drm/i915/fbc: Moved fence related code away from intel_fbc

As a preparation for Xe move HW fence details away from intel_fbc code.
Add new functions to check support for legacy fencing and fence id and use
these in fbc code. Xe doesn't support legacy fencing.

v2: Fix intel_gt_support_legacy_fencing macro
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230614051731.745821-4-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_fbc.c

@@ -47,6 +47,7 @@
 #include "i915_reg.h"
 #include "i915_utils.h"
 #include "i915_vgpu.h"
+#include "i915_vma.h"
 #include "intel_cdclk.h"
 #include "intel_de.h"
 #include "intel_display_trace.h"
@@ -607,7 +608,7 @@ static void ivb_fbc_activate(struct intel_fbc *fbc)
 	else if (DISPLAY_VER(i915) == 9)
 		skl_fbc_program_cfb_stride(fbc);
 
-	if (to_gt(i915)->ggtt->num_fences)
+	if (intel_gt_support_legacy_fencing(to_gt(i915)))
 		snb_fbc_program_fence(fbc);
 
 	intel_de_write(i915, ILK_DPFC_CONTROL(fbc->id),
@@ -991,11 +992,10 @@ static void intel_fbc_update_state(struct intel_atomic_state *state,
 	fbc_state->fence_y_offset = intel_plane_fence_y_offset(plane_state);
 
 	drm_WARN_ON(&i915->drm, plane_state->flags & PLANE_HAS_FENCE &&
-		    !plane_state->ggtt_vma->fence);
+		    !intel_gt_support_legacy_fencing(to_gt(i915)));
 
-	if (plane_state->flags & PLANE_HAS_FENCE &&
-	    plane_state->ggtt_vma->fence)
-		fbc_state->fence_id = plane_state->ggtt_vma->fence->id;
+	if (plane_state->flags & PLANE_HAS_FENCE)
+		fbc_state->fence_id =  i915_vma_fence_id(plane_state->ggtt_vma);
 	else
 		fbc_state->fence_id = -1;
 
@@ -1022,7 +1022,7 @@ static bool intel_fbc_is_fence_ok(const struct intel_plane_state *plane_state)
 	 */
 	return DISPLAY_VER(i915) >= 9 ||
 		(plane_state->flags & PLANE_HAS_FENCE &&
-		 plane_state->ggtt_vma->fence);
+		 i915_vma_fence_id(plane_state->ggtt_vma) != -1);
 }
 
 static bool intel_fbc_is_cfb_ok(const struct intel_plane_state *plane_state)

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

@@ -306,4 +306,6 @@ enum intel_gt_scratch_field {
 	INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA = 256,
 };
 
+#define intel_gt_support_legacy_fencing(gt) ((gt)->ggtt->num_fences > 0)
+
 #endif /* __INTEL_GT_TYPES_H__ */

drivers/gpu/drm/i915/i915_vma.h

@@ -418,6 +418,11 @@ i915_vma_unpin_fence(struct i915_vma *vma)
 		__i915_vma_unpin_fence(vma);
 }
 
+static inline int i915_vma_fence_id(const struct i915_vma *vma)
+{
+	return vma->fence ? vma->fence->id : -1;
+}
+
 void i915_vma_parked(struct intel_gt *gt);
 
 static inline bool i915_vma_is_scanout(const struct i915_vma *vma)