Re: [PATCH v6 13/35] drm/i915: Implement HDCP2.2 repeater authentication

On Wednesday 01 August 2018 04:00 PM, Shankar, Uma wrote:

...

-----Original Message----- From: C, Ramalingam Sent: Saturday, July 14, 2018 8:45 AM To: intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; daniel@ffwll.ch; seanpaul@chromium.org; Winkler, Tomas tomas.winkler@intel.com; Usyskin, Alexander alexander.usyskin@intel.com; Shankar, Uma uma.shankar@intel.com Cc: Sharma, Shashank shashank.sharma@intel.com; C, Ramalingam ramalingam.c@intel.com Subject: [PATCH v6 13/35] drm/i915: Implement HDCP2.2 repeater authentication

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

v2: Rebased. v3: No Changes. v4: -EINVAL is returned for topology error and rollover scenario. Endianness conversion func from drm_hdcp.h is used [Uma] v5: Rebased as part of patches reordering. Defined the mei service functions [Daniel] v6: Redefined the mei service functions as per comp redesign.

Signed-off-by: Ramalingam C ramalingam.c@intel.com

drivers/gpu/drm/i915/intel_hdcp.c | 171 ++++++++++++++++++++++++++++++++++++++ include/drm/drm_hdcp.h | 15 ++++ 2 files changed, 186 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c index ee1e06bac175..a08d80c710d7 100644 --- a/drivers/gpu/drm/i915/intel_hdcp.c +++ b/drivers/gpu/drm/i915/intel_hdcp.c @@ -1144,6 +1144,56 @@ static int hdcp2_prepare_skey(struct intel_connector *connector, return ret; }

+static int +hdcp2_verify_rep_topology_prepare_ack(

• 	struct intel_connector *connector,
  

• 	struct hdcp2_rep_send_receiverid_list *rep_topology,
  

• 	struct hdcp2_rep_send_ack *rep_send_ack) {
  

• struct mei_hdcp_data *data = &connector->hdcp.mei_data;
• struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
• struct i915_component_master *comp = dev_priv->comp_master;
• int ret;
• if (!comp)

• return -EINVAL;
  

• if (!comp->hdcp_ops || !comp->mei_cldev || data->port ==

INVALID_PORT)

• return -EINVAL;
  

• ret = comp->hdcp_ops->repeater_check_flow_prepare_ack(comp-

...

mei_cldev,

• 					      data,
  

• 					      rep_topology,
  

• 					      rep_send_ack);
  

Same as mentioned in earlier patch in the series.

comp->hdcp_ops and comp->mei_cldev are initialized at component binding of the mei_hdcp module. So until the component binding happens at mei_hdcp, members of the comp->hdcp_ops wont be utilized.

Otherwise overall the change looks ok to me.

...

• if (ret < 0)

• comp->hdcp_ops->close_hdcp_session(comp->mei_cldev, data);
  

• return ret;

+}

+static int +hdcp2_verify_mprime(struct intel_connector *connector,

•     struct hdcp2_rep_stream_ready *stream_ready) {
  

• struct mei_hdcp_data *data = &connector->hdcp.mei_data;
• struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
• struct i915_component_master *comp = dev_priv->comp_master;
• int ret;
• if (!comp)

• return -EINVAL;
  

• if (!comp->hdcp_ops || !comp->mei_cldev || data->port ==

INVALID_PORT)

• return -EINVAL;
  

• ret = comp->hdcp_ops->verify_mprime(comp->mei_cldev, data,

• 			    stream_ready);
  

• if (ret < 0)

• comp->hdcp_ops->close_hdcp_session(comp->mei_cldev, data);
  

• return ret;

+}

static int hdcp2_authenticate_port(struct intel_connector *connector) { struct mei_hdcp_data *data = &connector->hdcp.mei_data; @@ -1319,6 +1369,121 @@ static int hdcp2_session_key_exchange(struct intel_connector *connector) return 0; }

+static +int hdcp2_propagate_stream_management_info(struct intel_connector +*connector) {

• struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
• 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;
• /* Prepare RepeaterAuth_Stream_Manage msg */
• msgs.stream_manage.msg_id = HDCP_2_2_REP_STREAM_MANAGE;
• reverse_endianness(msgs.stream_manage.seq_num_m,

HDCP_2_2_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_2_2_msg(intel_dig_port, &msgs.stream_manage,

• 		  sizeof(msgs.stream_manage));
  

• if (ret < 0)

• return ret;
  

• ret = shim->read_2_2_msg(intel_dig_port,

HDCP_2_2_REP_STREAM_READY,

• 		 &msgs.stream_ready,
  

sizeof(msgs.stream_ready));

How the timeout of 100ms is ensured here.

shim->read_2_2_msg() waits for the required timeout for each HDCP2.2 msgs.

--Ram.

...

• if (ret < 0)

• return ret;
  

• hdcp->mei_data.seq_num_m = hdcp->seq_num_m;
• hdcp->mei_data.streams[0].stream_type = hdcp->content_type;
• ret = hdcp2_verify_mprime(connector, &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_connector +*connector) {

• struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
• struct intel_hdcp *hdcp = &connector->hdcp;
• union {

• struct hdcp2_rep_send_receiverid_list recvid_list;
  

• struct hdcp2_rep_send_ack rep_ack;
  

• } msgs;
• const struct intel_hdcp_shim *shim = hdcp->shim;
• uint8_t *rx_info;
• uint32_t seq_num_v;
• int ret;
• ret = shim->read_2_2_msg(intel_dig_port,

HDCP_2_2_REP_SEND_RECVID_LIST,

• 		 &msgs.recvid_list, sizeof(msgs.recvid_list));
  

• if (ret < 0)

• return ret;
  

• rx_info = msgs.recvid_list.rx_info;
• if (HDCP_2_2_MAX_CASCADE_EXCEEDED(rx_info[1]) ||

•    HDCP_2_2_MAX_DEVS_EXCEEDED(rx_info[1])) {
  

• DRM_DEBUG_KMS("Topology Max Size Exceeded\n");
  

• return -EINVAL;
  

• }
• /* Converting and Storing the seq_num_v to local variable as DWORD */
• reverse_endianness((u8 *)&seq_num_v, HDCP_2_2_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 -EINVAL;
  

• }
• ret = hdcp2_verify_rep_topology_prepare_ack(connector,

• 				    &msgs.recvid_list,
  

• 				    &msgs.rep_ack);
  

• if (ret < 0)

• return ret;
  

• hdcp->seq_num_v = seq_num_v;
• ret = shim->write_2_2_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_connector +*connector) {

• int ret;
• ret = hdcp2_authenticate_repeater_topology(connector);
• if (ret < 0)

• return ret;
  

• return hdcp2_propagate_stream_management_info(connector);

+}

static int hdcp2_authenticate_sink(struct intel_connector *connector) { struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector); @@ -1360,6 +1525,12 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector) sizeof(stream_type_msg)); if (ret < 0) return ret;

• } else if (hdcp->is_repeater) {

• ret = hdcp2_authenticate_repeater(connector);
  

• if (ret < 0) {
  

• 	DRM_DEBUG_KMS("Repeater Auth Failed. Err: %d\n",
  

ret);

• 	return ret;
  

• }
  

  }

  hdcp->mei_data.streams[0].stream_type = hdcp->content_type; diff --git

a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index 2b4cfb0b7324..c01cdb1d848d 100644 --- a/include/drm/drm_hdcp.h +++ b/include/drm/drm_hdcp.h @@ -252,4 +252,19 @@ struct hdcp2_dp_errata_stream_type { #define HDCP_2_2_HDMI_RXSTATUS_READY(x) ((x) & BIT(2)) #define HDCP_2_2_HDMI_RXSTATUS_REAUTH_REQ(x) ((x) & BIT(3))

+/*

• • Library functions for endianness are aligned for 16/32/64 bits.
• • But hdcp sequence numbers are 24bits. So for their Byte swapping,
• • a conversion function is developed.
• */

+static inline void reverse_endianness(u8 *dest, size_t sz, u8 *src) {

• u32 index;
• if (!sz || sz > sizeof(u32))

• return;
  

• for (index = 0; index < sz; index++)

• dest[sz - index - 1] = src[index];
  

+}

#endif

2.7.4