AHCI_STEP
int port = (offset - AHCI_OFFSET) / AHCI_STEP;
offset = (offset - AHCI_OFFSET) % AHCI_STEP;
else if (offset < (uint64_t)AHCI_OFFSET + sc->ports * AHCI_STEP)
int port = (offset - AHCI_OFFSET) / AHCI_STEP;
offset = (offset - AHCI_OFFSET) % AHCI_STEP;
else if (offset < (uint64_t)AHCI_OFFSET + sc->ports * AHCI_STEP)
AHCI_OFFSET + sc->ports * AHCI_STEP);