[Intel-gfx] [PATCH v14 26/33] misc/mei/hdcp: Verify L_prime

[Winkler, Tomas]

> Request to ME to verify the LPrime received from HDCP sink.
> 
> On Success, ME FW will verify the received Lprime by calculating and
> comparing with L.
> 
> This represents the completion of Locality Check.
> 
> 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]
>   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 | 60
> +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 59 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c
> b/drivers/misc/mei/hdcp/mei_hdcp.c
> index 29ef61fd21d2..869a6f22f68d 100644
> --- a/drivers/misc/mei/hdcp/mei_hdcp.c
> +++ b/drivers/misc/mei/hdcp/mei_hdcp.c
> @@ -351,6 +351,64 @@ mei_hdcp_initiate_locality_check(struct device *dev,
>  	return 0;
>  }
> 
> +/**
> + * mei_hdcp_verify_lprime() - Verify lprime.
> + * @dev: device corresponding to the mei_cl_device
> + * @data: Intel HW specific hdcp data
> + * @rx_lprime: LC_Send_L_prime msg for ME FW verification
> + *
> + * Return: 0 on Success, <0 on Failure
> + */
> +static int
> +mei_hdcp_verify_lprime(struct device *dev, struct hdcp_port_data *data,
> +		       struct hdcp2_lc_send_lprime *rx_lprime) {
> +	struct wired_cmd_validate_locality_in verify_lprime_in = { { 0 } };
> +	struct wired_cmd_validate_locality_out verify_lprime_out = { { 0 } };
> +	struct mei_cl_device *cldev;
> +	ssize_t byte;
> +
> +	if (!dev || !data || !rx_lprime)
> +		return -EINVAL;
> +
> +	cldev = to_mei_cl_device(dev);
> +
> +	verify_lprime_in.header.api_version = HDCP_API_VERSION;
> +	verify_lprime_in.header.command_id = WIRED_VALIDATE_LOCALITY;
> +	verify_lprime_in.header.status = ME_HDCP_STATUS_SUCCESS;
> +	verify_lprime_in.header.buffer_len =
> +
> 	WIRED_CMD_BUF_LEN_VALIDATE_LOCALITY_IN;
> +
> +	verify_lprime_in.port.integrated_port_type = data->port_type;
> +	verify_lprime_in.port.physical_port = mei_get_ddi_index(data->port);
> +
> +	memcpy(verify_lprime_in.l_prime, rx_lprime->l_prime,
> +	       HDCP_2_2_L_PRIME_LEN);
> +
> +	byte = mei_cldev_send(cldev, (u8 *)&verify_lprime_in,
> +			      sizeof(verify_lprime_in));
> +	if (byte < 0) {
> +		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
> +		return byte;
> +	}
> +
> +	byte = mei_cldev_recv(cldev, (u8 *)&verify_lprime_out,
> +			      sizeof(verify_lprime_out));
> +	if (byte < 0) {
> +		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
> +		return byte;
> +	}
> +
> +	if (verify_lprime_out.header.status != ME_HDCP_STATUS_SUCCESS) {
> +		dev_dbg(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
> +			WIRED_VALIDATE_LOCALITY,
> +			verify_lprime_out.header.status);
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
>  static __attribute__((unused))
>  struct i915_hdcp_component_ops mei_hdcp_ops = {
>  	.owner = THIS_MODULE,
> @@ -360,7 +418,7 @@ struct i915_hdcp_component_ops mei_hdcp_ops = {
>  	.verify_hprime = mei_hdcp_verify_hprime,
>  	.store_pairing_info = mei_hdcp_store_pairing_info,
>  	.initiate_locality_check = mei_hdcp_initiate_locality_check,
> -	.verify_lprime = NULL,
> +	.verify_lprime = mei_hdcp_verify_lprime,
>  	.get_session_key = NULL,
>  	.repeater_check_flow_prepare_ack = NULL,
>  	.verify_mprime = NULL,
> --
> 2.7.4