[PATCH v2 1/6] drm/xe/ggtt: Add xe_ggtt_insert_node_at

[Maarten Lankhorst <dev@lankhorst.se>]

Create a new function xe_ggtt_insert_node_at() which will be used
for reserving the part of GGTT where the initial framebuffer was
allocated.

This will allow us to either take over the initial mapping, or
reserve it to have the newly allocated GGTT mapping not overwriting
the initial mapping, which would cause flickering.

Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
---
 drivers/gpu/drm/xe/xe_ggtt.c | 35 +++++++++++++++++++++++++++++++----
 drivers/gpu/drm/xe/xe_ggtt.h |  2 ++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
index 8ec23862477fc..c9f84db3bfecd 100644
--- a/drivers/gpu/drm/xe/xe_ggtt.c
+++ b/drivers/gpu/drm/xe/xe_ggtt.c
@@ -636,14 +636,17 @@ static struct xe_ggtt_node *ggtt_node_init(struct xe_ggtt *ggtt)
 }
 
 /**
- * xe_ggtt_insert_node - Insert a &xe_ggtt_node into the GGTT
+ * xe_ggtt_insert_node_at - Insert a &xe_ggtt_node into the GGTT
  * @ggtt: the &xe_ggtt into which the node should be inserted.
  * @size: size of the node
  * @align: alignment constrain of the node
+ * @start: Starting offset of range to insert node
+ * @end: Last offset for node insertion
  *
  * Return: &xe_ggtt_node on success or a ERR_PTR on failure.
  */
-struct xe_ggtt_node *xe_ggtt_insert_node(struct xe_ggtt *ggtt, u32 size, u32 align)
+struct xe_ggtt_node *xe_ggtt_insert_node_at(struct xe_ggtt *ggtt, u32 size,
+					    u32 align, u64 start, u64 end)
 {
 	struct xe_ggtt_node *node;
 	int ret;
@@ -653,8 +656,19 @@ struct xe_ggtt_node *xe_ggtt_insert_node(struct xe_ggtt *ggtt, u32 size, u32 ali
 		return node;
 
 	guard(mutex)(&ggtt->lock);
-	ret = xe_ggtt_insert_node_locked(node, size, align,
-					 DRM_MM_INSERT_HIGH);
+	if (start >= ggtt->start)
+		start -= ggtt->start;
+	else
+		start = 0;
+
+	/* Should never happen, but since we handle start, fail graciously for end */
+	if (end >= ggtt->start)
+		end -= ggtt->start;
+	else
+		end = 0;
+
+	ret = drm_mm_insert_node_in_range(&ggtt->mm, &node->base, size, align,
+					  0, start, end, DRM_MM_INSERT_HIGH);
 	if (ret) {
 		ggtt_node_fini(node);
 		return ERR_PTR(ret);
@@ -663,6 +677,19 @@ struct xe_ggtt_node *xe_ggtt_insert_node(struct xe_ggtt *ggtt, u32 size, u32 ali
 	return node;
 }
 
+/**
+ * xe_ggtt_insert_node - Insert a &xe_ggtt_node into the GGTT
+ * @ggtt: the &xe_ggtt into which the node should be inserted.
+ * @size: size of the node
+ * @align: alignment constrain of the node
+ *
+ * Return: &xe_ggtt_node on success or a ERR_PTR on failure.
+ */
+struct xe_ggtt_node *xe_ggtt_insert_node(struct xe_ggtt *ggtt, u32 size, u32 align)
+{
+	return xe_ggtt_insert_node_at(ggtt, size, align, 0, ~0ULL);
+}
+
 /**
  * xe_ggtt_node_pt_size() - Get the size of page table entries needed to map a GGTT node.
  * @node: the &xe_ggtt_node
diff --git a/drivers/gpu/drm/xe/xe_ggtt.h b/drivers/gpu/drm/xe/xe_ggtt.h
index c864cc975a695..69974da523f74 100644
--- a/drivers/gpu/drm/xe/xe_ggtt.h
+++ b/drivers/gpu/drm/xe/xe_ggtt.h
@@ -22,6 +22,8 @@ void xe_ggtt_shift_nodes(struct xe_ggtt *ggtt, u64 new_base);
 u64 xe_ggtt_start(struct xe_ggtt *ggtt);
 u64 xe_ggtt_size(struct xe_ggtt *ggtt);
 
+struct xe_ggtt_node *
+xe_ggtt_insert_node_at(struct xe_ggtt *ggtt, u32 size, u32 align, u64 start, u64 end);
 struct xe_ggtt_node *
 xe_ggtt_insert_node(struct xe_ggtt *ggtt, u32 size, u32 align);
 struct xe_ggtt_node *
-- 
2.53.0