/* * uvm_km_suballoc: allocate a submap in the kernel map. once a submap * is allocated all references to that area of VM must go through it. this * allows the locking of VAs in kernel_map to be broken up into regions. * * => if `fixed' is true, *vmin specifies where the region described * pager_map => used to map "buf" structures into kernel space * by the submap must start * => if submap is non NULL we use that as the submap, otherwise we * alloc a new map */