#if defined(NV_DRM_ATOMIC_MODESET_AVAILABLE)
-+#include <linux/mm.h>
++#include <linux/version.h>
+
#include "nvidia-drm-gem-nvkms-memory.h"
#include "nvidia-drm-ioctl.h"
page_offset = vmf->pgoff - drm_vma_node_start(&gem->vma_node);
-+#if !defined(vm_insert_pfn)
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 20, 0)
+ return vmf_insert_pfn(vma, address, pfn + page_offset);
+#else
ret = vm_insert_pfn(vma, address, pfn + page_offset);