[PATCH v2] env: mmc: Add support for redundant env in both eMMC boot partitions

[Jaehoon Chung]

Hi Marek,

On 10/18/21 2:23 AM, Marek Vasut wrote:
> Currently the MMC environment driver supports storing redundant environment
> only in one eMMC partition at different offsets. This is sub-optimal, since
> if this one boot partition is erased, both copies of environment are lost.
> Since the eMMC has two boot partitions, add support for storing one copy of
> environment in each of the two boot partitions.
> 
> To enable this functionality, select CONFIG_SYS_REDUNDAND_ENVIRONMENT to
> indicate redundant environment should be used. Set CONFIG_SYS_MMC_ENV_PART
> to 1 to indicate environment should be stored in eMMC boot partition. Set
> CONFIG_ENV_OFFSET equal to CONFIG_ENV_OFFSET_REDUND, and both to the offset
> from start of eMMC boot partition where the environment should be located.

Is there any patch before apply this? When I had been trying to test this, I can't apply this from patchwork.

Best Regards,
Jaehoon Chung

> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Fabio Estevam <festevam at gmail.com>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> Cc: Peng Fan <peng.fan at nxp.com>
> Cc: Stefano Babic <sbabic at denx.de>
> ---
> V2: Add documentation of this behavior into Kconfig help text
> ---
>  env/Kconfig |  5 +++++
>  env/mmc.c   | 47 ++++++++++++++++++++++++++++++++++++++++++-----
>  2 files changed, 47 insertions(+), 5 deletions(-)
> 
> diff --git a/env/Kconfig b/env/Kconfig
> index f75f2b13536..06d72bad1dc 100644
> --- a/env/Kconfig
> +++ b/env/Kconfig
> @@ -200,6 +200,11 @@ config ENV_IS_IN_MMC
>  	  This value may also be positive or negative; this is handled in the
>  	  same way as CONFIG_ENV_OFFSET.
>  
> +	  In case CONFIG_SYS_MMC_ENV_PART is 1 (i.e. environment in eMMC boot
> +	  partition) then setting CONFIG_ENV_OFFSET_REDUND to the same value
> +	  as CONFIG_ENV_OFFSET makes use of the second eMMC boot partition for
> +	  the redundant environment copy.
> +
>  	  This value is also in units of bytes, but must also be aligned to
>  	  an MMC sector boundary.
>  
> diff --git a/env/mmc.c b/env/mmc.c
> index e111d8e5881..465b104559b 100644
> --- a/env/mmc.c
> +++ b/env/mmc.c
> @@ -26,6 +26,18 @@
>  
>  DECLARE_GLOBAL_DATA_PTR;
>  
> +/*
> + * In case the environment is redundant, stored in eMMC hardware boot
> + * partition and the environment and redundant environment offsets are
> + * identical, store the environment and redundant environment in both
> + * eMMC boot partitions, one copy in each.
> + * */
> +#if (defined(CONFIG_SYS_REDUNDAND_ENVIRONMENT) && \
> +     (CONFIG_SYS_MMC_ENV_PART == 1) && \
> +     (CONFIG_ENV_OFFSET == CONFIG_ENV_OFFSET_REDUND))
> +#define ENV_MMC_HWPART_REDUND
> +#endif
> +
>  #if CONFIG_IS_ENABLED(OF_CONTROL)
>  static inline int mmc_offset_try_partition(const char *str, int copy, s64 *val)
>  {
> @@ -126,13 +138,11 @@ __weak uint mmc_get_env_part(struct mmc *mmc)
>  
>  static unsigned char env_mmc_orig_hwpart;
>  
> -static int mmc_set_env_part(struct mmc *mmc)
> +static int mmc_set_env_part(struct mmc *mmc, uint part)
>  {
> -	uint part = mmc_get_env_part(mmc);
>  	int dev = mmc_get_env_dev();
>  	int ret = 0;
>  
> -	env_mmc_orig_hwpart = mmc_get_blk_desc(mmc)->hwpart;
>  	ret = blk_select_hwpart_devnum(IF_TYPE_MMC, dev, part);
>  	if (ret)
>  		puts("MMC partition switch failed\n");
> @@ -140,7 +150,7 @@ static int mmc_set_env_part(struct mmc *mmc)
>  	return ret;
>  }
>  #else
> -static inline int mmc_set_env_part(struct mmc *mmc) {return 0; };
> +static inline int mmc_set_env_part(struct mmc *mmc, uint part) {return 0; };
>  #endif
>  
>  static const char *init_mmc_for_env(struct mmc *mmc)
> @@ -157,7 +167,8 @@ static const char *init_mmc_for_env(struct mmc *mmc)
>  	if (mmc_init(mmc))
>  		return "MMC init failed";
>  #endif
> -	if (mmc_set_env_part(mmc))
> +	env_mmc_orig_hwpart = mmc_get_blk_desc(mmc)->hwpart;
> +	if (mmc_set_env_part(mmc, mmc_get_env_part(mmc)))
>  		return "MMC partition switch failed";
>  
>  	return NULL;
> @@ -209,6 +220,13 @@ static int env_mmc_save(void)
>  #ifdef CONFIG_ENV_OFFSET_REDUND
>  	if (gd->env_valid == ENV_VALID)
>  		copy = 1;
> +
> +#ifdef ENV_MMC_HWPART_REDUND
> +	ret = mmc_set_env_part(mmc, copy + 1);
> +	if (ret)
> +		goto fini;
> +#endif
> +
>  #endif
>  
>  	if (mmc_get_env_addr(mmc, copy, &offset)) {
> @@ -273,6 +291,12 @@ static int env_mmc_erase(void)
>  #ifdef CONFIG_ENV_OFFSET_REDUND
>  	copy = 1;
>  
> +#ifdef ENV_MMC_HWPART_REDUND
> +	ret = mmc_set_env_part(mmc, copy + 1);
> +	if (ret)
> +		goto fini;
> +#endif
> +
>  	if (mmc_get_env_addr(mmc, copy, &offset)) {
>  		ret = CMD_RET_FAILURE;
>  		goto fini;
> @@ -331,7 +355,20 @@ static int env_mmc_load(void)
>  		goto fini;
>  	}
>  
> +#ifdef ENV_MMC_HWPART_REDUND
> +	ret = mmc_set_env_part(mmc, 1);
> +	if (ret)
> +		goto fini;
> +#endif
> +
>  	read1_fail = read_env(mmc, CONFIG_ENV_SIZE, offset1, tmp_env1);
> +
> +#ifdef ENV_MMC_HWPART_REDUND
> +	ret = mmc_set_env_part(mmc, 2);
> +	if (ret)
> +		goto fini;
> +#endif
> +
>  	read2_fail = read_env(mmc, CONFIG_ENV_SIZE, offset2, tmp_env2);
>  
>  	ret = env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2,
>