[U-Boot] [PATCH v1] set the mmc specific addresss and range as power on write protection, you can't earse and write this range of data if you enable it after mmc power on.

Simon Glass sjg at chromium.org
Mon Dec 14 04:47:29 CET 2015


Hi Lin,

On 13 December 2015 at 19:14, Lin Huang <hl at rock-chips.com> wrote:
> Signed-off-by: Lin Huang <hl at rock-chips.com>
> ---
> Changes in v1:
> - Adviced by Simon:
> - use real error in errno.h to return
> - add full function comments for new function
>
>  drivers/mmc/mmc.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/mmc.h     | 37 +++++++++++++++++++++++
>  2 files changed, 124 insertions(+)
>

This looks OK except that you seem to have put the commit message into
the subject. Can you please fix that?

Also we have a standard way of doing function comments - please see below.

> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> index 3a34028..1308ce9 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -1821,6 +1821,93 @@ int mmc_initialize(bd_t *bis)
>         return 0;
>  }
>
> +int mmc_get_wp_status(struct mmc *mmc, lbaint_t addr, char *status)
> +{
> +       struct mmc_cmd cmd;
> +       struct mmc_data data;
> +       int err;
> +
> +       cmd.cmdidx = MMC_CMD_WRITE_PROT_TYPE;
> +       cmd.resp_type = MMC_RSP_R1;
> +       cmd.cmdarg = addr;
> +
> +       data.dest = status;
> +       data.blocksize = 8;
> +       data.blocks = 1;
> +       data.flags = MMC_DATA_READ;
> +
> +       err = mmc_send_cmd(mmc, &cmd, &data);
> +
> +       return err;
> +}
> +
> +int mmc_usr_power_on_wp(struct mmc *mmc, lbaint_t addr, unsigned int size)
> +{
> +       int err;
> +       unsigned int wp_group_size, wp_grp_num, i;
> +       struct mmc_cmd cmd;
> +       unsigned int timeout = 1000;
> +       ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
> +
> +       size = size / MMC_MAX_BLOCK_LEN;
> +
> +       err = mmc_send_ext_csd(mmc, ext_csd);
> +       if (err)
> +               return err;
> +
> +       if ((ext_csd[EXT_CSD_USER_WP] & EXT_CSD_USER_PERM_WP_EN) ||
> +           (ext_csd[EXT_CSD_USER_WP] & EXT_CSD_USER_PWR_WP_DIS)) {
> +               printf("Power on protection is disabled\n");
> +               return -EINVAL;
> +       }
> +
> +       if (ext_csd[EXT_CSD_ERASE_GROUP_DEF])
> +               wp_group_size = ext_csd[EXT_CSD_HC_WP_GRP_SIZE] *
> +                               ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] * 1024;
> +       else {
> +               int erase_gsz, erase_gmul, wp_grp_size;
> +
> +               erase_gsz = (mmc->csd[2] & 0x00007c00) >> 10;
> +               erase_gmul = (mmc->csd[2] & 0x000003e0) >> 5;
> +               wp_grp_size = (mmc->csd[2] & 0x0000001f);
> +               wp_group_size = (erase_gsz + 1) * (erase_gmul + 1) *
> +                               (wp_grp_size + 1);
> +       }
> +
> +       if (size < wp_group_size) {
> +               printf("wrong size, fail to set power on wp\n");
> +               return -EINVAL;
> +       }
> +
> +       err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
> +                                EXT_CSD_USER_WP, EXT_CSD_USER_PWR_WP_EN);
> +       if (err)
> +               return err;
> +
> +       wp_grp_num = DIV_ROUND_UP(size, wp_group_size);
> +       cmd.cmdidx = MMC_CMD_WRITE_PROT;
> +       cmd.resp_type = MMC_RSP_R1b;
> +
> +       for (i = 0; i < wp_grp_num; i++) {
> +               cmd.cmdarg = addr + i * wp_group_size;
> +               err = mmc_send_cmd(mmc, &cmd, NULL);
> +               if (err)
> +                       return err;
> +
> +               /* CMD28/CMD29 ON failure returns address out of range error */
> +               if ((cmd.response[0] >> 31) & 0x01) {
> +                       printf("address for CMD28/29 out of range\n");
> +                       return -EINVAL;
> +               }
> +
> +               err = mmc_send_status(mmc, timeout);
> +               if (err)
> +                       return err;
> +       }
> +
> +       return 0;
> +}
> +
>  #ifdef CONFIG_SUPPORT_EMMC_BOOT
>  /*
>   * This function changes the size of boot partition and the size of rpmb
> diff --git a/include/mmc.h b/include/mmc.h
> index cda9a19..2f13eea 100644
> --- a/include/mmc.h
> +++ b/include/mmc.h
> @@ -89,6 +89,8 @@
>  #define MMC_CMD_SET_BLOCK_COUNT         23
>  #define MMC_CMD_WRITE_SINGLE_BLOCK     24
>  #define MMC_CMD_WRITE_MULTIPLE_BLOCK   25
> +#define MMC_CMD_WRITE_PROT             28
> +#define MMC_CMD_WRITE_PROT_TYPE                31
>  #define MMC_CMD_ERASE_GROUP_START      35
>  #define MMC_CMD_ERASE_GROUP_END                36
>  #define MMC_CMD_ERASE                  38
> @@ -175,6 +177,7 @@
>  #define EXT_CSD_WR_REL_PARAM           166     /* R */
>  #define EXT_CSD_WR_REL_SET             167     /* R/W */
>  #define EXT_CSD_RPMB_MULT              168     /* RO */
> +#define EXT_CSD_USER_WP                        171
>  #define EXT_CSD_ERASE_GROUP_DEF                175     /* R/W */
>  #define EXT_CSD_BOOT_BUS_WIDTH         177
>  #define EXT_CSD_PART_CONF              179     /* R/W */
> @@ -231,6 +234,10 @@
>  #define EXT_CSD_WR_DATA_REL_USR                (1 << 0)        /* user data area WR_REL */
>  #define EXT_CSD_WR_DATA_REL_GP(x)      (1 << ((x)+1))  /* GP part (x+1) WR_REL */
>
> +#define EXT_CSD_USER_PWR_WP_DIS                (1 << 3) /* disable power-on write protect*/
> +#define EXT_CSD_USER_PERM_WP_EN                (1 << 2) /* enable permanent write protect */
> +#define EXT_CSD_USER_PWR_WP_EN         (1 << 0) /* enable power-on write protect */
> +
>  #define R1_ILLEGAL_COMMAND             (1 << 22)
>  #define R1_APP_CMD                     (1 << 5)
>
> @@ -478,6 +485,36 @@ int mmc_get_env_addr(struct mmc *mmc, int copy, u32 *env_addr);
>
>  struct pci_device_id;
>
> +/*
> + * This function specific user area address enable
> + * power on write protect
> + *
> + * Input Parameters:
> + * struct *mmc: pointer for the mmc device strcuture
> + * addr: address of power on write protect area, use block address
> + * size: size of power on write protect area, count by bytes
> + *
> + * Returns 0 on success.
> + */
> +int mmc_usr_power_on_wp(struct mmc *mmc, lbaint_t addr, unsigned int size);

Function style should follow conventions. Something like this:

/**
 * mmc_usr_power_on_wp() - Enable power-on write protect
 *
 * Description goes here if needed.
 *
 * @mmc: pointer to the mmc device structure
 * @addr: address of power-on write protect area, use block address
 * @size: size of power on write protect area, in bytes
 * @return 0 success, -ve on error
 */

> +
> +/*
> + * This function read specific user area address
> + * write protect status
> + *
> + * Input Parameters:
> + * struct *mmc: pointer for the mmc device strcuture
> + * addr: address you want to read the status, use block address
> + * status: write protect status you get, the value represent:
> + * “00” Write protection group not protected
> + * “01” Write protection group is protected by temporary write protection
> + * “10” Write protection group is protected by power-on write protection
> + * “11” Write protection group is protected by permanent write protection
> + *
> + * Returns 0 on success.
> + */
> +int mmc_get_wp_status(struct mmc *mmc, lbaint_t addr, char *status);
> +
>  /**
>   * pci_mmc_init() - set up PCI MMC devices
>   *
> --
> 1.9.1
>

Regards,
Simon


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