[PATCH 19/43] misc/mei/hdcp: Verify M_prime

Ramalingam C
2018-02-14T14:20:31Z

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.

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
---
drivers/misc/mei/mei_hdcp.c | 86 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/mei_hdcp.h | 8 +++++
2 files changed, 94 insertions(+)

diff --git a/drivers/misc/mei/mei_hdcp.c b/drivers/misc/mei/mei_hdcp.c
index c91a96bc45e9..d950361206e2 100644
--- a/drivers/misc/mei/mei_hdcp.c
+++ b/drivers/misc/mei/mei_hdcp.c
@@ -626,6 +626,92 @@ mei_repeater_check_flow_prepare_ack(struct mei_hdcp_data *data,
}
EXPORT_SYMBOL(mei_repeater_check_flow_prepare_ack);

+static inline void reverse_endianness(u8 *dest, size_t dst_sz, u8 *src)
+{
+ u32 index;
+
+ if (dest != NULL && dst_sz != 0) {
+ for (index = 0; index < dst_sz && index < sizeof(u32);
+ index++) {
+ dest[dst_sz - index - 1] = src[index];
+ }
+ }
+}
+
+/**
+ * mei_verify_mprime:
+ * Function to verify mprime.
+ *
+ * @data : Intel HW specific Data
+ * @stream_ready : pointer for RepeaterAuth_Stream_Ready message.
+ *
+ * Returns 0 on Success, <0 on Failure
+ */
+int mei_verify_mprime(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 } };
+ enum me_status status;
+ struct device *dev;
+ ssize_t byte;
+
+ if (!stream_ready || !data)
+ return -EINVAL;
+
+ /* check for the mei_device enabled or not */
+ if (!mei_cldev_active_and_enabled(data->cldev))
+ return -ENODEV;
+
+ dev = &data->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;
+
+ verify_mprime_in.k = data->k;
+ memcpy(verify_mprime_in.m_prime, stream_ready->m_prime,
+ sizeof(stream_ready->m_prime));
+ reverse_endianness((u8 *)&verify_mprime_in.seq_num_m, HDCP_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);
+
+ /* Request to ME */
+ byte = mei_cldev_send(data->cldev, (u8 *)&verify_mprime_in,
+ sizeof(verify_mprime_in));
+ if (byte < 0) {
+ dev_err(dev, "mei_cldev_send failed. %d\n", (int)byte);
+ return byte;
+ }
+
+ /* Response from ME */
+ byte = mei_cldev_recv(data->cldev, (u8 *)&verify_mprime_out,
+ sizeof(verify_mprime_out));
+ if (byte < 0) {
+ dev_err(dev, "mei_cldev_recv failed. %d\n", (int)byte);
+ return byte;
+ }
+
+ status = (enum me_status)verify_mprime_out.header.status;
+ if (status != ME_HDCP_STATUS_SUCCESS) {
+ dev_err(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
+ WIRED_REPEATER_AUTH_STREAM_REQ, status);
+ return -1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(mei_verify_mprime);
+
static int mei_hdcp_probe(struct mei_cl_device *cldev,
const struct mei_cl_device_id *id)
{
diff --git a/include/linux/mei_hdcp.h b/include/linux/mei_hdcp.h
index c8f6fc90f475..560fc62b2b41 100644
--- a/include/linux/mei_hdcp.h
+++ b/include/linux/mei_hdcp.h
@@ -126,6 +126,8 @@ mei_repeater_check_flow_prepare_ack(struct mei_hdcp_data *data,
struct hdcp2_rep_send_receiverid_list
*rep_topology,
struct hdcp2_rep_send_ack *rep_send_ack);
+int mei_verify_mprime(struct mei_hdcp_data *data,
+ struct hdcp2_rep_stream_ready *stream_ready);
#else
static inline
int mei_hdcp_cldev_get_reference(void *client_data,
@@ -193,5 +195,11 @@ mei_repeater_check_flow_prepare_ack(struct mei_hdcp_data *data,
{
return -ENODEV;
}
+static inline
+int mei_verify_mprime(struct mei_hdcp_data *data,
+ struct hdcp2_rep_stream_ready *stream_ready)
+{
+ return -ENODEV;
+}
#endif /* defined (CONFIG_INTEL_MEI_HDCP) */
#endif /* defined (_LINUX_MEI_HDCP_H) */