ahci_get_pmp_ccb
ccb = ahci_get_pmp_ccb(ap); /* Always returns non-NULL. */
struct ahci_ccb *ahci_get_pmp_ccb(struct ahci_port *);
ccb = ahci_get_pmp_ccb(ap); /* Always returns non-NULL. */
ccb = ahci_get_pmp_ccb(ap); /* Always returns non-NULL. */
ccb = ahci_get_pmp_ccb(ap); /* Always returns non-NULL. */