[Intel-gfx] [RFC] drm/i915/hdcp: Gen12 HDCP 1.4 support over DP MST

Anshuman Gupta anshuman.gupta at intel.com
Tue Sep 1 12:10:41 UTC 2020


Gen12 has measure changes with respect to HDCP display
engine instaces lies in Trascoder insead of DDI as in Gen11.

This requires hdcp driver to use mst_master_transcoder for link
authentication and stream trascoder for stream encryption
separately.

It also requires to validate the stream encryption status
in HDCP_STATUS_{TRANSCODER,PORT} driving that link register.

There is also some changes over existing HDCP 1.4  DP MST Gen11
implementation, related to Multistream HDCP Select bit in
TRANS_DDI_FUNC_CTL need to be required with respect to B.Spec
Documentation.

Cc: Ramalingam C <ramalingam.c at intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c      | 12 +--
 drivers/gpu/drm/i915/display/intel_ddi.h      |  6 +-
 .../drm/i915/display/intel_display_types.h    |  9 +++
 drivers/gpu/drm/i915/display/intel_dp_hdcp.c  | 73 ++++++++++++++++---
 drivers/gpu/drm/i915/display/intel_dp_mst.c   |  4 +-
 drivers/gpu/drm/i915/display/intel_hdcp.c     | 35 ++++++---
 drivers/gpu/drm/i915/display/intel_hdcp.h     |  4 +-
 drivers/gpu/drm/i915/display/intel_hdmi.c     | 16 ++--
 drivers/gpu/drm/i915/i915_reg.h               |  1 +
 9 files changed, 121 insertions(+), 39 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index a2b7dcf84430..5d6e4fd7bccd 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1849,9 +1849,9 @@ void intel_ddi_disable_transcoder_func(const struct intel_crtc_state *crtc_state
 	}
 }
 
-int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
-				     enum transcoder cpu_transcoder,
-				     bool enable)
+int intel_ddi_toggle_hdcp_bits(struct intel_encoder *intel_encoder,
+			       enum transcoder cpu_transcoder,
+			       bool enable, u32 hdcp_mask)
 {
 	struct drm_device *dev = intel_encoder->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -1866,9 +1866,9 @@ int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
 
 	tmp = intel_de_read(dev_priv, TRANS_DDI_FUNC_CTL(cpu_transcoder));
 	if (enable)
-		tmp |= TRANS_DDI_HDCP_SIGNALLING;
+		tmp |= hdcp_mask;
 	else
-		tmp &= ~TRANS_DDI_HDCP_SIGNALLING;
+		tmp &= ~hdcp_mask;
 	intel_de_write(dev_priv, TRANS_DDI_FUNC_CTL(cpu_transcoder), tmp);
 	intel_display_power_put(dev_priv, intel_encoder->power_domain, wakeref);
 	return ret;
@@ -3967,7 +3967,7 @@ static void intel_enable_ddi(struct intel_atomic_state *state,
 	if (conn_state->content_protection ==
 	    DRM_MODE_CONTENT_PROTECTION_DESIRED)
 		intel_hdcp_enable(to_intel_connector(conn_state->connector),
-				  crtc_state->cpu_transcoder,
+				  crtc_state,
 				  (u8)conn_state->hdcp_content_type);
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.h b/drivers/gpu/drm/i915/display/intel_ddi.h
index f5fb62fc9400..69d9e495992c 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.h
+++ b/drivers/gpu/drm/i915/display/intel_ddi.h
@@ -43,9 +43,9 @@ void intel_ddi_compute_min_voltage_level(struct drm_i915_private *dev_priv,
 					 struct intel_crtc_state *crtc_state);
 u32 bxt_signal_levels(struct intel_dp *intel_dp);
 u32 ddi_signal_levels(struct intel_dp *intel_dp);
-int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
-				     enum transcoder cpu_transcoder,
-				     bool enable);
+int intel_ddi_toggle_hdcp_bits(struct intel_encoder *intel_encoder,
+			       enum transcoder cpu_transcoder,
+			       bool enable, u32 hdcp_mask);
 void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder);
 
 #endif /* __INTEL_DDI_H__ */
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 413b60337a0b..dc71ee4d314a 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -317,6 +317,13 @@ struct intel_hdcp_shim {
 				 enum transcoder cpu_transcoder,
 				 bool enable);
 
+	/* Select/Deselect HDCP stream on the port DP MST Transport Link */
+	int (*toggle_select_hdcp)(struct intel_digital_port *intel_dig_port,
+				  bool enable);
+
+	/* Enable HDCP stream encyption on DP MST Transport Link */
+	int (*stream_encryption)(struct intel_digital_port *intel_dig_port);
+
 	/* Ensures the link is still protected */
 	bool (*check_link)(struct intel_digital_port *dig_port,
 			   struct intel_connector *connector);
@@ -410,6 +417,8 @@ struct intel_hdcp {
 	 * Hence caching the transcoder here.
 	 */
 	enum transcoder cpu_transcoder;
+	/* Only used for DP MST stream encryption */
+	enum transcoder stream_transcoder;
 };
 
 struct intel_connector {
diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
index 03424d20e9f7..8a6427f3690b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
@@ -16,6 +16,30 @@
 #include "intel_dp.h"
 #include "intel_hdcp.h"
 
+static unsigned int trasncoder_to_stream_enc_status(enum transcoder cpu_transcoder)
+{
+	u32 stream_enc_mask;
+
+	switch (cpu_transcoder) {
+	case TRANSCODER_A:
+		stream_enc_mask = HDCP_STATUS_STREAM_A_ENC;
+		break;
+	case TRANSCODER_B:
+		stream_enc_mask = HDCP_STATUS_STREAM_B_ENC;
+		break;
+	case TRANSCODER_C:
+		stream_enc_mask = HDCP_STATUS_STREAM_C_ENC;
+		break;
+	case TRANSCODER_D:
+		stream_enc_mask = HDCP_STATUS_STREAM_D_ENC;
+		break;
+	default:
+		stream_enc_mask = 0;
+	}
+
+	return stream_enc_mask;
+}
+
 static void intel_dp_hdcp_wait_for_cp_irq(struct intel_hdcp *hdcp, int timeout)
 {
 	long ret;
@@ -622,24 +646,51 @@ static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
 };
 
 static int
-intel_dp_mst_hdcp_toggle_signalling(struct intel_digital_port *dig_port,
-				    enum transcoder cpu_transcoder,
-				    bool enable)
+intel_dp_mst_toggle_select_hdcp_strem(struct intel_digital_port *dig_port,
+				      bool enable)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+	struct intel_dp *dp = &dig_port->dp;
+	struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
 	int ret;
 
-	if (!enable)
-		usleep_range(6, 60); /* Bspec says >= 6us */
+	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base,
+					 hdcp->stream_transcoder, enable,
+					 TRANS_DDI_HDCP_SELECT);
 
-	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base,
-					       cpu_transcoder, enable);
 	if (ret)
-		drm_dbg_kms(&i915->drm, "%s HDCP signalling failed (%d)\n",
-			      enable ? "Enable" : "Disable", ret);
+		drm_dbg_kms(&i915->drm, "%s HDCP select failed (%d)\n",
+			    enable ? "Enable" : "Disable", ret);
 	return ret;
 }
 
+static int
+intel_dp_mst_hdcp_strem_encryption(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *i915 = to_i915(idig_port->base.base.dev);
+	struct intel_dp *dp = &dig_port->dp;
+	struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
+	enum port port = dig_port->base.port;
+	enum transcoder cpu_transcoder = hdcp->cpu_transcoder;
+	u32 stream_enc_status;
+
+	stream_enc_status =  trasncoder_to_stream_enc_status(hdcp->stream_transcoder);
+
+	if (!stream_enc_status)
+		return -EINVAL;
+
+	/* Wait for encryption confirmation */
+	if (intel_de_wait_for_set(i915,
+				  HDCP_STATUS(i915, cpu_transcoder, port),
+				  stream_enc_status,
+				  ENCRYPT_STATUS_CHANGE_TIMEOUT_MS)) {
+		drm_err(&i915->drm, "Timed out waiting for stream encryption enabled\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
 static
 bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
 				  struct intel_connector *connector)
@@ -673,7 +724,9 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
 	.read_ksv_ready = intel_dp_hdcp_read_ksv_ready,
 	.read_ksv_fifo = intel_dp_hdcp_read_ksv_fifo,
 	.read_v_prime_part = intel_dp_hdcp_read_v_prime_part,
-	.toggle_signalling = intel_dp_mst_hdcp_toggle_signalling,
+	.toggle_signalling = intel_dp_hdcp_toggle_signalling,
+	.toggle_select_hdcp = intel_dp_mst_toggle_select_hdcp_strem,
+	.stream_encryption = intel_dp_mst_hdcp_strem_encryption,
 	.check_link = intel_dp_mst_hdcp_check_link,
 	.hdcp_capable = intel_dp_hdcp_capable,
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index b6424bf5d544..8d06931e0805 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -564,7 +564,7 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
 	if (conn_state->content_protection ==
 	    DRM_MODE_CONTENT_PROTECTION_DESIRED)
 		intel_hdcp_enable(to_intel_connector(conn_state->connector),
-				  pipe_config->cpu_transcoder,
+				  pipe_config,
 				  (u8)conn_state->hdcp_content_type);
 }
 
@@ -811,7 +811,7 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
 
 
 	/* TODO: Figure out how to make HDCP work on GEN12+ */
-	if (INTEL_GEN(dev_priv) < 12) {
+	if (INTEL_GEN(dev_priv) <= 12) {
 		ret = intel_dp_init_hdcp(dig_port, intel_connector);
 		if (ret)
 			DRM_DEBUG_KMS("HDCP init failed, skipping.\n");
diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 5492076d1ae0..1436fb2910d4 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -23,7 +23,6 @@
 #include "intel_connector.h"
 
 #define KEY_LOAD_TRIES	5
-#define ENCRYPT_STATUS_CHANGE_TIMEOUT_MS	50
 #define HDCP2_LC_RETRY_CNT			3
 
 static
@@ -700,6 +699,7 @@ static int intel_hdcp_auth(struct intel_connector *connector)
 	ret = shim->repeater_present(dig_port, &repeater_present);
 	if (ret)
 		return ret;
+
 	if (repeater_present)
 		intel_de_write(dev_priv, HDCP_REP_CTL,
 			       intel_hdcp_get_repeater_ctl(dev_priv, cpu_transcoder, port));
@@ -771,6 +771,11 @@ static int intel_hdcp_auth(struct intel_connector *connector)
 	 * XXX: If we have MST-connected devices, we need to enable encryption
 	 * on those as well.
 	 */
+	if (shim->toggle_select_hdcp)
+		ret = shim->toggle_select_hdcp(dig_port, true);
+
+	if (shim->stream_encryption)
+		ret = shim->stream_encryption(dig_port);
 
 	if (repeater_present)
 		return intel_hdcp_auth_downstream(connector);
@@ -797,12 +802,13 @@ static int _intel_hdcp_disable(struct intel_connector *connector)
 	 * it. Instead, toggle the HDCP signalling off on that particular
 	 * connector/pipe and exit.
 	 */
-	if (dig_port->num_hdcp_streams > 0) {
-		ret = hdcp->shim->toggle_signalling(dig_port,
-						    cpu_transcoder, false);
-		if (ret)
-			DRM_ERROR("Failed to disable HDCP signalling\n");
-		return ret;
+	if (intel_dig_port->num_hdcp_streams > 0) {
+		if (hdcp->shim->toggle_select_hdcp) {
+			ret = hdcp->shim->toggle_select_hdcp(dig_port, false);
+			if (ret)
+				DRM_ERROR("Failed to disable HDCP signalling\n");
+			return ret;
+		}
 	}
 
 	hdcp->hdcp_encrypted = false;
@@ -2072,7 +2078,7 @@ int intel_hdcp_init(struct intel_connector *connector,
 }
 
 int intel_hdcp_enable(struct intel_connector *connector,
-		      enum transcoder cpu_transcoder, u8 content_type)
+		      const struct intel_crtc_state *pipe_config, u8 content_type)
 {
 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
 	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
@@ -2088,10 +2094,17 @@ int intel_hdcp_enable(struct intel_connector *connector,
 	drm_WARN_ON(&dev_priv->drm,
 		    hdcp->value == DRM_MODE_CONTENT_PROTECTION_ENABLED);
 	hdcp->content_type = content_type;
-	hdcp->cpu_transcoder = cpu_transcoder;
+
+	if (intel_crtc_has_type(pipe_config, INTEL_OUTPUT_DP_MST)) {
+		hdcp->cpu_transcoder = pipe_config->mst_master_transcoder;
+		hdcp->stream_transcoder = pipe_config->cpu_transcoder;
+	} else {
+		hdcp->cpu_transcoder = pipe_config->cpu_transcoder;
+		hdcp->stream_transcoder = INVALID_TRANSCODER;
+	}
 
 	if (INTEL_GEN(dev_priv) >= 12)
-		hdcp->port_data.fw_tc = intel_get_mei_fw_tc(cpu_transcoder);
+		hdcp->port_data.fw_tc = intel_get_mei_fw_tc(hdcp->cpu_transcoder);
 
 	/*
 	 * Considering that HDCP2.2 is more secure than HDCP1.4, If the setup
@@ -2202,7 +2215,7 @@ void intel_hdcp_update_pipe(struct intel_atomic_state *state,
 
 	if (desired_and_not_enabled || content_protection_type_changed)
 		intel_hdcp_enable(connector,
-				  crtc_state->cpu_transcoder,
+				  crtc_state,
 				  (u8)conn_state->hdcp_content_type);
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.h b/drivers/gpu/drm/i915/display/intel_hdcp.h
index 1bbf5b67ed0a..36a1b81aca16 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.h
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.h
@@ -19,13 +19,15 @@ struct intel_hdcp_shim;
 enum port;
 enum transcoder;
 
+#define ENCRYPT_STATUS_CHANGE_TIMEOUT_MS	50
+
 void intel_hdcp_atomic_check(struct drm_connector *connector,
 			     struct drm_connector_state *old_state,
 			     struct drm_connector_state *new_state);
 int intel_hdcp_init(struct intel_connector *connector, enum port port,
 		    const struct intel_hdcp_shim *hdcp_shim);
 int intel_hdcp_enable(struct intel_connector *connector,
-		      enum transcoder cpu_transcoder, u8 content_type);
+		      const struct intel_crtc_state *pipe_config, u8 content_type);
 int intel_hdcp_disable(struct intel_connector *connector);
 void intel_hdcp_update_pipe(struct intel_atomic_state *state,
 			    struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 0978b0d8f4c6..955d2250b86f 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -1495,15 +1495,18 @@ static int kbl_repositioning_enc_en_signal(struct intel_connector *connector,
 		usleep_range(25, 50);
 	}
 
-	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base, cpu_transcoder,
-					       false);
+	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base, cpu_transcoder,
+					 false, TRANS_DDI_HDCP_SIGNALLING);
+
 	if (ret) {
 		drm_err(&dev_priv->drm,
 			"Disable HDCP signalling failed (%d)\n", ret);
 		return ret;
 	}
-	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base, cpu_transcoder,
-					       true);
+
+	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base, cpu_transcoder,
+					 true, TRANS_DDI_HDCP_SIGNALLING);
+
 	if (ret) {
 		drm_err(&dev_priv->drm,
 			"Enable HDCP signalling failed (%d)\n", ret);
@@ -1526,8 +1529,9 @@ int intel_hdmi_hdcp_toggle_signalling(struct intel_digital_port *dig_port,
 	if (!enable)
 		usleep_range(6, 60); /* Bspec says >= 6us */
 
-	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base, cpu_transcoder,
-					       enable);
+	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base,
+					 cpu_transcoder, enable,
+					 TRANS_DDI_HDCP_SIGNALLING);
 	if (ret) {
 		drm_err(&dev_priv->drm, "%s HDCP signalling failed (%d)\n",
 			enable ? "Enable" : "Disable", ret);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index ab4b1abd4364..f6e40a458f7b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -9945,6 +9945,7 @@ enum skl_power_gate {
 #define  TRANS_DDI_DP_VC_PAYLOAD_ALLOC	(1 << 8)
 #define  TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE (1 << 7)
 #define  TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ (1 << 6)
+#define  TRANS_DDI_HDCP_SELECT	(1 << 5)
 #define  TRANS_DDI_BFI_ENABLE		(1 << 4)
 #define  TRANS_DDI_HIGH_TMDS_CHAR_RATE	(1 << 4)
 #define  TRANS_DDI_HDMI_SCRAMBLING	(1 << 0)
-- 
2.26.2



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