[PATCH v2 3/6] drm/xe/display: Reserve the original GGTT space before creating a bo

[Maarten Lankhorst <dev@lankhorst.se>]

Annotate the original area of the framebuffer as reserved in the GGTT
before creating a new GGTT entry. This allows us to remove the
range restrictions of GGTT in xe_bo_create_pin_map_at_novm().

Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
---
 drivers/gpu/drm/xe/display/xe_initial_plane.c | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/xe/display/xe_initial_plane.c b/drivers/gpu/drm/xe/display/xe_initial_plane.c
index 0f86b73036d03..f49dda8e28255 100644
--- a/drivers/gpu/drm/xe/display/xe_initial_plane.c
+++ b/drivers/gpu/drm/xe/display/xe_initial_plane.c
@@ -37,6 +37,25 @@ static bool need_pte_local(struct xe_device *xe)
 	return IS_DGFX(xe) || has_lmembar(xe);
 }
 
+static struct xe_ggtt_node *reserve_original_node(struct xe_ggtt *ggtt, u32 base, u32 size, u64 page_size)
+{
+	u64 ggtt_start = xe_ggtt_start(ggtt), ggtt_end = ggtt_start + xe_ggtt_size(ggtt);
+
+	/* Completely truncated? */
+	if (base + size <= ggtt_start || base >= ggtt_end)
+		return NULL;
+
+	/* Partially truncated? */
+	if (base <= ggtt_start) {
+		size -= ggtt_start - base;
+		base = ggtt_start;
+	} else if (base + size >= ggtt_end) {
+		size = ggtt_end - base;
+	}
+
+	return xe_ggtt_insert_node_at(ggtt, size, page_size, base, base + size);
+}
+
 static struct xe_bo *
 initial_plane_bo(struct xe_device *xe,
 		 struct intel_initial_plane_config *plane_config)
@@ -46,6 +65,7 @@ initial_plane_bo(struct xe_device *xe,
 	resource_size_t phys_base;
 	u32 base, size, flags;
 	u64 page_size = xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K ? SZ_64K : SZ_4K;
+	struct xe_ggtt_node *original_ggtt_node;
 
 	if (plane_config->size == 0)
 		return NULL;
@@ -111,8 +131,15 @@ initial_plane_bo(struct xe_device *xe,
 		}
 	}
 
+	original_ggtt_node = reserve_original_node(tile0->mem.ggtt, base, size, page_size);
+	if (IS_ERR(original_ggtt_node))
+		return NULL;
+
 	bo = xe_bo_create_pin_map_at_novm(xe, tile0, size, phys_base,
 					  ttm_bo_type_kernel, flags, 0, false);
+	if (original_ggtt_node)
+		xe_ggtt_node_remove_noclear(original_ggtt_node);
+
 	if (IS_ERR(bo)) {
 		drm_dbg_kms(&xe->drm,
 			    "Failed to create bo phys_base=%pa size %u with flags %x: %li\n",
-- 
2.53.0