Implements the HDCP2.2 repeaters authentication steps such as verifying
the downstream topology and sending stream management information.

Signed-off-by: Ramalingam C <ramalinga...@intel.com>
---
 drivers/gpu/drm/i915/intel_hdcp.c | 133 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_hdcp.c 
b/drivers/gpu/drm/i915/intel_hdcp.c
index 64276f180e45..0cd637dd3f6b 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -1153,6 +1153,133 @@ static int hdcp2_session_key_exchange(struct intel_hdcp 
*hdcp)
        return 0;
 }
 
+/*
+ * Lib endianness functions are aligned for 16/32/64 bits. Since here sequence
+ * num is 24bits developed a small conversion function.
+ */
+static inline void reverse_endianness(u8 *dest, size_t dst_sz, u8 *src)
+{
+       u32 index;
+
+       if (dest != NULL && dst_sz != 0) {
+               for (index = 0; index < dst_sz && index < sizeof(u32);
+                    index++) {
+                       dest[dst_sz - index - 1] = src[index];
+               }
+       }
+}
+
+static int hdcp2_propagate_stream_management_info(struct intel_hdcp *hdcp)
+{
+       struct intel_digital_port *intel_dig_port =
+                                       conn_to_dig_port(hdcp->connector);
+       union {
+               struct hdcp2_rep_stream_manage stream_manage;
+               struct hdcp2_rep_stream_ready stream_ready;
+       } msgs;
+       const struct intel_hdcp2_shim *shim = hdcp->hdcp2_shim;
+       int ret;
+
+       /* Prepare RepeaterAuth_Stream_Manage msg */
+       msgs.stream_manage.msg_id = REP_STREAM_MANAGE;
+       reverse_endianness(msgs.stream_manage.seq_num_m, HDCP_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_msg(intel_dig_port, &msgs.stream_manage,
+                             sizeof(msgs.stream_manage));
+       if (ret < 0)
+               return ret;
+
+       ret = shim->read_msg(intel_dig_port, REP_STREAM_READY,
+                            &msgs.stream_ready, sizeof(msgs.stream_ready));
+       if (ret < 0)
+               return ret;
+
+       hdcp->mei_hdcp_data->seq_num_m = hdcp->seq_num_m;
+       hdcp->mei_hdcp_data->streams[0].stream_type = hdcp->content_type;
+
+       ret = hdcp2_verify_mprime(hdcp, &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_hdcp *hdcp)
+{
+       struct intel_digital_port *intel_dig_port =
+                                       conn_to_dig_port(hdcp->connector);
+       union {
+               struct hdcp2_rep_send_receiverid_list recvid_list;
+               struct hdcp2_rep_send_ack rep_ack;
+       } msgs;
+       const struct intel_hdcp2_shim *shim = hdcp->hdcp2_shim;
+       union hdcp2_rx_info *rx_info;
+       uint32_t seq_num_v;
+       int ret;
+
+       ret = shim->read_msg(intel_dig_port, REP_SEND_RECVID_LIST,
+                            &msgs.recvid_list, sizeof(msgs.recvid_list));
+       if (ret < 0)
+               return ret;
+
+       rx_info = &msgs.recvid_list.rx_info;
+
+       if (rx_info->fields.max_cascade_exceeded ||
+           rx_info->fields.max_devs_exceeded) {
+               DRM_DEBUG_KMS("Topology Max Size Exceeded\n");
+               return -1;
+       }
+
+       /* Converting and Storing the seq_num_v to local variable as DWORD */
+       reverse_endianness((u8 *)&seq_num_v, HDCP_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 -1;
+       }
+
+       ret = hdcp2_verify_rep_topology_prepare_ack(hdcp, &msgs.recvid_list,
+                                                   &msgs.rep_ack);
+       if (ret < 0)
+               return ret;
+
+       hdcp->seq_num_v = seq_num_v;
+       ret = shim->write_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_hdcp *hdcp)
+{
+       int ret;
+
+       ret = hdcp2_authenticate_repeater_topology(hdcp);
+       if (ret < 0)
+               return ret;
+
+       return hdcp2_propagate_stream_management_info(hdcp);
+}
+
 static int hdcp2_authenticate_sink(struct intel_hdcp *hdcp)
 {
        struct intel_digital_port *intel_dig_port =
@@ -1194,6 +1321,12 @@ static int hdcp2_authenticate_sink(struct intel_hdcp 
*hdcp)
                                               sizeof(stream_type_msg));
                if (ret < 0)
                        return ret;
+       } else if (hdcp->is_repeater) {
+               ret = hdcp2_authenticate_repeater(hdcp);
+               if (ret < 0) {
+                       DRM_DEBUG_KMS("Repeater Auth Failed. Err: %d\n", ret);
+                       return ret;
+               }
        }
 
        hdcp->mei_hdcp_data->streams[0].stream_type = hdcp->content_type;
-- 
2.7.4

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