[PATCH v6 33/35] misc/mei/hdcp: Verify M_prime

[Shankar, Uma]

>-----Original Message-----
>From: C, Ramalingam
>Sent: Saturday, July 14, 2018 8:45 AM
>To: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org;
>daniel at ffwll.ch; seanpaul at chromium.org; Winkler, Tomas
><tomas.winkler at intel.com>; Usyskin, Alexander <alexander.usyskin at intel.com>;
>Shankar, Uma <uma.shankar at intel.com>
>Cc: Sharma, Shashank <shashank.sharma at intel.com>; C, Ramalingam
><ramalingam.c at intel.com>
>Subject: [PATCH v6 33/35] misc/mei/hdcp: Verify M_prime
>
>Request to ME to verify the M_Prime received from the HDCP sink.
>
>ME FW will calculate the M and compare with M_prime received as part of
>RepeaterAuth_Stream_Ready, which is HDCP2.2 protocol msg.
>
>On successful completion of this stage, downstream propagation of the stream
>management info is completed.
>
>v2:
>  Rebased.
>v3:
>  cldev is passed as first parameter [Tomas]
>  Redundant comments and cast are removed [Tomas]
>v4:
>  %zd for ssize_t [Alexander]
>  %s/return -1/return -EIO [Alexander]
>  endianness conversion func is moved to drm_hdcp.h [Uma]
>v5:
>  Rebased.
>v6:
>  No change.
>

Looks ok to me.
Reviewed-by: Uma Shankar <uma.shankar at intel.com>

>Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>---
> drivers/misc/mei/hdcp/mei_hdcp.c | 70
>+++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 69 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c
>b/drivers/misc/mei/hdcp/mei_hdcp.c
>index be220f8a6393..7841fe94a96f 100644
>--- a/drivers/misc/mei/hdcp/mei_hdcp.c
>+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
>@@ -556,6 +556,74 @@ mei_repeater_check_flow_prepare_ack(struct
>mei_cl_device *cldev,
> 	return 0;
> }
>
>+/*
>+ * mei_verify_mprime:
>+ *	Function to verify mprime.
>+ *
>+ * cldev		: Pointer for mei client device
>+ * data			: Intel HW specific Data
>+ * stream_ready		: pointer for RepeaterAuth_Stream_Ready
>message.
>+ *
>+ * Returns 0 on Success, <0 on Failure
>+ */
>+static int mei_verify_mprime(struct mei_cl_device *cldev,
>+			     struct mei_hdcp_data *data,
>+			     struct hdcp2_rep_stream_ready *stream_ready) {
>+	struct wired_cmd_repeater_auth_stream_req_in
>+					verify_mprime_in = { { 0 } };
>+	struct wired_cmd_repeater_auth_stream_req_out
>+					verify_mprime_out = { { 0 } };
>+	struct device *dev;
>+	ssize_t byte;
>+
>+	if (!stream_ready || !data)
>+		return -EINVAL;
>+
>+	dev = &cldev->dev;
>+
>+	verify_mprime_in.header.api_version = HDCP_API_VERSION;
>+	verify_mprime_in.header.command_id =
>WIRED_REPEATER_AUTH_STREAM_REQ;
>+	verify_mprime_in.header.status = ME_HDCP_STATUS_SUCCESS;
>+	verify_mprime_in.header.buffer_len =
>+
>	WIRED_CMD_BUF_LEN_REPEATER_AUTH_STREAM_REQ_MIN_IN;
>+
>+	verify_mprime_in.port.integrated_port_type = data->port_type;
>+	verify_mprime_in.port.physical_port = data->port;
>+
>+	memcpy(verify_mprime_in.m_prime, stream_ready->m_prime,
>+	       HDCP_2_2_MPRIME_LEN);
>+	reverse_endianness((u8 *)&verify_mprime_in.seq_num_m,
>+			   HDCP_2_2_SEQ_NUM_LEN, (u8 *)&data-
>>seq_num_m);
>+	memcpy(verify_mprime_in.streams, data->streams,
>+	       (data->k * sizeof(struct hdcp2_streamid_type)));
>+
>+	verify_mprime_in.k = __swab16(data->k);
>+
>+	byte = mei_cldev_send(cldev, (u8 *)&verify_mprime_in,
>+			      sizeof(verify_mprime_in));
>+	if (byte < 0) {
>+		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
>+		return byte;
>+	}
>+
>+	byte = mei_cldev_recv(cldev, (u8 *)&verify_mprime_out,
>+			      sizeof(verify_mprime_out));
>+	if (byte < 0) {
>+		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
>+		return byte;
>+	}
>+
>+	if (verify_mprime_out.header.status != ME_HDCP_STATUS_SUCCESS) {
>+		dev_dbg(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
>+			WIRED_REPEATER_AUTH_STREAM_REQ,
>+			verify_mprime_out.header.status);
>+		return -EIO;
>+	}
>+
>+	return 0;
>+}
>+
> struct i915_hdcp_component_ops mei_hdcp_component_ops = {
> 	.owner					= THIS_MODULE,
> 	.initiate_hdcp2_session			= mei_initiate_hdcp2_session,
>@@ -568,7 +636,7 @@ struct i915_hdcp_component_ops
>mei_hdcp_component_ops = {
> 	.get_session_key			= mei_get_session_key,
> 	.repeater_check_flow_prepare_ack	=
>
>	mei_repeater_check_flow_prepare_ack,
>-	.verify_mprime				= NULL,
>+	.verify_mprime				= mei_verify_mprime,
> 	.enable_hdcp_authentication		= NULL,
> 	.close_hdcp_session			= NULL,
> };
>--
>2.7.4