Due to possible mode switching to 8D-8D-8D, it might not be possible to read the SFDP after the initial probe. To be able to dump the SFDP via sysfs afterwards, make a complete copy of it.
Signed-off-by: Michael Walle <[email protected]> --- drivers/mtd/spi-nor/core.h | 10 ++++++++ drivers/mtd/spi-nor/sfdp.c | 49 +++++++++++++++++++++++++++++++++++++ include/linux/mtd/spi-nor.h | 3 +++ 3 files changed, 62 insertions(+) diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h index 4a3f7f150b5d..668f22011b1d 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -407,6 +407,16 @@ struct spi_nor_manufacturer { const struct spi_nor_fixups *fixups; }; +/** + * struct sfdp - SFDP data + * @num_dwords: number of entries in the dwords array + * @dwords: array of double words of the SFDP data + */ +struct sfdp { + size_t num_dwords; + u32 *dwords; +}; + /* Manufacturer drivers. */ extern const struct spi_nor_manufacturer spi_nor_atmel; extern const struct spi_nor_manufacturer spi_nor_catalyst; diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c index 25142ec4737b..2b6c96e02532 100644 --- a/drivers/mtd/spi-nor/sfdp.c +++ b/drivers/mtd/spi-nor/sfdp.c @@ -16,6 +16,7 @@ (((p)->parameter_table_pointer[2] << 16) | \ ((p)->parameter_table_pointer[1] << 8) | \ ((p)->parameter_table_pointer[0] << 0)) +#define SFDP_PARAM_HEADER_PARAM_LEN(p) ((p)->length * 4) #define SFDP_BFPT_ID 0xff00 /* Basic Flash Parameter Table */ #define SFDP_SECTOR_MAP_ID 0xff81 /* Sector Map Table */ @@ -1263,6 +1264,8 @@ int spi_nor_parse_sfdp(struct spi_nor *nor, struct sfdp_parameter_header *param_headers = NULL; struct sfdp_header header; struct device *dev = nor->dev; + struct sfdp *sfdp; + size_t sfdp_size; size_t psize; int i, err; @@ -1285,6 +1288,9 @@ int spi_nor_parse_sfdp(struct spi_nor *nor, bfpt_header->major != SFDP_JESD216_MAJOR) return -EINVAL; + sfdp_size = SFDP_PARAM_HEADER_PTP(bfpt_header) + + SFDP_PARAM_HEADER_PARAM_LEN(bfpt_header); + /* * Allocate memory then read all parameter headers with a single * Read SFDP command. These parameter headers will actually be parsed @@ -1311,6 +1317,49 @@ int spi_nor_parse_sfdp(struct spi_nor *nor, } } + /* + * Cache the complete SFDP data. It is not (easily) possible to fetch + * SFDP after probe time and we need it for the sysfs access. + */ + for (i = 0; i < header.nph; i++) { + param_header = ¶m_headers[i]; + sfdp_size = max_t(size_t, sfdp_size, + SFDP_PARAM_HEADER_PTP(param_header) + + SFDP_PARAM_HEADER_PARAM_LEN(param_header)); + } + + /* + * Limit the total size to a reasonable value to avoid allocating too + * much memory just of because the flash returned some insane values. + */ + if (sfdp_size > PAGE_SIZE) { + dev_dbg(dev, "SFDP data (%zu) too big, truncating\n", + sfdp_size); + sfdp_size = PAGE_SIZE; + } + + sfdp = devm_kzalloc(dev, sizeof(*sfdp), GFP_KERNEL); + if (!sfdp) { + err = -ENOMEM; + goto exit; + } + + sfdp->num_dwords = DIV_ROUND_UP(sfdp_size, sizeof(*sfdp->dwords)); + sfdp->dwords = devm_kcalloc(dev, sfdp->num_dwords, + sizeof(*sfdp->dwords), GFP_KERNEL); + if (!sfdp->dwords) { + err = -ENOMEM; + goto exit; + } + + err = spi_nor_read_sfdp_dma_unsafe(nor, 0, sfdp_size, sfdp->dwords); + if (err < 0) { + dev_dbg(dev, "failed to read SFDP data\n"); + goto exit; + } + + nor->sfdp = sfdp; + /* * Check other parameter headers to get the latest revision of * the basic flash parameter table. diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index a0d572855444..55c550208949 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -351,6 +351,7 @@ enum spi_nor_cmd_ext { struct flash_info; struct spi_nor_manufacturer; struct spi_nor_flash_parameter; +struct sfdp; /** * struct spi_nor - Structure for defining the SPI NOR layer @@ -375,6 +376,7 @@ struct spi_nor_flash_parameter; * @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 + * @sfdp: the SFDP data of the flash * @controller_ops: SPI NOR controller driver specific operations. * @params: [FLASH-SPECIFIC] SPI NOR flash parameters and settings. * The structure includes legacy flash parameters and @@ -404,6 +406,7 @@ struct spi_nor { bool sst_write_second; u32 flags; enum spi_nor_cmd_ext cmd_ext_type; + struct sfdp *sfdp; const struct spi_nor_controller_ops *controller_ops; -- 2.20.1
