_mask, sorted_erase_mask;
> +
> + while (region) {
> + region_erase_mask = region->offset &
> SNOR_ERASE_TYPE_MASK;
> +
> + /* Replicate the sort done for the map's erase types. */
> + sorted_erase_mask = 0;
> + for (i = 0; i < SNOR_ERASE_TYPE_MAX; i++)
> + if (erase_type[i].size &&
> + region_erase_mask & BIT(erase_type[i].idx))
> + sorted_erase_mask |= BIT(i);
> +
> + /* Overwrite erase mask. */
> + region->offset = (region->offset & ~SNOR_ERASE_TYPE_MASK)
> |
> + sorted_erase_mask;
> +
> + region = spi_nor_region_next(region);
> + }
> +}
> +
> +/*
> + *spi_nor_init_uniform_erase_map() - Initialize uniform erase map
> + * @map: the erase map of the SPI NOR
> + * @erase_mask: bitmask encoding erase types that can erase
> the entire
> + * flash memory
> + * @flash_size: the spi nor flash memory size
> + */
> +static void spi_nor_init_uniform_erase_map(struct spi_nor_erase_map *map,
> + u8 erase_mask, u64 flash_size)
> +{
> + /* Offset 0 with erase_mask and SNOR_LAST_REGION bit set */
> + map->uniform_region.offset = (erase_mask &
> SNOR_ERASE_TYPE_MASK) |
> + SNOR_LAST_REGION;
> + map->uniform_region.size = flash_size;
> + map->regions = &map->uniform_region;
> + map->uniform_erase_type = erase_mask;
> +}
> +
> /**
> * spi_nor_parse_bfpt() - read and parse the Basic Flash Parameter Table.
> * @nor: pointer to a 'struct spi_nor'
> @@ -2224,12 +2621,14 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
> const struct sfdp_parameter_header *bfpt_header,
> struct spi_nor_flash_parameter *params) {
> - struct mtd_info *mtd = &nor->mtd;
> + struct spi_nor_erase_map *map = &nor->erase_map;
> + struct spi_nor_erase_type *erase_type = map->erase_type;
> struct sfdp_bfpt bfpt;
> size_t len;
> int i, cmd, err;
> u32 addr;
> u16 half;
> + u8 erase_mask;
>
> /* JESD216 Basic Flash Parameter Table length is at least 9 DWORDs. */
> if (bfpt_header->length < BFPT_DWORD_MAX_JESD216) @@ -2298,7
> +2697,12 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
> spi_nor_set_read_settings_from_bfpt(read, half, rd->proto);
> }
>
> - /* Sector Erase settings. */
> + /*
> + * Sector Erase settings. Reinitialize the uniform erase map using the
> + * Erase Types defined in the bfpt table.
> + */
> + erase_mask = 0;
> + memset(&nor->erase_map, 0, sizeof(nor->erase_map));
> for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_erases); i++) {
> const struct sfdp_bfpt_erase *er = &sfdp_bfpt_erases[i];
> u32 erasesize;
> @@ -2313,18 +2717,25 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
>
> erasesize = 1U << erasesize;
> opcode = (half >> 8) & 0xff;
> -#ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
> - if (erasesize == SZ_4K) {
> - nor->erase_opcode = opcode;
> - mtd->erasesize = erasesize;
> - break;
> - }
> -#endif
> - if (!mtd->erasesize || mtd->erasesize < erasesize) {
> - nor->erase_opcode = opcode;
> - mtd->erasesize = erasesize;
> - }
> + erase_mask |= BIT(i);
> + spi_nor_set_erase_settings_from_bfpt(&erase_type[i],
> erasesize,
> + opcode, i);
> }
> + spi_nor_init_uniform_erase_map(map, erase_mask, params->size);
> + /*
> + * Sort all the map's Erase Types in ascending order with the smallest
> + * erase size being the first member in the erase_type array.
> + */
> + sort(erase_type, SNOR_ERASE_TYPE_MAX, sizeof(erase_type[0]),
> + spi_nor_map_cmp_erase_type, NULL);
> + /*
> + * Sort the erase types in the uniform region in order to update the
> + * uniform_erase_type bitmask. The bitmask will be used later on when
> + * selecting the uniform erase.
> + */
> + spi_nor_regions_sort_erase_types(map);
> + map->uniform_erase_type = map->uniform_region.offset &
> + SNOR_ERASE_TYPE_MASK;
>
> /* Stop here if not JESD216 rev A or later. */
> if (bfpt_header->length < BFPT_DWORD_MAX) @@ -2480,6 +2891,9
> @@ static int spi_nor_init_params(struct spi_nor *nor,
> const struct flash_info *info,
> struct spi_nor_flash_parameter *params) {
> + struct spi_nor_erase_map *map = &nor->erase_map;
> + u8 i, erase_mask;
> +
> /* Set legacy flash parameters as default. */
> memset(params, 0, sizeof(*params));
>
> @@ -2519,6 +2933,28 @@ static int spi_nor_init_params(struct spi_nor *nor,
> spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP],
> SPINOR_OP_PP, SNOR_PROTO_1_1_1);
>
> + /*
> + * Sector Erase settings. Sort Erase Types in ascending order, with the
> + * smallest erase size starting at BIT(0).
> + */
> + erase_mask = 0;
> + i = 0;
> + if (info->flags & SECT_4K_PMC) {
> + erase_mask |= BIT(i);
> + spi_nor_set_erase_type(&map->erase_type[i], 4096u,
> + SPINOR_OP_BE_4K_PMC);
> + i++;
> + } else if (info->flags & SECT_4K) {
> + erase_mask |= BIT(i);
> + spi_nor_set_erase_type(&map->erase_type[i], 4096u,
> + SPINOR_OP_BE_4K);
> + i++;
> + }
> + erase_mask |= BIT(i);
> + spi_nor_set_erase_type(&map->erase_type[i], info->sector_size,
> + SPINOR_OP_SE);
> + spi_nor_init_uniform_erase_map(map, erase_mask, params->size);
> +
> /* Select the procedure to set the Quad Enable bit. */
> if (params->hwcaps.mask & (SNOR_HWCAPS_READ_QUAD |
> SNOR_HWCAPS_PP_QUAD)) {
> @@ -2546,20 +2982,20 @@ static int spi_nor_init_params(struct spi_nor *nor,
> params->quad_enable = info->quad_enable;
> }
>
> - /* Override the parameters with data read from SFDP tables. */
> - nor->addr_width = 0;
> - nor->mtd.erasesize = 0;
> 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));
> - if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
> - nor->addr_width = 0;
> - nor->mtd.erasesize = 0;
> - } else {
> + memcpy(&prev_map, &nor->erase_map, sizeof(prev_map));
> +
> + if (spi_nor_parse_sfdp(nor, &sfdp_params))
> + /* restore previous erase map */
> + memcpy(&nor->erase_map, &prev_map,
> + sizeof(nor->erase_map));
> + else
> memcpy(params, &sfdp_params, sizeof(*params));
> - }
> }
>
> return 0;
> @@ -2668,29 +3104,103 @@ static int spi_nor_select_pp(struct spi_nor *nor,
> return 0;
> }
>
> -static int spi_nor_select_erase(struct spi_nor *nor,
> - const struct flash_info *info)
> +/*
> + * spi_nor_select_uniform_erase() - select optimum uniform erase type
> + * @map: the erase map of the SPI NOR
> + * @wanted_size: the erase type size to search for. Contains the value of
> + * info->sector_size or of the "small sector" size in case
> + * CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is defined.
> + *
> + * Once the optimum uniform sector erase command is found, disable all
> +the
> + * other.
> + *
> + * Return: pointer to erase type on success, NULL otherwise.
> + */
> +static const struct spi_nor_erase_type *
> +spi_nor_select_uniform_erase(struct spi_nor_erase_map *map,
> + const u32 wanted_size)
> {
> - struct mtd_info *mtd = &nor->mtd;
> + const struct spi_nor_erase_type *tested_erase, *erase = NULL;
> + int i;
> + u8 uniform_erase_type = map->uniform_erase_type;
>
> - /* Do nothing if already configured from SFDP. */
> - if (mtd->erasesize)
> - return 0;
> + for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
> + if (!(uniform_erase_type & BIT(i)))
> + continue;
> +
> + tested_erase = &map->erase_type[i];
> +
> + /*
> + * If the current erase size is the one, stop here:
> + * we have found the right uniform Sector Erase command.
> + */
> + if (tested_erase->size == wanted_size) {
> + erase = tested_erase;
> + break;
> + }
>
> + /*
> + * Otherwise, the current erase size is still a valid canditate.
> + * Select the biggest valid candidate.
> + */
> + if (!erase && tested_erase->size)
> + erase = tested_erase;
> + /* keep iterating to find the wanted_size */
> + }
> +
> + if (!erase)
> + return NULL;
> +
> + /* Disable all other Sector Erase commands. */
> + map->uniform_erase_type &= ~SNOR_ERASE_TYPE_MASK;
> + map->uniform_erase_type |= BIT(erase - map->erase_type);
> + return erase;
> +}
> +
> +static int spi_nor_select_erase(struct spi_nor *nor, u32 wanted_size) {
> + struct spi_nor_erase_map *map = &nor->erase_map;
> + const struct spi_nor_erase_type *erase = NULL;
> + struct mtd_info *mtd = &nor->mtd;
> + int i;
> +
> + /*
> + * The previous implementation handling Sector Erase commands
> assumed
> + * that the SPI flash memory has an uniform layout then used only one
> + * of the supported erase sizes for all Sector Erase commands.
> + * So to be backward compatible, the new implementation also tries to
> + * manage the SPI flash memory as uniform with a single erase sector
> + * size, when possible.
> + */
> #ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
> /* prefer "small sector" erase if possible */
> - if (info->flags & SECT_4K) {
> - nor->erase_opcode = SPINOR_OP_BE_4K;
> - mtd->erasesize = 4096;
> - } else if (info->flags & SECT_4K_PMC) {
> - nor->erase_opcode = SPINOR_OP_BE_4K_PMC;
> - mtd->erasesize = 4096;
> - } else
> + wanted_size = 4096u;
> #endif
> - {
> - nor->erase_opcode = SPINOR_OP_SE;
> - mtd->erasesize = info->sector_size;
> +
> + if (spi_nor_has_uniform_erase(nor)) {
> + erase = spi_nor_select_uniform_erase(map, wanted_size);
> + if (!erase)
> + return -EINVAL;
> + nor->erase_opcode = erase->opcode;
> + mtd->erasesize = erase->size;
> + return 0;
> }
> +
> + /*
> + * For non-uniform SPI flash memory, set mtd->erasesize to the
> + * maximum erase sector size. No need to set nor->erase_opcode.
> + */
> + for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
> + if (map->erase_type[i].size) {
> + erase = &map->erase_type[i];
> + break;
> + }
> + }
> +
> + if (!erase)
> + return -EINVAL;
> +
> + mtd->erasesize = erase->size;
> return 0;
> }
>
> @@ -2737,7 +3247,7 @@ static int spi_nor_setup(struct spi_nor *nor, const
> struct flash_info *info,
> }
>
> /* Select the Sector Erase command. */
> - err = spi_nor_select_erase(nor, info);
> + err = spi_nor_select_erase(nor, info->sector_size);
> if (err) {
> dev_err(nor->dev,
> "can't select erase settings supported by both the SPI
> controller and memory.\n"); diff --git a/include/linux/mtd/spi-nor.h
> b/include/linux/mtd/spi-nor.h index 09a10fd..a873a0b 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -240,6 +240,94 @@ enum spi_nor_option_flags { };
>
> /**
> + * struct spi_nor_erase_type - Structure to describe a SPI NOR erase type
> + * @size: the size of the sector/block erased by the erase type.
> + * JEDEC JESD216B imposes erase sizes to be a power of 2.
> + * @size_shift: @size is a power of 2, the shift is stored in
> + * @size_shift.
> + * @size_mask: the size mask based on @size_shift.
> + * @opcode: the SPI command op code to erase the sector/block.
> + * @idx: Erase Type index as sorted in the Basic Flash Parameter
> + * Table. It will be used to synchronize the supported
> + * Erase Types with the ones identified in the SFDP
> + * optional tables.
> + */
> +struct spi_nor_erase_type {
> + u32 size;
> + u32 size_shift;
> + u32 size_mask;
> + u8 opcode;
> + u8 idx;
> +};
> +
> +/**
> + * struct spi_nor_erase_command - Used for non-uniform erases
> + * The structure is used to describe a list of erase commands to be
> +executed
> + * once we validate that the erase can be performed. The elements in
> +the list
> + * are run-length encoded.
> + * @list: for inclusion into the list of erase commands.
> + * @count: how many times the same erase command should be
> + * consecutively used.
> + * @size: the size of the sector/block erased by the command.
> + * @opcode: the SPI command op code to erase the sector/block.
> + */
> +struct spi_nor_erase_command {
> + struct list_head list;
> + u32 count;
> + u32 size;
> + u8 opcode;
> +};
> +
> +/**
> + * struct spi_nor_erase_region - Structure to describe a SPI NOR erase region
> + * @offset: the offset in the data array of erase region start.
> + * LSB bits are used as a bitmask encoding flags to
> + * determine if this region is overlaid, if this region is
> + * the last in the SPI NOR flash memory and to indicate
> + * all the supported erase commands inside this region.
> + * The erase types are sorted in ascending order with the
> + * smallest Erase Type size being at BIT(0).
> + * @size: the size of the region in bytes.
> + */
> +struct spi_nor_erase_region {
> + u64 offset;
> + u64 size;
> +};
> +
> +#define SNOR_ERASE_TYPE_MAX 4
> +#define SNOR_ERASE_TYPE_MASK
> GENMASK_ULL(SNOR_ERASE_TYPE_MAX - 1, 0)
> +
> +#define SNOR_LAST_REGION BIT(4)
> +#define SNOR_OVERLAID_REGION BIT(5)
> +
> +#define SNOR_ERASE_FLAGS_MAX 6
> +#define SNOR_ERASE_FLAGS_MASK
> GENMASK_ULL(SNOR_ERASE_FLAGS_MAX - 1, 0)
> +
> +/**
> + * struct spi_nor_erase_map - Structure to describe the SPI NOR erase map
> + * @regions: array of erase regions. The regions are consecutive in
> + * address space. Walking through the regions is done
> + * incrementally.
> + * @uniform_region: a pre-allocated erase region for SPI NOR with a uniform
> + * sector size (legacy implementation).
> + * @erase_type: an array of erase types shared by all the regions.
> + * The erase types are sorted in ascending order, with the
> + * smallest Erase Type size being the first member in the
> + * erase_type array.
> + * @uniform_erase_type: bitmask encoding erase types that can erase
> the
> + * entire memory. This member is completed at init by
> + * uniform and non-uniform SPI NOR flash memories if
> they
> + * support at least one erase type that can erase the
> + * entire memory.
> + */
> +struct spi_nor_erase_map {
> + struct spi_nor_erase_region *regions;
> + struct spi_nor_erase_region uniform_region;
> + struct spi_nor_erase_type erase_type[SNOR_ERASE_TYPE_MAX];
> + u8 uniform_erase_type;
> +};
> +
> +/**
> * struct flash_info - Forward declaration of a structure used internally by
> * spi_nor_scan()
> */
> @@ -263,6 +351,7 @@ struct flash_info;
> * @write_proto: the SPI protocol for write operations
> * @reg_proto the SPI protocol for read_reg/write_reg/erase
> operations
> * @cmd_buf: used by the write_reg
> + * @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
> @@ -298,6 +387,7 @@ struct spi_nor {
> bool sst_write_second;
> u32 flags;
> u8 cmd_buf[SPI_NOR_MAX_CMD_SIZE];
> + 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); @@ -
> 318,6 +408,23 @@ struct spi_nor {
> void *priv;
> };
>
> +static u64 __maybe_unused
> +spi_nor_region_is_last(const struct spi_nor_erase_region *region) {
> + return region->offset & SNOR_LAST_REGION; }
> +
> +static u64 __maybe_unused
> +spi_nor_region_end(const struct spi_nor_erase_region *region) {
> + return (region->offset & ~SNOR_ERASE_FLAGS_MASK) + region->size; }
> +
> +static bool __maybe_unused spi_nor_has_uniform_erase(const struct
> +spi_nor *nor) {
> + return !!nor->erase_map.uniform_erase_type;
> +}
> +
> static inline void spi_nor_set_flash_node(struct spi_nor *nor,
> struct device_node *np)
> {
> --
> 2.9.4
>
>
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