[PATCH v9 12/39] drm/i915: Implement HDCP2.2 repeater authentication

C, Ramalingam ramalingam.c at intel.com
Wed Dec 19 15:35:27 UTC 2018


On 12/19/2018 8:18 PM, Daniel Vetter wrote:
> On Thu, Dec 13, 2018 at 09:31:14AM +0530, Ramalingam C wrote:
>> Implements the HDCP2.2 repeaters authentication steps such as verifying
>> the downstream topology and sending stream management information.
>>
>> v2: Rebased.
>> v3:
>>    -EINVAL is returned for topology error and rollover scenario.
>>    Endianness conversion func from drm_hdcp.h is used [Uma]
>> v4:
>>    Rebased as part of patches reordering.
>>    Defined the mei service functions [Daniel]
>> v5:
>>    Redefined the mei service functions as per comp redesign.
>> v6:
>>    %s/uintxx_t/uxx
>>    Check for comp_master is removed.
>> v7:
>>    Adjust to the new mei interface.
>>    style issue fixed.
>> v8:
>>    drm_hdcp.h change is moved into separate patch [Daniel]
>>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> ---
>>   drivers/gpu/drm/i915/intel_hdcp.c | 123 +++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 121 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
>> index f1f0ef294e20..b52da5c3159d 100644
>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> @@ -978,7 +978,7 @@ static int hdcp2_prepare_skey(struct intel_connector *connector,
>>   	return ret;
>>   }
>>   
>> -static __attribute__((unused)) int
>> +static int
>>   hdcp2_verify_rep_topology_prepare_ack(struct intel_connector *connector,
>>   				      struct hdcp2_rep_send_receiverid_list
>>   								*rep_topology,
>> @@ -999,7 +999,7 @@ hdcp2_verify_rep_topology_prepare_ack(struct intel_connector *connector,
>>   	return ret;
>>   }
>>   
>> -static __attribute__((unused)) int
>> +static int
>>   hdcp2_verify_mprime(struct intel_connector *connector,
>>   		    struct hdcp2_rep_stream_ready *stream_ready)
>>   {
>> @@ -1182,6 +1182,119 @@ static int hdcp2_session_key_exchange(struct intel_connector *connector)
>>   	return 0;
>>   }
>>   
>> +static
>> +int hdcp2_propagate_stream_management_info(struct intel_connector *connector)
>> +{
>> +	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>> +	struct intel_hdcp *hdcp = &connector->hdcp;
>> +	union {
>> +		struct hdcp2_rep_stream_manage stream_manage;
>> +		struct hdcp2_rep_stream_ready stream_ready;
>> +	} msgs;
>> +	const struct intel_hdcp_shim *shim = hdcp->shim;
>> +	int ret;
>> +
>> +	/* Prepare RepeaterAuth_Stream_Manage msg */
>> +	msgs.stream_manage.msg_id = HDCP_2_2_REP_STREAM_MANAGE;
>> +	drm_hdcp2_u32_to_seq_num(msgs.stream_manage.seq_num_m, hdcp->seq_num_m);
>> +
>> +	/* K no of streams is fixed as 1. Stored as big-endian. */
>> +	msgs.stream_manage.k = __swab16(1);
>> +
>> +	/* For HDMI this is forced to be 0x0. For DP SST also this is 0x0. */
>> +	msgs.stream_manage.streams[0].stream_id = 0;
>> +	msgs.stream_manage.streams[0].stream_type = hdcp->content_type;
>> +
>> +	/* Send it to Repeater */
>> +	ret = shim->write_2_2_msg(intel_dig_port, &msgs.stream_manage,
>> +				  sizeof(msgs.stream_manage));
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = shim->read_2_2_msg(intel_dig_port, HDCP_2_2_REP_STREAM_READY,
>> +				 &msgs.stream_ready, sizeof(msgs.stream_ready));
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	hdcp->port_data.seq_num_m = hdcp->seq_num_m;
>> +	hdcp->port_data.streams[0].stream_type = hdcp->content_type;
>> +
>> +	ret = hdcp2_verify_mprime(connector, &msgs.stream_ready);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	hdcp->seq_num_m++;
>> +
>> +	if (hdcp->seq_num_m > HDCP_2_2_SEQ_NUM_MAX) {
>> +		DRM_DEBUG_KMS("seq_num_m roll over.\n");
>> +		return -1;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static
>> +int hdcp2_authenticate_repeater_topology(struct intel_connector *connector)
>> +{
>> +	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>> +	struct intel_hdcp *hdcp = &connector->hdcp;
>> +	union {
>> +		struct hdcp2_rep_send_receiverid_list recvid_list;
>> +		struct hdcp2_rep_send_ack rep_ack;
>> +	} msgs;
>> +	const struct intel_hdcp_shim *shim = hdcp->shim;
>> +	u8 *rx_info;
>> +	u32 seq_num_v;
>> +	int ret;
>> +
>> +	ret = shim->read_2_2_msg(intel_dig_port, HDCP_2_2_REP_SEND_RECVID_LIST,
>> +				 &msgs.recvid_list, sizeof(msgs.recvid_list));
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	rx_info = msgs.recvid_list.rx_info;
> There's a 2s timeout here that we're not checking, but again probably
> follow-up patch.
Timeout is taken care at shim.
>
>> +
>> +	if (HDCP_2_2_MAX_CASCADE_EXCEEDED(rx_info[1]) ||
>> +	    HDCP_2_2_MAX_DEVS_EXCEEDED(rx_info[1])) {
>> +		DRM_DEBUG_KMS("Topology Max Size Exceeded\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* Converting and Storing the seq_num_v to local variable as DWORD */
>> +	drm_hdcp2_seq_num_to_u32(&seq_num_v, msgs.recvid_list.seq_num_v);
>> +
>> +	if (seq_num_v < hdcp->seq_num_v) {
>> +		/* Roll over of the seq_num_v from repeater. Reauthenticate. */
>> +		DRM_DEBUG_KMS("Seq_num_v roll over.\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = hdcp2_verify_rep_topology_prepare_ack(connector,
>> +						    &msgs.recvid_list,
>> +						    &msgs.rep_ack);
>> +	if (ret < 0)
>> +		return ret;
> Spec talks about type0 vs type1 here, but for now we can ignore that.

Its already taken care at hdcp2_propagate_stream_management_info()

msgs.stream_manage.streams[0].stream_type = hdcp->content_type;
And mei also informed about the content_type through hdcp_port_data

>
>> +
>> +	hdcp->seq_num_v = seq_num_v;
>> +	ret = shim->write_2_2_msg(intel_dig_port, &msgs.rep_ack,
>> +				  sizeof(msgs.rep_ack));
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
>> +static int hdcp2_authenticate_repeater(struct intel_connector *connector)
>> +{
>> +	int ret;
>> +
>> +	ret = hdcp2_authenticate_repeater_topology(connector);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return hdcp2_propagate_stream_management_info(connector);
>> +}
>> +
>>   static int hdcp2_authenticate_sink(struct intel_connector *connector)
>>   {
>>   	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>> @@ -1223,6 +1336,12 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector)
>>   					       sizeof(stream_type_msg));
>>   		if (ret < 0)
>>   			return ret;
>> +	} else if (hdcp->is_repeater) {
>> +		ret = hdcp2_authenticate_repeater(connector);
>> +		if (ret < 0) {
>> +			DRM_DEBUG_KMS("Repeater Auth Failed. Err: %d\n", ret);
>> +			return ret;
>> +		}
>>   	}
> Spec for receiver auth is a bit more confusing than usual, but I think
> this matches.
>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Thank you

-Ram

>>   
>>   	hdcp->port_data.streams[0].stream_type = hdcp->content_type;
>> -- 
>> 2.7.4
>>


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