nvme_pcicfg_unmap_bar
nvme_pcicfg_unmap_bar(devhandle, bar, *mapped_addr);
ret = nvme_pcicfg_unmap_bar(ctrlr->pci_dev, cmbloc.bits.bir,
ret = nvme_pcicfg_unmap_bar(ctrlr->pci_dev, 0, addr);
int nvme_pcicfg_unmap_bar(void *devhandle, unsigned int bar, void *addr);