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From:   Avri Altman <Avri.Altman@wdc.com>
To:     "luserhker@gmail.com" <luserhker@gmail.com>,
        "beanhuo@micron.com" <beanhuo@micron.com>,
        "kenny.gibbons@oracle.com" <kenny.gibbons@oracle.com>,
        "kimito.sakata@oracle.com" <kimito.sakata@oracle.com>,
        "rkamdar@micron.com" <rkamdar@micron.com>,
        "chris@printf.net" <chris@printf.net>,
        "ulf.hansson@linaro.org" <ulf.hansson@linaro.org>
CC:     "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH RESEND v3] mmc-utils: Add eMMC erase command support
Thread-Topic: [PATCH RESEND v3] mmc-utils: Add eMMC erase command support
Thread-Index: AQHXO57NnhsDqu5+ekuwErAvlXojOarJaxCA
Date:   Wed, 28 Apr 2021 05:57:31 +0000
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Hi Kimito & Bean,

>=20
> From: Kimito Sakata <kimito.sakata@oracle.com>
>=20
> we have been using this erase feature for a while, but it is
> still not merged into the upstream mmc-utils. Especially, for
> the customer, every time when they update the mmc-utils, they
> should re-install this patch again, let's try to make this
> erase command upstreamed in the mmc-utils.
>=20
> We need to send 3 MMC commands and it is important that they
> stay in sequence. Therefore we are using MMC_IOC_MULTI_CMD.

You might also want to indicate on which platform it was tested.

>=20
> Co-developed-by: Bean Huo <beanhuo@micron.com>
> Signed-off-by: Bean Huo <beanhuo@micron.com>
> Signed-off-by: Kimito Sakata <kimito.sakata@oracle.com>
> Reviewed-by: Kenneth Gibbons <kenny.gibbons@oracle.com>
>=20
> Changelog:
> v2--v3:
>     1. Remove redundant ifndef
>=20
> V1--V2:
>     1. refactor Kimito's original patch
>     2. change to use MMC_IOC_MULTI_CMD
>     3. add checkup if eMMC devie supports secure erase/trim
> ---
>  mmc.c      |   8 ++++
>  mmc.h      |  13 +++++-
>  mmc_cmds.c | 130
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  mmc_cmds.h |   1 +
>  4 files changed, 151 insertions(+), 1 deletion(-)
>=20
> diff --git a/mmc.c b/mmc.c
> index f3d724b..eb2638b 100644
> --- a/mmc.c
> +++ b/mmc.c
> @@ -229,6 +229,14 @@ static struct Command commands[] =3D {
>                 "Run Field Firmware Update with <image name> on <device>.=
\n",
>           NULL
>         },
> +       { do_erase, -4,
> +       "erase", "<type> " "<start address> " "<end address> " "<device>\=
n"
> +               "Send Erase CMD38 with specific argument to the <device>\=
n\n"
> +               "NOTE!: This will delete all user data in the specified r=
egion of the
> device\n"
> +               "<type> must be: legacy | discard | secure-erase | "
> +               "secure-trim1 | secure-trim2 | trim \n",
> +       NULL
> +       },
>         { 0, 0, 0, 0 }
>  };
>=20
> diff --git a/mmc.h b/mmc.h
> index 5754a9d..e9766d7 100644
> --- a/mmc.h
> +++ b/mmc.h
> @@ -35,7 +35,15 @@
>  #define MMC_SET_WRITE_PROT     28    /* ac   [31:0] data addr   R1b */
>  #define MMC_CLEAR_WRITE_PROT   29    /* ac   [31:0] data addr   R1b */
>  #define MMC_SEND_WRITE_PROT_TYPE 31   /* ac   [31:0] data addr   R1  */
> -
> +#define MMC_ERASE_GROUP_START  35    /* ac   [31:0] data addr   R1  */
> +#define MMC_ERASE_GROUP_END    36    /* ac   [31:0] data addr   R1  */
> +#define MMC_ERASE              38    /* ac   [31] Secure request
> +                                             [30:16] set to 0
> +                                             [15] Force Garbage Collect =
request
> +                                             [14:2] set to 0
> +                                             [1] Discard Enable
> +                                             [0] Identify Write Blocks f=
or
> +                                             Erase (or TRIM Enable)  R1b=
 */
>  /*
>   * EXT_CSD fields
>   */
> @@ -62,6 +70,7 @@
>  #define EXT_CSD_CACHE_SIZE_2           251
>  #define EXT_CSD_CACHE_SIZE_1           250
>  #define EXT_CSD_CACHE_SIZE_0           249
> +#define EXT_CSD_SEC_FEATURE_SUPPORT    231
>  #define EXT_CSD_BOOT_INFO              228     /* R/W */
>  #define EXT_CSD_HC_ERASE_GRP_SIZE      224
>  #define EXT_CSD_HC_WP_GRP_SIZE         221
> @@ -190,6 +199,8 @@
>  #define EXT_CSD_REV_V4_2               2
>  #define EXT_CSD_REV_V4_1               1
>  #define EXT_CSD_REV_V4_0               0
> +#define EXT_CSD_SEC_GB_CL_EN           (1<<4)
> +#define EXT_CSD_SEC_ER_EN              (1<<0)
>=20
>=20
>  /* From kernel linux/mmc/core.h */
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index 6c24cea..24f80db 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -2514,6 +2514,136 @@ int do_cache_dis(int nargs, char **argv)
>         return do_cache_ctrl(0, nargs, argv);
>  }
>=20
> +static int erase(int dev_fd, __u32 argin, __u32 start, __u32 end)
> +{
> +       int ret =3D 0;
> +       struct mmc_ioc_multi_cmd *multi_cmd;
> +
> +       multi_cmd =3D calloc(1, sizeof(struct mmc_ioc_multi_cmd) +
> +                          3 * sizeof(struct mmc_ioc_cmd));
> +       if (!multi_cmd) {
> +               perror("Failed to allocate memory");
> +               return -ENOMEM;
> +       }
I am missing reference to ERASE_GROUP_DEF.
It affects the timeout, size of erase group etc.
Don't you need to query for before starting to build the command?

> +
> +       multi_cmd->num_of_cmds =3D 3;
> +       /* Set erase start address */
> +       multi_cmd->cmds[0].opcode =3D MMC_ERASE_GROUP_START;
> +       multi_cmd->cmds[0].arg =3D start;
> +       multi_cmd->cmds[0].flags =3D MMC_RSP_SPI_R1 | MMC_RSP_R1 |
> MMC_CMD_AC;
> +       multi_cmd->cmds[0].write_flag =3D 1;
> +
> +       /* Set erase end address */
> +       multi_cmd->cmds[1].opcode =3D MMC_ERASE_GROUP_END;
> +       multi_cmd->cmds[1].arg =3D end;
> +       multi_cmd->cmds[1].flags =3D MMC_RSP_SPI_R1 | MMC_RSP_R1 |
> MMC_CMD_AC;
> +       multi_cmd->cmds[1].write_flag =3D 1;
> +
> +       /* Send Erase Command */
> +       multi_cmd->cmds[2].opcode =3D MMC_ERASE;
> +       multi_cmd->cmds[2].arg =3D argin;
> +       multi_cmd->cmds[2].cmd_timeout_ms =3D 300*255*255;
> +       multi_cmd->cmds[2].flags =3D MMC_RSP_SPI_R1B | MMC_RSP_R1B |
> MMC_CMD_AC;
> +       multi_cmd->cmds[2].write_flag =3D 1;
> +
> +       /* send erase cmd with multi-cmd */
> +       ret =3D ioctl(dev_fd, MMC_IOC_MULTI_CMD, multi_cmd);
> +       if (ret)
> +               perror("Erase multi-cmd ioctl");
> +
> +       free(multi_cmd);
> +       return ret;
> +#endif
> +}
> +
> +int do_erase(int nargs, char **argv)
> +{
> +       int dev_fd, ret;
> +       char *print_str;
> +       char **eptr =3D NULL;
> +       __u8 ext_csd[512], checkup_mask =3D 0;
> +       __u32 arg, start, end;
> +
> +       if (nargs !=3D 5) {
> +               fprintf(stderr, "Usage: erase <type> <start addr> <end ad=
dr>
> </path/to/mmcblkX>\n");
> +               exit(1);
> +       }
> +
> +       if (strstr(argv[2], "0x") || strstr(argv[2], "0X"))
> +               start =3D strtol(argv[2], eptr, 16);
> +       else
> +               start =3D strtol(argv[2], eptr, 10);
> +
> +       if (strstr(argv[3], "0x") || strstr(argv[3], "0X"))
> +               end =3D strtol(argv[3], eptr, 16);
> +       else
> +               end =3D strtol(argv[3], eptr, 10);
You are not really using eptr - maybe just call strtol with NULL?=20

> +
> +       if (end < start) {
> +               fprintf(stderr, "erase start [0x%08x] > erase end [0x%08x=
]\n",
> +                       start, end);
> +               exit(1);
> +       }
Start & End are in bytes for media < 2GB, and in sectors for media >=3D2GB.=
=20
Should also check for legal erase group restrictions.

> +
> +       if (strcmp(argv[1], "legacy") =3D=3D 0) {
> +               arg =3D 0x00000000;
> +               print_str =3D "Legacy Erase";
> +       } else if (strcmp(argv[1], "discard") =3D=3D 0) {
> +               arg =3D 0x00000003;
> +               print_str =3D "Discard";
> +       } else if (strcmp(argv[1], "secure-erase") =3D=3D 0) {
> +               print_str =3D "Secure Erase";
> +               checkup_mask =3D EXT_CSD_SEC_ER_EN;
> +               arg =3D 0x80000000;
> +       } else if (strcmp(argv[1], "secure-trim1") =3D=3D 0) {
> +               print_str =3D "Secure Trim Step 1";
> +               checkup_mask =3D EXT_CSD_SEC_ER_EN | EXT_CSD_SEC_GB_CL_EN=
;
> +               arg =3D 0x80000001;
> +       } else if (strcmp(argv[1], "secure-trim2") =3D=3D 0) {
> +               print_str =3D "Secure Trim Step 2";
> +               checkup_mask =3D EXT_CSD_SEC_ER_EN | EXT_CSD_SEC_GB_CL_EN=
;
> +               arg =3D 0x80008000;
> +       } else if (strcmp(argv[1], "trim") =3D=3D 0) {
> +               print_str =3D "Trim";
> +               checkup_mask =3D EXT_CSD_SEC_GB_CL_EN;
> +               arg =3D 0x00000001;
> +       } else {
> +               fprintf(stderr, "Unknown erase type: %s\n", argv[1]);
> +               exit(1);
> +       }
Maybe use an enum for the erase type to avoid the strcmp?
Then need to update the usage message.

> +
> +       dev_fd =3D open(argv[4], O_RDWR);
> +       if (dev_fd < 0) {
> +               perror(argv[4]);
> +               exit(1);
> +       }
How do you differentiate between mmc and SD devices?
And for SD you should send different commands(35/36 vs. 32/33).
Do you intend to support SD devices as well? In another patch?

> +
> +       if (checkup_mask) {
> +               ret =3D read_extcsd(dev_fd, ext_csd);
> +               if (ret) {
> +                       fprintf(stderr, "Could not read EXT_CSD from %s\n=
",
> +                               argv[4]);
> +                       goto out;
> +               }
> +               if ((checkup_mask & ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT])=
 !=3D
> +                                                               checkup_m=
ask) {
> +                       fprintf(stderr, "%s is not supported in %s\n",
> +                               print_str, argv[4]);
> +                       ret =3D -ENOTSUP;
> +                       goto out;
> +               }
EXT_CSD_SEC_FEATURE_SUPPORT might also contains the sanitize bit,
as well as reserved bits that you shouldn't assume they are 0, so I am not =
sure that this condition is correct.
The checkup only refers to bit 0 and bit 4 - maybe add a helper that accept=
 &args and returns 0 if allowed...


Thanks,
Avri

> +
> +       }
> +       printf("Executing %s from 0x%08x to 0x%08x\n", print_str, start, =
end);
> +
> +       ret =3D erase(dev_fd, arg, start, end);
> +out:
> +       printf(" %s %s!\n\n", print_str, ret ? "Failed" : "Succeed");
> +       close(dev_fd);
> +       return ret;
> +}
> +
> +
>  int do_ffu(int nargs, char **argv)
>  {
>  #ifndef MMC_IOC_MULTI_CMD
> diff --git a/mmc_cmds.h b/mmc_cmds.h
> index 9d3246c..8331ab2 100644
> --- a/mmc_cmds.h
> +++ b/mmc_cmds.h
> @@ -45,3 +45,4 @@ int do_ffu(int nargs, char **argv);
>  int do_read_scr(int argc, char **argv);
>  int do_read_cid(int argc, char **argv);
>  int do_read_csd(int argc, char **argv);
> +int do_erase(int nargs, char **argv);
> --
> 2.24.1 (Apple Git-126)