ahci_write
ahci_write(sc, AHCI_REG_GHC, AHCI_REG_GHC_AE);
ahci_write(sc, AHCI_REG_GHC, AHCI_REG_GHC_AE | AHCI_REG_GHC_HR);
ahci_write(sc, AHCI_REG_GHC, AHCI_REG_GHC_AE);
ahci_write(sc, AHCI_REG_CAP, ahci_read(sc, AHCI_REG_CAP) | bios_cap);
ahci_write(sc, AHCI_REG_PI, pi);
ahci_write(ap->ap_sc, AHCI_REG_IS, 1 << i);
ahci_write(sc, AHCI_REG_IS, is);
ahci_write(sc, AHCI_REG_IS, 1 << port);
void ahci_write(struct ahci_softc *, bus_size_t, u_int32_t);
ahci_write(sc, AHCI_REG_GHC, AHCI_REG_GHC_AE | AHCI_REG_GHC_IE);
ahci_write(sc, AHCI_REG_GHC, 0);