[PATCH v6 13/35] drm/i915: Implement HDCP2.2 repeater authentication
Ramalingam C
ramalingam.c at intel.com
Thu Aug 30 06:49:09 UTC 2018
On Wednesday 01 August 2018 04:00 PM, Shankar, Uma wrote:
>
>> -----Original Message-----
>> From: C, Ramalingam
>> Sent: Saturday, July 14, 2018 8:45 AM
>> To: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org;
>> daniel at ffwll.ch; seanpaul at chromium.org; Winkler, Tomas
>> <tomas.winkler at intel.com>; Usyskin, Alexander <alexander.usyskin at intel.com>;
>> Shankar, Uma <uma.shankar at intel.com>
>> Cc: Sharma, Shashank <shashank.sharma at intel.com>; C, Ramalingam
>> <ramalingam.c at intel.com>
>> Subject: [PATCH v6 13/35] drm/i915: Implement HDCP2.2 repeater authentication
>>
>> Implements the HDCP2.2 repeaters authentication steps such as verifying the
>> downstream topology and sending stream management information.
>>
>> v2:
>> Rebased.
>> v3:
>> No Changes.
>> v4:
>> -EINVAL is returned for topology error and rollover scenario.
>> Endianness conversion func from drm_hdcp.h is used [Uma]
>> v5:
>> Rebased as part of patches reordering.
>> Defined the mei service functions [Daniel]
>> v6:
>> Redefined the mei service functions as per comp redesign.
>>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> ---
>> drivers/gpu/drm/i915/intel_hdcp.c | 171
>> ++++++++++++++++++++++++++++++++++++++
>> include/drm/drm_hdcp.h | 15 ++++
>> 2 files changed, 186 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c
>> b/drivers/gpu/drm/i915/intel_hdcp.c
>> index ee1e06bac175..a08d80c710d7 100644
>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> @@ -1144,6 +1144,56 @@ static int hdcp2_prepare_skey(struct intel_connector
>> *connector,
>> return ret;
>> }
>>
>> +static int
>> +hdcp2_verify_rep_topology_prepare_ack(
>> + struct intel_connector *connector,
>> + struct hdcp2_rep_send_receiverid_list *rep_topology,
>> + struct hdcp2_rep_send_ack *rep_send_ack) {
>> + struct mei_hdcp_data *data = &connector->hdcp.mei_data;
>> + struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> + struct i915_component_master *comp = dev_priv->comp_master;
>> + int ret;
>> +
>> + if (!comp)
>> + return -EINVAL;
>> +
>> + if (!comp->hdcp_ops || !comp->mei_cldev || data->port ==
>> INVALID_PORT)
>> + return -EINVAL;
>> +
>> + ret = comp->hdcp_ops->repeater_check_flow_prepare_ack(comp-
>>> mei_cldev,
>> + data,
>> + rep_topology,
>> + rep_send_ack);
> Same as mentioned in earlier patch in the series.
comp->hdcp_ops and comp->mei_cldev are initialized at component binding
of the mei_hdcp module. So until the component binding happens at mei_hdcp,
members of the comp->hdcp_ops wont be utilized.
> Otherwise overall the change looks ok to me.
>
>> + if (ret < 0)
>> + comp->hdcp_ops->close_hdcp_session(comp->mei_cldev, data);
>> +
>> + return ret;
>> +}
>> +
>> +static int
>> +hdcp2_verify_mprime(struct intel_connector *connector,
>> + struct hdcp2_rep_stream_ready *stream_ready) {
>> + struct mei_hdcp_data *data = &connector->hdcp.mei_data;
>> + struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> + struct i915_component_master *comp = dev_priv->comp_master;
>> + int ret;
>> +
>> + if (!comp)
>> + return -EINVAL;
>> +
>> + if (!comp->hdcp_ops || !comp->mei_cldev || data->port ==
>> INVALID_PORT)
>> + return -EINVAL;
>> +
>> + ret = comp->hdcp_ops->verify_mprime(comp->mei_cldev, data,
>> + stream_ready);
>> + if (ret < 0)
>> + comp->hdcp_ops->close_hdcp_session(comp->mei_cldev, data);
>> +
>> + return ret;
>> +}
>> +
>> static int hdcp2_authenticate_port(struct intel_connector *connector) {
>> struct mei_hdcp_data *data = &connector->hdcp.mei_data; @@ -1319,6
>> +1369,121 @@ 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;
>> + reverse_endianness(msgs.stream_manage.seq_num_m,
>> HDCP_2_2_SEQ_NUM_LEN,
>> + (u8 *)&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));
> How the timeout of 100ms is ensured here.
shim->read_2_2_msg() waits for the required timeout for each HDCP2.2 msgs.
--Ram.
>> + if (ret < 0)
>> + return ret;
>> +
>> + hdcp->mei_data.seq_num_m = hdcp->seq_num_m;
>> + hdcp->mei_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;
>> + uint8_t *rx_info;
>> + uint32_t 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;
>> +
>> + 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 */
>> + reverse_endianness((u8 *)&seq_num_v, HDCP_2_2_SEQ_NUM_LEN,
>> + 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;
>> +
>> + 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);
>> @@ -1360,6 +1525,12 @@ 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;
>> + }
>> }
>>
>> hdcp->mei_data.streams[0].stream_type = hdcp->content_type; diff --git
>> a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index
>> 2b4cfb0b7324..c01cdb1d848d 100644
>> --- a/include/drm/drm_hdcp.h
>> +++ b/include/drm/drm_hdcp.h
>> @@ -252,4 +252,19 @@ struct hdcp2_dp_errata_stream_type {
>> #define HDCP_2_2_HDMI_RXSTATUS_READY(x) ((x) & BIT(2))
>> #define HDCP_2_2_HDMI_RXSTATUS_REAUTH_REQ(x) ((x) & BIT(3))
>>
>> +/*
>> + * Library functions for endianness are aligned for 16/32/64 bits.
>> + * But hdcp sequence numbers are 24bits. So for their Byte swapping,
>> + * a conversion function is developed.
>> + */
>> +static inline void reverse_endianness(u8 *dest, size_t sz, u8 *src) {
>> + u32 index;
>> +
>> + if (!sz || sz > sizeof(u32))
>> + return;
>> + for (index = 0; index < sz; index++)
>> + dest[sz - index - 1] = src[index];
>> +}
>> +
>> #endif
>> --
>> 2.7.4
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