[Intel-gfx] [PATCH v8 22/35] misc/mei/hdcp: Verify H_prime

[Ramalingam C]

Requests for the verification of AKE_Send_H_prime.

ME will calculate the H and comparing it with received H_Prime.
The result will be returned as status.

Here AKE_Send_H_prime is a HDCP2.2 Authentication msg.

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]
  Styles and typos fixed [Uma]
v5:
  Rebased.
v6:
  No change.
v7:
  Collected the Rb-ed by.
  Rebasing.
v8:
  Adjust to the new mei interface.
  Fix for Kdoc.

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
Reviewed-by: Uma Shankar <uma.shankar at intel.com>
---
 drivers/misc/mei/hdcp/mei_hdcp.c | 60 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 59 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c
index b38836dbdb66..f5e6db9c0026 100644
--- a/drivers/misc/mei/hdcp/mei_hdcp.c
+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
@@ -164,12 +164,70 @@ mei_verify_receiver_cert_prepare_km(struct device *dev, void *hdcp_data,
 	return 0;
 }
 
+/*
+ * mei_verify_hprime :
+ * Function to verify AKE_Send_H_prime received, through ME FW.
+ *
+ * @dev : device corresponding to the mei_cl_device
+ * @hdcp_data : Intel HW specific hdcp data
+ * @rx_hprime : AKE_Send_H_prime msg for mei verification
+ *
+ * Returns 0 on Success, <0 on Failure
+ */
+static int mei_verify_hprime(struct device *dev, void *hdcp_data,
+			     struct hdcp2_ake_send_hprime *rx_hprime)
+{
+	struct wired_cmd_ake_send_hprime_in send_hprime_in = { { 0 } };
+	struct wired_cmd_ake_send_hprime_out send_hprime_out = { { 0 } };
+	struct mei_cl_device *cldev;
+	struct mei_hdcp_data *data = hdcp_data;
+	ssize_t byte;
+
+	if (!dev || !data || !rx_hprime)
+		return -EINVAL;
+
+	cldev = to_mei_cl_device(dev);
+
+	send_hprime_in.header.api_version = HDCP_API_VERSION;
+	send_hprime_in.header.command_id = WIRED_AKE_SEND_HPRIME;
+	send_hprime_in.header.status = ME_HDCP_STATUS_SUCCESS;
+	send_hprime_in.header.buffer_len = WIRED_CMD_BUF_LEN_AKE_SEND_HPRIME_IN;
+
+	send_hprime_in.port.integrated_port_type = data->port_type;
+	send_hprime_in.port.physical_port = data->port;
+
+	memcpy(send_hprime_in.h_prime, rx_hprime->h_prime,
+	       sizeof(rx_hprime->h_prime));
+
+	byte = mei_cldev_send(cldev, (u8 *)&send_hprime_in,
+			      sizeof(send_hprime_in));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
+		return byte;
+	}
+
+	byte = mei_cldev_recv(cldev, (u8 *)&send_hprime_out,
+			      sizeof(send_hprime_out));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
+		return byte;
+	}
+
+	if (send_hprime_out.header.status != ME_HDCP_STATUS_SUCCESS) {
+		dev_dbg(dev, "ME cmd 0x%08X Failed. Status: 0x%X\n",
+			WIRED_AKE_SEND_HPRIME, send_hprime_out.header.status);
+		return -EIO;
+	}
+
+	return 0;
+}
+
 static __attribute__((unused))
 struct i915_hdcp_component_ops mei_hdcp_ops = {
 	.owner = THIS_MODULE,
 	.initiate_hdcp2_session = mei_initiate_hdcp2_session,
 	.verify_receiver_cert_prepare_km = mei_verify_receiver_cert_prepare_km,
-	.verify_hprime = NULL,
+	.verify_hprime = mei_verify_hprime,
 	.store_pairing_info = NULL,
 	.initiate_locality_check = NULL,
 	.verify_lprime = NULL,
-- 
2.7.4