[PATCH v9 14/19] drm/i915/hdcp: MST streams support in hdcp port_data

Li, Juston juston.li at intel.com
Tue Jan 12 05:26:26 UTC 2021


On Mon, 2021-01-11 at 13:41 +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 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 at intel.com>
> Reviewed-by: Uma Shankar <uma.shankar at intel.com>
> Reviewed-by: Ramalingam C <ramalingam.c at intel.com>
> Tested-by: Karthik B S <karthik.b.s at intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> ---
>  .../drm/i915/display/intel_display_types.h    |   4 +-
>  drivers/gpu/drm/i915/display/intel_hdcp.c     | 113 +++++++++++++++-
> --
>  2 files changed, 102 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 b74c10c8b01c..b37a02a73de6 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1502,10 +1502,12 @@ struct intel_digital_port {
>         enum phy_fia tc_phy_fia;
>         u8 tc_phy_fia_idx;
>  
> -       /* protects num_hdcp_streams reference count, hdcp_port_data
> */
> +       /* protects num_hdcp_streams reference count, hdcp_port_data
> and hdcp_auth_status */
>         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 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;
>  }

Verified NULL pointer dereference fixed in cros with mst dock setup
Tested-by: Juston Li <juston.li at intel.com>
Acked-by: Juston Li <juston.li at intel.com>



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