drm/i915/hdcp: MST streams support in hdcp port_data

Add support for multiple mst stream in hdcp port data
which will be used by RepeaterAuthStreamManage msg and
HDCP 2.2 security f/w for m' validation.

Security f/w doesn't have any provision to mark the stream_type
for each stream separately, it just take single input of
stream_type while authenticating the port and applies the
same stream_type to all streams. So driver mark each stream_type
with common highest supported content type for all streams
in DP MST Topology.

Security f/w supports RepeaterAuthStreamManage msg and m'
validation only once during port authentication and encryption.
Though it is not compulsory, security fw should support dynamic
update of content_type and should support RepeaterAuthStreamManage
msg and m' validation whenever required.

v2:
- Init the hdcp port data k for HDMI/DP SST stream.
v3:
- Cosmetic changes. [Uma]
v4:
- 's/port_auth/hdcp_port_auth'. [Ram]
- Commit log improvement.
v5:
- Comment and commit log improvement. [Ram]
v6:
- Check first connector connected status before intel_encoder_is_mst
  to avoid any NULL pointer dereference.

Cc: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Tested-by: Karthik B S <karthik.b.s@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Tested-by: Juston Li <juston.li@intel.com>
Acked-by: Juston Li <juston.li@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111081120.28417-15-anshuman.gupta@intel.com

1 files changed, 99 insertions, 14 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 2bec26123a05..bd87694def74 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -26,6 +26,74 @@
 #define KEY_LOAD_TRIES	5
 #define HDCP2_LC_RETRY_CNT			3
 
+static int intel_conn_to_vcpi(struct intel_connector *connector)
+{
+	/* For HDMI this is forced to be 0x0. For DP SST also this is 0x0. */
+	return connector->port	? connector->port->vcpi.vcpi : 0;
+}
+
+/*
+ * intel_hdcp_required_content_stream selects the most highest common possible HDCP
+ * content_type for all streams in DP MST topology because security f/w doesn't
+ * have any provision to mark content_type for each stream separately, it marks
+ * all available streams with the content_type proivided at the time of port
+ * authentication. This may prohibit the userspace to use type1 content on
+ * HDCP 2.2 capable sink because of other sink are not capable of HDCP 2.2 in
+ * DP MST topology. Though it is not compulsory, security fw should change its
+ * policy to mark different content_types for different streams.
+ */
+static int
+intel_hdcp_required_content_stream(struct intel_digital_port *dig_port)
+{
+	struct drm_connector_list_iter conn_iter;
+	struct intel_digital_port *conn_dig_port;
+	struct intel_connector *connector;
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+	struct hdcp_port_data *data = &dig_port->hdcp_port_data;
+	bool enforce_type0 = false;
+	int k;
+
+	if (dig_port->hdcp_auth_status)
+		return 0;
+
+	drm_connector_list_iter_begin(&i915->drm, &conn_iter);
+	for_each_intel_connector_iter(connector, &conn_iter) {
+		if (connector->base.status == connector_status_disconnected)
+			continue;
+
+		if (!intel_encoder_is_mst(intel_attached_encoder(connector)))
+			continue;
+
+		conn_dig_port = intel_attached_dig_port(connector);
+		if (conn_dig_port != dig_port)
+			continue;
+
+		if (!enforce_type0 && !intel_hdcp2_capable(connector))
+			enforce_type0 = true;
+
+		data->streams[data->k].stream_id = intel_conn_to_vcpi(connector);
+		data->k++;
+
+		/* if there is only one active stream */
+		if (dig_port->dp.active_mst_links <= 1)
+			break;
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	if (drm_WARN_ON(&i915->drm, data->k > INTEL_NUM_PIPES(i915) || data->k == 0))
+		return -EINVAL;
+
+	/*
+	 * Apply common protection level across all streams in DP MST Topology.
+	 * Use highest supported content type for all streams in DP MST Topology.
+	 */
+	for (k = 0; k < data->k; k++)
+		data->streams[k].stream_type =
+			enforce_type0 ? DRM_MODE_HDCP_CONTENT_TYPE0 : DRM_MODE_HDCP_CONTENT_TYPE1;
+
+	return 0;
+}
+
 static
 bool intel_hdcp_is_ksv_valid(u8 *ksv)
 {
@@ -1471,13 +1539,14 @@ static
 int _hdcp2_propagate_stream_management_info(struct intel_connector *connector)
 {
 	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
+	struct hdcp_port_data *data = &dig_port->hdcp_port_data;
 	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;
+	int ret, streams_size_delta, i;
 
 	if (connector->hdcp.seq_num_m > HDCP_2_2_SEQ_NUM_MAX)
 		return -ERANGE;
@@ -1486,16 +1555,18 @@ int _hdcp2_propagate_stream_management_info(struct intel_connector *connector)
 	msgs.stream_manage.msg_id = HDCP_2_2_REP_STREAM_MANAGE;
 	drm_hdcp_cpu_to_be24(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);
+	msgs.stream_manage.k = cpu_to_be16(data->k);
 
-	/* 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;
+	for (i = 0; i < data->k; i++) {
+		msgs.stream_manage.streams[i].stream_id = data->streams[i].stream_id;
+		msgs.stream_manage.streams[i].stream_type = data->streams[i].stream_type;
+	}
 
+	streams_size_delta = (HDCP_2_2_MAX_CONTENT_STREAMS_CNT - data->k) *
+				sizeof(struct hdcp2_streamid_type);
 	/* Send it to Repeater */
 	ret = shim->write_2_2_msg(dig_port, &msgs.stream_manage,
-				  sizeof(msgs.stream_manage));
+				  sizeof(msgs.stream_manage) - streams_size_delta);
 	if (ret < 0)
 		goto out;
 
@@ -1504,8 +1575,7 @@ int _hdcp2_propagate_stream_management_info(struct intel_connector *connector)
 	if (ret < 0)
 		goto out;
 
-	dig_port->hdcp_port_data.seq_num_m = hdcp->seq_num_m;
-	dig_port->hdcp_port_data.streams[0].stream_type = hdcp->content_type;
+	data->seq_num_m = hdcp->seq_num_m;
 
 	ret = hdcp2_verify_mprime(connector, &msgs.stream_ready);
 
@@ -1666,6 +1736,7 @@ static int hdcp2_enable_encryption(struct intel_connector *connector)
 						 port),
 				    LINK_ENCRYPTION_STATUS,
 				    HDCP_ENCRYPT_STATUS_CHANGE_TIMEOUT_MS);
+	dig_port->hdcp_auth_status = true;
 
 	return ret;
 }
@@ -1740,11 +1811,9 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
 {
 	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
-	struct hdcp_port_data *data = &dig_port->hdcp_port_data;
-	struct intel_hdcp *hdcp = &connector->hdcp;
-	int ret, i, tries = 3;
+	int ret = 0, i, tries = 3;
 
-	for (i = 0; i < tries; i++) {
+	for (i = 0; i < tries && !dig_port->hdcp_auth_status; i++) {
 		ret = hdcp2_authenticate_sink(connector);
 		if (!ret) {
 			ret = hdcp2_propagate_stream_management_info(connector);
@@ -1754,7 +1823,7 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
 					    ret);
 				break;
 			}
-			data->streams[0].stream_type = hdcp->content_type;
+
 			ret = hdcp2_authenticate_port(connector);
 			if (!ret)
 				break;
@@ -1789,7 +1858,9 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
 
 static int _intel_hdcp2_enable(struct intel_connector *connector)
 {
+	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+	struct hdcp_port_data *data = &dig_port->hdcp_port_data;
 	struct intel_hdcp *hdcp = &connector->hdcp;
 	int ret;
 
@@ -1797,6 +1868,16 @@ static int _intel_hdcp2_enable(struct intel_connector *connector)
 		    connector->base.name, connector->base.base.id,
 		    hdcp->content_type);
 
+	/* Stream which requires encryption */
+	if (!intel_encoder_is_mst(intel_attached_encoder(connector))) {
+		data->k = 1;
+		data->streams[0].stream_type = hdcp->content_type;
+	} else {
+		ret = intel_hdcp_required_content_stream(dig_port);
+		if (ret)
+			return ret;
+	}
+
 	ret = hdcp2_authenticate_and_encrypt(connector);
 	if (ret) {
 		drm_dbg_kms(&i915->drm, "HDCP2 Type%d  Enabling Failed. (%d)\n",
@@ -1814,7 +1895,9 @@ static int _intel_hdcp2_enable(struct intel_connector *connector)
 
 static int _intel_hdcp2_disable(struct intel_connector *connector)
 {
+	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+	struct hdcp_port_data *data = &dig_port->hdcp_port_data;
 	int ret;
 
 	drm_dbg_kms(&i915->drm, "[%s:%d] HDCP2.2 is being Disabled\n",
@@ -1826,6 +1909,8 @@ static int _intel_hdcp2_disable(struct intel_connector *connector)
 		drm_dbg_kms(&i915->drm, "Port deauth failed.\n");
 
 	connector->hdcp.hdcp2_encrypted = false;
+	dig_port->hdcp_auth_status = false;
+	data->k = 0;
 
 	return ret;
 }