Re: [PATCH] drm/mediatek/dp: Add the HDCP feature for DisplayPort

[CK Hu (胡俊光)]

Hi, Mac:

On Fri, 2023-11-24 at 16:53 +0800, mac.shen wrote:
> Add tee client application, HDCP 1.x and 2.x authentication for
> DisplayPort
> to support the HDCP feature.
> 
> Signed-off-by: mac.shen <mac.shen@xxxxxxxxxxxx>
> ---

[snip]

> +static int dp_tee_op_send(struct dp_tee_private *dp_tee_priv, u8
> *buf, size_t len, u32 cmd_id)
> +{
> +	int rc;
> +	u8 *temp_buf;
> +	struct tee_ioctl_invoke_arg transceive_args;
> +	struct tee_param command_params[4];
> +	struct tee_shm *shm = dp_tee_priv->shm;
> +
> +	if (len > MAX_COMMAND_SIZE) {
> +		TLCERR("%s: len=%zd exceeds MAX_COMMAND_SIZE supported
> by dp TA\n", __func__, len);
> +		return -EIO;
> +	}
> +
> +	memset(&transceive_args, 0, sizeof(transceive_args));
> +	memset(command_params, 0, sizeof(command_params));
> +	dp_tee_priv->resp_len = 0;
> +
> +	/* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of dp TA */
> +	transceive_args = (struct tee_ioctl_invoke_arg) {
> +		.func = cmd_id,
> +		.session = dp_tee_priv->session,
> +		.num_params = 4,
> +	};
> +
> +	/* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */
> +	command_params[0] = (struct tee_param) {
> +		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
> +		.u.memref = {
> +			.shm = shm,
> +			.size = len,
> +			.shm_offs = 0,
> +		},
> +	};
> +
> +	temp_buf = tee_shm_get_va(shm, 0);
> +	if (IS_ERR(temp_buf)) {
> +		TLCERR("%s: tee_shm_get_va failed for transmit\n",
> __func__);
> +		return PTR_ERR(temp_buf);
> +	}
> +
> +	memcpy(temp_buf, buf, len);

temp_buf is equal to buf, so drop temp_buf.

Regards,
CK

> +
> +	command_params[1] = (struct tee_param) {
> +		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
> +		.u.memref = {
> +			.shm = shm,
> +			.size = MAX_RESPONSE_SIZE,
> +			.shm_offs = MAX_COMMAND_SIZE,
> +		},
> +	};
> +
> +	rc = tee_client_invoke_func(dp_tee_priv->ctx, &transceive_args,
> +				    command_params);
> +	if (rc < 0 || transceive_args.ret != 0) {
> +		TLCERR("%s: invoke error: 0x%x\n", __func__,
> transceive_args.ret);
> +		return (rc < 0) ? rc : transceive_args.ret;
> +	}
> +
> +	temp_buf = tee_shm_get_va(shm,
> command_params[1].u.memref.shm_offs);
> +	if (IS_ERR(temp_buf)) {
> +		TLCERR("%s: tee_shm_get_va failed for receive\n",
> __func__);
> +		return PTR_ERR(temp_buf);
> +	}
> +
> +	/* Sanity checks look good, cache the response */
> +	memcpy(dp_tee_priv->resp_buf, temp_buf, MAX_RESPONSE_SIZE / 2);
> +	dp_tee_priv->resp_len = MAX_RESPONSE_SIZE / 2;
> +
> +	return 0;
> +}
> +