[Intel-gfx] [PATCH] drm/i915: Add missing GSCCS documentation

[Rodrigo Vivi]

Introduce the basic documentation about GSC CS.

This "GPU Basics" section is focused on explaining the hardware
rather than the driver/uapi, so let's make sure GSC is also
properly documented here.

v2: Fixes from Matt: typos and acronym.

Fixes: 5fd974d164b4 ("drm/i915/mtl: add initial definitions for GSC CS")
Suggested-by: Matt Roper <matthew.d.roper at intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 Documentation/gpu/i915.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst
index 13de8bcaaa29..0ca1550fd9dc 100644
--- a/Documentation/gpu/i915.rst
+++ b/Documentation/gpu/i915.rst
@@ -279,6 +279,10 @@ An Intel GPU has multiple engines. There are several engine types:
   Also sometimes called 'VEBOX' in hardware documentation.
 - Compute Command Streamer (CCS). An engine that has access to the media and
   GPGPU pipelines, but not the 3D pipeline.
+- Graphics Security Controller (GSCCS). A dedicated engine for internal
+  communication with GSC controller on security related tasks like
+  High-bandwidth Digital Content Protection (HDCP), Protected Xe Path (PXP),
+  and HuC firmware authentication.
 
 The Intel GPU family is a family of integrated GPU's using Unified
 Memory Access. For having the GPU "do work", user space will feed the
-- 
2.41.0