drm/amdkfd: Get prange->offset after svm_range_vram_node_new

During miration to vram prange->offset is valid after vram buffer is located,
either use old one or allocate a new one. Move svm_range_vram_node_new before
migrate for each vma to get valid prange->offset.

v2: squash in warning fix

Fixes: 9473b6b2 ("drm/amdkfd: Fix BO offset for multi-VMA page migration")
Signed-off-by: Xiaogang Chen <Xiaogang.Chen@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_migrate.c

@@ -305,12 +305,6 @@ svm_migrate_copy_to_vram(struct amdgpu_device *adev, struct svm_range *prange,
 	src = scratch;
 	dst = (uint64_t *)(scratch + npages);
 
-	r = svm_range_vram_node_new(adev, prange, true);
-	if (r) {
-		dev_dbg(adev->dev, "fail %d to alloc vram\n", r);
-		goto out;
-	}
-
 	amdgpu_res_first(prange->ttm_res, ttm_res_offset,
 			 npages << PAGE_SHIFT, &cursor);
 	for (i = j = 0; i < npages; i++) {
@@ -391,7 +385,7 @@ svm_migrate_copy_to_vram(struct amdgpu_device *adev, struct svm_range *prange,
 		migrate->dst[i + 3] = 0;
 	}
 #endif
-out:
+
 	return r;
 }
 
@@ -520,6 +514,12 @@ svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
 
 	start = prange->start << PAGE_SHIFT;
 	end = (prange->last + 1) << PAGE_SHIFT;
+
+	r = svm_range_vram_node_new(adev, prange, true);
+	if (r) {
+		dev_dbg(adev->dev, "fail %ld to alloc vram\n", r);
+		return r;
+	}
 	ttm_res_offset = prange->offset << PAGE_SHIFT;
 
 	for (addr = start; addr < end;) {
@@ -543,6 +543,8 @@ svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
 
 	if (cpages)
 		prange->actual_loc = best_loc;
+	else
+		svm_range_vram_node_free(prange);
 
 	return r < 0 ? r : 0;
 }