[PATCH v10 11/40] drm/i915: Implement HDCP2.2 repeater authentication

Ramalingam C
2019-01-31T06:59:27Z

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]
v9:
%s/__swab16/cpu_to_be16. [Tomas]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
drivers/gpu/drm/i915/intel_hdcp.c | 125 +++++++++++++++++++++++++++++++++++++-
1 file changed, 123 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index 1c81e17dc6c4..3b8d3a4b5e6e 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -1032,7 +1032,7 @@ 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,
@@ -1061,7 +1061,7 @@ 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)
{
@@ -1270,6 +1270,119 @@ 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 = cpu_to_be16(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;
+
+ 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 */
+ seq_num_v = drm_hdcp2_seq_num_to_u32(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);
@@ -1303,6 +1416,14 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector)
return ret;
}

+ 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->port_data.streams[0].stream_type = hdcp->content_type;
ret = hdcp2_authenticate_port(connector);
if (ret < 0)
--
2.7.4