vma_hugecache_offset
idx = vma_hugecache_offset(h, vma, addr);
start = vma_hugecache_offset(h, vma, vma->vm_start);
end = vma_hugecache_offset(h, vma, vma->vm_end);
idx = vma_hugecache_offset(h, vma, vmf->address);
.pgoff = vma_hugecache_offset(h, vma,
pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);