[PATCH 2/3] drm/xe/hdcp: Enable HDCP for XE

[Suraj Kandpal <suraj.kandpal@intel.com>]

Enable HDCP for Xe by defining functions which take care of
interaction of HDCP as a client with the GSC CS interface.

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
---
 drivers/gpu/drm/xe/display/xe_hdcp_gsc.c | 188 ++++++++++++++++++++++-
 1 file changed, 184 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c b/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
index 0f11a39333e2..eca941d7b281 100644
--- a/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
+++ b/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
@@ -3,8 +3,24 @@
  * Copyright 2023, Intel Corporation.
  */
 
+#include "abi/gsc_command_header_abi.h"
 #include "i915_drv.h"
 #include "intel_hdcp_gsc.h"
+#include "xe_bo.h"
+#include "xe_map.h"
+#include "xe_gsc_submit.h"
+
+#define HECI_MEADDRESS_HDCP 18
+
+struct intel_hdcp_gsc_message {
+	struct xe_bo *hdcp_bo;
+	u64 hdcp_cmd_in;
+	u64 hdcp_cmd_out;
+};
+
+#define HOST_SESSION_CLIENT_MASK GENMASK_ULL(63, 56)
+#define HDCP_GSC_MESSAGE_SIZE sizeof(struct intel_hdcp_gsc_message)
+#define HDCP_GSC_HEADER_SIZE sizeof(struct intel_gsc_mtl_header)
 
 bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915)
 {
@@ -13,22 +29,186 @@ bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915)
 
 bool intel_hdcp_gsc_check_status(struct drm_i915_private *i915)
 {
-	return false;
+	return true;
+}
+
+/*This function helps allocate memory for the command that we will send to gsc cs */
+static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
+					     struct intel_hdcp_gsc_message *hdcp_message)
+{
+	struct xe_bo *bo = NULL;
+	u64 cmd_in, cmd_out;
+	int err, ret = 0;
+
+	/* allocate object of two page for HDCP command memory and store it */
+
+	xe_device_mem_access_get(i915);
+	bo = xe_bo_create_pin_map(i915, xe_device_get_root_tile(i915), NULL, PAGE_SIZE * 2,
+				  ttm_bo_type_kernel,
+				  XE_BO_CREATE_SYSTEM_BIT |
+				  XE_BO_CREATE_GGTT_BIT);
+
+	if (IS_ERR(bo)) {
+		drm_err(&i915->drm, "Failed to allocate bo for HDCP streaming command!\n");
+		ret = err;
+		goto out;
+	}
+
+	cmd_in = xe_bo_ggtt_addr(bo);
+
+	if (iosys_map_is_null(&bo->vmap)) {
+		drm_err(&i915->drm, "Failed to map gsc message page!\n");
+		ret = PTR_ERR(&bo->vmap);
+		goto out;
+	}
+
+	cmd_out = cmd_in + PAGE_SIZE;
+
+	xe_map_memset(i915, &bo->vmap, 0, 0, bo->size);
+
+	hdcp_message->hdcp_bo = bo;
+	hdcp_message->hdcp_cmd_in = cmd_in;
+	hdcp_message->hdcp_cmd_out = cmd_out;
+out:
+	xe_device_mem_access_put(i915);
+	return ret;
+}
+
+static int intel_hdcp_gsc_hdcp2_init(struct drm_i915_private *i915)
+{
+	struct intel_hdcp_gsc_message *hdcp_message;
+	int ret;
+
+	hdcp_message = kzalloc(sizeof(*hdcp_message), GFP_KERNEL);
+
+	if (!hdcp_message)
+		return -ENOMEM;
+
+	/*
+	 * NOTE: No need to lock the comp mutex here as it is already
+	 * going to be taken before this function called
+	 */
+	i915->display.hdcp.hdcp_message = hdcp_message;
+	ret = intel_hdcp_gsc_initialize_message(i915, hdcp_message);
+
+	if (ret)
+		drm_err(&i915->drm, "Could not initialize hdcp_message\n");
+
+	return ret;
 }
 
 int intel_hdcp_gsc_init(struct drm_i915_private *i915)
 {
-	drm_info(&i915->drm, "HDCP support not yet implemented\n");
-	return -ENODEV;
+	struct i915_hdcp_arbiter *data;
+	int ret;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	mutex_lock(&i915->display.hdcp.hdcp_mutex);
+	i915->display.hdcp.arbiter = data;
+	i915->display.hdcp.arbiter->hdcp_dev = i915->drm.dev;
+	i915->display.hdcp.arbiter->ops = &gsc_hdcp_ops;
+	ret = intel_hdcp_gsc_hdcp2_init(i915);
+	mutex_unlock(&i915->display.hdcp.hdcp_mutex);
+
+	return ret;
 }
 
 void intel_hdcp_gsc_fini(struct drm_i915_private *i915)
 {
+	struct intel_hdcp_gsc_message *hdcp_message =
+					i915->display.hdcp.hdcp_message;
+
+	xe_bo_unpin_map_no_vm(hdcp_message->hdcp_bo);
+	kfree(hdcp_message);
+
 }
 
+static int xe_gsc_send_sync(struct drm_i915_private *i915,
+			    struct intel_hdcp_gsc_message *hdcp_message,
+			    u32 msg_size_in, u32 msg_size_out,
+			    u32 addr_in_off, u32 addr_out_off,
+			    size_t msg_out_len)
+{
+	struct xe_gt *gt = hdcp_message->hdcp_bo->tile->media_gt;
+	struct iosys_map *map = &hdcp_message->hdcp_bo->vmap;
+	struct xe_gsc *gsc = &gt->uc.gsc;
+	int ret;
+
+	ret = xe_gsc_pkt_submit_kernel(gsc, hdcp_message->hdcp_cmd_in, msg_size_in,
+				       hdcp_message->hdcp_cmd_out, msg_size_out);
+	if (ret) {
+		drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
+		return ret;
+	}
+
+	ret = xe_gsc_check_and_update_pending(i915, map, 0, map, addr_out_off);
+
+	if (ret)
+		return -EAGAIN;
+
+	ret = xe_gsc_read_out_header(i915, map, addr_out_off,
+				     sizeof(struct hdcp_cmd_header), NULL);
+
+	return ret;
+}
 ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
 				size_t msg_in_len, u8 *msg_out,
 				size_t msg_out_len)
 {
-	return -ENODEV;
+	const size_t max_msg_size = PAGE_SIZE - HDCP_GSC_HEADER_SIZE;
+	struct intel_hdcp_gsc_message *hdcp_message;
+	u64 host_session_id;
+	u32 msg_size_in, msg_size_out, addr_in_off = 0, addr_out_off;
+	int ret, tries = 0;
+
+	if (msg_in_len > max_msg_size || msg_out_len > max_msg_size) {
+		ret = -ENOSPC;
+		goto out;
+	}
+
+	msg_size_in = msg_in_len + HDCP_GSC_HEADER_SIZE;
+	msg_size_out = msg_out_len + HDCP_GSC_HEADER_SIZE;
+	hdcp_message = i915->display.hdcp.hdcp_message;
+	addr_out_off = PAGE_SIZE;
+
+	get_random_bytes(&host_session_id, sizeof(u64));
+	host_session_id = host_session_id & ~HOST_SESSION_CLIENT_MASK;
+	xe_device_mem_access_get(i915);
+	addr_in_off = xe_gsc_emit_header(i915, &hdcp_message->hdcp_bo->vmap,
+					 addr_in_off,
+					 HECI_MEADDRESS_HDCP, host_session_id,
+					 msg_in_len);
+
+	xe_map_memcpy_to(i915, &hdcp_message->hdcp_bo->vmap, addr_in_off, msg_in, msg_in_len);
+	/*
+	 * Keep sending request in case the pending bit is set no need to add
+	 * message handle as we are using same address hence loc. of header is
+	 * same and it will contain the message handle. we will send the message
+	 * 20 times each message 50 ms apart
+	 */
+	do {
+		ret = xe_gsc_send_sync(i915, hdcp_message, msg_size_in, msg_size_out,
+				       addr_in_off, addr_out_off, msg_out_len);
+
+		/* Only try again if gsc says so */
+		if (ret != -EAGAIN)
+			break;
+
+		msleep(50);
+
+	} while (++tries < 20);
+
+	if (ret)
+		goto out;
+
+	xe_map_memcpy_from(i915, msg_out, &hdcp_message->hdcp_bo->vmap,
+			   addr_out_off + HDCP_GSC_HEADER_SIZE,
+			   msg_out_len);
+
+out:
+	xe_device_mem_access_put(i915);
+	return ret;
 }
-- 
2.25.1