drm/i915/mtl: add initial definitions for GSC CS

Starting on MTL, the GSC is no longer managed with direct MMIO access,
but we instead have a dedicated command streamer for it. As a first step
for adding support for this CS, add the required definitions.
Note that, although it is now a CS, the GSC retains its old
class:instance value (OTHER_CLASS instance 6)

Bspec: 65308, 45605
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221102171047.2787951-2-daniele.ceraolospurio@intel.com

drivers/gpu/drm/i915/gt/intel_engine_cs.c

@@ -244,6 +244,13 @@ static const struct engine_info intel_engines[] = {
 			{ .graphics_ver = 12, .base = GEN12_COMPUTE3_RING_BASE }
 		}
 	},
+	[GSC0] = {
+		.class = OTHER_CLASS,
+		.instance = OTHER_GSC_INSTANCE,
+		.mmio_bases = {
+			{ .graphics_ver = 12, .base = MTL_GSC_RING_BASE }
+		}
+	},
 };
 
 /**
@@ -324,6 +331,7 @@ u32 intel_engine_context_size(struct intel_gt *gt, u8 class)
 	case VIDEO_DECODE_CLASS:
 	case VIDEO_ENHANCEMENT_CLASS:
 	case COPY_ENGINE_CLASS:
+	case OTHER_CLASS:
 		if (GRAPHICS_VER(gt->i915) < 8)
 			return 0;
 		return GEN8_LR_CONTEXT_OTHER_SIZE;

drivers/gpu/drm/i915/gt/intel_engine_types.h

@@ -136,6 +136,7 @@ enum intel_engine_id {
 	CCS2,
 	CCS3,
 #define _CCS(n) (CCS0 + (n))
+	GSC0,
 	I915_NUM_ENGINES
 #define INVALID_ENGINE ((enum intel_engine_id)-1)
 };

drivers/gpu/drm/i915/gt/intel_engine_user.c

@@ -140,6 +140,7 @@ const char *intel_engine_class_repr(u8 class)
 		[COPY_ENGINE_CLASS] = "bcs",
 		[VIDEO_DECODE_CLASS] = "vcs",
 		[VIDEO_ENHANCEMENT_CLASS] = "vecs",
+		[OTHER_CLASS] = "other",
 		[COMPUTE_CLASS] = "ccs",
 	};
 

drivers/gpu/drm/i915/i915_reg.h

@@ -970,6 +970,7 @@
 #define GEN11_VEBOX2_RING_BASE		0x1d8000
 #define XEHP_VEBOX3_RING_BASE		0x1e8000
 #define XEHP_VEBOX4_RING_BASE		0x1f8000
+#define MTL_GSC_RING_BASE		0x11a000
 #define GEN12_COMPUTE0_RING_BASE	0x1a000
 #define GEN12_COMPUTE1_RING_BASE	0x1c000
 #define GEN12_COMPUTE2_RING_BASE	0x1e000