Re: [RFC PATCH v2 07/20] cxl: Add Set Feature command support for user submission

[Dave Jiang <dave.jiang@intel.com>]

On 11/21/24 10:49 AM, Jonathan Cameron wrote:
> On Fri, 15 Nov 2024 14:25:40 -0700
> Dave Jiang <dave.jiang@intel.com> wrote:
> 
>> Add enumeration of Set Feature mailbox command for the kernel to recognize
>> the command being passed in from user space.
> 
> This looks unwise to make available on the ioctl. 

Do you mean the current memdev char dev ioctl? Maybe we can introduce a restricted_commands mask to block that on the legacy ioctl? Trying to make the two ioctl paths co-exist is a bit of a pain right now.

DJ
 
> 
>>
>> CXL spec r3.1 8.2.9.6.3 Set Feature (Opcode 0502h)
>>
>> The feature requested is identified by specific UUID.
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>>  drivers/cxl/core/mbox.c      | 1 +
>>  include/uapi/linux/cxl_mem.h | 1 +
>>  2 files changed, 2 insertions(+)
>>
>> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
>> index 4b9abf9a5b2b..739444d34130 100644
>> --- a/drivers/cxl/core/mbox.c
>> +++ b/drivers/cxl/core/mbox.c
>> @@ -69,6 +69,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
>>  	CXL_CMD(GET_TIMESTAMP, 0, 0x8, 0),
>>  	CXL_CMD(GET_SUPPORTED_FEATURES, 0x8, CXL_VARIABLE_PAYLOAD, 0),
>>  	CXL_CMD(GET_FEATURE, 0x15, CXL_VARIABLE_PAYLOAD, 0),
>> +	CXL_CMD(SET_FEATURE, CXL_VARIABLE_PAYLOAD, 0, 0),
>>  };
>>  
>>  /*
>> diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
>> index 90dcb9723997..469dd481795f 100644
>> --- a/include/uapi/linux/cxl_mem.h
>> +++ b/include/uapi/linux/cxl_mem.h
>> @@ -52,6 +52,7 @@
>>  	___C(GET_SUP_LOG_SUBLIST, "Get Supported Logs Sub-List"),	  \
>>  	___C(GET_SUPPORTED_FEATURES, "Get Supported Features"),		  \
>>  	___C(GET_FEATURE, "Get Feature"),				  \
>> +	___C(SET_FEATURE, "Set Feature"),				  \
>>  	___C(MAX, "invalid / last command")
>>  
>>  #define ___C(a, b) CXL_MEM_COMMAND_ID_##a
>