AHCI_CAP_NPMASK
int nports = (ctlr->caps & AHCI_CAP_NPMASK) + 1;
ctlr->caps &= ~AHCI_CAP_NPMASK;
ctlr->caps &= ~AHCI_CAP_NPMASK;
ctlr->caps &= ~AHCI_CAP_NPMASK;
(ctlr->caps & AHCI_CAP_NPMASK) + 1);
(ctlr->caps & AHCI_CAP_NPMASK) + 1,
(ctlr->caps & AHCI_CAP_NPMASK) + 1);
((caps & (AHCI_CAP_NPMASK | AHCI_CAP_CCCS)) == 0 && pi == 1))