[PATCH 1/3] drm/xe: Add a function to zap page table by address range

[Oak Zeng]

Add a function xe_pt_zap_range. This is similar to xe_pt_zap_ptes
but is used when we don't have a vma to work with, such as zap
a range mapped to scratch page where we don't have vma.

Signed-off-by: Oak Zeng <oak.zeng at intel.com>
---
 drivers/gpu/drm/xe/xe_pt.c | 28 ++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_pt.h |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
index 1ddcc7e79a93..2363260da6a6 100644
--- a/drivers/gpu/drm/xe/xe_pt.c
+++ b/drivers/gpu/drm/xe/xe_pt.c
@@ -792,6 +792,34 @@ static const struct xe_pt_walk_ops xe_pt_zap_ptes_ops = {
 	.pt_entry = xe_pt_zap_ptes_entry,
 };
 
+/**
+ * xe_pt_zap_range() - Zap (zero) gpu ptes of an virtual address range
+ * @tile: The tile we're zapping for.
+ * @vm: The vm we're zapping for.
+ * @start: Start of the virtual address range, inclusive.
+ * @end: End of the virtual address range, exclusive.
+ *
+ * This is similar to xe_pt_zap_ptes() but it's used when we don't have a
+ * vma to work with. This is used for example when we're clearing the scratch
+ * page mapping during vm_bind.
+ *
+ */
+void xe_pt_zap_range(struct xe_tile *tile, struct xe_vm *vm, u64 start, u64 end)
+{
+	struct xe_pt_zap_ptes_walk xe_walk = {
+		.base = {
+			.ops = &xe_pt_zap_ptes_ops,
+			.shifts = xe_normal_pt_shifts,
+			.max_level = XE_PT_HIGHEST_LEVEL,
+		},
+		.tile = tile,
+	};
+	struct xe_pt *pt = vm->pt_root[tile->id];
+
+	(void)xe_pt_walk_shared(&pt->base, pt->level, start,
+				end, &xe_walk.base);
+}
+
 /**
  * xe_pt_zap_ptes() - Zap (zero) gpu ptes of an address range
  * @tile: The tile we're zapping for.
diff --git a/drivers/gpu/drm/xe/xe_pt.h b/drivers/gpu/drm/xe/xe_pt.h
index 9ab386431cad..b166b324f455 100644
--- a/drivers/gpu/drm/xe/xe_pt.h
+++ b/drivers/gpu/drm/xe/xe_pt.h
@@ -43,4 +43,6 @@ void xe_pt_update_ops_abort(struct xe_tile *tile, struct xe_vma_ops *vops);
 
 bool xe_pt_zap_ptes(struct xe_tile *tile, struct xe_vma *vma);
 
+void xe_pt_zap_range(struct xe_tile *tile, struct xe_vm *vm, u64 start, u64 end);
+
 #endif
-- 
2.26.3