[PATCH] drivers: mmc: support secure erase.

[Jaehoon Chung]

Hi,

CC'd Peng (mmc maintainer).

On 12/18/20 10:21 PM, dennis wrote:
> According to the JEDEC Standard, eMMC v4.4 cards can supoort secure erase.
> the first bit in ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT] - EXT_CSD_SEC_ER_EN
> is used to check if secure erase supoort by the device.

%s/supoort/supports/

Anyway, i don't know what

> 
> Signed-off-by: dennis <dennislaplacian1 at gmail.com>
> ---
>  drivers/mmc/Kconfig     |  8 ++++++++
>  drivers/mmc/mmc.c       |  4 ++++
>  drivers/mmc/mmc_write.c | 16 +++++++++++++---
>  include/mmc.h           |  5 ++++-
>  4 files changed, 29 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
> index 14d7913986..6105cbe960 100644
> --- a/drivers/mmc/Kconfig
> +++ b/drivers/mmc/Kconfig
> @@ -18,6 +18,14 @@ config MMC_WRITE
>  	help
>  	  Enable write access to MMC and SD Cards
>  
> +config MMC_SECURE_ERASE
> +	bool "Enable secure erase for eMMC"
> +	depends on MMC_WRITE
> +	default n
> +	help
> +	  This option replace the default erase with secure erase in eMMC v4.4
> +	  and above cards.
> +
>  config MMC_BROKEN_CD
>  	bool "Poll for broken card detection case"
>  	help
> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> index a6394bcf30..56b17070e7 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -2272,6 +2272,10 @@ static int mmc_startup_v4(struct mmc *mmc)
>  		if ((capacity >> 20) > 2 * 1024)
>  			mmc->capacity_user = capacity;
>  	}
> +#if CONFIG_IS_ENABLED(MMC_SECURE_ERASE)
> +	if (mmc->version >= MMC_VERSION_4_4 && IS_MMC(mmc))

if (IS_ENABLED())?

> +		mmc->sec_feature_support = ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT];
> +#endif
>  
>  	if (mmc->version >= MMC_VERSION_4_5)
>  		mmc->gen_cmd6_time = ext_csd[EXT_CSD_GENERIC_CMD6_TIME];
> diff --git a/drivers/mmc/mmc_write.c b/drivers/mmc/mmc_write.c
> index 6a4453ca02..0b720ccf7e 100644
> --- a/drivers/mmc/mmc_write.c
> +++ b/drivers/mmc/mmc_write.c
> @@ -15,7 +15,7 @@
>  #include <linux/math64.h>
>  #include "mmc_private.h"
>  
> -static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt)
> +static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt, uint arg)
>  {
>  	struct mmc_cmd cmd;
>  	ulong end;
> @@ -52,7 +52,7 @@ static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt)
>  		goto err_out;
>  
>  	cmd.cmdidx = MMC_CMD_ERASE;
> -	cmd.cmdarg = MMC_ERASE_ARG;
> +	cmd.cmdarg = arg;
>  	cmd.resp_type = MMC_RSP_R1b;
>  
>  	err = mmc_send_cmd(mmc, &cmd, NULL);
> @@ -81,6 +81,7 @@ ulong mmc_berase(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt)
>  	struct mmc *mmc = find_mmc_device(dev_num);
>  	lbaint_t blk = 0, blk_r = 0;
>  	int timeout_ms = 1000;
> +	uint arg = MMC_ERASE_ARG;
>  
>  	if (!mmc)
>  		return -1;
> @@ -105,6 +106,15 @@ ulong mmc_berase(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt)
>  		       ((start + blkcnt + mmc->erase_grp_size)
>  		       & ~(mmc->erase_grp_size - 1)) - 1);
>  
> +#if CONFIG_IS_ENABLED(MMC_SECURE_ERASE)
> +	if (!(mmc->sec_feature_support & EXT_CSD_SEC_ER_EN)) {

ditto. if (IS_ENABLED()) instead of #if.
And i don't know why doesn't check this in mmc_erase_t().
Then it doesn't need to pass arg as argument.

> +		printf("secure erase not supported on device\n"
> +		       "perform insecure erase\n");
> +	} else {
> +		arg = MMC_SECURE_ERASE_ARG;
> +	}
> +#endif
> +
>  	while (blk < blkcnt) {
>  		if (IS_SD(mmc) && mmc->ssr.au) {
>  			blk_r = ((blkcnt - blk) > mmc->ssr.au) ?
> @@ -113,7 +123,7 @@ ulong mmc_berase(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt)
>  			blk_r = ((blkcnt - blk) > mmc->erase_grp_size) ?
>  				mmc->erase_grp_size : (blkcnt - blk);
>  		}
> -		err = mmc_erase_t(mmc, start + blk, blk_r);
> +		err = mmc_erase_t(mmc, start + blk, blk_r, arg);
>  		if (err)
>  			break;
>  
> diff --git a/include/mmc.h b/include/mmc.h
> index 1d377e0281..bfdc712bdd 100644
> --- a/include/mmc.h
> +++ b/include/mmc.h
> @@ -80,7 +80,6 @@ struct bd_info;
>  #define MMC_MODE_1BIT		BIT(28)
>  #define MMC_MODE_SPI		BIT(27)
>  
> -

Not need to touch this.

>  #define SD_DATA_4BIT	0x00040000
>  
>  #define IS_SD(x)	((x)->version & SD_VERSION_SD)
> @@ -240,6 +239,7 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
>  #define EXT_CSD_HC_WP_GRP_SIZE		221	/* RO */
>  #define EXT_CSD_HC_ERASE_GRP_SIZE	224	/* RO */
>  #define EXT_CSD_BOOT_MULT		226	/* RO */
> +#define EXT_CSD_SEC_FEATURE_SUPPORT 231 /* RO */
>  #define EXT_CSD_GENERIC_CMD6_TIME       248     /* RO */
>  #define EXT_CSD_BKOPS_SUPPORT		502	/* RO */
>  
> @@ -247,6 +247,8 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
>   * EXT_CSD field definitions
>   */
>  
> +#define EXT_CSD_SEC_ER_EN   BIT(0)
> +
>  #define EXT_CSD_CMD_SET_NORMAL		(1 << 0)
>  #define EXT_CSD_CMD_SET_SECURE		(1 << 1)
>  #define EXT_CSD_CMD_SET_CPSECURE	(1 << 2)
> @@ -690,6 +692,7 @@ struct mmc {
>  	uint tran_speed;
>  	uint legacy_speed; /* speed for the legacy mode provided by the card */
>  	uint read_bl_len;
> +	u8 sec_feature_support;

This is located at below under MMC_WRITE and it's only used when MMC_SECURE_ERASE is enabled.

Best Regards,
Jaehoon Chung

>  #if CONFIG_IS_ENABLED(MMC_WRITE)
>  	uint write_bl_len;
>  	uint erase_grp_size;	/* in 512-byte sectors */
>