AHCI_PREG_CI
mask = ahci_pread(ap, AHCI_PREG_CI);
ahci_pwrite(ap, AHCI_PREG_CI, mask);
ahci_pwrite(ap, AHCI_PREG_CI, mask);
ahci_pwrite(ap, AHCI_PREG_CI, 1 << ccb->ccb_slot);
ci_saved = ahci_pread(ap, AHCI_PREG_CI);
ap->ap_active, ahci_pread(ap, AHCI_PREG_CI),
ci = ahci_pread(ap, AHCI_PREG_CI);
ci = ahci_pread(ap, AHCI_PREG_CI);
ahci_pread(ap, AHCI_PREG_CI),
ahci_pread(ap, AHCI_PREG_CI);
ahci_pwrite(ap, AHCI_PREG_CI, ci_saved);
ahci_pwrite(ap, AHCI_PREG_CI, 1 << i);