drm/msm: fix msm_gem_vma_new() allocations for managed GPUVMs

Since commit 3309323 ("drm/gpuvm: Kill drm_gpuva_init()") MSM
driver fails to init, failing with "[drm:msm_gpu_init] *ERROR* could not
allocate memptrs: -22" errors. The mentioned commit reworked the
function, but didn't take into account that op_map is initialized at the
top of the function, while ranges might change if GPUVM is managed by
the kernel.

Move op_mode initialization after finalizing all addresses and right
before the drm_gpuva_init_from_op() call.

Reported-by: Danct12 <danct12@disroot.org>
Fixes: 3309323 ("drm/gpuvm: Kill drm_gpuva_init()")
Suggested-by: Rob Clark <robin.clark@oss.qualcomm.com>
Reviewed-by: Rob Clark <robin.clark@oss.qualcomm.com>
Acked-by: Rob Clark <robin.clark@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250823-msm-fix-gpuvm-init-v1-1-e199cd5b1983@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Author: lumag

drivers/gpu/drm/msm/msm_gem_vma.c

@@ -371,12 +371,6 @@ struct drm_gpuva *
 msm_gem_vma_new(struct drm_gpuvm *gpuvm, struct drm_gem_object *obj,
 		u64 offset, u64 range_start, u64 range_end)
 {
-	struct drm_gpuva_op_map op_map = {
-		.va.addr = range_start,
-		.va.range = range_end - range_start,
-		.gem.obj = obj,
-		.gem.offset = offset,
-	};
 	struct msm_gem_vm *vm = to_msm_vm(gpuvm);
 	struct drm_gpuvm_bo *vm_bo;
 	struct msm_gem_vma *vma;
@@ -405,6 +399,13 @@ msm_gem_vma_new(struct drm_gpuvm *gpuvm, struct drm_gem_object *obj,
 	if (obj)
 		GEM_WARN_ON((range_end - range_start) > obj->size);
 
+	struct drm_gpuva_op_map op_map = {
+		.va.addr = range_start,
+		.va.range = range_end - range_start,
+		.gem.obj = obj,
+		.gem.offset = offset,
+	};
+
 	drm_gpuva_init_from_op(&vma->base, &op_map);
 	vma->mapped = false;