[Intel-gfx] [PATCH v14 27/33] misc/mei/hdcp: Prepare Session Key

[Winkler, Tomas]

> 
> Request to ME to prepare the encrypted session key.
> 
> On Success, ME provides Encrypted session key. Function populates the
> HDCP2.2 authentication msg SKE_Send_Eks.
> 
> 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]
>   Style 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]
> 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 | 59
> +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 58 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c
> b/drivers/misc/mei/hdcp/mei_hdcp.c
> index 869a6f22f68d..fe5070f901e8 100644
> --- a/drivers/misc/mei/hdcp/mei_hdcp.c
> +++ b/drivers/misc/mei/hdcp/mei_hdcp.c
> @@ -409,6 +409,63 @@ mei_hdcp_verify_lprime(struct device *dev, struct
> hdcp_port_data *data,
>  	return 0;
>  }
> 
> +/**
> + * mei_hdcp_get_session_key() - Prepare SKE_Send_Eks.
> + * @dev: device corresponding to the mei_cl_device
> + * @data: Intel HW specific hdcp data
> + * @ske_data: SKE_Send_Eks msg output from ME FW.
> + *
> + * Return: 0 on Success, <0 on Failure
> + */
> +static int mei_hdcp_get_session_key(struct device *dev,
> +				    struct hdcp_port_data *data,
> +				    struct hdcp2_ske_send_eks *ske_data) {
> +	struct wired_cmd_get_session_key_in get_skey_in = { { 0 } };
> +	struct wired_cmd_get_session_key_out get_skey_out = { { 0 } };
> +	struct mei_cl_device *cldev;
> +	ssize_t byte;
> +
> +	if (!dev || !data || !ske_data)
> +		return -EINVAL;
> +
> +	cldev = to_mei_cl_device(dev);
> +
> +	get_skey_in.header.api_version = HDCP_API_VERSION;
> +	get_skey_in.header.command_id = WIRED_GET_SESSION_KEY;
> +	get_skey_in.header.status = ME_HDCP_STATUS_SUCCESS;
> +	get_skey_in.header.buffer_len =
> WIRED_CMD_BUF_LEN_GET_SESSION_KEY_IN;
> +
> +	get_skey_in.port.integrated_port_type = data->port_type;
> +	get_skey_in.port.physical_port = mei_get_ddi_index(data->port);
> +
> +	byte = mei_cldev_send(cldev, (u8 *)&get_skey_in, sizeof(get_skey_in));
> +	if (byte < 0) {
> +		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
> +		return byte;
> +	}
> +
> +	byte = mei_cldev_recv(cldev, (u8 *)&get_skey_out,
> +sizeof(get_skey_out));
> +
> +	if (byte < 0) {
> +		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
> +		return byte;
> +	}
> +
> +	if (get_skey_out.header.status != ME_HDCP_STATUS_SUCCESS) {
> +		dev_dbg(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
> +			WIRED_GET_SESSION_KEY,
> get_skey_out.header.status);
> +		return -EIO;
> +	}
> +
> +	ske_data->msg_id = HDCP_2_2_SKE_SEND_EKS;
> +	memcpy(ske_data->e_dkey_ks, get_skey_out.e_dkey_ks,
> +	       HDCP_2_2_E_DKEY_KS_LEN);
> +	memcpy(ske_data->riv, get_skey_out.r_iv, HDCP_2_2_RIV_LEN);
> +
> +	return 0;
> +}
> +
>  static __attribute__((unused))
>  struct i915_hdcp_component_ops mei_hdcp_ops = {
>  	.owner = THIS_MODULE,
> @@ -419,7 +476,7 @@ struct i915_hdcp_component_ops mei_hdcp_ops = {
>  	.store_pairing_info = mei_hdcp_store_pairing_info,
>  	.initiate_locality_check = mei_hdcp_initiate_locality_check,
>  	.verify_lprime = mei_hdcp_verify_lprime,
> -	.get_session_key = NULL,
> +	.get_session_key = mei_hdcp_get_session_key,
>  	.repeater_check_flow_prepare_ack = NULL,
>  	.verify_mprime = NULL,
>  	.enable_hdcp_authentication = NULL,
> --
> 2.7.4