Re: [RESEND PATCH v3 10/20] mtd: spi-nor: Rework the SPI NOR lock/unlock logic

Vignesh Raghavendra
2019-08-27T06:36:14Z

On 26/08/19 5:38 PM, Tudor.Ambarus@microchip.com wrote:
> From: Boris Brezillon <boris.brezillon@bootlin.com>
>
> Add the SNOR_F_HAS_LOCK flag and set it when SPI_NOR_HAS_LOCK is set
> in the flash_info entry or when it's a Micron or ST flash.
>
> Move the locking hooks in a separate struct so that we have just
> one field to update when we change the locking implementation.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> [tudor.ambarus@microchip.com: use ->default_init() hook, introduce
> spi_nor_late_init_params(), set ops in nor->params]
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
> v3: no changes, clear_sr_bp() is handled in the last patch of the
> series.
>

Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>

One suggestion below:

> drivers/mtd/spi-nor/spi-nor.c | 50 ++++++++++++++++++++++++++++++++-----------
> include/linux/mtd/spi-nor.h | 23 ++++++++++++++------
> 2 files changed, 53 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 235e82a121a1..3f997797fa9d 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -1598,6 +1598,12 @@ static int stm_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
> return stm_is_locked_sr(nor, ofs, len, status);
> }
>
> +static const struct spi_nor_locking_ops stm_locking_ops = {
> + .lock = stm_lock,
> + .unlock = stm_unlock,
> + .is_locked = stm_is_locked,
> +};
> +
> static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> {
> struct spi_nor *nor = mtd_to_spi_nor(mtd);
> @@ -1607,7 +1613,7 @@ static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> if (ret)
> return ret;
>
> - ret = nor->flash_lock(nor, ofs, len);
> + ret = nor->params.locking_ops->lock(nor, ofs, len);
>
> spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_UNLOCK);
> return ret;
> @@ -1622,7 +1628,7 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> if (ret)
> return ret;
>
> - ret = nor->flash_unlock(nor, ofs, len);
> + ret = nor->params.locking_ops->unlock(nor, ofs, len);
>
> spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
> return ret;
> @@ -1637,7 +1643,7 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> if (ret)
> return ret;
>
> - ret = nor->flash_is_locked(nor, ofs, len);
> + ret = nor->params.locking_ops->is_locked(nor, ofs, len);
>
> spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
> return ret;
> @@ -4148,6 +4154,7 @@ static void macronix_set_default_init(struct spi_nor *nor)
>
> static void st_micron_set_default_init(struct spi_nor *nor)
> {
> + nor->flags = SNOR_F_HAS_LOCK;

This is okay for now. But Perhaps its safer to do:

nor->flags |= SNOR_F_HAS_LOCK;

so that we don't override flags if set earlier than
spi_nor_manufacturer_init_params(). I see that patch 20/20 does indeed
present one such case wrt atmel/Xilinix flashes IIUC

Regards
Vignesh

> nor->params.quad_enable = NULL;
> nor->params.set_4byte = st_micron_set_4byte;
> }
> @@ -4292,6 +4299,23 @@ static void spi_nor_info_init_params(struct spi_nor *nor)
> }
>
> /**
> + * spi_nor_late_init_params() - Late initialization of default flash parameters.
> + * @nor: pointer to a 'struct spi_nor'
> + *
> + * Used to set default flash parameters and settings when the ->default_init()
> + * hook or the SFDP parser let voids.
> + */
> +static void spi_nor_late_init_params(struct spi_nor *nor)
> +{
> + /*
> + * NOR protection support. When locking_ops are not provided, we pick
> + * the default ones.
> + */
> + if (nor->flags & SNOR_F_HAS_LOCK && !nor->params.locking_ops)
> + nor->params.locking_ops = &stm_locking_ops;
> +}
> +
> +/**
> * spi_nor_init_params() - Initialize the flash's parameters and settings.
> * @nor: pointer to a 'struct spi-nor'.
> *
> @@ -4316,6 +4340,10 @@ static void spi_nor_info_init_params(struct spi_nor *nor)
> * Please not that there is a ->post_bfpt() fixup hook that can overwrite the
> * flash parameters and settings imediately after parsing the Basic Flash
> * Parameter Table.
> + *
> + * 4/ Late default flash parameters initialization, used when the
> + * ->default_init() hook or the SFDP parser do not set specific params.
> + * spi_nor_late_init_params()
> */
> static void spi_nor_init_params(struct spi_nor *nor)
> {
> @@ -4326,6 +4354,8 @@ static void spi_nor_init_params(struct spi_nor *nor)
> if ((nor->info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
> !(nor->info->flags & SPI_NOR_SKIP_SFDP))
> spi_nor_sfdp_init_params(nor);
> +
> + spi_nor_late_init_params(nor);
> }
>
> static int spi_nor_select_read(struct spi_nor *nor,
> @@ -4707,6 +4737,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
> if (info->flags & SPI_S3AN)
> nor->flags |= SNOR_F_READY_XSR_RDY;
>
> + if (info->flags & SPI_NOR_HAS_LOCK)
> + nor->flags |= SNOR_F_HAS_LOCK;
> +
> /*
> * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
> * with the software protection bits set.
> @@ -4731,16 +4764,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
> mtd->_read = spi_nor_read;
> mtd->_resume = spi_nor_resume;
>
> - /* NOR protection support for STmicro/Micron chips and similar */
> - if (JEDEC_MFR(info) == SNOR_MFR_ST ||
> - JEDEC_MFR(info) == SNOR_MFR_MICRON ||
> - info->flags & SPI_NOR_HAS_LOCK) {
> - nor->flash_lock = stm_lock;
> - nor->flash_unlock = stm_unlock;
> - nor->flash_is_locked = stm_is_locked;
> - }
> -
> - if (nor->flash_lock && nor->flash_unlock && nor->flash_is_locked) {
> + if (nor->params.locking_ops) {
> mtd->_lock = spi_nor_lock;
> mtd->_unlock = spi_nor_unlock;
> mtd->_is_locked = spi_nor_is_locked;
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index 7da89dd483cb..ea3bcac54dc2 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -243,6 +243,7 @@ enum spi_nor_option_flags {
> SNOR_F_BROKEN_RESET = BIT(6),
> SNOR_F_4B_OPCODES = BIT(7),
> SNOR_F_HAS_4BAIT = BIT(8),
> + SNOR_F_HAS_LOCK = BIT(9),
> };
>
> /**
> @@ -466,6 +467,18 @@ enum spi_nor_pp_command_index {
> struct spi_nor;
>
> /**
> + * struct spi_nor_locking_ops - SPI NOR locking methods
> + * @lock: lock a region of the SPI NOR.
> + * @unlock: unlock a region of the SPI NOR.
> + * @is_locked: check if a region of the SPI NOR is completely locked
> + */
> +struct spi_nor_locking_ops {
> + int (*lock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
> + int (*unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
> + int (*is_locked)(struct spi_nor *nor, loff_t ofs, uint64_t len);
> +};
> +
> +/**
> * struct spi_nor_flash_parameter - SPI NOR flash parameters and settings.
> * Includes legacy flash parameters and settings that can be overwritten
> * by the spi_nor_fixups hooks, or dynamically when parsing the JESD216
> @@ -483,6 +496,7 @@ struct spi_nor;
> * Table.
> * @quad_enable: enables SPI NOR quad mode.
> * @set_4byte: puts the SPI NOR in 4 byte addressing mode.
> + * @locking_ops: SPI NOR locking methods.
> */
> struct spi_nor_flash_parameter {
> u64 size;
> @@ -496,6 +510,8 @@ struct spi_nor_flash_parameter {
>
> int (*quad_enable)(struct spi_nor *nor);
> int (*set_4byte)(struct spi_nor *nor, bool enable);
> +
> + const struct spi_nor_locking_ops *locking_ops;
> };
>
> /**
> @@ -536,10 +552,6 @@ struct flash_info;
> * @erase: [DRIVER-SPECIFIC] erase a sector of the SPI NOR
> * at the offset @offs; if not provided by the driver,
> * spi-nor will send the erase opcode via write_reg()
> - * @flash_lock: [FLASH-SPECIFIC] lock a region of the SPI NOR
> - * @flash_unlock: [FLASH-SPECIFIC] unlock a region of the SPI NOR
> - * @flash_is_locked: [FLASH-SPECIFIC] check if a region of the SPI NOR is
> - * completely locked
> * @clear_sr_bp: [FLASH-SPECIFIC] clears the Block Protection Bits from
> * the SPI NOR Status Register.
> * @params: [FLASH-SPECIFIC] SPI-NOR flash parameters and settings.
> @@ -579,9 +591,6 @@ struct spi_nor {
> size_t len, const u_char *write_buf);
> int (*erase)(struct spi_nor *nor, loff_t offs);
>
> - int (*flash_lock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
> - int (*flash_unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
> - int (*flash_is_locked)(struct spi_nor *nor, loff_t ofs, uint64_t len);
> int (*clear_sr_bp)(struct spi_nor *nor);
> struct spi_nor_flash_parameter params;
>
>

--
Regards
Vignesh