[PATCH 07/10] mtd: spi-nor: add mtd_is_locked() support

[Jagan Teki]

On 2 September 2015 at 01:27, Brian Norris <computersforpeace at gmail.com> wrote:
> This enables ioctl(MEMISLOCKED). Status can now be reported in the
> mtdinfo or flash_lock utilities found in mtd-utils.
>
> Signed-off-by: Brian Norris <computersforpeace at gmail.com>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 37 ++++++++++++++++++++++++++++++++++++-
>  include/linux/mtd/spi-nor.h   |  3 +++
>  2 files changed, 39 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 62fa1b4ff3c0..c4fb1205f1d3 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -519,6 +519,24 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>         return write_sr(nor, status_new);
>  }
>
> +/*
> + * Check if a region of the flash is (completely) locked. See stm_lock() for
> + * more info.
> + *
> + * Returns 1 if entire region is locked, 0 if any portion is unlocked, and
> + * negative on errors.
> + */
> +static int stm_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
> +{
> +       int status;
> +
> +       status = read_sr(nor);
> +       if (status < 0)
> +               return status;
> +
> +       return stm_is_locked_sr(nor, ofs, len, status);
> +}
> +
>  static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
>  {
>         struct spi_nor *nor = mtd_to_spi_nor(mtd);
> @@ -549,6 +567,21 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
>         return ret;
>  }
>
> +static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> +{
> +       struct spi_nor *nor = mtd_to_spi_nor(mtd);
> +       int ret;
> +
> +       ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_UNLOCK);
> +       if (ret)
> +               return ret;
> +
> +       ret = nor->flash_is_locked(nor, ofs, len);
> +
> +       spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
> +       return ret;
> +}
> +
>  /* Used when the "_ext_id" is two bytes at most */
>  #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)     \
>                 .id = {                                                 \
> @@ -1151,11 +1184,13 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
>         if (JEDEC_MFR(info) == SNOR_MFR_MICRON) {
>                 nor->flash_lock = stm_lock;
>                 nor->flash_unlock = stm_unlock;
> +               nor->flash_is_locked = stm_is_locked;
>         }
>
> -       if (nor->flash_lock && nor->flash_unlock) {
> +       if (nor->flash_lock && nor->flash_unlock && nor->flash_is_locked) {
>                 mtd->_lock = spi_nor_lock;
>                 mtd->_unlock = spi_nor_unlock;
> +               mtd->_is_locked = spi_nor_is_locked;

Need some understanding here, is this lock status call will be re-used
at the time of _erase and _write calls for skipping locked area or
sectors, if so how it re-used? Idea here is if user erase an area
out-of which some part is locked and other unlocked the erase call
should print the locked area and erase only unlocked area.

>         }
>
>         /* sst nor chips use AAI word program */
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index bd8068f6796a..8620bfaed261 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -176,6 +176,8 @@ struct mtd_info;
>   *                     at the offset @offs
>   * @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
>   * @priv:              the private data
>   */
>  struct spi_nor {
> @@ -212,6 +214,7 @@ struct spi_nor {
>
>         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);
>
>         void *priv;
>  };
> --
> 2.5.0.457.gab17608
>
>
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-- Jagan.