Re: [Intel-gfx] [PATCH v5 13/17] drm/i915/hdcp: MST streams support in hdcp port_data

[Ramalingam C <ramalingam.c@intel.com>]

On 2020-11-11 at 11:50:47 +0530, Anshuman Gupta wrote:
> 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 authentiating the
> port. 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.

Could we make a note in commit msg that we need to support content type per stream
when fw supports it?
> 
> 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.
> 
> Cc: Ramalingam C <ramalingam.c@intel.com>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> ---
>  .../drm/i915/display/intel_display_types.h    |   4 +-
>  drivers/gpu/drm/i915/display/intel_hdcp.c     | 103 +++++++++++++++---
>  2 files changed, 92 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 6e597f6aafe8..b93ecf4f21e3 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1445,10 +1445,12 @@ struct intel_digital_port {
>  	enum phy_fia tc_phy_fia;
>  	u8 tc_phy_fia_idx;
>  
> -	/* protects num_hdcp_streams reference count, port_data */
> +	/* protects num_hdcp_streams reference count, port_data and port_auth */
Either correct the variable names or refer it as "hdcp related
variables"
>  	struct mutex hdcp_mutex;
>  	/* the number of pipes using HDCP signalling out of this port */
>  	unsigned int num_hdcp_streams;
> +	/* port HDCP auth status */
> +	bool hdcp_auth_status;
>  	/* HDCP port data need to pass to security f/w */
>  	struct hdcp_port_data hdcp_port_data;
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 829176df89e7..6a48110c7cd7 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -26,6 +26,64 @@
>  #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;
> +}
> +
Lets add a comment about policy on content type selection and why. And
mention that ideally we should be able to support different content type
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 (!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 (connector->base.status == connector_status_disconnected)
> +			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)
>  {
> @@ -1476,13 +1534,14 @@ 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;
> @@ -1491,16 +1550,18 @@ 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;
>  
> @@ -1509,8 +1570,7 @@ 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);
>  
> @@ -1671,6 +1731,7 @@ 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;
>  }
> @@ -1745,11 +1806,9 @@ 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);
> @@ -1759,7 +1818,7 @@ 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;
> @@ -1794,7 +1853,9 @@ 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;
>  
> @@ -1802,6 +1863,16 @@ 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",
> @@ -1819,7 +1890,9 @@ 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",
> @@ -1831,6 +1904,8 @@ 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;
>  }
With these comments addressed LGTM.

Ram
> -- 
> 2.26.2
> 
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