Re: [External] : Re: [PATCH v2] mmc-utils: Add eMMC erase command support

[kimito.sakata@oracle.com]

On 3/30/2021 6:39 AM, Ulf Hansson wrote:
> On Wed, 24 Mar 2021 at 17:45, Bean Huo <huobean@gmail.com> wrote:
>> From: Kimito Sakata <kimito.sakata@oracle.com>
>>
>> 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.
>>
>> Co-developed-by: Bean Huo <beanhuo@micron.com>
>> Signed-off-by: Bean Huo <beanhuo@micron.com>
>> Reviewed-by: Kenneth Gibbons <kenny.gibbons@oracle.com>
>> ---
>>
>> Hi Ulf,
>> Please help us review this mmc-utils patch, and if agree, it is
>> possible to make it merged in the official mmc-utils.
>>
>> Changelog:
>>
>> 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 | 135 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   mmc_cmds.h |   1 +
>>   4 files changed, 156 insertions(+), 1 deletion(-)
>>
>> diff --git a/mmc.c b/mmc.c
>> index 50c9c9e..cb29a65 100644
>> --- a/mmc.c
>> +++ b/mmc.c
>> @@ -215,6 +215,14 @@ static struct Command commands[] = {
>>                  "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 region of the device\n"
>> +               "<type> must be: legacy | discard | secure-erase | "
>> +               "secure-trim1 | secure-trim2 | trim \n",
>> +       NULL
>> +       },
>>          { 0, 0, 0, 0 }
>>   };
>>
>> diff --git a/mmc.h b/mmc.h
>> index 648fb26..90b7fb5 100644
>> --- a/mmc.h
>> +++ b/mmc.h
>> @@ -34,7 +34,15 @@
>>   #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 for
>> +                                             Erase (or TRIM Enable)  R1b */
>>   /*
>>    * EXT_CSD fields
>>    */
>> @@ -61,6 +69,7 @@
>>   #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
>> @@ -177,6 +186,8 @@
>>   #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)
>>
>>
>>   /* From kernel linux/mmc/core.h */
>> diff --git a/mmc_cmds.c b/mmc_cmds.c
>> index fb37189..17986e3 100644
>> --- a/mmc_cmds.c
>> +++ b/mmc_cmds.c
>> @@ -2435,6 +2435,141 @@ int do_cache_dis(int nargs, char **argv)
>>          return do_cache_ctrl(0, nargs, argv);
>>   }
>>
>> +static int erase(int dev_fd, __u32 argin, __u32 start, __u32 end)
>> +{
>> +#ifndef MMC_IOC_MULTI_CMD
> In kernel v4.4 we added the multi cmd support, which is quite some
> time ago. So, I think it's time to drop these ifdef hackary from the
> userland tool. At least, we shouldn't need it for new kinds of
> features that we add.
Ulf
Do you want us to take out the  MMC_IOC_MULTI_CMD ifdef and resubmit?
Kimito

>
>> +       fprintf(stderr, "mmc-utils has been compiled without MMC_IOC_MULTI_CMD"
>> +                       " support, needed by erase.\n");
>> +       return -ENOTSUP;
>> +#else
>> +       int ret = 0;
>> +       struct mmc_ioc_multi_cmd *multi_cmd;
>> +
> [...]
>
> Kind regards
> Uffe