[PATCH v4 20/22] drm/xe: Use drm_gpusvm_scan_mm()

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

Use drm_gpusvm_scan_mm() to avoid unnecessarily calling into
drm_pagemap_populate_mm();

v3:
- New patch.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/gpu/drm/xe/xe_svm.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index 2fa73143fcd5..22281d69e26a 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -1625,11 +1625,23 @@ struct drm_pagemap *xe_vma_resolve_pagemap(struct xe_vma *vma, struct xe_tile *t
 int xe_svm_alloc_vram(struct xe_svm_range *range, const struct drm_gpusvm_ctx *ctx,
 		      struct drm_pagemap *dpagemap)
 {
-	struct xe_device *xe = range_to_vm(&range->base)->xe;
+	struct xe_vm *vm = range_to_vm(&range->base);
+	enum drm_gpusvm_scan_result migration_state;
+	struct xe_device *xe = vm->xe;
 
 	xe_assert(range_to_vm(&range->base)->xe, range->base.pages.flags.migrate_devmem);
 	range_debug(range, "ALLOCATE VRAM");
 
+	migration_state = drm_gpusvm_scan_mm(&range->base,
+					     xe_svm_private_page_owner(vm, false),
+					     dpagemap->pagemap);
+
+	if (migration_state == DRM_GPUSVM_SCAN_EQUAL) {
+		if (IS_ENABLED(CONFIG_DRM_XE_DEBUG_VM))
+			drm_dbg(dpagemap->drm, "Already migrated!\n");
+		return 0;
+	}
+
 	if (IS_ENABLED(CONFIG_DRM_XE_DEBUG_VM))
 		drm_dbg(&xe->drm, "Request migration to device memory on \"%s\".\n",
 			dpagemap->drm->unique);
-- 
2.51.1