drm/radeon: finally fix the racy VMA setup

Finally clean up the VMA setup for radeon now that TTM exports the
necessary functions.

No functional change, but only compile tested.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/339354/

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -881,9 +881,6 @@ void radeon_ttm_set_active_vram_size(struct radeon_device *rdev, u64 size)
 	man->size = size >> PAGE_SHIFT;
 }
 
-static struct vm_operations_struct radeon_ttm_vm_ops;
-static const struct vm_operations_struct *ttm_vm_ops = NULL;
-
 static vm_fault_t radeon_ttm_fault(struct vm_fault *vmf)
 {
 	struct ttm_buffer_object *bo;
@@ -891,34 +888,36 @@ static vm_fault_t radeon_ttm_fault(struct vm_fault *vmf)
 	vm_fault_t ret;
 
 	bo = (struct ttm_buffer_object *)vmf->vma->vm_private_data;
-	if (bo == NULL) {
+	if (bo == NULL)
 		return VM_FAULT_NOPAGE;
-	}
+
 	rdev = radeon_get_rdev(bo->bdev);
 	down_read(&rdev->pm.mclk_lock);
-	ret = ttm_vm_ops->fault(vmf);
+	ret = ttm_bo_vm_fault(vmf);
 	up_read(&rdev->pm.mclk_lock);
 	return ret;
 }
 
+static struct vm_operations_struct radeon_ttm_vm_ops = {
+	.fault = radeon_ttm_fault,
+	.open = ttm_bo_vm_open,
+	.close = ttm_bo_vm_close,
+	.access = ttm_bo_vm_access
+};
+
 int radeon_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	int r;
 	struct drm_file *file_priv = filp->private_data;
 	struct radeon_device *rdev = file_priv->minor->dev->dev_private;
 
-	if (rdev == NULL) {
+	if (rdev == NULL)
 		return -EINVAL;
-	}
+
 	r = ttm_bo_mmap(filp, vma, &rdev->mman.bdev);
-	if (unlikely(r != 0)) {
+	if (unlikely(r != 0))
 		return r;
-	}
-	if (unlikely(ttm_vm_ops == NULL)) {
-		ttm_vm_ops = vma->vm_ops;
-		radeon_ttm_vm_ops = *ttm_vm_ops;
-		radeon_ttm_vm_ops.fault = &radeon_ttm_fault;
-	}
+
 	vma->vm_ops = &radeon_ttm_vm_ops;
 	return 0;
 }