[Intel-gfx] [PATCH v14 23/33] misc/mei/hdcp: Verify H_prime

[Winkler, Tomas]

> Requests for the verification of AKE_Send_H_prime.
> 
> ME will calculate the H and comparing it with received H_Prime.
> The result will be returned as status.
> 
> Here AKE_Send_H_prime is a HDCP2.2 Authentication msg.
> 
> v2: Rebased.
> v3:
>   cldev is passed as first parameter [Tomas]
>   Redundant comments and cast are removed [Tomas]
> v4:
>   %zd for ssize_t [Alexander]
>   %s/return -1/return -EIO [Alexander]
>   Styles and typos fixed [Uma]
> v5: Rebased.
> v6:
>   Collected the Rb-ed by.
>   Rebasing.
> v7:
>   Adjust to the new mei interface.
>   Fix for Kdoc.
> v8:
>   K-Doc Addition [Tomas]
>   memcpy for const length.
> v9:
>   renamed func as mei_hdcp_* [Tomas]
>   Inline function is defined for DDI index [Tomas]
> v10:
>   K-Doc fix. [Tomas]
> 
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> Reviewed-by: Uma Shankar <uma.shankar at intel.com>
> Acked-by: Tomas Winkler <tomas.winkler at intel.com>
LGTM

> ---
>  drivers/misc/mei/hdcp/mei_hdcp.c | 58
> +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 57 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c
> b/drivers/misc/mei/hdcp/mei_hdcp.c
> index 922c6a76bb9f..0a4087a2efd5 100644
> --- a/drivers/misc/mei/hdcp/mei_hdcp.c
> +++ b/drivers/misc/mei/hdcp/mei_hdcp.c
> @@ -182,13 +182,69 @@ mei_hdcp_verify_receiver_cert_prepare_km(struct
> device *dev,
>  	return 0;
>  }
> 
> +/**
> + * mei_hdcp_verify_hprime() - Verify AKE_Send_H_prime at ME FW.
> + * @dev: device corresponding to the mei_cl_device
> + * @data: Intel HW specific hdcp data
> + * @rx_hprime: AKE_Send_H_prime msg for ME FW verification
> + *
> + * Return: 0 on Success, <0 on Failure
> + */
> +static int
> +mei_hdcp_verify_hprime(struct device *dev, struct hdcp_port_data *data,
> +		       struct hdcp2_ake_send_hprime *rx_hprime) {
> +	struct wired_cmd_ake_send_hprime_in send_hprime_in = { { 0 } };
> +	struct wired_cmd_ake_send_hprime_out send_hprime_out = { { 0 } };
> +	struct mei_cl_device *cldev;
> +	ssize_t byte;
> +
> +	if (!dev || !data || !rx_hprime)
> +		return -EINVAL;
> +
> +	cldev = to_mei_cl_device(dev);
> +
> +	send_hprime_in.header.api_version = HDCP_API_VERSION;
> +	send_hprime_in.header.command_id = WIRED_AKE_SEND_HPRIME;
> +	send_hprime_in.header.status = ME_HDCP_STATUS_SUCCESS;
> +	send_hprime_in.header.buffer_len =
> +WIRED_CMD_BUF_LEN_AKE_SEND_HPRIME_IN;
> +
> +	send_hprime_in.port.integrated_port_type = data->port_type;
> +	send_hprime_in.port.physical_port = mei_get_ddi_index(data->port);
> +
> +	memcpy(send_hprime_in.h_prime, rx_hprime->h_prime,
> +	       HDCP_2_2_H_PRIME_LEN);
> +
> +	byte = mei_cldev_send(cldev, (u8 *)&send_hprime_in,
> +			      sizeof(send_hprime_in));
> +	if (byte < 0) {
> +		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
> +		return byte;
> +	}
> +
> +	byte = mei_cldev_recv(cldev, (u8 *)&send_hprime_out,
> +			      sizeof(send_hprime_out));
> +	if (byte < 0) {
> +		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
> +		return byte;
> +	}
> +
> +	if (send_hprime_out.header.status != ME_HDCP_STATUS_SUCCESS) {
> +		dev_dbg(dev, "ME cmd 0x%08X Failed. Status: 0x%X\n",
> +			WIRED_AKE_SEND_HPRIME,
> send_hprime_out.header.status);
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
>  static __attribute__((unused))
>  struct i915_hdcp_component_ops mei_hdcp_ops = {
>  	.owner = THIS_MODULE,
>  	.initiate_hdcp2_session = mei_hdcp_initiate_session,
>  	.verify_receiver_cert_prepare_km =
>  				mei_hdcp_verify_receiver_cert_prepare_km,
> -	.verify_hprime = NULL,
> +	.verify_hprime = mei_hdcp_verify_hprime,
>  	.store_pairing_info = NULL,
>  	.initiate_locality_check = NULL,
>  	.verify_lprime = NULL,
> --
> 2.7.4