[Skiboot] [PATCH V6 20/21] core/pldm: Add file io write request

[Christophe Lombard]

Le 30/09/2022 à 08:27, Abhishek SIngh Tomar a écrit :
> Hello Christophe
> I am having some questions in this patch
>> +
>> +	if ((offset) && (offset > size))
>> +		return OPAL_PARAMETER;
> Why is offset need to be lesser than size of buffer to write?
Good catch ! The test is not correct. The good solution is:
     if ((offset) && ((size + offset) > file_length))
         return OPAL_PARAMETER;

>> +
>> +	request_length = sizeof(struct pldm_msg_hdr) +
>> +			 sizeof(struct pldm_write_file_req) +
>> +			 size;
> Why request payload is equal to size (size of buffer)?
> The Maximum request payload needed when size > MAX_TRANSFER_SIZE_BYTES
> is MAX_TRANSFER_SIZE_BYTES
>
request_length is the size of the complete PLDM request you send to the BMC.
We need to add the size of the common header + the specific header + the
size of lid file requested.

>> +
>> +	for (i = 0; i < num_transfers; i++) {
>> +		file_req.offset = offset + (i * MAX_TRANSFER_SIZE_BYTES);
>> +
>> +		/* Encode the file request */
>> +		rc = encode_write_file_req(
>> +				DEFAULT_INSTANCE_ID,
>> +				file_req.file_handle,
>> +				file_req.offset,
>> +				file_req.length,
>> +				(struct pldm_msg *)request_msg);
>> +		if (rc != PLDM_SUCCESS) {
>> +			prlog(PR_ERR, "Encode WriteFileReq Error, rc: %d\n", rc);
>> +			free(request_msg);
>> +			return OPAL_PARAMETER;
>> +		}
>> +
>> +		/* Send and get the response message bytes */
>> +		rc = pldm_requester_queue_and_wait(
>> +					request_msg, request_length - 1,
>> +					&response_msg, &response_len);
>> +		if (rc) {
>> +			prlog(PR_ERR, "Communication Error, req: WriteFileReq, rc: %d\n", rc);
>> +			free(request_msg);
>> +			return rc;
>> +		}
>> +
>> +		/* Decode the message */
>> +		payload_len = response_len - sizeof(struct pldm_msg_hdr);
>> +		rc = decode_write_file_resp(
>> +				response_msg,
>> +				payload_len,
>> +				&completion_code,
>> +				&resp_length);
>> +		if (rc != PLDM_SUCCESS || completion_code != PLDM_SUCCESS) {
>> +			prlog(PR_ERR, "Decode WriteFileResp Error, rc: %d, cc: %d\n",
>> +				      rc, completion_code);
>> +			free(request_msg);
>> +			free(response_msg);
>> +			return OPAL_PARAMETER;
>> +		}
>> +
>> +		if (resp_length == 0) {
>> +			free(response_msg);
>> +			break;
>> +		}
>> +
>> +		total_write += resp_length;
>> +		current_ptr += resp_length;
>> +		free(response_msg);
>> +
> In this loop, if size > MAX_TRANSFER_SIZE_BYTES, after sending
> MAX_TRANSFER_SIZE_BYTES once how is payload pointer increasing?
> I think we should copy current_ptr to request_msg payload
You are right. Good point.

>> +		if (total_write == size)
>> +			break;
>> +		else if (resp_length != file_req.length) {
>> +			/* end of file */
>> +			break;
>> +		} else if (MAX_TRANSFER_SIZE_BYTES > (size - total_write))
>> +			file_req.length = size - total_write;
>> +	}
>> +
> Reviewed-by: Abhishek Singh Tomar <abhishek at linux.ibm.com>