[Intel-gfx] [PATCH v8 08/35] drm/i915: Implement HDCP2.2 repeater authentication
C, Ramalingam
ramalingam.c at intel.com
Wed Dec 12 09:11:16 UTC 2018
On 12/6/2018 4:15 PM, Daniel Vetter wrote:
> On Tue, Nov 27, 2018 at 04:13:06PM +0530, Ramalingam C wrote:
>> 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.
>> v7:
>> %s/uintxx_t/uxx
>> Check for comp_master is removed.
>> v8:
>> Adjust to the new mei interface.
>> style issue fixed.
>>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> ---
>> drivers/gpu/drm/i915/intel_hdcp.c | 125 +++++++++++++++++++++++++++++++++++++-
>> include/drm/drm_hdcp.h | 15 +++++
>> 2 files changed, 138 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
>> index 0d7fea9c9bb1..679f3c164582 100644
>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> @@ -1069,7 +1069,7 @@ static int hdcp2_prepare_skey(struct intel_connector *connector,
>> return ret;
>> }
>>
>> -static __attribute__((unused)) int
>> +static int
>> hdcp2_verify_rep_topology_prepare_ack(struct intel_connector *connector,
>> struct hdcp2_rep_send_receiverid_list
>> *rep_topology,
>> @@ -1099,7 +1099,7 @@ hdcp2_verify_rep_topology_prepare_ack(struct intel_connector *connector,
>> return ret;
>> }
>>
>> -static __attribute__((unused)) int
>> +static int
>> hdcp2_verify_mprime(struct intel_connector *connector,
>> struct hdcp2_rep_stream_ready *stream_ready)
>> {
>> @@ -1315,6 +1315,121 @@ 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));
>> + 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;
>> + u8 *rx_info;
>> + u32 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);
>> @@ -1356,6 +1471,12 @@ 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 a6de09c5e47f..3e45a7618ab3 100644
>> --- a/include/drm/drm_hdcp.h
>> +++ b/include/drm/drm_hdcp.h
>> @@ -250,4 +250,19 @@ 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)
> This feels a bit fake-generic and doesn't fit that well into what you want
> it to do in the code actually. What about:
>
> u32 drm_hdcp2_seq_num_to_u32(u8 seq_num[HDCP_2_2_SEQ_NUM_LEN])
> {
> return seq_num[2] | seq_num[1] << 8 | seq_num[0] << 16;
> }
Understood the point. we need drm_hdcp2_u32_to_seq_num too... I will add
that too.
-Ram
>
> (I didn't check the math).
>
> I think this would both make the code more clearer and avoid the problem
> of "shouldn't we make sure this works for everything and put it into
> linux/string.h?"
>
> Again I'll check the actual hdcp2 flow later on.
>
> In general I'm kinda not happy with the shim midlayer design, but I wasn't
> happy with that with hdcp1 either, and hdcp2 is just an extension, and I
> don't really have a better idea either so seems all good to me.
> -Daniel
>
>> +{
>> + u32 index;
>> +
>> + if (!sz || sz > sizeof(u32))
>> + return;
>> + for (index = 0; index < sz; index++)
>> + dest[sz - index - 1] = src[index];
>> +}
>> +
>> #endif
>> --
>> 2.7.4
>>
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